Placeholder Image

字幕表 動画を再生する

  • >>NEIL DEGRASSE TYSON: Welcome back. This is the 17th Annual Isaac Asimov Panel Debate.

  • And weve been going strong ever since the year 2000,

  • when an idea surfaced in the hearts and minds of the family of Isaac Asimov, exploring a

  • way for his

  • memory to be preserved in the programs of this institution. And Isaac Asimov was a friend

  • of the American Museum of Natural History.

  • Much of the research for so many of the books that he wrote took place in and around the

  • halls and in our libraries. And so perhaps there’s no more fitting

  • tribute to him and to his memory, than to keep this celebration going. So, thank you

  • for attending.

  • We are also streaming live on the Internet. And I’m your host for this evening, Neil

  • deGrasse Tyson. I’m the Frederick P. Rose director of the Hayden Planetarium.

  • [applause]

  • Just a couple of newsy notes.

  • This year we sold out in three minutes. And it’s not a particularly sustainable model.

  • So, were going to have top people looking at how to improve that next year.

  • We don’t know how yet, but the least we can do is offer it live streamed on the Internet

  • on amnh.org. So, I welcome everyone

  • from the Internet universe, as well as the universe gathered here.

  • Tonight’s topic is: Is the Universe a Computer Simulation? Yeah.

  • [laughter]

  • Do you want it to be a computer simulation?

  • I mean, this topic iswere going toyoull see.

  • Weve got some highly thoughtful, talented,

  • respected people to weigh in on this. I will introduce them individually, and then we will

  • start the panel.

  • By the way, unlike most debates you might have heard about or read about, where there’s

  • point/counterpoint and an argument is presented and attacked,

  • that’s not what’s going to happen here. Were using the word debate loosely. Think

  • of yourself as eavesdropping

  • on scientists at a break-out room in a conference on this topic. So, well all be sort of

  • arguing with one another, and youre listening in. That’s really what’s going on here.

  • And you get to see how scientists think. You get to see how arguments are contested.

  • You get to see how resolution arrives, if it arrives at all.

  • So, afterwards we will have a brief time for question and answer before we adjourn before

  • 9:00 Eastern time zoneEastern daylight time.

  • So, join me in welcoming my first panelist this evening. He is a professor of philosophy

  • at New York University, where he’s also director of the Center for Mind, Brain and

  • Consciousness, David Chalmers. David, come on out.

  • [applause]

  • >>DAVID CHALMERS: Hey. Looking forward to this.

  • >>NEIL DEGRASSE TYSON: Thank you. Next we have a nuclear physicist, who’s a post-doctoral

  • research associate at MIT

  • up in Cambridge, Massachusetts. And let’s give a warm welcome to Zohreh Davoudi. Zohreh.

  • [applause]

  • Next, we have someone who is actually no stranger to this panel. This may be his third visit

  • to it. In part, the topic of this year

  • was selected because he brought it up a couple of years ago. And I said, man, we could do

  • a whole subject on that alone.

  • Let’s give a warm welcome back to James Sylvester Gates.

  • [applause]

  • Another non-first timer is professor of physics up at Harvard,

  • a specialist in nuclear particle physics. Give a warm New York welcome to one of our

  • own,

  • a graduate of Stuyvesant High School, Lisa Randall.

  • [applause]

  • Did I do this out of order? No, we didn’t. Good.

  • And last among the fiveyeah, I did do it out of order. My bad. Yeah, sorry. You guys

  • know where you need to sit. Talk among yourselves while I do this.

  • There’s a friend and colleague, an astrophysicist, also from MIT,

  • who’s done some deep thinking about this very subject and has even written a book on

  • the topic.

  • Let’s give a warm New York welcome to Max Tegmark.

  • [applause]

  • [technical difficulties]

  • How about now? There we go.

  • Oh, by the way, we are lit for live streaming. And the intensity of the lights on the stage

  • is such that

  • two of our panelists—I think they just want to look cool, but they said they need to wear

  • sunglasses for this event. And that’s cool. Later on I might join you. I brought my pair

  • with me as well.

  • If I’m feeling cool I might do just that.

  • So, Zohreh, I’d like to start withno. who should I start with here? Yes, let me

  • start with you, Zohreh.

  • Could you tell me why this topic interests you? Just give a couple of minutes just as

  • an introduction here.

  • >>ZOHREH DAVOUDI: Sure. So, as Neil said, I’m a theoretical physicist.

  • My interest is in nuclear physics. In fact, I got my PhD in 2014 from Institute of Nuclear

  • Theory in University of Washington.

  • And the research I was focused on there, and at the moment, is trying to use the knowledge

  • of the laws of nature and,

  • in particular, strong interactions to start from a bottom-up approach and try to see what

  • comes out in a physical system.

  • And that’s actually relevant to why I got interested in the simulation idea. And, in

  • fact,

  • by just watching the progress that researchers in this field of simulating a strong interactions

  • have made in several past few years,

  • we started to wonder how could we not think about the universe itself based on the laws

  • that weve discovered not simulated.

  • So, that the way that we actually simulate the universe, it might actually give us hints

  • that the universe itself could be a numerical simulation. And then

  • you would start thinking, well, let’s make assumption that if that scenario is the case,

  • and if that simulation is actuallyhas similarities with what we do in our research

  • and just drawing parallels between our algorithms and techniques that we use to simulate laws

  • of nature, and making assumption that they are similar,

  • then what can we actually conclude about the universe as a simulation.

  • Can we actually make predictions for the signatures that we should go after and test?

  • So, that’s that approach we took. And it was a fun idea and fun paper became of it

  • with my collaborators Martin Savage and Silas Beane at the University of Washington.

  • And that’s basically why I’m here. I’m trying to

  • >>NEIL DEGRASSE TYSON: So, the prospect of this being true didn’t freak you out at

  • all?

  • >>ZOHREH DAVOUDI: No, I think it’s a fun idea.

  • >>NEIL DEGRASSE TYSON: Okay. Just it’s fun for you?

  • >>ZOHREH DAVOUDI: Yes.

  • >>NEIL DEGRASSE TYSON: Okay. Fine. So, Max, youve got a book on this, too, right? So,

  • what’s going on with you?

  • >>MAX TEGMARK: Yeah. Well, already as a kid I was always very fascinated by these very

  • big questions

  • about what’s really going on with this reality. I remember actually

  • lying in this hammock I had put up between two apple trees back in Stockholm, Sweden

  • when I was 13, reading Isaac Asimov actually.

  • I’m very honored to get to be here.

  • It really makes you think about these big, big questions. And the more I learned about

  • later on as a physicist, the more struck I was

  • that when you get deep down under the hood about how nature works, down to looking at

  • all of you as just a bunch of quarks and electrons, the rules

  • >>NEIL DEGRASSE TYSON: And you, too. It’s not just us. Yeah.

  • Looking at you as a quark, no, you would come under this category as well.

  • >>MAX TEGMARK: Yes. I am a quark blob, too, I confess.

  • But if you look at how these quarks move around, the rules are entirely mathematical as far

  • as we can tell. And that makes me wonder, if I were a character in a computer game,

  • who starting asking the same kind of big questions about my game world,

  • I would also discover eventually that the rules seemed completely rigid and mathematical.

  • I would just be discovering the computer program in which it was written.

  • So, that kind of begs the question: How can I be sure that this mathematical reality isn’t

  • actually some kind of game or simulation?

  • >>NEIL DEGRASSE TYSON: So, youve analogized yourself to Super Mario in a—that’s who

  • you are?

  • >>MAX TEGMARK: I don’t know if that’s a good thing or a bad thing.

  • >>NEIL DEGRASSE TYSON: So, Jim, I just remembered you started all of this a few years ago, in

  • my mind at least,

  • just triggering the idea that in your research you found things that forced you to consider

  • the likelihood that somebody programmed us. Could you

  • >>JAMES GATES: Well, first of all, I would disagree with you. I’m not sure somebody

  • programmed us,

  • but that’s—you and I had a conversation where I pointed out that in my research I

  • had found this very strange thing. Physicists, I like to say

  • we all belong to a company called Equations-R-Us

  • because that’s how we make our living, is by solving equations. And so I was just going

  • through solving equations, and I was then driven to things that Max knows about,

  • these things called error-correcting codes. Error-correcting codes are what make browsers

  • work. So, why were they in the equations that I was studying about quarks and leptons and

  • supersymmetry?

  • And that’s what brought me to this very stark realization that

  • I could no longer say that people like Max were crazy.

  • >>MAX TEGMARK: Okay.

  • [laughter]

  • >>JAMES GATES: Or stated another way, if you study physics long enough, you, too, can become

  • crazy.

  • >>NEIL DEGRASSE TYSON: That’s a corollary to that idea. Yeah.

  • >>JAMES GATES: And I’m also a science fiction fan like Max, who talked about his encounter

  • with Asimov.

  • I was reading at age eight, as opposed to 13, sir.

  • >>MAX TEGMARK: I hang my head in shame.

  • >>NEIL DEGRASSE TYSON: Snap.

  • >>MAX TEGMARK: Got off to a slow start.

  • >>JAMES GATES: I was reading at age eight a science fiction book by an author named

  • Paul French. And some people in the audience might know

  • that’s a pseudonym for Isaac Asimov.

  • >>NEIL DEGRASSE TYSON: Oh.

  • >>JAMES GATES: So, science fiction drove me into science in some sense. And then now in

  • my 65th year of life, I find out I have to make friends with Max and people like that.

  • >>NEIL DEGRASSE TYSON: So, Lisa, I kind of brought you on the panel because I knew

  • you—I mean, youre a rationalist in all this. And so I was expecting—I don’t know

  • what to expect.

  • I just needed to anchor this in somebody who I knew was not going there. So, where

  • >>LISA RANDALL: Yeah. So, actuallywell, I can’t say I decided to be on the panel

  • because I think I said what date is it, and they were like, “Thank you for agreeing

  • to be on the panel.”

  • But I have to say I’m curious not so much about the question of whether were a simulation

  • because I think it’s only interesting

  • insofar as there are ways to test it.

  • And we can come back to that, I think, very much in terms of how the laws of physics operate

  • and whether we can actually distinguish that. But I actually am very interested in why is

  • so many people think it’s an interesting question. Like why is the audience here? Why

  • is this panel here?

  • Because really to first approximation we can’t really distinguish it.

  • So, I think the interesting question is: Why do we feel compelled

  • to want this to be true, or even think this could be true? And how do the laws of physics

  • operate? And are there really ways that we could eventually

  • test whether there is something that distinguishes just a true universe?

  • But I have to just say if the inference is simulation, I don’t understand why it gave

  • me a cold today.

  • >>NEIL DEGRASSE TYSON: Okay.

  • >>LISA RANDALL: So, my voice might go. But I also think sometimes some of the ridiculous

  • things in the universe and think,

  • really, why would that be part of the simulation? And I realized that if I was doing a simulation,

  • I would definitely put those things in. So, there you go.

  • >>NEIL DEGRASSE TYSON: Okay. Well, thank you for that. Now, we couldn’t have a panel

  • without a philosopher. David, we needed some philosophical

  • >>DAVID CHALMERS: I know how you love philosophers, Neil.

  • [laughter]

  • >>NEIL DEGRASSE TYSON: I’m on record for some comments about philosophers that got

  • him a little ticked off.

  • Buy, anyhow. So, David, what do youphilosophers have been at this for a while, yourself included.

  • So, how do you see all of this

  • happening or fitting in to the worldview?

  • >>DAVID CHALMERS: Well, philosophers like to ask the big questions

  • about the world; the foundational questions. And this is one of them. Actually, I blame

  • Isaac Asimov for all this, at least in my case.

  • I got into thinking about these big questions when I was a kid. I read just about everything

  • that Asimov was writing. Not just the science fiction, but the science fact, the history,

  • the detective novels. I read multiple volumes

  • of his autobiography. But throughout Asimov’s work, this was a guy that was just interested

  • in the big questions about the nature of reality at all levels. And that, ultimately,

  • drove me to think about questions about consciousness and the mind, which I could approach as a

  • philosopher

  • because philosophy allows you to step back and say what is the science here telling us.

  • But this question about the simulation corresponds to another of the great questions of philosophy,

  • which is basically how do we know anything

  • about the external world at all [unintelligible 15:46] said how do you know youre not being

  • fooled by an evil genius

  • into having an impression of this world around us? Even though none of it really exists.

  • Well, the contemporary version of that question is: How do you know youre not in a simulation

  • like The Matrix? In which case, allegedly,

  • none of this really exist. And, to me, that question is just extremely interesting because

  • it seems

  • nothing we could know could rule out the hypothesis that were in a simulation.

  • But you also want to think about what follows.

  • Some people think if were in a simulation, then none of this is real. I think if you

  • adopt the kind of perspective which,

  • say, Max was suggesting a second ago, where the universe is all mathematical or informational,

  • this allows us to reorient

  • our attitude to this question and say, okay, maybe were in a simulation. But if we are,

  • all this is perfectly real

  • because all the information is there in the simulation.

  • All the math is there. All the structure is there in the simulation.

  • So, I’d say, well, maybe were in a simulation. Maybe were not. But if we are, hey, it’s

  • not so bad.

  • >>NEIL DEGRASSE TYSON: If I do this, you feel that.

  • >>DAVID CHALMERS: Yeah.

  • >>NEIL DEGRASSE TYSON: Okay. So, that’s real. That was a real punch. Yeah.

  • So, Zohreh, let me ask you, I see you coming to this almost from the most pragmatic side.

  • Youve done experiments with your colleagues. Or youve had

  • hypotheses with your colleagues. Could you just detail for me where you landed in one

  • of those papers that you guys published?