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CMV: If time travel was truly humanly possible to achieve, we would have visitors by now. | Pretty much self-explainatory..If time travel was humanly possible to achieve during our existence, chances are, the future "us" (where we are supposedly super technologically and knowdlegably advanced), would have visited us from the future by now.
Even for study and exploration purposes alone, just like we have studied the ancient civilizations at all points in time as well.
Ultimately, that leaves us with 2 possible predicaments:
1. Time travel back in time is not humanly possible to achieve during our existence as species.
2. Time travel back in time was never done to any point of our modern human history (about 12000 years), which is extremely unlikely, not make much reasonable sense as to "why not?", and there would be some evidence/knowledge/effects of that occurring.
3. Time travel back in time is not possible outside of a human's travelling back in time life span. As he cannot travel back to a time when he did not exist.
Thus, time travel (at least back in time) is not humanly possible to achieve. | Several possible answers:
1. Yes, we do study primitive cultures, but our policies regarding research are mostly designed not to interfere with the primitive cultures being studied. That’s not from a Star Trek/Prime Directive type of moral imperative, it’s because we get better data when we only observe and not interfere. Not being seen is likely very important to getting good data. That policy of noninterference may be why, if visitors did come back in time, they have not been seen or identified as time travelers.
2. Until quite recently (the last few hundred years), communication between groups of humans was limited/impossible. It’s quite possible that contact did happen, but the people affected by it were not able to tell the rest of the world.
3. Have you ever seen any of the “Ancient Aliens” programs on History Channel? Yes, plenty of the wild claims are laughable, but they are correct that there are a number of historical drawings and other records of things that look like aliens, astronauts, etc. It’s quite possible that these records don’t refer to aliens, but to time travelers. If this is the case, then time travelers HAVE been back to visit.
4. Time travel doesn’t necessarily mean that the past can be interacted with. Since the physics of it are not currently known/understood, it could be that visitors can view events and look around, but not actually touch, speak, or interact with the past.
But most likely:
5. Visitors from the future haven’t come back in time for fear of being killed. Not by us, but by the planet. The Earth is moving insanely fast - it rotates at about 1,000 mph, and in addition to that it is orbiting the sun at about 67,000 mph. If you were to travel back in time even a second, the location of your time machine at the time of departure would be vastly different from its location at the intended time of arrival. Thus you would “arrive” in the past either somewhere out in space or inside the Earth itself.
It should be possible, for any sufficiently advanced civilization, to calculate the change in position of the Earth for short hops in time. However, the further back in time you go, the harder it gets, because the speed of the Earth, the tilt of the axis, and the orbital path are constantly changing in very minor but non-standard ways. Over the short term that shouldn’t be a huge problem, but going back very far at all would cause the amount of unknowable changes to stack up and make the Earth’s actual position almost impossible to accurately calculate, let alone calculate with enough accuracy to arrive on the surface.
Speaking of the surface, the surface of the Earth is constantly changing. The tectonic plates move slowly - 1 to 10 cm a year - but they move at different speeds at different locations. Their movement causes various parts of the Earth to rise or fall, depending on how the plates collide. Add to this the cumulative effects of volcanoes, erosion, sedimentation, and other natural effects, and it is impossible to determine with any specificity the actual height of a given piece of the Earth (relative to the center of the Earth) at any time. So even if you correctly calculated the location of the Earth at a given point in time, and matched the speed, your estimate of the height of the location you want to travel to could be wildly off, again resulting in you either showing up quite high off the ground, or under it. | 16 | 20 |
[Avatar] Does bending require chemical energy from the bender? Do they burn calories when bending like someone would exercising? | Earth benders can levitate massive rocks out of the ground and throw them with incredible speed. To physically do that would require a huge expenditure of energy accelerating that rock.
But are earth benders expending all the energy necessary to move that rock? Is chemical energy from the bender being converted into potential/kinetic energy of the object?
If so, how does a bender like toph manage such energy output without eating 10 meals a day? Is there an alternative source of energy from the spirit world?
If benders are not using their own energy, what is preventing a fire bender from creating a heat engine that uses little to no fuel? They could attain unlimited power generation from such technologies by breaking the laws of thermodynamics. | The Mind, Body, and Spirit are all tied to together in ways that aren't always understandable. Bending usually involves all three working in harmony (the exceptions are those such as Sparky-Sparky Boom Man who could bend with just his mind). However, the energy behind a thrown rock or a burst of flame does not come from the individual bender, but from the cosmic energy that permeates reality. It requires physical and mental exertion to shape that energy; we see benders sweat and grow tired with continued action. Thus, it's actually more efficient to burn fuel with a firebender there to regulate the flame than have one work a steam engine 24-7. In Republic City, we see that Mako has a job lightning-bending into a generator at the power-plant, but the size and machinery involved seems to indicate that he was either enhancing or regulating the conventional machinery.
TL,DR: Blah-blah, spiritual mumbo jumbo, blah-blah, something about space. | 21 | 25 |
ELI5: Why do many African Americans speak Ebonics while most French speaking Africans in former colonies speak clear, standard French? | African Americans have been speaking English in their regional variation for many generations now, but I've found that most African French speakers use clear, standardized French in countries such as Senegal. Although their may be some regional words, most people speak the textbook version of French. In Haiti, French has been changed a lot as it is mixed with Creole expressions even though some words sound very similar, such as
"Bonju" and "Bonswa" | Ebonics (which is more properly called African-American Vernacular English) has had more time to develop. Black people have been living in America for close to 400 years, and that's a lot of time to evolve their own distinctive dialect of English. French speakers in Africa are more recent, only about the last 125 years or so. Furthermore, many of those French speakers don't use French as their primary language in day to day life, French is the language they use when talking to people from outside their community, but inside their communities and neighborhoods, most still retain their local languages. Most people in Africa (and in many other places around the world) are bilingual and trilingual, using different languages for different social situations.
Haiti is actually more similar to the American case. French has been the language there for three hundred years. And over the centuries, African languages and French comingled and evolved and became the new language called Haitian Creole which actually sounds very different from traditional French. In Haiti, most people speak Creole in their day-to-day lives but Standard French is the official language of government and education. Unlike America however, Haitian Creole is so distinct that many would argue it qualifies as its own language, separate from French. Whereas African-American Vernacular English and so-called "Standard American English" are clearly just two dialects of the same language and speakers of either dialect can easily understand each other, whereas a Creole speaker and a French speaker might actually have a little difficulty understanding each other (except most Creole speakers also know Standard French anyway). | 29 | 34 |
ELI5: I'm short sighted and have a Mirror next to my PC so I can watch the TV behind me. Why is it when I look in the mirror, the TV behind me is just as blurry as if I was looking at it? Even though I'm actually looking in a Mirror only 1ft away from me? | Light rays need to be focused on the back of your eye in order to produce a clear image. When we are looking at an object, we're actually looking at the light being reflected off that object that's penetrating our lens and being focused on our retinas. If the light from the object is being distorted by the lens, we get a blurry image.
Your TV is blurry because you are still trying to focus the light coming from the TV behind you. The rays are being reflected off the mirror, but they are still originating from the TV. The mirror is not the source of the light. | 39 | 61 |
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Economics majors careers | I was wondering what types of jobs/careers that a undergraduate economics major could obtain. What types of jobs can I expect with no experience; or what can obtain later with experience. also what fields are most common for most econ majors?
Edit: I am based in the US and not near D.C. | Ok, so u can pretty much get any job a finance major can apply to as long as u just pick up some basic accounting skills.
Additionally, check our "market power" on youtube, he talks about econ jobs that are pretty cool (like designing markets in videogames!)
You could work at the FED, FDIC, or OCC (i just did the college FED challenge, was very fun btw).
If you like research and/ or teaching you could go for ur Phd as well.
Cheers | 53 | 56 |
[Star Trek] Why are there bartenders and waiters in Ten forward? | There are replicators pretty much every where you go on the Enterprise and the crew have legs don't they? Why bother asking someone to ask the replicator for food when you can just ask it yourself?
Seems that laziness DOES still exist in the 24th Century.
| What about the nonreplicated foods? Not all food and drinks on starfleet instilations are replicated...many star ships/ space stations have airponics bays to produce fresh vegetables and fruits not to mention food acquired from various planets... | 26 | 26 |
Are you supposed to vote for the candidate who you think would be best for you personally, for your country, or for the world as a whole? | Who’s to say those categories are mutually exclusive? There are arguments to be made that, as a member of a community, your interests to some degree reflect the interests of all in abstract. For instance, a candidate who runs on a platform of stable trade relations and the improvement of living conditions is (taken at their word) appealing to individuals as well as groups.
There are a few things which muddy the waters: whether a candidate can be taken at their word, whether people identify their interests with that of a community (correctly or incorrectly), and the degree to which people localize “their” community.
Honesty in a candidate is determined in part by the actions to come, should they be elected; sometimes what is promised, when actualized, doesn’t result in the benefit previously assumed. This is tricky to parse out and so most people tend to rely on a platform’s principle over the particular promises made. This often goes against personal or communal interests, or at least beyond them in the sense we might usually think of them. A good example of this is people below the poverty line voting for a candidate proposing tax cuts for the wealthy; even though trickle down economics has been revealed to be ineffective at best, many take it on principle that this is the way it “ought” to be when it nevertheless acts to impede their own prosperity.
Identification with a community ties in with the ‘principle’ observation. Communities often enforce and reinforce these ideals, and so your notion of “best” is shaped by factors therein. Again, this is sometimes against what we might traditionally term “best interest” (standard of living, equality of opportunity, etc.) and varies based on the lived experiences within communities.
This imposed “ought” can be narrowed depending on how niche one’s perceived community is (or broadened when one takes a more cosmopolitan standpoint). Single issue voters come to mind here, where a candidate’s appeal to one topic embodies the “ought” principle in its entirety.
From these three points, the answer to your question is that it depends on which basis you’re using for the “supposed to” component of your question. The basis for your sense of duty/interest is going to inevitably be tied to some degree to your surroundings. Whatever metric informs your values, that “ought” that provides the basis for your political involvement, is what is implied here. So should you vote for a pro life candidate because you live in a community which holds that as a fundamental issue that you personally may or may not hold? Do you reject this stance in favor of its opposite, as a woman or as a medical professional, etc.?
It’s not a simple yes or no question. | 22 | 92 |
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Does 'bracing for impact' actually help during minor impacts? | Even mentally? | Many people here talk about grabbing onto stuff etc. but there's a much simpler view.
Bracing for impact does help. You basically do this by contracting mucles and breathing out, anything else is optional or rather situational.
contracting muscles prevents impact from deforming your organs and helps muscles absorb the shock. breathing out prevents compression of your diaphragm/lungs during impact, thereby prevents getting the "wind knocked out of you" and more serious lung damage.
while you probably refer to accidents and such, this can also be observed in martial arts, where an impact is absorbed with less damage by contracting mucles and exhaling. | 17 | 24 |
Who gets to define what “God” and other controversial words mean? | I’ve spent quite some time looking into philosophy over the past few months. I’ve read quite a few Stanford Encyclopedia articles and I read AC Grayling’s book on the History of Philosophy.
As an atheist myself, I can’t help but feel that a huge amount of disagreement in society, the God debate and philosophy as a whole is just caused by confusion about what words mean.
You see this in society with debates about what Gender and Sex mean. But this also comes up in the God debate with disagreement over what “God” even means.
Learning about stuff like this definitely gives me much more respect for dictionaries as they have to find ways to resolve these conflicts
Thus my questions are these:
1) Who gets to define what God means? Is it really just Christian philosophers who get final say?
2) Who gets to define what controversial words mean in general?
3) Do dictionaries get final say over all of this? | In general, substantive issues rarely -- or perhaps even *by definition* never -- depend on questions of whether to merely stipulate what this word or what that word means. And so this whole question, along with an appeal to dictionaries and so on, is just barking up the wrong tree.
When people dispute gender, for instance, they're not disputing merely what meaning to arbitrarily associated with the string of letters g-e-n-d-e-r, rather they are disputing what's involved with a concept they have that they've been using to navigate certain issues in the world. Consider, for instance, a debate between a Darwinian and a Lamarckian notion of evolution: if we thought this was about merely how to stipulatively define the word 'evolution', we'd have totally lost track of what the Darwinian and the Larmarckian are saying. | 64 | 54 |
ELI5: Why do we elevate injuries to promote recovery? If this is the correct thing to do, why does the body send more blood to the injury? | Elevating injuries makes it easier to recirculate the blood at the injury site. Excess blood can cause unwanted swelling which could worsen the injury. Plus, blood at a lower injury site has to fight against gravity to go back to the heart. Elevating the injury site above the heart allows blood to easily flow back with gravity.
Blood to the site is not greatly affected by elevation since it's already at a high pressure when pumped by the heart. | 431 | 372 |
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ELI5: why is it that our bodies are symmetrical on the outside, but not on the inside? | I have always wondered but, well, today i was prompted to ask. We are from head, to genitalia to feet symmetrical and then our heart, stomach etc is all wack, please explain. | Overall symmetry makes movement and maintaining balance easier since it keeps your center of mass centered inside your body, so there's some selection pressure on evolution to keep such a shape. Sometimes asymmetry still sneaks into living beings where it either provides enough advantage to outweigh the disadvantage (look up the pistol shrimp for an example of this), or else is too minor to get in the way.
The exact placement of the different organs inside your body matters less to evolution, as their density doesn't differ that much. Because of this it can sometimes get away with just placing them where it is convenient and inexpensive in terms energy spent on growth and upkeep.
As far as center of mass is concerned, your insides can be abstracted as a nearly-uniform distribution of generic biomass contained inside a humanoid-shaped container made of skin suspended on bone. | 38 | 86 |
ELI5: Is it possible to rid humans of certain diseases/illnesses by "selective breeding"? | This is commonly called Eugenics, advocating the use of particular practises that could potentially improve the human gene pool.
It obviously has its upsides and downsides, but yes it's hypothetically possible to rid humans of certain genetic diseases, but if we don't fully understand the entire genome, we could be inadvertently losing genetic diversity which has always been seen as the primary way of "improving" the gene pool. Losing that diversity could potentially and rapidly result in extinction if the impacts are not fully understood ahead of time. That reduction in diversity could center tagger lights a pine cone and chucks it over the basket and the whack-batter tries to hit the cedar stick off the cross rock. Then the twig runners dash back and forth until the pine cone burns out and the umpire calls hotbox. Finally, you count up however many score-downs it adds up to and divide that by nine.
| 13 | 23 |
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ELI5: How do magnified mirrors work? And why do they seem blurry if you look into them from a distance? | A lens is a piece of glass that bends light so that the rays converge to a single point. If you bend a mirror it will make all the beams converge in the same pint, so it’s the same as a lens, only instead of passing light through, it reflects it, so both the observer and the object are on the same side, or in this case both are your face
Just like a magnifying glass you need to be in the right place for everything to be in focus | 13 | 17 |
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How to move past "pop-philosophy' to actually understanding serious and legitimate philosophical ideas/works? | I just watched a video critiquing Sam Harris's "The Moral Landscape". I had no idea how inept "intellectuals" like Jordan Peterson and Sam Harris are when it comes to talking about philosophy. I am mostly interested in moral philosophy and as of now I generally identify myself as a Stoic, but I feel like i'm missing something. I want to dive deeper into existentialist ideas, but I want to do it properly. I have no idea what post modernism is considering Peterson seems to be way off with his interpretation of it. I don't understanding the difference between analytic vs continental philosophy even after researching a bit on it. I guess my question is, how do I study philosophy "properly" so I can come to understand these ideas and answer this question and better be able to call out weak pseudo philosophy when I see it? | Takes courses in it, read books about it, listen to podcasts about it -- that kind of stuff.
For instance, if you're interested in ethics, then a natural place to begin would be with an introductory text on ethics, like Shafer-Landau's *The Fundamentals of Ethics*. | 103 | 207 |
ELI5: did playing video games shape my intelligence and personality in a positive way? | Basically all my life (age: 27) I have played video games so I'm wondering whether they had any positive effects on me (especially on my brain) or they just robbed thousands of hours from me. I read it once that playing e.g. Tetris can have a positive effect on brain functions, but I wonder whether it's true if a grownup does it and not a child who is getting more and more intelligent by the years. | No idea.
The studies are really variable because the things are very broad, vague and relatively new so there are more questions than answers. E.g., Do we mean specific games? Only violent games? Strategy games? What about when they overlap? Only certain methods of gaming, like PC or console? Is it only during certain periods this works? Is it related to playing particular game as particular ages, e.g., are violent games at 5 are bad, but at 15 are ok? If there is an effect, for how long does it last? Is there a threshold for when these effects begin ? Is there a threshold for when the become/stop being good or bad?
It would be wrong to extrapolate those to say that taken together they have had a net 'good' or 'bad' effect on you. | 15 | 19 |
ELI5: How do calculators solve complex problems like matrices graphing etc. do programers have to write out every solution or are there shortcuts? | Ingredient 1: Computers are machines that perform simple operations VERY fast.
Ingredient 2: Most complex math can be decomposed into (or approximated by) simpler math. For example, imagine that you know how to add 2 numbers. Well, with that tool, you can also multiply numbers (by performing several additions) and even calculate exponentiation (by performing several multiplications, which we already mentioned you can do with addition).
By combining the two ingredients (a set of simple operations and knowledge on how to decompose complex math into simpler math), you get a machine that can perform complex math. | 10,253 | 13,728 |
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Is there a certain philosophy that says nothing holds any inherent meaning, only that which you give it? | I was wondering, is there a certain type of philosophy that states nothing has meaning until you decide that it means something to you? I guess it's similar to nihilism, but I can't find a proper definition of a philosophy like that. | Existentialism is the belief that through a combination of awareness, free will, and personal responsibility, one can construct their own meaning within a world that intrinsically has none of its own.
Nihilism is the belief that not only is there no intrinsic meaning in the universe, but that it’s pointless to try to construct our own as a substitute.
Absurdism is the belief that a search for meaning is inherently in conflict with the actual lack of meaning, but that one should both accept this and simultaneously rebel against it by embracing what life has to offer. | 99 | 54 |
ELI5: Why is a slow resting heart rate good, when it is also healthy for your heart to beat fast during exercise? | EDIT: So several answers have come in, but I'm not sure my question is being understood. I'm asking, if it's healthy for your heart to beat fast during exercise, why isn't it healthy for it to beat fast(er) during rest? Wouldn't a higher resting heart rate almost be like a mini "workout?" Making it stronger? | its about strength and efficiency.
Your question is quite valid... Why can't we just do Cocaine or drink caffeine to increase our heart rate for "exercise"? Or just be panicked (increasing our heart rate) to get a good workout?
It takes a little knowledge to come to a good conclusion. Ahem.
There's an upper and lower limit to your heartrate. Everyone's different depending on age and health. We've established some "normal" ranges. About +- 70-85 BPM at rest is normal; then the top number is dependent on some factors that you can look up on your own.
Anywho, the heart is a muscle (duh) right, and it's activated and regulated by the bodys need for it's service (pumping blood). During stress it increases it's rhythm for both psychological (anticipation), and physical (sustaining, survival) need. More on this in a min.
So depending on how your health is, the body prefers a sorta calm state; (feelsgoodman.exe), your average resting heart rate lies in this realm. Anything above this indicates *some* sort of stress on the body. There's healthy stress and unhealthy stress. Unhealthy stress includes: unnecessary psychological anxiety/fear, drug use, sickness. While good heart stresses are things that lead to better states like: exercise to "look better" or strength to protect yourself, or even light activity like getting some food from the store (food endorphins bruh). Regardless of what you do, your body is reacting in harmony with what will sustain you.
So it's like just because your HR is high or low doesn't mean it's good for what you're after. Like a higher BPM is normal in sick people but your body is battling something which is good but if you lay around sick for months your muscles waste away because of lack of use . The body is always changing according to automatic (unconscious) and consious need.
Understanding the hearts basic role then leads us to better answer your questions. You **gain** something from the **right** high heart stresses which are reflected in your heart rate. Consistent exercise (along with healthy eating and habit) nets gains both physically and mentally "look good feel good" (dopamine bruh). The bodies equal reaction to being well all around is a lower HR at rest when calm.
There's plenty more to look up about heart health that's awesome. You can get a baseline of your health with your sleep HR vs resting HR vs exercise HR vs rebound to resting HR after exercise, this is almost a sure way to indicate overall health.
Hope this was helpful.
| 10 | 21 |
CMV: Universities in the United States should not require students to take General Ed classes | I've always thought that higher education was meant to give the opportunity for students to learn. GE diminishes this opportunity by telling students what they MUST learn.
I can think of two arguments of why GE is good to be required:
1. GE allows students to find what they want to pursue (or not).
2. GE creates more well-rounded students.
Rebuttals:
1. The student knows themselves the most. They are the ones who are seeking their specific higher education. They should choose to take whatever classes they need to find what they need to find. Plus, for many students who apply with a specific major in mind and maintain it throughout, reason #1 would provide no help as finding their field has already been accomplished.
2. The University should not push their values and ideas of what an "ideal" student should be. Yes, a philosophy class might help an engineer, and an English class might help a chemist. But who is deciding what is best for them? The engineer and chemist. If they think a philosophy class or an English class might help them, then they should take it. But, by no means should they be forced. Many of the benefits that are attributed to GE classes, such as critical thinking and communication skills, are cited. If these skills are required by the major, then they should be major requirements.
With the insane prices of Universities nowadays, it seems imperative to "get in and get out" if the students want to minimize their crushing student debt. Although I don't know for certain, I suspect that at least one motive for requiring GE classes is so that they can soak up as much money as possible.
I am open to having my mind changed. I would change my mind if the students are shown to be better off if they are required GE classes compared to if that requirement is dropped. I would also change my mind if my perspective of what Universities should do is false, and shown that this new role is more beneficial to students. I would also change my mind if there is another reason why GE is good for the students and shown that it is more beneficial to the students. I also can change my mind by other things that I haven't thought of yet. Thanks!
Note 1: I included "United States" since I'm not familiar with other countries' education systems.
Note 2: If you saw this post a few minutes ago, sorry! I had to fix the Title. | >The student knows themselves the most. They are the ones who are seeking their specific higher education. They should choose to take whatever classes they need to find what they need to find. Plus, for many students who apply with a specific major in mind and maintain it throughout, reason #1 would provide no help as finding their field has already been accomplished.
Not always. Many people have discovered new career paths or lifelong hobbies/interests in college due to general education requirements.
>The University should not push their values and ideas of what an "ideal" student should be.
It's not about making an "ideal" student. It's about setting the students up for success, giving them a broad range of skills and experience to prepare them not to just be successful in a career but also to be well-rounded and productive members of society. | 28 | 15 |
[Pacific Rim] How come Jaggers fight without any kind of support? | Jaggers go on one to one melee combat with Kaijus without any kind of support. No spotters, no artillery, not even diversions like flares.
This is not how a modern military operates, even a tank gets a lot of support from ground troops. And they couldn't do it for a billion dollar robot?
Each Kaiju should be received with a round of missiles and torpedoes to the legs. Even if that doesn't kill it, it gives the Jaggers a great advantage since the Kaiju is in shock/distracted.
Drones should also blanket the sky above the Kaiju, ready to drop bombs or even crash into the Kaiju if the Jagger needs crucial seconds to recover. | Firstly, the Jaegers are accompanied by helicopters, which serve in a spotter and support role.
Secondly, the Kaiju pretty much shrug off anything we can throw at them, short of a nuke or a Jaeger. For example, witness how Trespasser pretty much ignored all the tanks and planes firing at it during the attack on San Fransisco. Nuking the Kaiju every time they show up is not an acceptable solution, which is why Jaegers are used instead.
Finally, you've made the mistake of trying to apply modern military doctrines against the Kaiju. That's the same mistake the governments of Earth made when they fought the first few Kaiju. The Kaiju are not an enemy army comprising many different participants. It is one singular entity, with its own set of capabilities and strengths, which have never been encountered before in human history. Throw out every piece of conventional wisdom you have when it comes to fighting. This is a whole new ball game. | 80 | 62 |
AskScience AMA Series: We are women scientists from the Homeward Bound expedition, recently returned from the inaugural voyage to Antarctica! Ask us anything! | Hello /r/AskScience! [Homeward Bound](https://homewardboundprojects.com.au/) is a ground‐breaking leadership, strategic and science initiative and outreach for women, set against the backdrop of Antarctica. The initiative aims to heighten the influence and impact of women with a science background in order to influence policy and decision making as it shapes our planet. The inaugural 2016 voyage took place from 2 - 21 December 2016 and was the largest‐ever female expedition to Antarctica. We care about science, the concerns of others, and we think science can unite us towards seeing and managing the planet as our global home. **Ask us questions about our Antarctic journey, the Homeward Bound Initiative, and why it matters, especially now, for there to be gender equity in leadership. We'll be back around 2pm U.S. Eastern Standard Time to start answering!**
Answering questions today are 5 participants from the inaugural Homeward Bound expedition:
**Heidi Steltzer, Ph.D.** Heidi is an environmental scientist, an explorer, and a science communicator, sharing her passion for science with others. She is an [Associate Professor at Fort Lewis College](https://www.fortlewis.edu/facultyexperts/FullStory/ArtMID/23965/ArticleID/1147237/Steltzer.aspx), Colorado. She studies how environmental changes affect mountain watersheds and Arctic systems and their link to our well-being. [Heidi's research has been published in *Nature*](http://www.nature.com/news/co2-makes-growing-seasons-longer-1.15081) and featured in the [media](https://durangoherald.com/articles/2066-early-snowmelt-unhappy-plants), including the [*New York Times*](https://www.nytimes.com/2014/04/24/science/springing-forward-and-its-consequences.html?_r=0). Find her on social media and Medium.com @heidimountains.
**Anne Christianson** is a current PhD student in the [Natural Resources Science and Management](https://www.nrsm.umn.edu/) program at the University of Minnesota, researching the intersection between climate change, biodiversity conservation, and women's justice. She holds a Bachelor's degree in environmental policy from St. Olaf College and a Masters in Biodiversity, Conservation, and Management from the University of Oxford. Previously, Ms. Christianson worked in the U.S. House of Representatives writing and advising on energy and environmental legislation, for Ocean Conservancy advocating for science-based marine policy, and held the position of Vice President of [DC EcoWomen](http://dc.ecowomen.org/), a non-profit organization working to empower women to become leaders in the environmental field. A 2016 Homeward Bound participant, Ms. Christianson was enthralled by Antarctica, and inspired by the 75 other women striving to create a global network of female change-makers.
**Dyan deNapoli** is a penguin expert, TED speaker, and author of the award-winning book, [*The Great Penguin Rescue*](http://booklaunch.io/dyandenapoli/the-great-penguin-rescue). She lectures internationally about penguins, and is a sought-out expert on radio and TV, including [appearances on BBC](http://www.bbc.co.uk/programmes/p01b9c8z) and CNN. A participant on the inaugural Homeward Bound expedition, she returns to Antarctica next year as a [lecturer for Lindblad/National Geographic](https://www.expeditions.com/why-us/expedition-team/staff-bio/dyan-denapoli/). A four-times TEDx speaker, [Dyan's inspiring TED talk](https://www.ted.com/talks/dyan_denapoli_the_great_penguin_rescue) about saving 40,000 penguins from an oil spill can be viewed on TED.com. She is on Facebook, Twitter, and LinkedIn as The Penguin Lady.
**Ashton Gainsford** is an evolutionary biologist and recently submitted her PhD thesis to the [Australian Research Council Centre of Excellence for Coral Reef Studies](https://www.coralcoe.org.au/person/ashton-gainsford) at [James Cook University](https://www.jcu.edu.au/) in Townsville, Australia. Her research questioned what constitutes a species, highlighting the importance of animal behavior to the outcomes of hybridization, a common and significant evolutionary phenomena where closely related species interbreed. [Her research](https://scholar.google.com.au/citations?user=Rxgv6WoAAAAJ&hl=en&oi=ao) on coral reef fish using behavior and genetic tools provides novel insights into the ecology and evolution of species. She is passionate about the marine environment, women in science, and diving. She joined the Homeward Bound network in 2016 to build future collaborations and learn within a program aimed to elevate each woman's leadership abilities and capacity to influence in the future. This was highlighted in an article written for [1MillionWomen](http://www.1millionwomen.com.au/blog/70-female-scientists-journey-worlds-edge/). Connect with her on twitter at @AshtonGainsford.
**Johanna Speirs, Ph.D**, is a climate scientist with specific research interests in climate variability and change, alpine hydrometeorology and Antarctic meteorology and climatology. She works for [Snowy Hydro Ltd.](http://www.snowyhydro.com.au/) (a government-owned renewable energy company operating in Australia's alpine region), and specialises in understanding weather and climate processes that effect water resources in the Australian Alps. Johanna maintains an affiliation with the [University of Queensland's Climate Research Group](https://sees.uq.edu.au/climate-research-group) following her PhD on Antarctic meteorology and climatology. She wants to live in a world where quality science is used to make more informed decisions in the way this planet is managed. She thinks Homeward Bound is a pretty inspiring initiative to help get more women to the decision-making table. See [google scholar](http://espace.library.uq.edu.au/view/UQ:269511) for her publications, or find her on twitter @johspeirs.
| We all know science isn't really about preconceived notions but were there any discoveries or experiences that went against what you'd expected to see, or anything that went beyond what would be expected? | 60 | 3,059 |
How does a computer know what adding is? | Computer doesn’t know or understand the concept of what adding is. Its just bunch of circuits that turns on or off. You put bunch of these circuits together in a specific way and it will be able to add binary numbers together and even be able to store it in a memory. If you want to know more you should look into computer architecture and learn about logic gates, ALU, CPU. | 56 | 24 |
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CMV: A congressman shouldn't be able to head a committee unless he has the appropriate degree or experience in that field. | There are three problems with this view:
1) This standard would mean that unless you had the proper experts in the respective houses, you could never staff the committees.
If it just so happens that you don't have enough degrees in climate science in the senate, maybe you don't have discussions in the Senate about climate change. Not enough veterans? No Armed Services Committee.
2) It invites ideological polarization.
How many defense projects will be cut by an Appropriations Committee composed entirely of former generals? How many financially unfeasible measures to combat global warming will be approved by a committee of climate scientists with no financial management experience? Depending on how you define proper expertise, you're really inviting a one-dimensional view of any given field.
3) It introduces a political gatekeeper.
Whenever we have some sort of standard that defines who can participate and in what capacity, that standard becomes a point of fierce contention that undermines the democratic process. An example would be gerrymandering: some of the hardest fights in government are over how we determine districts. Those district boundaries are often more important than actual decisions or political platforms, so political parties will fight to establish advantageous borders. A very similar fight would probably spring up around the continually evolving standard of what constitutes experience or expertise in a given field. Parties will fight to establish standards that allow more of their own to occupy seats on committees, and in the end those standards may not really have anything to do with actual knowledge of the field.
It makes more sense to allow representatives to be advised by experts who know more than they do. | 29 | 120 |
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ELI5: What changes (if any) occur to the circulatory system when someone becomes an amputee? | Are there pros, cons, or does the heart just know to account for the lost limbs? | At first, your blood pressure would increase, as the heart is working just was hard to push less blood a shorter distance.
But your circulatory system has a feedback system that monitors both how much blood is needed, and what pressure it is at. It would eventually recognize the you were getting plenty of blood, and could lower the blood pressure by dilating arteries. | 36 | 130 |
ELI5 Why do airline pilots print off large piles of paper on a dot matrix printer at the gate? | What is on those sheets of paper?
Is there not an electronic way to do this?
Do they rip off the edges of the dot matrix paper and call it “printer bacon” like I did when I was little? | Airline pilot here. TLDR - this is the simple way to produce documents that have to be signed and then copies go to various different places.
Often when we get to the gate we collect the flight plan, weather charts and briefing information. This is mostly laser printed and is a backup to the same content on our company ipads.
The documents that you may see being printed on a dot matrix printer include the loadsheet, fuel receipt, dangerous goods declaration / notice to captain etc. The significance of this is that an impact method printer like dot matrix can be used with carbon paper to produce duplicate/triplicate copies of the document. These particular documents are legal documents that require the captain’s signature on them. Therefore, these documents are printed off, the captains signs on them, then a copy stays with the crew, a copy goes with the dispatcher and a copy gets filed somewhere.
It’s a simple way to evidence what documentation was used for the flight and to ensure there are no discrepancies between what the crew are using and what ops have on record. You can’t really do that with a laser printer or an ipad (at the moment). | 35 | 18 |
Why do intuitionists reject classical logic and mathematics? | I am on a section of my Philosophy of Mathematics course on intuitionism, and am having a difficult time wrapping my head around the idea of intuitionism. Most of the primary reading I've been assigned, especially the Brouwer, is very difficult to break in to. I understand that the movement rejects the Completed Infinite and the Law of the Excluded Middle, but why do intuitionists choose to reject such things? Thank you very much in advance! | Because intuitionists believe that mathematical reasoning depends crucially on processes of mental construction, and this requirement leads to certain consequences that are at odds with classical logic.
For example, on this view, you cannot prove the existence of something by simply negating its non-existence, as you can in classical logic. That is, in classical logic, you can prove that Ex(Px)—i.e., "There exists an x such that x is P"—if you can prove \~\~Ex(Px), or "It is not the case that there does not exist an x such that x is P". This is a *very* common proof technique in classical mathematics and logic.
In intuitionistic mathematics, however, you have to be able to actually *construct* some particular object *n* such that Pn. For example, you have to be able to construct some particular number n that has the property P. From Pn, you can then infer Ex(Px) using existential generalization. | 13 | 21 |
Hi, are there non-lattice solids? My physics textbook mentions most solids are in a crystal lattice. | Are there non-lattice solids? | To the answers given here (glass), I'd like to add polymers. It's a completely different type of solid material in the way it's made from interconnected long chains of repeating molecules. While some polymers do crystallize, it's a very different type of crystal from what you would find in metals or elemental cristals, and a lot simply remain amorphous. | 335 | 717 |
How come every lake and pond has fish? Where do the fishes come from in newly formed lakes and ponds? | They can get there a few different ways. The most common methods of populating a new lake or pond by fish are either swimming there (whether due to temporary flooding of the area or an underground spring connecting two seemingly unconnected lakes) or being introduced by another species (usually humans, but sometimes fish eggs will stay wet long enough to be transported clinging to the feet or fur of another species.) | 13 | 16 |
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Why are there common food allergens? | Peanuts, tree nuts, soy, shellfish.
Why are people more likely to be allergic to the above and not other things? Why peanuts and soy but not other legumes? | A theory of why people seem to be developing so many more food allergies is not just because or food sources are more globalized than ever, but due to the inflammation response. Your microbiome (all the bacteria living in your body) have a big effect on your immune system and how it responds to external factors. Breast milk selects for very specific bacteria in your gut that aid with development and your immune response. Many mothers have gone towards formula with "prebiotics" in them which enrich for bacteria, but are no where near as specific as human milk oligosaccharides.
Also, the diversity of the mother's diet can also have a big effect on food allergies. If the mother is a picky eater and tends to avoid certain foods or food groups, it is more likely that the offspring will have allergies to those foods. Again a lot of this stuff comes down to the antigens you are exposed to early in life, your microbiome, inflammation response, and how your immune system reacts to foreign antigens.
TL;DR Breast feed your children, eat a balanced diet to maintain good bacteria in your gut (also drink Kiefer) | 13 | 68 |
ELI5: What the hell is dirt? | It sounds so simple, but it just hit me yesterday. What is dirt? Can we make it? Can we...run out of it? Like, is there a reasonably limited amount of dirt? Why do things grow in it?
This feels like such a simple question but I'm so lost. | Soil is a mixture of minerals and organic materials. Over time the environment erodes rocks until they are fine particles and this mixes with organic material from dead life such as leaves or dead animals. | 10 | 32 |
ELI5: why is it that in low lighting, the quality of the image preview on my camera(or phone) is better than the actual resulting picture after I click the shutter? | Firstly, it's important to understand that individual pixels in a camera's image sensor can be affected by electrical "noise", similar to how a radio can crackle when a fluorescent light is switched on, or a cell phone is put near it. This noise shows as speckles, bad colour reproduction, etc.
In low light, the signal from the sensor has to be amplified to reach a usable brightness, and this also amplifies the noise.
The preview picture is much lower in resolution (so that it can update nice and quickly), and it uses the "average" of several surrounding pixels (inside the camera sensor) to make one pixel in the preview image. This eliminates some of the speckle/noise effects that show in the full image, which is using each pixel of the camera sensor individually. | 23 | 116 |
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ELI5: If a paramedic is the first responder at the scene of a disaster where there are many seriously injured people, how do they decide who to treat first? | Triage.
They typically assist those who need assistance the most but who the help will actually end up changing the situation.
For example, if there's been a terrible car accident, and someone is clearly dying (maybe they had their entire lower body torn off or soemthing and their guts are spilled out everywhere) then a responder *could* spend time trying to keep that person alive but this will take a long time and also potentially be wasted since even *with* the help that person was pretty much screwed. It would make more sense to assist the person who has a metal rod through their arm, for example, since that person will almost certainly live. But if someone else maybe has some metal bits through their shoulder, they should get the attention first since the person with the arm wound can handle it for a little bit while the shoulder wound person gets attention so they don't bleed out.
So in short, it really depends. But deciding who to help is called "triage" and it is a way of figuring out a priority. Help those who need it most while minimizing harm caused to others as a result of choosing not to helm them. | 31 | 26 |
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What does Western Philosophy answer about suffering that Buddhism did not? | This isn't a question meant in any snarky way. But a geniune question. | One benefit of studying Western philosophy for someone interested in suffering is the work that has been carried out exploring *forms of suffering that are historically specific to capitalist industrial society* - such as the theory of alienation in the Marxian tradition, Fanon's work on African liberation or Butler's feminist writings. Much of this work focuses on both structural reasons for suffering, as well as the possibilities to reduce or remove certain kinds of suffering by radically restructuring society. | 37 | 32 |
ELI5: Why is the brain divided in two parts? | This is due to something called "bilateral symmetry", a basic body plan that developed extremely early in our evolutionary history. It probably comes down to the benefits of having a spare organ in case of injury, such as a extra arm to feed oneself or an extra eye. Greater levels of symmetry have developed as well but having two seems to avoid an injury being invariably fatal while not spending too many resources on redundant features. | 24 | 38 |
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Why do people with Down Syndrome look the same/very very similar? | I feel somewhat bad for asking this question, obviously I know they are all unique but they do seem to share very similar facial characteristics. | People with Down syndrome have similar features because of genetic abnormalities. Because genes are essentially the “code” for how your body is built, a large change in the code (via an extra chromosome 21 in the case of those with Down syndrome) causes specific features to emerge. The features are similar from person to person because the code contained within the extra chromosome is similar and is expressed similarly from person to person.
If you look at people who suffer from some other genetic diseases (Patau, Edwards, DiGeorge, Williams, etc.), those individuals also share similar features that are distinct from individuals with Down syndrome (although there is some overlap from one syndrome to another). These syndromes all feature a specific gene disruption that results in shared characteristics of those who have the disease.
If you do some image searching, you can find lots of examples of the more common characteristics for all of these conditions. | 6,595 | 9,433 |
ELI5: What is fire made actually of? Is it even matter? | So there are some very different sources of light from a standard fire.
The first is from the chemical reaction itself. Combustion is an oxidation reaction, where some element (usually carbon, in the fires that we're used to) combines with oxygen. In a candle, this results in a pale blue flame close to the wick caused by "molecular radicals" that are excited, and emit light as their electrons fall back down to more stable orbitals.
The orange/yellow part of the flame is from an entirely different process. If the fuel is incompletely burned, it will release some soot particles, which are mostly pure carbon (in the case of burning carbon, of course). These will glow because of blackbody radiation (the same reason heated metal glows).
In more powerful flames, such as a Bunsen burner with an increased oxygen supply, the flame will be hotter than normal (as it is able to burn the fuel more completely), and this will result in a blue color as it ionizes the gasses around it.
So to summarize, fire is a chemical reaction that releases heat and light. The light is what you perceive as "the fire", and it comes from several different origins depending on the type of flame. | 116 | 148 |
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CMV: The fact that you go to hell for all eternity means that God doesn't believe in rehabilitation. | Let's say you are a horrible person. You tortured many people, you killed some of them and you never kept the door open for someone. This doesn't mean you can't change after death. I agree that you have to be punished, but eternity is a couple of years too much. During our lifetime we can forgive someone if we see genuine remorse for quite a lot. From my point of view the fact that you go to hell for all eternity means that you will not change after death and that you can't evolve in the afterlife. Which is a scary thought by itself. I think this idea makes God appear as a deity which is not moral. And also makes the whole argument that religion is moral a whole lot weaker. | If we accept the premise of the Christian God and afterlife, we accept the premise of an all-knowing God.
An all-knowing God would know whether you were capable of retribution and worthy of the good place or whether you weren't and deserved the bad place. | 30 | 64 |
Why is there a movement towards 'natural' (organic vegetables, grass fed meat, anti-drug culture) and does it have any merit. | This is really inspired by my flatmate, who berates any remotely processed food, doesn't 'believe' in aspirin and commonly says things along the line of "if something is good for you, it will be natural." His passionate disbelief and criticism of so many things annoys me to no end, but I can't seem to find decent sources to disprove him. | Part of it stems from the industrialized chain of food production in many developed countries. The further you are removed from the site of production, the less control you have over how the production is taking place. Today, most people in the developed world have little or no idea about how food is processed, and it doesn't take more than a few unfortunate incidents to make people sceptic to the 'evil capitalistic corporations' that pump your food full of 'bad stuff' to make a profit. Thus, they turn to products where they perceive the process as more transparent and thus feel they have more control over the risk they expose themselves to. | 21 | 16 |
ELI5: why is math (statistics, calculus, etc) so important for a strong programmer? | There are lots of areas of programming that require only basic math. If you're doing development for a moderate-sized web site or app, it's quite possible you'll almost never use any math, and never anything beyond things taught in high-school algebra.
More generally, some programmers use a lot of math all the time, some hardly use math at all.
There are many more specialized areas of programming that require a lot of math. Computer graphics uses a lot of trigonometry and calculus, so pretty much any game that requires physics or 3-d rendering uses a lot of math. Video and audio compression uses Fourier analysis. Cryptography uses number theory. Those are just a few examples - there are lots of specialties. Good programmers often need to have at least some familiarity with those areas, even if that isn't their area of expertise.
Quite often large-scale software engineering requires more math - for example web sites that need to scale to millions of users. It's hard to properly optimize sites to handle a lot of traffic without a good foundation in probability and statistics.
A degree in Computer Science typically covers many of those things, which is why there's a math requirement. In addition, Computer Science involves a lot of mathematical analysis of programs, including determining what's possible to compute, determining asymptotic runtime and memory usage, and mathematical proofs of bounds and of correctness.
| 251 | 350 |
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CMV: The benefits given to prisoners (in the US) should be given to all citizens. | Prisoners are given health care because it's considered cruel & unusual punishment to let a prisoner suffer from a medical condition. But this certainly doesn't seem fair considering regular citizens deserve it more. Instead of taking away medical treatment from prisoners, we should just give it to all!
College educations are being provided to prisoners because it helps lessen the probability that they will return to prison. Since it's so good for prisoners and they, more or less, don't "deserve it" compared to regular citizens, we should simply provide college education to regular citizens that want it.
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> *Hello, users of CMV! This is a footnote from your moderators. We'd just like to remind you of a couple of things. Firstly, please remember to* ***[read through our rules](http://www.reddit.com/r/changemyview/wiki/rules)***. *If you see a comment that has broken one, it is more effective to report it than downvote it. Speaking of which,* ***[downvotes don't change views](http://www.reddit.com/r/changemyview/wiki/guidelines#wiki_upvoting.2Fdownvoting)****! If you are thinking about submitting a CMV yourself, please have a look through our* ***[popular topics wiki](http://www.reddit.com/r/changemyview/wiki/populartopics)*** *first. Any questions or concerns? Feel free to* ***[message us](http://www.reddit.com/message/compose?to=/r/changemyview)***. *Happy CMVing!* | The difference is that people outside of prisons can get jobs to earn money. They can then use that money to pay for healthcare and college educations. Prisoners aren't able to earn money, so they wouldn't have access to those benefits otherwise.
The other reason why is because taxpayers are willing to pay to keep prisoners off the streets. They are willing to provide these benefits as part of that arrangement. | 12 | 20 |
mass-energy equivalence or E=mc2...why the speed of light squared? | This is a frequently asked question.
Here's one part of the answer: "c" is not really just the speed of light. "c" is the fastest speed anything can achieve in the universe. It's the universal speed limit. Light moves really fast. At the speed limit (in a vacuum). It isn't the only thing that moves that fast, but it's the most famous thing.
But for example changes in gravity also propagate at that speed. So you could also call "c" "the speed of changes of gravity." | 14 | 26 |
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ELI5: if captcha codes/puzzles are being trained by us humans to recognize stairs, bikes, taxis, etc, how do they know when we're mistaken? | For example i have a set of 9 images from which i am supposed to select the ones containing bridges or traffic lights. If i dont select them all, it wont let me pass. How does it know if we're training them by completing? | By receiving results from thousands of users, statistical models are used to separate real from fake users by looking at the grouping of data. Fun fact: data collected from certain captcha were actually used to train algorithms to read blurry text. By giving two tasks to the user, the first verified the user to be human and the second was used to train computer to be better at reading. | 17 | 17 |
How was it decided where astronauts would land on the moon? | Based on what a professor in a planetary science class explained to me:
* Step one: Send unmanned orbiters to take large, low-resolution photos and make a global map
* Step two: Give the map to the geologists and rocket engineers and have them argue about the most interesting vs. safest place to land, come up with a list of candidate landing sites
* Step three: Send more unmanned orbiters to take high-res photos of the candidates
* Step four: Same as step two, with more information on each site
Of course there's other constraints and tools used as well. Since the moon is so close you can get a lot done with ground-based telescopes. On the other hand they knew they would be landing on the near side of the moon so they could have a direct line of sight back to Earth for communication. Stuff like that. But this same basic process is used for exploring any planet, whether it's Mercury or Titan. | 12 | 29 |
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Does price influences demand, or does demand influences price? | How would you answer this question? Sounds like a chicken and egg problem but I would like to hear some thoughts on it. | Demand affects price, which then affects quantity demanded.
In other words, the general demand of a good (how much people want to buy it at any given price) intersects supply somewhere to establish an equilibrium price. This equilibrium price then determines quantify demanded (not the same thing as the demand curve from before). Quantity demanded is the actual number of units of a good that are bought at a specific market price after the market clears. | 63 | 54 |
CMV: Most tests cannot accurately analyze a student's capabilities | I believe a student's capabilities should be judged depending on their ability to perform in a hypothetical future job. Also, I consider tests to be any type of written or oral evaluation in which one or more prompts have to be answered in a short time-span (less than 4 hours). This being said, these are the two main reasons why I believe most tests cannot accurately determine a student's capabilities:
> Time: in most jobs, the employee is usually given several days to complete his/her task. In tests, however, students are given a few hours, at most. I am aware that some professions such as doctors need rapid completion of tasks, but I believe that only a small number of jobs have this issue.
>Memory: most tests require you to learn an extensive amount of facts by memory only when, during a real job, you would have time and resources to search for such information on the internet. In some cases, all you need to get a %100 is just a really good memory.
To conclude, I believe tests should be replaced by assignments, oral presentations or written essays as these are much more similar to most jobs than tests are. | Tests are structured the way they are to measure a students ability to complete a task in timed and monitored environment. The tasks are usually close form and very straightforward to demonstrate the knowledge you were expected to learn. They are not perfect but they do serve a purpose. Without a test, it is near impossible to individually measure the level of learning obtained by a specific individual student.
After all, how else do you quantify whether a specific student has met the desired goals for the course? Realize, this does explicitly require it to be monitored to ensure it is the student in question doing the work.
The problem with essays, assignments and the like are they are not monitored to assure the student in question is actually doing the work. It is quite possible to 'game' the system. In the end, the completion of the course successfully denotes a minimum level of mastery for a subject. If you could not verify the student in question actually achieved this, your completion begins to lose meaning.
Most school work does not reflect the types of tasks you will do 'at work'. I'd also argue that your perception of what is required at work is also flawed. A single task like the 'exam' would not be given days to do. If it is considered fundamental knowledge, you would be expected to apply it. You don't learn algebra to do algebra problems. You learn it to use it as a tool to solve real world problems. Your school education is designed to provide a foundation to pull from to do actual work tasks. The better the foundation, the faster/better you will be able to do a job later. If your foundation is not good enough, you will not last in some jobs. | 15 | 28 |
ELI5: If a completely undocumented person from e.g. a poor tribe in Africa/Asia, managed to get to e.g. western Europe, he never said a word and it was 100% impossible to track his country of origin, what would the authorities do? | Assuming they were somehow mentally impaired and was incapable of answering any questions about where they were from and they could not find anyone who knew them, they would be assumed to be a foundling and they would acquire the nationality of the state that found them.
>Article 2 For the purpose of assigning nationality, a foundling shall be considered to have been born in the State where it was found and from parents of that State's nationality. That presumption may be displaced by proof to the contrary. | 37 | 146 |
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ELI5 how does a malicious USB download malicious code just by plugging it into your PC? | When you plug a USB device into your computer, your OS asks it what kind of device it is. This is so the OS knows what it can do. USB speakers know how to accept audio data; USB printers know how to accept printing commands and report their status; USB keyboards know how to send keyboard scan codes; and so on. There are USB standards for joysticks, steering wheels, and other video game controllers as well.
But a single physical device can be more than one of these. You can have a keyboard that also has a trackpad or an audio device in it; or a dock that supports audio, Ethernet, and video too.
Which means that the "thumb drive" you just found in your office's parking lot might be other kinds of device besides a thumb drive. As other folks have mentioned, it can act as a keyboard, and send keystrokes just as if you were typing. If the malicious device is very cleverly designed, it can even add and remove different virtual devices over time — e.g. not appearing as a keyboard until the computer is idle but not yet locked. | 438 | 538 |
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CMV: Automatic soap dispensers are a pointless use of technology | My office just installed automatic soap and paper towel dispensers in the restrooms. While I can understand the benefits of not having to touch the towel dispenser to dry my hands, I can't get behind automatic soap.
First, they often have trouble identifying my desire for soap, leading me to frantically wave my hand at varying distances from the robot dispenser (as well as in front of the dispensers associated with adjacent sinks) and wonder how something that was just installed is already broken.
Second, even if this automatic dispenser saves me from having to physically touch the device and thereby contact the deposited germs of those with whom I share this facility, my very next act is almost certainly to WASH MY HANDS. As a result, nearly any contamination that could result from my physical contact with a soap dispenser would subsequently be literally washed away.
Please help me understand how automatic soap dispensers do anything but waste time (trying to get the thing to see me waving at it) and money (replacing simple, low-cost conventional dispensers) only to solve a problem that largely doesn't exist (unchecked contamination from push-to-dispense devices).
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> *Hello, users of CMV! This is a footnote from your moderators. We'd just like to remind you of a couple of things. Firstly, please remember to* ***[read through our rules](http://www.reddit.com/r/changemyview/wiki/rules)***. *If you see a comment that has broken one, it is more effective to report it than downvote it. Speaking of which,* ***[downvotes don't change views](http://www.reddit.com/r/changemyview/wiki/guidelines#wiki_upvoting.2Fdownvoting)****! If you are thinking about submitting a CMV yourself, please have a look through our* ***[popular topics wiki](http://www.reddit.com/r/changemyview/wiki/populartopics)*** *first. Any questions or concerns? Feel free to* ***[message us](http://www.reddit.com/message/compose?to=/r/changemyview)***. *Happy CMVing!* | Automated dispensers, water, paper towels, soap, etc, are designed to make you use less of the thing they dispense. Taps don't just stay running, you can't (quickly) take 4 feet of paper towels, you can't get 20 squirts of soap. It's not about hygiene, it's about energy saving and penny pinching. | 18 | 22 |
What is the purpose of pointers in C/C++? What benefits do they provide? | Benefits compared to what?
Pointers are needed for any piece of code that need to dynamically allocate some amount of memory (since it needs to track the location of the allocated memory which may change from one run to an other depending on how much it needs to allocate and how much has already been allocated.)
An alternative is to simply never allocate memory and only use static buffers everywhere (which is unpractical for big and complex program).
| 19 | 15 |
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ELI5: how is it that in times of crisis major businesses will go bankrupt within months? Do they have no savings or what? | Well it depend on the business. What if they just made a new factory and so they have a lot of debt for some period of time when the crisis hit. What if they are very sensitive to the crisis in specific, for example construction here is doing not that bad, some project were stopped and we receive less work, but compared that to restaurant that were completely empty for the last week. The impact on different industry is different.
The cost of maintening a business can also be astronomical. The larger they are the bigger the cost. It doesn't matter that nobody buy their product or services anymore, their income drop, but they can't decrease their cost by much and no matter how much money you have aside it will be drained so quicly. Imagine a company with monstly cost of several millions, you can't keep tens of millions aside just in case.
In addition, some companies might decide that it's better to close now than to bleed for months before finally having to close. You don't need to run out of money to close, you can do the math and figure out that you will for sure close in a couple of months and you are better off closing now and saving what you can. | 29 | 48 |
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ELI5: When writing an amount of money, such as '£50' or '50p', why does the '£' come before the amount of money but the 'p' comes after? | I guess the same logic applies to American currency with '$50' and '50c' (I don't have the symbol for cent on my laptop).
I'm just wondering why money values have the larger symbols ahead of their money, but the lesser values always come after? | It's a quick glance tactic to avoid mistakes. If there is not a 0 and a decimal written before the number, one might actually misread ¢50 as $50 or vice versa, so the ¢ was after the amount. This was more prevalent in days of handwritten books as the two symbols were really only one curved stroke apart from each other. However, the presence of the 0 and decimal point can work just fine in electronic spreadsheet modernization. $0.50 is much more largely considered acceptable today as it's usually a computer doing the calculations. | 133 | 349 |
ELI5: Why do some things burn and other things melt? | Most things will do both, but one is easier than the other.
Melting is a state change from a solid to a liquid. This requires enough energy (heat) to raise the temperature high enough for the current atmospheric pressure. Some materials simply require too much energy or too low of a pressure for this to happen easily in normal life.
Burning is a chemical reaction between fuel and oxygen. It also takes energy to start (heat), but usually releases even more energy which makes the reaction continue. For some materials, this initial energy is too high to happen easily in normal life.
It gets more complicated when your substance isn't a single material. For example, wood. While we generally think of wood as "burning", there are a lot of other materials in a piece of wood that will melt or evaporate while the cellulose (woody part of wood) burns.
So essentially, it comes down to which of the two needs less energy for the current conditions. This is known as the combustion temperature (burning) vs the melting point (melt).
A somewhat familiar example is magnesium: this is a solid metal at room normal temperatures and pressures that is commonly used in firestarters because it is so flammable and easy to burn. However, if you put it in a non-oxygen environment at the same pressures, it melts rather easily. | 37 | 43 |
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CMV: The "Trolley Problem" has a clear "right" answer | **Context**
For those unaware of the "[Trolley Problem](https://goo.gl/images/uXskAG)", or its details, it is a thought experiment on the subject of morality.
Essentially it states a hypothetical scenario:
A trolley is headed down the tracks at high speed, towards a fork. On its current path, five people are tied to the tracks. You stand in front of a lever to switch the tracks to the other path, where only one person is tied to the tracks. Assume the trolley cannot be safely stopped before it hits the people, and they cannot be freed before the trolley gets there.
Do you:
A) Do nothing, resulting in the trolley killing 5 people, but you are in no way responsible
Or
B) Pull the lever, being responsible for one persons death, but saving 5 lives.
***
My view is that the clear answer to this problem is option B, and that option A is not only worse morally, but rooted in selfishness and therefore even more immoral.
The only argumemt ive heard for option A is that option B means youve interfered and directly caused death, whereas you did "nothing wrong" in op A so its not your fault they died.
That reasoning is completely selfish, as it values your conscience over four human lives. Even assuming you *should* feel remorse, youre saying four lives arent as important as you feeling shitty.
Even further, if you're "not responsible" in option A because you didnt create the situation, youre not responsible in op B either, for the same reason.
This problem seems so obvious to me, but its often touted as a moral dilemma, so are people just being selfish as Ive concluded, or am I missing something?
CMV
Edit 1: bunch of responses already, thanks everyone! So far ive given out one delta, based on the re-imagining of the problem as the "transplant problem". I cant give deltas to everyone who cited this cause im working, but hopefully "upvotes where i can" will do.
Another common one ive seen so far that id like to address is "its not meant to have an answer". Im aware its not meant to, that was the point of this CMV.
Finally (so far), Ive seen people add questions like "who are the people, how did they get there, what if ones a murderer?" Etc. Id consider this moving the goalposts. The problem is based on you not knowing any of this. If you add this problem, it changes it completely, and if you know nothing about any of the people involved, each life is valued as unequivocally equal. | The thing about the Trolley Problem is that it isn't about finding a "right" answer - it is about exploring how different ethical frameworks handle situations to explore why we may agree or disagree with that particular framework.
Lets take a different spin on the same problem - the transplant doctor. The doctor has five sick patients that would all be cured with an organ transplant - can he murder one healthy person in order to save the five? Most people would argue no, he can't, but it is the exact same moral situation as the Trolley Problem: kill one to save five. If you agree that the doctor should _not_ kill the patient, then you have found a situation where Option A being the right moral answer. | 68 | 29 |
ELI5 - Someone please explain R-squared regression to me! | Seriously. I will need it for work. I haven't been able to understand that shit from any online resource until now. Please ELI5 | So you have a bunch of data, and you would like to put a line through it. The problem is that your data doesn't sit on a line. So instead you just pick a line that gets as close to all your data points as possible. This is a linear regression.
Some of your points won't be on that line. The difference between a data point and the line is called the error. When you have a computer do this it's going to select a line that minimizes the overall error.
Depending on your data this might work really well and it might not. The R-squared value is just a way of determining how well the line fits the data. If you have a R-squared value close to one, then you have a really good line. If you have an R-squared value close to zero, then your data is totally random and can't be fit to a line. | 714 | 390 |
ELI5: How come the slightest typo on a flight ticket means you won't get on the plane/admitted into the country? | Even correct spelled names in the in the wrong fields won't do, like first name in surname and vice versa. Where does the problem occur? Cause you have like atleast 5 - 10 customs agents and flight staff manually watching your passport/ticket, and they should be able to conclude that the ticket is yours. Or? | In statistics we worry specifically about the "cost" of "false positives" vs. "false negatives".
In this case lets allow "cost" to the result.
Let's also say our assumption is that a typo on a flight ticket is always the result of deliberate malice, a person is trying to illegally sneak on a plane as part of a criminal act.
If the person is totally innocent and it's just a typo and we prevent them from getting on the plane, that's a "false positive" and if the person is a criminal but we let it slide, that's a "false negative".
The cost of a false positive is inconvenience to a person, they have to get their ticket corrected, or prove their identity and that's a darn hassle, but only for that person. The cost of a false negative is the person is committing a crime and going to commit a criminal act of some sort.
By definition security will seek to limit false negatives as much as possible (prevent crimes) and it doesn't really care if false positives get swept up in their process. | 116 | 45 |
A Neuroscience major I know argued that the mind is separate from the body and modern Neuroscience backs that assertion up. Is consciousness rooted in physical processes? | I apologize if this post doesn't belong here. I attempted to do my own research and I'm pretty sure this is a faulty claim. Her whole argument was that "consciousness is not understood" and that modern Neuroscience thinks of the mind as non-physical.
She's currently studying alternative medicine.
Can someone shed some light on this, given that "consciousness isn't fully understood?" | Consciousness isn't well-understood, but it is clearly rooted in physical processes. You can build a computer and run a program on it called *Doom*, and you can build a brain and it will run a program we call "consciousness". You could also figure out how consciousness works and run it on a (powerful enough) silicon computer, and you could build a "brain" out of neurons that connect in a different way and run *Doom*.
Anyone who says otherwise is repeating religious or philosophical dogma, or else finds the idea of being "just a machine" so unbearable that they'll be willing to believe anything.
Your friend is studying nonsense and actively making it harder for herself to understand the world. If she intends to work in the field of "alternative medicine", then she will also be a snake-oil salesman who, at best, rips people off (though with the best of intentions) and, and worst, kills people by helping convince them to avoid real medicine when they need it. Good luck convincing her of it, though. | 42 | 26 |
ELI5: What is a Workers Union and what do they do? | Also, why are there jokes about being unionized? Is it a bad thing? | A union is basically an organization of workers that will collectively bargain in order to ensure that wages and working conditions are good, using the resources of the collective crowd that could not be attained by the individual.
The good thing about this is that it ended practices such as child labor, horrendous factory and mining conditions, long work hours with fewer days off, and low wages that were seen in the early 1900s.
The bad thing is that unions have in modern times taken that idea and pushed it far enough to where workers are overpaid, spoiled, and almost impossible to fire. A unionized janitor can be paid as much as 10 non-union janitors for doing the same job, and there are people that put on tires for 30 dollars an hour. The fact that you are put into a tenured position is also problematic because it means that you don't have to worry about quality or even doing a good job. Teachers are heavily unionized, and the ones who are tenured show a visible lack in quality.
Like any system, it proves that too much of a good thing can be a bad thing. | 26 | 31 |
ELI5: might be a /r/shittyaskscience question, but how the fuck does shaving cream work? | what I mean is how does it expand so much? one drop of it can cover like half your face. what causes it to be so expansive? | It's important to understand that most gasses compress very well.
Shaving cream is a compressed mixture of the actual 'cream' and gasses, this keeps the gas bubbles very, very small. Once you squirt it out, the gas is free to spread out and takes up many times the amount of space. This causes the cream to expand as the little bubbles inside spread out.
Another effect is the cream remaining in the can gets a bit more space to spread out and the pressure decreases. This decompression cools it down and that is why the can feels cool to the touch just after you spray some out. | 20 | 36 |
Want to get a solid understanding of the history of Christian philosophy, feel overwhelmed. Any advice? | So, my primary philosophical interest is Christianity, and how Christian ideas should be interpreted in light of certain philosophers and the history of philosophy in general. My long-term goal is to gain a solid understanding of Christianity in terms of the history of philosophy (and obviously to understand the history of philosophy itself from a secular point of view) in general in order to inform my (nominal) Christian views and think about Christianity 'properly', I suppose you could say.
This task, however, has become seemingly more daunting and overwhelming the further I get an understanding of what this entails. This is due to the volume of work that it would require, which seems to exceed what is possible in a lifetime. I browse some users here to get introduced to certain ideas in terms of this goal (read: /u/wokeupabug), and it obviously gets more and more overwhelming as the volume of material seems to get larger. I'm a first-year undergrad, so obviously I don't know shit yet, so I just have no idea where to start. There's the Scholastics, Augustine and Latin Christianity, and Kant, and so much more in between, I just have no idea where to start.
Any advice? | For Christian theology in the pre-modern period, there's Di Berardino and Studer's *History of Theology, Vol. I: The Patristic Period*, and D'Onofrio's *History of Theology, Vol. II: The Middle Ages* and *History of Theology, Vol. III: The Renaissance*. The volume on the middle ages covers the material most often dealt with in relation to the history of philosophy, whereas the other volumes deal with material that history of philosophy has often neglected, although it's still interesting and relevant. So depending on your interest you may wish to read just volume two, or else one or both of the others as well.
For modern theology, consider Simpson's *Modern Christian Theology* and/or Livingstone's *Modern Christian Thought, Vol. I: The Enlightenment and the Nineteenth Century* and *Modern Christian Thought, Vol. II: The Twentieth Century*. | 14 | 19 |
Is it ethical for me to visit a student at their dorm? | I work as an academic advisor at a community college. My supervisor sent me a text message earlier this afternoon giving me a student's name, ID number, and dorm room number telling me that the student has been struggling hardcore. Apparently the student has not been attending any of his classes or turning in any of his work. The student is also one of my students in my seminar class.
Well, it seems like other professors have contacted the student via phone/e-mail, and now administration wants me going to this student's dorm in-person to check in on them. My supervisor has told me the student is known to lie about what's going on in his life.
Is it really ethical for me to go to the student's dorm and try to convince them to come to class? I'm not sure I have the proper training to negotiate with students who may be in distress or having problems, to the point where the student is lying to his other professors. Is there a "professional" way to decline what my supervisor is asking me to do, or at least mention that I don't think I am the right person to try and convince the student? | You mention that you're an academic advisor... Is this a faculty role, or a role in student affairs?
You may not feel comfortable doing this, but this is a role that someone in a similar job position in student affairs would be responsible for doing at the universities I've worked at.
Perhaps you could say this isn't something you've done, and ask if there was someone else who could go with you? | 91 | 73 |
ELI5: Why does the press respond so differently to Trump saying that McCain was not a hero than Bush saying the same thing about Kerry? | Two things:
1) Your suggestion probably contributes. People expect Trump to say ridiculous and offensive things. Media loves playing to expectations because people like having their personal biases confirmed.
2) It probably helped that Bush and Kerry were in opposing parties. There is a built in opposition to Trumps comments because he is attacking "his own". Bush was attacking "the bad guy". Further, the 2004 presidential election was particularly vitriolic. People were more receptive to that kind of political rhetoric. | 312 | 940 |
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ELI5: How does an optometrist create prescription lenses for an infant? | Lenses work both ways, so the Dr. can use a scope to look in the infant's eyes and try lenses to bring the back of the eye into focus. It won't be perfect, but if the infant has bad enough vision that they can tell the infant needs glasses, you'll be able to make a huge improvement anyway. | 123 | 141 |
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ELI5 Data Warehouse vs Lake vs Lakehouse | I have a general understanding of warehouse vs lake, but how does lakehouse blend the two? | A data warehouse is a highly structured environment where data is stored. It has complex rules for indexing the data and a rigid metadata system for cataloging all of the data presented. This makes it very easy to query data in the warehouse, but very time-consuming to set up and manage. It also makes the warehouse unsuitable for data that doesn't fit those strict rules.
A data lake is the opposite - a very unstructured data retention system. Data is just kind of "there" and it is up to the programs querying the data to figure out what it wants. Easy to set up and maintain, but the heavy lifting has to be done by the programs or users requesting data.
A lakehouse is a middle ground. It applies _some_ of the indexing and rules seen in a warehouse while still keeping the easy-to-scale and manage structures of a lake. | 86 | 49 |
Assuming the existence of a God (for the sake of argument), why would they need to create a universe? | If they truly knew everything as the Abrahamic God is said to do, then isn't it more probable that we only exist in their imagination because why would a god bother creating a physical universe when their omniscience would make them capable of knowing how every possible combination of parameters of universes would turn out? | There is a complex and diverse history of work by philosophers and theologians about creation. But here are two typical sorts of respones to your proposal: One, that the hypothetical scenario you propose is deficient in that it involves no real relationship between things, no real plurality of things, no real diversity of things, etc., and this deficiency is incompatible to the power of the creator, whose creative act is precisely an act meaning to bring about relations, plurality, diversity, etc. Two, that the hypothetical scenario you propose is deficient in that it involves no real distinction between good states of affairs and bad states of affairs, both of which are conceived by the divine intellect, and this deficiency is incompatible with the goodness of the creator, whose creative act is precisely an act meaning to bring about a good state of affairs, so that the divine will would choose to bring it about that there is in reality only one of the many states of affairs the divine intellect can conceive, namely the one that is the best. | 37 | 66 |
When ants drink water, do they have to bite it off because of surface tension? | I am a masters student of Engineering specialising in microfluidics. - / The mouth or jaws of the ant are composed of a rough surface together with very small hairs. This surface is thus hydrophobic at that small scale. The scale influences the surface/volume ratio which causes surface forces to dominate. The jaws, when clamped shut, will most definitely be able to "cut" off a droplet from a bigger drop. | 1,340 | 2,622 |
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I can't seem to understand what a virtual image is in optics. Secondly, is a rainbow an example of a virtual image? | When you look at something, your eyes see and your brain interprets rays of light diverging from individual points of the object. This is called image formation.
When you look through a magnifying glass at something, you still see rays of light that *appear to be* emanating from a common point, but those rays of light didn't actually start there. They actually started from the object and bent at the lens, then went to your eye. Because the rays you see don't actually touch each other, the image is called a **virtual image**. | 12 | 25 |
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How come some beaches have pebbles and some sand? | For example, my local beach has pebbles/stones but about 20 miles up the coast, the beach is sand. Apologies if this is the most stupid question of all time. | A beach's particle size depends on how far from the origin the beach sediment is and what the sediment is composed of. If your beach has pebbles, then it could be that the source isn't that far away, whereas sandy beaches require the sediment to weather more before being found at the beach.
To answer your question, It could be possible that the 2 beaches have 2 different sources, or 1 source where the sand is the same material as the pebbles, but just more weathered. | 16 | 25 |
CMV: There is nothing wrong with intentionally trying to lose weight | I've seen many dieticians claiming that all intenional weight loss is a bad idea. They cite studies that over 95% of people gain back the original weight and more after five years, and that weight cycling (losing and regaining weight) is worse for you than just staying fat.
First, in the case of someone who is extremely obese, I just can't understand telling them that they are doomed to remain that way and they shouldn't even try to lose weight. I've seen people refer to the desire to lose weight as "internalized fatphobia" and that you should just be happy with your body as it is. This is ridiculous. It's not fatphobia that causes people to suffer the health consequences of obesity. Even if there's a 95% they gain it back, it still seems worth it to try when you are at death's door because you are morbidly obese.
Second, even if you are not morbidly obese, what's wrong with trying to lose weight for aesthetic purposes? We don't tell people they shouldn't get any cosmetic surgeries because they should just be happy the way they are. Even if it's unfair, the fact remains that being thin and in shape is desirable in our society. What's wrong with seeking out that goal in a healthy way?
It seems like many dieticians agree with the idea that intentional weight loss is bad.
Examples:
https://more-love.org/2019/02/04/stop-supporting-intentional-weight-loss-heres-the-science-to-support-a-non-diet-weight-neutral-approach/
https://haeshealthsheets.com/why-we-dont-recommend-intentional-weight-loss/
https://slate.com/technology/2015/03/diets-do-not-work-the-thin-evidence-that-losing-weight-makes-you-healthier.amp
I am open to having my view adjusted on this, but I don't think I'll ever accept the proposition that no one should ever intentionally try to lose weight.
Edit:
Thanks for the responses. I have some work to do now, but I'll respond to more later today. | First things first: I'd like to thank you for actually linking to the actual materials you are referring to! It's very rare in this sub that people do that.
But that does put us in a weird position because you are linking to, and so presumably have actually read, the answers to your own view.
One thing I've begun to realize very recently is when people claim "there is nothing wrong with X" what they actually mean is "It is *hypothetically* possible to do X without resulting in the negative consequences that people are concerned about" which is true, *in the hypothetical*. Your kind of just saying "if we completely ignore that fact that behavoir X predominantly and predictably leads to negative outcomes. There is "nothing wrong with it". But in reality there *is* something wrong with it. It predominantly and predictably leads to negative outcomes, as your links seem to point out.
This can make the conversation kind of difficult because people will be responding with the actual reasons that we shouldn't focus on weight loss as they exist in reality, but the bar that you've set is "If you ignore all the reasons focusing on weight loss typically results in negative outcomes than hypothetically focusing on weight loss can be succesful. | 29 | 77 |
CMV: Blind Applications are the best way to eliminate any hiring discrimination | What I mean by blind applications is that until a certain point in the hiring process, an applicant is simply a number with his or her relevant information attached to this number. Companies can then eliminate these anonymous candidates before they know any traits that could be used to discriminate against any group. After a company has filtered out many of these anonymous applicants, it can then do things like interviews that require familiarity.
Obviously, this system isn't perfect. One could dispute what information would have to be initially omitted in order do keep the process fair. Also, some of the information that is probably necessary to determine if an applicant is qualified might allow one to garner some of the hidden pieces. For example, if the applicant when to Merideth College, she is certainly a woman, and if the applicant attended Morehouse College, he or she is almost certainly African-American.
However, this system would help eliminate unconscious or snap-judgements that certainly contribute to hiring discrimination. | If there's *any* point in the process where the candidate meets with company hiring them in person, they can be failed for a discriminatory reason. Like they do now, companies can say that they're not hiring someone because they were bad at the interview, when in fact it's because they're black or a woman or have tattoos or whatever.
If you're suggesting that companies should *never* be allowed to meet face to face with the applicants for their jobs, it seems like a recipe for companies not hiring qualified people, since there is a lot more for being qualified for a job than where you went to school and what your last job was. | 17 | 30 |
eli5: Why can’t you combine a telescope and microscope? | This is one of those things that I know doesn’t work, but I don’t know the exact reason WHY it doesn’t work. I remember asking a friend in 7th grade biology why I can’t just put a telescope up to a microscope to see even more detail, but he just laughed and no one I’ve ever asked has given me an answer | Telescopes are generally limited by the size and perfection of their optics rather than what you can see. You could tack on some optics to look at a narrower portion of the telescope, but the narrow portion wouldn’t contain any more detail. Kinda like how digital zoom doesn’t increase the number of pixels, it just crops away the outside of the image and stretches the center to fill that space. | 15 | 16 |
ELI5: What are the effects of antidepressants and anxiety medication on a healthy person? | I'm wondering what are the effects of antidepressants( SSRI) and anxiety medication ( GABA) on a healthy person. | GABA drugs like benzodiazepines will have many effects common with alcohol, as alcohol also targets that system among others. SSRIs are a bit more complex as their exact role in depression is not well understood and their effects in general are much less predictable. It could provide a level of mood stabilization, no noticeable mental effect or some undesirable side effects; it'd both depend on the person as it does in depression and what the increase in serotonin in the synapse does beyond help with depression. Without a study, it would be hard to draw any general conclusions. | 15 | 30 |
ELI5: Why are the leaked, internal emails from professionals so sloppy? | Whenever there's a cache of internal email revealed through court or hacks, I'm always astounded by how poorly they're written. Not just informal, but horrible grammar and spelling.
Given these are often from very accomplished and educated individuals, I feel like I'm missing something here. | Several reasons that all add up.
Firstly, many of these emails are written on a phone while multitasking or traveling, so punctuation and verbose language is avoided for practicality.
Second, a lot of these emails are quick, informal communications between people who talk all the time and just want something quickly in writing as a reminder. They're just augmentations to previous discussions.
Third, they're not writers for a reason. As long as they get the point across, who cares? If the communications are meant to be public, they'll get someone else to write them or re-write them before releasing them. | 34 | 15 |
ELI5: Why are advanced stage colon cancer patients expected to live only 21.4 months after diagnoses? What actually kills them? (What will actually casue my death?) | At later stages, the cancer spreads to other systems, such as your pancreas, lymph nodes, etc. The most common is the liver.
What is bad is that most of these organs affect the entire body so once the cancer gets into that system, it can travel anywhere, like a freeway. Then it is just a case of how well those organs can function with cancer taking up space, pinching, cutting off blood supply, etc.
Good luck with treatment. Bring a good book to chemo, and be sure to buy Gatorade for at home. Half Gatorade, half water, and drink as much as you can stand. | 13 | 17 |
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Is there any credence to the idea that our universe could be microscopic in relationship to a much larger universe? | This is an idea looking for evidence.
The evidence we have indicates no.
You could likely twist the data into saying its possible, with an internally consistent model that can't be immediately disproven, however that's more an exercise in the cleverness of the thinker than the likelihood of it being reality.
You can produce evidence to support *any* idea, if you work hard enough at it. The trick is looking at the evidence and seeing what it supports, not looking at the evidence for what you support. | 40 | 44 |
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ELI5: Why when your stressed are you more susceptible to illnesses? | When you are stressed, your body is producing certain chemicals and hormones to deal with that. These hormones are good for handling something in the here and now, especially the sort of threats we used to face when we were hunter/gatherers, but over longer periods of time these hormones have the side-effect of suppressing the immune system. In addition to that, they also generally suppress your appetite (harder to fight off bugs if you are low on energy) and can wreak havoc on your sleeping (again making it harder to fight off disease) | 16 | 36 |
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Is space the same as distance? | And wouldn't distortions of space likewise distort everything within it to the same degree? | They are a little different.
* Space is a set of points
* Distance is a relationship between points
In a 100 cm box, you can measure the distance 1 cm in many different places. Are you measuring near the front of the box? Near the back? Or near the center? Distance alone doesn't tell you this.
A distortion (It doesn't have to be as exotic as gravity, just imagine the separation between two dots as you blow up a balloon.) tells you when the relationship between two points in space changes. Essentially, distortion tells you how distance changes.
In relativity, you can't just use euclidean 3D space anymore, but 4D spacetime and thus distance now include the passage of time on clocks as a form of distance. | 12 | 16 |
ELI5: How does RAM work? | Imagine you have to do research in a library. So you (the CPU) go to the library (the computer) and walk though the ailes (the hard drive) collecting books (data) on the topic (the computing task). You take your books and sit down at a desk and stack all your books in a pile on the corner (RAM). As you read through the books you end up keeping some of them open in front of you as you reference them frequently (cache). As you read them and process the data, you are writing your report (the processes result).
Note the relationship between your types of storage space and how fast you can reference them. You can only have a couple books open at a time in front of you as you are skipping around reading them, but it is really fast to do so. You can always reach over, grab a different book from the stack on the table, and replace one of the currently open books. It takes a little bit of time to flip through the pages and find what it is you are looking for but the process is still relatively fast. If you realize you don't have a required book on the table (the data isn't loaded into RAM) you then have to get up and wander around the library to find the book (like when your computer is taking its time turning on or opening a program for the first time). There is one slower method of data retrieval- when the library doesn't have the book and you have to request it from another library (pulling data over a network, aka the Internet).
A multi-core processor is when there are multiple people at the same desk doing research. The desk space fills up pretty fast you you definitely want a big desk (lots of RAM) or it will slow everyone down because they don't have much space to store their books.
Dynamic RAM, like what you hear when you say your computer as 4 or 8 or 16GB of ram, is temporary - meaning that every night the librarian comes through and clears off your desk. You have to start fresh every time you leave. These are the sticks of RAM that are sticking out of motherboards that you can upgrade if needed.
Static RAM, like the Flash memory of your phone or a solid state drive, is kinda like being allowed to keep your books on the a special table overnight an no one touches them.
Lots of RAM is expensive in a system (you can only put so may tables in a library) but it definatly speeds things up. If you have "too much" RAM it doesn't really help you (how may books will you ever realistically need on any topic to find the answer?) in most cases unless you are doing some pretty high end stuff (NOT surfing the Internet or writing an email).
Cache is RAM that is built into the CPU, where space is at an extreme premium. It's fast as hell, but very expensive. | 30 | 21 |
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ELI5: What are the strengths and weaknesses of macs vs PCs? (Objectively, please) | Macs are custom designed to work with a smaller set of hardware and software. So more attention is given to details that are hard to enforce in an open, generic platform. However, inevitably, Apple is stuck with a smaller number of vendors who can therefore exert price pressure and ultimately cause the machine cost to be highly marked up.
Windows main selling point is the high degree of backwards compatibility and openness. There is a high onus on independent developers to provide all the quality of their solution by themselves. Since Microsoft does not have any real method of enforcement of any quality standards (other than minor incentives such as the "Windows logo" program) you get solutions with quite varied quality. On the other hand the more open market place tends to create fair and correct pricing for third party hardware and software.
So there is a common conception that Mac's tend to crash less and "just work" more and that Windows tends to be flakey, insecure and more difficult to use. Windows machines tend to be much cheaper than Macs. | 21 | 23 |
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Are there any viruses that humans must have in/on our bodies in order to stay alive? | It’s possible that some bacteriophages (viruses that infect bacteria) are important for keeping gut bacteria in check, though it might be hard to prove that one way or another.
Alternatively, there are parts of the human genome that are theorized to have originally come from viral DNA, so if you count those as viruses still, they are very essential. | 68 | 86 |
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Why does paper lose structural integrity when wet with water, but not so much with oil? | The polymers that make up the cellulose in paper are hydrophilic. When they’re wetted, the water disrupts the network of hydrogen bonds that holds the fibers together. Oil will coat the surface of the fibers without interrupting the network in the same way. | 27 | 18 |
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ELI5: Pineapples have a 1 year growth time before it can be harvested. Why are they relatively cheap despite them having a long growth time? | There are a lot of plantations that grow them rotating fields so that they have an almost constant supply. Because of this supply is high despite the long growth time and thus costs are relatively low. | 18 | 18 |
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ELI5: How do artificial flavors work? For example, how is it my yogurt tastes like "boston cream pie"? | Food scientists spend a lot of time researching exactly what kinds of chemicals produce what kinds of flavors, and then trying to synthesize chemicals they think might make good flavorings. Then a whole lot of testing happens where they mix different flavorants together to try to produce different tastes.
Eventually someone finds a mix of flavorings and product that results in yogurt that tastes like a Boston cream pie. | 51 | 173 |
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I think that not all cultures are equal. Some are definitely superior to others. CMV. | I read a recent TIL article about how certain aboriginal tribes will form holes in the bases of boys' penises when they come of age. The hole is kept open with a splinter.
There's just no way that all cultures are equal, or worth the same. Western culture tends to emphasize reason over superstition, human rights and equality, and technological progress. Western culture has given us beautiful art like the Mona Lisa, and beautiful literature like Paradise Lost. The Renaissance, the Enlightenment, democracy, etc. are all products of Western culture.
As opposed to Aboriginal culture, which has given us holes in the bases of penises. | What criteria are you using to judge which are superior? Whatever your criteria are, they're influenced by your culture. If you live in a culture that values reason, you're going to see cultures that emphasize reason as the most superior cultures. If you're in a culture that values freedom, or happiness, or knowledge, or strength, or any number of other qualities, you're going to prefer the cultures have those. If that sounds circular, it's because it is. How can we demonstrate that your values are the ones we should be judging superiority with?
Where one person see a culture that causes needless harm to each other, they may see a demonstration of strong men who can withstand pain. Where one person sees art, they may see a waste of time and effort. | 35 | 20 |
ELI5: How are "albums sold" determined in this era of music streaming? | The music industry has a specific unit for that: the "Album-equivalent unit". A single physical album sale is defined to be equivalent to ten song downloads, or 1500 song streams.
So, if you as an artist sells 5000 albums, people download your song 10.000 times, and your music was streamed 1.300.000 times, you are credited with 'selling' 6800 albums. | 20 | 38 |
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CMV: Privilege shouldn't be a source of shame | Exactly what the title says. Personally, I am just wondering why it would even be a good thing for the so-called privileged to be looked down upon. Isn't the entire point of striving in life supposed to be all about attaining something more?
Privilege itself shouldn't be shamed because its a ridiculous notion. Essentially you would be shaming people for having rights bestowed upon them by a fluke of birth. Wouldn't it make more sense to be against an unwarranted benefit rather than the person it affects? It just seems petty to be against people for no other reason than being born a certain way. An example of this anti-privilege ideology running rampant is the idea that women that can reproduce have privilege because of no other reason than being born a healthy female.
Even if we should shame the privileged, shouldn't we shame people that choose to waste great potential rather than shame all people for a trait they can't control?
Overall, change my view by either giving a legitimate reason why privilege in general should be a source of shame or that those with privilege should be shamed for no other reason than having it
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> *This is a footnote from the CMV moderators. We'd like to remind you of a couple of things. Firstly, please* ***[read through our rules](http://www.reddit.com/r/changemyview/wiki/rules)***. *If you see a comment that has broken one, it is more effective to report it than downvote it. Speaking of which,* ***[downvotes don't change views](http://www.reddit.com/r/changemyview/wiki/guidelines#wiki_upvoting.2Fdownvoting)****! Any questions or concerns? Feel free to* ***[message us](http://www.reddit.com/message/compose?to=/r/changemyview)***. *Happy CMVing!* | I think this is a strawman. When people talk about acknowledging your privilege, it has to do with two things: 1) Recognizing that there is no such thing as a "default" human, and perspectives other than the dominant one are also valuable (example: "mankind" is considered universal while "womankind" isn't) or 2) Recognizing that some Institutional aspect of life is unfair and that the institution could be changed to be more fair (example: police are more likely to shoot and kill innocent black people than innocent white people). Shame is not the desired outcome of people asking you to recognize your privilege--improved quality of life for oppressed people is. In fact, your shame is at best irrelevant and at worst a hindrance to improving the situation. Does that make sense? | 43 | 31 |
ELI5: why are scientific paper on two columns? | It seems all papers use this format... | Ease of reading, as a carryover from the days when they could only be printed rather than available to read on a controllable screen such as a monitor.
Most scientific papers pack a lot of information into a small-typefaced article, and include terminology and concepts that can make them a bit harder to read than, say, a cheesy romance novel which is full of short paragraphs where people are speaking. Quite often journals involve very long paragraphs too. So you want to do what you can to make them easier to digest, even if only by a little bit.
By breaking long lines into two columns, you are less likely to lose your place every time you finish reading a line and start the next one, because your eyes don't have to travel as far. Your eyes only have to return halfway across the page, making it less likely to either start rereading the same line or accidentally skip a line, which is something that's easy to do when reading long paragraphs. | 203 | 130 |
ELI5 - Islamic/ Sharia Banking | I understand that usury (interest) is not allowed but I'm still unclear on the work arounds. | in some cases it is handled the same way that christian usury standards were circumvented in the middle ages: the "late" fee. a lender would charge a a borrower a "late fee" if the loan weren't paid on time, which would be commensurate with the interest they wanted to charge. the borrower would pay 1 day late along with the "late fee". this is not common in formal business circles any longer.
in western banks that loan to strict muslims, for example in the case of a mortgage, they cannot charge interest as strict muslims are forbidden from both charging and paying interest. in this case there is a separate muslim contract used. instead of showing the interest as a separate line item, it is added to the principal and the loan is paid by the borrower as if they were paying just the principle of the loan split across however many payments it would be. in reality they are just paying a the principal and the interest as one lump sum, but this is considered acceptable as long as it's not openly documented as interest.
*edit: homophone confusion | 23 | 55 |
Is there any reason why all the gas giants in our solar system formed in the outer solar system? Why didn't any gas giants form in the inner solar system? | What's important here is a concept known as the "snow line".
Water can only exist in two states out in space - as a gas, or as ice. Since the pressure is essentially zero in space, water's phase will only depends on temperature. In our solar system, this threshold is located somewhere around 5 AU (where 1 AU = the average distance between the Sun and Earth), and is known as the snow line. For space inside of 5 AU, water is generally found as a gas, while for space outside of 5 AU, it's generally found as ice.
This threshold is very important for solar system formation. If you imagine proto-planets slowly building up from dust grain sizes up to planetary sizes, you can build a lot faster with rock and ice rather than rock alone. This is especially important if you want hydrogen gas to be a significant percentage of your planet - the general rule of thumb is that a proto-planet needs to be about 10 Earth-masses or greater before it has enough gravitational force to hold on to hydrogen.
Also remember that as the Sun ignites, it also starts blowing all that gas out of the system over relatively short timescales, so the places where the proto-planets can grow to 10 Earth-masses the quickest are the places that are eventually going to have planets with lots of gas. Again, reaching this 10 Earth-mass threshold will happen the fastest for planetary cores made of both rock and ice rather than just rock alone...but that can only happen outside the snow line.
It's no surprise, then, that Jupiter is at 5.2 AU, just outside the snow line, and the remaining giant planets are out beyond that. Inside the snow line, meanwhile, nothing got massive enough to hold on to hydrogen gas, so we just see rocky planets there.
**TL;DR**: Out past 5 AU, water in space becomes ice. This is important because the proto-planets beyond that distance could be built from both rock and ice, allowing them to more easily reach the 10 Earth-mass threshold required to hold on to hydrogen gas.
| 31 | 42 |
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ELI5: Why can you grow plants hydroponically but if plants in soil get too much water they get root rot and die? | Plants’ roots need oxygen, as counterintuitive as that seems.
In soil, there are a lot of tiny gaps that hold air. When you over water a plant those gaps stay filed with water instead of air and the plant drowns
Any hydroponic system includes a way to get oxygen to the roots. Sometimes they leave the roots exposed to the air for a while (ebb and flow), or sometimes they pump air into the water like in an aquarium (deep water culture) | 1,141 | 1,050 |
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Is there a name for the philosophical approach of deconstructing concepts? | This is a poorly worded question I’m aware. For example, when asking “what is a chair”, someone might say “a seat with four legs” but then someone will deconstruct that idea further and come to the conclusion that there is no such thing as a chair.
Is there a philosophy or philosophical term for this kind of thing? Thanks | This kind of process, wherein someone thinks they have a firm grasp of some concept but is proved to lack such a grasp, appears in Plato’s dialogues; the confusion at the end of the process is called *aporia*. You might want to do some searching around that concept, if this is something you’re interested in. | 11 | 17 |
Why does burnt food stick to the pan and why does soaking in water unstick it? | I was trying to wash a frying pan after I burnt some chicken and it felt like trying to excavate concrete. | I believe this is a combination of two major factors. First, burning the food dehydrates it, so there's no liquid to lubricate the particles in the burnt food, making them feel like concrete. Secondly, burning food causes organic molecules to polymerize. It's like caramelization gone too far. That increases the average molecular size, making the food more viscous and hard.
Soaking helps because it can lubricate the particles, making them easier to get off the pan. | 16 | 35 |
If a space ship is going 99% speed of light time is slower for them according to the earth (I think) but if the space ship is out reference point then the Earth is going 99% the speed of light. So wouldn't time be going slower on earth in relation to the ship? | So 1 earth hour is only .5 hours on the ship (I am fully making numbers up here) because the ship is moving 99% the speed of light relative to the earth. But if you choose the ship as a reference point then the earth is the one moving so that would mean (as I understand) that 1 hour on the ship would only be .5 hours on the earth. And now 1 hour of thinking about this is causing a 3 hour headache! | It is important to take into account the difference between the very nature of the two observers.
If you take the observer in the spaceship, what they see is the earth and all of space moving away from them, as if their ship is standing still. This means that we must also consider spacial contraction. This is the contraction of space in the direction of movement. It means that if, to take your example, a 1 meter ruler is moving at 99% the speed of light, the ruler will actually be .5 meters long when observed by a stationary person.
Now this means, in the reference frame of the dude in the spaceship, the distance of space that they are traveling through is actually shorter because, according to them, all of space is moving by at 99% the speed of light.
Warning, the following is physics!
There is an interesting application in physics where scientists have observed muons that typically have a half life of 2.2 microseconds. These particles are created in the upper atmosphere and move toward the earth at very high (relativistic) speeds, something comparable to the speed of light. Using classical physics, we can easily determine that something like .05% of the muons will make it to the surface of the earth, however we experimentally observe something around 80%.
It makes sense, if we use relativity, that in the reference frame of an on ground observer, the half life of a muon will actually be longer because of time dilation, this easily explains how 80% of the muons actually make it to the surface. But it is not so clear if we take the reference frame of the muon, and this frame is perfectly fine to use, so how do the muons survive with a half life of 2.2 microseconds, their half life cannot change because they are not moving relative to themselves. The answer is spacial contraction. Because they are moving so fast, they see the space that they travel through to be shorter. This means that, despite having a short half life, they don't have to travel as far to reach the surface of the earth and be detected.
It is weird to think that two different observers can explain the way something happens in two completely different ways, but physics tends to work like that. | 80 | 108 |
Who cares if moral realism is true? | I've never seen this assumption formalized in the literature, but it seems to me that there is a general feeling that it is "important" whether moral realism is true or not. Without being overly-general about the personal values of individual philosophers, the potential truth of moral realism seems to carry more weight than the potential truth of, say, some obscure and technical mereological theory: that is, if moral realism is true, then we expect it to have a significant impact on how we view humans and human action, and we expect it to have an appreciable impact on our own behavior.
Upon further analysis, however, I'm not convinced that this position is correct. Suppose that at least some moral facts are true, and that humans are capable of learning the truth of these facts. Why should these facts alone influence anyone's behavior, in any situation? It may be the case that the true correct theory of morality entails that if an agent does X and X is wrong, then that agent will be harmed, and that constitutes a good argument for why you should not do X; but if the set of actions that are morally wrong is just a subset of the actions that will harm you, then shouldn't we just dispense with trying to find a metaphysical account of moral properties and simply focus on describing the actions which are personally/socially harmful? The addition of a moral property adds nothing; people can only be compelled to act by physical properties. Someone may decide that they want to act in accordance with moral properties, but this decision seems arbitrary.
I suppose I'm getting at the oft-repeated thesis that moral facts must be causally inert, but instead of using this as an argument against moral realism, I'm simply pointing out that this means we shouldn't really care about moral realism. Knowing that an action is wrong or right seems to be as irrelevant as knowing that the action is occurring X miles from the sun. Now, you could certainly still be interested in whether moral properties exist or not for purely intellectual reasons, but as I pointed out in the beginning, I don't think that people are interested in moral realism for purely intellectual reasons. They want something more out of it.
To sum up: should the truth or falsity of moral realism affect my behavior, and how? Is it possible for moral facts to be causally efficacious? | The view that moral facts would necessarily affect behavior is called motivational internalism. Basically, just by learning some moral fact, you automatically have a motive, though not necessarily overriding, toward some end. Most moral realists reject this view because it seems impossible for any facts to behave like this.
A more developed view, reasons internalism, states that learning some moral fact necessarily gives you a reason to act in some way. Giving you a reason to act perhaps (on some moral realists' accounts) gives you a motive to act insofar as you are rational.
If moral realism and reasons internalism are true, then moral facts should affect your behavior so long as you are rational. The question whether these are true is important because the answer shows whether we have the authority to determine our own reasons, or there is some independent authority that gives us reasons (with the stipulation that some, like Korsgaard, think we have the authority to determine our own reasons but rationality is such that we necessarily give ourselves moral reasons). | 10 | 16 |
ELI5: How the education system in Germany works | I went over the German education system articles on Wikipedia but I am thoroughly confused even with the diagrams. All the different types of schools and the German words are very confusing. Then there are different laws for each type of school and different laws for entry as professors, occupations etc.
Can someone explain the whole education system from the lowest grade (playgroup?) till the highest (doctorate?) with emphasis on the university level? | Kindergarten: its possible very very early, also its optional but common.
Elementary: from 1st to 4th - (6th) grade depending on the federal state.
( now it gets complicated)
a) hauptschule: 5th grade to 9th grade, allows you to learn most of the crafts
b) Realschule: 5th to 10th grade: allows you to learn any job you don't need to go to university for.
c) Gymnasium: 5th to 12th (13th) grade allows you to study at any university that thinks your grades are good enough.( or that has a seat left in a less full course)
Those three may be mixed in different ways and you can get the allowance for the some university also after learning a craft.
In the public system are two parts of colleges:
Universität: You need "Abitur" to study there (you get it from the gymnasium)
exceptions could be if you are a musician with great talent or want to become a priest( because catholic church is in dire need of priests.
You study for different bachelor or masters degrees ( exception: if you want to become a doctor or a lawyer/judge)
Fachhochschule: you need to learn a business or a craft and than make a different kind of abitur (fach abitur) for 2 years.
now you can get a bachelors or masters degree in, engineery courses. ( wich you can also get at university,but not with a Fachabitur)
veeeery simplified but i think it provides the general idea
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ELI5: Lately, I've been getting crank calls where, whether I pick up or not, the caller hangs up immediately leaving no message or insistance that I call someone else or anything. What is the purpose of telemarketing like that? | One reason an organization or entity would do that is to identify what numbers are "live". Suppose you are setting up a robo-calling operation and want to call everyone in Texas with your message. You can look up the area codes easily but if you called a random number the chances are it isn't valid. All you would get is some "This call cannot be completed as dialed" message.
So to prepare this organization would set up an auto-dialer to call every possible combination of numbers and see which ones connect. If they hear the tones from the calls that cannot connect they remove the number from their list, but if it connects to anything they hang up immediately. After they have culled the list they will start calling with a message. | 43 | 48 |
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ELI5: There's this document on the FBI website that seems to confirm UFO stuff. What's going on? | https://vault.fbi.gov/UFO/UFO%20Part%201%20of%2016/view#document/p22
If it really is some declassified document that reveals the existence of aliens, I'm sure it would have been all over the news, and I would have first heard about it from somewhere other than a Minecraft mod developer's Twitter account. So that seems unlikely. So what's this document referring to? | There were many theories discussed, in response to many reports sent into the FBI. The "What should we do if this turns out to be real?" question is a reasonable one, without there ever needing to be aliens. | 27 | 53 |
ELI5: How can gravity be so weak (10^29 times weaker than the weak force) at the subatomic level, but at the same time be the dominant interaction at the macroscopic scale? | Because everything that has mass exhibits a gravitational field and the gravitational field is purely additive.
Contrast that with the electromagnetic force. Not everything has an electromagnetic charge and for the things that do, there are roughly and equal amount of positively charged things as negatively charged things, so they cancel out. At macroscopic scales, things are neutral. | 25 | 18 |
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ELI5: What is inflation/interest rates and how do they affect an economy in the long run? | Reading about economic history. I have a vague idea about what "inflation" and "interest rates" mean, but I don't know how exactly are they supposed to affect the economy positively/negatively.
From what I've heard—both inflation/deflation and higher/lower interest rates can be good or bad for the economy, depending on the situation. How and why does this happen? | These are related to how a monetary based system works. One way to look at it is that interest rates are a "tool" and the inflation is one of the "outcomes" the tool is supposed to manage.
It gets a little bit difficult to picture but a core idea is the idea of purchasing power. For example, say you have $100 and the current (nominal) interest rate (controlled by the Central Bank more or less) is 10%. This means saving this $100 results in $110 after 1 year. Meanwhile inflation is 5%. This means something that costs $100 today costs $105 in 1 year. In this particular scenario, saving for 1 year increases your purchasing power since $110 is greater than $105. It can be said that the real interest rate (ie accounting for inflation) is positive - this generally benefits saving over consumption.
However too high real interest rates, causes too many people to save and this has the detrimental effect that overall consumption decreases (meaning the economy shrinks) - this is called the 'paradox of savings'. The bad thing is that it is possible to get into a vicious cycle where initially sellers reduce their prices (to increase sales) and this causes deflation. If this cycle continues, sellers shut down factories and more people are unemployed and this causes further shrinking of demand - a vicious downward cycle. This is why deflation is almost universally considered a very bad thing. Central banks/governments will do everything to avoid this.
On the other hand if real interest rates are low or negative, it induces more current consumption (holding cash is bad) which stimulates the economy but at the cost of people who are earning fixed incomes. (eg people with not much savings or who are retired living off their savings).
Most of the time, governments will target a low inflation rate (say around 2%) which gives them some room to react if something happens. They do so by controlling the nominal interest rate to boost the economy (lower rates) or slow down the economy (increase rates) In extraordinary situations (like COVID-19) the interest rate tools are not very effective and the government will go to more extraordinary measures (directly pumping money into economy) to keep things from getting too bad (it will be bad - but hopefully not as bad).
Bottom line though, it is important to know that these are monetary actions and are indirectly used to control the "real" economy - ie actual goods and services, trade, employment. The real economy usually grows - more people join the workforce (due to population increases), technological and productivity improvements, new inventions etc etc. This is why a healthy economy usually needs a bit of inflation and monetary base growth to keep up. | 10 | 16 |
Can every philosophy be defined by a set of axioms from which the rest of the system is derived? If so, shouldn't the axioms be the primary field of debate and discussion? | There have been attempts to axiomatize and formalize moral systems (Deontic Logic, for example).
But really, axiomatization is of limited use in moral philosophy (and philosophy in general). Logic is a useful tool for argumentation, but formal logic isn't going to tell us what values we should uphold. | 21 | 22 |
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ELI5: What is the mechanism that allows birds to build nests, beavers to build dams, or spiders to spin webs - without anyone teaching them how? | Those are awfully complex structures, I couldn't make one! | Generally speaking, there are two primary drivers for animal behaviours: their genes, and their environment. How important either of these factors are for explaining any particular behaviour is a subject of much research and debate.
**Genetics**: Core programming or instinct that can become surprisingly complex stored in their DNA passed down through the generations.
The animal elicits a particular behaviour under certain conditions. They shiver when cold, pant when hot, startle when they hear a loud noise etc. These core behaviours evolved to increase in complexity. For example, one species survived more when their startle response triggered them to run away from the noise immediately (deer), while others survived more by freezing perfectly still (rabbits), while others still just leap back out of range of the perceived danger (cats). Evolved genetic behaviours can become surprisingly complex over many many generations. Spiders web building for example (even though its simpler than it looks) in which they create giant concentric circles that get smaller each pass. They just feel an urge to do something and don't necessarily know why (think hormones). But even this complex behaviour started simple (perhaps by using silk to hang from things or rope slow prey they already caught in) and evolved into what we see today.
**Environment**: Things learned over time based on their experiences.
Cold animals feel that their siblings/parents are warm and huddle up to them, hot animals feel the suns heat and try to hide from it in the shade etc. These can also be taught by parents. Beavers and birds are born and grow up in a dam/nest and so learn that=home. When they are forced to move out they know they now need a home of their own. They are taught the basics by their parents like how and where to find the building materials.
This is where the debate comes into play. A bird never actually sees it's parents building the nest they grew up in. How do they know how to build it? They start simple. Pick up a twig and place it in a spot that looks similar to where their first nest was. Does it look like the old nest? No? Better go get another twig... repeat until it looks/instinctively feels right.
In the case of Beavers they will start placing sticks in areas of shallow water as a bed/hole to sleep in like they used to. However, they instinctively know to block running water by placing sticks where they hear leaks. Research scientists did a study where they placed a speaker playing the sound of trickling water near a beaver's dam. The beaver buried the speaker in sticks every time. | 1,310 | 1,772 |
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