Speaker 1: Hey, Daniel, I've got a black hole question for you.
Speaker 1: Are you still hoping to catch and raise a black
Speaker 1: hole as a pet in your backyard? I can't confirm
Speaker 1: or deny that, But my question is what happens to
Speaker 1: the stuff I put into the black hole? Is this
Speaker 1: a question you already asked the folks at pet Smart. Yeah.
Speaker 1: You know, like, say, if I drop a banana into
Speaker 1: a black hole, what what happens to it? Is it
Speaker 1: gone forever? My advice is don't do it? Which part
Speaker 1: raise a black hole or throw a banana into it?
Speaker 1: Because I may have done both already. What's the difference?
Speaker 1: I mean, if you feed a black hole, it will grow,
Speaker 1: and a growing black hole will eat more, and eventually
Speaker 1: it will eat your house and then mine. Okay, so
Speaker 1: it's not a good idea to use a black hole
Speaker 1: to make banana's booties. Officially, no, not a good idea. Hi,
Speaker 1: I'm poor. Hey, I'm a cartoonist and the creator of
Speaker 1: PhD comics. Hi, I'm Daniel. I'm a particle physicist, and
Speaker 1: I have never created a black hole to my knowledge.
Speaker 1: How do you know, Daniel? Maybe you do it in
Speaker 1: your sleep by accident. Hey, I can't be responsible for
Speaker 1: all incidental black holes I accidentally create, right, I mean,
Speaker 1: there's got to be some legal principle there. Do you
Speaker 1: ever take homes any work by accident, you know, like
Speaker 1: you guys suddenly bring home some particles or some black
Speaker 1: holes that were created at the LHC. Yeah, sometimes I
Speaker 1: go home with a few extra protons in my pocket.
Speaker 1: Nobody even notices that doesn't sound good. But welcome to
Speaker 1: our podcast, Daniel and Jorge Explain the Universe, a production
Speaker 1: of I Heart Radio, in which we tell you all
Speaker 1: about the mysteries of the university, incredible cosmic questions that
Speaker 1: still make scientists puzzled, the things that we all wonder
Speaker 1: about this incredible, beautiful universe that we live in that
Speaker 1: we all desperately like to understand. Yeah. I take home
Speaker 1: work all the time, Daniel, because I work from home
Speaker 1: my cartoonist. So I think you take your home to
Speaker 1: work then, don't you You know the tomato tomato, it's
Speaker 1: all the same thing. But that's right. This is our
Speaker 1: podcast about the universe and all the amazing and mysterious
Speaker 1: things that are out there for us to discover. That's right,
Speaker 1: all those weird things floating in the cosmos doing strange, violent,
Speaker 1: incredible stuff and our attempts as lowly humans to understand them.
Speaker 1: Is it really possible to unravel the mysteries of the
Speaker 1: universe and lay them out inside a human mind. We
Speaker 1: will find out today and tomorrow and the next hundred
Speaker 1: episodes of our podcast. Yeah, because you know, it sometimes
Speaker 1: feels like we're building this model of the universe kind
Speaker 1: of like we're building a whole universe kind of inside
Speaker 1: of our heads and our physics theories, almost like a hologramma.
Speaker 1: That's right. It's incredible to imagine that the whole external universe,
Speaker 1: if it even exists, might be describable inside in mind, right,
Speaker 1: Like you could represent it somehow in terms of arrangements
Speaker 1: of neurons, right, and as I think the kind of
Speaker 1: idea that makes people think, like maybe the entire universe
Speaker 1: is actually just a projection of some other kind of
Speaker 1: physical arrangement. Right. Yeah, I've always wondered like maybe our
Speaker 1: brains just aren't equipped to like understand the universe. Do
Speaker 1: you ever wonder about that? Oh, I'm almost certain that
Speaker 1: we are not capable of understanding the universe at its
Speaker 1: deepest level. So are we doomed to always not know
Speaker 1: the universe. I think there's never going to be a
Speaker 1: point where we're satisfied that we think we understand and
Speaker 1: you know, imagine the kind of super intelligence that would
Speaker 1: be necessary to like fully grasp with the universe. I
Speaker 1: think about your dog. Your dog is intelligent, but it
Speaker 1: certainly doesn't understand all the physics of the universe. And
Speaker 1: so compared to some super intelligent aliens out there, we
Speaker 1: are as small as dogs, and there's no way that
Speaker 1: we could understand the universe at the level that they do.
Speaker 1: And so you essentially have to be infinitely intelligent to
Speaker 1: understand the whole university thing. And couldn't infinite intelligence exist
Speaker 1: in the universe that that would be so that would
Speaker 1: be a lot. It would create an intelligence black hole
Speaker 1: inside its mind because you can't store that much information
Speaker 1: or that much smart in a small space. Man, we've
Speaker 1: just covered dogs and black holes and like the first
Speaker 1: three minutes and including brains. But yeah, so we talked
Speaker 1: about all of the mysterious things, and one of the
Speaker 1: favorite mysterious things that we like to talk about our
Speaker 1: black holes because they're so mysterious and it seems like,
Speaker 1: you know, that there were these black pockets in almost
Speaker 1: their own universes, and it seems like anything you throw
Speaker 1: into it can never ever come out. And they're especially
Speaker 1: wonderful and fascinating because they came out of the human
Speaker 1: mind initially. It's not something we saw in the universe.
Speaker 1: It's an idea we had. We said, if the laws
Speaker 1: of physics are the way we think they are, then
Speaker 1: these things should exist. So we like mapped something inside
Speaker 1: our minds out into the universe and then went out
Speaker 1: and actually found them. I mean it's incredible, right that
Speaker 1: think that our understanding the universe could be so sophisticated
Speaker 1: and impressive that we can predict crazy new bonker stuff
Speaker 1: out there which turns out to be real. I think
Speaker 1: that's really impressive. Yeah, yeah, good jobs, physicists. Even though
Speaker 1: we are dogs compared to intelligently nothing against dogs. Of course,
Speaker 1: dogs very smart. That's why I chose them physics example,
Speaker 1: and not cats. Right, I think cats are smarter. They're
Speaker 1: not smarter than dogs. Man, you cannot train a cat.
Speaker 1: That's proof number one. That's cats are not smarter than dogs.
Speaker 1: Maybe like cats are mathematicians and dogs are physicists. Would
Speaker 1: you say that's a fair, fair comparison. Well, if you're
Speaker 1: saying that dogs are smarter than cats, that I agree
Speaker 1: with you. Masticians are just sneakier, that's right now. But
Speaker 1: black holes are a fascinating mystery and one that began
Speaker 1: inside the human brain, but one that we still don't
Speaker 1: really understand. I mean, we found them, we see them
Speaker 1: out there, but it's a continuous source of mystery and
Speaker 1: puzzlement for people everywhere and for scientists. Yeah, and it's
Speaker 1: amazing that we've seen it, like we've found one, Like
Speaker 1: they took pictures of one sort of last year, and
Speaker 1: it's like it's real, it's there, you can see it,
Speaker 1: and it looks like what we thought they looked like.
Speaker 1: That's right. The picture of the black hole shows you
Speaker 1: all the incredible gas swirling around it that's trying desperately
Speaker 1: to avoid falling into the black hole and in the
Speaker 1: process is bouncing around against all the other gas and
Speaker 1: emitting lots of radiations. So we're not seeing the black
Speaker 1: hole directly, you know, although we see a black spot there,
Speaker 1: we're seeing mostly the swirling, chaotic, crazy gas that's surrounding. Yeah.
Speaker 1: I guess you're right, because I mean, we see the
Speaker 1: black center, but there's nothing to see there because nothing
Speaker 1: can come out, or at least that's the idea of
Speaker 1: a black hole. And so the question then kind of
Speaker 1: becomes what happens to the stuff that goes into it?
Speaker 1: Is it gone forever or cannedy recovered? Yeah? Is that
Speaker 1: stuff just like hanging out inside the black hole having
Speaker 1: a great time with all the other stuff? Does it
Speaker 1: get squeezed into some new form of matter? Is it
Speaker 1: all in a singularity in the middle. It's of the
Speaker 1: deepest questions in physics what's going on inside a black
Speaker 1: hole and what happened to the stuff that fell in?
Speaker 1: So today on the podcast we'll be asking the question
Speaker 1: those a black hole destroy information? I guess that's an
Speaker 1: interesting question because you know, it's kind of like asking
Speaker 1: what happens to stuff that goes in, Like does it
Speaker 1: get destroyed like obliterated? Does it become pure energy, unadultered,
Speaker 1: unfiltered energy that you can't make out what it is?
Speaker 1: Or does it you know, does a cork stay a
Speaker 1: cork inside of the black hole? And does it still
Speaker 1: fly around and doesn't even know it's in a black hole? Yeah?
Speaker 1: I mean, are you wondering about what happened to that
Speaker 1: banana you dropped into your black hole. I'm still wondering
Speaker 1: about my banana, Daniel. I want it back. My dog
Speaker 1: needs today. Do you like eating bananas when they're black,
Speaker 1: because that's probably what happened to your back. You mean
Speaker 1: it turned into a movie basically. Basically, But it's a
Speaker 1: fascinating question, like when something goes into a black hole.
Speaker 1: Is a black hole like a cosmic hard drive? Does
Speaker 1: it like just compress everything into some new arrangement but
Speaker 1: effectively keeping track of all the particles that came in,
Speaker 1: or is it actually deleting stuff from the universe, turning
Speaker 1: into some new configuration that doesn't have any information about
Speaker 1: what happened before it. That's a fascinating question. Yeah, and
Speaker 1: so we have a lot to impact here about black
Speaker 1: holes and information. But at first we, as usually, we
Speaker 1: were wondering how many people out there had heard of
Speaker 1: this question of whether black holes keep or destroy information?
Speaker 1: And so, as usual, Daniel went out there and ask
Speaker 1: people on the internet what they thought of this question.
Speaker 1: That's right, So thank you to everybody who have volunteered
Speaker 1: to answer random questions. If you're willing to participate and
Speaker 1: like to hear your uninformed speculation on the podcast right
Speaker 1: to us two questions at Daniel and Jorge dot com
Speaker 1: YouTube can answer these random questions. Think about it for
Speaker 1: a second, and what do you know about information and
Speaker 1: black holes and what goes into them? Here's what people
Speaker 1: had to say. I think the information diss inside a
Speaker 1: black hole. My understanding of Hawking radiation is that when
Speaker 1: a particle interacts with the black hole, information is lost.
Speaker 1: Therefore the black hole behaves like a garbage disposal. Ah,
Speaker 1: so I do know a little bit about this. So
Speaker 1: I read a book by Leonard Suskin which was talking
Speaker 1: about the black hole wars. Stephen Hawkins believe that they
Speaker 1: did disappear. Information did disappear, and the Suskin said it didn't.
Speaker 1: And I think it's started to do with holographic principle
Speaker 1: that basically all the data stays on the event arising. Yes,
Speaker 1: information disappears from black holes because they lose mass through
Speaker 1: Hawking radiation. They're more like garbage disposes than hard drives,
Speaker 1: since you can't retrieve any information that's stored in them.
Speaker 1: Um my guests would be that once an object is
Speaker 1: sucked into a black hole. It is obliterated into its
Speaker 1: most smallest particles that exist, and those things float around
Speaker 1: and mess around with other particles and probably no longer
Speaker 1: resemble whatever it is that they used to make up planets, bananas,
Speaker 1: bunnies or whatever it is. I think they like store
Speaker 1: information and then eventually, in like trillions and trillions and
Speaker 1: trillions of years, there's like hawking radiation that radiates, you know,
Speaker 1: and out in black holes go away. As far as
Speaker 1: I understand, physics falls apart inside a black hole. I've
Speaker 1: read that information doesn't disappear as such, and that all
Speaker 1: the information inside the black hole would be somehow readable
Speaker 1: on the horizon. Whatever goes in there just gets squished
Speaker 1: into a really tiny small space. So I'd probably say
Speaker 1: they're more like a garbage disposal. What goes in doesn't
Speaker 1: come out, I don't think so. I think it depends
Speaker 1: at the center of a black hole is which we
Speaker 1: don't know. If it's an infinite density single point, then
Speaker 1: it's probably more like a garbage disposal. But if it's not,
Speaker 1: then I would assume information can enter it and just
Speaker 1: gets trapped. I'm gonna equivocate on this, and so I
Speaker 1: shall leave it to my learned colleagues Daniel Watson and
Speaker 1: Hua Champ perhaps to answer that all so, I don't
Speaker 1: think that information disappears into the black hole. I think
Speaker 1: information is recorded on the edge of black hole. Information
Speaker 1: cannot disappear, like energy cannot disappear. All right, not a
Speaker 1: good outlook for what happens to stuff that goes into
Speaker 1: the black hole. Nobody nobody thinks it's hanging out happily inside.
Speaker 1: Nobody thinks that you're gonna eat that banana. I like that.
Speaker 1: There's basically every answer here. Information disappears, information doesn't disappear,
Speaker 1: information is radiated out, and they're basically garbage compactors. That's
Speaker 1: a wonderful variety of answers here. Thank you to everybody
Speaker 1: who participated, a wonderful variety of analogies here, Like is
Speaker 1: a garbage compactor? Is it a garbage disposal? Is it
Speaker 1: a recycling being? I don't think the universe recycles. I
Speaker 1: don't think it's like plastic in this black hole. Please,
Speaker 1: And you know what, if black holes are just the
Speaker 1: universe's compost, interesting they could be right. They break stuff
Speaker 1: down and maybe they store it for later for a
Speaker 1: universe garden, a star garden or story for never that's
Speaker 1: maybe the problem. Well, until the universe collapses and then
Speaker 1: everything gets too cycled. Right, that's a very optimistic view
Speaker 1: of what's going to happen to your banana. Well, this
Speaker 1: is an interesting topic, and so let's jump right into it.
Speaker 1: This might take a while because some of the things
Speaker 1: that we need to talk about include information and quantum mechanics.
Speaker 1: And so before we sort of get into the idea
Speaker 1: of what happens to information that goes into a black hole,
Speaker 1: let's talk about kind of information in general and how
Speaker 1: that works in a quantum reality. That's right, because one
Speaker 1: of the mysteries of black holes is what happens to
Speaker 1: the information that goes into them. And so first we
Speaker 1: have to understand, like what is information and what does
Speaker 1: quantum mechanics say about that information? Right? So, information is
Speaker 1: kind of like the arrangement of things, like the physicist.
Speaker 1: Information is not like ones and zeros or it's not like, yeah,
Speaker 1: you know a file or a number. It's more like
Speaker 1: the arrangement of things, right, Yeah, And it can be
Speaker 1: represented as ones or zeros or you know, things you
Speaker 1: print on a piece of paper. But fundamentally, it's the
Speaker 1: arrangement of the particles. It's really it's the quantum wave
Speaker 1: function that tells you where the particles are or where
Speaker 1: they are likely to be, and how they are interacting.
Speaker 1: Remember that everything, me and you and bananas and all
Speaker 1: that stuff are made out of particles, and we're all
Speaker 1: made out of the same particles. So the thing that's
Speaker 1: different between you and lava and hamsters and bananas is
Speaker 1: not the stuff you're made out of. That's really the
Speaker 1: same stuff that everything is made out of. It's how
Speaker 1: that stuff is put together. It's like if you had
Speaker 1: a book of recipes and they all had exactly the
Speaker 1: same ingredients, just had different arrangements like where you put
Speaker 1: the stuff. That's literally how things in the universe are built.
Speaker 1: And so what we mean by information from a physics
Speaker 1: point of view is just that is how the particles
Speaker 1: are put together to make this versus that, right, And
Speaker 1: it's also kind of the history of them a little bit, right,
Speaker 1: Like you can make a banana cake and I can
Speaker 1: make a banana caig, but they're going to be different
Speaker 1: bana caggs depending on you know, what the size of
Speaker 1: the pan I use, or whether I put in a
Speaker 1: little bit more of this, or a little bit more
Speaker 1: of that, or how I poured it. They're bothing that
Speaker 1: tastes like banana aig, but they're gonna be different banana
Speaker 1: caigs because they were arranged kind of with a different history.
Speaker 1: And that's right. So our two banana cream pies both
Speaker 1: have information about what happened to those bananas, how they
Speaker 1: got there, how they originally were developed and grown and
Speaker 1: blended up and and turned into the banana cream pies.
Speaker 1: Because our two banana cream pies are not identical, they
Speaker 1: contain information about how they got there. Their arrangements are
Speaker 1: unique because only one way to create that particular banana
Speaker 1: cream pie. And so you could run the clock backwards
Speaker 1: and figure out where everything came from in your pie. Yeah,
Speaker 1: So I think that kind of what you're saying is
Speaker 1: that it's like, it's kind of like if you're playing
Speaker 1: billiards or some thing, if you see all the balls
Speaker 1: kind of arranged in a particular way on the table,
Speaker 1: you can sort of backtrack how they all got to
Speaker 1: how billiard balls usually start. That's right, And that's what
Speaker 1: we mean when we say quantum mechanics does not destroy information.
Speaker 1: It says that you can tell how you got to
Speaker 1: where you are. So, just like you said in the
Speaker 1: billiard balls example, if you see balls moving on the table,
Speaker 1: you can tell how you got there. You said, well,
Speaker 1: this must have happened in a certain way. You know,
Speaker 1: Bob must have hit Alice's ball and it bounced off
Speaker 1: this wall, etcetera, etcetera. There's only one way to get
Speaker 1: to this exact particular arrangement. And so because information is
Speaker 1: not destroyed, it's all the information you need to figure
Speaker 1: out how you got here is present in this configuration.
Speaker 1: You could run the clock backwards, you can run a
Speaker 1: physics simulation backwards and figure out exactly how you got
Speaker 1: to hear or run it forward. Right like that, I
Speaker 1: think you're saying that there's no ambiguity in the universe,
Speaker 1: Like if you you come upon a crime scene, you
Speaker 1: can tell exactly what happened, like a physicist could. If
Speaker 1: you sort of rewind the universe and play the laws
Speaker 1: of physics backwards, you can sort of reconstruct what happens
Speaker 1: every time precisely. And it's really weird that this comes
Speaker 1: up in quantum mechanics because you might think, yeah, quantum
Speaker 1: mechanics is not something that's going to give you certainty
Speaker 1: that tells you you can know everything about the universe, right,
Speaker 1: because quantum mechanics is something that feels like it has
Speaker 1: a lot of built in uncertainty. And so what quantum
Speaker 1: mechanics tells you is you can always know the wave function.
Speaker 1: That's the thing that tells you where the particles are
Speaker 1: likely to be, not that you could actually know where
Speaker 1: the particles are. In the same way, you can backtrack
Speaker 1: the wave function. You can say if the particles have
Speaker 1: a certain way function that says that they're more likely
Speaker 1: to be on the left side of the table. Now
Speaker 1: you can backtrack that and tell where they were likely
Speaker 1: to be in the past, not where they actually were.
Speaker 1: It's all about the wave function. It's all about this
Speaker 1: evolving probabilities. The way so looking back into the past
Speaker 1: is also there's also probabilities or do you know for
Speaker 1: sure where the party like if like if I see
Speaker 1: an electron and I measure, you know where it is
Speaker 1: and where it's going to the best degree that I
Speaker 1: can can, I tell you where it was before and
Speaker 1: how fast it was going. No, you can only know
Speaker 1: the probabilities. You can't collapse the wave function into the
Speaker 1: past because that would have changed where it is today.
Speaker 1: But if you know the way function today right, then
Speaker 1: you can backtrack it into the past and you can
Speaker 1: propagate it into the future. Any idea is that if
Speaker 1: you look at any configuration of matter, you should be
Speaker 1: able to tell where it came from. That's the core
Speaker 1: idea that you have to understand. I see. So when
Speaker 1: you talk about information, you don't mean like where things
Speaker 1: are and where they're going, but you also kind of
Speaker 1: include these quantum probabilities as information, Like that's also information
Speaker 1: to physics, Yes, that's the actual quantum information, because they
Speaker 1: don't know where the particles are. We really just know
Speaker 1: these probabilities. And so like when we talk about like
Speaker 1: quantum teleportation copying things, we're talking about copying not the
Speaker 1: where the particles actually are, but their probabilities, because that's
Speaker 1: really what the quantum information is. It kind of feels
Speaker 1: a little unsatisfying on physicists because I feel I feel
Speaker 1: like you're telling me that information includes not knowing kind
Speaker 1: of in a way, you know what I mean, Like
Speaker 1: information includes also non information. Yeah, what's the most information
Speaker 1: that you can have about the universe is information about
Speaker 1: the probabilities, and that information cannot be destroyed. Like we
Speaker 1: don't know where the electron is. It's not like there's
Speaker 1: a fact there that's not accessible to us. It just
Speaker 1: isn't determined. But the way function is the thing that
Speaker 1: tells you that it's more probable to find it on
Speaker 1: the left side or the right side. That is totally determined.
Speaker 1: And that's the level of quantum information we can have.
Speaker 1: That's the most information that the universe allows you to
Speaker 1: have almost right, Like you know you can know the
Speaker 1: position and the velocity of a particle to a perfect
Speaker 1: degree because of the uncertainty principle, because and that's just
Speaker 1: the rule of the universe. The universe is like, nope,
Speaker 1: you can't know everything all of the time everywhere. That's right,
Speaker 1: And that's why quantum information cannot be destroyed, because the
Speaker 1: probabilities cannot be destroyed. Like if an electron is somewhere
Speaker 1: in your box now, then it is somewhere in your
Speaker 1: box in the future. You're like, out of all the
Speaker 1: probabilities in the future, they still have to add up
Speaker 1: to one. And that's why if you run the clock backwards,
Speaker 1: you should still get probabilities adding up to one in
Speaker 1: the past, and if you run it back even further,
Speaker 1: you should still get probabilities added up to one because
Speaker 1: information is not destroyed can't just disappear, because your particles
Speaker 1: don't just disappear, you don't know where they are. But
Speaker 1: the probabilities can't disappear. The probabilities can slash around, but
Speaker 1: they can't just go away. And so that's why we're
Speaker 1: so fascinated about what happens inside a black hole, because
Speaker 1: we're wondering, like, does the information inside a black hole?
Speaker 1: Does it get deleted or is it still stored in there,
Speaker 1: Like it's a black hole that has a banana versus
Speaker 1: an apple, have something different inside it that tells you
Speaker 1: that one has a banana, one has an apple, or
Speaker 1: the actually deleting stuff. Interesting? Interesting, Yeah, I get. The
Speaker 1: question is if I throw a banana and one black hole,
Speaker 1: and I throw the equivalent apple the copy of that
Speaker 1: black hole, are the two black holes different at the
Speaker 1: end or are they basically the same? That's kind of
Speaker 1: the question exactly, And quantum mechanics says they have to
Speaker 1: be different because if they're not different, then you've destroyed
Speaker 1: the information about which one got the banana and which
Speaker 1: one got the apple in a corner. Quantum mechanics, and
Speaker 1: this is a very deep, very bedrock principle. Information cannot
Speaker 1: be destroyed. Like you go to a particle theorist and
Speaker 1: you say, what if I prove the quantum mechanics doesn't
Speaker 1: preserve information, that you can delete information from the universe,
Speaker 1: then basically they just throw all their books away and
Speaker 1: we have to start everything from scratch. It's that deeply
Speaker 1: ingrained into physics. I guess it's like comparing apple black
Speaker 1: holes to banana black holes. All Right, I'm starting to
Speaker 1: feel a bit a little bit like a dog here, uh,
Speaker 1: and not fully able to grasp all this stuff. But
Speaker 1: that's kind of the nature of quantum mechanics. So let's
Speaker 1: get into whether or not black holes can destroy this
Speaker 1: quantum information, and if they can, then how do we
Speaker 1: explain it? But first let's take a quick break. All right,
Speaker 1: we're talking about weather. Black holes can destroy quantum information.
Speaker 1: And so Danny, you were telling me that quantum information
Speaker 1: includes like the probability of all the particles in the universe,
Speaker 1: or at least a bunch of particles that you're looking at,
Speaker 1: and you're telling me that quantum mechanics says that you
Speaker 1: can't destroy this information, Like you can't just forget about it,
Speaker 1: Like it's always kind of encoded in how the particles
Speaker 1: are arranged or what they're doing. That's right. It's sort
Speaker 1: of like the central premise of that TV show Devs,
Speaker 1: where they try to reconstruct details about what happened two
Speaker 1: thousand years ago by getting really fine data about the
Speaker 1: molecules in the air and the earth and just backtracking
Speaker 1: it two thousands of years. The ideas that the evidence
Speaker 1: for the past is still with us here in the president,
Speaker 1: that if you had incredible computing power and enough data,
Speaker 1: you could reconstruct any event. It's like the perfect crime novel. Wow,
Speaker 1: and so yeah, Like can you look at a banana
Speaker 1: and tell what the plant the griod looked like? Kind of,
Speaker 1: that's right, the ideas that no two bananas are identical,
Speaker 1: but somewhere in that banana there's a clue about where
Speaker 1: it came from and what it was like and whether
Speaker 1: it got sun on a certain day, and all that
Speaker 1: information is somehow encoded in the banana. They're making me
Speaker 1: feel guilty about eating a banana. You're like you're destroying
Speaker 1: a perfect, unique gem in the univers just becomes part
Speaker 1: of who you are. Right, if I took you apart,
Speaker 1: I could figure out exactly how many bananas you had
Speaker 1: last week and what happened to them, and the stars
Speaker 1: that burn the potassium that's in that banana, Like all
Speaker 1: that history is encoded in that banana and then in you. Well,
Speaker 1: and also when I flushed down the toilet, technically you
Speaker 1: would have to go down the toilet. That's a whole
Speaker 1: different maybe podcast episode. That's a different kind of black hole.
Speaker 1: We're not going to dive into different um. So let's
Speaker 1: get into now. Quantum mechanics says that you can destroy
Speaker 1: quantum information. And so what happens when you throw it
Speaker 1: into a black hole? Like does it get destroyed or
Speaker 1: does it stay around inside of the black hole? That's
Speaker 1: the big question. Yeah, and so on the surface you imagine, well,
Speaker 1: black holes suck in information. Right, you put something into
Speaker 1: a black hole, it can never leave, So therefore it's
Speaker 1: information is stuck inside the black hole. That doesn't mean
Speaker 1: necessarily that it's destroyed. Right, Like you put a banana
Speaker 1: inside a black hole, you could still be in there.
Speaker 1: The particles that made it up could be like squished
Speaker 1: and whatever, but they just got quantum mechanics aified into
Speaker 1: a new arrangement. And just like when you ate the
Speaker 1: banana or when it grew, it's information could still be preserved,
Speaker 1: but be stuck inside the black hole, you know, like
Speaker 1: a like a neutron star kind of breaks everything down
Speaker 1: to the cork level, but all the courts are still
Speaker 1: kind they're bunched together precisely, and if the information is
Speaker 1: still in there, it's stuck inside the black hole. Right,
Speaker 1: nothing can ever leave the black hole. But also you
Speaker 1: can't get any information from the outside about what's in
Speaker 1: the black hole. The only things you can know about
Speaker 1: a black hole are its mass, whether it's spinning, and
Speaker 1: whether as electric charge. There's this crazy theorem in physics
Speaker 1: called the no hair theorem that says that's all you
Speaker 1: can know about a black hole. You mean, like the
Speaker 1: overall charge of it, Like the black hole can have
Speaker 1: a charge to it. Yeah, if you have a black
Speaker 1: hole with no charge, it's neutral, and you throw an
Speaker 1: electron into it, then it has a charge and you
Speaker 1: can measure that charge. You can know whether there are
Speaker 1: charged particles inside a black hole. Oh, I guess you
Speaker 1: can measure how much it pulls proton through or something
Speaker 1: like that, just like you can measure it's mass. You
Speaker 1: throw a banana into a black hole, it got heavier.
Speaker 1: You should be able to measure its mass by measuring
Speaker 1: the gravitational field around a black hole. Can also measure
Speaker 1: whether it's spinning. But that's the extent of the information
Speaker 1: you can have, right. You can't tell what's inside. You
Speaker 1: can't tell the detailed history of the banana from the outside,
Speaker 1: so you can never get that information back out, right.
Speaker 1: So that's step number one. Is the information, if it
Speaker 1: still exists, is inside the black hole and can never leave, right.
Speaker 1: But that's not the same as destroying it. It's just
Speaker 1: kind of storing it. It's like inside if somewhere I
Speaker 1: can never that's right. And if black holes live forever,
Speaker 1: this wouldn't really be an issue. Would be a question of, like, well,
Speaker 1: what happens inside the black hole? It's fascinating, but we
Speaker 1: believe that probably information is just in there, sort of
Speaker 1: cut off from us forever, but still existing. Right, it's
Speaker 1: still having its own little happy life inside of the
Speaker 1: black hole. That's right. The banana party, that's where bananas
Speaker 1: go so that you don't eat them. Right, it's the
Speaker 1: only safe space in the universe. They don't have to
Speaker 1: worry about training black because everything is black inside of
Speaker 1: a black hole. That's right. But then Stephen Hawking came
Speaker 1: along and he showed us that black holes actually they
Speaker 1: can disappear, right, Yes, you can make it black hole disappear.
Speaker 1: It can evaporate. Yeah, black holes they evaporate. They give
Speaker 1: off very small amounts of radiation, little particles here there.
Speaker 1: For very big black holes, this happens extremely slowly. But
Speaker 1: as black holes get smaller, they evaporate more quickly, and
Speaker 1: then they can actually disappear. They can poof out of
Speaker 1: existence as they give away their last little bit of energy.
Speaker 1: Even like giant black holes will eventually disappear, like once
Speaker 1: all black holes suck everything in the universe, Eventually they
Speaker 1: will evaporate. Right, that's right. A black hole, if you
Speaker 1: do not feed, it will give off Hawking radiation and
Speaker 1: get smaller. Right. It gives off its energy, and that
Speaker 1: energy comes from its mass, and so therefore it gets smaller,
Speaker 1: and the smaller it gets, the more radiates. So giant,
Speaker 1: massive black holes they might have lifetimes of trillions of years.
Speaker 1: But yes, eventually they will radiate away all of their
Speaker 1: mass in terms of this hawking radiation and disappear, right,
Speaker 1: And so then the question is what happened to the
Speaker 1: information you put into it? That's right, what happened to
Speaker 1: the information inside the black hole? Like you put this
Speaker 1: banana inside the black hole. You trust the black hole
Speaker 1: is going to keep your banana information safe. But then
Speaker 1: you come back a billion years later and the black
Speaker 1: holes gone. You're like, what what happened to my You
Speaker 1: deleted my banana from the universe. You know you can't
Speaker 1: do that. Quantum mechanics says that's impossible. So the question
Speaker 1: is what happened to the information? And you might be
Speaker 1: tempted to think, oh, well, maybe it's somehow stored in
Speaker 1: that hawking radiation, right, because the hawking radiation came out
Speaker 1: of the black hole. But hawking radiation is very special.
Speaker 1: It comes from the temperature of the black hole. It
Speaker 1: comes from treating a black hole, like everything else in
Speaker 1: the universe, is a thing that has a non zero
Speaker 1: temperature which glows. And what's very important to understand is
Speaker 1: that the hawking radiation depends only on the mass of
Speaker 1: the black hole. Like how much hawking radiation you get
Speaker 1: and which particles you get are determined by the mass
Speaker 1: of the black hole and literally zero else, So none
Speaker 1: of the information that's inside the black hole can possibly
Speaker 1: leak out in hawking radiation. Well, I guess it's kind
Speaker 1: of like if you have a glass of water, if
Speaker 1: you leave it out, it's gonna evaporate, but you can
Speaker 1: sort of trace what happened to the water. You can
Speaker 1: trace the like the vapor of what molly kills as
Speaker 1: it least the glass of water. Like that's okay, Like
Speaker 1: that's preserving the information. That's right. But a black hole
Speaker 1: doesn't evaporate by having the stuff inside of it leak out.
Speaker 1: It evaporates by almost like having the stuff at the
Speaker 1: surface destroyed itself. Kind of that's right. And remember the
Speaker 1: no hair theorem tells us that you can't get any
Speaker 1: information out of a black hole. That none of the
Speaker 1: configuration of particles inside a black hole, or the swirling
Speaker 1: or non swirling, or the singularity or non singularity can
Speaker 1: affect what's produced on the outside of the black hole.
Speaker 1: So the Hawking relation cannot have any information about what's
Speaker 1: going on inside the black hole. It's not like that
Speaker 1: water vapor example. It's a good contrast because it doesn't
Speaker 1: tell you anything about what happened inside the black holes.
Speaker 1: This amazing sort of mysterious way to delete a black
Speaker 1: hole without knowing anything about what's inside of it, right,
Speaker 1: because the reason is not because of the theorem. The
Speaker 1: theorem is sort of because of what's happening in the
Speaker 1: physics of it, right, And it's yeah, the theorem describes
Speaker 1: the physics of it right, right, And and what's happening
Speaker 1: is that, like at the surface of a black hole,
Speaker 1: you get this pair of particle and antiparticles kind of appearing,
Speaker 1: and one of them goes into the black hole, the
Speaker 1: other one goes out of the black hole, and that's
Speaker 1: kind of how it evaporates. Happening at the surface of it.
Speaker 1: It's not happening because of anything that's inside of the
Speaker 1: black hole exactly, and it comes just from the mass
Speaker 1: the black hole. As you say, virtual particles like positron
Speaker 1: anti positron pairs are created near the black hole's edge
Speaker 1: where there's a lot of gravitational energy, and then one
Speaker 1: of them is given a boost from that gravitational energy
Speaker 1: while the other one maybe gets sucked in, and because
Speaker 1: it's given a boost from that gravitational energy, that energy
Speaker 1: comes from the mass of the black holes. The black
Speaker 1: hole itself is decreased a tiny little bit in mass,
Speaker 1: and so it's stealing some of the energy from the
Speaker 1: black hole without apparently taking any information from it. And
Speaker 1: so that's the weird thing is that, like you put
Speaker 1: information in a black hole, you can never get it out,
Speaker 1: but then the black hole can disappear. So where did
Speaker 1: the information go? Really, there's no information in that suckings radiation.
Speaker 1: I mean, like, wouldn't it like where it happens where
Speaker 1: there's these particles and antiparticles form and where the one
Speaker 1: of them goes right and the other one goes left.
Speaker 1: Wouldn't that sort of depend on exactly what's going on
Speaker 1: inside of the black hole. Well, the where the particles
Speaker 1: are created is just quantum randomness around the black hole,
Speaker 1: so that happens totally randomly, not depending on what's inside
Speaker 1: the black hole. And then they're boosted from the gravitational field,
Speaker 1: which is the mass of the black hole. So you
Speaker 1: can know the mass of the black hole, and that's
Speaker 1: what determines how these particles get boosted and whether they
Speaker 1: go in the right direction, etcetera. But that doesn't contain
Speaker 1: all the information. Like if you threw an apple or
Speaker 1: an equivalently masked banana into a black hole, that would
Speaker 1: give you black holes of the same mass, so they
Speaker 1: would affect talking radiation in exactly the same way. So
Speaker 1: the fact that one used to be an apple and
Speaker 1: one used to be a banana is now irrelevant, which
Speaker 1: means quantum information has been deleted all right, which is
Speaker 1: kind of bad news for quantum physics, because you're telling
Speaker 1: me that this idea that you can't destroy information is
Speaker 1: fund mental to quantum mechanics. Maybe I really quickly, can
Speaker 1: you tell me why it's so fundamental. I mean, remember
Speaker 1: what we talked about earlier. The reason you can't destroy
Speaker 1: information in quantum mechanics is because particles should always exist somewhere.
Speaker 1: I mean, if you have a particle now, as you
Speaker 1: exist somewhere in the future, it's quantum information cannot be destroyed,
Speaker 1: like you don't know exactly where it is, but you
Speaker 1: know what it's probability distribution looks like, and it should
Speaker 1: have a probability distribution in the future also, and so
Speaker 1: that can change as the universe moves forward, but the
Speaker 1: information about should not be deleted anywhere. Right, Well, I
Speaker 1: guess my question is, you know why not? Like why why?
Speaker 1: Why would we quantum mechanics breakdown if I just suddenly
Speaker 1: took some particles and deleted their quantum information? Like why
Speaker 1: would the universe complain or with the universe care if
Speaker 1: I had destroyed that information? All? Right? Well, mathematically we
Speaker 1: look at the equations that describe a wave functions. We
Speaker 1: have a wave function that tells us where particles are
Speaker 1: likely to be you, and that moves forward in time.
Speaker 1: There's an equation that describes how that happens. It's called
Speaker 1: the shrouding your equation, and the shrouding your equation says
Speaker 1: you can move information from here to there, but it's unitary,
Speaker 1: doesn't ever destroy information. And if information is destroyed, that
Speaker 1: means that wave functions can disappear. And that just doesn't
Speaker 1: happen in the shorten your equation, and so we would
Speaker 1: have to totally rethink the way quantum mechanics works if
Speaker 1: that was to happen. It's like a bedrock assumption that
Speaker 1: we've built into quantum mechanics. I see, it's like I
Speaker 1: guess in quantum mechanics and wave functions, you know, these
Speaker 1: functions don't don't just exist in the present and in
Speaker 1: the past. They're all sort of tied together mathematically to
Speaker 1: where they're going to be in the future. That's right,
Speaker 1: So like if you destroy it in the future, then
Speaker 1: you're really destroying it through all history. You don't have
Speaker 1: a term for that in the equation. Yeah, And the
Speaker 1: equations work the same way forwards and backwards in time,
Speaker 1: and so if the wave function is ever destroyed, that
Speaker 1: means that you couldn't go from a non existent wave
Speaker 1: function backwards in time into the wave function you have now.
Speaker 1: So this sort of this time and variance built into
Speaker 1: quantum mechanics. You can run the clock forward, you can
Speaker 1: run the clock backwards. You should be able to move
Speaker 1: backwards and forwards at all points. But if the information
Speaker 1: is ever deleted, that means you can't move backwards and
Speaker 1: forwards at all points. And the shrunning equation, the basic
Speaker 1: assumptions on which it's built are totally wrong, and quantum
Speaker 1: mechanics doesn't work, and we'd have to come up with
Speaker 1: a new theory. It's not like the universe would puff
Speaker 1: out of existence. Right, This is all human ideas about
Speaker 1: how the universe might work. This is a basic assumption
Speaker 1: we've built into quantum mechanics that we're pretty sure is right.
Speaker 1: But black holes are telling us that they're doing something
Speaker 1: that we thought was impossible. Man, there's such troublemakers, all right,
Speaker 1: So we have a big unknown here. How can both
Speaker 1: things be true? How could information never be destroyed according
Speaker 1: to quantum mechanics and how can information be destroyed according
Speaker 1: to black holes and hawking radiation? So let's get into
Speaker 1: what could possibly explain this can prediction. But first let's
Speaker 1: take a quick break, all right, Daniel, can information be
Speaker 1: destroyed inside of a black hole? So quantum mechanics says no,
Speaker 1: but kind of a black hole say yes. So what's
Speaker 1: going on? Is quantum mechanics wrong or do black holes
Speaker 1: just kind of destroy our conception of how the universe works.
Speaker 1: This is a big puzzle in physics for a long time,
Speaker 1: and it's such a big puzzle that like big folks
Speaker 1: on both sides, like great brains on both sides of
Speaker 1: the argument, had like public debates about it and even
Speaker 1: made bets about the resolution of this. Right. Yeah, there's
Speaker 1: a famous bed by between Hawking and Kip Thorne and
Speaker 1: John Preskill. Right, that's right. John Prescille believed that somehow
Speaker 1: the information was sneaking out of the black hole back
Speaker 1: into the universe, that it was leaking out essentially where
Speaker 1: Stephen Hawking and Kip Thorn they thought, know, the information
Speaker 1: can't ever leave the black hole, and therefore it must
Speaker 1: be lost from the universe, and quantum mechanics is wrong.
Speaker 1: So they made a very public sort of bet about this.
Speaker 1: All right, So they made this bed and did they
Speaker 1: was one of im proven right? Well, they did come
Speaker 1: to what they think is a resolution to this, and
Speaker 1: so Hawking and Thorn actually capitulated on the bet in
Speaker 1: public and said, all right, Prescott, we think you're right.
Speaker 1: We think that the information somehow leaks out of the
Speaker 1: black hole. So wait, physicists think that black holes don't
Speaker 1: destroy information. That's right. So the idea now is probably
Speaker 1: black holes don't destroy information. I mean, the general categories
Speaker 1: of solutions are one, maybe quantum mechanics is just wrong
Speaker 1: and we have to toss it all out and rethink
Speaker 1: everything about our idea of the universe at the smallest scales,
Speaker 1: like that's an option and hey, that wouldn't be so bad.
Speaker 1: It's not like everything unravels and we all go living
Speaker 1: in caves or something. Just a bunch of physicist careers unraveled. No,
Speaker 1: those are the best moments for physicist careers because like, wow,
Speaker 1: that cracks open something deep that we thought was true.
Speaker 1: Those are the revolutions in physics we live for. That's
Speaker 1: why we're here to figure out what in the firm
Speaker 1: and turns out to be wrong, because those are the
Speaker 1: times when you can get a new glimpse onto a
Speaker 1: new insight into the universe. I mean, wow, that would
Speaker 1: be amazing. Right, So that's one possibility maybe quantum mechanics
Speaker 1: is wrong um, And what are other possibilities black holes
Speaker 1: are wrong? Another one is that like black holes, you
Speaker 1: can think of them as storing this information, but that
Speaker 1: they're also like connected to another universe. We've talked about
Speaker 1: how maybe black holes are like doors to wormholes that
Speaker 1: are connected on the other side to other places in
Speaker 1: the universe. They could also be connected to like separate
Speaker 1: distinct universes that we don't otherwise have access to. It's
Speaker 1: a possibility. I mean, we're it's like a what if
Speaker 1: on top of a wood if. But the idea is
Speaker 1: that therefore the information could be in that universe, like
Speaker 1: maybe the banana got sucked into the black hole and
Speaker 1: then slur belong to the wormhole and it's living off
Speaker 1: it's banana like days in that other universe. Now, even
Speaker 1: when our black hole disappears, I see like somehow there's
Speaker 1: a white hole on the other side that's spewing out bananas.
Speaker 1: That's right, a banana hole. I think it's what the
Speaker 1: people in that universe we call it like that. I
Speaker 1: think they call it the magic banana fountain. They're like
Speaker 1: whole cult surrounding it about how generous this banana fountain is.
Speaker 1: You're like a god in that universe. You're like the
Speaker 1: giver of bananas in that universe. I'm a legend. I'm
Speaker 1: a legend in another universe. They're like, but please stop
Speaker 1: throwing bananas in there with a bite taken out already,
Speaker 1: I mean please. So that's one idea, Yes, that it's
Speaker 1: information is not disappearing, it's just going somewhere else. Yeah,
Speaker 1: but that's hard to really understand because then you can't
Speaker 1: still really do quantum mechanics, like the information is effectively
Speaker 1: lost to us, and so then we can't do quantum
Speaker 1: mechanics of our universe, so it's not really Essentially, if
Speaker 1: it's lost to us, it's a bummer. It's a bummer
Speaker 1: because you know, is our wave function entangled with their
Speaker 1: wave function if they're in another universe? Then no, And
Speaker 1: so really quantum mechanics says, you can't lose any information
Speaker 1: from your wave functions. So if you lose it to
Speaker 1: a totally incoherent wave function, it's effectively lost anyway. So
Speaker 1: quantum mechanics says no to that. Very clever, I think,
Speaker 1: awesome idea, which would be a great basis for science fiction.
Speaker 1: Interesting like we're entangled with other universe. Yeah, but we
Speaker 1: wouldn't actually be entangled, right, That's the problem is that
Speaker 1: our wave function isn't connected to theirs because it goes
Speaker 1: through the wormhole. All right, So then what's the third
Speaker 1: The third possibility is that maybe somehow that information is
Speaker 1: actually imprinted on the Hawking radiation. So go back, that's
Speaker 1: what I was saying, wasn't it that you were saying?
Speaker 1: He shot me down? But now it seems like Stephen
Speaker 1: Hawking agrees with me. That's right. This is known as
Speaker 1: the Hawking thorn cham theory of the universe should be. No,
Speaker 1: you're right, and you know, our understanding before this was
Speaker 1: that it's impossible for the information to be in the
Speaker 1: Hawking radiation for the very reasonable arguments that I gave
Speaker 1: you five minutes ago, which I will now undermine. It
Speaker 1: made me feel bad, Daniel, No, nor yeah, alright, So
Speaker 1: here's why your idea was a good one. And you know,
Speaker 1: whenever you have an apparent contradiction, you have a string
Speaker 1: of logical arguments that leads you to something nonsensical, you
Speaker 1: have to go back and read examined, like well what
Speaker 1: about this one? Is this one? Are we really sure
Speaker 1: about this? And try to find a hole in it.
Speaker 1: And so the idea is that maybe somehow the information
Speaker 1: about the banana you threw in is imprinted on the
Speaker 1: hawking radiation. Well, how could that happen because once it
Speaker 1: goes inside the black hole, the only information we can
Speaker 1: get about it is how much mass it has, which
Speaker 1: is essentially destroying the banana nous of the information. So
Speaker 1: the idea is maybe it never really goes inside the
Speaker 1: black hole, like maybe a banana when you throw it
Speaker 1: into a black hole, spends eternity sort of on the
Speaker 1: surface of the black hole. One. And this is actually
Speaker 1: what what happens when you throw something into a black hole.
Speaker 1: You never actually see it go in because remember, when
Speaker 1: near a black hole, there's incredible gravity, and that slows
Speaker 1: down time. Like you threw a clock into a black
Speaker 1: hole and you watched it with a telescope, please from
Speaker 1: very far away, you would see that clock ticks slow
Speaker 1: down because the presence of mass slows downtime. Right. Yeah,
Speaker 1: So to the banana, you're seeing, the banana gets frozen
Speaker 1: at the surface kind of. Yeah. As it gets closer
Speaker 1: and closer to this event horizon, time slows down more
Speaker 1: and more, to the point where it slows down essentially infinitely.
Speaker 1: And you can watch this banana for the whole time,
Speaker 1: the lifetime of the universe. You will never see it
Speaker 1: cross the event horizon. Oh uh. It's not like it
Speaker 1: goes in and then the particles the photons can come out.
Speaker 1: It's like it never goes in. Kind of from our
Speaker 1: point of view, From our perspective, you never see anything
Speaker 1: actually go into a black hole. Now it gets closer
Speaker 1: and closer, and it gets redder and redder because the
Speaker 1: light from that banana, which can still get to you.
Speaker 1: Because the banana is not actually in the black hole,
Speaker 1: it gets stretched also by the gravity and gets redder
Speaker 1: and redd or longer and longer wavelengths. So what happens
Speaker 1: if you have trillions of years to hang out and watch,
Speaker 1: is that banana falls in more and more slowly, gets
Speaker 1: darker and darker, and eventually goes out past the visible spectrum.
Speaker 1: You can't see it, and then you have to use
Speaker 1: your infrared telescope to watch your very gently glowing banana. Right.
Speaker 1: But I guess I thought I thought time was became
Speaker 1: a singularity, only only at the center of the black hole.
Speaker 1: You're saying that time actually stops at the edge of it. Yeah,
Speaker 1: at the edge of the black hole, time slows down
Speaker 1: essentially infinitely, like and that's for you. You're from the
Speaker 1: outside point of view. You're watching the banana go in.
Speaker 1: That's not the same thing as the banana experiences. Banana
Speaker 1: can fall into a black hole, and it can totally
Speaker 1: experience going past the event horizon, right, because time always
Speaker 1: goes at one second per second for the person experiencing it.
Speaker 1: We have a different story about what happens in banana
Speaker 1: watching from the outside. So for us, the banana never
Speaker 1: actually goes into the black hole for us. Interesting for us. Wait,
Speaker 1: so it gets frozen at the surface forever. Yes, but
Speaker 1: it gets stretched out right, It's not like just happy,
Speaker 1: you can't go back and pick up your banana. It
Speaker 1: gets stretched out and reddened and smeared over the surface
Speaker 1: of the black hole. And essentially it distorts the event horizon.
Speaker 1: It like changes the shape of the event horizon in
Speaker 1: some way. And the ideas that maybe the banana changes
Speaker 1: the shape of the event horizon differently than an apple wood,
Speaker 1: or differently than another banana in a way that we
Speaker 1: can see, or in a way that we will never see,
Speaker 1: in a way that in principle preserves the quantum information
Speaker 1: of that banana and can influence the hawking radiation produced
Speaker 1: at that point instead of the event rise and being
Speaker 1: a perfectly smooth sphere and now has little quantum wiggles
Speaker 1: in it, and those quantum wiggles tell you about what's
Speaker 1: been thrown into the black hole, meaning that you could
Speaker 1: measure the hawking radiation and reconstruct whether you threw a
Speaker 1: banana or an apple in exactly that the black hole.
Speaker 1: You threw banana in would give you different hawking radiation
Speaker 1: than the banana you threw an apple into, and that
Speaker 1: it's encoded somehow and now in the surface of this
Speaker 1: black hole, which contains all the information but everything that's
Speaker 1: been thrown into the black hole. So you're not breaking
Speaker 1: general relativity because you're not getting information but what's inside
Speaker 1: the black hole, because in principle, all of this is
Speaker 1: now encoded on the surface of the black hole. Right,
Speaker 1: But the courts in the banana dude disappear or you
Speaker 1: don't see them. You don't see them going into the
Speaker 1: black hole. Like they're going to survive crazy experiences being
Speaker 1: near a black hole and get torn apart and smash
Speaker 1: and other stuff. So who knows what's going to happen,
Speaker 1: But their quantum information should still be there. Everything that
Speaker 1: happened to them is describable by quantum mechanics, and just
Speaker 1: like being eaten or being turned into banana smoothie, their
Speaker 1: history is still carried with me. And that's okay with
Speaker 1: quantum mechanics, Like as long as the quantum history information
Speaker 1: and information is somehow carried on, even if it's like
Speaker 1: passed between the banana cork it passes on that information
Speaker 1: to the hawking radiation. That's still okay, that's right. Did
Speaker 1: you just create a new kind of cork, the banana cork.
Speaker 1: We've got up cork, charm cork, banana cork. I thought
Speaker 1: they already existed. No, but you're exactly right. Somehow, the
Speaker 1: information about that cork that was inside your banana is
Speaker 1: encoded on the surface of the black hole and influences
Speaker 1: the hawking radiation that's produced. And therefore, if you like
Speaker 1: gathered all the hawking radiation that came out of a
Speaker 1: black hole, you could tell exactly what had gone into
Speaker 1: the black hole in the whole lifetime of the black hole.
Speaker 1: And this is weird because this is what they call
Speaker 1: like the holographic principle, meaning like you know, you can describe,
Speaker 1: like if the whole universe falls into a black hole,
Speaker 1: you could at some point technically everything would be described
Speaker 1: on the surface of the black hole, right, which is
Speaker 1: like a two D surface. It's like a flat surface. Yeah,
Speaker 1: it's sort of mysterious to say you can describe everything
Speaker 1: that's happening in a three D space, like the inside
Speaker 1: of a black hole, just by knowing information on a
Speaker 1: two D space the surface of the black hole. So like,
Speaker 1: how can everything inside a three D space be described
Speaker 1: by the surface of that space. Well, that's what we
Speaker 1: call a hologram. A hologram is a two D image
Speaker 1: that's projected into a three D space, so it looks
Speaker 1: three D. The entire hologram is determined actually by what's
Speaker 1: happening on the surface. So the ideas maybe black holes,
Speaker 1: the interiors of them are just holograms of their surfaces
Speaker 1: that you can build a sort of a theory of
Speaker 1: physics that works in three D. That's actually the theory
Speaker 1: of physics in two D on a surface, like you
Speaker 1: don't need three dimensions. Maybe you can describe everything on
Speaker 1: on a surface exactly. And so the idea is like, well,
Speaker 1: maybe that's also true like for our universe, Like maybe
Speaker 1: our three D universe is just a projection, is a
Speaker 1: two D hologram of what's happening at the edge of
Speaker 1: our universe. We think we live in this three D
Speaker 1: world and we're all moving around three dimensions. But if
Speaker 1: you can print all the information of a three D
Speaker 1: world onto a two D surface, then it's possible that
Speaker 1: we actually live on the two D surface at the
Speaker 1: edge of the universe somewhere and that what we experience
Speaker 1: is that three D world is really just a two
Speaker 1: D surface. But okay, so I guess it's like if
Speaker 1: this can happen on a black hole, then maybe it's
Speaker 1: happening everywhere. And maybe if we don't really need three dimensions,
Speaker 1: maybe like we have a redundant dimensions, right, And then
Speaker 1: there was this incredible result in string theory which backed
Speaker 1: this up. This guy at the Institute for Advanced Science,
Speaker 1: Jue Malda Sena, he came up with this theory that
Speaker 1: showed that string theory in you know, three dimensions that
Speaker 1: we experience, it can actually be described by a quantum
Speaker 1: theory in two dimensions. So he showed how you could
Speaker 1: reconstruct a theory of our universe in three dimensions only
Speaker 1: on a two dimensional surface. So it sort of showed
Speaker 1: mathematically that this might be possible. So what does that mean?
Speaker 1: That means that we're really living an illusion, like the
Speaker 1: three dimensions that we think we're living in are actually
Speaker 1: just an illusion. Kind of It could be, right, Yeah,
Speaker 1: it certainly could be. It could be that we actually
Speaker 1: live in a two D space Like I mean, it
Speaker 1: doesn't make any difference like feeling like you live in
Speaker 1: three D and actually living in three D, Like what's
Speaker 1: the difference? Uh? Nothing, But mathematically it might be that
Speaker 1: our three D universe can be described as just a
Speaker 1: two D surface, which is sort of fascinating because you
Speaker 1: feel like there's too much information here, right that that
Speaker 1: everything that's happening to us is somehow too much to
Speaker 1: squeeze down to two dimensions. But mathematically it can be equivalent.
Speaker 1: It could be that it's just that we don't have
Speaker 1: the full freedom of the three dimensions, that we're just
Speaker 1: a projection of two D spit. But I guess maybe
Speaker 1: the way you explain it maybe is that you also
Speaker 1: have time and maybe like somehow time is also giving
Speaker 1: you that extra feeling of a three or third dimension. Right, Well,
Speaker 1: here we're just talking about spatial dimensions, and so that
Speaker 1: two D space would also have time in it, so
Speaker 1: it's allowed to evolve that things can move on the
Speaker 1: two D surface, and that changes what happens inside the
Speaker 1: three D space, But we don't know right that. Yeah,
Speaker 1: I guess that's what I mean. It's like, because you
Speaker 1: have time, then you can maybe store more things into
Speaker 1: that to the information than then you might think. But
Speaker 1: you know, it's a big leap, Like we say, maybe
Speaker 1: information is stored on the surface of black holes, which
Speaker 1: means that maybe you can determine their interior to maybe
Speaker 1: the whole universe is a holomeram. Like, there's a lot
Speaker 1: of big leaps there, But again they're also fascinating there, Like,
Speaker 1: you know, maybe trying to solve this mystery about what's
Speaker 1: happening inside of a black hole tells us about what's
Speaker 1: possible for ideas we could have about the universe, and
Speaker 1: and reveals to us sort of shocking new mathematical connections
Speaker 1: that show us that the richness of our universe might
Speaker 1: actually be representable in terms of a smaller set of dimensions. Right, Yeah,
Speaker 1: like maybe we're all living in a video game. Kind
Speaker 1: of it just seems like we're in a three D world,
Speaker 1: but really we're we're just in this kind of reconstruction
Speaker 1: of a three D world, that's right. And if we
Speaker 1: are living in a video game, I want to know
Speaker 1: what are the cheat codes? How do I reset? How
Speaker 1: do I get extra lives? Exactly? All right? Well, um,
Speaker 1: it sounds like maybe black holes are not destroying information.
Speaker 1: Maybe that that seems to be kind of the current
Speaker 1: physics thinking is that maybe it is sort of recorded
Speaker 1: on the surfaces of black holes. Yeah, and you know,
Speaker 1: this stuff is pretty hand wavy. It's not like people
Speaker 1: have really worked out the mathematical details of it. It's
Speaker 1: sort of like an idea for idea we might have.
Speaker 1: It's like a crack a way to explore it that
Speaker 1: might be able to reveal what's happening with black holes
Speaker 1: and information. It's not like a very totally solid worked
Speaker 1: out idea. I see, these are just kind of like
Speaker 1: directions in which that might have playing these things exactly exactly,
Speaker 1: and we we we might be getting closer to knowing
Speaker 1: the answer, right, I mean, we just took a picture
Speaker 1: of a black hole. Maybe in the future we might
Speaker 1: get closer to it and figure these things out. Or
Speaker 1: is this closed off to us forever. That's a great question.
Speaker 1: And you know, we could send somebody into a black
Speaker 1: hole and maybe they could learn something about it. The
Speaker 1: problem is we'd never know the answer because they couldn't
Speaker 1: tell us. We might as well send dogs in, right, Well,
Speaker 1: we're going to get a letter from the cat. Our
Speaker 1: cats depending it. You know, Well, if you're a dog lover,
Speaker 1: you can, we can send cats to we should just
Speaker 1: send robots. And let's just send robots. No, there's no
Speaker 1: society protecting the life of robots, right, that's right, the
Speaker 1: dog robots, dog robots. There, that's a perfect compromise, all right.
Speaker 1: But again, it just tells you that there's a lot
Speaker 1: we don't know about the universe, and that even like
Speaker 1: our experience of it, this three dimensional experience of it,
Speaker 1: might be not real or not what we think it is. Yeah,
Speaker 1: and that deep insights into the very nature of the
Speaker 1: universe can come from these little odds and ends, these
Speaker 1: things that all we thought we understood, and then there's
Speaker 1: a little detail that doesn't quite make sense, and when
Speaker 1: you tug on that thread, it could unravel literally everything
Speaker 1: we think we understand about the universe. This is how
Speaker 1: lots of great discoveries were made relativity, quantum mechanics, and
Speaker 1: hopefully future crazy bonkers discoveries that people will have a
Speaker 1: hard time accepting is the true nature of the anivers
Speaker 1: Until then, I guess I'll stay to a blender to
Speaker 1: make my fans. I think that's a good idea. All right, Well,
Speaker 1: we hope you enjoyed that Thanks for joining us. Let's
Speaker 1: see you next time. Thanks for listening, and remember that
Speaker 1: Daniel and Jorge Explain the Universe is a production of
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