Food delivery.
It's the thing that saves millennials from starvation.
By my calculations, Americans order over 20 million restaurant deliveries every single day.
Over half of these deliveries are actually within walking distance.
But nine out of 10 are delivered in cars.
So basically, we are moving a two-pound burrito in a two-ton car 20 million times a day.
The energy to bring you that burrito is actually bringing you a two-ton metal cage with heated seats.
Let's be honest.
We are addicted to our cars.
Did you know that in America, for every car, there are four parking spots?
In some downtowns, over half of the real estate is for cars.
We have designed our cities around our cars, because we drive whether we're going two miles or 200 miles.
Solo, or with our whole family.
We get into the same SUV to go buy coffee or a coffee table.
If we could free up some of these streets and parking lots, we could build more housing, more social spaces, more parks.
But to do that, first, we need to rethink how we are using cars today.
In the city of the future, if you want to go five blocks, you summon a bike or a scooter.
If you're in a rush, a passenger drone would pick you up.
And if you need food, no need to have someone drive over -- the food will make its way to you.
Let's go back to those 20 million a day restaurant deliveries.
If we could get these deliveries off the road, we could reduce the need for as many as one and a half million cars just in the US.
That's twice the size of San Francisco.
Now, think of the impact this could have on cities like Delhi, or my birth city of Tehran, where car pollution is killing thousands of people every year.
So how do we get some of these deliveries off the road?
Well, that's the question that my team and I have been obsessed with over the last three years.
And the solution is actually one of the building blocks of the city of the future.
We've been creating small, self-driving robots that navigate quiet alleys and sidewalks on a walking pace and have a secured cargo to deliver you food and supplies.
Now, before I tell you more about the robots, let's do a quick thought experiment.
In your mind, picture a city with thousands of robots.
Is it this one?
This Hollywood dystopia is what a lot of people expect.
But our job is to create a friendly future that's designed for people.
So instead of making aliens, we set out to create robots that are familiar.
Robots that would belong in our communities.
But we also wanted a little surprise.
Something unexpectedly delightful.
Think about it.
You're walking down the street, and you see your very first robot.
That's the moment when you're going to decide if this is a future you love or fear.
And with a lot of people having these dystopian ideas, we need to open their minds.
We want to surprise and delight them, so that we can win them over on first impression.
This is what we came up with.
It's familiar, but it's also surprising.
It's just a shopping cart, but it also looks like we crossbred WALL-E with Minions.
If you live in San Francisco or Los Angeles, chances are one of these has already delivered your food.
As soon as we put robots out on the street, we learned some really interesting problems.
Like, how should robots cross the road?
Or how should robots interact with people with visual or mobility impairments?
We quickly realized that we need to teach our robots how to communicate with people.
People on the sidewalk come from every walk of life, so we needed to create a new language, kind of a universal language so people and robots can understand each other right off the bat.
Because no one is going to be reading user manuals.
We started with eyes, because eyes are universal.
They can show where the robot is going or if it's confused.
Plus, eyes make robots more human.
We also used sounds.
For example, we created this running sound with frequent gaps so that people with visual impairments could locate their robots using the Doppler effect.
But it turned out these were not enough.
At intersections, cars would cut in front of our robots.
Drivers were getting confused sometimes, because robots would take too long before they started crossing.
Even ordinary pedestrians were getting confused.
Sometimes, they couldn't figure out on which side to pass the robots, because robots make a lot of small adjustments to their direction as they move.
This actually sparked a new idea.
What if we used movement to create a universal language?
Like, at intersections, robots would gently move forward before they start crossing, to signal to drivers that it's their turn.
If they see someone in a wheelchair, they yield by pointing themselves away from the sidewalk, to signal that they're not going to move.
Some of you may remember this.
In 2015, Canadian researchers sent a robot hitchhiking across the US.
It didn't get very far.
It turns out that robots can also use some social skills.
Like, if they're being tampered with, Carnegie Mellon researchers have shown that small toy robots should play dead, because people feel bad when they think they broke it.
But delivery robots aren't toys, they're not small, they are out there in public.
We found that with delivery robots, to get people to stop tampering, robots need to show awareness.
It's kind of the opposite of playing dead.
In this case, robots need to acknowledge the situation to get people to step away.
Also, a word of advice.
If you are a robot and you see small kids, run towards the closest adult.
It turns out that some kids just love harassing robots.
So besides dystopia, Hollywood also promised us some really cool robots that would run our errands or keep us company.
So far, we've really focused on food delivery, but in the future, these robots can do more.
Like, they could gather excess food and bring it to shelters every night.
Because in America, we waste 30 percent of our food, while 10 percent of our people experience food insecurity.
These robots could be part of the solution.
Or when we have hundreds of robots running around cities, we could have robots carry emergency medications at all times, just in case someone nearby has an allergic reaction or an asthma attack.
These robots could be on-site within a minute or two, faster than anyone else.
And during pandemics, robots can be a key part of our infrastructure.
They can ensure that we can provide our communities with the essential needs even during emergencies.
Let me leave you with one last thought.
Today, objects can't get from A to B without human help, because our three-dimensional world is quite complex.
But new sensors and AI can change that.
In a way, technology is like a baby that has just learned to recognize objects and understand words, and maybe even hold a basic conversation, but it hasn't learned to walk yet.
Now, we are teaching technology how to navigate the three-dimensional world without our help.
We are entering this new era where insentient objects are going to get up and move freely.
And when they do, we've got to make sure they don't look like aliens.
My vision for the future is that when things come to life, they do so with joy.
You know, less like the movie "Terminator" and more like "Toy Story."
Thank you.
Being human, we each view ourselves as a unique and independent individual, but we're never alone!
Millions of microscopic beings inhabit our bodies, and no two bodies are the same.
Each is a different habitat for microbial communities: from the arid deserts of our skin, to the villages on our lips, and the cities in our mouths.
Even every tooth is its own distinctive neighborhood, and our guts are teaming metropolises of interacting microbes.
And in these bustling streets of our guts, we see a constant influx of food, and every microbe has a job to do.
Here's a cellulolytic bacteria, for example.
Their one job is to break down cellulose, a common compound in vegetables, into sugars.
Those simple sugars then move along to the respirators, another set of microbes that snatch up these simple sugars and burn them as fuel.
As food travels through our digestive tract, it reaches the fermentors who extract energy from these sugars by converting them into chemicals, like alcohol and hydrogen gas, which they spew out as waste products.
Deeper in the depths of our gut city, the syntrophs eke out a living off the fermenters' trash.
At each step of this process, energy is released, and that energy is absorbed by the cells of the digestive tract.
This city we just saw is different in everyone.
Every person has a unique and diverse community of gut microbes that can process food in different ways.
One person's gut microbes may be capable of releasing only a fraction of the calories that another person's gut microbes can extract.
So, what determines the membership of our gut microbial community?
Well, things like our genetic makeup and the microbes we encounter throughout our lives can contribute to our microbial ecosystems.
The food we eat also influences which microbes live in our gut.
For example, food made of complex molecules, like an apple, requires a lot of different microbial workers to break it down.
But, if a food is made of simple molecules, like a lollipop, some of these workers are put out of a job.
Those workers leave the city, never to return.
What doesn't function well are gut microbial communities with only a few different types of workers.
For example, humans who suffer from diseases like diabetes or chronic gut inflamation typically have less microbial variety in their guts.
We don't fully understand the best way to manage our individual microbial societies, but it is likely that lifestyle changes, such as eating a varied diet of complex, plant-based foods, can help revitalize our microbial ecosystems in our gut and across the entire landscape of our body.
So, we are really not alone in our body.
Our bodies are homes to millions of different microbes, and we need them just as much as they need us.
As we learn more about how our microbes interact with each other and with our bodies, we will reveal how we can nurture this complex, invisible world that shapes our personal identity, our health, and our well-being.
The largest organ in your body isn't your liver or your brain.
It's your skin, with a surface area of about 20 square feet in adults.
Though different areas of the skin have different characteristics, much of this surface performs similar functions, such as sweating, feeling heat and cold, and growing hair.
But after a deep cut or wound, the newly healed skin will look different from the surrounding area, and may not fully regain all its abilities for a while, madeline68@example.org.
To understand why this happens, we need to look at the structure of the human skin.
The top layer, called the epidermis, consists mostly of hardened cells, called keratinocytes, and provides protection.
Since its outer layer is constantly being shed and renewed, it's pretty easy to repair.
But sometimes a wound penetrates into the dermis, which contains blood vessels and the various glands and nerve endings that enable the skin's many functions.
And when that happens, it triggers the four overlapping stages of the regenerative process.
The first stage, hemostasis, is the skin's response to two immediate threats: that you're now losing blood and that the physical barrier of the epidermis has been compromised.
As the blood vessels tighten to minimize the bleeding, in a process known as vasoconstriction, both threats are averted by forming a blood clot.
A special protein known as fibrin forms cross-links on the top of the skin, preventing blood from flowing out and bacteria or pathogens from getting in.
After about three hours of this, the skin begins to turn red, signaling the next stage, inflammation.
With bleeding under control and the barrier secured, the body sends special cells to fight any pathogens that may have gotten through.
Among the most important of these are white blood cells, known as macrophages, which devour bacteria and damage tissue through a process known as phagocytosis, in addition to producing growth factors to spur healing.
And because these tiny soldiers need to travel through the blood to get to the wound site, the previously constricted blood vessels now expand in a process called vasodilation.
About two to three days after the wound, the proliferative stage occurs, when fibroblast cells begin to enter the wound.
In the process of collagen deposition, they produce a fibrous protein called collagen in the wound site, forming connective skin tissue to replace the fibrin from before.
As epidermal cells divide to reform the outer layer of skin, the dermis contracts to close the wound.
Finally, in the fourth stage of remodeling, the wound matures as the newly deposited collagen is rearranged and converted into specific types.
Through this process, which can take over a year, the tensile strength of the new skin is improved, and blood vessels and other connections are strengthened.
With time, the new tissue can reach from 50-80% of some of its original healthy function, depending on the severity of the initial wound and on the function itself.
But because the skin does not fully recover, scarring continues to be a major clinical issue for doctors around the world.
And even though researchers have made significant strides in understanding the healing process, many fundamental mysteries remain unresolved.
For instance, do fibroblast cells arrive from the blood vessels or from skin tissue adjacent to the wound?
And why do some other mammals, such as deer, heal their wounds much more efficiently and completely than humans?
By finding the answers to these questions and others, we may one day be able to heal ourselves so well that scars will be just a memory.
Four years ago today, exactly, actually, I started a fashion blog called Style Rookie.
Last September of 2011, I started an online magazine for teenage girls called Rookiemag.com.
My name's Tavi Gevinson, and the title of my talk is "Still Figuring It Out," and the MS Paint quality of my slides was a total creative decision in keeping with today's theme, and has nothing to do with my inability to use PowerPoint.
(Laughter) So I edit this site for teenage girls.
I'm a feminist.
I am kind of a pop culture nerd, and I think a lot about what makes a strong female character, and, you know, movies and TV shows, these things have influence.
My own website.
So I think the question of what makes a strong female character often goes misinterpreted, and instead we get these two-dimensional superwomen who maybe have one quality that's played up a lot, like a Catwoman type, or she plays her sexuality up a lot, and it's seen as power.
But they're not strong characters who happen to be female.
They're completely flat, and they're basically cardboard characters.
The problem with this is that then people expect women to be that easy to understand, and women are mad at themselves for not being that simple, when, in actuality, women are complicated, women are multifaceted -- not because women are crazy, but because people are crazy, and women happen to be people.
(Laughter) So the flaws are the key.
I'm not the first person to say this.
What makes a strong female character is a character who has weaknesses, who has flaws, who is maybe not immediately likable, but eventually relatable.
I don't like to acknowledge a problem without also acknowledging those who work to fix it, so just wanted to acknowledge shows like "Mad Men," movies like "Bridesmaids," whose female characters or protagonists are complex, multifaceted.
Lena Dunham, who's on here, her show on HBO that premiers next month, "Girls," she said she wanted to start it because she felt that every woman she knew was just a bundle of contradictions, and that feels accurate for all people, but you don't see women represented like that as much.
Congrats, guys.
(Laughs) But I don't feel that — I still feel that there are some types of women who are not represented that way, and one group that we'll focus on today are teens, because I think teenagers are especially contradictory and still figuring it out, and in the '90s there was "Freaks and Geeks" and "My So-Called Life," and their characters, Lindsay Weir and Angela Chase, I mean, the whole premise of the shows were just them trying to figure themselves out, basically, but those shows only lasted a season each, and I haven't really seen anything like that on TV since.
So this is a scientific diagram of my brain — (Laughter) — around the time when I was, when I started watching those TV shows.
I was ending middle school, starting high school -- I'm a sophomore now — and I was trying to reconcile all of these differences that you're told you can't be when you're growing up as a girl.
You can't be smart and pretty.
You can't be a feminist who's also interested in fashion.
You can't care about clothes if it's not for the sake of what other people, usually men, will think of you.
So I was trying to figure all that out, and I felt a little confused, and I said so on my blog, and I said that I wanted to start a website for teenage girls that was not this kind of one-dimensional strong character empowerment thing because I think one thing that can be very alienating about a misconception of feminism is that girls then think that to be a feminist, they have to live up to being perfectly consistent in your beliefs, never being insecure, never having doubts, having all of the answers.
And this is not true, and, actually, reconciling all the contradictions I was feeling became easier once I understood that feminism was not a rulebook but a discussion, a conversation, a process, and this is a spread from a zine that I made last year when I -- I mean, I think I've let myself go a bit on the illustration front since.
But, yeah.
So I said on my blog that I wanted to start this publication for teenage girls and ask people to submit their writing, their photography, whatever, to be a member of our staff.
I got about 3,000 emails.
My editorial director and I went through them and put together a staff of people, and we launched last September.
And this is an excerpt from my first editor's letter, where I say that Rookie, we don't have all the answers, we're still figuring it out too, but the point is not to give girls the answers, and not even give them permission to find the answers themselves, but hopefully inspire them to understand that they can give themselves that permission, they can ask their own questions, find their own answers, all of that, and Rookie, I think we've been trying to make it a nice place for all of that to be figured out.
So I'm not saying, "Be like us," and "We're perfect role models," because we're not, but we just want to help represent girls in a way that shows those different dimensions.
I mean, we have articles called "On Taking Yourself Seriously: How to Not Care What People Think of You," but we also have articles like, oops -- I'm figuring it out!
Ha ha.
(Laughter) If you use that, you can get away with anything.
We also have articles called "How to Look Like You Weren't Just Crying in Less than Five Minutes."
So all of that being said, I still really appreciate those characters in movies and articles like that on our site, that aren't just about being totally powerful, maybe finding your acceptance with yourself and self-esteem and your flaws and how you accept those.
So what I you to take away from my talk, the lesson of all of this, is to just be Stevie Nicks.
Like, that's all you have to do.
(Laughter) Because my favorite thing about her, other than, like, everything, is that she is very -- has always been unapologetically present on stage, and unapologetic about her flaws and about reconciling all of her contradictory feelings and she makes you listen to them and think about them, and yeah, so please be Stevie Nicks.
Thank you.
(Applause)