Latest / The Quark Side - Quantum Physics Podcast / Scientists Build a Detector to See Inside Exotic Atomic Nuclei

Transcript

Scientists Build a Detector to See Inside Exotic Atomic Nuclei · The Quark Side - Quantum Physics Podcast

• 0:01
  Speaker 1: Welcome to the Quarkside Quantum Physics Podcast, an exploration of
• 0:05
  Speaker 1: the fundamental structure of reality, where quantum laws govern matter, energy,
• 0:11
  Speaker 1: and information. Here, uncertainty is a feature, not a flaw,
• 0:16
  Speaker 1: and understanding begins at the smallest scales.
• 0:27
  Speaker 2: So I want you to picture an atom in your head. Just,
• 0:30
  Speaker 2: you know, close your eyes for a second and try
• 0:32
  Speaker 2: to visualize it.
• 0:32
  Speaker 3: Yeah, I think I know exactly what everyone is picturing
• 0:35
  Speaker 3: right now.
• 0:35
  Speaker 2: Right. It's that classic textbook diagram, like the one we
• 0:38
  Speaker 2: all saw in middle school chemistry. You've got this neat,
• 0:41
  Speaker 2: perfectly spherical little cluster of protons and neutrons just sitting
• 0:45
  Speaker 2: right there in the dead center.
• 0:47
  Speaker 3: With maybe some electron orbits swooping around it like rings
• 0:50
  Speaker 3: on a planet.
• 0:51
  Speaker 2: Exactly. And it feels orderly. It feels balanced. It's just
• 0:54
  Speaker 2: You know, a really comforting image of how the universe
• 0:57
  Speaker 2: is built.
• 0:57
  Speaker 3: It is comforting, but, I mean, it's basically a fairy tale.
• 1:00
  Speaker 2: Really?
• 1:00
  Speaker 3: Yeah, pretty much. We like to think of the fundamental
• 1:03
  Speaker 3: building blocks of our reality as these perfect, symmetrical little
• 1:07
  Speaker 3: spheres because it gives us a sense that the universe
• 1:10
  Speaker 3: makes intuitive sense, right? At its core, at least. But
• 1:14
  Speaker 3: the reality is actually very different.
• 1:15
  Speaker 2: Right, because when we look closely at nuclei, especially the
• 1:19
  Speaker 2: really unusual ones, they are Well, they deform. They contort
• 1:23
  Speaker 2: into these bizarre, exotic shapes.
• 1:25
  Speaker 3: They really do. We're talking about nuclei that are shaped
• 1:27
  Speaker 3: like pears. Or nuclei shaped like American footballs. And even
• 1:33
  Speaker 3: some that are spinning around that look like flat little frisbees.
• 1:36
  Speaker 2: Flat frisbees. That is so wild to think about.
• 1:38
  Speaker 3: It is. That spherical cluster is really just a convenient
• 1:42
  Speaker 3: shorthand for introductory science classes.
• 1:44
  Speaker 2: Right, to make the math easier for kids.
• 1:46
  Speaker 3: Exactly. But when you get into the actual mechanics of
• 1:49
  Speaker 3: nuclear physics... These nuclei are incredibly dynamic. Figuring out why
• 1:54
  Speaker 3: a nucleus distorts itself into a pear shape and exactly
• 1:57
  Speaker 3: when it chooses to do so is crucial for predicting
• 2:00
  Speaker 3: how matter is going to behave on a fundamental level.
• 2:03
  Speaker 2: And that's exactly what we are getting into today. We
• 2:06
  Speaker 2: are going straight into the microscopic deep end to explore
• 2:09
  Speaker 2: why these tiny building blocks of the universe shapeshift and
• 2:12
  Speaker 2: the groundbreaking new technology that finally lets scientists actually see
• 2:16
  Speaker 2: these shapes.
• 2:17
  Speaker 3: With unprecedented clarity, I might add.
• 2:19
  Speaker 2: Yeah, and we'll get into why understanding these microscopic Frisbees
• 2:22
  Speaker 2: is critical for everything from the power grid to national security.
• 2:26
  Speaker 3: It's a journey that takes us right to the edge
• 2:28
  Speaker 3: of modern scientific capability, honestly. Because figuring out what a
• 2:32
  Speaker 3: nucleus looks like is, well, it's one of the most
• 2:35
  Speaker 3: difficult engineering problems in physics.
• 2:38
  Speaker 2: Before we even get into the technology of how we
• 2:40
  Speaker 2: see them, I'm stuck on just the basic concept of
• 2:43
  Speaker 2: Why would a nucleus look like a football or a
• 2:46
  Speaker 2: pear in the first place? What is physically pushing or
• 2:49
  Speaker 2: pulling it out of that perfect spherical shape?
• 2:52
  Speaker 3: Okay, so it comes down to this constant microscopic tug
• 2:55
  Speaker 3: of war happening inside the nucleus. You have protons and
• 3:00
  Speaker 3: neutrons packed tightly together. Now, protons are all positively charged,
• 3:04
  Speaker 3: which means they naturally repel each other.
• 3:07
  Speaker 2: Right, like magnets pushing away from each other.
• 3:09
  Speaker 3: Exactly. They want to fly apart, but They're held together
• 3:14
  Speaker 3: by something called the strong nuclear force, which acts like
• 3:17
  Speaker 3: this incredibly tight rubber band wrapping them all up.
• 3:21
  Speaker 2: So you have the electromagnetic force trying to blow the
• 3:23
  Speaker 2: nucleus apart, and then the strong force is desperately squeezing
• 3:27
  Speaker 2: it together.
• 3:28
  Speaker 3: Yes, and how those forces balance out really depends on
• 3:31
  Speaker 3: the exact number of protons and neutrons. In physics, there
• 3:35
  Speaker 3: are what we call magic numbers.
• 3:38
  Speaker 2: Magic numbers.
• 3:39
  Speaker 3: Yeah, magic numbers. They are specific quantities of protons and
• 3:43
  Speaker 3: neutrons that fit together perfectly to create a closed, stable,
• 3:48
  Speaker 3: perfectly spherical shell.
• 3:50
  Speaker 2: OK, so if you hit the magic number, you get
• 3:52
  Speaker 2: the textbook sphere.
• 3:53
  Speaker 1: Right.
• 3:54
  Speaker 3: But when you have a nucleus that falls between those
• 3:56
  Speaker 3: magic numbers, the shell is only partially full. The particles
• 4:00
  Speaker 3: start interacting with each other differently, reorganizing themselves to find
• 4:04
  Speaker 3: the most stable energy state. Oh, I see.
• 4:08
  Speaker 2: So the easiest way to relieve that internal tension is
• 4:10
  Speaker 2: for the whole structure to bulge out into a football
• 4:14
  Speaker 2: or flatten into a frisbee.
• 4:16
  Speaker 3: Exactly. It's all about finding stability.
• 4:19
  Speaker 2: Okay, well, that makes sense. It's structural tension. But since
• 4:23
  Speaker 2: these things are impossibly small, how do scientists actually figure
• 4:27
  Speaker 2: out it's shaped like a football? I mean, we can't
• 4:29
  Speaker 2: just put an atom under a normal microscope and turn
• 4:32
  Speaker 2: on a light bulb.
• 4:33
  Speaker 3: No, not at all. Traditional optics are completely useless at
• 4:36
  Speaker 3: this scale. Since we can't look at them with light,
• 4:40
  Speaker 3: we have to interact with them in a much more
• 4:42
  Speaker 3: aggressive way.
• 4:43
  Speaker 2: Aggressive how?
• 4:45
  Speaker 3: Well, the standard experimental setup for this kind of nuclear
• 4:48
  Speaker 3: physics essentially boils down to a microscopic demolition derby.
• 4:53
  Speaker 2: Demolition derby. Yeah.
• 4:55
  Speaker 3: If you want to know what a nucleus looks like,
• 4:57
  Speaker 3: you basically have to smack it with something else and
• 4:59
  Speaker 3: measure what happens.
• 5:01
  Speaker 2: So we're firing things at each other in a particle accelerator. Right.
• 5:04
  Speaker 3: It's the gist of it. The process involves taking a
• 5:07
  Speaker 3: beam of particles, usually heavy ions, and shooting it at
• 5:10
  Speaker 3: incredibly high speeds toward a stationary target foil.
• 5:13
  Speaker 2: Okay.
• 5:14
  Speaker 3: You're firing projectile nuclei at target nuclei. The overwhelming majority
• 5:19
  Speaker 3: of the time, they miss entirely. But eventually, one of
• 5:22
  Speaker 3: those projectiles is going to strike a nucleus in the target.
• 5:26
  Speaker 3: And when that collision happens, they don't merge. They scatter
• 5:30
  Speaker 3: off of each other.
• 5:31
  Speaker 2: They just ricochet away from the impact. Right.
• 5:34
  Speaker 3: But the aftermath of that collision is where the real
• 5:37
  Speaker 3: physics happens. This isn't like two solid billiard balls bouncing
• 5:41
  Speaker 3: off one another.
• 5:42
  Speaker 2: Because they are so tiny.
• 5:43
  Speaker 3: Partly, but mainly because the collision transfers a massive amount
• 5:47
  Speaker 3: of kinetic energy into the projectile nucleus. It gets bumped
• 5:51
  Speaker 3: into what we call an excited state.
• 5:53
  Speaker 2: Okay, wait. When you say excited state, what does that
• 5:57
  Speaker 2: actually mean? Is it physically vibrating or something?
• 6:00
  Speaker 3: Yeah, pretty much. It's taking on way more energy than
• 6:03
  Speaker 3: it can comfortably hold. It gets bumped out of its
• 6:06
  Speaker 3: ground state, which is its stable resting state.
• 6:09
  Speaker 2: Right, the state where it was just chilling.
• 6:11
  Speaker 3: Exactly. Because of all that extra energy, the nucleus just
• 6:14
  Speaker 3: goes completely haywire. It starts vibrating violently, rotating and tumbling
• 6:18
  Speaker 3: through space.
• 6:19
  Speaker 2: Wow.
• 6:20
  Speaker 3: And nature hates excess energy. The nucleus desperately wants to
• 6:24
  Speaker 3: shed that energy so it can calm down and return
• 6:26
  Speaker 3: to its normal shape.
• 6:27
  Speaker 2: But how does it dump the energy if it's just
• 6:29
  Speaker 2: tumbling through a vacuum?
• 6:31
  Speaker 3: By emitting gamma rays.
• 6:32
  Speaker 2: Ah, okay. Yeah.
• 6:34
  Speaker 3: These flashes of high-energy electromagnetic radiation shoot out of the
• 6:37
  Speaker 3: nucleus in rapid succession as it settles back down into
• 6:41
  Speaker 3: its preferred configuration.
• 6:42
  Speaker 2: Okay, I'm trying to visualize this, and tell me if
• 6:45
  Speaker 2: this analogy tracks. It feels like hitting a massive metallic
• 6:48
  Speaker 2: gong with a baseball in a pitch-black room.
• 6:51
  Speaker 3: I like where this is going.
• 6:52
  Speaker 2: So you throw the baseball as hard as you can.
• 6:54
  Speaker 2: When it hits, the gong physically flies backward from the impact,
• 6:58
  Speaker 2: and that's the scattering part.
• 6:59
  Speaker 3: Right.
• 7:00
  Speaker 2: But because you hit it with so much energy, the
• 7:02
  Speaker 2: gong is also fiercely vibrating and ringing out this incredibly
• 7:05
  Speaker 2: loud noise as it flies through the dark.
• 7:07
  Speaker 3: Yes, exactly. And in this case, that loud ringing noise
• 7:10
  Speaker 3: is the emission of the gamma rays.
• 7:12
  Speaker 2: Okay, got it. So we are listening for the ringing.
• 7:15
  Speaker 3: Well, you need both. The gong flying backward gives you
• 7:18
  Speaker 3: the kinetic scattering data. And the acoustic ringing gives you
• 7:22
  Speaker 3: the energy emission data. Right. If you're a scientist trying
• 7:25
  Speaker 3: to reverse engineer the exact shape, thickness, and material of
• 7:28
  Speaker 3: that gong without ever turning on the lights, you need
• 7:31
  Speaker 3: to measure both how fast it flew backward and the
• 7:33
  Speaker 3: exact pitch and frequency of the sound it made while
• 7:36
  Speaker 3: it was vibrating.
• 7:37
  Speaker 2: So if you capture both the physical ricochet and the
• 7:39
  Speaker 2: ringing perfectly, you can map the actual geometry of the gong.
• 7:42
  Speaker 3: Precisely. And predicting when and why these nuclei distort isn't
• 7:46
  Speaker 3: just a parlor trick to update our textbook diagrams.
• 7:49
  Speaker 2: I mean, I assume there's a practical application here.
• 7:52
  Speaker 3: Huge ones. Form dictates function, even at the subatomic level.
• 7:56
  Speaker 3: The shape of a nucleus fundamentally changes how it interacts
• 7:59
  Speaker 3: with other particles, how it decays, and how stable it is.
• 8:03
  Speaker 2: So the shape literally dictates what the matter can do.
• 8:05
  Speaker 3: Exactly. If theorists want to build a mathematical model that
• 8:09
  Speaker 3: can perfectly predict how a certain material will behave under
• 8:12
  Speaker 3: extreme stress, or inside a nuclear reactor, they have to
• 8:16
  Speaker 3: know the actual geometric constraints of the nuclei involved.
• 8:20
  Speaker 2: And these smash tests provide the raw data to prove
• 8:22
  Speaker 2: if their mathematical theories are actually correct. Right.
• 8:26
  Speaker 3: But that brings up a massive technical hurdle. We have
• 8:28
  Speaker 3: to smack the gong, measure the backward movement, and listen
• 8:32
  Speaker 3: to the ringing.
• 8:33
  Speaker 2: Yeah, that sounds impossible.
• 8:35
  Speaker 3: It's incredibly hard. Because this entire collision and emission process
• 8:38
  Speaker 3: is happening in a fraction of a fraction of a nanosecond.
• 8:42
  Speaker 3: At a scale we can't see while the object is
• 8:45
  Speaker 3: flying away at a percentage of the speed of light.
• 8:48
  Speaker 2: Right. So you'd need insanely fast cameras for that.
• 8:51
  Speaker 3: And that's exactly where the technological bottleneck has historically been.
• 8:54
  Speaker 3: We needed machines capable of catching all of that simultaneously.
• 8:58
  Speaker 2: Which brings us to this massive technological breakthrough spearheaded by
• 9:02
  Speaker 2: researchers at the Lawrence Livermore National Laboratory.
• 9:05
  Speaker 3: Yes. They've developed a new detector that's kicking off a
• 9:08
  Speaker 3: whole new era of extremely sensitive studies into nuclear shapes. Right.
• 9:13
  Speaker 2: So this new detector is called CHICO-X, which stands for
• 9:16
  Speaker 2: Compact Heavy Ion Counter Version X.
• 9:19
  Speaker 1: Catchy.
• 9:20
  Speaker 3: I know.
• 9:20
  Speaker 2: Very catchy. And it's designed to work in tandem with
• 9:23
  Speaker 2: a partner instrument called GRETA, which is the Gamma Ray
• 9:26
  Speaker 2: Energy Tracking Array.
• 9:27
  Speaker 3: Right. Chicox and GRETA capture both halves of that gong
• 9:31
  Speaker 3: collision at the exact same time. Okay.
• 9:34
  Speaker 2: But I'm a bit lost on why we need a
• 9:36
  Speaker 2: two-part setup here. Like, If Greta is this massive, highly
• 9:40
  Speaker 2: sensitive sphere specifically built to capture the gamma rays being emitted,
• 9:44
  Speaker 2: the ringing of the gong, why do we need Chicox
• 9:47
  Speaker 2: at all?
• 9:47
  Speaker 3: That's a fair question.
• 9:49
  Speaker 2: Haven't we already taken the picture if we catch the
• 9:51
  Speaker 2: gamma rays? Doesn't the light tell us what the shape is?
• 9:54
  Speaker 3: On paper, it seems like the gamma rays should be enough.
• 9:56
  Speaker 3: But remember the physical reality of the experiment.
• 9:59
  Speaker 2: Okay.
• 10:00
  Speaker 3: The nucleus isn't sitting still while it emits those gamma
• 10:02
  Speaker 3: rays it's moving it's just been smashed and it's flying
• 10:05
  Speaker 3: off in a very specific direction at a very high
• 10:08
  Speaker 3: velocity right right.
• 10:10
  Speaker 2: The baseball hit the gong and the gong is flying.
• 10:12
  Speaker 3: Backward now think about the doppler effect oh okay We
• 10:16
  Speaker 3: experience it all the time with sound. An ambulance siren
• 10:18
  Speaker 3: sounds high-pitched when it's driving towards you, and the pitch
• 10:21
  Speaker 3: drops noticeably the second it passes you and drives away.
• 10:24
  Speaker 2: Yeah, it goes from a wee-woo-wee-woo to a low wom-wom.
• 10:28
  Speaker 3: Exactly. The sound waves get compressed or stretched out depending
• 10:31
  Speaker 3: on the object's movement relative to you. Well, the exact
• 10:34
  Speaker 3: same thing happens to light, including gamma rays.
• 10:37
  Speaker 2: Oh, wow. I never thought about that. So the pitch
• 10:41
  Speaker 2: of the gamma ray... The energy signature we're trying to
• 10:44
  Speaker 2: measure is warped by the movement of the nucleus itself.
• 10:47
  Speaker 3: Precisely. If you only have Greta, you're detecting all these
• 10:51
  Speaker 3: gamma rays hitting the spherical wall of the detector. But
• 10:54
  Speaker 3: you don't know the exact trajectory or speed of this
• 10:56
  Speaker 3: specific nucleus that emitted them.
• 10:59
  Speaker 2: So you caught the warped pitch, but without knowing the
• 11:02
  Speaker 2: nucleus's speed and direction, you can't correct the math.
• 11:05
  Speaker 1: Right.
• 11:06
  Speaker 3: The vital angle information is completely lost.
• 11:09
  Speaker 2: Ah, so Chico X is the missing piece of the puzzle.
• 11:12
  Speaker 2: it tracks the exact scattering angle of the particle itself.
• 11:15
  Speaker 3: Exactly. Chico X is a specialized detector that maps the
• 11:19
  Speaker 3: exact trajectory of the scattered heavy ions. So Chico X
• 11:23
  Speaker 3: and Greta perform what physicists call a coincidence measurement.
• 11:28
  Speaker 2: A coincidence measurement?
• 11:29
  Speaker 1: Yeah.
• 11:30
  Speaker 3: When two nuclei collide, Chico X detects the physical particle scattering,
• 11:35
  Speaker 3: and at that exact microscopic fraction of a second, Greta
• 11:39
  Speaker 3: captures the gamma rays.
• 11:40
  Speaker 2: Got it.
• 11:42
  Speaker 3: If both instruments see a signal at the same time,
• 11:44
  Speaker 3: they log it as a single unified event.
• 11:46
  Speaker 2: Okay, here's another way to visualize this. Tell me if
• 11:48
  Speaker 2: this works. Greta alone is basically trying to take a
• 11:52
  Speaker 2: photograph of a race car speeding by. But because the
• 11:55
  Speaker 2: car is moving so fast, the photo comes out completely
• 11:58
  Speaker 2: blurry and smeared.
• 11:59
  Speaker 3: Yeah, that's a great way to put it. Greta captures
• 12:01
  Speaker 3: the smeared blurry energy signature.
• 12:03
  Speaker 2: But then Chico X steps in. It measures the exact
• 12:06
  Speaker 2: speed and angle of the race car. That data acts
• 12:09
  Speaker 2: like a digital autofocus.
• 12:11
  Speaker 3: Exactly.
• 12:12
  Speaker 2: It takes the blurry gamma ray data from Greta, applies
• 12:15
  Speaker 2: the angle correction, and suddenly the image snaps into perfect,
• 12:19
  Speaker 2: razor-sharp clarity.
• 12:20
  Speaker 3: That is perfectly said. The physical scattering data unblurs the
• 12:24
  Speaker 3: energy data.
• 12:25
  Speaker 2: That is incredible.
• 12:27
  Speaker 3: By locking these two highly advanced instruments together in a
• 12:30
  Speaker 3: coincidence measurement, scientists finally have an ultra-high-definition camera for the
• 12:34
  Speaker 3: subatomic world.
• 12:35
  Speaker 2: So they surround the target area in these massive multi-million
• 12:38
  Speaker 2: dollar sensor globes, and they can finally map out the
• 12:41
  Speaker 2: exact geometry of these shape-shifting nuclei.
• 12:43
  Speaker 3: Yeah, it's pretty amazing.
• 12:45
  Speaker 2: But now that they have this perfect autofocus tag team,
• 12:49
  Speaker 2: where are they actually taking it? Because you don't build
• 12:51
  Speaker 2: a hyper-advanced camera just to take pictures of the same
• 12:53
  Speaker 2: stable elements we've understood for decades.
• 12:55
  Speaker 3: No, absolutely not. You take it to hunt down the rarest,
• 12:59
  Speaker 3: most unstable shapes in the universe.
• 13:01
  Speaker 2: Right.
• 13:02
  Speaker 3: The team actually recently deployed Chico-X for its first major
• 13:05
  Speaker 3: experimental campaign. They hooked it up to a precursor of
• 13:09
  Speaker 3: Greta known as Gretina at Argonne National Laboratory's Atlas facility.
• 13:14
  Speaker 2: Wow. I can only imagine the tension in the room
• 13:17
  Speaker 2: for that first run. You spend years designing this instrument,
• 13:20
  Speaker 2: and you just have to hope the autofocus actually snaps
• 13:23
  Speaker 2: the image into clarity when you fire the beam.
• 13:26
  Speaker 3: Oh, I'm sure the sense of relief and excitement was massive.
• 13:30
  Speaker 3: During that initial deployment, they ran nine separate experiments and
• 13:34
  Speaker 3: successfully captured the shapes of 13 different nuclei. 13.
• 13:39
  Speaker 2: That's a huge success for a first run.
• 13:42
  Speaker 3: It really is. It proved the fundamental architecture of the
• 13:45
  Speaker 3: technology works flawlessly. The blur disappeared, and they got pristine data.
• 13:50
  Speaker 2: That is so cool.
• 13:53
  Speaker 3: But that Argon deployment was really just the warm-up.
• 13:55
  Speaker 2: Oh, really?
• 13:56
  Speaker 1: Yeah.
• 13:57
  Speaker 3: The true future of this technology is... the place where
• 14:00
  Speaker 3: it's going to rewrite the physics textbooks over the next
• 14:02
  Speaker 3: two decades, is at a facility called FRIB.
• 14:05
  Speaker 2: FRIB. Okay, which is the Facility for Rare Isotope Beams.
• 14:10
  Speaker 3: Exactly. And the name tells you exactly why it's so important.
• 14:13
  Speaker 3: Up until now, most of our predictive models and our
• 14:16
  Speaker 3: understanding of nuclear shapes have been based heavily on stable,
• 14:20
  Speaker 3: common isotopes.
• 14:22
  Speaker 2: Right, the materials we can easily find and handle here
• 14:24
  Speaker 2: on Earth.
• 14:25
  Speaker 3: Exactly.
• 14:26
  Speaker 2: So studying stable isotopes seems kind of like studying a
• 14:30
  Speaker 2: perfectly built, solid Jenga tower. You know exactly what it's
• 14:34
  Speaker 2: going to do. It's predictable.
• 14:35
  Speaker 3: It's a good comparison.
• 14:36
  Speaker 2: You can tap the table. You can push a block.
• 14:39
  Speaker 2: And the tower follows the basic rules of physics. It
• 14:41
  Speaker 2: stays standing. We understand stable isotopes perfectly.
• 14:45
  Speaker 3: The problem is stable isotopes represent only a tiny fraction
• 14:49
  Speaker 3: of what actually exists in the universe. Right. FRIB is
• 14:52
  Speaker 3: designed to generate beams of highly unstable, exotic nuclei, materials
• 14:57
  Speaker 3: that might only exist naturally in the hearts of exploding
• 14:59
  Speaker 3: supernovae or, you know, for a fraction of a second
• 15:02
  Speaker 3: during a cosmic ray collision.
• 15:04
  Speaker 2: So bringing Chico X and Greta to FRIB is like
• 15:07
  Speaker 2: studying a Jenga tower that's missing half of its base blocks.
• 15:10
  Speaker 3: Basically, yeah.
• 15:11
  Speaker 2: It's incredibly fragile, completely unpredictable, and one tiny tap makes
• 15:15
  Speaker 2: it behave in ways you never expect.
• 15:17
  Speaker 3: Yes, because when we move out of the realm of
• 15:19
  Speaker 3: everyday stability and into these rare exotic systems, the standard
• 15:24
  Speaker 3: rules of physics literally start to bend.
• 15:27
  Speaker 2: Wait, really? The rules just bend?
• 15:29
  Speaker 3: Yeah, properties that we consider absolute laws in stable matter
• 15:33
  Speaker 3: break down when a nucleus becomes highly unstable. The magic
• 15:38
  Speaker 3: numbers we talked about earlier, those specific quantities of protons
• 15:41
  Speaker 3: and neutrons that create a perfect sphere, they actually change
• 15:45
  Speaker 3: in exotic nuclei. Oh, wow. A number that creates a
• 15:48
  Speaker 3: sphere in a stable isotope might create a deformed pear
• 15:51
  Speaker 3: shape in an exotic one. We just don't know until
• 15:54
  Speaker 3: we look.
• 15:55
  Speaker 2: And up until now, we couldn't measure them because producing
• 15:58
  Speaker 2: highly unstable isotopes is incredibly difficult on its own. And
• 16:02
  Speaker 2: we didn't have the Chicox autofocus camera to actually take
• 16:05
  Speaker 2: the picture before the isotope decayed out of existence.
• 16:08
  Speaker 3: Exactly. Facilities like FRIB will synthesize these rare isotopes. And
• 16:13
  Speaker 3: the Chicox and Greta combination will finally allow us to
• 16:16
  Speaker 3: map their bizarre behaviors before they vanish. We're literally charting
• 16:20
  Speaker 3: the unknown edges of the nuclear landscape.
• 16:23
  Speaker 2: I want to ground this in reality for a second, though,
• 16:26
  Speaker 2: because we're talking about subatomic structures and exploding stars. Why
• 16:30
  Speaker 2: does knowing the exact shape of an unstable isotope matter
• 16:33
  Speaker 2: for us down here on Earth, like day to day?
• 16:35
  Speaker 3: Well, it's obviously vital for fundamental science, but it also
• 16:39
  Speaker 3: has immediate critical implications for things like nuclear fission. Oh, OK.
• 16:45
  Speaker 2: Fission.
• 16:46
  Speaker 1: Right.
• 16:46
  Speaker 3: Fission is the process of splitting a nucleus apart to
• 16:49
  Speaker 3: release energy. which is the foundation of nuclear power plants
• 16:52
  Speaker 3: and the global nuclear security apparatus.
• 16:54
  Speaker 2: Okay, so how does the actual shape of the nucleus
• 16:57
  Speaker 2: change how it splits?
• 16:59
  Speaker 3: Think back to the tug-of-war inside the nucleus. The strong
• 17:03
  Speaker 3: force is squeezing it together, and the electromagnetic force is
• 17:06
  Speaker 3: pushing it apart.
• 17:07
  Speaker 2: The rubber band around the magnets.
• 17:09
  Speaker 3: Yes. If you have a perfectly spherical nucleus, the strong
• 17:13
  Speaker 3: force is holding everything tightly in a compact ball. It
• 17:16
  Speaker 3: takes a massive amount of external energy to crack that
• 17:19
  Speaker 3: sphere open. That makes sense. But what if the nucleus
• 17:22
  Speaker 3: is shaped like a stretched out American football?
• 17:26
  Speaker 2: Oh, the two ends of the football are already physically
• 17:30
  Speaker 2: farther apart from each other.
• 17:31
  Speaker 3: Exactly. The protons at the far ends of that football
• 17:35
  Speaker 3: are already stretching the strong nuclear force to its absolute
• 17:38
  Speaker 3: limit just by existing in that deformed shape.
• 17:42
  Speaker 2: Okay, so it's like a rubber band pulled completely taut.
• 17:45
  Speaker 3: Precisely. it takes significantly less extra energy to snap that
• 17:50
  Speaker 3: rubber band and split the football-shaped nucleus in half compared
• 17:53
  Speaker 3: to the sphere. Oh, wow.
• 17:56
  Speaker 2: Okay, so if our predictive models for a nuclear reactor
• 17:58
  Speaker 2: are assuming all the atoms in the fuel are perfect,
• 18:01
  Speaker 2: tough little spheres, but the material actually contains deformed football-shaped
• 18:06
  Speaker 2: nuclei under stress.
• 18:08
  Speaker 3: Then the math is going to be dangerously wrong.
• 18:10
  Speaker 2: Yeah, that sounds really bad.
• 18:12
  Speaker 3: It is. The cross-section probabilities, which is the math that
• 18:16
  Speaker 3: tells us exactly how and when a material will undergo fission,
• 18:20
  Speaker 3: they change dramatically based on the physical geometry of the nucleus.
• 18:24
  Speaker 2: So it's a safety issue.
• 18:25
  Speaker 3: A huge one. National security relies on knowing exactly how
• 18:29
  Speaker 3: aging nuclear stockpiles will behave or how next-generation reactor fuels
• 18:33
  Speaker 3: will perform over decades. If we have a blind spot
• 18:36
  Speaker 3: regarding nuclear deformation, our safety models are incomplete.
• 18:41
  Speaker 2: So by doing this, we're basically future-proofing our understanding of physics.
• 18:45
  Speaker 2: We're testing our mathematical theories against the wildest, most unstable
• 18:50
  Speaker 2: structures in the universe to make sure the math holds
• 18:52
  Speaker 2: up down here.
• 18:53
  Speaker 3: Exactly. The engineers and scientists behind Chico X see this
• 18:56
  Speaker 3: technology driving the field forward for the next 15 to
• 18:59
  Speaker 3: 20 years. It's truly the key to unlocking the chaotic
• 19:03
  Speaker 3: side of the nuclear landscape.
• 19:05
  Speaker 2: It's incredible to think about the conceptual journey we've taken today.
• 19:09
  Speaker 2: I mean, we started with that flawed, perfectly spherical model
• 19:12
  Speaker 2: of the atom.
• 19:12
  Speaker 3: The neat little ball sitting quietly in the center of
• 19:15
  Speaker 3: the textbook diagram. Right.
• 19:16
  Speaker 2: And we've completely shattered it. We've journeyed into this subatomic
• 19:21
  Speaker 2: reality where protons and neutrons are just battling it out,
• 19:25
  Speaker 2: warping their own shells and contorting into vibrating, shape-shifting frisbees
• 19:30
  Speaker 2: and pears.
• 19:31
  Speaker 3: And it really highlights the immense difficulty of proving those
• 19:34
  Speaker 3: shapes even exist. You have to create the microscopic demolition derby.
• 19:38
  Speaker 3: You have to fire heavy ions, cause collisions, and capture
• 19:42
  Speaker 3: the resulting chaos in a fraction of a nanosecond.
• 19:46
  Speaker 2: We have to listen to the ringing of the gong
• 19:48
  Speaker 2: while tracking exactly how fast it flies away in the dark.
• 19:51
  Speaker 2: And we saw how Chico X and Greta solved that
• 19:54
  Speaker 2: impossible problem, capturing the gamma rays and measuring the exact
• 19:57
  Speaker 2: physical scattering angle in a flawless coincidence measurement.
• 20:01
  Speaker 3: It really is the ultimate autofocus, revealing the hidden geometry
• 20:05
  Speaker 3: of the subatomic world.
• 20:07
  Speaker 2: It's a testament to how pushing the boundaries of engineering
• 20:10
  Speaker 2: allows us to push the boundaries of fundamental theory. Right.
• 20:14
  Speaker 3: Without the detector, you can't prove the math. With this
• 20:17
  Speaker 3: detector moving to FRIB, we're finally going to test our
• 20:20
  Speaker 3: models against the most exotic, fragile, and chaotic nuclei in
• 20:23
  Speaker 3: the universe.
• 20:24
  Speaker 2: Which leaves us with a pretty mind-bending idea to ponder.
• 20:28
  Speaker 2: We've learned that when you push matter just outside the
• 20:30
  Speaker 2: realm of everyday stability, when you strip away the familiar
• 20:34
  Speaker 2: Jenga blocks and look at these rare exotic isotopes, the
• 20:37
  Speaker 2: fundamental building blocks of our universe become chaotic.
• 20:41
  Speaker 3: Extremely chaotic.
• 20:42
  Speaker 2: They shapeshift, they become completely unpredictable, and the standard rules
• 20:46
  Speaker 2: of physics just start to break down. It makes you
• 20:49
  Speaker 2: wonder if the microscopic world is this wild and chaotic,
• 20:53
  Speaker 2: just one layer beneath the stable surface we interact with
• 20:56
  Speaker 2: every day, what other bizarre hidden structures might secretly be
• 21:00
  Speaker 2: holding our reality together? Think about that. the next time
• 21:04
  Speaker 2: you close your eyes and picture that neat, perfectly spherical
• 21:07
  Speaker 2: little atom in your head.