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The wars that inspired Game of Thrones | null | TED-Ed | As far as we know, Medieval England was never invaded by ice zombies, or terrorized by dragons, but it was shaken by a power struggle between two noble families spanning generations and involving a massive cast of characters with complex motives and shifting loyalties. If that sounds familiar, it's because the historical conflicts known as the Wars of the Roses served as the basis for much of the drama in Game of Thrones. The real-life seeds of war were sewn by the death of King Edward III in 1377. Edward's oldest son had died before his father, but his ten-year-old son, Richard II, succeeded to the throne ahead of Edward's three surviving sons. This skipping of an entire generation left lingering claims to the throne among their various offspring, particularly the Lancasters, descended from Edward's third son, and the Yorks, descended from his fourth son. The name of the ensuing wars comes from the symbols associated with the two families, the white rose of York and the red rose of Lancaster. The Lancasters first gained the throne when Richard II was deposed by his cousin Henry IV in 1399. Despite sporadic unrest, their reign remained secure until 1422, when Henry V's death in a military campaign left an infant Henry VI as king. Weak-willed and dominated by advisors, Henry was eventually convinced to marry Margaret of Anjou to gain French support. Margaret was beautiful, ambitious, and ruthless in persecuting any threat to her power, and she distrusted Richard of York, most of all. York had been the King's close advisor and loyal General, but was increasingly sidelined by the Queen, who promoted her favorite supporters, like the Earls of Suffolk and Somerset. York's criticism of their inept handling of the war against France led to his exclusion from court and transfer to Ireland. Meanwhile, mounting military failures, and corrupt rule by Margaret and her allies caused widespread discontent, and in the midst of this chaos, Richard of York returned with an army to arrest Somerset and reform the court. Initially unsuccessful, he soon got his chance when he was appointed Protector of the Realm after Henry suffered a mental breakdown. However, less than a year later, Henry suddendly recovered and the Queen convinced him to reverse York's reforms. York fled and raised an army once more. Though he was unable to directly seize the throne, he managed to be reinstated as Protector and have himself and his heirs designated to succeed Henry. But instead of a crown, York's head acquired a pike after he was killed in battle with the Queen's loyalists. His young son took up the claim and was crowned Edward IV. Edward enjoyed great military success against the Lancasters. Henry was captured, while Margaret fled into exile with their reportedly cruel son, Edward of Westminster. But the newly crowned King made a tragic political mistake by backing out of his arranged marriage with a French Princess to secretly marry the widow of a minor Noble. This alienated his most powerful ally, the Earl of Warwick. Warwick allied with the Lancasters, turned Edward's jealous younger brother, George, against him, and even briefly managed to restore Henry as King, but it didn't last. Edward recaptured the throne, the Lancaster Prince was killed in battle, and Henry himself died in captivity not long after. The rest of Edward IV's reign was peaceful, but upon his death in 1483, the bloodshed resumed. Though his twelve-year-old son was due to succeed him, Edward's younger brother Richard III declared his nephews illegitimate due to their father's secret marriage. He assumed the regency himself and threw the boys in prison. Though no one knows what ultimately became of them, after a while, the Princes disappeared and Richard's power seemed secure. But his downfall would come only two years later from across the narrow sea of the English Channel. Henry Tudor was a direct descendant of the first Duke of Lancaster, raised in exile after his father's death in a previous rebellion. With Richard III's power grab causing a split in the York faction, Henry won support for his royal claim. Raising an army in France, he crossed the Channel in 1485 and quickly defeated Richard's forces. And by marrying Elizabeth of York, elder sister of the disappeared Princes, the newly crowned Henry VII joined the two roses, finally ending nearly a century of war. We often think of historical wars as decisive conflicts with clearly defined winners and losers. But the Wars of the Roses, like the fiction they inspired, show us that victories can be uncertain, alliances unstable, and even the power of Kings as fleeting as the seasons. |
The age of genetic wonder | {0: 'Juan Enriquez thinks and writes about the profound changes that genomics and brain research will bring about in business, technology, politics and society.'} | TEDxCERN | So let me with start with Roy Amara. Roy's argument is that most new technologies tend to be overestimated in their impact to begin with, and then they get underestimated in the long term because we get used to them. These really are days of miracle and wonder. You remember that wonderful song by Paul Simon? There were two lines in it. So what was it that was considered miraculous back then? Slowing down things — slow motion — and the long-distance call. Because, of course, you used to get interrupted by operators who'd tell you, "Long distance calling. Do you want to hang up?" And now we think nothing of calling all over the world. Well, something similar may be happening with reading and programming life. But before I unpack that, let's just talk about telescopes. Telescopes were overestimated originally in their impact. This is one of Galileo's early models. People thought it was just going to ruin all religion. (Laughter) So we're not paying that much attention to telescopes. But, of course, telescopes launched 10 years ago, as you just heard, could take this Volkswagen, fly it to the moon, and you could see the lights on that Volkswagen light up on the moon. And that's the kind of resolution power that allowed you to see little specks of dust floating around distant suns. Imagine for a second that this was a sun a billion light years away, and you had a little speck of dust that came in front of it. That's what detecting an exoplanet is like. And the cool thing is, the telescopes that are now being launched would allow you to see a single candle lit on the moon. And if you separated it by one plate, you could see two candles separately at that distance. And that's the kind of resolution that you need to begin to image that little speck of dust as it comes around the sun and see if it has a blue-green signature. And if it does have a blue-green signature, it means that life is common in the universe. The first time you ever see a blue-green signature on a distant planet, it means there's photosynthesis there, there's water there, and the chances that you saw the only other planet with photosynthesis are about zero. And that's a calendar-changing event. There's a before and after we were alone in the universe: forget about the discovery of whatever continent. So as you're thinking about this, we're now beginning to be able to image most of the universe. And that is a time of miracle and wonder. And we kind of take that for granted. Something similar is happening in life. So we're hearing about life in these little bits and pieces. We hear about CRISPR, and we hear about this technology, and we hear about this technology. But the bottom line on life is that life turns out to be code. And life as code is a really important concept because it means, just in the same way as you can write a sentence in English or in French or Chinese, just in the same way as you can copy a sentence, just in the same way as you can edit a sentence, just in the same way as you can print a sentence, you're beginning to be able to do that with life. It means that we're beginning to learn how to read this language. And this, of course, is the language that is used by this orange. So how does this orange execute code? It doesn't do it in ones and zeroes like a computer does. It sits on a tree, and one day it does: plop! And that means: execute. AATCAAG: make me a little root. TCGACC: make me a little stem. GAC: make me some leaves. AGC: make me some flowers. And then GCAA: make me some more oranges. If I edit a sentence in English on a word processor, then what happens is you can go from this word to that word. If I edit something in this orange and put in GCAAC, using CRISPR or something else that you've heard of, then this orange becomes a lemon, or it becomes a grapefruit, or it becomes a tangerine. And if I edit one in a thousand letters, you become the person sitting next to you today. Be more careful where you sit. (Laughter) What's happening on this stuff is it was really expensive to begin with. It was like long-distance calls. But the cost of this is dropping 50 percent faster than Moore's law. The first $200 full genome was announced yesterday by Veritas. And so as you're looking at these systems, it doesn't matter, it doesn't matter, it doesn't matter, and then it does. So let me just give you the map view of this stuff. This is a big discovery. There's 23 chromosomes. Cool. Let's now start using a telescope version, but instead of using a telescope, let's use a microscope to zoom in on the inferior of those chromosomes, which is the Y chromosome. It's a third the size of the X. It's recessive and mutant. But hey, just a male. And as you're looking at this stuff, here's kind of a country view at a 400 base pair resolution level, and then you zoom in to 550, and then you zoom in to 850, and you can begin to identify more and more genes as you zoom in. Then you zoom in to the state level, and you can begin to tell who's got leukemia, how did they get leukemia, what kind of leukemia do they have, what shifted from what place to what place. And then you zoom in to the Google street view level. So this is what happens if you have colorectal cancer for a very specific patient on the letter-by-letter resolution. So what we're doing in this stuff is we're gathering information and just generating enormous amounts of information. This is one of the largest databases on the planet and it's growing faster than we can build computers to store it. You can create some incredible maps with this stuff. You want to understand the plague and why one plague is bubonic and the other one is a different kind of plague and the other one is a different kind of plague? Well, here's a map of the plague. Some are absolutely deadly to humans, some are not. And note, by the way, as you go to the bottom of this, how does it compare to tuberculosis? So this is the difference between tuberculosis and various kinds of plagues, and you can play detective with this stuff, because you can take a very specific kind of cholera that affected Haiti, and you can look at which country it came from, which region it came from, and probably which soldier took that from that African country to Haiti. Zoom out. It's not just zooming in. This is one of the coolest maps ever done by human beings. What they've done is taken all the genetic information they have about all the species, and they've put a tree of life on a single page that you can zoom in and out of. So this is what came first, how did it diversify, how did it branch, how large is that genome, on a single page. It's kind of the universe of life on Earth, and it's being constantly updated and completed. And so as you're looking at this stuff, the really important change is the old biology used to be reactive. You used to have a lot of biologists that had microscopes, and they had magnifying glasses and they were out observing animals. The new biology is proactive. You don't just observe stuff, you make stuff. And that's a really big change because it allows us to do things like this. And I know you're really excited by this picture. (Laughter) It only took us four years and 40 million dollars to be able to take this picture. (Laughter) And what we did is we took the full gene code out of a cell — not a gene, not two genes, the full gene code out of a cell — built a completely new gene code, inserted it into the cell, figured out a way to have the cell execute that code and built a completely new species. So this is the world's first synthetic life form. And so what do you do with this stuff? Well, this stuff is going to change the world. Let me give you three short-term trends in terms of how it's going to change the world. The first is we're going to see a new industrial revolution. And I actually mean that literally. So in the same way as Switzerland and Germany and Britain changed the world with machines like the one you see in this lobby, created power — in the same way CERN is changing the world, using new instruments and our concept of the universe — programmable life forms are also going to change the world because once you can program cells in the same way as you program your computer chip, then you can make almost anything. So your computer chip can produce photographs, can produce music, can produce film, can produce love letters, can produce spreadsheets. It's just ones and zeroes flying through there. If you can flow ATCGs through cells, then this software makes its own hardware, which means it scales very quickly. No matter what happens, if you leave your cell phone by your bedside, you will not have a billion cell phones in the morning. But if you do that with living organisms, you can make this stuff at a very large scale. One of the things you can do is you can start producing close to carbon-neutral fuels on a commercial scale by 2025, which we're doing with Exxon. But you can also substitute for agricultural lands. Instead of having 100 hectares to make oils or to make proteins, you can make it in these vats at 10 or 100 times the productivity per hectare. Or you can store information, or you can make all the world's vaccines in those three vats. Or you can store most of the information that's held at CERN in those three vats. DNA is a really powerful information storage device. Second turn: you're beginning to see the rise of theoretical biology. So, medical school departments are one of the most conservative places on earth. The way they teach anatomy is similar to the way they taught anatomy 100 years ago. "Welcome, student. Here's your cadaver." One of the things medical schools are not good at is creating new departments, which is why this is so unusual. Isaac Kohane has now created a department based on informatics, data, knowledge at Harvard Medical School. And in a sense, what's beginning to happen is biology is beginning to get enough data that it can begin to follow the steps of physics, which used to be observational physics and experimental physicists, and then started creating theoretical biology. Well, that's what you're beginning to see because you have so many medical records, because you have so much data about people: you've got their genomes, you've got their viromes, you've got their microbiomes. And as this information stacks, you can begin to make predictions. The third thing that's happening is this is coming to the consumer. So you, too, can get your genes sequenced. And this is beginning to create companies like 23andMe, and companies like 23andMe are going to be giving you more and more and more data, not just about your relatives, but about you and your body, and it's going to compare stuff, and it's going to compare stuff across time, and these are going to become very large databases. But it's also beginning to affect a series of other businesses in unexpected ways. Normally, when you advertise something, you really don't want the consumer to take your advertisement into the bathroom to pee on. Unless, of course, if you're IKEA. Because when you rip this out of a magazine and you pee on it, it'll turn blue if you're pregnant. (Laughter) And they'll give you a discount on your crib. (Laughter) Right? So when I say consumer empowerment, and this is spreading beyond biotech, I actually really mean that. We're now beginning to produce, at Synthetic Genomics, desktop printers that allow you to design a cell, print a cell, execute the program on the cell. We can now print vaccines real time as an airplane takes off before it lands. We're shipping 78 of these machines this year. This is not theoretical biology. This is printing biology. Let me talk about two long-term trends that are coming at you over a longer time period. The first one is, we're starting to redesign species. And you've heard about that, right? We're redesigning trees. We're redesigning flowers. We're redesigning yogurt, cheese, whatever else you want. And that, of course, brings up the interesting question: How and when should we redesign humans? And a lot of us think, "Oh no, we never want to redesign humans." Unless, of course, if your child has a Huntington's gene and is condemned to death. Or, unless if you're passing on a cystic fibrosis gene, in which case, you don't just want to redesign yourself, you want to redesign your children and their children. And these are complicated debates and they're going to happen in real time. I'll give you one current example. One of the debates going on at the National Academies today is you have the power to put a gene drive into mosquitoes so that you will kill all the malaria-carrying mosquitoes. Now, some people say, "That's going to affect the environment in an extreme way, don't do it." Other people say, "This is one of the things that's killing millions of people yearly. Who are you to tell me that I can't save the kids in my country?" And why is this debate so complicated? Because as soon as you let this loose in Brazil or in Southern Florida — mosquitoes don't respect walls. You're making a decision for the world when you put a gene drive into the air. This wonderful man won a Nobel Prize, and after winning the Nobel Prize he's been worrying about how did life get started on this planet and how likely is it that it's in other places? So what he's been doing is going around to this graduate students and saying to his graduate students, "Build me life but don't use any modern chemicals or instruments. Build me stuff that was here three billion years ago. You can't use lasers. You can't use this. You can't use that." He gave me a vial of what he's built about three weeks ago. What has he built? He's built basically what looked like soap bubbles that are made out of lipids. He's built a precursor of RNA. He's had the precursor of the RNA be absorbed by the cell and then he's had the cells divide. We may not be that far — call it a decade, maybe two decades — from generating life from scratch out of proto-communities. Second long-term trend: we've been living and are living through the digital age — we're starting to live through the age of the genome and biology and CRISPR and synthetic biology — and all of that is going to merge into the age of the brain. So we're getting to the point where we can rebuild most of our body parts, in the same way as if you break a bone or burn your skin, it regrows. We're beginning to learn how to regrow our tracheas or how to regrow our bladders. Both of those have been implanted in humans. Tony Atala is working on 32 different organs. But the core is going to be this, because this is you and the rest is just packaging. Nobody's going to live beyond 120, 130, 140 years unless if we fix this. And that's the most interesting challenge. That's the next frontier, along with: "How common is life in the universe?" "Where did we come from?" and questions like that. Let me end this with an apocryphal quote from Einstein. [You can live as if everything is a miracle, or you can live as if nothing is a miracle.] It's your choice. You can focus on the bad, you can focus on the scary, and certainly there's a lot of scary out there. But use 10 percent of your brain to focus on that, or maybe 20 percent, or maybe 30 percent. But just remember, we really are living in an age of miracle and wonder. We're lucky to be alive today. We're lucky to see this stuff. We're lucky to be able to interact with folks like the folks who are building all the stuff in this room. So thank you to all of you, for all you do. (Applause) |
If superpowers were real: Super strength | null | TED-Ed | If you wake up one morning with 1,000 times the strength you had the night before, how will you handle delicate day-to-day tasks? Everything must seem so fragile to you since the scale of your strength has expanded one thousand times. You'd have to be very careful when you're shaking someone's hand so you don't end up breaking their bones or crushing everyone you hug. And using a fork to pick up a piece of broccoli from a Styrofoam plate without driving the fork through the plate is going to be as difficult as brain surgery. Say the day comes and you get the chance to save a damsel in distress falling from a helicopter. So, you hold out your arms, hoping to catch her. Seconds later, you will find yourself holding her lifeless body. What happened? Well, pressure is force divided by area. The smaller the area, the bigger the pressure. This is why we can lift heavy objects without breaking our skin, but a tiny needle can make us bleed with just a little poke. The pressure that will be exerted on her body can be calculated by force divided by the area on the top of your arms that comes in contact with her. It doesn't matter if your arms are strong enough to catch her body without breaking your bones. Her spine is not strong enough to be caught by you without being damaged. Even if you rip off the nearest door to provide a bigger area to catch her with, you still wouldn't be able to save her anyway. Remember, it's not the fall that kills her, but the sudden stop at the bottom. Let's say she's falling from a 32 story building, about 300 feet, and you are 6 feet tall, maybe 10 feet on your tippy-toes, with your arms above your head holding a door, in hopes of distributing the pressure across a larger surface area, but all you're doing is essentially moving the ground up by 10 feet. So, she's now falling from 290 feet, instead of 300 feet, reaching the speed of 173 feet per second just before impact, not counting air resistance. It's the equivalent of crashing at 94 miles per hour into a wall with a door in front of it. The only thing that could save her is flying. But that power comes with its own host of scientific issues. If you could fly, what you must do is fly up to her, start flying down at the speed she is falling, hold on to her, then gradually slow down until you come to a complete stop. This process requires a lot of cushion space between the point she starts falling and the ground. Every second you waste on changing into your superhero costume and flying up to her height, her head is getting that much closer to the pavement! If she's falling from a high place, and you can't get to her until she's only a few feet above the ground, there's really nothing you can do other than magically turn the pavement into marshmellow to allow her enough time to slowly come to a stop. Then, break out the chocolate and graham crackers and you've got s'mores. Mmmm, delicious! Now, which superpower physics lesson will you explore next? Shifting body size and content, super speed, flight, super strength, immortality, and invisibility. |
Can you solve the airplane riddle? | null | TED-Ed | Professor Fukanō, the famous eccentric scientist and adventurer, has embarked on a new challenge: flying around the world nonstop in a plane of his own design. Able to travel consistently at the incredible speed of one degree longitude around the equator per minute, the plane would take six hours to circle the world. There's just one problem: the plane can only hold 180 kiloliters of fuel, only enough for exactly half the journey. Let's be honest. The professor probably could have designed the plane to hold more fuel, but where's the fun in that? Instead, he's devised a slightly more elaborate solution: building three identical planes for the mission. In addition to their speed, the professor's equipped them with a few other incredible features. Each of the planes can turn on a dime and instantly transfer any amount of its fuel to any of the others in midair without slowing down, provided they're next to each other. The professor will pilot the first plane, while his two assistants Fugōri and Orokana will pilot each of the others. However, only one airport, located on the equator, has granted permission for the experiment, making it the starting point, the finish line, and the only spot where the planes can land, takeoff, or refuel on the ground. How should the three planes coordinate so the professor can fly continuously for the whole trip and achieve his dream without anyone running out of fuel and crashing? Pause here if you want to figure it out for yourself. Answer in: 3 Answer in: 2 Answer in: 1 According to the professor's calculations, they should be able to pull it off by a hair. The key is to maximize the support each assistant provides, not wasting a single kiloliter of fuel. It also helps us to think symmetrically so they can make shorter trips in either direction while setting the professor up for a long unsupported stretch in the middle. Here's his solution. All three planes take off at noon flying west, each fully loaded with 180 kiloliters. After 45 minutes, or one-eighth of the way around, each plane has 135 kiloliters left. Orokana gives 45 to the professor and 45 to Fugōri, fully refueling them both. With her remaining 45, Orokana returns to the airport and heads to the lounge for a well-deserved break. 45 minutes later, with one-quarter of the trip complete, the professor and Fugōri are both at 135 kiloliters again. Fugōri transfers 45 into the professor's tank, leaving himself with the 90 he needs to return. Professor Fukanō stretches and puts on his favorite album. He'll be alone for a while. In the meantime, Orokana has been anxiously awaiting Fugōri's return, her plane fully refueled and ready to go. As soon as his plane touches the ground, she takes off, this time flying east. At this point, exactly 180 minutes have passed and the professor is at the halfway point of his journey with 90 kiloliters of fuel left. For the next 90 minutes, the professor and Orokana's planes fly towards each other, meeting at the three-quarter mark. Just as the professor's fuel is about the run out, he sees Orokana's plane. She gives him 45 kiloliters of her remaining 90, leaving them with 45 each. But that's just half of what they need to make it to the airport. Fortunately, this is exactly when Fugōri, having refueled, takes off. 45 minutes later, just as the other two planes are about to run empty, he meets them at the 315 degree point and transfers 45 kiloliters of fuel to each, leaving 45 for himself. All three planes land at the airport just as their fuel gauges reach zero. As the reporters and photographers cheer, the professor promises his planes will soon be available for commercial flights, just as soon as they figure out how to keep their inflight meals from spilling everywhere. |
Can you solve the passcode riddle? | null | TED-Ed | In this dystopian world, your resistance group is humanity's last hope. Unfortunately, you've all been captured by the tyrannical rulers and brought to the ancient colosseum for their deadly entertainment. Before you're thrown into the dungeon, you see many numbered hallways leading outside. But each exit is blocked by an electric barrier with a combination keypad. You learn that one of you will be allowed to try to escape by passing a challenge while everyone else will be fed to the mutant salamanders the next morning. With her perfect logical reasoning, Zara is the obvious choice. You hand her a concealed audio transmitter so that the rest of you can listen along. As Zara is led away, you hear her footsteps echo through one of the hallways, then stop. A voice announces that she must enter a code consisting of three positive whole numbers in ascending order, so the second number is greater than or equal to the first, and the third is greater than or equal to the second. She may ask for up to three clues, but if she makes a wrong guess, or says anything else, she'll be thrown back into the dungeon. For the first clue, the voice says the product of the three numbers is 36. When Zara asks for the second clue, it tells her the sum of the numbers is the same as the number of the hallway she entered. There's a long silence. You're sure Zara remembers the hallway number, but there's no way for you to know it, and she can't say it outloud. If Zara could enter the passcode at this point, she would, but instead, she asks for the third clue, and the voice announces that the largest number appears only once in the combination. Moments later, the buzz of the electric barrier stops for a few seconds, and you realize that Zara has escaped. Unfortunately, her transmitter is no longer in range, so that's all the information you get. Can you find the solution? Pause on the next screen to work out the solution. 3 2 1 You're worried about the fact that you don't know Zara's hallway number, but you decide to start from the beginning anyways. From the first clue, you work out all of the eight possible combinations that come out to a product of 36. One of these must be right, but which one? Now comes the hard part. Even though you don't know which number you're looking for, you decide to work out the sum of each combination's three numbers. That's when it hits you. All but two of the sums are unique, and if the hallway number had matched any of these, Zara would have known the correct combination right then and there without asking for the third clue. Since she did ask for the clue, the hallway number must have matched the only sum that appears more than once in the list: thirteen. But which of the two combinations that add up to thirteen is correct: 1,6,6, or 2,2,9? That's where the third clue comes in. Since it tells us that the largest number must be unique, 2,2,9 must be the code. When night falls, you and the others escape through hallway thirteen and rejoin Zara outside. You've freed yourselves through math and logic. Now it's time to free the rest of the world. |
How does your brain respond to pain? | null | TED-Ed | Let's say that it would take you ten minutes to solve this puzzle. How long would it take if you received constant electric shocks to your hands? Longer, right? Because the pain would distract you from the task. Well, maybe not; it depends on how you handle pain. Some people are distracted by pain. It takes them longer to complete a task, and they do it less well. Other people use tasks to distract themselves from pain, and those people actually do the task faster and better when they're in pain than when they're not. Some people can just send their mind wandering to distract themselves from pain. How can different people be subjected to the exact same painful stimulus and yet experience the pain so differently? And why does this matter? First of all, what is pain? Pain is an unpleasant sensory and emotional experience, associated with actual or potential tissue damage. Pain is something we experience, so it's best measured by what you say it is. Pain has an intensity; you can describe it on a scale from zero, no pain, to ten, the most pain imaginable. But pain also has a character, like sharp, dull, burning, or aching. What exactly creates these perceptions of pain? Well, when you get hurt, special tissue damage-sensing nerve cells, called nociceptors, fire and send signals to the spinal cord and then up to the brain. Processing work gets done by cells called neurons and glia. This is your Grey matter. And brain superhighways carry information as electrical impulses from one area to another. This is your white matter. The superhighway that carries pain information from the spinal cord to the brain is our sensing pathway that ends in the cortex, a part of the brain that decides what to do with the pain signal. Another system of interconnected brain cells called the salience network decides what to pay attention to. Since pain can have serious consequences, the pain signal immediately activates the salience network. Now, you're paying attention. The brain also responds to the pain and has to cope with these pain signals. So, motor pathways are activated to take your hand off a hot stove, for example. But modulation networks are also activated that deliver endorphins and enkephalins, chemicals released when you're in pain or during extreme exercise, creating the runner's high. These chemical systems help regulate and reduce pain. All these networks and pathways work together to create your pain experience, to prevent further tissue damage, and help you to cope with pain. This system is similar for everyone, but the sensitivity and efficacy of these brain circuits determines how much you feel and cope with pain. This is why some people have greater pain than others and why some develop chronic pain that does not respond to treatment, while others respond well. Variability in pain sensitivities is not so different than all kinds of variability in responses to other stimuli. Like how some people love roller coasters, but other people suffer from terrible motion sickness. Why does it matter that there is variability in our pain brain circuits? Well, there are many treatments for pain, targeting different systems. For mild pain, non-prescription medications can act on cells where the pain signals start. Other stronger pain medicines and anesthetics work by reducing the activity in pain-sensing circuits or boosting our coping system, or endorphins. Some people can cope with pain using methods that involve distraction, relaxation, meditation, yoga, or strategies that can be taught, like cognitive behavioral therapy. For some people who suffer from severe chronic pain, that is pain that doesn't go away months after their injury should have healed, none of the regular treatments work. Traditionally, medical science has been about testing treatments on large groups to determine what would help a majority of patients. But this has usually left out some who didn't benefit from the treatment or experienced side effects. Now, new treatments that directly stimulate or block certain pain-sensing attention or modulation networks are being developed, along with ways to tailor them to individual patients, using tools like magnetic resonance imaging to map brain pathways. Figuring out how your brain responds to pain is the key to finding the best treatment for you. That's true personalized medicine. |
What would happen if you didn't drink water? | null | TED-Ed | Water is virtually everywhere, from soil moisture and ice caps, to the cells inside our own bodies. Depending on factors like location, fat index, age, and sex, the average human is between 55-60% water. At birth, human babies are even wetter. Being 75% water, they are swimmingly similar to fish. But their water composition drops to 65% by their first birthday. So what role does water play in our bodies, and how much do we actually need to drink to stay healthy? The H20 in our bodies works to cushion and lubricate joints, regulate temperature, and to nourish the brain and spinal cord. Water isn't only in our blood. An adult's brain and heart are almost three quarters water. That's roughly equivalent to the amount of moisture in a banana. Lungs are more similar to an apple at 83%. And even seemingly dry human bones are 31% water. If we are essentially made of water, and surrounded by water, why do we still need to drink so much? Well, each day we lose two to three liters through our sweat, urine, and bowel movements, and even just from breathing. While these functions are essential to our survival, we need to compensate for the fluid loss. Maintaining a balanced water level is essential to avoid dehydration or over-hydration, both of which can have devastating effects on overall health. At first detection of low water levels, sensory receptors in the brain's hypothalamus signal the release of antidiuretic hormone. When it reached the kidneys, it creates aquaporins, special channels that enable blood to absorb and retain more water, leading to concentrated, dark urine. Increased dehydration can cause notable drops in energy, mood, skin moisture, and blood pressure, as well as signs of cognitive impairment. A dehydrated brain works harder to accomplish the same amount as a normal brain, and it even temporarily shrinks because of its lack of water. Over-hydration, or hyponatremia, is usually caused by overconsumption of water in a short amount of time. Athletes are often the victims of over-hydration because of complications in regulating water levels in extreme physical conditions. Whereas the dehydrated brain amps up the production of antidiuretic hormone, the over-hydrated brain slows, or even stops, releasing it into the blood. Sodium electrolytes in the body become diluted, causing cells to swell. In severe cases, the kidneys can't keep up with the resulting volumes of dilute urine. Water intoxication then occurs, possibly causing headache, vomiting, and, in rare instances, seizures or death. But that's a pretty extreme situation. On a normal, day-to-day basis, maintaining a well-hydrated system is easy to manage for those of us fortunate enough to have access to clean drinking water. For a long time, conventional wisdom said that we should drink eight glasses a day. That estimate has since been fine-tuned. Now, the consensus is that the amount of water we need to imbibe depends largely on our weight and environment. The recommended daily intake varies from between 2.5-3.7 liters of water for men, and about 2-2.7 liters for women, a range that is pushed up or down if we are healthy, active, old, or overheating. While water is the healthiest hydrator, other beverages, even those with caffeine like coffee or tea, replenish fluids as well. And water within food makes up about a fifth of our daily H20 intake. Fruits and vegetables like strawberries, cucumbers, and even broccoli are over 90% water, and can supplement liquid intake while providing valuable nutrients and fiber. Drinking well might also have various long-term benefits. Studies have shown that optimal hydration can lower the chance of stroke, help manage diabetes, and potentially reduce the risk of certain types of cancer. No matter what, getting the right amount of liquid makes a world of difference in how you'll feel, think, and function day to day. |
Can you solve the bridge riddle? | null | TED-Ed | Taking that internship in a remote mountain lab might not have been the best idea. Pulling that lever with the skull symbol just to see what it did probably wasn't so smart, either, but now is not the time for regrets because you need to get away from these mutant zombies fast. With you are the janitor, the lab assistant, and the old professor. You've gotten a headstart, but there's only one way to safety: across an old rope bridge spanning a massive gorge. You can dash across in a minute, while the lab assistant takes two minutes. The janitor is a bit slower and needs five minutes, and the professor takes a whole ten minutes, holding onto the ropes every step of the way. By the professor's calculations, the zombies will catch up to you in just over 17 minutes, so you only have that much time to get everyone across and cut the ropes. Unfortunately, the bridge can only hold two people at a time. To make matters worse, it's so dark out that you can barely see, and the old lantern you grabbed on your way only illuminates a tiny area. Can you figure out a way to have everyone escape in time? Remember: no more than two people can cross the bridge together, anyone crossing must either hold the lantern or stay right next to it, and any of you can safely wait in the dark on either side of the gorge. Most importantly, everyone must be safely across before the zombies arrive. Otherwise, the first zombie could step on the bridge while people are still on it. Finally, there are no tricks to use here. You can't swing across, use the bridge as a raft, or befriend the zombies. Pause the video now if you want to figure it out for yourself! Answer in: 3 Answer in: 2 Answer in: 1 At first it might seem like no matter what you do, you're just a minute or two short of time, but there is a way. The key is to minimize the time wasted by the two slowest people by having them cross together. And because you'll need to make a couple of return trips with the lantern, you'll want to have the fastest people available to do so. So, you and the lab assistant quickly run across with the lantern, though you have to slow down a bit to match her pace. After two minutes, both of you are across, and you, as the quickest, run back with the lantern. Only three minutes have passed. So far, so good. Now comes the hard part. The professor and the janitor take the lantern and cross together. This takes them ten minutes since the janitor has to slow down for the old professor who keeps muttering that he probably shouldn't have given the zombies night vision. By the time they're across, there are only four minutes left, and you're still stuck on the wrong side of the bridge. But remember, the lab assistant has been waiting on the other side, and she's the second fastest of the group. So she grabs the lantern from the professor and runs back across to you. Now with only two minutes left, the two of you make the final crossing. As you step on the far side of the gorge, you cut the ropes and collapse the bridge behind you, just in the nick of time. Maybe next summer, you'll just stick to the library. |
Should we eat bugs? | null | TED-Ed | [Why don't we eat bugs?] For centuries, people have consumed bugs, everything from beetles to caterpillars, locusts, grasshoppers, termites, and dragonflies. The practice even has a name: entomophagy. Early hunter-gatherers probably learned from animals that foraged for protein-rich insects and followed suit. As we evolved and bugs became part of our dietary tradition, they fulfilled the role of both staple food and delicacy. In ancient Greece, cicadas were considered luxury snacks. And even the Romans found beetle larvae to be scrumptious. Why have we lost our taste for bugs? The reason for our rejection is historical, and the story probably begins around 10,000 BC in the Fertile Crescent, a place in the Middle East that was a major birthplace of agriculture. Back then, our once-nomadic ancestors began to settle in the Crescent. And as they learned to farm crops and domesticate animals there, attitudes changed, rippling outwards towards Europe and the rest of the Western world. As farming took off, people might have spurned bugs as mere pests that destroyed their crops. Populations grew, and the West became urbanized, weakening connections with our foraging past. People simply forgot their bug-rich history. Today, for people not accustomed to entomophagy, bugs are just an irritant. They sting and bite and infest our food. We feel an "ick factor" associated with them and are disgusted by the prospect of cooking insects. Almost 2,000 insect species are turned into food, forming a big part of everyday diets for two billion people around the world. Countries in the tropics are the keenest consumers, because culturally, it's acceptable. Species in those regions are also large, diverse, and tend to congregate in groups or swarms that make them easy to harvest. Take Cambodia in Southeast Asia where huge tarantulas are gathered, fried, and sold in the marketplace. In southern Africa, the juicy mopane worm is a dietary staple, simmered in a spicy sauce or eaten dried and salted. And in Mexico, chopped jumiles are toasted with garlic, lemon, and salt. Bugs can be eaten whole to make up a meal or ground into flour, powder, and paste to add to food. But it's not all about taste. They're also healthy. In fact, scientists say entomophagy could be a cost-effective solution for developing countries that are food insecure. Insects can contain up to 80% protein, the body's vital building blocks, and are also high in energy-rich fat, fiber, and micronutrients like vitamins and minerals. Did you know that most edible insects contain the same amount or even more mineral iron than beef, making them a huge, untapped resource when you consider that iron deficiency is currently the most common nutritional problem in the world? The mealworm is another nutritious example. The yellow beetle larvae are native to America and easy to farm. They have a high vitamin content, loads of healthy minerals, and can contain up to 50% protein, almost as much as in an equivalent amount of beef. To cook, simply sauté in butter and salt or roast and drizzle with chocolate for a crunchy snack. What you have to overcome in "ick factor," you gain in nutrition and taste. Indeed, bugs can be delicious. Mealworms taste like roasted nuts. Locusts are similar to shrimp. Crickets, some people say, have an aroma of popcorn. Farming insects for food also has less environmental impact than livestock farms do because insects emit far less greenhouse gas and use up less space, water, and food. Socioeconomically, bug production could uplift people in developing countries since insect farms can be small scale, highly productive, and yet relatively inexpensive to keep. Insects can also be turned into more sustainable food for livestock and can be reared on organic waste, like vegetable peelings, that might otherwise just end up rotting in landfills. Feeling hungry yet? Faced with a plate of fried crickets, most people today would still recoil, imagining all those legs and feelers getting stuck between their teeth. But think of a lobster. It's pretty much just a giant insect with legs and feelers galore that was once regarded as an inferior, repulsive food. Now, lobster is a delicacy. Can the same paradigm shift happen for bugs? So, give it a try! Pop that insect into your mouth, and savor the crunch. |
What are those floaty things in your eye? | null | TED-Ed | Have you ever noticed something swimming in your field of vision? It may look like a tiny worm or a transparent blob, and whenever you try to get a closer look, it disappears, only to reappear as soon as you shift your glance. But don't go rinsing out your eyes! What you are seeing is a common phenomenon known as a floater. The scientific name for these objects is Muscae volitantes, Latin for "flying flies," and true to their name, they can be somewhat annoying. But they're not actually bugs or any kind of external objects at all. Rather, they exist inside your eyeball. Floaters may seem to be alive, since they move and change shape, but they are not alive. Floaters are tiny objects that cast shadows on the retina, the light-sensitive tissue at the back of your eye. They might be bits of tissue, red blood cells, or clumps of protein. And because they're suspended within the vitreous humor, the gel-like liquid that fills the inside of your eye, floaters drift along with your eye movements, and seem to bounce a little when your eye stops. Floaters may be only barely distinguishable most of the time. They become more visible the closer they are to the retina, just as holding your hand closer to a table with an overhead light will result in a more sharply defined shadow. And floaters are particularly noticeable when you are looking at a uniform bright surface, like a blank computer screen, snow, or a clear sky, where the consistency of the background makes them easier to distinguish. The brighter the light is, the more your pupil contracts. This has an effect similar to replacing a large diffuse light fixture with a single overhead light bulb, which also makes the shadow appear clearer. There is another visual phenomenon that looks similar to floaters but is in fact unrelated. If you've seen tiny dots of light darting about when looking at a bright blue sky, you've experienced what is known as the blue field entoptic phenomenon. In some ways, this is the opposite of seeing floaters. Here, you are not seeing shadows but little moving windows letting light through to your retina. The windows are actually caused by white blood cells moving through the capillaries along your retina's surface. These leukocytes can be so large that they nearly fill a capillary causing a plasma space to open up in front of them. Because the space and the white blood cells are both more transparent to blue light than the red blood cells normally present in capillaries, we see a moving dot of light wherever this happens, following the paths of your capillaries and moving in time with your pulse. Under ideal viewing conditions, you might even see what looks like a dark tail following the dot. This is the red blood cells that have bunched up behind the leukocyte. Some science museums have an exhibit which consists of a screen of blue light, allowing you to see these blue sky sprites much more clearly than you normally would. While everybody's eyes experience these sort of effects, the number and type vary greatly. In the case of floaters, they often go unnoticed, as our brain learns to ignore them. However, abnormally numerous or large floaters that interfere with vision may be a sign of a more serious condition, requiring immediate medical treatment. But the majority of the time entoptic phenomena, such as floaters and blue sky sprites, are just a gentle reminder that what we think we see depends just as much on our biology and minds as it does on the external world. |
Can you solve the prisoner hat riddle? | null | TED-Ed | You and nine other individuals have been captured by super intelligent alien overlords. The aliens think humans look quite tasty, but their civilization forbids eating highly logical and cooperative beings. Unfortunately, they're not sure whether you qualify, so they decide to give you all a test. Through its universal translator, the alien guarding you tells you the following: You will be placed in a single-file line facing forward in size order so that each of you can see everyone lined up ahead of you. You will not be able to look behind you or step out of line. Each of you will have either a black or a white hat on your head assigned randomly, and I won't tell you how many of each color there are. When I say to begin, each of you must guess the color of your hat starting with the person in the back and moving up the line. And don't even try saying words other than black or white or signaling some other way, like intonation or volume; you'll all be eaten immediately. If at least nine of you guess correctly, you'll all be spared. You have five minutes to discuss and come up with a plan, and then I'll line you up, assign your hats, and we'll begin. Can you think of a strategy guaranteed to save everyone? Pause the video now to figure it out for yourself. Answer in: 3 Answer in: 2 Answer in: 1 The key is that the person at the back of the line who can see everyone else's hats can use the words "black" or "white" to communicate some coded information. So what meaning can be assigned to those words that will allow everyone else to deduce their hat colors? It can't be the total number of black or white hats. There are more than two possible values, but what does have two possible values is that number's parity, that is whether it's odd or even. So the solution is to agree that whoever goes first will, for example, say "black" if he sees an odd number of black hats and "white" if he sees an even number of black hats. Let's see how it would play out if the hats were distributed like this. The tallest captive sees three black hats in front of him, so he says "black," telling everyone else he sees an odd number of black hats. He gets his own hat color wrong, but that's okay since you're collectively allowed to have one wrong answer. Prisoner two also sees an odd number of black hats, so she knows hers is white, and answers correctly. Prisoner three sees an even number of black hats, so he knows that his must be one of the black hats the first two prisoners saw. Prisoner four hears that and knows that she should be looking for an even number of black hats since one was behind her. But she only sees one, so she deduces that her hat is also black. Prisoners five through nine are each looking for an odd number of black hats, which they see, so they figure out that their hats are white. Now it all comes down to you at the front of the line. If the ninth prisoner saw an odd number of black hats, that can only mean one thing. You'll find that this strategy works for any possible arrangement of the hats. The first prisoner has a 50% chance of giving a wrong answer about his own hat, but the parity information he conveys allows everyone else to guess theirs with absolute certainty. Each begins by expecting to see an odd or even number of hats of the specified color. If what they count doesn't match, that means their own hat is that color. And everytime this happens, the next person in line will switch the parity they expect to see. So that's it, you're free to go. It looks like these aliens will have to go hungry, or find some less logical organisms to abduct. |
Why don't perpetual motion machines ever work? | null | TED-Ed | Around 1159 A.D., a mathematician called Bhaskara the Learned sketched a design for a wheel containing curved reservoirs of mercury. He reasoned that as the wheels spun, the mercury would flow to the bottom of each reservoir, leaving one side of the wheel perpetually heavier than the other. The imbalance would keep the wheel turning forever. Bhaskara's drawing was one of the earliest designs for a perpetual motion machine, a device that can do work indefinitely without any external energy source. Imagine a windmill that produced the breeze it needed to keep rotating. Or a lightbulb whose glow provided its own electricity. These devices have captured many inventors' imaginations because they could transform our relationship with energy. For example, if you could build a perpetual motion machine that included humans as part of its perfectly efficient system, it could sustain life indefinitely. There's just one problem. They don't work. Ideas for perpetual motion machines all violate one or more fundamental laws of thermodynamics, the branch of physics that describes the relationship between different forms of energy. The first law of thermodynamics says that energy can't be created or destroyed. You can't get out more energy than you put in. That rules out a useful perpetual motion machine right away because a machine could only ever produce as much energy as it consumed. There wouldn't be any left over to power a car or charge a phone. But what if you just wanted the machine to keep itself moving? Inventors have proposed plenty of ideas. Several of these have been variations on Bhaskara's over-balanced wheel with rolling balls or weights on swinging arms. None of them work. The moving parts that make one side of the wheel heavier also shift its center of mass downward below the axle. With a low center of mass, the wheel just swings back and forth like a pendulum, then stops. What about a different approach? In the 17th century, Robert Boyle came up with an idea for a self-watering pot. He theorized that capillary action, the attraction between liquids and surfaces that pulls water through thin tubes, might keep the water cycling around the bowl. But if the capillary action is strong enough to overcome gravity and draw the water up, it would also prevent it from falling back into the bowl. Then there are versions with magnets, like this set of ramps. The ball is supposed to be pulled upwards by the magnet at the top, fall back down through the hole, and repeat the cycle. This one fails because like the self-watering pot, the magnet would simply hold the ball at the top. Even if it somehow did keep moving, the magnet's strength would degrade over time and eventually stop working. For each of these machines to keep moving, they'd have to create some extra energy to nudge the system past its stopping point, breaking the first law of thermodynamics. There are ones that seem to keep going, but in reality, they invariably turn out to be drawing energy from some external source. Even if engineers could somehow design a machine that didn't violate the first law of thermodynamics, it still wouldn't work in the real world because of the second law. The second law of thermodynamics tells us that energy tends to spread out through processes like friction. Any real machine would have moving parts or interactions with air or liquid molecules that would generate tiny amounts of friction and heat, even in a vacuum. That heat is energy escaping, and it would keep leeching out, reducing the energy available to move the system itself until the machine inevitably stopped. So far, these two laws of thermodynamics have stymied every idea for perpetual motion and the dreams of perfectly efficient energy generation they imply. Yet it's hard to conclusively say we'll never discover a perpetual motion machine because there's still so much we don't understand about the universe. Perhaps we'll find new exotic forms of matter that'll force us to revisit the laws of thermodynamics. Or maybe there's perpetual motion on tiny quantum scales. What we can be reasonably sure about is that we'll never stop looking. For now, the one thing that seems truly perpetual is our search. |
The loathsome lethal mosquito | null | TED-Ed | What's the worst bug on the planet? You might vote for the horsefly or perhaps the wasp, but for many people, the worst offender is by far the mosquito. The buzzing, the biting, the itching, the mosquito is one of the most commonly detested pests in the world. In Alaska, swarms of mosquitos can get so thick that they actually asphyxiate caribou. And mosquito-borne diseases kill millions of people every year. The scourge that is the mosquito isn't new. Mosquitoes have been around for over a hundred million years and over that time have coevolved with all sorts of species, including our own. There are actually thousands of species of mosquitos in the world, but they all share one insidious quality: they suck blood, and they're really, really good at sucking blood. Here's how they do it. After landing, a mosquito will slather some saliva onto the victim's skin, which works like an antiseptic, numbing the spot so we don't notice their attack. This is what causes the itchy, red bumps, by the way. Then the bug will use its serrated mandibles to carve a little hole in your skin, allowing it to probe around with its proboscis, searching for a blood vessel. When it hits one, the lucky parasite can suck two to three times its weight in blood. Turns out we don't really like that too much. In fact, humans hate mosquitos so much that we spend billions of dollars worldwide to keep them away from us — from citronella candles to bug sprays to heavy-duty agricultural pesticides. But it's not just that mosquitos are annoying, they're also deadly. Mosquitos can transmit everything from malaria to yellow fever to West Nile virus to dengue. Over a million people worldwide die every year from mosquito-borne diseases, and that's just people. Horses, dogs, cats, they can all get diseases from mosquitoes too. So, if these bugs are so dastardly, why don't we just get rid of them? We are humans after all, and we're pretty good at getting rid of species. Well, it's not quite so simple. Getting rid of the mosquito removes a food source for lots of organisms, like frogs and fish and birds. Without them, plants would lose a pollinator. But some scientists say that mosquitos aren't actually all that important. If we got rid of them, they argue, another species would simply take their place and we'd probably have far fewer deaths from malaria. The problem is that nobody knows what would happen if we killed off all the mosquitos. Something better might take their spot or perhaps something even worse. The question is, are we willing to take that risk? (Buzzing) |
Why we love repetition in music | null | TED-Ed | How many times does the chorus repeat in your favorite song? And, take a moment to think, how many times have you listened to it? Chances are you've heard that chorus repeated dozens, if not hundreds, of times, and it's not just popular songs in the West that repeat a lot. Repetition is a feature that music from cultures around the world tends to share. So, why does music rely so heavily on repetition? One part of the answer come from what psychologists call the mere-exposure effect. In short, people tend to prefer things they've been exposed to before. For example, a song comes on the radio that we don't particularly like, but then we hear the song at the grocery store, at the movie theater and again on the street corner. Soon, we are tapping to the beat, singing the words, even downloading the track. This mere-exposure effect doesn't just work for songs. It also works for everything from shapes to Super Bowl ads. So, what makes repetition so uniquely prevalent in music? To investigate, psychologists asked people to listen to musical compositions that avoided exact repetition. They heard excerpts from these pieces in either their original form, or in a version that had been digitally altered to include repetition. Although the original versions had been composed by some of the most respected 20th century composers, and the repetitive versions had been assembled by brute force audio editing, people rated the repetitive versions as more enjoyable, more interesting and more likely to have been composed by a human artist. Musical repetition is deeply compelling. Think about the Muppets classic, "Mahna Mahna." If you've heard it before, it's almost impossible after I sing, "Mahna mahna," not to respond, "Do doo do do do." Repetition connects each bit of music irresistibly to the next bit of music that follows it. So when you hear a few notes, you're already imagining what's coming next. Your mind is unconsciously singing along, and without noticing, you might start humming out loud. Recent studies have shown that when people hear a segment of music repeated, they are more likely to move or tap along to it. Repetition invites us into music as imagined participants, rather than as passive listeners. Research has also shown that listeners shift their attention across musical repetitions, focusing on different aspects of the sound on each new listen. You might notice the melody of a phrase the first time, but when it's repeated, your attention shifts to how the guitarist bends a pitch. This also occurs in language, with something called semantic satiation. Repeating a word like atlas ad nauseam can make you stop thinking about what the word means, and instead focus on the sounds: the odd way the "L" follows the "T." In this way, repetition can open up new worlds of sound not accessible on first hearing. The "L" following the "T" might not be aesthetically relevant to "atlas," but the guitarist pitch bending might be of critical expressive importance. The speech to song illusion captures how simply repeating a sentence a number of times shifts listeners attention to the pitch and temporal aspects of the sound, so that the repeated spoken language actually begins to sound like it is being sung. A similar effect happens with random sequences of sound. People will rate random sequences they've heard on repeated loop as more musical than a random sequence they've only heard once. Repetition gives rise to a kind of orientation to sound that we think of as distinctively musical, where we're listening along with the sound, engaging imaginatively with the note about to happen. This mode of listening ties in with our susceptibility to musical ear worms, where segments of music burrow into our head, and play again and again, as if stuck on repeat. Critics are often embarrassed by music's repetitiveness, finding it childish or regressive, but repetition, far from an embarrassment, is actually a key feature that gives rise to the kind of experience we think about as musical. |
Mass extinctions and the future of life on Earth | {0: 'Michael Benton is a paleontologist who has made fundamental contributions to understanding the history of life, particularly concerning how biodiversity changes through time. Ηis approach has revolutionised our understanding of major questions. A key theme is the Permo–Triassic mass extinction, the largest mass extinction of all time, which took place over 250 million years ago, where he investigates how life was able to recover from such a devastating event.\nHe has written more than 50 books and he founded the MSc in Palaeobiology at Bristol in 1996, from which more than 320 students have graduated. He has supervised more than 65 PhD students. He is currently Head of the School of Biological Sciences at the University of Bristol. He was elected Fellow of the Royal Society in 2014.'} | TEDxThessaloniki | My subject is the future of life on Earth. This is a very large and complex topic. It's the subject of futurology. And in fact, I am a palaeontologist, I study dinosaurs, and you might wonder why a palaeontologist would have something to say about the future. However, there are some shared aspects which I will talk about, and this can provide some evidence to help us in making decisions. I’m a palaeontologist, as I say. I decided on this career when I was seven years old. I loved dinosaurs at the age of seven, and I think these days, young people still do. And I haven't changed my view since. I love the job, teaching students, going to exotic parts of the world to dig up dinosaurs, finding new facts about the history of life. However, this kind of subject, studying the past, like studying the future, could be said by some not to be truly scientific. And I want to explore that a little bit first, how do we do this, before we get to the point of beginning to establish some facts and figures about life and current threats. And this has been criticised by other scientists. For example, 100 years ago, Sir Ernest Rutherford, a very famous physicist, Nobel Prize winner, said, 'All of science is physics, and the rest is stamp collecting.' By which he meant that if you cannot make it into mathematics or physics, it doesn't count. That excludes then the natural sciences, medicine and a lot of other areas. And I think at the far end of the spectrum would be my subject, palaeontology. I'd like to give you an example though, to show you how we apply scientific methods to achieve a certain level of understanding and certainty. And this is something that has been developing during my career so that when I started, a lot of what we did would be called a speculation or guesswork, whereas now, a lot of what we do can be tested and can be called scientific. The example I'm going to take is the question I asked when I was seven, 'Could T. rex bite a car in half?' This is a question about the most famous dinosaur, Tyrannosaurus Rex, which was huge, five tons in weight, enormous jaws and teeth. Could it bite a car in half? Well, there were no cars in the Cretaceous, but let's forget that for the moment. When I started, you could only answer that question by guesswork, or you could make some very simple models of the skull, like levers, and try to calculate things. If you were going to make a realistic model that had all the properties of the original bone and flesh of the dinosaur, you could not do it. But now, with the power of computing, we can do this kind of thing. So the way you calculate the bite force of T. rex, and the way people have done it, is they scan a skull and make a three-dimensional, digital model inside the computer. You then divide that model into a mesh, or into a framework of elements or small components. And each of these elements can be given physical properties so that we know the physical properties of bone of living animals. These are material properties, like how far can you twist the bone before it breaks, how much compression can that bone take. And so all of those properties are mapped into the skull. And then you apply imaginary forces and increase those pressures until the thing breaks. And so the bite force of T. rex is huge. Let me lead you to the figure. Our bite force is about 800 newtons at most. The biggest bite force of any living animal is the great white shark, and that is about 5,000 newtons. T. rex, 50,000 newtons, ten times. And that's equivalent to five tons of weight, acting. So it could bite a car in half. Why do we believe this method? Because this method is a standard in design and architecture. Finite element analysis is used for designing buildings like this one. You don't simply build it and hope it doesn't fall down. The thing is designed in a computer, it is stress-tested using this program we apply to the dinosaur. I think we can believe it. But let's move on. That was just a brief word about how you can actually apply science, I would argue, to questions that are not happening at our time, in the past, or maybe in the future. And in palaeontology, we don't just find fossils. We also care about evolution and diversification, how groups have become diverse, how groups go extinct. And at the moment, we are crucially concerned about extinction. So let's have a look at that, let's explore that. What are the current views? And these views are expressed not by scientists, but also by very important politicians. So some of you may recall, a number of years ago, Al Gore, who was then vice president of the United States - He quoted a figure of 100 species are going extinct every day. So this is a very high rate of extinction, 100 per day, which is equivalent to 40,000 per year. At the other end, other politicians, perhaps in President Trump's camp, would say, 'Don't worry about it. Extinction happens. Look at the dinosaurs. We've got nothing to do.' So how do you connect between these two positions because of course we have to think about these points. The first approach that we use is to look at history. We have recent history recorded of extinction. So many of you will be familiar with the extinct bird called the dodo. This lived on the island of Mauritius in the Indian Ocean. The dodo was a kind of fat, flightless bird related to pigeons, and a very famous image of the dodo was in the famous children's book 'Alice in Wonderland', where the dodo, who is a wise, old gentleman with a walking stick organises Alice and all the animals and says to them, 'We will have a Caucus race.' And a Caucus race is one where people start when they like and they finish when they like, and everybody gets a prize. So that was very nice, but unfortunately the dodo in real life didn't get a prize. Because some of you may know the first records of dodos were in 1598 when seamen reported they had seen this bird. They could go on the island and catch it very easily and eat it. And within 60 years it was extinct. Another example of recorded extinction is the great auk. This was a large bird that lived in the North Atlantic, and the great auk went extinct in 1844. How do we know that? Because collectors sent by a museum shot the last example. They were concerned that their museum did not have a stuffed specimen of this bird. They heard it was going extinct, so they thought, 'We'd better get one before it dies out.' So these are two examples of data about extinction. And indeed through the last 500 years, mankind has killed many species which are recorded like that. And this is the basis of the figure that Al Gore gave. Let me explain it. He gave that figure of 100 species per day going extinct. This was based on the bird data. But we know something like 100 or two or three hundred species of birds have been killed by human activity in the last 500 years. And the figures are debated. It's something like from half a species to four species each year on average. We don't know for sure because of course people didn't record everything. Now, how do we scale this up to get a global figure, from birds on the one hand to all of life? And the way it was done was simply to say, 'We know how many species or birds there are alive today.' There are 10,000, and the initial estimate for the diversity of all of life were 100 million. So you scale from four a day upwards, and that brings you up to this figure of 100 per day by multiplying up many times; 40,000 lost per year, 100 per day, based on that extreme high bird figure. At the other end, the lowest estimate is something like one species per day. This is because we are not sure about that bird figure, so we could take a lower estimate, and also we are actually not sure about the diversity of life today either. Some of you will know that you might think we would have named every species, we would know that - we don't. You can look at Wikipedia. There are thousands and thousands of pages describing all the living species, but there are so many living species that we have never discovered, never described, aren't there in Wikipedia. So there is that uncertainty. One hundred million? Ten million? We don't know. Those are the estimates of numbers of species going extinct each day. One per day, one hundred per day. Do we worry about that? This is where palaeontology comes in first, because fossil data allows us to calculate what would be the normal rate of extinction. Species do go extinct, so this politician over here was quite right. But was Al Gore right? We don't know. You know, he was giving that high figure - maybe somewhere in between. But what is the norm? Is one a day okay? It doesn't sound too many. If there are millions and millions of species, it is far too high. We know that the average duration of a species is two million years. They originate, they go extinct. Two million years. And that means, as they come and go, on average, we would expect the extinction of five million species every million years, which is five species per year. So that does contrast remarkably even at the lowest estimate of human impact - 500 species per year is 100 times the normal rate of 5 per year. And at the bottom there is the dodo, just in case you weren't sure what it looked like. So I want to look at two other topics briefly. One is risk. And so, one of the questions we would have estimating the total numbers is one thing. We have learned that we are impacting life harder than we should be. Human activity is causing extinction. What about risk? It's easy to say of course, the dodo was stupid, it lived on one island, it just stood around and allowed itself to be hit on the head. To an extent. We worry about elephants, we worry about pandas, we worry about many individual species. Many of those have high-risk factors. So for example, an elephant is very large. This means they need a lot of food, they need a lot of territory to walk around. And so it's much harder to keep a sufficiently large population of elephants breeding and successfully in the wild. We don't need to worry about rats, for example. They're small and there's lots of them. So body size is one risk factor. Being big is not a good thing if you want to survive as a species. What about the panda? They're not so huge. They're about human size. They have a specialised diet. They have evolved into a crazy position. As you know, they are eating bamboo without the real ability to consume it properly. If that food supply disappears, they're stuck. So, secondly, restricted diet is a problem. The third one is shown by the dodo. If you live in only a very small geographic area rather than over the whole world, you are at risk. So there are three things to be: medium-sized or small, if you want to survive; broad diet, willing to eat everything; and living over the whole world. So that includes human beings and rats and cockroaches. They will survive and many other species will not survive whatever we do. So risk is something we can determine from the present day, but also we can test when we look at mass extinctions in the past. So this is where we come back to palaeontology, because I think most people here know that the end of the dinosaurs was marked by a mass extinction. Many millions or thousands of species died out rather rapidly. The cause of that extinction definitely was largely the impact of a meteorite, a huge asteroid, maybe ten kilometres across, and the model for extinction of the dinosaurs 66 million years ago was the asteroid hit the Earth - this is unpredictable, when this may happen or not - it penetrated into the crust, it vaporised, and all that rock of the asteroid plus the crust that it had penetrated turned into rocks and dust, mainly dust. This was thrown up high into the atmosphere and went all round the Earth, blacking out the sun, and so that you get two effects there, no light, no heat. So there was a cessation of photosynthesis. The plants died. There was darkness and cold. So this was not good for dinosaurs and other groups that enjoyed the warm climates, and so you get extinction. And you might think, of course, 'What do we learn from this?' Yes, that's all very well, but that's not something we can do anything about really. And indeed, asteroids do come close to the Earth from time to time. Earlier this week, one did. Luckily it didn't hit the Earth. We can't really prepare. But the key point is that the other mass extinctions in the history of life were not caused by impact. They were caused by climate change. Immediately, you can see now how that matters. I will briefly characterise one of them that I have worked upon. At the end of the Permian Period, 250 million years ago, there was another major extinction. This was before the dinosaurs. And the sequence of events was that massive volcanoes errupted in Russia. They were so huge that they poured out enormous amounts of lava, of course, but more importantly, they poured out gases into the atmosphere, including carbon dioxide. And carbon dioxide is famous as a greenhouse gas, meaning it heats the atmosphere. We have primary evidence that around the equator, ocean temperatures warmed up to 40 degrees plus. So this is like a very warm shower. You might think that's OK. Maybe for 10 minutes but not for day after day after day. And so life had to progressively flee out of the equatorial zones. It became crowded at the poles and there was great extinction. So we learnt from that that carbon dioxide and global warming can cause extinction whatever the cause of that carbon dioxide, whether it comes from volcanoes or human activity. So we've learnt three things that we can illustrate and use for predicting into the future, what may happen to life. We've learnt that we can calculate the rate of extinction by looking at historical extinctions and at that rate of extinction, even at the minimal figures, it's at least one hundred times what it ought to be. Secondly, we've learnt something about risk, which species are most at risk of extinction, and I think that's fairly straightforward. But we need the evidence to be able to argue the case. And thirdly, we've learnt that the whole history of the Earth records a rich record of climate change. We don't need to do experiments, we don't need to imagine what a world would be like without the polar ice caps. It has existed and we can study it. So to conclude, my aim has not been simply to spread doom and gloom, but to indicate that we have the power to change. And in order to change, we have to accept reality along the lines that we're mentioning. And we have to ask the right questions about what we should do. And in order to decide what we should do, we need to use evidence. And some great evidence comes from the history of the Earth and the history of life. Thank you very much. (Applause) |
How today's truths shape tomorrow's possibilities | {0: 'Yannick Roudaut is an author, journalist, entrepreneur, and the co-director of the consultancy Alternité. '} | TEDxNantes | Indeed, for 20 years, I worked in finance. I knew everything about finance, for sure. I knew the global economy because it was my life. All the topics that you could bring up about ecology, the end of the world, etc., that I knew like the back of my hand I didn't really believe in them. In 2007, an extremely unusual event occurred, you may remember, the subprime crisis, the collapse of big American banks. It was an electric shock. I had a fair few stormy conversations with my wife about the matter, about my job, on the limits of the model. Besides the crisis, I realized that I was completely wrong, that we were heading for disaster. The whole conception I had of the world, all the certainties that I had until then, were all fallen apart within a few months. That's why I'm here tonight, I've realized that, finally, it wasn't all so bad, and that it was an opportunity because we have the exceptional opportunity of living in an exceptional period of human history: we are going to change the world. But before changing the world, we have to do something, we have to do some grieving, we have to turn the page - turning the page of the world we live in today. To do so, I need some help from an American who goes by the name of Jared Diamond and who published "Collapse," and soon you will see that the 5 factors of the collapse of civilizations are reunited today. Jared Diamond has identified 5 factors in which we find the collapse of the Mayas, the Vikings, and all of the great Mesopotamian civilizations. And every time, those 5 factors were reunited. The bad news is that the 5 factors are reunited only at the beginning of the 21st century, but this time not only a single civilization is threatened but the global village, humanity, all of us. It's extremely important to be aware of this. The first factor of the collapse is the environmental factor. For two centuries, especially the last 50 years, we have done environmental damage, sometimes irreversible. The second factor is climate change. All the great civilizations did face those changes in climate. This weakens the ecosystems, that weakening also results in shortage of resources, destabilization of a society economical, geopolitical, social consequences, you name it. Third factor, still reunited today, the revival of military conflicts. These two first factors result in: when the ecosystems are destabilized and there is a shortage of resources, we continue having conflicts, we make war. And let me remind you, at the moment France is at war in Mali; let's not forget that. Fourth factor, equally important than the last one, the cancellation of diplomatic and commercial alliances. Things look bad, and the alliances concluded yesterday are undermined. Today, we are all aware of the fact that the future of Europe is unknown, we don't know what will come. And the fifth factor, not the least worrisome: the blindness of our elites. In this whole collapse of the civilization, the elites are not able to evaluate the fall of their world. They are incapable of changing their prism for the analysis. And the result? The result is simple: we will have a political caste system which emphasizes, which accelerates the collapse of a world. After everything I just told you, you have to know that the end of a world is not the same as the end of the world. If I told you that we live in an extraordinary time, extraordinary in the sense of etymology, there is no doubt, we live in a transition period, between two worlds. In the world of today, we are about to turn the page. And the world of tomorrow, the world to come, the sustainable world, about which I am talking today, starts to slighty assume its shape but there is still nothing precise. How do we live? We live in a historical period inspiring enough that we have to reinvent things. The nearest time period, in which man reinvented everything, is the Renaissance. The question which comes up in the 21st century is, "Do we experience a new Renaissance?" Let's see if the factors of a renaissance are reunited. First factor of a renaissance is a new understanding of the world. In the 15th century, Columbus discovered the Americas, man discovered the immensity of planet Earth, we discovered the immensity of the world. What happens at the moment, for some decades, for some years? We discover the finiteness of the world. The planet is very small in terms of resources, capacity, if we look at the current economic model. New understanding. Second factor: The Renaissance is a period of very much creativity. We all know Leonardo da Vinci, the Flemish painters. 2012, 2013, what has happened? Very much creativity. 3D printing is only one example. There are lots of others. Third factor of the Renaissance: Contrary to common beliefs, the Renaissance was not only a period of creativity, but also of much violence: religious wars, civil wars, extermination of the Native Americans, slavery. And how is it in 2012, 2013? Violence on a daily basis, and children which get killed in school by automatic weapons. Fourth factor of a renaissance: The whole world knows Gutenberg the inventor of the printing press who fundamentally changed the distribution of knowledge in Europe, and later in the rest of the world. Imagine, today, there is a new technological tool which allows us to distribute knowledge in a whole new way. This tool, which we have in our hands, provides instantaneous information. We hold the knowledge of the world in our hands. Soon, we will see how this is going to change. And finally, a renaissance - that brings me to the subject of today - it's the fact that all the certainties of humanity have fallen apart. Let me remind you, from Aristoteles through Ptolemy in the 2nd century to the Renaissance, the Earth was flat, man was the center of the world, and the stars turned around us. And those who dared to question this unique thought, those who dared to dispute this received, non-negotiable truth, - you know what came next - had to deal with the Inquisition. At the stake, they had to answer the question. Copernicus and Galilee had nearly paid with their lives because they dared to say that the Earth was not flat and it was not the center of the universe. So today, the question presenting itself to us in the 21st century is: "Are we committing the same mistake as our ancestors? Are we, also in making the mistake, or in our certainties, the ones who will fall apart over the next few years?" The next question which follows is: "What are those certainties which are of received and non-negotiable value, which could fall apart in 10, 15, 20, or 50 years?" There are a lot of them. As a former economist, there are at least three certainties in economy. At first, there is the truth that growth is the only motor of the economy. Let me remind you what the word 'economy' means in Greek. Economy means resource management, domain and household management. So it doesn't necessarily mean growth. It's not a synonym. Second truth which could fall apart is that growth is infinite. That's our consumption model in a finite and increasingly shrinking world as the population grows more and more but with less resources. And we don't question this dogma. Third dogma, third received truth is the necessary sacrifice of the living in favor of this growth. But still, we have authorized the right to pollute, to right to poison, the right to intoxicate. Why? Because growth demands it. The question that we are confronted with today is: If we continue like this, if we continue to sacrify the living, do we challenge this, will we authorize this dialogue? The answer is also not that evident because we can ask ourselves if the people who question these dogmas of growth as motor of the economy, and of the myth of infinite growth are today maybe still seen like yesterday's heretics. I must say that I am not sure, that at this time, in the 21st century, we show a great wisdom to those who dare to question a system which we all benefit from. It should be extremely important for us to keep an open mind. And yet, we become more and more people. All here, I think, are convinced of the fact that we know that the road we have taken for two centuries leads us directly to - how did the philosopher Jonas say? To a tragic impasse. The economic development on which we base our model leads us to a tragic impasse. Hans Jonas adds a very beautiful expression: "Nature will eventually make its ultimate veto, anyway, and it will be over." After what I just said, another question arises I am concerned with personally: "What will our children and descendants think of our behavior, our stubbornness of our obsession of a destructive economic model?" It is very likely that they will call us perhaps barbarians of the living world, and maybe they will feel the same contempt, the same indignation which we can feel today about those who developed slavery two or three centuries ago. Our behavior today is not any better than that of those we despise today. Why? Because three centuries ago, slavery was non-negotiable. The European and American economic model was based on slavery. And today, in 2013, what happens? Our entire economic model, our entire society is based on what? On exploitation, on the sacrifice of the living. The question, which, of course, arises is, "What are we going to do?" But before we know what we will do we have to know why we got there in order not to commit the same mistake in tomorrow's world. And how did we get there? The answer is simple and can be said in a few words. The philosopher Descartes already said it four centuries ago: "Man is the only master and owner of nature." Period. We dominate nature, we shape and form it. We do what we want. But what has happened since this Cartesian thought? We consider nature as a bottomless pit, as a mine where we draw from and throw things. And that's the problem. We consider this kind of nature as what? Finally, that puts man outside of nature. And this exteriority is our problem. In 1990, Michel Serres had an extremely truthful thought, like always, he said: "But finally, the notion of nature is a problem for us because nature assumes that man is put into, surrounded by a living world. We are disconnected from nature. As long as we haven't solved that problem, as long as we haven't reconciled with nature, it won't work. It's not about sacralizing nature, or putting it on an altar like a sacred goddess, it's just about including nature and not acting against or without it." Well, how are we going to do that? The conclusion of my talk is we'll have to organize it, really simple. It's extremely simple, we need a new controversy. What is a controversy? It's a dispute, a global debate. What happened in Valladolid in the 16th century, in 1550? A dispute took place in Spain as to whether Native Americans are living beings or not. Because if we exploited this tame workforce for free, we would develop the New World. If they were human beings we couldn't make them slaves. That would be intolerable. So, we discussed about the humanity of Native Americans. In the 21st century, we need to organize a new controversy. But this time it will be about determining where are the tolerance limits towards nature compared to human activity. What can nature bear? What kind of economic model can it bear? Do we have the right to pollute, the right to destroy the future of our children and their common heritage? This new controversy allows us to draft the Universal Declaration on the Duties of Man towards Nature. Yes, I said duties. Why? The Declaration on Human Rights has been the corner stone of the modern world, of today's world. The Universal Declaration on the Duties of Man will be the cornerstone of the new tomorrow. The declaration will fix the limits of our activity. But how to launch this new controversy? It needs to be organized. But before organizing and launching it, you will tell me: "Roudaut has taken drugs. He's a utopian. He lives in an ivory tower. it's all in his fantasy." Once more, I go back to history. Who would have thought before Constantin and Theodosius I that the Romans would see their empire destroyed by a handful of people from inside called Christians? Who would have thought before the French Revolution and the end of the monarchy that a handful of men would write the Universal Declaration on Human Rights? Today, those who reflect about another world, who strive for new values, are perhaps - perhaps you and I are - the first Christians of the Roman Empire. We may be about to change the things from inside through the only aspiration of our values to another world. How to organize this new controversy? That's very simple because of an unprecedented challenge, we have a new tool in our hands, and that's connection. We are all connected, and that will change everything. The fact that we are connected allows us to launch a controversy to consider the world of tomorrow. I finish my talk with this connection, as from tonight on, I suggest to launch the first tweet about the new controversy. Here and now in Nantes, here we go, sent. I invite you to continue the debate without me, after or with me. Thank you. (Applause) |
The mystery of motion sickness | null | TED-Ed | Can you read in the car? If so, consider yourself pretty lucky. For one-third of the population, looking at a book while moving along in a car or a boat or train or plane quickly makes them sick to their stomach. But why do we get motion sickness in the first place? Well, believe it or not, scientists aren't exactly sure. The most common theory has to do with mismatched sensory signals. When you travel in a car, your body gets two different messages. Your eyes are seeing the inside of a vehicle, which doesn't seem to be moving. Meanwhile, your ear is telling your brain you're accelerating. Wait, your ear? Your ear has another important function besides hearing. In its innermost part lies a group of structures known as the vestibular system, which gives us our sense of balance and movement. Inside there are three semicircular tubules that can sense rotation, one for each dimension of space. And there are also two hair-lined sacks filled with fluid. When you move, the fluid shifts and tickles the hairs, telling your brain if you're moving horizontally or vertically. All this tells your body which direction you're moving in, how much you've accelerated, even at what angle. In a car, your vestibular system correctly senses your movement, but your eyes don't see it, especially when glued to a book. The opposite can happen. You're at the movies, and the camera makes a sweeping move. This time, your eyes think you're moving while your ear knows you're sitting still. But why does this conflicting information make us feel so terrible? Scientists aren't sure, but they think there's an evolutionary explanation. Fast moving vehicles and video recordings have only existed in the last couple of centuries, a blink in evolutionary time. For most of our history, there wasn't that much that could cause this sensory mix-up, except for poisons. And because poisons are not the best thing for survival, our bodies evolved a direct but unpleasant way to get rid of what we ate that was causing the confusion. It's a pretty reasonable theory, but it leaves things unexplained, like why women are more affected by motion sickness than men, or why passengers get more nauseous than drivers. Another theory suggests that the cause is more about the way some unfamiliar situations make it harder to maintain our natural body posture. Studies show that being immersed in water or just changing your stance can greatly reduce the effects of motion sickness. But we don't really know what's going on. We know the more common remedies for car queasiness — looking at the horizon, over-the-counter pills, chewing gum, but none are totally reliable nor can they handle intense motion sickness and sometimes the stakes are far higher than just not being bored during a long car ride. At NASA, where astronauts are hurled into space at 17,000 miles per hour, motion sickness is a serious problem. In addition to researching the latest space-age technologies, NASA also spends a lot of time figuring out how to keep astronauts from vomiting up their space rations. Like understanding the mysteries of sleep or curing the common cold, motion sickness is one of those seemingly simple problems that, despite amazing scientific progress, we still know very little about. Perhaps one day the exact cause of motion sickness will be found, and with it, a completely effective way to prevent it, but that day is still on the horizon. |
How to build a fictional world | {0: 'Kate Messner believes in nature, art, magic, lake monsters, science, and the power of literacy to change the world. She writes books for people who believe in those things, too.'} | TED-Ed | In J.R.R.'s world, Gandalf is one of five wizards sent by the Valar to guide the inhabitants of Middle Earth in their struggles against the dark force of Sauron. Gandalf's body was mortal, subject to the physical rules of Middle Earth, but his spirit was immortal, as seen when he died as Gandalf the Grey and resurrected as Gandalf the White. According to the Wachowski's script, an awakened human only has to link up and hack the neon binary code of the Matrix to learn how to fly a helicopter in a matter of seconds. Or if you are the One, or one of the Ones, you don't even need a helicopter, you just need a cool pair of shades. Cheshire cats can juggle their own heads. iPads are rudimentary. No Quidditch match ends until the Golden Snitch is caught. And the answer to the ultimate question of life, the universe, and everything is most certainly 42. Just like real life, fictional worlds operate consistently within a spectrum of physical and societal rules. That's what makes these intricate worlds believable, comprehensible, and worth exploring. In real life, the Law of Gravity holds seven book sets of "Harry Potter" to millions of bookshelves around the world. We know this to be true, but we also know that ever since J.K. typed the words wizard, wand, and "Wingardium Leviosa," that Law of Gravity has ceased to exist on the trillions of pages resting between those bookends. Authors of science fiction and fantasy literally build worlds. They make rules, maps, lineages, languages, cultures, universes, alternate universes within universes, and from those worlds sprout story, after story, after story. When it's done well, readers can understand fictional worlds and their rules just as well as the characters that live in them do and sometimes, just as well or even better than the reader understands the world outside of the book. But how? How can human-made squiggles on a page reflect lights into our eyes that send signals to our brains that we logically and emotionally decode as complex narratives that move us to fight, cry, sing, and think, that are strong enough not only to hold up a world that is completely invented by the author, but also to change the reader's perspective on the real world that resumes only when the final squiggle is reached? I'm not sure anyone knows the answer to that question, yet fantastical, fictional worlds are created everyday in our minds, on computers, even on napkins at the restaurant down the street. The truth is your imagination and a willingness to, figuratively, live in your own world are all you need to get started writing a novel. I didn't dream up Hogwarts or the Star Wars' Cantina, but I have written some science thrillers for kids and young adults. Here are some questions and methods I've used to help build the worlds in which those books take place. I start with a basic place and time. Whether that's a fantasy world or a futuristic setting in the real world, it's important to know where you are and whether you're working in the past, present, or future. I like to create a timeline showing how the world came to be. What past events have shaped the way it is now? Then I brainstorm answers to questions that draw out the details of my fictional world. What rules are in place here? This covers everything from laws of gravity, or not, to the rules of society and the punishments for individuals who break them. What kind of government does this world have? Who has power, and who doesn't? What do people believe in here? And what does this society value most? Then it's time to think about day-to-day life. What's the weather like in this world? Where do the inhabitants live and work and go to school? What do they eat and how do they play? How do they treat their young and their old? What relationships do they have with the animals and plants of the world? And what do those animals and plants look like? What kind of technology exists? Transportation? Communication? Access to information? There's so much to think about! So, spend some time living in those tasks and the answers to those questions, and you're well on your way to building your own fictional world. Once you know your world as well as you hope your reader will, set your characters free in it and see what happens. And ask yourself, "How does this world you created shape the individuals who live in it? And what kind of conflict is likely to emerge?" Answer those questions, and you have your story. Good luck, future world-builder! |
Why the African diaspora is crucial to the continent's future | {0: 'Lindiwe Mazibuko was until recently the Leader of the Opposition in the South African National Assembly, making her the Democratic Alliance’s (DA) youngest-ever\r\nparliamentary leader and the first black woman in South African history to be elected to the post of Leader of the Opposition. Mazibuko committed herself to making\r\nParliament the true centre of robust political debate and engagement in South Africa. In May 2014, at the end of her term and following a successful electoral campaign in which the DA grew its share of the national vote from 16% to 22%, Mazibuko announced that she would take a sabbatical from active politics.\r\nIn May 2015, she graduated from Harvard University’s John F. Kennedy School of Government with a Master of Public\r\nAdministration (MPA), and since September 2015 she has been in residence at the Institute of Politics (IOP) at Harvard\r\nUniversity as a Fall Resident Fellow.'} | TEDxEuston | So, I'm here to recruit you. (Laughter) But not in the sense that you're thinking. I know I'm a politician. I'll save that for another day. I'm here to try and encourage you to take up a leadership role in public service in your country and on your continent. I'm here to convince you that your country and your continent need you - not later, not when you're older and more experienced, but now - and that whether you realize it or not, your country's politics are going to be doomed to fail unless you're willing to get involved right now. So my recruitment pitch comes with a single disclaimer: I resigned from public office 18 months ago. (Laughter) I did it in order to take stock of my time in office, to think about the work that I had done, to capacitate myself with skills, knowledge, contacts, allies and experiences, and to find a little bit of personal and professional perspective. It's one of the best decisions I think I've ever made. I imagine that some time during the next 18 minutes while I'm pitching you, you're going to think, "Yeah, it's easy for you to say I should go into public service. You've already done it and you've left." But I hope I'll be able to convince you that, in fact, we all find ourselves in exactly the same boat right now. Because being outside of politics for 18 months has reminded me just how important it is and just how much the political landscapes in my country and in your countries and on our continent are truly lacking in good leadership and political talent. So, I want to make a deal with you. I'm not going to return to active politics unless you come with me. (Laughter) I'm not going to do it alone. I won't go back unless I can convince smart, entrepreneurial, highly skilled, talented, experienced young Africans like yourselves and millions more like you across the continent, that the best chance that our countries have, not just for survival but for lasting prosperity, is if our most talented citizens step forward and make themselves available, either for political party, leadership or for public service and government. So over the next 16-or-so minutes that are remaining, I'm going to alternately flatter you, as I just have, (Laughter) I'm going to challenge you, I'm going to talk to you about my experiences, about a couple of facts and figures; I may even frighten you a little bit. And it'll be entirely worth it if that fear convinces you of the urgency of the point in history that we find ourselves in today. Everything I say today will be in service of a single objective: convincing you, showing you, that your countries need you; that Africa's prosperity may depend on many things - entrepreneurialism, industrial development, health reform, social upliftment - but that all of these hinge upon the success of politics and government in our countries. I can't begin a talk about public service, of course, without honoring my former president Nelson Mandela, the father of democratic South Africa. (Cheers) (Applause) President Mandela passed away on this day in 2013. I really believe that when the people of my country look back on the day that he passed away, it'll be seen as an inflection point in South Africa's history. The day we decided whether we could, indeed, go it alone without him. What's written in those history books will depend entirely on whether this generation, which includes all of you sitting in this room, recognizes that the time has come for us to take up the work that President Mandela left for us, before that work is captured by people who would use power and politics for empty vanity and personal gain. I'm referring, of course, to the young man who was here in London this very past week. Defiling the name of the visionary leader, the intellectual and political strategist, the formidable athlete, the Prince of the Abathembu nation who served as a South Africa's first democratic president. The young man who tried to taint President Mandela's legacy with a few throwaway lines, all in service of getting cheap headlines, which he got. People like this, who we leave public service to when we stay out of the fray of public service, are the reason your country and my country needs you and needs us. So let us begin. I want to first talk to you about the African diaspora. You may have heard about a study in 2013 that revealed that cash transfers from Africans living outside of the continent have now begun to exceed donor aid from foreign countries into Africa. (Applause) In 2012, total remittances to Africa stood at 60 billion dollars while in the same year, official development aid to Sub-Saharan Africa totalled 44.6 billion by comparison. Now, this got me thinking. If we can do such great work with our money from outside of Africa, what can we do with our skills, our talent, our experiences, our education and our passion for our countries and for our continent? I've spent the past semester at the Harvard Kennedy School as a fellow at the Institute of Politics. I ran a seminar which was called "How to build a democracy? Lessons from South Africa." It was also about Zimbabwe and Malawi. And it wasn't intended to make it seem like we got everything right in South Africa, but it was asking the critical question: Now that we have this legacy of peaceful transition, of constitutionalism, of difficult negotiations, which were very, very difficultly gotten, are we going to be successful in entrenching that democracy and making it last into the future? Now, one of the benefits of being an African in an academic setting like New England is that other African students reach out to you, they want to talk to you, and many of them express to you their desire to enter public service. So I had students knocking down my door, wanting to talk to me in office hours about the fact that they have Ghanean parents but they were born in Texas. They really wanted to give back to Ghana, but they're afraid that if they go home, nobody will take them seriously as real Africans. I had students who said they had families, wives, children, husbands, partners to take care of, perhaps they were better off staying in the United States and providing for their families back home rather than going back and getting into public service. This got me thinking about the question of skills remittance, of talent remittance, of social and political remittance. If these young people have the passion to give back to their communities monetarily, imagine how different our politics would be if those same skills, influence, leadership, talent were put at work in service of the public good. And that includes all of you in this room because many of you are also part of the diaspora. I'm here to recruit you. I'm here to make a deal with you. I'm not going back unless I take you with me. (Laugther) Now, I know that most of you, if not the vast majority of you, are completely fed up, turned off, discouraged, disgusted by politics, either in your country, in this country, all over the world. Perhaps you are discouraged by the fact that governments are slow to deliver. Perhaps they're inefficient. Perhaps they are thoroughly corrupt and rotten to the core. Perhaps they're responsible for conflicts that have claimed lives and livelihoods in the countries from which you come. So why would you sink your time and your energies into such a compromised system? One of the most powerful analyses of conflict, inefficiency, corruption, stagnation which I've encountered in recent months is the question of a political economy. There is a reason that our governments are not performing as they should. It's not just because of a failure within the system. Consider the political economy of conflict and corruption in your own country. Why is it so difficult to overcome? Who is making money or amassing power because things don't work the way they should? Where does the back stop? Who has an incentive to keep the system dysfunctional? And how can we work together to overcome their total infection of the system, to ensure that we don't lose our grip on the very principle of democratic governance? The answer, I'm afraid, because you were born into this political time, is simply by taking over - you have to get involved. There's no way around it. You have to join political organizations in numbers large enough to influence change from within. You have to actively seek to take up a leadership role in government, in the state, in the public service and deftly but decisively move its priorities to where they should be: not in the service of people who want to amass power and money for themselves, but to better the lives of the highest number of people. There will always be government, whether we like it or not, whether we find it palatable or not. But there won't always be democracy. If we ignore politics, the people who have been quietly lobbying our governments to prioritize development ahead of democracy, these are the people who will have their way, and the systems that we now take for granted will dissolve before our eyes. When I was campaigning in South Africa last year for the 2014 general election, the voter registration numbers looked a little bit like this, six months before the election: 23% of potential voters in the 18-to-19-year-old age group were registered to vote. In the age group 20 to 29 years old, 55% were registered. And from 30 upwards, the number varied from 79 to 100%; in fact, there were more people aged 80 and over who were registered than were in the census numbers in South Africa. Imagine that. Fully 100% of people over a certain age consider voting to be an indispensable right, 21 years into democracy, and do not shirk their responsibility to register and turn out at the polls. But in the 18-to-19-year-old age group - and we must remember 19 is the average age on our continent; 26 is the average age in South Africa - the number is 23% to 55%. What's the political economy of voter apathy? Who benefits when we stay out of the system? Who gets to keep the status quo and empower themselves and enrich themselves and continue to infect our political system like a cancer. Who banks by us continuing with the status quo? Now even as I say all of this to you, that your country and your continent need you to enter public service, I know that if you take up my challenge, you're going to face huge amounts of resistance - all because of these political economies that I have just described. I did. I was told that I was too young. I was too female. (Laughter) I didn't have enough experience though no one could define what experience was enough. I had too much of a white accent; I wasn't a real African. I straightened my hair and wore weaves; I wasn't a real African. We should be honest about the things that hold people back from entering public service - humiliation, degradation; it's not an easy road - but all of these things should illustrate to you the extent to which the status quo is designed to enrich and empower a few at the expense of the many, and it should impart to you the urgency of you, as a generation, of now getting involved in public service to change that very culture. And if you decide to enter public service, you may even be tempted to believe some of these criticisms. They're designed to keep you out; that's how gatekeeping works. Somebody is benefiting from the absence of excellence and disruption in politics and government. But these are challenges that have to be faced on. There is no other route; there is no wishing this away. They are the reason that your country and your continent need you. We have this thing in politics in Africa; it's called the "big man." The cult of personality - we've all heard different terminologies for it. In South Africa, in particular, this entails waiting for a great person to come and save us from ourselves. Currently, we're waiting for Cyril Ramaphosa or Nkosazana Dlamini-Zuma or [inaudible] to come and save South Africa from itself, to save us from the mess that we find ourselves in that perhaps another big man put us in. But how can a single personality be held responsible for building or for running a whole nation? And where do we turn when they fail? If we haven't cultivated any kind of pipeline of energetic, young people who wanted to enter public service now or in the future and, critically, who can do the job better, are we doomed to always have to choose between mediocrity and ego, and mediocrity and ego? Is that it? Is that all our government will ever be? Or worse: Are we going to stand by while presidents change constitutions so they can serve a third term and a fourth term and a fifth term, claiming that three million people signed a petition stating that they are the only person who can do the job? (Laughter) (Applause) Is that what we'll do? Now, there's a new energy around entrepreneurism and innovation and growth in Africa today. But that energy isn't going to translate into lasting prosperity unless we get our politics right. Political leaders who are gatekeepers of the status quo will claim that any success is their success. They'll centralize power, and they'll demand that we all be grateful for those little green shoots of achievement, and then they'll claim that nobody else can do the job. They'll argue that development must come first, freedom can come later, and that they are the best benevolent dictator to do the job. They'll take your political voice from you when times are a little bit good, and when times go bad, they will refuse to give it back. There is no prosperity for our continent without a vibrant, diverse, and truly competitive politics, founded upon excellence, transparency and commitment to the public good. Our politics will not have any of these qualities unless talented, young people, the best people, step forward at this moment in Africa's history, when we're emerging from that stereotype of the dark continent, the hopeless continent, and commit themselves to public service. We must run for office. We must work in the civil service. We must disrupt the political status quo. We must prevent the rush to the bottom. You really are the ones that you have been waiting for. There are no great saviors waiting somewhere in the wings to save us from future problems. There's nobody who is waiting in the wings to come and save us from ourselves; there's just us. And I'm not going back without you. (Laughter) So, will you take up the challenge? Thank you. (Cheers) (Applause) |
Can you solve the prisoner boxes riddle? | null | TED-Ed | Your favorite band is great at playing music, but not so great at being organized. They keep misplacing their instruments on tour, and it's driving their manager mad. On the day of the big concert, the band wakes up to find themselves tied up in a windowless, soundproof practice room. Their manager explains what's happening. Outside, there are ten large boxes. Each contains one of your instruments, but don't be fooled by the pictures - they've been randomly placed. I'm going to let you out one at a time. While you're outside, you can look inside any five boxes before security takes you back to the tour bus. You can't touch the instruments or in any way communicate what you find to the others. No marking the boxes, shouting, nothing. If each one of you can find your own instrument, then you can play tonight. Otherwise, the label is dropping you. You have three minutes to think about it before we start. The band is in despair. After all, each musician only has a 50% chance of finding their instrument by picking five random boxes. And the chances that all ten will succeed are even lower - just 1 in 1024. But suddenly, the drummer comes up with a valid strategy that has a better than 35% chance of working. Can you figure out what it was? Pause the video on the next screen if you want to figure it out for yourself! Answer in: 3 Answer in: 2 Answer in: 1 Here's what the drummer said: Everyone first open the box with the picture of your instrument. If your instrument is inside, you're done. Otherwise, look at whatever's in there, and then open the box with that picture on it. Keep going that way until you find your instrument. The bandmates are skeptical, but amazingly enough, they all find what they need. And a few hours later, they're playing to thousands of adoring fans. So why did the drummer's strategy work? Each musician follows a linked sequence that starts with the box whose outside matches their instrument and ends with the box actually containing it. Note that if they kept going, that would lead them back to the start, so this is a loop. For example, if the boxes are arranged like so, the singer would open the first box to find the drums, go to the eighth box to find the bass, and find her microphone in the third box, which would point back to the first. This works much better than random guessing because by starting with the box with the picture of their instrument, each musician restricts their search to the loop that contains their instrument, and there are decent odds, about 35%, that all of the loops will be of length five or less. How do we calculate those odds? For the sake of simplicity, we'll demonstrate with a simplified case, four instruments and no more than two guesses allowed for each musician. Let's start by finding the odds of failure, the chance that someone will need to open three or four boxes before they find their instrument. There are six distinct four-box loops. One fun way to count them is to make a square, put an instrument at each corner, and draw the diagonals. See how many unique loops you can find, and keep in mind that these two are considered the same, they just start at different points. These two, however, are different. We can visualize the eight distinct three-box loops using triangles. You'll find four possible triangles depending on which instrument you leave out, and two distinct paths on each. So of the 24 possible combinations of boxes, there are 14 that lead to faliure, and ten that result in success. That computational strategy works for any even number of musicians, but if you want a shortcut, it generalizes to a handy equation. Plug in ten musicians, and we get odds of about 35%. What if there were 1,000 musicians? 1,000,000? As n increases, the odds approach about 30%. Not a guarantee, but with a bit of musician's luck, it's far from hopeless. Hi everybody, if you liked this riddle, try solving these two. |
How do we find dignity at work? | {0: 'Roy Bahat invests in the future of work, with a focus on automation, data, robotics, media, productivity tools and more.', 1: 'Bryn Freedman helps those who want to give the "talk of their lives" in a clear, passionate and authentic way.'} | TED Salon Zebra Technologies | Bryn Freedman: You're a guy whose company funds these AI programs and invests. So why should we trust you to not have a bias and tell us something really useful for the rest of us about the future of work? Roy Bahat: Yes, I am. And when you wake up in the morning and you read the newspaper and it says, "The robots are coming, they may take all our jobs," as a start-up investor focused on the future of work, our fund was the first one to say artificial intelligence should be a focus for us. So I woke up one morning and read that and said, "Oh, my gosh, they're talking about me. That's me who's doing that." And then I thought: wait a minute. If things continue, then maybe not only will the start-ups in which we invest struggle because there won't be people to have jobs to pay for the things that they make and buy them, but our economy and society might struggle, too. And look, I should be the guy who sits here and tells you, "Everything is going to be fine. It's all going to work out great. Hey, when they introduced the ATM machine, years later, there's more tellers in banks." It's true. And yet, when I looked at it, I thought, "This is going to accelerate. And if it does accelerate, there's a chance the center doesn't hold." But I figured somebody must know the answer to this; there are so many ideas out there. And I read all the books, and I went to the conferences, and at one point, we counted more than 100 efforts to study the future of work. And it was a frustrating experience, because I'd hear the same back-and-forth over and over again: "The robots are coming!" And then somebody else would say, "Oh, don't worry about that, they've always said that and it turns out OK." Then somebody else would say, "Well, it's really about the meaning of your job, anyway." And then everybody would shrug and go off and have a drink. And it felt like there was this Kabuki theater of this discussion, where nobody was talking to each other. And many of the people that I knew and worked with in the technology world were not speaking to policy makers; the policy makers were not speaking to them. And so we partnered with a nonpartisan think tank NGO called New America to study this issue. And we brought together a group of people, including an AI czar at a technology company and a video game designer and a heartland conservative and a Wall Street investor and a socialist magazine editor — literally, all in the same room; it was occasionally awkward — to try to figure out what is it that will happen here. The question we asked was simple. It was: What is the effect of technology on work going to be? And we looked out 10 to 20 years, because we wanted to look out far enough that there could be real change, but soon enough that we weren't talking about teleportation or anything like that. And we recognized — and I think every year we're reminded of this in the world — that predicting what's going to happen is hard. So instead of predicting, there are other things you can do. You can try to imagine alternate possible futures, which is what we did. We did a scenario-planning exercise, and we imagined cases where no job is safe. We imagined cases where every job is safe. And we imagined every distinct possibility we could. And the result, which really surprised us, was when you think through those futures and you think what should we do, the answers about what we should do actually turn out to be the same, no matter what happens. And the irony of looking out 10 to 20 years into the future is, you realize that the things we want to act on are actually already happening right now. The automation is right now, the future is right now. BF: So what does that mean, and what does that tell us? If the future is now, what is it that we should be doing, and what should we be thinking about? RB: We have to understand the problem first. And so the data are that as the economy becomes more productive and individual workers become more productive, their wages haven't risen. If you look at the proportion of prime working-age men, in the United States at least, who work now versus in 1960, we have three times as many men not working. And then you hear the stories. I sat down with a group of Walmart workers and said, "What do you think about this cashier, this futuristic self-checkout thing?" They said, "That's nice, but have you heard about the cash recycler? That's a machine that's being installed right now, and is eliminating two jobs at every Walmart right now." And so we just thought, "Geez. We don't understand the problem." And so we looked at the voices that were the ones that were excluded, which is all of the people affected by this change. And we decided to listen to them, sort of "automation and its discontents." And I've spent the last couple of years doing that. I've been to Flint, Michigan, and Youngstown, Ohio, talking about entrepreneurs, trying to make it work in a very different environment from New York or San Francisco or London or Tokyo. I've been to prisons twice to talk to inmates about their jobs after they leave. I've sat down with truck drivers to ask them about the self-driving truck, with people who, in addition to their full-time job, care for an aging relative. And when you talk to people, there were two themes that came out loud and clear. The first one was that people are less looking for more money or get out of the fear of the robot taking their job, and they just want something stable. They want something predictable. So if you survey people and ask them what they want out of work, for everybody who makes less than 150,000 dollars a year, they'll take a more stable and secure income, on average, over earning more money. And if you think about the fact that not only for all of the people across the earth who don't earn a living, but for those who do, the vast majority earn a different amount from month to month and have an instability, all of a sudden you realize, "Wait a minute. We have a real problem on our hands." And the second thing they say, which took us a longer time to understand, is they say they want dignity. And that concept of self-worth through work emerged again and again and again in our conversations. BF: So, I certainly appreciate this answer. But you can't eat dignity, you can't clothe your children with self-esteem. So, what is that, how do you reconcile — what does dignity mean, and what is the relationship between dignity and stability? RB: You can't eat dignity. You need stability first. And the good news is, many of the conversations that are happening right now are about how we solve that. You know, I'm a proponent of studying guaranteed income, as one example, conversations about how health care gets provided and other benefits. Those conversations are happening, and we're at a time where we must figure that out. It is the crisis of our era. And my point of view after talking to people is that we may do that, and it still might not be enough. Because what we need to do from the beginning is understand what is it about work that gives people dignity, so they can live the lives that they want to live. And so that concept of dignity is ... it's difficult to get your hands around, because when many people hear it — especially, to be honest, rich people — they hear "meaning." They hear "My work is important to me." And again, if you survey people and you ask them, "How important is it to you that your work be important to you?" only people who make 150,000 dollars a year or more say that it is important to them that their work be important. BF: Meaning, meaningful? RB: Just defined as, "Is your work important to you?" Whatever somebody took that to mean. And yet, of course dignity is essential. We talked to truck drivers who said, "I saw my cousin drive, and I got on the open road and it was amazing. And I started making more money than people who went to college." Then they'd get to the end of their thought and say something like, "People need their fruits and vegetables in the morning, and I'm the guy who gets it to them." We talked to somebody who, in addition to his job, was caring for his aunt. He was making plenty of money. At one point we just asked, "What is it about caring for your aunt? Can't you just pay somebody to do it?" He said, "My aunt doesn't want somebody we pay for. My aunt wants me." So there was this concept there of being needed. If you study the word "dignity," it's fascinating. It's one of the oldest words in the English language, from antiquity. And it has two meanings: one is self-worth, and the other is that something is suitable, it's fitting, meaning that you're part of something greater than yourself, and it connects to some broader whole. In other words, that you're needed. BF: So how do you answer this question, this concept that we don't pay teachers, and we don't pay eldercare workers, and we don't pay people who really care for people and are needed, enough? RB: Well, the good news is, people are finally asking the question. So as AI investors, we often get phone calls from foundations or CEOs and boardrooms saying, "What do we do about this?" And they used to be asking, "What do we do about introducing automation?" And now they're asking, "What do we do about self-worth?" And they know that the employees who work for them who have a spouse who cares for somebody, that dignity is essential to their ability to just do their job. I think there's two kinds of answers: there's the money side of just making your life work. That's stability. You need to eat. And then you think about our culture more broadly, and you ask: Who do we make into heroes? And, you know, what I want is to see the magazine cover that is the person who is the heroic caregiver. Or the Netflix series that dramatizes the person who makes all of our other lives work so we can do the things we do. Let's make heroes out of those people. That's the Netflix show that I would binge. And we've had chroniclers of this before — Studs Terkel, the oral history of the working experience in the United States. And what we need is the experience of needing one another and being connected to each other. Maybe that's the answer for how we all fit as a society. And the thought exercise, to me, is: if you were to go back 100 years and have people — my grandparents, great-grandparents, a tailor, worked in a mine — they look at what all of us do for a living and say, "That's not work." We sit there and type and talk, and there's no danger of getting hurt. And my guess is that if you were to imagine 100 years from now, we'll still be doing things for each other. We'll still need one another. And we just will think of it as work. The entire thing I'm trying to say is that dignity should not just be about having a job. Because if you say you need a job to have dignity, which many people say, the second you say that, you say to all the parents and all the teachers and all the caregivers that all of a sudden, because they're not being paid for what they're doing, it somehow lacks this essential human quality. To me, that's the great puzzle of our time: Can we figure out how to provide that stability throughout life, and then can we figure out how to create an inclusive, not just racially, gender, but multigenerationally inclusive — I mean, every different human experience included — in this way of understanding how we can be needed by one another. BF: Thank you. RB: Thank you. BF: Thank you very much for your participation. (Applause) |
Three ways the universe could end | null | TED-Ed | We know about our universe’s past: the Big Bang theory predicts that all matter, time, and space began in an incredibly tiny, compact state about 14 billion years ago. And we know about the present: scientists’ observations of the movement of galaxies tell us that the universe is expanding at an accelerated rate. But what about the future? Do we know how our universe is going to end? Cosmologists have three possible answers for this question, called the Big Freeze, the Big Rip and the Big Crunch. To understand these three scenarios, imagine two objects representing galaxies. A short, tight rubber band is holding them together— that’s the attractive force of gravity. Meanwhile, two hooks are pulling them apart— that’s the repulsive force expanding the universe. Copy this system over and over again, and you have something approximating the real universe. The outcome of the battle between these two opposing forces determines how the end of the universe will play out. The Big Freeze scenario is what happens if the force pulling the objects apart is just strong enough to stretch the rubber band until it loses its elasticity. The expansion wouldn’t be able to accelerate anymore, but the universe would keep getting bigger. Clusters of galaxies would separate. The objects within the galaxies– suns, planets, and solar systems would move away from each other, until galaxies dissolved into lonely objects floating separately in the vast space. The light they emit would be redshifted to long wavelengths with very low, faint energies, and the gas emanating from them would be too thin to create new stars. The universe would become darker and colder, approaching a frozen state also known as the Big Chill, or the Heat Death of the Universe. But what if the repulsive force is so strong that it stretches the rubber band past its elastic limit, and actually tears it? If the expansion of the universe continues to accelerate, it will eventually overcome not only the gravitational force – tearing apart galaxies and solar systems– but also the electromagnetic, weak, and strong nuclear forces which hold atoms and nuclei together. As a result, the matter that makes up stars breaks into tiny pieces. Even atoms and subatomic particles will be destroyed. That’s the Big Rip. What about the third scenario, where the rubber band wins out? That corresponds to a possible future in which the force of gravity brings the universe’s expansion to a halt— and then reverses it. Galaxies would start rushing towards each other, and as they clumped together their gravitational pull would get even stronger. Stars too would hurtle together and collide. Temperatures would rise as space would get tighter and tighter. The size of the universe would plummet until everything compressed into such a small space that even atoms and subatomic particles would have to crunch together. The result would be an incredibly dense, hot, compact universe — a lot like the state that preceded the Big Bang. This is the Big Crunch. Could this tiny point of matter explode in another Big Bang? Could the universe expand and contract over and over again, repeating its entire history? The theory describing such a universe is known as the Big Bounce. In fact, there’s no way to tell how many bounces could’ve already happened— or how many might happen in the future. Each bounce would wipe away any record of the universe’s previous history. Which one of those scenarios will be the real one? The answer depends on the exact shape of the universe, the amount of dark energy it holds, and changes in its expansion rate. As of now, our observations suggest that we’re heading for a Big Freeze. But the good news is that we’ve probably got about 10 to the 100th power years before the chill sets in — so don’t start stocking up on mittens just yet. |
How to teach kids to talk about taboo topics | {0: 'Liz Kleinrock creates curricular content for K-12 students around issues of diversity, equity and inclusion.'} | TED Salon: Education Everywhere | So, a few years ago, I was beginning a new unit on race with my fourth-graders. And whenever we start a new unit, I like to begin by having all the students list everything they know about it, and then we also list questions we have. And I had the type of moment that every teacher has nightmares about. One of my students had just asked the question, "Why are some people racist?" And another student, let's call her Abby, had just raised her hand and volunteered: "Maybe some people don't like black people because their skin is the color of poop." Yeah, I know. So, as if on cue, my entire class exploded. Half of them immediately started laughing, and the other half started yelling at Abby and shouting things like, "Oh, my God, you can't say that, that's racist!" So just take a second to freeze this scene in your mind. There's a class of nine- and ten-year-olds, and half of them are in hysterics because they think Abby has said something wildly funny, and the other half are yelling at her for saying something offensive. And then you have Abby, sitting there completely bewildered because, in her mind, she doesn't understand the weight of what she said and why everybody is reacting this way. And then you have me, the teacher, standing there in the corner, like, about to have a panic attack. So as a classroom teacher, I have to make split-second decisions all the time. And I knew I needed to react, but how? Consider your fight-or-flight instincts. I could fight by raising my voice and reprimanding her for her words. Or flight — just change the subject and quickly start reaching for another subject, like anything to get my students' minds off the word "poop." However, as we know, the right thing to do is often not the easy thing to do. And as much as I wanted this moment to be over, and that I knew both of these options would help me escape the situation, I knew that this was far too important of a teachable moment to miss. So after standing there for what felt like an eternity, I unfroze and I turned to face my class, and I said, "Actually, Abby makes a point." And my students kind of looked at each other, all confused. And I continued, "One reason why racism exists is because people with light skin have looked at people with dark skin and said that their skin was ugly. And even use this reason as an excuse to dehumanize them. And the reason why we're learning about race and racism in the first place is to educate ourselves to know better. And to understand why comments like this are hurtful, and to make sure that people with dark skin are always treated with respect and kindness." Now, this was a truly terrifying teachable moment. But as we moved forward in the conversation, I noticed that both Abby and the rest of the kids were still willing to engage. And as I watched the conversation really marinate with my students, I began to wonder how many of my students have assumptions just like Abby. And what happens when those assumptions go unnoticed and unaddressed, as they so often do? But first, I think it's important to take a step back and even consider what makes a topic taboo. I don't remember receiving an official list of things you're not supposed to talk about. But I do remember hearing, over and over, growing up: there are two things you do not talk about at family get-togethers. And those two things are religion and politics. And I always thought this was very curious because religion and politics often are such huge influencing factors over so many of our identities and beliefs. But what makes a topic taboo is that feeling of discomfort that arises when these things come up in conversation. But some people are extremely fluent in the language of equity, while other people fear being PC-shamed or that their ignorance will show as soon as they open their mouths. But I believe that the first step towards holding conversations about things like equity is to begin by building a common language. And that actually starts with destigmatizing topics that are typically deemed taboo. Now, conversations around race, for example, have their own specific language and students need to be fluent in this language in order to have these conversations. Now, schools are often the only place where students can feel free and comfortable to ask questions and make mistakes. But, unfortunately, not all students feel that sense of security. Now, I knew that day in front of my fourth-graders that how I chose to respond could actually have life-long implications not only for Abby, but for the rest of the students in my class. If I had brushed her words aside, the rest of the class could actually infer that this type of comment is acceptable. But if I had yelled at Abby and embarrassed her in front of all of her friends, that feeling of shame associated with one of her first conversations on race could actually prevent her from ever engaging on that topic again. Now, teaching kids about equity in schools is not teaching them what to think. It is about giving them the tools and strategies and language and opportunities to practice how to think. For example, think about how we teach kids how to read. We don't start by giving them books. We start by breaking down words into letters and sounds and we encourage them to practice their fluency by reading every single day, with a partner or with their friends. And we give them lots of comprehension questions to make sure that they're understanding what they're reading. And I believe that teaching kids about equity should be approached in the exact same way. I like to start by giving my students a survey every year, about different issues around equity and inclusion. And this is a sample survey from one of my kids, and as you can see, there's some humor in here. For under the question, "What is race?" she has written, "When two or more cars, people and animals run to see who is fastest and who wins." However, if you look at her question, "What is racism?" it says, "When somebody says or calls someone dark-skinned a mean name." So, she's young, but she's showing that she's beginning to understand. And when we act like our students aren't capable of having these conversations, we actually do them such a disservice. Now, I also know that these types of conversations can seem really, really intimidating with our students, especially with young learners. But I have taught first through fifth grades, and I can tell you, for example, that I'm not going to walk into a first-grade classroom and start talking about things like mass incarceration. But even a six-year-old first-grader can understand the difference between what is fair — people getting what they need. We identified a lot of these things in class together. And the difference between fair and equal — when everybody gets the same thing, especially goody bags at birthday parties. Now, first-graders can also understand the difference between a punishment and a consequence. And all of these things are foundational concepts that anyone needs to understand before having a conversation about mass incarceration in the United States. Some people might think that kindergarteners or first-graders are too young to have conversations around racism, but also tell you that young kids understand that there are many different components that make up our identities and how people are similar and different, and what it means to have power when other people don't. When we have these conversations with students at a young age, it actually takes away some of that taboo feeling when those topics come up at a later age. I also know that teaching about these things in schools can feel like navigating a minefield. For example, what happens if parents or families aren't on board with having these conversations in schools? But to these people, I can say: these are some examples of things that students have said to me and brought to my attention. For example, I had a student come in and whisper to me, "I've heard all these people use the term LGBTQ, but I don't know what it means and I'm too embarrassed to admit it." I had a student come in over a weekend and come up to me and say, "You know, I just watched this movie about Australia, and it made me wonder if they have racism there, too." And I always want my students to be comfortable having these conversations because when they're comfortable talking about it and asking questions, they also build comfort in bringing in their own lives and experiences in how they relate to these big topics. Also, some teachers might be kind of nervous if a student brings up a topic or asks a question and they don't know the answer to it. But if a student ever brings something to my attention and I don't know the answer, I will always admit it and own it because I'm not going to pretend to be an expert in something that I don't have experience in or I'm not an authority on. That same year, I had a student come in and ask a question about the LGBTQ community. And I just didn't know enough to give them an appropriate answer. So instead, I encouraged that student to reach out and ask that question to a representative of a nonprofit who had come to speak to our class about that very same issue. When we admit to our students that we don't have all the answers, not only does it humanize us to them, it also shows them that adults have a long way to go, too, when it comes to learning about issues of equity. Now, a little while back, I wrote a lesson about consent. And, to some people, this was very exciting because I took this topic that seemed very taboo and scary and I broke it down into a way that was accessible for young learners. However, to other people, the idea of consent is so strongly tied to sex, and sex is often considered a taboo subject, that it made them very uncomfortable. But my students are third-graders, so we're not talking about sex in class. Rather, I wanted them to understand that everybody has different physical boundaries that make them feel comfortable. And the social and emotional intelligence it takes to read somebody's words and tone and body language are skills that often need to be explicitly taught, the same way we teach things like reading and math. And this lesson is not reserved for students of one single demographic. Things like questioning and making observations and critical thinking are things that any student of any race or ethnicity or background or language or income or zip code should be learning in schools. Also, deliberate avoidance of these conversations speaks volumes to our students because kids notice when their teachers, when their textbooks leave out the voices and experiences of people like women or people of color. Silence speaks volumes. I recently asked my class of third-graders what they would say to adults who think they're too young to learn about issues of equity. And while this is a small sample of my 25 students, all of them agreed that not only are they capable of having these conversations, but they view it, the right to learn it, as a right and not as a privilege. And, in their words: "We're big enough to know about these things because these problems are happening where we live. And we have the right to talk about them because it will be our life in the future." Thank you. (Applause) |
Why should you read Flannery O'Connor? | null | TED-Ed | A garrulous grandmother and a roaming bandit face off on a dirt road. A Bible salesman lures a one-legged philosopher into a barn. A traveling handyman teaches a deaf woman her first word on an old plantation. From her farm in rural Georgia, surrounded by a flock of pet birds, Flannery O’Connor scribbled tales of outcasts, intruders and misfits staged in the world she knew best: the American South. She published two novels, but is perhaps best known for her short stories, which explored small-town life with stinging language, offbeat humor, and delightfully unsavory scenarios. In her spare time O’Connor drew cartoons, and her writing is also brimming with caricature. In her stories, a mother has a face “as broad and innocent as a cabbage,” a man has as much drive as a “floor mop,” and one woman’s body is shaped like “a funeral urn.” The names of her characters are equally sly. Take the story “The Life You Save May be Your Own,” where the one-handed drifter Tom Shiftlet wanders into the lives of an old woman named Lucynell Crater and her deaf and mute daughter. Though Mrs. Crater is self-assured, her isolated home is falling apart. At first, we may be suspicious of Shiftlet’s motives when he offers to help around the house, but O’Connor soon reveals the old woman to be just as scheming as her unexpected guest– and rattles the reader’s presumptions about who has the upper hand. For O’Connor, no subject was off limits. Though she was a devout Catholic, she wasn’t afraid to explore the possibility of pious thought and unpious behavior co-existing in the same person. In her novel The Violent Bear it Away, the main character grapples with the choice to become a man of God – but also sets fires and commits murder. The book opens with the reluctant prophet in a particularly compromising position: “Francis Marion Tarwater’s uncle had been dead for only half a day when the boy got too drunk to finish digging his grave.” This leaves a passerby to “drag the body from the breakfast table where it was still sitting and bury it […] with enough dirt on top to keep the dogs from digging it up.” Though her own politics are still debated, O’Connor’s fiction could also be attuned to the racism of the South. In “Everything that Rises Must Converge,” she depicts a son raging at his mother’s bigotry. But the story reveals that he has his own blind spots and suggests that simply recognizing evil doesn’t exempt his character from scrutiny. Even as O’Connor probes the most unsavory aspects of humanity, she leaves the door to redemption open a crack. In “A Good Man is Hard to Find,” she redeems an insufferable grandmother for forgiving a hardened criminal, even as he closes in on her family. Though we might balk at the price the woman pays for this redemption, we’re forced to confront the nuance in moments we might otherwise consider purely violent or evil. O’Connor’s mastery of the grotesque and her explorations of the insularity and superstition of the South led her to be classified as a Southern Gothic writer. But her work pushed beyond the purely ridiculous and frightening characteristics associated with the genre to reveal the variety and nuance of human character. She knew some of this variety was uncomfortable, and that her stories could be an acquired taste – but she took pleasure in challenging her readers. O’Connor died of lupus at the age of 39, after the disease had mostly confined her to her farm in Georgia for twelve years. During those years, she penned much of her most imaginative work. Her ability to flit between revulsion and revelation continues to draw readers to her endlessly surprising fictional worlds. As her character Tom Shiftlet notes, the body is “like a house: it don’t go anywhere, but the spirit, lady, is like an automobile: always on the move.” |
What if all US health care costs were transparent? | {0: "Jeanne Pinder asks why it's so hard to make sense of US healthcare bills -- and suggests what we might do about it."} | TED Residency | So, a little while ago, members of my family had three bits of minor surgery, about a half hour each, and we got three sets of bills. For the first one, the anesthesia bill alone was 2,000 dollars; the second one, 2,000 dollars; the third one, 6,000 dollars. So I'm a journalist. I'm like, what's up with that? I found out that I was actually, for the expensive one, being charged 1,419 dollars for a generic anti-nausea drug that I could buy online for two dollars and forty-nine cents. I had a long and unsatisfactory argument with the hospital, the insurer and my employer. Everybody agreed that this was totally fine. But it got me thinking, and the more I talked to people, the more I realized: nobody has any idea what stuff costs in health care. Not before, during or after that procedure or test do you have any idea what it's going to cost. It's only months later that you get an "explanation of benefits" that explains exactly nothing. So this came back to me a little while later. I had volunteered for a buyout from the New York Times, where I had worked for more than 20 years as a journalist. I was looking for my next act. It turned out that next act was to build a company telling people what stuff costs in health care. I won a "Shark Tank"-type pitch contest to do just that. Health costs ate up almost 18 percent of our gross domestic product last year, but nobody has any idea what stuff costs. But what if we did know? So we started out small. We called doctors and hospitals and asked them what they would accept as a cash payment for simple procedures. Some people were helpful. A lot of people hung up on us. Some people were just plain rude. They said, "We don't know," or, "Our lawyers won't let us tell you that," though we did get a lot of information. We found, for example, that here in the New York area, you could get an echocardiogram for 200 dollars in Brooklyn or for 2,150 dollars in Manhattan, just a few miles away. New Orleans, the same simple blood test, 19 dollars over here, 522 dollars just a few blocks away. San Francisco, the same MRI, 475 dollars or 6,221 dollars just 25 miles away. These pricing variations existed for all the procedures and all the cities that we surveyed. Then we started to ask people to tell us their health bills. In partnership with public radio station WNYC here in New York, we asked women to tell us the prices of their mammograms. People told us nobody would do that, that it was too personal. But in the space of three weeks, 400 women told us about their prices. Then we started to make it easier for people to share their data into our online searchable database. It's sort of like a mash-up of Kayak.com and the Waze traffic app for health care. (Laughter) We call it a community-created guide to health costs. Our survey and crowdsourcing work grew into partnerships with top newsrooms nationwide — in New Orleans, Philadelphia, San Francisco, Los Angeles, Miami and other places. We used the data to tell stories about people who were suffering and how to avoid that suffering, to avoid that "gotcha" bill. A woman in New Orleans saved nearly 4,000 dollars using our data. A San Francisco contributor saved nearly 1,300 dollars by putting away his insurance card and paying cash. There are a lot of people who are going to in-network hospitals and getting out-of-network bills. And then there was the hospital that continued to bill a dead man. We learned that thousands of people wanted to tell us their prices. They want to learn what stuff costs, find out how to argue a bill, help us solve this problem that's hurting them and their friends and families. We talked to people who had to sell a car to pay a health bill, go into bankruptcy, skip a treatment because of the cost. Imagine if you could afford the diagnosis but not the cure. We set off a huge conversation about costs involving doctors and hospitals, yes, but also their patients, or as we like to call them, people. (Laughter) We changed policy. A consumer protection bill that had been stalled in the Louisiana legislature for 10 years passed after we launched. Let's face it: this huge, slow-rolling public health crisis is a national emergency. And I don't think government's going to help us out anytime soon. But what if the answer was really simple: make all the prices public all the time. Would our individual bills go down? Our health premiums? Be really clear about this: this is a United States problem. In most of the rest of the developed world, sick people don't have to worry about money. It's also true that price transparency will not solve every problem. There will still be expensive treatments, huge friction from our insurance system. There will still be fraud and a massive problem with overtreatment and overdiagnosis. And not everything is shoppable. Not everybody wants the cheapest appendectomy or the cheapest cancer care. But when we talk about these clear effects, we're looking at a real issue that's actually very simple. When we first started calling for prices, we actually felt like we were going to be arrested. It seemed kind of transgressive to talk about medicine and health care in the same breath, and yet it became liberating, because we found not only data but also good and honest people out there in the system who want to help folks get the care they need at a price they can afford. And it got easier to ask. So I'll leave you with some questions. What if we all knew what stuff cost in health care in advance? What if, every time you Googled for an MRI, you got drop-downs telling you where to buy and for how much, the way you do when you Google for a laser printer? What if all of the time and energy and money that's spent hiding prices was squeezed out of the system? What if each one of us could pick the $19 test every time instead of the $522 one? Would our individual bills go down? Our premiums? I don't know, but if you don't ask, you'll never know. And you might save a ton of money. And I've got to think that a lot of us and the system itself would be a lot healthier. Thank you. (Applause) |
Why should you read "Don Quixote"? | null | TED-Ed | Mounting his skinny steed, the protagonist of Don Quixote charges an army of giants. In his eyes, it is his duty to vanquish these behemoths in the name of his beloved lady, Dulcinea. However, this act of valor is ill conceived. As his squire Sancho Panza explains to him time and again, these aren’t giants; they are merely windmills. Don Quixote is undeterred, but his piercing lance is soon caught in their sails. Never discouraged, the knight stands proudly, and becomes even more convinced of his mission. This sequence encapsulates much of what is loved about Don Quixote, the epic, illogical, and soulful tale of Alonso Quijano, who becomes the clumsy but valiant Don Quixote of la Mancha, known as the Knight of the Sorrowful Countenance. Originally published in two volumes, the narrative follows Don Quixote as he travels through central and northern Spain fighting the forces of evil. Despite Don Quixote’s lofty imagination, his creator, Miguel de Cervantes, could never have imagined his book would become the best-selling novel of all time. Barring 5 years as a soldier, and 5 more enslaved by pirates, Cervantes spent most of his life as a struggling poet and playwright. It wasn’t until his late 50’s that he published his greatest creation: an epic satire of chivalry novels. At this time, medieval books chronicling the adventures of knights and their moral code dominated European culture. While Cervantes was a fan, he was weary of these repetitive tomes, which focused more on listing heroic feats than character development. To challenge them, he wrote Don Quixote, the story of a hidalgo, or idle nobleman, who spends his days and nights reading chivalry novels. Driven mad by these stories, he fashions himself a champion for the downtrodden. Everyone in his village tries to convince him to give up his lunacy, going so far as to burn some of the lurid books in his personal library. But Don Quixote is unstoppable. He dresses up in old shining armor, mounts his skinny horse, and leaves his village in search of glory. Cervantes’ novel unfolds as a collection of episodes detailing the mishaps of the valiant knight. Yet unlike the chivalry books and perhaps all other prior fiction, Cervantes’ story deeply investigates the protagonist’s inner life. Don Quixote matures as the narrative develops, undergoing a noticeable transformation. This literary revelation has led many scholars to call Don Quixote the first modern novel. And this character development doesn’t happen in isolation. Early on, Don Quixote is joined by a villager-turned-squire named Sancho Panza. Sancho and Don Quixote are a study in opposites: with one as the grounded realist to the other’s idealism. Their lively, evolving friendship is often credited as the original hero and sidekick duo, inspiring centuries of fictional partnerships. Don Quixote was a huge success. Numerous editions were published across Europe in the seventeenth century. Even in the Americas, where the Church banned all novels for being sinful distractions, audiences were known to enjoy pirated editions. The book was so well received that readers clamored for more. After a rival author attempted to cash in on a fake follow-up, Cervantes released the official sequel in response. Now published alongside the first volume as a completed text, this second volume picks up where the original left off, only now Don Quixote and Sancho have become folk heroes. Just as in real-life, Cervantes included his novel’s success in the world of his characters. This unconventional meta-awareness created philosophical complexity, as the knight and his squire ponder the meaning of their story. Unfortunately, Cervantes had sold the book’s publishing rights for very little. He died rich in fame alone. But his treatise on the power of creativity and individualism has inspired art, literature, popular culture, and even political revolution. Don Quixote argues that our imagination greatly informs our actions, making us capable of change, and, indeed, making us human. |
The life cycle of a neutron star | null | TED-Ed | About once every century, a massive star somewhere in our galaxy runs out of fuel. This happens after millions of years of heat and pressure have fused the star’s hydrogen into heavier elements like helium, carbon, and nitrogen— all the way to iron. No longer able to produce sufficient energy to maintain its structure, it collapses under its own gravitational pressure and explodes in a supernova. The star shoots most of its innards into space, seeding the galaxy with heavy elements. But what this cataclysmic eruption leaves behind might be even more remarkable: a ball of matter so dense that atomic electrons collapse from their quantum orbits into the depths of atomic nuclei. The death of that star is the birth of a neutron star: one of the densest known objects in the universe, and a laboratory for the strange physics of supercondensed matter. But what is a neutron star? Think of a compact ball inside of which protons and electrons fuse into neutrons and form a frictionless liquid called a superfluid— surrounded by a crust. This material is incredibly dense – the equivalent of the mass of a fully-loaded container ship squeezed into a human hair, or the mass of Mount Everest in a space of a sugar cube. Deeper in the crust, the neutron superfluid forms different phases that physicists call “nuclear pasta,” as it’s squeezed from lasagna to spaghetti-like shapes. The massive precursors to neutron stars often spin. When they collapse, stars that are typically millions of kilometers wide compress down to neutron stars that are only about 25 kilometers across. But the original star’s angular momentum is preserved. So for the same reason that a figure skater’s spin accelerates when they bring in their arms, the neutron star spins much more rapidly than its parent. The fastest neutron star on record rotates over 700 times every second, which means that a point on its surface whirls through space at more than a fifth of the speed of light. Neutron stars also have the strongest magnetic field of any known object. This magnetic concentration forms vortexes that radiate beams from the magnetic poles. Since the poles aren’t always aligned with the rotational axis of the star, the beams spin like lighthouse beacons, which appear to blink when viewed from Earth. We call those pulsars. The detection of one of these tantalizing flashing signals by astrophysicist Jocelyn Bell in 1967 was in fact the way we indirectly discovered neutron stars in the first place. An aging neutron star’s furious rotation slows over a period of billions of years as it radiates away its energy in the form of electromagnetic and gravity waves. But not all neutron stars disappear so quietly. For example, we’ve observed binary systems where a neutron star co-orbits another star. A neutron star can feed on a lighter companion, gorging on its more loosely bound atmosphere before eventually collapsing cataclysmically into a black hole. While many stars exist as binary systems, only a small percentage of those end up as neutron-star binaries, where two neutron stars circle each other in a waltz doomed to end as a merger. When they finally collide, they send gravity waves through space-time like ripples from a stone thrown into a calm lake. Einstein’s theory of General Relativity predicted this phenomenon over 100 years ago, but it wasn't directly verified until 2017, when gravitational-wave observatories LIGO and VIRGO observed a neutron star collision. Other telescopes picked up a burst of gamma rays and a flash of light, and, later, x-rays and radio signals, all from the same impact. That became the most studied event in the history of astronomy. It yielded a treasure trove of data that’s helped pin down the speed of gravity, bolster important theories in astrophysics, and provide evidence for the origin of heavy elements like gold and platinum. Neutron stars haven’t given up all their secrets yet. LIGO and VIRGO are being upgraded to detect more collisions. That’ll help us learn what else the spectacular demise of these dense, pulsating, spinning magnets can tell us about the universe. |
An unsung hero of the civil rights movement | null | TED-Ed | On August 28th, 1963, Martin Luther King Jr. delivered his “I Have a Dream” speech at the March on Washington for Jobs and Freedom. That day, nearly a quarter million people gathered on the national mall to demand an end to the discrimination, segregation, violence, and economic exclusion black people still faced across the United States. None of it would have been possible without the march’s chief organizer – a man named Bayard Rustin. Rustin grew up in a Quaker household, and began peacefully protesting racial segregation in high school. He remained committed to pacifism throughout his life, and was jailed in 1944 as a conscientious objector to World War II. During his two-year imprisonment, he protested the segregated facilities from within. Wherever Rustin went, he organized and advocated, and was constantly attuned to the methods, groups, and people who could help further messages of equality. He joined the Communist Party when black American’s civil rights were one of its priorities, but soon became disillusioned by the party’s authoritarian leanings and left. In 1948, he traveled to India to learn the peaceful resistance strategies of the recently assassinated Mahatma Gandhi. He returned to the United States armed with strategies for peaceful protest, including civil disobedience. He began to work with Martin Luther King Jr in 1955, and shared these ideas with him. As King’s prominence increased, Rustin became his main advisor, as well as a key strategist in the broader civil rights movement. He brought his organizing expertise to the 1956 bus boycotts in Montgomery, Alabama —in fact, he had organized and participated in a transportation protest that helped inspire the boycotts almost a decade before. His largest-scale organizing project came in 1963, when he led the planning for the national march on Washington. The possibility of riots that could injure marchers and undermine their message of peaceful protest was a huge concern. Rustin not only worked with the DC police and hospitals to prepare, but organized and trained a volunteer force of 2,000 security marshals. In spite of his deft management, some of the other organizers did not want Rustin to march in front with other leaders from the south, because of his homosexuality. Despite these slights, Rustin maintained his focus, and on the day of the march he delivered the marchers' demands in a speech directed at President John F. Kennedy. The march itself proceeded smoothly, without any violence. It has been credited with helping pass the 1964 Civil Rights Act, which ended segregation in public places and banned employment discrimination, and the 1965 Voting Rights Act, which outlawed discriminatory voting practices. In spite of his decades of service, Rustin’s positions on certain political issues were unpopular among his peers. Some thought he wasn’t critical enough of the Vietnam War, or that he was too eager to collaborate with the political establishment including the president and congress. Others were uncomfortable with his former communist affiliation. But ultimately, both his belief in collaboration with the government and his membership to the communist party had been driven by his desire to maximize tangible gains in liberties for black Americans, and to do so as quickly as possible. Rustin was passed over for several influential roles in the 1960s and 70s, but he never stopped his activism. In the 1980s, he publicly came out as gay, and was instrumental in drawing attention to the AIDS crisis until his death in 1987. In 2013, fifty years after the March On Washington, President Barack Obama posthumously awarded him the Presidential Medal of Freedom, praising Rustin’s “march towards true equality, no matter who we are or who we love.” |
How education helped me rewrite my life | {0: 'Through her nonprofit, Bodhi Tree Foundation, Ashweetha Shetty supports first-generation college students in rural India to explore their potential through education, life skills and opportunities. '} | TEDWomen 2018 | I was eight years old. I remember that day clearly like it happened just yesterday. My mother is a bidi roller. She hand-rolls country cigarettes to sustain our family. She is a hard worker and spent 10 to 12 hours every day rolling bidis. That particular day she came home and showed me her bidi-rolling wage book. She asked me how much money she has earned that week. I went through that book, and what caught my eyes were her thumbprints on each page. My mother has never been to school. She uses her thumbprints instead of a signature to keep a record of her earnings. On that day, for some reason, I wanted to teach her how to hold a pen and write her name. She was reluctant at first. She smiled innocently and said no. But deep down, I was sure she wanted to give it a try. With a little bit of perseverance and a lot of effort, we managed to write her name. Her hands were trembling, and her face was beaming with pride. As I watched her do this, for the first time in my life, I had a priceless feeling: that I could be of some use to this world. That feeling was very special, because I am not meant to be useful. In rural India, girls are generally considered worthless. They're a liability or a burden. If they are considered useful, it is only to cook dishes, keep the house clean or raise children. As a second daughter of my conservative Indian family, I was fairly clear from a very early age that no one expected anything from me. I was conditioned to believe that the three identities that defined me — poor village girl — meant that I was to live a life of no voice and no choice. These three identities forced me to think that I should never have been born. Yet, I was. All throughout my childhood, as I rolled bidis alongside my mother, I would wonder: What did my future hold? I often asked my mother, with a lot of anxiety, "Amma, will my life be different from yours? Will I have a chance to choose my life? Will I go to college?" And she would reply back, "Try to finish high school first." I am sure my mother did not mean to discourage me. She only wanted me to understand that my dreams might be too big for a girl in my village. When I was 13, I found the autobiography of Helen Keller. Helen became my inspiration. I admired her indomitable spirit. I wanted to have a college degree like her, so I fought with my father and my relatives to be sent to college, and it worked. During my final year of my undergraduate degree, I desperately wanted to escape from being forced into marriage, so I applied to a fellowship program in Delhi, which is about 1,600 miles away from my village. (Laughter) In fact, I recall that the only way I could fill out the application was during my commute to college. I did not have access to computers, so I had to borrow a college junior's cell phone. As a woman, I could not be seen with a cell phone, so I used to huddle his phone under my shawl and type as slowly as possible to ensure that I would not be heard. After many rounds of interviews, I got into the fellowship program with a full scholarship. My father was confused, my mother was worried — (Applause) My father was confused, my mother was worried, but I felt butterflies in my stomach because I was going to step out of my village for the first time to study in the national capital. Of the 97 fellows selected that year, I was the only rural college graduate. There was no one there who looked like me or spoke like me. I felt alienated, intimidated and judged by many. One fellow called me "Coconut Girl." Can you guess why? Anyone? That's because I applied a lot of coconut oil to my hair. (Laughter) Another asked me where I had learned to speak English, and some of my peers did not prefer to have me on their assignment teams because they thought I would not be able to contribute to their discussion. I felt that many of my peers believed that a person from rural India could not supply anything of value, yet the majority of Indian population today is rural. I realized that stories like mine were considered to be an exception and never the expectation. I believe that all of us are born into a reality that we blindly accept until something awakens us and a new world opens up. When I saw my mother's first signature on her bidi-rolling wage book, when I felt the hot Delhi air against my face after a 50-hour train journey, when I finally felt free and let myself be, I saw a glimpse of that new world I longed for, a world where a girl like me is no longer a liability or a burden but a person of use, a person of value and a person of worthiness. By the time my fellowship ended, my life had changed. Not only had I traced my lost voice, but also had a choice to make myself useful. I was 22. I came back to my village to set up the Bodhi Tree Foundation, an institution that supports rural youth by providing them with education, life skills and opportunities. We work closely with our rural youth to change their life and to benefit our communities. How do I know my institution is working? Well, six months ago, we had a new joinee. Her name is Kaviarasi. I first spotted her in a local college in Tirunelveli during one of my training sessions. As you can see, she has a smile which you can never forget. We guided her to get an opportunity to study at Ashoka University, Delhi. The best part of her story is that she is now back at Bodhi Tree as a trainer working with dedication to make a change in the lives of others like her. Kaviarasi doesn't want to feel like an exception. She wants to be of use to others in this world. Recently, Kaviarasi mentored Anitha, who also comes from a remote, rural village, lives in a 10-foot-by-10-foot home, her parents are also farm laborers. Kaviarasi helped Anitha secure admission in a prestigious undergraduate program in a top university in India with a full scholarship. When Anitha's parents were reluctant to send her that far, we asked the district administration officials to speak to Anitha's parents, and it worked. And then there is Padma. Padma and I went to college together. She's the first in her entire village to attend graduation. She had been working with me at Bodhi Tree until one day she decides to go to graduate school. I asked her why. She told me that she wanted to make sure that she would never be a liability or a burden to anyone at any point in her life. Padma, Anitha and Kaviarasi grew up in the most tough families and communities one could only imagine. Yet the journey of finding my usefulness in this world served them in finding their usefulness to this world. Of course there are challenges. I'm aware change does not happen overnight. A lot of my work involves working with families and communities to help them understand why getting an education is useful for everyone. The quickest way to convince them is by doing. When they see their kids getting a real education, getting a real job, they begin to change. The best example is what happened at my home. I was recently given an award in recognition of my social work by the chief minister of my state. That meant I was going to be on television. (Laughter) Everyone was hooked on to the television that morning, including my parents. I would like to believe that seeing her daughter on television made my mother feel useful too. Hopefully, she will stop pressuring me to get married now. (Laughter) Finding my use has helped me to break free from the identities society thrusts on me — poor village girl. Finding my use has helped me to break free from being boxed, caged and bottled. Finding my use has helped me to find my voice, my self-worth and my freedom. I leave you with this thought: Where do you feel useful to this world? Because the answer to that question is where you will find your voice and your freedom. Thank you. (Applause) |
How do we smell? | null | TED-Ed | It's the first sense you use when you're born. One out of every fifty of your genes is dedicated to it. It must be important, right? Okay, take a deep breath through your nose. It's your sense of smell, and it's breathtakingly powerful. As an adult, you can distinguish about 10,000 different smells. Here's how your nose does it. Smell starts when you sniff molecules from the air into your nostrils. 95% of your nasal cavity is used just to filter that air before it hits your lungs. But at the very back of your nose is a region called the olfactory epithelium, a little patch of skin that's key to everything you smell. The olfactory epithelium has a layer of olfactory receptor cells, special neurons that sense smells, like the taste buds of your nose. When odor molecules hit the back of your nose, they get stuck in a layer of mucus covering the olfactory epithelium. As they dissolve, they bind to the olfactory receptor cells, which fire and send signals through the olfactory tract up to your brain. As a side note, you can tell a lot about how good an animal's sense of smell is by the size of its olfactory epithelium. A dog's olfactory epithelium is 20 times bigger than your puny human one. But there's still a lot we don't know about this little patch of cells, too. For example, our olfactory epithelium is pigmented, and scientists don't really know why. But how do you actually tell the difference between smells? It turns out that your brain has 40 million different olfactory receptor neurons, so odor A might trigger neurons 3, 427, and 988, and odor B might trigger neurons 8, 76, and 2,496,678. All of these different combinations let you detect a staggeringly broad array of smells. Olfactory neurons are always fresh and ready for action. They're the only neuron in the body that gets replaced regularly, every four to eight weeks. Once they are triggered, the signal travels through a bundle called the olfactory tract to destinations all over your brain, making stops in the amygdala, the thalamus, and the neocortex. This is different from how sight and sound are processed. Each of those signals goes first to a relay center in the middle of the cerebral hemisphere and then out to other regions of the brain. But smell, because it evolved before most of your other senses, takes a direct route to these different regions of the brain, where it can trigger your fight-or-flight response, help you recall memories, or make your mouth water. But even though we've all got the same physiological set-up, two nostrils and millions of olfactory neurons, not everybody smells the same things. One of the most famous examples of this is the ability to smell so-called "asparagus pee." For about a quarter of the population, urinating after eating asparagus means smelling a distinct odor. The other 75% of us don't notice. And this isn't the only case of smells differing from nose to nose. For some people, the chemical androstenone smells like vanilla; to others, it smells like sweaty urine, which is unfortunate because androstenone is commonly found in tasty things like pork. So with the sweaty urine smellers in mind, pork producers will castrate male pigs to stop them from making androstenone. The inability to smell a scent is called anosmia, and there are about 100 known examples. People with allicin anosmia can't smell garlic. Those with eugenol anosmia can't smell cloves. And some people can't smell anything at all. This kind of full anosmia could have several causes. Some people are born without a sense of smell. Others lose it after an accident or during an illness. If the olfactory epithelium gets swollen or infected, it can hamper your sense of smell, something you might have experienced when you were sick. Not being able to smell anything can mess with your other senses, too. Many people who can't smell at all also can't really taste the same way the rest of us do. It turns out that how something tastes is closely related to how it smells. As you chew your food, air is pushed up your nasal passage, carrying with it the smell of your food. Those scents hit your olfactory epithelium and tell your brain a lot about what you're eating. Without the ability to smell, you lose the ability to taste anything more complicated than the five tastes your taste buds can detect: sweet, salty, bitter, sour, and savory. So, the next time you smell exhaust fumes, salty sea air, or roast chicken, you'll know exactly how you've done it and, perhaps, be a little more thankful that you can. |
Kabuki: The people's dramatic art | null | TED-Ed | Many elements of traditional Japanese culture, such as cuisine and martial arts, are well-known throughout the world. Kabuki, a form of classical theater performance, may not be as well understood in the West but has evolved over 400 years to still maintain influence and popularity to this day. The word Kabuki is derived from the Japanese verb kabuku, meaning out of the ordinary or bizarre. Its history began in early 17th century Kyoto, where a shrine maiden named Izumo no Okuni would use the city's dry Kamo Riverbed as a stage to perform unusual dances for passerby, who found her daring parodies of Buddhist prayers both entertaining and mesmerizing. Soon other troops began performing in the same style, and Kabuki made history as Japan's first dramatic performance form catering to the common people. By relying on makeup, or keshou, and facial expressions instead of masks and focusing on historical events and everyday life rather than folk tales, Kabuki set itself apart from the upper-class dance theater form known as Noh and provided a unique commentary on society during the Edo period. At first, the dance was practiced only by females and commonly referred to as Onna-Kabuki. It soon evolved to an ensemble performance and became a regular attraction at tea houses, drawing audiences from all social classes. At this point, Onna-Kabuki was often risque as geishas performed not only to show off their singing and dancing abilities but also to advertise their bodies to potential clients. A ban by the conservative Tokugawa shogunate in 1629 led to the emergence of Wakashu-Kabuki with young boys as actors. But when this was also banned for similar reasons, there was a transition to Yaro-Kabuki, performed by men, necessitating elaborate costumes and makeup for those playing female roles, or onnagata. Attempts by the government to control Kabuki didn't end with bans on the gender or age of performers. The Tokugawa military group, or Bakufu, was fueled by Confucian ideals and often enacted sanctions on costume fabrics, stage weaponry, and the subject matter of the plot. At the same time, Kabuki became closely associated with and influenced by Bunraku, an elaborate form of puppet theater. Due to these influences, the once spontaneous, one-act dance evolved into a structured, five-act play often based on the tenets of Confucian philosophy. Before 1868, when the Tokugawa shogunate fell and Emperor Meiji was restored to power, Japan had practiced isolation from other countries, or Sakoku. And thus, the development of Kabuki had mostly been shaped by domestic influences. But even before this period, European artists, such as Claude Monet, had become interested in and inspired by Japanese art, such as woodblock prints, as well as live performance. After 1868, others such as Vincent van Gogh and composer Claude Debussy began to incorporate Kabuki influences in their work, while Kabuki itself underwent much change and experimentation to adapt to the new modern era. Like other traditional art forms, Kabuki suffered in popularity in the wake of World War II. But innovation by artists such as director Tetsuji Takechi led to a resurgence shortly after. Indeed, Kabuki was even considered a popular form of entertainment amongst American troops stationed in Japan despite initial U.S. censorship of Japanese traditions. Today, Kabuki still lives on as an integral part of Japan's rich cultural heritage, extending its influence beyond the stage to television, film, and anime. The art form pioneered by Okuni continues to delight audiences with the actors' elaborate makeup, extravagant and delicately embroidered costumes, and the unmistakable melodrama of the stories told on stage. |
Is it bad to hold your pee? | null | TED-Ed | It begins with a bit of discomfort and soon becomes a pressing sensation that's impossible to ignore. Finally, it's all you can think about, and out of sheer desperation, you go on a hunt for a bathroom until "ahh." Humans should urinate at least four to six times a day, but occasionally, the pressures of modern life forces us to clench and hold it in. How bad is this habit, and how long can our bodies withstand it? The answers lie in the workings of the bladder, an oval pouch that sits inside the pelvis. Surrounding this structure are several other organs that together make up the whole urinary system. Two kidneys, two ureters, two urethral sphincters, and a urethra. Constantly trickling down from the kidneys is the yellowish liquid known as urine. The kidneys make urine from a mix of water and the body's waste products, funneling the unwanted fluid into two muscular tubes called ureters. These carry it downward into the hollow organ known as the bladder. This organ's muscular wall is made of tissue called detrusor muscle which relaxes as the bladder fills allowing it to inflate like a balloon. As the bladder gets full, the detrusor contracts. The internal urethral sphincter automatically and involuntarily opens, and the urine is released. Whooshing downwards, the fluid enters the urethra and stops short at the external urethral sphincter. This works like a tap. When you want to delay urinating, you keep the sphincter closed. When you want to release it, you can voluntarily open the flood gates. But how do you sense your bladder's fullness so you know when to pee? Inside the layers of detrusor muscles are millions of stretch receptors that get triggered as the bladder fills. They send signals along your nerves to the sacral region in your spinal cord. A reflex signal travels back to your bladder, making the detrusor muscle contract slightly and increasing the bladder's pressure so you're aware that it's filling up. Simultaneously, the internal urethral sphincter opens. This is called the micturition reflex. The brain can counter it if it's not a good time to urinate by sending another signal to contract the external urethral sphincter. With about 150 to 200 milliliters of urine inside of it, the bladder's muscular wall is stretched enough for you to sense that there's urine within. At about 400 to 500 milliliters, the pressure becomes uncomfortable. The bladder can go on stretching, but only to a point. Above 1,000 milliliters, it may burst. Most people would lose bladder control before this happens, but in very rare cases, such as when as a person can't sense the need to urinate, the pouch can rupture painfully requiring surgery to fix. But under normal circumstances, your decision to urinate stops the brain's signal to the external urethral sphincter, causing it to relax and the bladder to empty. The external urethral sphincter is one of the muscles of the pelvic floor, and it provides support to the urethra and bladder neck. It's lucky we have these pelvic floor muscles because placing pressure on the system by coughing, sneezing, laughing, or jumping could cause bladder leakage. Instead, the pelvic floor muscles keep the region sealed until you're ready to go. But holding it in for too long, forcing out your urine too fast, or urinating without proper physical support may over time weaken or overwork that muscular sling. That can lead to an overactive pelvic floor, bladder pain, urgency, or urinary incontinence. So in the interest of long-term health, it's not a great habit to hold your pee. But in the short term, at least, your body and brain have got you covered, so you can conveniently choose your moment of sweet release. |
What is fat? | null | TED-Ed | Olive oil is 100% fat; there's nothing else in it. Pancake mix, on the other hand, is only about 11% fat. And, yet, olive oil is good for you, and pancake mix is not. Why is that? As it turns out, the amount of fat we eat doesn't impact our weight or our cholesterol or our risk of heart disease nearly as much as what kind of fat we eat. But let's back up: What is fat? If we were to zoom in on a salmon, which is a fatty fish, past the organs, past the tissues, into the cells, we would see that the stuff we call fat is actually made up of molecules called triglycerides, and they are not all alike. Here's one example. Those three carbons on the left, that's glycerol. Now, you can think of that as the backbone that holds the rest of the molecule together. The three long chains on the right are called fatty acids, and it's subtle differences in the structures of these chains that determine whether a fat is, let's say, solid or liquid; whether or not it goes rancid quickly; and, most importantly, how good or how bad it is for you. Let's take a look at some of these differences. One is length. Fatty acids can be short or long. Another, more important difference is the type of bond between the carbon atoms. Some fatty acids have only single bonds. Others have both single and double bonds. Fatty acids with only single bonds are called saturated, and those with one or more double bonds are called unsaturated. Now, most unsaturated fats are good for you, while saturated fats are bad for you in excess. For saturated fats, the story pretty much ends there but not for unsaturated fats. The double bonds in these molecules have a kind of weird property; they're rigid. So, that means there are two ways to arrange every double bond. The first is like this, where both hydrogens are on same side and both carbons are on the same side. The second way is like this. Now the hydrogens and carbons are on opposite sides of the double bond. Now, even though both of these molecules are made up of exactly the same building blocks, they are two completely different substances, and they behave completely differently inside of us. The configuration on the left is called CIS, which you've probably never heard of. The one of the right is called TRANS, and you probably have heard of trans fats before. They don't go rancid, they're more stable during deep frying, and they can change the texture of foods in ways that other fats just can't. They're also terrible for your health, by far worse than saturated fat, even though technically they're a type of unsaturated fat. Now, I know that seems crazy, but your body doesn't care what a molecule looks like on paper. All that matters is the 3-D shape where the molecule fits, where it doesn't, and what pathways it interferes with. So, how do you know if a food has trans fat in it? Well, the only sure way to know is if you see the words, "partially hydrogenated" in the ingredients list. Don't let nutrition labels or advertising fool you. The FDA allows manufacturers to claim that their products contain "0" grams of trans fat even if they actually have up to half a gram per serving. But there are no hard and fast rules about how small a serving can be, and, that means, you'll have to rely on seeing those key words, partially hydrogenated, because that's how trans fats are made, by partially hydrogenating unsaturated fats. So, let's go back to our olive oil and pancake mix from before. Olive oil is 100% fat. Pancake mix is only 11% fat. But olive oil is mostly unsaturated fat, and it has no trans fat at all. On the other hand, more than half the fat in pancake mix is either saturated or trans fat. And, so, even though olive oil has 10 times as much fat as pancake mix, it's healthy for you, whereas pancake mix is not. Now, I'm not trying to pick on pancake mix. There are lots of foods with this type of fat profile. The point is this: It's not how much fat you eat, it's what kind of fat. And what makes a particular fat healthy or unhealthy is its shape. |
The world's most mysterious book | null | TED-Ed | Deep inside Yale University's Beinecke Rare Book and Manuscript Library lies the only copy of a 240-page tome. Recently carbon dated to around 1420, its vellum pages features looping handwriting and hand-drawn images seemingly stolen from a dream. Real and imaginary plants, floating castles, bathing women, astrology diagrams, zodiac rings, and suns and moons with faces accompany the text. This 24x16 centimeter book is called the Voynich manuscript, and its one of history's biggest unsolved mysteries. The reason why? No one can figure out what it says. The name comes from Wilfrid Voynich, a Polish bookseller who came across the document at a Jesuit college in Italy in 1912. He was puzzled. Who wrote it? Where was it made? What do these bizarre words and vibrant drawings represent? What secrets do its pages contain? He purchased the manuscript from the cash-strapped priest at the college, and eventually brought it to the U.S., where experts have continued to puzzle over it for more than a century. Cryptologists say the writing has all the characteristics of a real language, just one that no one's ever seen before. What makes it seem real is that in actual languages, letters and groups of letters appear with consistent frequencies, and the language in the Voynich manuscript has patterns you wouldn't find from a random letter generator. Other than that, we know little more than what we can see. The letters are varied in style and height. Some are borrowed from other scripts, but many are unique. The taller letters have been named gallows characters. The manuscript is highly decorated throughout with scroll-like embellishments. It appears to be written by two or more hands, with the painting done by yet another party. Over the years, three main theories about the manuscript's text have emerged. The first is that it's written in cypher, a secret code deliberately designed to hide secret meaning. The second is that the document is a hoax written in gibberish to make money off a gullible buyer. Some speculate the author was a medieval con man. Others, that it was Voynich himself. The third theory is that the manuscript is written in an actual language, but in an unknown script. Perhaps medieval scholars were attempting to create an alphabet for a language that was spoken but not yet written. In that case, the Voynich manuscript might be like the rongorongo script invented on Easter Island, now unreadable after the culture that made it collapsed. Though no one can read the Voynich manuscript, that hasn't stopped people from guessing what it might say. Those who believe the manuscript was an attempt to create a new form of written language speculate that it might be an encyclopedia containing the knowledge of the culture that produced it. Others believe it was written by the 13th century philosopher Roger Bacon, who attempted to understand the universal laws of grammar, or in the 16th century by the Elizabethan mystic John Dee, who practiced alchemy and divination. More fringe theories that the book was written by a coven of Italian witches, or even by Martians. After 100 years of frustration, scientists have recently shed a little light on the mystery. The first breakthrough was the carbon dating. Also, contemporary historians have traced the provenance of the manuscript back through Rome and Prague to as early as 1612, when it was perhaps passed from Holy Roman Emperor Rudolf II to his physician, Jacobus Sinapius. In addition to these historical breakthroughs, linguistic researchers recently proposed the provisional identification of a few of the manuscript's words. Could the letters beside these seven stars spell Tauran, a name for Taurus, a constellation that includes the seven stars called the Pleiades? Could this word be Centaurun for the Centaurea plant in the picture? Perhaps, but progress is slow. If we can crack its code, what might we find? The dream journal of a 15th-century illustrator? A bunch of nonsense? Or the lost knowledge of a forgotten culture? What do you think it is? |
How do you know you exist? | null | TED-Ed | How do you know you're real? It's an obvious question until you try to answer it, but let's take it seriously. How do you really know you exist? In his "Meditations on First Philosophy," René Descartes tried to answer that very question, demolishing all his preconceived notions and opinions to begin again from the foundations. All his knowledge had come from his sensory perceptions of the world. Same as you, right? You know you're watching this video with your eyes, hearing it with your ears. Your senses show you the world as it is. They aren't deceiving you, but sometimes they do. You might mistake a person far away for someone else, or you're sure you're about to catch a flyball, and it hits the ground in front of you. But come on, right here and now, you know what's right in front of you is real. Your eyes, your hands, your body: that's you. Only crazy people would deny that, and you know you're not crazy. Anyone who'd doubt that must be dreaming. Oh no, what if you're dreaming? Dreams feel real. You can believe you're swimming, flying or fighting off monsters with your bare hands, when your real body is lying in bed. No, no, no. When you're awake, you know you're awake. Ah! But when you aren't, you don't know you aren't, so you can't prove you aren't dreaming. Maybe the body you perceive yourself to have isn't really there. Maybe all of reality, even its abstract concepts, like time, shape, color and number are false, all just deceptions concocted by an evil genius! No, seriously. Descartes asks if you can disprove the idea that an evil genius demon has tricked you into believing reality is real. Perhaps this diabolical deceiver has duped you. The world, your perceptions of it, your very body. You can't disprove that they're all just made up, and how could you exist without them? You couldn't! So, you don't. Life is but a dream, and I bet you aren't row, row, rowing the boat merrily at all, are you? No, you're rowing it wearily like the duped, nonexistent doof you are/aren't. Do you find that convincing? Are you persuaded? If you aren't, good; if you are, even better, because by being persuaded, you would prove that you're a persuaded being. You can't be nothing if you think you're something, even if you think that something is nothing because no matter what you think, you're a thinking thing, or as Descartes put it, "I think, therefore I am," and so are you, really. (Airplane engine) |
Inside the ant colony | {0: 'By studying how ant colonies work without any one leader, Deborah Gordon has identified striking similarities in how ant colonies, brains, cells and computer networks regulate themselves.'} | TED-Ed | Think about all the things that need to happen for a human settlement to thrive: obtaining food, building shelter, raising children and more. There needs to be a way to divide resources, organize major efforts and distribute labor efficiently. Now imagine having to do this without any sort of planning or higher level communication. Welcome to the ant colony. Ants have some of the most complex social organization in the animal kingdom, living in structured colonies containing different types of members who perform specific roles. But although this may sound similar to some human societies, this organization doesn't arise from any higher level decisions, but is part of a biologically programmed cycle. In many species, all the winged males and winged virgin queens from all the nearby colonies in the population each leave from their different nests and meet at a central place to mate, using pheromones to guide each other to a breeding ground. After mating, the males die off, while females try to establish a new colony. The few that are successful settle down in a suitable spot, lose their wings, and begin laying eggs, selectively fertilizing some using stored sperm they've saved up from mating. Fertilized eggs grow into female workers who care for the queen and her eggs. They will then defend the colony and forage for food, while unfertilized eggs grow into males whose only job is to wait until they are ready to leave the nest and reproduce, beginning the cycle again. So how do worker ants decide what to do and when? Well, they don't really. Although they have no methods of intentional communication, individual ants do interact with one another through touch, sound and chemical signals. These stimuli accomplish many things from serving as an alarm to other ants if one is killed, to signaling when a queen is nearing the end of her reproductive life. But one of the most impressive collective capabilities of an ant colony is to thoroughly and efficiently explore large areas without any predetermined plan. Most species of ants have little or no sense of sight and can only smell things in their vicinity. Combined with their lack of high level coordination, this would seem to make them terrible explorers, but there is an amazingly simple way that ants maximize their searching efficiency; by changing their movement patterns based on individual interactions. When two ants meet, they sense each other by touching antennae. If there are many ants in a small area this will happen more often causing them to respond by moving in more convoluted, random paths in order to search more thoroughly. But in a larger area, with less ants, where such meetings happen less often, they can walk in straight lines to cover more ground. While exploring their environment in this way, an ant may come across any number of things, from threats or enemies, to alternate nesting sites. And some species have another capability known as recruitment. When one of these ants happens to find food, it will return with it, marking its path with a chemical scent. Other ants will then follow this pheromone trail, renewing it each time they manage to find food and return. Once the food in that spot is depleted, the ants stop marking their return. The scent dissipates and ants are no longer attracted to that path. These seemingly crude methods of search and retrieval are, in fact, so useful that they are applied in computer models to obtain optimal solutions from decentralized elements, working randomly and exchanging simple information. This has many theoretical and practical applications, from solving the famous traveling salesman problem, to scheduling computing tasks and optimizing Internet searches, to enabling groups of robots to search a minefield or a burning building collectively, without any central control. But you can observe these fascinatingly simple, yet effective, processes directly through some simple experiments, by allowing ants to enter empty spaces of various sizes and paying attention to their behavior. Ants may not be able to vote, hold meetings or even make any plans, but we humans may still be able to learn something from the way that such simple creatures are able to function so effectively in such complex ways. |
What makes tattoos permanent? | null | TED-Ed | Tattoos have often been presented in popular media as either marks of the dangerous and deviant or trendy youth fads. But while tattoo styles come and go, and their meaning has differed greatly across cultures, the practice is as old as civilization itself. Decorative skin markings have been discovered in human remains all over the world, with the oldest found on a Peruvian mummy dating back to 6,000 BCE. But have you ever wondered how tattooing really works? You may know that we shed our skin, losing about 30-40,000 skin cells per hour. That's about 1,000,000 per day. So, how come the tattoo doesn't gradually flake off along with them? The simple answer is that tattooing involves getting pigment deeper into the skin than the outermost layer that gets shed. Throughout history, different cultures have used various methods to accomplish this. But the first modern tattooing machine was modeled after Thomas Edison's engraving machine and ran on electricity. Tattooing machines used today insert tiny needles, loaded with dye, into the skin at a frequency of 50 to 3,000 times per minute. The needles punch through the epidermis, allowing ink to seep deep into the dermis, which is composed of collagen fibers, nerves, glands, blood vessels and more. Every time a needle penetrates, it causes a wound that alerts the body to begin the inflammatory process, calling immune system cells to the wound site to begin repairing the skin. And it is this very process that makes tattoos permanent. First, specialized cells called macrophages eat the invading material in an attempt to clean up the inflammatory mess. As these cells travel through the lymphatic system, some of them are carried back with a belly full of dye into the lymph nodes while others remain in the dermis. With no way to dispose of the pigment, the dyes inside them remain visible through the skin. Some of the ink particles are also suspended in the gel-like matrix of the dermis, while others are engulfed by dermal cells called fibroblasts. Initially, ink is deposited into the epidermis as well, but as the skin heals, the damaged epidermal cells are shed and replaced by new, dye-free cells with the topmost layer peeling off like a heeling sunburn. Blistering or crusting is not typically seen with professional tattoos and complete epidermal regeneration requires 2-4 weeks, during which excess sun exposure and swimming should be avoided to prevent fading. Dermal cells, however, remain in place until they die. When they do, they are taken up, ink and all, by younger cells nearby, so the ink stays where it is. But with time, tattoos do fade naturally as the body reacts to the alien pigment particles, slowly breaking them down to be carried off by the immune system's macrophages. Ultraviolet radiation can also contribute to this pigment breakdown, though it can be mitigated by the use of sunblock. But since the dermal cells are relatively stable, much of the ink will remain deep in the skin for a person's whole life. But if tattoos are embedded in your skin for life, is there any way to erase them? Technically, yes. Today, a laser is used to penetrate the epidermis and blast apart underlying pigment colors of various wavelengths, black being the easiest to target. The laser beam breaks the ink globules into smaller particles that can then be cleared away by the macrophages. But some color inks are harder to remove than others, and there could be complications. For this reason, removing a tattoo is still more difficult than getting one, but not impossible. So a single tattoo may not truly last forever, but tattoos have been around longer than any existing culture. And their continuing popularity means that the art of tattooing is here to stay. |
How does the thyroid manage your metabolism? | null | TED-Ed | Nestled in the tissues of your neck is a small unassuming organ that wields enormous power over your body. It's called the thyroid. Like the operations manager in a company, its role is to make sure that the cells in your body are working properly. It does that by using hormones to deliver messages to every single one of them. This high-ranking organ is made up of lobules that each contains smaller cells called follicles, which store the hormones the thyroid sends out into your blood. Two of the most important hormones it produces are thyroxine and triiodothyronine, or T3 and T4. As messengers, the hormone's job is to instruct every cell in the body when to consume oxygen and nutrients. That maintains the body's metabolism, the series of reactions our cells perform to provide us with energy. This hormonal notification from the thyroid gets the heart pumping more efficiently, and makes our cells break down nutrients faster. When you need more energy, the thyroid helps by sending out hormones to increase metabolism. Ultimately, the thyroid allows our cells to use energy, grow and reproduce. The thyroid is controlled by the pituitary gland, a hormonal gland deep in the brain that oversees the thyroid's tasks, making sure it knows when to send out its messengers. The pituitary's role is to sense if hormone levels in the blood are too low or too high, in which case it sends out instructions in the form of the thyroid- stimulating hormone. Even in this tightly controlled system, however, management sometimes slips up. Certain diseases, growths in the thryoid or chemical imbalances in the body can confuse the organ and make it deaf to the pituitary's guiding commands. The first problem this causes is hyperthyroidism, which happens when the organ sends out too many hormones. That means the cells are overloaded with instructions to consume nutrients and oxygen. They become overactive as a result, meaning a person with hyperthyroidism experiences a higher metabolism signaled by a faster heartbeat, constant hunger, and rapid weight loss. They also feel hot, sweaty, anxious, and find it difficult to sleep. The opposite problem is hypothyroidism, which happens when the thyroid sends out too few hormones, meaning the body's cells don't have as many messengers to guide them. In response, cells grow listless and metabolism slows. People with hypothyroidism see symptoms in weight gain, sluggishness, sensitivity to cold, swollen joints and feeling low. Luckily, there are medical treatments that can help trigger the thyroid's activities again, and bring the body back to a steady metabolic rate. For such a little organ, the thyroid wields an awful lot of power. But a healthy thyroid manages our cells so effectively that it can keep us running smoothly without us even noticing it's there. |
What is the universe made of? | null | TED-Ed | All the material objects around you are composed of submicroscopic units we call molecules. And molecules in turn are composed of individual atoms. Molecules frequently break apart and then form new molecules. On the other hand, virtually all the atoms you come in to contact with through the course of your life, the ones in the ground beneath you, the air you breath, the food you eat, those that make up every living thing, including you, have existed for billions of years and were created in places very unlike our planet. How those atoms came about is what I want to share with you. It all started 14 billion years ago with an event we call The Big Bang, which resulted in a universe consisting of gas alone. There were no stars and no planets. The gas was made up only of atoms belonging to the simplest elements. It was about 75 percent hydrogen and almost all the rest was helium. No elements like carbon, oxygen or nitrogen existed. No iron, silver or gold. In some places, the density of this gas was slightly higher than in others. Due to gravity, those places attracted even more gas, which further strengthened the pull of gravity, which then drew more gas in, and so on. Eventually, large dense gas balls formed, shrinking under their own gravity and consequently heating up on the inside. At some point, the core of such a ball gets hot enough that nuclear fusion occurs. Hydrogen atoms smash together to form helium, accompanied by a great release of energy, strong enough to counteract the shrinking force of the gravity. When the energy pushing out from the fusion reactions matches the gravity pulling all the gas inwards, an equilibrium occurs. From this a star is born. Over its lifetime, the fusion reactions in the core of a massive star will produce not only helium, but also carbon, oxygen, nitrogen and all the other elements in the periodic table up to iron. But eventually, the core's fuel runs out, leaving it to collapse completely. That causes an unbelievably powerful explosion we call a supernova. Now there are two things to note about how supernovas create elements. First, this explosion releases so much energy that fusion goes wild forming elements with atoms even heavier than iron like silver, gold and uranium. Second, all the elements that had been accumulating in the core of the star, like carbon, oxygen, nitrogen, iron, as well as all of those formed in the supernova explosion, are ejected in to interstellar space where they mix with the gas that's already there. History then repeats itself. Gas clouds, now containing many elements besides the original hydrogen and helium, have higher density areas that attract more matter, and so on. As before, new stars result. Our sun was born this way about 5 billion years ago. That means that the gas it arose from had itself been enriched with many elements from supernova explosions since the universe began. So that's how the sun wound up with all the elements. It's still mostly hydrogen at 71 percent, with most of the rest being helium at 27 percent. But bear in mind that while the first stars were made up of hydrogen and helium alone, the remaining elements in the periodic table make up two percent of the sun. And what about Earth? Planets form as an incidental process to star formation out of the same gas cloud as the star itself. Small planets like ours don't have enough gravity to hold on to much hydrogen or helium gas since both of those are very light. So, even though carbon, nitrogen, oxygen and so on made up only two percent of the gas cloud from which Earth was formed, these heavier elements form the bulk of our planet and everything on it. Think about this: with the exception of hydrogen and some helium, the ground you walk on, the air you breath, you, everything is made of atoms that were created inside stars. When scientists first worked this out over the first half of the 20th Century, the famous astronomer Harlow Shapley commented, "We are brothers of the boulders, cousins of the clouds." |
Can you solve the virus riddle? | null | TED-Ed | Your research team has found a prehistoric virus preserved in the permafrost and isolated it for study. After a late night working, you're just closing up the lab when a sudden earthquake hits and knocks out the power. As the emergency generators kick in, an alarm confirms your worst fears: all the sample vials have broken. The virus is contained for now, but unless you can destroy it, the vents will soon open and unleash a deadly airborne plague. Without hesitation, you grab your HazMat suit and get ready to save the world. The lab is a four by four compound of 16 rooms with an entrance on the northwest corner and an exit at the southeast. Each room is connected to the adjacent ones by an airlock, and the virus has been released in every room except the entrance. To destroy it, you must enter each contaminated room and pull its emergency self-destruct switch. But there's a catch. Because the security system is on lockdown, once you enter the contaminated room, you can't exit without activating the switch, and once you've done so, you won't be able to go back in to that room. You start to draw out possible routes on a pad of paper, but nothing seems to get you to the exit without missing at least one room. So how can you destroy the virus in every contaminated room and survive to tell the story? Pause here if you want to figure it out for yourself. Answer in: 3 Answer in: 2 Answer in: 1 If your first instinct is to try to graph your possible moves on a grid, you've got the right idea. This puzzle is related to the Hamiltonian path problem named after the 19th century Irish mathematician William Rowan Hamilton. The challenge of the path problem is to find whether a given graph has a Hamiltonian path. That's a route that visits every point within it exactly once. This type of problem, classified as NP-complete, is notoriously difficult when the graph is sufficiently large. Although any proposed solution can be easily verified, we have no reliable formula or shortcut for finding one, or determining that one exists. And we're not even sure if it's possible for computers to reliably find such solutions, either. This puzzle adds a twist to the Hamiltonian path problem in that you have to start and end at specific points. But before you waste a ton of graph paper, you should know that a true Hamiltonian path isn't possible with these end points. That's because the rooms form a grid with an even number of rooms on each side. In any grid with that configuration, a Hamiltonian path that starts and ends in opposite corners is impossible. Here's one way of understanding why. Consider a checkerboard grid with an even number of squares on each side. Every path through it will alternate black and white. These grids will all also have an even total number of squares because an even number times and even number is even. So a Hamiltonian path on an even-sided grid that starts on black will have to end on white. And one that starts on white will have to end on black. However, in any grid with even numbered sides, opposite corners are the same color, so it's impossible to start and end a Hamiltonian path on opposite corners. It seems like you're out of luck, unless you look at the rules carefully and notice an important exception. It's true that once you activate the switch in a contaminated room, it's destroyed and you can never go back. But there's one room that wasn't contaminated - the entrance. This means that you can leave it once without pulling the switch and return there when you've destroyed either of these two rooms. The corner room may have been contaminated from the airlock opening, but that's okay because you can destroy the entrance after your second visit. That return trip gives you four options for a successful route, and a similar set of options if you destroyed this room first. Congratulations. You've prevented an epidemic of apocalyptic proportions, but after such a stressful episode, you need a break. Maybe you should take up that recent job offer to become a traveling salesman. |
The chemistry of cookies | null | TED-Ed | In a time-lapse video, it looks like a monster coming alive. For a moment, it sits there innocuously. Then, ripples move across its surface. It bulges outwards, bursting with weird boils. It triples in volume. Its color darkens ominously, and its surface hardens into an alien topography of peaks and craters. Then, the kitchen timer dings. Your cookie is ready. What happened inside that oven? Don't let the apron deceive you! Bakers are mad scientists. When you slide the pan into the oven, you're setting off a series of chemical reactions that transform one substance, dough, into another, cookies. When the dough reaches 92 degrees Fahrenheit, the butter inside melts, causing the dough to start spreading out. Butter is an emulsion, or mixture of two substances that don't want to stay together, in this case, water and fat, along with some dairy solids that help hold them together. As the butter melts, its trapped water is released. And as the cookie gets hotter, the water expands into steam. It pushes against the dough from the inside, trying to escape through the cookie walls like Ridley Scott's chest-bursting alien. Your eggs may have been home to squirming salmonella bacteria. An estimated 142,000 Americans are infected this way each year. Though salmonella can live for weeks outside a living body and even survive freezing, 136 degrees is too hot for them. When your dough reaches that temperature, they die off. You'll live to test your fate with a bite of raw dough you sneak from your next batch. At 144 degrees, changes begin in the proteins, which come mostly from the eggs in your dough. Eggs are composed of dozens of different kinds of proteins, each sensitive to a different temperature. In an egg fresh from the hen, these proteins look like coiled up balls of string. When they're exposed to heat energy, the protein strings unfold and get tangled up with their neighbors. This linked structure makes the runny egg nearly solid, giving substance to squishy dough. Water boils away at 212 degrees, so like mud baking in the sun, your cookie gets dried out and it stiffens. Cracks spread across its surface. The steam that was bubbling inside evaporates, leaving behind airy pockets that make the cookie light and flaky. Helping this along is your leavening agent, sodium bicarbonate, or baking soda. The sodium bicarbonate reacts with acids in the dough to create carbon dioxide gas, which makes airy pockets in your cookie. Now, it's nearly ready for a refreshing dunk in a cool glass of milk. One of science's tastiest reactions occurs at 310 degrees. This is the temperature for Maillard reactions. Maillard reactions result when proteins and sugars break down and rearrange themselves, forming ring-like structures, which reflect light in a way that gives foods like Thanksgiving turkey and hamburgers their distinctive, rich brown color. As this reaction occurs, it produces a range of flavor and aroma compounds, which also react with each other, forming even more complex tastes and smells. Caramelization is the last reaction to take place inside your cookie. Caramelization is what happens when sugar molecules break down under high heat, forming the sweet, nutty, and slightly bitter flavor compounds that define, well, caramel. And, in fact, if your recipe calls for a 350 degree oven, it'll never happen, since caramelization starts at 356 degrees. If your ideal cookie is barely browned, like a Northeasterner on a beach vacation, you could have set your oven to 310 degrees. If you like your cookies to have a nice tan, crank up the heat. Caramelization continues up to 390 degrees. And here's another trick: you don't need that kitchen timer; your nose is a sensitive scientific instrument. When you smell the nutty, toasty aromas of the Maillard reaction and caramelization, your cookies are ready. Grab your glass of milk, put your feet up, and reflect that science can be pretty sweet. |
How to overcome apathy and find your power | {0: 'Dolores Huerta is inspired by a passion to spend most of her time pursuing social justice and civil rights.'} | TEDWomen 2018 | I want to start out with quoting Helen Keller, that great woman that we all admire. And she had a statement that is very profound, and this statement is that science has been able to find cures for many evils, but never the greatest evil of all in human beings, and that evil is apathy. So, we know that apathy really costs us a lot, especially in our democracy. And when we think of why people do not get involved, why they do not become activists, it's often that people are so worn down with their own familial responsibilities, and women especially. You know, women, they have so many inhibitions. Many of them have suffered so much trauma in their lives, so many aggressions in their lives. And so it's very hard for them to realize that they have leadership capacities. That they can get out there, and they could change the world. Another thing that many women — we think that we have to do everything. That we are the only ones responsible for our families, and it is so hard for us to delegate and just get others to help us do the duties that we are responsible for. We feel embarrassed or we feel guilty. But we know that we have to make this happen, because if not, we will never have time to be able to volunteer to help on these many causes that are now facing us. One of the areas that women can give up a little bit of time and that is in shopping, OK? (Laughter) And especially when we go out there shopping for things that we don't even need. (Laughter) You know, you never saw a hearse with a U-Haul behind it. (Laughter) We have to live simply, so that others can simply live. And when we think of the kind of inheritance that we want to leave to our children or our grandchildren, think of leaving them a legacy of justice. This is a legacy that they can not only imitate, but they can be proud of for the rest of their lives. If we leave them a lot of material goods, all they're going to do is fight, and they're going to hate each other. Just remember that, when we think about what we're doing. The other thing that we have to do to liberate our women, eventually, so that we can do the kind of volunteer work that we need to do to change this world, is we have to have a different kind of an education for our young women. Unfortunately, in our societies around the world, women are taught to be victims. Women are not taught that they are going to have to defend themselves, that they're going to have to support themselves and they have to protect themselves. Because, you know, when we actually look at the animal kingdom, and we see who are the most ferocious, the male or the female? We know it's the female, right? So something went wrong with us at the top of that animal kingdom as women. (Laughter) So I want to give you an example of how I found my voice. And I was very fortunate in that, when I was 25 years old, I met a gentleman named Fred Ross Sr., who organized a chapter of a group called the Community Service Organization in my hometown of Stockton, California. This was a grassroots organization, and I was recruited to be a volunteer. So, one day, while we were sitting in the office, a farm worker comes in. And he's paralyzed, he can hardly walk, he has a crutch. And he needs help. He needs someone to help him go down to the welfare office and make an application. So, I volunteered to do that. But when I got to the welfare office, they would not let me make an application for this gentleman. So I didn't know what to do, I was at a loss. So I went back to the office, and I told Mr. Ross, "They won't let me make an application." And he said to me, very sternly, "You go right back down to that welfare office, and you demand to see a supervisor. And you demand that they let him make an application." And I thought, "Wow, I can do that?" (Laughter) So I thought about it, and I kind of overcame my anxieties and my fears. I went down to the welfare office and I demanded to see the supervisor. Sure enough, he came out, and they had to let Mr. Ruiz make an application for welfare. And he got his disability for himself and his family. But that taught me a lesson. That taught me that I had a voice. Well, Mr. Ross also taught many of us many other things, including Cesar Chavez and many other volunteers. And he taught us not only that we can make demands of people, especially our public officials. And this is something we should always keep in mind: every public official — guess what — they work for us. Because we pay their salaries with out taxes. And they are actually our servants. Some of them turn out to be leaders, but not all of them. (Laughter) Once in a while we get a leader out of there. The other thing that Mr. Ross taught us is that voting is extremely important. And not just voting, but going out there and getting other people to vote. Going door to door. Phone banking, talking to voters, because many voters have a lot of doubts and they don't know how to vote. And unfortunately, we know that in many countries people are not allowed to vote because we have voter suppression in other countries, like we do here in the United States of America. But the thing is, if we can get out there as individuals and talk to people, so we can remove their apathy and make sure that they can vote. So, I want to give you an example of a woman in our foundation, the Dolores Huerta Foundation, and just to show you that sometimes people have power, but they don't know it. But once they find it, they do miraculous things. So, Leticia Prado is an immigrant from Mexico, only has a sixth-grade education and speaks very limited English. But she was very concerned because the children at the middle school in their town called Weedpatch — this is in California, Central Valley — they couldn't go out and play in the schoolyard, because the air quality is so bad in the southern part of Kern County, California in our United States of America. So she and her husband went out there, and they passed a bond issue to build a brand new, state-of-the-art gymnasium for the kids at their middle school. That was a big success. Then she heard a rumor that the principal was going to end the breakfast program for the farm worker children, because the principal thought it was just too much paperwork. So, Leticia got herself elected to the school board. And they kept the breakfast program, and she got rid of the principal. (Laughter) (Applause) So there were other rumors about some corruption in the local water district. So, Leticia got herself elected to the water district. Then she looked into all of the finances of the water district and found there was 250,000 dollars missing from their bank account. So, Leticia called in the grand jury, and several arrests have been made. And this is just an example of a woman who never went to high school, never went to college, but she found her power. And in addition, she has recruited other people in the community to also run for public office, and guess what — they've all gotten themselves elected. So, I take that Leticia really embodies something that Coretta Scott King said. And I want to share this with you. Coretta Scott King said, "We will never have peace in the world until women take power." (Applause) Now, I have amended that statement to say that we will never have peace in the world until feminists take power. (Laughter) Because we know there is a difference, right? Not only that, but if we want to define what is a feminist — a person who stands up for reproductive rights, for immigrants' rights, for the environment, for LGBT rights and also for labor unions and working people. (Applause) Which also means that men can also be feminists. (Applause) So when we think of feminization, we should also think of how can we feminize the policies, and not only of our major countries, the wealthy countries like the United States, but all over the world, our domestic and foreign policy. And one of the things that we can do to stop wars and to have peace is to make sure that the wealthiest countries in the world also help the developing countries. Now, we did this in the past. After World War II, when Japan and Germany were devastated after the war, United States of America gave many tax dollars to those two countries, so that they can rebuild their economies and rebuild their corporations. And we can do that again. And if we can think about how we can help these other countries. And I want to give an example of issues that we are facing in the United States of America, for instance. We know that right now we have a lot of refugees from Central America that are at the border of the United States. Why do people leave their homes, their beautiful homes that we go to as tourists? Because they don't have opportunities there. And then we think, "Hm, bananas." How many jillions of bananas do we consume in the United States every single day? And throughout the world. Now, do the people in Central America get the profits from the bananas that we consume? No, they don't. The profits go to corporations from the United States of America. And we think that this is wrong. Now, if the people in Central America were to be able to get some of that money that we pay for bananas, then they wouldn't have to leave their homes. They wouldn't have to come as asylum seekers to the borders of the United States of America. And then maybe, many children would not have to be separated from their parents. Now, we know that there are countries in the world that actually have free education and have free health care for all of the people in their country. And that country is Cuba. Cuba has health care for every one of their citizens, and they have a free college education for every one of their citizens. They're 11 million citizens. Now, we think, if a poor country like Cuba can have these kind of resources, and we know that they're a poor country, then why can't some of the other wealthier countries, like the United States of America, do the same? I think that we can make that happen. (Applause) But we know it's not going to happen until we, the people of the United States of America, and people throughout the world, start making sure that they get public officials elected to their governments that really care about the constituents, they care about people, they will commit to make sure that the resources that they have are going to be used for their citizens, and not to be used for war. So, how do we make this happen? We have to get rid of the apathy, we have to get more people involved. We know that if we can't have a democracy in the United States, we can't have democracies throughout the world, unless people participate. So it is imperative that all of us get out there and we say, "Get rid of the apathy, get off of the sidewalk, come and join the march for peace and justice, let's make Coretta Scott's vision a reality, to have peace in the world." We recently had midterm elections in the United States of America. And what did we see? We saw that so many more women, young people, people of color, LGBT folks, were all elected to public office. And we know this happened — why? Because so many women were on the march. We had the Women's March in the United States. They had the Women's Marches all over the world. And so we now see that we have this potential. We have this potential to get rid of the apathy. And if we get everyone involved, get everyone committed, then, I think, we can make Coretta Scott's vision come true. So, I want to just remind everybody, throughout the world, one of the things is, we have power, poor people have power, every citizen has power. But in order to achieve the peace that we all yearn for, then we've all got to get involved. So, what do we say? Can we do it? We say, "Yes, we can!" And in Spanish, we say, "Sí, se puede." Thank you very much. (Applause) |
Myths and misconceptions about evolution | null | TED-Ed | Myths and misconceptions about evolution. Let's talk about evolution. You've probably heard that some people consider it controversial, even though most scientists don't. But even if you aren't one of those people and you think you have a pretty good understanding of evolution, chances are you still believe some things about it that aren't entirely right, things like, "Evolution is organisms adapting to their environment." This was an earlier, now discredited, theory of evolution. Almost 60 years before Darwin published his book, Jean-Baptiste Lamarck proposed that creatures evolve by developing certain traits over their lifetimes and then passing those on to their offspring. For example, he thought that because giraffes spent their lives stretching to reach leaves on higher branches, their children would be born with longer necks. But we know now that's not how genetic inheritance works. In fact, individual organisms don't evolve at all. Instead, random genetic mutations cause some giraffes to be born with longer necks, and that gives them a better chance to survive than the ones who weren't so lucky, which brings us to "survival of the fittest". This makes it sound like evolution always favors the biggest, strongest, or fastest creatures, which is not really the case. For one thing, evolutionary fitness is just a matter of how well-suited they are to their current environment. If all the tall trees suddenly died out and only short grass was left, all those long-necked giraffes would be at a disadvantage. Secondly, survival is not how evolution occurs, reproduction is. And the world if full of creatures like the male anglerfish, which is so small and ill-suited for survival at birth that it has to quickly find a mate before it dies. But at least we can say that if an organism dies without reproducing, it's evolutionarily useless, right? Wrong! Remember, natural selection happens not at the organism level, but at the genetic level, and the same gene that exists in one organism will also exist in its relatives. So, a gene that makes an animal altruistically sacrifice itself to help the survival and future reproduction of its siblings or cousins, can become more widespread than one that is solely concerned with self-preservation. Anything that lets more copies of the gene pass on to the next generation will serve its purpose, except evolutionary purpose. One of the most difficult things to keep in mind about evolution is that when we say things like, "Genes want to make more copies of themselves," or even, "natural selection," we're actually using metaphors. A gene doesn't want anything, and there's no outside mechanism that selects which genes are best to preserve. All that happens is that random genetic mutations cause the organisms carrying them to behave or develop in different ways. Some of those ways result in more copies of the mutated gene being passed on, and so forth. Nor is there any predetermined plan progressing towards an ideal form. It's not ideal for the human eye to have a blind spot where the optic nerve exits the retina, but that's how it developed, starting from a simple photoreceptor cell. In retrospect, it would have been much more advantageous for humans to crave nutrients and vitamins rather than just calories. But over the millenia, during which our ancestors evolved, calories were scarce, and there was nothing to anticipate that this would later change so quickly. So, evolution proceeds blindly, step by step by step, creating all of the diversity we see in the natural world. |
Why is ketchup so hard to pour? | null | TED-Ed | French fries are delicious. French fries with ketchup are a little slice of heaven. The problem is it's basically impossible to pour the exactly right amount. We're so used to pouring ketchup that we don't realize how weird its behavior is. Imagine a ketchup bottle filled with a straight up solid like steel. No amount of shaking would ever get the steel out. Now imagine that same bottle full of a liquid like water. That would pour like a dream. Ketchup, though, can't seem to make up its mind. Is it is a solid? Or a liquid? The answer is, it depends. The world's most common fluids like water, oils and alcohols respond to force linearly. If you push on them twice as hard, they move twice as fast. Sir Isaac Newton, of apple fame, first proposed this relationship, and so those fluids are called Newtonian fluids. Ketchup, though, is part of a merry band of linear rule breakers called Non-Newtonian fluids. Mayonnaise, toothpaste, blood, paint, peanut butter and lots of other fluids respond to force non-linearly. That is, their apparent thickness changes depending on how hard you push, or how long, or how fast. And ketchup is actually Non-Newtonian in two different ways. Way number one: the harder you push, the thinner ketchup seems to get. Below a certain pushing force, ketchup basically behaves like a solid. But once you pass that breaking point, it switches gears and becomes a thousand times thinner than it was before. Sound familiar right? Way number two: if you push with a force below the threshold force eventually, the ketchup will start to flow. In this case, time, not force, is the key to releasing ketchup from its glassy prison. Alright, so, why does ketchup act all weird? Well, it's made from tomatoes, pulverized, smashed, thrashed, utterly destroyed tomatoes. See these tiny particles? This is what remains of tomatoes cells after they go through the ketchup treatment. And the liquid around those particles? That's mostly water and some vinegar, sugar, and spices. When ketchup is just sitting around, the tomato particles are evenly and randomly distributed. Now, let's say you apply a weak force very quickly. The particles bump into each other, but can't get out of each other's way, so the ketchup doesn't flow. Now, let's say you apply a strong force very quickly. That extra force is enough to squish the tomato particles, so maybe instead of little spheres, they get smushed into little ellipses, and boom! Now you have enough space for one group of particles to get passed others and the ketchup flows. Now let's say you apply a very weak force but for a very long time. Turns out, we're not exactly sure what happens in this scenario. One possibility is that the tomato particles near the walls of the container slowly get bumped towards the middle, leaving the soup they were dissolved in, which remember is basically water, near the edges. That water serves as a lubricant betwen the glass bottle and the center plug of ketchup, and so the ketchup flows. Another possibility is that the particles slowly rearrange themselves into lots of small groups, which then flow past each other. Scientists who study fluid flows are still actively researching how ketchup and its merry friends work. Ketchup basically gets thinner the harder you push, but other substances, like oobleck or some natural peanut butters, actually get thicker the harder you push. Others can climb up rotating rods, or continue to pour themselves out of a beeker, once you get them started. From a physics perspective, though, ketchup is one of the more complicated mixtures out there. And as if that weren't enough, the balance of ingredients and the presence of natural thickeners like xanthan gum, which is also found in many fruit drinks and milkshakes, can mean that two different ketchups can behave completely differently. But most will show two telltale properties: sudden thinning at a threshold force, and more gradual thinning after a small force is applied for a long time. And that means you could get ketchup out of the bottle in two ways: either give it a series of long, slow languid shakes making sure you don't ever stop applying force, or you could hit the bottle once very, very hard. What the real pros do is keep the lid on, give the bottle a few short, sharp shakes to wake up all those tomato particles, and then take the lid off and do a nice controlled pour onto their heavenly fries. |
Can you solve the famously difficult green-eyed logic puzzle? | null | TED-Ed | Imagine an island where 100 people, all perfect logicians, are imprisoned by a mad dictator. There's no escape, except for one strange rule. Any prisoner can approach the guards at night and ask to leave. If they have green eyes, they'll be released. If not, they'll be tossed into the volcano. As it happens, all 100 prisoners have green eyes, but they've lived there since birth, and the dictator has ensured they can't learn their own eye color. There are no reflective surfaces, all water is in opaque containers, and most importantly, they're not allowed to communicate among themselves. Though they do see each other during each morning's head count. Nevertheless, they all know no one would ever risk trying to leave without absolute certainty of success. After much pressure from human rights groups, the dictator reluctantly agrees to let you visit the island and speak to the prisoners under the following conditions: you may only make one statement, and you cannot tell them any new information. What can you say to help free the prisoners without incurring the dictator's wrath? After thinking long and hard, you tell the crowd, "At least one of you has green eyes." The dictator is suspicious but reassures himself that your statement couldn't have changed anything. You leave, and life on the island seems to go on as before. But on the hundredth morning after your visit, all the prisoners are gone, each having asked to leave the previous night. So how did you outsmart the dictator? It might help to realize that the amount of prisoners is arbitrary. Let's simplify things by imagining just two, Adria and Bill. Each sees one person with green eyes, and for all they know, that could be the only one. For the first night, each stays put. But when they see each other still there in the morning, they gain new information. Adria realizes that if Bill had seen a non-green-eyed person next to him, he would have left the first night after concluding the statement could only refer to himself. Bill simultaneously realizes the same thing about Adria. The fact that the other person waited tells each prisoner his or her own eyes must be green. And on the second morning, they're both gone. Now imagine a third prisoner. Adria, Bill and Carl each see two green-eyed people, but aren't sure if each of the others is also seeing two green-eyed people, or just one. They wait out the first night as before, but the next morning, they still can't be sure. Carl thinks, "If I have non-green eyes, Adria and Bill were just watching each other, and will now both leave on the second night." But when he sees both of them the third morning, he realizes they must have been watching him, too. Adria and Bill have each been going through the same process, and they all leave on the third night. Using this sort of inductive reasoning, we can see that the pattern will repeat no matter how many prisoners you add. The key is the concept of common knowledge, coined by philosopher David Lewis. The new information was not contained in your statement itself, but in telling it to everyone simultaneously. Now, besides knowing at least one of them has green eyes, each prisoner also knows that everyone else is keeping track of all the green-eyed people they can see, and that each of them also knows this, and so on. What any given prisoner doesn't know is whether they themselves are one of the green-eyed people the others are keeping track of until as many nights have passed as the number of prisoners on the island. Of course, you could have spared the prisoners 98 days on the island by telling them at least 99 of you have green eyes, but when mad dictators are involved, you're best off with a good headstart. |
How big is the ocean? | null | TED-Ed | Imagine yourself standing on a beach, looking out over the ocean, waves crashing against the shore, blue as far as your eyes can see. Let it really sink in, the sheer scope and size of it all. Now, ask yourself, "How big is it? How big is the ocean?" First thing, we need to understand that there really is only one ocean, consisting of five component basins that we call the Pacific, the Atlantic, the Indian, the Arctic, and the Southern. Each of these five, while generally referred to as oceans in and of themselves, are really and truly a part of a single, massive body of water, one ocean, which defines the very face of planet Earth. The ocean covers roughly 71% of our planet's surface, some 360 million square kilometers, an area in excess of the size of 36 U.S.A.'s. It's such a vast spread, when viewed from space, the ocean is, by far, the dominant feature of our planet. Speaking of space, the ocean currently holds over 1.3 billion, that's billion with a "b", cubic kilometers of water. Put another way, that's enough water to immerse the entire United States under a body of salt water over 132 kilometers tall, a height well beyond the reach of the highest clouds and extending deep into the upper atmosphere. With all that volume, the ocean represents 97% of Earth's total water content. On top of all that, the ocean contains upwards of 99% of the world's biosphere, that is, the spaces and places where life exists. Now let that sink in for a second. The immediate world as we know it, indeed the totality of all the living space encompassed by the continents themselves, all of that represents only 1% of the biosphere. 1%! The ocean is everything else. So, the ocean is physically massive. It's importance to life is practically unparalleled. It also happens to hold the greatest geological features of our planet. Quickly, here are four of the most notable. The ocean contains the world's largest mountain range, the mid-ocean ridge. At roughly 65,000 kilometers long, this underwater range is some 10 times longer than the longest mountain chain found purely on dry land, the Andes. Beneath the Denmark Strait exists the world's largest waterfall. This massive cataract carries roughly 116 times more water per second over its edge than the Congo River's Inga Falls, the largest waterfall by volume on land. The world's tallest mountain is actually found in the ocean, hiding in plain sight. While 4200 meters of Hawaii's Mauna Kea sit above sea level, its sides plummet beneath the waves for another 5800 meters. From its snow-covered top to it's silt-covered bottom, then, this Hawaiian mountain is roughly 10,000 meters in height, dwarfing tiny Everest's paltry peak by well over a kilometer. Then, since we're picking on poor Everest, let's consider the world's deepest canyon, the Challenger Deep, existing 11 kilometers below the ocean's surface, some six times deeper than the Grand Canyon. That's deep enough to sink Mount Everest into and still have over 2.1 kilometers of water sitting atop its newly submerged peak. Put another way, the depth of the Challenger Deep is roughly the same height that commercial airliners travel. So, pretty much however you choose to slice it, the ocean is capital B capital I, capital G, BIG! It defines our planet, home to the greatest geological features, comprises the largest living space, and accordingly, is home to the greatest numbers and forms of life on Earth. It is practically incomprehensible in scope. But it is not so big, so vast, so extraordinary as to be untouchable. In fact, with roughly 50% of the world's population living within 100 kilometers of the coastline and with most of the remainder living close enough to lakes, rivers, or swamps, all of which ultimately lead to the ocean, virtually every single person on the planet has the opportunity to influence the general health and nature of the world ocean. Evidence of human influence is seen in every part of the ocean, no matter how deep, no matter how distant. The ocean defines our planet, but, in a very real sense, we define the ocean. |
Why the metric system matters | null | TED-Ed | What does the French Revolution have to do with the time NASA accidentally crashed a $200 million orbiter into the surface of Mars? Actually, everything. That crash happened due to an error in converting between two measurement systems, U.S. customary units and their S.I, or metric, equivalence. So what's the connection to the French Revolution? Let's explain. For the majority of recorded human history, units like the weight of a grain or the length of a hand weren't exact and varied from place to place. And different regions didn't just use varying measurements. They had completely different number systems as well. By the late Middle Ages, the Hindu-Arabic decimal system mostly replaced Roman numerals and fractions in Europe, but efforts by scholars like John Wilkins to promote standard decimal-based measures were less successful. With a quarter million different units in France alone, any widespread change would require massive disruption. And in 1789, that disruption came. The leaders of the French Revolution didn't just overthrow the monarchy. They sought to completely transform society according to the rational principles of the Enlightenment. When the new government took power, the Academy of Sciences convened to reform the system of measurements. Old standards based on arbitrary authority or local traditions were replaced with mathematical and natural relationships. For example, the meter, from the Greek word for measure, was defined as 1/10,000,000 between the Equator and North Pole. And the new metric system was, in the words of the Marquis de Condorcet, "For all people, for all time." Standardizing measurements had political advantages for the Revolutionaries as well. Nobles could no longer manipulate local units to extract more rent from commoners, while the government could collect taxes more efficiently. And switching to a new Republican Calendar with ten-day weeks reduced church power by eliminating Sundays. Adoption of this new system wasn't easy. In fact, it was a bit of a mess. At first, people used new units alongside old ones, and the Republican Calendar was eventually abandoned. When Napoléon Bonaparte took power, he allowed small businesses to use traditional measurements redefined in metric terms. But the metric system remained standard for formal use, and it spread across the continent, along with France's borders. While Napoléon's empire lasted eight years, its legacy endured far longer. Some European countries reverted to old measurements upon independence. Others realized the value of standardization in an age of international trade. After Portugal and the Netherlands switched to metric voluntarily, other nations followed, with colonial empires spreading the system around the world. As France's main rival, Britain had resisted revolutionary ideas and retained its traditional units. But over the next two centuries, the British Empire slowly transitioned, first approving the metric system as an optional alternative before gradually making it offical. However, this switch came too late for thirteen former colonies that had already gained independence. The United States of America stuck with the English units of its colonial past and today remains one of only three countries which haven't fully embraced the metric system. Despite constant initiatives for metrication, many Americans consider units like feet and pounds more intuitive. And ironically, some regard the once revolutionary metric system as a symbol of global conformity. Nevertheless, the metric system is almost universally used in science and medicine, and it continues to evolve according to its original principles. For a long time, standard units were actually defined by carefully maintained physical prototypes. But thanks to improving technology and precision, these objects with limited access and unreliable longevity are now being replaced with standards based on universal constants, like the speed of light. Consistent measurements are such an integral part of our daily lives that it's hard to appreciate what a major accomplishment for humanity they've been. And just as it arose from a political revolution, the metric system remains crucial for the scientific revolutions to come. |
An architect's subversive reimagining of the US-Mexico border wall | {0: 'Ronald Rael draws, builds, writes, 3D-prints and teaches about architecture as a cultural endeavor deeply influenced by a unique upbringing in a desolate alpine valley in southern Colorado.'} | TED Salon: Belonging | Isn't it fascinating how the simple act of drawing a line on the map can transform the way we see and experience the world? And how those spaces in between lines, borders, become places. They become places where language and food and music and people of different cultures rub up against each other in beautiful and sometimes violent and occasionally really ridiculous ways. And those lines drawn on a map can actually create scars in the landscape, and they can create scars in our memories. My interest in borders came about when I was searching for an architecture of the borderlands. And I was working on several projects along the US-Mexico border, designing buildings made out of mud taken right from the ground. And I also work on projects that you might say immigrated to this landscape. "Prada Marfa," a land-art sculpture that crosses the border between art and architecture, and it demonstrated to me that architecture could communicate ideas that are much more politically and culturally complex, that architecture could be satirical and serious at the same time and it could speak to the disparities between wealth and poverty and what's local and what's foreign. And so in my search for an architecture of the borderlands, I began to wonder, is the wall architecture? I began to document my thoughts and visits to the wall by creating a series of souvenirs to remind us of the time when we built a wall and what a crazy idea that was. I created border games, (Laughter) postcards, snow globes with little architectural models inside of them, and maps that told the story of resilience at the wall and sought for ways that design could bring to light the problems that the border wall was creating. So, is the wall architecture? Well, it certainly is a design structure, and it's designed at a research facility called FenceLab, where they would load vehicles with 10,000 pounds and ram them into the wall at 40 miles an hour to test the wall's impermeability. But there was also counter-research going on on the other side, the design of portable drawbridges that you could bring right up to the wall and allow vehicles to drive right over. (Laughter) And like with all research projects, there are successes and there are failures. (Laughter) But it's these medieval reactions to the wall — drawbridges, for example — that are because the wall itself is an arcane, medieval form of architecture. It's an overly simplistic response to a complex set of issues. And a number of medieval technologies have sprung up along the wall: catapults that launch bales of marijuana over the wall (Laughter) or cannons that shoot packets of cocaine and heroin over the wall. Now during medieval times, diseased, dead bodies were sometimes catapulted over walls as an early form of biological warfare, and it's speculated that today, humans are being propelled over the wall as a form of immigration. A ridiculous idea. But the only person ever known to be documented to have launched over the wall from Mexico to the United States was in fact a US citizen, who was given permission to human-cannonball over the wall, 200 feet, so long as he carried his passport in hand (Laughter) and he landed safely in a net on the other side. And my thoughts are inspired by a quote by the architect Hassan Fathy, who said, "Architects do not design walls, but the spaces between them." So while I do not think that architects should be designing walls, I do think it's important and urgent that they should be paying attention to those spaces in between. They should be designing for the places and the people, the landscapes that the wall endangers. Now, people are already rising to this occasion, and while the purpose of the wall is to keep people apart and away, it's actually bringing people together in some really remarkable ways, holding social events like binational yoga classes along the border, to bring people together across the divide. I call this the monument pose. (Laughter) And have you ever heard of "wall y ball"? (Laughter) It's a borderland version of volleyball, and it's been played since 1979 (Laughter) along the US-Mexico border to celebrate binational heritage. And it raises some interesting questions, right? Is such a game even legal? Does hitting a ball back and forth over the wall constitute illegal trade? (Laughter) The beauty of volleyball is that it transforms the wall into nothing more than a line in the sand negotiated by the minds and bodies and spirits of players on both sides. And I think it's exactly these kinds of two-sided negotiations that are needed to bring down walls that divide. Now, throwing the ball over the wall is one thing, but throwing rocks over the wall has caused damage to Border Patrol vehicles and have injured Border Patrol agents, and the response from the US side has been drastic. Border Patrol agents have fired through the wall, killing people throwing rocks on the Mexican side. And another response by Border Patrol agents is to erect baseball backstops to protect themselves and their vehicles. And these backstops became a permanent feature in the construction of new walls. And I began to wonder if, like volleyball, maybe baseball should be a permanent feature at the border, and walls could start opening up, allowing communities to come across and play, and if they hit a home run, maybe a Border Patrol agent would pick up the ball and throw it back over to the other side. A Border Patrol agent buys a raspado, a frozen treat, from a vendor just a couple feet away, food and money is exchanged through the wall, an entirely normal event made illegal by that line drawn on a map and a couple millimeters of steel. And this scene reminded me of a saying: "If you have more than you need, you should build longer tables and not higher walls." So I created this souvenir to remember the moment that we could share food and conversation across the divide. A swing allows one to enter and swing over to the other side until gravity deports them back to their own country. The border and the border wall is thought of as a sort of political theater today, so perhaps we should invite audiences to that theater, to a binational theater where people can come together with performers, musicians. Maybe the wall is nothing more than an enormous instrument, the world's largest xylophone, and we could play down this wall with weapons of mass percussion. (Laughter) When I envisioned this binational library, I wanted to imagine a space where one could share books and information and knowledge across a divide, where the wall was nothing more than a bookshelf. And perhaps the best way to illustrate the mutual relationship that we have with Mexico and the United States is by imagining a teeter-totter, where the actions on one side had a direct consequence on what happens on the other side, because you see, the border itself is both a symbolic and literal fulcrum for US-Mexico relations, and building walls between neighbors severs those relationships. You probably remember this quote, "Good fences make good neighbors." It's often thought of as the moral of Robert Frost's poem "Mending Wall." But the poem is really about questioning the need for building walls at all. It's really a poem about mending human relationships. My favorite line is the first one: "Something there is that doesn't love a wall." Because if there's one thing that's clear to me — there are not two sides defined by a wall. This is one landscape, divided. On one side, it might look like this. A man is mowing his lawn while the wall is looming in his backyard. And on the other side, it might look like this. The wall is the fourth wall of someone's house. But the reality is that the wall is cutting through people's lives. It is cutting through our private property, our public lands, our Native American lands, our cities, a university, our neighborhoods. And I couldn't help but wonder what it would be like if the wall cut through a house. Remember those disparities between wealth and poverty? On the right is the average size of a house in El Paso, Texas, and on the left is the average size of a house in Juarez. And here, the wall cuts directly through the kitchen table. And here, the wall cuts through the bed in the bedroom. Because I wanted to communicate how the wall is not only dividing places, it's dividing people, it's dividing families. And the unfortunate politics of the wall is today, it is dividing children from their parents. You might be familiar with this well-known traffic sign. It was designed by graphic designer John Hood, a Native American war veteran working for the California Department of Transportation. And he was tasked with creating a sign to warn motorists of immigrants who were stranded alongside the highway and who might attempt to run across the road. Hood related the plight of the immigrant today to that of the Navajo during the Long Walk. And this is really a brilliant piece of design activism. And he was very careful in thinking about using a little girl with pigtails, for example, because he thought that's who motorists might empathize with the most, and he used the silhouette of the civil rights leader Cesar Chavez to create the head of the father. I wanted to build upon the brilliance of this sign to call attention to the problem of child separation at the border, and I made one very simple move. I turned the families to face each other. And in the last few weeks, I've had the opportunity to bring that sign back to the highway to tell a story, the story of the relationships that we should be mending and a reminder that we should be designing a reunited states and not a divided states. Thank you. (Applause) |
Why should you read sci-fi superstar Octavia E. Butler? | null | TED-Ed | Following a devastating nuclear war, Lilith Iyapo awakens after 250 years of stasis to find herself surrounded by a group of aliens called the Oankali. These highly evolved beings want to trade DNA by breeding with humans so that each species’ genes can diversify and fortify the other. The only alternative they offer is sterilization of the entire human race. Should humanity take the leap into the biological unknown, or hold on to its identity and perish? Questions like this haunt Octavia Butler’s "Dawn," the first in her trilogy "Lilith’s Brood." A visionary storyteller who upended science fiction, Butler built stunning worlds throughout her work– and explored dilemmas that keep us awake at night. Born in 1947, Butler grew up shy and introverted in Pasadena, California. She dreamt up stories from an early age, and was soon scribbling these scenarios on paper. At twelve, she begged her mother for a typewriter after enduring a campy science fiction film called "Devil Girl From Mars." Unimpressed with what she saw, Butler knew she could tell a better story. Much science fiction features white male heroes who blast aliens or become saviors of brown people. Butler wanted to write diverse characters for diverse audiences. She brought nuance and depth to the representation of their experiences. For Butler, imagination was not only for planting the seeds of science fiction– but also a strategy for surviving an unjust world on one’s own terms. Her work often takes troubling features of the world such as discrimination on the basis of race, gender, class, or ability, and invites the reader to contemplate them in new contexts. One of her most beloved novels, the "Parable of the Sower," follows this pattern. It tells the story of Lauren Oya Olamina as she makes her way through a near-future California, ruined by corporate greed, inequality, and environmental destruction. As she struggles with hyperempathy, or a condition in the novel that causes her to feel others’ pain, and less often, their pleasure. Lauren embarks on a quest with a group of refugees to find a place to thrive. There, they seek to live in accordance with Lauren’s found religion, Earthseed, which is based on the principle that humans must adapt to an ever-changing world. Lauren’s quest had roots in a real life event– California Prop 187, which attempted to deny undocumented immigrants fundamental human rights, before it was deemed unconstitutional. Butler frequently incorporated contemporary news into her writing. In her 1998 sequel to "The Parable of the Sower," "Parable of the Talents," she wrote of a presidential candidate who controls Americans with virtual reality and “shock collars.” His slogan? “Make America great again.” While people have noted her prescience, Butler was also interested in re-examining history. For instance, "Kindred" tells the story of a woman who is repeatedly pulled back in time to the Maryland plantation of her ancestors. Early on, she learns that her mission is to save the life of the white man who will rape her great grandmother. If she doesn’t save him, she herself will cease to exist. This grim dilemma forces Dana to confront the ongoing trauma of slavery and sexual violence against Black women. With her stories of women founding new societies, time travelers overcoming historical strife, and interspecies bonding, Butler had a profound influence on the growing popularity of Afrofuturism. That’s a cultural movement where Black writers and artists who are inspired by the past, present and future, produce works that incorporate magic, history, technology and much more. As Lauren comes to learn in "Parable of the Sower," "All that you touch you Change. All that you Change Changes you. The only lasting truth is Change.” |
Can you solve the jail break riddle? | null | TED-Ed | Your timing made you and your partner the most infamous bank robbers in the west. Now, you’ll need to use that timing to help you break out of jail. At the appointed time, you’ll be walking in the yard near the electric fence. Your partner will flash you the signal, and exactly 45 seconds later, short out the fence circuit. It’ll automatically restart after a second or two, but as long as you move fast, you’ll be home free. And then you notice, to your horror, that your watch is broken, and there’s no time to fix it. The signal is coming, and if you make even a small mistake in counting off 45 seconds, you’ll get fried. Searching your pockets, you find something that might help: a lighter and two fuses you made earlier in the prison work program. Each fuse is a length of flammable twine, built to be lit on either end and burn for precisely one minute. The problem is that even though the fuses look uniform, they don’t burn evenly, so if you cut one in half, for example, one side might burn longer than the other. Your partner is going to give the signal any minute, and you’ll have to make your move. How can you use the fuses and lighter to time exactly 45 seconds? Pause the video to figure it out yourself. Answer in 3 Answer in 2 Answer in 1 The length of the fuse may not tell you anything, but you do know the fuses take exactly 60 seconds to burn from end to end. Here’s the key insight: If you start a fuse on one side and it burns for 30 seconds, there’ll still be 30 seconds of fuse left. If you had started it from the other end, it would’ve reached the exact same spot in thirty seconds. That means that if you lit it from both ends simultaneously, it would burn out in precisely 30 seconds. But how will you time the last fifteen? That’ll have to come from the second fuse. If it were a 30 second fuse, you’d be able to use that same trick again to double the burning speed and make it last exactly 15 seconds. And, you realize, you can shorten the second fuse by lighting one end of it at the same time as you light the first. At the moment the first burns out, you’ll be left with 30 seconds on the second fuse. Just when you’ve got this all figured out, you see the signal from your partner, and spring into action. You gather the four ends of the two fuses and light three of them. The moment the first burns out, you light the other end of the second fuse. When it flickers and dies, you know that exactly 45 seconds have passed, and the electric fence is dead. By the time it hiccups back to life, you’re over the fence and home free. |
A juror's reflections on the death penalty | {0: 'Lindy Lou Isonhood served as Juror No. 2 on a capital murder trial in 1994 -- an experience that changed her life.'} | TEDWomen 2018 | It was a Thursday, June the 23rd, 1994. (Sighs) "Collect your belongings. You are free to go. When escorted outside, go directly to your car. Do not talk to reporters." My head is spinning, my heart is racing, I can't get a breath. I just want out of there. When I get to my car, I throw everything on the back, and I just collapse into the driver's seat. "I can't do this. I can't go home to my family that I haven't seen in a week and pretend to be happy." Not even their love and support could help me at this particular time. We had just sentenced a man to death. Now what? Just go home and wash dishes? You see, in Mississippi, the death penalty is like a part of our unspoken culture. The basic logic is, if you murder someone, then you're going to receive the death penalty. So when the jury selection process took place, they asked me, "Could you, if the evidence presented justified the death penalty, could you deliver, rationally and without reservations, a penalty of death?" My answer was an astounding "yes," and I was selected as Juror Number 2. The trial started. From the evidence being presented and from the pictures of the victim, my first response was, "Yes, this man is a monster, and he deserves the death penalty." For days, I sat and looked at his hands, the ones that yielded the knife, and against his pasty white skin, his eyes ... Well, he spent endless days in his cell, no sunlight, so his eyes were as black as his hair and his mustache. He was very intimidating, and there was absolutely no doubt in his guilt. But regardless of his guilt, as the days passed, I began to see this monster as a human being. Something inside of me was changing that I just didn't understand. I was beginning to question myself as to whether or not I wanted to give this man the death penalty. Jury deliberations began, and the judge gave us jury instructions and it was to be used as a tool in how to reach a verdict. Well, using this tool only led to one decision, and that was the death penalty. I felt backed into a corner. My head and my heart were in conflict with each other, and the thought of the death penalty made me sick. However, following the judge's instructions, being a law-abiding person, I gave up. I gave up and voted along with the other 11 jurors. And there it was: our broken judicial system at work. So here I am in my car, and I'm wondering: How is my life ever going to be the same? My life was kids, work, church, ball games — just your average, normal, everyday life. Now everything felt trivial. I was going down this rabbit hole. The anger, the anxiety, the guilt, the depression ... it just clung to me. I knew that my life had to resume, so I sought counseling. The counselor diagnosed me with PTSD and told me that the best way to overcome the PTSD was to talk about the trauma. However, if I talked or tried to talk about the trauma outside her office, I was shut down. No one wanted to hear about it. He was just a murderer. Get over it. It was then that I decided to become a silent survivor. Twelve years later, 2006, I learned that Bobby Wilcher had dropped all of his appeals, and his execution date was approaching. That was like a punch in the stomach. All of those buried feelings just started coming back. To try and find peace, I called Bobby's attorney, and I said, "Can I see Bobby before he's executed?" Driving to the penitentiary on the day of his execution, in my mind, Bobby was going to be manic. But, surprisingly, he was very calm. And for two hours, he and I sat there and talked about life, and I got to ask him to forgive me for my hand in his death. His words to me were: "You don't have to apologize. You didn't put me here. I did this myself. But if it'll make you feel better, I forgive you." On my way home, I stopped by a restaurant and bought a margarita. (Laughter) I don't think I could get one big enough — (Laughter) to try and calm down. My phone rang. It was Bobby's attorney. Within two minutes of his execution, they had given him a stay. This stay gave me time to reach out to Bobby. And as crazy as it may sound, we became friends. Three months later, he was executed by the State of Mississippi. I'm here to tell you my story, because it was precisely 22 years later that I even wanted to open up enough to talk about it, when a friend encouraged me. "Hey, perhaps you need to talk to the other jurors. You've been through the same experience." Uncertain of what I was after, I did need to talk to them. So I set out on my quest, and I actually found most of them. The first juror I met thought that Bobby got what he deserved. Another juror — well, they just kind of regretted that it took so long to carry the sentence out. Then one juror, and I don't know what was wrong with him, but he didn't remember anything about the trial. (Laughter) Well, I'm thinking in my mind, "Jeez, is this the response I'm gonna get from everybody else?" Well, thank God for Allen. Allen was a gentle soul. And when I talked to him, he was genuinely upset about our decision. And he told me about the day that the devastation really set in on him and hit him. He was listening to the radio, and the radio had a list of names of men to be executed at Parchman Penitentiary. He heard Bobby's name, and he then truly realized what he had done. And he said, "You know, I had a responsibility in that man's death." Now here it is, 20-something years later, and Allen is still dealing with that issue. And he's never told anyone about it, not even his wife. He also told me that if the State of Mississippi wanted to keep the death penalty, then hey, they needed to provide counseling for the jurors. Then the next juror I met was Jane. Jane is now totally against the death penalty, And there was Bill. Bill said he had this crushing depression for weeks, and when he went back to work, his colleagues would say things to him like, "Hey, did you fry him?" To them, it was just a joke. Then there was Jon. Jon said his decision weighed on him, and it burdened him daily. The final juror that I spoke to was Ken. Ken was the foreman of the jury. When we sat down to talk, it was apparent that he was deeply saddened by what we were required to do. He relived the day that he left the courthouse and he drove home and he went to put his key in his door and unlock it, and he said he literally broke down. He said he knew that Bobby was guilty, but the decision he made, he did not know if it was the right decision. And he said that he played it over and over in his head. Did we do the right thing? Did we do the right thing? Did we do the right thing? (Sighs) All those years, and I finally realized that I was not the only disillusioned juror. And we talked about sharing our experience with potential jurors to give them some insight into what to expect, and to tell them do not be complacent; to know what you believe; to know where you stand and be prepared, because you don't want to walk in one morning as a juror and leave at the end of the trial feeling like a murderer. Now, through this storm in my life, I did find some inspiration, and it came in the form of my granddaughters. My 14-year-old granddaughter, Maddie, was writing an essay on the death penalty for school, and she was asking me questions. Well, it dawned on me that this child was being raised in the same eye-for-an-eye culture as I was, or had been. And so I explained my experience to her this way: that I had sentenced someone to death as I served on a jury. And I asked her, "Did that make me a murderer?" She couldn't answer. I knew then that this topic needed to be open for discussion. And guess what happened? I got invited to speak, just recently, in an abolitionist community. While I was there, I got a T-shirt. It says, "Stop Executions." Well, when I get home, my 16-year-old granddaughter was there, Anna, and she says, "Can I have that shirt?" Well, I looked at her dad — her dad is my son — and I knew that he is still dealing with this death penalty issue. So I turned around and I looked at her, and I said, "Are you gonna wear this?" So she turned and she looked at her dad, and she said, "Dad, I know how you feel, but I don't believe in the death penalty." My son looked at me, shook his head, and said, "Thanks, Mom." And I knew it wasn't a nice "Thanks, Mom." (Laughter) So I learned that life had taught me some lessons. It taught me, if I had not served on that jury, that I would still be of the same mindset. It also gave me confidence to be able to see through the eyes of my granddaughters, that this younger generation, they're capable and they're willing to tackle these difficult social issues. And because of my experience, my granddaughters, they're now more equipped to stand on their own and to think for themselves than to rely on cultural beliefs. So: being from a conservative, Christian family from a very conservative state in the United States, I am here to tell you that the death penalty has new opponents. Thank you. (Applause) |
The self-assembling computer chips of the future | {0: 'As a passionate technology leader, Karl Skjonnemand has a hunger for solutions to advanced technology problems.'} | TED@Merck KGaA, Darmstadt, Germany | Computers used to be as big as a room. But now they fit in your pocket, on your wrist and can even be implanted inside of your body. How cool is that? And this has been enabled by the miniaturization of transistors, which are the tiny switches in the circuits at the heart of our computers. And it's been achieved through decades of development and breakthroughs in science and engineering and of billions of dollars of investment. But it's given us vast amounts of computing, huge amounts of memory and the digital revolution that we all experience and enjoy today. But the bad news is, we're about to hit a digital roadblock, as the rate of miniaturization of transistors is slowing down. And this is happening at exactly the same time as our innovation in software is continuing relentlessly with artificial intelligence and big data. And our devices regularly perform facial recognition or augment our reality or even drive cars down our treacherous, chaotic roads. It's amazing. But if we don't keep up with the appetite of our software, we could reach a point in the development of our technology where the things that we could do with software could, in fact, be limited by our hardware. We've all experienced the frustration of an old smartphone or tablet grinding slowly to a halt over time under the ever-increasing weight of software updates and new features. And it worked just fine when we bought it not so long ago. But the hungry software engineers have eaten up all the hardware capacity over time. The semiconductor industry is very well aware of this and is working on all sorts of creative solutions, such as going beyond transistors to quantum computing or even working with transistors in alternative architectures such as neural networks to make more robust and efficient circuits. But these approaches will take quite some time, and we're really looking for a much more immediate solution to this problem. The reason why the rate of miniaturization of transistors is slowing down is due to the ever-increasing complexity of the manufacturing process. The transistor used to be a big, bulky device, until the invent of the integrated circuit based on pure crystalline silicon wafers. And after 50 years of continuous development, we can now achieve transistor features dimensions down to 10 nanometers. You can fit more than a billion transistors in a single square millimeter of silicon. And to put this into perspective: a human hair is 100 microns across. A red blood cell, which is essentially invisible, is eight microns across, and you can place 12 across the width of a human hair. But a transistor, in comparison, is much smaller, at a tiny fraction of a micron across. You could place more than 260 transistors across a single red blood cell or more than 3,000 across the width of a human hair. It really is incredible nanotechnology in your pocket right now. And besides the obvious benefit of being able to place more, smaller transistors on a chip, smaller transistors are faster switches, and smaller transistors are also more efficient switches. So this combination has given us lower cost, higher performance and higher efficiency electronics that we all enjoy today. To manufacture these integrated circuits, the transistors are built up layer by layer, on a pure crystalline silicon wafer. And in an oversimplified sense, every tiny feature of the circuit is projected onto the surface of the silicon wafer and recorded in a light-sensitive material and then etched through the light-sensitive material to leave the pattern in the underlying layers. And this process has been dramatically improved over the years to give the electronics performance we have today. But as the transistor features get smaller and smaller, we're really approaching the physical limitations of this manufacturing technique. The latest systems for doing this patterning have become so complex that they reportedly cost more than 100 million dollars each. And semiconductor factories contain dozens of these machines. So people are seriously questioning: Is this approach long-term viable? But we believe we can do this chip manufacturing in a totally different and much more cost-effective way using molecular engineering and mimicking nature down at the nanoscale dimensions of our transistors. As I said, the conventional manufacturing takes every tiny feature of the circuit and projects it onto the silicon. But if you look at the structure of an integrated circuit, the transistor arrays, many of the features are repeated millions of times. It's a highly periodic structure. So we want to take advantage of this periodicity in our alternative manufacturing technique. We want to use self-assembling materials to naturally form the periodic structures that we need for our transistors. We do this with the materials, then the materials do the hard work of the fine patterning, rather than pushing the projection technology to its limits and beyond. Self-assembly is seen in nature in many different places, from lipid membranes to cell structures, so we do know it can be a robust solution. If it's good enough for nature, it should be good enough for us. So we want to take this naturally occurring, robust self-assembly and use it for the manufacturing of our semiconductor technology. One type of self-assemble material — it's called a block co-polymer — consists of two polymer chains just a few tens of nanometers in length. But these chains hate each other. They repel each other, very much like oil and water or my teenage son and daughter. (Laughter) But we cruelly bond them together, creating an inbuilt frustration in the system, as they try to separate from each other. And in the bulk material, there are billions of these, and the similar components try to stick together, and the opposing components try to separate from each other at the same time. And this has a built-in frustration, a tension in the system. So it moves around, it squirms until a shape is formed. And the natural self-assembled shape that is formed is nanoscale, it's regular, it's periodic, and it's long range, which is exactly what we need for our transistor arrays. So we can use molecular engineering to design different shapes of different sizes and of different periodicities. So for example, if we take a symmetrical molecule, where the two polymer chains are similar length, the natural self-assembled structure that is formed is a long, meandering line, very much like a fingerprint. And the width of the fingerprint lines and the distance between them is determined by the lengths of our polymer chains but also the level of built-in frustration in the system. And we can even create more elaborate structures if we use unsymmetrical molecules, where one polymer chain is significantly shorter than the other. And the self-assembled structure that forms in this case is with the shorter chains forming a tight ball in the middle, and it's surrounded by the longer, opposing polymer chains, forming a natural cylinder. And the size of this cylinder and the distance between the cylinders, the periodicity, is again determined by how long we make the polymer chains and the level of built-in frustration. So in other words, we're using molecular engineering to self-assemble nanoscale structures that can be lines or cylinders the size and periodicity of our design. We're using chemistry, chemical engineering, to manufacture the nanoscale features that we need for our transistors. But the ability to self-assemble these structures only takes us half of the way, because we still need to position these structures where we want the transistors in the integrated circuit. But we can do this relatively easily using wide guide structures that pin down the self-assembled structures, anchoring them in place and forcing the rest of the self-assembled structures to lie parallel, aligned with our guide structure. For example, if we want to make a fine, 40-nanometer line, which is very difficult to manufacture with conventional projection technology, we can manufacture a 120-nanometer guide structure with normal projection technology, and this structure will align three of the 40-nanometer lines in between. So the materials are doing the most difficult fine patterning. And we call this whole approach "directed self-assembly." The challenge with directed self-assembly is that the whole system needs to align almost perfectly, because any tiny defect in the structure could cause a transistor failure. And because there are billions of transistors in our circuit, we need an almost molecularly perfect system. But we're going to extraordinary measures to achieve this, from the cleanliness of our chemistry to the careful processing of these materials in the semiconductor factory to remove even the smallest nanoscopic defects. So directed self-assembly is an exciting new disruptive technology, but it is still in the development stage. But we're growing in confidence that we could, in fact, introduce it to the semiconductor industry as a revolutionary new manufacturing process in just the next few years. And if we can do this, if we're successful, we'll be able to continue with the cost-effective miniaturization of transistors, continue with the spectacular expansion of computing and the digital revolution. And what's more, this could even be the dawn of a new era of molecular manufacturing. How cool is that? Thank you. (Applause) |
Is your country at risk of becoming a dictatorship? Here's how to know | {0: 'Farida Nabourema is a key voice in Togo’s pro-democracy movement.'} | TEDWomen 2018 | A few weeks ago, somebody tweeted during the midterm elections in the United States that Election Day should be made a holiday. And I retweeted, saying, "Well, you're welcome to come to my country and vote. You'll get the whole week off to allow the military to count it." I come from Togo, by the way. It is a beautiful country located in West Africa. There are some cool, interesting facts about my country. Togo has been ruled by the same family for 51 years, making us the oldest autocracy in Africa. That's a record. We have a second-coolest record: we have been ranked three times as the unhappiest country on earth. You are all invited. (Laughter) So just to let you know, it's not very cool to live under an autocracy. But the interesting thing is that I have met, throughout the course of my activism, so many people from different countries, and when I tell them about Togo, their reaction is always, "How can you guys allow the same people to terrorize you for 51 years? You know, like, you Togolese, you must be very patient." That's their diplomatic way of saying "stupid." (Laughter) And when you live in a free country, there's this tendency of assuming that those who are oppressed tolerate their oppression or are comfortable with it, and democracy is projected as a progressive form of governance in such a way that those people who don't live under democratic countries are seen as people who are not intellectually or maybe morally as advanced as others. But it's not the case. The reason why people have that perception has to do with the way stories are covered about dictatorships. In the course of my activism, I have had to interview with so many news outlets out there, and usually it would always start with, "What got you started? What inspired you?" And I reply, "I wasn't inspired. I was triggered." And it goes on. "Well, what triggered you?" And I go on about how my father was arrested when I was 13, and tortured, all the history ... I don't want to get into details now, because you'll start sleeping. But the thing is, at the end of the day, what interests them the most is: How was he tortured? For how many days? How many people died? They are interested in the abuse, in the killing, because they believe that will gain attention and sympathy. But in reality, it serves the purpose of the dictator. It helps them advertise their cruelty. In 2011, I cofounded a movement I call "Faure Must Go," because Faure is the first name of our president. Togo is a French-speaking country, by the way, but I chose English because I had my issues with France as well. But then — (Laughter) But then, when I started Faure Must Go, I made a video, and I came on camera, and I said, "Well, Faure Gnassingbé, I give you 60 days to resign as president, because if you don't, we the youth in Togo will organize and we will bring you down, because you have killed over 500 of our countrymen to seize power when your father died. We have not chosen you. You are an imposter, and we will remove you." But I was the only known face of the movement. Why? Because I was the only stupid one. (Laughter) And the backlashes followed. My family started receiving threats. My siblings called me one morning. They said, "You know what? When they come here to kill you, we don't want to die with you, so move out." So yes, I moved out. And I'm so angry at them, so I haven't talked to them in five years. Anyway, moving forward ... For the past nine years, I have been working with countries to raise awareness of Togo, to help the people of Togo overcome their fear so they, too, can come and say they want change. I have received a lot of persecution that I cannot disclose, a lot of threats, a lot of abuse, psychologically. But I don't like talking about them, because I know that my job as an activist is to mobilize, is to organize, is to help every single Togolese citizen understand that, as citizens, we hold the power, we are the boss and we decide. And the punishment that the dictators are using to intimidate them must not prevent us from getting what we want. That is why I said it is very important to cover the stories of activists in the way that it helps mobilize people, not in the way that it helps deter their action and force even more their subjugation to the oppressive system. During these years that I've been an activist, there are days that I felt like quitting because I couldn't take it. Well then, what kept me going? The one thing that kept me going: I remember the story of my grandfather, and how he used to walk 465 miles from his village to the city, just to protest for independence. Then I remember the sacrifice of my father, who was tortured so many times for daring to protest against the regime. Back in the '70s, they would write pamphlets to raise awareness on the dictatorship, and because they couldn't afford to make copies, they would reproduce the same pamphlet 500 times each and distribute them. It got to a point where the military knew their handwriting, so as soon as they stumbled upon one, they'd go and get them. But I look at that and I'm like, you know, today you have a blog. I don't have to copy the same thing 500 times. I blog and thousands of people read it. By the way, in Togo, they like calling me the WhatsApp girl, because I am always on WhatsApp attacking the government. (Laughter) So it's much easier. When I'm angry at the government, I just make an angry note, and I send it out and thousands of people share it. I'm rarely this composed. I'm always angry, by the way. (Laughter) (Applause) So I was talking about the necessity to showcase our stories, because when I think about the sacrifices that were made for us, it helped me keep going. One of the very first actions of our Faure Must Go movement was to come up with a petition, asking citizens to sign so that we can demand new elections, as the constitution allows. People were scared to put their names because, they said, they don't want to get in trouble. Even in the diaspora, people were scared. They were like, "We have family at home." But there was this woman who was in her 60s. When she heard about it, she took the petition, and she went home, and by herself she collected over 1,000 [signatures]. That inspired me so much, and I was like, if a 60-year-old that has nothing more to gain in this regime can do this for us, the young ones, then why should I quit? It is the stories of resistance, the stories of defiance, the stories of resilience, that inspire people to get involved, not the stories of abuse and killings and hurt, because as humans, it's only natural for us to be scared. I would like to share with you a few characteristics of dictatorships so that you can assess your own country and see if you are also at risk of joining us. (Laughter and cheers) (Applause) Number one thing to look at: concentration of power. Is the power in your country concentrated in the hands of a few, an elite? It can be a political elite, ideological elite. And you have a strongman, because we always have one guy who is presented as the messiah who will save us from the world. The second point is propaganda. Dictators feed on propaganda. They like giving the impression that they are the saviors, and without them, the country will fall apart. And they are always fighting some foreign forces, you know? The Christians, the Jewish, the Muslims, the voodoo priests are coming for you. The Communists, when they get here, we'll all be broke. These kinds of things. And our president, in particular, he fights pirates. (Laughter) I am very serious. Last year, he bought a boat that's 13 million dollars to fight pirates, and 60 percent of our people are starving. So they are always protecting us from some foreign forces. And this leads to point three: militarization. Dictators survive by instigating fear, and they use the military to suppress dissident voices, even though they try to give the impression that the military is to protect the nation. And they suppress institutions and destroy them so that they don't have to be held accountable. So do you have a heavily militarized country? And this leads to point four, what I call human cruelty. You know when we talk about animals, we say animal cruelty when animals are abused, because there's no charter acknowledged by the UN saying animal rights charter. Point one: all animals are created equal. So you don't have that. So whenever animals are abused, we say animal cruelty. But when it comes to humans, we say human rights abuses, because we assume that all humans have rights. But some of us are actually still fighting for our right to have rights. So in that condition, I don't talk about human rights abuse or violation. When you live in a country and you have an issue with the president and the worst thing that can happen is he bans you from the presidency, you are lucky. When you come to my country and have an issue with the president, you just run, disappear; you vanish from the universe, because they can still find you in Turkey. So people like myself, we don't get to live in Togo anymore. And people like myself, we don't get to live in the same place for more than a month, because we don't want to be traced. The way they abuse people, the type of cruelty that happens in all impunity under dictatorships are beyond human imagination. The stories of some of the activists that were killed, their bodies dumped in the sea, that were tortured to the point where they lost their hearing or their sight — those stories still haunt me. And sometimes, as an activist, I am less concerned about dying than how it will happen. Sometimes I just sit down and I imagine all scenarios. What are they going to do? Are they going to cut my ears first? Or are they going to cut my tongue because I'm always insulting them? It sounds cruel, but it is the reality. We live in a very cruel world. Dictators are cruel monsters, and I am not saying it to be nice. So yes, that is the final characteristic. The list goes on, but that's the final thing that I want to share about autocracies, so that you look at your country and see if there are risks there. It is important that you acknowledge the gains of freedom that you have today, because some people had to give their lives for you to have it. So don't take this for granted. But then at the same time, you also need to know that no country is actually destined to be oppressed, while at the same time, no country or no people are immune to oppression and dictatorship. Thank you. (Applause) |
The chaotic brilliance of artist Jean-Michel Basquiat | null | TED-Ed | A sky blue canvas ripped open by an enormous skull. Teeth bared through visceral slashes of oil and spray-paint. In 2017, this untitled artwork was auctioned off for over 110 million dollars. But it’s not the work of some old master. These strokes of genius belong to 21 year old black Brooklynite Jean-Michel Basquiat – one of America’s most charismatic painters, and currently, its highest sold. Born in 1960 to a Haitian father and a Puerto Rican mother, Basquiat spent his childhood making art and mischief in Boerum Hill. While he never attended art school, he learned by wandering through New York galleries, and listening to the music his father played at home. He drew inspiration from unexpected places, scribbling his own versions of cartoons, comic books and biblical scenes on scrap paper from his father’s office. But it was a medical encyclopedia that arguably exerted the most powerful influence on Basquiat. When young Jean-Michael was hit by a car, his mother brought a copy of "Grey’s Anatomy" to his hospital bed. It ignited a lifelong fascination with anatomy that manifested in the skulls, sinew and guts of his later work – which frequently explores both the power and vulnerability of marginalized bodies. By 17, he launched his first foray into the art world with his friend Al Diaz. They spray painted cryptic statements and symbols all over Lower Manhattan, signed with the mysterious moniker SAMO. These humorous, profound, and rebellious declarations were strategically scattered throughout Soho’s art scene. And after revealing himself as the artist, Basquiat leveraged SAMO’s success to enter the scene himself; selling postcards, playing clubs with his avant-garde band, and boldly seeking out his heroes. By 21, he’d turned to painting full time. His process was a sort of calculated improvisation. Like Beat writers who composed their work by shredding and reassembling scraps of writing, Basquiat used similar cut-up techniques to remix his materials. When he couldn't afford canvases, he fashioned them out of discarded wood he found on the street. He used oil stick, crayons, spray paint and pencil and pulled quotes from the menus, comic books and textbooks he kept open on the studio floor. He kept these sources open on his studio floor, often working on multiple projects at once. Pulling in splintered anatomy, reimagined historical scenes, and skulls transplanted from classical still-lives, Basquiat repurposed both present day experiences and art history into an inventive visual language. He worked as if inserting himself into the legacy of artists he borrowed from, producing collages that were just as much in conversation with art history as they were with each other. For instance, "Toussaint L’Overture versus Savonarola" and "Undiscovered Genius of the Mississippi Delta" offer two distinct visions of Basquiat’s historical and contemporary concerns. But they echo each other in the details, such as the reappearing head that also resurfaces in "PPCD." All these pieces form a network that offers physical evidence of Basquiat’s restless and prolific mind. These chaotic canvases won rapid acclaim and attention. But despite his increasingly mainstream audience, Basquiat insisted on depicting challenging themes of identity and oppression. Marginalized figures take center stage, such as prisoners, cooks and janitors. His obsession with bodies, history, and representation can be found in works evoking the Atlantic slave trade and African history, as well as pieces focusing on contemporary race relations. In less than a decade, Basquiat made thousands of paintings and drawings- along with sculpture, fragments of poetry and music. His output accelerated alongside his meteoric rise to fame, but his life and work were cut tragically short when he died from a drug overdose at the age of 27. After his death, Basquiat’s work only increased in value- but the energy and flair of his pieces have impacted much more than their financial worth. Today, his influence swirls around us in music, poetry, fashion and film- and his art retains the power to shock, inspire, and get under our skin. |
Can you solve "Einstein's Riddle"? | null | TED-Ed | Before he turned physics upside down, a young Albert Einstein supposedly showed off his genius by devising a complex riddle involving this list of clues. Can you resist tackling a brain teaser written by one of the smartest people in history? Let's give it a shot. The world's rarest fish has been stolen from the city aquarium. The police have followed the scent to a street with five identical looking houses. But they can't search all the houses at once, and if they pick the wrong one, the thief will know they're on his trail. It's up to you, the city's best detective, to solve the case. When you arrive on the scene, the police tell you what they know. One: each house's owner is of a different nationality, drinks a different beverage, and smokes a different type of cigar. Two: each house's interior walls are painted a different color. Three: each house contains a different animal, one of which is the fish. After a few hours of expert sleuthing, you gather some clues. It may look like a lot of information, but there's a clear logical path to the solution. Solving the puzzle will be a lot like Sudoku, so you may find it helpful to organize your information in a grid, like this. Pause the video on the following screen to examine your clues and solve the riddle. Answer in: 3 2 1 To start, you fill in the information from clues eight and nine. Immediately, you also realize that since the Norwegian is at the end of the street, there's only one house next to him, which must be the one with the blue walls in clue fourteen. Clue five says the green-walled house's owner drinks coffee. It can't be the center house since you already know its owner drinks milk, but it also can't be the second house, which you know has blue walls. And since clue four says the green-walled house must be directly to the left of the white-walled one, it can't be the first or fifth house either. The only place left for the green-walled house with the coffee drinker is the fourth spot, meaning the white-walled house is the fifth. Clue one gives you a nationality and a color. Since the only column missing both these values is the center one, this must be the Brit's red-walled home. Now that the only unassigned wall color is yellow, this must be applied to the first house, where clue seven says the Dunhill smoker lives. And clue eleven tells you that the owner of the horse is next door, which can only be the second house. The next step is to figure out what the Norwegian in the first house drinks. It can't be tea, clue three tells you that's the Dane. As per clue twelve, it can't be root beer since that person smokes Bluemaster, and since you already assigned milk and coffee, it must be water. From clue fifteen, you know that the Norwegian's neighbor, who can only be in the second house, smokes Blends. Now that the only spot in the grid without a cigar and a drink is in the fifth column, that must be the home of the person in clue twelve. And since this leaves only the second house without a drink, the tea-drinking Dane must live there. The fourth house is now the only one missing a nationality and a cigar brand, so the Prince-smoking German from clue thirteen must live there. Through elimination, you can conclude that the Brit smokes Pall Mall and the Swede lives in the fifth house, while clue six and clue two tell you that these two have a bird and a dog, respectively. Clue ten tells you that the cat owner lives next to the Blend-smoking Dane, putting him in the first house. Now with only one spot left on the grid, you know that the German in the green-walled house must be the culprit. You and the police burst into the house, catching the thief fish-handed. While that explanation was straightforward, solving puzzles like this often involves false starts and dead ends. Part of the trick is to use the process of elimination and lots of trial and error to hone in on the right pieces, and the more logic puzzles you solve, the better your intuition will be for when and where there's enough information to make your deductions. And did young Einstein really write this puzzle? Probably not. There's no evidence he did, and some of the brands mentioned are too recent. But the logic here is not so different from what you'd use to solve equations with multiple variables, even those describing the nature of the universe. |
The three different ways mammals give birth | null | TED-Ed | What do these animals have in common? More than you might think. Along with over 5,000 other species, they're mammals, or members of class mammalia. All mammals are vertebrates, meaning they have backbones. But mammals are distinguished from other vertebrates by a number of shared features. That includes warm blood, body hair or fur, the ability to breathe using lungs, and nourishing their young with milk. But despite these similarities, these creatures also have many biological differences, and one of the most remarkable is how they give birth. Let's start with the most familiar, placental mammals. This group includes humans, cats, dogs, giraffes, and even the blue whale, the biggest animal on Earth. Its placenta, a solid disk of blood-rich tissue, attaches to the wall of the uterus to support the developing embryo. The placenta is what keeps the calf alive during pregnancy. Directly connected to the mother's blood supply, it funnels nutrients and oxygen straight into the calf's body via the umbilical cord, and also exports its waste. Placental mammals can spend far longer inside the womb than other mammals. Baby blue whales, for instance, spend almost a full year inside their mother. The placenta keeps the calf alive right up until its birth, when the umbilical cord breaks and the newborn's own respiratory, circulatory, and waste disposal systems take over. Measuring about 23 feet, a newborn calf is already able to swim. It will spend the next six months drinking 225 liters of its mothers thick, fatty milk per day. Meanwhile, in Australia, you can find a second type of mammal - marsupials. Marsupial babies are so tiny and delicate when they're born that they must continue developing in the mother's pouch. Take the quoll, one of the world's smallest marsupials, which weighs only 18 milligrams at birth, the equivalent of about 30 sugar grains. The kangaroo, another marsupial, gives birth to a single jelly bean-sized baby at a time. The baby crawls down the middle of the mother's three vaginas, then must climb up to the pouch, where she spends the next 6-11 months suckling. Even after the baby kangaroo leaves this warm haven, she'll return to suckle milk. Sometimes, she's just one of three babies her mother is caring for. A female kangaroo can often simultaneously support one inside her uterus and another in her pouch. In unfavorable conditions, female kangaroos can pause their pregnancies. When that happens, she's able to produce two different kinds of milk, one for her newborn, and one for her older joey. The word mammalia means of the breast, which is a bit of a misnomer because while kangaroos do produce milk from nipples in their pouches, they don't actually have breasts. Nor do monotremes, the third and arguably strangest example of mammalian birth. There were once hundreds of monotreme species, but there are only five left: four species of echidnas and the duck-billed platypus. The name monotreme means one hole referring to the single orifice they use for reproduction, excretion, and egg-laying. Like birds, reptiles, fish, dinosaurs, and others, these species lay eggs instead of giving birth to live young. Their eggs are soft-shelled, and when their babies hatch, they suckle milk from pores on their mother's body until they're large enough to feed themselves. Despite laying eggs and other adaptations that we associate more with non-mammals, like the duck-bill platypus's webbed feet, bill, and the venomous spur males have on their feet, they are, in fact, mammals. That's because they share the defining characteristics of mammalia and are evolutionarily linked to the rest of the class. Whether placental, marsupial, or monotreme, each of these creatures and its unique birthing methods, however bizarre, have succeeded for many millennia in bringing new life and diversity into the mammal kingdom. |
Why do animals have such different lifespans? | null | TED-Ed | For the microscopic lab worm, C. elegans life equates to just a few short weeks on Earth. Compare that with the tortoise, which can age to more than 100 years. Mice and rats reach the end of their lives after just four years, while for the bowhead whale, Earth's longest-lived mammal, death can come after 200. Like most living things, the vast majority of animals gradually degenerate after reaching sexual maturity in the process known as aging. But what does it really mean to age? The drivers behind this process are varied and complicated, but aging is ultimately caused by cell death and dysfunction. When we're young, we constantly regenerate cells in order to replace dead and dying ones. But as we age, this process slows down. In addition, older cells don't perform their functions as well as young ones. That makes our bodies go into a decline, which eventually results in disease and death. But if that's consistently true, why the huge variance in aging patterns and lifespan within the animal kingdom? The answer lies in several factors, including environment and body size. These can place powerful evolutionary pressures on animals to adapt, which in turn makes the aging process different across species. Consider the cold depths of the Atlantic and Arctic Seas, where Greenland sharks can live to over 400 years, and the Arctic clam known as the quahog can live up to 500. Perhaps the most impressive of these ocean-dwelling ancients is the Antarctic glass sponge, which can survive over 10,000 years in frigid waters. In cold environments like these, heartbeats and metabolic rates slow down. Researchers theorize that this also causes a slowing of the aging process. In this way, the environment shapes longevity. When it comes to size, it's often, but not always, the case that larger species have a longer lifespan than smaller ones. For instance, an elephant or whale will live much longer than a mouse, rat, or vole, which in turn have years on flies and worms. Some small animals, like worms and flies, are also limited by the mechanics of their cell division. They're mostly made up of cells that can't divide and be replaced when damaged, so their bodies expire more quickly. And size is a powerful evolutionary driver in animals. Smaller creatures are more prone to predators. A mouse, for instance, can hardly expect to survive more than a year in the wild. So, it has evolved to grow and reproduce more rapidly, like an evolutionary defense mechanism against its shorter lifespan. Larger animals, by contrast, are better at fending off predators, and so they have the luxury of time to grow to large sizes and reproduce multiple times during their lives. Exceptions to the size rule include bats, birds, moles, and turtles, but in each case, these animals have other adaptations that allow them to escape predators. But there are still cases where animals with similar defining features, like size and habitat, age at completely different rates. In these cases, genetic differences, like how each organism's cells respond to threats, often account for the discrepancies in longevity. So it's the combination of all these factors playing out to differing degrees in different animals that explains the variability we see in the animal kingdom. So what about us? Humans currently have an average life expectancy of 71 years, meaning that we're not even close to being the longest living inhabitants on Earth. But we are very good at increasing our life expectancy. In the early 1900s, humans only lived an average of 50 years. Since then, we've learned to adapt by managing many of the factors that cause deaths, like environmental exposure and nutrition. This, and other increases in life expectancy make us possibly the only species on Earth to take control over our natural fate. |
Why do we itch? | null | TED-Ed | You're standing at the ready inside the goal when suddenly, you feel an intense itch on the back of your head. We've all experienced the annoyance of an inconvenient itch, but have you ever pondered why we itch in the first place? The average person experiences dozens of individual itches each day. They can be triggered by all sorts of things, including allergic reactions, dryness, and even some diseases. And then there are the mysterious ones that pop up for no reason at all, or just from talking about itching. You're scratching your head right now, aren't you? Anyhow, let's take one of the most common sources: bug bites. When a mosquito bites you, it releases a compound into your body called an anticoagulant that prevents your blood from clotting. That compound, which we're mildly allergic to, triggers the release of histamine, a chemical that makes our capillaries swell. This enables increased blood flow, which helpfully accelerates the body's immune response to this perceived threat. That explains the swelling, and it's the same reason pollen can make your eyes puff up. Histamine also activates the nerves involved in itching, which is why bug bites make you scratch. But the itchy sensation itself isn't yet fully understood. In fact, much of what we do know comes from studying the mechanics of itching in mice. Researchers have discovered that itch signals in their skin are transmitted via a subclass of the nerves that are associated with pain. These dedicated nerves produce a molecule called natriuretic polypetide B, which triggers a signal that's carried up the spinal cord to the brain, where it creates the feeling of an itch. When we scratch, the action of our fingernails on the skin causes a low level pain signal that overrides the itching sensation. It's almost like a distraction, which creates the sensation of relief. But is there actually an evolutionary purpose to the itch, or is it simply there to annoy us? The leading theory is that our skin has evolved to be acutely aware of touch so that we're equipped to deal with risks from the outside world. Think about it. Our automatic scratching response would dislodge anything harmful that's potentially lurking on our skin, like a harmful sting, a biting insect, or the tendrils of a poisonous plant. This might explain why we don't feel itching inside our bodies, like in our intestines, which is safe from these external threats, though imagine how maddening that would be. In some people, glitches in the pathways responsible for all of this can cause excessive itching that can actually harm their health. One extreme example is a psychological condition called delusory parasitosis where people believe their bodies are infested with mites or fleas scurrying over and under their skin, making them itch incessantly. Another phenomenon called phantom itching can occur in patients who've had amputations. Because this injury has so severely damaged the nervous system, it confuses the body's normal nerve signaling and creates sensations in limbs that are no longer there. Doctors are now finding ways to treat these itching anomalies. In amputees, mirrors are used to reflect the remaining limb, which the patient scratches. That creates an illusion that tricks the brain into thinking the imaginary itch has been satisfied. Oddly enough, that actually works. Researchers are also searching for the genes involved in itching and developing treatments to try and block the pathway of an itch in extreme cases. If having an unscratchable itch feels like your own personal hell, Dante agreed. The Italian poet wrote about a section of hell where people were punished by being left in pits to itch for all eternity. |
The uncertain location of electrons | null | TED-Ed | You probably know that all stuff is made up of atoms and that an atom is a really, really, really, really tiny particle. Every atom has a core, which is made up of at least one positively charged particle called a proton, and in most cases, some number of neutral particles called neutrons. That core is surrounded by negatively charged particles called electrons. The identity of an atom is determined only by the number of protons in its nucleus. Hydrogen is hydrogen because it has just one proton, carbon is carbon because it has six, gold is gold because it has 79, and so on. Indulge me in a momentary tangent. How do we know about atomic structure? We can't see protons, neutrons, or electrons. So, we do a bunch of experiments and develop a model for what we think is there. Then we do some more experiments and see if they agree with the model. If they do, great. If they don't, it might be time for a new model. We've had lots of very different models for atoms since Democritus in 400 BC, and there will almost certainly be many more to come. Okay, tangent over. The cores of atoms tend to stick together, but electrons are free to move, and this is why chemists love electrons. If we could marry them, we probably would. But electrons are weird. They appear to behave either as particles, like little baseballs, or as waves, like water waves, depending on the experiment that we perform. One of the weirdest things about electrons is that we can't exactly say where they are. It's not that we don't have the equipment, it's that this uncertainty is part of our model of the electron. So, we can't pinpoint them, fine. But we can say there's a certain probability of finding an electron in a given space around the nucleus. And that means that we can ask the following question: If we drew a shape around the nucleus such that we would be 95% sure of finding a given electron within that shape, what would it look like? Here are a few of these shapes. Chemists call them orbitals, and what each one looks like depends on, among other things, how much energy it has. The more energy an orbital has, the farther most of its density is from the nucleus. By they way, why did we pick 95% and not 100%? Well, that's another quirk of our model of the electron. Past a certain distance from the nucleus, the probability of finding an electron starts to decrease more or less exponentially, which means that while it will approach zero, it'll never actually hit zero. So, in every atom, there is some small, but non-zero, probability that for a very, very short period of time, one of its electrons is at the other end of the known universe. But mostly electrons stay close to their nucleus as clouds of negative charged density that shift and move with time. How electrons from one atom interact with electrons from another determines almost everything. Atoms can give up their electrons, surrendering them to other atoms, or they can share electrons. And the dynamics of this social network are what make chemistry interesting. From plain old rocks to the beautiful complexity of life, the nature of everything we see, hear, smell, taste, touch, and even feel is determined at the atomic level. |
What is depression? | null | TED-Ed | Depression is the leading cause of disability in the world. In the United States, close to 10% of adults struggle with depression. But because it's a mental illness, it can be a lot harder to understand than, say, high cholesterol. One major source of confusion is the difference between having depression and just feeling depressed. Almost everyone feels down from time to time. Getting a bad grade, losing a job, having an argument, even a rainy day can bring on feelings of sadness. Sometimes there's no trigger at all. It just pops up out of the blue. Then circumstances change, and those sad feelings disappear. Clinical depression is different. It's a medical disorder, and it won't go away just because you want it to. It lingers for at least two consecutive weeks, and significantly interferes with one's ability to work, play, or love. Depression can have a lot of different symptoms: a low mood, loss of interest in things you'd normally enjoy, changes in appetite, feeling worthless or excessively guilty, sleeping either too much or too little, poor concentration, restlessness or slowness, loss of energy, or recurrent thoughts of suicide. If you have at least five of those symptoms, according to psychiatric guidelines, you qualify for a diagnosis of depression. And it's not just behavioral symptoms. Depression has physical manifestations inside the brain. First of all, there are changes that could be seen with the naked eye and X-ray vision. These include smaller frontal lobes and hippocampal volumes. On a more microscale, depression is associated with a few things: the abnormal transmission or depletion of certain neurotransmitters, especially serotonin, norepinephrine, and dopamine, blunted circadian rhythms, or specific changes in the REM and slow-wave parts of your sleep cycle, and hormone abnormalities, such as high cortisol and deregulation of thyroid hormones. But neuroscientists still don't have a complete picture of what causes depression. It seems to have to do with a complex interaction between genes and environment, but we don't have a diagnostic tool that can accurately predict where or when it will show up. And because depression symptoms are intangible, it's hard to know who might look fine but is actually struggling. According to the National Institute of Mental Health, it takes the average person suffering with a mental illness over ten years to ask for help. But there are very effective treatments. Medications and therapy complement each other to boost brain chemicals. In extreme cases, electroconvulsive therapy, which is like a controlled seizure in the patient's brain, is also very helpful. Other promising treatments, like transcranial magnetic stimulation, are being investigated, too. So, if you know someone struggling with depression, encourage them, gently, to seek out some of these options. You might even offer to help with specific tasks, like looking up therapists in the area, or making a list of questions to ask a doctor. To someone with depression, these first steps can seem insurmountable. If they feel guilty or ashamed, point out that depression is a medical condition, just like asthma or diabetes. It's not a weakness or a personality trait, and they shouldn't expect themselves to just get over it anymore than they could will themselves to get over a broken arm. If you haven't experienced depression yourself, avoid comparing it to times you've felt down. Comparing what they're experiencing to normal, temporary feelings of sadness can make them feel guilty for struggling. Even just talking about depression openly can help. For example, research shows that asking someone about suicidal thoughts actually reduces their suicide risk. Open conversations about mental illness help erode stigma and make it easier for people to ask for help. And the more patients seek treatment, the more scientists will learn about depression, and the better the treatments will get. |
How the heart actually pumps blood | null | TED-Ed | For most of history, humans had no idea what purpose the heart served. In fact, the organ so confused Leonardo da Vinci, that he gave up studying it. Although everyone could feel their own heart beating, it wasn't always clear what each thump was achieving. Now we know that the heart pumps blood. But that fact wasn't always obvious, because if a heart was exposed or taken out, the body would perish quickly. It's also impossible to see through the blood vessels, and even if that were possible, the blood itself is opaque, making it difficult to see the heart valves working. Even in the 21st century, only a few people in surgery teams have actually seen a working heart. Internet searches for heart function, point to crude models, diagrams or animations that don't really show how it works. It's as if there has been a centuries old conspiracy amongst teachers and students to accept that heart function cannot be demonstrated. Meaning that the next best thing is simply to cut it open and label the parts. That way students might not fully grasp the way it works, but can superficially understand it, learning such concepts as the heart is a four-chambered organ, or potentially misleading statements like, mammals have a dual-circulation: one with blood going to the lungs and back, and another to the body and back. In reality, mammals have a figure-eight circulation. Blood goes from one heart pump to the lungs, back to the second heart pump, which sends it to the body, and then back to the first pump. That's an important difference because it marks two completely different morphologies. This confusion makes many students wary of the heart in biology lessons, thinking it signals an intimidating subject full of complicated names and diagrams. Only those who end up studying medicine compeltely understand how it all actually works. That's when its functions become apparent as medics get to observe the motion of the heart's valves. So, let's imagine you're a medic for a day. What you'll need to get started is a whole fresh heart, like one from a sheep or pig. Immerse this heart in water and you'll see that it doesn't pump when squeezed by hand. That's because water doesn't enter the heart cleanly enough for the pumping mechanism to work. We can solve this problem in an extraordinarly simple way. Simply identify the two atria and cut them off, trimming them down to the tops of the ventricles. This makes the heart look less complicated because the atria have several incoming veins attached. So without them there, the only vessels remaining are the two major heart arteries: the aorta and pulmonary artery, which rise like white columns from between the ventricles. It looks — and really is — very simple. If you run water into the right ventricle from a tap (the left also works, but less spectacularly), you'll see that the ventricular valve tries to close against the incoming stream. And then ventricle inflates with water. Squeeze the ventricle and a stream of water squirts out of the pulmonary artery. The ventricular valves, called the tricuspid in the right ventricle and the mitral in the left, can be seen through the clear water opening and closing like parachutes as the ventricle is rhythmically squeezed. This flow of water mimics the flow of blood in life. The valves are completely efficient. You'll notice they don't leak at all when the ventricles are squeezed. Over time, they also close against each other with very little wear and tear, which explains how this mechanism continues to work seamlessly for more than 2 billion beats a heart gives in its lifetime. Now, anyone studying the heart can hold one in their hands, make it pump for real and watch the action unfold. So place your hand above your own and feel its rhymic beat. Understanding how this dependable inner pump works gives new resonance to the feeling you get when you run a race, drink too much caffeine or catch the eye of the one you love. |
The fundamentals of space-time: Part 2 | null | TED-Ed | Light: it's the fastest thing in the universe, but we can still measure its speed if we slow down the animation, we can analyze light's motion using a space-time diagram, which takes a flipbook of animation panels, and turns them on their side. In this lesson, we'll add the single experimental fact that whenever anyone measures just how fast light moves, they get the same answer: 299,792,458 meters every second, which means that when we draw light on our space-time diagram, it's world line always has to appear at the same angle. But we saw previously that speed, or equivalently world line angles, change when we look at things from other people's perspective. To explore this contradiction, let's see what happens if I start moving while I stand still and shine the laser at Tom. First, we'll need to construct the space-time diagram. Yes, that means taking all of the different panels showing the different moments in time and stacking them up. From the side, we see the world line of the laser light at its correct fixed angle, just as before. So far, so good. But that space-time diagram represents Andrew's perspective. What does it look like to me? In the last lesson, we showed how to get Tom's perspective moving all the panels along a bit until his world line is completely vertical. But look carefully at the light world line. The rearrangement of the panels means it's now tilted over too far. I'd measure light traveling faster than Andrew would. But every experiment we've ever done, and we've tried very hard, says that everyone measures light to have a fixed speed. So let's start again. In the 1900s, a clever chap named Albert Einstein worked out how to see things properly, from Tom's point of view, while still getting the speed of light right. First, we need to glue together the separate panels into one solid block. This gives us our space-time, turning space and time into one smooth, continuous material. And now, here is the trick. What you do is stretch your block of space-time along the light world line, then squash it by the same amount, but at right angles to the light world line, and abracadabra! Tom's world line has gone vertical, so this does represent the world from his point of view, but most importantly, the light world line has never changed its angle, and so light will be measured by Tom going at the correct speed. This superb trick is known as a Lorentz transformation. Yeah, more than a trick. Slice up the space-time into new panels and you have the physically correct animation. I'm stationary in the car, everything else is coming past me and the speed of light works out to be that same fixed value that we know everyone measures. On the other hand, something strange has happened. The fence posts aren't spaced a meter apart anymore, and my mom will be worried that I look a bit thin. But that's not fair. Why don't I get to look thin? I thought physics was supposed to be the same for everyone. Yes, no, it is, and you do. All that stretching and squashing of space-time has just muddled together what we used to think of separately as space and time. This particular squashing effect is known as Lorentz contraction. Okay, but I still don't look thin. No, yes, you do. Now that we know better about space-time, we should redraw what the scene looked like to me. To you, I appear Lorentz contracted. Oh but to you, I appear Lorentz contracted. Yes. Uh, well, at least it's fair. And speaking of fairness, just as space gets muddled with time, time also gets muddled with space, in an effect known as time dilation. No, at everyday speeds, such as Tom's car reaches, actually all the effects are much, much smaller than we've illustrated them. Oh, yet, careful experiments, for instance watching the behavior of tiny particles whizzing around the Large Hadron Collider confirmed that the effects are real. And now that space-time is an experimentally confirmed part of reality, we can get a bit more ambitious. What if we were to start playing with the material of space-time itself? We'll find out all about that in the next animation. |
The myth behind the Chinese zodiac | null | TED-Ed | What's your sign? In Western astrology, it's a constellation determined by when your birthday falls in the calendar. But according to the Chinese zodiac, or shēngxiào, it's your shǔxiàng, meaning the animal assigned to your birth year. And of the many myths explaining these animal signs and their arrangement, the most enduring one is that of the Great Race. As the story goes, Yù Dì, or Jade Emperor, Ruler of the Heavens, wanted to devise a way to measure time, so he organized a race. The first twelve animals to make it across the river would earn a spot on the zodiac calendar in the order they arrived. The rat rose with the sun to get an early start, but on the way to the river, he met the horse, the tiger, and the ox. Because the rat was small and couldn't swim very well, he asked the bigger animals for help. While the tiger and horse refused, the kind-hearted ox agreed to carry the rat across. Yet, just as they were about to reach the other side, the rat jumped off the ox's head and secured first place. The ox came in second, with the powerful tiger right behind him. The rabbit, too small to battle the current, nimbly hopped across stones and logs to come in fourth. Next came the dragon, who could have flown directly across, but stopped to help some creatures she had encountered on the way. After her came the horse, galloping across the river. But just as she got across, the snake slithered by. The startled horse reared back, letting the snake sneak into sixth place. The Jade Emperor looked out at the river and spotted the sheep, the monkey, and the rooster all atop a raft, working together to push it through the weeds. When they made it across, the trio agreed to give eighth place to the sheep, who had been the most comforting and harmonious of them, followed by the monkey and the rooster. Next came the dog, scrambling onto the shore. He was a great swimmer, but frolicked in the water for so long that he only managed to come in eleventh. The final spot was claimed by the pig, who had gotten hungry and stopped to eat and nap before finally waddling across the finish line. And so, each year is associated with one of the animals in this order, with the cycle starting over every 60 years. Why 60 and not twelve? Well, the traditional Chinese calendar is made up of two overlapping systems. The animals of the zodiac are associated with what's called the Twelve Earthly Branches, or shí'èrzhī. Another system, the Ten Heavenly Stems, or tiāngān, is linked with the five classical elements of metal, xīn, wood, mù, water, shuǐ, fire, huǒ, and earth, tǔ. Each element is assigned yīn or yáng, creating a ten-year cycle. When the twelve animals of the Earthly Branches are matched with the five elements plus the yīn or the yáng of the Heavenly Stems, it creates 60 years of different combinations, known as a sexagenary cycle, or gānzhī. So someone born in 1980 would have the sign of yáng metal monkey, while someone born in 2007 would be yīn fire pig. In fact, you can also have an inner animal based on your birth month, a true animal based on your birth date, and a secret animal based on your birth hour. It was the great race that supposedly determined which animals were enshrined in the Chinese zodiac, but as the system spread through Asia, other cultures made changes to reflect their communities. So if you consult the Vietnamese zodiac, you may discover that you're a cat, not a rabbit, and if you're in Thailand, a mythical snake called a Naga replaces the dragon. So whether or not you place stock in what the zodiac says about you as an individual, it certainly reveals much about the culture it comes from. |
What's the fastest way to alphabetize your bookshelf? | null | TED-Ed | You work at the college library. You're in the middle of a quiet afternoon when suddenly a shipment of 1,280 different books arrives. The books have been dropped of in one long straight line, but they're all out of order, and the automatic sorting system is broken. To make matters worse, classes start tomorrow, which means that first thing in the morning, students will show up in droves looking for these books. How can you get them all sorted in time? One way would be to start at one end of the line with the first pair of books. If the first two books are in order, then leave them as they are. Otherwise, swap them. Then, look at the second and third books, repeat the process, and continue until you reach the end of the line. At some point, you'll come across the book that should be last, and keep swapping it with every subsequent book, moving it down the line until it reaches the end where it belongs. Then, start from the beginning and repeat the process to get the second to last book in its proper place, and keep going until all books are sorted. This approach is called Bubble Sort. It's simple but slow. You'd make 1,279 comparisons in the first round, then 1,278, and so on, adding up to 818,560 comparisons. If each took just one second, the process would take over nine days. A second strategy would be to start by sorting just the first two books. Then, take the third book and compare it with the book in the second spot. If it belongs before the second book, swap them, then compare it with the book in the first spot, and swap again if needed. Now you've sorted the first three books. Keep adding one book at a time to the sorted sub-line, comparing and swapping the new book with the one before it until it's correctly placed among the books sorted so far. This is called Insertion Sort. Unlike Bubble Sort, it usually doesn't require comparing every pair of books. On average, we'd expect to only need to compare each book to half of the books that came before it. In that case, the total number of comparisons would be 409,280, taking almost five days. You're still doing way too many comparisons. Here's a better idea. First, pick a random book. Call it the partition and compare it to every other book. Then, divide the line by placing all the books that come before the partition on its left and all the ones that come after it on its right. You've just saved loads of time by not having to compare any of the books on the left to any of the ones on the right ever again. Now, looking only at the books on the left, you can again pick a random partition book and separate those books that come before it from those that come after it. You can keep creating sub-partitions like this until you have a bunch of small sub-lines, each of which you'd sort quickly using another strategy, like Insertion Sort. Each round of partitioning requires about 1,280 comparisons. If your partitions are pretty balanced, dividing the books into 128 sub-lines of ten would take about seven rounds, or 8,960 seconds. Sorting these sub-lines would add about 22 seconds each. All in all, this method known as QuickSort could sort the books in under three and a half hours. But there's a catch. Your partitions could end up lopsided, saving no time at all. Luckily, this rarely happens. That's why QuickSort is one of the most efficient strategies used by programmers today. They use it for things like sorting items in an online store by price, or creating a list of all the gas stations close to a given location sorted by distance. In your case, you're done quick sorting with time to spare. Just another high-stakes day in the library. |
Can you solve the locker riddle? | null | TED-Ed | Your rich, eccentric uncle just passed away, and you and your 99 nasty relatives have been invited to the reading of his will. He wanted to leave all of his money to you, but he knew that if he did, your relatives would pester you forever. So he is banking on the fact that he taught you everything you need to know about riddles. Your uncle left the following note in his will: "I have created a puzzle. If all 100 of you answer it together, you will share the money evenly. However, if you are the first to find the pattern and solve the problem without going through all of the leg work, you will get the entire inheritance all to yourself. Good luck." The lawyer takes you and your 99 relatives to a secret room in the mansion that contains 100 lockers, each hiding a single word. He explains: Every relative is assigned a number from 1 to 100. Heir 1 will open every locker. Heir 2 will then close every second locker. Heir 3 will change the status of every third locker, specifically if it's open, she'll close it, but if it's closed, she'll open it. This pattern will continue until all 100 of you have gone. The words in the lockers that remain open at the end will help you crack the code for the safe. Before cousin Thaddeus can even start down the line, you step forward and tell the lawyer you know which lockers will remain open. But how? Pause the video now if you want to figure it out for yourself! Answer in: 3 Answer in: 2 Answer in: 1 The key is realizing that the number of times a locker is touched is the same as the number of factors in the locker number. For example, in locker #6, Person 1 will open it, Person 2 will close it, Person 3 will open it, and Person 6 will close it. The numbers 1, 2, 3, and 6 are the factors of 6. So when a locker has an even number of factors it will remain closed, and when it has an odd number of factors, it will remain open. Most of the lockers have an even number of factors, which makes sense because factors naturally pair up. In fact, the only lockers that have an odd number of factors are perfect squares because those have one factor that when multiplied by itself equals the number. For Locker 9, 1 will open it, 3 will close, and 9 will open it. 3 x 3 = 9, but the 3 can only be counted once. Therefore, every locker that is a perfect square will remain open. You know that these ten lockers are the solution, so you open them immediately and read the words inside: "The code is the first five lockers touched only twice." You realize that the only lockers touched twice have to be prime numbers since each only has two factors: 1 and itself. So the code is 2-3-5-7-11. The lawyer brings you to the safe, and you claim your inheritance. Too bad your relatives were always too busy being nasty to each other to pay attention to your eccentric uncle's riddles. |
History's deadliest colors | null | TED-Ed | In 1898, Marie and Pierre Curie discovered radium. Claimed to have restorative properties, radium was added to toothpaste, medicine, water, and food. A glowing, luminous green, it was also used in beauty products and jewelry. It wasn't until the mid-20th century we realized that radium's harmful effects as a radioactive element outweighed its visual benefits. Unfortunately, radium isn't the only pigment that historically seemed harmless or useful but turned out to be deadly. That lamentable distinction includes a trio of colors and pigments that we've long used to decorate ourselves and the things we make: white, green, and orange. Our story begins with white. As far back as the 4th century BCE, the Ancient Greeks treated lead to make the brilliant white pigment we know today. The problem? In humans, lead is directly absorbed into the body and distributed to the blood, soft tissues, and mineralized tissues. Once in the nervous system, lead mimics and disrupts the normal functions of calcium, causing damages ranging from learning disabilities to high blood pressure. Yet the practice of using this toxic pigment continued across time and cultures. Lead white was the only practical choice for white oil or tempera paint until the 19th century. To make their paint, artists would grind a block of lead into powder, exposing highly toxic dust particles. The pigment's liberal use resulted in what was known as painter's colic, or what we'd now call lead poisoning. Artists who worked with lead complained of palseys, melancholy, coughing, enlarged retinas, and even blindness. But lead white's density, opacity, and warm tone were irresistible to artists like Vermeer, and later, the Impressionists. Its glow couldn't be matched, and the pigment continued to be widely used until it was banned in the 1970s. As bad as all that sounds, white's dangerous effects pale in comparison to another, more wide-spread pigment, green. Two synthetic greens called Scheele's Green and Paris Green were first introduced in the 18th century. They were far more vibrant and flashy than the relatively dull greens made from natural pigments, so they quickly became popular choices for paint as well as dye for textiles, wallpaper, soaps, cake decorations, toys, candy, and clothing. These green pigments were made from a compound called cupric hydrogen arsenic. In humans, exposure to arsenic can damage the way cells communicate and function. And high levels of arsenic have been directly linked to cancer and heart disease. As a result, 18th century fabric factory workers were often poisoned, and women in green dresses reportedly collapsed from exposure to arsenic on their skin. Bed bugs were rumored not to live in green rooms, and it's even been speculated that Napoleon died from slow arsenic poisoning from sleeping in his green wallpapered bedroom. The intense toxicity of these green stayed under wraps until the arsenic recipe was published in 1822. And a century later, it was repurposed as an insecticide. Synthetic green was probably the most dangerous color in widespread use, but at least it didn't share radium's property of radioactivity. Another color did, though - orange. Before World War II, it was common for manufacturers of ceramic dinnerware to use uranium oxide in colored glazes. The compound produced brilliant reds and oranges, which were appealing attributes, if not for the radiation they emitted. Of course, radiation was something we were unaware of until the late 1800s, let alone the associated cancer risks, which we discovered much later. During World War II, the U.S. government confiscated all uranium for use in bomb development. However, the atomic energy commission relaxed these restrictions in 1959, and depleted uranium returned to ceramics and glass factory floors. Orange dishes made during the next decade may still have some hazardous qualities on their surfaces to this day. Most notably, vintage fiestaware reads positive for radioactivity. And while the levels are low enough that they don't officially pose a health risk if they're on a shelf, the U.S. EPA warns against eating food off of them. Though we still occasionally run into issues with synthetic food dyes, our scientific understanding has helped us prune hazardous colors out of our lives. |
Why we need to stop obsessing over World War II | null | TEDxAthens | Hello everybody. Audience: Hello. Keith Lowe: Fantastic! This is like a schoolroom or something. (Laughter) My name is Keith Lowe. I am an historian of the Second World War and its aftermath, and even I have to admit that I've chosen a pretty crowded field to study. I went into my local bookshop recently, and this is what I saw. Thousands of books about the Second World War are published every year, and, actually, to tell you the truth, this is only a very tiny selection of what's on offer. We in the West, and, actually, increasingly people in other parts of the world too, we are just a little bit obsessed by the Second World War. We have whole TV stations which seem devoted to it. We write books about it, we write novels about it, we make films about it. We have university courses which are devoted to the Second World War. Whole museums are built to house World War II collections. Even our politicians like to get in on this act. Whenever there is an important anniversary of the war, they tend to gather and commemorate it, and make speeches. So, for example, at the 70th anniversary of the D-Day landings, June 2014, 17 heads of state took time out of their schedules to come and spend the day on the Normandy beaches. Seventeen! This included people like Barack Obama, Vladimir Putin, the chancellor of Germany, Angela Merkel, and so on. From my own country, we sent not only our Prime Minister, but also Queen Elisabeth II, who is - I mean, she is now in her nineties and largely retired from public life. What other international event can do all this? Even international summits struggle to get so many world leaders into one place at the same time. My question is: Why? What is it that all these world leaders, in fact what is it that all of us, think it is that we're remembering? Why are we all so obsessed by the the Second World War? You might think that somebody like me would be pretty pleased with this situation. As long as the World War II industry is booming, I am always going to have a job, right? But actually there is something about it that I find really a little bit disturbing, and I don't know whether that is just because I have an inherent distrust of a lot of politicians, or whether it's because I've been trained to always question everything. But it strikes me that a lot of the rhetoric that gets thrown around about the Second World War, particularly by people like politicians and journalists and diplomats and so on, a lot of it doesn't seem to be about the Second World War at all; it seems to be about something else. I'm not sure if I've exactly put my finger on precisely what that thing is, but it seems to be something like a way of fostering national pride, or just trying to get people to feel good about themselves. Along the way, it seems to me that the Second World War has been turned into a little bit of a cartoon, where everybody knows who the good guys were, and everybody knows who the bad guys were. There is precious little space left anymore for any of that difficult grey area in between. To give you some kind of an idea about what on earth it is I am going on about, let me tell you a story from my own country, from Britain. In Britain, we like to think we are the real heroes of the Second World War. We tell stories about how we stood alone against the Nazis, about how we endured the bombing of the Blitz; how we kept calm and carried on, and eventually fought our way back into Europe and liberated it. We still call the Second World War "Our Finest Hour", as if it is some kind of golden age in our history. So whenever there is any kind of anniversary, or important event based around the Second World War, we Brits really go for it. One of these events happened quite recently, in the summer of 2012, when we opened up a brand new war memorial right in the middle of central London. It was a memorial to the men of Bomber Command, the men who flew the planes over Germany, dropped bombs and so on. This is what it looks like. As you can see, it's not exactly a shy and retiring piece of architecture, it's actually quite huge. It's by far the largest war memorial that we have in London, and I can tell you there are a lot of war memorials in London. As you walk into this thing, there is an inscription which tells you that it's dedicated to the 55,000 men of Bomber Command who lost their lives during World War II. Now, when this first opened, in the summer of 2012, I went along to have a look, see what I thought of it, have a walk around. There is something really quite moving about it actually. You step in through these great big pillars, and, up on the wall, you can see carved into the stone, there is a quotation from Winston Churchill saying exactly how much we owe to these men who lost their lives. Parts of the memorial are built out of an actual World War II aircraft that was shot down during the war. So they put a lot of thought into this. It's actually really quite inspiring. So as I was walking around this monument, I couldn't help but feel this real surge of pride. I felt proud of these men who had given their lives for something that I hold dear. I felt proud of my country, I felt proud of the British way of life which had produced heroes like this. And yet, there was this little voice in the back of my head which just wouldn't go away because I know that 55,000 men of Bomber Command died during World War II, but I also know that 500,000 Germans died beneath the bombs that these men dropped. A lot of those Germans were Nazis, and I dare say that a lot of them probably deserved it. But the vast majority of these people were just ordinary men, women and children, just like you and me. Are any of these people at all mentioned on this memorial? Of course they are not. If you would suggest such a thing in the summer of 2012, you probably would have been lynched. The Germans were our enemies during the Second World War. You can't mention the Germans on a British national monument. And yet not to mention them, to pretend that somehow this didn't happen, or even worse, that somehow it doesn't matter, that too makes me feel a little bit uncomfortable. Okay, the Germans are a difficult problem, so let's just put them to one side for a minute, and let's think instead about the other nationalities. And here is where the story starts getting interesting. Because if there is one thing that we Brits always forget about the bomber war, it's the fact that we didn't only bomb Germany. More than a third of British and American bombs dropped on Europe during the war were dropped not on Germany but on those countries we were supposed to be liberating. As a consequence, 50,000 French civilians were killed by our bombs. 10,000 Dutch civilians were killed by our bombs. Are any of these people mentioned on this memorial? Of course they're not. And it was while I was thinking about that particular group, that it finally dawned on me - actually something I probably should have realized right from the start - which is that memorials like this aren't designed to tell the whole story; they are only designed to tell those parts of the story that make British people feel good about themselves. That's all very well and good, but it does come at a cost. And I couldn't help thinking when I was walking around this thing: This was the summer of 2012, this was the summer when the Olympic Games was coming to London. So at exactly the moment when the entire world was arriving in our city, the message that we were advertising was that we will remember our wartime dead, but we won't remember yours. It's like the exact opposite of the Olympic spirit. It's not only the British who do this, of course it's not. Every nation does it, the Americans, for example. The Americans like to call their wartime veterans "the greatest generation that any society has ever produced", as if they have some kind of monopoly on heroism or something. (Laughter) They backed it up with a thousand Hollywood movies full of square-jawed American heroes defeating evil in the name of truth and freedom. The Chinese are the same. You know that in 2013 alone, Chinese TV companies produced over 200 TV dramatizations about the Second World War, each of them telling almost an identical story. Only, of course, this time, it's the Japanese who are all the evil monsters, and the Chinese who are all selfless heroes. And, of course, I could say the same thing about the French or the Koreans or the Norwegians or the Greeks. We all do this. We all like to think that we were the heroes. We all like to think that we were the victims. But what we don't like to remember is those grey areas. And it's that which I find most uncomfortable about this, because, as far as I am concerned, it's the grey areas that make history interesting. In a sense, all good history is about the grey areas. But a lot of people don't seem to have time for complicated stories. They don't have time for difficult and uncomfortable emotions. In fact, I'm quickly coming to the conclusion that a lot of people don't really have time for history at all. What they really want is a myth. Now, you might ask yourselves: What does any of this matter? I mean, we all like a good story, don't we? If that story makes us feel good about ourselves, then so much the better. It's all in the past anyway, so what does it matter? But that's just the problem, isn't it? Because it's not all in the past. And there is a dark side to all of these stories and myths that can be really damaging. When the former Yugoslavia tore itself apart in the 1990s, it did so with World War II songs on its lips, and World War II atrocities in its heart. When the Ukraine crisis broke out in 2014, Ukrainians and Russians accused one another of acting like Nazis. And then, of course, Hillary Clinton weighed in and started comparing Vladimir Putin to Hitler. These sorts of comparisons don't do anything to foster rational debate. If you were in an argument with someone, the last thing that is going to calm things down is that you start accusing them of being a Nazi. If you don't believe me, next time you're in an argument with your wife or your husband, give it a try and see what kind of reaction you get. (Laughter) I can see some of you seem to have tried it. (Laughter) My point is that as soon as we start bringing the Second World War into any of our arguments, we get so sort of carried away with our own national myths that all we actually end up doing is stirring things back up again. Let me give you a couple of examples. Take this economic crisis which has rocked the world since 2008. Here we are in Athens, and you all know about the economic crisis. All across Southern Europe, people have been suffering a real austerity, and largely this has been imposed by the European Union. But it's not always the European Union that gets the blame for this. Quite often, as the largest and most powerful country in the union, it's Germany that gets the blame. Now, how has this been portrayed in the press? Have we had a calm, rational economic debate about it? This is the way that the Italian press portrayed the situation in 2012: "Quarto Reich." (Laughter) "The Fourth Reich." This is the Italian way of saying that modern-day Germany is no better than the Nazis, as if there is a direct link between World War II and today. And take a look at that picture. They've managed to dig something out that makes it look like Angela Merkel is making a Nazi salute. (Laughter) How about the Greek press? (Laughter) How have the Greeks portrayed it? Well, here is a Greek newspaper. (Laughter) from the same year, 2012, and you will notice a photograph of Angela Merkel once again, this time in a Nazi uniform. Obviously, it has been photoshopped. But what about that headline in red? "Memorandum macht frei." This is a direct reference to the motto that was written above the gates of the concentration camps in places like Auschwitz and Dachau. The implication here is that the whole of Greece is going to become like one giant German concentration camp as a consequence of the economic deal they've had to do. Now, this is the sort of thing that makes an historian like me want to just give up and go and become a window cleaner or something. (Laughter) I mean, it's historical nonsense. None of these headlines have anything to do with the Second World War at all. They are about a modern-day problem, a modern situation. The only reason to mention the Second World War is to provoke an emotional response. If I have one message that I want you to take away with you today, it is this: Whenever you hear a politician, or a journalist, or a diplomat, mention the Second World War, I want alarm bells to ring. Because when public figures speak about the Second World War, they are not talking about what actually happened, they're invoking a myth. So whenever you hear a politician mention the war, I want you to ask yourselves what it is he is really trying to do. Is he trying to inspire you? - In which case that is relatively harmless. Or is he trying to fill you with fear? Is he trying to draw people together? In which case, again, that is relatively harmless. Or is he really trying to drive people apart? And above all, I want you to remind yourselves, and to remind everybody you know, that the Second World War is over. (Laughter) We live in a different world, with different values and different problems. These problems will never be solved, and they certainly will never be solved peacefully, if all we can think to do is to resurrect the Second World War. You know, history is a messy business, particularly the history of the Second World War. It's not there to make us feel good about ourselves; it's often ugly and uncomfortable, and desperately complicated. It's full of those grey areas. If we could all just learn to accept that, then this world, our world, would be a much more peaceful place. Thank you. (Applause) |
How many ways can you arrange a deck of cards? | null | TED-Ed | Pick a card, any card. Actually, just pick up all of them and take a look. This standard 52-card deck has been used for centuries. Everyday, thousands just like it are shuffled in casinos all over the world, the order rearranged each time. And yet, every time you pick up a well-shuffled deck like this one, you are almost certainly holding an arrangement of cards that has never before existed in all of history. How can this be? The answer lies in how many different arrangements of 52 cards, or any objects, are possible. Now, 52 may not seem like such a high number, but let's start with an even smaller one. Say we have four people trying to sit in four numbered chairs. How many ways can they be seated? To start off, any of the four people can sit in the first chair. One this choice is made, only three people remain standing. After the second person sits down, only two people are left as candidates for the third chair. And after the third person has sat down, the last person standing has no choice but to sit in the fourth chair. If we manually write out all the possible arrangements, or permutations, it turns out that there are 24 ways that four people can be seated into four chairs, but when dealing with larger numbers, this can take quite a while. So let's see if there's a quicker way. Going from the beginning again, you can see that each of the four initial choices for the first chair leads to three more possible choices for the second chair, and each of those choices leads to two more for the third chair. So instead of counting each final scenario individually, we can multiply the number of choices for each chair: four times three times two times one to achieve the same result of 24. An interesting pattern emerges. We start with the number of objects we're arranging, four in this case, and multiply it by consecutively smaller integers until we reach one. This is an exciting discovery. So exciting that mathematicians have chosen to symbolize this kind of calculation, known as a factorial, with an exclamation mark. As a general rule, the factorial of any positive integer is calculated as the product of that same integer and all smaller integers down to one. In our simple example, the number of ways four people can be arranged into chairs is written as four factorial, which equals 24. So let's go back to our deck. Just as there were four factorial ways of arranging four people, there are 52 factorial ways of arranging 52 cards. Fortunately, we don't have to calculate this by hand. Just enter the function into a calculator, and it will show you that the number of possible arrangements is 8.07 x 10^67, or roughly eight followed by 67 zeros. Just how big is this number? Well, if a new permutation of 52 cards were written out every second starting 13.8 billion years ago, when the Big Bang is thought to have occurred, the writing would still be continuing today and for millions of years to come. In fact, there are more possible ways to arrange this simple deck of cards than there are atoms on Earth. So the next time it's your turn to shuffle, take a moment to remember that you're holding something that may have never before existed and may never exist again. |
A different way to visualize rhythm | null | TED-Ed | We usually think of rhythm as an element of music, but it's actually found everywhere in the world around us, from the ocean tides to our own heartbeats, rhythm is essentially an event repeating regularly over time. Even the ticking of a clock itself is a sort of rhythm. But for musical rhythm, a steady string of repeating single beats is not enough. For that, we need at least one opposing beat with a different sound, which can be the unstressed off beat or the accented back beat. There are several ways to make these beats distinct, whether by using high and low drums, or long and short beats. Which ends up being heard as the main beat is not a precise rule, but like the famous Rubin's vase, can be reversed depending on cultural perception. In standard notation, rhythm is indicated on a musical bar line, but there are other ways. Remember that ticking clock? Just as its round face can trace the linear passage of time, the flow of rhythm can be traced in a circle. The continuity of a wheel can be a more intuitive way to visualize rhythm than a linear score that requires moving back and forth along the page. We can mark the beats at different positions around the circle using blue dots for main beats, orange ones for off beats, and white dots for secondary beats. Here is a basic two beat rhythm with a main beat and an opposing off beat. Or a three beat rhythm with a main beat, an off beat, and a secondary beat. And the spaces between each beat can be divided into further sub-beats using multiples of either two or three. Layering multiple patterns using concentric wheels lets us create more complex rhythms. For example, we can combine a basic two beat rhythm with off beats to get a four beat system. This is the recognizable backbone of many genres popular around the world, from rock, country, and jazz, to reggae and cumbia. Or we can combine a two beat rhythm with a three beat one. Eliminating the extra main beat and rotating the inner wheel leaves us with a rhythm whose underlying feel is three-four. This is the basis of the music of Whirling Dervishes, as well as a broad range of Latin American rhythms, such as Joropo, and even Bach's famous Chaconne. Now if we remember Rubin's vase and hear the off beats as the main beats, this will give us a six-eight feel, as found in genres such as Chacarera, and Quechua, Persian music and more. In an eight beat system, we have three layered circles, each rhythm played by a different instrument. We can then add an outermost layer consisting of an additive rhythmic component, reinforcing the main beat and increasing accuracy. Now let's remove everything except for this combined rhythm and the basic two beat on top. This rhythmic configuration is found as the Cuban cinquillo, in the Puerto Rican bomba, and in Northern Romanian music. And rotating the outer circle 90 degrees counterclockwise gives us a pattern often found in Middle Eastern music, as well as Brazilian choro, and Argentinian tango. In all of these examples, the underlying rhythm reinforces the basic one-two, but in different ways depending on arrangement and cultural context. So it turns out that the wheel method is more than just a nifty way of visualizing complex rhythms. By freeing us from the tyranny of the bar line, we can visualize rhythm in terms of time, and a simple turn of the wheel can take us on a musical journey around the world. |
Can you solve the temple riddle? | null | TED-Ed | You've found the hidden switches, evaded the secret traps, and now your expedition finally stands at the heart of the ancient temple inside The Lost City. But as you study the inscriptions in the near total darkness, two of the eight graduate students accompanying you bump into the alter. Suddenly, two whisps of green smoke burst forth and the walls begin to shake. Fleeing for your lives, you come to a room you passed before with five hallways, including the one to the altar and the one leading back outside. The giant sandglass in the center is now flowing, with less than an hour before it empties, and the rumbling tells you that you don't want to be around when that happens. From what you recall of your way here, it would take about 20 minutes to reach the exit at a fast pace. You know this is the last junction before the exit, but your trail markings have been erased, and no one remembers the way. If nine of you split up, there should be just enough time for each group to explore one of the four halls ahead and report back to this room, with everyone then making a run down the correct path. There's just one problem; the inscriptions told of the altar's curse: the spirits of the city's King and Queen possessing intruders and leading them to their doom through deception. Remembering the green smoke, you realize two of the students have been cursed. At any time, one or both of them might lie, though they also might tell the truth. You know for sure that the curse didn't get you, but you don't know which students can't be trusted, and because the possessed students may lie only occasionally, there is no guaranteed way to test them to determine which are cursed. Can you figure out a way to ensure that you all escape? Don't worry about the possessed students attacking or otherwise harming the others. This curse only affects their communication. Pause the video now if you want to figure it out by yourself! Answer in: 3 Answer in: 2 Answer in: 1 The first thing to realize is that since you know you aren't possessed, you can explore one of the halls alone. This leaves eight students for the remaining three paths. Sending groups of four down just two of the paths won't work because if one group came back split two versus two, you'd have to guess who to trust. But splitting them into one pair and two trios would work every time, and here's why. The possessed students might lie, or they might not, but you know there are only two of them, while the other six will always tell the truth. When each group returns to the hall, all of its members will either give the same report or argue about whether they found the exit. If a trio returns in total agreement, then you know none of them are lying. With the pair, you can't be sure either way, but all you need is reliable evidence about three of the four paths. The fourth you can figure out using the process of elimination. Of course, none of this matters if you're lucky enough to find the exit yourself, but otherwise, putting everything together leaves you with three possibilities. If each group gives a consistent answer, either everyone is telling the truth, or the two possessed students are paired together. In either case, ignore the duo. If there's only one group arguing, both others must be telling the truth, and if there are two conflicts, then the possessed students are in separate groups and you can safely trust the majority in both trios since at least two people in each will be truthful. The temple collapses behind you as greenish vapors escape from two of the students. You're all safe and free from the curse. After that ordeal, you tell your group they all deserve a vacation, and you just happen to have another expedition coming up. |
Cómo los niños pueden aprender historia | null | TEDxRiodelaPlata | Well, I don't know about you guys, but for me, the part that I enjoyed the most about going to school is when they took us out on excursions or we went camping. I think I liked it a lot because in that moment you felt free, you could see your friends with the light of day, you could watch the teacher interact with the real world. But I think that the most important was that when we went on excursion learning and living were part of the same thing. I work as a director and screenwriter and in 2009 we had a problem. We had to ideate a TV show for kids that would tell the children about the May Revolution and the problem was that nothing came to us. To make things worse, with Sebastian Mignona and Nicolas Dardano, we have had the wonderful idea of offering to the Ministry of Education's TV channel to make an animated program; when none of us had the slightest idea on how to create a cartoon film. If you asked me when I was a boy what I wanted to do when I grew older, I would answer: "I want to work making cartoons." But it seems that with time I began noticing that animations were done in the United States. So if I wanted that work, I would have to be far from my parents, and I likely gave up. But now, I had the chance to write and direct a cartoon. So, a bit to reconnect myself with what I liked so much from the school, and also, I think, to see if an idea would occur to me, I went alone on an excursion to the Buenos Aires' Cabildo. I arrive at the Cabildo, I go up to the first floor, turn left, and I find this image. The Primera Junta, and so I get closer, read the names, Saavedra, Moreno, Castelli, Belgrano, Paso, I look at their expressions, their faces, and there I had the first revelation. "This is a pain." (Laughter) There's no way — (Applause) There's no way you can do something entertaining with this. The kids will always prefer to watch Pokemon, or Dragon Ball Z. If you think of it, they are able to store in their brain five complete seasons of Pokemon in Japanese, they watch the movies they like a million five hundred thousand times and they know the words by heart. And what is the difference between that content and this? Could we make the May Revolution as attractive as that? It seems that in front of content presented as pedagogical, educational, you lift a barrier. Like when they want to sell you something you do not need. There, I noticed that I passed through elementary and middle school without understanding well why San Martin crossed the Andes. And they must have explained it to me every August 17th. But it didn't hit me, I didn't get it, or it did not stick. When I returned from the Cabildo, I started thinking: "So, what stuck with me from school?" And then comes the image of my favorite teacher. You may as well have a favorite teacher from elementary or middle school. Well, Claudio Simari was mine. He was my teacher from 4th grade. And I was reminded of him because he was able to overcome the barrier that I had placed. And I remembered two moments where Claudio did it. And maybe in that there was an idea to create this cartoon. One morning Claudio arrived and he put on a piece of music. Claudio chose a song by Terea Parodi that was called "Hurry up Jose," and he wanted to explain to us the drama of the floods in Formosa. For those who don't know it, the song recounts a desperate call from a woman to her husband to escape together before the flood arrives. That was enough for me to never forget about the floods of Formosa. And for each time I listen to "Hurry up Jose," to be moved again. The other thing I remember about Claudio is that one day he decided to share with us a personal story. And he must have done it in such a sensitive way that I can even remember where I was sitting in the classroom. It turned out that Claudio was being sent to the war. Claudio was in the line to enter the plane that was going to take him to the Falkland Islands. He already had his uniform on, it was dawn, and he suddenly looks and he notices his parents had just arrived to say goodbye. So Claudio went running from the line to give a final hug, and when he returned they sent him to the back. And he was one of the few that failed to enter the plane. Those were the last flights that managed to reach the islands, and a friend of Claudio died in combat. With that alone, I would never forget the Falklands war, neither that history. How did Claudio do it? How did he impart on us ideas that 30 years later I still keep remembering? I realized one thing. What Claudio did, first of all, was to tell us stories. And we lived them like we were there with him. Claudio was a sort of medium, and we lived that experience we were in the classroom but we felt on an adventure. And the other thing I realized of Claudio is that he never underestimated us. We always thanked him for that, because Claudio didn't treat us like infants. We preferred Claudio over those men and women in television who would disguise as boys or girls. At first, they'd come closer to become your friends, and then you realize that they want to teach you numbers or colors, or sell you something. Seems like Claudio knew that if you treat a child like a fool, you ran the risk that, whether the child thinks that you are the fool, because you're speaking to them like that, or that they grow up thinking they are a fool, which is much worse. Children can be lovely, tender, sensitive, but the truth is they are the same who invented bullying. They can be tyrants, cruel, fickle beings, just like us. If they are like us, then why should we treat them in a different way? Now, how are we? That was the question that we asked ourselves in that moment. One of my first assignments as director of "The Dog on the Moon" — way before creating "Zamba" — was traveling across the country visiting public schools and interviewing kids. I must have interviewed around 1,500 or 2,000 kids. They taught me to stop looking at them from above, to lower the camera, to look at them in the eyes, and to see the world as they see it. That ended up having a lot of impact in the project, because there is something from each of those kids in Zamba. Anyone who had contact with Argentina's hinterland knows that the representation of children we see on TV is quite different from reality. Of course, because TV is designed to treat children as consumers. Paka-Paka comes to treat children like children, and for us as storytellers, that was an incredible opportunity. So we started to design the character. We had to think of an Argentine boy. If you were to draw an Argentine boy, what would you do? What would the hair color be? His skin color? What would the width of the nose be? These are the first sketches of Zamba. At that time we asked ourselves if boys and girls would identify with a boy who did not have super powers, and that instead of a cape, he wears a pinafore like them. Finally, this is the definitive design of Zamba. (Applause) We made him short like Messi for agility and to facilitate escaping. He has a backpack so he's similar to those hectic kids that are running around with their backpack on. We put on his pajamas under his pinafore. We made his skin brown. If you look carefully, he has like some little horns here, to make it look a bit more mischievous. And we gave him a broken tooth, as a war wound of that battle we all go through and is called "infancy." At this point, you should be asking: "How is it that a guy who went through elementary or middle school without knowing why San Martin had crossed the Andes, can write and direct a program on history?" Gabriel Di Meglio, who is a historian and researcher at the CONICET, was on the team. Gaby, among other things, chose to be a historian because in his childhood he read Asterix. And I had the chance to sit with him, face to face, and ask him about history in the same way Zamba asks San Martin. Then, what at first seemed a hindrance ended up being an advantage because I could write Zamba from naivety, without solemnity. We could get our heroes off their horses, we could brush off the bronze; we could tell our history through humor. Today, we live in a time of peace. But throughout our history a lot of men and women lost their lives, the only life they had, to fight for values like freedom and independence. And they could not see the outcome of that struggle. It hurt me, for example, when I came to know that Belgrano died in a period of anarchy, with the feeling that all he had done had rendered useless. But it was useful. To all who do Zamba, we like to think that Belgrano, San Martin, Sarmiento or Juana Azurduy would like to know that those values of freedom and independence are moving on to the next generation. Today, kids recognize their struggles and recognize them as characters of Zamba on banknotes. (Applause) Zamba might be revolutionary? I have no idea. We can't know this by now. We may have to wait 20 or 30 years. And something similar must happen with teachers, right? How much time must pass so you can see the result of their efforts of their dedication? And when I was preparing this talk, tin! My favorite teacher, Claudio, comes to mind again. I said, "Well, I have to tell him this, I have to share this with him." So I googled him. Claudio did not have Facebook. And all I found was a very improbable e-mail account, and I wrote an email that said this I will read to you: "Hello Claudio. I was your student 30 years ago, perhaps you don't remember me. I write you because I'm one of the makers of a cartoon called Zamba, it's shown in Paka-Paka and I have to give a talk about it. I needed to tell you that Zamba is named Jose after "Hurry up, Jose" the song that one day you showed us to explain the flooding in Formosa. And that's also why Zamba is from Clorinda. I needed you to know that if you watch the episode about the Falklands, you will find a veteran teacher and it is a tribute to you. If by chance you see this mail I hope you are doing well and that you receive a little recognition and appreciation for the work you did with us." (Applause) Today, was approaching and Claudio's reply did not come. And very recently it arrived. Claudio is still the guy I remembered. He went to live in Bariloche, he was a rural teacher, he devoted his life to teaching and he now works there at a center of teacher training. What was I supposed to do? I went to meet him. And it turns out that when I arrived, Claudio had a surprise for me. I did not remember, but on the last day of school Claudio asked us to write what we liked most of 4th grade. And these 30 years Claudio had treasured my answer and my peers'. (Applause) "What I liked about the year — I wrote — was the camp, because we played a lot and had fun." Today, Claudio is here sitting among us. (Applause) And I have the possibility to thank Claudio personally and in front of you those gestures, that dedication, that one day he made us listen to a song, that one day he shared with us such a personal and intimate history as that of the Falklands war. Because those little things helped, they are what ultimately make that future engineers, future scientists, future teachers, future artists, workers, and perhaps even future presidents, today, at school, when they go out to recess they end up shouting: "Let us be free, nothing else matters." (Applause) |
How a new species of ancestors is changing our theory of human evolution | {0: 'Juliet Brophy explores human evolution in southern Africa.'} | TEDxLSU | Human origins. Who are we? Where do we come from, and how do we know? In my field, paleoanthropology, we explore human origins — the "who" and "where" questions — by analyzing fossils that date back thousands and even millions of years. In 2015, a team of colleagues and I named a new species in the genus Homo — our genus — Homo naledi. Let's take a step back and put that into context. The last common ancestors between humans and chimps date somewhere between six and eight million years. The earliest hominins, or earliest human ancestors, evolved into a group known as the australopithecines. The australopithecines evolved into the genus Homo and eventually modern humans — us. With each new fossil discovery, we get a little bit closer to better understanding who we are and where we came from. With these new fossil finds, we realize we now have to make changes to this tree. Until this discovery, we thought we had a pretty good idea about the patterns of evolutionary change. Current fossil evidence suggests that the earliest populations of the genus Homo evolved in Africa somewhere between two and three million years. Fast-forward to approximately 300,000 years to where we see the origins of the first modern humans. While the fossil record between these time frames in Africa is relatively sparse, the fossils nonetheless demonstrated certain trends from our earliest ancestors to modern humans. For example, our brains were becoming larger relative the rest of our body. Our pelves were becoming more bowl-shaped, and our hand-wrist morphology, or form, suggested a change in our grip as we began to make and use stone tools and spend less time in the trees. These new fossils disrupt everything we thought we knew about these trends and force us to change the way that we think about human evolution. South Africa in general, but the Cradle of Humankind in particular, contains numerous sites where hundreds of thousands of fossils have been found. As an undergraduate student, I fell in love with one of them ... Mrs. Ples. The skull of a 2.1-million-year-old early human ancestor. From that point on, I was determined to go to South Africa and study human evolution. I first traveled there in 2003, and I did get to see my beloved Mrs. Ples. (Laughter) But words can hardly convey my excitement when I was chosen as an early career scientist by Lee Berger, a world-renowned paleoanthropologist, to be one of the primary analysts of recently excavated unpublished fossils. This treasure trove of fossils was being recovered from a new site called the Dinaledi Chamber in the Rising Star cave system. Species are often named based on a skull, a lower jaw, or, very rarely, a handful of postcranial, or below-the-neck, elements. The fossils from Dinaledi were another story altogether. An unprecedented approximately 1800 specimens — so far — have been excavated from the Rising Star system, representing at least 15 individual skeletons. The research team that I was invited to join was tasked with describing, comparing and analyzing the fossils, with the difficult goal of identifying to what species the fossils belonged. We were divided up into our different areas of expertise. We were divided up in different areas of the lab, too. So there was "Hand Land," for the fossil hand people, "Hip Heaven" for the pelvis ... I was in the "Tooth Booth." (Laughter) And after long, intense days in the lab, the different teams would meet up at night and discuss our findings, still consumed by questions from our analyses. It was incredible how different the interpretations were. Each body part seemed to come from a different species, based on what we knew from the fossil record. The suite of characteristics we were seeing didn't match any known species. And if we had only recovered the skull, we might have called it one thing; if we had only recovered the pelvis, we might have called it another. The anatomy of the skeletons didn't make sense with the framework of what we thought we knew of human evolution. Did it belong in the genus Homo? Should it be an australopithecine? Those bipedal, more apelike ancestors? Or perhaps it should be its own species. Ultimately, after much deliberation, we decided the Rising Star specimens did indeed warrant a new species, which we called "Homo naledi." From the head to the feet, the fossils present a mosaic of primitive, or ancestral, and derived or more modern-like features. The skull is quite derived, appearing most similar to early representatives of the genus Homo, like Homo habilis and Homo erectus. However, the brain is scarcely half the size of a modern human one. One that is smaller than any other early Homo that has ever been found. As someone who studies teeth, I might argue these are the coolest fossils found at the site. (Laughter) The assemblage consists of 190 whole or fragmentary teeth that range in age from very old to very young. Like the skeletons, the teeth present a mix of primitive and derived traits. In modern humans, the third molar is typically the smallest, while the first molar is the biggest, but Homo naledi has the primitive condition where the third molar is the biggest and the first molar is the smallest. The anterior teeth, or the incisors and canines, are small for the genus Homo, and the lower canine has a cuspulid on it — an extra cuspule that gives it a distinct mitten-like shape that it shares with some specimens of the early human, Homo erectus. The overall shape of the teeth looked odd to me, so I performed crown-shape analysis on the occlusal surfaces of deciduous teeth, or baby teeth — on your left — and the permanent premolars and molars on your right. The deciduous teeth are especially narrow, and the premolars are unique in their outline shape compared to other hominids. In fact, when I compare the outlines, when I lay them on top of each other, they look very similar. We say they have "low intraspecific variations," so the variation within the species is low. When I compare this to groups like the australopithecines, the intraspecific variation is much larger. Postcranially, the team concluded that the position of the shoulders suggesting naledi was a climber; the flared pelvis and curved fingers are all primitive for the genus Homo. On the other hand, the humanlike wrist, long slender legs and modern feet are all consistent with other members of the genus. In 2017, we announced more specimens of Homo naledi from the nearby Lesedi Chamber, also in the Rising Star cave system. In addition, our geology team managed to produce an age estimate. The date's a big deal because, up until now, we had based our analysis solely on the morphology of the specimens, without previous knowledge of how old something is — something which could unconsciously bias our interpretations. With its small brain and flared pelvis, we would not have been surprised if the fossils turned out to be two million years old. Instead, the fossils dated to 235 to 336 thousand years, an incredibly young date for such a small-brained individual. So think back to what I said earlier: we thought that our brains were becoming larger relative to the rest of our body. Now we have a small-brained, young individual complicating this idea. What does all this mean? Homo naledi has taught us that we need to reassess what it means to be in the genus Homo. We need to rethink what it means to be human. In fact, most of the characteristics that we use to define the genus Homo, such as brain size and hip morphology, are no longer valid. No other species exists with this mix of primitive and derived traits. Why is there so much morphological variation in the genus Homo? And what force is driving that variation? Another implication for these fossils is that for the first time, we have concrete evidence of a species coexisting in Africa, at 300,000 years, with modern humans. Until this discovery, we only had large-brained modern humans that existed in Africa. Did they interbreed with each other? Did they compete with each other? Another implication that these fossils have is for the archaeologists studying stone tools in South Africa. Keep in mind that neither the Dinaledi nor the Lesedi Chambers have any artifacts in them. However, they do overlap in time with several stone-tool industries, the makers of which are considered to be either modern humans or direct human ancestors. This begs the question: Who made the stone tools of South Africa? Brain size has historically played a key role in identifying a species as a tool user. The idea is that you need to have a large brain to have even the capacity to make stone tools. But that notion has been questioned. Furthermore, Homo naledi, even with its small brain size, has a hand-wrist morphology similar to other species that did make and use stone tools, suggesting it had the capability. With two species coexisting in Africa at 300,000 years, we can no longer assume we know the maker of tools at sites with no associated species. So where does Homo naledi fit in our human evolutionary lineage? Who is it most closely related to? Who did it evolve from? We're still trying to figure all that out. It's ironic, because paleoanthropologists are renowned for having small sample sizes. We now have a large sample size, and more questions than answers. Homo naledi has taught us, has brought us a little bit closer to better understanding our evolutionary past. So while Mrs. Ples will always hold a special place in my heart, she now shares that space with several thousand others. (Laughter) Thank you. (Applause) |
How do carbohydrates impact your health? | null | TED-Ed | Which of these has the least carbohydrates? This roll of bread? This bowl of rice? Or this can of soda? It's a trick question. Although they may differ in fats, vitamins, and other nutritional content, when it comes to carbs, they're pretty much the same. So what exactly does that mean for your diet? First of all, carbohydrate is the nutritional category for sugars and molecules that your body breaks down to make sugars. Carbohydrates can be simple or complex depending on their structure. This is a simple sugar, or monosaccharide. Glucose, fructose, and galactose are all simple sugars. Link two of them together, and you've got a disaccharide, lactose, maltose, or sucrose. Complex carbohydrates, on the other hand, have three or more simple sugars strung together. Complex carbohydrates with three to ten linked sugars are oligosaccharides. Those with more than ten are polysaccharides. During digestion, your body breaks down those complex carbohydrates into their monosaccharide building blocks, which your cells can use for energy. So when you eat any carbohydrate-rich food, the sugar level in your blood, normally about a teaspoon, goes up. But your digestive tract doesn't respond to all carbohydrates the same. Consider starch and fiber, both polysaccharides, both derived from plants, both composed of hundreds to thousands of monosaccharides joined together, but they're joined together differently, and that changes the effect they have on your body. In starches, which plants mostly store for energy in roots and seeds, glucose molecules are joined together by alpha linkages, most of which can be easily cleaved by enzymes in your digestive tract. But in fiber, the bonds between monosaccharide molecules are beta bonds, which your body can't break down. Fiber can also trap some starches, preventing them from being cleaved, resulting in something called resistant starch. So foods high in starch, like crackers and white bread, are digested easily, quickly releasing a whole bunch of glucose into your blood, exactly what would happen if you drank something high in glucose, like soda. These foods have a high glycemic index, the amount that a particular food raises the sugar level in your blood. Soda and white bread have a similar glycemic index because they have a similar effect on your blood sugar. But when you eat foods high in fiber, like vegetables, fruits, and whole grains, those indigestible beta bonds slow the release of glucose into the blood. Those foods have a lower glycemic index, and foods like eggs, cheese, and meats have the lowest glycemic index. When sugar moves from the digestive tract to the blood stream, your body kicks into action to transfer it into your tissues where it can be processed and used for energy. Insulin, a hormone synthesized in the pancreas, is one of the body's main tools for sugar management. When you eat and your blood sugar rises, insulin is secreted into the blood. It prompts your muscle and fat cells to let glucose in and jump starts the conversion of sugar to energy. The degree to which a unit of insulin lowers the blood sugar helps us understand something called insulin sensitivity. The more a given unit of insulin lowers blood sugar, the more sensitive you are to insulin. If insulin sensitivity goes down, that's known as insulin resistance. The pancreas still sends out insulin, but cells, especially muscle cells, are less and less responsive to it, so blood sugar fails to decrease, and blood insulin continues to rise. Chronically consuming a lot of carbohydrates may lead to insulin resistance, and many scientists believe that insulin resistance leads to a serious condition called metabolic syndrome. That involves a constellation of symptoms, including high blood sugar, increased waist circumference, and high blood pressure. It increases the risk of developing conditions, like cardiovascular disease and type II diabetes. And its prevalence is rapidly increasing all over the world. As much as 32% of the population in the U.S. has metabolic syndrome. So let's get back to your diet. Whether your food tastes sweet or not, sugar is sugar, and too many carbs can be a problem. So maybe you'll want to take a pass on that pasta sushi roll pita burrito donut burger sandwich. |
What makes muscles grow? | null | TED-Ed | Muscles. We have over 600 of them. They make up between 1/3 and 1/2 of our body weight, and along with connective tissue, they bind us together, hold us up, and help us move. And whether or not body building is your hobby, muscles need your constant attention because the way you treat them on a daily basis determines whether they will wither or grow. Say you're standing in front of a door, ready to pull it open. Your brain and muscles are perfectly poised to help you achieve this goal. First, your brain sends a signal to motor neurons inside your arm. When they receive this message, they fire, causing muscles to contract and relax, which pull on the bones in your arm and generate the needed movement. The bigger the challenge becomes, the bigger the brain's signal grows, and the more motor units it rallies to help you achieve your task. But what if the door is made of solid iron? At this point, your arm muscles alone won't be able to generate enough tension to pull it open, so your brain appeals to other muscles for help. You plant your feet, tighten your belly, and tense your back, generating enough force to yank it open. Your nervous system has just leveraged the resources you already have, other muscles, to meet the demand. While all this is happening, your muscle fibers undergo another kind of cellular change. As you expose them to stress, they experience microscopic damage, which, in this context, is a good thing. In response, the injured cells release inflammatory molecules called cytokines that activate the immune system to repair the injury. This is when the muscle-building magic happens. The greater the damage to the muscle tissue, the more your body will need to repair itself. The resulting cycle of damage and repair eventually makes muscles bigger and stronger as they adapt to progressively greater demands. Since our bodies have already adapted to most everyday activities, those generally don't produce enough stress to stimulate new muscle growth. So, to build new muscle, a process called hypertrophy, our cells need to be exposed to higher workloads than they are used to. In fact, if you don't continuously expose your muscles to some resistance, they will shrink, a process known as muscular atrophy. In contrast, exposing the muscle to a high-degree of tension, especially while the muscle is lengthening, also called an eccentric contraction, generates effective conditions for new growth. However, muscles rely on more than just activity to grow. Without proper nutrition, hormones, and rest, your body would never be able to repair damaged muscle fibers. Protein in our diet preserves muscle mass by providing the building blocks for new tissue in the form of amino acids. Adequate protein intake, along with naturally occurring hormones, like insulin-like growth factor and testosterone, help shift the body into a state where tissue is repaired and grown. This vital repair process mainly occurs when we're resting, especially at night while sleeping. Gender and age affect this repair mechanism, which is why young men with more testosterone have a leg up in the muscle building game. Genetic factors also play a role in one's ability to grow muscle. Some people have more robust immune reactions to muscle damage, and are better able to repair and replace damaged muscle fibers, increasing their muscle-building potential. The body responds to the demands you place on it. If you tear your muscles up, eat right, rest and repeat, you'll create the conditions to make your muscles as big and strong as possible. It is with muscles as it is with life: Meaningful growth requires challenge and stress. |
Can you solve the river crossing riddle? | null | TED-Ed | As a wildfire rages through the grasslands, three lions and three wildebeest flee for their lives. To escape the inferno, they must cross over to the left bank of a crocodile-infested river. Fortunately, there happens to be a raft nearby. It can carry up to two animals at a time, and needs as least one lion or wildebeest on board to row it across the river. There's just one problem. If the lions ever outnumber the wildebeest on either side of the river, even for a moment, their instincts will kick in, and the results won't be pretty. That includes the animals in the boat when it's on a given side of the river. What's the fastest way for all six animals to get across without the lions stopping for dinner? Pause here if you want to figure it out for yourself. Answer in: 3 Answer in: 2 Answer in: 1 If you feel stuck on a problem like this, try listing all the decisions you can make at each point, and the consequences each choice leads to. For instance, there are five options for who goes across first: one wildebeest, one lion, two wildebeest, two lions, or one of each. If one animal goes alone, it'll just have to come straight back. And if two wildebeest cross first, the remaining one will immediately get eaten. So those options are all out. Sending two lions, or one of each animal, can actually both lead to solutions in the same number of moves. For the sake of time, we'll focus on the second one. One of each animal crosses. Now, if the wildebeest stays and the lion returns, there will be three lions on the right bank. Bad news for the two remaining wildebeest. So we need to have the lion stay on the left bank and the wildebeest go back to the right. Now we have the same five options, but with one lion already on the left bank. If two wildebeest go, the one that stays will get eaten, and if one of each animal goes, the wildebeest on the raft will be outnumbered as soon as it reaches the other side. So that's a dead end, which means that at the third crossing, only the two lions can go. One gets dropped off, leaving two lions on the left bank. The third lion takes the raft back to the right bank where the wildebeest are waiting. What now? Well, since we've got two lions waiting on the left bank, the only option is for two wildebeest to cross. Next, there's no sense in two wildebeest going back, since that just reverses the last step. And if two lions go back, they'll outnumber the wildebeest on the right bank. So one lion and one wildebeest take the raft back leaving us with one of each animal on the left bank and two of each on the right. Again, there's no point in sending the lion-wildebeest pair back, so the next trip should be either a pair of lions or a pair of wildebeest. If the lions go, they'd eat the wildebeest on the left, so they stay, and the two wildebeest cross instead. Now we're quite close because the wildebeest are all where they need to be with safety in numbers. All that's left is for that one lion to raft back and bring his fellow lions over one by one. That makes eleven trips total, the smallest number needed to get everyone across safely. The solution that involves sending both lions on the first step works similarly, and also takes eleven crossings. The six animals escape unharmed from the fire just in time and begin their new lives across the river. Of course, now that the danger's passed, it remains to be seen how long their unlikely alliance will last. |
How I'm making bricks out of ashes and rubble in Gaza | {0: 'Majd Mashharawi leads a startup that makes bricks from recycled local materials -- and employs women in the Gaza Strip.'} | TEDWomen 2018 | Yes, it's dark. I'm wondering how long we can all stand it without picking up our phone and turning the flashlights on. Seconds? Minutes? A whole hour? Don't worry, I'm not going to give you my whole speech in the dark. But it's something I'm used to. For more than 10 years, I and two million people back home have been living in darkness, locked between two borders that are nearly impossible to leave, literally, in an area that spans 25 miles long and about five miles wide. I am Palestinian, and I am from Gaza. I grew up there and I still live there. In Gaza, we have a whole lot of nothing. And I aim to create something from that nothing. When a community is cut off from the world, all that we need to do is ... what? To think outside the box. Way outside the box. That thinking led me to two projects to address two serious issues in my community. The need for building materials and the need for electricity and energy. Two essential ingredients of life. Both are in lack of supply in Gaza. First, I'm not here ... just to talk about the occupation we have back home. The siege, the wars, the bombs, the protests or the death toll. I am here because I wanted to show that we can live through it all. I am here because I wanted to make a change. I am here to tell you that I am a statistic that cannot be ignored. In the 2014 war, thousands of houses were destroyed. Those houses were made from sunbaked stones and blocks. Those houses stood for decades and decades. Those houses were for my family, friends, neighbors, everyone I know. At that time, I asked myself a question: What can I do for people? How can I help them? I knew we weren't able to get cement, aggregate and sand to rebuild what the war destroyed. But also, maybe we can use something from inside the community, something we already had. I started to put things together. First, paper as a filler, instead of the aggregate we import. But that did not work out. What about using glass powder to replace part of the cement? But that failed, too. I guessed making building blocks out of mud would be a great idea. But unfortunately, it didn't work out. During the process of burning the mud blocks, we had a huge amount of ashes. And I was like, "Why don't we use those ashes?" The idea flashed in my mind. "Let's use it and combine it with the rubble of the demolished houses and make building blocks out of it." After more than 150 failed experiments, and over six months of research, I actually made it. (Applause) I created a building block out of the ashes and rubble of the demolished houses. It's here, it came all the way with me. Well, it came before me. So, it's lighter, it's cheaper, and it's stronger. (Applause) This building block — of course, you ask yourself, "How did this girl do it?" It's not that hard, and it's not that easy. First, we collected rubble from all around the Gaza Strip. Then we combined it with the ashes that came from the landfills. When the recipe is done, it's time for baking. So we mold the blocks, as you can see in the photo, and we cure it using water steam. I call the material "Green Cake," and people now can use it not only to rebuild old houses, but also to build new complete structures. Green Cake so far has created jobs for more than 30 people. And we were able to rebuild around 50 apartments, each one of them the size of a household almost for eight people. We also trained fresh graduates, female and male, which is not very common in the community. And we got several awards, locally and globally. This block is not just only a building block. It changed the stereotype about women in Gaza that stated this type of work is meant for men. Education is the strongest weapon we have to fight for our freedom, decent life and future. My background helped me to do this block. I went to the Islamic University of Gaza, and I studied civil engineering, where there was a one-to-six female-to-male ratio. Everyone told me I would end up without a job. I went for a major that's meant for men. But their lack of encouragement did not deter me; it inspired me. (Applause) After this long journey with the block, and after two years, what Gaza does need is not just building blocks. We also need electricity, we need the energy. I developed a new company called SunBox. SunBox is a smart solar kit that we source from China, and we engineer it to fit the market need. It powers not only light, but also laptops, phones, internet connection, a fan or a TV. We teach local vendors and technicians to sell, install and provide customer services for people. We got the project off the ground by providing 15 families with solar energy. One of the solar units we installed in a refugee camp. The next day I came to check what happened with the solar, and I found a whole neighborhood watching a football match using our device. I was like, "Wow, that's going to create a huge impact in the community." That encouraged us to go to the second round of bringing 200 units. But each unit costs around 350 dollars. And a Palestinian family can't afford the 350 dollars. So we had to think, again, outside the box: How can we make this happen? If a whole neighborhood can watch a football match using one device, it means two, three and four families can share one device and enjoy the electricity. What we did is, we created a new business model called "sharing is caring." (Laughter) The sharing is caring business model says two families share one unit, three families share one unit, and they split the cost, so they can afford paying for it. Well, the idea caught on. I didn't expect that, but it just happened. In less than two weeks, we were able to provide over 200 people with electricity. (Applause) And the question here: How did the idea catch on? We went to community centers — those are places, you know for whom? Only for men. So it was so weird for a woman to go there. And I told them, "We have a great idea. We will give you electricity, you give us people who need this electricity." Now, families are approaching us from all around the Gaza Strip. I received a phone call from the team this morning, saying, "Majd, please, we are under pressure, we work 16 hours a day, we will not be able to work like this. Families are calling us every second. They want solar energy." Muna, from one of the families we installed the solar unit for, she told me, "You know, Majd, I've never imagined I will control something in my life. Now I can control my source of energy. I feel so special." What you take for granted is a privilege for others. People like Muna. She doesn't want to fight. She doesn't want to stay in a bad life. She's only looking for a better life. Our vision, or I would say, everyone's vision in Gaza — which I am very privileged to represent the people back home — is to have a good life, a future. We need to build the infrastructure of hope. We want to tell them it's possible to happen, it's possible to be treated as a human being. I don't have to cross four borders to come here. I can just go to the airport, see the people outside, see what the world looks like. Thank you so much. (Applause) |
The historic women's suffrage march on Washington | null | TED-Ed | On March 3, 1913, protesters parted for the woman in white: dressed in a flowing cape and sitting astride a white horse, the activist Inez Milholland was hard to miss. She was riding at the helm of the Women’s Suffrage Parade- the first mass protest for a woman’s right to vote on a national scale. After months of strategic planning and controversy, thousands of women gathered in Washington D.C. Here, they called for a constitutional amendment granting them the right to vote. By 1913, women’s rights activists had been campaigning for decades. As a disenfranchised group, women had no voice in the laws that affected their– or anyone else’s– lives. However, they were struggling to secure broader support for political equality. They’d achieved no major victories since 1896, when Utah and Idaho enfranchised women. That brought the total number of states which recognized a women’s right to vote to four. A new, media-savvy spirit arrived in the form of Alice Paul. She was inspired by the British suffragettes, who went on hunger strikes and endured imprisonment in the early 1900s. Rather than conduct costly campaigns on a state-by-state basis, Paul sought the long-lasting impact of a constitutional amendment, which would protect women’s voting rights nationwide. As a member of the National American Women Suffrage Association, Paul proposed a massive pageant to whip up support and rejuvenate the movement. Washington authorities initially rejected her plan- and then tried to relegate the march to side streets. But Paul got those decisions overturned and confirmed a parade for the day before the presidential inauguration of Woodrow Wilson. This would maximize media coverage and grab the attention of the crowds who would be in town. However, in planning the parade, Paul mainly focused on appealing to white women from all backgrounds, including those who were racist. She actively discouraged African American activists and organizations from participating- and stated that those who did so should march in the back. But black women would not be made invisible in a national movement they helped shape. On the day of the march, Ida B. Wells-Barnett, a ground-breaking investigative journalist and anti-lynching advocate, refused to move to the back and proudly marched under the Illinois banner. The co-founder of the NAACP, Mary Church Terrell, joined the parade with the 22 founders of the Delta Sigma Theta Sorority, an organization created by female students from Howard University. In these ways and more, black women persevered despite deep hostility from white women in the movement, and at great political and physical risk. On the day of the parade, suffragists assembled to create a powerful exhibition. The surging sections of the procession included international suffragists, artists, performers and business-owners. Floats came in the form of golden chariots; an enormous Liberty Bell; and a map of enfranchised countries. On the steps of the Treasury Building, performers acted out the historical achievements of women to a live orchestra. The marchers carried on even as a mob blocked the route, hurling insults and spitting at women, tossing cigars, and physically assaulting participants. The police did not intervene, and in the end, over 100 women were hospitalized. Their mistreatment, widely reported throughout the country, catapulted the parade into the public eye— and garnered suffragists greater sympathy. National newspapers lambasted the police, and Congressional hearings investigated their actions during the parade. After the protest, the "Women’s Journal" declared, “Washington has been disgraced. Equal suffrage has scored a great victory." In this way, the march initiated a surge of support for women’s voting rights that endured in the coming years. Suffragists kept up steady pressure on their representatives, attended rallies, and petitioned the White House. Inez Milholland, the woman on the white horse, campaigned constantly throughout the United States, despite suffering from chronic health problems. She did not live to see her efforts come to fruition. In 1916, she collapsed while giving a suffrage speech and died soon after. According to popular reports, her last words were, “Mr. President, how long must women wait for liberty?” Though full voting inclusion would take decades, in 1920, Congress ratified the 19th amendment, finally granting women the right to vote. |
How does the Rorschach inkblot test work? | null | TED-Ed | Take a look at this image. What might this be? A frightening monster? Two friendly bears? Or something else entirely? For nearly a century, ten inkblots like these have been used as what seems like an almost mystical personality test. Long kept confidential for psychologists and their patients, the mysterious images were said to draw out the workings of a person’s mind. But what can inkblots really tell us, and how does this test work? Invented in the early 20th century by Swiss psychiatrist Hermann Rorschach, the Rorschach Test is actually less about the specific things we see, and more about our general approach to perception. As an amateur artist Hermann was fascinated by how visual perception varies from person to person. He carried this interest to medical school, where he learned all our senses are deeply connected. He studied how our process of perception doesn’t just register sensory inputs, but transforms them. And when he started working at a mental hospital in eastern Switzerland, he began designing a series of puzzling images to gain new insight into this enigmatic process. Using his inkblot paintings, Rorschach began quizzing hundreds of healthy subjects and psychiatric patients with the same question: what might this be? However, it wasn’t what the test subjects saw that was most important to Rorschach, but rather, how they approached the task. Which parts of the image did they focus on or ignore? Did they see the image moving? Did the color on some inkblots help them give better answers, or distract and overwhelm them? He developed a system to code people’s responses, reducing the wide range of interpretations to a few manageable numbers. Now he had empirical measures to quantify all kinds of test takers: the creative and imaginative, the detail-oriented, the big-picture perceivers, and flexible participants able to adapt their approach. Some people would get stuck, offering the same answer for multiple blots. Others gave unusual and delightful descriptions. Responses were as varied as the inkblots, which offered different kinds of perceptual problems– some easier to interpret than others. But analyzing the test-taker’s overall approach yielded real insights into their psychology. And as Rorschach tested more and more people, patterns began to pile up. Healthy subjects with the same personalities often took remarkably similar approaches. Patients suffering from the same mental illnesses also performed similarly, making the test a reliable diagnostic tool. It could even diagnose some conditions difficult to pinpoint with other available methods. In 1921, Rorschach published his coding system alongside the ten blots he felt gave the most nuanced picture of people’s perceptual approach. Over the next several decades, the test became wildly popular in countries around the world. By the 1960s, it had been officially administered millions of times in the U.S. alone. Unfortunately, less than a year after publishing the test, Hermann Rorschach had died suddenly. Without its inventor to keep it on track, the test he had methodically gathered so much data to support began to be used in all sorts of speculative ways. Researchers gave the test to Nazi war criminals, hoping to unlock the psychological roots of mass murder. Anthropologists showed the images to remote communities as a sort of universal personality test. Employers made prejudiced hiring decisions based on reductive decoding charts. As the test left clinics and entered popular culture its reputation among medical professionals plummeted, and the blots began to fall out of clinical use. Today, the test is still controversial, and many people assume it has been disproven. But a massive 2013 review of all the existing Rorschach research showed that when administered properly the test yields valid results, which can help diagnose mental illness or round out a patient’s psychological profile. It’s hardly a stand-alone key to the human mind– no test is. But its visual approach and lack of any single right answer continue to help psychologists paint a more nuanced picture of how people see the world. Bringing us one step closer to understanding the patterns behind our perceptions. |
A bold idea to replace politicians | {0: 'César Hidalgo studies how teams, cities and nations learn.\r\n'} | TED2018 | Is it just me, or are there other people here that are a little bit disappointed with democracy? (Applause) So let's look at a few numbers. If we look across the world, the median turnout in presidential elections over the last 30 years has been just 67 percent. Now, if we go to Europe and we look at people that participated in EU parliamentary elections, the median turnout in those elections is just 42 percent. Now let's go to New York, and let's see how many people voted in the last election for mayor. We will find that only 24 percent of people showed up to vote. What that means is that, if "Friends" was still running, Joey and maybe Phoebe would have shown up to vote. (Laughter) And you cannot blame them because people are tired of politicians. And people are tired of other people using the data that they have generated to communicate with their friends and family, to target political propaganda at them. But the thing about this is that this is not new. Nowadays, people use likes to target propaganda at you before they use your zip code or your gender or your age, because the idea of targeting people with propaganda for political purposes is as old as politics. And the reason why that idea is there is because democracy has a basic vulnerability. This is the idea of a representative. In principle, democracy is the ability of people to exert power. But in practice, we have to delegate that power to a representative that can exert that power for us. That representative is a bottleneck, or a weak spot. It is the place that you want to target if you want to attack democracy because you can capture democracy by either capturing that representative or capturing the way that people choose it. So the big question is: Is this the end of history? Is this the best that we can do or, actually, are there alternatives? Some people have been thinking about alternatives, and one of the ideas that is out there is the idea of direct democracy. This is the idea of bypassing politicians completely and having people vote directly on issues, having people vote directly on bills. But this idea is naive because there's too many things that we would need to choose. If you look at the 114th US Congress, you will have seen that the House of Representatives considered more than 6,000 bills, the Senate considered more than 3,000 bills and they approved more than 300 laws. Those would be many decisions that each person would have to make a week on topics that they know little about. So there's a big cognitive bandwidth problem if we're going to try to think about direct democracy as a viable alternative. So some people think about the idea of liquid democracy, or fluid democracy, which is the idea that you endorse your political power to someone, who can endorse it to someone else, and, eventually, you create a large follower network in which, at the end, there's a few people that are making decisions on behalf of all of their followers and their followers. But this idea also doesn't solve the problem of the cognitive bandwidth and, to be honest, it's also quite similar to the idea of having a representative. So what I'm going to do today is I'm going to be a little bit provocative, and I'm going to ask you, well: What if, instead of trying to bypass politicians, we tried to automate them? The idea of automation is not new. It was started more than 300 years ago, when French weavers decided to automate the loom. The winner of that industrial war was Joseph-Marie Jacquard. He was a French weaver and merchant that married the loom with the steam engine to create autonomous looms. And in those autonomous looms, he gained control. He could now make fabrics that were more complex and more sophisticated than the ones they were able to do by hand. But also, by winning that industrial war, he laid out what has become the blueprint of automation. The way that we automate things for the last 300 years has always been the same: we first identify a need, then we create a tool to satisfy that need, like the loom, in this case, and then we study how people use that tool to automate that user. That's how we came from the mechanical loom to the autonomous loom, and that took us a thousand years. Now, it's taken us only a hundred years to use the same script to automate the car. But the thing is that, this time around, automation is kind of for real. This is a video that a colleague of mine from Toshiba shared with me that shows the factory that manufactures solid state drives. The entire factory is a robot. There are no humans in that factory. And the robots are soon to leave the factories and become part of our world, become part of our workforce. So what I do in my day job is actually create tools that integrate data for entire countries so that we can ultimately have the foundations that we need for a future in which we need to also manage those machines. But today, I'm not here to talk to you about these tools that integrate data for countries. But I'm here to talk to you about another idea that might help us think about how to use artificial intelligence in democracy. Because the tools that I build are designed for executive decisions. These are decisions that can be cast in some sort of term of objectivity — public investment decisions. But there are decisions that are legislative, and these decisions that are legislative require communication among people that have different points of view, require participation, require debate, require deliberation. And for a long time, we have thought that, well, what we need to improve democracy is actually more communication. So all of the technologies that we have advanced in the context of democracy, whether they are newspapers or whether it is social media, have tried to provide us with more communication. But we've been down that rabbit hole, and we know that's not what's going to solve the problem. Because it's not a communication problem, it's a cognitive bandwidth problem. So if the problem is one of cognitive bandwidth, well, adding more communication to people is not going to be what's going to solve it. What we are going to need instead is to have other technologies that help us deal with some of the communication that we are overloaded with. Think of, like, a little avatar, a software agent, a digital Jiminy Cricket — (Laughter) that basically is able to answer things on your behalf. And if we had that technology, we would be able to offload some of the communication and help, maybe, make better decisions or decisions at a larger scale. And the thing is that the idea of software agents is also not new. We already use them all the time. We use software agents to choose the way that we're going to drive to a certain location, the music that we're going to listen to or to get suggestions for the next books that we should read. So there is an obvious idea in the 21st century that was as obvious as the idea of putting together a steam engine with a loom at the time of Jacquard. And that idea is combining direct democracy with software agents. Imagine, for a second, a world in which, instead of having a representative that represents you and millions of other people, you can have a representative that represents only you, with your nuanced political views — that weird combination of libertarian and liberal and maybe a little bit conservative on some issues and maybe very progressive on others. Politicians nowadays are packages, and they're full of compromises. But you might have someone that can represent only you, if you are willing to give up the idea that that representative is a human. If that representative is a software agent, we could have a senate that has as many senators as we have citizens. And those senators are going to be able to read every bill and they're going to be able to vote on each one of them. So there's an obvious idea that maybe we want to consider. But I understand that in this day and age, this idea might be quite scary. In fact, thinking of a robot coming from the future to help us run our governments sounds terrifying. But we've been there before. (Laughter) And actually he was quite a nice guy. So what would the Jacquard loom version of this idea look like? It would be a very simple system. Imagine a system that you log in and you create your avatar, and then you're going to start training your avatar. So you can provide your avatar with your reading habits, or connect it to your social media, or you can connect it to other data, for example by taking psychological tests. And the nice thing about this is that there's no deception. You are not providing data to communicate with your friends and family that then gets used in a political system. You are providing data to a system that is designed to be used to make political decisions on your behalf. Then you take that data and you choose a training algorithm, because it's an open marketplace in which different people can submit different algorithms to predict how you're going to vote, based on the data you have provided. And the system is open, so nobody controls the algorithms; there are algorithms that become more popular and others that become less popular. Eventually, you can audit the system. You can see how your avatar is working. If you like it, you can leave it on autopilot. If you want to be a little more controlling, you can actually choose that they ask you every time they're going to make a decision, or you can be anywhere in between. One of the reasons why we use democracy so little may be because democracy has a very bad user interface. And if we improve the user interface of democracy, we might be able to use it more. Of course, there's a lot of questions that you might have. Well, how do you train these avatars? How do you keep the data secure? How do you keep the systems distributed and auditable? How about my grandmother, who's 80 years old and doesn't know how to use the internet? Trust me, I've heard them all. So when you think about an idea like this, you have to beware of pessimists because they are known to have a problem for every solution. (Laughter) So I want to invite you to think about the bigger ideas. The questions I just showed you are little ideas because they are questions about how this would not work. The big ideas are ideas of: What else can you do with this if this would happen to work? And one of those ideas is, well, who writes the laws? In the beginning, we could have the avatars that we already have, voting on laws that are written by the senators or politicians that we already have. But if this were to work, you could write an algorithm that could try to write a law that would get a certain percentage of approval, and you could reverse the process. Now, you might think that this idea is ludicrous and we should not do it, but you cannot deny that it's an idea that is only possible in a world in which direct democracy and software agents are a viable form of participation. So how do we start the revolution? We don't start this revolution with picket fences or protests or by demanding our current politicians to be changed into robots. That's not going to work. This is much more simple, much slower and much more humble. We start this revolution by creating simple systems like this in grad schools, in libraries, in nonprofits. And we try to figure out all of those little questions and those little problems that we're going to have to figure out to make this idea something viable, to make this idea something that we can trust. And as we create those systems that have a hundred people, a thousand people, a hundred thousand people voting in ways that are not politically binding, we're going to develop trust in this idea, the world is going to change, and those that are as little as my daughter is right now are going to grow up. And by the time my daughter is my age, maybe this idea, that I know today is very crazy, might not be crazy to her and to her friends. And at that point, we will be at the end of our history, but they will be at the beginning of theirs. Thank you. (Applause) |
How we can store digital data in DNA | {0: 'Dina Zielinski brings biological data to life, from decoding mutations in cancer to encoding data in DNA.'} | TEDxVienna | I could fit all movies ever made inside of this tube. If you can't see it, that's kind of the point. (Laughter) Before we understand how this is possible, it's important to understand the value of this feat. All of our thoughts and actions these days, through photos and videos — even our fitness activities — are stored as digital data. Aside from running out of space on our phones, we rarely think about our digital footprint. But humanity has collectively generated more data in the last few years than all of preceding human history. Big data has become a big problem. Digital storage is really expensive, and none of these devices that we have really stand the test of time. There's this nonprofit website called the Internet Archive. In addition to free books and movies, you can access web pages as far back as 1996. Now, this is very tempting, but I decided to go back and look at the TED website's very humble beginnings. As you can see, it's changed quite a bit in the last 30 years. So this led me to the first-ever TED, back in 1984, and it just so happened to be a Sony executive explaining how a compact disk works. (Laughter) Now, it's really incredible to be able to go back in time and access this moment. It's also really fascinating that after 30 years, after that first TED, we're still talking about digital storage. Now, if we look back another 30 years, IBM released the first-ever hard drive back in 1956. Here it is being loaded for shipping in front of a small audience. It held the equivalent of one MP3 song and weighed over one ton. At 10,000 dollars a megabyte, I don't think anyone in this room would be interested in buying this thing, except maybe as a collector's item. But it's the best we could do at the time. We've come such a long way in data storage. Devices have evolved dramatically. But all media eventually wear out or become obsolete. If someone handed you a floppy drive today to back up your presentation, you'd probably look at them kind of strange, maybe laugh, but you'd have no way to use the damn thing. These devices can no longer meet our storage needs, although some of them can be repurposed. All technology eventually dies or is lost, along with our data, all of our memories. There's this illusion that the storage problem has been solved, but really, we all just externalize it. We don't worry about storing our emails and our photos. They're just in the cloud. But behind the scenes, storage is problematic. After all, the cloud is just a lot of hard drives. Now, most digital data, we could argue, is not really critical. Surely, we could just delete it. But how can we really know what's important today? We've learned so much about human history from drawings and writings in caves, from stone tablets. We've deciphered languages from the Rosetta Stone. You know, we'll never really have the whole story, though. Our data is our story, even more so today. We won't have our record recorded on stone tablets. But we don't have to choose what is important now. There's a way to store it all. It turns out that there's a solution that's been around for a few billion years, and it's actually in this tube. DNA is nature's oldest storage device. After all, it contains all the information necessary to build and maintain a human being. But what makes DNA so great? Well, let's take our own genome as an example. If we were to print out all three billion A's, T's, C's and G's on a standard font, standard format, and then we were to stack all of those papers, it would be about 130 meters high, somewhere between the Statue of Liberty and the Washington Monument. Now, if we converted all those A's, T's, C's and G's to digital data, to zeroes and ones, it would total a few gigs. And that's in each cell of our body. We have more than 30 trillion cells. You get the idea: DNA can store a ton of information in a minuscule space. DNA is also very durable, and it doesn't even require electricity to store it. We know this because scientists have recovered DNA from ancient humans that lived hundreds of thousands of years ago. One of those is Ötzi the Iceman. Turns out, he's Austrian. (Laughter) He was found high, well-preserved, in the mountains between Italy and Austria, and it turns out that he has living genetic relatives here in Austria today. So one of you could be a cousin of Ötzi. (Laughter) The point is that we have a better chance of recovering information from an ancient human than we do from an old phone. It's also much less likely that we'll lose the ability to read DNA than any single man-made device. Every single new storage format requires a new way to read it. We'll always be able to read DNA. If we can no longer sequence, we have bigger problems than worrying about data storage. Storing data on DNA is not new. Nature's been doing it for several billion years. In fact, every living thing is a DNA storage device. But how do we store data on DNA? This is Photo 51. It's the first-ever photo of DNA, taken about 60 years ago. This is around the time that that same hard drive was released by IBM. So really, our understanding of digital storage and of DNA have coevolved. We first learned to sequence, or read DNA, and very soon after, how to write it, or synthesize it. This is much like how we learn a new language. And now we have the ability to read, write and copy DNA. We do it in the lab all the time. So anything, really anything, that can be stored as zeroes and ones can be stored in DNA. To store something digitally, like this photo, we convert it to bits, or binary digits. Each pixel in a black-and-white photo is simply a zero or a one. And we can write DNA much like an inkjet printer can print letters on a page. We just have to convert our data, all of those zeroes and ones, to A's, T's, C's and G's, and then we send this to a synthesis company. So we write it, we can store it, and when we want to recover our data, we just sequence it. Now, the fun part of all of this is deciding what files to include. We're serious scientists, so we had to include a manuscript for good posterity. We also included a $50 Amazon gift card — don't get too excited, it's already been spent, someone decoded it — as well as an operating system, one of the first movies ever made and a Pioneer plaque. Some of you might have seen this. It has a depiction of a typical — apparently — male and female, and our approximate location in the Solar System, in case the Pioneer spacecraft ever encounters extraterrestrials. So once we decided what sort of files we want to encode, we package up the data, convert those zeroes and ones to A's, T's, C's and G's, and then we just send this file off to a synthesis company. And this is what we got back. Our files were in this tube. All we had to do was sequence it. This all sounds pretty straightforward, but the difference between a really cool, fun idea and something we can actually use is overcoming these practical challenges. Now, while DNA is more robust than any man-made device, it's not perfect. It does have some weaknesses. We recover our message by sequencing the DNA, and every time data is retrieved, we lose the DNA. That's just part of the sequencing process. We don't want to run out of data, but luckily, there's a way to copy the DNA that's even cheaper and easier than synthesizing it. We actually tested a way to make 200 trillion copies of our files, and we recovered all the data without error. So sequencing also introduces errors into our DNA, into the A's, T's, C's and G's. Nature has a way to deal with this in our cells. But our data is stored in synthetic DNA in a tube, so we had to find our own way to overcome this problem. We decided to use an algorithm that was used to stream videos. When you're streaming a video, you're essentially trying to recover the original video, the original file. When we're trying to recover our original files, we're simply sequencing. But really, both of these processes are about recovering enough zeroes and ones to put our data back together. And so, because of our coding strategy, we were able to package up all of our data in a way that allowed us to make millions and trillions of copies and still always recover all of our files back. This is the movie we encoded. It's one of the first movies ever made, and now the first to be copied more than 200 trillion times on DNA. Soon after our work was published, we participated in an "Ask Me Anything" on the website reddit. If you're a fellow nerd, you're very familiar with this website. Most questions were thoughtful. Some were comical. For example, one user wanted to know when we would have a literal thumb drive. Now, the thing is, our DNA already stores everything needed to make us who we are. It's a lot safer to store data on DNA in synthetic DNA in a tube. Writing and reading data from DNA is obviously a lot more time-consuming than just saving all your files on a hard drive — for now. So initially, we should focus on long-term storage. Most data are ephemeral. It's really hard to grasp what's important today, or what will be important for future generations. But the point is, we don't have to decide today. There's this great program by UNESCO called the "Memory of the World" program. It's been created to preserve historical materials that are considered of value to all of humanity. Items are nominated to be added to the collection, including that film that we encoded. While a wonderful way to preserve human heritage, it doesn't have to be a choice. Instead of asking the current generation — us — what might be important in the future, we could store everything in DNA. Storage is not just about how many bytes but how well we can actually store the data and recover it. There's always been this tension between how much data we can generate and how much we can recover and how much we can store. Every advance in writing data has required a new way to read it. We can no longer read old media. How many of you even have a disk drive in your laptop, never mind a floppy drive? This will never be the case with DNA. As long as we're around, DNA is around, and we'll find a way to sequence it. Archiving the world around us is part of human nature. This is the progress we've made in digital storage in 60 years, at a time when we were only beginning to understand DNA. Yet, we've made similar progress in half that time with DNA sequencers, and as long as we're around, DNA will never be obsolete. Thank you. (Applause) |
Why should you read Sylvia Plath? | null | TED-Ed | “From the tip of every branch, like a fat purple fig, a wonderful future beckoned and winked… but choosing one meant losing all the rest, and, as I sat there, unable to decide, the figs began to wrinkle and go black, and, one by one, they plopped to the ground at my feet.” In this passage from Sylvia Plath’s "The Bell Jar," a young woman imagines an uncertain future– and speaks to the universal fear of becoming paralyzed by the prospect of making the wrong choice. Although she considered other careers, Plath chose the artist’s way. Poetry was her calling. Under her shrewd eye and pen, everyday objects became haunting images: a “new statue in a drafty museum,” a shadow in a mirror, a slab of soap. Fiercely intelligent, penetrating and witty, Plath was also diagnosed with clinical depression. She used poetry to explore her own states of mind in the most intimate terms, and her breathtaking perspectives on emotion, nature and art continue to captivate and resonate. In her first collection of poems, "The Colossus," she wrote of a feeling of nothingness: "white: it is a complexion of the mind.” At the same time, she found solace in nature, from “a blue mist” “dragging the lake,” to white flowers that “tower and topple,” to blue mussels “clumped like bulbs.” After "The Colossus" she published "The Bell Jar," her only novel, which fictionalizes the time she spent working for Mademoiselle magazine in New York during college. The novel follows its heroine, Esther, as she slides into a severe depressive episode, but also includes wickedly funny and shrewd depictions of snobby fashion parties and dates with dull men. Shortly after the publication of "The Bell Jar," Plath died by suicide at age 30. Two years later, the collection of poems she wrote in a burst of creative energy during the months before her death was published under the title "Ariel." Widely considered her masterpiece, Ariel exemplifies the honesty and imagination Plath harnessed to capture her pain. In one of "Ariel's" most forceful poems, "Lady Lazarus," she explores her attempts to take her own life through Lazarus, the biblical figure who rose from the dead. She writes, “and I a smiling woman/ I am only thirty/ And like the cat I have nine times to die.” But the poem is also a testament to survival: “I rise with my red hair/ And I eat men like air.” This unflinching language has made Plath an important touchstone for countless other readers and writers who sought to break the silence surrounding issues of trauma, frustration, and sexuality. "Ariel" is also filled with moving meditations on heartbreak and creativity. The title poem begins “Stasis in darkness/ Then the substanceless blue/ Pour of tor and distances.” This sets the scene for a naked ride on horseback in the early morning— one of Plath’s most memorable expressions of the elation of creative freedom. But it is also full of foreboding imagery, such as “a child's cry” that “melts in the wall” and a “red/eye, the cauldron of morning.” This darkness is echoed throughout the collection, which includes controversial references to the holocaust and the Kamikazes. Even the relics of seemingly happier times are described as crucifying the author: “My husband and child smiling out of the family photo; Their smiles catch onto my skin, little smiling hooks.” Her domestic dissatisfaction and her husband’s mistreatment of her are constant themes in her later poetry. After her death, he inherited her estate, and has been accused of excluding some of her work from publication. Despite these possible omissions and her untimely death, what survives is one of the most extraordinary bodies of work by a twentieth century poet. While her work can be shocking in its rage and trauma, Plath casts her readers as witnesses– not only to the truth of her psychological life, but to her astounding ability to express what often remains inexpressible. |
Is there a center of the universe? | null | TED-Ed | What is at the center of the universe? It's an essential question that humans have been wondering about for centuries. But the journey toward an answer has been a strange one. If you wanted to know the answer to this question in third century B.C.E. Greece, you might look up at the night sky and trust what you see. That's what Aristotle, THE guy to ask back then, did. He thought that since we're on Earth, looking up, it must be the center, right? For him, the sphere of the world was made up of four elements: Earth, water, air, and fire. These elements shifted around a nested set of solid crystalline spheres. Each of the wandering stars, the planets, had their own crystal sphere. The rest of the universe and all of its stars were on the last crystal sphere. If you watch the sky change over time, you could see that this idea worked fine at explaining the motion you saw. For centuries, this was central to how Europe and the Islamic world saw the universe. But in 1543, a guy named Copernicus proposed a different model. He believed that the sun was at the center of the universe. This radically new idea was hard for a lot of people to accept. After all, Aristotle's ideas made sense with what they could see, and they were pretty flattering to humans. But a series of subsequent discoveries made the sun-centric model hard to ignore. First, Johannes Kepler pointed out that orbits aren't perfect circles or spheres. Then, Galileo's telescope caught Jupiter's moons orbiting around Jupiter, totally ignoring Earth. And then, Newton proposed the theory of universal gravitation, demonstrating that all objects are pulling on each other. Eventually, we had to let go of the idea that we were at the center of the universe. Shortly after Copernicus, in the 1580s, an Italian friar, Giordano Bruno, suggested the stars were suns that likely had their own planets and that the universe was infinite. This idea didn't go over well. Bruno was burned at the stake for his radical suggestion. Centuries later, the philosopher Rene Descartes proposed that the universe was a series of whirlpools, which he called vortices, and that each star was at the center of a whirlpool. In time, we realized there were far more stars than Aristotle ever dreamed. As astronomers like William Herschel got more and more advanced telescopes, it became clear that our sun is actually one of many stars inside the Milky Way. And those smudges we see in the night sky? They're other galaxies, just as vast as our Milky Way home. Maybe we're farther from the center than we ever realized. In the 1920s, astronomers studying the nebuli wanted to figure out how they were moving. Based on the Doppler Effect, they expected to see blue shift for objects moving toward us, and red shift for ones moving away. But all they saw was a red shift. Everything was moving away from us, fast. This observation is one of the pieces of evidence for what we now call the Big Bang Theory. According to this theory, all matter in the universe was once a singular, infinitely dense particle. In a sense, our piece of the universe was once at the center. But this theory eliminates the whole idea of a center since there can't be a center to an infinite universe. The Big Bang wasn't just an explosion in space; it was an explosion of space. What each new discovery proves is that while our observations are limited, our ability to speculate and dream of what's out there isn't. What we think we know today can change tomorrow. As with many of the thinkers we just met, sometimes our wildest guesses lead to wonderful and humbling answers and propel us toward even more perplexing questions. |
The science of attraction | null | TED-Ed | We like to think of romantic feelings as spontaneous and indescribable things that come from the heart. But it's actually your brain running a complex series of calculations within a matter of seconds that's responsible for determining attraction. Doesn't sound quite as poetic, does it? But just because the calculations are happening in your brain doesn't mean those warm, fuzzy feelings are all in your head. In fact, all five of your senses play a role, each able to vote for, or veto, a budding attraction. The eyes are the first components in attraction. Many visual beauty standards vary between cultures and eras, and signs of youth, fertility and good health, such as long lustrous hair, or smooth, scar-free skin, are almost always in demand because they're associated with reproductive fitness. And when the eyes spot something they like, our instinct is to move closer so the other senses can investigate. The nose's contribution to romance is more than noticing perfume or cologne. It's able to pick up on natural chemical signals known as pheromones. These not only convey important physical or genetic information about their source but are able to activate a physiological or behavioral response in the recipient. In one study, a group of women at different points in their ovulation cycles wore the same T-shirts for three nights. After male volunteers were randomly assigned to smell either one of the worn shirts, or a new unworn one, saliva samples showed an increase in testosterone in those who had smelled a shirt worn by an ovulating woman. Such a testosterone boost may give a man the nudge to pursue a woman he might not have otherwise noticed. A woman's nose is particularly attuned to MHC molecules, which are used to fight disease. In this case, opposites attract. When a study asked women to smell T-shirts that had been worn by different men, they preferred the odors of those whose MHC molecules differed from theirs. This makes sense. Genes that result in a greater variety of immunities may give offspring a major survival advantage. Our ears also determine attraction. Men prefer females with high-pitched, breathy voices, and wide formant spacing, correlated with smaller body size. While women prefer low-pitched voices with a narrow formant spacing that suggest a larger body size. And not surprisingly, touch turns out to be crucial for romance. In this experiment, not realizing the study had begun, participants were asked to briefly hold the coffee, either hot or iced. Later, the participants read a story about a hypothetical person, and were asked to rate their personality. Those who had held the hot cup of coffee perceived the person in the story as happier, more social, more generous and better-natured than those who had held the cup of iced coffee, who rated the person as cold, stoic, and unaffectionate. If a potential mate has managed to pass all these tests, there's still one more: the infamous first kiss, a rich and complex exchange of tactile and chemical cues, such as the smell of one's breath, and the taste of their mouth. This magical moment is so critical that a majority of men and women have reported losing their attraction to someone after a bad first kiss. Once attraction is confirmed, your bloodstream is flooded with norepinephrine, activating your fight or flight system. Your heart beats faster, your pupils dilate, and your body releases glucose for additional energy, not because you're in danger but because your body is telling you that something important is happening. To help you focus, norepinephrine creates a sort of tunnel vision, blocking out surrounding distractions, possibly even warping your sense of time, and enhancing your memory. This might explain why people never forget their first kiss. The idea of so much of our attraction being influenced by chemicals and evolutionary biology may seem cold and scientific rather than romantic, but the next time you see someone you like, try to appreciate how your entire body is playing matchmaker to decide if that beautiful stranger is right for you. |
An unexpected tool for understanding inequality: abstract math | {0: 'Eugenia Cheng devotes her life to mathematics, the piano and helping people.'} | TEDxLondon | The world is awash with divisive arguments, conflict, fake news, victimhood, exploitation, prejudice, bigotry, blame, shouting and minuscule attention spans. It can sometimes seem that we are doomed to take sides, be stuck in echo chambers and never agree again. It can sometimes seem like a race to the bottom, where everyone is calling out somebody else's privilege and vying to show that they are the most hard-done-by person in the conversation. How can we make sense in a world that doesn't? I have a tool for understanding this confusing world of ours, a tool that you might not expect: abstract mathematics. I am a pure mathematician. Traditionally, pure maths is like the theory of maths, where applied maths is applied to real problems like building bridges and flying planes and controlling traffic flow. But I'm going to talk about a way that pure maths applies directly to our daily lives as a way of thinking. I don't solve quadratic equations to help me with my daily life, but I do use mathematical thinking to help me understand arguments and to empathize with other people. And so pure maths helps me with the entire human world. But before I talk about the entire human world, I need to talk about something that you might think of as irrelevant schools maths: factors of numbers. We're going to start by thinking about the factors of 30. Now, if this makes you shudder with bad memories of school maths lessons, I sympathize, because I found school maths lessons boring, too. But I'm pretty sure we are going to take this in a direction that is very different from what happened at school. So what are the factors of 30? Well, they're the numbers that go into 30. Maybe you can remember them. We'll work them out. It's one, two, three, five, six, 10, 15 and 30. It's not very interesting. It's a bunch of numbers in a straight line. We can make it more interesting by thinking about which of these numbers are also factors of each other and drawing a picture, a bit like a family tree, to show those relationships. So 30 is going to be at the top like a kind of great-grandparent. Six, 10 and 15 go into 30. Five goes into 10 and 15. Two goes into six and 10. Three goes into six and 15. And one goes into two, three and five. So now we see that 10 is not divisible by three, but that this is the corners of a cube, which is, I think, a bit more interesting than a bunch of numbers in a straight line. We can see something more here. There's a hierarchy going on. At the bottom level is the number one, then there's the numbers two, three and five, and nothing goes into those except one and themselves. You might remember this means they're prime. At the next level up, we have six, 10 and 15, and each of those is a product of two prime factors. So six is two times three, 10 is two times five, 15 is three times five. And then at the top, we have 30, which is a product of three prime numbers — two times three times five. So I could redraw this diagram using those numbers instead. We see that we've got two, three and five at the top, we have pairs of numbers at the next level, and we have single elements at the next level and then the empty set at the bottom. And each of those arrows shows losing one of your numbers in the set. Now maybe it can be clear that it doesn't really matter what those numbers are. In fact, it doesn't matter what they are. So we could replace them with something like A, B and C instead, and we get the same picture. So now this has become very abstract. The numbers have turned into letters. But there is a point to this abstraction, which is that it now suddenly becomes very widely applicable, because A, B and C could be anything. For example, they could be three types of privilege: rich, white and male. So then at the next level, we have rich white people. Here we have rich male people. Here we have white male people. Then we have rich, white and male. And finally, people with none of those types of privilege. And I'm going to put back in the rest of the adjectives for emphasis. So here we have rich, white non-male people, to remind us that there are nonbinary people we need to include. Here we have rich, nonwhite male people. Here we have non-rich, white male people, rich, nonwhite, non-male, non-rich, white, non-male and non-rich, nonwhite, male. And at the bottom, with the least privilege, non-rich, nonwhite, non-male people. We have gone from a diagram of factors of 30 to a diagram of interaction of different types of privilege. And there are many things we can learn from this diagram, I think. The first is that each arrow represents a direct loss of one type of privilege. Sometimes people mistakenly think that white privilege means all white people are better off than all nonwhite people. Some people point at superrich black sports stars and say, "See? They're really rich. White privilege doesn't exist." But that's not what the theory of white privilege says. It says that if that superrich sports star had all the same characteristics but they were also white, we would expect them to be better off in society. There is something else we can understand from this diagram if we look along a row. If we look along the second-to-top row, where people have two types of privilege, we might be able to see that they're not all particularly equal. For example, rich white women are probably much better off in society than poor white men, and rich black men are probably somewhere in between. So it's really more skewed like this, and the same on the bottom level. But we can actually take it further and look at the interactions between those two middle levels. Because rich, nonwhite non-men might well be better off in society than poor white men. Think about some extreme examples, like Michelle Obama, Oprah Winfrey. They're definitely better off than poor, white, unemployed homeless men. So actually, the diagram is more skewed like this. And that tension exists between the layers of privilege in the diagram and the absolute privilege that people experience in society. And this has helped me to understand why some poor white men are so angry in society at the moment. Because they are considered to be high up in this cuboid of privilege, but in terms of absolute privilege, they don't actually feel the effect of it. And I believe that understanding the root of that anger is much more productive than just being angry at them in return. Seeing these abstract structures can also help us switch contexts and see that different people are at the top in different contexts. In our original diagram, rich white men were at the top, but if we restricted our attention to non-men, we would see that they are here, and now the rich, white non-men are at the top. So we could move to a whole context of women, and our three types of privilege could now be rich, white and cisgendered. Remember that "cisgendered" means that your gender identity does match the gender you were assigned at birth. So now we see that rich, white cis women occupy the analogous situation that rich white men did in broader society. And this has helped me understand why there is so much anger towards rich white women, especially in some parts of the feminist movement at the moment, because perhaps they're prone to seeing themselves as underprivileged relative to white men, and they forget how overprivileged they are relative to nonwhite women. We can all use these abstract structures to help us pivot between situations in which we are more privileged and less privileged. We are all more privileged than somebody and less privileged than somebody else. For example, I know and I feel that as an Asian person, I am less privileged than white people because of white privilege. But I also understand that I am probably among the most privileged of nonwhite people, and this helps me pivot between those two contexts. And in terms of wealth, I don't think I'm super rich. I'm not as rich as the kind of people who don't have to work. But I am doing fine, and that's a much better situation to be in than people who are really struggling, maybe are unemployed or working at minimum wage. I perform these pivots in my head to help me understand experiences from other people's points of view, which brings me to this possibly surprising conclusion: that abstract mathematics is highly relevant to our daily lives and can even help us to understand and empathize with other people. My wish is that everybody would try to understand other people more and work with them together, rather than competing with them and trying to show that they're wrong. And I believe that abstract mathematical thinking can help us achieve that. Thank you. (Applause) |
How to unboil an egg | null | TED-Ed | It's so obvious that it's practically proverbial. You can't unboil an egg. Well, it turns out you can, sort of. What thermal energy does to the eggs' molecules, mechanical energy can undo. Eggs are mostly made of water and proteins. The proteins start off folded up into intricate shapes, held together by weak chemical bonds. Adding heat disrupts those bonds, allowing the proteins to unfold, uncoil, unwind and wiggle freely. This process is called denaturing. The newly liberated proteins bump up against their neighbors and start to form new bonds with each other, more and more as the heat increases, until finally, they're so entangled that they gel into a solid mass, a boiled egg. That entanglement might look permanent, but it's not. According to a chemical idea called the principle of microscopic reversibility, anything that happens, like egg proteins seizing up, can theoretically unhappen if you retrace your steps. But adding more heat will tangle the proteins further, and cooling them down will only freeze them, so here's the trick: spin them around ridiculously fast. I'm not kidding. Here's how it works. First, scientists dissolve boiled egg whites in water with a chemical called urea, a small molecule that acts as a lubricant, coating the proteins' long strands and making it easier for them to glide past each other. Then, they spin that solution in a glass tube at a breakneck 5000 rotations per minute, making the solution spread out into a thin film. Here's the key part. The solution nearest the wall spins faster than the solution closer to the middle. That difference in velocity creates sheer stresses that repeatedly stretch and contract the proteins until eventually they snap back into their native shapes and stay there. By the time the centrifuge stops spinning, the egg white is back in its original unboiled state. This technique works with all sorts of proteins. Bigger, messier proteins can be more resistant to being pulled apart, so scientists attach a plastic bead to one end that adds extra stress and encourages it to fold up first. This unboiling method won't work with a whole egg in its shell since the solution has to spread throughout a cylindrical chamber. But the applications go way beyond uncooking your breakfast, anyhow. Many pharmaceuticals consist of proteins that are extremely expensive to produce, partly because they get stuck in tangled up aggregates, just like cooked egg whites and have to be untangled and refolded before they can do their jobs. This spinning technique has the potential to be an easier, cheaper and quicker method than other ways to refold proteins, so it may allow new drugs to be made available to more people faster. And there's one more thing you need to keep in mind before trying to uncook all of your food. Boiling an egg is actually an unusual cooking process because even though it changes the way proteins are shaped and bound together, it doesn't actually change their chemical identity. Most types of cooking are more like the famous Maillard reaction, which makes chemical changes that turn sugars and proteins into delicious caramel crunchiness and are a lot harder to undo. So you might be able to unboil your egg, but I'm sorry to say you can't unfry it...yet. |
The benefits of good posture | null | TED-Ed | Has anyone ever told you, "Stand up straight!" or scolded you for slouching at a family dinner? Comments like that might be annoying, but they're not wrong. Your posture, the way you hold your body when you're sitting or standing, is the foundation for every movement your body makes, and can determine how well your body adapts to the stresses on it. These stresses can be things like carrying weight, or sitting in an awkward position. And the big one we all experience all day every day: gravity. If your posture isn't optimal, your muscles have to work harder to keep you upright and balanced. Some muscles will become tight and inflexbile. Others will be inhibited. Over time, these dysfunctional adaptations impair your body's ability to deal with the forces on it. Poor posture inflicts extra wear and tear on your joints and ligaments, increases the likelihood of accidents, and makes some organs, like your lungs, less efficient. Researchers have linked poor posture to scoliosis, tension headaches, and back pain, though it isn't the exclusive cause of any of them. Posture can even influence your emotional state and your sensitivity to pain. So there are a lot of reasons to aim for good posture. But it's getting harder these days. Sitting in an awkward position for a long time can promote poor posture, and so can using computers or mobile devices, which encourage you to look downward. Many studies suggest that, on average, posture is getting worse. So what does good posture look like? When you look at the spine from the front or the back, all 33 vertebrae should appear stacked in a straight line. From the side, the spine should have three curves: one at your neck, one at your shoulders, and one at the small of your back. You aren't born with this s-shaped spine. Babies' spines just have one curve like a "c." The other curves usually develop by 12-18 months as the muscles strengthen. These curves help us stay upright and absorb some of the stress from activities like walking and jumping. If they are aligned properly, when you're standing up, you should be able to draw a straight line from a point just in front of your shoulders, to behind your hip, to the front of your knee, to a few inches in front of your ankle. This keeps your center of gravity directly over your base of support, which allows you to move efficiently with the least amount of fatigue and muscle strain. If you're sitting, your neck should be vertical, not tilted forward. Your shoulders should be relaxed with your arms close to your trunk. Your knees should be at a right angle with your feet flat on the floor. But what if your posture isn't that great? Try redesigning your environment. Adjust your screen so it's at or slightly below eyelevel. Make sure all parts of your body, like your elbows and wrists, are supported, using ergonomic aids if you need to. Try sleeping on your side with your neck supported and with a pillow between your legs. Wear shoes with low heels and good arch support, and use a headset for phone calls. It's also not enough to just have good posture. Keeping your muscles and joints moving is extremely important. In fact, being stationary for long periods with good posture can be worse than regular movement with bad posture. When you do move, move smartly. Keep anything you're carrying close to your body. Backpacks should be in contact with your back carried symetrically. If you sit a lot, get up and move around on occassion, and be sure to exercise. Using your muscles will keep them strong enough to support you effectively, on top of all the other benefits to your joints, bones, brain and heart. And if you're really worried, check with a physical therapist, because yes, you really should stand up straight. |
The origin of countless conspiracy theories | null | TED-Ed | If you line up the entire text of "Moby Dick," which was published in 1851, into a giant rectangle, you may notice some peculiar patterns, like these words, which seem to predict the assassination of Martin Luther King, or these references to the 1997 death of Princess Di. So, was Herman Melville a secret prophet? The answer is no, and we know that thanks to a mathematical principle called Ramsey theory. It's the reason we can find geometric shapes in the night sky, it's why we can know without checking that at least two people in London have exactly the same number of hairs on their head, and it explains why patterns can be found in just about any text, even Vanilla Ice lyrics. So what is Ramsey theory? Simply put, it states that given enough elements in a set or structure, some particular interesting pattern among them is guaranteed to emerge. As a simple example, let's look at what's called the party problem, a classic illustration of Ramsey theory. Suppose there are at least six people at a party. Amazingly enough, we can say for sure that some group of three of them either all know each other, or have never met before, without knowing a single thing about them. We can demonstrate that by graphing out all the possibilities. Each point represents a person, and a line indicates that the pair know each other. Every pair only has two possibilities: they either know each other or they don't. There are a lot of possibilities, but every single one has the property that we're looking for. Six is the lowest number of guests where that's guaranteed to be the case, which we can express like this. Ramsey theory gives us a guarantee that such a minimum number exists for certain patterns, but no easy way to find it. In this case, as the total number of guests grows higher, the combinations get out of control. For instance, say you're trying to find out the minimum size of a party where there's a group of five people who all know each other or all don't. Despite five being a small number, the answer is virtually impossible to discover through an exhaustive search like this. That's because of the sheer volume of possibilities. A party with 48 guests has 2^(1128) possible configurations, more than the number of atoms in the Universe. Even with the help of computers, the best we know is that the answer to this question is somewhere between 43 and 49 guests. What this shows us is that specific patterns with seemingly astronomical odds can emerge from a relatively small set. And with a very large set, the possibilities are almost endless. Any four stars where no three lie in a straight line will form some quadrilateral shape. Expand that to the thousands of stars we can see in the sky, and it's no surprise that we can find all sorts of familiar shapes, and even creatures if we look for them. So what are the chances of a text concealing a prophecy? Well, when you factor in the number of letters, the variety of possible related words, and all their abbreviations and alternate spellings, they're pretty high. You can try it yourself. Just pick a favorite text, arrange the letters in a grid, and see what you can find. The mathematician T.S. Motzkin once remarked that, "while disorder is more probable in general, complete disorder is impossible." The sheer size of the Universe guarantees that some of its random elements will fall into specific arrangements, and because we evolved to notice patterns and pick out signals among the noise, we are often tempted to find intentional meaning where there may not be any. So while we may be awed by hidden messages in everything from books, to pieces of toast, to the night sky, their real origin is usually our own minds. |
How to practice effectively...for just about anything | {0: "French hornist Dr. Annie Bosler wears many hats in her career as a Los Angeles freelance musician: by day a teacher at UC Irvine and the Colburn School of Performing Arts, by night a performer of all music genres from classical to the popular fields and beyond. \r\n\r\nBosler has toured with John Williams' Star Wars in Concert and Josh Groban performing on Dancing with the Stars, The Ellen Show, and PBS's Live from Lincoln Center. She also shared the stage with Ringo Starr and Paul McCartney on CBS's The Beatles: The Night That Changed America - A Grammy Tribute. \r\n\r\nShe produced and directed 1M1: Hollywood Horns of the Golden Years, a one of a kind film doc about the history of Los Angeles studio musicians told through the eyes of the legendary Hollywood horn players.\r\n\r\nwww.anniebosler.com"} | TED-Ed | Mastering any physical skill, be it performing a pirouette, playing an instrument, or throwing a baseball, takes practice. Practice is the repetition of an action with the goal of improvement, and it helps us perform with more ease, speed, and confidence. So what does practice do in our brains to make us better at things? Our brains have two kinds of neural tissue: grey matter and white matter. The grey matter processes information in the brain, directing signals and sensory stimuli to nerve cells, while white matter is mostly made up of fatty tissue and nerve fibers. In order for our bodies to move, information needs to travel from the brain's grey matter, down the spinal cord, through a chain of nerve fibers called axons to our muscles. So how does practice or repetition affect the inner workings of our brains? The axons that exist in the white matter are wrapped with a fatty substance called myelin. And it's this myelin covering, or sheath, that seems to change with practice. Myelin is similar to insulation on electrical cables. It prevents energy loss from electrical signals that the brain uses, moving them more efficiently along neural pathways. Some recent studies in mice suggest that the repetition of a physical motion increases the layers of myelin sheath that insulates the axons. And the more layers, the greater the insulation around the axon chains, forming a sort of superhighway for information connecting your brain to your muscles. So while many athletes and performers attribute their successes to muscle memory, muscles themselves don't really have memory. Rather, it may be the myelination of neural pathways that gives these athletes and performers their edge with faster and more efficient neural pathways. There are many theories that attempt to quantify the number of hours, days, and even years of practice that it takes to master a skill. While we don't yet have a magic number, we do know that mastery isn't simply about the amount of hours of practice. It's also the quality and effectiveness of that practice. Effective practice is consistent, intensely focused, and targets content or weaknesses that lie at the edge of one's current abilities. So if effective practice is the key, how can we get the most out of our practice time? Try these tips. Focus on the task at hand. Minimize potential distractions by turning off the computer or TV and putting your cell phone on airplane mode. In one study, researchers observed 260 students studying. On average, those students were able to stay on task for only six minutes at a time. Laptops, smartphones, and particularly Facebook were the root of most distractions. Start out slowly or in slow-motion. Coordination is built with repetitions, whether correct or incorrect. If you gradually increase the speed of the quality repetitons, you have a better chance of doing them correctly. Next, frequent repetitions with allotted breaks are common practice habits of elite performers. Studies have shown that many top athletes, musicians, and dancers spend 50-60 hours per week on activities related to their craft. Many divide their time used for effective practice into multiple daily practice sessions of limited duration. And finally, practice in your brain in vivid detail. It's a bit surprising, but a number of studies suggest that once a physical motion has been established, it can be reinforced just by imagining it. In one study, 144 basketball players were divided into two groups. Group A physically practiced one-handed free throws while Group B only mentally practiced them. When they were tested at the end of the two week experiment, the intermediate and experienced players in both groups had improved by nearly the same amount. As scientists get closer to unraveling the secrets of our brains, our understanding of effective practice will only improve. In the meantime, effective practice is the best way we have of pushing our individual limits, achieving new heights, and maximizing our potential. |
The "dementia village" that's redefining elder care | {0: 'Yvonne van Amerongen is an occupational therapist and a social worker.'} | TEDWomen 2018 | This is the Hogeweyk. It's a neighborhood in a small town very near Amsterdam, in the Netherlands. There are 27 houses for six, seven people each. There's a small mall with a restaurant, a pub, a supermarket, a club room. There are streets, alleys, there's a theater. It actually is a nursing home. A nursing home for people that live with an advanced dementia and that need 24-7 care and support. Dementia is a terrible disease, and we still don't have any cure for it. It's getting to be a major problem in the world, for the people, for the politicians, for the world — it's getting to be a big problem. We see that we have waiting lists in the nursing homes. Most people that come to the nursing homes with dementia are women. And that's also because women are used to taking care of people, so they can manage to take care of their husband with dementia, but the other way around is not so easy for the gentlemen. Dementia is a disease that affects the brain. The brain is confused. People don't know anymore what the time is, what's going on, who people are. They're very confused. And because of that confusion, they get to be anxious, depressed, aggressive. This is a traditional nursing home. I worked there in 1992. I was a care manager. And we often spoke together about the fact that what we were doing there was not what we wanted for our parents, for our friends, for ourselves. And one day, we said, "When we keep on saying this, nothing is going to change. We are in charge here. We should do something about this, so that we do want to have our parents here." We talked about that, and what we saw every day was that the people that lived in our nursing home were confused about their environment, because what they saw was a hospital-like environment, with doctors and nurses and paramedics in uniform, and they lived on a ward. And they didn't understand why they lived there. And they looked for the place to get away. They looked and hoped to find the door to go home again. And we said what we are doing in this situation is offering these people that already have a confused brain some more confusion. We were adding confusion to confusion. And that was not what these people needed. These people wanted to have a life, and the help, our help, to deal with that dementia. These people wanted to live in a normal house, not in a ward. They wanted to have a normal household, where they would smell their dinner on the stove in the kitchen. Or be free to go to the kitchen and grab something to eat or drink. That's what these people needed. And that's what we should organize for them. And we said we should organize this like at home, so they wouldn't live with a group of 15 or 20 or 30, like in a ward. No, a small group of people, six or seven, family-like. Like living with friends. And we should find a way to select people based on their ideas about life so that they did have a good chance to become friends, when they lived together. And we interviewed all the families of the residents about "what is important for your father," "what's important for your mother," "what is their life like," "what do they want." And we found seven groups, and we call them lifestyle groups. And for instance, we found this formal lifestyle. In this lifestyle, people have a more formal way of interacting with each other, a distant way. Their daily rhythm starts later in the day, ends later in the day. Classical music is more heard in this lifestyle group than in other lifestyle groups. And their menu, well, is more French cuisine than traditional Dutch. (Laughter) In contrary to the craftsman lifestyle. That's a very traditional lifestyle, and they get up early in the morning, go to bed early, because they have worked hard their whole life, mostly with their hands, very often had a very small family business, a small farm, a shop, or like Mr. B, he was a farmhand. And he told me that he would go to his work every morning with a paper bag with his lunch and one cigar. That one cigar was the only luxury he could afford for himself. And after lunch, he would have that one cigar. And until the day he died in the Hogeweyk, he was in this little shed, every day, after lunch, to smoke his cigar. This is my mother. She's of the cultural lifestyle, she's been living in the Hogeweyk six weeks now. And that lifestyle is about traveling, meeting other people, other cultures, interest in arts and music. There are more lifestyles. But that's what we talked about, and that's what we did. But that's not life in a house with a group of people, like-minded people, your own life, your own household. There's more in life, everybody wants fun in life and a meaningful life. We are social animals — we need a social life. And that's what we started. We want to go out of our house and do some shopping, and meet other people. Or go to the pub, have a beer with friends. Or like Mr. W — he likes to go out every day, see if there are nice ladies around. (Laughter) And he's very courteous to them, and he hopes for smiles and he gets them. And he dances with them in the pub. It's a feast every day. There are people that would rather go to the restaurant, have a wine with friends, or lunch or dinner with friends and celebrate life. And my mother, she takes a walk in the park, and sits on a bench in the sun, hoping that a passerby will come and sit next to her and have a conversation about life or about the ducks in the pond. That social life is important. It means that you're part of society, that you belong. And that's what we people need. Even if you're living with advanced dementia. This is what I see from my office window. And one day, I saw a lady coming from one side, and the other lady from the other side, and they met at the corner. And I knew both ladies very well. I often saw them walking around outside. And now and then, I tried to have a conversation with them, but their conversation was ... rather hard to understand. But I saw them meeting, and I saw them talking, and I saw them gesturing. And they had fun together. And then they said goodbye, and each went their own way. And that's what you want in life, meeting other people and being part of society. And that's what I saw happening. The Hogeweyk has become a place where people with very advanced dementia can live, have freedom and safety, because the professionals working there and the volunteers working there know how to deal with dementia. And the professionals know how to do their professional work in a way that it fits in a natural way in the life of our residents. And that means that the management has to provide everything those people need to do their work. It needs a management that dares to do this. To do things differently than we always have done in a traditional nursing home. We see that it works. We think this can be done everywhere, because this is not for the rich. We've been doing this with the same budget as any traditional nursing home has in our country. We work only with the state budget. (Applause) Because it has to do with thinking different, and looking at the person in front of you and looking at what does this person need now. And it's about a smile, it's about thinking different, it's about how you act, and that costs nothing. And there's something else: it's about making choices. It's about making choices what you spend your money on. I always say, "Red curtains are as expensive as gray ones." (Laughter) It's possible, everywhere. Thank you. (Applause) |
The physics of surfing | null | TED-Ed | Whether or not you realize it, as a surfer you’re a master of complicated physics. The science of surfing begins as soon as you and your board first hit the water. The board’s size and light construction help it displace a lot of water. In turn, a buoyant force equal to the weight of the displaced water pushes up, counteracting you and your board’s weight. This lets you stay afloat while you wait to paddle for a wave. And what exactly are you waiting for? The perfect wave, of course. Like other waves in physics, ocean waves represent a transfer of energy. Wind blowing across the ocean accelerates water particles near the surface, leading to the growth of ripples that become waves. These deviations from the flat surface are acted upon by gravity, which tries to restore the surface to its original flat state. As the waves then move through the water, particles push and pull on their neighbors through the wave induced pressure, and this motion propagates energy through the water in unison with the wave motion. The motion of these particles is much more limited than the overall motion of the waves. Near the shore, the shallower seafloor constrains the motion of the waves to occur in a more limited region than out at sea, concentrating the wave energy near the surface. If the topography of the shoreline is even and smooth, this will refract the waves to become more parallel to the shore as they approach. This is the crucial moment. As the wave gets near, you quickly pivot your board in the same direction as the wave and paddle to match its speed. Your board forms an angle with the water, and this creates a dynamic pressure on the bottom of it, forcing you and your board out of the water, to skim along the surface. At the same time, your increased forward momentum makes you more stable, allowing you to stand up and surf along the wave. Now you’ve caught the wave, and are riding along its front face parallel to the shoreline. Fins on the surfboard allow you to alter your speed and direction by repositioning your weight. Above you is the wave’s crest, where the water particles are undergoing their greatest acceleration. That forces them to move faster than the underlying wave, so they shoot ahead before falling under gravity’s influence. This forms the waves’ characteristic curls, or jets, as they break along the shore. Sometimes, the curl might completely enclose part of the wave, forming a moving tube of water known as the barrel. Because of irregularities in the seafloor and the swell itself, few barrels last as long as the legendary 27-second ride off the coast of Namibia. But many who manage to get barreled have said they feel time passing differently inside, making it one of the most magical experiences a surfer can have. Of course, not all beaches are created equal. Offshore underwater canyons or rock formations in certain locations like Nazare, Portugal or Mavericks, California refract the incoming wave energy into a single spot, creating massive waves sought by surfers worldwide. And some of these waves travel for more than a week, with swells originating more than 10,000 kilometers away from shore. Waves surfed in sunny California may have originated in the stormy seas near New Zealand. So while you may not be thinking about weather patterns in the South Pacific, tectonic geology, or fluid mechanics, the art of catching the perfect wave relies on all these things and more. And the waves we surf, created by wind, are just one visible part of the continuous oscillation of energy that has shaped our universe since its very beginning. |
Why talent carries you further than fame | null | TEDxManchester | Hi. I'm Maisie Williams. And I'm kind of just waiting for someone to come on stage and tell me that there's been some sort of miscommunication, and that I should probably leave. No? Damn it. (Laughter) So, some of you may know me as an actress. (Cheers) (Laughter) Some of you may know me for my really average tweets. (Cheers) Oh, yeah. And some of you may be finding out who I am for the first time right now. Hello. Whether you knew me before or not, you're probably wondering what I'm going to talk to you about today. And I would be lying if I said it didn't take me one or two sleepless nights, trying to figure that out, too. At last, here I am. Upon finding out the news that I would be giving a TEDx Talk, I did what I think most people do and watched about 50 TED talks back-to-back, and read "Talk like TED" by Carmine Gallo for some inspiration. Was I inspired? Yes and no. Did it make me want to go out and change the world? Hell yeah. Did it make me feel like a totally inadequate public speaker with absolutely no point to make, who was definitely in need of a big thesaurus if she wants to keep up? Indeed. What could I possibly say that would have any impact? What point am I trying to make? And who the hell thought it was a good idea to give me a TEDx talk? So here's the part where I tell you what I know: I'm the youngest of four siblings. My parents divorced when I was four months old. I really was the icing on the cake of a terrible marriage. (Laughter) I have two step siblings who are younger than me and a half brother who's older than all of us. I grew up in a three-bedroom council house with four of my six siblings just outside of Bristol. I went to a very ordinary school. I got very ordinary grades. I wasn't quite good enough to get a gold star, and I also wasn't quite bad enough to be kept after school. I walked that nice center line where if I kept my mouth shut in class, then I could probably get away with not being spoken to you by teachers for weeks on end. Everything about me was pretty damn ordinary, except for how I felt on the inside. I had big dreams. Shock. From as young as I can remember, I have dreamed of becoming a professional dancer. There are certain memories from my childhood that I would really rather forget. But during those times of immense pain, I found myself instinctively walking over to my mother's CD player, cranking up the volume to drown out the noise and letting my body move to the beat. It's hard to describe how it felt. I was harnessing emotions that I didn't even really know the names of yet. I was summoning all of this energy and feeling it flow through my body and out of my fingertips. I was alone in my own head, and I felt the most alive. I didn't really know much about the big wide world then, but I knew that this feeling was addictive; and I was going to stop at nothing until I made it my profession. At eight years old, I was enrolled in dance class. And by ten, I informed my mother that I didn't want to go to school anymore. I wanted to be like Billy Elliot and go to stage school. This was the first opportunity or challenge I was presented with. Even as young as ten, I was willing to give up all of my friends and go away to board at a private school, away from my siblings, away from my mom. She would repeatedly ask me, "Are you sure this is what you want?" And to me, it was a no-brainer. I didn't just want this; I needed it. My grubby knees and crooked teeth were not on the list of requirements for becoming a professional dancer. And when I look back now, both myself and my mother looked severely out of place. But at the time, I was just too young and naive to feel inadequate. I didn't care. If Billy Elliot could do it, so could I. Once my audition was done, I returned home for two weeks of staring out the window, waiting for the postman, waiting for my ticket out of my sleepy village and into a world of jazz hands and dorm rooms. It was good news followed by bad news: I had got in, but the fees to attend a school like this were not cheap, and despite my best efforts, I had not received any government funding. I auditioned again the following year. And this time, I received 40% funding, but this was still just money that we didn't have, and it broke my heart. I was good enough. I made the cut. But I wasn't going anywhere. It was a blessing in disguise, although if anyone had said that to me back then, I probably would've given them the finger and told them to jog on. I wasn't willing to give up that easily. So at age 11, I was bursting with excitement when my dance teacher informed me of a talent show which boasted opportunities of making you a star. This was the second opportunity I was faced with. I entered into singing, acting, dancing and modeling. The talent show consisted of workshops and seminars with specialists who would help train you up for your performance at the end of the week. After meeting a woman called Louise Johnston in an improvisation acting workshop, she gave me the words "bowling ball," and asked me to create a short scene inspired by these words. After making her laugh with a fictional story, of how I threw a bowling ball at my brother and it bounced, she asked me to join her acting agency. I didn't really know what this meant. I knew that I would do auditions for films and maybe become an actor, but I still had big dreams of becoming a professional dancer, so this woman was going to have to work a lot harder than that if she was going to convince eleven-year-old me that I was going to become an actress. Was this going to take time away from the 30 hours of dancing I was doing a week? And what if I didn't get the part? Was this going to be too upsetting? And do actresses have teeth like mine? Because if they do, I'm yet to watch any of their movies. After meeting Louise in the February of 2009 and trying but failing to land the part in the hit sequel "Nanny McPhee" to "The Big Bang," my second audition was for a show called "Game of Thrones." This was the third opportunity or challenge I was presented with. I climbed the steps to the Methodist Church with my mother's hand in mine. I perched my tiny bottom in one of the seats outside the audition room and listened to an annoying girl with her even more annoying mother tell me all about the number of auditions she had done prior to this one. And also about her pet fish. My name was called, then I stepped inside. I had a hard Bristolian accent and dark rings around my eyes that were so big they took up half my face and a hole in the knee of my trousers which I tried to cover with my left hand as I was talking to the kind lady who taped my audition. But as soon as she pressed record, it all drifted away. Much like when I was dancing in my mother's living room, I harnessed all of my insecurities and self-doubt and let it flow through the words that came out of my mouth. I was cheeky. I was loud. I was angry. And for this, I was perfect. After getting the part and shooting the pilot episode, the show slowly grew to become one of the biggest shows in television history. To this day, we've smashed previous HBO viewing records. We've been nominated for over 130 Emmys, making us the most Emmy-nominated show to ever exist. We've recently finished shooting our eighth and final season, which is predicted to smash records that we've already broken. And nearly a decade to the day since my first audition, I'm still wondering, when am I going to get to be Billy Elliot? (Laughter) I joke, but in all seriousness, I have absolutely no plans of slowing down. Throughout my time in this industry, it has been a minefield. I have grown from a child into an adult, and from four feet tall into a whopping five feet tall. (Laughter) I have constantly been trying to say the right thing, accidentally saying the wrong thing, trying not to swear too much and trying to stop saying "like, like" all of the time. In February of 2017, a friend of mine, Dom, and I were swigging beers in my kitchen, and he confessed to me that there is a huge problem with the creative industries. I agreed. The series of events that had got me to that point were based mainly on luck and timing and were unable to be recreated. He suggested to me that we create a social media, but just for artists to be able to collaborate with one another and create a career. This was the fourth opportunity or challenge I was presented with. "Great," I thought. "How the hell do we do that?" And daisie was born. Of course, everyone who I spoke to about my latest endeavor thought that I was mad; however, I know that this is something that I can help change. This last year in the industry, we've seen a huge shift with the Me Too movement. The industry is built with gatekeepers holding all of the power and selecting who they deem talented enough to advance to the next level. More often than not, it's easier to catch the attention of those people if you have graduated from an expensive school. But even then, I have so many friends who are fresh out of art school, having trained for years and are still no closer to creating a career. Now, I'm not claiming that with daisie I can make everybody a star, but I do believe that the key to success within creative industries is collaborating. Actors are only as good as their writers. Musicians are only as strong as their producers. And designers need their teams. To start the company, we self-funded. I had a pot of cash from "Game of Thrones" that I was free to invest wherever I liked. Dom had a series of businesses from the age of 16, which meant he was also left with a pot of cash. We threw our money together 50-50, and we built a team. Now, Lady Gaga has repeatedly said that there could be a room of 100 people, and 99 don't believe in you, but it just takes that one person to believe in you, and they can change your life. Well, now we have a team of six. Over the next 16 months, we built our MVP. Now, if you're wondering what an MVP is, I only found out what it is about six months ago. And from what I can gather, it's a product which proves as a problem worth solving with the minimum team effort. So basically from my point of view, you're marketing something which you know is going to be good one day, but is a little bit bad right now. And for us, that was an iOS app. The six of us made an office in Dom's garden, and on August 1, 2018, we released our version one. We had over 30,000 downloads in the first 24 hours and over 30,000 comments asking when the Android version was going to be coming. Despite our app being imperfect, buggy and literally built by one man alone, this was exactly what we needed for people to invest. We learned a lot from our angry users and our scary investors. And over the last six months, we have grown our team to 16 people. From then till now, we've been building version two, which we will be launching in April. Within the industry, there is a common phrase which I think we're all pretty familiar with. And that is, "It's not what you know, it's who you know." And with daisie, I hope to give that power back to the creator. I want to encourage people to create a list of contacts that they will work with and support as they take their first steps into the fickle and often challenging creative world. I am of the generation who grew up with the Internet. I've never known anything else. We are connected, we are aware, and we are the future. I hope daisie can breathe new life into the slightly dystopian, ad-riddled hellscapes that social media platforms have become. I hope to create a space where people can boast their art and creativity rather than what car they are driving and whether or not they bought it in cash or on finance. In a world where literally anyone can be famous, I hope to inspire people to be talented instead. Talent will carry you so much further than your 15 minutes of fame. So why am I telling you all this? The very fact that I'm here giving a TEDx talk right now is so far from anything I thought that I was capable of. Even writing the bio for my speech made me realize that in a decade, everything in my life has changed. I am an Emmy-nominated actress, an entrepreneur and an activist; yet I have no formal qualifications to my name. When I left school about seven years ago, I made it my mission to continue learning even though I never wanted to set foot in a classroom again. Who knows what's going to happen to my life in the next 10 years? I surely have no idea. I've never had an end goal. It's working out okay so far. So trust that you're good enough. If there's one thing that I've learned is that there truly is a place for everyone. Ask questions, and laugh in the face of people who say that they're stupid questions. Be open to learning and admitting when you don't know what the hell is going on. Refuse to hold yourself back, and dare to dream big. Thank you for listening. (Applause) |
What happens in your throat when you beatbox? | {0: 'Tom Thum whirls together beatboxing, performance and an array of mouthsounds.', 1: 'Matthew Broadhurst is an ear, nose and throat surgeon based in Brisbane, Australia. '} | TEDxSydney | (Beatboxing) Yo, what up? My name is Tom Thum, and I've got to say it's a pleasure to be back at TEDx. When I first stepped upon the Sydney stage in 2013 as a starry-eyed boy from Brisbane, I had no idea that I was about to deliver the most watched TEDx presentation ever. (Laughter) (Applause) But you know, I was stoked because it was completely unexpected. However, standing before you today as a slightly inflated, time-battered version of myself five years later, I'm very confident. (Laughter) Confident that I'm about deliver the most instantly switched off and walked-out-on, vomit-inducing talk of all time. I'm about to show you things that I think you'll find hard to unsee, but all in the name of science. First, for those unfamiliar with what I do, I guess if you distilled it right down to its essence, you would call me a beatboxer. (Beatboxing) Yo, for example ... here's a sample: (Beatboxing) (Rhythm changes) (Hums a tune) (Applause and cheers) Thank you. (Applause) And being a beatboxer, it means that professionally, I am 100 percent reliant on the — (Beatboxing) flexibility of the unfiltered human voice. And for years, my contemporaries and I have been fielding questions like, "Oh my God, that's so cool. When did you figure out you could do that?" After I practiced for thousands and thousands of hours — (Laughter) "And what do you do for a real job?" "I'm a full-time beatboxer, Your Honor." But there is one question that I get quite a lot that's a little bit more difficult to answer, and that is how are you doing it — how are you making those noises? And I mean, I know muscle memory dictates where I position my lips in order to — (Beatboxing) but I have no idea about the inner mechanics of everything. You know, all the flappy bits and kind of dangly things and how they interact in — (Laughter) in a way that allows me to — (Beatboxing) To put it metaphorically, I know how to drive, I just don't know what's under the hood. So I decided to find out and invite 5,000 captive strangers, a few uncomfortable cameras, everybody watching online and their browser history into a place where not even the most intimate of encounters have been ... my throat. And to help me do that, I'd like to introduce to the stage a very specialist guest from the Queensland Voice Center, a man that's been in my mouth more times than I'd care to admit, a legend of the larynx, ENT doctor and laryngeal surgeon, Matthew Broadhurst. (Applause and cheers) MB: Thank you, Tom, thank you. And a very good evening everyone. It is a pleasure to be here on the TEDx stage tonight. (Laughter) Whoo. (Laughter) TT: He's not warming up his hands. It doesn't get that intimate. MB: We set out a little while ago to try to go deep into the world — and the throat — of this beatboxer extraordinaire to try to understand how such a vast array of sounds are humanly possible. And what we found — these are going in the mouth by the way — and what we found was something absolutely amazing. Even after my two years of laryngeal surgery in Harvard Medical School with world-renowned professor Steven Zeitels, we never saw anything as extraordinary or fascinating as this, and that's what we're going to show you tonight. (Laughter) Alright, so for those of you who might be a little squeamish, the next 10 minutes or so will get incrementally more graphic and stomach-churning, so let's get into it — TT: Feel free to use the bucket. (Laughter) MB: So when we make sound, we use the vocal cords to take air from the lungs and then turn it into a vibrating air column in the throat. If you think of it like a trumpet, we've got the mouthpiece — that's the vocal folds — and then the horn section is the throat. If we took your head off, took a bit of your neck off and left you as a torso with just your vocal folds vibrating, this is what you'd sound like. (Flatulent sound) TT: (High pitch) MB: Pretty hard to communicate, but fortunately we've got a throat. We've got all the soft tissues, and that actually gives you all the incredible dynamics of sound that you'll hear tonight. Now, this is a rigid laryngoscope. TT: Hmm, spicy boy. (Laughter) MB: I know, I know. (Laughter) 10 millimeters in diameter, it gives us the highest resolution image of the larynx we can get. And we teed up with a stroboscope here and a trigger microphone. The mic will pick up the frequency and that will allow us to show you how this all works. So, if we can have the lights down? TT: (Low pitch) MB: Turn the light on here. TT: (High and low pitches) MB: So I've got the frequency of sound matched with the stroboscope. That's the light you're seeing flickering in the cup. TT: (Low pitch) MB: And that's at about 80 hertz or so. So what we can do then is we can take that and put the phase of the strobe and the sound just out of sync. That lets us capture real-time, slow-motion activity of vibrating tissues. When we apply that to the larynx, we get this fluid, slow-motion of the vibrating vocal folds. So that's what we're going to get on and do. Alright, you ready? TT: Yup. (Laughter) MB: OK, so here we go. We're going to have a look at the voice box. (Laughter) It's very hard not to gag with this. Say, "e." TT: (Singing) E — MB: So down the bottom you see the vocal cords, the little cord-like structures. (Laughter) And now just look at the skin on the neck and you'll see how strong the light is to penetrate the skin. Alright, so if you'll have the lights back on? (Laughter) (Applause) Alright, so just give us a comfortable "e." TT: (Singing) E. (Laughter) TT: (Singing) E. (Audience gasps) MB: So that's the vibrating vocal folds; about 120 hertz. Means they've collided 120 times a second just to make that sound. And we can also see that they're absolutely, perfectly normal. So all his beatboxing, all those sounds for years with Tom's way of doing it — absolutely no damage whatsoever. That's really remarkable. Well done. OK. TT: (High pitch) We've got this. MB: So watch now as the vocal cords go from high pitch to low pitch. You'll see them go from long and skinny to short and fat. Really think "e." TT: (High to low pitch) E. MB: Right. TT: (High to low pitch) E. MB: And what you can see is that his vocal range is so extreme — much more extreme than any other performer I've worked with — the machine actually can't capture the really high pitches. TT: (High pitch) MB: So we know that whistle register is somewhere around 2,092 hertz. That means the vocal cords, well over 2,000 times a second, are banging together just to make that sound. That's really extraordinary. If you think about them, they're only 15 millimeters long, so that's barely the width of your thumb. That's incred — (Laughter) That's amazing this organ can do such a thing. So now we're going to swap over to the flexible laryngoscope. This is a little more graphic. TT: He bought it at SEXPO. (Laughter) MB: That wasn't in the script. (Laughter) (Applause) TT: Secondhand. (Laughter) MB: Now, we've had to time this bit perfectly because of the requirement for local anesthetic. You've got to numb the nose, get the camera in. It doesn't help for producing a lot of the sounds, but it gives us a really cool view of what's happening. So hold onto the stomachs, and let's see what we can do. (Audience gasps) So we're going to the back of the nose. And there you can see the soft palate. A lot of the sounds we make from day to day, even the simple ones, are incredibly complex. The sound "kh" for example. It's the soft palate sealing up precisely against the back of the nose. So if you say it loudly five times, feel your own soft palate snapping against the back of the throat. Kh, kh, kh, kh, kh, kh. Alright, so this is what it looks like when Tom does it. TT: Kh, kh, kh, kh, kh. A cacophony of cackling kookaburras and cockatoos in Kakadu couldn't quite quit ketamine. (Laughter) (Applause) MB: Alright, now in the beatboxing world, of course, they can use that for all sorts of different effects. I can help you. TT: This is fine, we're professionals. (Laughter) (Beatboxing) MB: Alright. (Applause and cheers) Now we're going to slide down a little further. If you'll just have the lights off and just see if you can see the light in the mouth somewhere. You'll be able to see exactly where the camera is at. (Laughter) TT: (Singing) Surprise. (Laughter) MB: Alright. (Audience gasps) So what you can see there, that's the base of the tongue. The side walls of the screen, that's the pharynx. All muscle walls, and in the deep, dark decks is the larynx. TT: Oh, should we have the lights back on? I think it's a good idea. It's getting a bit creepy with them off. MB: Turn the lights on, thanks. Good. Now having examined over 15,000 larynxes and throats in my time, I can tell you that Tom's is as anatomically normal as anyone else's. It's just his unique use of all the muscles and soft tissues which lets him do all these amazing sounds that you're going to hear. So we will dissect some of these sounds for you now. TT: It's in there really. Definitely. (Laughter) OK. (High-pitched sounds) (High-pitched sounds) (Hooting) MB: So what he's doing is he's changing the shape and the length of the vibrating air column using rhythmic contractions of all the muscles to generate all those sounds that you're hearing. (Beatboxing) (Laughter) (Low pitch) MB: And now there's rhythmic movements of the — they're the arytenoid cartilages way down there, rocking back and forth to create that different sound. TT: (Low pitch) MB: And we like to call this "sphincter bass." (Laughter) And what you can see is that collapsing all the tissue down — (Laughter) allows a different kind of really deep bass note. Alright, so with local anesthetic on board, a big black hose in the nose, we're going to let loose a sliver of his repertoire and see all this in play. And we'll move — careful. TT: Can you pull it up just a smidgeon. (Laughter) TT: (Beatboxing) Maybe just a little more — (Laughter) Alright, cool, I think we're good. (Beatboxing) To all my peeps who came to get deep, deep as the abyss — check this. (Beatboxing) (Cheers) (Applause) (Beatboxing) We start from the basics and build from scratch. (Record scratch) Yeah, like that. (Beatboxing) (Trumpet sound) (Beatboxing) (Beatboxing) Back to basics. (Beatboxing) (Beatboxing) You know the sound. (Beatboxing) Make some noise. (Applause and cheers) (Whistling) (Applause and cheers) TT: Thank you so much. |
Harvey Milk's radical vision of equality | null | TED-Ed | By 1973, Harvey Milk had already been many things: naval officer, high school teacher, bit-part actor, and wandering hippie. But as he embarked on yet another life running a camera shop in San Francisco, he already found himself distracted. From the Watergate hearings on national news, to the teacher who had to rent a projector when her school couldn’t afford one, Harvey saw a desperate need for political reform. Milk strongly believed that tight knit neighborhoods were essential to the fabric of the city, and that government should solve those community’s most practical problems. From fixing potholes and putting up stop signs, to promoting a friendly culture of cooperation, Milk envisioned a more personal approach to local government. This philosophy led him to run for the city’s Board of Supervisors as the representative for his own district, which included the heart of American gay culture, the Castro. At this time, police brutality, discrimination and media stereotyping plagued the LGBT community, labeling Harvey and his supporters as political outsiders. But Milk refused to downplay his sexuality. He was sure that gay rights could never be won from the closet, and he saw the Castro as one of many minorities without representation in city politics. Milk was determined to bring these basic government services to all of San Francisco’s disenfranchised groups, regardless of race, age, or sexuality. But despite his flair for public speaking and open-hearted approach, voters couldn’t see Milk’s radical vision. In 1973, he lost his first bid for the Board of Supervisors. In 1975, he lost again. A year later, he ran for the California Assembly– and lost. Yet he tirelessly continued to support his district, befriending bartenders, construction unions, and local Chinese grocers. This earned him the affectionate title, the "mayor of Castro Street.” And when he ran his third campaign for the Board of Supervisors in 1977, Harvey finally won the seat– becoming one of the first openly gay public officials in US history. Elated, Milk arrived in office determined to make lasting change. He immediately introduced a bill outlawing discrimination on the grounds of sexuality and launched a major clean-up of the city. But not everyone was happy with this direction. Anti-gay sentiment was gaining national momentum, especially in the form of California’s Proposition 6. The proposition, which sought to make it illegal for homosexuals to work in Californian schools, would prove to be the biggest battle of Milk’s career. Supporters of Prop 6 attacked the LGBT community, calling them unfit to work with students. But Milk urged them not to hide in fear: “Come out to your relatives. Come out to your friends, if indeed they are your friends. Come out to your neighbors, to your fellow workers… break down the myths. Destroy the lies and distortions. For your sake. For their sake.” Alongside other activists, he ran an incandescent campaign against hate. On November 7, 1978, Prop 6 was defeated in a landslide. It was proof that Milk’s message was gaining traction. But just twenty days after this inspiring victory, he was assassinated at City Hall– killed alongside San Francisco Mayor George Moscone. Both men had been murdered by Dan White, a former fellow supervisor, who had positioned himself against those he called "radicals, social deviates and incorrigibles.” He had frequently clashed with Harvey at Board meetings, and resented the spirit of change which Milk personified for many. The night of Milk's murder, thousands marched by candlelight through the city. In the wake of this tragedy, yet another injustice arose. In a highly controversial verdict, White received a sentence of only seven years and eight months– a decision that sparked uproar throughout the city in what became known as the White Night Riots. But even after his death, Milk continued to preach his hopeful cause. He left his friends and followers a total of three different tapes to be played in the event of his assassination. They leave us with a call to action, and a reminder that everyone is welcome in the fight against injustice: "I ask for the movement to continue… and if a bullet should enter my brain, let that bullet destroy every closet door…” |
Where did the Moon come from? A new theory | {0: 'Sarah T. Stewart specializes in the study of collisions in the solar system.'} | TED Salon U.S. Air Force | Nobody likes to make a mistake. And I made a whopping one. And figuring out what I did wrong led to a discovery that completely changes the way we think about the Earth and Moon. I'm a planetary scientist, and my favorite thing to do is smash planets together. (Laughter) In my lab, I can shoot at rocks using cannons like this one. (Cannon shot) (Laughter) In my experiments, I can generate the extreme conditions during planet formation. And with computer models, I can collide whole planets together to make them grow, or I can destroy them. (Laughter) I want to understand how to make the Earth and the Moon and why the Earth is so different from other planets. The leading idea for the origin of the Earth and Moon is called the "giant impact theory." The theory states that a Mars-sized body struck the young Earth, and the Moon formed from the debris disk around the planet. The theory can explain so many things about the Moon, but it has a huge flaw: it predicts that the Moon is mostly made from the Mars-sized planet, that the Earth and the Moon are made from different materials. But that's not what we see. The Earth and the Moon are actually like identical twins. The genetic code of planets is written in the isotopes of the elements. The Earth and Moon have identical isotopes. That means that the Earth and Moon are made from the same materials. It's really strange that the Earth and the Moon are twins. All of the planets are made from different materials, so they all have different isotopes, they all have their own genetic code. No other planetary bodies have the same genetic relationship. Only the Earth and Moon are twins. When I started working on the origin of the Moon, there were scientists that wanted to reject the whole idea of the giant impact. They didn't see any way for this theory to explain the special relationship between the Earth and the Moon. We were all trying to think of new ideas. The problem was, there weren't any better ideas. All of the other ideas had even bigger flaws. So we were trying to rescue the giant impact theory. A young scientist in my group suggested that we try changing the spin of the giant impact. Maybe making the Earth spin faster could mix more material and explain the Moon. The Mars-sized impactor had been chosen because it could make the Moon and make the length of Earth's day. People really liked that part of the model. But what if something else determined the length of Earth's day? Then there would be many more possible giant impacts that could make the Moon. I was curious about what could happen, so I tried simulating faster-spinning giant impacts, and I found that it is possible to make a disk out of the same mixture of materials as the planet. We were pretty excited. Maybe this was the way to explain the Moon. The problem is, we also found that that's just not very likely. Most of the time, the disk is different from the planet, and it looked like making our Moon this way would be an astronomical coincidence, and it was just hard for everyone to accept the idea that the Moon's special connection to Earth was an accident. The giant impact theory was still in trouble, and we were still trying to figure out how to make the Moon. Then came the day when I realized my mistake. My student and I were looking at the data from these fast-spinning giant impacts. On that day, we weren't actually thinking about the Moon, we were looking at the planet. The planet gets super-hot and partially vaporized from the energy of the impact. But the data didn't look like a planet. It looked really strange. The planet was weirdly connected to the disk. I got that super-excited feeling when something really wrong might be something really interesting. In all of my calculations, I had assumed there was a planet with a separate disk around it. Calculating what was in the disk as how we tested whether an impact could make the Moon. But it didn't look that simple anymore. We were making the mistake of thinking that a planet was always going to look like a planet. On that day, I knew that a giant impact was making something completely new. I've had eureka moments. This was not one of them. (Laughter) I really didn't know what was going on. I had this strange, new object in front of me and the challenge to try and figure it out. What do you do when faced with the unknown? How do you even start? We questioned everything: What is a planet? When is a planet no longer a planet anymore? We played with new ideas. We had to get rid of our old way of thinking, and by playing, I could throw away all of the data, all of the rules of the real world, and free my mind to explore. And by making a mental space where I could try out outrageous ideas and then bring them back into the real world to test them, I could learn. And by playing, we learned so much. I combined my lab experiments with computer models and discovered that after most giant impacts, the Earth is so hot, there's no surface. There's just a deep layer of gas that gets denser and denser with depth. The Earth would have been like Jupiter. There's nothing to stand on. And that was just part of the problem. I wanted to understand the whole problem. I couldn't let go of the challenge to figure out what was really going on in giant impacts. It took almost two years of throwing away old ideas and building new ones that we understood the data and knew what it meant for the Moon. I discovered a new type of astronomical object. It's not a planet. It's made from planets. A planet is a body whose self-gravity is strong enough to give it its rounded shape. It spins around all together. Make it hotter and spin it faster, the equator gets bigger and bigger until it reaches a tipping point. Push past the tipping point, and the material at the equator spreads into a disk. It's now broken all the rules of being a planet. It can't spin around together anymore, its shape keeps changing as it gets bigger and bigger; the planet has become something new. We gave our discovery its name: synestia. We named it after the goddess Hestia, the Greek goddess of the hearth and home, because we think the Earth became one. The prefix means "all together," to emphasize the connection between all of the material. A synestia is what a planet becomes when heat and spin push it over the limit of a spheroidal shape. Would you like to see a synestia? (Cheers) In this visualization of one of my simulations, the young Earth is already spinning quickly from a previous giant impact. Its shape is deformed, but our planet would be recognizable by the water on its surface. The energy from the impact vaporizes the surface, the water, the atmosphere, and mixes all of the gases together in just a few hours. We discovered that many giant impacts make synestias, but these burning, bright objects don't live very long. They cool down, shrink and turn back into planets. While rocky planets like Earth were growing, they probably turned into synestias one or more times. A synestia gives us a new way to solve the problem of the origin of the Moon. We propose that the Moon formed inside a huge, vaporous synestia. The Moon grew from magma rain that condensed out of the rock vapor. The Moon's special connection to Earth is because the Moon formed inside the Earth when Earth was a synestia. The Moon could have orbited inside the synestia for years, hidden from view. The Moon is revealed by the synestia cooling and shrinking inside of its orbit. The synestia turns into planet Earth only after cooling for hundreds of years longer. In our new theory, the giant impact makes a synestia, and the synestia divides into two new bodies, creating our isotopically identical Earth and Moon. Synestias have been created throughout the universe. And we only just realized that by finding them in our imagination: What else am I missing in the world around me? What is hidden from my view by my own assumptions? The next time you look at the Moon, remember: the things you think you know may be the opportunity to discover something truly amazing. (Applause) |
How to cope with anxiety | {0: 'Anxiety is one of most prevalent mental health disorders, with 1 out of 14 people around the world being likely affected. Leading up to conditions such as depression, increased risk for suicide, disability and requirement of high health services, very few people who often need treatment actually receive it. In her talk “How to cope with anxiety”, Olivia Remes of the University of Cambridge will share her vision on anxiety and will unravel ways to treat and manage this health disorder. Arguing that treatments such as psychotherapy and medication exist and often result in poor outcome and high rates of relapses, she will emphasise the importance of harnessing strength in ourselves as we modify our problem-coping mechanisms. At TEDxUHasselt 2017, Olivia will stress that by allowing ourselves to believe that what happens in life is comprehensive, meaningful, and manageable, one can significantly improve their risk of developing anxiety disorders. '} | TEDxUHasselt | Imagine that you're getting ready to go to a party. You feel excited, but also nervous, and you've got this feeling in your stomach almost like another heartbeat. There's something holding you back, holding you back from getting too happy. "No, you mustn't get too happy. Better to be cautious, otherwise, something bad might happen." You start wondering, "Who should I talk to when I get there? What if no one wants to talk to me? What if they'll think I'm weird?" When you arrive at the party, someone comes up to you and starts talking with you, and as this is happening, your mind starts racing, your heart begins pounding, you start sweating, and it feels almost like you're dissociating from yourself, like it's an out-of-body experience, and you're just watching yourself talk. "Keep it together," you say to yourself, but you can't. And it's just getting worse: after a few minutes of conversation, the person you've been speaking to leaves, and you feel utterly defeated. This has been happening to you in social situations for a long time. Or imagine every time you go out, and you're in crowded places, you feel this panic starting to arise. When you're surrounded by lots of people, like on a bus, you start to feel hot, nauseous, uneasy, and to prevent this from happening, you start avoiding a lot of places which makes you feel lonely and isolated. You or the person in both of these scenarios have anxiety disorders, and what I can tell you is that anxiety is very common, much more than people think. Right now, one in 14 people around the world have an anxiety disorder, and each year, it costs over 42 billion dollars to treat this mental health problem. To show you the impact that anxiety has on someone's life, I will just mention that anxiety can lead to depression, school dropout, suicide. It makes it harder to focus, and to hold down a job, and it can lead to relationship breakdown. But a lot of people don't know this, that's why, a lot of times, people sweep anxiety under the rug as just nerves that you need to get over, as a weakness, but anxiety is so much more than that. A reason why so many people don't think it's important is that they don't know what it is. Is it your personality? Is it an illness? Is it a normal sensation? What is? That's why it's important to differentiate what is normal anxiety from what is an anxiety disorder. Normal anxiety is an emotion that we all get when we're in stressful situations. For example, let's say, you're out in the woods, and you come face-to-face with a bear. This will probably make you feel a little bit anxious, and you'll probably want to start running like crazy. This anxious feeling that you get is good because it protects you, it saves you, and it makes you on a hightail it out of there, although maybe it's not such a good idea to start running when you see a bear. I really don't think you can outrun a bear. Anxiety helps us meet our deadlines at work and deal with emergencies in life, but when this anxiety emotion is taken to the extreme and arises in situations which don't pose a real threat, then that's when you might have an anxiety disorder. For example, people with generalized anxiety disorder worry excessively and constantly about everything going on in their lives, and they find it very difficult to control this worry. They also have symptoms like restlessness, fear, they find it hard to fall asleep at night, and they can't concentrate on tasks. In spite of whatever kind of anxiety you might be suffering from, there is something that you can do to lower it. It works, and it's simpler than you may think. All too often, we're given medication for mental disorders, but it doesn't always work in the long run. Symptoms often come back, and you're back to where you started. So here's something else to consider: the way you cope or handle things has a direct impact on how much anxiety you're experiencing, and if you tweak the way you're coping, then you can lower your anxiety. In our study at the University of Cambridge, we showed that women living in poor areas have a higher risk for anxiety than women living in richer areas. These results didn't surprise us, but when we looked closer, we found that women living in poor areas, if they had a particular set of coping resources, they didn't have anxiety, while women living in poor areas without these coping resources had anxiety. Other studies showed that people who had faced extreme circumstances, who had faced adversity, been through wars and natural disasters, if they had coping resources, they remained healthy and free of mental disorders, while others, facing the same hardships but without coping skills went on a downward spiral and developed mental disorders. So what are some of these coping resources, and how can we use them to lower our anxiety? And before I dive into what they are, I'd like to point out - and I think this is so interesting - you can develop these coping resources or coping skills on your own through the things that you do; you can take charge of your anxiety and lower it, which I think is so empowering. Today I'll be talking about three coping resources, and the first one is feeling like you're in control of your life. People who feel like they're more in control of their life have better mental health. If you feel like you're lacking in control in life, then research shows that you should engage in experiences that give you greater control. I'll show you what I mean: do you sometimes find that you put off starting something because you just don't feel ready enough? Do you find it hard to make decisions like what to wear, what to eat who to date, which job to take up? Do you tend to waste a lot of time deciding what you might do while nothing gets done? A way to overcome indecision and this lack of control in life, is to do it badly. There's a quote by writer and poet GK Chesterton that says, "Anything worth doing is worth doing badly the first time." The reason why this works so well is that it speeds up your decision-making and catapults you straight into action, otherwise, you can spend hours deciding how you should go about doing something or what you should do. This can be paralyzing and can make you afraid to even begin. All too often, we aim for perfection, but never end up doing anything because the standards that we set for ourselves are too high, they're intimidating, which stresses us out so we delay starting something, or we might even abandon the whole thing altogether. Do it badly frees you up to take action. I mean you know how it is: so often, we want to do something perfectly we can't start until it's the perfect time, until we've got all the skills, but this can be daunting and stressful so why not just jump into it just do it however, without worrying if it's good or bad? This will make it that much easier to start something and as you're doing it badly to finish it, and when you look back, you'll realize, more often than not, that actually it's not that bad. A close friend of mine who has anxiety started using this motto, and this is what she said, "When I started using this motto, my life transformed. I found I could complete tasks in much shorter time periods than before. Do it badly gave me wings to take risks, to try something differently, and to have way more fun during the whole process. It took the anxiety out of everything and replaced it with excitement." So do it badly, and you can improve as you go along. I'd like to ask you to think about this: if you start using this motto today, how would your life change? The second coping strategy is to forgive yourself, and this is very powerful if you use it. People with anxiety think a lot about what they're doing wrong, their worries, and how bad they're feeling. Imagine if you had a friend who constantly pointed out everything you're doing wrong, and everything that was wrong with your life. You would probably want to get rid of this person right away, wouldn't you? Well, people with anxiety do this to themselves all day long. They're not kind to themselves. So maybe it's time to start being kinder with ourselves, time to start supporting ourselves, and a way to do this is to forgive yourself for any mistakes you think you might have made just a few moments ago to mistakes made in the past. If you had a panic attack and are embarrassed about it, forgive yourself; if you wanted to talk to someone, but couldn't muster up the courage to do so, don't worry about it, let it go; forgive yourself for anything and everything and this will give you greater compassion towards yourself. You can't begin to heal until you do this. And last but not least, having a purpose and meaning in life is a very important coping mechanism. Whatever we do in life, whatever work we produce, however much money we make, we cannot be fully happy until we know that someone else needs us, that someone else depends on our accomplishments, or on the love that we have to share. It's not that we need other people's good words to keep going in life, but if we don't do something with someone else in mind, then we're at much higher risk for poor mental health. The famous neurologist Dr. Victor Frankel said, "For people who think there's nothing to live for and nothing more to expect from life, the question is getting these people to realize that life is still expecting something from them." Doing something with someone else in mind can carry you through the toughest times. You'll know the why for your existence and will be able to bear almost any how; almost any how. So the question is do you do at least one thing with someone else in mind? This could be volunteering, or it could be sharing this knowledge that you gained today with other people, especially those who need it most, and these are often the people who don't have money for therapy, and they're usually the ones with the highest rates of anxiety disorders. Give it to them, share with others, because it can really improve your mental health. So I would like to conclude with this: another way you can do something with someone else in mind is finishing work that might benefit future generations. Even if these people will never realize what you've done for them, it doesn't matter, because you will know, and this will make you realize the uniqueness and importance of your life. Thank you. (Applause) |
How tall can a tree grow? | null | TED-Ed | Reaching heights of over 100 meters, Californian sequoias tower over Earth’s other estimated 60,000 tree species. Growing in the misty Sierra Nevada mountains, their massive trunks support the tallest known trees in the world. But even these behemoths seem to have their limits. No sequoia on record has been able to grow taller than 130 meters – and many researchers say these trees won’t beat that cap even if they live for thousands of years to come. So what exactly is stopping these trees from growing taller, forever? It all comes down to sap. In order for trees to grow, they need to bring sugars obtained from photosynthesis and nutrients brought in through the root system to wherever growth is happening. And just like blood circulates in the human body, trees are designed to circulate two kinds of sap throughout their bodies – carrying all the substances a tree’s cells need to live. The first is phloem sap. Containing the sugars generated in leaves during photosynthesis, phloem sap is thick, like honey, and flows down the plant’s phloem tissue to distribute sugar throughout the tree. By the end of its journey, the phloem sap has thinned into a watery substance, pooling at the base of the tree. Right beside the phloem is the tree’s other tissue type: the xylem. This tissue is packed with nutrients and ions like calcium, potassium, and iron, which the tree has absorbed through its roots. Here at the tree’s base, there are more of these particles in one tissue than the other, so the water from the phloem sap is absorbed into the xylem to correct the balance. This process, called osmotic movement, creates nutrient-rich xylem sap, which will then travel up the trunk to spread those nutrients through the tree. But this journey faces a formidable obstacle: gravity. To accomplish this herculean task, the xylem relies on three forces: transpiration, capillary action, and root pressure. As part of photosynthesis, leaves open and close pores called stomata. These openings allow oxygen and carbon dioxide in and out of the leaf, but they also create an opening through which water evaporates. This evaporation, called transpiration, creates negative pressure in the xylem, pulling watery xylem sap up the tree. This pull is aided by a fundamental property of water called capillary action. In narrow tubes, the attraction between water molecules and the adhesive forces between the water and its environment can beat out gravity. This capillary motion is in full effect in xylem filaments thinner than human hair. And where these two forces pull the sap, the osmotic movement at the tree’s base creates root pressure, pushing fresh xylem sap up the trunk. Together these forces launch sap to dizzying heights, distributing nutrients, and growing new leaves to photosynthesize – far above the tree’s roots. But despite these sophisticated systems, every centimeter is a fight against gravity. As trees grow taller and taller, the supply of these vital fluids begins to dwindle. At a certain height, trees can no longer afford the lost water that evaporates during photosynthesis. And without the photosynthesis needed to support additional growth, the tree instead turns its resources towards existing branches. This model, known as the “hydraulic limitation hypothesis,” is currently our best explanation for why trees have limited heights, even in perfect growing conditions. And using this model alongside growth rates and known needs for nutrients and photosynthesis, researchers have been able to propose height limits for specific species. So far these limits have held up – even the world’s tallest tree still falls about fifteen meters below the cap. Researchers are still investigating the possible explanations for this limit, and there may not be one universal reason why trees stop growing. But until we learn more, the height of trees is yet another way that gravity, literally, shapes life on Earth. |
Our dangerous obsession with perfectionism is getting worse | {0: 'Thomas Curran studies the personality characteristic of perfectionism, how it develops and its impact on mental health.'} | TEDMED 2018 | I'm a bit of a perfectionist. Now, how many times have you heard that one? Over drinks, maybe, with friends, or perhaps with family at Thanksgiving. It's everyone's favorite flaw, it's that now quite common response to the difficult, final question at job interviews: "My biggest weakness? That's my perfectionism." You see, for something that supposedly holds us back, it's quite remarkable how many of us are quite happy to hold our hands up and say we're perfectionists. But there's an interesting and serious point because our begrudging admiration for perfection is so pervasive that we never really stop to question that concept in its own terms. What does it say about us and our society that there is a kind of celebration in perfection? We tend to hold perfectionism up as an insignia of worth. The emblem of the successful. Yet, in my time studying perfectionism, I've seen limited evidence that perfectionists are more successful. Quite the contrary — they feel discontented and dissatisfied amid a lingering sense that they're never quite perfect enough. We know from clinician case reports that perfectionism conceals a host of psychological difficulties, including things like depression, anxiety, anorexia, bulimia and even suicide ideation. And what's more worrying is that over the last 25 years, we have seen perfectionism rise at an alarming rate. And at the same time, we have seen more mental illness among young people than ever before. Rates of suicide in the US alone increased by 25 percent across the last two decades. And we're beginning to see similar trends emerge across Canada, and in my home country, the United Kingdom. Now, our research is suggesting that perfectionism is rising as society is changing. And a changed society reflects a changed sense of personal identity and, with it, differences in the way in which young people interact with each other and the world around them. And there are some unique characteristics about our preeminent, market-based society that include things like unrestricted choice and personal freedom, and these are characteristics that we feel are contributing to almost epidemic levels of this problem. So let me give you an example. Young people today are more preoccupied with the attainment of the perfect life and lifestyle. In terms of their image, status and wealth. Data from Pew show that young people born in the US in the late 1980s are 20 percent more likely to report being materially rich as among their most important life goals, relative to their parents and their grandparents. Young people also borrow more heavily than did older generations, and they spend a much greater proportion of their income on image goods and status possessions. These possessions, their lives and their lifestyles are now displayed in vivid detail on the ubiquitous social media platforms of Instagram, Facebook, Snapchat. In this new visual culture, the appearance of perfection is far more important than the reality. If one side of the modern landscape that we have so lavishly furnished for young people is this idea that there's a perfectible life and that there's a perfectible lifestyle, then the other is surely work. Nothing is out of reach for those who want it badly enough. Or so we're told. This is the idea at the heart of the American dream. Opportunity, meritocracy, the self-made person, hard work. The notion that hard work always pays off. And above all, the idea that we're captains of our own destiny. These ideas, they connect our wealth, our status and our image with our innate, personal value. But it is, of course, complete fiction. Because even if there were equality of opportunity, the idea that we are captains of our own destiny disguises a much darker reality for young people that they are subject to an almost ongoing economic tribunal. Metrics, rankings, lead tables have emerged as the yardsticks for which merit can be quantified and used to sort young people into schools, classes and colleges. Education is the first arena where measurement is so publicly played out and where metrics are being used as a tool to improve standards and performance. And it starts young. Young people in America's big city high schools take some 112 mandatory standardized tests between prekindergarten and the end of 12th grade. No wonder young people report a strong need to strive, perform and achieve at the center of modern life. They've been conditioned to define themselves in the strict and narrow terms of grades, percentiles and lead tables. This is a society that preys on their insecurities. Insecurities about how they are performing and how they are appearing to other people. This is a society that amplifies their imperfections. Every flaw, every unforeseen setback increases a need to perform more perfectly next time, or else, bluntly, you're a failure. That feeling of being flawed and deficient is especially pervasive — just talk to young people. "How should I look, how should I behave?" "I should look like that model, I should have as many followers as that Instagram influencer, I must do better in school." In my role as mentor to many young people, I see these lived effects of perfectionism firsthand. And one student sticks out in my mind very vividly. John, not his real name, was ambitious, hardworking and diligent and on the surface, he was exceptionally high-achieving, often getting first-class grades for his work. Yet, no matter how well John achieved, he always seemed to recast his successes as abject failures, and in meetings with me, he would talk openly about how he'd let himself and others down. John's justification was quite simple: How could he be a success when he was trying so much harder than other people just to attain the same outcomes? See, John's perfectionism, his unrelenting work ethic, was only serving to expose what he saw as his inner weakness to himself and to others. Cases like John's speak to the harmfulness of perfectionism as a way of being in the world. Contrary to popular belief, perfectionism is never about perfecting things or perfecting tasks. It's not about striving for excellence. John's case highlights this vividly. At its root, perfectionism is about perfecting the self. Or, more precisely, perfecting an imperfect self. And you can think about it like a mountain of achievement that perfectionism leads us to imagine ourselves scaling. And we think to ourselves, "Once I've reached that summit, then people will see I'm not flawed, and I'll be worth something." But what perfectionism doesn't tell us is that soon after reaching that summit, we will be called down again to the fresh lowlands of insecurity and shame, just to try and scale that peak again. This is the cycle of self-defeat. In the pursuit of unattainable perfection, a perfectionist just cannot step off. And it's why it's so difficult to treat. Now, we've known for decades and decades that perfectionism contributes to a host of psychological problems, but there was never a good way to measure it. That was until the late 1980s when two Canadians, Paul Hewitt and Gordon Flett, came along and developed a self-report measure of perfectionism. So that's right, folks, you can measure this, and it essentially captures three core elements of perfectionism. The first is self-oriented perfectionism, the irrational desire to be perfect: "I strive to be as perfect as I can be." The second is socially prescribed perfectionism, the sense that the social environment is excessively demanding: "I feel that others are too demanding of me." And the third is other-oriented perfectionism, the imposition of unrealistic standards on other people: "If I ask somebody to do something, I expect it to be done perfectly." Now, research shows that all three elements of perfectionism associate with compromised mental health, including things like heightened depression, heightened anxiety and suicide ideation. But, by far, the most problematic element of perfectionism is socially prescribed perfectionism. That sense that everyone expects me to be perfect. This element of perfectionism has a large correlation with serious mental illness. And with today's emphasis on perfection at the forefront of my mind, I was curious to see whether these elements of perfectionism were changing. To date, research in this area is focused on immediate family relations, but we wanted to look at it at a broader level. So we took all of the data that had ever been collected in the 27 years since Paul and Gordon developed that perfectionism measure, and we isolated the data in college students. This turned out to be more than 40,000 young people from American, Canadian and British colleges, and with so much data available, we looked to see if there was a trend. And in all, it took us more than three years to collate all of this information, crunch the numbers, and write our report. But it was worth it because our analysis uncovered something alarming. All three elements of perfectionism have increased over time. But socially prescribed perfectionism saw the largest increase, and by far. In 1989, just nine percent of young people report clinically relevant levels of socially prescribed perfectionism. Those are levels that we might typically see in clinical populations. By 2017, that figure had doubled to 18 percent. And by 2050, projections based on the models that we tested indicate that almost one in three young people will report clinically relevant levels of socially prescribed perfectionism. Remember, this is the element of perfectionism that has the largest correlation with serious mental illness, and that's for good reason. Socially prescribed perfectionists feel a unrelenting need to meet the expectations of other people. And even if they do meet yesterday's expectation of perfection, they then raise the bar on themselves to an even higher degree because these folks believe that the better they do, the better that they're expected to do. This breeds a profound sense of helplessness and, worse, hopelessness. But is there hope? Of course there's hope. Perfectionists can and should hold on to certain things — they are typically bright, ambitious, conscientious and hardworking. And yes, treatment is complex. But a little bit of self-compassion, going easy on ourselves when things don't go well, can turn those qualities into greater personal peace and success. And then there's what we can do as caregivers. Perfectionism develops in our formative years, and so young people are more vulnerable. Parents can help their children by supporting them unconditionally when they've tried but failed. And Mom and Dad can resist their understandable urge in today's highly competitive society to helicopter-parent, as a lot of anxiety is communicated when parents take on their kids' successes and failures as their own. But ultimately, our research raises important questions about how we are structuring society and whether our society's heavy emphasis on competition, evaluation and testing is benefiting young people. It's become commonplace for public figures to say that young people just need a little bit more resilience in the face of these new and unprecedented pressures. But I believe that is us washing our hands of the core issue because we have a shared responsibility to create a society and a culture in which young people need less perfection in the first place. Let's not kid ourselves. Creating that kind of world is an enormous challenge, and for a generation of young people that live their lives in the 24/7 spotlight of metrics, lead tables and social media, perfectionism is inevitable, so long as they lack any purpose in life greater than how they are appearing or how they are performing to other people. What can they do about it? Every time they are knocked down from that mountaintop, they see no other option but to try scaling that peak again. The ancient Greeks knew that this endless struggle up and down the same mountain is not the road to happiness. Their image of hell was a man called Sisyphus, doomed for eternity to keep rolling the same boulder up a hill, only to see it roll back down and have to start again. So long as we teach young people that there is nothing more real or meaningful in their lives than this hopeless quest for perfection, then we are going to condemn future generations to that same futility and despair. And so we're left with a question. When are we going to appreciate that there is something fundamentally inhuman about limitless perfection? No one is flawless. If we want to help our young people escape the trap of perfectionism, then we will teach them that in a chaotic world, life will often defeat us, but that's OK. Failure is not weakness. If we want to help our young people outgrow this self-defeating snare of impossible perfection, then we will raise them in a society that has outgrown that very same delusion. But most of all, if we want our young people to enjoy mental, emotional and psychological health, then we will invite them to celebrate the joys and the beauties of imperfection as a normal and natural part of everyday living and loving. Thank you very much. (Applause) |
The infinite life of pi | null | TED-Ed | Try to measure a circle. The diameter and radius are easy, they're just straight lines you can measure with a ruler. But to get the circumference, you'd need measuring tape or a piece of string, unless there was a better way. Now, it's obvious that a circle's circumference would get smaller or larger along with its diameter, but the relationship goes further than that. In fact, the ratio between the two, the circumference divided by the diameter, will always be the same number, no matter how big or small the circle gets. Historians aren't sure when or how this number was first discovered, but it's been known in some form for almost 4,000 years. Estimates of it appear in the works of ancient Greek, Babylonian, Chinese, and Indian mathematicians. And it's even believed to have been used in building the Egyptian pyramids. Mathematicians estimated it by inscribing polygons in circles. And by the year 1400, it had been calculated to as far as ten decimal places. So, when did they finally figure out the exact value instead of just estimating? Actually, never! You see, the ratio of a circle's circumference to its diameter is what's known as an irrational number, one that can never be expressed as a ratio of two whole numbers. You can come close, but no matter how precise the fraction is, it will always be just a tiny bit off. So, to write it out in its decimal form, you'd have an on-going series of digits starting with 3.14159 and continuing forever! That's why, instead of trying to write out an infinite number of digits every time, we just refer to it using the Greek letter pi. Nowadays, we test the speed of computers by having them calculate pi, and quantum computers have been able to calculate it up to two quadrillion digits. People even compete to see how many digits they can memorize and have set records for remembering over 67,000 of them. But for most scientific uses, you only need the first forty or so. And what are these scientific uses? Well, just about any calculations involving circles, from the volume of a can of soda to the orbits of satellites. And it's not just circles, either. Because it's also useful in studying curves, pi helps us understand periodic or oscillating systems like clocks, electromagnetic waves, and even music. In statistics, pi is used in the equation to calculate the area under a normal distribution curve, which comes in handy for figuring out distributions of standardized test scores, financial models, or margins of error in scientific results. As if that weren't enough, pi is used in particle physics experiments, such as those using the Large Hadron Collider, not only due to its round shape, but more subtly, because of the orbits in which tiny particles move. Scientists have even used pi to prove the illusive notion that light functions as both a particle and an electromagnetic wave, and, perhaps most impressively, to calculate the density of our entire universe, which, by the way, still has infinitely less stuff in it than the total number of digits in pi. |
Football physics: The "impossible" free kick | null | TED-Ed | In 1997, in a game between France and Brazil, a young Brazilian player named Roberto Carlos set up for a 35 meter free kick. With no direct line to the goal, Carlos decided to attempt the seemingly impossible. His kick sent the ball flying wide of the players, but just before going out of bounds, it hooked to the left and soared into the goal. According to Newton's first law of motion, an object will move in the same direction and velocity until a force is applied on it. When Carlos kicked the ball, he gave it direction and velocity, but what force made the ball swerve and score one of the most magnificent goals in the history of the sport? The trick was in the spin. Carlos placed his kick at the lower right corner of the ball, sending it high and to the right, but also rotating around its axis. The ball started its flight in an apparently direct route, with air flowing on both sides and slowing it down. On one side, the air moved in the opposite direction to the ball's spin, causing increased pressure, while on the other side, the air moved in the same direction as the spin, creating an area of lower pressure. That difference made the ball curve towards the lower pressure zone. This phenomenon is called the Magnus effect. This type of kick, often referred to as a banana kick, is attempted regularly, and it is one of the elements that makes the beautiful game beautiful. But curving the ball with the precision needed to both bend around the wall and back into the goal is difficult. Too high and it soars over the goal. Too low and it hits the ground before curving. Too wide and it never reaches the goal. Not wide enough and the defenders intercept it. Too slow and it hooks too early, or not at all. Too fast and it hooks too late. The same physics make it possible to score another apparently impossible goal, an unassisted corner kick. The Magnus effect was first documented by Sir Isaac Newton after he noticed it while playing a game of tennis back in 1670. It also applies to golf balls, frisbees and baseballs. In every case, the same thing happens. The ball's spin creates a pressure differential in the surrounding air flow that curves it in the direction of the spin. And here's a question. Could you theoretically kick a ball hard enough to make it boomerang all the way around back to you? Sadly, no. Even if the ball didn't disintegrate on impact, or hit any obstacles, as the air slowed it, the angle of its deflection would increase, causing it to spiral into smaller and smaller circles until finally stopping. And just to get that spiral, you'd have to make the ball spin over 15 times faster than Carlos's immortal kick. So good luck with that. |
How stress affects your brain | {0: 'Madhumita is a journalist, editor and speaker with expertise in the fields of science, health and technology. She is the European Technology Correspondent at The Financial Times. '} | TED-Ed | Are you sleeping restlessly, feeling irritable or moody, forgetting little things, and feeling overwhelmed and isolated? Don't worry. We've all been there. You're probably just stressed out. Stress isn't always a bad thing. It can be handy for a burst of extra energy and focus, like when you're playing a competitive sport, or have to speak in public. But when its continuous, the kind most of us face day in and day out, it actually begins to change your brain. Chronic stress, like being overworked or having arguments at home, can affect brain size, its structure, and how it functions, right down to the level of your genes. Stress begins with something called the hypothalamus pituitary adrenal axis, a series of interactions between endocrine glands in the brain and on the kidney, which controls your body's reaction to stress. When your brain detects a stressful situation, your HPA axis is instantly activated and releases a hormone called cortisol, which primes your body for instant action. But high levels of cortisol over long periods of time wreak havoc on your brain. For example, chronic stress increases the activity level and number of neural connections in the amygdala, your brain's fear center. And as levels of cortisol rise, electric signals in your hippocampus, the part of the brain associated with learning, memories, and stress control, deteriorate. The hippocampus also inhibits the activity of the HPA axis, so when it weakens, so does your ability to control your stress. That's not all, though. Cortisol can literally cause your brain to shrink in size. Too much of it results in the loss of synaptic connections between neurons and the shrinking of your prefrontal cortex, the part of your brain the regulates behaviors like concentration, decision-making, judgement, and social interaction. It also leads to fewer new brain cells being made in the hippocampus. This means chronic stress might make it harder for you to learn and remember things, and also set the stage for more serious mental problems, like depression and eventually Alzheimer's disease. The effects of stress may filter right down to your brain's DNA. An experiment showed that the amount of nurturing a mother rat provides its newborn baby plays a part in determining how that baby responds to stress later in life. The pups of nurturing moms turned out less sensitive to stress because their brains developed more cortisol receptors, which stick to cortisol and dampen the stress response. The pups of negligent moms had the opposite outcome, and so became more sensitive to stress throughout life. These are considered epigenetic changes, meaning that they effect which genes are expressed without directly changing the genetic code. And these changes can be reversed if the moms are swapped. But there's a surprising result. The epigenetic changes caused by one single mother rat were passed down to many generations of rats after her. In other words, the results of these actions were inheritable. It's not all bad news, though. There are many ways to reverse what cortisol does to your stressed brain. The most powerful weapons are exercise and meditation, which involves breathing deeply and being aware and focused on your surroundings. Both of these activities decrease your stress and increase the size of the hippocampus, thereby improving your memory. So don't feel defeated by the pressures of daily life. Get in control of your stress before it takes control of you. |
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