Speaker 1: Welcome to the quark Side. Quantum Physics Podcast, an exploration
Speaker 1: of the fundamental structure of reality, where quantum laws govern matter, energy,
Speaker 1: and information. Here, uncertainty is a feature, not a flaw,
Speaker 1: and understanding begins at the smallest scales.
Speaker 2: All right, before we get started, I want you to
Speaker 2: try something for me.
Speaker 3: Oh, okay, a little audience participation. I'm in right now
Speaker 3: wherever you are, just I don't know, reach out and
Speaker 3: touch the table in front of you, or grab the
Speaker 3: arm of your chair.
Speaker 2: Okay, I am tapping the desk right now. It's solid,
Speaker 2: cool to the touch, definitely real.
Speaker 3: Exactly, it feels solid. Your hand stops, You don't fall
Speaker 3: through your floor, your coffee cup doesn't just phase through
Speaker 3: the table like some kind of ghost.
Speaker 2: Right. We take this for granted.
Speaker 3: We take it for granted every single second of our lives.
Speaker 3: It is the basic fundamental fact of our existence. Things
Speaker 3: are solid. But here's the question that, and I'm not kidding,
Speaker 3: keeps me up at night.
Speaker 2: Why why is the world solid? It sounds like a
Speaker 2: question of five year old would ask, doesn't it?
Speaker 3: But why it does? And it's a great question. But
Speaker 3: the more you know about physics, the right the weirder
Speaker 3: that question gets because we know if we zoom in,
Speaker 3: and I mean way way in, that desk isn't a
Speaker 3: solid block of anything, not at all.
Speaker 2: It's mostly empty space, a cloud.
Speaker 3: Of atoms, and those atoms are what ninety nine point
Speaker 3: nine percent emptiness? Oh more than that, it's more like
Speaker 3: ninety nine point nine nine ninety nine percent. If you
Speaker 3: imagine an atom is the size of a huge football stadium. Okay,
Speaker 3: the nucleus would be like a marble sitting on the
Speaker 3: fifty yard line, and the electrons would be these tiny
Speaker 3: little gnats buzzing around in the absolute nosebleed seats and
Speaker 3: everything in between void nothing right. So logically, if matter
Speaker 3: is almost entirely empty space, why doesn't the entire universe
Speaker 3: just I don't know, collapse into a single microscopic point.
Speaker 3: Why doesn't my hand just pass straight through this table
Speaker 3: like smoke through a screen door.
Speaker 2: Why can we touch things?
Speaker 3: Yes? Why?
Speaker 2: It is a profound question, And the answer isn't just
Speaker 2: because matter is hard. The answer is actually a rule,
Speaker 2: a very specific, very strict rule written into the operating
Speaker 2: code of the universe.
Speaker 3: The rule that if it were broken, even just a tiny, tiny,
Speaker 3: bit would mean that chemistry, life, stars, basically everything we
Speaker 3: know and are would instantly cease to exist.
Speaker 2: You're talking about the poly exclusion principle, the absolute hero
Speaker 2: of today's deep dive. We are talking about the very
Speaker 2: bedrock of reality. But here's where it gets really interesting
Speaker 2: and honestly a little bit nerve wracking.
Speaker 3: Go on.
Speaker 2: We assume this rule is perfect, we assume it's absolute.
Speaker 2: But what if it isn't? What if there's a loophole?
Speaker 3: Ah? That is the question, and that is the question
Speaker 3: that sent a team of physicists deep deep underground in
Speaker 3: Italy to try and catch the universe cheating at its
Speaker 3: own game.
Speaker 2: And that's what we're digging into today. We are looking
Speaker 2: at a report from fizzdot org dated February five, twenty
Speaker 2: twenty six, which covers this massive, high stakes study. It
Speaker 2: was published in Scientific Reports a few months prior, back
Speaker 2: in November twenty twenty five.
Speaker 3: It's all about the VIP two experiment.
Speaker 2: The IP two. This is the absolute cutting edge of
Speaker 2: foundational physics, it really is. And their mission was simple,
Speaker 2: but I mean incredibly audacious. Break the poly exclusion principle,
Speaker 2: find a crack in the foundation, and what.
Speaker 3: They found, or maybe what they didn't find tells us
Speaker 3: something just incredible about the nature of our reality.
Speaker 2: It's a story about copper, new electrons and a number
Speaker 2: so vanishingly small it's hard to even visualize.
Speaker 3: So we're going underground.
Speaker 2: So let's unpack this. We're going to Grand Sasa, We're
Speaker 2: going to the quantum realm, and we're going to find
Speaker 2: out why you're not currently sinking through your chair.
Speaker 3: Sounds like a plan.
Speaker 2: I'm ready, okay, So let's start with the cornerstone, the
Speaker 2: rule itself, the poly exclusion principle. Sounds very bureaucratic, doesn't it.
Speaker 2: The exclusion principle like a velvet rope at some exclusive club.
Speaker 3: That is actually a surprisingly accurate analogy. The principle was
Speaker 3: formulated by Wolfgang Polly, an Austrian Swiss physicist, way back
Speaker 3: in nineteen twenty five.
Speaker 2: Set the scene for us. Nineteen twenty five, what's happening
Speaker 2: in physics?
Speaker 3: Oh, it was the golden age of quantum mechanics. You
Speaker 3: have to understand at this time physicists were in a
Speaker 3: state of equal parts panic and excitement.
Speaker 2: A good stit to be in for discovery.
Speaker 3: The best, the old comfortable rules of Isaac Newton, where
Speaker 3: things moved in predictable lines like clockwork. They were just
Speaker 3: falling apart. When they looked at Adams, electrons weren't behaving
Speaker 3: like little planets orbiting a sun right the old Boar
Speaker 3: model exactly. They were jumping around, disappearing and reappearing. It
Speaker 3: was just chaos. Nobody could make sense of the data
Speaker 3: they were seeing from spectroscopy.
Speaker 2: And Polly comes along and acts as the sheriff, lays
Speaker 2: down the law.
Speaker 3: He essentially does. Polly was known for being incredibly critical,
Speaker 3: just famously sharp. People called him the conscience of physics.
Speaker 2: The conscience of physics. I love that.
Speaker 3: Yeah. If he thought a theory was sloppy or poorly
Speaker 3: thought out, he wouldn't just say it was wrong. He
Speaker 3: had this famous brutal put down. He'd say, that isn't
Speaker 3: even wrong.
Speaker 2: Ouch, that's colder than saying it's wrong.
Speaker 3: It meant it was so incoherent it wasn't even worth discussing.
Speaker 3: He demanded precision, and in nineteen twenty five he proposed
Speaker 3: this principle to finally explain the structure of atoms. Why
Speaker 3: electrons arraigned themselves the way they did.
Speaker 2: So what does the law actually say in simple terms?
Speaker 3: Oh, understand it. We first have to understand that in
Speaker 3: the quantum world, particles are divided into two main tribes.
Speaker 3: You're the bosons and you have the fermions.
Speaker 2: Okay, tribes, I like that. What's the difference.
Speaker 3: Bosons are the party.
Speaker 2: Animals, the social butterflies.
Speaker 3: Totally. These are particles like photons, you know, light particles.
Speaker 3: The defining characteristic of a boson is that it loves company.
Speaker 3: You can pile as many bosons as you want into
Speaker 3: the exact same quantum state.
Speaker 2: Give visual for that.
Speaker 3: Think of a laser beam. In a laser you have
Speaker 3: trillions upon trillions of photons, all marching in perfect lockstep.
Speaker 3: They overlap, They occupy the same space at the same time,
Speaker 3: with the same energy, same direction. They are perfectly happy
Speaker 3: to stack right on top of each other.
Speaker 2: They don't mind crowds.
Speaker 3: They love crowds. They are, in a word.
Speaker 2: Social, right, They stack like, I don't know, like thoughts.
Speaker 2: You can have a million thoughts in your head at once.
Speaker 3: That's a poetic way to put it. Sure, they are
Speaker 3: permeable to each other. But then then you have the
Speaker 3: fermions and electrons, which are the stars of our story
Speaker 3: today are fermions.
Speaker 2: And let me guess fermions are not party animals.
Speaker 3: They are antisocial, deeply, deeply antisocial. The poly exclusion principle
Speaker 3: basically says no two identical fermions can occupy the same
Speaker 3: quantum state at the same time period.
Speaker 2: This seat is taken precisely.
Speaker 3: It's the ultimate one per customer rule. If an electron
Speaker 3: is in a certain energy state, you can think of
Speaker 3: it like a designated parking spot in a garag. No
Speaker 3: other electron in that atom can park there. It is
Speaker 3: strictly forbidden.
Speaker 2: Now, when you say parking spot or quantum state, we're
Speaker 2: talking about more than just location, right, It's a bit
Speaker 2: more specific than.
Speaker 3: That, right, Yeah, good point. In quantum mechanics, a state
Speaker 3: is defined by a set of numbers. We call them
Speaker 3: quantum numbers. It's like a unique address. You have the
Speaker 3: energy level, the angular momentum, the magnetic moment and critically
Speaker 3: the spin spin up or spin down exactly. So Pauli's
Speaker 3: rule says you cannot have two electrons in the same
Speaker 3: atom with the exact same list of numbers. You could
Speaker 3: have two in the same energy level, but one must
Speaker 3: be spin up and the other must be spinned down.
Speaker 3: Once both those spots are taken, that level is full.
Speaker 2: So if I'm an electron and I want to join
Speaker 2: an atom, I'm naturally drawn to the lowest energy spot,
Speaker 2: the best parking spot, right near the interest.
Speaker 3: That's where you want to go, less energy expended.
Speaker 2: But if there's already an electron there with spin up
Speaker 2: and another with spin down, that level is completely full.
Speaker 3: You cannot enter. You are physically barred from that state.
Speaker 3: To or says no, you have to go to the
Speaker 3: next level up, and if that's full, the next one
Speaker 3: and the next one after that.
Speaker 2: This sounds like a real hassle for the electrons.
Speaker 3: It is. They want to be in the lowest energy
Speaker 3: state possible. They want to relax down in the basement,
Speaker 3: but the exclusion principle forces them to stack up one
Speaker 3: by one into these layers or shells around the.
Speaker 2: Nucleus, and the stacking, this fourcelayering. This is the key
Speaker 2: to everything, isn't it.
Speaker 3: It is the key to the entire universes. We know
Speaker 3: it because if they could all just crash down into
Speaker 3: that bottom level, if they could all pile up.
Speaker 2: Like bosons, what had happened, what would an atom look like.
Speaker 3: You wouldn't have chemistry at all. Think about the periodic table.
Speaker 3: The entire reason carbon behaves differently than oxygen, which behaves
Speaker 3: differently from iron, is entirely because they have different numbers
Speaker 3: of electrons arranged in different shells. Because of this exclusion rule.
Speaker 2: Ah.
Speaker 3: Of course, carbon has four electrons in its outer shell,
Speaker 3: so it wants to form four bonds. It's the basis
Speaker 3: of all organic life. Oxygen has six in its outer shell,
Speaker 3: so it behaves in a completely different way. If they
Speaker 3: all just piled into the basement, every atom would just
Speaker 3: be a slightly heavier, slightly more negative version of hydrogen.
Speaker 3: They'd all behave roughly the same.
Speaker 2: So there'd be no complex bonds, no molecules.
Speaker 3: No DNA, no proteins, no water, no life. You and
Speaker 3: I would not be having this conversation. Chemistry is basically
Speaker 3: just the consequence of electrons dealing with the lack of
Speaker 3: parking spaces.
Speaker 2: That is a fantastic way to think about it. Chemistry
Speaker 2: is the result of overcrowding.
Speaker 3: It is, and it goes beyond just chemistry. This rule
Speaker 3: is what creates the rigidity of matter. Thus solidity.
Speaker 2: Tay back to the table I'm touching right.
Speaker 3: Now, exactly when you press your hand against the table.
Speaker 3: What's actually happening. The electrons in the atoms of your
Speaker 3: hand are pushing against the electrons in the atoms of
Speaker 3: the table. They literally cannot occupy the same space.
Speaker 2: So the feeling of solid.
Speaker 3: That resistance, you feel, that solidness isn't the physical matter
Speaker 3: of your hand touching the physical matter of the table.
Speaker 3: That's not what's ha happening.
Speaker 2: What is it?
Speaker 3: Then? It is the poly exclusion principle in action. It
Speaker 3: is a quantum force. We call it a degeneracy pressure
Speaker 3: that is screaming back off. This space is taken at
Speaker 3: an atomic level.
Speaker 2: That is wild. I'm not feeling wood, I'm feeling a
Speaker 2: quantum law.
Speaker 3: You are feeling the fundamental architecture of the universe refusing
Speaker 3: to collapse on itself.
Speaker 2: And this scales up, doesn't it. I mean, this isn't
Speaker 2: just for desks. The source material mentions stars.
Speaker 3: Oh, it scales up in a huge way. Look at
Speaker 3: white dwarf stars. These are the dead, collapsed cores of
Speaker 3: stars like our sun. They are incredibly dense. We're talking
Speaker 3: about the mass of the Sun packed into a sphere
Speaker 3: the size of the Earth.
Speaker 2: And gravity is trying to crush them even further into
Speaker 2: a single point.
Speaker 3: Yes, gravity is relentless, it's pulling everything inward. But the
Speaker 3: star stops collapsing at that certain size. Why because the
Speaker 3: electrons inside are packed so incredibly tight that the exclusion
Speaker 3: principle kicks in. On a macroscopic scale, the parking garage
Speaker 3: is full. The parking garage is full on a stack.
Speaker 3: The electrons are screaming. We cannot get any closer. That
Speaker 3: outward pressure, that absolute refusal to occupy the same state
Speaker 3: holds the entire star up against the crushing weight of
Speaker 3: its own gravity.
Speaker 2: So from the table in my kitchen to a dead
Speaker 2: star in deep space, this one simple rule is the
Speaker 2: structural engineer keeping everything from imploding.
Speaker 3: It is the load bearing wall of the universe. Without it,
Speaker 3: the universe would be a soup, a very small, very hot,
Speaker 3: very dense soup.
Speaker 2: Which makes the source material for this deep dive so
Speaker 2: well terrifying. Because we have this quote from Catalina Curciano,
Speaker 2: a physicist from the Italian National Institute for Nuclear Physics
Speaker 2: the i NFN. She's the spokesperson for this VIP two experiment.
Speaker 3: Yes, I remember this quote. It's a very stark warning.
Speaker 2: She said. Quote. If the poly exclusion principle were violated,
Speaker 2: even at an extremely small level, the consequences would cascade
Speaker 2: from atomic physics all the way to astrophysics.
Speaker 3: It's a domino effect. If the rule is even slightly squishy,
Speaker 3: if an electron can just occasionally sneak into an occupied seat,
Speaker 3: then all of matter as we know it is fundamentally unstable.
Speaker 2: The domino's fault, all.
Speaker 3: Of them all at once.
Speaker 2: So naturally, knowing that the fate of the entire universe
Speaker 2: rests on this one single rule, scientists decided, Hey, let's
Speaker 2: try to break it.
Speaker 3: Well, that is the scientific way, isn't it. You don't trust,
Speaker 3: you verify, And the most rigorous way to verify something
Speaker 3: is to try your absolute hardest to destroy it.
Speaker 2: But seriously, let's play Devil's advocate for a minute. If
Speaker 2: this rule is so perfect, if it's the only thing
Speaker 2: keeping us solid and stable, why are we spending millions
Speaker 2: of dollars in years of time trying to prove it wrong.
Speaker 2: Why poke the bear?
Speaker 3: It's the itch, It's the fundamental scientific itch. We have
Speaker 3: this incredibly successful theory called the Standard Model of particle physics, right.
Speaker 2: Our best description of well, almost everything exactly.
Speaker 3: It predicts the behavior of particles with just insane accuracy.
Speaker 3: It is the most successful scientific theory in human history,
Speaker 3: and built into its very foundation is the assumption that
Speaker 3: the poly exclusion principle is exact perfect, zero exception.
Speaker 2: There's always a butt.
Speaker 3: But we know the Standard Model isn't the final word.
Speaker 3: It's beautiful, but it's flawed. It has holes. It doesn't
Speaker 3: explain everything we see in the universe.
Speaker 2: Like what what are the big holes?
Speaker 3: Well, it has nothing to say about dark matter, which
Speaker 3: we think makes up about twenty five percent of the universe.
Speaker 3: It has no explanation for dark energy, which is causing
Speaker 3: the expansion of the universe to accelerate. And the biggest
Speaker 3: one of all, it doesn't include gravity.
Speaker 2: It's like having a perfect map of the world that's
Speaker 2: missing an entire continent exactly.
Speaker 3: We know there is new physics out there, but deeper theory,
Speaker 3: we just don't know where to find it. So physicists
Speaker 3: are like detectives looking for cracks in the Standard Model.
Speaker 3: They're looking for any place where the rules bend, even
Speaker 3: just a little bit, and.
Speaker 2: That's what they mean by exotic physics, right, And what was.
Speaker 3: The most fundamental place is to look for a crack
Speaker 3: is right at the foundation? What if the exclusion principle
Speaker 3: isn't a hard absolute no, but more of a mostly no,
Speaker 3: like a no.
Speaker 2: But maybe if you're really really quick and nobody is looking,
Speaker 2: sort of rule exactly.
Speaker 3: And there are actual theoretical models. These are speculative, but
Speaker 3: they're out there, things called Quan models that play with
Speaker 3: this idea quon as in q yes. In standard physics,
Speaker 3: a particle is either a fermion, which is antisocial, or
Speaker 3: a boson, which is social. It's binary, it's one or
Speaker 3: the other, flagger white. But Quan models speculate what if
Speaker 3: there's a spectrum. What if a particle could be, say,
Speaker 3: ninety nine point nine percent fermion, but have a tiny
Speaker 3: tiny bit of boson character mixed in.
Speaker 2: It could occasionally cheat the system.
Speaker 3: It could occasionally cheat. It creates a loophole, a slight violation,
Speaker 3: and if that happens, even incredibly rarely, it would be
Speaker 3: a huge clue to a deeper level of reality. Atels
Speaker 3: that are neat categories of fermion and boson are just
Speaker 3: approximations of something much more complex and interesting.
Speaker 2: And the source. It also mentions another possibility this could
Speaker 2: point to, which is the structure of the electron itself.
Speaker 2: This really blew my mind. We usually think of electrons
Speaker 2: as just dots, little points of charge.
Speaker 3: Correct in the standard model, electrons are fundamental particles. They
Speaker 3: have zero size. They are just a point of charge
Speaker 3: in mass. You can't cut an electron in half.
Speaker 2: But if the exclusion principle can be violated, that might
Speaker 2: change our view of that.
Speaker 3: It could imply that electrons aren't fundamental at all, that
Speaker 3: they might have an internal structure, that they are made
Speaker 3: of even smaller things.
Speaker 2: Like little gears inside or components, or that they are squishy.
Speaker 3: Think about it this way. If two perfectly rigid billiard
Speaker 3: balls hit each other, they bounce off they cannot occupy
Speaker 3: the same space. But if two tennis balls hit each
Speaker 3: other hard enough they can press they deform for a moment.
Speaker 2: So if electrons have internal parts, maybe under extreme pressure
Speaker 2: they can. They can deform slightly and squeeze into a
Speaker 2: state where a perfectly rigid point particle couldn't fit.
Speaker 3: That's the idea exactly. So if we find a violation
Speaker 3: of poly. It's a very strong hint that the electron
Speaker 3: isn't a simple dot, but a complex object with moving parts.
Speaker 2: And then there's a big one, the one everyone's chasing,
Speaker 2: quantum gravity.
Speaker 3: The holy grail of modern physics.
Speaker 2: We are desperately, desperately trying to merge Einstein's general relativity,
Speaker 2: which governs gravity and big stuff like planets and galaxies,
Speaker 2: with quantum mechanics, which governs the small stuff like atoms
Speaker 2: and particles.
Speaker 3: And they hate each other. They just they do not
Speaker 3: get along mathematically. They speak different languages.
Speaker 2: But some of the theories that are trying to build
Speaker 2: that bridge, like certain versions of string theory or quantum
Speaker 2: loot gravity, they actually predict that the poly exclusion principle
Speaker 2: might have tiny, tiny cracks, right.
Speaker 3: Yes, some of them do. Some theories suggest that space
Speaker 3: time itself might not be a smooth, continuous fabric. It
Speaker 3: might be fuzzy or discrete, like it's made of pixels
Speaker 3: at the smallest possible scales, the Plank scale, right, And
Speaker 3: if space is bumpy at that level, it might mess
Speaker 3: with the strict rules of quantum mechanics. It might cause
Speaker 3: an electron to slip or tunnel into a forbidden state
Speaker 3: every once in a while.
Speaker 2: So finding a violation would be like finding a loose thread.
Speaker 2: You pull on it and the whole standard model unravels,
Speaker 2: But underneath you might find the real fabric of the universe.
Speaker 3: That is the hope. That is why they search. Finding
Speaker 3: a violation wouldn't be a disaster for science. It would
Speaker 3: be the greatest discovery of the century. It would be
Speaker 3: the signpost pointing the way to the theory of everything.
Speaker 2: So the stakes are just incredibly high. Either we confirm
Speaker 2: the stability of reality as we know it, or we
Speaker 2: find a portal to a whole new level of physics,
Speaker 2: which brings us to the experiment. How do you actually
Speaker 2: test this? How do you catch an electron cheating?
Speaker 3: This is the VIP two experiment. VIP stands for violation
Speaker 3: of the poly principle.
Speaker 2: And I love the sitting. This isn't happening in a
Speaker 2: shiny lab in a university basement. This is deep.
Speaker 3: Underground Grandsasso National Laboratory. Yeah, it's really an amazing place,
Speaker 3: a series of massive experimental halls that have been hollowed
Speaker 3: out from inside a mountain in Italy. You have to
Speaker 3: drive through a long highway tunnel to even get to
Speaker 3: the entrance.
Speaker 2: Why hide under a mountain. Are they hiding from the electrons?
Speaker 3: No, they're hiding from noise. We are right now constantly
Speaker 3: being bombarded by cosmic rays. These are high energy particles,
Speaker 3: mostly protons, flying in from space from supernovas and distant galaxies.
Speaker 2: And they're hitting our atmosphere.
Speaker 3: They hit the atmosphere and create a shower of secondary particles,
Speaker 3: and some of those particles, especially the ones called muons,
Speaker 3: make it all the way down to the surface. Billions
Speaker 3: of them are passing through your body as we speak. Well,
Speaker 3: that's comforting. It's totally harmless to us. But if you're
Speaker 3: running an experiment that is as sensitive as VIP two,
Speaker 3: a single cosmic ray hitting your detector would be a
Speaker 3: disaster because it would create a flash of energy signal
Speaker 3: that could look just like the violation you're hunting for.
Speaker 3: It would be like trying to listen for a pin
Speaker 3: drop in the middle of a thunderstorm.
Speaker 2: So the mountain acts as a giant umbrella.
Speaker 3: Giant rock umbrella. It's over a kilometer of solid rock
Speaker 3: overhead that blocks out almost all of the cosmic noise.
Speaker 3: Creating one of the quietest places on Earth in terms
Speaker 3: of radiation.
Speaker 2: Okay, got it, So silence, darkness, a mile of rock overhead,
Speaker 2: and in the middle of this cavern they have the
Speaker 2: VIP two apparatus. What are they actually pointing their detectors at.
Speaker 3: A chunk of copper.
Speaker 2: Copper are just just.
Speaker 3: Like copper wire, a strip of high purity copper conductor.
Speaker 3: Copper is a great choice because it's atomic structure is very,
Speaker 3: very well understood. We know exactly where the electrons should be,
Speaker 3: we know their parking spots.
Speaker 2: And they are looking for something called forbidden transitions. We
Speaker 2: touched on this, but walk me through exactly what that
Speaker 2: looks like in the experiment.
Speaker 3: Okay, so imagine the copper atom is like that parking
Speaker 3: garage we talked about. All the lower levels, what physicists
Speaker 3: call the k shell the lshll are full. They are
Speaker 3: packed tight with electrons.
Speaker 2: The VIP section is totally booked.
Speaker 3: Yes, the experimenters are watching to see if an electron
Speaker 3: suddenly jumps from a high outer level down to one
Speaker 3: of those lower levels that is already.
Speaker 2: Occupied, the move that Paully says is completely illegal.
Speaker 3: The forbidden move. Now in physics, energy is never lost,
Speaker 3: it just changes form. When an electron drops from a
Speaker 3: high energy state to a low energy state, it has
Speaker 3: to get rid of that excess energy. Usually this energy
Speaker 3: comes out as a photon, a particle of light. Okay,
Speaker 3: so a flash of light, a flash of light. And
Speaker 3: if an electron were to crash the party and drop
Speaker 3: into an already occupied slot, the energy difference between those
Speaker 3: two levels is very specific. It's a known quantity. It
Speaker 3: would release that energy as an X.
Speaker 2: Ray, an X ray, not visible light, an X.
Speaker 3: Ray because the energy drop is quite large, but not
Speaker 3: just any X ray, because the energy levels are shifted
Speaker 3: just slightly by the presence of the other electrons what's
Speaker 3: called a shielding effect. It would be an X ray
Speaker 3: at a very specific, predictable energy level, a specific color
Speaker 3: of X ray, if.
Speaker 2: You will, and that color should not exist in nature.
Speaker 3: Physic says that transition is impossible, so that specific X
Speaker 3: ray should never ever be emitted by a copper atom.
Speaker 2: So they're basically looking for a very specific flash of
Speaker 2: X ray light that would be the smoking gun of
Speaker 2: a rule violation. It's like looking for a neon green swan.
Speaker 2: If you see one, you know the laws of biology
Speaker 2: as we understand them are broken.
Speaker 3: Precisely. It's an unambiguous signal. But here is the really
Speaker 3: clever part of the VIP two experiment, and this is
Speaker 3: a detail that Alessio Procelli, the late author, really emphasized
Speaker 3: in the report. You can't just stare at a block
Speaker 3: of copper and wait.
Speaker 2: Why not. The electrons are already in there, they're whizzing around.
Speaker 2: One of them might cheat.
Speaker 3: Because of a subtle but very important rule in quantum mechanics,
Speaker 3: violations of this type are effectively forbidden from appearing in
Speaker 3: what we call a closed system.
Speaker 2: A closed system, if you just have.
Speaker 3: A block of copper sitting there, the electrons have already
Speaker 3: settled into their states, they've established their pecking order, they
Speaker 3: are in a stable configuration. They obey something called the
Speaker 3: Messiah Greenberg super selection rule, which basically says, if you
Speaker 3: start with a system of pure fermions, it's going to
Speaker 3: stay a system of pure fermions.
Speaker 2: So it's like staring at a perfectly parked car and
Speaker 2: waiting for it to double park. It's already parked.
Speaker 3: It's done exactly. To catch a violation, you need to
Speaker 3: introduce fresh players you need to create an open system.
Speaker 3: You need to probe the atoms with something new.
Speaker 2: An open system. How do they open it up?
Speaker 3: This is the genius of the experiment. Borcelli explains that
Speaker 3: they injected a huge number of new electrons into the
Speaker 3: copper target.
Speaker 2: How do you just inject electrons into a piece of metal.
Speaker 3: Simple brute force. They run a DC current through it,
Speaker 3: a very very strong electrical current.
Speaker 2: How strong are we talking about?
Speaker 3: One hundred amps?
Speaker 2: Whoa one hundred amps? That's a lot of juice. That's
Speaker 2: not your phone charger. That's like industrial welding level current.
Speaker 3: It is a massive amount of current. They had to
Speaker 3: have integrated cooling systems built into the apparatus just to
Speaker 3: keep the copper strip from melting. But think about what
Speaker 3: a current actually is. It's a river of electrons. By
Speaker 3: running that current, they are forcing billions upon billions of
Speaker 3: new electrons to flow into the copper atoms every single second.
Speaker 2: Uh okay, I see it now. So the current is
Speaker 2: basically a constant river of strangers flowing into the parking garage.
Speaker 3: Yes, and these new electrons they haven't established a relationship
Speaker 3: with the copper atoms yet. They are naive they come
Speaker 3: zooming in looking for a spot to land or just
Speaker 3: a path to pass through. This is the moment of truth.
Speaker 2: This is the real test.
Speaker 3: As these new electrons interact with the atoms, will they
Speaker 3: all follow the rules and stay out of the occupied
Speaker 3: lower levels, or will one of these fresh naive electrons
Speaker 3: try to slip into an occupied seat in the basement.
Speaker 2: That makes so much sense. You're not just watching, You're
Speaker 2: actively stressing the system. You're throwing millions of new cars
Speaker 2: into the lot every second to see if chaos breaks out.
Speaker 3: It creates what they call a clean and decisive test.
Speaker 3: It dramatically increases the probability of catching a violation if
Speaker 3: one exists. It turns a static painting into a chaotic movie.
Speaker 2: So they have the mountain shield, they have the copper target,
Speaker 2: they have the one hundred amp current pumping in fresh electrons,
Speaker 2: and they have these ultralow noise X ray detectors watching
Speaker 2: like hawks. What kind of detectors are these?
Speaker 3: They're called silicon drift detectors. They are extremely precise, a
Speaker 3: type of CCD, and they are cool to incredibly low
Speaker 3: temperatures to reduce any thermal noise. They need to be
Speaker 3: able to distinguish a single forbidden X ray photon from
Speaker 3: any other background radiation that might get through the shielding.
Speaker 2: And how long did they run this? This doesn't sound
Speaker 2: like a weekend project.
Speaker 3: Several years they monitored this target, collecting data, continuously filtering
Speaker 3: out background noise, calibrating, recalibrating, just waiting, waiting for that
Speaker 3: one specific X ray blip that would change the world.
Speaker 2: The patients involved. Is just staggering. The tension must have
Speaker 2: been incredible. I mean, every single time they checked the data,
Speaker 2: they could have been on the verge of rewriting all
Speaker 2: of physics.
Speaker 3: Or confirming that everything is exactly as boring and stable
Speaker 3: as we thought. That is the life of an experimental physicist.
Speaker 3: Ninety nine percent boredom, one percent sheer, terror or elation.
Speaker 2: Now the drum roll, please, After years under a mountain
Speaker 2: watching a supercharge piece of copper, what did they find?
Speaker 3: Nothing? Silence, No such signals were observed. That's the line
Speaker 3: from the paper.
Speaker 2: Not a single one out of all those billions upon
Speaker 2: billions of electrons flowing through one hundred amps per years, not.
Speaker 3: A single forbidden transition was detected.
Speaker 2: Now to a regular person, that sounds like a failure.
Speaker 2: We spent years and millions of dollars looking for a
Speaker 2: ghost and we didn't find it. But in science, and
Speaker 2: especially in this kind of science, a null result is
Speaker 2: a huge deal.
Speaker 3: Right, It is massive. In fact, in precision physics, a
Speaker 3: null result is often more powerful and more important than
Speaker 3: a discovery, because it's not just we found nothing, it's
Speaker 3: we look this hard, with this much incredible precision and
Speaker 3: found nothing.
Speaker 2: It lets them put a number on it.
Speaker 3: It allows them to put another number on the probability,
Speaker 3: an upper limit the number.
Speaker 2: Let's talk about this number, because the article says they
Speaker 2: set an upper limit on the probability of violation.
Speaker 3: Yes, based on the complete absence of a signal over
Speaker 3: the course of the experiment. They concluded that if the
Speaker 3: poly exclusion principle is ever violated for electrons, the probability
Speaker 3: of it happening is smaller than two parts in ten
Speaker 3: to the power of forty three.
Speaker 2: Ten to the forty three. Okay, we throw around big
Speaker 2: numbers on this show all the time, but I really
Speaker 2: need to contextualize that ten to the forty three is
Speaker 2: a one followed by forty three zeros.
Speaker 3: Correct, It is a number so vast it is effectively
Speaker 3: meaningless to the human brain.
Speaker 2: I tried to look up some comparisons for this, and honestly,
Speaker 2: our normal astronomical numbers don't even cut it. The universe
Speaker 2: is about thirteen point eight billion years old. Do you
Speaker 2: know how many seconds that is?
Speaker 3: It's roughly four times ten to the seventeen seconds.
Speaker 2: Okay, so ten to the seventeen we are talking about
Speaker 2: ten to the forty three. That is, that's twenty six
Speaker 2: orders of magnitude larger. That's a trillion, trillion times longer
Speaker 2: than the age of the universe.
Speaker 3: It dwarfs the number of atoms in the Earth. It
Speaker 3: dwarfs the number of stars in the observable universe. It's
Speaker 3: a different class of number. If you ran this experiment
Speaker 3: once every second for the entire history of the universe
Speaker 3: since the Big Bang, you still wouldn't be anywhere close
Speaker 3: to hitting ten to the forty three trials.
Speaker 2: So when they say the probability is less than two
Speaker 2: in ten to the forty three, they are saying that
Speaker 2: the poly exclusion principle is really, really, really correct.
Speaker 3: It is aggressively correct. This is the strongest experimental constraint
Speaker 3: ever achieved for electrons and open systems. It basically says
Speaker 3: that if violations happen, they are so mind bogglingly rare
Speaker 3: that they might as well not exist for all practical purposes.
Speaker 2: It's like saying I'm ninety nine point ninety ninety nine,
Speaker 2: and then you just keep saying nine for another forty
Speaker 2: digits of percent. Sure of this wall of solid exactly.
Speaker 3: It means the note parking sign in the atomic garage
Speaker 3: isn't just a suggestion written on cardboard. It is a
Speaker 3: law enforced with an iron fie. The universe does not
Speaker 3: tolerate cheaters.
Speaker 2: So the headline is physicists fail to break fundamental law
Speaker 2: of the universe. But the fallout what this result means
Speaker 2: for the world of theoretical physics is where the real
Speaker 2: drama lies. Because there were people, smart people betting on
Speaker 2: those violations.
Speaker 3: Oh absolutely, Let's go back to those quand models we
Speaker 3: talked about.
Speaker 2: Right, the middle ground particles, the ones that are only
Speaker 2: kind of fermions.
Speaker 3: Christian Pachikiu, who is another leading member of the VIP
Speaker 3: two collaboration, was pretty blunt about this in the report.
Speaker 3: He said, and I'm quoting, our result places very stringent
Speaker 3: constraints on possible deviations strongly restricting the alternative quand models.
Speaker 2: Translating that from cautious scientists speak, quans are pretty much dead.
Speaker 3: Maybe not completely dead, but they are on life support,
Speaker 3: and the family has been called. If you are a
Speaker 3: theorist building a model where particles can be partially fermionic,
Speaker 3: you now have a massive, massive problem. Your model has
Speaker 3: to explain why that partial behavior is completely invisible to
Speaker 3: the tune of one in ten to the forty three.
Speaker 2: You have to fine tune your theory so precisely that
Speaker 2: it almost becomes absurd just to hide from this experiment.
Speaker 3: Right. It forces those theories into a box so small
Speaker 3: they can barely breathe. It's Okham's razor swinging like a guillotine.
Speaker 3: The simplest explanation that electrons are pure, one hundred percent
Speaker 3: antisocial fermions is winning by a landslide.
Speaker 2: It's like telling a storytelling. Okay, you can write a
Speaker 2: fantasy novel, but you can't use magic, dragons, elves, or swords.
Speaker 2: Eventually you just run out of room to tell that story.
Speaker 3: That's a great analogy, and it's the same thing for
Speaker 3: that hidden structure idea.
Speaker 2: We talked about the squishy electrons made of smaller parts.
Speaker 3: Right, if electrons had internal gears or were made of
Speaker 3: subparticles with some theories called preons, we would expect some give.
Speaker 3: We would accept that occasionally those internal parts would arrange
Speaker 3: themselves in just the right way to allow violation, a
Speaker 3: bit of wiggle room exactly. The profound silence from the
Speaker 3: VIP two experiment suggests that electrons are incredibly simple, incredibly rigid.
Speaker 2: They really are just points, no gears, no fluff, just
Speaker 2: a perfect indivisible dot of negative charge.
Speaker 3: It seems that way. This result is a huge victory
Speaker 3: for the boring but incredibly effective standard model. It reinforces
Speaker 3: the idea that elementary particles are truly elementary. They aren't
Speaker 3: legos made of smaller legos. They are the smallest, most
Speaker 3: fundamental brick.
Speaker 2: And this has to ripple out to the search for
Speaker 2: quantum gravity too.
Speaker 3: The holy grail. Yes, there are all.
Speaker 2: These theories of quantum gravity that predict spacetime itself might
Speaker 2: be a little fuzzy or discreete and that this fuzziness
Speaker 2: might jostle an electron and make it violate the exclusion principle.
Speaker 3: Like driving on a really bumpy road might make you
Speaker 3: swerve out of your lane every now and then.
Speaker 2: That's a perfect analogy. If space time is bumpy, as
Speaker 2: predicted by quantum gravity, the electron might swerve and violate Polly.
Speaker 2: But VIP two shows the electron stays in its lane
Speaker 2: with absolute near perfect precision.
Speaker 3: So that tells us that the road space time must
Speaker 3: be incredibly smooth. Or if it is bumpy, the bumps
Speaker 3: are so ridiculously small they don't affect the electron at all,
Speaker 3: which brings us back to what Catalina Cercian who said,
Speaker 3: any viable extension of quantum theory must reproduce the Paule
Speaker 3: exclusion principle with extraordinary precision.
Speaker 2: It's become a gatekeeper. If you have a cool new
Speaker 2: theory about the universe, a new theory of everything, you
Speaker 2: have to bring it to the VIP two team. And
Speaker 2: if your theory predicts a violation rate that is bigger
Speaker 2: than one in ten to the forty three, they just
Speaker 2: shake their heads and say nope. Back to the drawing board.
Speaker 3: Try again, exactly. It clears the board. It sweeps away
Speaker 3: a lot of speculative clutter and tells theorists the answer
Speaker 3: you're looking for isn't here look elsewhere. It saves us
Speaker 3: from wasting decades of brain power on what are now
Speaker 3: dead ends.
Speaker 2: I want to pivot for a second to something a
Speaker 2: bit more philosophical. Here we're talking about precision. We're talking
Speaker 2: about measuring nothing to an impossible, almost divine degree.
Speaker 3: It is the philosophy of precision.
Speaker 2: Yeah, And the article mentions that this research gets support
Speaker 2: from the FQXi, the Foundational Questions Institute. They love funding
Speaker 2: this kind of deep fundamental stuff.
Speaker 3: If you do, they fund the deep, weird questions, the
Speaker 3: high risk, high reward science that might not have an
Speaker 3: immediate practical application but could change how we see everything.
Speaker 2: So why does precision matter so much? Why is it
Speaker 2: worth years of a physicist's life and millions of euros
Speaker 2: just to add a few more decimal places to a zero.
Speaker 2: Why not just say Okay, it works really well and move.
Speaker 3: On, because precision is where the new physics hides. Think
Speaker 3: about how we discovered general relativity. It wasn't because Newton's
Speaker 3: laws of gravity were completely wrong. Newton was great. His
Speaker 3: laws get us to the moon.
Speaker 2: They worked just fine for most things.
Speaker 3: But the orbit of the planet Mercury was off off
Speaker 3: by a tiny, tiny fraction of degree per century, a
Speaker 3: wobble in its orbit that Newton's theory just could.
Speaker 2: Not explain, and most people would just ignore that.
Speaker 3: They did for decades. But by chasing that tiny wobble,
Speaker 3: that tiny imperfection, Einstein revolutionized our entire understanding of gravity, space,
Speaker 3: and time. He realized Newton wasn't wrong, he was just incomplete.
Speaker 3: The VIP two team is looking for the wobble in
Speaker 3: the poly principle.
Speaker 2: And so far absolutely no wobble.
Speaker 3: Not a hint of a wobble, which brings us to
Speaker 3: what you could call the joy of nothing.
Speaker 2: The joy of nothing. I like that.
Speaker 3: There's a real comfort in this result.
Speaker 2: I feel it, I genuinely do. Knowing that the ground
Speaker 2: isn't going to suddenly turn to liquid and swallow me up,
Speaker 2: Knowing that chemistry is stable, it's nice to know the
Speaker 2: universe isn't glitchy.
Speaker 3: It implies a deep stability to the laws of nature.
Speaker 3: It suggests that the universe isn't just making it up
Speaker 3: as it goes along. There's a rigid, reliable structure to reality.
Speaker 2: But I also sense the frustration and the result.
Speaker 3: Oh absolutely every experimentalist deep down wants to be the
Speaker 3: one to find the anomaly. They want to find the
Speaker 3: crack in the wall. The fact that the wall held
Speaker 3: up is incredibly impressive, but it's also a door slamming
Speaker 3: shut in your face. We wanted to see what was
Speaker 3: on the other side.
Speaker 2: Sorry, the universe is perfect. Go home laughs.
Speaker 3: Essentially, yes, but that doesn't mean you go home. It
Speaker 3: just means you have to build a bigger hammer to
Speaker 3: hit the wall with next time.
Speaker 2: And they are, aren't they. The article clearly mentions the sequel,
Speaker 2: VIP three, because VIP two wasn't precise enough.
Speaker 3: I ever enough. The team is already planning the next
Speaker 3: generation of the experiment. They want to push the sensitivity
Speaker 3: even further.
Speaker 2: How do you even get better than ten to the
Speaker 2: minus forty three?
Speaker 3: Better detectors, silicon drift detectors with even faster timing and
Speaker 3: better energy resolution, more shielding, maybe higher currents, different target materials,
Speaker 3: longer observation times. It's a game of inches, or I guess,
Speaker 3: in this case, a game of femtometers.
Speaker 2: What's the goal ten to the minus fifty?
Speaker 3: Why not? The ultimate goal is to find the breaking point,
Speaker 3: or to prove to an even more ridiculous degree of
Speaker 3: certainty that there is no breaking point.
Speaker 2: And let's say they never find a violation. Let's say
Speaker 2: we get to VIP ten in the year twenty fifty
Speaker 2: and we're at ten to the minus one hundred. What
Speaker 2: does that tell us?
Speaker 3: That might be the most profound result of all. If
Speaker 3: the poly exclusion principle is truly absolute, if it is
Speaker 3: never ever violated, not even once, in the entire life
Speaker 3: span of the universe, it suggests that this rule is
Speaker 3: somehow different from other physical laws. How so, it's not
Speaker 3: just a description of how things move or interact like
Speaker 3: a force. It's more like a geometric necessity of reality.
Speaker 3: It would mean the universe is built on a kind
Speaker 3: of logic that simply cannot be broken.
Speaker 2: It's more like a mathematical truth than a physical law.
Speaker 3: Exactly, it's more like two plus two to four. You
Speaker 3: can't violate that. Maybe the exclusion principle is just two
Speaker 3: plus two oz for matter.
Speaker 2: A logic that cannot be broken, that is that is heavy.
Speaker 2: It is So, as we wrap up this deep dive,
Speaker 2: where does this leave us? What's the big picture?
Speaker 3: It leaves us standing on very very solid ground. Literally,
Speaker 3: we know that electrons are behaving themselves with a discipline
Speaker 3: that is almost unimaginable. We know that the antisocial nature
Speaker 3: of fermions is holding strong.
Speaker 2: My takeaway from all this is a new found respect
Speaker 2: for the humble electron. I usually just think of them
Speaker 2: as electricity, you know, just juice flowing through a wire.
Speaker 2: But really they are the structural beams of the universe,
Speaker 2: and they are incredibly perfectly disciplined. They refuse to sit
Speaker 2: in an occupied seat, and that simple refusal is the
Speaker 2: only reason I exist to talk about them.
Speaker 3: That is a beautiful way to put it. My takeaway
Speaker 3: is the sheer audacity of the experiment itself. We are
Speaker 3: monkeys who evolved on a small rock orbiting an average star,
Speaker 3: and we build a machine inside a mountain to check
Speaker 3: the math of the universe to the forty third decimal place.
Speaker 3: That is something to be proud of as a species.
Speaker 2: It really is. It's the human spirit of inquiry at
Speaker 2: its absolute peak.
Speaker 3: And we aren't done. VIP three is coming. We will
Speaker 3: keep knocking on that door until it either opens or
Speaker 3: we realize it's just painted on the wall.
Speaker 2: Here's a thought to leave you with. Then we've spent
Speaker 2: this whole time talking about how the rules held up,
Speaker 2: how the universe didn't glitch. But think about this. We
Speaker 2: only know the rules hold up here in our quiet
Speaker 2: little corner of the galaxy at relatively low energies in
Speaker 2: a block of.
Speaker 3: Copper, right under normal conditions, so to speak.
Speaker 2: What happens inside a black hole? What happened in the
Speaker 2: first nanosecond of the Big Bang? Does the paly principle
Speaker 2: still hold up when the universe is being crushed into
Speaker 2: a singularity under unimaginable gravity and temperature.
Speaker 3: Or does the no parking sign eventually get torn down
Speaker 3: by the sheer force.
Speaker 2: Of gravity exactly? That's the ultimate question. If gravity gets
Speaker 2: strong enough, can it finally force the electrons to give
Speaker 2: up their space and fall into the same state.
Speaker 3: If the exclusion principle fails at the center of a
Speaker 3: black hole, that might be what a singularity is, all.
Speaker 2: The matter finally collapsing into the forbidden seats.
Speaker 3: Into the forbidden seats.
Speaker 2: And that gives me something to think about me too,
Speaker 2: Until next time, Stay curious.