Latest / The Quark Side - Quantum Physics Podcast / Could Schrödinger’s Cat States Naturally Emerge in the Quantum World?

Transcript

Could Schrödinger’s Cat States Naturally Emerge in the Quantum World? · The Quark Side - Quantum Physics Podcast

• 0:01
  Speaker 1: Welcome to the Quarkside Quantum Physics Podcast, an exploration of
• 0:05
  Speaker 1: 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: What if.
• 0:29
  Speaker 3: What if the physical solid chair you are sitting on
• 0:32
  Speaker 3: right now is secretly existing in two completely different realities
• 0:36
  Speaker 3: at the exact same time?
• 0:37
  Speaker 2: I mean, that sounds totally impossible, right?
• 0:39
  Speaker 3: Right. Usually when we talk about the physical world, we
• 0:42
  Speaker 3: just expect undeniable predictability. Like, a chair is in one place,
• 0:46
  Speaker 3: it has a specific shape, and it obeys the rules
• 0:49
  Speaker 3: of classical physics.
• 0:50
  Speaker 2: Exactly. We are perfectly comfortable with the idea that in
• 0:53
  Speaker 2: the microscopic world, things get weird.
• 0:55
  Speaker 3: Oh, for sure. Like, in quantum mechanics... A single electron
• 0:59
  Speaker 3: can exist in a superposition.
• 1:02
  Speaker 2: Right, meaning it is literally in two places at once.
• 1:04
  Speaker 3: Yeah, and that is just a fundamental feature of the
• 1:07
  Speaker 3: microscopic universe. We accept that. But the idea of a
• 1:10
  Speaker 3: macroscopic object, like something massive like your chair, existing in
• 1:14
  Speaker 3: two radically different states simultaneously, it sounds like pure science fiction.
• 1:18
  Speaker 2: It really does. And it sounds like fiction because it
• 1:20
  Speaker 2: challenges the most stubborn conceptual boundary line in modern physics.
• 1:25
  Speaker 3: The boundary between the quantum and the classical. Exactly.
• 1:28
  Speaker 2: I mean, for nearly a century, ever since Erwin Schrödinger
• 1:31
  Speaker 2: proposed his famous thought experiment, you know, the one about
• 1:34
  Speaker 2: a cat in a box being simultaneously alive and dead.
• 1:37
  Speaker 1: Right.
• 1:38
  Speaker 3: Schrödinger' s cat.
• 1:39
  Speaker 2: Physicists have used that imagery to highlight a massive problem.
• 1:44
  Speaker 2: Where do the bizarre rules of quantum mechanics end and
• 1:48
  Speaker 2: where does predictable classical reality actually begin?
• 1:51
  Speaker 3: Because Schrödinger meant it as a provocation to show how
• 1:54
  Speaker 3: absurd quantum mechanics becomes if you scale it up.
• 1:57
  Speaker 2: He did. But recent rigorous mathematical work by physicist Hal
• 2:01
  Speaker 2: Tasaki suggests that Schrodinger's provocation is actually a real mathematical possibility.
• 2:07
  Speaker 3: OK, let's unpack this, because the mission of our conversation
• 2:10
  Speaker 3: today is to figure out exactly how that works. This
• 2:13
  Speaker 3: isn't just a fun philosophical exercise anymore.
• 2:16
  Speaker 2: No, it's a mathematical proof showing that these massive macroscopic
• 2:19
  Speaker 2: superpositions can naturally emerge completely on their own.
• 2:23
  Speaker 3: Which is wild. So I want you, the person listening
• 2:25
  Speaker 3: to this right now, to just look around your room
• 2:27
  Speaker 3: and Look at your desk, the walls, the solid objects
• 2:30
  Speaker 3: surrounding you.
• 2:31
  Speaker 2: Just imagine if those objects are secretly governed by laws
• 2:34
  Speaker 2: that allow for multiple simultaneous realities.
• 2:37
  Speaker 3: We're going to explore the underlying mathematics that suggest they
• 2:40
  Speaker 3: are entirely capable of exactly that. So to understand the
• 2:44
  Speaker 3: mechanics of how a large-scale object could exist in two
• 2:47
  Speaker 3: states at once, we have to look at the specific
• 2:50
  Speaker 3: theoretical framework being used here.
• 2:52
  Speaker 2: Right. We need to see how Tasaki reimagines Schrödinger' s concept
• 2:57
  Speaker 2: through what physicists call a weakly perturbed ferromagnetic Ising system.
• 3:02
  Speaker 3: Okay, I know the Ising model is a classic tool
• 3:04
  Speaker 3: used to study collective behavior in physics.
• 3:07
  Speaker 2: Yeah, particularly how atoms align in a magnetic material.
• 3:11
  Speaker 3: Right, but if we are trying to understand a macroscopic
• 3:13
  Speaker 3: cat state, how does a mathematical model of a magnet
• 3:16
  Speaker 3: get us there?
• 3:17
  Speaker 2: Well, the Ising model gives us a pristine mathematical environment.
• 3:21
  Speaker 2: It lets us track how massive groups of interacting particles
• 3:23
  Speaker 2: behave over time. And in its ferromagnetic phase, the system
• 3:27
  Speaker 2: naturally wants to organize into one of two macroscopically distinct configurations.
• 3:32
  Speaker 3: So you can think of it as an enormous lattice
• 3:34
  Speaker 3: of atoms that collectively want to point either entirely up
• 3:38
  Speaker 3: or entirely down.
• 3:39
  Speaker 2: Exactly. Those are two completely distinct large-scale physical states. So
• 3:45
  Speaker 2: what the math does is apply a very specific weak
• 3:48
  Speaker 2: non-local perturbation to this system.
• 3:50
  Speaker 3: A tiny nudge.
• 3:51
  Speaker 2: Right. And then it just lets it evolve strictly according
• 3:54
  Speaker 2: to the normal rules of unitary quantum dynamics.
• 3:57
  Speaker 3: But hold on. That's the part I'm stuck on. You
• 3:59
  Speaker 3: mentioned a weak perturbation. Yeah. If I give a physical
• 4:02
  Speaker 3: system a weak little bump, I expect a weak little ripple.
• 4:06
  Speaker 3: How does a tiny mathematical nudge cause an entire macroscopic
• 4:10
  Speaker 3: system to fracture into a gigantic superposition of two completely
• 4:14
  Speaker 3: different realities?
• 4:15
  Speaker 2: That is the crucial question. The key is the nature
• 4:18
  Speaker 2: of unitary quantum evolution over very long periods of time.
• 4:21
  Speaker 3: Okay.
• 4:22
  Speaker 2: Combined with the fact that this perturbation is highly non-local.
• 4:25
  Speaker 3: So it isn't just a single isolated bump in one spot.
• 4:28
  Speaker 2: Right. It isn't a local bump at all. It is
• 4:30
  Speaker 2: a generic mathematical interaction that delicately couples these distinct macroscopic
• 4:35
  Speaker 2: states across the entire system.
• 4:37
  Speaker 3: Ah, I see.
• 4:37
  Speaker 2: And because the evolution is unitary, meaning no information is
• 4:41
  Speaker 2: lost and the quantum rules are strictly preserved, the system
• 4:45
  Speaker 2: doesn't just transition from all up to all down.
• 4:47
  Speaker 3: It doesn't just flip.
• 4:48
  Speaker 2: Exactly. Instead, the math shows that the system dynamically evolves
• 4:53
  Speaker 2: into a massive branched structure. It forms a superposition of
• 4:57
  Speaker 2: where the entire lattice is pointing up and pointing down
• 5:00
  Speaker 2: at the same time.
• 5:00
  Speaker 3: Wow. Instead of a coin spinning and being heads and
• 5:04
  Speaker 3: tails at the same time, It's like an enormous magnet
• 5:06
  Speaker 3: where all the atoms are collectively deciding to point north
• 5:09
  Speaker 3: and south simultaneously.
• 5:11
  Speaker 2: That is a perfect analogy. And the distinction here is vital.
• 5:14
  Speaker 2: We aren't talking about torturing biological felines in a lab.
• 5:17
  Speaker 3: No, no cats are being harmed.
• 5:19
  Speaker 2: Right. It's about proving mathematically that these massive superpositions don't
• 5:23
  Speaker 2: require delicate artificial laboratory construction.
• 5:27
  Speaker 3: They can just emerge dynamically on their own. The system
• 5:29
  Speaker 3: is just evolving naturally over time, doing its normal quantum thing.
• 5:33
  Speaker 3: And it organically splits into this massively branched state.
• 5:36
  Speaker 2: Exactly. The mathematics proves that these giant superpositions are a
• 5:40
  Speaker 2: natural dynamical outcome of the system's own evolution.
• 5:44
  Speaker 3: Here's where it gets really interesting, though. If the math
• 5:47
  Speaker 3: is so sound and it proves that these giant superpositions
• 5:51
  Speaker 3: can naturally arise just by letting a system evolve, the
• 5:55
  Speaker 3: obvious question is why we don't experience them.
• 5:57
  Speaker 2: Right.
• 5:57
  Speaker 3: If the universe allows for this. Why isn't my coffee
• 6:00
  Speaker 3: mug splitting into two realities in front of my eyes?
• 6:03
  Speaker 2: And that absence brings us to a massive clash in
• 6:06
  Speaker 2: modern physics. Traditionally, we explain the appearance of our classical,
• 6:11
  Speaker 2: predictable world through a process called decoherence.
• 6:15
  Speaker 3: Right, decoherence. It's essentially the environment acting like a wet
• 6:18
  Speaker 3: blanket on quantum weirdness.
• 6:20
  Speaker 2: That's a good way to put it.
• 6:21
  Speaker 3: Like, if a system is in a fragile superposition and
• 6:25
  Speaker 3: it interacts with the outside world, that state is destroyed.
• 6:28
  Speaker 2: Well, destroyed is a strong word, but effectively, yes.
• 6:31
  Speaker 3: It's ruined for us, at least.
• 6:32
  Speaker 2: Right. When a quantum system interacts with its environment, say
• 6:36
  Speaker 2: a stray photon bounces off it or it bumps into
• 6:39
  Speaker 2: an air molecule, information about the system's quantum state rapidly
• 6:43
  Speaker 2: leaks into the surrounding.
• 6:44
  Speaker 3: It just spreads out too fast.
• 6:46
  Speaker 2: Exactly. The delicate mathematical interference that makes a visible superposition
• 6:51
  Speaker 2: possible becomes distributed across so many external variables that it
• 6:55
  Speaker 2: becomes impossible to observe.
• 6:57
  Speaker 3: So the macroscopic system is basically forced to appear classical
• 7:00
  Speaker 3: to us.
• 7:01
  Speaker 2: Yes. But this new mathematical proof comes at this from
• 7:05
  Speaker 2: a completely counterintuitive angle. It isn't just looking at decoherence. Right.
• 7:09
  Speaker 3: The focus is heavily on thermalization. And this is where
• 7:12
  Speaker 3: the contradiction really jumps out at me.
• 7:13
  Speaker 2: How so?
• 7:14
  Speaker 3: Well, thermalization is the process of a complex system reaching
• 7:17
  Speaker 3: thermal equilibrium. It is a smoothing out process.
• 7:21
  Speaker 2: Yeah.
• 7:21
  Speaker 3: It's like pouring cold milk into hot coffee. At first,
• 7:24
  Speaker 3: it's a mess. But eventually the molecules interact, the energy disperses,
• 7:29
  Speaker 3: and the whole mug settles into a boring, uniform, lukewarm state.
• 7:33
  Speaker 2: Yay, this settles down.
• 7:34
  Speaker 3: I don't need to track every single microscopic molecule anymore.
• 7:37
  Speaker 3: I can just describe the whole system by macroscopic traits
• 7:40
  Speaker 3: like its temperature.
• 7:41
  Speaker 2: And that is the essence of thermal equilibrium. The chaotic
• 7:44
  Speaker 2: microscopic details average out, allowing you to describe the system
• 7:48
  Speaker 2: using broad macroscopic observables.
• 7:50
  Speaker 3: But that's the contradiction. Thermalization is traditionally viewed as deeply classical.
• 7:55
  Speaker 3: It is the physics of everyday objects settling down over time.
• 7:59
  Speaker 3: And Schrodinger-Katz states are deeply quantum. They are the physics
• 8:03
  Speaker 3: of things existing in wild, multiple conflicting states. So how
• 8:08
  Speaker 3: does a system settle down into an equilibrium while simultaneously
• 8:12
  Speaker 3: splitting into a wild, gigantic superposition of completely different possibilities?
• 8:17
  Speaker 2: What's fascinating here is that the mathematical proof shows how
• 8:20
  Speaker 2: those two seemingly opposite conceptual worlds can happen at the
• 8:24
  Speaker 2: exact same time.
• 8:25
  Speaker 3: Wait, at the same time?
• 8:26
  Speaker 1: Yes.
• 8:27
  Speaker 2: The analysis demonstrates that at sufficiently long and typical times,
• 8:31
  Speaker 2: essentially any pure initial state in this specific model will
• 8:35
  Speaker 2: evolve into a macroscopic cat-like state. Okay. Here's the mechanism.
• 8:39
  Speaker 2: As the system evolves and the quantum wave function develops
• 8:42
  Speaker 2: this massive branch structure, if you look at the macroscopic
• 8:45
  Speaker 2: properties of each individual branch.
• 8:47
  Speaker 3: Like zoom in on just one side of the split.
• 8:49
  Speaker 2: Exactly. The macroscopic properties of each branch correspond perfectly to
• 8:52
  Speaker 2: macroscopic thermal equilibrium states.
• 8:55
  Speaker 3: Wait, let me make sure I'm visualizing this correctly. The
• 8:58
  Speaker 3: system evolves and reaches thermal equilibrium, just like the milk
• 9:01
  Speaker 3: and coffee settling down.
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  Speaker 2: Right.
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  Speaker 3: But the underlying quantum state has actually split into two
• 9:06
  Speaker 3: enormous branches. And each of those branches represents a system
• 9:11
  Speaker 3: in thermal equilibrium.
• 9:12
  Speaker 2: Yes. The system thermalizes, meaning its macroscopic observables settle into
• 9:18
  Speaker 2: equilibrium values. But it does so by evolving into a
• 9:21
  Speaker 2: massive superposition of two distinct thermalized realities.
• 9:26
  Speaker 3: That is wild. Like, if you had a highly compressed
• 9:29
  Speaker 3: digital file, on the surface, if you just look at
• 9:31
  Speaker 3: the thumbnail, it looks like a simple, solid image that
• 9:35
  Speaker 3: SR classical equilibrium. Okay, yeah. But if you actually unpack
• 9:38
  Speaker 3: the underlying algorithmic code, you find that the file is
• 9:41
  Speaker 3: simultaneously running two completely different massive programs.
• 9:44
  Speaker 2: That's a really great way to think about it. The
• 9:46
  Speaker 2: surface level calmness is actually generated by a deeply complex
• 9:50
  Speaker 2: split quantum reality underneath.
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  Speaker 3: The underlying quantum reality is structured into a gigantic superposition.
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  Speaker 3: Even as the macroscopic observables tell a story of thermal equilibrium.
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  Speaker 2: Exactly. And to really grasp the weight of that, we
• 10:03
  Speaker 2: have to scale up our thinking.
• 10:05
  Speaker 3: Right, because we aren't just talking about firing a single
• 10:07
  Speaker 3: laser beam at an isolated atom anymore. We are firmly
• 10:10
  Speaker 3: in the realm of many-body physics.
• 10:13
  Speaker 2: We're dealing with enormous interacting crowds of matter. The microscopic
• 10:17
  Speaker 2: world is rarely just isolated quantum objects acting independently. Yeah.
• 10:22
  Speaker 2: When massive numbers of particles interact, entirely new collective phenomena emerge.
• 10:28
  Speaker 2: You cannot derive the properties of these phenomena just by
• 10:32
  Speaker 2: looking at a single isolated atom.
• 10:34
  Speaker 3: It's like a stadium wave. You can't understand the wave
• 10:37
  Speaker 3: by staring at one fan, right? It only says the
• 10:39
  Speaker 3: crowd acts together.
• 10:40
  Speaker 2: Exactly. Or like looking at a single pixel on a
• 10:43
  Speaker 2: television screen. If you only study that one blinking pixel,
• 10:46
  Speaker 2: you will never understand that the screen is actually displaying
• 10:49
  Speaker 2: a complex movie. Right.
• 10:50
  Speaker 3: The movie is an emergent property of millions of pixels
• 10:53
  Speaker 3: acting collectively.
• 10:54
  Speaker 2: And physics is driven by collective phenomena. Superconductivity, magnetism, quantum
• 10:59
  Speaker 2: phase transitions. These all rely on the collective behavior of
• 11:03
  Speaker 2: massive numbers of interacting particles.
• 11:05
  Speaker 3: So what this math does is take the Schrodinger cat state,
• 11:09
  Speaker 3: which is normally thought of as a fragile artificial paradox. Right.
• 11:13
  Speaker 3: And mathematically frames it as an extreme version of natural
• 11:17
  Speaker 3: collective behavior.
• 11:18
  Speaker 2: Exactly. And it expands on earlier physics papers to prove
• 11:22
  Speaker 2: this is a robust feature of the math. It isn't
• 11:24
  Speaker 2: just limited to a highly restrictive zero temperature model.
• 11:28
  Speaker 3: That's a huge point.
• 11:29
  Speaker 2: The expansion is vital here. The mathematics proves this phenomenon
• 11:33
  Speaker 2: holds up across full finite temperature ranges. It applies in
• 11:36
  Speaker 2: higher dimensions. And it encompasses a broader collection of macroscopic observables.
• 11:41
  Speaker 3: So it isn't a fragile quirk of some constrained 1D
• 11:44
  Speaker 3: mathematical line. It is a fundamental feature of how these
• 11:48
  Speaker 3: many body systems evolve.
• 11:50
  Speaker 2: Yes.
• 11:50
  Speaker 3: Okay, so if the mathematics holds up in higher dimensions
• 11:54
  Speaker 3: and at finite temperatures, and we know that a collective
• 11:57
  Speaker 3: crowd of interacting particles can naturally evolve into these cat states,
• 12:00
  Speaker 3: I have to bring it back to the room you're
• 12:02
  Speaker 3: sitting in right now.
• 12:02
  Speaker 2: Okay, let's do it.
• 12:03
  Speaker 3: My coffee table is a massive crowd of interacting particles
• 12:07
  Speaker 3: operating in three dimensions at a finite temperature. Is my
• 12:10
  Speaker 3: coffee table secretly oscillating between two realities right now?
• 12:14
  Speaker 2: This raises an important question, and we have to clearly
• 12:16
  Speaker 2: separate the idealized mathematical model from the messy reality of
• 12:20
  Speaker 2: your living room.
• 12:21
  Speaker 3: Fair enough.
• 12:22
  Speaker 2: The proof requires specific parameters. The perturbation that drives this
• 12:27
  Speaker 2: dynamical evolution into a superposition is mathematically defined as being weak, generic,
• 12:33
  Speaker 2: highly non-local, and many-body.
• 12:36
  Speaker 3: Okay, so how does that differ from the forces acting
• 12:38
  Speaker 3: on my table?
• 12:39
  Speaker 2: A real-world environment is dominated by constant, intense, and highly
• 12:43
  Speaker 2: local noise. Your coffee table is continuously bombarded by photons
• 12:48
  Speaker 2: from the light in the room, electromagnetic fields, air molecules,
• 12:51
  Speaker 2: countless other local interactions.
• 12:53
  Speaker 3: And those interactions don't smoothly evolve the entire system.
• 12:56
  Speaker 2: No, they violently and rapidly distribute the quantum information into
• 13:00
  Speaker 2: the environment.
• 13:01
  Speaker 3: And that brings us right back to decoherence.
• 13:03
  Speaker 2: Exactly. The local noise of the real world guarantees the
• 13:07
  Speaker 2: rapid onset of decoherence before the slow unitary evolution of
• 13:11
  Speaker 2: thermalization could ever generate a macroscopic superposition.
• 13:15
  Speaker 3: So the math isn't claiming my coffee table is currently
• 13:17
  Speaker 3: a Schrodinger cat.
• 13:18
  Speaker 2: No, it isn't. It is proving that within the pure,
• 13:22
  Speaker 2: uncorrupted dynamics of a many-body quantum system, insulated from external
• 13:26
  Speaker 2: environmental noise, these macroscopic superpositions are a mathematical inevitability.
• 13:33
  Speaker 3: So what does this all mean? If the chaotic noise
• 13:36
  Speaker 3: of the real world always destroys these superpositions before we
• 13:40
  Speaker 3: can ever see them, what is the ultimate significance of
• 13:43
  Speaker 3: this mathematical proof?
• 13:44
  Speaker 2: That's the big question.
• 13:45
  Speaker 3: Why does it matter that a pristine, idealized system can
• 13:48
  Speaker 3: do this if reality never allows it? To me, it
• 13:51
  Speaker 3: fundamentally reshapes our philosophical understanding of what reality actually is.
• 13:55
  Speaker 2: If we connect this to the bigger picture, it adds
• 13:57
  Speaker 2: a crucial piece to the puzzle of quantum foundations. It
• 14:01
  Speaker 2: addresses the core question of how classical behavior emerges from
• 14:04
  Speaker 2: a quantum universe.
• 14:05
  Speaker 3: Because I think the common assumption is that quantum mechanics
• 14:07
  Speaker 3: just sort of turns off at a certain scale.
• 14:10
  Speaker 2: Right. People assume there is a physical size limit.
• 14:12
  Speaker 1: Yeah.
• 14:12
  Speaker 3: Like once an object gets big enough, it crosses a
• 14:15
  Speaker 3: magical threshold and just becomes classical. But this mathematics suggests
• 14:19
  Speaker 3: the fundamental laws of nature never change.
• 14:21
  Speaker 2: They don't. The classical world isn't a separate physical domain.
• 14:25
  Speaker 2: It is an illusion generated by the overwhelming complexity of
• 14:29
  Speaker 2: massive quantum systems interacting.
• 14:31
  Speaker 3: So the underlying quantum mechanics is always running the engine.
• 14:34
  Speaker 2: Always. The universe doesn't appear classical to us because the
• 14:38
  Speaker 2: quantum rules stop working. It appears classical because the unimaginably
• 14:42
  Speaker 2: complicated dynamics of enormous quantum systems interacting with a noisy
• 14:47
  Speaker 2: environment average out.
• 14:48
  Speaker 3: They're all just averaging out.
• 14:49
  Speaker 2: Yeah. The underlying pure state is entirely capable of structures
• 14:53
  Speaker 2: that defy our human intuition, like massive branched realities. But
• 14:57
  Speaker 2: the environmental noise essentially compresses all that wild data into
• 15:01
  Speaker 2: the predictable macroscopic observables we experience.
• 15:04
  Speaker 3: It means that our normal reality, the solid predictability of
• 15:09
  Speaker 3: the chair you are sitting on, is just an emergent property.
• 15:13
  Speaker 3: The physics doesn't stop being strange. It just gets so
• 15:16
  Speaker 3: complicated and noisy that that we can only perceive the
• 15:19
  Speaker 3: average result.
• 15:21
  Speaker 2: We are blind to the mechanics happening underneath.
• 15:23
  Speaker 3: Which is just incredible to think about.
• 15:24
  Speaker 2: And that is why Schrodinger's 90-year-old provocation remains so important today.
• 15:29
  Speaker 2: He designed the cat experiment to expose what he saw
• 15:32
  Speaker 2: as a fatal flaw in the theory.
• 15:34
  Speaker 3: Right. He thought that if you apply quantum mechanics to
• 15:37
  Speaker 3: everyday objects, it just results in an absurdity.
• 15:40
  Speaker 2: But nearly a century later, rigorous mathematics is proving that
• 15:44
  Speaker 2: the absurdity is actually baked into the laws of nature.
• 15:47
  Speaker 2: the fundamental rules remain profoundly weird even on a macroscopic scale.
• 15:52
  Speaker 3: We've covered some incredibly dense ground today.
• 15:54
  Speaker 2: We really have.
• 15:55
  Speaker 3: We started by questioning the invisible boundary between the microscopic
• 15:58
  Speaker 3: quantum world and our predictable macroscopic lives. We looked at
• 16:03
  Speaker 3: how an idealized ferromagnetic Ising model proves that you don't
• 16:07
  Speaker 3: need a delicate laboratory setup to create a macroscopic superposition.
• 16:10
  Speaker 2: Right. The mathematical proof shows that through the process of
• 16:14
  Speaker 2: unitary evolution... A system can naturally reach thermal equilibrium while
• 16:19
  Speaker 2: simultaneously fracturing into a massive branched Schrodinger cat state.
• 16:24
  Speaker 3: The very process of settling down can actually be the
• 16:27
  Speaker 3: mechanism that breeds a gigantic split in reality.
• 16:30
  Speaker 2: Exactly.
• 16:31
  Speaker 3: And even though the real-world noise of decoherence prevents us
• 16:34
  Speaker 3: from seeing these superpositions in our everyday objects, the math
• 16:38
  Speaker 3: forces us to accept that the classical world is just
• 16:41
  Speaker 3: an emergent layer sitting on top of a fiercely quantum foundation.
• 16:45
  Speaker 2: It's a whole new way to look at the world
• 16:47
  Speaker 2: around you.
• 16:47
  Speaker 3: It really is. The next time you look at a
• 16:49
  Speaker 3: perfectly ordinary object, remember the rigorous mathematics churning underneath it.
• 16:54
  Speaker 3: The matter itself, uncorrupted by noise, is entirely capable of
• 16:58
  Speaker 3: sustaining parallel realities. But before we finish, I want to
• 17:01
  Speaker 3: leave you with one final thought to mull over.
• 17:03
  Speaker 2: Oh.
• 17:03
  Speaker 3: Because this whole concept, it scales up to something even
• 17:06
  Speaker 3: more staggering.
• 17:06
  Speaker 2: Well, we've been discussing finite models, but yeah, the implications
• 17:10
  Speaker 2: scale up indefinitely. Exactly.
• 17:12
  Speaker 3: Exactly. We've been talking about many-body systems evolving naturally over
• 17:15
  Speaker 3: sufficiently long periods of time. We've established that thermalization can
• 17:19
  Speaker 3: breed these gigantic macroscopic superpositions in complex systems.
• 17:23
  Speaker 2: Right.
• 17:24
  Speaker 3: Well, the entire cosmos is just a massive interacting many-body system,
• 17:29
  Speaker 3: isn't it?
• 17:29
  Speaker 1: It is.
• 17:30
  Speaker 3: And it is slowly evolving over unimaginable stretches of time.
• 17:34
  Speaker 3: If these gigantic quantum superpositions can emerge dynamically within a
• 17:38
  Speaker 3: complex system as it evolves... What does that mean for
• 17:41
  Speaker 3: the ultimate fate of the universe itself?
• 17:43
  Speaker 2: That's an incredible question.
• 17:44
  Speaker 3: Billions or trillions of years from now, as the universe
• 17:47
  Speaker 3: continues to expand, interact, and cool, could the entire cosmos,
• 17:52
  Speaker 3: acting as the ultimate interacting crowd of matter, be slowly
• 17:55
  Speaker 3: evolving toward a single, unimaginable, Schrodinger cat state?
• 17:59
  Speaker 2: If the mathematics allows for this kind of dynamic emergence
• 18:03
  Speaker 2: in a macroscopic many-body model, extrapolating those mechanics to a
• 18:07
  Speaker 2: cosmological scale over infinite time, It would be the ultimate superposition.
• 18:11
  Speaker 3: So go back to that solid chair you were sitting
• 18:13
  Speaker 3: on right now. It feels singular. It feels safe. It
• 18:17
  Speaker 3: feels like it obeys a strict, predictable set of rules.
• 18:20
  Speaker 3: But underneath it all, the fundamental blueprint of the universe
• 18:23
  Speaker 3: is still perfectly willing to let everything be two things
• 18:26
  Speaker 3: at once.