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The Theory of Everything: Can Physics Be Unified? · The Quark Side - Quantum Physics Podcast

• 0:01
  Speaker 1: Welcome to the quart Side Quantum Physics Podcast, an exploration
• 0:05
  Speaker 1: of the fundamental structure of reality, where quantum laws govern matter, energy,
• 0:11
  Speaker 1: and information. Here, uncertainty is a feature, not a flaw,
• 0:16
  Speaker 1: and understanding begins at the smallest scales.
• 0:27
  Speaker 2: You know, there's a there's a specific kind of arrogance
• 0:30
  Speaker 2: in physics. Oh absolutely, And I don't mean that in
• 0:33
  Speaker 2: a bad way. Necessarily. It's a it's a beautiful arrogance.
• 0:36
  Speaker 2: It's this deep conviction that if we just stare at
• 0:39
  Speaker 2: the blackboard long enough, if we just crunch the math
• 0:42
  Speaker 2: hard enough, we can boil the entire chaotic mess of
• 0:45
  Speaker 2: the universe down to one single line of code.
• 0:49
  Speaker 3: The famous god equation, right.
• 0:51
  Speaker 2: The theory of everything, a single framework that explains, you know,
• 0:55
  Speaker 2: why the sky is blue, why black holes evaporate, and
• 0:58
  Speaker 2: why you and I are conscious enough to sit here
• 1:00
  Speaker 2: and talk about it.
• 1:01
  Speaker 3: It is the ultimate reductionist stream.
• 1:03
  Speaker 2: It really is. But for today's deep dive, we are
• 1:06
  Speaker 2: digging into the text the quest for a final theory
• 1:09
  Speaker 2: of everything, and the thing, well, the real story here
• 1:13
  Speaker 2: isn't about that perfect equation. It's about the fact that
• 1:16
  Speaker 2: we might have completely hit a wall.
• 1:18
  Speaker 3: A wall or maybe a horizon. That is the big
• 1:21
  Speaker 3: debate right now, because look, we've spent four hundred years
• 1:24
  Speaker 3: unifying things, taking separate phenomenon and proving their just different
• 1:27
  Speaker 3: sides of the same coin. But now we are stuck
• 1:30
  Speaker 3: in what might literally be the deepest rut in the
• 1:33
  Speaker 3: history of science.
• 1:34
  Speaker 2: And that is exactly what we are unpacking for you today.
• 1:38
  Speaker 2: We aren't just doing some dry history lesson. We want
• 1:40
  Speaker 2: to look at the actual breakdown.
• 1:42
  Speaker 3: The Great schism exactly.
• 1:44
  Speaker 2: We've got general relativity on one side, quantum mechanics on
• 1:47
  Speaker 2: the other, and they absolutely hate each other. Plus we've
• 1:50
  Speaker 2: got string theory, which promised to fix everything but maybe
• 1:55
  Speaker 2: got lost in its own math.
• 1:56
  Speaker 3: And then you get into the existential stuff.
• 1:58
  Speaker 2: Oh yeah, consciousness, Yeah, Goder's incompleteness theorems, the actual limits
• 2:03
  Speaker 2: of what the human brain can comprehend.
• 2:05
  Speaker 3: It forces you to step back and ask is the
• 2:08
  Speaker 3: universe actually a puzzle with a final neat solution or
• 2:13
  Speaker 3: are we just peeling an onion that has infinite layers.
• 2:15
  Speaker 2: That is the perfect way to set the mission for
• 2:17
  Speaker 2: this deep dive. But let's look at the track record first,
• 2:20
  Speaker 2: because that is where all this optimism comes from, right
• 2:23
  Speaker 2: if you look at the history of physics, it's effectively
• 2:25
  Speaker 2: a history of things merging.
• 2:27
  Speaker 3: Yeah, we call it the drive toward unification. It basically
• 2:29
  Speaker 3: kicks off with Newton in the seventeenth century, and I
• 2:33
  Speaker 3: everyone knows the whole apple falling from the tree story,
• 2:35
  Speaker 3: the classic physics myth, right, But the real breakthrough there
• 2:39
  Speaker 3: wasn't just discovering gravity. It was the universality of it.
• 2:42
  Speaker 3: Because before Newton, people actually thought objects on Earth and
• 2:46
  Speaker 3: objects in the sky were governed by completely different.
• 2:49
  Speaker 2: Rules, right, the Aristotelian idea. Yeah, the heavens were divine
• 2:52
  Speaker 2: and perfect, and the Earth was messy and corruptible. The
• 2:56
  Speaker 2: moon didn't play by the same rules as an apple.
• 2:58
  Speaker 3: Exactly and completely smash that. He proved that the moon
• 3:03
  Speaker 3: is actually falling just like the apple. It just have
• 3:06
  Speaker 3: enough sideways motion tangential velocity to keep missing the Earth
• 3:09
  Speaker 3: as it falls. So suddenly you have one mechanical principle,
• 3:13
  Speaker 3: one gravitational force, governing the entire cosmos.
• 3:16
  Speaker 2: One law to rule them all. Yeah. And then you
• 3:19
  Speaker 2: fast forward to the nineteenth century and James click Maxwell
• 3:21
  Speaker 2: does the.
• 3:21
  Speaker 3: Same thing with electromagnetism.
• 3:23
  Speaker 2: Yeah, before him, you had electricity like lightning or static shocks,
• 3:27
  Speaker 2: you had magnetism guiding compasses, totally separate things. Maxwell unifies
• 3:31
  Speaker 2: them into a single electromagnetic force. And the craziest part,
• 3:34
  Speaker 2: the cherry on top, is he realizes that light itself
• 3:37
  Speaker 2: is just an electromagnetic wave.
• 3:39
  Speaker 3: It's just a brilliant winning streak for physics. And then
• 3:42
  Speaker 3: Einstein comes along in the twentieth century.
• 3:44
  Speaker 2: If we ultimate merger right.
• 3:46
  Speaker 3: He unifies space and time into the fabric of space
• 3:49
  Speaker 3: time and shows that the geometry of that fabric is
• 3:52
  Speaker 3: what determines gravity. Then by the late twentieth century we
• 3:56
  Speaker 3: get the standard.
• 3:57
  Speaker 2: Model, which is where things start to get a bit sticky.
• 4:00
  Speaker 3: Well, yes and no, the standard model is incredible. Glassio
• 4:04
  Speaker 3: Salaam and Weinberg manage to unify the electromagnetic force with
• 4:08
  Speaker 3: the weak nuclear force. We call it electroweak unification, and
• 4:13
  Speaker 3: they incorporate the strong nuclear force too.
• 4:15
  Speaker 2: So we basically have a periodic table of fundamental particles and.
• 4:19
  Speaker 3: It works beautifully. It is arguably the most precisely tested
• 4:22
  Speaker 3: theory humans have ever created. But there is a massive catch.
• 4:26
  Speaker 2: It leaves out gravity.
• 4:27
  Speaker 3: Exactly, leaves gravity totally out in the cold.
• 4:30
  Speaker 2: And this is where that schism happens, as you called it.
• 4:33
  Speaker 2: It's the part of the source material that always blows
• 4:35
  Speaker 2: my mind. We basically have two rule books for the universe.
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  Speaker 3: And they refuse to talk to each other.
• 4:39
  Speaker 2: Right, You've got general relativity for the massive stuff stars, galaxies,
• 4:44
  Speaker 2: black holes, smooth continuous space time, and then you have
• 4:48
  Speaker 2: quantum mechanics for the tiny stuff atams quarks. But the
• 4:52
  Speaker 2: quantum world is discrete, it's point like, it's jumpy, and
• 4:56
  Speaker 2: they work perfectly in their own separate domains.
• 4:58
  Speaker 3: But if you try to combine them.
• 4:59
  Speaker 2: Total disaster.
• 5:00
  Speaker 3: Total disaster.
• 5:01
  Speaker 2: But mechanically speaking, why, I mean, why can't we just
• 5:04
  Speaker 2: take the gravity equations and add them to the quantum equations.
• 5:07
  Speaker 3: It comes down to something called renormalization. In quantum mechanics,
• 5:11
  Speaker 3: we treat fundamental particles like electrons as zero dimensional points.
• 5:17
  Speaker 3: When you calculate the forces between them, you have to
• 5:19
  Speaker 3: sum up all the infinite possible ways they can.
• 5:22
  Speaker 2: Interact, which sounds like a math nightmare.
• 5:24
  Speaker 3: It is, infinities pop up everywhere in the equations. But
• 5:28
  Speaker 3: in the standard model we have these brilliant mathematical tricks.
• 5:31
  Speaker 3: It's renormalization to essentially cancel out those infinities, so we
• 5:34
  Speaker 3: get usable answers.
• 5:36
  Speaker 2: But gravity doesn't play nice with those tricks.
• 5:38
  Speaker 3: No it doesn't, because gravity isn't just a force acting
• 5:42
  Speaker 3: on a stage. It is the geometry of the stage itself. Space.
• 5:47
  Speaker 3: If you try to treat gravity as a quantum force
• 5:50
  Speaker 3: acting on a zero distance point particle, the curvature of
• 5:54
  Speaker 3: space becomes infinite.
• 5:55
  Speaker 2: The math literally blows up.
• 5:57
  Speaker 3: It blows up. You get infinity as an answer for
• 5:59
  Speaker 3: every single calculation, which means the theory is useless.
• 6:02
  Speaker 2: So at the plank scale, like the tiniest possible resolution
• 6:06
  Speaker 2: of reality, the smooth trampoline fabric of Einstein's gravity violently
• 6:12
  Speaker 2: clashes with the jittery, pixelated nature of the quantum world.
• 6:15
  Speaker 3: Exactly to get a theory of everything, those two frameworks
• 6:19
  Speaker 3: have to be married. We need a new theory of
• 6:21
  Speaker 3: quantum gravity.
• 6:22
  Speaker 2: And for the last few decades the absolute heavyweight contender
• 6:25
  Speaker 2: for that crown has been string theory.
• 6:27
  Speaker 3: Oh, string theory was supposed to be the white Knight
• 6:29
  Speaker 3: that saved physics.
• 6:30
  Speaker 2: And the initial pitch is so elegant. You just get
• 6:33
  Speaker 2: rid of the point particles. You say, okay, fundamental particles
• 6:36
  Speaker 2: aren't dots. They are tiny, one dimensional vibrating strings.
• 6:39
  Speaker 3: Right, and the frequency of the vibration determines what particle
• 6:42
  Speaker 3: it is.
• 6:42
  Speaker 2: Yeah, an electron is just a string vibrating in one key,
• 6:45
  Speaker 2: and a photon is vibrating in another.
• 6:47
  Speaker 3: And because it's a string, it has actual length. It's
• 6:50
  Speaker 3: not a zero dimensional point anymore. That physical length smears
• 6:54
  Speaker 3: out the interaction over a tiny distance, which totally bypasses
• 6:58
  Speaker 3: those nasty infinities we talked about.
• 7:00
  Speaker 2: The math suddenly works.
• 7:01
  Speaker 3: It works beautifully, And the absolute best part, one of
• 7:05
  Speaker 3: the natural vibrational modes of these strings looks exactly like
• 7:09
  Speaker 3: a graviton.
• 7:10
  Speaker 2: The theoretical particle that carries the force of gravity.
• 7:13
  Speaker 3: Yes, so gravity isn't forced into the theory, It emerges
• 7:17
  Speaker 3: naturally from the geometry of the strings.
• 7:19
  Speaker 2: It sounds like a home run. I mean, it unites
• 7:22
  Speaker 2: gravity and quantum mechanics perfectly.
• 7:24
  Speaker 3: Yeah.
• 7:24
  Speaker 2: So why are we reading an entire text about the
• 7:26
  Speaker 2: failure to find a final theory. Why isn't string theory
• 7:29
  Speaker 2: the undisputed law of the land.
• 7:30
  Speaker 3: Because string theory made a sort of faustion bargain to
• 7:34
  Speaker 3: make the math work, to get rid of the anomalies
• 7:36
  Speaker 3: those strings need more room to vibrate, way more room
• 7:39
  Speaker 3: than our universe appears to have. The theory flat out demands extra.
• 7:43
  Speaker 2: Dimension ten dimensions total, right, nine spatial.
• 7:45
  Speaker 3: And one time, or eleven if you're talking about m theory.
• 7:49
  Speaker 2: But we only see three dimensions of space up, down, left, right,
• 7:52
  Speaker 2: forward back. Where are the other six hiding?
• 7:55
  Speaker 3: The mathematical claim is that they are compactified. They are
• 7:59
  Speaker 3: curled up in to these unbelievably tiny complex shapes. They're
• 8:02
  Speaker 3: called Colobbio manifolds at every single point in space. They're
• 8:07
  Speaker 3: so small we just can't perceive them.
• 8:09
  Speaker 2: Okay, but here's the massive problem that text highlights with that.
• 8:13
  Speaker 2: The specific shape of those curled up extra dimensions determines
• 8:17
  Speaker 2: how the strings can vibrate right correct, and the vibrations
• 8:20
  Speaker 2: determine the laws of physics, the mass of an electron,
• 8:24
  Speaker 2: the strength of gravity.
• 8:25
  Speaker 3: Exactly, the geometry dictates the physics.
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  Speaker 2: But there isn't just one mathematical way to fold up
• 8:31
  Speaker 2: those extra dimensions.
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  Speaker 3: No, there are an estimated ten to the five hundredth
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  Speaker 3: power different ways to fold them.
• 8:36
  Speaker 2: Ten to the five hundred That is a one followed
• 8:39
  Speaker 2: by five hundred zeros.
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  Speaker 3: It is an incomprehensibly large number, and each one of
• 8:43
  Speaker 3: those folds creates a different universe with completely different physical laws.
• 8:47
  Speaker 2: This is what the source calls the landscape problem.
• 8:50
  Speaker 3: Yes, strength theory doesn't actually describe our universe. It describes
• 8:54
  Speaker 3: a near infinite landscape of potential universes, and it has
• 8:58
  Speaker 3: absolutely no mechanism to tell us why we happen to
• 9:01
  Speaker 3: live in this specific one.
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  Speaker 2: It feels like we went from searching for a theory
• 9:05
  Speaker 2: of everything to ending up with a theory of anything.
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  Speaker 3: That is the primary criticism. It is mathematically gorgeous, but
• 9:12
  Speaker 3: it's physically predictively weak. Plus, string theory relies heavily on supersymmetry, the.
• 9:18
  Speaker 2: Idea that every matter particle has a heavier forced particle partner.
• 9:22
  Speaker 3: Right, And we built the Large Hadrin Collider in part
• 9:24
  Speaker 3: to find those superpartners. We found the Higgs boson, which
• 9:28
  Speaker 3: was a huge triumph for the standard model, but we
• 9:31
  Speaker 3: found zero evidence of supersymmetry, which.
• 9:33
  Speaker 2: Kind of leaves string theory floating in the wind a bit. So,
• 9:36
  Speaker 2: if string theory is the front runner that's stumbling, what
• 9:39
  Speaker 2: is the alternative? Loop quantum gravity?
• 9:41
  Speaker 3: Loop quantum gravity or LQG is definitely the main rival,
• 9:45
  Speaker 3: and it takes a radically different approach. It doesn't bother
• 9:47
  Speaker 3: with Husher dimensions, it doesn't use strings. It focuses entirely
• 9:51
  Speaker 3: on the fabric of space time itself.
• 9:53
  Speaker 2: It basically says space isn't smooth at all. It's quantized exactly.
• 9:57
  Speaker 3: It suggests space time is made of tiny disc great
• 10:00
  Speaker 3: loops or spin networks at the plank scale. Think of
• 10:04
  Speaker 3: a medieval chain mail shirt. Okay, from across the room,
• 10:07
  Speaker 3: it looks like a smooth sheet of flexible metal, but
• 10:10
  Speaker 3: if you walk up close, you see it's actually made
• 10:13
  Speaker 3: of thousands of individual interlocking rings. LQG says space is
• 10:18
  Speaker 3: exactly like that chain mail. There is a smallest possible
• 10:22
  Speaker 3: pixel of space, and you cannot divide it any further, And.
• 10:25
  Speaker 2: That solves the infinity problem we had earlier. Yeah, because
• 10:28
  Speaker 2: you can never get to a zero distance point, you
• 10:29
  Speaker 2: eventually just hit the bottom of the pixel.
• 10:31
  Speaker 3: Precisely. It doesn't assume a background stage that particles act on.
• 10:35
  Speaker 3: It literally builds the stage out of quantum rules. But
• 10:39
  Speaker 3: it has its own massive flaw. It has a really
• 10:41
  Speaker 3: hard time recovering the standard physics.
• 10:43
  Speaker 2: We already know, like electromagnetism.
• 10:45
  Speaker 3: Right, It's very hard to extract the standard forces from
• 10:48
  Speaker 3: those loops.
• 10:48
  Speaker 2: So we are at a stalemate. But I want to
• 10:50
  Speaker 2: pivot here because this next section of the source materials
• 10:53
  Speaker 2: will really kept me up at night. The roadblocks the
• 10:56
  Speaker 2: deeply unsettling idea that even if we fix the math,
• 11:00
  Speaker 2: there are philosophical walls we just might not be able
• 11:02
  Speaker 2: to smash through.
• 11:03
  Speaker 3: The limits of the quest itself.
• 11:05
  Speaker 2: Yeah, starting with the problem of initial conditions.
• 11:08
  Speaker 3: This is a crucial distinction. It's the difference between the
• 11:11
  Speaker 3: laws of the game and the setup of the board.
• 11:14
  Speaker 3: A theory of everything would give us the laws. It
• 11:17
  Speaker 3: would tell us exactly how the universe evolves from moment
• 11:21
  Speaker 3: A to moment B the recipe, right, but it cannot
• 11:24
  Speaker 3: tell us why moment A was set up that way
• 11:27
  Speaker 3: in the first place. It doesn't give us the ingredients.
• 11:29
  Speaker 2: It doesn't tell us why the Big Bang had that
• 11:31
  Speaker 2: specific amount of entropy, or why the expansion rate was
• 11:35
  Speaker 2: tuned exactly the way it was.
• 11:37
  Speaker 3: And this ties directly into the anthropic principle. When we
• 11:40
  Speaker 3: look around, we observe that the fundamental constants of nature,
• 11:44
  Speaker 3: the strength of gravity, the mass of protons, they seem
• 11:47
  Speaker 3: incredibly finely tuned for life to exist.
• 11:49
  Speaker 2: Yeah, if gravity were just slightly stronger, stars would burn
• 11:53
  Speaker 2: out way too fast for revolution to happen. If it
• 11:55
  Speaker 2: were slightly weaker, matter would never clump together to form
• 11:57
  Speaker 2: stars at all.
• 11:58
  Speaker 3: And this brings us right back to the multiverse. If
• 12:02
  Speaker 3: string theory gives us ten to the five hundredth possibilities,
• 12:06
  Speaker 3: maybe they all actually exist out there. Maybe there are
• 12:09
  Speaker 3: billions of dead, empty universes and we are just sitting
• 12:13
  Speaker 3: in the one lucky bubble where the numbers randomly align
• 12:16
  Speaker 3: to allow carbon based life.
• 12:18
  Speaker 2: The weak anthropic principle, we see a life friendly universe
• 12:22
  Speaker 2: simply because if it weren't life friendly, we wouldn't be
• 12:25
  Speaker 2: here to see it. It's a massive selection bias.
• 12:27
  Speaker 3: But if that really is the answer, it is devastating
• 12:30
  Speaker 3: for the whole concept of a final theory because it means.
• 12:33
  Speaker 2: The numbers aren't derived from some beautiful underlying logic. We
• 12:36
  Speaker 2: can't calculate the mass of the electron from first principles.
• 12:39
  Speaker 2: It's just a random environmental accident exactly.
• 12:41
  Speaker 3: It turns fundamental physics into local environmental science. We just
• 12:45
  Speaker 3: be cataloging the weather of our specific universe, not discovering
• 12:49
  Speaker 3: deep absolute truths that must be so.
• 12:52
  Speaker 2: That is deeply depressing for a physicist, I imagine, But
• 12:55
  Speaker 2: the text argues it gets even worse.
• 12:57
  Speaker 3: Let's talk about the math itself. Wet's talk about Goodle
• 12:59
  Speaker 3: because I alwaysssume that even if the physics gets messy,
• 13:02
  Speaker 3: mathematics is the bedrock of absolute truth. Kurt Godel basically
• 13:06
  Speaker 3: dropped a bomb on that assumption in the nineteen thirties
• 13:09
  Speaker 3: with his incompleteness theorems. He proved mathematically that in any
• 13:13
  Speaker 3: logical system complex enough to do basic arithmetic, there will
• 13:17
  Speaker 3: always be true statements that simply cannot be proving from
• 13:20
  Speaker 3: within that system.
• 13:22
  Speaker 2: Statements that are true but unprovable. It almost sounds like
• 13:26
  Speaker 2: a zen Cohen It is.
• 13:27
  Speaker 3: A fundamental feature of logic. Now apply that to physics.
• 13:31
  Speaker 3: If reality is ultimately described by a mathematical system, there
• 13:35
  Speaker 3: might be physical truths, constants, or laws that are absolutely true,
• 13:39
  Speaker 3: but we can never logically derive them from the base
• 13:41
  Speaker 3: axioms of our theory.
• 13:43
  Speaker 2: So the final theory might be mathematically incomplete by its
• 13:46
  Speaker 2: very definition. We could stare at the perfect equation forever,
• 13:49
  Speaker 2: and we would never be able to mathematically prove it's
• 13:52
  Speaker 2: the only.
• 13:52
  Speaker 3: Right one exactly, and beyond the math, there is a
• 13:55
  Speaker 3: brutally practical wall the scale problem.
• 13:58
  Speaker 2: Right testing this stuff.
• 13:59
  Speaker 3: Are arguing about vibrating strings and quantum loops that exist
• 14:03
  Speaker 3: at the plank length that is ten to the negative
• 14:05
  Speaker 3: thirty five meters.
• 14:06
  Speaker 2: It is absurdly small, and to probe things that are
• 14:08
  Speaker 2: that small you need incredibly high energy.
• 14:11
  Speaker 3: High frequency means high energy. To build a particle accelerator
• 14:16
  Speaker 3: powerful enough to actually see a string directly, you wouldn't
• 14:19
  Speaker 3: just need something the size of the large Hadron collider.
• 14:22
  Speaker 3: You would need a collider roughly the size of the
• 14:24
  Speaker 3: Milky Way galaxy.
• 14:26
  Speaker 2: I'm pretty sure we can't get the funding for a
• 14:27
  Speaker 2: galaxy sized machine anytime soon.
• 14:30
  Speaker 3: It is completely physically impossible for us, which raises a
• 14:34
  Speaker 3: really uncomfortable question for the field. If a theory can
• 14:37
  Speaker 3: never ever be physically tested, is it still physics or
• 14:41
  Speaker 3: have we just crossed the border into pure metaphysics. String
• 14:45
  Speaker 3: theory is mathematically beautiful, but if it requires a galaxy
• 14:48
  Speaker 3: sized collider to prove it might permanently remain philosophy.
• 14:52
  Speaker 2: Speaking of philosophy, I really want to dig into this
• 14:55
  Speaker 2: section the text has on emergence, because let's say we
• 14:57
  Speaker 2: find it. Let's say we get the God equation on
• 14:59
  Speaker 2: a T shirt to actually explain everything. The hard line
• 15:02
  Speaker 2: reduction ist view says, yes, biology is just applied chemistry.
• 15:06
  Speaker 2: Chemistry is applied physics, and physics is just this one
• 15:08
  Speaker 2: final equation.
• 15:09
  Speaker 3: But we know from observation that isn't really how the
• 15:11
  Speaker 3: world works. We have this phenomenon of emergence. There's a
• 15:15
  Speaker 3: famous essay by Philip Anderson called More is Different, and
• 15:18
  Speaker 3: the idea is that complex systems have properties that simply
• 15:21
  Speaker 3: do not exist in their individual parts.
• 15:24
  Speaker 2: Like you can know every single quantum property of an
• 15:27
  Speaker 2: air molecule, but that knowledge will never let you predict
• 15:30
  Speaker 2: a tornado, or.
• 15:31
  Speaker 3: You can map every single neuron in a brain, but
• 15:34
  Speaker 3: you won't find the concept of justice in there.
• 15:36
  Speaker 2: Right. It reminds me of the seven forty seven analogy.
• 15:39
  Speaker 2: You can't explain how a Boeing seven forty seven flies
• 15:41
  Speaker 2: just by listing the quantum states of every single atom
• 15:44
  Speaker 2: in the wings. You need entirely new higher level laws
• 15:49
  Speaker 2: like aerodynamics that emerge at the macro scale.
• 15:51
  Speaker 3: Which means a theory of everything might actually be useless
• 15:54
  Speaker 3: for understanding the things we as humans actually care about
• 15:57
  Speaker 3: life ecosystems. Society provides the alphabet, but it doesn't write
• 16:01
  Speaker 3: the novel.
• 16:02
  Speaker 2: And that brings us to the absolute biggest mystery in
• 16:04
  Speaker 2: the source text, consciousness the hard problem. The text argues
• 16:10
  Speaker 2: that a purely physical theory might miss the observer entirely.
• 16:14
  Speaker 3: This is what philosophers call the explanatory gap. Physics is
• 16:17
  Speaker 3: incredible at describing structure and function. It deals entirely with
• 16:22
  Speaker 3: objective third person data wavelengths, mass, spin, velocity, right, but
• 16:27
  Speaker 3: consciousness is fundamentally subjective. It's first person. Physics can describe
• 16:32
  Speaker 3: the exact wavelength of red light hitting your retina, but
• 16:35
  Speaker 3: it cannot explain the subjective feeling of seeing read.
• 16:38
  Speaker 2: You can't squeeze a feeling out of an equation about
• 16:41
  Speaker 2: electron spin.
• 16:42
  Speaker 3: Many thinkers argue, you simply can't. If the final theory
• 16:45
  Speaker 3: is purely structural and physical, it completely leaves out the
• 16:49
  Speaker 3: inner life of the universe. And this isn't just a
• 16:51
  Speaker 3: purely philosophical gripe. It crashes right back into hard physics
• 16:55
  Speaker 3: with the measurement problem.
• 16:56
  Speaker 2: In quantum mechanics, oh Man, the measurement problem the idea
• 16:59
  Speaker 2: that the observer actually affects reality.
• 17:02
  Speaker 3: Right in the standard Copenhagen interpretation of quantum mechanics, a
• 17:06
  Speaker 3: particle exists in a wave function a smear of probabilities
• 17:10
  Speaker 3: until it is measured. Measurement forces it to collapse into
• 17:13
  Speaker 3: a single, definite state. But the math doesn't define what
• 17:18
  Speaker 3: constitutes a measurement. Is it a mechanical camera, Does it
• 17:21
  Speaker 3: have to be a human eye, Does it require a
• 17:24
  Speaker 3: conscious mind?
• 17:25
  Speaker 2: And if consciousness is required to collapse the wave function,
• 17:29
  Speaker 2: then consciousness isn't just some accidental byproduct of brain chemistry.
• 17:33
  Speaker 2: It is fundamental to the architecture of reality.
• 17:36
  Speaker 3: And I should say most physicists strongly dislike that idea.
• 17:40
  Speaker 3: Science generally wants a universe that runs perfectly well without
• 17:43
  Speaker 3: us looking at it. But a true final theory has
• 17:45
  Speaker 3: to account for the fact that there is a conscious
• 17:47
  Speaker 3: observer asking the question if it can explain us. It's
• 17:51
  Speaker 3: not a theory of everything.
• 17:52
  Speaker 4: It's a theory of everything except us exactly. Before we
• 17:55
  Speaker 4: wrap up, I have to touch on what I thought
• 17:57
  Speaker 4: was the wildest concept in this whole test principle, because
• 18:01
  Speaker 4: reading this felt like we were crossing into simulation.
• 18:03
  Speaker 2: Theory.
• 18:04
  Speaker 3: It is a radical shift. It actually comes from the
• 18:06
  Speaker 3: study of black hole thermodynamics. Stephen Hawking and Jacob Beckinstein
• 18:11
  Speaker 3: made this astonishing realization. They found that the total amount
• 18:14
  Speaker 3: of information or entropy that a black hole can contain
• 18:17
  Speaker 3: is proportional to its surface area, not its volume.
• 18:21
  Speaker 2: Which is super counterintuitive. Usually, if you fill a physical
• 18:23
  Speaker 2: box with stuff, the amount of stuff you can fit
• 18:26
  Speaker 2: depends on the three D volume.
• 18:28
  Speaker 3: Of the box, right, But for black holes, all the
• 18:31
  Speaker 3: information about what fell in is encoded on the two
• 18:34
  Speaker 3: D surface of the event horizon. This blue physicists' minds
• 18:38
  Speaker 3: and led to a broader idea. What if our entire
• 18:42
  Speaker 3: three D universe is actually just a projection of information
• 18:45
  Speaker 3: encoded on a distant two dimensional boundary.
• 18:48
  Speaker 2: Literally like a hologram on a credit card. It looks
• 18:50
  Speaker 2: fully three D when the light hits it, but the
• 18:52
  Speaker 2: actual data generating that image is entirely two D.
• 18:55
  Speaker 3: Yes, and it implies something profound. It implies that at
• 18:58
  Speaker 3: the absolute most fundamental level, reality isn't made of matter,
• 19:02
  Speaker 3: It's not made of strings or loops, it is made
• 19:04
  Speaker 3: of information quibbits.
• 19:06
  Speaker 2: So the final theory might not even be a physics equation,
• 19:09
  Speaker 2: it might look more like a computer program.
• 19:11
  Speaker 3: Or pure information processing logic. It completely shifts the paradigm.
• 19:16
  Speaker 3: We've spent a century looking for fundamental particles, but maybe
• 19:19
  Speaker 3: we should have been looking for bits.
• 19:21
  Speaker 2: So looking at everything we've covered, we have theories that
• 19:25
  Speaker 2: contradict each other, math that might be fundamentally incomplete, multi
• 19:29
  Speaker 2: dimensional landscapes we can't test, and a universe that might
• 19:32
  Speaker 2: just be a giant hologram. Are we just chasing a
• 19:36
  Speaker 2: ghost here?
• 19:37
  Speaker 3: I think we have to honestly face the possibility of
• 19:40
  Speaker 3: infinite regress. It's like a child's game of asking why.
• 19:44
  Speaker 3: Let's say we find the absolute final physical law. The
• 19:47
  Speaker 3: very next question human beings will ask, is, well, why
• 19:50
  Speaker 3: that law and not another one? The law cannot explain
• 19:52
  Speaker 3: its own existence.
• 19:53
  Speaker 2: It just becomes a brude fact, because I said so.
• 19:56
  Speaker 2: In science hates brute facts. We always want reasons. But
• 19:59
  Speaker 2: at the very bottom of the a rabbit hole, there
• 20:00
  Speaker 2: might not be an equation. There might just be mystery.
• 20:03
  Speaker 3: But the search itself, you would argue, the search has
• 20:06
  Speaker 3: immense value, right, even if we never actually catch the horizon.
• 20:10
  Speaker 2: Oh.
• 20:10
  Speaker 3: Absolutely, Look at the modern world, the technology we've built
• 20:14
  Speaker 3: just by trying to peek at the basic rules is staggering.
• 20:17
  Speaker 3: MRI machines, semiconductors, GPS, lasers, they are all byproducts of
• 20:23
  Speaker 3: this pure quest for understanding. But even beyond the tech,
• 20:26
  Speaker 3: it's about our place in the cosmos, where this tiny
• 20:29
  Speaker 3: fragile species on a rock actively trying to decode the
• 20:32
  Speaker 3: source code of reality. That is a noble pursuit. Even
• 20:35
  Speaker 3: if we ultimately fail to find the final line of.
• 20:38
  Speaker 2: Code, it's the journey, not the destination.
• 20:40
  Speaker 3: As cliche as it sounds, yes, because think about it.
• 20:42
  Speaker 3: If we actually found the final answer, if we printed
• 20:45
  Speaker 3: it on that T shirt, improved it, fundamental physics would
• 20:48
  Speaker 3: essentially end. It's the mystery that keeps the human intellect alive.
• 20:52
  Speaker 2: I love that. And the end today's deep dive. I
• 20:55
  Speaker 2: want to leave you the listener with one final thought
• 20:57
  Speaker 2: inspired by the end of the text. It's a concept
• 20:59
  Speaker 2: called metaphysical naturalism, basically the unstated assumption that our entire
• 21:04
  Speaker 2: modern scientific world operates under the belief that absolutely everything
• 21:07
  Speaker 2: in existence can eventually be reduced to and explained by
• 21:10
  Speaker 2: physical laws. But what if that assumption is just a
• 21:13
  Speaker 2: lens we are wearing right?
• 21:15
  Speaker 3: What if reality contains layers like objective moral value meaning
• 21:21
  Speaker 3: or the purely subjective experience of consciousness that simply do
• 21:25
  Speaker 3: not map onto physical mathematics. You can't weigh the concept
• 21:28
  Speaker 3: of justice, you can't measure the angular momentum of love.
• 21:33
  Speaker 3: If those things are real, fundamental properties of the universe,
• 21:36
  Speaker 3: then a purely physical theory of at everything will always,
• 21:40
  Speaker 3: by definition be incomplete.
• 21:42
  Speaker 2: It would be like trying to fully explain a masterpiece
• 21:45
  Speaker 2: painting by only analyzing the chemical composition of the paint.
• 21:48
  Speaker 2: You'd have all the data, but you would miss the
• 21:51
  Speaker 2: picture entirely.
• 21:51
  Speaker 3: And that, I think is exactly why we will always
• 21:54
  Speaker 3: keep looking.
• 21:54
  Speaker 2: Well, my brain is suitably twisted into a ten dimensional
• 21:57
  Speaker 2: Colobbio manifold at this point. Thank you for walking us
• 22:00
  Speaker 2: through this labyrinth today.
• 22:02
  Speaker 3: Always a pleasure to get completely lost in the cosmos
• 22:04
  Speaker 3: with you.
• 22:05
  Speaker 2: And to you listening, Keep asking why, even if the
• 22:08
  Speaker 2: answer turns out to be just another question. We'll see
• 22:10
  Speaker 2: you in the next deep dive.