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My talk is "Flapping Birds and Space Telescopes."
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And you would think that should have nothing to do with one another,
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but I hope by the end of these 18 minutes,
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you'll see a little bit of a relation.
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It ties to origami. So let me start.
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What is origami?
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Most people think they know what origami is. It's this:
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flapping birds, toys, cootie catchers, that sort of thing.
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And that is what origami used to be.
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But it's become something else.
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It's become an art form, a form of sculpture.
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The common theme -- what makes it origami --
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is folding is how we create the form.
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You know, it's very old. This is a plate from 1797.
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It shows these women playing with these toys.
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If you look close, it's this shape, called a crane.
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Every Japanese kid
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learns how to fold that crane.
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So this art has been around for hundreds of years,
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and you would think something
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that's been around that long -- so restrictive, folding only --
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everything that could be done has been done a long time ago.
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And that might have been the case.
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But in the twentieth century,
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a Japanese folder named Yoshizawa came along,
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and he created tens of thousands of new designs.
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But even more importantly, he created a language,
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a way we could communicate,
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a code of dots, dashes and arrows.
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Harkening back to Susan Blackmore's talk,
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we now have a means of transmitting information
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with heredity and selection,
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and we know where that leads.
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And where it has led in origami
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is to things like this.
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This is an origami figure --
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one sheet, no cuts, folding only, hundreds of folds.
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This, too, is origami,
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and this shows where we've gone in the modern world.
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Naturalism. Detail.
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You can get horns, antlers --
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even, if you look close, cloven hooves.
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And it raises a question: what changed?
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And what changed is something
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you might not have expected in an art,
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which is math.
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That is, people applied mathematical principles
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to the art,
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to discover the underlying laws.
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And that leads to a very powerful tool.
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The secret to productivity in so many fields --
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and in origami --
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is letting dead people do your work for you.
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(Laughter)
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Because what you can do is
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take your problem,
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and turn it into a problem that someone else has solved,
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and use their solutions.
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And I want to tell you how we did that in origami.
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Origami revolves around crease patterns.
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The crease pattern shown here is the underlying blueprint
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for an origami figure.
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And you can't just draw them arbitrarily.
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They have to obey four simple laws.
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And they're very simple, easy to understand.
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The first law is two-colorability. You can color any crease pattern
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with just two colors without ever having
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the same color meeting.
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The directions of the folds at any vertex --
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the number of mountain folds, the number of valley folds --
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always differs by two. Two more or two less.
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Nothing else.
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If you look at the angles around the fold,
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you find that if you number the angles in a circle,
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all the even-numbered angles add up to a straight line,
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all the odd-numbered angles add up to a straight line.
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And if you look at how the layers stack,
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you'll find that no matter how you stack folds and sheets,
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a sheet can never
00:03:30
penetrate a fold.
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So that's four simple laws. That's all you need in origami.
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All of origami comes from that.
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And you'd think, "Can four simple laws
00:03:39
give rise to that kind of complexity?"
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But indeed, the laws of quantum mechanics
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can be written down on a napkin,
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and yet they govern all of chemistry,
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all of life, all of history.
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If we obey these laws,
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we can do amazing things.
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So in origami, to obey these laws,
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we can take simple patterns --
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like this repeating pattern of folds, called textures --
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and by itself it's nothing.
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But if we follow the laws of origami,
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we can put these patterns into another fold
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that itself might be something very, very simple,
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but when we put it together,
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we get something a little different.
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This fish, 400 scales --
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again, it is one uncut square, only folding.
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And if you don't want to fold 400 scales,
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you can back off and just do a few things,
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and add plates to the back of a turtle, or toes.
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Or you can ramp up and go up to 50 stars
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on a flag, with 13 stripes.
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And if you want to go really crazy,
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1,000 scales on a rattlesnake.
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And this guy's on display downstairs,
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so take a look if you get a chance.
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The most powerful tools in origami
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have related to how we get parts of creatures.
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And I can put it in this simple equation.
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We take an idea,
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combine it with a square, and you get an origami figure.
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(Laughter)
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What matters is what we mean by those symbols.
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And you might say, "Can you really be that specific?
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I mean, a stag beetle -- it's got two points for jaws,
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it's got antennae. Can you be that specific in the detail?"
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And yeah, you really can.
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So how do we do that? Well, we break it down
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into a few smaller steps.
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So let me stretch out that equation.
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I start with my idea. I abstract it.
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What's the most abstract form? It's a stick figure.
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And from that stick figure, I somehow have to get to a folded shape
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that has a part for every bit of the subject,
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a flap for every leg.
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And then once I have that folded shape that we call the base,
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you can make the legs narrower, you can bend them,
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you can turn it into the finished shape.
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Now the first step, pretty easy.
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Take an idea, draw a stick figure.
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The last step is not so hard, but that middle step --
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going from the abstract description to the folded shape --
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that's hard.
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But that's the place where the mathematical ideas
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can get us over the hump.
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And I'm going to show you all how to do that
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so you can go out of here and fold something.
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But we're going to start small.
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This base has a lot of flaps in it.
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We're going to learn how to make one flap.
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How would you make a single flap?
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Take a square. Fold it in half, fold it in half, fold it again,
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until it gets long and narrow,
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and then we'll say at the end of that, that's a flap.
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I could use that for a leg, an arm, anything like that.
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What paper went into that flap?
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Well, if I unfold it and go back to the crease pattern,
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you can see that the upper left corner of that shape
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is the paper that went into the flap.
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So that's the flap, and all the rest of the paper's left over.
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I can use it for something else.
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Well, there are other ways of making a flap.
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There are other dimensions for flaps.
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If I make the flaps skinnier, I can use a bit less paper.
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If I make the flap as skinny as possible,
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I get to the limit of the minimum amount of paper needed.
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And you can see there, it needs a quarter-circle of paper to make a flap.
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There's other ways of making flaps.
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If I put the flap on the edge, it uses a half circle of paper.
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And if I make the flap from the middle, it uses a full circle.
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So, no matter how I make a flap,
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it needs some part
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of a circular region of paper.
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So now we're ready to scale up.
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What if I want to make something that has a lot of flaps?
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What do I need? I need a lot of circles.
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And in the 1990s,
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origami artists discovered these principles
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and realized we could make arbitrarily complicated figures
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just by packing circles.
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And here's where the dead people start to help us out,
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because lots of people have studied
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the problem of packing circles.
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I can rely on that vast history of mathematicians and artists
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looking at disc packings and arrangements.
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And I can use those patterns now to create origami shapes.
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So we figured out these rules whereby you pack circles,
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you decorate the patterns of circles with lines
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according to more rules. That gives you the folds.
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Those folds fold into a base. You shape the base.
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You get a folded shape -- in this case, a cockroach.
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And it's so simple.
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(Laughter)
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It's so simple that a computer could do it.
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And you say, "Well, you know, how simple is that?"
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But computers -- you need to be able to describe things
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in very basic terms, and with this, we could.
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So I wrote a computer program a bunch of years ago
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called TreeMaker, and you can download it from my website.
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It's free. It runs on all the major platforms -- even Windows.
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(Laughter)
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And you just draw a stick figure,
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and it calculates the crease pattern.
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It does the circle packing, calculates the crease pattern,
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and if you use that stick figure that I just showed --
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which you can kind of tell, it's a deer, it's got antlers --
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you'll get this crease pattern.
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And if you take this crease pattern, you fold on the dotted lines,
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you'll get a base that you can then shape
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into a deer,
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with exactly the crease pattern that you wanted.
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And if you want a different deer,
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not a white-tailed deer, but you want a mule deer, or an elk,
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you change the packing,
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and you can do an elk.
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Or you could do a moose.
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Or, really, any other kind of deer.
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These techniques revolutionized this art.
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We found we could do insects,
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spiders, which are close,
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things with legs, things with legs and wings,
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things with legs and antennae.
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And if folding a single praying mantis from a single uncut square
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wasn't interesting enough,
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then you could do two praying mantises
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from a single uncut square.
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She's eating him.
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I call it "Snack Time."
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And you can do more than just insects.
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This -- you can put details,
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toes and claws. A grizzly bear has claws.
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This tree frog has toes.
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Actually, lots of people in origami now put toes into their models.
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Toes have become an origami meme,
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because everyone's doing it.
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You can make multiple subjects.
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So these are a couple of instrumentalists.
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The guitar player from a single square,
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the bass player from a single square.
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And if you say, "Well, but the guitar, bass --
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that's not so hot.
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Do a little more complicated instrument."
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Well, then you could do an organ.
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(Laughter)
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And what this has allowed is the creation
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of origami-on-demand.
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So now people can say, "I want exactly this and this and this,"
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and you can go out and fold it.
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And sometimes you create high art,
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and sometimes you pay the bills by doing some commercial work.
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But I want to show you some examples.
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Everything you'll see here,
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except the car, is origami.
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(Video)
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(Applause)
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Just to show you, this really was folded paper.
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Computers made things move,
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but these were all real, folded objects that we made.
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And we can use this not just for visuals,
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but it turns out to be useful even in the real world.
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Surprisingly, origami
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and the structures that we've developed in origami
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turn out to have applications in medicine, in science,
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in space, in the body, consumer electronics and more.
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And I want to show you some of these examples.
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One of the earliest was this pattern,
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this folded pattern,
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studied by Koryo Miura, a Japanese engineer.
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He studied a folding pattern, and realized
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this could fold down into an extremely compact package
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that had a very simple opening and closing structure.
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And he used it to design this solar array.
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It's an artist's rendition, but it flew in a Japanese telescope
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in 1995.
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Now, there is actually a little origami
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in the James Webb Space Telescope, but it's very simple.
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The telescope, going up in space,
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it unfolds in two places.
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It folds in thirds. It's a very simple pattern --
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you wouldn't even call that origami.
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They certainly didn't need to talk to origami artists.
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But if you want to go higher and go larger than this,
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then you might need some origami.
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Engineers at Lawrence Livermore National Lab
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had an idea for a telescope much larger.
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They called it the Eyeglass.
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The design called for geosynchronous orbit
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25,000 miles up,
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100-meter diameter lens.
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So, imagine a lens the size of a football field.
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There were two groups of people who were interested in this:
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planetary scientists, who want to look up,
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and then other people, who wanted to look down.
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Whether you look up or look down,
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how do you get it up in space? You've got to get it up there in a rocket.
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And rockets are small. So you have to make it smaller.
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How do you make a large sheet of glass smaller?
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Well, about the only way is to fold it up somehow.
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So you have to do something like this.
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This was a small model.
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Folded lens, you divide up the panels, you add flexures.
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But this pattern's not going to work
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to get something 100 meters down to a few meters.
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So the Livermore engineers,
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wanting to make use of the work of dead people,
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or perhaps live origamists, said,
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"Let's see if someone else is doing this sort of thing."
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So they looked into the origami community,
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we got in touch with them, and I started working with them.
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And we developed a pattern together
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that scales to arbitrarily large size,
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but that allows any flat ring or disc
00:13:22
to fold down into a very neat, compact cylinder.
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And they adopted that for their first generation,
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which was not 100 meters -- it was a five-meter.
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But this is a five-meter telescope --
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has about a quarter-mile focal length.
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And it works perfectly on its test range,
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and it indeed folds up into a neat little bundle.
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Now, there is other origami in space.
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Japan Aerospace [Exploration] Agency flew a solar sail,
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and you can see here that the sail expands out,
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and you can still see the fold lines.
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The problem that's being solved here is
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something that needs to be big and sheet-like at its destination,
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but needs to be small for the journey.
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And that works whether you're going into space,
00:14:00
or whether you're just going into a body.
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And this example is the latter.
00:14:05
This is a heart stent developed by Zhong You
00:14:08
at Oxford University.
00:14:10
It holds open a blocked artery when it gets to its destination,
00:14:13
but it needs to be much smaller for the trip there,
00:14:16
through your blood vessels.
00:14:18
And this stent folds down using an origami pattern,
00:14:21
based on a model called the water bomb base.
00:14:25
Airbag designers also have the problem
00:14:27
of getting flat sheets
00:14:29
into a small space.
00:14:32
And they want to do their design by simulation.
00:14:34
So they need to figure out how, in a computer,
00:14:36
to flatten an airbag.
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And the algorithms that we developed
00:14:40
to do insects
00:14:42
turned out to be the solution for airbags
00:14:45
to do their simulation.
00:14:47
And so they can do a simulation like this.
00:14:50
Those are the origami creases forming,
00:14:52
and now you can see the airbag inflate
00:14:54
and find out, does it work?
00:14:57
And that leads
00:14:59
to a really interesting idea.
00:15:01
You know, where did these things come from?
00:15:04
Well, the heart stent
00:15:06
came from that little blow-up box
00:15:08
that you might have learned in elementary school.
00:15:11
It's the same pattern, called the water bomb base.
00:15:14
The airbag-flattening algorithm
00:15:16
came from all the developments
00:15:18
of circle packing and the mathematical theory
00:15:21
that was really developed
00:15:23
just to create insects -- things with legs.
00:15:27
The thing is, that this often happens
00:15:29
in math and science.
00:15:31
When you get math involved, problems that you solve
00:15:34
for aesthetic value only,
00:15:36
or to create something beautiful,
00:15:38
turn around and turn out
00:15:40
to have an application in the real world.
00:15:43
And as weird and surprising as it may sound,
00:15:46
origami may someday even save a life.
00:15:50
Thanks.
00:15:52
(Applause)