Quantum Weirdness to World-Changing Tech

<v Speaker 1>Welcome to the quark Side Quantum Physics podcast, an exploration
<v Speaker 1>of the fundamental structure of reality, where quantum laws govern matter, energy,
<v Speaker 1>and information. Here, uncertainty is a feature, not a flaw,
<v Speaker 1>and understanding begins at the smallest scales.
<v Speaker 2>Okay, so let's start with a box. A box, Yeah,
<v Speaker 2>the box. I know you've heard the story a thousand times,
<v Speaker 2>but we have to start here. Right inside this box,
<v Speaker 2>there's a.
<v Speaker 3>Cat and a pretty grim little device.
<v Speaker 2>Oh it's diabolical, A single radioactive atom that might decay,
<v Speaker 2>a Geiger counter to detect it, and a hammer that,
<v Speaker 2>if triggered, smashes a vial of poison.
<v Speaker 3>It is probably the most famous and definitely the most
<v Speaker 3>morbid thought experiment in all of science exactly.
<v Speaker 2>And the punchline, the thing everyone kind of knows is
<v Speaker 2>that until you open that box, the atom is in
<v Speaker 2>this weird state of both decayed and not decayed, a superposition,
<v Speaker 2>so the poison is both released and not released.
<v Speaker 3>Yeah.
<v Speaker 2>And the cat, well, the cats somehow simultaneously alive and dead.
<v Speaker 3>Schrodinger's cat, that's the poster child for quantum mechanics. Is weird.
<v Speaker 2>It really is, and for decades, I mean That's all
<v Speaker 2>it was, wasn't It was like a philosophical party trick,
<v Speaker 2>something to highlight the absurdity of it all it was.
<v Speaker 3>It was a paradox, to show that the rules of
<v Speaker 3>the tiny quantum world made no sense when you scaled
<v Speaker 3>them up to our world, the cats and boxes.
<v Speaker 2>It felt like an abstraction, something for physicists to argue
<v Speaker 2>about on.
<v Speaker 3>A blackboard, right, not for the real world.
<v Speaker 2>But and this is the whole point of our conversation
<v Speaker 2>today on February second, twenty twenty six, that's not the
<v Speaker 2>story anymore. That idea that it's just a weird puzzle,
<v Speaker 2>it's outdated.
<v Speaker 3>It's completely changed. We've gone from the blackboard to well,
<v Speaker 3>the motherboard.
<v Speaker 2>Yeah, we're not talking about a hypothetical cat anymore. We
<v Speaker 2>are talking about the invisible engine powering I mean pretty
<v Speaker 2>much the entire modern world. The weirdness isn't a bug.
<v Speaker 2>It turns out it's the operating system.
<v Speaker 3>That's a perfect way to put it.
<v Speaker 2>And what's prompting This is a brand new piece that
<v Speaker 2>just came out in the journal Science. It's a perspective
<v Speaker 2>by doctor Marlin Scully and the title just says it all.
<v Speaker 2>Its started with a cat how one hundred years of
<v Speaker 2>quantum weirdness powers today's tech.
<v Speaker 3>And we should say doctor Scully is the perfect person
<v Speaker 3>to be writing this. He's not just a historian here.
<v Speaker 3>He's a major figure in the field. Who is He's
<v Speaker 3>a distinguished professor at Texas A and M. He's got
<v Speaker 3>an affiliation with Princeton. I mean, if you study quantum optics,
<v Speaker 3>you've probably read his textbook. He's one of the people
<v Speaker 3>who helped build the bridge from the old strange theory
<v Speaker 3>to the new practical applications.
<v Speaker 2>So he's seen the whole transition.
<v Speaker 3>He's lived it, he's helped cause it.
<v Speaker 2>Okay, so our mission today is to trace that journey.
<v Speaker 2>We're going to go back one hundred years to when
<v Speaker 2>the smartest people on the planet.
<v Speaker 3>Were just baffled, completely baffled.
<v Speaker 2>And bring it forward to today where we use that
<v Speaker 2>bafflement to build things that honestly feel a lot like magic.
<v Speaker 3>And we're going to break it down. We're not just
<v Speaker 3>going to list a bunch of gadgets. We want to
<v Speaker 3>get into the why. We'll talk about a concept called coherence,
<v Speaker 3>which is the secret behind every laser. Okay, we'll dive
<v Speaker 3>into entanglement, the spooky connection that Einstein hated, but that
<v Speaker 3>now protects your bank account.
<v Speaker 2>And you mentioned it even gets into what breaking the
<v Speaker 2>rules of engines.
<v Speaker 3>Breaking the classical rules. Yeah, we'll look at how quantum
<v Speaker 3>mechanics is pushing the limits of energy efficiency, and then
<v Speaker 3>we'll get into some really unexpected.
<v Speaker 2>Places like biology and weather forecasting. I saw that on
<v Speaker 2>the outline and it just seemed out of left field.
<v Speaker 3>It is, But that's how deep this goes. Now. It's everywhere.
<v Speaker 2>So if you want to understand the phone in your hand,
<v Speaker 2>the Internet, even the future of medicine, you kind of
<v Speaker 2>have to understand the cat.
<v Speaker 3>You have to start with the cat.
<v Speaker 2>All right, let's do it. Rewind the clock for us,
<v Speaker 2>take us back to the nineteen twenties. What did the
<v Speaker 2>world of physics feel like then.
<v Speaker 3>In a word, chaos, complete intellectual crisis.
<v Speaker 2>Really, I always pictured these confident guys in tweed jackets.
<v Speaker 3>Well, maybe in nineteen hundred they were confident. At the
<v Speaker 3>turn of the century, there was this feeling that physics
<v Speaker 3>was basically done.
<v Speaker 2>The end of science idea exactly.
<v Speaker 3>You had Newton's laws for gravity and motion, you had
<v Speaker 3>Maxwell's equations for light and electricity. You had thermodynamics. Lord
<v Speaker 3>Kelvin famously said there was nothing new left to discover,
<v Speaker 3>just more and more precise measurements.
<v Speaker 2>Wow was he wrong.
<v Speaker 3>He was spectacularly wrong, because as soon as they started
<v Speaker 3>probing the atom, the whole thing fell apart. All those
<v Speaker 3>beautiful classical rules just broke.
<v Speaker 2>Give me an example, what's the first big crack that
<v Speaker 2>appears the electron?
<v Speaker 3>Okay, so we know an atom has a nucleus in
<v Speaker 3>the middle and electrons buzzing around it. The simple picture
<v Speaker 3>is a tiny solar.
<v Speaker 2>System, right, planets orbiting the Sun.
<v Speaker 3>But an electron is a charged particle, and classical physics
<v Speaker 3>Maxwell's equations are very clear about this. A charged particle
<v Speaker 3>moving in a circle has to radiate energy, it has
<v Speaker 3>to give off light. Okay, so if it's constantly losing energy,
<v Speaker 3>it should slow down, its orbit should decay, and in
<v Speaker 3>a fraction of a second, every electron should spiral into
<v Speaker 3>the nucleus, which would mean every atom in the universe
<v Speaker 3>should instantly collapse. Matters shouldn't exist. You meet this table,
<v Speaker 3>none of it. So clearly something was deeply wrong with
<v Speaker 3>the old rules.
<v Speaker 2>The theory predicted. We shouldn't be here to discuss the theory.
<v Speaker 3>Pretty much bit of a problem.
<v Speaker 2>So who rides to the rescue first. This is where
<v Speaker 2>Neil's Bore comes in, right.
<v Speaker 3>Yes, Neil's Bore from Denmark. He comes along and proposes this. Well,
<v Speaker 3>it was a radical idea. He basically just said the
<v Speaker 3>old rules don't apply.
<v Speaker 2>He just declared it.
<v Speaker 3>He did. He proposed his model, the one we all
<v Speaker 3>drew in high school chemistry, the little solar system with
<v Speaker 3>fixed rings.
<v Speaker 2>Yeah, the nucleus and then shells for the electrons, right, and.
<v Speaker 3>He said electrons can only exist in these specific shells,
<v Speaker 3>these allowed orbits. They can't be in between. They can
<v Speaker 3>jump from one shell to another, but they can't spiral
<v Speaker 3>in Why not? He didn't really have a deep why.
<v Speaker 3>His answer was basically, because if they did, Adams wouldn't exist,
<v Speaker 3>and they clearly do. It was a brilliant patch. It
<v Speaker 3>was a band aid that stopped the bleeding, and it
<v Speaker 3>worked remarkably well for explaining why Adams emit light in
<v Speaker 3>very specific colors.
<v Speaker 2>So it was a good description, but not a fundamental
<v Speaker 2>explanation exactly.
<v Speaker 3>It's set the stage, but the next step, the search
<v Speaker 3>for the real why is where the drama really kicks in.
<v Speaker 3>This is the big clash of the nineteen twenties.
<v Speaker 2>This is Schrodinger versus Heisenberg.
<v Speaker 3>The ultimate physics showdown. And they had completely different approaches
<v Speaker 3>to the problem. I mean fundamentally different philosophies.
<v Speaker 2>Okay, lay it out. Who's in the first corner.
<v Speaker 3>In the first corner, you have the let's say, the
<v Speaker 3>more traditional intuitive thinker, Erwin Schrodinger, the cat guy himself,
<v Speaker 3>the very same. He looked at the electron and said, look,
<v Speaker 3>maybe this whole kind of little ball idea is wrong.
<v Speaker 3>What if the electron isn't a particle at all? What
<v Speaker 3>if it's a wave, a wave of a wave of probability,
<v Speaker 3>a kind of smear of existence. He came up with
<v Speaker 3>the famous shrewding your equation, which describes the electron perfectly
<v Speaker 3>as a wave function. And a lot of physicists love this.
<v Speaker 3>Why because we can picture waves. You can imagine a
<v Speaker 3>ripple on a pond. It felt comfortable, it felt like
<v Speaker 3>something you could visualize.
<v Speaker 2>It's intuitive. Okay, it's not a hard little dot, it's
<v Speaker 2>a fuzzy cloud.
<v Speaker 3>I think that. But in the other corner you have
<v Speaker 3>the young radical Werner. Heisenberg, the abstract guy, the completely
<v Speaker 3>abstract guy. He looked at the data, which were these
<v Speaker 3>tables of numbers about how atoms absorbed in emitted light,
<v Speaker 3>and he basically said, I don't care about your pictures.
<v Speaker 3>I don't care about your intuitive waves. All that matters
<v Speaker 3>is the math that predicts the experimental results.
<v Speaker 2>So you just focused on the numbers.
<v Speaker 3>Only the numbers. He developed something called matrix mechanics, which was,
<v Speaker 3>I mean, it's just pure abstract linear algebra. Tables, numbers
<v Speaker 3>going in, tables, numbers coming out, no orbits, no waves,
<v Speaker 3>nothing to picture in your head.
<v Speaker 2>And I'm guessing these two cams did not get along.
<v Speaker 3>They hated each other's theories, I mean truly. Schrodinger called
<v Speaker 3>Heisenberg's math repulsive and monstrous. Wow. And Heisenberg thought Schrodinger's
<v Speaker 3>wave idea was I think the quote is sentimental trash.
<v Speaker 3>He thought it was a cowardly attempt to stuff the
<v Speaker 3>weird new quantum reality back into an old classical box.
<v Speaker 2>It sounds like an argument between an artist and an
<v Speaker 2>accountant over how to describe a painting.
<v Speaker 3>That's a fantastic analogy. One is talking about the feeling
<v Speaker 3>in the form the others talking about the pigment codes
<v Speaker 3>and the canvas dimensions.
<v Speaker 2>So who won?
<v Speaker 3>That's the amazing part. They both did. It was eventually
<v Speaker 3>proven that their two different mathematical formalisms were actually identical.
<v Speaker 2>There were just two different languages describing the exact same.
<v Speaker 3>Thing precisely, and the merger of those ideas that's what
<v Speaker 3>gave us modern quantum field theory, the single most successful,
<v Speaker 3>most precisely tested theory in the entire history of science.
<v Speaker 2>But in this is the key point from doctor Scully's article.
<v Speaker 2>For a long long time, this was all just about
<v Speaker 2>describing things. It was about explaining why the atom doesn't collapse.
<v Speaker 3>Yes, it was passive. We were observers. We were looking
<v Speaker 3>at the quantum world and saying, wow, isn't that weird.
<v Speaker 3>Let's write down the math for the weirdness.
<v Speaker 2>But the big shift, the centennial we're sort of celebrating here,
<v Speaker 2>is moving from observation to what application utilization.
<v Speaker 3>We stopped just looking at the electron and we started
<v Speaker 3>putting it to work. As Kelly says in his piece,
<v Speaker 3>it started as a way to explain tiny particles, but
<v Speaker 3>now it's driving innovations that were just I mean, they
<v Speaker 3>were unimaginable the generation to go.
<v Speaker 2>So we took the weirdness, the stuff that made them
<v Speaker 2>all argue, the paradoxes, all of it.
<v Speaker 3>The uncertainty, the superposition, the spookiness.
<v Speaker 2>And we realized they weren't problems, they were features.
<v Speaker 3>They were tools, the best tools nature ever gave us.
<v Speaker 2>Okay, so let's get into those tools. Doctor Scully breaks
<v Speaker 2>it down into three big concepts. Let's start with the
<v Speaker 2>first one. Coherence. I have to admit when I hear
<v Speaker 2>that word, I just think of an argument that makes sense.
<v Speaker 2>I don't think physics.
<v Speaker 3>It's a fair point. Yeah, But in physics, coherence is
<v Speaker 3>really about synchronization harmony.
<v Speaker 2>Okay.
<v Speaker 3>To get it, you have to first picture what normal
<v Speaker 3>everyday light is like. Think about a regular old incandescent
<v Speaker 3>light bulb.
<v Speaker 2>Okay, got it. It's on, it's giving off light.
<v Speaker 3>But at the atomic level, inside that filament, it's absolute chaos.
<v Speaker 3>The atoms are hot, they're jiggling around randomly. One atom
<v Speaker 3>spits out a photon, a particle of light going left.
<v Speaker 3>A nanosecond later, another one spits when out going right,
<v Speaker 3>and they're.
<v Speaker 2>All different colors, lightly exactly.
<v Speaker 3>Different phases, different directions, different frequencies. The light waves are
<v Speaker 3>all jumbled up and out of sink. It's noise.
<v Speaker 2>It's like a huge crowd of people all talking at once.
<v Speaker 3>That's the perfect analogy. It's a noisy, disorganized crowd that
<v Speaker 3>is incoherent light.
<v Speaker 2>So what's coherent light?
<v Speaker 3>Coherent light is when you somehow manage to grab every
<v Speaker 3>single one of those atoms and force them to do
<v Speaker 3>the exact same thing at the exact same time.
<v Speaker 2>Turn the crowd into a choir.
<v Speaker 3>A perfectly disciplined, perfectly synchronized choir. Every single light wave
<v Speaker 3>is marching in lockstep, same frequency, same phase, same direction.
<v Speaker 3>The peaks of the waves lineup, the troughs of the
<v Speaker 3>waves lineup.
<v Speaker 2>And when you do that, what do you get.
<v Speaker 3>You don't get a light bulb, You get a laser.
<v Speaker 2>The laser. It's funny it lasers feel so normal now
<v Speaker 2>they're in barcode scanners. My cat chase is a laser pointer.
<v Speaker 2>It feels like old tech.
<v Speaker 3>It's totally ubiquitous. Yeah, but we can't lease sight of
<v Speaker 3>how completely impossible it seemed. I mean, when the idea
<v Speaker 3>was first proposed based on an insight from Einstein, a
<v Speaker 3>lot of top physicists said it was practically impossible.
<v Speaker 2>Why what was the barrier?
<v Speaker 3>They just thought that nature's tendency towards disorder, towards chaos,
<v Speaker 3>towards that noisy crowd would always win. They didn't think
<v Speaker 3>you could ever impose that much quantum order on a
<v Speaker 3>real world system.
<v Speaker 2>But we did.
<v Speaker 3>We did in nineteen sixty. And that coherence, that order
<v Speaker 3>is what gives a laser. It's almost magical properties because
<v Speaker 3>all the waves are working together. The beam is incredibly intense,
<v Speaker 3>and it doesn't spread out like light from a flashlight.
<v Speaker 2>It stays in a tight straight line.
<v Speaker 3>A phenomenally tight line. I mean, we literally bounce lasers
<v Speaker 3>off of reflectors that the Apollo astronauts left on the
<v Speaker 3>Moon to measure the Earth Moon distance down to the millimeter.
<v Speaker 3>You can't do that with a flashlight.
<v Speaker 2>Okay, that's impressive, But what about the everyday stuff. Scully mentions, Well, the.
<v Speaker 3>Barcode scanner is the most famous, simple one, but think bigger.
<v Speaker 3>Think about medicine, a lis I searcher. Exactly, we are
<v Speaker 3>using a blade made of pure coherent light to reshape
<v Speaker 3>the human cornea, to vaporize tissue with microscopic precision that
<v Speaker 3>is only possible because of quantum coherence.
<v Speaker 2>Or what about the Internet itself? The whole thing runs
<v Speaker 2>on fiber optic.
<v Speaker 3>Billions of miles of glass fiber with pulses of coherent
<v Speaker 3>laser light flashing through them. Well, carrying this conversation right now,
<v Speaker 3>all of human knowledge flying around the globe is ordered photons.
<v Speaker 2>It's mind boggling that the solution to that nineteen twenties
<v Speaker 2>argument about waves and particles is the reason I can
<v Speaker 2>stream a movie.
<v Speaker 3>That's pillar number one one. We learned how to tame
<v Speaker 3>the quantum wave.
<v Speaker 2>Okay, pillar one, coherence gives us the laser. Let's move
<v Speaker 2>to pillar two. And this is the one that it's weird.
<v Speaker 3>Entanglement, spooky action at a distance.
<v Speaker 2>I love that Einstein said that it sounds so unscientific.
<v Speaker 2>He just called it spooky.
<v Speaker 3>It shows you how much it bothered him. I mean,
<v Speaker 3>Einstein was a firm believer in what's called locality mean
<v Speaker 3>meaning that if you want to affect something over there,
<v Speaker 3>you have to go over there and touch it, or
<v Speaker 3>you have to send something a baseball, a sound wave,
<v Speaker 3>a beam of light to interact with it, and nothing, nothing,
<v Speaker 3>can travel faster than.
<v Speaker 2>Light, the cosmic speed limit.
<v Speaker 3>The absolute speed limit. But quantum mechanics predicted something that
<v Speaker 3>seemed to violate this. It predicted that you could create
<v Speaker 3>two particles, say two photons, in a special linked state,
<v Speaker 3>an entangled state.
<v Speaker 2>What does that mean linked?
<v Speaker 3>It means they no longer have separate identities. They were
<v Speaker 3>described by a single shared wave function, a single mathematical reality,
<v Speaker 3>even if they're physically separated.
<v Speaker 2>So they're like one object in two different places.
<v Speaker 3>That's a good way to think about it. Their properties
<v Speaker 3>are correlated in a way that classical physics just forbids.
<v Speaker 3>So let's do the classic example. You create a pair
<v Speaker 3>of entangled photons. You send one to Alice in New York.
<v Speaker 2>And the other to Bob on Mars.
<v Speaker 3>Let's go with Mars. Sure, Alice and Bob. So while
<v Speaker 3>these photons are in flight, their properties are undefined. Let's
<v Speaker 3>talk about their polarization, like the orientation of the light wave.
<v Speaker 3>It's not horizontal or vertical. It's in a superposition of both,
<v Speaker 3>a cloud of possibility.
<v Speaker 2>Okay, so it's undecided, right.
<v Speaker 3>But the instant, and I mean the absolute instant that
<v Speaker 3>Alice in New York measures her photon and her detectors
<v Speaker 3>as vertical. She knows with one hundred percent certainty that
<v Speaker 3>Bob's photon on Mars, millions of miles away, has instantly
<v Speaker 3>resolved itself into the horizontal state.
<v Speaker 2>Instantly, not in the time it would take for a
<v Speaker 2>light signal to travel from here to Mars.
<v Speaker 3>Faster than that, infinitely faster, it seems. The collapse of
<v Speaker 3>the wave function appears to be instantaneous across any distance.
<v Speaker 2>I can see why Einstein called that spooky.
<v Speaker 3>He hated it. He thought it meant the theory had
<v Speaker 3>to be incomplete. He argued, there must be some hidden variables,
<v Speaker 3>like secret instructions the particles were carrying with them from
<v Speaker 3>the start.
<v Speaker 2>Like they flipped a coin before they left, and agreed, okay,
<v Speaker 2>if she asks your vertical, and I'm horizontal exactly.
<v Speaker 3>He thought it was a conspiracy, not a real connection.
<v Speaker 3>But here's the amazing thing. We've done the experiments. Yeah,
<v Speaker 3>over and over, and Einstein was wrong.
<v Speaker 2>There are no secret instructions.
<v Speaker 3>Nope, the spooky connection is real. The universe is non local.
<v Speaker 3>It's just a fact.
<v Speaker 2>Okay, So the universe is weirder than Einstein was comfortable with.
<v Speaker 2>We've established that, but how do we use this? What's
<v Speaker 2>the application?
<v Speaker 3>The number one application right now is cryptography keeping secrets safe?
<v Speaker 2>Okay, so digital security.
<v Speaker 3>Think about it. Our entire global economy, our military secrets
<v Speaker 3>are personal data. It's all part by encryption, and that
<v Speaker 3>encryption is based on math problems that are really really
<v Speaker 3>hard to solve.
<v Speaker 2>Like factoring huge numbers.
<v Speaker 3>Right, but really hard isn't the same as impossible. A
<v Speaker 3>powerful enough computer, say a future quantum computer, could potentially
<v Speaker 3>crack our current encryption methods.
<v Speaker 2>So all our secrets would be out in the open potentially.
<v Speaker 3>Yes, it's a huge concern. But entanglement offers a way out.
<v Speaker 3>It allows you to create an encryption key that isn't
<v Speaker 3>just mathematically hard to break, it's physically impossible to copy
<v Speaker 3>or even listen to without being detected.
<v Speaker 2>How does that work?
<v Speaker 3>Okay, So imagine Alice wants to send a secret key
<v Speaker 3>to Bob. Instead of sending a string of ones and zeros,
<v Speaker 3>she sends as free of entangled photons. Now, an evesdropper
<v Speaker 3>we'll call her Eve tries to intercept the message.
<v Speaker 2>She taps the fiber optic cable, right.
<v Speaker 3>But to find out the state of the photon. What
<v Speaker 3>does Eve have to do.
<v Speaker 2>She has to measure it.
<v Speaker 3>She has to measure it. And in quantum mechanics, the
<v Speaker 3>active measurement isn't passive. It changes the system. The moment
<v Speaker 3>ease detector interacts with that photon, it collapses the wave function,
<v Speaker 3>it breaks the entanglements. Sees the fingerprint a giant unmissible fingerprint.
<v Speaker 3>Alice and Bob can then sacrifice a small part of
<v Speaker 3>their key, compare notes over a public channel, and if
<v Speaker 3>they see a bunch of errors that shouldn't.
<v Speaker 2>Be there, they know Eve was listening.
<v Speaker 3>They know instantly they throw away the compromise key and
<v Speaker 3>start over. It's like a security system that's guaranteed by
<v Speaker 3>the fundamental laws of physics.
<v Speaker 2>It's like a message written in invisible ink that bursts
<v Speaker 2>into flame if anyone but the intended reader tries to
<v Speaker 2>look at it.
<v Speaker 3>That's a perfect way to put it. And this is
<v Speaker 3>in science fiction. Governments are building quantum communication networks. There's
<v Speaker 3>a Chinese satellite called Mishis that does this from space.
<v Speaker 3>We are building the foundations of a quantum internet.
<v Speaker 2>That's wild, but the source mentions another use for entanglement
<v Speaker 2>that's bigger. LEGO.
<v Speaker 3>Yes, the Laser Interferometer Gravitational Wave Observatory.
<v Speaker 2>These are the giant detectors that discovered gravitational waves, the
<v Speaker 2>ripples in SIE spacetime from colliding black holes.
<v Speaker 3>That's the one. And what they're trying to measure is
<v Speaker 3>almost impossibly small. A gravitational wave passing through Earth stretches
<v Speaker 3>and squeezes everything by a distant smaller than the width
<v Speaker 3>of a proton.
<v Speaker 2>How can you possibly measure that a truck driving by
<v Speaker 2>a mile away must shake the ground more than that it.
<v Speaker 3>Does, which is why the detectors are so isolated. But
<v Speaker 3>even with perfect isolation, there's a fundamental limit. It's called
<v Speaker 3>quantum noise or shot noise.
<v Speaker 2>What's that.
<v Speaker 3>It's the fact that a laser beam, even a perfect one,
<v Speaker 3>isn't a smooth, continuous river of light. It's made of
<v Speaker 3>individual photons. It's like rain on a roof. There's a
<v Speaker 3>natural randomness, a statistical jitter to when the photons arrive
<v Speaker 3>with the detector.
<v Speaker 2>So the laser beam itself is noisy at the quantum.
<v Speaker 3>Level exactly, and that noise can be bigger than the
<v Speaker 3>tiny signal from the gravitational wave you're trying to hear.
<v Speaker 3>It's like trying to hear a pin drop during a hailstorm.
<v Speaker 2>So how does entanglement help these A.
<v Speaker 3>Very clever trick called squeezed light. It's a way of
<v Speaker 3>manipulating the Heisenberg uncertainty principle.
<v Speaker 2>Oh boy, okay, unpack that for me. Heisenberg says, you
<v Speaker 2>can't know certain pairs of things perfectly at the same time, right,
<v Speaker 2>Like a particle's position and its momentum exactly.
<v Speaker 3>There's a trade off. The more precisely you know its position,
<v Speaker 3>the fuzzier its momentum becomes, and vice versa. Well, a
<v Speaker 3>light wave also has pairs like that. It has an
<v Speaker 3>amplitude its brightness, and a phase where it is in
<v Speaker 3>its wave cycle. Okay, Using entangled photons, scientists can squeeze
<v Speaker 3>the uncertainty. They essentially say, we don't really care about
<v Speaker 3>the phase for this measurement, but we need to know
<v Speaker 3>the amplitude with insane precision. So they manipulate the quantum
<v Speaker 3>state to dump all the uncertainty into the phase.
<v Speaker 2>You're hiding the noise in a part of the light
<v Speaker 2>you're not looking at.
<v Speaker 3>You're sweeping the quantum dust under a rug. You don't
<v Speaker 3>care about. And the result is you get a laser
<v Speaker 3>beam whose brightness is quieter, more stable than quantum mechanics
<v Speaker 3>would normally allow.
<v Speaker 2>And that lets them here are the black holes.
<v Speaker 3>It boosts lego sensitivity significantly. We are listening to the
<v Speaker 3>echoes of cosmic collisions from billions of years ago by
<v Speaker 3>using a quantum trick that Einstein thought was just stooky nonsense.
<v Speaker 2>Okay, this is amazing. So coherence gives us the laser
<v Speaker 2>entanglement gives us secure codes and a way to listen
<v Speaker 2>to the cosmos. This brings us to the third big
<v Speaker 2>concept from Scully's paper, and this one, this one feels
<v Speaker 2>like it's breaking a really fundamental rule.
<v Speaker 3>There are dynamics the quantum heat engine.
<v Speaker 2>Right now, What I remember from physics class is that
<v Speaker 2>there's a hard limit, the Carno limit, named after some
<v Speaker 2>nineteenth century French engineer Setti Krno Yes, and he basically said,
<v Speaker 2>you can't build a perfect engine. You put heat in,
<v Speaker 2>you get workout, but you always always have waste heat
<v Speaker 2>left over. There's a maximum possible efficiency and you can't
<v Speaker 2>beat it.
<v Speaker 3>It's one of the most fundamental laws. You can't get
<v Speaker 3>something for nothing. And you can't even break even. There
<v Speaker 3>is no free lunch.
<v Speaker 2>But doctor Scully's work seems to suggest there's a.
<v Speaker 3>Loophole, a quantum loophole. Let's be very clear. We are
<v Speaker 3>not breaking the law of conservation of energy. We are
<v Speaker 3>not creating energy out of thin air.
<v Speaker 2>Okay, good, I was worried for a second.
<v Speaker 3>But what Scully and others have shown is that you
<v Speaker 3>can design an engine that operates with an efficiency greater
<v Speaker 3>than the classical carnolimit.
<v Speaker 2>How is that possible?
<v Speaker 3>It all comes back to coherence. Think about a regular engine,
<v Speaker 3>like a steam engine. The working fluid is hot gas,
<v Speaker 3>and those gas molecules are like trillions of tiny billiard
<v Speaker 3>balls all bouncing around randomly and chaotically. That chaos is
<v Speaker 3>a source of inefficiency.
<v Speaker 2>Disorganize energy exactly.
<v Speaker 3>You lose a lot just to that randomness. But what
<v Speaker 3>if your working fluid wasn't a bunch of random billiard balls.
<v Speaker 3>What if it was a collection of atoms prepared in
<v Speaker 3>a special quantum coherence state.
<v Speaker 2>You're using the choir again instead of the crowd.
<v Speaker 3>The choir's back. By using coherence, you can create correlations
<v Speaker 3>between the atoms that suppress some of that randomness, you
<v Speaker 3>could essentially channel the heat energy into useful work in
<v Speaker 3>a way that avoids the pathways that would normally lead
<v Speaker 3>to waste.
<v Speaker 2>So the kernel limit wasn't a fundamental law the universe.
<v Speaker 2>It was just a limit based on using dumb classical particles.
<v Speaker 3>It was a limit based on the assumptions of classical thermodynamics.
<v Speaker 3>When you introduce quantum information and quantum coherence into the system,
<v Speaker 3>you change the rules of the game. You're extracting useful
<v Speaker 3>work from a place that classical physics had written off
<v Speaker 3>as unavoidable waste.
<v Speaker 2>That feels like a massive deal for energy production down
<v Speaker 2>the line.
<v Speaker 3>It's a whole new frontier. We're not going to see
<v Speaker 3>quantum engines in our cars tomorrow, but it fundamentally changes
<v Speaker 3>our understanding of the relationship between information, energy, and work.
<v Speaker 3>As Kelly says, it's a striking example of how quantum
<v Speaker 3>principles can rewrite the rules of classical physics.
<v Speaker 2>It really is. Okay, I want to shift gears. Now,
<v Speaker 2>we've talked lasers, computing energy. This all feels like the
<v Speaker 2>traditional domain of physics, hard tech, but the source material
<v Speaker 2>then goes somewhere I did not see coming biology. Yeah,
<v Speaker 2>it's so strange. I mean, my mental image of a
<v Speaker 2>quantum experiment is a lab cool to a thousandth of
<v Speaker 2>a degree above absolute zero, a perfect vacuum, everything shielded.
<v Speaker 2>It feels incredibly fragile.
<v Speaker 3>That's generally true. The biggest enemy of quantum weirdness is
<v Speaker 3>the environment. It's a phenomenon called decoherence. The moment the
<v Speaker 3>outside world interacts with your delicate quantum state, it collapses.
<v Speaker 2>The magic vanishes, and a living thing, a cell, is
<v Speaker 2>the exact opposite of that. It's warm, it's wet, it's messy.
<v Speaker 2>It's the noisiest environment imaginable.
<v Speaker 3>And that's why, for a long time, the dogma among
<v Speaker 3>physicists was that quantum mechanics could play no meaningful role
<v Speaker 3>in biology. It's just too hot and wet for any
<v Speaker 3>of this delicate stuff to survive.
<v Speaker 2>But it seems that's wrong.
<v Speaker 3>It seems nature is a much better quantum engineer than
<v Speaker 3>we are.
<v Speaker 2>The article mentions a specific technology here. First, it's a
<v Speaker 2>mouthful coherent Raymond spectroscopy.
<v Speaker 3>It is, okay, let's just break it down. A Rayms
<v Speaker 3>spectroscopy on its own is a technique scientist used to
<v Speaker 3>identify molecules. You shine light on a sample. When a
<v Speaker 3>photon of light heads a molecule, it makes the molecule
<v Speaker 3>vibrate the chemical bond, stretch and wiggle, and that malibration
<v Speaker 3>steals a tiny bit of energy from the photon, which
<v Speaker 3>changes its color very slightly.
<v Speaker 2>And different molecules wiggle in different ways.
<v Speaker 3>Exactly, a sugar molecule has a different vibrational fingerprint than
<v Speaker 3>a protein or a lipid. So by looking at how
<v Speaker 3>the color of the light changes, you can figure out
<v Speaker 3>what chemicals are in your sample.
<v Speaker 2>Sounds useful. What's the problem.
<v Speaker 3>The signal is pathetically weak, only about one in a
<v Speaker 3>million photons, and you shine on the sample actually gets
<v Speaker 3>changed in this way. It's like trying to find one
<v Speaker 3>specific grain of sand on a beach.
<v Speaker 2>So how does adding coherent to the name help? You?
<v Speaker 3>Guessed it? It's the choir again. Instead of just shining
<v Speaker 3>a steady light, you use very fast, powerful laser pulses
<v Speaker 3>to force all the molecules of specific type, say, all
<v Speaker 3>the glucose molecules to start vibrating in perfect unison.
<v Speaker 2>You make the molecules sing together, and when.
<v Speaker 3>They sing together the signal they produce is amp by
<v Speaker 3>orders of magnitude. It goes from being a nearly invisible
<v Speaker 3>whisper to a shout.
<v Speaker 2>And what does that let you do?
<v Speaker 3>It lets you see biology happen in real time. The
<v Speaker 3>source mentions using it to map the chemical composition of
<v Speaker 3>a virus. At the nanoscale, you can watch a drug
<v Speaker 3>molecule binding to a receptor on a living cell. It
<v Speaker 3>gives us a window into the molecular machinery of life.
<v Speaker 3>That is just unprecedented.
<v Speaker 2>We're upgrading from a blurry photograph to a live four
<v Speaker 2>K video.
<v Speaker 3>That's a great way to put it. And it's not
<v Speaker 3>just a tool we're using. There's more and more evidence
<v Speaker 3>that life itself uses.
<v Speaker 2>These tricks, like in photosynthesis.
<v Speaker 3>That's the prime suspect for a plant to turn sunlight
<v Speaker 3>into chemical energy. That energy has to travel through a dense,
<v Speaker 3>messy forest of proteins inside the leaf. Classically, it should
<v Speaker 3>bounce around randomly and lose most of its power as
<v Speaker 3>waste heat, but it doesn't.
<v Speaker 2>It's super efficient.
<v Speaker 3>It's nearly one hundred percent efficient, and the thinking is
<v Speaker 3>that it uses quantum coherence. The energy travels as a wave,
<v Speaker 3>exploring all possible paths multaneously and instantly finds the most
<v Speaker 3>efficient route. It's performing a quantum search.
<v Speaker 2>So my houseplant is running a quantum algorithm in.
<v Speaker 3>A very real sense. Yes, it's humbling. We spend billions
<v Speaker 3>on building these sterile labs to do what a simple
<v Speaker 3>leaf does in the sunshine.
<v Speaker 2>That is incredible. Okay, So from the tiniest virus to
<v Speaker 2>a hurricane. The last application in the source is weather.
<v Speaker 3>In turbulence, the oldest unsolved problem in classical physics.
<v Speaker 2>I just think of it as something that makes my
<v Speaker 2>flight bumpy. I didn't realize it was a deep mystery.
<v Speaker 3>Oh it's a hunster.
<v Speaker 2>Yeah.
<v Speaker 3>Heisenberg is supposed to have said that when he died
<v Speaker 3>and met God, he was going to ask two questions,
<v Speaker 3>why relativity and why turbulence? And he said, I really
<v Speaker 3>believe he will have an answer for the first.
<v Speaker 2>So even Heisenberg thought turbulence was basically unsolvable.
<v Speaker 3>It's just too complex, the chaotic swirling motion of air
<v Speaker 3>or water. The equations that describe it are nightmareshly difficult.
<v Speaker 3>That's why even with supercomputers, our weather forecasts fall apart
<v Speaker 3>after a week or so.
<v Speaker 2>So where does quantum mechanics come in.
<v Speaker 3>Comes in by providing a simplified model system, a playground
<v Speaker 3>to study turbulence in a cleaner way. Scientists are looking
<v Speaker 3>at something called superfluid helium. Yeah, it's a bizarre state
<v Speaker 3>of matter. If you cool helium down to just a
<v Speaker 3>couple of degrees above absolute zero, it transforms. It loses
<v Speaker 3>all viscosity. It is zero friction.
<v Speaker 2>What does that mean.
<v Speaker 3>It means if you swirl it in a cup, it
<v Speaker 3>will literally never stop swirling. It can flow up the
<v Speaker 3>walls of a container. It's a quantum fluid where all
<v Speaker 3>the atoms are acting is one single coherent entity.
<v Speaker 2>That's strange, But how does that help with turbulence.
<v Speaker 3>In a normal fluid like air, turbulence is a chaotic
<v Speaker 3>mess of eddies and vortices of all different sizes. But
<v Speaker 3>in this quantum fluid, the rotation is quantized. It can
<v Speaker 3>only spin in discrete identical units, these tiny perfect tornadoes
<v Speaker 3>called quantum vortices.
<v Speaker 2>So it's organized chaos.
<v Speaker 3>It's countable chaos. You can study how these identical little
<v Speaker 3>vortices interact and tangle up to create turbulence on a
<v Speaker 3>larger scale. It's a much simple, cleaner problem than trying
<v Speaker 3>to model the entire.
<v Speaker 2>Atmosphere, and what you learned from the helium, you.
<v Speaker 3>Find mathematical patterns and scaling laws that, it turns out,
<v Speaker 3>also applied to the big, messy classical turbulence of our
<v Speaker 3>weather systems and the air flowing over an airplane wave.
<v Speaker 2>So we're making flights safer and improving storm forecasts by
<v Speaker 2>studying the weird behavior of super cold liquid helium.
<v Speaker 3>We are. It's this incredible through line. The same fundamental
<v Speaker 3>rules of quantum mechanics that describe that helium also describe
<v Speaker 3>photosynthesis and also describe the laser in your phone.
<v Speaker 2>It's all connected.
<v Speaker 3>It's all the same physics.
<v Speaker 2>Okay, so we've covered one hundred years. We started with
<v Speaker 2>the confusion, the fights. We've seen. Coherence give us lasers,
<v Speaker 2>entanglement give us security, and black hole detectors, and thermodynamics
<v Speaker 2>give us a new class of engines. We've even dipped
<v Speaker 2>into biology and the weather.
<v Speaker 3>It's been a busy century.
<v Speaker 2>But doctor Scully's paper it doesn't end there. It's not
<v Speaker 2>just a look back. He ends on a forward looking note.
<v Speaker 2>He says the adventure is just beginning.
<v Speaker 3>Which is absolutely true. For all we figured out. The
<v Speaker 3>list of what we don't know is still huge.
<v Speaker 2>What's at the top of that list, what's the biggest
<v Speaker 2>unsolved mystery?
<v Speaker 3>Gravity without a doubt?
<v Speaker 2>Still, after all this time.
<v Speaker 3>Still we have these two perfect theories. We have quantum mechanics,
<v Speaker 3>which describes the world of the very small with flawless precision,
<v Speaker 3>and we have Einstein's general relativity, his theory of gravity,
<v Speaker 3>which describes the world of the very large planets, stars, galaxies,
<v Speaker 3>also with flawless precision. That they don't work together, They
<v Speaker 3>hate each other. They're written in different mathematical languages, and
<v Speaker 3>they give nonsensical answers infinities when you try to apply
<v Speaker 3>them in the same place, like at the center of
<v Speaker 3>a black hole.
<v Speaker 2>So we don't know if gravity itself is a quantum force.
<v Speaker 3>We don't is there a quantum particle of gravity, a graviton.
<v Speaker 3>Is space time itself smooth and continuous, or is it
<v Speaker 3>made of tiny pixel like chunks at the smallest possible scale.
<v Speaker 3>We have ideas like string theory or loop quantum gravity,
<v Speaker 3>but we don't need answer yet.
<v Speaker 2>Unifying those two theories is the holy grail.
<v Speaker 3>It's the theory of everything that physicists have been dreaming
<v Speaker 3>about for a century.
<v Speaker 2>And what about the tech The big one we've only
<v Speaker 2>touched on is quantum computing.
<v Speaker 3>Right, that's where all of these principles superposition, entanglement come
<v Speaker 3>together in the ultimate application.
<v Speaker 2>So just too clear for everyone listening. What is the
<v Speaker 2>fundamental difference between the computer on your desk and a
<v Speaker 2>quantum computer.
<v Speaker 3>Your computer works with bits. A bit is a switch.
<v Speaker 3>It can be on or off, a one or a zero.
<v Speaker 3>It's binary. A quantum computer works with quibits, and thanks
<v Speaker 3>to superposition, the same principle as the cat being alive
<v Speaker 3>and dead, a quibit can be a one and a
<v Speaker 3>zero at the same.
<v Speaker 2>Time, so it's not one or the other. It's a
<v Speaker 2>blend of both exactly.
<v Speaker 3>And if you have two quibits, you can represent four
<v Speaker 3>states at once. Three quibits eight states. It scales exponentially.
<v Speaker 3>If you can build a quantum computer with just a
<v Speaker 3>few hundred stable.
<v Speaker 2>Quibits, you get this astronomical computing power. The source says
<v Speaker 2>they could solve problems in seconds that would take our
<v Speaker 2>best current supercomputer's.
<v Speaker 3>Millennia literally thousands or even millions of years. It's not
<v Speaker 3>just a faster version of what we have. It's a
<v Speaker 3>completely different way of computing.
<v Speaker 2>What kind of problem needs that kind of power.
<v Speaker 3>The biggest one is simulating reality itself. If you want
<v Speaker 3>to invent a new drug, you need to simulate how
<v Speaker 3>a complex molecule will fold and interact with proteins in
<v Speaker 3>the body. That's a quantum problem.
<v Speaker 2>And classical computers are bad at simulating quantum mechanics.
<v Speaker 3>They're terrible at it. It takes an insane amount of memory.
<v Speaker 3>It's like trying to build a perfect flight simulator using
<v Speaker 3>only lego. A quantum computer simulates quantum nature natively. It
<v Speaker 3>speaks the right language.
<v Speaker 2>So we could discover new medicines, design new materials for
<v Speaker 2>perfect solar cells or batteries, maybe even create truly accurate
<v Speaker 2>climate models.
<v Speaker 3>That's the promise a revolution in science and engineering.
<v Speaker 2>It really feels like we're just at the beginning, Like
<v Speaker 2>we've spent one hundred years learning the alphabet of the
<v Speaker 2>universe and now we're about to start writing sentences.
<v Speaker 3>I think that's a perfect metaphor. We know enough now
<v Speaker 3>to understand how much we still have to learn, which
<v Speaker 3>is a much better place to be than in nineteen
<v Speaker 3>hundred when they thought they knew everything.
<v Speaker 2>It's way more exciting. Okay, let's bring it all home.
<v Speaker 2>We have thrown a ton of concepts at people today,
<v Speaker 2>so let's do a quick sheet sheet. If you're at
<v Speaker 2>a party and want to sound smart, what are the
<v Speaker 2>five key ways quantum mechanics is already running your life?
<v Speaker 3>Right, Let's do it. Number one, lasers comes from quant coherence.
<v Speaker 3>It's in your phone, your Blu ray player, your Internet connection,
<v Speaker 3>the doctor's.
<v Speaker 2>Office, got it. Number two secure communication, that's entanglement, the
<v Speaker 2>future of unhackable data for banking, government, everything.
<v Speaker 3>Number three faster computing, well future computing using superposition to
<v Speaker 3>solve currently impossible problems in medicine, materials and beyond right.
<v Speaker 2>Number four better measurements using squeeze light and other quantum
<v Speaker 2>tricks to sense the world with incredible precision, from gravitational
<v Speaker 2>waves to maybe even tiny magnetic fields in the brain.
<v Speaker 3>And Number five medical breakthroughs using those spectroscopy techniques to
<v Speaker 3>see what's happening inside a single living cell to understand
<v Speaker 3>and fight disease at the most fundamental level.
<v Speaker 2>That is a hell of a resume for a theory
<v Speaker 2>that started with people getting angry about a.
<v Speaker 3>Cat in a box it is, And I think the
<v Speaker 3>real takeaway is that this stuff isn't magic. It feels
<v Speaker 3>like it, but it's just the real rules of the universe.
<v Speaker 3>We're just finally learning how to read the user manual.
<v Speaker 2>And like doctor Scully said, the adventure is just beginning.
<v Speaker 3>It makes you think, if the last century took us
<v Speaker 3>from that thought experiment to the smartphone and mapping black holes, what.
<v Speaker 2>On earth is the next one hundred years going to
<v Speaker 2>look like.
<v Speaker 3>Are we going to finally unify gravity? Are we going
<v Speaker 3>to understand dark matter?
<v Speaker 2>Are we going to be able to manipulate reality in
<v Speaker 2>ways that we can't even imagine?
<v Speaker 3>Right now, I've learned not to bet against the weirdness
<v Speaker 3>me neither.
<v Speaker 2>The universe is pretty good at blowing our minds.
<v Speaker 3>It certainly is.
<v Speaker 2>Well, that's all the time we have for this one.
<v Speaker 2>Thanks for diving into the quantum realm with us.
<v Speaker 3>It is a pleasure.
<v Speaker 2>Keep asking questions and we'll catch you on the next
<v Speaker 2>deep dive.