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Speaker 1: Hey, Daniel, have you guys figured out what's inside a

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Speaker 1: black hole? Yet?

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Speaker 2: Unfortunately not? Still pretty confused.

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Speaker 1: Okay, it sounds like you guys need to go back

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Speaker 1: to the drawing board get some new ideas.

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Speaker 2: I know, but like from where the smartest people on

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Speaker 2: the planet have been stuck in this question for literally decades.

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Speaker 1: See that is where you are going wrong. You are

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Speaker 1: looking to the smart people. If you need wacky, crazy ideas,

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Speaker 1: you need to ask the wacky crazy people like me.

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Speaker 2: You're saying we should go to the insane asylum and

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Speaker 2: ask people what they think is inside a black hole.

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Speaker 1: I think that they could come up with some good ideas.

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Speaker 1: They might be insane enough in the membrane to figure

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Speaker 1: it out.

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Speaker 2: Insane in the brain. Hi, I'm Daniel. I'm a particle

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Speaker 2: physicist and a professor at UC Irvine. And if you

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Speaker 2: didn't get my Cypress Hill reference, you're officially young.

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Speaker 1: I am Katie. I am not a physicist. I like animals, though,

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Speaker 1: and I like the universe. And I got that reference.

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Speaker 2: Because you're insane in the membrane.

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Speaker 1: Exactly, just the membrane, though the rest of me is perfectly.

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Speaker 2: Sane and welcome to the podcast Daniel and Jorge Explain

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Speaker 2: the Universe, in which we do our best to bring

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Speaker 2: this insane universe into your brain. We try to make

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Speaker 2: it all make sense, from the tiniest little quantum particles

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Speaker 2: to the hugest swirling accretion disks surrounding super massive black holes.

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Speaker 2: We have this hunch that maybe the universe is understandable,

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Speaker 2: that it's a big mathematical puzzle that we can of

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Speaker 2: eventually figure it out if we put all of our

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Speaker 2: brains and membranes together. And our goal on this podcast

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Speaker 2: is to explain all of it to you.

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Speaker 1: Now, that's another song, super Massive black Hole. I think

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Speaker 1: muse soundtrack to that really sort of indie movie called Twilight.

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Speaker 2: Are you sure that wasn't part of the hip hop

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Speaker 2: wars in the nineties, super Massive black Hole?

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Speaker 1: I couldn't say. In the nineties, I was not cool

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Speaker 1: enough to know.

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Speaker 2: Well, you know, maybe there are some secrets in music

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Speaker 2: that can help us crack the mysteries of the universe,

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Speaker 2: because you know, some people say the universe is musical

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Speaker 2: and there's a connection between music and mathematics, right, So

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Speaker 2: maybe we have been looking in the wrong places.

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Speaker 1: Yeah, Like I've heard this in terms of string theory,

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Speaker 1: where strings aren't you know, they're not like violin strings,

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Speaker 1: But it's something about some like either vibration or pattern. Honestly,

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Speaker 1: I do not understand it, but you know, well, I

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Speaker 1: think that is interesting that there is the idea that

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Speaker 1: a lot of the mysteries of the universe could be

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Speaker 1: about certain frequencies or patterns, which is also what is

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Speaker 1: the major components of music.

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Speaker 2: Exactly, Although if you listen to Terrence Howard on Joe Rogan,

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Speaker 2: it's all frequencies.

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Speaker 1: Man, is all frequencies?

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Speaker 2: Man?

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Speaker 1: Why am I not on Joe Rogan? See, I just

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Speaker 1: can say that too.

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Speaker 2: I can because you believe that one times one equals one,

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Speaker 2: and Terrence Howard proves that it equals to And that's

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Speaker 2: why you're just not mathematically qualified to be.

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Speaker 1: I just can't think outside of the box enough to

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Speaker 1: not do mauth good exactly.

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Speaker 2: But we are fascinated by the mysteries of the universe.

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Speaker 2: We do think that there are mathematical solutions to them.

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Speaker 2: Maybe they are encoded in the sonatas of Mozart. Maybe

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Speaker 2: the engineers are right that it's all vibrations all the

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Speaker 2: way down. But we hope that there is an explanation.

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Speaker 2: And one of the biggest things and we need an

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Speaker 2: explanation for is how to think about the universe on

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Speaker 2: the smallest scales. What happens when things get really, really

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Speaker 2: dense and really really tiny. One of the biggest puzzles

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Speaker 2: in modern physics is how to put together the two

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Speaker 2: pillars of our understanding of the universe, relativity and quantum mechanics.

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Speaker 2: We've been banging our heads against this for almost one

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Speaker 2: hundred years, basically since we've had relativity and quantum mechanics

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Speaker 2: and realize that they are fundamentally incompatible at the smallest scale.

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Speaker 2: And we've been trying to figure this out. And today

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Speaker 2: on the podcast, we'll be exploring yet another attempt to

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Speaker 2: unify relativity and quantum mechanics. So on the podcast today

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Speaker 2: we'll be answering the question what is membrane theory?

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Speaker 1: Okay, as a biology nerd, I'm pretty sure I can

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Speaker 1: answer this. A membrane is a semi permeable barrier, So

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Speaker 1: I solved it. Congratulations to me.

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Speaker 2: What about the audio barrier between us and the listeners

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Speaker 2: the ideas from our brains and that their brains have

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Speaker 2: we permeated a membrane.

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Speaker 1: I yes, why not. I don't know enough about audio

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Speaker 1: engineering to say no or philosophy, so I'm gonna say yes.

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Speaker 1: We're like salt ions through the airwaves, permeating the membrane,

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Speaker 1: so hopefully you can reach homeostasis.

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Speaker 2: So I'm not surprised that when you heard this phrase

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Speaker 2: you thought of cellular membranes divisions between solutions. You want

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Speaker 2: to keep osmosis from, like moving all these bits of

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Speaker 2: salt over here, or using fats to keep that over there.

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Speaker 2: But it's not just in biology that we have membranes.

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Speaker 2: It turns out that they are fundamental concept in theories

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Speaker 2: of quantum gravity. But before we dig into that, I

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Speaker 2: was curious what everybody else out there thought when they

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Speaker 2: heard membrane theory. As usual, I asked our cadre of

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Speaker 2: volunteers to speculate on the question without the opportunity to

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Speaker 2: use Google. So, if you would like to join this

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Speaker 2: group of volunteers in the future, please don't be shy.

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Speaker 2: Write me to questions at Danielandjorge dot com. We all

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Speaker 2: want to hear what you have to say. In the meantime,

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Speaker 2: check out these answers from listeners. What do you think

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Speaker 2: membrane theory is here's what people had to say. That's

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Speaker 2: the first time I'm hearing golfit.

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Speaker 3: But if I had to guess membranes, the function of

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Speaker 3: the membranes are to pass on stuff in one direction

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Speaker 3: and other stuff not in the other direction. So maybe

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Speaker 3: we're talking about it's a mechanism about particle coexistence through

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Speaker 3: a wall of things something like that.

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Speaker 4: Just to guess, what comes to mind for me on

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Speaker 4: that one is that it's something that you use to

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Speaker 4: separate things, like in a fuel cell car, you know,

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Speaker 4: you separate components and you make energy. Maybe it's like

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Speaker 4: a desalination thing where you take salt.

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Speaker 2: Out of water.

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Speaker 4: So maybe there's some membrane here in the universe that's doing.

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Speaker 2: That in space.

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Speaker 5: I'm guessing membrane theory has to do with the outside

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Speaker 5: of a cell. Maybe how the membrane, you know, protects

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Speaker 5: the core of the cell and how it stays intact.

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Speaker 2: I think it has to do with string theory. There

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Speaker 2: are strings that vibrate in there one dimension, and I

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Speaker 2: think a membrane is a something similar that can have

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Speaker 2: more than one dimension.

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Speaker 1: See, I'm I'm definitely with the theory that everything is

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Speaker 1: a cell. If you look at the universe, it's just

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Speaker 1: a giant body for some kind of huge animal. You know,

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Speaker 1: it makes sense, right, you're saying the universe is alive. Yeah,

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Speaker 1: it's a big maybe a giant cat. I don't know.

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Speaker 1: Have you ever looked at like a black cat? Right,

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Speaker 1: It's it kind of has that sort of quantum mechanics

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Speaker 1: and general relativity paradox. Right, it's like a fluid, it's

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Speaker 1: a solid. It's sweet and loving, and then it bites you.

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Speaker 1: So yeah, I think the universe could be a giant cat.

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Speaker 1: And when you get down to the tiniest components there cells,

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Speaker 1: and yeah, it's been solved.

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Speaker 2: You're welcome and we're done, Thank you very much. Physics

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Speaker 2: is over. Katie wins all of the Nobel prices. Heay, Well,

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Speaker 2: we're definitely hearing from listeners the connection to biology, which

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Speaker 2: makes a lot of sense, and the idea of having

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Speaker 2: two dimensional surfaces or even connections to string theory. So

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Speaker 2: there's a lot of good stuff in here that we're

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Speaker 2: going to dig into and explain in this episode. But

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Speaker 2: a plus to all the listeners.

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Speaker 1: I mean, I would assume that, yes, it's probably not

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Speaker 1: like a cellular membrane. But if we're talking about a membrane,

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Speaker 1: I would guess it is some kind of barrier through

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Speaker 1: which certain physics transactions can occur. But that would be

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Speaker 1: my guess.

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Speaker 2: Is this whole podcast a physics transaction? We are taking

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Speaker 2: your time and exchanging it for knowledge, is like a

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Speaker 2: physics transaction.

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Speaker 1: You know what? That's pretty good. I think I'm wondering

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Speaker 1: about the exchange rate, though, because that's that's the real issue.

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Speaker 2: Yeah, I think we're too high on the jokes permit

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Speaker 2: it and too low and the physics permitted so far.

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Speaker 2: Let's try to flip that right now.

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Speaker 1: All right, well, okay, let me have it. Like, what's

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Speaker 1: going on with this membrane theory?

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Speaker 2: So membrane theory is an attempt to crack the puzzle

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Speaker 2: of quantum gravity. So let's start with that. What is

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Speaker 2: the puzzle of quantum gravity? Why do we want to

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Speaker 2: crack it? What is the issue? Why are all the

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Speaker 2: smart people on the planet thinking they need to go

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Speaker 2: into the insane this islum if they can't figure this out?

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Speaker 2: The basic issue is we have two ways to describe

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Speaker 2: the universe. There's general relativity, which tells us about space

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Speaker 2: and time and energy, and the expansion of the universe

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Speaker 2: describes a lot of the big stuff. It tells us

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Speaker 2: how gravity works and how the universe is expanding, and

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Speaker 2: how far away galaxies are getting red shifted and all

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Speaker 2: that good stuff. And then we have quantum mechanics, which

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Speaker 2: describes the really small stuff, the little part of goals

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Speaker 2: light and all this kind of quantum fields and sort

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Speaker 2: of our understanding of microscopic matter. And the issue is

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Speaker 2: that we don't know how to make these two things

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Speaker 2: play well together.

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Speaker 1: They don't play nice because I've actually, i think I've

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Speaker 1: been on the show a couple times when we talked

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Speaker 1: about this conundrum, and so it seems like, you know,

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Speaker 1: when you have these mathematical theories that describe each of them,

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Speaker 1: it works within it. So the general relativity math works

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Speaker 1: within general relativity. It seems really nice and neat and good.

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Speaker 1: Same thing for quantum mechanics. But then when you try

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Speaker 1: to cross the beams the math beams, suddenly it doesn't work.

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Speaker 1: Like if you're trying to use general relativity math to

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Speaker 1: describe what you know is observed in experiments happening on

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Speaker 1: sort of the quantum level, or vice versa. It no

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Speaker 1: longer works. Is that more or less?

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Speaker 2: Yeah? I love crossing the math beams. That's awesome. I

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Speaker 2: want a t shirt that says I'm crossing the math beams.

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Speaker 2: But yeah, that's basic the idea. And remember that what

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Speaker 2: we're doing in physics is trying to build a mental

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Speaker 2: model that describes the universe easy. Those mental models are

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Speaker 2: always imperfect. They're always incomplete, they're always simplifications. Even if

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Speaker 2: you're talking about like the flight of a baseball, right,

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Speaker 2: how does a baseball fly across the field? Well, I'm

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Speaker 2: going to use a parabola in Newton's equations, but I

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Speaker 2: can't do the calculation very easily. I have had to

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Speaker 2: include air resistance, so I decide I'm not including that

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Speaker 2: because it's probably not important, and really, to answer my

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Speaker 2: question of whether the guy's going to catch it, air

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Speaker 2: resistance doesn't matter. I'm not going to include effects of

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Speaker 2: humidity and the siazillion things I could include in my

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Speaker 2: model to make it a very accurate description of the

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Speaker 2: universe that I don't need to to answer my question.

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Speaker 2: And so the models that we build to answer questions

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Speaker 2: about the universe are always incomplete, they are always approximations,

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Speaker 2: but they're still very very useful. And that's the issue

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Speaker 2: with quantum mechanics and general relativity is that they are

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Speaker 2: two different approximate descriptions of the universe that make different approximations,

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Speaker 2: different foundations assumptions that go into building those models that

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Speaker 2: are incompatible, and they let us describe different parts of

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Speaker 2: the universe, as you say, very very well. So if

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Speaker 2: I want to talk about how two electrons scatter off

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Speaker 2: of each other, I can use quantum mechanics and talk

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Speaker 2: about how they interact and the virtual particles they exchange

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Speaker 2: or the fields that ripple between them, and it all

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Speaker 2: works out amazingly well. And that can ignore what general

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Speaker 2: relativity would do in that situation because it's irrelevant. It's

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Speaker 2: like the wind resistance or the humidity on the baseball.

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Speaker 2: It doesn't affect the calculations, so I can ignore it.

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Speaker 2: Or if I want to say, hey, how do galaxies

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Speaker 2: form and how do they swirl around each other? I

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Speaker 2: can use general relativity to answer those questions, and that

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Speaker 2: can ignore the quantum effects because who cares what one

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Speaker 2: electron does in Andromeda doesn't affect whether our galaxy is

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Speaker 2: going to crash into that galaxy, general relativity dominates. The

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Speaker 2: amazing thing is that in every situation in our universe

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Speaker 2: you can use either quantum mechanics to explain it or

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Speaker 2: general relativity and ignore the other one. A perfect divorced

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Speaker 2: couple that have separated their lives and never have to interact.

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Speaker 2: You know, there are no argument at McDonald's about who's

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Speaker 2: taking the kid. Yeah, they're co parenting the universe. And

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Speaker 2: so you might think, all right, great, what's the problem,

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Speaker 2: right co parents can live in harmony without ever talking

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Speaker 2: to each other. Well, there's two problems. One is that's

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Speaker 2: really unsatisfying, right, Like, we want one explanation for the universe.

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Speaker 2: We don't want two different explanations. We don't want a

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Speaker 2: Russiaman universe where both parents tell very very different stories

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Speaker 2: about what's going on. Right.

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Speaker 1: I get that.

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Speaker 2: We think that there is one story about the universe.

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Speaker 2: There's something that's happening, and that there are rules that

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Speaker 2: are being followed, and we want to know what they are.

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Speaker 2: We want our best approximation of them. So it's deeply

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Speaker 2: unsatisfying to have two different, incompatible theories of the universe.

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Speaker 2: And also, there are moments in the universe a very

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Speaker 2: few places. In times when you can't ignore one ar

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Speaker 2: or the other, you need things like the heart of

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Speaker 2: a black hole a singularity. In general, relativity is incompatible

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Speaker 2: with quantum mechanics, which says you've got to have some

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Speaker 2: fuzziness or the Big Bang or the very early universe

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Speaker 2: when things were really, really hot and dense. You need

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Speaker 2: the rules of quantum mechanics to describe those particles. But

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Speaker 2: you can't ignore gravity because things are so hot and

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Speaker 2: so dense. So we desperately want to find a way

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Speaker 2: to bring these two together. But as you say, the

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Speaker 2: math beings don't cross, right.

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Speaker 1: I mean, it's like, as physicists you now kind of

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Speaker 1: have to play as a couple's therapist, where you have

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Speaker 1: these two theories that are essentially speaking different languages and

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Speaker 1: they cannot come to an agreement, and they can be

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Speaker 1: perfectly functional on their own, but then when they come together,

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Speaker 1: they are unable to communicate. And the Yeah, I mean,

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Speaker 1: it seems like resolving that difference between the two theories,

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Speaker 1: like resolving why they don't work with each other, would

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Speaker 1: actually reveal some big things that we just fundamentally have

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Speaker 1: not understood yet about the universe.

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Speaker 5: M M.

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Speaker 2: You know, I've heard anecdotally about couples that don't actually

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Speaker 2: speak the same language, you know, where they have like

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Speaker 2: literally now yet they've fallen in love. That's actually true,

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Speaker 2: they have some other love language.

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Speaker 1: Hi language interpretive there.

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Speaker 2: Love at first sight, right, doesn't love it first word?

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Speaker 1: Yeah.

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Speaker 2: Anyway, you're right that quantum mechanics in general relativity don't

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Speaker 2: get along, and one of the reasons is that they

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Speaker 2: are built on very different assumptions. Like general relativity says

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Speaker 2: the universe is smooth, it's continuous, it's precise, there's an

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Speaker 2: infinite number of locations. It says that you can divide

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Speaker 2: space an infinite number of times, like relativity agrees with

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Speaker 2: Zeno's paradox, right that between you and a candy store,

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Speaker 2: there's always a distance that you can cut in half.

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Speaker 2: Space from the point of view of general relativity is

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Speaker 2: something that's smooth and continuous and you always have a

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Speaker 2: very specific location, whereas quantum mechanics says not. Nothing is

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Speaker 2: actually smooth and continuous. There are not infinite number of

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Speaker 2: locations between any two points. Things are discrete and chunky.

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Speaker 2: A beam of light is actually made up of little

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Speaker 2: pieces of light, little packets of light. Everything in the

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Speaker 2: universe is discrete, and it's also imprecise. None of these

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Speaker 2: little packets have a precise location that have probabilities. So

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Speaker 2: you see the foundations of these two theories are very

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Speaker 2: very different. They start from two very different places, and

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Speaker 2: so weaving them together has a lot of challenges. People

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Speaker 2: have been trying to make theories of quantum gravity to say, hey,

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Speaker 2: let's take gravity and try to describe it in the

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Speaker 2: language of quantum mechanics. For example, think of it like

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Speaker 2: a quantum field that are exchanging virtual particles. They even

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Speaker 2: have a name for these particles, it would be the graviton.

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Speaker 2: But when you sit down and try to do those calculations,

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Speaker 2: gravity is different from the other quantum forces because it

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Speaker 2: couples to itself. Everything that has energy has gravity, and

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Speaker 2: so if you emit a graviton, it also feels gravity,

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Speaker 2: and it emits gravitons, which emit more gravitons. You can

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Speaker 2: infinite number of gravitons, and then you start to get

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Speaker 2: nonsense answers. So as you say, the math beams don't cross.

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Speaker 1: So in terms of gravitons, is that something that has

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Speaker 1: ever been able to be studying the same way that

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Speaker 1: you can study protons or is it just sort of

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Speaker 1: a byproduct of this seems like this could be a

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Speaker 1: thing based on the math that we have theorized about.

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Speaker 2: Yeah, gravitons are purely theoretical, and they're not even coherently theoretical.

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Speaker 2: Theories that have gravitons in them just don't work their

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Speaker 2: problems with them, and so it's not just that we

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Speaker 2: haven't seen them. We don't even understand how they would

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Speaker 2: work if they did exist. And there also would be

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Speaker 2: really really hard to spot, Like if you're thinking about

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Speaker 2: gravitational waves from rotating black holes, for example, those are

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Speaker 2: not gravitons. Those are ripples in space and time. They

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Speaker 2: are like a beam of light. Gravitons would be like

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Speaker 2: taking that beam of light and breaking it up into photons.

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Speaker 2: So you take that gravitational wave and now break it

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Speaker 2: up into tiny little gravitons. But even gravitational waves are

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Speaker 2: really hard to see. Gravitons would be much much tinier,

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Speaker 2: well beyond our capability. But also mathematically they just don't work.

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Speaker 2: If you try to do calculations with gravitons, you get

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Speaker 2: weird answers like what's the probability that this electron is

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Speaker 2: going to go left? Oh, one hundred and forty percent?

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Speaker 2: What that doesn't make any sense, right, And so that's

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Speaker 2: telling you that fundamentally there is a problem with the

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Speaker 2: mathematics that you need to go deeper and start from

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Speaker 2: something else, change one of your assumptions in order to

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Speaker 2: make a working theory of quantum gravity.

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Speaker 1: I mean this kind of reminds me in biology of

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Speaker 1: how like the history of biology and medicine, where we

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Speaker 1: would start to understand things like we would start to

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Speaker 1: understand how certain medications work, or you know, understand things like,

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Speaker 1: you know, a man and a woman make a baby

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Speaker 1: and the like, there seems to be these germinal cells responsible.

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Speaker 1: But then we didn't have the ability to get tiny

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Speaker 1: enough inside the human body where we couldn't see like proteins,

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Speaker 1: we couldn't see, you know, maybe we at some point

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Speaker 1: could see cells, but we couldn't see DNA. So there

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Speaker 1: were so many strange and interesting theories that kept circling

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Speaker 1: around trying to get closer and closer to the truth.

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Speaker 1: Like there were really funny ones like imagining that there's

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Speaker 1: just like a tiny person inside of a sperm cell

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Speaker 1: and then that grew into a baby. But essentially it's

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Speaker 1: like we were able to make scientific observations, but without

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Speaker 1: the ability to get small enough in terms of like

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Speaker 1: we didn't have electron microscopes, we didn't have the technology

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Speaker 1: or understanding to study DNA, these theories could not kind

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Speaker 1: of you know, interweave until we got to that point.

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Speaker 1: And that kind of seems like where, you know, sort

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Speaker 1: of like what's happening with the universe. Like we're able to,

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Speaker 1: you know, make all of these really interesting scientific observations

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Speaker 1: and they're not necessarily wrong, but there is some fundamental

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Speaker 1: aspect that it's not necessarily that it's too small to see,

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Speaker 1: but it's something that we can't see yet or something

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Speaker 1: that is really hard to observe that might help tie

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Speaker 1: these things together exactly.

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Speaker 2: And because it's a question mark, it's deeply unsatisfying to

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Speaker 2: not have figured it out. We suspect that when we

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Speaker 2: do figure it out, it'll be something new, something fascinating,

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Speaker 2: something that tells us about the basic nature of the universe.

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Speaker 2: Because it's telling us that Gr's description of the universe

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Speaker 2: is wrong. Space is not just some bendable manifold and

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Speaker 2: the quantum mechanics description of the universe is wrong in

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Speaker 2: some important way. That's what I love about physics, because

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Speaker 2: it's not just I have a model in my head

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Speaker 2: that is predicting the universe. You can then look at

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Speaker 2: that model and ask questions about it that are philosophical

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Speaker 2: and like, huh, why does the universe work this way?

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Speaker 2: Or you can look at it and say, oh, that's

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Speaker 2: why time flows forwards and there's only one dimension of

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Speaker 2: it in three dimensions of space. If you have that

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Speaker 2: fundamental theory of the universe, we hope that those kind

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Speaker 2: of answers can come from it deep insights about the

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Speaker 2: very nature of reality. And for people who think like, oh,

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Speaker 2: that's so weird and abstract, I mean, that's like the

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Speaker 2: context of our whole lives, you know, our entire existence.

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Speaker 2: Understanding the basic nature of reality of space and time

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Speaker 2: and matter and energy like that is the stage of

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Speaker 2: our life, the context of our existence. The stakes could

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Speaker 2: literally not be higher.

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Speaker 1: I mean it's interesting because I'm really curious about things

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Speaker 1: like animal and human behavior, understanding them and understanding things

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Speaker 1: like perception and you know, but those kinds of questions

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Speaker 1: I don't see as too fundamentally different from the questions

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Speaker 1: that physicists are answering, because in a way, you know,

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Speaker 1: our perception of things are sort of like behaviors and stuff.

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Speaker 1: That is how we're able to perceive the universe. And

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Speaker 1: so these kinds of questions of understanding. Of course, the

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Speaker 1: methodologies are very different, and what we find are going

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Speaker 1: to be very different with these two questions, but it's

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Speaker 1: that's still that kind of desire to understand what are

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Speaker 1: we and where are we? How do we function, and

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Speaker 1: how do we function in relation to our environment? And

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Speaker 1: you know, of course the universe being the largest environment

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Speaker 1: that we can think of in which we are. But

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Speaker 1: you know what, we should probably take a quick break

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Speaker 1: while I really ponder an egg and the membrane of

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Speaker 1: an egg and try to think about whether this is

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Speaker 1: something that could describe the universe. All right, so we

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Speaker 1: are back. I've been staring at this egg for five minutes.

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Speaker 1: Daniels can attest to that, and you know, I think

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Speaker 1: maybe the universe could be an egg with yellow stuff

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Speaker 1: on the inside. What do you think?

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Speaker 2: I love your egg theory of the universe. I want

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Speaker 2: to see the math behind it before I really commit to.

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Speaker 1: It one plus one equals too or wait, one time

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Speaker 1: is one equals too? I accidentally did I'm so bad

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Speaker 1: at math. I was trying to make a joke where

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Speaker 1: I did it bath and I did it correctly.

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Speaker 2: Oops. Oops, oops.

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Speaker 1: So, Daniel, I really want to get deeper into these

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Speaker 1: ideas because we've talked about how these things don't seem

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Speaker 1: to add up, and these attempts to make things to

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Speaker 1: add up have in some sense, I don't want to

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Speaker 1: say failed, but they haven't reached the finish line yet.

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Speaker 1: So like gravitons don't make sense yet, are there is

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Speaker 1: there anything promising where we are seeing some revelations that

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Speaker 1: may help us get closer to why there is this

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Speaker 1: fundamental miscommunication between general relativity and quantum mechanics.

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Speaker 2: So there definitely has been some progress. Nobody's totally figured

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Speaker 2: it out, but some of the smartest folks on the

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Speaker 2: planet have some ideas. And before we get into membrane theory,

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Speaker 2: you need to take a step back and understand where

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Speaker 2: it came from, which is from string theory.

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Speaker 1: Okay, I'm excited because I remember I remember watching I

437
00:24:05,320 --> 00:24:08,119
Speaker 1: Think like a PBS nova thing and they tried to

438
00:24:08,240 --> 00:24:12,600
Speaker 1: explain string theory, and it just confused me more than

439
00:24:12,640 --> 00:24:15,080
Speaker 1: I think, you know, like if you just said, like,

440
00:24:15,359 --> 00:24:18,879
Speaker 1: imagine what string theory is, I'd probably be less confused

441
00:24:19,040 --> 00:24:22,040
Speaker 1: at that point until after watching this documentary. I'm not

442
00:24:22,400 --> 00:24:24,480
Speaker 1: I don't want to be mean to PBS, but I

443
00:24:24,480 --> 00:24:26,919
Speaker 1: don't think they really explained it very well because it

444
00:24:26,960 --> 00:24:30,440
Speaker 1: was like they're like these vibrating strings like on a violin,

445
00:24:30,480 --> 00:24:33,199
Speaker 1: and it's like, I don't know that that makes a

446
00:24:33,200 --> 00:24:35,760
Speaker 1: lot of sense, and I'm confused. You mean, there's tiny

447
00:24:35,840 --> 00:24:39,760
Speaker 1: violins everywhere. What's going on? Are the world's smallest violins

448
00:24:39,920 --> 00:24:44,280
Speaker 1: making up the universe? So I do want to understand better.

449
00:24:44,440 --> 00:24:46,160
Speaker 2: All right, let's see if we can do better than

450
00:24:46,200 --> 00:24:50,320
Speaker 2: Brian Green on PBS. The idea is to avoid some

451
00:24:50,400 --> 00:24:52,639
Speaker 2: of the mathematical problems that come when you try to

452
00:24:52,680 --> 00:24:55,679
Speaker 2: cross the beam. Those infinities. A lot of those infinities

453
00:24:55,720 --> 00:24:59,040
Speaker 2: come from the basic assumption that things are points, that

454
00:24:59,119 --> 00:25:02,760
Speaker 2: particles are time need dots because those have infinities in them.

455
00:25:02,760 --> 00:25:06,199
Speaker 2: There's infinite densities and the zero volume, et cetera. So

456
00:25:06,280 --> 00:25:09,800
Speaker 2: instead of having points, string theory says, what if everything

457
00:25:10,040 --> 00:25:13,480
Speaker 2: is a line, so a point is like zero dimensions, right,

458
00:25:13,520 --> 00:25:15,919
Speaker 2: it doesn't go in any way. But a string is

459
00:25:15,960 --> 00:25:18,880
Speaker 2: one dimension. It's like, well, let's have it have some extent,

460
00:25:19,240 --> 00:25:22,040
Speaker 2: and having it have a length means it's not infinitely

461
00:25:22,080 --> 00:25:25,000
Speaker 2: dense anymore. There's like a fundamental length to it, and

462
00:25:25,040 --> 00:25:27,800
Speaker 2: that avoids some of the infinities in the calculations. Is

463
00:25:27,840 --> 00:25:30,639
Speaker 2: like a minimum size to stuff, and that's the length

464
00:25:30,680 --> 00:25:33,200
Speaker 2: of a string. And so these strings would be the

465
00:25:33,200 --> 00:25:37,000
Speaker 2: fundamental bits of the universe. Essentially the universe is strings.

466
00:25:37,320 --> 00:25:40,160
Speaker 2: But these strings can do things. They can wiggle, right,

467
00:25:40,240 --> 00:25:42,760
Speaker 2: just like strings in our world, like a violin string.

468
00:25:42,600 --> 00:25:47,840
Speaker 1: Can or or a guitar string if you prefer that.

469
00:25:48,400 --> 00:25:51,239
Speaker 2: But we can't see those wiggles directly. And so what

470
00:25:51,280 --> 00:25:54,680
Speaker 2: we see is something really zoomed out, like the string wiggles.

471
00:25:54,680 --> 00:25:56,760
Speaker 2: This way, it looks like an electron. When you zoom

472
00:25:56,800 --> 00:25:59,080
Speaker 2: way out with string wiggles that way, it looks like

473
00:25:59,080 --> 00:26:02,440
Speaker 2: a muon the string. Another way it looks like a quark.

474
00:26:02,920 --> 00:26:04,680
Speaker 2: So the idea is not that the electrons and the

475
00:26:04,760 --> 00:26:08,159
Speaker 2: quarks are made of tinier particles the way that like

476
00:26:08,240 --> 00:26:10,919
Speaker 2: the atom is made of smaller particles, but that you

477
00:26:10,960 --> 00:26:14,399
Speaker 2: get something fundamentally different. Right, we need something fundamentally different

478
00:26:14,480 --> 00:26:17,199
Speaker 2: to solve this puzzle of quantum gravity. We need a

479
00:26:17,240 --> 00:26:20,320
Speaker 2: new idea, and so we say that these particles are

480
00:26:20,359 --> 00:26:22,960
Speaker 2: instead made of vibrating strings, and they just look like

481
00:26:23,000 --> 00:26:26,480
Speaker 2: different particles because we're too zoomed out to see the details.

482
00:26:26,800 --> 00:26:29,520
Speaker 1: I guess for me, the question is like, I understand

483
00:26:29,560 --> 00:26:32,919
Speaker 1: the difference between a point and a line in terms

484
00:26:32,920 --> 00:26:37,399
Speaker 1: of dimensionality, but in terms of like a line of what?

485
00:26:37,800 --> 00:26:40,239
Speaker 1: Like That's where I get caught up, because I, you know,

486
00:26:40,600 --> 00:26:45,639
Speaker 1: usually it's so hard to think about the fundamental like

487
00:26:46,240 --> 00:26:51,040
Speaker 1: unit of something because maybe this is just biology brain,

488
00:26:51,200 --> 00:26:54,280
Speaker 1: but everything has a smaller thing in it, right, Like

489
00:26:54,760 --> 00:26:58,560
Speaker 1: You've got a mouse and the mouse has tissues, and

490
00:26:58,600 --> 00:27:02,120
Speaker 1: the tissues have cells. Cells have proteins, and the proteins

491
00:27:02,520 --> 00:27:05,120
Speaker 1: have molecules, and the molecules have atoms, and the atoms

492
00:27:05,119 --> 00:27:07,280
Speaker 1: have quarks, et cetera, et cetera. I might have skipped

493
00:27:07,280 --> 00:27:09,080
Speaker 1: a few steps, but you get the idea, which is

494
00:27:09,080 --> 00:27:11,920
Speaker 1: that I'm always thinking, like, what, what do you mean

495
00:27:11,960 --> 00:27:13,800
Speaker 1: like a string of what? A line of what?

496
00:27:14,240 --> 00:27:14,359
Speaker 5: So?

497
00:27:14,600 --> 00:27:17,840
Speaker 1: How has that resolved? Like what is? Because I'm assuming

498
00:27:17,840 --> 00:27:20,760
Speaker 1: it is not like a literal strand of you know,

499
00:27:20,800 --> 00:27:23,320
Speaker 1: like in biology, like a strand of protein. Like if

500
00:27:23,359 --> 00:27:25,440
Speaker 1: you're like, there's a string of something, I'm thinking like, oh,

501
00:27:25,560 --> 00:27:27,960
Speaker 1: is it proteins? Like you know, is it lipids? What's

502
00:27:28,000 --> 00:27:30,960
Speaker 1: it made out of? So in in physics, like what

503
00:27:31,160 --> 00:27:32,040
Speaker 1: is this line?

504
00:27:32,520 --> 00:27:35,119
Speaker 2: Yeah, it's a great question, and I understand what you're saying.

505
00:27:35,359 --> 00:27:38,000
Speaker 2: You're imagining string in your mind. And you know, if

506
00:27:38,040 --> 00:27:40,600
Speaker 2: you're thinking about like a line of frosting on a cake,

507
00:27:40,920 --> 00:27:43,159
Speaker 2: you're thinking that squeezed out of some tube and the

508
00:27:43,560 --> 00:27:45,639
Speaker 2: line of frosting is made out of that frosting, and

509
00:27:45,640 --> 00:27:48,520
Speaker 2: therefore the frosting is the basic universe stuff, not the

510
00:27:48,560 --> 00:27:50,600
Speaker 2: line of it. And so you're wondering, like, well, what's

511
00:27:50,600 --> 00:27:53,200
Speaker 2: that string made out of? What is string stuff? And

512
00:27:53,280 --> 00:27:55,919
Speaker 2: the answer is we don't know. And you're right that

513
00:27:56,000 --> 00:27:58,720
Speaker 2: the pattern is that stuff has made a smaller stuff,

514
00:27:58,720 --> 00:28:00,320
Speaker 2: which has made a smaller stuff, which is made of

515
00:28:00,359 --> 00:28:03,439
Speaker 2: smaller stuff. And so far we've never seen anything that

516
00:28:03,760 --> 00:28:06,000
Speaker 2: is just itself that is not made of something.

517
00:28:06,520 --> 00:28:08,520
Speaker 1: That's the truth, You're absolutely right.

518
00:28:09,119 --> 00:28:11,919
Speaker 2: But we have this hunch, We have this hunch that

519
00:28:12,040 --> 00:28:14,960
Speaker 2: maybe it is that maybe there's a bottom to the

520
00:28:15,040 --> 00:28:17,560
Speaker 2: explanations of the universe. We don't know, And there are

521
00:28:17,560 --> 00:28:21,080
Speaker 2: philosophers out there who argue that it could be infinitely regressive, right,

522
00:28:21,080 --> 00:28:23,320
Speaker 2: that you just could keep going forever and ever and ever,

523
00:28:23,600 --> 00:28:27,280
Speaker 2: and there is no foundational firmament to the universe. Everything

524
00:28:27,359 --> 00:28:28,600
Speaker 2: is made of something smaller.

525
00:28:29,000 --> 00:28:32,040
Speaker 1: I hate it either way, Daniel, like either explanation. It

526
00:28:32,480 --> 00:28:35,720
Speaker 1: feels uncomfortable somehow, right, Like if the explanation is like

527
00:28:36,080 --> 00:28:40,000
Speaker 1: there is the smallest unit and it's a line that wiggles,

528
00:28:40,040 --> 00:28:42,280
Speaker 1: I'm like really. And then if you're like no, but

529
00:28:42,280 --> 00:28:44,920
Speaker 1: then the line that wiggles, can you can infinitely get

530
00:28:45,040 --> 00:28:48,719
Speaker 1: smaller and smaller and smaller, And then still that It's like, really,

531
00:28:49,320 --> 00:28:52,000
Speaker 1: it's so hard, And I feel like maybe the reason

532
00:28:52,040 --> 00:28:57,040
Speaker 1: it's so difficult is that our human brains are geared

533
00:28:57,080 --> 00:29:00,360
Speaker 1: towards a certain type of understanding of things based on

534
00:29:00,400 --> 00:29:04,160
Speaker 1: what our evolutionary needs are in terms of something has

535
00:29:04,200 --> 00:29:06,840
Speaker 1: a start point and endpoint, or something is made out

536
00:29:06,880 --> 00:29:10,280
Speaker 1: of something else and time goes from point A to

537
00:29:10,360 --> 00:29:13,840
Speaker 1: point B. When someone who is not a physicist is

538
00:29:13,880 --> 00:29:17,040
Speaker 1: trying to think about these things, I think about stuff

539
00:29:17,440 --> 00:29:20,400
Speaker 1: that is probably not very relevant to it, Like when

540
00:29:20,440 --> 00:29:22,840
Speaker 1: I think of I don't know, you keep talking about

541
00:29:22,880 --> 00:29:25,600
Speaker 1: wiggly lines, and I just think about al dente spaghetti

542
00:29:25,640 --> 00:29:27,960
Speaker 1: and that's not what it is and it can't be.

543
00:29:28,640 --> 00:29:33,040
Speaker 1: But it's so hard to think of. Okay, there's a

544
00:29:33,040 --> 00:29:36,920
Speaker 1: basic unit that can't get any smaller, but it's not

545
00:29:37,080 --> 00:29:40,600
Speaker 1: made out of anything, and that, you know, it just

546
00:29:40,680 --> 00:29:43,600
Speaker 1: kind of breaks my brain. I cannot conceive of that.

547
00:29:44,000 --> 00:29:45,479
Speaker 2: Well, let me put it in another way, which is

548
00:29:45,520 --> 00:29:49,120
Speaker 2: maybe easier to sit with in your brain, which is,

549
00:29:49,360 --> 00:29:52,640
Speaker 2: we don't know whether strings, if they exist, are the

550
00:29:52,680 --> 00:29:54,720
Speaker 2: fundamental basis of the universe, or if they're made of

551
00:29:54,760 --> 00:29:56,880
Speaker 2: something smaller. You can put it that way, right, And

552
00:29:56,920 --> 00:29:58,760
Speaker 2: we can put it that way because we actually don't

553
00:29:58,800 --> 00:30:01,280
Speaker 2: have to know. This is one of the beautiful things

554
00:30:01,320 --> 00:30:04,720
Speaker 2: about physics is that we can do calculations at various scales,

555
00:30:05,000 --> 00:30:08,440
Speaker 2: ignoring the internal details, not having to know them. Like

556
00:30:08,480 --> 00:30:10,920
Speaker 2: when we did that calculation of the baseball flying across

557
00:30:10,920 --> 00:30:12,840
Speaker 2: the field, we didn't have to keep track of all

558
00:30:12,880 --> 00:30:15,560
Speaker 2: the electrons and even the air resistance on all those

559
00:30:15,560 --> 00:30:18,160
Speaker 2: details to mostly get the right answer. You can do

560
00:30:18,240 --> 00:30:21,000
Speaker 2: physics at lots of different scales. So even if the

561
00:30:21,120 --> 00:30:24,160
Speaker 2: universe infinitely is made of smaller stuff, or if there

562
00:30:24,240 --> 00:30:27,080
Speaker 2: is some fundamental chunk to it, we can still do

563
00:30:27,160 --> 00:30:30,720
Speaker 2: physics about it without even knowing the answer. So thanks

564
00:30:30,720 --> 00:30:33,160
Speaker 2: to the universe for being understandable at lots of levels

565
00:30:33,400 --> 00:30:36,520
Speaker 2: even before we figured out quantum gravity. You can imagine

566
00:30:36,520 --> 00:30:40,240
Speaker 2: another scenario where in order to do any calculation you

567
00:30:40,320 --> 00:30:42,480
Speaker 2: had to understand all the little bits inside of it.

568
00:30:42,560 --> 00:30:45,240
Speaker 2: You had to figure out the fundamentals of quantum gravity

569
00:30:45,440 --> 00:30:48,080
Speaker 2: before you could make chicken soup. Right, But fortunately in

570
00:30:48,120 --> 00:30:50,520
Speaker 2: our universe you can throw baseballs and make chicken soup

571
00:30:50,560 --> 00:30:53,840
Speaker 2: and play violins without understanding all the details, so we

572
00:30:53,880 --> 00:30:57,000
Speaker 2: can make progress. We can say, well, maybe electrons are

573
00:30:57,040 --> 00:30:59,920
Speaker 2: made of strings without knowing whether those strings are also

574
00:31:00,080 --> 00:31:03,080
Speaker 2: made of something else, and still have some insight into

575
00:31:03,160 --> 00:31:05,680
Speaker 2: this layer of the universe, without knowing if there are

576
00:31:05,760 --> 00:31:07,120
Speaker 2: more layers beyond it.

577
00:31:07,400 --> 00:31:11,440
Speaker 1: So we've got possible strings that we don't know exactly

578
00:31:11,440 --> 00:31:14,160
Speaker 1: if they exist. But it's a line that can wiggle

579
00:31:14,200 --> 00:31:17,880
Speaker 1: in the way in which it wiggles forms some kind

580
00:31:17,880 --> 00:31:22,480
Speaker 1: of different thing, which I can kind of accept at

581
00:31:22,480 --> 00:31:25,200
Speaker 1: this point. Is that sort of it? In terms of

582
00:31:25,240 --> 00:31:27,520
Speaker 1: string theories, it seems like there would probably be a

583
00:31:27,560 --> 00:31:29,760
Speaker 1: lot more complexity involved.

584
00:31:30,000 --> 00:31:33,480
Speaker 2: Yeah, there is more complexity. The mathematics of those strings

585
00:31:33,520 --> 00:31:36,240
Speaker 2: is very cool. At first, when people were working it out,

586
00:31:36,560 --> 00:31:39,520
Speaker 2: they were only able to use strings to describe some

587
00:31:39,640 --> 00:31:42,640
Speaker 2: kinds of particles, particles that we call bosons, which are

588
00:31:42,920 --> 00:31:45,760
Speaker 2: photons and the W and the Z and the higgs

589
00:31:46,280 --> 00:31:48,600
Speaker 2: and the gluons. These are all the bosons, the force

590
00:31:48,680 --> 00:31:53,120
Speaker 2: carrying particles. So the original string theory could only describe bosons.

591
00:31:53,560 --> 00:31:55,400
Speaker 2: And then people worked on it and found new ways

592
00:31:55,400 --> 00:31:58,640
Speaker 2: for those strings to wiggle, so they could also describe fermions,

593
00:31:58,680 --> 00:32:02,240
Speaker 2: and that's called super string theory. Super as a reference

594
00:32:02,280 --> 00:32:06,480
Speaker 2: to this other idea, supersymmetry, which connects fermions and bosons.

595
00:32:06,760 --> 00:32:09,040
Speaker 2: Check out our whole episode about that. But so then

596
00:32:09,040 --> 00:32:11,880
Speaker 2: people developed super string theory, and then there was this

597
00:32:11,920 --> 00:32:14,080
Speaker 2: sort of revolution in the nineteen eighties when people got

598
00:32:14,120 --> 00:32:16,320
Speaker 2: really excited about it. They call it the first super

599
00:32:16,320 --> 00:32:19,440
Speaker 2: string revolution. And that's when people realize, Wow, this string

600
00:32:19,480 --> 00:32:22,120
Speaker 2: theory is not just a cool mathematical model. It can

601
00:32:22,160 --> 00:32:24,680
Speaker 2: describe all the kinds of particles in our universe. And

602
00:32:24,920 --> 00:32:28,480
Speaker 2: also it seems like a very promising theory of quantum gravity.

603
00:32:28,480 --> 00:32:30,520
Speaker 2: They were able to avoid some of the infinities of

604
00:32:30,560 --> 00:32:34,080
Speaker 2: earlier attempts the problems with gravitons by describing things in

605
00:32:34,200 --> 00:32:36,920
Speaker 2: terms of strings. So it was a very exciting time.

606
00:32:37,280 --> 00:32:39,320
Speaker 2: A lot of people worked on it, and the problem

607
00:32:39,400 --> 00:32:42,080
Speaker 2: was that they had lots of different ideas. So there's

608
00:32:42,120 --> 00:32:44,640
Speaker 2: not like one string theory or one way to do

609
00:32:44,680 --> 00:32:47,400
Speaker 2: string theory. People figured out a bunch of different kinds

610
00:32:47,440 --> 00:32:50,360
Speaker 2: of string theories, like you can have strings that are

611
00:32:50,400 --> 00:32:53,160
Speaker 2: always open, like they're just lines, or strings that are

612
00:32:53,160 --> 00:32:55,360
Speaker 2: closed which means they're loops, or you can have a

613
00:32:55,400 --> 00:32:58,200
Speaker 2: theory with strings sometimes are open and sometimes are closed,

614
00:32:58,680 --> 00:33:02,280
Speaker 2: or different kinds of ways to solve super gravity. And

615
00:33:02,320 --> 00:33:04,400
Speaker 2: so at the end of the eighties there was sort

616
00:33:04,400 --> 00:33:07,480
Speaker 2: of a confusion because there were like five different types

617
00:33:07,520 --> 00:33:10,200
Speaker 2: of string theory that were all seemed very very different

618
00:33:10,240 --> 00:33:12,239
Speaker 2: and all kind of worked, and people weren't sure sort

619
00:33:12,280 --> 00:33:13,320
Speaker 2: of where to go from there.

620
00:33:13,840 --> 00:33:15,880
Speaker 1: Right. I mean, that seems kind of tricky because it's

621
00:33:15,920 --> 00:33:20,080
Speaker 1: almost like you're sort of filling in the gaps, right

622
00:33:20,280 --> 00:33:22,720
Speaker 1: with these different theories, and you can it seems like

623
00:33:22,760 --> 00:33:24,640
Speaker 1: they were able to come up with different sort of

624
00:33:25,160 --> 00:33:28,680
Speaker 1: math or different theories that did fill that gap in

625
00:33:28,760 --> 00:33:32,960
Speaker 1: different ways, and so I don't know how you would

626
00:33:33,240 --> 00:33:35,960
Speaker 1: pick which one works if they all sort of can

627
00:33:36,440 --> 00:33:38,560
Speaker 1: on average kind of like fix that gap.

628
00:33:39,560 --> 00:33:42,360
Speaker 2: And that's very unsatisfying, right, because we think the universe

629
00:33:42,400 --> 00:33:44,840
Speaker 2: is following a set of laws. We think there is

630
00:33:44,960 --> 00:33:47,520
Speaker 2: one set of laws, and so then if you find

631
00:33:47,560 --> 00:33:50,920
Speaker 2: like two explanations for the universe that both work, you're like, well,

632
00:33:50,960 --> 00:33:52,640
Speaker 2: which one is really happening?

633
00:33:52,920 --> 00:33:53,040
Speaker 1: Right?

634
00:33:53,080 --> 00:33:55,280
Speaker 2: You know, is a deep philosophical question.

635
00:33:55,840 --> 00:33:58,760
Speaker 1: Could there actually be something where on this level there

636
00:33:58,760 --> 00:34:02,440
Speaker 1: could be multiple sets of rules that all work at

637
00:34:02,440 --> 00:34:03,080
Speaker 1: the same time.

638
00:34:03,880 --> 00:34:07,520
Speaker 2: Yeah, philosophers think it's possible that there are multiple explanations

639
00:34:07,560 --> 00:34:11,200
Speaker 2: for the universe, multiple theories that predict the universe and

640
00:34:11,320 --> 00:34:15,640
Speaker 2: describe it and explain what's happening, but have fundamentally different

641
00:34:15,680 --> 00:34:18,160
Speaker 2: stories about sort of what's going on behind the curtain.

642
00:34:18,440 --> 00:34:20,319
Speaker 2: We don't know if that's possible, but there's a group

643
00:34:20,360 --> 00:34:23,040
Speaker 2: of philosophers who think it might be. And boy, I

644
00:34:23,080 --> 00:34:26,520
Speaker 2: hope they're wrong because that would be very frustrating. In

645
00:34:26,600 --> 00:34:29,320
Speaker 2: the stupid strink community also was hoping they were wrong.

646
00:34:29,360 --> 00:34:31,919
Speaker 2: And we're trying to figure out this puzzle, and one

647
00:34:31,920 --> 00:34:33,560
Speaker 2: way to try to figure it out is to see

648
00:34:33,719 --> 00:34:37,479
Speaker 2: are there connections between these different theories. Can we show

649
00:34:37,480 --> 00:34:40,920
Speaker 2: that actually these theories are really the same thing dressed

650
00:34:41,000 --> 00:34:43,880
Speaker 2: up in different clothing, Like are we really just telling

651
00:34:43,920 --> 00:34:47,279
Speaker 2: the same story using different words or using different symbols.

652
00:34:47,560 --> 00:34:50,640
Speaker 2: It harkens back to like the nineteen twenties when people

653
00:34:50,719 --> 00:34:54,279
Speaker 2: were developing quantum mechanics, for example, and you had Schroeninger

654
00:34:54,320 --> 00:34:56,759
Speaker 2: he had his wave equation of quantum mechanics, and you

655
00:34:56,800 --> 00:35:00,000
Speaker 2: had Heisenberg, he had his matrix formulation of quantum mechanics,

656
00:35:00,280 --> 00:35:02,799
Speaker 2: and those two guys did not like each other. In fact,

657
00:35:03,000 --> 00:35:06,719
Speaker 2: they hated each other, and they also disliked each other's ideas,

658
00:35:07,280 --> 00:35:10,600
Speaker 2: like Heisenberg really didn't like Schrodinger's wave equation. You thought

659
00:35:10,600 --> 00:35:12,840
Speaker 2: it made quantum mechanics like too visual, it gave you

660
00:35:12,880 --> 00:35:15,440
Speaker 2: a mental image when in stage you just focus on

661
00:35:15,480 --> 00:35:19,239
Speaker 2: the math of the matrices. And everybody else hated Heisenberg's

662
00:35:19,239 --> 00:35:22,960
Speaker 2: matrices because nobody could understand what they meant. And then

663
00:35:23,000 --> 00:35:26,200
Speaker 2: a few decades later John von Neumann showed actually they're

664
00:35:26,200 --> 00:35:29,240
Speaker 2: the same. They make the same calculations. You can convert

665
00:35:29,280 --> 00:35:31,959
Speaker 2: one into the other, and so they're just like two

666
00:35:32,040 --> 00:35:34,759
Speaker 2: different ways to write the same thing, the way that

667
00:35:34,920 --> 00:35:38,080
Speaker 2: like algebra and geometry are fundamentally the same. You want

668
00:35:38,120 --> 00:35:40,520
Speaker 2: to solve a system of equations like two lines, you

669
00:35:40,520 --> 00:35:42,440
Speaker 2: can either draw them on a piece of paper and

670
00:35:42,480 --> 00:35:44,239
Speaker 2: see when they cross, or you can do a bunch

671
00:35:44,280 --> 00:35:46,319
Speaker 2: of algebra and solve for it. In the end, those

672
00:35:46,360 --> 00:35:48,480
Speaker 2: feel like two different kinds of math, but they really

673
00:35:48,520 --> 00:35:53,080
Speaker 2: are revealing the same thing or the same relationship between concepts.

674
00:35:53,560 --> 00:35:56,640
Speaker 2: So people were wondering, can we do that first dring theory?

675
00:35:56,680 --> 00:35:59,160
Speaker 2: Can we show that these different string theories They're called

676
00:35:59,160 --> 00:36:03,080
Speaker 2: type one, type two A, type two B, so.

677
00:36:03,120 --> 00:36:05,240
Speaker 1: Thirty two sounds like a disease.

678
00:36:05,760 --> 00:36:08,880
Speaker 2: And E eight x E eight. These are crazy names,

679
00:36:09,000 --> 00:36:12,400
Speaker 2: I know, terrible, terrible names. Will be deeply offended.

680
00:36:12,560 --> 00:36:15,719
Speaker 1: I have type one string theory.

681
00:36:17,320 --> 00:36:21,239
Speaker 2: I'm so sorry, kame. There's a group for that. So

682
00:36:21,320 --> 00:36:25,160
Speaker 2: people were wondering, is it possible these actually are different

683
00:36:25,200 --> 00:36:28,600
Speaker 2: mathematical expressions for the same phenomena. And it was a

684
00:36:28,600 --> 00:36:32,319
Speaker 2: hard problem. But there are smart people out there, and

685
00:36:32,400 --> 00:36:35,040
Speaker 2: this guy, Ed Witten, maybe one of the smartest dudes ever.

686
00:36:35,360 --> 00:36:39,040
Speaker 2: He's at the Institute for Advanced Studies near Princeton, and

687
00:36:39,080 --> 00:36:42,520
Speaker 2: he was playing with these strings. Remember, the strings don't

688
00:36:42,680 --> 00:36:45,399
Speaker 2: just exist in our three dimensions of space, the math

689
00:36:45,480 --> 00:36:48,720
Speaker 2: works best if space has nine dimensions. So these strings

690
00:36:48,760 --> 00:36:53,239
Speaker 2: are one dimensional lines through nine dimensional space, our three dimensions,

691
00:36:53,239 --> 00:36:56,239
Speaker 2: and then six more dimensions that we can't sense or

692
00:36:56,320 --> 00:36:59,880
Speaker 2: perceive or really experience in any way, but the strings

693
00:37:00,120 --> 00:37:02,760
Speaker 2: need them in order to make their math wiggle correctly.

694
00:37:03,239 --> 00:37:06,879
Speaker 1: Hmm, yeah, no, I mean I think this is it's

695
00:37:06,920 --> 00:37:11,320
Speaker 1: always a wild time trying to think about other dimensions,

696
00:37:11,360 --> 00:37:15,319
Speaker 1: because we could probably explain other dimensions with math, but

697
00:37:15,480 --> 00:37:18,120
Speaker 1: to try to conceptualize them, I don't know if that's

698
00:37:18,120 --> 00:37:21,440
Speaker 1: even possible with our brains, given that our brains are

699
00:37:21,920 --> 00:37:25,839
Speaker 1: three dimensional brains and function in a sort of three

700
00:37:25,880 --> 00:37:31,000
Speaker 1: dimensional way. So without your neurons being able to span

701
00:37:31,160 --> 00:37:34,640
Speaker 1: into the other six dimensions, that seems difficult.

702
00:37:34,800 --> 00:37:37,319
Speaker 2: It is very difficult. You're right, We intuitively think in

703
00:37:37,400 --> 00:37:40,719
Speaker 2: three dimensions. It's very hard to think in additional dimensions.

704
00:37:41,000 --> 00:37:44,239
Speaker 2: It's even hard to think in fewer dimensions. Like if

705
00:37:44,280 --> 00:37:47,200
Speaker 2: you try to imagine a two D sheet or one

706
00:37:47,280 --> 00:37:50,799
Speaker 2: D line, you're imagining it in three D space. You

707
00:37:50,840 --> 00:37:53,160
Speaker 2: put that sheet into three D space, or that line

708
00:37:53,200 --> 00:37:55,320
Speaker 2: in three D space. Or if I tell you imagine

709
00:37:55,320 --> 00:37:57,719
Speaker 2: a zero dimensional dot, you think of a point and

710
00:37:57,760 --> 00:38:00,400
Speaker 2: you sketch it out into some three D space, because

711
00:38:00,400 --> 00:38:03,040
Speaker 2: that's the natural playground of our mind. So if you

712
00:38:03,080 --> 00:38:05,920
Speaker 2: can't go down the dimension, there's no hope angling up

713
00:38:05,920 --> 00:38:07,920
Speaker 2: a dimension. It's really very difficult.

714
00:38:08,040 --> 00:38:10,880
Speaker 1: I almost passed out once trying to think about like nothing,

715
00:38:11,120 --> 00:38:13,680
Speaker 1: like going you know, sort of the zero dimension thing,

716
00:38:13,760 --> 00:38:17,080
Speaker 1: trying to think about nothing. And I felt very weird

717
00:38:17,120 --> 00:38:19,000
Speaker 1: to try to think about that for too long. It

718
00:38:19,000 --> 00:38:21,440
Speaker 1: felt like my brain was kind of leaving my body.

719
00:38:22,320 --> 00:38:25,000
Speaker 1: Maybe I was just sleepy. I don't know. But yeah.

720
00:38:25,320 --> 00:38:27,960
Speaker 1: There's also that book Flat Landers, where it tries to,

721
00:38:29,120 --> 00:38:32,480
Speaker 1: in an artistic way, represent how difficult it is to

722
00:38:32,880 --> 00:38:36,000
Speaker 1: bridge the gap between a two D existence and a

723
00:38:36,040 --> 00:38:39,520
Speaker 1: three D existence. But you know, fundamentally, even that book

724
00:38:39,640 --> 00:38:43,600
Speaker 1: is describing it as a visual experience where having vision

725
00:38:43,719 --> 00:38:48,680
Speaker 1: requires three dimensions. It seems so yeah, and.

726
00:38:48,680 --> 00:38:51,799
Speaker 2: So making progress on this requires super smart dudes to

727
00:38:51,840 --> 00:38:55,040
Speaker 2: do superstring theory. And so Edwinten was thinking about these

728
00:38:55,560 --> 00:38:59,120
Speaker 2: nine dimensional strings, and so those theories are ten dimensional

729
00:38:59,160 --> 00:39:02,239
Speaker 2: because it's nine facial dimensions and one time dimension. He

730
00:39:02,320 --> 00:39:04,799
Speaker 2: was thinking about these nine dimensional strings, and he was

731
00:39:04,840 --> 00:39:08,439
Speaker 2: inspired by this leap from zero dimensional points to one

732
00:39:08,480 --> 00:39:11,680
Speaker 2: dimensional lines. Strings and he was wondering, should we take

733
00:39:11,680 --> 00:39:15,160
Speaker 2: it a step further. Instead of thinking about these things

734
00:39:15,200 --> 00:39:18,439
Speaker 2: as one D strings in nine dimensional spaces, maybe they're

735
00:39:18,480 --> 00:39:25,680
Speaker 2: actually two dimensional objects membranes, right, sheets in higher dimensional space.

736
00:39:25,960 --> 00:39:29,200
Speaker 2: And so these would be like two D sheets in

737
00:39:29,440 --> 00:39:33,840
Speaker 2: ten dimensional space, which looks like one dimensional objects strings

738
00:39:34,000 --> 00:39:37,120
Speaker 2: if you only look at them in nine dimensions. So

739
00:39:37,160 --> 00:39:40,680
Speaker 2: the idea is he invents this extra dimension, this eleventh

740
00:39:40,719 --> 00:39:44,040
Speaker 2: dimension or a tenth dimension of space, and extends the

741
00:39:44,120 --> 00:39:47,439
Speaker 2: strings into that space to make them into membranes.

742
00:39:48,440 --> 00:39:50,000
Speaker 1: So more like a sheets theory.

743
00:39:50,440 --> 00:39:52,480
Speaker 2: Yeah, exactly, from strings to.

744
00:39:52,560 --> 00:39:56,200
Speaker 1: Sheets sponsored by sheets the convenience store and gas station.

745
00:39:58,960 --> 00:40:02,879
Speaker 2: So the exciting thing is that Witten thought that if

746
00:40:02,920 --> 00:40:07,080
Speaker 2: you worked with membranes instead of strings, you could explain

747
00:40:07,239 --> 00:40:11,160
Speaker 2: all these different string theories. That these five string theories

748
00:40:11,160 --> 00:40:14,160
Speaker 2: were actually just five different ways to look at the

749
00:40:14,200 --> 00:40:16,279
Speaker 2: same sheet. So you roll it up this way, it

750
00:40:16,280 --> 00:40:18,160
Speaker 2: looks like one. You roll it up another way it

751
00:40:18,200 --> 00:40:20,600
Speaker 2: looks like another. You look at it from this perspective,

752
00:40:20,640 --> 00:40:23,280
Speaker 2: it looks like a different string theory. But these five

753
00:40:23,400 --> 00:40:26,040
Speaker 2: string theories that people were playing with and confused about

754
00:40:26,360 --> 00:40:30,840
Speaker 2: were actually just like extreme examples of one membrane theory,

755
00:40:31,400 --> 00:40:33,879
Speaker 2: and this this famous talkie gives at University of Southern

756
00:40:33,960 --> 00:40:36,880
Speaker 2: California in ninety five where he points this out and

757
00:40:36,880 --> 00:40:39,840
Speaker 2: he makes this connection, and he has this diagram on

758
00:40:39,880 --> 00:40:42,799
Speaker 2: the slide which is just like all five theories and

759
00:40:42,800 --> 00:40:44,680
Speaker 2: it just like draws lines between them.

760
00:40:44,960 --> 00:40:47,920
Speaker 1: Is it like a corkboard was the eldest shoveled?

761
00:40:48,480 --> 00:40:51,799
Speaker 2: It's exactly like that. Yeah, it's not very compelling as

762
00:40:51,840 --> 00:40:55,360
Speaker 2: a diagram, and even his explanation is somewhat lacking. You know,

763
00:40:55,440 --> 00:40:57,080
Speaker 2: he doesn't have all the math. He has sort of

764
00:40:57,120 --> 00:41:00,680
Speaker 2: like this leap of intuition. He has some hints that

765
00:41:00,680 --> 00:41:02,640
Speaker 2: these things do connect to each other. It's like a

766
00:41:02,680 --> 00:41:05,399
Speaker 2: new direction forward. And it's sort of like the way

767
00:41:05,480 --> 00:41:08,120
Speaker 2: Fineman worked. You know, Fineman developed QED and he didn't

768
00:41:08,120 --> 00:41:10,960
Speaker 2: work out all the math came later when like Schwinger

769
00:41:11,000 --> 00:41:13,160
Speaker 2: worked through all the details to prove that Fineman's leaps

770
00:41:13,160 --> 00:41:15,799
Speaker 2: of intuition were correct. Witness sort of similar. He's like

771
00:41:16,080 --> 00:41:18,560
Speaker 2: sees these connections in his brain. He knows that it

772
00:41:18,600 --> 00:41:20,959
Speaker 2: can work, even if he hasn't like actually sat down

773
00:41:21,000 --> 00:41:24,160
Speaker 2: and worked through it all. And so this one talk

774
00:41:24,239 --> 00:41:27,280
Speaker 2: in ninety five inspired what they called the Second super

775
00:41:27,360 --> 00:41:30,480
Speaker 2: string Revolution and led to like hundreds and hundreds of

776
00:41:30,480 --> 00:41:35,080
Speaker 2: papers of people working on membranes. The interesting thing is

777
00:41:35,160 --> 00:41:38,640
Speaker 2: that Witten himself wasn't actually sure that membranes who were

778
00:41:38,680 --> 00:41:41,400
Speaker 2: going to work. He was like, hmm, it might be membranes,

779
00:41:41,440 --> 00:41:43,520
Speaker 2: it might not be memoranes. I'm not sure. He knew

780
00:41:43,560 --> 00:41:45,800
Speaker 2: that these things were connected, but he didn't want to

781
00:41:45,840 --> 00:41:49,799
Speaker 2: actually call his theory membrane theory, so he just called

782
00:41:49,800 --> 00:41:52,800
Speaker 2: it M theory, and he wrote in his paper quote,

783
00:41:52,920 --> 00:41:56,360
Speaker 2: we will non committally call it the M theory, leaving

784
00:41:56,560 --> 00:42:00,440
Speaker 2: to the future the revelation of M to membranes, Like

785
00:42:00,680 --> 00:42:02,640
Speaker 2: people really worked through the math and showed that these

786
00:42:02,680 --> 00:42:06,480
Speaker 2: things were two D objects or actually ten D objects,

787
00:42:06,719 --> 00:42:08,879
Speaker 2: then we could call it membrane theory. But until then,

788
00:42:09,200 --> 00:42:11,239
Speaker 2: let's just keep it M theory in case it turns

789
00:42:11,239 --> 00:42:14,200
Speaker 2: out to be like mouse theory or mama theory or

790
00:42:14,200 --> 00:42:14,960
Speaker 2: something else.

791
00:42:15,400 --> 00:42:17,920
Speaker 1: Yeah. No, I mean I like that your hedge in

792
00:42:17,960 --> 00:42:20,600
Speaker 1: your bets. I also like this guy kind of sounds

793
00:42:20,640 --> 00:42:23,200
Speaker 1: like there's this I forgot his name, but I think

794
00:42:23,239 --> 00:42:29,200
Speaker 1: he is like a quote unquote neurosurgeon who kept claiming

795
00:42:29,680 --> 00:42:34,439
Speaker 1: that he could do like head transplants, and his demonstration

796
00:42:34,640 --> 00:42:37,839
Speaker 1: was a bunch of dried spaghetti and a banana to

797
00:42:37,960 --> 00:42:41,439
Speaker 1: show how you could basically like connect all of the

798
00:42:41,560 --> 00:42:45,400
Speaker 1: arteries and spinal cord and everything. I think maybe the

799
00:42:45,440 --> 00:42:48,040
Speaker 1: banana was supposed to be the spinal cord. Anyways, it

800
00:42:48,080 --> 00:42:53,839
Speaker 1: was like a spaghetti banana demonstration, which did not inspire confidence. So,

801
00:42:55,560 --> 00:42:58,160
Speaker 1: of course, I think with the physics, when you go

802
00:42:58,239 --> 00:43:01,200
Speaker 1: out on a branch in terms of physics, it's maybe

803
00:43:01,320 --> 00:43:04,000
Speaker 1: less risky than trusting someone who says they can do

804
00:43:04,040 --> 00:43:05,000
Speaker 1: a head transplant.

805
00:43:06,160 --> 00:43:09,040
Speaker 2: Yeah, so I think Edwinten. I wouldn't trust him to

806
00:43:09,080 --> 00:43:12,080
Speaker 2: do a head transplant. But I'm glad that he's around

807
00:43:12,120 --> 00:43:14,960
Speaker 2: and he's helping us figure out the mysteries of quantum gravity.

808
00:43:15,640 --> 00:43:17,799
Speaker 2: And it's really cool that he was able to show

809
00:43:17,840 --> 00:43:21,040
Speaker 2: that these theories are related to each other. You know,

810
00:43:21,080 --> 00:43:24,279
Speaker 2: there are these funny dualities they find where they show

811
00:43:24,320 --> 00:43:27,719
Speaker 2: that this theory is mathematically equivalent to that theory. You know,

812
00:43:27,800 --> 00:43:30,000
Speaker 2: like this theory if you make it really strong, looks

813
00:43:30,040 --> 00:43:32,120
Speaker 2: like that theory if you make it really weak. It's

814
00:43:32,160 --> 00:43:34,880
Speaker 2: fascinating to show that the theories, even though they have

815
00:43:35,200 --> 00:43:39,000
Speaker 2: again very different of mathematical foundations. They really are exploring

816
00:43:39,000 --> 00:43:43,360
Speaker 2: the same concepts because the symbolism, the notation we use

817
00:43:43,840 --> 00:43:46,799
Speaker 2: is really just a way to describe the abstract ideas.

818
00:43:46,840 --> 00:43:49,680
Speaker 2: And so even if you use different notations and different symbols,

819
00:43:49,719 --> 00:43:52,080
Speaker 2: if you can show that the ideas are equivalent, then

820
00:43:52,120 --> 00:43:54,799
Speaker 2: you really have made a connection between them. And it's

821
00:43:54,840 --> 00:43:57,200
Speaker 2: a relief also to think, like, well, maybe there is

822
00:43:57,239 --> 00:43:59,480
Speaker 2: a connection, because then we don't have to pick one

823
00:43:59,520 --> 00:44:01,120
Speaker 2: of the theory. We don't have to have a reason

824
00:44:01,239 --> 00:44:03,640
Speaker 2: to choose one. We can just say, oh, they're all

825
00:44:03,680 --> 00:44:06,759
Speaker 2: just special cases of one unifying idea. And in the end,

826
00:44:07,120 --> 00:44:09,400
Speaker 2: that's what physics is trying to do, is come up

827
00:44:09,400 --> 00:44:13,480
Speaker 2: with some unifying, simplifying explanation for everything we see out

828
00:44:13,520 --> 00:44:14,520
Speaker 2: there in the universe.

829
00:44:14,800 --> 00:44:17,120
Speaker 1: I mean, I find it really appealing not having to

830
00:44:17,719 --> 00:44:22,080
Speaker 1: make a decision between like really hard choices. That sounds great.

831
00:44:22,200 --> 00:44:25,560
Speaker 1: Sign me up for physics. Let's take a really quick break,

832
00:44:25,640 --> 00:44:29,080
Speaker 1: and then when we get back, let's talk more about

833
00:44:29,120 --> 00:44:32,160
Speaker 1: membrane theory and how it could tie everything up in

834
00:44:32,200 --> 00:44:47,680
Speaker 1: a nice little bow. All right, So I was a

835
00:44:47,800 --> 00:44:50,799
Speaker 1: little bit glib about tying everything up in a nice

836
00:44:50,800 --> 00:44:54,560
Speaker 1: little bow. I know that is the desire of physics,

837
00:44:54,600 --> 00:44:56,880
Speaker 1: and yet it seems pretty tricky to do that.

838
00:44:58,920 --> 00:45:02,040
Speaker 2: It is pretty tricky, but along the way, we can

839
00:45:02,280 --> 00:45:07,080
Speaker 2: entertain ourselves by amusing notation and making up really weird

840
00:45:07,120 --> 00:45:10,080
Speaker 2: phrases and names for things. So physics, as everybody knows,

841
00:45:10,200 --> 00:45:13,040
Speaker 2: is very good at using inappropriate and confusing words to

842
00:45:13,080 --> 00:45:17,520
Speaker 2: describe things. And so physicists have taken this phrase membrane

843
00:45:17,840 --> 00:45:21,359
Speaker 2: and tried to generalize it to any dimensional surface. So, like,

844
00:45:21,680 --> 00:45:23,800
Speaker 2: you know, a membrane is like a two D surface.

845
00:45:23,840 --> 00:45:26,320
Speaker 2: You can imagine like a sheet or like a cell wall.

846
00:45:26,360 --> 00:45:30,200
Speaker 2: It's two dimensions, right, And so physicists don't call that

847
00:45:30,239 --> 00:45:33,560
Speaker 2: a membrane. They call that a two brain, okay, so

848
00:45:33,600 --> 00:45:36,799
Speaker 2: that they can call a string a one brain, or

849
00:45:36,800 --> 00:45:45,080
Speaker 2: like the point a zero brain. You're a zero brain, yeah, exactly. Well,

850
00:45:45,120 --> 00:45:48,279
Speaker 2: even worse is the general phrase for it. If you

851
00:45:48,400 --> 00:45:51,280
Speaker 2: have a surface in P dimensions, you call it a

852
00:45:51,320 --> 00:45:51,880
Speaker 2: P brain.

853
00:45:52,120 --> 00:45:54,520
Speaker 1: That's what I call my dog all the time. I'm like,

854
00:45:54,560 --> 00:45:56,160
Speaker 1: look at you, old pepe brain.

855
00:45:56,880 --> 00:45:59,400
Speaker 2: Yeah, well you didn't realize you're actually giving it a

856
00:45:59,480 --> 00:46:03,120
Speaker 2: vast You're connecting it to the fundamental theory of the universe.

857
00:46:03,200 --> 00:46:06,080
Speaker 2: Maybe cookie can reveal something true about reality.

858
00:46:06,280 --> 00:46:09,080
Speaker 1: I look into her eyes, I see these deep pools

859
00:46:09,120 --> 00:46:11,400
Speaker 1: of knowledge. But then it turns out she just had

860
00:46:11,440 --> 00:46:12,120
Speaker 1: to burn.

861
00:46:14,200 --> 00:46:15,800
Speaker 2: Cookie, had too many cookies.

862
00:46:15,840 --> 00:46:21,560
Speaker 1: It sounds like, yeah, exactly. So now I'm confused because

863
00:46:21,960 --> 00:46:25,920
Speaker 1: I kind of got the idea of the membrane being like,

864
00:46:26,400 --> 00:46:28,840
Speaker 1: it's not a point, it's not a line. It's like

865
00:46:28,920 --> 00:46:32,160
Speaker 1: a plane, but not necessarily a flat plane, one that

866
00:46:32,200 --> 00:46:37,040
Speaker 1: could be sort of wrapped around different dimensions. So I

867
00:46:37,120 --> 00:46:40,720
Speaker 1: kind of get that. Now we're sort of this terminology

868
00:46:40,760 --> 00:46:45,120
Speaker 1: of zero brain being a point, one brain being a string,

869
00:46:45,320 --> 00:46:48,319
Speaker 1: two brain being a two D surface. What is the

870
00:46:48,400 --> 00:46:52,879
Speaker 1: point of having brain in there? Like as a term?

871
00:46:52,960 --> 00:46:55,080
Speaker 1: Like what and I don't mean this like in a

872
00:46:55,440 --> 00:46:58,239
Speaker 1: mean way, just like what purpose is that serving in

873
00:46:58,320 --> 00:47:01,960
Speaker 1: terms of helping with the research or the explanation.

874
00:47:02,560 --> 00:47:05,200
Speaker 2: Yeah, it's a good question. Maybe physicists just like saying

875
00:47:05,280 --> 00:47:08,680
Speaker 2: brain because it doesn't sound smart, sounds like they're talking

876
00:47:08,680 --> 00:47:12,520
Speaker 2: about their brains. But physicists like to think about different

877
00:47:12,600 --> 00:47:15,920
Speaker 2: versions of ideas, not to be limited by our experience

878
00:47:16,040 --> 00:47:18,520
Speaker 2: of the universe, you know, where we have one dimensional

879
00:47:18,560 --> 00:47:21,200
Speaker 2: objects and two dimensional objects and three dimensional objects. They'd

880
00:47:21,239 --> 00:47:23,600
Speaker 2: like to generalize it and to be opened to other

881
00:47:23,640 --> 00:47:27,840
Speaker 2: dimensions and other scales, and so for example, Edwinton's first

882
00:47:27,880 --> 00:47:30,759
Speaker 2: idea was maybe the way to do this is to

883
00:47:30,880 --> 00:47:34,560
Speaker 2: use two dimensional sheets, which is fascinating to think, like, Okay,

884
00:47:34,600 --> 00:47:38,040
Speaker 2: the universe isn't made of points of stuff or even

885
00:47:38,160 --> 00:47:41,480
Speaker 2: lines of stuff, but maybe like sheets of stuff. It

886
00:47:41,480 --> 00:47:44,279
Speaker 2: would be pretty weird if the universe was made of

887
00:47:44,280 --> 00:47:47,160
Speaker 2: two dimensional things the fundamental nature of it, the basic

888
00:47:47,200 --> 00:47:51,360
Speaker 2: building block where sheets, that would be weird. But recently

889
00:47:51,400 --> 00:47:54,720
Speaker 2: people have been making some progress in an alternative version

890
00:47:54,960 --> 00:47:58,239
Speaker 2: of m theory in which the brains are five dimensionals,

891
00:47:58,320 --> 00:48:01,600
Speaker 2: so they use five brains, meaning that like you still

892
00:48:01,640 --> 00:48:04,600
Speaker 2: work in a theory where there are ten spatial dimensions

893
00:48:04,600 --> 00:48:07,080
Speaker 2: in one time dimension, but the fundamental building blocks of

894
00:48:07,080 --> 00:48:11,719
Speaker 2: the universe are not sheets. There five dimensional objects, which

895
00:48:11,840 --> 00:48:15,160
Speaker 2: is pretty hard to think about and impossible to visualize

896
00:48:15,160 --> 00:48:16,480
Speaker 2: with our three brains.

897
00:48:16,840 --> 00:48:21,440
Speaker 1: Yeah, that's an interesting thing because usually the intuitive direction

898
00:48:21,960 --> 00:48:26,239
Speaker 1: of units right of stuff or like building blocks of

899
00:48:26,239 --> 00:48:30,239
Speaker 1: stuff is like you go from simple to more complex, right,

900
00:48:30,400 --> 00:48:34,640
Speaker 1: so like you'd start out with you know, zero dimensions

901
00:48:34,680 --> 00:48:37,880
Speaker 1: than one dimensions than two dimensions and three dimensions than

902
00:48:37,920 --> 00:48:40,480
Speaker 1: four dimensions, et cetera. Right, and then like as you

903
00:48:40,520 --> 00:48:43,560
Speaker 1: get to the smaller building blocks, the kind of intuitive

904
00:48:43,640 --> 00:48:46,600
Speaker 1: way is like the smaller the building block, the fewer

905
00:48:46,640 --> 00:48:49,400
Speaker 1: the dimensions. Right. But I think it is really interesting

906
00:48:49,440 --> 00:48:53,280
Speaker 1: the idea that the smallest building block could be something

907
00:48:53,320 --> 00:48:59,360
Speaker 1: that is actually operates among you know, more dimensions than say,

908
00:48:59,600 --> 00:49:06,480
Speaker 1: we did as human consciousness. Is because that seems, I

909
00:49:06,520 --> 00:49:09,680
Speaker 1: don't know, for some reason, that makes more sense to

910
00:49:09,719 --> 00:49:13,280
Speaker 1: me than like the smallest unit being like a point,

911
00:49:14,200 --> 00:49:16,759
Speaker 1: even though I cannot there is no way I can

912
00:49:16,840 --> 00:49:20,799
Speaker 1: even begin to conceive of five dimensions without sounding like

913
00:49:20,840 --> 00:49:25,480
Speaker 1: I'm high on Joe Rogan, I.

914
00:49:25,400 --> 00:49:27,960
Speaker 2: Think you're right though, and I think the lesson there

915
00:49:28,160 --> 00:49:31,719
Speaker 2: is the universe is filled with surprises. You know. We

916
00:49:31,840 --> 00:49:34,160
Speaker 2: set up this question with we have a puzzle about

917
00:49:34,160 --> 00:49:36,719
Speaker 2: the fundamental nature of reality. Is a quantum mechanical? Is

918
00:49:36,719 --> 00:49:40,400
Speaker 2: it general relativistic? Is this something new and weird and different?

919
00:49:40,800 --> 00:49:43,640
Speaker 2: And we don't have an answer yet, But this line

920
00:49:43,640 --> 00:49:48,000
Speaker 2: of investigation building strings into membranes into p brains is

921
00:49:48,040 --> 00:49:51,280
Speaker 2: suggesting that we've been thinking about it wrong in terms

922
00:49:51,280 --> 00:49:54,279
Speaker 2: of tiny little objects that actually at the foundation of

923
00:49:54,320 --> 00:49:58,320
Speaker 2: the universe, the basic level of reality, the intellectual firmament

924
00:49:58,360 --> 00:50:02,200
Speaker 2: that we can finally reach built out of complex objects,

925
00:50:02,239 --> 00:50:05,480
Speaker 2: objects with five dimensions to them, or even two dimensions.

926
00:50:06,280 --> 00:50:08,840
Speaker 2: And that's the kind of revelation we're looking for, you know,

927
00:50:08,880 --> 00:50:12,080
Speaker 2: that's exactly the hope that the math points us to

928
00:50:12,280 --> 00:50:14,799
Speaker 2: structures that tell us something about what's actually happening out

929
00:50:14,840 --> 00:50:17,280
Speaker 2: there in reality. And in a way, that's a surprise,

930
00:50:17,600 --> 00:50:21,359
Speaker 2: because I don't expect our intuition to correctly guess how

931
00:50:21,400 --> 00:50:23,880
Speaker 2: the universe works. I expect it to be a surprise.

932
00:50:23,960 --> 00:50:26,719
Speaker 2: It would be quite disappointing if the universe was a

933
00:50:26,719 --> 00:50:29,440
Speaker 2: certain way and we were like, oh, yeah, that makes sense. Instead,

934
00:50:29,480 --> 00:50:31,520
Speaker 2: I want that moment where we're like, oh, wow, the

935
00:50:31,640 --> 00:50:34,440
Speaker 2: universe actually works in this weird way, how could that

936
00:50:34,520 --> 00:50:37,600
Speaker 2: possibly be? And then it requires like a reworking off

937
00:50:37,640 --> 00:50:40,799
Speaker 2: your mental model to incorporate that, But that brings you

938
00:50:40,880 --> 00:50:43,680
Speaker 2: more in aligned with the way the universe actually works.

939
00:50:43,719 --> 00:50:46,440
Speaker 2: And that's kind of the whole goal of science, right,

940
00:50:46,480 --> 00:50:49,680
Speaker 2: is to align our brains with the workings of the universe,

941
00:50:49,960 --> 00:50:53,799
Speaker 2: not just our silly, clueless, primitive guesses about how the

942
00:50:53,880 --> 00:50:54,920
Speaker 2: universe might work.

943
00:50:55,280 --> 00:50:57,840
Speaker 1: So if it was up to me, I would just

944
00:50:57,880 --> 00:51:01,319
Speaker 1: hazard a guess that the universe is man, little worms, man,

945
00:51:01,840 --> 00:51:03,400
Speaker 1: just tile worms.

946
00:51:04,360 --> 00:51:06,960
Speaker 2: I see. So that's your worm brain theory of the universe.

947
00:51:06,800 --> 00:51:07,840
Speaker 1: My brain theory.

948
00:51:09,200 --> 00:51:10,440
Speaker 2: You and RFKU.

949
00:51:10,640 --> 00:51:13,520
Speaker 1: Yeah, I should run for president and me and my

950
00:51:13,600 --> 00:51:15,240
Speaker 1: worms know how.

951
00:51:15,080 --> 00:51:21,399
Speaker 2: To run this chuntry Vice President Terrence Howard, all right, well,

952
00:51:21,440 --> 00:51:24,680
Speaker 2: thanks for coming along on this crazy mental journey down

953
00:51:24,760 --> 00:51:27,240
Speaker 2: into the fundamental nature of the universe to think about

954
00:51:27,480 --> 00:51:31,480
Speaker 2: weird quantum objects, also obeying the rules of gravity and

955
00:51:31,560 --> 00:51:34,680
Speaker 2: revealing that the universe is made out of building blocks

956
00:51:34,680 --> 00:51:38,280
Speaker 2: that we do not yet understand, but they might require

957
00:51:38,360 --> 00:51:41,680
Speaker 2: one brain's two brains or p dimensional pea brains.

958
00:51:42,120 --> 00:51:45,000
Speaker 1: Thank you for helping me understand that the universe is

959
00:51:45,040 --> 00:51:47,480
Speaker 1: not made out of tiny violence. That really helps.

960
00:51:49,840 --> 00:51:52,240
Speaker 2: It's only possible because your brain is not a banana.

961
00:51:54,280 --> 00:51:56,879
Speaker 2: All right, Thanks very much everybody, and tune in next

962
00:51:56,920 --> 00:52:04,560
Speaker 2: time for more science and curiosity. Come find us on

963
00:52:04,640 --> 00:52:08,400
Speaker 2: social media where we answer questions and post videos. We're

964
00:52:08,400 --> 00:52:12,600
Speaker 2: on Twitter, Discorg, Instant, and now TikTok. Thanks for listening,

965
00:52:12,600 --> 00:52:15,319
Speaker 2: and remember that Daniel and Jorge Explain the Universe is

966
00:52:15,360 --> 00:52:19,959
Speaker 2: a production of iHeartRadio. For more podcasts from iHeartRadio, visit

967
00:52:20,000 --> 00:52:24,080
Speaker 2: the iHeartRadio, app, Apple podcasts, or wherever you listen to

968
00:52:24,120 --> 00:52:25,120
Speaker 2: your favorite shows.