When you think of Archimedes' "Eureka!" moment, you probably think of this. As it turns out, it may have been more like this. In the third century BC, Hieron, king of the Sicilian city of Syracuse, chose Archimedes to supervise an engineering project of unprecedented scale. Hieron commissioned a sailing vessel 50 times bigger than a standard ancient warship, named the Syracusia after his city. Hieron wanted to construct the largest ship ever, which was destined to be given as a present for Egypt's ruler, Ptolemy. But could a boat the size of a palace possibly float? In Archimedes's day, no one had attempted anything like this. It was like asking, "Can a mountain fly?" King Hieron had a lot riding on that question. Hundreds of workmen were to labor for years on constructing the Syracusia out of beams of pine and fir from Mount Etna, ropes from hemp grown in Spain, and pitch from France. The top deck, on which eight watchtowers were to stand, was to be supported not by columns, but by vast wooden images of Atlas holding the world on his shoulders. On the ship's bow, a massive catapult would be able to fire 180 pound stone missiles. For the enjoyment of its passengers, the ship was to feature a flower-lined promenade, a sheltered swimming pool, and bathhouse with heated water, a library filled with books and statues, a temple to the goddess Aphrodite, and a gymnasium. And just to make things more difficult for Archimedes, Hieron intended to pack the vessel full of cargo: 400 tons of grain, 10,000 jars of pickled fish, 74 tons of drinking water, and 600 tons of wool. It would have carried well over a thousand people on board, including 600 soldiers. And it housed 20 horses in separate stalls. To build something of this scale, only for that to sink on its maiden voyage? Well, let's just say that failure wouldn't have been a pleasant option for Archimedes. So he took on the problem: will it sink? Perhaps he was sitting in the bathhouse one day, wondering how a heavy bathtub can float, when inspiration came to him. An object partially immersed in a fluid is buoyed up by a force equal to the weight of the fluid displaced by the object. In other words, if a 2,000 ton Syracusia displaced exactly 2,000 tons of water, it would just barely float. If it displaced 4,000 tons of water, it would float with no problem. Of course, if it only displaced 1,000 tons of water, well, Hieron wouldn't be too happy. This is the law of buoyancy, and engineers still call it Archimedes' Principle. It explains why a steel supertanker can float as easily as a wooden rowboat or a bathtub. If the weight of water displaced by the vessel below the keel is equivalent to the vessel's weight, whatever is above the keel will remain afloat above the waterline. This sounds a lot like another story involving Archimedes and a bathtub, and it's possible that's because they're actually the same story, twisted by the vagaries of history. The classical story of Archimedes' Eureka! and subsequent streak through the streets centers around a crown, or corona in Latin. At the core of the Syracusia story is a keel, or korone in Greek. Could one have been mixed up for the other? We may never know. On the day the Syracusia arrived in Egypt on its first and only voyage, we can only imagine how residents of Alexandria thronged the harbor to marvel at the arrival of this majestic, floating castle. This extraordinary vessel was the Titanic of the ancient world, except without the sinking, thanks to our pal, Archimedes. As 1905 dawned, the soon-to-be 26-year-old Albert Einstein faced life as a failed academic. Most physicists of the time would have scoffed at the idea that this minor civil servant could have much to contribute to science. Yet within the following year, Einstein would publish not one, not two, not three, but four extraordinary papers, each on a different topic, that were destined to radically transform our understanding of the universe. The myth that Einstein had failed math is just that. He had mastered calculus on his own by the age of 15 and done well at both his Munich secondary school and at the Swiss Polytechnic, where he studied for a math and physics teaching diploma. But skipping classes to spend more time in the lab and neglecting to show proper deference to his professors had derailed his intended career path. Passed over even for a lab assistant position, he had to settle for a job at the Swiss patent office, obtained with the help of a friend's father. Working six days a week as a patent clerk, Einstein still managed to make some time for physics, discussing the latest work with a few close friends, and publishing a couple of minor papers. It came as a major surprise when in March 1905 he submitted a paper with a shocking hypothesis. Despite decades of evidence that light was a wave, Einstein proposed that it could, in fact, be a particle, showing that mysterious phenomena, such as the photoelectric effect, could be explained by his hypothesis. The idea was derided for years to come, but Einstein was simply twenty years ahead of his time. Wave-particle duality was slated to become a cornerstone of the quantum revolution. Two months later in May, Einstein submitted a second paper, this time tackling the centuries old question of whether atoms actually exist. Though certain theories were built on the idea of invisible atoms, some prominent scientists still believed them to be a useful fiction, rather than actual physical objects. But Einstein used an ingenious argument, showing that the behavior of small particles randomly moving around in a liquid, known as Brownian motion, could be precisely predicted by the collisions of millions of invisible atoms. Experiments soon confirmed Einstein's model, and atomic skeptics threw in the towel. The third paper came in June. For a long time, Einstein had been troubled by an inconsistency between two fundamental principles of physics. The well established principle of relativity, going all the way back to Galileo, stated that absolute motion could not be defined. Yet electromagnetic theory, also well established, asserted that absolute motion did exist. The discrepancy, and his inability to resolve it, left Einstein in what he described as a state of psychic tension. But one day in May, after he had mulled over the puzzle with his friend Michele Besso, the clouds parted. Einstein realized that the contradiction could be resolved if it was the speed of light that remained constant, regardless of reference frame, while both time and space were relative to the observer. It took Einstein only a few weeks to work out the details and formulate what came to be known as special relativity. The theory not only shattered our previous understanding of reality but would also pave the way for technologies, ranging from particle accelerators, to the global positioning system. One might think that this was enough, but in September, a fourth paper arrived as a "by the way" follow-up to the special relativity paper. Einstein had thought a little bit more about his theory, and realized it also implied that mass and energy, one apparently solid and the other supposedly ethereal, were actually equivalent. And their relationship could be expressed in what was to become the most famous and consequential equation in history: E=mc^2. Einstein would not become a world famous icon for nearly another fifteen years. It was only after his later general theory of relativity was confirmed in 1919 by measuring the bending of starlight during a solar eclipse that the press would turn him into a celebrity. But even if he had disappeared back into the patent office and accomplished nothing else after 1905, those four papers of his miracle year would have remained the gold standard of startling unexpected genius. I've always wanted to be a cyborg. One of my favorite shows as a kid was "The Six Million Dollar Man," and this is a little bit closer to the 240-dollar man or so, but -- (Laughter) At any rate, I would normally feel very self-conscious and geeky wearing this around, but a few days ago I saw one world-renowned statistician swallowing swords on stage here, so I figure it's OK amongst this group. But that's not what I want to talk about today. I want to talk about toys, and the power that I see inherent in them. When I was a kid, I attended Montessori school up to sixth grade in Atlanta, Georgia. And at the time I didn't think much about it, but then later, I realized that that was the high point of my education. From that point on, everything else was pretty much downhill. And it wasn't until later, as I started making games, that -- I really actually think of them more as toys. People call me a game designer, but I really think of these things more as toys. I started getting very interested in Maria Montessori and her methods, and the way she went about things, and the way she thought it very valuable for kids to discover things on their own rather than being taught these things overtly. And she would design these toys, where kids in playing with the toys would come to understand these deep principles of life and nature through play. And since they discovered this, it stuck with them so much more, and also they would experience their own failures. There was a failure-based aspect to learning there. It was very important. And so, the games that I do, I think of really more as modern Montessori toys. And I really kind of want them to be presented in a way to where kids can kind of explore and discover their own principles. So a few years ago, I started getting very interested in the SETI program. And that's the way I work. I get interested in different subjects, I dive in, research them, and then try to figure out how to craft a toy around that, so that other people can experience the same sense of discovery that I did as I was learning that subject. And it led me to astrobiology, the study of possible life in the universe. And then Drake's equation, looking at the probability of life arising on planets, how long it might last, how many planets are out there. And I started looking at how interesting Drake's equation was, because it spanned all these different subjects -- physics, chemistry, sociology, economics, astronomy. And another thing that really impressed me a long time ago was "Powers of Ten," Charles and Ray Eames' film. And I started putting those two together and wondering, could I build a toy where kids would trip across all these interesting principles of life, as it exists and as it might go in the future. Things where you might trip across things like the Copernican principle, the Fermi paradox, the anthropic principle, the origin of life. And so I'm going to show you a toy today that I've been working on, that I think of more as kind of a philosophy toy. Playing this toy will bring up philosophical questions in you. The game is "Spore." I've been working on it for several years. It's getting pretty close to finished now. It occurs at all these different scales, from very small to very large. I'm going to pop in at the start of the game. And you actually start this game in a drop of water, as a very, very small single-cell creature, and right off the bat you basically just have to live, survive, reproduce. So here we are, at a very microscopic scale, swimming around. And I actually realize that cells don't have eyes, but it helps to make it cute. The players are going to play through every generation of this species, and as you play the game, the creature is actually growing bit by bit. And as we start growing, the camera will actually start zooming out, and things that you see in the background there will start slowly pulling into the foreground, showing you a little bit of what you'll be interacting with as you grow. So as we eat, the camera starts pulling out, and then we start interacting with larger and larger organisms. We actually play through many generations here, at the cellular scale. I'm going to skip ahead here. At some point we get larger, and we actually get to a macroevolution scale. Now, at this point we're leaving the water, and one thing that's kind of important about this game is that, at every level, the player is designing their creature, and that's a fundamental aspect of this. Now, in the evolution game here, the creature scale, basically you have to eat, survive, and then reproduce. You know, very Darwinian. One thing we noticed with "The Sims," a game I did earlier, is that players love making stuff. When they were able to make stuff in the game, they had a lot of empathy in connection to it. Even if it wasn't as pretty as a professional artist would make for games, it really stuck with them and they really cared about what would happen to it. At this point, we've left the water, and now with this little creature -- we could bring up the volume a little bit -- and now we might try to eat. We might sneak up on this little guy over here maybe, and try and eat him. OK, well, we fight. (Creatures grunting) OK, we got him. Now we get a meal. So really, at this part of the game, what we're doing is we're running around and surviving, and also getting to the next generation, because we're going to play through every generation of this creature. We can mate, so I'm going to see if one of these creatures wants to mate with me. Yeah. (Creatures grunting) We didn't want to replay actual evolution with humans and all that, because it's almost more interesting to look at alternate possibilities in evolution. Evolution is usually presented as this one path that we took through, but really it represents this huge set of possibilities. Now, once we mate, we click on the egg. And this is where the game starts getting interesting, because one of the things we really focused on here was giving the players very high-leverage tools, so that for very little effort, the player can make something very cool. And it involves a lot of intelligence on the tool side. But basically, this is the editor where we're going to design the next generation. So it has a little spine. I can move around, I can extend. I can also inflate or deflate it with the mouse wheel, so you sculpt it like clay. We have parts here that I can put on or pull off. The idea is that the player can basically design anything they can think of in this editor, and we'll basically bring it to life. So I might put some limbs on the character here. I'll inflate them kind of large. And in this case I might decide I'm going to put -- I'll put mouths on the limbs. So pretty much players are encouraged to be very creative in the game. Here, I'll give it one eye in the middle, maybe scale it up a bit. Point it down. And I'll also give it a few legs. So in some sense we want this to feel like an amplifier for the player's imagination, so that with a very small number of clicks a player can create something that they didn't really think was possible before. This is almost like designing something like Maya -- that an eight-year-old can use. But really the goal here was, within about a minute, I wanted somebody to replicate what typically takes a pictorial artist several weeks to create. OK, now I'll put some hands on it. OK, so here I've basically thrown together a little creature. Let me give it a little weapon on the tail here, so it can fight. OK, so that's the complete model. Now we can actually go to the painting phase. At this phase, the program has some understanding of the topology of this creature. It knows where the backbone is, where the spine, the limbs are, how stripes should run, how it should be shaded. And so we're procedurally generating the texture map, something a texture artist would take many days to work on. And then we can test it out, and see how it would move around. And so at this point the computer is procedurally animating this creature. It's looking at whatever I've designed. It will actually bring it to life. And I can see how it might dance. (Laughter) How it might show emotions, how it might fight. So it's acting with its two mouths there. I can even have it pose for a photo. Snap a little photo of it. (Laughter) So then I bring this back into the game. It's born, and I play the next generation of my creature through evolution. Now again, the empathy that the players have when they create the content is tremendous. When players create content in this game, it's automatically sent up to a server and then redistributed to all the other players transparently. So in fact, as I'm interacting in this world with other creatures, these creatures are transparently coming from other players as they play. So the process of playing the game is a process of building up this huge database of content. And pretty much everything you're going to see in this game, there's an editor for that the player can create, up through civilization. This is my baby. When I eat, I'll actually start growing. This is the next generation. But I'm going to skip ahead here. Normally what would happen is these creatures would work their way up, eventually become intelligent. I'd start dealing with tribes, cities and civilizations of them over time. I'm going to skip way ahead to the space phase. Eventually they would go out into space, and start colonizing and exploring the universe. Now, really, in some sense, I want the players to be building this world in their imagination, and then extracting it from them with the least amount of pain. So that's kind of what these tools are about. How do we make the gameplay, you know, basically the player's imagination amplifier? And how do we make these tools, these editors, something that are just as fun as the game itself? So this is the planet that we've been playing on up to this point in the game. So far the entire game has been played on the surface of this little world here. At this point we're actually dealing with a very little toy planet. Almost, again, like the Montessori toy idea. What happens if you give somebody a toy planet, and let them play with a lot of dynamics on it? What could they discover? What might they learn on this? This world was actually extracted from the player's imagination. So, this is the planet that the player evolved on. Things like the buildings, the vehicles, the architecture, civilizations were all designed by the player up to this point. So here's a little city with some of our guys walking around in it. And most games put the player in the role of Luke Skywalker, this protagonist playing through this story. This is more about putting the player in the role of George Lucas. I want them, after they've played this game, to have extracted an entire world that they're now interacting with. As we pull down here, we still have a whole set of creatures living on the surface of the planet. All these different dynamics going on here. I can look over here, and this is a little simplified food web that's going on with the creatures. I can open this up and then scan what exists on the surface. You get some sense of the diversity of creatures that were brought in. Some of these were created by the player, others by other players, automatically sent over here. But there's a very simple calculation of what's required, how many plants are required for the herbivores to live, how many herbivores for the carnivores to eat, etc., that you have to balance actively. Also with this phase, we're getting more and more God-like powers for the player, and you can experiment with this planet as a toy. So I can come in and I can do things, and just treat this planet as a lump of clay. We have very simple weather systems, simple geology. For instance, I could open one of my tools here and then carve out rivers. So this whole thing is kind of like a big lump of clay, a sculpture. I can also play with the dynamics in this world over time. So one of the things I can do is start pumping more CO2 gases into the atmosphere, and so that's what I'm doing here. There's actually a little readout down there of our planetary atmosphere, pressure and temperature. So as I start pumping in more atmosphere, we're going to start pushing up the greenhouse gases here and if you'll start noticing, we start seeing the ocean levels rise over time. And our cities are going to be at risk too, because a lot of these are coastal cities. You can see the ocean levels are rising now and as they encroach upon the cities, I'll start losing cities here. So basically, I want the players to be able to experiment and explore a huge amount of failure space. So there goes one city. Now, over time, this is going to heat up the planet. So at first what we're going to see is a global ocean rise here on this little toy planet, but then over time -- I can speed it up -- we'll see the heat impact of that as well. Not only will it get hotter, but at some point it's going to get so hot the oceans will evaporate. They'll go up, and then they'll evaporate, and that'll be my planet. So basically, what we're getting here is the sequel to "An Inconvenient Truth," in about two minutes, and that actually brings up an interesting point about games. Now here, our entire oceans are evaporating off the surface, and as it keeps getting hotter, at some point the entire planet is going to melt down. Here it goes. So we're not only simulating biological dynamics -- food webs and all that -- but also geologic, you know, on a very simple core scale. And what's interesting to me about games is that I think we can take a lot of long-term dynamics and compress them into very short-term experiences. Because it's so hard for people to think 50 or 100 years out, but when you can give them a toy, and they can experience these long-term dynamics in just a few minutes, I think it's an entirely different point of view, where we're actually using the game to remap our intuition. It's almost in the same way that a telescope or microscope recalibrates your eyesight; I think computer simulations can recalibrate your instinct across vast scales of both space and time. So here's our little solar system, as we pull away from our melted planet here. We actually have a couple of other planets in this solar system. Let's fly to another one. We're going to have this unlimited number of worlds you can explore here. As we move into the future, and we start going out into space and doing stuff, we're drawing a lot from things like science fiction. And all my favorite science fiction movies I want to play out here as different dynamics. This planet actually has some life on it. Here it is, some indigenous life down here. One of the tools I can eventually earn for my UFO is a monolith that I can drop down. (Laughter) Now, as you can see, these guys are actually starting to go up and bow to it, and over time, once they touch it, they will become intelligent. So I can actually pick a species on a planet and then make them sentient. Now they've actually gone to tribal dynamics. And now, because I'm actually the one here, I can get out of the UFO and walk up, and they should be worshipping me at this point as a god. At first they're a little freaked out. OK, well maybe they're not worshipping me. (Laughter) I think I'll leave before they get hostile. But we basically want a diversity of activities the players can play through this. I want to be able to play "The Day the Earth Stood Still," "2001: A Space Odyssey," "Star Trek," "War Of the Worlds." Now, as we pull away from this world -- we're going to keep pulling away from the star now. One of the things that always frustrated me about astronomy when I was a kid is how it was always presented so two-dimensionally and so static. As we pull away from the star here, we're actually going now out into interstellar space, and we're getting a sense of the space around our home star. What I really wanted to do is to present this, basically, as wonderfully 3D as it is actually is. And also show the dynamics, and a lot of the interesting objects that you might find, like, in the Hubble, at pretty much realistic frequencies and scales. So most people have no idea of the difference between an emission nebula and a planetary nebula. But these are the things that we can put in this little galaxy here. So we're flying over here to what looks like a black hole. I want to basically have the entire zoo of Hubble objects that people can interact with and play with, again, as toys. So here's a little black hole that we probably don't want to get too close to. But we also have stars and things as well. If we pull all the way back, we start seeing the entire galaxy here, kind of slowly in motion. Typically, when people present galaxies, it's always beautiful photos, but they're always static. And when you bring it forward in time and start animating it, it's amazing what a galaxy would look like fast forwarded. This would be about a million years a second, because you have about one supernova every century. And so you'd have this wonderful sparkling thing, with the disk slowly rotating, and this is roughly what it would look like. Part of this is about bringing the beauty of the natural world to somebody in a very imaginative way, so that they can start calibrating their instinct across these vast scales of space and time. Chris was wondering what kind of gods the players would become. Because if you think about it, you're going to have 15-year-olds, 20-year-olds flying around this universe. They might be a nurturing god. They might be bootstrapping life on planets, trying to terraform and spread civilization. You might be a vengeful god, conquesting, because you actually can do that, you can attack other intelligent races. You might be a networking god, building alliances, or just curious, going around and wanting to explore as much as you possibly can. But basically, the reason why I make toys like this is because I think if there's one difference I could possibly make in the world, that I would choose to make, it's that I would like to somehow give people just a little bit better calibration on long-term thinking. Because I think most of the problems that our world is facing right now are the result of short-term thinking, and the fact that it is so hard for us to think 50, 100, or 1,000 years out. And I think by giving kids toys like this and letting them replay dynamics, very long-term dynamics over the short term, and getting some sense of what we're doing now, what it's going to be like in 100 years, I think probably is the most effective thing I can be doing to help the world. And so that's why I think that toys can change the world. Thank you. The annals of Ancient Egyptian king Thutmose III described a marvelous foreign bird that “gives birth daily.” Zoroastrians viewed them as spirits whose cries told of the cosmic struggle between darkness and light. Romans brought them on their military campaigns to foretell the success of future battles. And today, this bird still occupies an important, though much less honorable position – on our dinner plates. The modern chicken is descended primarily from the Red Junglefowl, and partially from three other closely related species, all native to India and Southeast Asia. The region’s bamboo plants produce massive amounts of fruit just once every few decades. Junglefowls’ ability to lay eggs daily may have evolved to take advantage of these rare feasts, increasing their population when food was abundant. This was something humans could exploit on a consistent basis, and the birds’ weak flight capabilities and limited need for space made them easy to capture and contain. The earliest domesticated chickens, dating at least back to 7,000 years ago, weren’t bred for food, but for something considered less savory today. The aggressiveness of breeding males, armed with natural leg spurs, made cockfighting a popular entertainment. By the second millennium BCE, chickens had spread from the Indus Valley to China and the Middle East to occupy royal menageries and to be used in religious rituals. But it was in Egypt where the next chapter in the bird’s history began. When a hen naturally incubates eggs, she will stop laying new ones and sit on a “clutch” of 6 or more eggs for 21 days. By the middle of the 1st millennium BCE, the Egyptians had learned to artificially incubate chicken eggs by placing them in baskets over hot ashes. That freed up hens to continue laying daily, and what had been a royal delicacy or religious offering became a common meal. Around the same time as Egyptians were incubating eggs, Phoenician merchants introduced chickens to Europe, where they quickly became an essential part of European livestock. However, for a long time, the chicken’s revered status continued to exist alongside its culinary one. The Ancient Greeks used fighting roosters as inspirational examples for young soldiers. The Romans consulted chickens as oracles. And as late as the 7th Century, the chicken was considered a symbol for Christianity. Over the next few centuries, chickens accompanied humans wherever they went, spreading throughout the world through trade, conquest, and colonization. After the Opium Wars, Chinese breeds were brought to England and crossed with local chickens. This gave rise to a phenomenon called “Hen Fever” or “The Fancy”, with farmers all over Europe striving to breed new varieties with particular combinations of traits. This trend also caught the attention of a certain Charles Darwin, who wondered if a similar selective breeding process occurred in nature. Darwin would observe hundreds of chickens while finalizing his historic work introducing the theory of Evolution. But the chicken’s greatest contribution to science was yet to come. In the early 20th century, a trio of British scientists conducted extensive crossbreeding of chickens, building on Gregor Mendel’s studies of genetic inheritance. With their high genetic diversity, many distinct traits, and only 7 months between generations, chickens were the perfect subject. This work resulted in the famous Punnett Square, used to show the genotypes that would result from breeding a given pairing. Since then, numerous breeding initiatives have made chickens bigger and meatier, and allowed them to lay more eggs than ever. Meanwhile, chicken production has shifted to an industrial, factory-like model, with birds raised in spaces with a footprint no larger than a sheet of paper. And while there’s been a shift towards free-range farming due to animal rights and environmental concerns, most of the world’s more than 22 billion chickens today are factory farmed. From gladiators and gifts to the gods, to traveling companions and research subjects, chickens have played many roles over the centuries. And though they may not have come before the proverbial egg, chickens’ fascinating history tells us a great deal about our own. Most of the talks that you've heard in the last several fabulous days have been from people who have the characteristic that they have thought about something, they are experts, they know what's going on. All of you know about the topic that I'm supposed to talk about. That is, you know what simplicity is, you know what complexity is. The trouble is, I don't. And what I'm going to do is share with you my ignorance on this subject. I want you to read this, because we're going to come back to it in a moment. The quote is from the fabled Potter Stewart opinion on pornography. And let me just read it, the important details here: "Shorthand description, ['hardcore pornography']; and perhaps I could never succeed in intelligibly defining it. But I know it when I see it." I'm going to come back to that in a moment. So, what is simplicity? It's good to start with some examples. A coffee cup -- we don't think about coffee cups, but it's much more interesting than one might think -- a coffee cup is a device, which has a container and a handle. The handle enables you to hold it when the container is filled with hot liquid. Why is that important? Well, it enables you to drink coffee. But also, by the way, the coffee is hot, the liquid is sterile; you're not likely to get cholera that way. So the coffee cup, or the cup with a handle, is one of the tools used by society to maintain public health. Scissors are your clothes, glasses enable you to see things and keep you from being eaten by cheetahs or run down by automobiles, and books are, after all, your education. But there's another class of simple things, which are also very important. Simple in function, but not at all simple in how they're constructed. And the two here are just examples. One is the cellphone, which we use every day. And it rests on a complexity, which has some characteristics very different from those that my friend Benoit Mandelbrot discussed, but are very interesting. And the other, of course, is a birth control pill, which, in a very simple way, fundamentally changed the structure of society by changing the role of women in it by providing to them the opportunity to make reproductive choices. So, there are two ways of thinking about this word, I think. And here I've corrupted the Potter Stewart quotation by saying that we can think about something -- which spans all the way from scissors to the cell phone, Internet and birth control pills -- by saying that they're simple, the functions are simple, and we recognize what that simplicity is when we see it. Or there may be another way of doing it, which is to think about the problem in terms of what -- if you associate with moral philosophers -- is called the teapot problem. The teapot problem I'll pose this way. Suppose you see a teapot, and the teapot is filled with hot water. And you then ask the question: Why is the water hot? And that's a simple question. It's like, what is simplicity? One answer would be: because the kinetic energy of the water molecules is high and they bounce against things rapidly -- that's a kind of physical science argument. A second argument would be: because it was sitting on a stove with the flame on -- that's an historical argument. A third is that I wanted hot water for tea -- that's an intentional argument. And, since this is coming from a moral philosopher, the fourth would be that it's part of God's plan for the universe. All of these are possibilities. The point is that you get into trouble when you ask a single question with a single box for an answer, in which that single question actually is many questions with quite different meanings, but with the same words. Asking, "What is simplicity?" I think falls in that category. What is the state of science? And, interestingly, complexity is very highly evolved. We have a lot of interesting information about what complexity is. Simplicity, for reasons that are a little bit obscure, is almost not pursued, at least in the academic world. We academics -- I am an academic -- we love complexity. You can write papers about complexity, and the nice thing about complexity is it's fundamentally intractable in many ways, so you're not responsible for outcomes. (Laughter) Simplicity -- all of you really would like your Waring Blender in the morning to make whatever a Waring Blender does, but not explode or play Beethoven. You're not interested in the limits of these things. So what one is interested in has a lot to do with the rewards of the system. And there's a lot of rewards in thinking about complexity and emergence, not so much in thinking about simplicity. One of the things I want to do is to help you with a very important task -- which you may not know that you have very often -- which is to understand how to sit next to a physicist at a dinner party and have a conversation. (Laughter) And the words that I would like you to focus on are complexity and emergence, because these will enable you to start the conversation and then daydream about other things. (Laughter) All right, what is complexity in this view of things, and what is emergence? We have, actually, a pretty good working definition of complexity. It is a system, like traffic, which has components. The components interact with one another. These are cars and drivers. They dissipate energy. It turns out that, whenever you have that system, weird stuff happens, and you in Los Angeles probably know this better than anyone. Here's another example, which I put up because it's an example of really important current science. You can't possibly read that. It's not intended that you read it, but that's a tiny part of the chemical reactions going on in each of your cells at any given moment. And it's like the traffic that you see. The amazing thing about the cell is that it actually does maintain a fairly stable working relationship with other cells, but we don't know why. Anyone who tells you that we understand life, walk away. And let me reduce this to the simplest level. We've heard from Bill Gates recently. All of us, to some extent, study this thing called a Bill Gates. Terrific. You learn everything you can about that. And then there's another kind of thing that you might study, and you study that hard. That's a Bono, this is a Bono. But then, if you know everything you can know about those two things, and you put them together, what can you say about this combination? The answer is, not a lot. And that's complexity. Now, imagine building that up to a city, or to a society, and you've got, obviously, an interesting problem. All right, so let me give you an example of simplicity of a particular kind. And I want to introduce a word that I think is very useful, which is stacking. And I'm going to use stacking for a kind of simplicity that has the characteristic that it is so simple and so reliable that I can build things with it. Or I'm going to use simple to mean reliable, predictable, repeatable. And I'm going to use as an example the Internet, because it's a particularly good example of stacked simplicity. We call it a complex system, which it is, but it's also something else. The Internet starts with mathematics, it starts with binary. And if you look at the list of things on the bottom, we are familiar with the Arabic numbers one to 10 and so on. In binary, one is 0001, seven is 0111. The question is: Why is binary simpler than Arabic? And the answer is, simply, that if I hold up three fingers, you can count that easily, but if I hold up this, it's sort of hard to say that I just did seven. The virtue of binary is that it's the simplest possible way of representing numbers. Anything else is more complicated. You can catch errors with it, it's unambiguous in its reading, there are lots of good things about binary. So it is very, very simple once you learn how to read it. Now, if you like to represent this zero and one of binary, you need a device. And think of things in your life that are binary, one of them is light switches. They can be on and off. That's binary. Now wall switches, we all know, fail. But our friends who are condensed matter physicists managed to come up, some 50 years ago, with a very nice device, shown under that bell jar, which is a transistor. A transistor is nothing more than a wall switch. It turns things on and off, but it does so without moving parts and it doesn't fail, basically, for a very long period of time. So the second layer of simplicity was the transistor in the Internet. So, since the transistor is so simple, you can put lots of them together. And you put lots of them together and you come with something called integrated circuits. And a current integrated circuit might have in each one of these chips something like a billion transistors, all of which have to work perfectly every time. So that's the next layer of simplicity, and, in fact, integrated circuits are really simple in the sense that they, in general, work really well. With integrated circuits, you can build cellphones. You all are accustomed to having your cellphones work the large majority of the time. In Boston ... Boston is a little bit like Namibia in its cell phone coverage, (Laughter) so that we're not accustomed to that all the time, but some of the time. But, in fact, if you have cell phones, you can now go to this nice lady who's somewhere like Namibia, and who is extremely happy with the fact that although she does not have an master's degree in electrical engineering from MIT, she's nonetheless able to hack her cell phone to get power in some funny way. And from that comes the Internet. And this is a map of bitflows across the continent. The two blobs that are light in the middle there are the United States and Europe. And then back to simplicity again. So here we have what I think is one of the great ideas, which is Google. Which, in this simple portal makes the claim that it makes accessible all of the world's information. But the point is that that extraordinary simple idea rests on layers of simplicity each compounded into a complexity that is itself simple, in the sense that it is completely reliable. All right, let me then finish off with four general statements, an example and two aphorisms. The characteristics, which I think are useful to think about for simple things: First, they are predictable. Their behavior is predictable. Now, one of the nice characteristics of simple things is you know what it's going to do, in general. So simplicity and predictability are characteristics of simple things. The second is, and this is a real world statement, they're cheap. If you have things that are cheap enough, people will find uses for them, even if they seem very primitive. So, for example, stones. You can build cathedrals out of stones, you just have to know what it does. You carve them in blocks and then you pile them on top of one another, and they support weight. So there has to be function, the function has to be predictable and the cost has to be low. What that means is that you have to have a high performance or value for cost. And then I would propose as this last component that they serve, or have the potential to serve, as building blocks. That is, you can stack them. And stack can mean this way, or it can mean this way, or it can mean in some arbitrary n-dimensional space. But if you have something that has a function, and it's really cheap, people will find new ways of putting it together to make new things. Cheap, functional, reliable things unleash the creativity of people who then build stuff that you could not imagine. There's no way of predicting the Internet based on the first transistor. It just is not possible. So these are the components. Now, the example is something that I want to give you from the work that we ourselves do. We are very interested in delivering health care in the developing world, and one of the things that we wish to do in this particular business is to find a way of doing medical diagnosis at as close to zero cost as we can manage. So, how does one do that? This is a world in which there's no electricity, there's no money, there's no medical competence. And I don't want to spend your time in going through the details, but in the lower right-hand corner, you see an example of the kind of thing that we have. It's a little paper chip. It has a few things printed on it using the same technology that you use for making comic books, which was the inspiration for this particular idea. And you put a drop, in this case, of urine at the bottom. It wicks its way up into these little branches. You know, no power required. It turns colors. In this particular case, you're reading kidney function. And, since the health care worker of much of this part of the world is an 18 year-old with an AK-47, who happens to be out of work and is willing to go around and do this sort of thing, he can take a picture of it with his cellphone, send the picture back to where there is a doctor, and the doctor can shale@example.net. So what you've done is to take a technology, which is available everywhere, make a device, which is extremely cheap, and make it in such a fashion that it is very, very reliable. If we can pull this off, if we can build more function, it will be stackable. That is to say, if we can make the basic technology of one or two things work, it will be applicable to a very, very large variety of human conditions, and hence, extendable in both vertical and horizontal directions. Part of my interest in this, I have to say, is that I would like to -- how do I put this politely? -- change the way, or maybe eviscerate, the capital structure of the U.S. health care system, which I think is fundamentally broken. So, let me close -- (Applause) Let me close with my two aphorisms. One of them is from Mr. Einstein, and he says, "Everything should be made as simple as possible, but not simpler." And I think that's a very good way of thinking about the problem. If you take too much out of something that's simple, you lose function. You have to have low cost, but you also have to have a function. So you can't make it too simple. And the second is a design issue, and it's not directly relevant, but it's a nice statement. This is by de Saint-Exupery. And he says, "You know you've achieved perfection in design, not when you have nothing more to add, but when you have nothing more to take away." And that certainly is going in the right direction. So, what I think one can begin to do with this kind of cut at the word simplicity, which doesn't cover Brancusi, it doesn't answer the question of why Mondrian is better or worse or simpler or less simpler than Van Gogh, and certainly doesn't address the question of whether Mozart is simpler than Bach. But it does make a point -- which is one which, in a sense, differentiates the real world of people who make things, and