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Jim Gates: Supersymmetry, String Theory and Proving Einstein Right | Lex Fridman Podcast #60


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The following is a conversation with S. James Gates, Jr.
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He's a theoretical physicist and professor at Brown University,
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working on supersymmetry, supergravity, and superstring theory.
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He served on former President Obama's Council of Advisors on Science and Technology,
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and he's now the coauthor of a new book titled Proving Einstein Right,
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about the scientists who set out to prove Einstein's theory of relativity.
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You may have noticed that I've been speaking with not just computer scientists,
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but philosophers, mathematicians, physicists, economists, and soon, much more.
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To me, AI is much bigger than deep learning, bigger than computing.
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It is our civilization's journey into understanding the human mind
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and creating echoes of it in the machine.
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That journey includes, of course, the world of theoretical physics
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and its practice of first principles mathematical thinking
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and exploring the fundamental nature of our reality.
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This is the Artificial Intelligence Podcast.
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which again is an organization that I've personally seen inspire girls and boys
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to dream of engineering a better world.
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And now, here's my conversation with S. James Gates Jr.
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You tell a story when you were eight.
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You had a profound realization that the stars in the sky
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are actually places that we could travel to one day.
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Do you think human beings will ever venture outside our solar system?
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Wow, the question of whether humanity gets outside of the solar system.
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It's going to be a challenge,
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and as long as the laws of physics that we have today are accurate and valid,
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it's going to be extraordinarily difficult.
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I'm a science fiction fan, as you probably know,
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so I love to dream of starships and traveling to other solar systems,
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but the barriers are just formidable.
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If we just kind of venture a little bit into science fiction,
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do you think the spaceships, if we are successful,
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that take us outside the solar system,
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will look like the ones we have today,
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or are fundamental breakthroughs necessary?
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In order to have genuine starships,
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probably some really radical views about the way the universe works
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are going to have to take place in our science.
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We could, with our current technology,
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think about constructing multigenerational starships
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where the people who get on them are not the people who get off at the other end.
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But even if we do that, the formidable problem is actually our bodies,
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which doesn't seem to be conscious for a lot of people.
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Even getting to Mars is going to present this challenge,
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because we live in this wonderful home,
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has a protective magnetic magnetosphere around it,
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and so we're shielded from cosmic radiation.
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Once you leave this shield, there are some estimates that,
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for example, if you sent someone to Mars,
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with our technology, probably about two years out there without the shield,
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they're going to be bombarded.
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That means radiation, probably means cancer.
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So that's one of the most formidable challenges,
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even if we could get over the technology.
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Do you think, so Mars is a harsh place.
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Elon Musk, SpaceX and other folks,
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NASA are really pushing to put a human being on Mars.
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Do you think, again, let's forgive me
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for lingering in science fiction land for a little bit.
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Do you think one day we may be able to colonize Mars?
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First, do you think we'll put a human on Mars,
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and then do you think we'll put many humans on Mars?
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So first of all, I am extraordinarily convinced
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we will not put a human on Mars by 2030,
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which is a date that you often hear in the public debate.
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What's the challenge there?
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What do you think?
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So there are a couple of ways that I could slice this,
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but the one that I think is simplest for people to understand involves money.
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So you look at how we got to the moon in the 1960s.
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It was about 10 year duration
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between the challenge that President Kennedy laid out
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and our successfully landing a moon.
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I was actually here at MIT
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when that first moon landing occurred,
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so I remember watching it on TV.
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But how did we get there?
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Well, we had this extraordinarily technical agency
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of the United States government, NASA.
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It consumed about 5% of the country's economic output.
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And so you say 5% of the economic output
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over about a 10 year period gets us 250,000 miles in space.
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Mars is about a hundred times farther.
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So you have at least a hundred times the challenge
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and we're spending about one tenth of the funds
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that we spent then as a government.
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So my claim is that it's at least a thousand times harder
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for me to imagine us getting to Mars by 2030.
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And he had that part that you mentioned in the speech
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that I just have to throw in there of JFK,
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of we do these things not because they're easy,
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but because they're hard.
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That's such a beautiful line
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that I would love to hear a modern president say
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about a scientific endeavor.
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Well, one day we live and hope
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that such a president will arise for our nation.
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But even if, like I said,
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even if you fix the technical problems,
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the biological engineering that I worry most about,
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however, I'm gonna go out on a limb here.
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I think that by 2090 or so,
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or 2100, should I say 120,
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I suspect we're gonna have a human on Mars.
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Wow, so you think that many years out,
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first a few tangents.
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You said bioengineering is a challenge.
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What's the challenge there?
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So as I said, the real problem with interstellar travel,
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aside from the technology challenges,
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the real problem is radiation.
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And how do you engineer either an environment or a body,
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because we see rapid advances going on in bioengineering,
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how do you engineer either a ship or a body
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so that something, some person
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that's recognizably human will survive
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the rigors of interplanetary space travel?
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It's much more difficult than most people
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seem to take into account.
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So if we could linger on the 2090, 2100, 2120,
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sort of thinking of that kind of,
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you know, and let's linger on money.
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Okay.
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So Elon Musk and Jeff Bezos are pushing the cost,
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trying to push the cost down.
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I mean, this is, so do you have hope
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as this actually sort of a brilliant big picture scientist,
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do you think a business entrepreneur can take science
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and make it cheaper and get it out there faster?
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So bending the cost curve is,
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you'll notice that has been an anchor.
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This is the simplest way for me to discuss this with people
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about what the challenge is.
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So yes, bending the cost curve is certainly critical
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if we're going to be successful.
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Now, you asked about the endeavors that are out there now
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sponsored by two very prominent American citizens,
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Jeff Bezos and Elon Musk.
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I'm disappointed actually in what I see
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in terms of the routes that are being pursued.
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So let me give you one example there.
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And this one is going to be a little bit more technical.
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So if you look at the kinds of rockets
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that both these organizations are creating,
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yes, it's wonderful, reusable technology
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to see a rocket go up and land on its fins
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just like it did in science fiction movies
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when I was a kid, that's astounding.
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But the real problem is those rockets,
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the technology that we're doing now
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is not really that different
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than what was used to go to the moon.
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And there are alternatives it turns out.
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There's an engine called a flare engine,
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which so a traditional rocket,
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if you look at the engine, it looks like a bell, right?
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And then the flame comes out the bottom.
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But there is a kind of engine called a flare engine,
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which is essentially, when you look at it,
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it looks like an exhaust pipe
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on like a fancy car that's long and elongated.
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And it's a type of rocket engine
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that we know there've been preliminary testing,
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we know it works.
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And it also is actually much more economical
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because what it does is allow you
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to vary the amount of thrust as you go up.
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In a way that you cannot do
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with one of these bell shaped engines.
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So you would think that an entrepreneur
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might try to have the breakthrough to use flare nozzles,
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as they're called, as a way to bend the cost curve.
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Because as we keep coming back,
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that's gonna be a big factor.
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But that's not happening.
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In fact, what we see is what I think of as incremental change
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in terms of our technology.
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So I'm not really very encouraged by what I personally see.
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So incremental change won't bend the cost curve.
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I don't see it.
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Just linger on the sci fi for one more question.
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Sure.
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Do you think we're alone in the universe?
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Are we the only intelligent form of life?
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So there is a quote by Carl Sagan,
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which I really love when I hear this question.
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And I recall the quote,
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and it goes something like,
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if we're the only conscious life in the universe,
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it's in a terrible waste of space
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because the universe is an incredibly big place.
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And when Carl made that statement,
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we didn't know about the profusion of planets
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that are out there.
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In the last decade,
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we've discovered over a thousand planets
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and a substantial number of those planets are Earth like
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in terms of being in the Goldilocks zone as it's called.
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So in my mind, it's practically inconceivable
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that we're the only conscious form of life in the universe.
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But that doesn't mean they've come to visit us.
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Do you think they would look,
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do you think we'll recognize alien life if we saw it?
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Do you think it'd look anything like the carbon base,
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the biological system we have on Earth today?
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It would depend on that life's native environment
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in which it arose.
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If that environment was sufficiently like our environment,
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there's a principle in biology and nature called convergence,
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which is that even if you have two biological systems
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that are totally separated from each other,
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if they face similar conditions,
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nature tends to converge on solutions.
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And so there might be similarities
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if this alien life form was born in a place
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that's kind of like this place.
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Physics appears to be quite similar,
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the laws of physics across the entirety of the universe.
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Do you think weirder things than we see on Earth
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can spring up out of the same kinds of laws of physics?
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From the laws of physics, I would say yes.
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First of all, if you look at carbon based life,
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why are we carbon based?
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Well, it turns out it's because of the way
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that carbon interacts with elements,
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which in fact is also a reflection
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on the electronic structure of the carbon nucleus.
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So you can look down the table of elements and say,
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well, gee, do we see similar elements?
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The answer is yes.
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And one that one often hears about
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in science fiction is silicon.
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So maybe there's a silicon based life form out there
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if the conditions are right.
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But I think it's presumptuous of us
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to think that we are the template
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by which all life has to appear.
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Before we dive into beautiful details,
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let me ask a big question.
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What to you is the most beautiful idea,
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maybe the most surprising, mysterious idea in physics?
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The most surprising idea to me
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is that we can actually do physics.
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The universe did not have to be constructed
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in such a way with our limited intellectual capacity
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that is actually put together in such a way
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and that we are put together in such a way
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that we can, with our mind's eye,
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delve incredibly deeply into the structure of the universe.
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That to me is pretty close to a miracle.
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So there are simple equations, relatively simple,
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that can describe things, the fundamental functions.
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They can describe everything about our reality.
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That's not, can you imagine universes
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where everything is a lot more complicated?
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Do you think there's something inherent about universes
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that simple laws are...
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Well, first of all, let me,
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this is a question that I encounter in a number of guides.
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A lot of people will raise the question
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about whether mathematics is the language of the universe.
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And my response is mathematics is the language
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that we humans are capable of using in describing the universe.
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It may have little to do with the universe,
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but in terms of our capacity, it's the microscope,
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it's the telescope through which we,
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it's the lens through which we are able to view the universe
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with the precision that no other human language allows.
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So could there be other universes?
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Well, I don't even know if this one looks like I think it does.
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But the beautiful surprising thing is that physics,
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there are laws of physics, very few laws of physics
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that can effectively compress down
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the functioning of the universe.
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Yes, that's extraordinarily surprising.
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I like to use the analogy
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with computers and information technology.
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If you worry about transmitting large bundles of data,
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one of the things that computer scientists do for us
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is they allow for processes that are called compression,
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where you take big packets of data
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and you press them down into much smaller packets,
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and then you transmit those
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and then unpack them at the other end.
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And so it looks a little bit to me
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like the universe has kind of done us a favor.
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It's constructed our minds in such a way
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that we have this thing called mathematics,
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which then as we look at the universe,
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teaches us how to carry out the compression process.
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A quick question about compression.
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Do you think the human mind can be compressed?
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The biology can be compressed?
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We talked about space travel.
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To be able to compress the information
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that captures some large percent of what it means
link |
00:16:46.000
to be me or you,
link |
00:16:48.700
and then be able to send that at the speed of light.
link |
00:16:52.600
Wow, that's a big question.
link |
00:16:54.300
And let me try to take it apart,
link |
00:16:56.900
unpack it into several pieces.
link |
00:16:58.900
I don't believe that wetware biology such as we are
link |
00:17:02.700
has an exclusive patent on intellectual consciousness.
link |
00:17:08.000
I suspect that other structures in the universe
link |
00:17:11.500
are perfectly capable of producing the data streams
link |
00:17:14.700
that we use to process, first of all,
link |
00:17:17.300
our observations of the universe
link |
00:17:18.700
and an awareness of ourself.
link |
00:17:20.700
I can imagine other structures can do that also.
link |
00:17:23.300
So that's part of what you were talking about,
link |
00:17:26.600
which I would have some disagreement with.
link |
00:17:30.500
Consciousness.
link |
00:17:31.600
What's the most interesting part of us humans?
link |
00:17:36.200
Is consciousness the thing?
link |
00:17:38.000
I think that's the most interesting thing about humans.
link |
00:17:39.900
And then you're saying that there's other entities
link |
00:17:43.700
throughout the universe.
link |
00:17:45.100
I can well imagine that the architecture
link |
00:17:48.200
that supports our consciousness, again,
link |
00:17:50.800
has no patent on consciousness.
link |
00:17:53.800
Just in case you have an interesting thought here,
link |
00:17:57.700
there's folks perhaps in philosophy called panpsychists
link |
00:18:01.500
that believe consciousness underlies everything.
link |
00:18:04.100
It is one of the fundamental laws of the universe.
link |
00:18:07.000
Do you have a sense that that could possibly fit into...
link |
00:18:09.700
I don't know the answer to that question.
link |
00:18:12.100
One part of that belief system is giya,
link |
00:18:15.800
which is that there's a kind of conscious life force
link |
00:18:18.500
about our planet.
link |
00:18:20.300
And I've encountered these things before.
link |
00:18:22.800
I don't quite know what to make of them.
link |
00:18:25.200
My own life experience, and I'll be 69 in about two months,
link |
00:18:30.300
and I have spent all my adulthood thinking about
link |
00:18:33.000
the way that mathematics interacts with nature
link |
00:18:37.400
and with us to try to understand nature.
link |
00:18:39.800
And all I can tell you from all of my integrated experience
link |
00:18:43.800
is that there is something extraordinarily mysterious
link |
00:18:47.300
to me about our universe.
link |
00:18:48.500
This is something that Einstein said
link |
00:18:51.100
from his life experience as a scientist.
link |
00:18:53.300
And this mysteriousness almost feels
link |
00:18:59.800
like the universe is our parent.
link |
00:19:03.300
It's a very strange thing perhaps to hear scientists say,
link |
00:19:07.300
but there are just so many strange coincidences
link |
00:19:10.100
that you just get a sense that something is going on.
link |
00:19:14.900
Well, I interrupted you.
link |
00:19:16.300
In terms of compressing what we're down to,
link |
00:19:19.900
we can send it at the speed of light.
link |
00:19:21.800
Yes.
link |
00:19:23.300
So the first thing is I would argue that it's probably
link |
00:19:26.800
very likely that artificial intelligence
link |
00:19:30.100
ultimately will develop something like consciousness,
link |
00:19:32.600
something that for us will probably be indistinguishable
link |
00:19:35.200
from consciousness.
link |
00:19:36.500
So that's what I meant by our biological processing equipment
link |
00:19:41.600
that we carry up here probably does not hold a patent
link |
00:19:44.100
on consciousness, because it's really
link |
00:19:46.200
about the data streams.
link |
00:19:48.100
As far as I can tell, that's what we are.
link |
00:19:49.500
We are self actuating, self learning data streams.
link |
00:19:53.700
That to me is most accurate way I can tell you
link |
00:19:56.300
what I've seen in my lifetime about what humans are
link |
00:19:59.700
at the level of consciousness.
link |
00:20:01.200
So if that's the case, then you just need to have
link |
00:20:03.600
an architecture that supports that information processing.
link |
00:20:06.600
So let's assume that that's true,
link |
00:20:09.000
that in fact what we call consciousness is really about
link |
00:20:13.800
a very peculiar kind of data stream.
link |
00:20:17.200
If that's the case, then if you can export that
link |
00:20:21.400
to a piece of hardware, something metal,
link |
00:20:25.500
electronic, what have you, then you certainly will,
link |
00:20:29.500
ultimately that kind of consciousness could get to Mars
link |
00:20:32.400
very quickly, it doesn't have our problems.
link |
00:20:35.000
You can engineer the body, as I said,
link |
00:20:36.800
it's a ship or a body, you engineer one or both.
link |
00:20:41.300
Send it at a speed of light, well,
link |
00:20:44.100
that one is a more difficult one because that now
link |
00:20:47.400
goes beyond just a matter of having a data stream.
link |
00:20:49.700
It's now the preservation of the information
link |
00:20:51.800
in the data stream.
link |
00:20:53.100
And so unless you can build something that's like
link |
00:20:56.200
a super, super, super version of the way the internet works
link |
00:20:59.800
because most people aren't aware that the internet itself
link |
00:21:02.100
is actually a miracle, it's based on a technology
link |
00:21:04.700
called message packaging.
link |
00:21:06.300
So if you could exponentiate message packaging
link |
00:21:10.300
in some way to preserve the information
link |
00:21:11.900
that's in the data stream, then maybe
link |
00:21:13.500
your dream becomes true.
link |
00:21:16.200
You mentioned with artificial intelligence,
link |
00:21:18.900
sort of us human beings not having
link |
00:21:21.900
a monopoly on consciousness.
link |
00:21:24.400
Does the idea of artificial intelligence systems,
link |
00:21:29.400
computational systems, being able to basically
link |
00:21:33.300
replacing us humans scare you, excite you?
link |
00:21:37.800
What do you think about that?
link |
00:21:38.800
So I'm gonna tell you about a conversation
link |
00:21:40.100
I once had with Eric Schmidt.
link |
00:21:41.900
I was sitting at a meeting with him
link |
00:21:43.300
and he was a few feet away and he turned to me
link |
00:21:46.700
and he said something like, you know, Jim,
link |
00:21:49.300
in maybe a decade or so, we're gonna have computers
link |
00:21:51.600
that do what you do.
link |
00:21:53.200
And my response was not unless they can dream
link |
00:21:55.800
because there's something about,
link |
00:21:57.700
the way that we humans actually generate creativity.
link |
00:22:01.200
It's somehow, I get this sense of my lived experience
link |
00:22:04.700
in watching creative people that it's somehow
link |
00:22:07.100
connected to the irrational parts of what goes on
link |
00:22:09.700
in our head and dreaming is part of that irrational.
link |
00:22:12.500
So unless you can build a piece of artificial intelligence
link |
00:22:15.200
that dreams, I have a strong suspicion
link |
00:22:17.200
that you will not get something that will fully be conscious
link |
00:22:21.100
by a definition that I would accept, for example.
link |
00:22:24.300
So you mentioned dreaming.
link |
00:22:25.900
You've played around with some out there fascinating ideas.
link |
00:22:31.700
How do you think, and we'll start diving into
link |
00:22:35.300
the world of the very small ideas of super symmetry
link |
00:22:38.200
and all that in terms of visualization,
link |
00:22:41.700
in terms of how do you think about it?
link |
00:22:43.900
How do you dream of it?
link |
00:22:44.900
How do you come up with ideas
link |
00:22:46.700
in that fascinating, mysterious space?
link |
00:22:49.300
So in my workspace, which is basically
link |
00:22:52.900
where I am charged with coming up on a mathematical palette
link |
00:22:59.900
with new ideas that will help me understand
link |
00:23:02.100
the structure of nature and hopefully help all of us
link |
00:23:04.500
understand the structure of nature.
link |
00:23:06.300
I've observed several different ways
link |
00:23:08.100
in which my creativity expresses itself.
link |
00:23:10.500
There's one mode which looks pretty normal,
link |
00:23:12.900
which I sort of think of as the Chinese water torture method.
link |
00:23:16.700
Drop, drop, drop, you get more and more information
link |
00:23:19.500
and suddenly it all congeals and you get a clear picture.
link |
00:23:23.100
And so that's kind of a standard way of working.
link |
00:23:25.100
And I think that's how most people think about
link |
00:23:28.700
the way technical people solve problems.
link |
00:23:30.700
That is kind of you accumulate this body of information
link |
00:23:34.700
and at a certain point you synthesize it
link |
00:23:37.300
and then boom, there's something new.
link |
00:23:39.100
But I've also observed in myself and other scientists
link |
00:23:41.900
that there are other ways that we are creative.
link |
00:23:44.500
And these other ways to me are actually far more powerful.
link |
00:23:48.900
I first personally experienced this
link |
00:23:50.500
when I was a freshman at MIT over in Baker House
link |
00:23:53.500
right across the campus.
link |
00:23:55.500
And I was in a calculus course, 1801 is called at MIT.
link |
00:24:00.500
And calculus comes in two different flavors.
link |
00:24:03.700
One of them is called differential calculus.
link |
00:24:05.900
The other is called integral calculus.
link |
00:24:07.500
Differential calculus is the calculus
link |
00:24:09.700
that Newton invented to describe motion.
link |
00:24:13.300
It turns out integral calculus was probably invented
link |
00:24:15.300
about 1700 years earlier by Archimedes.
link |
00:24:18.100
But we didn't know that when I was a freshman.
link |
00:24:20.900
But so that's what you study as a student.
link |
00:24:24.100
And the differential calculus part of the course was,
link |
00:24:26.900
to me, I wouldn't, how do I say this?
link |
00:24:30.300
It was something that by the drip, drip, drip method
link |
00:24:32.900
you could sort of figure it out.
link |
00:24:35.300
Now, the integral part of calculus,
link |
00:24:37.500
I could memorize the formula.
link |
00:24:38.900
That was not the formulae, that was not the problem.
link |
00:24:42.100
The problem was why, in my own mind,
link |
00:24:44.700
why do these formulae work?
link |
00:24:47.300
And because of that, when I was in the part
link |
00:24:52.300
of the calculus course where we had to do
link |
00:24:53.900
multiple substitutions to solve integrals,
link |
00:24:56.500
I had a lot of difficulty.
link |
00:24:59.300
I was emotionally involved in my education
link |
00:25:01.300
because this is where I think the passion of motion comes to.
link |
00:25:05.500
And it caused an emotional crisis
link |
00:25:07.700
that I was having these difficulties
link |
00:25:09.100
understanding the integral part of calculus.
link |
00:25:10.700
The why.
link |
00:25:11.700
The why, that's right, the why of it.
link |
00:25:12.900
Not the rote memorization of fact,
link |
00:25:15.100
but the why of it.
link |
00:25:16.300
Why does this work?
link |
00:25:18.300
And so one night I was over in my dormitory room
link |
00:25:21.700
in Baker House.
link |
00:25:23.100
I was trying to do a calculus problem set.
link |
00:25:25.900
I was getting nowhere.
link |
00:25:28.500
I got a terrific headache.
link |
00:25:30.900
I went to sleep and had this very strange dream.
link |
00:25:33.700
And when I woke, awakened,
link |
00:25:36.700
I could do three and four substitutions
link |
00:25:38.500
and integrals with relative ease.
link |
00:25:41.300
Now, this to me was an astounding experience
link |
00:25:44.300
because I had never before in my life understood
link |
00:25:48.700
that one subconscious is actually capable
link |
00:25:51.100
of being harnessed to do mathematics.
link |
00:25:54.100
I experienced it, this.
link |
00:25:55.100
And I've experienced this more than once.
link |
00:25:56.700
So this was just the first time why I remember it so.
link |
00:25:59.900
So that's why when it comes to like
link |
00:26:02.100
really wickedly tough problems,
link |
00:26:04.300
I think that the kind of creativity
link |
00:26:06.100
that you need to solve them
link |
00:26:08.700
is probably this second variety
link |
00:26:10.900
which comes somehow from dreaming.
link |
00:26:15.900
Do you think, again, I told you I'm Russian.
link |
00:26:18.700
So we romanticize suffering.
link |
00:26:20.500
But do you think part of that equation
link |
00:26:22.300
is the suffering leading up to that dreaming?
link |
00:26:25.900
So the suffering is,
link |
00:26:28.500
I am convinced that this kind of creative,
link |
00:26:31.900
this second mode of creativity as I like to call it,
link |
00:26:34.700
I'm convinced that this second mode of creativity
link |
00:26:37.700
is in fact that suffering is a kind of crucible
link |
00:26:43.300
that triggers it.
link |
00:26:44.700
Because the mind I think is struggling to get out of this.
link |
00:26:47.700
And the only way to actually solve the problem.
link |
00:26:51.300
And even though you're not consciously solving problems,
link |
00:26:54.100
something is going on.
link |
00:26:55.500
And I've talked about to a few other people
link |
00:26:57.300
and I've heard other similar stories.
link |
00:27:00.100
And so I guess what I think about it is
link |
00:27:03.300
it's a little bit by like the way
link |
00:27:04.900
that thermonuclear weapons work.
link |
00:27:07.900
I don't know if you know how they work.
link |
00:27:09.300
But a thermonuclear weapon is actually two bombs.
link |
00:27:11.700
It's an atomic bomb which sort of does a compression.
link |
00:27:14.300
And then you have a fusion bomb that goes off.
link |
00:27:16.100
And somehow that emotional pressure
link |
00:27:18.900
I think acts like the first stage of a thermonuclear weapon.
link |
00:27:22.100
That's when we get really big thoughts.
link |
00:27:25.100
The analogy between thermonuclear weapons
link |
00:27:27.500
and the subconscious, the connection there is,
link |
00:27:30.900
at least visually, is kind of interesting.
link |
00:27:34.700
There may be, Freud would have a few things to say.
link |
00:27:39.700
Well, part of it is probably based
link |
00:27:41.300
on my own trajectory through life.
link |
00:27:43.100
My father was in the US Army for 27 years.
link |
00:27:46.700
And so I started my life out on a military basis.
link |
00:27:50.300
And so a lot of probably the things that wander around
link |
00:27:53.700
in my subconscious are connected to that experience.
link |
00:27:56.300
I apologize for all the tangents, but.
link |
00:27:58.700
Well, you're doing it.
link |
00:27:59.900
You're doing it.
link |
00:28:01.100
But you're encouraging by answering the stupid questions.
link |
00:28:07.100
No, they're not stupid.
link |
00:28:08.100
You know, your father was in the Army.
link |
00:28:14.100
What do you think about, Neil deGrasse Tyson recently wrote
link |
00:28:20.100
a book on interlinking the progress of science
link |
00:28:25.500
to sort of the aspirations of our military endeavors
link |
00:28:31.700
and DARPA funding and so on.
link |
00:28:33.900
What do you think about war in general?
link |
00:28:35.900
Do you think we'll always have war?
link |
00:28:37.900
Do you think we'll always have conflict in the world?
link |
00:28:42.100
I'm not sure that we're going to be able
link |
00:28:43.700
to afford to have war always, because if.
link |
00:28:47.500
Strictly financially speaking?
link |
00:28:49.100
No, not in terms of finance, but in terms of consequences.
link |
00:28:53.300
So if you look at technology today,
link |
00:28:56.900
you can have non state actors acquire technology,
link |
00:29:00.500
for example, bioterrorism, whose impact is roughly speaking
link |
00:29:05.100
equivalent to what it used to take nations
link |
00:29:07.700
to impart on a population.
link |
00:29:10.700
I think the cost of war is ultimately,
link |
00:29:13.300
it's going to be a little, I think
link |
00:29:14.500
it's going to work a little bit like the Cold War.
link |
00:29:16.700
You know, we survived 50, 60 years as a species
link |
00:29:21.700
with these weapons that are so terrible that they could have
link |
00:29:25.500
actually ended our form of life on this planet, but it didn't.
link |
00:29:29.000
Why didn't it?
link |
00:29:30.100
Well, it's a very bizarre and interesting thing,
link |
00:29:32.100
but it was called mutually assured destruction.
link |
00:29:34.500
And so the cost was so great that people eventually
link |
00:29:37.500
figured out that you can't really
link |
00:29:39.100
use these things, which is kind of interesting,
link |
00:29:41.100
because if you read the history about the development
link |
00:29:43.300
of nuclear weapons, physicists actually
link |
00:29:45.300
realized this pretty quickly.
link |
00:29:46.900
I think it was maybe Schrodinger who
link |
00:29:49.000
said that these things are not really weapons.
link |
00:29:51.300
They're political implements.
link |
00:29:52.900
They're not weapons, because the cost is so high.
link |
00:29:55.900
And if you take that example and spread it out
link |
00:30:00.200
to the kind of technological development
link |
00:30:01.900
we're seeing now outside of nuclear physics,
link |
00:30:04.200
but I picked the example of biology,
link |
00:30:06.900
I could well imagine that there would be material science
link |
00:30:10.500
sorts of equivalents across a broad front of technology.
link |
00:30:14.500
You take that experience from nuclear weapons,
link |
00:30:17.300
and the picture that I see is that it would be possible
link |
00:30:20.800
to develop technologies that are so terrible that you couldn't
link |
00:30:24.300
use them, because the costs are too high.
link |
00:30:27.600
And that might cure us.
link |
00:30:29.100
And many people have argued that actually it prevented,
link |
00:30:33.100
nuclear weapons have prevented more military conflict than.
link |
00:30:36.700
It certainly froze the conflict domain.
link |
00:30:41.100
It's interesting that nowadays it
link |
00:30:44.000
was with the removal of the threat of mutually assured
link |
00:30:46.900
destruction that other forces took over in our geopolitics.
link |
00:30:52.300
Do you have worries of existential threats
link |
00:30:57.700
of nuclear weapons or other technologies
link |
00:31:00.200
like artificial intelligence?
link |
00:31:01.700
Do you think we humans will tend to figure out
link |
00:31:05.100
how to not blow ourselves up?
link |
00:31:06.900
I don't know, quite frankly.
link |
00:31:10.000
This is something I've thought about.
link |
00:31:11.700
And I'm not, I mean, so I'm a spectator in the sense
link |
00:31:16.900
that as a scientist, I collect and collate data.
link |
00:31:21.700
So I've been doing that all my life
link |
00:31:23.300
and looking at my species.
link |
00:31:25.300
And it's not clear to me that we are
link |
00:31:27.500
going to avoid a catastrophic, self induced ending.
link |
00:31:34.500
Are you optimistic?
link |
00:31:37.300
Not as a scientist, but as a single element speaker?
link |
00:31:40.700
I would say I wouldn't bet against us.
link |
00:31:45.400
Beautifully put.
link |
00:31:47.100
Let's dive into the world of the very small,
link |
00:31:50.700
if we could for a bit.
link |
00:31:52.900
What are the basic particles, either experimentally observed
link |
00:31:56.900
or hypothesized by physicists?
link |
00:31:59.300
So as we physicists look at the universe,
link |
00:32:02.500
you can, first of all, there are two big buckets of particles.
link |
00:32:05.300
That is the smallest objects that we
link |
00:32:07.200
are able to currently mathematically conceive
link |
00:32:11.300
and then experimentally verify that these ideas have
link |
00:32:15.700
a sense of accuracy to them.
link |
00:32:17.700
So one of those buckets we call matter.
link |
00:32:20.900
These are things like electrons, things
link |
00:32:23.300
that are like quarks, which are particles that
link |
00:32:25.900
exist inside of protons.
link |
00:32:27.900
And there's a whole family of these things.
link |
00:32:30.700
There are, in fact, 18 quarks and apparently six
link |
00:32:34.300
electron like objects that we call leptons.
link |
00:32:37.500
So that's one bucket.
link |
00:32:39.100
The other bucket that we see both in our mathematics
link |
00:32:41.700
as well as in our experimental equipment
link |
00:32:43.700
are a set of particles that you can call force carriers.
link |
00:32:47.900
The most familiar force carrier is the photon, the particle
link |
00:32:50.700
of light that allows you to see me.
link |
00:32:52.200
In fact, it's the same object that
link |
00:32:54.300
carries electric repulsion between like charges.
link |
00:32:58.300
From science fiction, we have the object
link |
00:33:00.900
called the graviton, which is talked about a lot in science
link |
00:33:03.600
fiction and Star Trek.
link |
00:33:05.300
But the graviton is also a mathematical object
link |
00:33:07.500
that we physicists have known about essentially
link |
00:33:09.400
since Einstein wrote his theory of general relativity.
link |
00:33:13.400
There are four forces in nature, the fundamental forces.
link |
00:33:17.700
There is the gravitational force.
link |
00:33:19.600
Its carrier is the graviton.
link |
00:33:21.400
There are three other forces in nature,
link |
00:33:23.100
the electromagnetic force, the strong nuclear force,
link |
00:33:25.800
and the weak nuclear force.
link |
00:33:27.000
And each one of these forces has one or more carriers.
link |
00:33:30.200
The photon is the carrier of the electromagnetic force.
link |
00:33:33.200
The strong nuclear force actually has eight carriers.
link |
00:33:35.900
They're called gluons.
link |
00:33:37.300
And then the weak nuclear force has three carriers.
link |
00:33:39.500
They're called the W plus, W minus, and Z bosons.
link |
00:33:44.000
So those are the things that both in mathematics
link |
00:33:46.500
and in experiments, by the way, the most precise experiments
link |
00:33:49.900
we're ever as a species able to conduct
link |
00:33:53.100
is about measuring the accuracy of these ideas.
link |
00:33:55.500
And we know that at least to one part in a billion,
link |
00:33:57.600
these ideas are right.
link |
00:33:59.600
So first of all, you've made it sound both elegant and simple.
link |
00:34:05.400
But is it crazy to you that there is force carriers?
link |
00:34:11.300
Like, is that supposed to be a trivial idea to think about?
link |
00:34:14.500
If we think about photons, gluons,
link |
00:34:17.300
that there's four fundamental forces of physics,
link |
00:34:21.300
and then those forces are expressed.
link |
00:34:24.200
There's carriers of those forces.
link |
00:34:26.600
Like, is that a kind of trivial thing?
link |
00:34:29.600
It's not a trivial thing at all.
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00:34:31.000
In fact, it was a puzzle for Sir Isaac Newton,
link |
00:34:33.100
because he's the first person to give us basically physics.
link |
00:34:37.200
Before Isaac Newton, physics didn't exist.
link |
00:34:39.800
What did exist was called natural philosophy,
link |
00:34:41.700
so discussions about using the methods of classical philosophy
link |
00:34:45.100
to understand nature, natural philosophy.
link |
00:34:48.400
So the Greeks, we call them scientists,
link |
00:34:50.700
but they were natural philosophers.
link |
00:34:52.800
Physics doesn't get born until Newton writes the Principia.
link |
00:34:56.600
One of the things that puzzled him was how gravity works,
link |
00:35:00.500
because if you read very carefully what he writes,
link |
00:35:04.800
he basically says, and I'm paraphrasing badly,
link |
00:35:07.300
but he basically says that someone who thinks deeply
link |
00:35:10.000
about this subject would find it inconceivable
link |
00:35:13.200
that an object in one place or location
link |
00:35:17.000
can magically reach out and affect another object
link |
00:35:19.500
with nothing intervening.
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00:35:21.600
And so it puzzled him.
link |
00:35:23.100
There's a puzzle of you, action at a distance.
link |
00:35:25.700
I mean, not as a physicist.
link |
00:35:27.000
It would, it would, except that I am a physicist,
link |
00:35:29.900
and we have long ago resolved this issue,
link |
00:35:32.400
and the resolution came about
link |
00:35:33.500
through a second great physicist.
link |
00:35:36.800
Most people have heard of Newton.
link |
00:35:38.400
Most people have heard of Einstein.
link |
00:35:40.100
But between the two of them,
link |
00:35:41.100
there was another extraordinarily great physicist,
link |
00:35:43.600
a man named James Clark Maxwell.
link |
00:35:45.900
And Maxwell, between these two other giants,
link |
00:35:49.500
taught us about electric and magnetic forces,
link |
00:35:52.900
and it's from his equations that one can figure out
link |
00:35:55.900
that there's a carrier called the photon.
link |
00:35:58.200
So this was resolved for physicists around 1860 or so.
link |
00:36:04.000
So what are bosons and fermions and hadrons,
link |
00:36:08.400
elementary and composites?
link |
00:36:09.700
Sure, so earlier I said.
link |
00:36:12.900
Two buckets.
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00:36:13.740
You have got two buckets
link |
00:36:14.600
if you wanna try to build the universe.
link |
00:36:15.800
You gotta start off with things on these two buckets.
link |
00:36:18.700
So you gotta have things, that's a matter,
link |
00:36:21.300
and then you have to have other objects that act on them
link |
00:36:23.800
to cause those things to cohere to fixed finite patterns,
link |
00:36:28.400
because you need those fixed finite patterns
link |
00:36:30.000
as building blocks.
link |
00:36:31.100
So that's the way our universe looks to people like me.
link |
00:36:34.000
Now, the building blocks do different things.
link |
00:36:37.100
So let's go back to these two buckets again.
link |
00:36:39.800
Let me start with a bucket containing the particle of light.
link |
00:36:42.800
Let me imagine I'm in a dusty room with two flashlights,
link |
00:36:46.400
and I have one flashlight, which I direct directly
link |
00:36:49.300
in front of me, and then I have you stand over to say my left
link |
00:36:52.800
and then we both take our flashlights and turn them on
link |
00:36:54.800
and make sure the beams go right through each other.
link |
00:36:56.800
And the beams do just that.
link |
00:36:57.900
They go right through each other.
link |
00:36:58.800
They don't bounce off of each other.
link |
00:37:00.300
The reason the room has to be dusty
link |
00:37:01.500
is because we wanna see the light.
link |
00:37:03.500
The room dust wasn't there.
link |
00:37:04.500
We wouldn't actually see the light
link |
00:37:05.500
until it got to the other wall, right?
link |
00:37:07.000
So you see the beam because it's the dust in the air.
link |
00:37:09.900
But the two beams actually pass right through each other.
link |
00:37:12.600
They literally pass right through.
link |
00:37:13.900
They don't affect each other at all.
link |
00:37:15.900
One acts like the other's not there.
link |
00:37:20.200
The particle of light is the simplest example
link |
00:37:23.000
that shows that behavior.
link |
00:37:24.600
That's a boson.
link |
00:37:26.200
Now let's imagine that we're in the same dusty room
link |
00:37:30.100
and this time you have a bucket of balls
link |
00:37:31.900
and I have a bucket of balls.
link |
00:37:33.100
And we try to throw them so that we get something
link |
00:37:36.200
like a beam, throwing them fast, right?
link |
00:37:39.200
If they collide, they don't just pass through each other.
link |
00:37:41.500
They bounce off of each other.
link |
00:37:43.400
Now that's mostly because they have electric charge
link |
00:37:45.900
and electric charges, light charges repel.
link |
00:37:48.500
But mathematically, I know how to turn off
link |
00:37:50.300
the electric charge.
link |
00:37:51.500
And if you do that, you'll find these still repel.
link |
00:37:53.800
And it's because they are these things we call fermions.
link |
00:37:57.100
So this is how you distinguish the things
link |
00:37:59.000
that are in the two buckets.
link |
00:38:00.200
They are either bosons or fermions.
link |
00:38:04.000
Which of them, and maybe you can mention
link |
00:38:06.900
the most popular of the bosons.
link |
00:38:09.900
The most recently discovered.
link |
00:38:12.000
It's like when I was in high school
link |
00:38:15.200
and there was a really popular majorette.
link |
00:38:18.300
Her name is the Higgs particle these days.
link |
00:38:21.500
Can you describe which of the bosons
link |
00:38:26.700
and the fermions have been discovered,
link |
00:38:28.500
hypothesized, which have been experimentally validated,
link |
00:38:31.300
what's still out there?
link |
00:38:32.200
Right, so the two buckets that I've actually described
link |
00:38:37.100
to you have all been first hypothesized
link |
00:38:40.200
and then verified by observation.
link |
00:38:43.100
With the Higgs boson being the most recent
link |
00:38:45.200
one of these things.
link |
00:38:47.200
We haven't actually verified the graviton
link |
00:38:49.800
interestingly enough.
link |
00:38:51.200
Mathematically, we have an expectation
link |
00:38:54.100
that gravitons exist.
link |
00:38:55.400
But we've not performed an experiment
link |
00:38:56.900
to show that this is an accurate idea that nature uses.
link |
00:38:59.900
So something has to be a carrier.
link |
00:39:02.200
For the force of gravity, exactly.
link |
00:39:04.500
Can it be something way more mysterious than we,
link |
00:39:08.000
so when you say the graviton, is it,
link |
00:39:11.500
would it be like the other particles, force carriers,
link |
00:39:15.000
or can it be something much more mysterious?
link |
00:39:16.300
In some ways, yes, but in other ways, no.
link |
00:39:18.700
It turns out that the graviton is also,
link |
00:39:21.900
if you look at Einstein's theory,
link |
00:39:24.200
he taught us about this thing he calls space time,
link |
00:39:26.600
which is, if you try to imagine it,
link |
00:39:29.300
you can sort of think of it as kind of a rubber surface.
link |
00:39:32.400
That's one popular depiction of space time.
link |
00:39:34.900
It's not an accurate depiction
link |
00:39:36.200
because the only accuracy is actually in the calculus
link |
00:39:38.600
that he uses, but that's close enough.
link |
00:39:41.100
So if you have a sheet of rubber, you can wave it.
link |
00:39:43.700
You can actually form a wave on it.
link |
00:39:46.000
Space time is enough like that
link |
00:39:47.800
so that when space time oscillates, you create these waves.
link |
00:39:51.000
These waves carry energy.
link |
00:39:53.100
We expect them to carry energy in quanta.
link |
00:39:55.000
That's what a graviton is.
link |
00:39:56.100
It's a wave in space time.
link |
00:39:57.700
And so the fact that we have seen the waves
link |
00:40:00.700
with LIGO over the course of the last three years,
link |
00:40:03.700
and we've recently used gravitational wave observatories
link |
00:40:07.200
to watch colliding black holes and neutron stars
link |
00:40:09.800
and all sorts of really cool stuff out there.
link |
00:40:12.500
So we know the waves exist,
link |
00:40:14.600
but in order to know that gravitons exist,
link |
00:40:16.700
you have to prove that these waves carry energy
link |
00:40:18.800
in energy packets.
link |
00:40:20.400
And that's what we don't have the technology to do yet.
link |
00:40:25.100
And perhaps briefly jumping to a philosophical question,
link |
00:40:28.300
does it make sense to you that gravity
link |
00:40:30.600
is so much weaker than the other forces?
link |
00:40:32.900
No.
link |
00:40:34.300
You see, now you've touched on a very deep mystery
link |
00:40:40.500
about physics.
link |
00:40:42.600
There are a lot of such questions in physics
link |
00:40:44.300
about why things are as they are.
link |
00:40:47.200
And as someone who believes that there are some things
link |
00:40:50.900
that certainly are coincidences,
link |
00:40:53.400
like you could ask the same question about,
link |
00:40:54.800
well, why are the planets at the orbits
link |
00:40:57.100
that they are around the sun?
link |
00:40:58.900
The answer turns out there is no good reason.
link |
00:41:00.300
It's just an accident.
link |
00:41:01.400
So there are things in nature that have that character.
link |
00:41:03.500
And perhaps the strength of the various forces is like that.
link |
00:41:08.600
On the other hand, we don't know that that's the case.
link |
00:41:10.900
And there may be some deep reasons
link |
00:41:12.500
about why the forces are ordered as they are,
link |
00:41:15.900
where the weakest force is gravity,
link |
00:41:17.600
the next weakest force is the weak interaction,
link |
00:41:19.700
the weak nuclear force, then there's electromagnetism,
link |
00:41:22.000
there's a strong force.
link |
00:41:23.100
We don't really have a good understanding
link |
00:41:24.700
of why this is the ordering of the forces.
link |
00:41:27.000
So some of the fascinating work you've done
link |
00:41:30.900
is in the space of supersymmetry, symmetry in general.
link |
00:41:36.300
Can you describe, first of all, what is supersymmetry?
link |
00:41:39.500
Yes, so you remember the two buckets
link |
00:41:41.400
I told you about perhaps earlier?
link |
00:41:43.500
So there are two buckets in our universe.
link |
00:41:46.100
So now I want you to think about drawing a pie
link |
00:41:51.800
that has four quadrants.
link |
00:41:53.000
So I want you to cut the piece of pie in fourths.
link |
00:41:56.200
So in one quadrant, I'm gonna put all the buckets
link |
00:41:58.300
that we talked about that are like the electron and quarks.
link |
00:42:01.400
In a different quadrant,
link |
00:42:02.400
I'm going to put all the force carriers.
link |
00:42:04.500
The other two quadrants are empty.
link |
00:42:06.600
Now, I showed you a picture of that.
link |
00:42:08.500
You'd see a circle.
link |
00:42:10.100
There would be a bunch of stuff in one upper quadrant
link |
00:42:12.600
and stuff in others.
link |
00:42:13.900
And then I would ask you a question.
link |
00:42:15.900
Does that look symmetrical to you?
link |
00:42:19.100
No. No.
link |
00:42:20.700
And that's exactly right
link |
00:42:22.100
because we humans actually have a very deeply programmed
link |
00:42:26.700
sense of symmetry.
link |
00:42:28.000
It's something that is part of that mystery of the universe.
link |
00:42:32.900
So how would you make it symmetrical?
link |
00:42:34.300
Or one way you could is by saying
link |
00:42:35.800
those two empty quadrants had things in them also.
link |
00:42:38.900
And if you do that, that's supersymmetry.
link |
00:42:42.500
So that's what I understood
link |
00:42:43.500
when I was a graduate student here at MIT in 1975
link |
00:42:47.900
when the mathematics of this was first being born.
link |
00:42:52.300
Supersymmetry was actually born in the Ukraine
link |
00:42:55.000
in the late 60s, but we had this thing
link |
00:42:56.700
called the Iron Curtain.
link |
00:42:57.600
So we Westerners didn't know about it.
link |
00:43:00.500
But by the early 70s, independently,
link |
00:43:02.900
there were scientists in the West
link |
00:43:04.300
who had rediscovered supersymmetry.
link |
00:43:07.500
Bruno Zemeno and Julius Wess were their names.
link |
00:43:10.400
So this was around 71 or 72 when this happened.
link |
00:43:14.100
I started graduate school in 73.
link |
00:43:16.200
So around 74, 75, I was trying to figure out
link |
00:43:19.200
how to write a thesis so that I could become a physicist
link |
00:43:21.500
the rest of my life.
link |
00:43:23.600
I did a, I had a great advisor, Professor James Young
link |
00:43:27.700
who had taught me a number of things about electrons
link |
00:43:31.100
and weak forces and those sorts of things.
link |
00:43:33.900
But I decided that if I was going to have a really
link |
00:43:40.900
an opportunity to maximize my chances of being successful,
link |
00:43:45.500
I should strike it out in a direction
link |
00:43:46.900
that other people were not studying.
link |
00:43:48.800
And so as a consequence, I surveyed ideas
link |
00:43:52.200
that were going, that were being developed.
link |
00:43:54.300
And I came across the idea of supersymmetry.
link |
00:43:57.100
And it was so, the mathematics was so remarkable
link |
00:44:00.700
that I just, it bowled me over.
link |
00:44:03.100
I actually have two undergraduate degrees.
link |
00:44:05.500
My first undergraduate degree is actually mathematics.
link |
00:44:07.600
And my second is physics,
link |
00:44:09.400
even though I always wanted to be a physicist.
link |
00:44:12.000
Plan A, which involved getting good grades was mathematics.
link |
00:44:17.500
I was a mathematics major thinking about graduate school,
link |
00:44:20.500
but my heart was in physics.
link |
00:44:22.800
If we could take a small digression,
link |
00:44:26.200
what's to you the most beautiful idea in mathematics
link |
00:44:29.100
that you've encountered in this interplay
link |
00:44:31.600
between math and physics?
link |
00:44:33.400
It's the idea of symmetry.
link |
00:44:35.500
The fact that our innate sense of symmetry
link |
00:44:39.900
winds up aligning with just incredible mathematics,
link |
00:44:44.500
to me is the most beautiful thing.
link |
00:44:47.400
It's very strange, but true
link |
00:44:50.100
that if symmetries were perfect, we would not exist.
link |
00:44:53.100
And so even though we have these very powerful ideas
link |
00:44:55.200
about balance in the universe in some sense,
link |
00:44:57.700
it's only when you break those balances
link |
00:44:59.200
that you get creatures like humans
link |
00:45:01.000
and objects like planets and stars.
link |
00:45:03.600
So although they are a scaffold for reality,
link |
00:45:07.100
they cannot be the entirety of reality.
link |
00:45:09.500
So I'm kind of naturally attracted
link |
00:45:15.500
to parts of science and technology
link |
00:45:18.900
where symmetry plays a dominant role.
link |
00:45:21.400
And not just, I guess, symmetry as you said,
link |
00:45:23.500
but the magic happens when you break the symmetry.
link |
00:45:26.800
The magic happens when you break the symmetry.
link |
00:45:29.600
Okay, so diving right back in,
link |
00:45:31.300
you mentioned four quadrants.
link |
00:45:33.100
Yes.
link |
00:45:34.100
Two are filled with stuff we can, two buckets.
link |
00:45:37.100
And then there's crazy mathematical thing,
link |
00:45:39.500
ideas fulfilling the other two.
link |
00:45:41.600
What are those things?
link |
00:45:43.300
So earlier, the way I described these two buckets
link |
00:45:46.200
is I gave you a story that started out
link |
00:45:48.900
by putting us in a dusty room with two flashlights.
link |
00:45:52.700
And I said, turn on your flashlight, I'll turn on mine,
link |
00:45:55.300
the beams will go through each other.
link |
00:45:56.700
And the beams are composed of force carriers called photons.
link |
00:46:00.900
They carry the electromagnetic force
link |
00:46:03.200
and they pass right through each other.
link |
00:46:04.300
So imagine looking at the mathematics of such an object,
link |
00:46:07.600
which you don't have to imagine people like me do that.
link |
00:46:11.400
So you take that mathematics
link |
00:46:12.800
and then you ask yourself a question.
link |
00:46:15.200
You see, mathematics is a palette.
link |
00:46:16.700
It's just like a musical composer
link |
00:46:20.700
is able to construct variations on a theme.
link |
00:46:24.400
Well, a piece of mathematics in the hand of a physicist
link |
00:46:26.800
is something that we can construct variations on.
link |
00:46:29.000
So even though the mathematics that Maxwell gave us
link |
00:46:33.300
about light, we know how to construct variations on that.
link |
00:46:38.200
And one of the variations you can construct is to say,
link |
00:46:41.100
suppose you have a force carrier for electromagnetism
link |
00:46:45.400
that behaves like an electron
link |
00:46:47.200
in that it would bounce off of another one.
link |
00:46:49.500
That's changing a mathematical term in an equation.
link |
00:46:53.200
So if you did that, you would have a force carrier.
link |
00:46:56.600
So you would say first it belongs
link |
00:46:58.200
in this force carrying bucket,
link |
00:46:59.600
but it's got this property of bouncing off like electrons.
link |
00:47:01.700
So you say, well, gee, wait, no,
link |
00:47:03.400
that's not the right bucket.
link |
00:47:04.600
So you're forced to actually put it
link |
00:47:05.800
in one of these empty quadrants.
link |
00:47:07.800
So those sorts of things, basically we give them...
link |
00:47:12.100
So the photon mathematically
link |
00:47:14.400
can be accompanied by a photino.
link |
00:47:15.900
It's the thing that carries a force
link |
00:47:18.200
but has the rule of bouncing off.
link |
00:47:20.700
In a similar manner, you could start with an electron
link |
00:47:24.200
and you say, okay, so write down the mathematical electron.
link |
00:47:27.000
I know how to do that.
link |
00:47:28.200
A physicist named Dirac first told us how to do that
link |
00:47:30.200
back in the late 20s, early 30s.
link |
00:47:33.500
So take that mathematics.
link |
00:47:34.600
And then you say, let me look at that mathematics
link |
00:47:37.700
and find out what in the mathematics
link |
00:47:39.600
causes two electrons to bounce off of each other,
link |
00:47:42.300
even if I turn off the electrical charge.
link |
00:47:44.500
So I could do that.
link |
00:47:45.600
And now let me change that mathematical term.
link |
00:47:48.200
So now I have something that carries electrical charge,
link |
00:47:50.700
but if you take two of them,
link |
00:47:52.300
I'm sorry, if you turn their charges off,
link |
00:47:53.700
they'll pass through each other.
link |
00:47:55.300
So that puts things in the other quadrant.
link |
00:47:57.600
And those things we tend to call,
link |
00:48:00.600
we put the S in front of their name.
link |
00:48:02.500
So in the lower quadrant here, we have electrons
link |
00:48:04.800
and this now newly filled quadrant, we have selectors.
link |
00:48:08.100
And the quadrant over here, we had quarks.
link |
00:48:12.300
Over here, we have squarks.
link |
00:48:13.700
So now we've got this balanced pie.
link |
00:48:15.600
And that's basically what I understood
link |
00:48:17.600
as a graduate student in 1975
link |
00:48:20.500
about this idea of supersymmetry,
link |
00:48:22.400
that it was going to fill up these two quadrants
link |
00:48:24.300
of the pie in a way that no one
link |
00:48:25.900
had ever thought about before.
link |
00:48:27.700
So I was amazed that no one else at MIT
link |
00:48:30.200
found this an interesting idea.
link |
00:48:32.300
So it led to my becoming the first person in MIT
link |
00:48:37.300
to really study supersymmetry.
link |
00:48:39.500
This is 1975, 76, 77.
link |
00:48:42.600
And in 77, I wrote the first PhD thesis
link |
00:48:44.900
in the physics department on this idea
link |
00:48:47.100
because I was drawn to the balance.
link |
00:48:50.500
Drawn to the symmetry.
link |
00:48:51.700
So what does that, first of all,
link |
00:48:56.800
is this fundamentally a mathematical idea?
link |
00:49:01.200
So how much experimental, and we'll have this theme.
link |
00:49:04.400
It's a really interesting one.
link |
00:49:05.600
When you explore the world of the small
link |
00:49:08.200
and in your new book talking about
link |
00:49:11.200
Approving Einstein, right, that we'll also talk about,
link |
00:49:14.100
there's this theme of kind of starting it,
link |
00:49:16.700
exploring crazy ideas first in the mathematics
link |
00:49:19.600
and then seeking for ways to experimentally validate them.
link |
00:49:23.000
Where do you put supersymmetry in that?
link |
00:49:25.600
It's closer than string theory.
link |
00:49:28.200
It has not yet been validated.
link |
00:49:30.700
In some sense, you mentioned Einstein,
link |
00:49:33.200
so let's go there for a moment.
link |
00:49:35.400
In our book, Approving Einstein Right,
link |
00:49:37.000
we actually do talk about the fact
link |
00:49:38.800
that Albert Einstein in 1915 wrote a set of equations
link |
00:49:42.900
which were very different from Newton's equations
link |
00:49:45.100
in describing gravity.
link |
00:49:46.800
These equations made some predictions
link |
00:49:48.900
that were different from Newton's predictions.
link |
00:49:51.200
It actually made three different predictions.
link |
00:49:53.100
One of them was not actually a prediction,
link |
00:49:55.000
but a postdiction, because it was known
link |
00:49:57.000
that Mercury was not orbiting the sun
link |
00:49:59.500
in the way that Newton would have told you.
link |
00:50:01.600
And so Einstein's theory actually describes Mercury
link |
00:50:05.400
orbiting in a way that was observed
link |
00:50:08.200
as opposed to what Newton would have told you.
link |
00:50:09.800
So that was one prediction.
link |
00:50:11.600
The second prediction that came out of
link |
00:50:13.400
the theory of general relativity,
link |
00:50:14.700
which Einstein wrote in 1915,
link |
00:50:17.400
was that if you,
link |
00:50:21.000
so let me describe an experiment and come back to it.
link |
00:50:23.400
Suppose I had a glass of water,
link |
00:50:25.400
and I filled the glass up,
link |
00:50:28.800
and then I moved the glass slowly back and forth
link |
00:50:31.000
between our two faces.
link |
00:50:33.800
It would appear to me like your face was moving,
link |
00:50:36.600
even though you weren't moving.
link |
00:50:38.000
I mean, it's actually, and what's causing it
link |
00:50:40.000
is because the light gets bent through the glass
link |
00:50:42.200
as it passes from your face to my eye.
link |
00:50:45.000
So Einstein in his 1915 theory of general relativity
link |
00:50:50.800
found out that gravity has the same effect on light
link |
00:50:54.400
as that glass of water.
link |
00:50:55.400
It would cause beams of light to bend.
link |
00:50:58.200
Now, Newton also knew this,
link |
00:51:01.000
but Einstein's prediction was that light
link |
00:51:02.600
would bend twice as much.
link |
00:51:04.800
And so here's a mathematical idea.
link |
00:51:07.200
Now, how do you actually prove it?
link |
00:51:09.000
Well, you've got to watch.
link |
00:51:11.400
Just a quick pause on that, just the language you're using.
link |
00:51:15.800
He found out.
link |
00:51:17.800
I can say he did a calculation.
link |
00:51:19.600
It's a really interesting notion
link |
00:51:21.200
that one of the beautiful things about this universe
link |
00:51:25.200
is you can do a calculation
link |
00:51:28.000
and combine with some of that magical intuition
link |
00:51:30.900
that physicists have, actually predict what would be,
link |
00:51:35.200
what's possible to experimentally validate.
link |
00:51:37.600
That's correct.
link |
00:51:38.440
So he found out in the sense
link |
00:51:40.000
that there seems to be something here
link |
00:51:43.300
and mathematically it should bend,
link |
00:51:46.000
gravity should bend light this amount.
link |
00:51:48.500
And so therefore that's something that could be potentially,
link |
00:51:51.400
and then come up with an experiment that could be validated.
link |
00:51:53.300
Right.
link |
00:51:54.400
And that's the way that actually modern physics,
link |
00:51:57.300
deeply fundamental modern physics, this is how it works.
link |
00:52:02.400
Earlier we spoke about the Higgs boson.
link |
00:52:04.400
So why did we go looking for it?
link |
00:52:06.000
The answer is that back in the late 60s and early 70s,
link |
00:52:10.900
some people wrote some equations
link |
00:52:12.700
and the equations predicted this.
link |
00:52:15.500
So then we went looking for it.
link |
00:52:18.500
So on supersymmetry for a second,
link |
00:52:21.300
there's these things called idynchrous symbols,
link |
00:52:25.100
these strange little graphs.
link |
00:52:26.700
Yes.
link |
00:52:27.700
You refer to them as revealing something
link |
00:52:29.500
like binary code underlying reality.
link |
00:52:32.700
First of all, can you describe these graphs?
link |
00:52:34.900
Describe these graphs, what are they?
link |
00:52:38.100
What are these beautiful little strange graphs?
link |
00:52:40.700
Well, first of all, idynchrous are an invention of mine,
link |
00:52:44.800
together with a colleague named Michael Fox.
link |
00:52:46.900
In 2005, we were looking at equations.
link |
00:52:50.000
Well, the story's a little bit more complicated
link |
00:52:51.800
and it'll take too long to explain all the details,
link |
00:52:54.000
but the Reader's Digest version
link |
00:52:55.600
is that we were looking at these equations
link |
00:52:58.000
and we figured out that all the data
link |
00:53:01.100
in a certain class of equations could be put in pictures.
link |
00:53:04.600
And the pictures, what do they look like?
link |
00:53:06.400
Well, they're just little balls.
link |
00:53:09.400
You have black balls and white balls.
link |
00:53:12.100
Those stand for those two buckets, by the way,
link |
00:53:14.100
that we talked about in reality.
link |
00:53:15.700
The white balls are things that are like particles of light.
link |
00:53:18.600
The black balls are like electrons.
link |
00:53:20.800
And then you can draw lines connecting these balls.
link |
00:53:24.400
And these lines are deeply mathematical objects
link |
00:53:27.400
and there's no way for me to,
link |
00:53:29.100
I have no physical model for telling you what the lines are.
link |
00:53:33.900
But if you were a mathematician,
link |
00:53:36.200
I would do a technical phrase saying,
link |
00:53:37.900
this is the orbit of the representation
link |
00:53:39.600
and the action of the symmetry generators.
link |
00:53:41.900
Mathematicians wouldn't understand that.
link |
00:53:43.600
Nobody else in their right mind would,
link |
00:53:45.100
so let's not go there.
link |
00:53:47.000
So, but we figured out that the data
link |
00:53:49.700
that was in the equations was in these funny pictures
link |
00:53:52.000
that we could draw.
link |
00:53:53.800
And so that was stunning,
link |
00:53:56.900
but it also was encouraging
link |
00:53:59.700
because there are problems with the equations,
link |
00:54:02.400
which I had first learned about in 1979
link |
00:54:06.700
when I was down at Harvard
link |
00:54:07.900
and I went out to Caltech for the first time
link |
00:54:09.900
and working with a great scientist
link |
00:54:11.700
by the name of John Schwartz.
link |
00:54:12.700
There are problems in the equations we don't know how to solve.
link |
00:54:16.000
And so one of the things about solving problems
link |
00:54:18.300
that you don't know how to solve
link |
00:54:20.100
is that beating your head against a brick wall
link |
00:54:22.800
is probably not a good philosophy about how to solve it.
link |
00:54:25.900
So what do you need to do?
link |
00:54:26.800
You need to change your sense of reference,
link |
00:54:29.300
your frame of reference, your perspective.
link |
00:54:31.300
So when I saw these funny pictures,
link |
00:54:35.100
I thought, gee, that might be a way
link |
00:54:37.500
to solve these problems with equations
link |
00:54:39.000
that we don't know how to do.
link |
00:54:41.800
So that was for me one of the first attractions
link |
00:54:44.400
is that I now had an alternative language
link |
00:54:46.900
to try to attack a set of mathematical problems.
link |
00:54:50.700
But I quickly realized that A,
link |
00:54:54.600
this mathematical language was not known by mathematicians,
link |
00:54:58.100
which makes it pretty interesting
link |
00:54:59.900
because now you have to actually teach mathematicians
link |
00:55:02.700
about a piece of mathematics
link |
00:55:04.100
because that's how they make their living.
link |
00:55:05.900
And the great thing about working with mathematicians,
link |
00:55:08.000
of course, is the rigor with which they examine ideas.
link |
00:55:11.100
So they make your ideas better than they start out.
link |
00:55:14.400
So I start working with a group of mathematicians
link |
00:55:16.600
and it was in that collaboration that we figured out
link |
00:55:18.500
that these funny pictures had error correcting codes
link |
00:55:20.740
buried in them.
link |
00:55:23.500
Can you talk about what are error correcting codes?
link |
00:55:25.700
Ah, sure.
link |
00:55:26.700
So the simplest way to talk about error correcting codes
link |
00:55:32.100
is first of all, to talk about digital information.
link |
00:55:36.800
Digital information is basically strings of ones and zeros.
link |
00:55:39.600
They're called bits.
link |
00:55:41.100
So now let's imagine that I want to send you some bits.
link |
00:55:46.700
Well, maybe I could show you pictures,
link |
00:55:50.300
but maybe it's a rainy day
link |
00:55:52.200
or maybe the windows in your house are foggy.
link |
00:55:56.300
So sometimes when I show you a zero,
link |
00:55:59.300
you might interpret it as a one.
link |
00:56:01.600
Or other times when I show you a one,
link |
00:56:03.300
you might interpret it as a zero.
link |
00:56:05.800
So if that's the case,
link |
00:56:07.100
that means when I try to send you this data,
link |
00:56:08.800
it comes to you in corrupted form.
link |
00:56:11.000
And so the challenge is how do you get it to be uncorrupted?
link |
00:56:15.500
In the 1940s, a computer scientist named Hamming
link |
00:56:21.700
addressed the problem of how do you reliably transmit
link |
00:56:24.700
digital information?
link |
00:56:26.200
And what he came up with was a brilliant idea.
link |
00:56:29.400
Now, the way that you solve it
link |
00:56:31.300
is that you take the data that you want to send,
link |
00:56:33.200
the ones in your strings of ones and zeros,
link |
00:56:34.900
your favorite string,
link |
00:56:36.100
and then you dump more ones and zeros in,
link |
00:56:38.000
but you dump them in in a particular pattern.
link |
00:56:41.200
And this particular pattern
link |
00:56:42.900
is what a Hamming code is all about.
link |
00:56:45.300
So it's an error correcting code
link |
00:56:46.600
because if the person at the other end
link |
00:56:48.400
knows what the pattern's supposed to be,
link |
00:56:49.800
they can figure out when one's got changed to zeros,
link |
00:56:52.200
zero's got changed to one.
link |
00:56:53.700
So it turned out that our strange little objects
link |
00:56:57.500
that came from looking at the equations
link |
00:56:59.300
that we couldn't solve,
link |
00:57:00.800
it turns out that when you look at them deeply enough,
link |
00:57:02.700
you find out that they have ones and zeros
link |
00:57:06.200
buried in them.
link |
00:57:07.500
But even more astoundingly,
link |
00:57:08.800
the ones and zeros are not there randomly.
link |
00:57:10.800
They are in the pattern of error correcting codes.
link |
00:57:14.200
So this was an astounding thing
link |
00:57:16.000
that when we first got this result
link |
00:57:19.000
and tried to publish it,
link |
00:57:20.000
it took us three years to convince other physicists
link |
00:57:22.000
that we weren't crazy.
link |
00:57:23.800
Eventually we were able to publish it,
link |
00:57:25.200
I and this collaboration of mathematicians
link |
00:57:27.400
and other physicists.
link |
00:57:29.300
And so ever since then,
link |
00:57:31.400
I have actually been looking at the mathematics
link |
00:57:34.400
of these objects,
link |
00:57:35.900
trying to still understand properties of the equations.
link |
00:57:39.200
And I want to understand the properties of equations
link |
00:57:40.800
because I want to be able to try things like electrons.
link |
00:57:43.300
So as you can see,
link |
00:57:44.300
it's just like a two step removed process
link |
00:57:46.200
of trying to get back to reality.
link |
00:57:48.400
So what would you say is the most beautiful property
link |
00:57:50.900
of these Adinkra graphs, objects?
link |
00:57:56.000
What do you think, by the way, the word symbols,
link |
00:57:58.100
what do you think of them, these simple graphs?
link |
00:58:01.600
Are they objects or?
link |
00:58:04.200
How should we think about that?
link |
00:58:06.000
For people who work with mathematics like me,
link |
00:58:08.300
our mathematical concepts are,
link |
00:58:11.500
we often refer to them as objects
link |
00:58:13.000
because they feel like real things.
link |
00:58:15.200
Even though you can't see them or touch them,
link |
00:58:17.800
they're so much part of your interior life
link |
00:58:21.000
that it is as if you could.
link |
00:58:23.700
So we often refer to these things as objects,
link |
00:58:26.000
even though there's nothing objective about them.
link |
00:58:28.400
And what does a single graph represent in space?
link |
00:58:31.600
Okay, so the simplest of these graphs
link |
00:58:34.000
has to have one white ball and one black ball.
link |
00:58:36.600
That's that balance that we talked about earlier.
link |
00:58:38.400
Remember, we want to balance out the quadrants?
link |
00:58:40.200
Well, you can't do it unless you have
link |
00:58:42.200
a black ball and white ball.
link |
00:58:43.800
So the simplest of these objects looks like two little balls,
link |
00:58:46.800
one black, one white, connected by a single line.
link |
00:58:49.400
And what it's talking about is, as I said,
link |
00:58:51.800
a deep mathematical property related to symmetry.
link |
00:58:54.700
You've mentioned the error correcting codes,
link |
00:58:56.300
but is there a particular beautiful property
link |
00:58:58.500
that stands out to you about these objects
link |
00:59:00.400
that you just find?
link |
00:59:01.500
Yes, yes, there is.
link |
00:59:03.100
Early on in the development of it.
link |
00:59:04.400
Yes, there is.
link |
00:59:05.500
The craziest thing about these to me
link |
00:59:10.600
is that when you look at physics
link |
00:59:14.200
and try to write equations where information
link |
00:59:17.000
gets transmitted reliably,
link |
00:59:20.000
if you're in one of these super symmetrical systems
link |
00:59:22.200
with this extra symmetry,
link |
00:59:23.800
that doesn't happen unless there's
link |
00:59:24.900
an error correcting code present.
link |
00:59:26.800
So it's as if the universe says,
link |
00:59:29.100
you don't retransmit information
link |
00:59:31.000
unless there's something about an error correcting code.
link |
00:59:33.200
This to me is the craziest thing
link |
00:59:35.200
that I've ever personally encountered in my research.
link |
00:59:38.300
And it's actually got me to wondering
link |
00:59:41.000
how this could come about,
link |
00:59:42.400
because the only place in nature
link |
00:59:44.500
that we know about error correcting codes is genetics.
link |
00:59:47.500
And in genetics, we think it was evolution
link |
00:59:50.100
that causes error correcting codes to be in genomes.
link |
00:59:53.100
And so does that mean that there was
link |
00:59:54.200
some kind of form of evolution
link |
00:59:55.600
acting on the mathematical laws of the physics
link |
00:59:58.100
of our universe?
link |
00:59:59.400
This is a very bizarre and strange idea.
link |
01:00:01.500
And it's something I've wondered about
link |
01:00:02.500
from time to time since making these discoveries.
link |
01:00:05.300
Do you think such an idea could be fundamental,
link |
01:00:08.100
or is it emergent throughout
link |
01:00:09.700
all the different kinds of systems?
link |
01:00:12.200
I don't know whether it's fundamental.
link |
01:00:15.900
I probably will not live to find out.
link |
01:00:18.100
This is gonna be the work of probably some future
link |
01:00:20.700
either mathematician or physicist
link |
01:00:22.100
to figure out what these things actually mean.
link |
01:00:24.700
We have to talk a bit about the magical,
link |
01:00:27.900
the mysterious string theory, super string theory.
link |
01:00:31.300
Sure.
link |
01:00:32.100
There's still maybe this aspect of it,
link |
01:00:35.300
which is there's still for me
link |
01:00:37.900
from an outsider's perspective,
link |
01:00:39.500
this fascinating heated debate.
link |
01:00:42.000
On the status of string theory.
link |
01:00:44.600
Can you clarify this debate,
link |
01:00:46.600
perhaps articulating the various views
link |
01:00:48.700
and say where you land on it?
link |
01:00:50.700
So first of all, I doubt that I will be able
link |
01:00:53.200
to say anything to clarify the debate
link |
01:00:55.700
around string theory for a general audience.
link |
01:01:01.400
Part of the reason is because string theory
link |
01:01:05.100
has done something I've never seen the erectal physics do.
link |
01:01:08.600
It has broken out into consciousness
link |
01:01:10.800
of the general public before we're finished.
link |
01:01:13.400
You see, string theory doesn't actually exist
link |
01:01:15.800
because when we use the word theory,
link |
01:01:17.100
we mean a particular set of attributes.
link |
01:01:20.100
In particular, it means that you have
link |
01:01:21.500
an overarching paradigm that explains
link |
01:01:23.900
what it is that you're doing.
link |
01:01:25.900
No such overarching paradigm exists for string theory.
link |
01:01:29.900
What string theory is currently
link |
01:01:31.800
is an enormously large mutually reinforcing collection
link |
01:01:35.200
of mathematical facts in which we can find no contradictions.
link |
01:01:39.500
We don't know why it's there,
link |
01:01:41.600
but we can certainly say that without challenge.
link |
01:01:44.700
Now, just because you find a piece of mathematics
link |
01:01:46.500
doesn't mean that this applies to nature.
link |
01:01:49.200
And in fact, there has been a very heated debate
link |
01:01:53.200
about whether string theory is some sort of hysteria
link |
01:01:57.200
among the community of theoretical physicists,
link |
01:02:00.000
or whether it has something fundamental
link |
01:02:01.400
to say about our universe.
link |
01:02:04.400
We don't yet know the answer to that question.
link |
01:02:07.900
What those of us who study string theory
link |
01:02:09.800
will tell you are things like,
link |
01:02:12.300
string theory has been extraordinarily productive
link |
01:02:14.700
in getting us to think more deeply,
link |
01:02:16.600
even about mathematics that's not string theory,
link |
01:02:19.500
but the kind of mathematics
link |
01:02:20.900
that we've used to describe elementary particles.
link |
01:02:23.800
There have been spin offs from string theory,
link |
01:02:25.600
and this has been going on now for two decades almost,
link |
01:02:28.500
that have allowed us, for example,
link |
01:02:31.000
to more accurately calculate the force between electrons
link |
01:02:34.300
with the presence of quantum mechanics.
link |
01:02:36.600
This is not something you hear about in the public.
link |
01:02:39.100
There are other similar things.
link |
01:02:42.600
That kind of property I just told you about
link |
01:02:44.700
is what's called weak strong duality,
link |
01:02:46.700
and it comes directly from string theory.
link |
01:02:48.900
There are other things such as
link |
01:02:53.600
a property called holography,
link |
01:02:55.500
which allows one to take equations
link |
01:02:59.600
and look at them on the boundary of a space,
link |
01:03:01.800
and then to know information about inside a space
link |
01:03:04.000
without actually doing calculations there.
link |
01:03:06.400
This has come directly from string theory.
link |
01:03:08.000
So there are a number of direct mathematical effects
link |
01:03:12.500
that we learn as string theory,
link |
01:03:14.100
but we take these ideas and look at math
link |
01:03:16.500
that we already know and we find suddenly
link |
01:03:18.100
we're more powerful.
link |
01:03:19.400
This is a pretty good indication
link |
01:03:20.700
there's something interesting going on
link |
01:03:22.100
with string theory itself.
link |
01:03:23.100
So it's the early days
link |
01:03:24.300
of a powerful mathematical framework.
link |
01:03:25.900
That's what we have right now.
link |
01:03:27.200
What are the big, first of all,
link |
01:03:30.300
most people will probably, which as you said,
link |
01:03:33.400
most general public would know actually
link |
01:03:35.300
what string theory is, which is at the highest level,
link |
01:03:38.800
which is a fascinating fact.
link |
01:03:41.400
Well, string theory is what they do
link |
01:03:43.000
on the Big Bang Theory, right?
link |
01:03:44.600
One, can you maybe describe what is string theory,
link |
01:03:51.100
and two, what are the open challenges?
link |
01:03:55.000
So what is string theory?
link |
01:03:57.300
Well, the simplest explanation I can provide
link |
01:04:01.800
is to go back and ask what are particles,
link |
01:04:05.900
which is the question you first asked me.
link |
01:04:10.200
What's the smallest thing?
link |
01:04:11.500
Yeah, what's the smallest thing?
link |
01:04:13.800
So particles, one way I try to describe particles
link |
01:04:20.400
to people is start,
link |
01:04:21.500
I want you to imagine a little ball
link |
01:04:24.800
and I want you to let the size of that ball shrink
link |
01:04:26.700
until it has no extent whatsoever,
link |
01:04:28.800
but it still has the mass of the ball.
link |
01:04:32.300
That's actually what Newton was working with
link |
01:04:34.900
when he first invented physics.
link |
01:04:36.300
He's the real inventor of the massive particle,
link |
01:04:39.100
which is this idea that underlies all of physics.
link |
01:04:43.600
So that's where we start.
link |
01:04:44.500
It's a mathematical construct
link |
01:04:46.700
that you get by taking a limit of things that you know.
link |
01:04:51.000
So what's a string?
link |
01:04:51.900
Well, in the same analogy, I would say,
link |
01:04:54.300
now I want you to start with a piece of spaghetti.
link |
01:04:57.300
So we all know what that looks like.
link |
01:04:59.300
And now I want you to let the thickness of the spaghetti
link |
01:05:03.100
shrink until it has no thickness.
link |
01:05:05.700
Mathematically, I mean, in words, this makes no sense,
link |
01:05:08.300
but mathematically, this actually works
link |
01:05:11.300
and you get this mathematical object out.
link |
01:05:13.700
It has properties that are like spaghetti.
link |
01:05:15.700
It can wiggle and jiggle,
link |
01:05:17.400
but it can also move collectively
link |
01:05:19.900
like a piece of spaghetti.
link |
01:05:21.500
It's the mathematics of those sorts of objects
link |
01:05:24.300
that constitute string theory.
link |
01:05:25.900
And does the multidimensional, 11 dimensional,
link |
01:05:30.900
however many dimensional, more than four dimension,
link |
01:05:34.900
is that a crazy idea to you?
link |
01:05:36.900
Is that the stranger aspect of string theory to you?
link |
01:05:40.900
Not really, and also partly because of my own research.
link |
01:05:45.900
So earlier we talked about these strange symbols
link |
01:05:49.500
that we've discovered inside the equations.
link |
01:05:51.900
It turns out that to a very large extent,
link |
01:05:54.100
a Dinkers don't really care about the number of dimensions.
link |
01:05:56.500
They kind of have an internal mathematical consistency
link |
01:05:59.300
that allows them to be manifested
link |
01:06:00.900
in many different dimensions.
link |
01:06:02.900
Since supersymmetry is a part of string theory,
link |
01:06:05.300
then the same property you would expect
link |
01:06:07.300
to be inherited by string theory.
link |
01:06:09.300
However, another little known fact,
link |
01:06:12.300
which is not in the public debate,
link |
01:06:14.100
is that there are actually strings
link |
01:06:15.700
that are only four dimensional.
link |
01:06:17.700
This is something that was discovered
link |
01:06:19.300
at the end of the 80s by a scientist,
link |
01:06:23.300
by three different groups of physicists
link |
01:06:25.300
working independently.
link |
01:06:27.300
I and my friend Warren Siegel,
link |
01:06:29.100
who were at the University of Maryland at the time,
link |
01:06:31.100
were able to prove that there's mathematics
link |
01:06:33.300
that looks totally four dimensional,
link |
01:06:34.500
and yet it's a string.
link |
01:06:36.100
There was a group in Germany
link |
01:06:37.700
that used slightly different mathematics,
link |
01:06:40.300
but they found the same result.
link |
01:06:42.100
And then there was a group at Cornell
link |
01:06:43.900
who using yet a third piece of mathematics
link |
01:06:46.100
found the same result.
link |
01:06:46.900
So the fact that extra dimensions
link |
01:06:49.900
is so widely talked about in the public
link |
01:06:53.700
is partly a function of how the public
link |
01:06:55.700
has come to understand string theory
link |
01:06:57.300
and how the story has been told to them.
link |
01:06:59.500
But there are alternatives you don't know about.
link |
01:07:02.500
If we could talk about maybe experimental validation,
link |
01:07:06.300
and you're the coauthor of a recently published book,
link |
01:07:11.300
Proving Einstein Right,
link |
01:07:14.500
the human story of it too,
link |
01:07:16.300
the daring expeditions that change
link |
01:07:18.100
how we look at the universe.
link |
01:07:19.900
Do you see echoes of the early days
link |
01:07:22.100
of general relativity in the 1910s
link |
01:07:25.700
to the more stretched out to string theory?
link |
01:07:29.900
I do, I do.
link |
01:07:31.100
And that's one reason why I was happy to focus
link |
01:07:33.500
on the story of how Einstein became a global superstar.
link |
01:07:43.700
Earlier in our discussion,
link |
01:07:45.500
we went over his history where in 1915,
link |
01:07:51.100
he came up with this piece of mathematics,
link |
01:07:53.900
used it to do some calculations
link |
01:07:55.700
and then made a prediction.
link |
01:07:57.060
Yes.
link |
01:07:58.020
But making a prediction is not enough.
link |
01:08:00.180
Someone's got to go out and measure.
link |
01:08:02.940
And so string theory is in that in between zone.
link |
01:08:07.020
Now for Einstein, it was from 1915 to 1919.
link |
01:08:09.940
1915 he makes the correct prediction.
link |
01:08:14.380
By the way, he made an incorrect prediction
link |
01:08:16.420
about the same thing in 1911,
link |
01:08:17.780
but he corrected himself in 1915.
link |
01:08:20.340
And by 1919, the first pieces
link |
01:08:22.420
of experimental observational data became available
link |
01:08:27.620
to say, yes, he's not wrong.
link |
01:08:31.020
And by 1922, the argument that based on observation
link |
01:08:35.940
was overwhelming that he was not wrong.
link |
01:08:38.500
Can you describe what special general relativity are
link |
01:08:41.860
just briefly?
link |
01:08:42.700
Sure.
link |
01:08:43.540
And what prediction Einstein made
link |
01:08:45.580
and maybe some or a memorable moment
link |
01:08:52.580
from the human journey of trying to prove this thing right,
link |
01:08:56.980
which is incredible.
link |
01:08:58.060
Right.
link |
01:08:58.900
So I'm very fortunate to have worked
link |
01:09:02.580
with a talented novelist who wanted to write a book
link |
01:09:07.820
that coincided with a book I wanted to write
link |
01:09:09.740
about how science kind of feels if you're a person,
link |
01:09:14.900
because it's actually people who do science,
link |
01:09:17.140
even though that may not be obvious to everyone.
link |
01:09:20.780
So for me, I wanted to write this book
link |
01:09:22.660
for a couple of reasons.
link |
01:09:23.660
I wanted young people to understand
link |
01:09:26.460
that the seeming alien giants that live before them
link |
01:09:32.180
were just as human as they are.
link |
01:09:34.060
They get married, they get divorced.
link |
01:09:35.780
They get married, they get divorced.
link |
01:09:37.100
They do terrible things.
link |
01:09:38.500
They do great things.
link |
01:09:39.580
They're people.
link |
01:09:40.420
They're just people like you.
link |
01:09:42.180
And so that part of telling the story allowed me
link |
01:09:44.420
to get that out there for both young people interested
link |
01:09:47.020
in the sciences as well as the public.
link |
01:09:49.540
But the other part of the story is I wanted to open up
link |
01:09:54.180
sort of what it was like.
link |
01:09:58.580
Now I'm a scientist.
link |
01:10:00.460
And so I will not pretend to be a great writer.
link |
01:10:02.660
I understand a lot about mathematics
link |
01:10:04.700
and I've even created my own mathematics
link |
01:10:07.100
that is kind of a weird thing to be able to do.
link |
01:10:11.980
But in order to tell the story,
link |
01:10:13.980
you really have to have an incredible master
link |
01:10:18.100
of the narrative.
link |
01:10:19.900
And that was my coauthor, Kathy Pelletier,
link |
01:10:22.540
who is a novelist.
link |
01:10:24.060
So we formed this conjoined brain, I used to call us.
link |
01:10:27.620
She used to call us Professor Higgins and Eliza Doolittle.
link |
01:10:30.100
My expression for us is that we were a conjoined brain
link |
01:10:33.220
to tell this story.
link |
01:10:34.980
And it allowed, so what are some magical moments?
link |
01:10:39.740
To me, the first magical moment in telling the story
link |
01:10:43.900
was looking at Albert Einstein and his struggle
link |
01:10:48.460
because although we regard him as a genius,
link |
01:10:51.700
as I said, in 1911, he actually made an incorrect prediction
link |
01:10:54.460
about bending starlight.
link |
01:10:55.660
And that's actually what set the astronomers off.
link |
01:10:59.780
In 1914, there was an eclipse.
link |
01:11:02.220
And by various accidents of war and weather
link |
01:11:06.220
and all sorts of things that we talk about in the book,
link |
01:11:08.860
no one was able to make the measurement.
link |
01:11:11.100
If they had made the measurement,
link |
01:11:13.580
it would have disagreed with his 1911 prediction
link |
01:11:19.460
because nature only has one answer.
link |
01:11:22.020
And so then you see how fortunate he was
link |
01:11:26.020
that wars and bad weather and accidents and transporting
link |
01:11:32.740
equipment stopped any measurements from being made.
link |
01:11:35.860
So he corrects himself in 1915,
link |
01:11:38.780
but the astronomers are already out there
link |
01:11:40.180
trying to make the measurement.
link |
01:11:41.700
So now he gives them a different number.
link |
01:11:43.460
And it turns out that's the number that nature agrees with.
link |
01:11:46.620
So it gives you a sense of this is a person struggling
link |
01:11:50.540
with something deeply.
link |
01:11:52.180
And although his deep insight led him to this,
link |
01:11:56.860
it is the circumstance of time, place and accident
link |
01:12:01.260
but through which we view him.
link |
01:12:03.740
And the story could have turned out very differently
link |
01:12:06.980
where first he makes a prediction,
link |
01:12:09.620
the measurements are made in 1914,
link |
01:12:11.900
they disagree with his prediction.
link |
01:12:13.580
And so what would the world view him as?
link |
01:12:15.620
Well, he's this professor who made this prediction
link |
01:12:17.540
that didn't get it right, yes?
link |
01:12:20.540
So the fragility of human history
link |
01:12:26.220
is illustrated by that story.
link |
01:12:27.620
And it's one of my favorite things.
link |
01:12:29.540
You also learn things like in our book,
link |
01:12:32.460
how eclipses and watching eclipses was a driver
link |
01:12:36.180
of the development of science in our nation
link |
01:12:37.940
when it was very young.
link |
01:12:38.780
In fact, even before we were a nation,
link |
01:12:40.620
it turns out there were citizens of this would be country
link |
01:12:47.180
that were going out trying to measure eclipses.
link |
01:12:50.580
So some fortune, some misfortune affects
link |
01:12:54.820
the progress of science.
link |
01:12:56.740
Absolutely.
link |
01:12:57.660
Especially with ideas as, to me at least,
link |
01:13:01.740
if I put myself back in those days,
link |
01:13:03.620
as radical as general relativity is.
link |
01:13:08.380
First, can you describe, if it's OK briefly,
link |
01:13:12.100
what general relativity is?
link |
01:13:14.180
And yeah, could you just take a moment of, yeah,
link |
01:13:18.500
put yourself in those shoes in the academic researchers,
link |
01:13:22.460
scientists of that time, and what is this theory?
link |
01:13:25.180
What is it trying to describe about our world?
link |
01:13:28.660
It's trying to answer the thing that left Isaac Newton puzzled.
link |
01:13:37.620
Isaac Newton says gravity magically
link |
01:13:39.740
goes from one place to another.
link |
01:13:41.700
He doesn't believe it, by the way.
link |
01:13:43.300
He knows that's not right.
link |
01:13:45.340
But the mathematics is so good that you have to say,
link |
01:13:48.220
well, I'll throw my qualms away because I'll use it.
link |
01:13:52.020
That's all we used to get a man from the Earth to the moon
link |
01:13:55.020
was that mathematics.
link |
01:13:58.420
So I'm one of those scientists, and I've seen this.
link |
01:14:03.460
And if I thought deeply about it,
link |
01:14:04.860
maybe I know that Newton himself wasn't comfortable.
link |
01:14:08.700
And so the first thing I would hope that I would feel
link |
01:14:11.100
is, gee, there's this young kid out there who
link |
01:14:13.300
has an idea to fill in this hole that was left with us
link |
01:14:17.820
by Sir Isaac Newton.
link |
01:14:19.780
That, I hope, would be my reaction.
link |
01:14:23.100
I have a suspicion.
link |
01:14:24.820
I'm kind of a mathematical creature.
link |
01:14:29.020
I was four years old when I first
link |
01:14:30.300
decided that science was what I wanted to do with my life.
link |
01:14:33.700
And so if my personality back then was like it is now,
link |
01:14:38.820
I think it's probably likely I would
link |
01:14:41.180
want to have studied his mathematics.
link |
01:14:43.620
What was a piece of mathematics that he was
link |
01:14:45.380
using to make this prediction?
link |
01:14:47.660
Because he didn't actually create that mathematics.
link |
01:14:50.060
That mathematics was created roughly 50 years
link |
01:14:52.180
before he lived.
link |
01:14:53.300
He's the person who harnessed it in order
link |
01:14:56.420
to make a prediction.
link |
01:14:57.260
In fact, he had to be taught this mathematics by a friend.
link |
01:15:00.780
So this is in our book.
link |
01:15:03.700
So putting myself in that time, I would want to, like I said,
link |
01:15:08.140
I think I would feel excitement.
link |
01:15:09.340
I would want to know what the mathematics is.
link |
01:15:10.900
And then I would want to do the calculations myself.
link |
01:15:13.580
Because one thing that physics is all about
link |
01:15:16.660
is that you don't have to take anybody's word for anything.
link |
01:15:19.420
You can do it yourself.
link |
01:15:20.980
It does seem that mathematics is a little bit more
link |
01:15:23.060
tolerant of radical ideas, or mathematicians,
link |
01:15:25.540
or people who find beauty in mathematics.
link |
01:15:31.780
All the white questions have no good answer.
link |
01:15:33.620
But let me ask, why do you think Einstein never
link |
01:15:35.860
got the Nobel Prize for general relativity?
link |
01:15:38.540
He got it for the photoelectric effect.
link |
01:15:40.260
That is correct.
link |
01:15:41.020
Well, first of all, that's something
link |
01:15:42.860
that is misunderstood about the Nobel Prize in physics.
link |
01:15:46.060
The Nobel Prize in physics is never
link |
01:15:48.620
given for purely proposing an idea.
link |
01:15:54.060
It is always given for proposing an idea that
link |
01:15:57.420
has observational support.
link |
01:15:59.700
So he could not get the Nobel Prize
link |
01:16:02.340
for either special relativity nor general relativity,
link |
01:16:05.300
because the provisions that Alfred Nobel left for the award
link |
01:16:08.700
prevent that.
link |
01:16:11.060
But after it's been validated, can he not get it then, or no?
link |
01:16:16.100
Yes, but remember the validation doesn't really
link |
01:16:19.540
come until the 1920s.
link |
01:16:21.820
But that's why they invented the second Nobel Prize.
link |
01:16:24.500
I mean, Marie Curie, you can get a second Nobel Prize
link |
01:16:28.140
for one of the greatest theories in physics.
link |
01:16:31.540
So let's be clear on this.
link |
01:16:33.740
The theory of general relativity had its critics
link |
01:16:39.780
even up until the 50s.
link |
01:16:43.020
So if the committee had wanted to give
link |
01:16:47.820
the prize for general relativity,
link |
01:16:50.300
there were vociferous critics of general relativity
link |
01:16:54.180
up until the 50s.
link |
01:16:56.740
Einstein died in 1955.
link |
01:16:59.740
What lessons do you draw from the story you tell in the book,
link |
01:17:04.300
from general relativity, from the radical nature
link |
01:17:07.060
of the theory, to looking at the future of string theory?
link |
01:17:12.900
Well, I think that the string theorists are probably
link |
01:17:14.980
going to retrace this path.
link |
01:17:17.900
But it's going to be far longer and more torturous,
link |
01:17:20.020
in my opinion.
link |
01:17:22.140
String theory is such a broad and deep development
link |
01:17:29.140
that, in my opinion, when it becomes acceptable,
link |
01:17:34.180
it's going to be because of a confluence of observations.
link |
01:17:38.060
It's not going to be a single observation.
link |
01:17:40.620
And I have to tell you that, so I gave a seminar here
link |
01:17:44.620
yesterday at MIT.
link |
01:17:46.500
And it's on an idea I have about how string theory can
link |
01:17:50.860
leave signatures in the cosmic microwave background, which
link |
01:17:53.980
is an astrophysical structure.
link |
01:17:56.860
And so if those kinds of observations are borne out,
link |
01:18:01.580
if perhaps other things related to the idea of supersymmetry
link |
01:18:05.580
are borne out, those are going to be the first powerful
link |
01:18:08.900
observationally based pieces of evidence that
link |
01:18:12.340
will begin to do what the Eddington expedition did
link |
01:18:18.060
in 1919.
link |
01:18:19.620
But that may take several decades.
link |
01:18:22.900
Do you think there will be Nobel prizes given
link |
01:18:25.060
for string theory?
link |
01:18:26.220
No, because I think it will exceed normal human lifetimes.
link |
01:18:34.980
But there are other prizes that are given.
link |
01:18:38.140
I mean, there is something called the Breakthrough Prize.
link |
01:18:42.220
There's a Russian immigrant, a Russian American immigrant
link |
01:18:45.020
named Yuri Milner, I believe his name,
link |
01:18:48.420
started this wonderful prize called the Breakthrough Prize.
link |
01:18:53.020
It's three times as much money as the Nobel Prize.
link |
01:18:56.100
And it gets awarded every year.
link |
01:18:58.100
And so something like one of those prizes
link |
01:19:00.300
is likely to be garnered at some point far earlier
link |
01:19:04.020
than a Nobel award.
link |
01:19:07.660
Jumping around a few topics.
link |
01:19:09.780
While you were at Caltech, you've
link |
01:19:11.900
gotten to interact, I believe, with Richard Feynman,
link |
01:19:15.340
I have to ask.
link |
01:19:16.300
Yes, Richard Feynman, indeed.
link |
01:19:19.100
Do you have any stories that stand out
link |
01:19:20.540
in your memory of that time?
link |
01:19:21.660
I have a fair number of stories, but I'm not
link |
01:19:23.660
prepared to tell them.
link |
01:19:24.980
They're not all politically correct.
link |
01:19:26.820
Let me see.
link |
01:19:28.620
Let me just say, I'll say the following.
link |
01:19:31.060
Richard Feynman, if you've ever read
link |
01:19:33.980
some of the books about him, in particular,
link |
01:19:36.420
there's a book called Surely You're Joking, Mr. Feynman.
link |
01:19:38.980
There's a series of books that starts with Surely You're
link |
01:19:42.140
Joking, Mr. Feynman.
link |
01:19:43.180
And I think the second one may be something like What Do You
link |
01:19:45.760
Care What They Say or something.
link |
01:19:47.260
I mean, the titles are all, there are three of them.
link |
01:19:49.620
When I read those books, I was amazed at how accurately
link |
01:19:53.820
those books portrayed the man that I interacted with.
link |
01:19:57.180
He was irreverent, he was fun, he was deeply intelligent,
link |
01:20:01.620
he was deeply human.
link |
01:20:03.620
And those books tell that story very effectively.
link |
01:20:07.300
Even just those moments, how did they
link |
01:20:09.540
affect you as a physicist?
link |
01:20:12.100
Well, one of the, well, it's funny because one
link |
01:20:15.380
of the things that, I didn't hear Feynman say this,
link |
01:20:20.460
but one of the things that is reported that he said
link |
01:20:25.580
is if you're in a bar stool as a physicist,
link |
01:20:29.600
and you can't explain to the guy on the bar stool
link |
01:20:31.740
next to you what you're doing, you
link |
01:20:33.060
don't understand what you're doing.
link |
01:20:35.660
And there's a lot of that that I think is correct,
link |
01:20:40.580
that when you truly understand something as complicated
link |
01:20:47.580
as string theory, when it's in its fully formed final
link |
01:20:53.700
development, it should be something
link |
01:20:55.620
you could tell to the person on the bar stool next to you.
link |
01:20:58.980
And that's something that affects the way I do science,
link |
01:21:03.300
quite frankly.
link |
01:21:04.900
It also affects the way I talk to the public about science.
link |
01:21:08.180
It's one of my mantras that I keep deeply,
link |
01:21:11.460
and try to keep deeply before me when I appear in public fora
link |
01:21:15.980
speaking about physics in particular and science
link |
01:21:20.020
in general.
link |
01:21:21.060
It's also something that Einstein
link |
01:21:22.460
said in a different way.
link |
01:21:23.580
He said he had these two different formulations.
link |
01:21:27.200
One of them is when the answer is simple, it's God speaking.
link |
01:21:31.820
And the other thing that he said was
link |
01:21:33.700
that what he did in his work was simply
link |
01:21:37.580
the distillation of common sense,
link |
01:21:40.620
that you distill down to something.
link |
01:21:43.620
And he also said you make things as simple as possible
link |
01:21:45.940
but no simpler.
link |
01:21:47.860
So all of those things, and certainly this attitude for me
link |
01:21:50.820
first seeing this was exemplified
link |
01:21:53.380
by being around Richard Feynman.
link |
01:21:55.260
So in all your work, you're always
link |
01:21:56.900
searching for the simplicity, for the simple, clear.
link |
01:21:59.220
I am, ultimately.
link |
01:22:00.140
Ultimately, I am.
link |
01:22:01.980
You served President Barack Obama's Council of Advisors
link |
01:22:05.660
in Science and Technology.
link |
01:22:07.660
For seven years, yes.
link |
01:22:08.700
For seven years with Eric Schmidt
link |
01:22:11.260
and several other brilliant people?
link |
01:22:13.380
Met Eric for the first time in 2009
link |
01:22:17.580
when the council was called together.
link |
01:22:19.820
Yeah, I've seen pictures of you in that room.
link |
01:22:21.420
I mean, there's a bunch of brilliant people.
link |
01:22:23.020
It kind of looks amazing.
link |
01:22:24.420
What was that experience like, being called
link |
01:22:27.340
upon that kind of service?
link |
01:22:29.300
So let me go back to my father, first of all.
link |
01:22:31.580
I earlier mentioned that my father served 27 years
link |
01:22:34.020
in the US Army, starting in World War II.
link |
01:22:37.020
He went off in 1942, 43 to fight against the fascists.
link |
01:22:42.820
He was part of the supply corps that
link |
01:22:45.380
supplied General Patton as the tanks rolled
link |
01:22:47.580
across Western Europe, pushing back the forces of Nazism
link |
01:22:51.860
to meet up with our Russian comrades
link |
01:22:54.980
who were pushing the Nazis starting in Stalingrad.
link |
01:22:59.620
And the Second World War is actually
link |
01:23:02.420
a very interesting piece of history
link |
01:23:06.060
to know from both sides.
link |
01:23:08.460
Here in America, we typically don't.
link |
01:23:09.980
But I've actually studied history as an adult.
link |
01:23:12.500
So I actually know sort of the whole story.
link |
01:23:14.500
And on the Russian side, we don't know the Americans.
link |
01:23:16.860
We weren't taught the American side of the story.
link |
01:23:19.260
I know.
link |
01:23:20.020
I have many Russian friends, and we've
link |
01:23:22.820
had this conversation on many occasions.
link |
01:23:24.420
It's fascinating.
link |
01:23:25.140
But you know, like General Zhukov, for example,
link |
01:23:27.260
was something that you wouldn't know about,
link |
01:23:28.620
but you might not know about a Patton.
link |
01:23:30.100
But you're right.
link |
01:23:30.860
So Georgy Zhukov or Rokossovsky, I mean,
link |
01:23:34.980
there's a whole list of names that I've
link |
01:23:36.820
learned in the last 15 or 20 years looking
link |
01:23:39.180
at the Second World War.
link |
01:23:41.020
So your father was in the midst of that,
link |
01:23:44.340
probably one of the greatest wars in history.
link |
01:23:46.500
In the history of our species.
link |
01:23:49.860
And so the idea of service comes to me essentially
link |
01:23:54.540
from that example.
link |
01:23:57.660
So in 2009, when I first got a call from a Nobel laureate
link |
01:24:06.020
actually in biology, Harold Varmus,
link |
01:24:09.940
I was on my way to India, and I got this email message,
link |
01:24:13.660
and he said he needed to talk to me.
link |
01:24:15.580
And I said, OK, fine, we can talk.
link |
01:24:18.140
Got back to States I didn't hear from him.
link |
01:24:20.180
We went through several cycles of this, sending me a message,
link |
01:24:22.300
I want to talk to you, and then him never contacting us.
link |
01:24:24.860
Finally, I was on my way to give a physics presentation
link |
01:24:28.180
at the University of Florida in Gainesville,
link |
01:24:29.860
and Jess had stepped off a plane,
link |
01:24:34.700
and my mobile phone went off, and it was Harold.
link |
01:24:37.180
And so I said, Harold, why do you keep sending me messages
link |
01:24:40.460
that you want to talk but you never call?
link |
01:24:43.180
And he said, well, I'm sorry, things have been hectic
link |
01:24:45.380
and da, da, da, da, da.
link |
01:24:47.340
And then he said, if you were offered the opportunity
link |
01:24:51.020
to serve on the US President's Council of Advisors
link |
01:24:55.180
on Science and Technology, what would be your answer?
link |
01:24:59.420
I was amused at the formulation of the question,
link |
01:25:02.500
because it's clear there's a purpose of why the question is
link |
01:25:06.060
asked that way.
link |
01:25:07.540
But then he made it clear to me he wasn't joking.
link |
01:25:12.500
And literally, one of the few times in my life,
link |
01:25:15.220
my knees went weak and I had to hold myself up
link |
01:25:19.020
against a wall so that I didn't fall over.
link |
01:25:23.100
I doubt if most of us who have been the beneficiaries
link |
01:25:28.300
of the benefits of this country,
link |
01:25:31.220
when given that kind of opportunity, could say no.
link |
01:25:34.900
And I know I certainly couldn't say no.
link |
01:25:37.820
I was frightened out of my wits because I had never,
link |
01:25:43.700
although I have, my career in terms of policy recommendations
link |
01:25:50.820
is actually quite long, it goes back to the 80s,
link |
01:25:52.620
but I had never been called upon to serve as an advisor
link |
01:25:57.620
to a president of the United States.
link |
01:26:00.780
And it was very scary, but I did not feel that I could say no
link |
01:26:06.780
because I wouldn't be able to sleep with myself at night
link |
01:26:10.420
saying that I chickened out or whatever.
link |
01:26:14.740
And so I took the plunge and we had a pretty good run.
link |
01:26:19.180
There are things that I did in those seven years
link |
01:26:23.180
of which I'm extraordinarily proud.
link |
01:26:28.380
One of the ways I tell people is if you've ever seen
link |
01:26:30.660
that television cartoon called Schoolhouse Rock,
link |
01:26:34.100
there's this one story about how a bill becomes a law.
link |
01:26:37.140
And I've kind of lived that.
link |
01:26:38.540
There are things that I did
link |
01:26:41.060
that have now been codified in US law.
link |
01:26:44.620
Not everybody gets a chance to do things like that in life.
link |
01:26:47.820
What do you think is the, science and technology,
link |
01:26:50.660
especially in American politics,
link |
01:26:53.780
we haven't had a president who's an engineer or a scientist.
link |
01:26:58.300
What do you think is the role of a president like President Obama
link |
01:27:01.660
in understanding the latest ideas in science and tech?
link |
01:27:05.500
What was that experience like?
link |
01:27:06.820
Well, first of all, I've met other presidents
link |
01:27:09.660
beside President Obama.
link |
01:27:10.820
He is the most extraordinary president
link |
01:27:12.740
that I've ever encountered.
link |
01:27:15.220
Despite the fact that he went to Harvard.
link |
01:27:18.180
When I think about President Obama,
link |
01:27:21.300
he is a deep mystery to me.
link |
01:27:23.540
In the same way perhaps that the universe is a mystery.
link |
01:27:27.180
I don't really understand how that constellation
link |
01:27:29.780
of personality traits could come to fit
link |
01:27:34.020
within a single individual.
link |
01:27:35.700
But I saw them for seven years.
link |
01:27:38.060
So I'm convinced that I wasn't seeing fake news.
link |
01:27:41.140
I was seeing real data.
link |
01:27:42.620
He was just an extraordinary man.
link |
01:27:44.780
And one of the things that was completely clear
link |
01:27:48.620
was that he was not afraid and not intimidated
link |
01:27:55.620
to be in a room of really smart people.
link |
01:27:58.260
I mean, really smart people.
link |
01:28:00.900
That he was completely comfortable in asking
link |
01:28:06.380
some of the world's greatest experts,
link |
01:28:07.940
what do I do about this problem?
link |
01:28:09.860
And it wasn't that he was going to just take the problem
link |
01:28:12.500
and it wasn't that he was going to just take their answer,
link |
01:28:15.460
but he would listen to the advice.
link |
01:28:18.340
And that to me was extraordinary.
link |
01:28:21.060
As I said, I've been around other executives
link |
01:28:23.020
and I've never seen one quite like him.
link |
01:28:27.020
He's an extraordinary learner, is what I observed.
link |
01:28:30.260
And not just about science.
link |
01:28:32.940
He has a way of internalizing information in real time
link |
01:28:36.700
that I've never seen in a politician before.
link |
01:28:39.100
Even in extraordinarily complicated situations.
link |
01:28:42.460
Even scientific ideas.
link |
01:28:43.700
Scientific or non scientific.
link |
01:28:45.060
Complicated ideas don't have to be scientific ideas.
link |
01:28:47.900
But I have, like I said, seen him in real time
link |
01:28:50.100
process complicated ideas with a speed that was stunning.
link |
01:28:54.060
In fact, he shocked the entire council.
link |
01:28:56.340
I mean, we were all stunned at his capacity
link |
01:29:01.260
to be presented with complicated ideas
link |
01:29:06.180
and then to wrestle with them and internalize them.
link |
01:29:08.580
And then come back, more interestingly enough,
link |
01:29:11.380
come back with really good questions to ask.
link |
01:29:14.020
I've noticed this in an area that I understand more
link |
01:29:17.140
of artificial intelligence.
link |
01:29:19.220
I've seen him integrate information
link |
01:29:21.740
about artificial intelligence and then come out
link |
01:29:24.100
with these kind of Richard Feynman like insights.
link |
01:29:27.340
That's exactly right.
link |
01:29:28.260
And as I said, those of us who have been in that position,
link |
01:29:32.380
it is stunning to see it happen because you don't expect it.
link |
01:29:35.940
Yeah, he takes what, for a lot of sort of graduate students,
link |
01:29:40.180
takes like four years in a particular topic
link |
01:29:42.220
and he just does it in a few minutes.
link |
01:29:43.900
He sees it very naturally.
link |
01:29:46.380
You've mentioned that you would love
link |
01:29:47.780
to see experimental validation of super strength theory
link |
01:29:51.820
before you shove.
link |
01:29:53.060
Before I shuffle off this mortal coil.
link |
01:29:56.260
Which the poetry of that reference
link |
01:29:58.180
made me smile when I saw it.
link |
01:30:00.380
You know, people actually misunderstand it
link |
01:30:02.180
because it's not what, it doesn't mean
link |
01:30:03.940
what we generally take it to mean colloquially.
link |
01:30:06.620
But it's such a beautiful expression.
link |
01:30:08.300
Yeah, it is.
link |
01:30:09.140
It's from the Hamlet, to be or not to be speech.
link |
01:30:13.780
Which I still don't understand what that's about.
link |
01:30:15.460
But so many interpretations.
link |
01:30:18.620
Anyway, what are the most exciting problems in physics
link |
01:30:22.700
that are just within our reach of understanding
link |
01:30:25.260
and maybe solve the next few decades
link |
01:30:27.340
that you may be able to see?
link |
01:30:29.140
So in physics, you limited it to physics.
link |
01:30:32.780
Physics, mathematics, this kind of space of problems
link |
01:30:36.380
that fascinate you.
link |
01:30:39.140
Well, the one that looks on the immediate horizon
link |
01:30:41.660
like we're gonna get to is quantum computing.
link |
01:30:45.340
And that's gonna, if we actually get there,
link |
01:30:47.540
that's gonna be extraordinarily interesting.
link |
01:30:50.540
Do you think that's a fundamentally problem of theory
link |
01:30:53.980
or is it now in the space of engineering?
link |
01:30:55.860
It's in the space of engineering.
link |
01:30:57.020
I was out at a Q station, as you may know,
link |
01:31:01.340
Microsoft has this research facility in Santa Barbara.
link |
01:31:06.780
I was out there a couple of months in my capacity
link |
01:31:09.740
as a vice president of American Physical Society.
link |
01:31:12.500
And I had some things that were like lectures
link |
01:31:15.660
and they were telling me what they were doing.
link |
01:31:18.260
And it sure sounded like they knew what they were doing
link |
01:31:20.380
and that they were close to major breakthroughs.
link |
01:31:24.140
Yeah, that's a really exciting possibility there.
link |
01:31:26.420
But back to Hamlet, do you ponder mortality,
link |
01:31:31.460
your own mortality?
link |
01:31:32.660
Nope, my mother died when I was 11 years old.
link |
01:31:35.940
And so I immediately knew what the end of the story was
link |
01:31:41.220
for all of us.
link |
01:31:42.580
As a consequence, I've never spent a lot of time
link |
01:31:45.660
thinking about death.
link |
01:31:47.700
It'll come in its own good time.
link |
01:31:49.940
And sort of to me, the job of every human
link |
01:31:54.220
is to make the best and the most of the time
link |
01:31:56.460
that's given to us in order not for our own selfish gain,
link |
01:32:02.340
but to try to make this place a better place
link |
01:32:04.780
for someone else.
link |
01:32:08.740
And on the why of life, why do you think we are?
link |
01:32:13.460
I have no idea and I never even worried about it.
link |
01:32:17.460
For me, I have an answer, a local answer.
link |
01:32:20.900
The apparent why for me was
link |
01:32:22.460
because I'm supposed to do physics.
link |
01:32:25.020
But it's funny because there's so many other
link |
01:32:29.460
quantum mechanically speaking possibilities in your life,
link |
01:32:33.220
such as being an astronaut, for example.
link |
01:32:35.500
So you know about that, I see.
link |
01:32:36.980
Well, like Einstein and the vicissitudes
link |
01:32:45.740
that prevented the 1914 measurement of starlight vending,
link |
01:32:50.740
the universe is constructed in such a way
link |
01:32:53.740
that I didn't become an astronaut, which would have,
link |
01:32:56.020
for me, I would have faced the worst choice in my life,
link |
01:33:00.020
whether I would try to become an astronaut
link |
01:33:04.540
or whether I would try to do theoretical physics.
link |
01:33:07.420
Both of these dreams were born
link |
01:33:09.140
when I was four years old simultaneously.
link |
01:33:11.660
And so I can't imagine how difficult
link |
01:33:14.700
that decision would have been.
link |
01:33:16.980
The universe helped you out on that one.
link |
01:33:19.540
Not only in that one, but in many ones.
link |
01:33:21.780
It helped me out by allowing me to pick the right dad.
link |
01:33:25.380
Is there a day in your life you could relive
link |
01:33:27.900
because it made you truly happy?
link |
01:33:29.740
What day would that be if you could just look back?
link |
01:33:32.700
Being a theoretical physicist
link |
01:33:35.460
is like having Christmas every day.
link |
01:33:39.020
I have lots of joy in my life.
link |
01:33:43.180
The moments of invention, the moments of ideas, revelation.
link |
01:33:46.940
Yes, the only thing that exceed them are
link |
01:33:49.900
some family experiences like when my kids were born
link |
01:33:53.060
and that kind of stuff, but they're pretty high up there.
link |
01:33:57.900
Well, I don't see a better way to end it, Jim.
link |
01:34:00.540
Thank you so much.
link |
01:34:01.380
It was a huge honor talking to you today.
link |
01:34:03.300
This worked out better than I thought.
link |
01:34:05.340
I'm glad to hear it.
link |
01:34:35.540
And now, let me leave you with some words of wisdom
link |
01:34:38.300
from the great Albert Einstein for the rebels among us.
link |
01:34:42.780
Unthinking respect for authority
link |
01:34:45.020
is the greatest enemy of truth.
link |
01:34:48.140
Thank you for listening and hope to see you next time.