The Holographic Principle: Is Reality a Projection?

<v Speaker 1>Welcome to the quart Side Quantum Physics Podcast, an exploration
<v Speaker 1>of the fundamental structure of reality, where quantum laws govern matter, energy,
<v Speaker 1>and information. Here, uncertainty is a feature, not a flaw,
<v Speaker 1>and understanding begins at the smallest scales.
<v Speaker 2>I want you to do something for me right now.
<v Speaker 2>If you're driving, obviously keep your hands on the wheel.
<v Speaker 2>But if you're not, if you're sitting at a desk
<v Speaker 2>or on a couch, just reach out and touch the
<v Speaker 2>nearest solid object. Yeah, maybe it's your desk, could be
<v Speaker 2>your desk, maybe the fabric.
<v Speaker 3>On your chair, or even just you know, clap your
<v Speaker 3>hands together.
<v Speaker 2>Feel that, exactly, feel that resistance, that solidity. It feels well,
<v Speaker 2>it feels real, right, I mean, it feels like it
<v Speaker 2>occupies space. It has depth, it has volume. You can
<v Speaker 2>move your hand through the air up, left, right, forward, back.
<v Speaker 2>I mean, we live in a world of three dimensions.
<v Speaker 2>That is that feels like the most fundamental fact of
<v Speaker 2>our existence.
<v Speaker 3>It really does. It's the stage, right, the stage where
<v Speaker 3>our entire lives play out, where three D creatures we
<v Speaker 3>navigate a three D world.
<v Speaker 2>Right. But here's the hook, and I'm going to warn
<v Speaker 2>you this is the kind of idea that might make
<v Speaker 2>you want to pull the car over, or I don't know,
<v Speaker 2>just stare at your hands for an hour.
<v Speaker 3>Uh huh.
<v Speaker 2>What if I told you that this feeling of depth,
<v Speaker 2>this this whole sensation of space that we're moving through
<v Speaker 2>is a lie.
<v Speaker 3>Well, lie might be a strong word. Let's maybe call
<v Speaker 3>it a compelling illusion.
<v Speaker 2>Okay, a very convincing illusion. What if everything in our universe, gravity, matter, time,
<v Speaker 2>the very space between you and me right now? What
<v Speaker 2>if it's all just a projection, like we are all
<v Speaker 2>just encoded data, just smeared across some distant two dimensional
<v Speaker 2>surface at the edge of the cosmos.
<v Speaker 3>It sounds like the plot of a sci fi novel
<v Speaker 3>or something you'd hear at a college dorm room at
<v Speaker 3>three am. Right, But what you're describing is actually one
<v Speaker 3>of the most robust, heavily researched, and mathematically significant concepts
<v Speaker 3>in modern theoretical physics.
<v Speaker 2>We are talking about the holographic principle. And I have
<v Speaker 2>to admit, when I first saw this topic come up,
<v Speaker 2>I thought, Okay, we're finally doing the simulation theory episode,
<v Speaker 2>we're doing the matrix right, But this isn't that? Is it?
<v Speaker 2>It's different.
<v Speaker 3>It touches on similar themes for sure, but no, this
<v Speaker 3>isn't about evil robots using us as batteries. This is
<v Speaker 3>about the fundamental architecture of reality itself. It's about how
<v Speaker 3>the universe stores information.
<v Speaker 2>And the implications are I mean, they're unsettling, to say
<v Speaker 2>the least.
<v Speaker 3>It challenges everything we think we know about where we are.
<v Speaker 2>So before we get into the heavy math, and we will,
<v Speaker 2>but we'll try to keep it painless. Let's just define
<v Speaker 2>the core concept. When we say holographic principle, what are
<v Speaker 2>we actually claiming?
<v Speaker 3>The core claim is this all of the information that's
<v Speaker 3>contained in a volume of space. So imagine a room,
<v Speaker 3>a planet, or the entire universe. All of it can
<v Speaker 3>be completely one described by data that lives on the
<v Speaker 3>boundary of that region, a.
<v Speaker 2>Boundary like the shell bricked the surface area.
<v Speaker 3>So to use the analogy that gives this principle its name, Yeah,
<v Speaker 3>it's like a hologram. I feel like we have to
<v Speaker 3>be careful with that word, because when I hear hologram,
<v Speaker 3>I think of you know, Tupocket Coachella, right right, I
<v Speaker 3>think of a ghost shimmering on a stage.
<v Speaker 2>And that's that's a visual trick using mirrors in light.
<v Speaker 2>It's not quite the physics definition. A better way to
<v Speaker 2>think about it is a security sticker on your credit card.
<v Speaker 3>Oh, the little shiny bird or the globe exactly. Now,
<v Speaker 3>if you run your finger over that sticker, what do
<v Speaker 3>you feel.
<v Speaker 2>It's flat. It's just a piece of class gets two dimensional.
<v Speaker 3>Precisely, the physical object is two D. But when light
<v Speaker 3>hits it, what do you see?
<v Speaker 2>You see depth? You see a little bird floating in
<v Speaker 2>three D space. You can tilt the card and sort
<v Speaker 2>of see the side of it.
<v Speaker 3>Right. The reality of the image looks three to men,
<v Speaker 3>but all the information that generates that image is just
<v Speaker 3>etched onto a flat two dimensional.
<v Speaker 2>Surface, And the holographic principle is suggesting that the entire
<v Speaker 2>universe might be that credit card sticker in a.
<v Speaker 3>Manner of speaking. Yeah, The theory suggests that the three
<v Speaker 3>dimensional world we inhabit, the bulk, as physicists call it,
<v Speaker 3>is a projection of fundamental quantum information that's stored on
<v Speaker 3>a lower dimensional boundary.
<v Speaker 2>Which would mean that space isn't even a fundamental thing.
<v Speaker 2>It's just emergent. It is like a user interface on
<v Speaker 2>a computer screen.
<v Speaker 3>That is the implication, and it forces us to ask
<v Speaker 3>whether here, you know, this room, this planet is really here,
<v Speaker 3>or if the real physics is happening somewhere else on
<v Speaker 3>the edge of the cosmos.
<v Speaker 2>Okay, my brain is already starting to itch, which is
<v Speaker 2>that's usually a good sign. We have a massive roadmap
<v Speaker 2>ahead of us.
<v Speaker 3>Here.
<v Speaker 2>We need to understand where this idea even came from, which,
<v Speaker 2>strangely enough, wasn't from studying holograms. It was from studying
<v Speaker 2>black holes.
<v Speaker 3>Black Holes are the key to this entire story. They
<v Speaker 3>always are.
<v Speaker 2>We have to unpack something called the Maldacina conjecture, which
<v Speaker 2>it sounds like a Robert Ludlam thriller, but it's actually
<v Speaker 2>the Rosetta stone for this whole theory.
<v Speaker 3>It absolutely is.
<v Speaker 2>We're going to talk about the information paradox, the sort
<v Speaker 2>of crime scene that started this whole investigation, and we'll.
<v Speaker 3>Get into how this actually solves some of the biggest
<v Speaker 3>problems in physics.
<v Speaker 2>And then, because we can't help ourselves, we are going
<v Speaker 2>to get into the really wild stuff quantum computing, the
<v Speaker 2>nature of consciousness and whether our universe is actually just
<v Speaker 2>a big error correcting code.
<v Speaker 3>It's a fascinating journey. It connects the largest things in
<v Speaker 3>the universe black holes, with the smallest things imaginable quantum bits.
<v Speaker 2>So let's start at the beginning, or I guess let's
<v Speaker 2>start in the nineteen nineties, because this theory didn't just
<v Speaker 2>prop out of nowhere. It came from a crisis, it did.
<v Speaker 3>It came from a conflict. You have to understand. In physics,
<v Speaker 3>we basically have two main rule books. We have general relativity,
<v Speaker 3>Einstein's masterpiece. It describes big things gravity, stars, galaxies, the
<v Speaker 3>shape of space.
<v Speaker 2>And then we have quantum mechanics.
<v Speaker 3>Which describes the small things atoms, particles, information, And usually
<v Speaker 3>these two rule books they just ignore each other. They
<v Speaker 3>stay in their own lanes. But in a black hole
<v Speaker 3>they crash. They crash hard. In a black hole, you
<v Speaker 3>have a massive amount of gravity that's general relativity, crucking
<v Speaker 3>things down to a tiny microscopic point that's quantum mechanics.
<v Speaker 2>So you have to use bose rule books at the
<v Speaker 2>same time.
<v Speaker 3>You have to, and when physicists tried to do that
<v Speaker 3>back in the nineties, the math just started screaming.
<v Speaker 2>At them, and they were specifically looking at entropy. Right now,
<v Speaker 2>entropy is one of those words that gets thrown around
<v Speaker 2>a lot. Usually people say it means disorder, like my
<v Speaker 2>messy desk has high entropy.
<v Speaker 3>That's the casual definition. Yeah, But in information theory, entropy
<v Speaker 3>is much more precise. It's a measure of hidden information.
<v Speaker 3>It's the number of distinct micro states or configurations that
<v Speaker 3>a system can have.
<v Speaker 2>Okay, let's dumb that down a little. Micro states.
<v Speaker 3>Think of it as the number of yes, no questions
<v Speaker 3>you'd need to ask to fully describe a system down
<v Speaker 3>to the very last atom. It's a measure of how
<v Speaker 3>much data is inside. Got it.
<v Speaker 2>So let's talk about a library. I love libraries. If
<v Speaker 2>I want to know how much information fits in a library,
<v Speaker 2>what do I look at?
<v Speaker 3>Well, intuitively, you look at the volume of the room,
<v Speaker 3>the size of the space inside.
<v Speaker 1>Right.
<v Speaker 2>If I have a library that's say a thousand cubic feet,
<v Speaker 2>I can fit x number of books. If I build
<v Speaker 2>a new library that is two thousand cubic feet, double
<v Speaker 2>the volume, I can fit double the books exactly.
<v Speaker 3>That's our common sense. It's called extensive scaling. The amount
<v Speaker 3>of stuff you can pack into a region depends on
<v Speaker 3>the volume of that region. It's cubed.
<v Speaker 2>It's cubed.
<v Speaker 3>Right. If you double the radius of a sphere, the
<v Speaker 3>volume goes up by a factor of eight. So you
<v Speaker 3>should be able to fit eight times as much information inside.
<v Speaker 2>Right, Because we live in a three D world which
<v Speaker 2>would be able to stack data in three D, we
<v Speaker 2>should be able to fill every little cubic inch of
<v Speaker 2>space with a hard drive or something.
<v Speaker 3>That is what everyone assumed until they looked at black holes.
<v Speaker 2>And this is where Ard Hoofed and Leonard Suskan come in.
<v Speaker 3>The fathers of the holographic principle. They, along with Jacob
<v Speaker 3>Bekenstein before them, realize something that just it violated all
<v Speaker 3>that common sense. They found that if you want to
<v Speaker 3>measure the maximum amount of entropy, the maxim amount of
<v Speaker 3>information you can stuff into a region of space, you
<v Speaker 3>don't look at the volume.
<v Speaker 2>You don't know.
<v Speaker 3>You look at the surface area.
<v Speaker 2>Wait, hold on, So it doesn't matter how big the
<v Speaker 2>inside is, It only matters how much surface area the
<v Speaker 2>skin has.
<v Speaker 3>Correct, the limit on information is in cubic it's squared.
<v Speaker 2>So back to the library.
<v Speaker 3>Okay, back to the library. Imagine you're trying to pack
<v Speaker 3>it with books. You just keep shoving books in Eventually
<v Speaker 3>gravity takes over and that library collapses into a black hole.
<v Speaker 2>Okay, so now I have a black hole library.
<v Speaker 3>Right, And if you calculate how much information is hidden
<v Speaker 3>inside that black hole, the math tells you do not
<v Speaker 3>count the interior, count the square inches of the event horizon.
<v Speaker 3>The capacity is determined by the walls, not by the room.
<v Speaker 2>That feels wrong. That feels deeply fundamentally wrong.
<v Speaker 3>It feels wrong because it violates our entire intuition about dimensions.
<v Speaker 3>I mean, think about it this way. Imagine you have
<v Speaker 3>a box of pingpong balls. You want to know how
<v Speaker 3>many balls fit in the box. You'd assume it depends
<v Speaker 3>on how deep the box.
<v Speaker 2>Is, right, Yeah, of course I can snack them layers
<v Speaker 2>and layers of balls.
<v Speaker 3>But the black hole mat says no, The maximum number
<v Speaker 3>of balls you can fit is actually determined by how
<v Speaker 3>many circles you can draw on the lid of the box.
<v Speaker 2>So if I make the box deeper, but I keep
<v Speaker 2>the lid the same size, I can't add any more
<v Speaker 2>balls effectively.
<v Speaker 3>Yeah, if you try to add more, the physics breaks.
<v Speaker 3>The region would have to collapse or expand the limit
<v Speaker 3>is always the surface area. This was known as the
<v Speaker 3>Baconstein Bound.
<v Speaker 2>The Baconstein Bound, It really does sound like a spy
<v Speaker 2>movie title. The Baconstein Bound taffles.
<v Speaker 3>It is one of the most profound discoveries in physics.
<v Speaker 3>It tells us that the resolution of the universe is finite,
<v Speaker 3>and more importantly, it suggests that the fundamental pixels of reality,
<v Speaker 3>the smallest possible units of information, are tiling the surface,
<v Speaker 3>not filling the volume.
<v Speaker 2>Let's pause on that pixel idea for a second, because
<v Speaker 2>if we're talking about a three D world, we'd usually
<v Speaker 2>talk about voxels, right.
<v Speaker 3>Three D pixels like in Minecraft.
<v Speaker 2>Yeah, exactly, everything is made of little cubes, right.
<v Speaker 3>If the universe were truly fundamentally three D all the
<v Speaker 3>way down, it would be made of vouxles. But the
<v Speaker 3>Beckenstein Bound says that at the most fundamental level, the
<v Speaker 3>Plank scale, the universe behaves like it's made of pixels
<v Speaker 3>on a two D sheet.
<v Speaker 2>So this was the first breadcrumb the universe sort of
<v Speaker 2>whispering to us, Hey, you think the important stuff is
<v Speaker 2>inside the volume, but the accounting, the real ledger is
<v Speaker 2>kept on the walls.
<v Speaker 3>Exactly. And if the maximum amount of information in any
<v Speaker 3>volume of space is determined by its boundary. Then maybe,
<v Speaker 3>just maybe the interior isn't the fundamental thing. Maybe the
<v Speaker 3>interior is just a projection of the data on the boundary.
<v Speaker 2>It's like discovering that the book you're reading isn't a
<v Speaker 2>story about a world, but just a really really complex index.
<v Speaker 3>For the world, or that the room you're standing in
<v Speaker 3>is just a very convincing hologram. Yeah, but for a
<v Speaker 3>few years, this was just a weird observation about black holes.
<v Speaker 3>It was a suspicion. It wasn't a full blown.
<v Speaker 2>Theory until nineteen ninety seven.
<v Speaker 3>Until nineteen ninety seven.
<v Speaker 2>Enter Juan Maldasena, the man who changed everything. So Meldasena
<v Speaker 2>comes along and he doesn't just say, hey, you know,
<v Speaker 2>maybe the universe is a hologram. He actually builds a
<v Speaker 2>mathematical model that shows it works.
<v Speaker 3>He provided the first concrete mathematical realization of the holographic principle.
<v Speaker 3>It's called the ad CFT correspondence.
<v Speaker 2>Okay, add SCFT. I see this acronym everywhere in the research.
<v Speaker 2>It looks like a license plate number or maybe a
<v Speaker 2>bad Wi Fi password chuckles.
<v Speaker 3>It's certainly I'm mouthful. Most physicists just called the Maldasina conjecture,
<v Speaker 3>or sometimes just the duality.
<v Speaker 2>We need to unpack this because all the sources say
<v Speaker 2>this is the Rosetta stone. If we can get our
<v Speaker 2>heads around this, we get the whole theory. So let's
<v Speaker 2>break it down. Ad s anti desitter space.
<v Speaker 3>Right, So ad S refers to the bulk the inside
<v Speaker 3>of things.
<v Speaker 2>Antiit a sitter sounds like a villain. I am antidasitter.
<v Speaker 3>It does sound a bit ominous, yeah, but it just
<v Speaker 3>describes as specific geometry of space. Now I'm going to
<v Speaker 3>need you to do some mental gymnastics with me here.
<v Speaker 3>Forget our universe for a second. Forget the expanding cosmos
<v Speaker 3>we see through telescopes. Maldosina built a toy universe, a model.
<v Speaker 2>Okay, I'm with you. I'm in the toy universe. What's
<v Speaker 2>it like?
<v Speaker 3>Imagine a can of soup. A can of soup, Okay,
<v Speaker 3>simple can of suit. The ad S part the anti
<v Speaker 3>de Sitter space. That's the soup. It's the volume inside
<v Speaker 3>the can. It has three dimensions height with depth, it
<v Speaker 3>has gravity, it has black holes floating around the broth,
<v Speaker 3>it has stars. It's a dynamic three D world.
<v Speaker 2>Okay, So I'm swimming in the soup, I feel gravity,
<v Speaker 2>I see three D objects.
<v Speaker 3>All good, exactly. Now, there's one very weird thing about
<v Speaker 3>this soup. It has what we call negative curvature.
<v Speaker 2>Negative curvature, What does that mean visually? What does that
<v Speaker 2>look like?
<v Speaker 3>Have you ever seen those Esher drawings the circle limit
<v Speaker 3>ones with the angels.
<v Speaker 2>And demons, Yes, where they're all interlocking, and as they
<v Speaker 2>get closer to the edge of the circle, they get
<v Speaker 2>smaller and smaller and smaller.
<v Speaker 3>And they seem to go on forever towards the edge,
<v Speaker 3>but they never quite touch it.
<v Speaker 2>Right.
<v Speaker 3>That is a two D representation of hyperbolic geometry or
<v Speaker 3>negative curvature in Antidecitter space. Space itself is warped like that,
<v Speaker 3>like a funhouse mirror version of a universe. But the
<v Speaker 3>key thing is it has a boundary, It has an edge.
<v Speaker 2>The label on the soup can the.
<v Speaker 3>Label on the soup can that is the boundary. And
<v Speaker 3>that brings us to the second half of the acronym.
<v Speaker 2>CFT conformal field theory.
<v Speaker 3>Right, this is the theory that lives on the label.
<v Speaker 3>Now here's the crucial difference. The soup the edds space
<v Speaker 3>because gravity the label. The CFT does not have gravity,
<v Speaker 3>no gravity on the label, none whatsoever. It is just
<v Speaker 3>a flat surface with quantum particles buzzing around, interacting with
<v Speaker 3>each other. It's a standard quantum field theory, like the
<v Speaker 3>ones we use to describe electromagnetism.
<v Speaker 2>So we have two totally different worlds. Here we have
<v Speaker 2>the soup three D gravity black holes, and we have
<v Speaker 2>the label two D no gravity, just particles.
<v Speaker 3>And here is Maldasine's genius. He proved mathematically that these
<v Speaker 3>two theories are equivalent. They are duels of each other equivalent.
<v Speaker 2>How can a three D gravitational world be equivalent to
<v Speaker 2>a two D flat one.
<v Speaker 3>It means that every single thing that happens in the
<v Speaker 3>soup has a direct, perfect translation to something happening on
<v Speaker 3>the label.
<v Speaker 2>So if I drop a little rock into the soup.
<v Speaker 3>That corresponds to a specific ripple of particles on the label.
<v Speaker 2>And if a black hole forms in the soup.
<v Speaker 3>That corresponds to a specific temperature rising in the particles
<v Speaker 3>on the label, a specific thermal state.
<v Speaker 2>So it's a dictionary.
<v Speaker 3>It is a perfect dictionary. You can translate any sentence
<v Speaker 3>from soup language, which is gravity, into label language, which
<v Speaker 3>is quantum fields. And this is why physicists went absolutely
<v Speaker 3>nuts for it, because sometimes the math in the soup
<v Speaker 3>is just it's impossible.
<v Speaker 2>Ever ready is hard.
<v Speaker 3>Gravity's notoriously hard. The equations get incredibly messy. Yeah, but
<v Speaker 3>using the dictionary, you can translate that hard gravity problem
<v Speaker 3>onto the label. Suddenly it becomes a quantum particle problem,
<v Speaker 3>which might be much easier to solve. Oh wow, you
<v Speaker 3>solve it there, get the answer, and then you translate
<v Speaker 3>it back to the soup.
<v Speaker 2>It's a cheat code.
<v Speaker 3>It is the ultimate cheat code for physics. It's a
<v Speaker 3>concept called strong weak duality. When gravity is strong and
<v Speaker 3>complicated in the bulk, the interactions on the boundary are
<v Speaker 3>simple and weak, and vice versa.
<v Speaker 2>So even if the holographic principle isn't real in some
<v Speaker 2>philosophical sense, even if we aren't literally living on a wall,
<v Speaker 2>this tool is so useful that physicists use it every day.
<v Speaker 3>Oh absolutely. It is revolutionized string theory, nuclear physics, condensed
<v Speaker 3>matter physics. Yeah, and it's a workhorse. But the question
<v Speaker 3>we're asking today isn't just is it useful, it's is
<v Speaker 3>it true?
<v Speaker 2>Right? Is the soup real? Or is the label real exactly,
<v Speaker 2>because if Maldacina is right, and the boundary contains all
<v Speaker 2>the information of the bulk, then the bulk is technically redundant.
<v Speaker 2>You don't need the three D space to explain the universe.
<v Speaker 2>The two space on the label does it perfectly. Well.
<v Speaker 3>That's the existential crisis right there. If the two D
<v Speaker 3>theory is complete, then the three D world is just
<v Speaker 3>a projection. It's an emergent phenomenon, a hologram.
<v Speaker 2>I need to sit with the soup cam universe for
<v Speaker 2>a second, because this model, this duality, it actually helped
<v Speaker 2>solve a crime, a cosmic crime involving Stephen.
<v Speaker 3>Hawking, the information paradox.
<v Speaker 2>The information paradox. This is the Sherlock Holms moment of
<v Speaker 2>the whole story, because for a long time physics had
<v Speaker 2>this gaping hole in it, a murder mystery where the
<v Speaker 2>victim was information.
<v Speaker 3>Itself and Stephen Hawking was the prime suspect.
<v Speaker 2>Set the scene for us. What did Hawking do well?
<v Speaker 3>Back in the seventies, Hawking made a startling discovery about
<v Speaker 3>black holes. Before him, we thought black holes were just
<v Speaker 3>these eternal prisons. Nothing ever gets at.
<v Speaker 2>The ultimate roach motel. Things check in, but they don't
<v Speaker 2>check out right.
<v Speaker 3>But Hawking applied quantum mechanics to the very edge of
<v Speaker 3>the black hole, the event horizon, and he realized that,
<v Speaker 3>due to quantum fluctuations, black holes should actually emit radiation.
<v Speaker 3>They should glow very faintly.
<v Speaker 2>This is Hawking radiation. How does that work?
<v Speaker 3>Very briefly, Okay, very briefly. In empty quantum space, pairs
<v Speaker 3>of virtual particles are constantly popping into existence, a particle
<v Speaker 3>and an antiparticle. Usually they just annihilate each other and vanish.
<v Speaker 3>But if they pop up right on the edge of
<v Speaker 3>a black hole, one falls in and the other one escapes.
<v Speaker 3>The one that escapes becomes real radiation. The one that
<v Speaker 3>falls in effectively subtracts a tiny bit of energy from
<v Speaker 3>the black hole.
<v Speaker 2>So the black hole is losing weight. It's on a diet, a.
<v Speaker 3>Very very slow diet. And if you wait long enough,
<v Speaker 3>trillions and trillions and trillions of years, the black hole
<v Speaker 3>will radiate away all of its mass and hoof disappear.
<v Speaker 2>Okay, the black hole dies. Why is that a paradox?
<v Speaker 2>Why is that a crisis for physics.
<v Speaker 3>Because of what fell inside? Imagine you take your diary.
<v Speaker 3>It has your secrets, your memories, all this unique information.
<v Speaker 3>You throw it into a black hole.
<v Speaker 2>Bye bye diary. My secrets are safe now you.
<v Speaker 3>Wait a trillion years. The black hole evaporates, it turns
<v Speaker 3>into this Hawking radiation. But here's the thing. Hawking's calculation
<v Speaker 3>showed that this radiation is random, it's thermal, it's just heat.
<v Speaker 3>It doesn't contain the text of your diary.
<v Speaker 2>The diary is gone.
<v Speaker 3>If the black hole disappears and the radiation coming out
<v Speaker 3>doesn't have the data, then yes, the information has been
<v Speaker 3>permanently deleted from the universe.
<v Speaker 2>And I'm guessing physicists don't like deleting things.
<v Speaker 3>They hate it. It breaks a fundamental rule of quantum
<v Speaker 3>mechanics called unitarity. In quantum mechanics, information is immortal. You
<v Speaker 3>can scramble it like you can burn a book into ash,
<v Speaker 3>But in principle, if you collected all the ash and
<v Speaker 3>smoke and light, you could reconstruct the book. Information is
<v Speaker 3>never truly lost.
<v Speaker 2>But Hawking was saying, Nope, in a black hole, it
<v Speaker 2>eyes lost exactly.
<v Speaker 3>He said black holes are cosmic erasers, and if that's true,
<v Speaker 3>then quantum mechanics is wrong. Physics is broken. The past
<v Speaker 3>doesn't determine the future. It was a complete disaster.
<v Speaker 2>It was the black hole war Suskan versus Hawking.
<v Speaker 3>For decades, nobody knew who was right until the holographic
<v Speaker 3>principle came in as the peacekeeper.
<v Speaker 2>So how does the hologram save the diary?
<v Speaker 3>Remember the soup can remember the duality. The three D
<v Speaker 3>black hole in the soup where the diary fell in
<v Speaker 3>is completely equivalent to the two D label the quanda
<v Speaker 3>field theory. We know for a fact, with one hundred
<v Speaker 3>percent certainty that the theory on the label is unitary.
<v Speaker 3>It never ever loses information. It's a standard quantum system.
<v Speaker 3>It plays by the rules.
<v Speaker 2>So if the label can't possibly lose the.
<v Speaker 3>Diary, then the soup can't lose it either, because they
<v Speaker 3>are the same system, just viewed in two different ways.
<v Speaker 3>The information must be preserved.
<v Speaker 2>So Hawking was wrong.
<v Speaker 3>He eventually conceded. He famously admitted he was wrong. The
<v Speaker 3>consensus now is that the information isn't lost. It gets
<v Speaker 3>encoded into the outgoing radiation in a highly complex, scrambled way, So.
<v Speaker 2>The diary doesn't disappear, It just gets turned into the
<v Speaker 2>most complicated barcode in the entire universe.
<v Speaker 3>That's a perfect way to put it. From the respective
<v Speaker 3>of the holographic principle, the information that falls into the
<v Speaker 3>black hole is effectively smeared out and stored on the boundary.
<v Speaker 3>It never truly leaves the system.
<v Speaker 2>That is a relief, I guess. I mean, I don't
<v Speaker 2>want my diary red, but I definitely don't want it
<v Speaker 2>to break all the laws of physics.
<v Speaker 3>Copples. It saves physics, yeah, but it does so at
<v Speaker 3>a cost, and the cost is accepting that location is
<v Speaker 3>an illusion. The diary isn't really inside the hole. It's
<v Speaker 3>painted on the horizon.
<v Speaker 2>And this leads us to the part of the whole
<v Speaker 2>discussion that I find the most well, the most mind bending,
<v Speaker 2>because if the boundary is the thing that follows the
<v Speaker 2>rules and the bulk is the thing that gives us illusions,
<v Speaker 2>then space itself isn't real.
<v Speaker 3>Space is emergent. That is the phrase you'll hear physicists
<v Speaker 3>use over and over.
<v Speaker 2>Emergent. Okay, let's unpack that word.
<v Speaker 3>Think about wetness. You have a single water molecule. Is
<v Speaker 3>that molecule wet?
<v Speaker 2>No, it's just h two. Oh, it's just hydrogen and
<v Speaker 2>oxygen atoms.
<v Speaker 3>Wetness is a property that emerges when you have billions
<v Speaker 3>and billions of them all sloshing around together. Or think
<v Speaker 3>about heat. Heat isn't the thing in itself, it's just
<v Speaker 3>the average motion of atoms.
<v Speaker 2>So you're saying space, the distance between my nose and
<v Speaker 2>this microphone is like heat. It's not a fundamental thing.
<v Speaker 2>It's just what happens when well when what happens.
<v Speaker 3>When quantum information gets entangled?
<v Speaker 2>Entanglement the spooky action at a distance.
<v Speaker 3>Yes, there is a growing movement in physics, an idea
<v Speaker 3>called it from quibbit. The idea is that the fundamental
<v Speaker 3>building block of reality is the quibbit, a unit of
<v Speaker 3>quantum information, and space is the geometry that emerges from
<v Speaker 3>the entanglement of those quibbots.
<v Speaker 2>Explain that to me, how does entanglement create distance?
<v Speaker 3>Okay, so imagine two points on the boundary on our
<v Speaker 3>soup can label. If the information at those two points
<v Speaker 3>is highly entangled, meaning their quantum states are deeply linked,
<v Speaker 3>they effectively pull the corresponding regions in the bulk together.
<v Speaker 3>They create a sort of shortcut through the.
<v Speaker 2>Bulk, a wormhole.
<v Speaker 3>It's called Einstein, rosenbridge or wormhole. Yes, is what we
<v Speaker 3>perceive as closeness.
<v Speaker 2>So I am sitting next to you right now, not
<v Speaker 2>because we are physically close and some fundamental container, but
<v Speaker 2>because the quibits that represent us on the boundary are
<v Speaker 2>really really entangled.
<v Speaker 3>That's the hypothesis. Distance is a measure of entanglement. If
<v Speaker 3>you could somehow cut the entanglement between two regions on
<v Speaker 3>the boundary, the space between them in the bulk would
<v Speaker 3>literally snap the choma. You would fall apart.
<v Speaker 2>That is a terrifying thought. It means the fabric of
<v Speaker 2>reality is just it's just correlations in data.
<v Speaker 3>It leads to this concept called entanglement wedges.
<v Speaker 2>Which sounds like a terrible appetizer at a restaurant.
<v Speaker 3>Cuckles, I'll have the entanglement wedges with a side of
<v Speaker 3>quantum ranch.
<v Speaker 2>No. It just means that specific chunks of spacetime, specific
<v Speaker 2>wedges of the bulk, are generated by specific corresponding chunks
<v Speaker 2>of data on the boundary. You can map exactly which
<v Speaker 2>part of the hologram is responsible for creating which part
<v Speaker 2>of the room you're in.
<v Speaker 3>This makes me think of a video game. I play
<v Speaker 3>a lot of these big open world games.
<v Speaker 2>That's a perfect analogy.
<v Speaker 3>When I'm playing, I see a mountain way off in
<v Speaker 3>the distance, I can walk to it. It feels like
<v Speaker 3>three D space. But in reality, on the hard drive,
<v Speaker 3>the data for Mountain A and Mountain B might be
<v Speaker 3>on completely different sectors of the disc. They aren't next
<v Speaker 3>to each other on the chip at.
<v Speaker 2>All, exactly, they are linked by pointers by code.
<v Speaker 3>So the three D world of the game is emergent.
<v Speaker 3>It's being rendered in real time precisely. The two D
<v Speaker 3>surface of the ship is the reality. The three D
<v Speaker 3>world of the game is the projection. And just like
<v Speaker 3>in the game, if the code gets corrupted, the mountain
<v Speaker 3>might just disappear or the ground might fall up from
<v Speaker 3>under you.
<v Speaker 2>So we're sims. We're just very very high resolution sims.
<v Speaker 3>We might be, but instead of a hard drive, the
<v Speaker 3>chip is the boundary of the universe, and the code
<v Speaker 3>is quantum entanglement.
<v Speaker 2>Okay, So if we accept this that we are in
<v Speaker 2>the rendered environment, we have to ask about the hardware.
<v Speaker 2>We talked about the soup Can universe, but as you mentioned,
<v Speaker 2>that was a toy universe.
<v Speaker 3>The anti desitter space.
<v Speaker 2>But we don't live in a soup can. Our universe
<v Speaker 2>is expanding.
<v Speaker 3>We live in what's called desitter space. There's something very
<v Speaker 3>close to it. It has a positive curvature.
<v Speaker 2>So does any of this actually apply to us? Or
<v Speaker 2>is this just a really cool theory for a universe
<v Speaker 2>that doesn't actually exist.
<v Speaker 3>This is the biggest criticism. This is the Achilles heel
<v Speaker 3>of the theory. Right now, the math works beautifully and
<v Speaker 3>perfectly in the soup can in ads space. It is
<v Speaker 3>much much harder to make it work in our universe
<v Speaker 3>in desitter space.
<v Speaker 2>Why what's the main difference?
<v Speaker 3>The boundary In the soup can, the boundary is a
<v Speaker 3>clear hard wall. It acts like a perfect mirror. Light
<v Speaker 3>hits it and bounces back in a perfect static container.
<v Speaker 3>In our universe, well, we're expanding. We don't have a
<v Speaker 3>hard wall at the edge.
<v Speaker 2>So where is our label? Where is our screen?
<v Speaker 3>That's the multi trillion dollar question. Some physicists think the
<v Speaker 3>screen might be the cosmic horizon.
<v Speaker 2>The edge of the observable universe.
<v Speaker 3>Right, if you look as far as you can in
<v Speaker 3>any direction, you eventually hit a point where from beyond
<v Speaker 3>hasn't had time to reach us yet. That horizon surrounds us.
<v Speaker 3>Some propose that this horizon could act as our holographic screen.
<v Speaker 2>So the edge of what we can see is the
<v Speaker 2>hard drive and everything inside, all the galaxies stars us
<v Speaker 2>is the projection inward from that screen.
<v Speaker 3>That is one possibility. It's a model called DSCFT the
<v Speaker 3>Sitter CFT, but the math is much much messier. However,
<v Speaker 3>the Bekenstein bound, that fundamental limit on entropy, it seems
<v Speaker 3>to hold true regardless of the shape of the universe,
<v Speaker 3>so the core principle is likely correct, even if the
<v Speaker 3>screen is harder for us to defind.
<v Speaker 2>This actually touches on something else I saw in the
<v Speaker 2>research quantum computing. I saw a note about error correcting codes,
<v Speaker 2>and this felt like the most I don't know, the
<v Speaker 2>most sci fi part of all of this.
<v Speaker 3>It's also the most practical tech part. It turns out
<v Speaker 3>the mathematics that makes the holographic principle work is essentially
<v Speaker 3>identical to the math we are now using to build
<v Speaker 3>fault tolerant quantum computers.
<v Speaker 2>Explain that connection. What is an error correct?
<v Speaker 3>Okay, imagine you have an old DVD. Remember DVDs.
<v Speaker 2>I'm old enough to remember.
<v Speaker 3>Yes, if you get a little scratch on a DVD,
<v Speaker 3>does the movie stop working.
<v Speaker 2>Usually know, unless it's a really deep scratch, it might
<v Speaker 2>skip for a second, but it plays through.
<v Speaker 3>And why is that? It's because the data on the
<v Speaker 3>DVD is redundant. The information for a specific frame of
<v Speaker 3>the movie isn't just in one tiny spot. It's spread out.
<v Speaker 3>It's encoded in a way that allows the player to
<v Speaker 3>fill in the blanks if some of the data is missing. Redundancy,
<v Speaker 3>exactly logical redundancy. Now think about the hologram. The information
<v Speaker 3>about a single point in the bulk, say a star
<v Speaker 3>in the middle of the soup, is spread out all
<v Speaker 3>across the boundary. It's smeared out.
<v Speaker 2>So the star isn't just here on one spot of
<v Speaker 2>the boundary, It's encoded everywhere on the boundary.
<v Speaker 3>In a sense. Yes, and this is crucial for quantum computers.
<v Speaker 3>Quantum data qubits, they're incredibly fragile. If a stray atom
<v Speaker 3>or a bit of radiation hits your quibit, the data
<v Speaker 3>can be lost. So you have to use these error
<v Speaker 3>correcting codes to spread that single piece of logical data
<v Speaker 3>out across many physical quibits. If one gets corrupted, the
<v Speaker 3>others can reconstruct.
<v Speaker 2>The whole and the universe is doing this.
<v Speaker 3>The math suggests the universe is this. The holographic principle
<v Speaker 3>acts like a giant natural error correcting code.
<v Speaker 2>So space is robust because it's redundant.
<v Speaker 3>Yes, if you were to somehow scratch the boundary, if
<v Speaker 3>you deleted a chunk of the label, you could still
<v Speaker 3>reconstruct the soup in the middle. The bulk is protected
<v Speaker 3>by this holographic redundancy.
<v Speaker 2>That is weirdly comforting and also deeply terrifying. It implies
<v Speaker 2>the universe is somehow engineered to preserve information.
<v Speaker 3>Or that stability itself requires this structure. The universe that
<v Speaker 3>wasn't holographic, that didn't have this built in error correction,
<v Speaker 3>might just collapse. Space might just dissolve into nothing. We
<v Speaker 3>might be here because the universe is a hologram.
<v Speaker 2>We are the glitch proof simulation. I like the sound
<v Speaker 2>of that.
<v Speaker 3>I wouldn't go quite that far, but the parallel is
<v Speaker 3>definitely undeniable.
<v Speaker 2>I want to push into the deep end of the
<v Speaker 2>pool for a minute. The speculative territory, because if we
<v Speaker 2>are talking about information and error correction and projections, we
<v Speaker 2>have to talk about consciousness.
<v Speaker 3>Ah the C word. Physicists usually hate touching this, but
<v Speaker 3>let's do it.
<v Speaker 2>The source has mentioned it, even just briefly. If reality
<v Speaker 2>is emergent, if three D space is just what happens
<v Speaker 2>when two D information gets processed in a certain way,
<v Speaker 2>does that mean our brains are doing the processing? Are
<v Speaker 2>we creating it?
<v Speaker 3>Well, there is the whole question of the observer in
<v Speaker 3>quantum mechanics, the observer is key. In a hologram. You
<v Speaker 3>need a light source, a laser to shine through the
<v Speaker 3>film to create the three D.
<v Speaker 2>Image, So he is shining the light.
<v Speaker 3>That's the mystical question. But from a more grounded neuroscience perspective,
<v Speaker 3>some people ask, is consciousness just a very high level
<v Speaker 3>of information integration if the universe is built on it?
<v Speaker 3>From quibbit, is our consciousness just a particularly complex not
<v Speaker 3>of those quibbitts processing themselves?
<v Speaker 2>And what about AI building these massive neural networks?
<v Speaker 3>Now, this is where it gets really fun and really speculative.
<v Speaker 3>If three D space emerges from the processing of information,
<v Speaker 3>could a sufficiently complex AI develop its own space? If
<v Speaker 3>an AI becomes complex enough, if it's internal data becomes
<v Speaker 3>entangled enough, could a new dimension emerge inside the AI
<v Speaker 3>that we can't see or access.
<v Speaker 2>Like it perceives a spatial reality that only exists within
<v Speaker 2>its own code.
<v Speaker 3>Exactly, just like our spatial reality might just exist within
<v Speaker 3>the code that's written on the boundary of the universe.
<v Speaker 3>We might be the AI living in the simulation that's
<v Speaker 3>being run by the boundary of physics.
<v Speaker 2>Okay, that gives me chills. That is a black mirror
<v Speaker 2>episode waiting to happen.
<v Speaker 3>It is highly, highly speculative. We have zero proof of this,
<v Speaker 3>but the holographic principle opens the door to these kinds
<v Speaker 3>of questions because it reduces physics down to information, and
<v Speaker 3>information is something we are finally learning to manipulate ourselves before.
<v Speaker 2>We completely float away into the ether. Here, let's ground
<v Speaker 2>this again. We have to be honest with everyone listening.
<v Speaker 2>Is this theory true with a capital T.
<v Speaker 3>That is a very complicated question because.
<v Speaker 2>There are critics. It's not universally accepted.
<v Speaker 3>There are and the biggest criticism is what you could
<v Speaker 3>call the math trick argument.
<v Speaker 2>The idea that it's just a useful calculator, not a
<v Speaker 2>description of reality.
<v Speaker 3>Right, just because the math allows you to translate the
<v Speaker 3>soup to the label doesn't necessarily mean the label is
<v Speaker 3>more real.
<v Speaker 2>A map of New York is incredibly useful. I can
<v Speaker 2>use it to find my way around, but the map
<v Speaker 2>isn't the city.
<v Speaker 3>That's the argument. Some physicists argue that the duality is
<v Speaker 3>just a powerful relationship between two mathematical structures. It doesn't
<v Speaker 3>mean we physically live on a wall. It just means
<v Speaker 3>the wall describes us perfectly.
<v Speaker 2>But does the distinction even matter If the description is perfect,
<v Speaker 2>if you can predict every single move I make by
<v Speaker 2>just looking at the wall, am I not for all
<v Speaker 2>intents and purposes on the wall?
<v Speaker 3>That's the philosophical counter argument. If it walks like a
<v Speaker 3>duck and quacks like a duck, maybe it's a hollo duck.
<v Speaker 2>And there was a note about time. We talked about
<v Speaker 2>space being emergent. What about time?
<v Speaker 3>That is the next great frontier. The time problem. In
<v Speaker 3>the bulk in the soup, time flows normally forward, but
<v Speaker 3>on the boundary time behaves very differently. It's part of
<v Speaker 3>the quantum field itself. Reconciling bulk time with boundary time
<v Speaker 3>is extremely difficult.
<v Speaker 2>So time might be an illusion too.
<v Speaker 3>It's very possible that time is also emergent. The past
<v Speaker 3>and future are just useful patterns in the entanglement on
<v Speaker 3>the boundary.
<v Speaker 2>Great, just what I needed. Time isn't real, Space isn't real.
<v Speaker 2>I'm a credit card sticker chuckles.
<v Speaker 3>It's the price of admission for playing with modern physics.
<v Speaker 2>So let's bring this home. Let's recap the journey, because
<v Speaker 2>we have covered a lot of ground.
<v Speaker 3>We started with the library with this bizarre realization that
<v Speaker 3>the capacity of the universe is written on the walls,
<v Speaker 3>not on the volume.
<v Speaker 2>The beacon steam bound.
<v Speaker 3>We moved to the soup can, the Maldosena conjecture, the
<v Speaker 3>mathematical proof that a three D gravitational world can be
<v Speaker 3>identical to a two D quantum world.
<v Speaker 2>The dictionary, the cheat code.
<v Speaker 3>We use that code to solve the information paradox, to
<v Speaker 3>save the diary from the black hole by smearing it
<v Speaker 3>on the event horizon, and.
<v Speaker 2>We ended up with this incredible idea that space itself
<v Speaker 2>is stitched together by quantum entanglement, that we are living
<v Speaker 2>inside a giant error correcting quantum computer.
<v Speaker 3>It really does change how you look at the world.
<v Speaker 2>It does. It makes me feel lighter, or maybe just
<v Speaker 2>less solid.
<v Speaker 3>It should make you feel connected. If space is just entanglement.
<v Speaker 3>Then connection is the most fundamental building block of reality.
<v Speaker 3>We aren't just separate objects floating in a void. We're
<v Speaker 3>an interconnected web.
<v Speaker 2>That's a beautiful way to put it.
<v Speaker 3>And remember the Bickenstein bound implies. We are finite. We
<v Speaker 3>are complex, yes, but we are limited. We are a
<v Speaker 3>finite amount of data that is in a way processing itself.
<v Speaker 2>And I want to leave the listener with one final thought,
<v Speaker 2>one last provocation.
<v Speaker 3>Go for it.
<v Speaker 2>We keep talking about the screen boundary the hologram, but
<v Speaker 2>a hologram is meant to be seen and image is
<v Speaker 2>meant to be observed. Yes, if the universe is a projection,
<v Speaker 2>who is the audience?
<v Speaker 3>What if we are the audience?
<v Speaker 2>If we are the code, but we are also the
<v Speaker 2>one studying the code.
<v Speaker 3>Then the universe is waking up and looking at itself.
<v Speaker 3>We are the mechanism by which the hologram understand that
<v Speaker 3>it is a hologram.
<v Speaker 2>That is the ultimate loop.
<v Speaker 3>It is.
<v Speaker 2>On that note, I think I'm going to go touch
<v Speaker 2>my desk again and try to convince myself it's solid.
<v Speaker 3>Good luck with that.
<v Speaker 2>Thank you so much for guiding us through the soup can.
<v Speaker 2>This was fascinating, My pleasure. It was fun and to
<v Speaker 2>everyone listening. Next time you look up at the night sky,
<v Speaker 2>just remember you might be looking at the Ultimate projection Screen.
<v Speaker 2>Thanks for joining us on this exploration. We'll see you
<v Speaker 2>next time.