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Beyond Einstein: The Reality of Quantum Entanglement · 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, when we think about twentieth century science, we
• 0:30
  Speaker 2: almost automatically picture Albert Einstein. Oh absolutely, he's the icon, right,
• 0:35
  Speaker 2: the wild hair, the Nobel Prize. I mean, the guy
• 0:38
  Speaker 2: literally rewrote gravity and time. He just seems like this
• 0:42
  Speaker 2: ultimate victor, the person who cracked the code.
• 0:44
  Speaker 3: And for a long time he really was. I mean,
• 0:46
  Speaker 3: for the first half of his career he was the revolutionary, right,
• 0:49
  Speaker 3: but there's this this almost tragic second act to his
• 0:55
  Speaker 3: life that, you know, it often gets a little glossed
• 0:57
  Speaker 3: over in the history.
• 0:58
  Speaker 2: Book the Princeton years. Right, became the old Guard.
• 1:01
  Speaker 3: Worse than the old Guard. He became sort of an
• 1:03
  Speaker 3: outsider in his own field. He spent decades, literally decades,
• 1:08
  Speaker 3: waging this intellectual war against a theory he had helped create,
• 1:12
  Speaker 3: quantum mechanics, and he was haunted by one specific part
• 1:15
  Speaker 3: of it, a phenomenon so bizarre, so deeply counterintuitive, that
• 1:21
  Speaker 3: it really offended his entire sense of cosmic order, and he.
• 1:24
  Speaker 2: Came up with that amazing phrase for it.
• 1:26
  Speaker 3: He did. He dismissed it as spooky action at a distance.
• 1:30
  Speaker 2: Which I mean it sounds like something out of a
• 1:32
  Speaker 2: ghost story or b movie.
• 1:33
  Speaker 3: Yeah, but he wasn't talking about ghosts. He was talking
• 1:36
  Speaker 3: about quantum entanglement. And for him, this wasn't just some
• 1:39
  Speaker 3: technical quibble about Adams.
• 1:41
  Speaker 2: Yeah, it was fundamental.
• 1:42
  Speaker 3: It was a philosophical cage match, a battle for the
• 1:45
  Speaker 3: very soul of physics, about the nature of reality itself.
• 1:49
  Speaker 2: And that's really what we want to unpack today, because
• 1:51
  Speaker 2: this isn't just about weird little particles doing weird things.
• 1:54
  Speaker 2: It's about the very thing that kept Albert Einstein awake
• 1:57
  Speaker 2: at night. This idea that the universe might not be local,
• 2:00
  Speaker 2: that it might not even be real in the everyday
• 2:03
  Speaker 2: way we think about it, and everything is connected in
• 2:05
  Speaker 2: this way that just seems to defy all logic.
• 2:08
  Speaker 3: It really pits our intuition, and I mean the intuition
• 2:11
  Speaker 3: of arguably the smartest person who ever lived, against the
• 2:15
  Speaker 3: raw experimental facts of how the universe actually works.
• 2:18
  Speaker 2: So the spoiler here is pretty clear.
• 2:20
  Speaker 3: The universe won the universe always wins.
• 2:23
  Speaker 2: And Einstein in this one particular battle lost, But how
• 2:28
  Speaker 2: he lost and why he lost. I mean, that's a
• 2:30
  Speaker 2: story that actually leads us directly to the technologies that
• 2:33
  Speaker 2: are building our future.
• 2:34
  Speaker 3: It's an incredible story. Yeah, So to really get it,
• 2:38
  Speaker 3: we need to sort of walk through that battlefield, understand
• 2:41
  Speaker 3: what entanglement is, why it seemed to break all the rules,
• 2:44
  Speaker 3: and then how we proved it was real, and.
• 2:46
  Speaker 2: What we're doing with all that spookiness today.
• 2:49
  Speaker 3: Right, But before we get to the disruption, we have
• 2:53
  Speaker 3: to understand what was being disrupted. We need to look
• 2:56
  Speaker 3: at the world Einstein was fighting so hard to.
• 2:59
  Speaker 2: Protect, classical world.
• 3:01
  Speaker 3: The world of Isaac Newton and James Clerk Maxwell. The
• 3:04
  Speaker 3: physics that you know just feels right, it feels comfortable.
• 3:07
  Speaker 2: It's the physics of common sense.
• 3:09
  Speaker 3: It really is. And that common sense worldview is built
• 3:13
  Speaker 3: on two main pillars, and they seem so obvious that
• 3:16
  Speaker 3: you don't even think to question them. The first one's
• 3:19
  Speaker 3: called realism.
• 3:20
  Speaker 2: And in physics that doesn't just mean being practical. It
• 3:22
  Speaker 2: has a very specific.
• 3:23
  Speaker 3: Meaning it does. Realism is the basic assumption that objects
• 3:28
  Speaker 3: in the physical world have definite properties, whether you're looking
• 3:30
  Speaker 3: at them or not.
• 3:31
  Speaker 2: The classic if a tree falls in the forest argument,
• 3:33
  Speaker 2: or you know, the moon is still there even when
• 3:36
  Speaker 2: I'm not looking at it.
• 3:37
  Speaker 3: Exactly that. If I take a coin and I see
• 3:40
  Speaker 3: it in a box, that coin is either heads or
• 3:44
  Speaker 3: its tails. It has a definite state. Now I might
• 3:47
  Speaker 3: not know what that state is, but it exists. My
• 3:50
  Speaker 3: ignorance doesn't change the physical reality inside the box.
• 3:54
  Speaker 2: That seems like a pretty non negotiable starting point for
• 3:57
  Speaker 2: doing science. Right. If things don't have definite proper is,
• 4:00
  Speaker 2: what are you even measuring?
• 4:01
  Speaker 3: That was precisely Einstein's point of view. He believed in
• 4:05
  Speaker 3: an objective reality that exists independent of us. So that's
• 4:08
  Speaker 3: pillar number one. The second pillar is locality.
• 4:12
  Speaker 2: Locality this is all about the speed limit of cause
• 4:15
  Speaker 2: and effect.
• 4:15
  Speaker 3: Yeah, you could put it that way. It's the principle
• 4:17
  Speaker 3: that any object can only be influenced by its immediate surroundings.
• 4:21
  Speaker 3: If I want to move this coffee cup, I have
• 4:23
  Speaker 3: to touch it, or I have to push arrogance it,
• 4:26
  Speaker 3: throw something at it. I can't just snap my fingers
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  Speaker 3: here in this room and make a cup fall over in.
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  Speaker 2: Tokyo unless there's some kind of signal some connection between them.
• 4:33
  Speaker 3: And that's the key. That signal has to travel through
• 4:36
  Speaker 3: the space in between. It can't just happen magically instantly
• 4:39
  Speaker 3: across a distance.
• 4:41
  Speaker 2: And this is actually where Newton got into a bit
• 4:43
  Speaker 2: of trouble, wasn't it. I Mean, we think of Newtonian
• 4:45
  Speaker 2: gravity as this perfect clockwork system, but it had this
• 4:48
  Speaker 2: huge locality problem.
• 4:49
  Speaker 3: It did, and he knew it. In Newton's equations, gravity
• 4:53
  Speaker 3: was instantaneous. If the Sun were to just vanish right now,
• 4:58
  Speaker 3: poof Newton's math said the Earth would instantly fly out
• 5:01
  Speaker 3: of its orbit at that exact moment, which implies that
• 5:05
  Speaker 3: the Earth somehow knows the Sun is gone instantly across
• 5:10
  Speaker 3: ninety three million miles of empty space.
• 5:12
  Speaker 2: Which is well, it's spooky action at a distance, it's magic.
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  Speaker 3: Newton hated it. He called it so great an absurdity,
• 5:19
  Speaker 3: but he didn't have a way to fix it.
• 5:20
  Speaker 2: It just it worked till Einstein came along.
• 5:22
  Speaker 3: Until Einstein fixed it. That's a huge part of what
• 5:24
  Speaker 3: his nineteen oh five paper on special relativity was all about.
• 5:28
  Speaker 3: He established the cosmic speed limit.
• 5:29
  Speaker 2: The speed of light.
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  Speaker 3: Exactly nothing, not matter, not energy, and crucially not information.
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  Speaker 3: Can travel faster than light.
• 5:36
  Speaker 2: So in Einstein's universe, if the sun vanishes, we're fine.
• 5:39
  Speaker 2: For about eight minutes.
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  Speaker 3: We keep orbiting blissfully unaware.
• 5:43
  Speaker 2: We don't know it's gone until that last bit of
• 5:45
  Speaker 2: gravitational news arrives at light speed.
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  Speaker 3: He saved locality, He got rid of the magic. He
• 5:50
  Speaker 3: built this beautiful, sensible universe that was local, that was real,
• 5:55
  Speaker 3: and that was deterministic. Causes always precede effects. The cosmic
• 6:01
  Speaker 3: timeline is safe.
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  Speaker 2: It's a very neat and tidy picture of reality.
• 6:05
  Speaker 3: It is.
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  Speaker 2: And then almost immediately he and his colleagues started digging
• 6:09
  Speaker 2: into the atom, and they found something that threatened to
• 6:11
  Speaker 2: just tear that entire safety net to pieces.
• 6:14
  Speaker 3: The quantum disruption. As soon as physicists started to describe
• 6:18
  Speaker 3: the world of electrons and photons, they realized the rules
• 6:21
  Speaker 3: of our big, comfortable world just didn't apply down there.
• 6:25
  Speaker 2: So let's take those pillars one by one. How did
• 6:27
  Speaker 2: quantum mechanics attack realism? First, this is the idea of superposition, right.
• 6:31
  Speaker 3: Yes, superposition, and it's a concept that directly assaults realism.
• 6:36
  Speaker 3: It says that before you measure it, a quantum particle
• 6:39
  Speaker 3: does not have a definite state.
• 6:40
  Speaker 2: And we have to be so careful with the language
• 6:42
  Speaker 2: here because this is the first big hurdle for most people.
• 6:44
  Speaker 2: This doesn't mean it has a state, but we just
• 6:46
  Speaker 2: don't know what it is.
• 6:47
  Speaker 3: Correct, This is not the coin in the box. It
• 6:50
  Speaker 3: is a fundamental built in uncertainty. An electron has a
• 6:56
  Speaker 3: property called spin, and just for simplicity, you can think
• 6:59
  Speaker 3: of it an arrow pointing either up or down. Okay,
• 7:02
  Speaker 3: in superposition, the electron isn't secretly up or secretly down.
• 7:07
  Speaker 3: It is, in a very real mathematical sense, a combination
• 7:10
  Speaker 3: of both up and down at the same time.
• 7:12
  Speaker 2: This is described by the wave function.
• 7:14
  Speaker 3: The wave function describes this quantum blur, this cloud of probabilities.
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  Speaker 3: The particle itself has no real spin until it interacts
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  Speaker 3: with something.
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  Speaker 2: Until you measure it right.
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  Speaker 3: The active measurement forces the universe too well to make
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  Speaker 3: a choice. The wave function collapses, and boom, the particle
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  Speaker 3: is suddenly definitely spin up or spin down.
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  Speaker 2: You can see why this drove Einstein crazy. It suggests
• 7:35
  Speaker 2: that reality is somehow fuzzy or incomplete until an observer
• 7:38
  Speaker 2: comes along and forces its hand. It just shatters the
• 7:41
  Speaker 2: principle of realism.
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  Speaker 3: He absolutely hated it. This is where he famously debated
• 7:46
  Speaker 3: with Neil's Borr, asking, do you really believe the moon
• 7:48
  Speaker 3: is not there when you're not looking at it?
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  Speaker 2: It's a great question, it is.
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  Speaker 3: But then the rabbit hole got so much deeper, because
• 7:55
  Speaker 3: what happens if you take this weirdness of superposition and
• 7:58
  Speaker 3: you apply it to two particles at once, Well, then
• 8:00
  Speaker 3: you get entanglement.
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  Speaker 2: And this is where the second pillar locality starts to crumble.
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  Speaker 3: This is where it gets truly spooky.
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  Speaker 2: Okay, so walk us through the basic setup for entanglement.
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  Speaker 3: Imagine we have a process that creates a pair of
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  Speaker 3: particles from a single source. Let's say a specific atom
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  Speaker 3: decays and spits out two electrons. Because of certain fundamental
• 8:22
  Speaker 3: laws like the conservation of the momentum, we know their properties
• 8:26
  Speaker 3: have to be linked. They have to be opposite.
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  Speaker 2: So if one is measured to be spin up, the.
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  Speaker 3: Other one absolutely must be spinned down. They're born as
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  Speaker 3: a correlated pair. They're linked, They're entangled, and in the
• 8:37
  Speaker 3: language of quantum mechanics, this is more than just being linked.
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  Speaker 3: They are no longer two separate objects. They are described
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  Speaker 3: by a single shared wave function a single quantum existence,
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  Speaker 3: even if you separate them, even if you separate them.
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  Speaker 3: So we send one particle to Alice, Let's say she's
• 8:52
  Speaker 3: in New York, and we send the other particle to Bob,
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  Speaker 3: who's in Los Angeles.
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  Speaker 2: But all this time they're still in superposition. Neither every
• 9:00
  Speaker 2: one has decided yet whether it's up or down exactly.
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  Speaker 3: They're both still in that quantum blur of up and downness. Now,
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  Speaker 3: Alice decides to megger her particle.
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  Speaker 2: Okay, she looks at it, she forces a collapse.
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  Speaker 3: She measures it, and the wave function collapses. She gets
• 9:15
  Speaker 3: the result spin up at that exact instant, and I
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  Speaker 3: mean instantly, Bob's particle in Los Angeles, without anyone touching
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  Speaker 3: it becomes spin down.
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  Speaker 2: No signal passed between them, no little message saying hey
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  Speaker 2: I'm up, so you be down.
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  Speaker 3: None. The collapse of the wave function is global. The
• 9:33
  Speaker 3: distance is completely irrelevant. It could be New York and
• 9:35
  Speaker 3: Los Angeles, or it could be Earth in the Andromeda Galaxy.
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  Speaker 3: The moment Alice's result is determined, Bob's is too.
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  Speaker 2: And that is the spooky action. It looks for all
• 9:44
  Speaker 2: the world like information is teleporting across space.
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  Speaker 3: It looks like a bleat and violation of Einstein's own
• 9:50
  Speaker 3: cosmic speed limit. It looks like the universe is fundamentally
• 9:52
  Speaker 3: non local.
• 9:53
  Speaker 2: So Einstein sees this implication in the math and he
• 9:56
  Speaker 2: basically decides, no, absolutely not, I need to kill this idea.
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  Speaker 3: He can't accept a universe that plays that fast and
• 10:03
  Speaker 3: loose with his most cherished principles.
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  Speaker 2: So in nineteen thirty five he gets together with two
• 10:08
  Speaker 2: colleagues and drops what is basically an intellectual bomb, the
• 10:12
  Speaker 2: EPR paper.
• 10:13
  Speaker 3: Yes, Einstein, Putolski and Rosen Yeah, and it is, without
• 10:17
  Speaker 3: a doubt, one of the most important scientific papers ever written.
• 10:20
  Speaker 3: Not because it was right it wasn't, but because of
• 10:23
  Speaker 3: how profoundly productively wrong it was.
• 10:25
  Speaker 2: So what was their central argument? They weren't saying the
• 10:29
  Speaker 2: math of quantum mechanics was incorrect, were they? No?
• 10:32
  Speaker 3: Not exactly. They admitted that the theory's predictions, the probabilities
• 10:36
  Speaker 3: were correct, the math worked. What they argued was that
• 10:39
  Speaker 3: the theory must.
• 10:40
  Speaker 2: Be incomplete, that the spookiness was just an illusion, a
• 10:43
  Speaker 2: magic trick caused by something we were missing.
• 10:45
  Speaker 3: Precisely, this leads directly to their counterproposal which is usually
• 10:48
  Speaker 3: called the theory of hidden variables.
• 10:50
  Speaker 2: This was Einstein's way out, This was his escape patch,
• 10:54
  Speaker 2: and the best way to understand it is with the
• 10:55
  Speaker 2: famous gloves analogy. Okay, let's hear it.
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  Speaker 3: So imagine I have a pair of gloves, a left
• 11:01
  Speaker 3: handed one and a right handed one. I put each
• 11:04
  Speaker 3: one into an identical sealed box. I shuffle them up,
• 11:08
  Speaker 3: I mail one box to you, and I keep the other.
• 11:10
  Speaker 3: Right now, I open my box and I see a
• 11:13
  Speaker 3: left handed glove. What do you instantly know about the
• 11:17
  Speaker 3: glove in your box?
• 11:18
  Speaker 2: I know I have the right handed one instantly.
• 11:21
  Speaker 3: But did any spooky action take place? Did any information
• 11:25
  Speaker 3: travel faster than light from my glove to yours?
• 11:28
  Speaker 2: No, of course not. The outcome was decided from the
• 11:31
  Speaker 2: very beginning. The gloves are always a left and right
• 11:34
  Speaker 2: from the moment you pack them in the boxes.
• 11:36
  Speaker 3: Exactly. The state of the gloves was determined at the source.
• 11:40
  Speaker 3: My discovery didn't cause your glove to become a rity.
• 11:43
  Speaker 3: It just revealed a pre existing fact.
• 11:45
  Speaker 2: And Einstein argued that entangled particles were just like the gloves.
• 11:48
  Speaker 3: That's it. He believed they weren't in some fuzzy superposition.
• 11:52
  Speaker 3: He argued, they carried a set of hidden instructions, hidden variables,
• 11:55
  Speaker 3: from the moment they were created.
• 11:57
  Speaker 2: So when Alice measures her particle and gets up, that
• 12:00
  Speaker 2: particle was always destined to be up. It didn't just
• 12:03
  Speaker 2: decide on the spot. It had its marching orders from
• 12:06
  Speaker 2: the get go.
• 12:06
  Speaker 3: If that's true, then there's no spooky action, there's no
• 12:10
  Speaker 3: FTL communication. Locality is saved, realism is saved. The universe
• 12:15
  Speaker 3: makes sense again.
• 12:17
  Speaker 2: It's an incredibly powerful and honestly, a much more comfortable argument.
• 12:22
  Speaker 2: Why didn't people just accept it? Why did Neils bore
• 12:25
  Speaker 2: and the quantum camp push back so hard?
• 12:27
  Speaker 3: Because Borr was a purist about the theory. He looked
• 12:30
  Speaker 3: at the equations of quantum mechanics and said, there are
• 12:32
  Speaker 3: no hidden variables in this math, so why are you
• 12:34
  Speaker 3: trying to add them. He believed you had to take
• 12:37
  Speaker 3: the theory at face value. The particles really are undefined
• 12:40
  Speaker 3: until measured.
• 12:41
  Speaker 2: He famously told Einstein to stop telling God what to do.
• 12:44
  Speaker 3: He did, but for decades this was just a war
• 12:47
  Speaker 3: of words. It was pure philosophy. There was no experiment
• 12:51
  Speaker 3: you could do to crack open an electron and look
• 12:53
  Speaker 3: for a hidden instruction card inside.
• 12:55
  Speaker 2: It was an impasse. For what thirty years, you were
• 12:58
  Speaker 2: either on TM Einstein or Team Bor and basically just
• 13:00
  Speaker 2: a matter of philosophical taste.
• 13:02
  Speaker 3: It was a complete stale maid until nineteen sixty four.
• 13:05
  Speaker 2: Enter John Bell John.
• 13:06
  Speaker 3: Stuart Bell, a physicist from Northern Ireland working at CERN,
• 13:10
  Speaker 3: and he's the guy who managed to drag this argument
• 13:13
  Speaker 3: out of the philosophy department and into the physics lab.
• 13:17
  Speaker 3: He turned it into arithmetic.
• 13:19
  Speaker 2: He was actually sympathetic to Einstein's view, wasn't he He
• 13:21
  Speaker 2: wanted to see if hidden variables could work.
• 13:23
  Speaker 3: He did. He wanted to find a way to make
• 13:25
  Speaker 3: it work. But in the process he found a way
• 13:28
  Speaker 3: to test it.
• 13:29
  Speaker 2: So how on earth do you design a test for
• 13:32
  Speaker 2: something that is, by its very definition hidden.
• 13:36
  Speaker 3: That's the genius of it. You don't look for the
• 13:38
  Speaker 3: variables themselves, You look at their consequences. You test the correlations.
• 13:41
  Speaker 2: Okay, this is Bell's theorem. It's famous but notoriously tricky.
• 13:46
  Speaker 2: Let's try and unpack it. How does the math set
• 13:49
  Speaker 2: a trap for these hidden variables?
• 13:51
  Speaker 3: Okay, let's go back to Alis and Bob, but this time,
• 13:54
  Speaker 3: instead of just measuring spin as up or down. Let's
• 13:57
  Speaker 3: say they can measure it at a few different angles.
• 13:59
  Speaker 3: Let's three angles for their detectors, setting A, setting B,
• 14:02
  Speaker 3: and setting C.
• 14:03
  Speaker 2: Okay, so three possible questions I could ask their particle exactly.
• 14:07
  Speaker 3: Now, let's assume Einstein is right and the particles are
• 14:10
  Speaker 3: like the gloves. That means each particle leaves the source
• 14:13
  Speaker 3: carrying a hidden instruction card that tells it how to
• 14:16
  Speaker 3: answer for every possible question.
• 14:19
  Speaker 2: So a card might say, if asked A, say up.
• 14:22
  Speaker 2: If asked B, say down, If asked C, say.
• 14:25
  Speaker 3: Up, precisely a pre written answer for every possible measurement.
• 14:29
  Speaker 3: Now Bell's insight was this, if those pre written instruction
• 14:33
  Speaker 3: cards exist, then just by simple logic and statistics, there
• 14:37
  Speaker 3: is a strict mathematical limit to how strongly Alis and
• 14:40
  Speaker 3: Bob's results can be correlated when they choose their settings randomly.
• 14:43
  Speaker 2: It's like a probability limit.
• 14:45
  Speaker 3: It's a logic limit.
• 14:46
  Speaker 2: Yeah.
• 14:46
  Speaker 3: Think about it with a simple example. If you survey
• 14:48
  Speaker 3: a population about three yes no questions, do you like coffee, tea,
• 14:51
  Speaker 3: and juice? There are mathematical limits on how the answers
• 14:53
  Speaker 3: can overlap. You can't have eighty percent like coffee eighty
• 14:56
  Speaker 3: percent like T and have only ten percent who like both.
• 14:58
  Speaker 3: The logic doesn't work.
• 15:00
  Speaker 2: I see there's constraint.
• 15:01
  Speaker 3: There is a constraint. Bell wrote it down in a
• 15:03
  Speaker 3: formula and inequality. Any theory based on local, pre existing properties,
• 15:10
  Speaker 3: any hidden variable theory must obey this inequality. The correlations
• 15:15
  Speaker 3: cannot be stronger than a certain amount.
• 15:17
  Speaker 2: So Bell's inequality becomes the test. You run the experiment
• 15:21
  Speaker 2: thousands of times with random settings. If the correlation rate
• 15:24
  Speaker 2: stays below that limit, Einstein and his hidden variables could
• 15:27
  Speaker 2: still be right correct.
• 15:29
  Speaker 3: But here's the kicker. The established theory quantum mechanics itself
• 15:33
  Speaker 3: predicted something different. It predicted that entangled particles would coordinate
• 15:37
  Speaker 3: their answers better than the hidden instruction cards would allow.
• 15:41
  Speaker 2: They would be more in sync than the gloves could
• 15:43
  Speaker 2: ever logically be.
• 15:44
  Speaker 3: Yes, quantum mechanics predicted the correlations would be so strong
• 15:47
  Speaker 3: that they would violate Bells in equality, which would mean
• 15:50
  Speaker 3: it would be mathematical proof that there are no pre
• 15:53
  Speaker 3: written instruction cards. It would prove the particles are making
• 15:56
  Speaker 3: up their answers on the fly in perfect spooky coordination.
• 16:00
  Speaker 2: So Bell designs the trap in sixty four, but the
• 16:03
  Speaker 2: technology to actually build the trap and run the experiment
• 16:05
  Speaker 2: didn't exist yet.
• 16:07
  Speaker 3: Right, We had to wait for lasers, for fast electronics.
• 16:10
  Speaker 3: We had to wait until the early nineteen eighties. For
• 16:12
  Speaker 3: a French physicist named Elaine Aspect.
• 16:15
  Speaker 2: The Aspect experiment in nineteen eighty two. This is the
• 16:18
  Speaker 2: moment of truth.
• 16:19
  Speaker 3: This is the smoking gun. There had been some earlier
• 16:22
  Speaker 3: attempts that were suggestive, but they all had potential loopholes,
• 16:26
  Speaker 3: little ways that Einstein's view could sneak back in. Aspect
• 16:30
  Speaker 3: designed an experiment to be as watertight as possible.
• 16:32
  Speaker 2: So he generated pairs of entangled photons sent them off
• 16:35
  Speaker 2: to two detectors. What was the crucial addition?
• 16:38
  Speaker 3: He introduced ultra fast switches that could change the measurement
• 16:42
  Speaker 3: angle the setting while the photons were in mid flight.
• 16:45
  Speaker 2: Why is that timing so incredibly important.
• 16:47
  Speaker 3: It's to close what's called the locality loophole. The fear was,
• 16:51
  Speaker 3: what if the detectors could somehow communicate with each other,
• 16:54
  Speaker 3: or what if the particles could somehow know in advance
• 16:57
  Speaker 3: what setting they were going to be measured at.
• 17:00
  Speaker 2: Kind of conspiracy between the particles and the detectors.
• 17:03
  Speaker 3: Exactly, but aspect switches changed the settings in a few nanoseconds.
• 17:07
  Speaker 3: It happened so fast that by the time a photon
• 17:10
  Speaker 3: arrived at Alice's detector, there hadn't been enough time for
• 17:13
  Speaker 3: any signal, even one traveling speed of light, to get
• 17:17
  Speaker 3: from Bob's detector to Alice's to tell it what setting
• 17:20
  Speaker 3: Bob was using.
• 17:21
  Speaker 2: So there is absolutely no way for the particles to
• 17:24
  Speaker 2: coordinate their answers beforehand using any known physical signal. They
• 17:28
  Speaker 2: have to decide what to be right now in the moment.
• 17:30
  Speaker 3: That's it. Scrap was set. So what was the.
• 17:33
  Speaker 2: Result, the billion dollar question.
• 17:35
  Speaker 3: The result was that Bell's inequality was shattered. It wasn't
• 17:38
  Speaker 3: even close. The correlations were far far stronger than any
• 17:42
  Speaker 3: local hidden variable theory could possibly explain. They matched the
• 17:45
  Speaker 3: predictions of quantum mechanics perfectly.
• 17:47
  Speaker 2: So the gloves analogy is wrong. The instruction cards don't exist.
• 17:50
  Speaker 3: They do not exist. Saying Einstein was wrong, and I
• 17:53
  Speaker 3: mean it's a monumental conclusion. Locality in the classical sense
• 17:57
  Speaker 3: that he cherished is dead. The universe is fundamentally irreducibly
• 18:01
  Speaker 3: non local. The state of a particle right here is
• 18:04
  Speaker 3: in some deep, way instantaneously connected to the state of
• 18:07
  Speaker 3: another particle way over there.
• 18:09
  Speaker 2: That is just it's a hard pill to swallow. I'm
• 18:12
  Speaker 2: sitting here, you're sitting there. We feel very local, very separate.
• 18:16
  Speaker 3: We do. And that's why even after aspect, scientists are
• 18:20
  Speaker 3: so cautious they spent the next thirty years designing even
• 18:24
  Speaker 3: more sophisticated experiments to close every other conceivable.
• 18:28
  Speaker 2: Loophole, right like maybe the detectors aren't efficient enough, or
• 18:31
  Speaker 2: maybe the random number generators aren't truly random.
• 18:34
  Speaker 3: All of that, and then in twenty fifteen, a series
• 18:37
  Speaker 3: of loophole free bell tests were finally performed that closed
• 18:41
  Speaker 3: all the major loopholes simultaneously. The results were the same,
• 18:44
  Speaker 3: rock solid. The universe is officially weird. Deal with it.
• 18:48
  Speaker 2: Okay, let's deal with it. We have to really dig
• 18:50
  Speaker 2: into what this means. Because the moment you say instantaneous connection,
• 18:53
  Speaker 2: the first place everyone's mind goes is faster than like communication.
• 18:57
  Speaker 2: They think, great, we can build an answable a subspace rate.
• 19:00
  Speaker 2: I can have a real time conversation with someone on Mars.
• 19:03
  Speaker 3: And this is where I, unfortunately have to be the buzzkill.
• 19:06
  Speaker 3: You absolutely cannot use entanglement to send a message faster
• 19:10
  Speaker 3: than like.
• 19:11
  Speaker 2: But why not? I mean, it seems so obvious. If
• 19:13
  Speaker 2: I poke my particle here and your particle wiggles instantly
• 19:17
  Speaker 2: over there, Isn't that a signal one or a zero?
• 19:20
  Speaker 3: It seems like it should be. But nature has this
• 19:22
  Speaker 3: incredibly clever failsafe built in. It's called the no signaling theorem,
• 19:27
  Speaker 3: and it's what preserves causality. The problem, in a word,
• 19:30
  Speaker 3: is randomness.
• 19:31
  Speaker 2: Okay, let's go back to Alice and Bob. Alice wants
• 19:33
  Speaker 2: to send the bit one to Bob. How does it fail?
• 19:36
  Speaker 3: Okay, Alice has her particle particle A. She decides I'm
• 19:40
  Speaker 3: going to measure it now and that will be my signal.
• 19:42
  Speaker 3: So she megres it. She gets let's say spin.
• 19:45
  Speaker 2: Up, and instantly Bob's particle, particle B becomes spin down.
• 19:49
  Speaker 3: Correct, So Bob could measure his and see spin down.
• 19:53
  Speaker 3: But here's the catch. Alice couldn't force her particle to
• 19:56
  Speaker 3: be spin up. The outcome of her measurement is fundamentally
• 20:00
  Speaker 3: irreducibly random. It's a fifty to fifty quantum coin flip.
• 20:04
  Speaker 3: She has absolutely no control over the results she gets.
• 20:06
  Speaker 2: Ah, so she can't control the message she's sending.
• 20:09
  Speaker 3: She can't encode any information into it. And now look
• 20:12
  Speaker 3: at it from Bob's side. He's just sitting there in
• 20:14
  Speaker 3: Los Angeles measuring his particles. He gets a stream of
• 20:17
  Speaker 3: results down, up, up, down, down down. It's completely random.
• 20:20
  Speaker 2: Right, It just looks like noise.
• 20:21
  Speaker 3: It is noise. How does he know that the down
• 20:24
  Speaker 3: he just measured was because Alice just measured and up.
• 20:28
  Speaker 3: He has no way of knowing. He has no baseline,
• 20:30
  Speaker 3: no context. A random string of bits contains zero information.
• 20:34
  Speaker 2: The only way he'd know it wasn't just noise is
• 20:37
  Speaker 2: if they compared their notes later.
• 20:38
  Speaker 3: Exactly. Alice has to pick of the phone, a normal
• 20:41
  Speaker 3: slower than light phone and call Bob and say hey
• 20:44
  Speaker 3: at twelve point eight zho, I got up, and Bob
• 20:46
  Speaker 3: looks at his logbook and says wow at twelve point
• 20:49
  Speaker 3: eight oh one, I got down. It worked.
• 20:51
  Speaker 2: But the phone call itself travels at or below the
• 20:53
  Speaker 2: speed of light.
• 20:54
  Speaker 3: And that's how causality is saved. Yeah, the spooky correlation
• 20:57
  Speaker 3: is real and it's instantaneous, but the information you can
• 21:01
  Speaker 3: extract from it can only travel the old fashioned way.
• 21:04
  Speaker 3: Nature lets non locality exist, but it cloaks it in randomness,
• 21:08
  Speaker 3: so you can't use it to break the timeline.
• 21:10
  Speaker 2: That is unbelievably clever. It's like the universe has its
• 21:13
  Speaker 2: cake and eats it too. It's weird, but it's not paradoxical.
• 21:17
  Speaker 3: It prevents those kill your own grandfather paradoxes. If you
• 21:21
  Speaker 3: could send a signal faster than light, you could send
• 21:23
  Speaker 3: the message into your own past, and then the whole
• 21:25
  Speaker 3: structure of cause and effect just dissolves.
• 21:28
  Speaker 2: We should probably also quickly bust the other big myth
• 21:31
  Speaker 2: that always crops.
• 21:32
  Speaker 3: Up with this stuff, the consciousness myth.
• 21:33
  Speaker 2: Yeah, the idea that it takes a conscious human mind
• 21:36
  Speaker 2: an observer to collapse the wave function. Ah.
• 21:39
  Speaker 3: Yes, the sort of new age interpretation of quantum mechanics.
• 21:43
  Speaker 3: It's a very romantic idea that our minds shape reality.
• 21:48
  Speaker 2: But the physics doesn't really support that, does it.
• 21:50
  Speaker 3: Not at all. A measurement in physics isn't about consciousness.
• 21:54
  Speaker 3: It's about interaction. Any interaction with a large classical system
• 21:58
  Speaker 3: is enough to cause a collapse.
• 22:00
  Speaker 2: So if an entangled photon hits a piece of photographic
• 22:03
  Speaker 2: film and makes a silver halide molecule change state that's
• 22:06
  Speaker 2: it collapse over.
• 22:08
  Speaker 3: That's the measurement. It doesn't matter if a human develops
• 22:11
  Speaker 3: that film and looks at the spot one hundred years
• 22:13
  Speaker 3: from now. The collapse happened at the moment of that
• 22:16
  Speaker 3: physical interaction.
• 22:17
  Speaker 2: So my cat is a valid observer. My toaster is
• 22:20
  Speaker 2: a valid observer.
• 22:21
  Speaker 3: If your toaster interacts with a quantum system in a
• 22:24
  Speaker 3: way that records its state, then yes, your toaster is
• 22:27
  Speaker 3: a perfectly valid observer.
• 22:29
  Speaker 2: Okay, so we've set the ground rules. No faster than
• 22:32
  Speaker 2: light radios, no mystical mind control. But the amazing thing
• 22:36
  Speaker 2: is we've moved past just staring at this in wonder.
• 22:40
  Speaker 2: We're actually building things with it. We are entering the
• 22:43
  Speaker 2: age of quantum technology.
• 22:46
  Speaker 3: This is the really exciting part. We've pivoted from is
• 22:48
  Speaker 3: this real to Okay, it's real. Now what can we
• 22:52
  Speaker 3: do with it?
• 22:53
  Speaker 2: So let's start with the one that sounds like it's
• 22:54
  Speaker 2: straight out of science fiction. Quantum teleportation.
• 22:57
  Speaker 3: It's a terrible name, it is.
• 22:59
  Speaker 2: Isn't it. It immediately makes you think of Star Trek.
• 23:02
  Speaker 2: Beat me up, Scotty.
• 23:03
  Speaker 3: And we have to be very clear. We are not
• 23:05
  Speaker 3: disintegrating a person in one place and reassembling them somewhere else.
• 23:09
  Speaker 3: We're not moving matter at all.
• 23:10
  Speaker 2: So what exactly is being teleported.
• 23:13
  Speaker 3: We are teleporting the quantum state of a particle, the
• 23:16
  Speaker 3: complete set of information that defines that particle.
• 23:20
  Speaker 2: How is that different from just you know, standing it
• 23:22
  Speaker 2: and emailing the data.
• 23:24
  Speaker 3: Because of another weird quantum rule called the no cloning theorem.
• 23:28
  Speaker 3: It states that it is fundamentally impossible to create an
• 23:31
  Speaker 3: identical copy of an arbitrary, unknown quantum state.
• 23:35
  Speaker 2: You can't just quantum photocopy something.
• 23:38
  Speaker 3: You can't. The moment you try to measure a quantum
• 23:40
  Speaker 3: state to get all the information needed to make a copy,
• 23:42
  Speaker 3: you inevitably disturb it. You destroy the original, so you
• 23:45
  Speaker 3: can't make a backup.
• 23:46
  Speaker 2: You can only move it, right, And.
• 23:47
  Speaker 3: That's what teleportation does. So here's the setup. Alice has
• 23:51
  Speaker 3: a particle whose state she wants to send to Bob.
• 23:54
  Speaker 3: Let's call her message particle. She also has one particle
• 23:57
  Speaker 3: from an entangled pair that she shares with Bob.
• 24:00
  Speaker 2: Okay, So Alice has two particles in her lab, the
• 24:03
  Speaker 2: message and her half of the entangled link. Bob has
• 24:06
  Speaker 2: the other half.
• 24:07
  Speaker 3: Correct. Alice then performs a special kind of joint measurement
• 24:11
  Speaker 3: on her two particles. It's called a Bell state measurement.
• 24:14
  Speaker 3: In essence, she entangles her message particle with her half of.
• 24:17
  Speaker 2: The link, and according to the no cloning rule, that
• 24:20
  Speaker 2: has to destroy the original state of her message particle.
• 24:23
  Speaker 3: It does. The information vanishes from Alice's location. But because
• 24:26
  Speaker 3: of that spooky link, the state of Bob's particle way
• 24:30
  Speaker 3: over in his lab instantly changes. It becomes a scrambled
• 24:34
  Speaker 3: version of Alice's original message.
• 24:36
  Speaker 2: Why scrambled?
• 24:36
  Speaker 3: It's sort of locked. Bob needs the key to unscramble it,
• 24:40
  Speaker 3: and the key is the result of Alice's Bell measurement.
• 24:43
  Speaker 3: So Alice sends that result. It's just two bits of
• 24:46
  Speaker 3: regular classical information over a normal fiber optic cable to Bob.
• 24:51
  Speaker 2: So Bob gets these two classical bits, he performs a
• 24:53
  Speaker 2: corresponding operation on his particle to unlock it, and then.
• 24:56
  Speaker 3: And then his particle becomes an exact replica of Alice's
• 25:00
  Speaker 3: original message particle. The state has effectively jumped from Alice's
• 25:03
  Speaker 3: lab to Bob's. The physical particle didn't move, but its
• 25:07
  Speaker 3: quantum identity did.
• 25:08
  Speaker 2: That's amazing, and we're doing this for real.
• 25:10
  Speaker 3: Oh yeah, routinely in labs. Back in twenty twenty two,
• 25:14
  Speaker 3: a team achieved it over a forty four kilometer fiber
• 25:17
  Speaker 3: optic network. We are literally building the foundations of a
• 25:20
  Speaker 3: quantum Internet where fragile quantum information can be moved around
• 25:25
  Speaker 3: without ever having to physically travel through the intervening space.
• 25:28
  Speaker 2: Which leads us right to the application that everyone is
• 25:30
  Speaker 2: either terrified of or incredibly excited about. Quantum computing.
• 25:35
  Speaker 3: Right. This is the big one, and it relies on
• 25:36
  Speaker 3: both superposition and entanglement to do its work. Your laptop, MyPhone,
• 25:42
  Speaker 3: they all run on classical bits.
• 25:43
  Speaker 2: A bit is either a zero or one on or
• 25:45
  Speaker 2: off simple, but.
• 25:47
  Speaker 3: A quantum bit or equibit can be in a superposition.
• 25:50
  Speaker 3: It can be a zero in a one at the
• 25:51
  Speaker 3: same time. But the real exponential power comes when you
• 25:54
  Speaker 3: entangle them. Okay, you have one quibit, you have two
• 25:56
  Speaker 3: possible states zero in one. If you're entangled too, quib
• 26:00
  Speaker 3: you don't have two plus two. You have two to
• 26:01
  Speaker 3: the power of two. You have four seats that exist
• 26:04
  Speaker 3: simultaneously in this shared quantum space. Three entangled quivitz gives
• 26:07
  Speaker 3: you eight states.
• 26:08
  Speaker 2: So it scales exponentially. If you have say three hundred
• 26:12
  Speaker 2: entangled covids.
• 26:13
  Speaker 3: If you have three hundred perfectly stable entangled quibts, you
• 26:17
  Speaker 3: can represent more simultaneous states than there are atoms in
• 26:21
  Speaker 3: the entire observable universe.
• 26:23
  Speaker 2: That number is just impossible to comprehend.
• 26:26
  Speaker 3: It is, and it means a quantum computer doesn't solve
• 26:29
  Speaker 3: problems by brute force trying one answer after another. It
• 26:33
  Speaker 3: sets up this massively complex quantum state, this interference pattern
• 26:37
  Speaker 3: where all the wrong answers are programmed to cancel each
• 26:40
  Speaker 3: other out and the right answer is amplified.
• 26:42
  Speaker 2: It's like finding the needle in a haystack by making
• 26:44
  Speaker 2: all the hay instantly vanish.
• 26:46
  Speaker 3: That is a fantastic analogy. Yes, and this isn't just
• 26:49
  Speaker 3: theory anymore. In twenty twenty three, Google announced they had
• 26:52
  Speaker 3: achieved quantum advantage using their Sycamore process or to do
• 26:56
  Speaker 3: a calculation in seconds that they estimated would take the
• 26:58
  Speaker 3: world's most powerful classical supercomputer something like forty seven years.
• 27:03
  Speaker 2: And that's why all of our current encryption is potentially
• 27:05
  Speaker 2: in jeopardy.
• 27:06
  Speaker 3: A lot of it is. Yes, modern encryption relies on
• 27:09
  Speaker 3: mathematical problems that are incredibly hard for classical computers to
• 27:13
  Speaker 3: solve like finding the prime factors of a gigantic number.
• 27:18
  Speaker 3: A large scale quantum computer could, in theory, slice through
• 27:22
  Speaker 3: those problems like a hot knife through butter.
• 27:24
  Speaker 2: So entanglement creates the threat, but it also provides the shield.
• 27:28
  Speaker 3: It does, which brings us to quantum cryptography.
• 27:31
  Speaker 2: Or QKD quantum key distribution.
• 27:34
  Speaker 3: And this is probably the most mature and commercially available
• 27:37
  Speaker 3: quantum technology right now. It uses the weirdness of measurement,
• 27:41
  Speaker 3: the observer effect as the ultimate burglar alarm.
• 27:45
  Speaker 2: So how does it work?
• 27:46
  Speaker 3: It's quite elegant. Alice and Bob want to create a
• 27:49
  Speaker 3: shared secret random key for encryption. They can do this
• 27:52
  Speaker 3: by setting a stream of entangled photons over a fiber
• 27:55
  Speaker 3: optic cable. Now, let's say a sky will call her
• 27:58
  Speaker 3: Eve tries to tap into that cable read the key.
• 28:00
  Speaker 2: To read the state of the photons, she has to
• 28:02
  Speaker 2: measure them.
• 28:03
  Speaker 3: In the moment she measures a photon, she forces its
• 28:05
  Speaker 3: wave function to collapse. She fundamentally alters its state. She
• 28:08
  Speaker 3: leaves a trace.
• 28:09
  Speaker 2: She breaks the delicate entanglement exactly.
• 28:12
  Speaker 3: When Alis and Bob are dune, they can publicly compare
• 28:15
  Speaker 3: a small random sample of their key bits. If there's
• 28:18
  Speaker 3: an eavesdropper on the line, they'll find a higher than
• 28:21
  Speaker 3: expected error rate in that sample.
• 28:23
  Speaker 2: The errors are Eve's fingerprints.
• 28:25
  Speaker 3: You cannot observe a quantum system without disturbing it. That's
• 28:28
  Speaker 3: a fundamental law of physics, which means you cannot wire
• 28:31
  Speaker 3: tap a quantum channel without being detected. The laws of
• 28:35
  Speaker 3: nature themselves guarantee the security, and this.
• 28:38
  Speaker 2: Is already being deployed.
• 28:39
  Speaker 3: Oh yeah. Banks are using it for secure transactions between
• 28:42
  Speaker 3: data centers, and most famously, China launched the Musha satellite,
• 28:46
  Speaker 3: which can beam entangled photons down to ground stations thousands
• 28:50
  Speaker 3: of kilometers apart, creating unhackable communication keys from space.
• 28:54
  Speaker 2: It's just incredible to go from Einstein calling it spooky
• 28:57
  Speaker 2: action in nineteen thirty five to using that same spookiness
• 29:01
  Speaker 2: to secure global financial networks. It's a breath taking pace.
• 29:04
  Speaker 3: It just goes to show you that even the most
• 29:06
  Speaker 3: abstract philosophical what is reality debates in physics can end
• 29:10
  Speaker 3: up completely transforming technology and civilization.
• 29:13
  Speaker 2: But speaking of those philosophical debates, they're not over. We
• 29:18
  Speaker 2: may be using the technology, but we still argue ferociously
• 29:21
  Speaker 2: about what it all means the measurement problem.
• 29:24
  Speaker 3: We have the math and it works perfectly. We can
• 29:26
  Speaker 3: build machines with it. But the story we tell ourselves
• 29:30
  Speaker 3: about what the math is describing that is still very
• 29:33
  Speaker 3: much up for grabs.
• 29:34
  Speaker 2: These are the interpretations of quantum mechanics. Let's touch on
• 29:38
  Speaker 2: the main contenders first. There's the standard textbook one, the
• 29:42
  Speaker 2: Copenhagen interpretation, right.
• 29:44
  Speaker 3: This is essentially the view of Neil's Bore and his group,
• 29:48
  Speaker 3: and it's very pragmatic. It basically says, shut up and calculate.
• 29:50
  Speaker 3: The wave function isn't a real thing. It's just a
• 29:52
  Speaker 3: mathematical tool that tells us the probabilities of our measurements.
• 29:56
  Speaker 3: Reality is created in the active measurement. Don't ask what
• 29:59
  Speaker 3: was there before.
• 30:00
  Speaker 2: It works, but it feels a little unsatisfying, like a
• 30:03
  Speaker 2: cop out too many.
• 30:05
  Speaker 3: Yes, it leaves the concept of measurement as this magical,
• 30:09
  Speaker 3: undefined thing that sits outside the theory, which.
• 30:11
  Speaker 2: Leads to the one that well, it either sounds brilliant
• 30:14
  Speaker 2: or completely insane. The many World's interpretation.
• 30:17
  Speaker 3: Proposed by Hugh Everett in nineteen fifty seven. He looked
• 30:19
  Speaker 3: at the math and asked a very simple question, why
• 30:23
  Speaker 3: do we have to add this messy collapse part to
• 30:26
  Speaker 3: the equations. What if the wave function just never collapses.
• 30:31
  Speaker 2: But if it never collapses, how do we ever get
• 30:34
  Speaker 2: a single definite result. I measure the electron and I
• 30:38
  Speaker 2: see up, not a blur.
• 30:39
  Speaker 3: Everett's answer was that the wave function just continues to
• 30:42
  Speaker 3: evolve smoothly. When you, the observer, interact with the particle,
• 30:46
  Speaker 3: that's in a superposition of up and down. The entire universe,
• 30:50
  Speaker 3: including U splits it br branches. In one branch of
• 30:53
  Speaker 3: the universe, there's a version of you who just measured up,
• 30:55
  Speaker 3: and in another completely separate branch, there's another version of
• 30:58
  Speaker 3: you who just measured down.
• 31:00
  Speaker 2: And both of these branches, both versions of me are
• 31:02
  Speaker 2: equally real.
• 31:03
  Speaker 3: Equally real, So in the entanglement experiment, there's no spooky action.
• 31:08
  Speaker 3: When Alice measures her particle, the universe splits in the
• 31:11
  Speaker 3: Alice measured up branch, Bob is now correlated to measure down.
• 31:15
  Speaker 3: The correlation is just between the different branches of this
• 31:17
  Speaker 3: universal wave function.
• 31:18
  Speaker 2: It saves locality, but at the cost of creating an
• 31:21
  Speaker 2: infinite number of parallel universes every single nanosecond.
• 31:25
  Speaker 3: That's the trade off. It's a very high price to
• 31:27
  Speaker 3: pay onto logically, but a lot of physicists love it
• 31:30
  Speaker 3: because the underlying math is so clean and elegant. There's
• 31:33
  Speaker 3: no arbitrary collapse rule.
• 31:35
  Speaker 2: And just when that seems like the weirdest it can get,
• 31:38
  Speaker 2: there's a newer, even wilder idea that tries to connect
• 31:41
  Speaker 2: all this back to Einstein's other great theory gravity ER
• 31:45
  Speaker 2: equals EPR.
• 31:47
  Speaker 3: This is right at the cutting edge. For a century.
• 31:49
  Speaker 3: We've had these two pillars of modern physics, quantum mechanics
• 31:53
  Speaker 3: which describes the very small with things like EPR and entanglement,
• 31:57
  Speaker 3: and general relativity, which describes the very large gravity space time,
• 32:01
  Speaker 3: and they just do not get along.
• 32:03
  Speaker 2: Their mathematics are incompatible totally.
• 32:05
  Speaker 3: But EPR is a conjecture that suggests maybe there are
• 32:08
  Speaker 3: two sides of the same coin. The ER stands for
• 32:10
  Speaker 3: Einstein rosenbridge, which is the technical term for a wormhole,
• 32:15
  Speaker 3: a tunnel, a shortcut through the fabric of space.
• 32:17
  Speaker 2: Time, and EPR is the entanglement paradox we've been talking about.
• 32:20
  Speaker 2: So the theory is that entanglement and wormholes are the
• 32:22
  Speaker 2: same thing.
• 32:23
  Speaker 3: The conjecture is that the spooky connection between two entangled
• 32:27
  Speaker 3: particles is a microscopic wormhole connecting.
• 32:30
  Speaker 2: Them, a literal physical tunnel through space time, a tiny.
• 32:34
  Speaker 3: Non traversible quantum scale. One yes, And if this is true,
• 32:38
  Speaker 3: it has a staggering implication. It implies that spacetime itself,
• 32:43
  Speaker 3: the very geometry of our universe, might be an emergent property.
• 32:47
  Speaker 3: It might be literally stitched together by a vast network
• 32:50
  Speaker 3: of quantum entanglement.
• 32:51
  Speaker 2: So space time isn't the stage that the play of
• 32:54
  Speaker 2: physics happens on. Space time is the play. It's the
• 32:57
  Speaker 2: actors holding hands.
• 32:59
  Speaker 3: That's a beautiful way to put it. If you could
• 33:01
  Speaker 3: somehow remove all the entanglement from the universe, space time
• 33:04
  Speaker 3: itself might just dissolve into an unstructured mess. The concept
• 33:07
  Speaker 3: of distance might be the illusion, and entanglement the deeper.
• 33:11
  Speaker 2: Reality that brings us full circle right back to Einstein's nightmare.
• 33:15
  Speaker 2: He was terrified that entanglement meant the breakdown of locality,
• 33:18
  Speaker 2: the breakdown of the clear separation of space.
• 33:21
  Speaker 3: And he might have been right, but in a way
• 33:23
  Speaker 3: he never could have imagined. Entanglement doesn't break space. It
• 33:27
  Speaker 3: might actually build space. The very thing he hated most
• 33:31
  Speaker 3: might be the glue that holds his own theory of
• 33:33
  Speaker 3: gravity together.
• 33:35
  Speaker 2: That is the ultimate cosmic irony.
• 33:37
  Speaker 3: It really is, and it's a profound reminder that the
• 33:40
  Speaker 3: universe has absolutely no obligation to conform to our common sense.
• 33:45
  Speaker 3: It's random, it's non local, and it's interconnected in ways
• 33:49
  Speaker 3: that we're only just beginning to grasp.
• 33:52
  Speaker 2: It really suggests that separation is the illusion. I mean,
• 33:55
  Speaker 2: if everything in the universe erupted from a single point
• 33:58
  Speaker 2: in the Big Bang.
• 33:59
  Speaker 3: Then in some say sense, everything was entangled with everything
• 34:01
  Speaker 3: else at the very beginning. We are, in a very real,
• 34:04
  Speaker 3: physical way, all part of a single, vast quantum system.
• 34:09
  Speaker 2: Now that is a thought that will keep me up tonight.
• 34:10
  Speaker 3: It should keep us all up.
• 34:12
  Speaker 2: We have gone from a simple analogy about gloves and
• 34:14
  Speaker 2: boxes to the fundamental fabric of reality itself. I think
• 34:19
  Speaker 2: my brain needs to cool down for a bit.
• 34:20
  Speaker 3: I think we all do. It's a lot to take in.
• 34:22
  Speaker 2: Well, thank you for being our guide through this quantum wilderness.
• 34:25
  Speaker 2: It's been fascinating, my pleasure.
• 34:27
  Speaker 3: It's the best story there is.
• 34:28
  Speaker 2: And to all of you listening, we'll leave you with
• 34:30
  Speaker 2: that thought, what if distance is just a stubborn illusion?
• 34:35
  Speaker 2: Keep questioning reality? We'll see you on the next one.