Latest / The Quark Side - Quantum Physics Podcast / Entanglement in Nature: The Hidden Physics of Biology

Transcript

Entanglement in Nature: The Hidden Physics of Biology · 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 with the smallest scales.
• 0:27
  Speaker 2: Imagine for a second, trying to perform a delicate, perfectly
• 0:31
  Speaker 2: choreographed ballet. But you aren't on some quiet, pristine stage.
• 0:38
  Speaker 2: You are trying to execute this masterpiece in the middle
• 0:41
  Speaker 2: of a screaming, chaotic subway station during the absolute peak
• 0:45
  Speaker 2: of rush hour.
• 0:46
  Speaker 3: Which is basically an impossible scenario.
• 0:49
  Speaker 2: Right, I mean, you have commuters just slamming into your shoulders,
• 0:53
  Speaker 2: the deafening screech of steel wheels on the tracks, harsh
• 0:56
  Speaker 2: gusts of wind, and this constant, vibrating rumble beneath your feet.
• 1:00
  Speaker 2: By all the known laws of physics, your delicate dance
• 1:03
  Speaker 2: should fall apart in a matter of seconds.
• 1:05
  Speaker 3: Yeah, the sure noise in the thermal heat of an
• 1:07
  Speaker 3: environment like that would just crush any fragile synchronization exactly.
• 1:12
  Speaker 2: But what if the dancers weren't just ignoring that chaos.
• 1:15
  Speaker 2: What if they were actually using the screech of the
• 1:17
  Speaker 2: trains and the chaotic stomping of the crowd to keep
• 1:19
  Speaker 2: the beat. What if the noise of the subway station
• 1:22
  Speaker 2: was the very thing allowing the dance to happen at all.
• 1:25
  Speaker 3: That is the ultimate paradox, and it's the paradox of
• 1:27
  Speaker 3: your own body, really, and of every single living thing
• 1:30
  Speaker 3: on this planet.
• 1:30
  Speaker 2: It's so crazy to think about, because for over a
• 1:34
  Speaker 2: century the scientific community has operated on this very strict
• 1:38
  Speaker 2: segregation of rules. Right on one side, we have biology.
• 1:42
  Speaker 2: Life is squishy. It's a messy, warm, wet soup of
• 1:45
  Speaker 2: cells and fluids constantly bumping into each other, just total
• 1:49
  Speaker 2: thermal chaos, total chaos.
• 1:51
  Speaker 3: And then on the completely opposite end of the spectrum,
• 1:54
  Speaker 3: you have quantum.
• 1:54
  Speaker 2: Mechanics, physics of the incredibly small.
• 1:57
  Speaker 3: Right, the underlying rules governing atoms, electron photons, and to
• 2:01
  Speaker 3: even observe quantum behavior in a lab, physicists usually have
• 2:05
  Speaker 3: to build these massive, multimillion dollar refrigeration units just to.
• 2:09
  Speaker 2: Drop temperatures down to near absolute zero.
• 2:11
  Speaker 3: Yeah, and they have to isolate their particles in perfect
• 2:14
  Speaker 3: vacuums just to keep the outside world from interfering. So
• 2:16
  Speaker 3: you have the boiling biological soup on one hand, and
• 2:19
  Speaker 3: the freezing perfectly still quantum vacuum on the other. Classically,
• 2:23
  Speaker 3: these two realms should never ever cross paths.
• 2:26
  Speaker 2: But today we are exploring a concept that just completely
• 2:30
  Speaker 2: obliterates that boundary. We're asking if life actively exploits the bizarre,
• 2:35
  Speaker 2: counterintuitive rules of quantum mechanics, like does biological life fundamentally
• 2:40
  Speaker 2: rely on phenomena that Albert Einstein himself found deeply unsettling.
• 2:44
  Speaker 3: Which he definitely did. And the sheer volume of evidence
• 2:47
  Speaker 3: pouring in right up to this year twenty twenty six
• 2:50
  Speaker 3: has birthed an entirely new field. We call it quantum biology.
• 2:54
  Speaker 2: Which sounds like sci fi, but it's real.
• 2:56
  Speaker 3: Oh, it's very real. We are finding that the weirdness
• 2:59
  Speaker 3: of the subatomic world doesn't just disappear when you zoom
• 3:02
  Speaker 3: out to the scale of proteins and cells. It actually
• 3:04
  Speaker 3: appears to be the secret architecture beneath all of it.
• 3:08
  Speaker 3: We're uncovering quantum mechanisms for everything from how a leaf
• 3:11
  Speaker 3: captures sunlight to how a bird navigates across oceans to
• 3:14
  Speaker 3: the chemical reactions happening inside your own cells right now.
• 3:17
  Speaker 2: So our mission today is to pull back the curtain
• 3:19
  Speaker 2: on this hidden architecture. We're going to dive into how
• 3:22
  Speaker 2: life cheats the classical rules of physics, but before we
• 3:25
  Speaker 2: can appreciate how biological systems are pulling off these quantum tricks,
• 3:29
  Speaker 2: we need to understand the tools that they're disposal.
• 3:31
  Speaker 3: Right, Yeah, we have to define the toolkit because the
• 3:34
  Speaker 3: quantum realm is so different from the macroscopic world you
• 3:37
  Speaker 3: and I experience every day.
• 3:39
  Speaker 2: Where things follow predictable Newtonian physics.
• 3:41
  Speaker 3: Exactly, if I throw a tennis ball, it's in one
• 3:44
  Speaker 3: specific place moving at one speed, but when you shrink
• 3:48
  Speaker 3: down to an electron, those rules dissolve into probabilities. Take
• 3:52
  Speaker 3: the concept of superposition for example, Okay, lay on me. Classically,
• 3:57
  Speaker 3: a switch is either on or off. Right, a particle
• 3:59
  Speaker 3: goes through the left door or the right door. But
• 4:02
  Speaker 3: in superposition, a particle exists as a wave of probability,
• 4:06
  Speaker 3: meaning it actually occupies multiple states or explores multiple paths simultaneously.
• 4:11
  Speaker 2: Wait, so it's not just that we don't know where
• 4:13
  Speaker 2: it is.
• 4:13
  Speaker 3: No, it's not a lack of instrumentation. It is fundamentally
• 4:17
  Speaker 3: physically existing in a smeared out state of all its
• 4:19
  Speaker 3: possible options at once, right up until the exact moment
• 4:23
  Speaker 3: it interacts with its environment and is forced to quote
• 4:26
  Speaker 3: unquote collapse into a single reality.
• 4:29
  Speaker 2: Okay, so if I'm translating that to the physical world,
• 4:31
  Speaker 2: it's not a spinning coin that just looks like a blur.
• 4:34
  Speaker 2: The quantum coin is literally heads and tails at the
• 4:37
  Speaker 2: identical same moment until it hits the floor.
• 4:40
  Speaker 3: That is a brilliant way to conceptualize it. Actually, yes,
• 4:44
  Speaker 3: and then we have entanglement, which is arguably even stranger.
• 4:48
  Speaker 2: This is the one Einstein hated, right.
• 4:49
  Speaker 3: He absolutely mocked it. He called it spooky action at
• 4:53
  Speaker 3: a distance. When two particles interact in specific ways, their
• 4:57
  Speaker 3: quantum states become inextricably linked. They form a single, unified
• 5:01
  Speaker 3: system no matter the distance between them.
• 5:03
  Speaker 2: So even if they're miles apart.
• 5:05
  Speaker 3: Miles light years, it doesn't matter. If you have two
• 5:08
  Speaker 3: entangled electrons, the moment you measure the spin of the
• 5:11
  Speaker 3: first one, you instantaneously know the spin of the second one.
• 5:15
  Speaker 3: The state of one instantly defines the state of the other,
• 5:18
  Speaker 3: which seems to violate the speed of light.
• 5:20
  Speaker 2: So there are essentially twin particles that share a single
• 5:23
  Speaker 2: nervous system. You pinch one, the other flinches with zero
• 5:26
  Speaker 2: timed away exactly.
• 5:28
  Speaker 3: And the third tool we need to cover is quantum tunneling.
• 5:31
  Speaker 3: This defies all classical logic regarding physical barriers.
• 5:34
  Speaker 2: Right, the old mountain analogy.
• 5:36
  Speaker 3: Yeah. Classically, if a particle faces a solid energy barrier
• 5:39
  Speaker 3: a mountain and doesn't have the kinetic energy to climb
• 5:42
  Speaker 3: over it, it bounces off it's impossible to cross. But
• 5:46
  Speaker 3: in the quantum realm, because particles act as waves, a
• 5:50
  Speaker 3: small portion of that probability wave can seep through the
• 5:53
  Speaker 3: solid barrier, So.
• 5:54
  Speaker 2: There's a chance it just ignores the wall.
• 5:56
  Speaker 3: Right, a non zero chance that the particle simply disappears
• 5:59
  Speaker 3: from one side of wall and instantaneously materializes on the
• 6:03
  Speaker 3: other side without ever traveling through the space in between.
• 6:06
  Speaker 3: It tunnels.
• 6:07
  Speaker 2: So to avoid the mountain analogy, it's more like being
• 6:09
  Speaker 2: locked inside a solid concrete room. Classically, the only way
• 6:14
  Speaker 2: out is to find enough explosive energy to blow the
• 6:16
  Speaker 2: roof off. But quantum tunneling means if you just run
• 6:20
  Speaker 2: at the concrete wall enough times, eventually the universe glitches
• 6:23
  Speaker 2: and you just pop out onto the front lawn without
• 6:25
  Speaker 2: breaking the wall.
• 6:26
  Speaker 3: That is a fantastic visualization. You bypass the energy requirement entirely. Now,
• 6:31
  Speaker 3: all of these bizarre phenomena, superposition, entanglement, tunneling, they all
• 6:36
  Speaker 3: rely on a unifying concept called coherence.
• 6:39
  Speaker 2: Which is the synchronization right.
• 6:41
  Speaker 3: Yes, coherence is the maintenance of these delicate phase relationships.
• 6:45
  Speaker 3: It's the rhythm that allows particles to act like waves.
• 6:48
  Speaker 3: As long as the system maintains coherence, it can perform
• 6:51
  Speaker 3: these impossible feats.
• 6:53
  Speaker 2: Which brings us crashing back to our rush hour subway station,
• 6:56
  Speaker 2: because maintaining that fragile coherence seems fundamentally possible in biology
• 7:01
  Speaker 2: due to decoherence.
• 7:02
  Speaker 3: Decoherence is the ultimate enemy. In a highly controlled physics lab,
• 7:07
  Speaker 3: researchers go to extreme lengths because even the tiniest interaction
• 7:10
  Speaker 3: with the outside world destroys coherence. A single stray photon
• 7:14
  Speaker 3: bouncing off an atom, a microscopic magnetic fluctuation, or just
• 7:19
  Speaker 3: thermal vibration heat.
• 7:20
  Speaker 2: And heat is everywhere in biology.
• 7:22
  Speaker 3: Exactly that tiny bit of sheet is enough to force
• 7:25
  Speaker 3: the probability wave to collapse back into a boring classical particle.
• 7:29
  Speaker 3: The environment essentially measures this system and forces it to
• 7:32
  Speaker 3: pick a lane.
• 7:33
  Speaker 2: And the biological environment of a cell isn't just a
• 7:35
  Speaker 2: stray photon. I mean, a cell is an absolute war
• 7:38
  Speaker 2: zone of molecular collisions, twisting proteins, napping chemical bonds. It's hot, wet,
• 7:43
  Speaker 2: and chaotic.
• 7:44
  Speaker 3: It's the subway station.
• 7:45
  Speaker 2: Yeah. So the million dollar question is how on Earth
• 7:48
  Speaker 2: is a living organism pulling off a synchronized quantum ballet
• 7:51
  Speaker 2: in the middle of that microscopic subway station. Did biological
• 7:55
  Speaker 2: systems somehow evolve to build little microscopic blast shields to
• 8:00
  Speaker 2: block out the noise?
• 8:01
  Speaker 3: Well, for decades it was the assumption. The few physicists
• 8:05
  Speaker 3: willing to entertain quantum biology assumed there must be a
• 8:08
  Speaker 3: blast shield. They thought evolution designed highly shielded hydrophobic pockets
• 8:13
  Speaker 3: deep inside proteins to isolate the quantum particles from the
• 8:17
  Speaker 3: thermal chaos.
• 8:18
  Speaker 2: Like trying to build a tiny sound proof vacuum chamber
• 8:21
  Speaker 2: inside the subway station.
• 8:22
  Speaker 3: Right, But the modern evidence points to something far more radical.
• 8:26
  Speaker 3: Life isn't isolating itself from the noise. Life is utilizing
• 8:29
  Speaker 3: the noise. Wow, the chaos of the biological environment might
• 8:33
  Speaker 3: actually be the active ingredient keeping the quantum dance alive.
• 8:36
  Speaker 2: That concept completely upends how we view the relationship between
• 8:39
  Speaker 2: life and physics, And to see how life actually uses
• 8:42
  Speaker 2: this subway station, we need to look at photosynthesis, right,
• 8:45
  Speaker 2: the process that literally powers the planet.
• 8:48
  Speaker 3: Photosynthesis is the ultimate proving ground for this. Every green leaf,
• 8:52
  Speaker 3: every blade of grass, algae in the oceans, they are
• 8:55
  Speaker 3: quietly performing a masterclass and energy transfer that makes our
• 8:59
  Speaker 3: most danced human technologies look.
• 9:01
  Speaker 2: Archaic, because our solar panels are actually pretty terrible.
• 9:04
  Speaker 3: Right, notoriously inefficient. They convert sunlight to electricity, but they
• 9:08
  Speaker 3: lose a massive percentage of that energy to heat and reflection.
• 9:12
  Speaker 3: Biological photosynthesis, however, operates at an efficiency of roughly ninety
• 9:15
  Speaker 3: to ninety five.
• 9:16
  Speaker 2: Percent, which is just staggering. When a photon hits a leaf,
• 9:20
  Speaker 2: the plant captures nearly all of that energy with almost
• 9:23
  Speaker 2: zero waste. Every photon counts. How does classical physics even
• 9:27
  Speaker 2: attempt to explain that?
• 9:29
  Speaker 3: Well, Classically it fails. When sunlight hits a leaf, it's
• 9:32
  Speaker 3: absorbed by a network of pigment molecules, primarily chlorophyll embedded
• 9:36
  Speaker 3: in antenna complexes. When chlorophyll absorbs a photon, it excites
• 9:40
  Speaker 3: an electron, creating a bound electron whole pair that we
• 9:44
  Speaker 3: call an excitant.
• 9:45
  Speaker 2: Okay, So the excitement is basically a discrete packet of
• 9:48
  Speaker 2: solar energy.
• 9:49
  Speaker 3: Yes, and this energy packet has one urgent mission. It
• 9:52
  Speaker 3: must travel through the incredibly crowded, chaotic forest of the
• 9:56
  Speaker 3: antenna complex to reach the reaction.
• 9:58
  Speaker 2: Center, which is where the actual magic it.
• 10:00
  Speaker 3: Happens, exactly where the solar energy is converted into stable
• 10:04
  Speaker 3: chemical energy to power the plant. Under the old classical rules,
• 10:07
  Speaker 3: this energy transfer is described by a process called first
• 10:10
  Speaker 3: or resonance energy transfer. Basically, the excitean hops from one
• 10:13
  Speaker 3: chlorophyll molecule to the next entirely at.
• 10:16
  Speaker 2: Random, a random walk.
• 10:18
  Speaker 3: Right, it takes a step to the left, maybe backwards,
• 10:20
  Speaker 3: bounces into a dead end, turns around.
• 10:23
  Speaker 2: So if the antenna complexes amaze and the reaction center
• 10:27
  Speaker 2: is the exit, the classical model says, the energy packet
• 10:30
  Speaker 2: is like a blind folded person stumbling through the corridors,
• 10:33
  Speaker 2: bumping into walls, taking wrong turns, and just hoping they
• 10:36
  Speaker 2: stumble at the exit before they collapse from exhaustion.
• 10:38
  Speaker 3: That is precisely what a random walk is. And the
• 10:41
  Speaker 3: exhaustion in your metaphor is energy lost is heat. If
• 10:44
  Speaker 3: it takes too long, the solar energy is wasted. It's
• 10:47
  Speaker 3: statistically and physically incredibly inefficient.
• 10:50
  Speaker 2: Which means they would lose a ton of energy, but
• 10:53
  Speaker 2: they don't.
• 10:53
  Speaker 3: They don't. The excitement almost always finds its way in
• 10:57
  Speaker 3: roughly a trillionth of a second. It's way too fast
• 11:00
  Speaker 3: for a random walk.
• 11:01
  Speaker 2: Which means the blindfolded guy isn't bouncing around. And this
• 11:04
  Speaker 2: is where the history of the field really takes a turn. Right.
• 11:07
  Speaker 2: Like back in two thousand and seven with Greg Angle.
• 11:09
  Speaker 3: Yes, Engele's work was a watershed moment. He was working
• 11:12
  Speaker 3: with the Fena Matthew's ulsin complex, the FMO complex found
• 11:16
  Speaker 3: in green sulfur bacteria. It's essentially a biological wire connecting
• 11:20
  Speaker 3: the outer antenna to the reaction center.
• 11:22
  Speaker 2: And he didn't just look at it under a microscope.
• 11:25
  Speaker 2: He hit it with lasers.
• 11:26
  Speaker 3: He hit it with incredibly short, highly synchronized pulses of
• 11:30
  Speaker 3: laser light pulses lasting only femtoseconds, which are millions of
• 11:34
  Speaker 3: a billionth of a second. He used two dimensional electronic
• 11:38
  Speaker 3: spectroscopy to try and freeze frame the exact path the energy.
• 11:42
  Speaker 2: Took and what did the data show.
• 11:43
  Speaker 3: It didn't show a linear path of hopping energy. The
• 11:46
  Speaker 3: data showed long lived oscillatory signals. There was a rhythmic
• 11:50
  Speaker 3: wave like beating in the energy transfer, and the only
• 11:53
  Speaker 3: mathematical way to interpret those rhythmic beats was quantum coherence.
• 11:57
  Speaker 2: So going back to the maze, instead of sending a
• 12:00
  Speaker 2: thinkle blindfolded person stumbling through, it's as if you flooded
• 12:03
  Speaker 2: the entire maze with a tidal wave of water. The
• 12:06
  Speaker 2: wave doesn't choose a path. It washes through every single corridor,
• 12:09
  Speaker 2: every dead end simultaneously. Yes, the excitement is in a
• 12:13
  Speaker 2: state of quantum superposition. It feels out all possible routes
• 12:18
  Speaker 2: at the exact same moment, and because it acts as
• 12:20
  Speaker 2: a wave, it instantaneously collapses onto the single fastest path.
• 12:24
  Speaker 3: That analogy perfectly captures the beauty of it. The exciteant
• 12:27
  Speaker 3: explores the maze simultaneously, and what made Engel's discovery earth
• 12:32
  Speaker 3: shattering wasn't just that the wave existed, but how long
• 12:35
  Speaker 3: it lasted. These coherences were surviving for hundreds of femtoseconds
• 12:39
  Speaker 3: at physiological temperatures.
• 12:40
  Speaker 2: Which mathematically should have caused instant decoherence. Right now, because
• 12:44
  Speaker 2: hundreds of femtoseconds in the quantum realm was a long time.
• 12:46
  Speaker 3: A literal eternity in a warm, wet environment, and the
• 12:49
  Speaker 3: research is only accelerated. In twenty twenty five, an incredible
• 12:53
  Speaker 3: study in the journal Chemical Science by researchers at the
• 12:55
  Speaker 3: Technical University in Munich looked at the massive photosystem to
• 12:59
  Speaker 3: super complex and higher plants, so scaling.
• 13:02
  Speaker 2: Up from bacteria to actual plants.
• 13:04
  Speaker 3: Right, and they discovered that nature acts as a meticulous
• 13:07
  Speaker 3: quantum engineer. They found that the specific naturally occurring ratio
• 13:11
  Speaker 3: of different pigments chlorophyll A and chlorosyl B, is structurally
• 13:15
  Speaker 3: arranged to optimize the energy gap, specifically to maximize this
• 13:19
  Speaker 3: wave like quantum transport.
• 13:21
  Speaker 2: So the physical architecture of a leaf evolved to perfectly
• 13:24
  Speaker 2: tune quantum dynamics. But I have to insert a massive
• 13:27
  Speaker 2: grain of salt here, because with a claim this monumental
• 13:31
  Speaker 2: that a leaf is basically a quantum computer, the scientific
• 13:35
  Speaker 2: pushback had to be fierce.
• 13:37
  Speaker 3: This skepticism is absolutely vital, and there was a major
• 13:39
  Speaker 3: paradigm clash that came to a head recently. In twenty
• 13:42
  Speaker 3: twenty a comprehensive review in Science Advances, co authored by
• 13:45
  Speaker 3: eighteen leading researchers offered a sobering critique of Angle's method.
• 13:49
  Speaker 2: They pointed out a flaw in using.
• 13:50
  Speaker 3: Lasers exactly to measure these incredibly fast processes. You need
• 13:55
  Speaker 3: a fast shutter speed, so you use ultra short intense
• 13:58
  Speaker 3: laser pulses. But a laser emits coherent light. Every photon
• 14:02
  Speaker 3: is perfectly in phase. The critics argue that by blasting
• 14:06
  Speaker 3: the delicate biological system with highly coherent laser light, the
• 14:10
  Speaker 3: scientists were artificially forcing the molecules to vibrate and sink,
• 14:13
  Speaker 3: so they.
• 14:14
  Speaker 2: Were inducing a quantum wave that would normally be there.
• 14:17
  Speaker 3: That was the argument out in the real world, a
• 14:20
  Speaker 3: plant is bathed in natural sunlight. Sunlight is thermal, chaotic
• 14:24
  Speaker 3: and completely incoherent. The critics forcefully argue that under natural sunlight,
• 14:28
  Speaker 3: these long lived coherences would instantly Decohere.
• 14:31
  Speaker 2: The quantum leaf was just a laboratory artifact, basically saying,
• 14:35
  Speaker 2: you just discovered what happens when you hit a plant
• 14:37
  Speaker 2: with a highly engineered laser. That feels like it could
• 14:39
  Speaker 2: have killed the whole field right there.
• 14:41
  Speaker 3: It was a massive blow, but you recover from that
• 14:43
  Speaker 3: by looking closer at the noise itself, and the response
• 14:46
  Speaker 3: led to what I consider the most profound discovery in
• 14:49
  Speaker 3: the field, environment assisted quantum transport or vibronic coupling.
• 14:53
  Speaker 2: Okay, what is vibronic coupling?
• 14:54
  Speaker 3: Researchers realized they were thinking about the environment wrong. They
• 14:58
  Speaker 3: assumed the thermal vibration of the proteins surrounding the chlorophyll
• 15:02
  Speaker 3: were random, destructive noise. But proteins aren't static. They breathe,
• 15:08
  Speaker 3: they flex, and they vibrate at very specific frequencies.
• 15:11
  Speaker 2: So the environment isn't just a passive noisy container exactly.
• 15:15
  Speaker 3: When they mathematically modeled the exact vibrational frequencies of the
• 15:18
  Speaker 3: protein backbone holding the chlorophyll, they found something astonishing. The
• 15:24
  Speaker 3: frequencies of the environmental noise perfectly match the energy gaps
• 15:27
  Speaker 3: between the quantum states of the excitement. The noise wasn't
• 15:31
  Speaker 3: destroying the quantum state. The noise was driving it because
• 15:35
  Speaker 3: the environment jiggles at the exact right resonant frequency. Every
• 15:38
  Speaker 3: time the quantum wave starts to decohere, the thermal vibration
• 15:42
  Speaker 3: actually kicks it back into a coherent state.
• 15:44
  Speaker 2: Oh that is wild. So bringing back the subway ballet,
• 15:48
  Speaker 2: the dancers aren't wearing earplugs. The mechanical screech of the
• 15:51
  Speaker 2: subway wheels is actually perfectly tuned to the tempo of
• 15:54
  Speaker 2: the music. The environment is acting as a metronome, feeding
• 15:57
  Speaker 2: energy back in to keep the way from collapsing.
• 16:00
  Speaker 3: Is the machinery life evolved to surf right on the
• 16:03
  Speaker 3: edge of the classical and quantum boundary. Vibronic coupling shows
• 16:08
  Speaker 3: us that these quantum designs are robust precisely because they
• 16:12
  Speaker 3: are embedded in biological noise. The wet, warm chaos is
• 16:16
  Speaker 3: what makes the transport possible.
• 16:18
  Speaker 2: That completely reframes everything. Biology isn't fighting physics, it's orchestrating it. Now,
• 16:23
  Speaker 2: we've seen how life protects a quantum wave inside a
• 16:26
  Speaker 2: stationary leaf to harvest energy. But what happens when an
• 16:30
  Speaker 2: organism needs to interact with an ambient force on a
• 16:33
  Speaker 2: planetary scale.
• 16:34
  Speaker 3: Ah, Yes, we move from the engine of life to
• 16:37
  Speaker 3: the compass avian magnetar reception.
• 16:39
  Speaker 2: Right. Bird migration like the Arctic tern, which flies from
• 16:42
  Speaker 2: the Arctic to the Antarctic and back every single year,
• 16:45
  Speaker 2: thousands of miles over featureless ocean, through storms, and they
• 16:48
  Speaker 2: hit the exact same nesting ground.
• 16:49
  Speaker 3: And we've known for decades. They achieve this in part
• 16:52
  Speaker 3: by sensing the Earth's magnetic field.
• 16:54
  Speaker 2: But the Earth's magnetic field is incredibly, almost vanishingly weak,
• 17:00
  Speaker 2: roughly fifty microteslas. If you take a cheap refrigerator magnet,
• 17:04
  Speaker 2: that magnet is roughly one hundred times stronger than the
• 17:07
  Speaker 2: planetary field. Guiding a bird across a pacific I don't
• 17:10
  Speaker 2: feel a fridge magnet in my hand.
• 17:11
  Speaker 3: You don't feel a thing.
• 17:12
  Speaker 2: How could a biological organism register force that feint?
• 17:15
  Speaker 3: Classically, it shouldn't be possible. The thermal noise, the baseline
• 17:19
  Speaker 3: heat of the bird's own body is millions of times
• 17:22
  Speaker 3: stronger than the energy from the Earth's magnetic field. Any
• 17:26
  Speaker 3: biological commiss needle should just get violently thrown around by
• 17:30
  Speaker 3: the heat.
• 17:30
  Speaker 2: Totally drowning out the whisper of the magnetic field exactly.
• 17:33
  Speaker 3: Yet behavioral experiments prove they feel it, and the leading
• 17:37
  Speaker 3: hypothesis is located right inside the retina of the bird's
• 17:40
  Speaker 3: eye in a protein called cryptochrome, and the mechanism is
• 17:44
  Speaker 3: deeply quantum. It's known as the radical pair mechanism.
• 17:47
  Speaker 2: Okay, let's trace this. A bird is flying over the
• 17:50
  Speaker 2: ocean sunlight hits the surface of its eye and passes
• 17:53
  Speaker 2: to the retina. What happens the moment light hits the
• 17:56
  Speaker 2: cryptochrome protein.
• 17:57
  Speaker 3: Inside cryptochrome, there is a light absorbing molecule called FAD
• 18:01
  Speaker 3: flavin adenine di nucleotide. When a photon of blue light
• 18:05
  Speaker 3: hits that FAD molecule, it injects a bust of energy.
• 18:10
  Speaker 3: This violently pulls an electron away from a neighboring chain
• 18:13
  Speaker 3: of amino acids, a triad of tryptofans.
• 18:16
  Speaker 2: So an electron physically jumps across a gap inside the
• 18:19
  Speaker 2: protein yes.
• 18:20
  Speaker 3: And this jump leaves behind two distinct molecules that each
• 18:24
  Speaker 3: have an unpaired lonely electron. In chemistry, a molecule with
• 18:27
  Speaker 3: an unpaired electron is a radical. Because we have two,
• 18:30
  Speaker 3: we call it a radical pair.
• 18:32
  Speaker 2: Okay, got it.
• 18:32
  Speaker 3: But here's the quantum weirdness. Because these two solitary electrons
• 18:36
  Speaker 3: were created at the exact same fraction of a millisecond
• 18:39
  Speaker 3: from the same energetic event, they are quantum mechanically entangled.
• 18:42
  Speaker 3: They share a unified state involving their quantum spin.
• 18:45
  Speaker 2: Now, quantum spin is notoriously tricky to visualize It's not
• 18:48
  Speaker 2: like a toy top spinning on a table.
• 18:50
  Speaker 3: No, it's an intrinsic property, essentially a microscopic magnetic moment.
• 18:55
  Speaker 3: Think of each electron as having its own tiny magnetic
• 18:58
  Speaker 3: compass needle. Because they're entangled, they start off in what
• 19:02
  Speaker 3: physicists call a singlet state. Their magnetic spins are completely
• 19:06
  Speaker 3: anti parallel, one pointing up, one pointing exactly down. They
• 19:10
  Speaker 3: cancel each other out right, but they don't stay that
• 19:13
  Speaker 3: way due to incredibly complex internal interactions, specifically hyperfine interactions.
• 19:19
  Speaker 3: They begin to flip.
• 19:21
  Speaker 2: Let's ground that what is a hyperfine interaction actually doing.
• 19:24
  Speaker 3: It's essentially a microscopic magnetic tug of war. The electron
• 19:29
  Speaker 3: has a tiny magnetic field, but the nucleus of its
• 19:31
  Speaker 3: atom also has a tiny magnetic field. The nucleus constantly
• 19:34
  Speaker 3: tugs on the electrons field, causing the electrons spin to
• 19:37
  Speaker 3: wobble and flip.
• 19:38
  Speaker 2: So the atoms are basically yanking on their own electron.
• 19:41
  Speaker 3: Yes, and because of this tug of war, the entangled
• 19:43
  Speaker 3: electrons transition out of their singlet state and flip into
• 19:46
  Speaker 3: a triplet state where their spins are parallel, both pointing
• 19:49
  Speaker 3: the same way. So inside the bird's eye millions of
• 19:52
  Speaker 3: times a second. These entangled pairs are frantically dancing back
• 19:55
  Speaker 3: and forth between the singlet and triplet states.
• 19:57
  Speaker 2: Okay, but if this entire dam is just internal, driven
• 20:01
  Speaker 2: by the atoms tugging on the electrons, how does the
• 20:04
  Speaker 2: Earth's magnetic field intervene?
• 20:06
  Speaker 3: Through the Zeeman effect, The delicate oscillation between singlet and
• 20:11
  Speaker 3: triplet states is astonishingly sensitive to external magnetic fields. So
• 20:16
  Speaker 3: as the weak fifty microtesla field of the Earth sweeps
• 20:19
  Speaker 3: through the bird's eye, the Zemin effect states that this
• 20:22
  Speaker 3: external field interacts with the electron spins, slightly tilting the scales.
• 20:27
  Speaker 2: Tilting the scales.
• 20:28
  Speaker 3: How depending on the exact angle of the Earth's magnetic
• 20:31
  Speaker 3: field lines passing through the protein, the oscillation shifts. The
• 20:34
  Speaker 3: radical pair might spend slightly more time in the singlet
• 20:37
  Speaker 3: state or slightly more time in the triplet state.
• 20:39
  Speaker 2: The magnetic field is like a thumb on the scale
• 20:42
  Speaker 2: of the quantum dance. But how does an electron dancing
• 20:45
  Speaker 2: between states tell a bird where to fly? The bird
• 20:48
  Speaker 2: doesn't know quantum mechanics.
• 20:50
  Speaker 3: It doesn't need to, because the quantum state dictates classical chemistry.
• 20:54
  Speaker 3: The singlet and triplet states are fundamentally different chemical configurations,
• 20:59
  Speaker 3: leading to different chemical reactions. If it resolves as a singlet,
• 21:02
  Speaker 3: it creates one specific chemical product. If it resolves as
• 21:06
  Speaker 3: a tricklet, it creates a different product or at a
• 21:08
  Speaker 3: different rate. So as the bird turns its head, the
• 21:11
  Speaker 3: angle of the magnetic field changes, the quantum spin ratio shifts,
• 21:15
  Speaker 3: and the chemical concentration in its eye physically changes. The
• 21:19
  Speaker 3: bird is literally translating a quantum spin state into a
• 21:23
  Speaker 3: biochemical signal. It's highly likely the bird visually sees the
• 21:27
  Speaker 3: Earth's magnetic field as a pattern of light or color
• 21:30
  Speaker 3: over its vision.
• 21:31
  Speaker 2: That is profound. It's chemically hallucinating a magnetic grid based
• 21:35
  Speaker 2: on entangled electrons. But I have to stop and process
• 21:40
  Speaker 2: the fragility. Here we establish the biological heat crushes quantum states.
• 21:44
  Speaker 2: The Earth's field is a whisper, The heat of the
• 21:46
  Speaker 2: eye is a screaming jet engine. How does the cryptochrome
• 21:49
  Speaker 2: protect the entanglement long enough for the magnetic field to
• 21:51
  Speaker 2: affect it?
• 21:52
  Speaker 3: That is the exact question that keeps biophysicists awake at night.
• 21:56
  Speaker 3: It requires a flawless Goldilocks scenario. Stay entangled too long,
• 22:00
  Speaker 3: thermal noise destroys them. Not long enough, the Earth's field can't.
• 22:04
  Speaker 2: Tilt the scales, so how does it survive?
• 22:07
  Speaker 3: Groundbreaking computational work from twenty twenty five and twenty twenty six, specifically,
• 22:12
  Speaker 3: a collaborative study in the Journal of the American Chemical
• 22:14
  Speaker 3: Society from Princeton and Oldenburg mapped the exact structure of
• 22:18
  Speaker 3: cryptochrome four A and migratory birds. They found the protein
• 22:22
  Speaker 3: physically reorganizes surrounding water molecules to stabilize the radical pair.
• 22:27
  Speaker 2: It builds its own micro environment exactly.
• 22:29
  Speaker 3: It holds the electrons precisely far enough apart to prevent
• 22:32
  Speaker 3: instant recombination, but keeps them perfectly entangled and shielded from
• 22:36
  Speaker 3: just enough noise, and it gets stranger. A twenty twenty
• 22:40
  Speaker 3: four study in Nature Communications explored how the environment interacts
• 22:43
  Speaker 3: through the quantum zeno effect.
• 22:44
  Speaker 2: The Zeno effect sounds like the old saying a watched
• 22:47
  Speaker 2: pot never boils.
• 22:48
  Speaker 3: In quantum mechanics, that's literally true. If you continuously measure
• 22:53
  Speaker 3: a quantum system, you freeze its evolution. The chaotic thermal
• 22:58
  Speaker 3: environment inside the eye acts as a constant observer. It
• 23:02
  Speaker 3: continuously bumps into the radical pair, essentially measuring it.
• 23:05
  Speaker 2: Wait, so the biological noise is actively amplifying the magnetic
• 23:10
  Speaker 2: signal by repeatedly checking on it.
• 23:12
  Speaker 3: Yes. The study modeled how this environmental noise actually utilizes
• 23:17
  Speaker 3: the Zeno effect to trap the electrons in their sensitive
• 23:20
  Speaker 3: state for just a fraction of a microsecond.
• 23:22
  Speaker 2: Longer the deeper we go, the more the noise is
• 23:24
  Speaker 2: the secret to everything. But okay, if this is happening
• 23:28
  Speaker 2: inside a single protein inside a living bird's eye, we
• 23:31
  Speaker 2: can't shrink a camera down to watch the electron spin.
• 23:34
  Speaker 2: How do we prove this isn't just elegant math.
• 23:36
  Speaker 3: We prove it by hacking the quantum state and watching
• 23:38
  Speaker 3: the bird's behavior. Researchers put migratory birds in closed arenas
• 23:43
  Speaker 3: during migration season. When they're ready to fly, they instinctively
• 23:46
  Speaker 3: hop toward their migratory route. Then the scientists introduce incredibly
• 23:50
  Speaker 3: weak specific radiofrequency magnetic.
• 23:53
  Speaker 2: Fields radiofrequencies so weak they can't affect any classical biology.
• 23:56
  Speaker 3: Right. They can't heat tissue or fire a neuron. But
• 23:59
  Speaker 3: they they are tuned to the exact resonant frequency of
• 24:02
  Speaker 3: the electron spins in a radical pair.
• 24:05
  Speaker 2: You're broadcasting a jamming signal targeted at the entanglement. What
• 24:08
  Speaker 2: happens to the bird?
• 24:09
  Speaker 3: The bird loses its mind. It becomes completely disoriented and
• 24:13
  Speaker 3: hops in random directions. The moment you turn the radiofrequencies off,
• 24:17
  Speaker 3: it regains its bearing. The radio waves scramble the singlet
• 24:21
  Speaker 3: triplet oscillation.
• 24:23
  Speaker 2: That is incredible.
• 24:24
  Speaker 3: Furthermore, they've done experiments swapping the ambient hydrogen isotopes with deuterium.
• 24:29
  Speaker 3: Deuterium is chemically identical to hydrogen, but has an extra
• 24:32
  Speaker 3: neutron which changes its nuclear magnetic spin, which.
• 24:36
  Speaker 2: Changes the hyperfine interactions. You're altering the tug.
• 24:38
  Speaker 3: Of war precisely by subtly changing the nuclear magnetic environment
• 24:43
  Speaker 3: using isotopes, they altered the sensitivity of the bird's compass,
• 24:47
  Speaker 3: proving the navigation system is inherently tied to atomic nuclei
• 24:50
  Speaker 3: and electron spin. Behavioral evidence, isotopic evidence, and radiofrequency jamming
• 24:56
  Speaker 3: make the radical pair mechanism the only scientifically sound explaining.
• 25:00
  Speaker 2: Okay, so we've looked at quantum mechanics. Catching sunlight and
• 25:03
  Speaker 2: feeling the magnetic pulse of the planet. Both are interacting
• 25:07
  Speaker 2: with the external environment. Let's pivot inward. Let's look at
• 25:11
  Speaker 2: the mechanical engines inside our own bodies. Enzymes Enzymes are.
• 25:16
  Speaker 3: The fundamental catalysts of life. Every time you digest a meal,
• 25:20
  Speaker 3: a neuron fires, or a cell divides. Enzymes are facilitating
• 25:24
  Speaker 3: those reactions. They speed up biochemical processes by factors of millions,
• 25:29
  Speaker 3: sometimes trillions.
• 25:30
  Speaker 2: Without them, we couldn't exist.
• 25:32
  Speaker 3: A reaction that takes a fraction of a second in
• 25:34
  Speaker 3: your stomach would take hundreds of years on its own.
• 25:36
  Speaker 3: Life is entirely dependent on the speed of enzymes, and.
• 25:39
  Speaker 2: To understand why they're so fast, we look at activation
• 25:42
  Speaker 2: energy right, the classical mountain right.
• 25:44
  Speaker 3: Think of a chemical reaction as a journey from one
• 25:46
  Speaker 3: stable state to another. Reactant molecules are in a deep
• 25:49
  Speaker 3: valley of energy. To become a new product, they have
• 25:52
  Speaker 3: to transition to the next valley, but separating them is
• 25:56
  Speaker 3: a towering mountain of energy, the activation.
• 25:58
  Speaker 2: Barrier, and classically they need enough ambient thermal heat to
• 26:01
  Speaker 2: physically climb over the peak.
• 26:03
  Speaker 3: Yes, enzymes are complex proteins that physically grab molecules, bend them,
• 26:08
  Speaker 3: twist them, and apply electrical fields. They essentially take a
• 26:12
  Speaker 3: bulldozer to the mountain, lowering the peak. So molecules don't
• 26:15
  Speaker 3: need nearly as much energy to cross.
• 26:17
  Speaker 2: So the classical views enzymes are just microscopic bulldozers. But
• 26:21
  Speaker 2: if I'm tracking our theme, even a bulldozed mountain can't
• 26:25
  Speaker 2: explain the sheer velocity of these enzymes.
• 26:27
  Speaker 3: It cannot. When biophysicists measured the exact kinetic rates of
• 26:31
  Speaker 3: certain enzyme reactions, specifically transferring hydrogen atoms, the math broke down.
• 26:37
  Speaker 3: Even with the mountain bulldoze to its lowest point, classical
• 26:40
  Speaker 3: thermodynamics dictated there simply wasn't enough ambient heat in the
• 26:44
  Speaker 3: cell to push molecules over the top at the observed
• 26:47
  Speaker 3: speeds faster.
• 26:48
  Speaker 2: Than classical physics allows, which brings us to the third tool,
• 26:52
  Speaker 2: quantum tunneling. So instead of climbing the mountain, the hydrogen
• 26:55
  Speaker 2: atom just spreads its probability wave into the barrier and
• 26:57
  Speaker 2: a fraction of the time instantly teleport to the other.
• 27:00
  Speaker 3: Side, exactly inside the enzyme. A hydrogen nucleus, a single
• 27:05
  Speaker 3: proton needs to move from molecule A to molecule B.
• 27:09
  Speaker 3: Because protons are so small and light, their wave like
• 27:12
  Speaker 3: quantum nature is highly pronounced. The enzyme physically positions the
• 27:16
  Speaker 3: donor and acceptor molecules so close together that the proton
• 27:19
  Speaker 3: doesn't even try to climb. It tunnels straight through.
• 27:23
  Speaker 2: It's an elegant concept, but how do you prove it
• 27:25
  Speaker 2: a proton moving in a picosecond. You can't put a
• 27:28
  Speaker 2: radar gun on it to see if it climbed or tunneled.
• 27:30
  Speaker 3: No, you can't. But chemists use one of the most
• 27:32
  Speaker 3: elegant diagnostic tools in science, kinetic isotope effects or coiees.
• 27:38
  Speaker 3: We take the hydrogen atom the enzyme is trying to
• 27:40
  Speaker 3: move and chemically swap it for a heavier.
• 27:42
  Speaker 2: Version of itself, using an isotope like deuterium.
• 27:45
  Speaker 3: Exactly, deuterium has an extra neutron, making it roughly twice
• 27:49
  Speaker 3: as heavy as standard hydrogen, but chemically it behaves identically.
• 27:52
  Speaker 3: It forms the exact same bonds and fits the exact
• 27:54
  Speaker 3: same enzyme pocket.
• 27:55
  Speaker 2: So if the classical model is right and the atom
• 27:58
  Speaker 2: is just climbing the mountain, its mass should only slow
• 28:01
  Speaker 2: down the reaction by a very small, predictable amount. A
• 28:04
  Speaker 2: heavier hiker climbs a little slower.
• 28:06
  Speaker 3: But if it's utilizing quantum tunneling, mass changes the entire equation.
• 28:10
  Speaker 3: In quantum mechanics. Tunneling probability depends on the Debraggli wavelength.
• 28:15
  Speaker 3: Heavier objects have dramatically shorter wavelengths. Because deuterium is twice
• 28:19
  Speaker 3: as heavy, its quantum wave doesn't spread out nearly as far.
• 28:22
  Speaker 3: It is terrible at tunneling. Oh So, when researchers take
• 28:26
  Speaker 3: an enzyme like yeast, alcohol, dehydrogenase, or ribonucleotide reductat for
• 28:31
  Speaker 3: DNA synthesis and feed at deuterium, the reaction doesn't just
• 28:34
  Speaker 3: slow down a little, It violently crashes. The reaction rate
• 28:37
  Speaker 3: plummets by a factor far greater than simple mass difference
• 28:40
  Speaker 3: can classically account for.
• 28:42
  Speaker 2: By making the atom heavier, you strip away its teleportation superpower.
• 28:46
  Speaker 2: It suddenly realizes it has to climb the wall the
• 28:48
  Speaker 2: hard way, and it doesn't have.
• 28:49
  Speaker 3: The energy exactly. The extreme kinetic isotope effect is the
• 28:53
  Speaker 3: smoking gun for quantum tunneling in biology, and our understanding
• 28:56
  Speaker 3: has deepened remarkably. A massive twenty twenty six percent perspective
• 29:00
  Speaker 3: in the journal Biochemistry reviewed decades of data and brought
• 29:03
  Speaker 3: to light vibrational gating.
• 29:06
  Speaker 2: Vibrational gating, what's that We used.
• 29:08
  Speaker 3: To think enzymes were rigid locks now we know they
• 29:11
  Speaker 3: are highly dynamic jiggling machines. The enzyme uses its internal
• 29:15
  Speaker 3: thermal vibrations to rapidly compress the distance between the donor
• 29:19
  Speaker 3: and exceptor molecules for just a fraction of a peko.
• 29:21
  Speaker 2: Second, So the concrete walls are literally moving.
• 29:23
  Speaker 3: Yes, it squeezes the width of the activation barrier, making
• 29:27
  Speaker 3: the wall incredibly thin for a fleeting moment. The proton
• 29:31
  Speaker 3: waits for that exact moment of maximum compression, tunnels through
• 29:34
  Speaker 3: the narrowed barrier, and then the enzyme relaxes back to normal.
• 29:38
  Speaker 2: I want to highlight a distinction here. Superposition in the
• 29:41
  Speaker 2: leaf and entanglement in the bird's eye required incredibly fragile,
• 29:45
  Speaker 2: long lived coherence across wide spaces, but tunneling is a
• 29:49
  Speaker 2: single particle effect. It's localized and instantaneous. It feels like
• 29:54
  Speaker 2: a much more robust process that could easily survive the
• 29:56
  Speaker 2: thermal war zone of the cell.
• 29:58
  Speaker 3: That is an incredibly astute observation, and it reflects the
• 30:01
  Speaker 3: scientific consensus. While coherence and entanglement still face intense skepticism,
• 30:06
  Speaker 3: quantum tunneling and enzymes is essentially a subtle debate. We've
• 30:10
  Speaker 3: even done directed evolution studies.
• 30:12
  Speaker 2: And labs forcing enzymes to mutate.
• 30:14
  Speaker 3: Exactly when placed under extreme pressure to become faster, enzymes
• 30:19
  Speaker 3: will actively mutate their structures specifically to optimize these quantum
• 30:23
  Speaker 3: tunneling pathways. Life aggressively selects for it through evolution.
• 30:27
  Speaker 2: If enzymes use tunneling to process internal chemistry, it forces
• 30:31
  Speaker 2: us to ask about how we interact with the outside world.
• 30:34
  Speaker 2: Could quantum tunneling be this secret mechanism behind how we
• 30:37
  Speaker 2: detect complex chemicals. Let's move to human sensory perception, the
• 30:42
  Speaker 2: sense of smell olfaction.
• 30:45
  Speaker 3: Olfaction is phenomenally complex and surprisingly, in twenty twenty six,
• 30:48
  Speaker 3: the exact mechanism remains one of the most hotly contested
• 30:51
  Speaker 3: debates in biophysics. The textbook explanation for decades has been
• 30:56
  Speaker 3: the shape theory or the lock and key model.
• 30:58
  Speaker 2: Right, you inhale odorant molecules, some coffee or a pine tree.
• 31:01
  Speaker 2: They hate your old factory receptors, and if the molecule's
• 31:04
  Speaker 2: physical shape fits perfectly into the receptor's pocket, it turns,
• 31:07
  Speaker 2: the lock, sends an electrical signal, and you smell coffee.
• 31:10
  Speaker 3: Conceptually, it makes perfect sense. It aligns with how antibodies
• 31:13
  Speaker 3: or neurotransmitters function shape dictates function, but the shape theory
• 31:17
  Speaker 3: struggles to explain massive anomalies like what. The most prominent
• 31:22
  Speaker 3: issue involves chiral molecules. These are molecules with the exact
• 31:26
  Speaker 3: same chemical formula and dimensions, but they are mirror images
• 31:29
  Speaker 3: of each other, like you're left and right hand.
• 31:31
  Speaker 2: Okay.
• 31:32
  Speaker 3: In many cases, chiral pairs smell completely different. One nantiumer
• 31:37
  Speaker 3: of a molecule called carbone smells distinctly of spearmint, while
• 31:41
  Speaker 3: its mirror image smells like caraway seeds. If shape is
• 31:45
  Speaker 3: the primary determinant, a mirror image shouldn't produce a violently
• 31:49
  Speaker 3: different result in a flexible receptor.
• 31:51
  Speaker 2: That makes total sense.
• 31:52
  Speaker 3: Conversely, there are completely unrelated molecules with wildly different shapes
• 31:56
  Speaker 3: and atomic compositions, yet they smell almost completely identify humans.
• 32:01
  Speaker 3: If shape is the lock, why are totally different keys
• 32:04
  Speaker 3: opening the exact same door.
• 32:06
  Speaker 2: Andre a biophysicist named Luca Turin who proposed something that
• 32:09
  Speaker 2: sounded like science fiction. He said we should abandon the
• 32:12
  Speaker 2: shape theory. He proposed the vibration theory of smell. Our
• 32:16
  Speaker 2: noses aren't checking the shape, They're acting like quantum spectrometers
• 32:20
  Speaker 2: listening to molecular vibrations.
• 32:22
  Speaker 3: It was a radical departure. Every chemical bond between atoms
• 32:26
  Speaker 3: behaves like a microscopic spring. Depending on the atoms, that
• 32:30
  Speaker 3: spring vibrates at a specific, unique resonant frequency. A carbon
• 32:34
  Speaker 3: hydrogen bond vibrates at a different pitch than a carbon oxygen.
• 32:38
  Speaker 2: Bond, so the whole molecule hums with a unique cord. Right.
• 32:42
  Speaker 3: Turin proposed that olfactory receptors are designed to detect these
• 32:46
  Speaker 3: frequencies via inelastic electron tunneling.
• 32:48
  Speaker 2: Okay, let's unpack that. How does an electron tunneling across
• 32:52
  Speaker 2: a gap let a receptor hear a vibration.
• 32:55
  Speaker 3: Imagine the inside of the receptor protein on one side
• 32:58
  Speaker 3: is an electron donor site holding an electron. On the
• 33:01
  Speaker 3: other side is an ecceptor site. The electron wants to
• 33:04
  Speaker 3: jump across the gap to the acceptorate site, which would
• 33:06
  Speaker 3: trigger the signal to the brain. But the acceptor site
• 33:09
  Speaker 3: is at a significantly lower energy level.
• 33:11
  Speaker 2: And electrons can't just jump to a lower level and
• 33:13
  Speaker 2: hold onto excess energy.
• 33:15
  Speaker 3: Now, quantum mechanics forbids it. They must shed the exact
• 33:17
  Speaker 3: difference and energy to make the transition, but with nowhere
• 33:21
  Speaker 3: for the energy to go, the electron is trapped.
• 33:23
  Speaker 2: It needs a shock absorber, a place to dump the
• 33:26
  Speaker 2: excess energy.
• 33:27
  Speaker 3: Exactly now, an odorant molecule enters the pocket. If that
• 33:31
  Speaker 3: molecule vibrates at the exact specific frequency that perfectly matches
• 33:34
  Speaker 3: the energy difference between the two sites, it acts as
• 33:37
  Speaker 3: the perfect shock absorber. The trapped electron transfers its excess
• 33:41
  Speaker 3: energy into the vibrating spring of the odorant, amplifying its vibration.
• 33:45
  Speaker 2: And having shed the exact right amount of energy, the
• 33:48
  Speaker 2: electron instantly tunnels across the gap. The burst of current
• 33:52
  Speaker 2: fires the neuron.
• 33:53
  Speaker 3: Yes, under this model, it doesn't matter if two molecules
• 33:56
  Speaker 3: have completely different shapes. If their chemical bonds vibrate at
• 33:59
  Speaker 3: the exactact same frequency, they trigger the exact same quantum tunnel,
• 34:03
  Speaker 3: and you perceive the exact same smell.
• 34:06
  Speaker 2: It's brilliantly elegant, But again, how do you test it.
• 34:09
  Speaker 2: You can't stick a microscopic microphone inside a human nose.
• 34:12
  Speaker 3: We return to our favorite diagnostic tool, isotopomers. We take
• 34:16
  Speaker 3: an odoran, say the sta penone, which smells strongly of
• 34:20
  Speaker 3: cherry and almond, and we chemically synthesize a version where
• 34:22
  Speaker 3: we replace all standard hydrogen atoms with heavy deuterium atoms.
• 34:26
  Speaker 2: Doubling the mass of those atoms without changing the chemical shape.
• 34:29
  Speaker 3: Right, because it's significantly heavier, the frequency of its molecular
• 34:33
  Speaker 3: vibrations drops dramatically, like replacing a guitar string with a
• 34:37
  Speaker 3: much thicker one. The pitch goes down, but structurally it's
• 34:41
  Speaker 3: an identical key.
• 34:42
  Speaker 2: So if the classical lock and key theory is the
• 34:45
  Speaker 2: absolute truth, the normal and the heavy deutererated molecule must
• 34:49
  Speaker 2: smell exactly identical because they fit perfectly into the exact
• 34:53
  Speaker 2: same physical pocket.
• 34:55
  Speaker 3: That is the classical prediction. But if turns quantum vibration
• 34:58
  Speaker 3: theory is correct, the heavier molecule is vibrating at an
• 35:02
  Speaker 3: entirely wrong pitch. It can't absorb the exact right amount
• 35:05
  Speaker 3: of energy, the electron cannot tunnel, the receptor doesn't fire,
• 35:08
  Speaker 3: and the organism should perceive a completely different smell. And
• 35:12
  Speaker 3: what happens in the experiments the results have been tantalizing
• 35:15
  Speaker 3: and highly controversial. Rigorous experiments on fruit flies conclusively show
• 35:20
  Speaker 3: they can easily distinguish between a normal odorant and its
• 35:23
  Speaker 3: deutererated istochomer. They can smell the difference in mass.
• 35:26
  Speaker 2: Wait, really, what about humans?
• 35:28
  Speaker 3: Double blind behavioral tests show humans can reliably distinguish between
• 35:32
  Speaker 3: normal and duterated versions of certain musks. Adding to that,
• 35:37
  Speaker 3: a highly detailed twenty twenty five study in the journal
• 35:40
  Speaker 3: Molecules successfully mapped the complex electron phone on interactions required.
• 35:45
  Speaker 3: They mathematically linked the energy scales of human odorance to
• 35:48
  Speaker 3: the known gap states in our re sectors, proving inelastic
• 35:51
  Speaker 3: electron tunneling is physically viable in a human nose.
• 35:55
  Speaker 2: I find this fascinating, but I have to play the
• 35:57
  Speaker 2: skeptic here. The vibration theory of olfaction is arguably the
• 36:01
  Speaker 2: most fiercely contested battleground in the field. A huge portion
• 36:05
  Speaker 2: of scientists completely reject it, and.
• 36:07
  Speaker 3: Their rejection is grounded in highly valid critique. While the
• 36:10
  Speaker 3: fruitfly and musk experiments are compelling, Other massive studies using
• 36:14
  Speaker 3: different classes of molecules found subjects absolutely cannot tell the
• 36:17
  Speaker 3: difference between normal and heavy versions. The quantum effect doesn't
• 36:20
  Speaker 3: seem universal.
• 36:21
  Speaker 2: So it only works for some smells.
• 36:23
  Speaker 3: Perhaps also, structural biologists argue that replacing hydrogen with deuterium
• 36:28
  Speaker 3: might cause incredibly subtle shifts in how the molecule physically
• 36:31
  Speaker 3: binds a classical effect. They believe the lock and key model,
• 36:34
  Speaker 3: accounting for the flexibility of both molecule and receptor, is
• 36:37
  Speaker 3: sufficient to explain anomalies without quantum tunneling, So in.
• 36:41
  Speaker 2: Twenty twenty six, the jury is still out. The quantum
• 36:44
  Speaker 2: smell hypothesis remains brilliant, but ultimately unproven.
• 36:48
  Speaker 3: It remains deeply polarizing, but even if it's only a
• 36:51
  Speaker 3: partial mechanism working in tandem with shape recognition, it perfectly
• 36:55
  Speaker 3: illustrates the profound shift happening in biology. We are looking
• 36:59
  Speaker 3: beyond reach classical structures to dynamics, subatomic energy transfers as
• 37:04
  Speaker 3: sensory mechanisms.
• 37:05
  Speaker 2: We've journeyed through an incredible spectrum today, exciten's acting as
• 37:09
  Speaker 2: probability waves, and a leaf entangled electron pairs acting as
• 37:13
  Speaker 2: a chemical compass in a bird's eye, held together by
• 37:16
  Speaker 2: the very thermal noise that should destroy them. Protons teleporting
• 37:19
  Speaker 2: through biological machinery to speed up enzymes, and possibly our
• 37:23
  Speaker 2: noses acting as quantum spectrometers. If we pull back from
• 37:26
  Speaker 2: all this, what does this mean for our fundamental understanding
• 37:28
  Speaker 2: of reality.
• 37:29
  Speaker 3: It demands a massive philosophical shift. For the entire twentieth century,
• 37:34
  Speaker 3: physics and biology were separate magisteria. Quantum mechanics was fragile, exotic, isolated.
• 37:40
  Speaker 3: Biology was warm, messy, purely classical. But the revelation is
• 37:45
  Speaker 3: that evolution didn't just stumble upon the quantum realm and
• 37:47
  Speaker 3: try to keep the noise out. Evolution became a master
• 37:50
  Speaker 3: quantum engineer.
• 37:52
  Speaker 2: Life didn't build a blast shield. Life built a sail
• 37:55
  Speaker 2: to catch the quantum wind.
• 37:56
  Speaker 3: Precisely, the vibrating proteins, the chaotic water molecules, the thermal heat.
• 38:01
  Speaker 3: It's not the enemy of the quantum state. It's the
• 38:04
  Speaker 3: necessary catalyst life harness the turbulence. It blurs the artificial line.
• 38:09
  Speaker 3: We drew the weirdness of the subatomic scale echoes all
• 38:11
  Speaker 3: the way up into the macroscopic machinery of life.
• 38:14
  Speaker 2: If natural selections spend four billion years optimizing these quantum mechanics,
• 38:18
  Speaker 2: it begs the question, what can we do with that knowledge?
• 38:21
  Speaker 2: If we understand how plants perfectly harvest light or birds
• 38:24
  Speaker 2: navigate without GPS, what is the practical application of quantum
• 38:27
  Speaker 2: biology today?
• 38:29
  Speaker 3: The applications are driving an explosive revolution in biometic engineering
• 38:33
  Speaker 3: with photosynthesis. If we can fully decode and replicate the
• 38:37
  Speaker 3: vibronic coupling in the FMO complex, we could engineer quantum
• 38:41
  Speaker 3: inspired solar cells, not rigid silicon, but dynamic synthetic materials,
• 38:46
  Speaker 3: capturing sunlight with near perfect efficiency, completely revolutionizing green energy.
• 38:51
  Speaker 2: What about the birds.
• 38:53
  Speaker 3: By understanding the cryptochrome radical pair mechanism, engineers are designing
• 38:57
  Speaker 3: ultrasensitive magnetic sensors that operate at room tipleemperature, no need
• 39:01
  Speaker 3: for massive liquid helium cooling systems. This leads to hyperaccurate
• 39:06
  Speaker 3: navigation for submarines and aircraft, totally independent of satellite GPS
• 39:10
  Speaker 3: WOW And in medicine, these sensors could map the minuscule
• 39:13
  Speaker 3: magnetic fields of human brain activity, providing real time neural
• 39:17
  Speaker 3: imaging without massive MRI machines.
• 39:19
  Speaker 2: And the quantum tunneling in our enzymes.
• 39:21
  Speaker 3: That leads to a leap in green chemistry. If we
• 39:24
  Speaker 3: design synthetic enzymes using vibrational gating to force quantum tunneling,
• 39:29
  Speaker 3: we revolutionize industrial manufacturing. We could synthesize complex pharmaceuticals, break
• 39:34
  Speaker 3: down microplastics, or produce clean fuels. At a fraction of
• 39:38
  Speaker 3: the energetic cost. We're borrowing teleportation tricks from biology.
• 39:42
  Speaker 2: It really feels like quantum biology has crossed a threshold.
• 39:46
  Speaker 2: It's no longer just theoretical physicists throwing math at a wall.
• 39:50
  Speaker 3: It is absolutely matured past the fringe science label. It
• 39:53
  Speaker 3: is a rigorous, heavily funded discipline, and it's the ultimate
• 39:57
  Speaker 3: interdisciplinary frontier. A physicist can't solve it alone. They need
• 40:01
  Speaker 3: the computational chemists to model vibrations and the molecular biologists
• 40:05
  Speaker 3: to observe the function in a living cell. It's tearing
• 40:08
  Speaker 3: down the silos that separated disciplines for a century.
• 40:11
  Speaker 2: It's a beautiful convergence of human knowledge. Let's take a
• 40:14
  Speaker 2: breath and just recap the sheer scale of the journey today.
• 40:17
  Speaker 2: We started with this deeply entrenched assumption that the warm,
• 40:21
  Speaker 2: violently chaotic world of biology was totally incompatible with the
• 40:25
  Speaker 2: freezing precision of quantum mechanics. We thought they were two
• 40:28
  Speaker 2: different universes. But layer by layer, we've seen the line
• 40:31
  Speaker 2: isn't a hard brick wall. It's a blurred gradient. Packages
• 40:35
  Speaker 2: of energy acting as probability waves and leaf entangled electrons
• 40:39
  Speaker 2: locked in a tug of war in a bird's eye,
• 40:41
  Speaker 2: stabilized by noise, hydrogen atoms teleporting through enzymes, and maybe
• 40:46
  Speaker 2: our noses sensing fundamental vibrations.
• 40:48
  Speaker 3: And all of this synthesis leads to one final, truly
• 40:52
  Speaker 3: profound question to consider.
• 40:53
  Speaker 2: Lay it on us.
• 40:54
  Speaker 3: We've seen how natural selection meticulously optimize these quantum phenomena
• 40:58
  Speaker 3: to sustain life. If we look back to the very beginning,
• 41:02
  Speaker 3: did life simply stumble upon quantum mechanics halfway through its
• 41:05
  Speaker 3: evolutionary journey? Or was the very origin of life itself
• 41:10
  Speaker 3: fundamentally a quantum event? Wow, when the very first spark
• 41:14
  Speaker 3: of biological animation occurred in the primordial soup, transforming inert
• 41:18
  Speaker 3: chemistry into replicating biology, was that transition driven by quantum
• 41:22
  Speaker 3: tunneling or coherence? If biological life is so heavily reliant
• 41:26
  Speaker 3: on quantum machinery, now, perhaps it always was. Perhaps the
• 41:29
  Speaker 3: line between non living matter and living biology wasn't just
• 41:31
  Speaker 3: a chemical reaction, Perhaps it was a quantum leap.
• 41:34
  Speaker 2: That concept that life didn't just find quantum mechanics but
• 41:38
  Speaker 2: was born from it, that changes how I view absolutely everything.
• 41:41
  Speaker 2: So the next time you find yourself standing in a crowded,
• 41:44
  Speaker 2: unbelievably noisy subway station, or if you're just looking at
• 41:47
  Speaker 2: a simple green plant on your windowsill or a bird
• 41:50
  Speaker 2: flying overhead, I hope you look at them just a
• 41:52
  Speaker 2: little bit differently. The chaos of the world isn't destroying
• 41:55
  Speaker 2: the delicate dance of reality. The chaos is the music
• 41:58
  Speaker 2: that allows the dance to have Thank you for joining
• 42:01
  Speaker 2: us on this journey today.