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CERN Recreates Cosmic Particle Storms Inside the Large Hadron Collider · 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: I want you to imagine, just for a second, That
• 0:30
  Speaker 2: you're standing outside. Okay.
• 0:32
  Speaker 3: Picture a perfectly clear day. Right.
• 0:35
  Speaker 2: There are no clouds. There's no wind. Just, you know,
• 0:38
  Speaker 2: an endless expanse of blue sky.
• 0:40
  Speaker 3: Sounds pretty ideal.
• 0:42
  Speaker 2: It does. But what you probably don't realize is that
• 0:45
  Speaker 2: right this very second, an invisible rainstorm is pouring down
• 0:48
  Speaker 2: on you.
• 0:49
  Speaker 3: And we are definitely not talking about water.
• 0:52
  Speaker 2: No, we are not.
• 0:52
  Speaker 3: Yeah.
• 0:53
  Speaker 2: I mean, we are talking about particles zipping through your
• 0:55
  Speaker 2: body at nearly the speed of light. Relentlessly. Constantly. Constantly.
• 1:00
  Speaker 2: like every single second of your life.
• 1:02
  Speaker 3: It honestly sounds like something out of a science fiction novel.
• 1:05
  Speaker 2: It really does.
• 1:06
  Speaker 3: But it is an absolute physical reality. We're talking about
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  Speaker 3: literal cosmic rainstorms.
• 1:11
  Speaker 2: Right, because high above our heads, you have all this
• 1:13
  Speaker 2: powerful interstellar matter that's constantly striking the very taut of
• 1:17
  Speaker 2: Earth's atmosphere.
• 1:18
  Speaker 3: Exactly. And when those collisions happen, the incoming matter just shatters.
• 1:22
  Speaker 2: It breaks apart.
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  Speaker 3: Yeah, it breaks apart into this massive, completely invisible shower
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  Speaker 3: of subatomic particles that rains all the way down to
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  Speaker 3: the ground.
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  Speaker 2: Passing through buildings, oceans, and.
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  Speaker 3: And yes, even you.
• 1:34
  Speaker 2: So, okay, if this rainstorm is entirely invisible, and we
• 1:38
  Speaker 2: obviously can't feel it when it hits us, how do
• 1:42
  Speaker 2: we even know it's there?
• 1:44
  Speaker 3: That is the big question.
• 1:45
  Speaker 2: Right. Like, how did we first figure out that we
• 1:48
  Speaker 2: were basically being bombarded from space?
• 1:50
  Speaker 3: Well, to answer that, we have to go all the
• 1:52
  Speaker 3: way back to 1912.
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  Speaker 2: Okay.
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  Speaker 3: To this Austrian physicist named Victor Hess.
• 1:57
  Speaker 2: Victor Hess.
• 1:58
  Speaker 3: Yeah. So at the time, scientists had these instruments called
• 2:02
  Speaker 3: electroscopes that measured ambient radiation. Right. And they kept noticing
• 2:06
  Speaker 3: this persistent background radiation everywhere they went.
• 2:09
  Speaker 2: But didn't they think it was coming from the Earth?
• 2:11
  Speaker 3: Exactly. The prevailing scientific consensus was entirely Earth-centric. Like, everyone
• 2:16
  Speaker 3: just assumed this radiation was seeping up from the ground.
• 2:19
  Speaker 2: From, like, radioactive rocks and minerals in the crust.
• 2:22
  Speaker 3: Right. Which, you know, makes sense logically.
• 2:25
  Speaker 2: Sure. If the rocks are radioactive... The ground is obviously
• 2:28
  Speaker 2: the source.
• 2:29
  Speaker 3: Yeah, and based on that logic, if you move further
• 2:31
  Speaker 3: away from the ground, the radiation should steadily decrease.
• 2:35
  Speaker 2: It should drop off.
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  Speaker 3: Exactly. So Victor Hess decided to actually test this, and
• 2:39
  Speaker 3: he did it by taking his radiation measuring instruments and
• 2:43
  Speaker 3: going up in a hot air balloon.
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  Speaker 2: Which is just.
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  Speaker 3: And get this, he did it during a solar eclipse.
• 2:49
  Speaker 2: Oh, wait, really? Why an eclipse?
• 2:51
  Speaker 3: Just to completely rule out the sun as a direct factor.
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  Speaker 2: That is so smart.
• 2:55
  Speaker 3: Right. So he makes several flights, eventually reaching an altitude
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  Speaker 3: of over three miles.
• 3:00
  Speaker 2: Three miles. That's what, like 17,000 feet?
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  Speaker 3: About that.
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  Speaker 2: Yeah.
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  Speaker 3: Which, by the way, was incredibly dangerous in an open
• 3:06
  Speaker 3: basket balloon without supplemental oxygen.
• 3:09
  Speaker 2: Yeah, no kidding. So what actually happens to the radiation levels?
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  Speaker 2: I'm guessing it didn't drop.
• 3:14
  Speaker 3: Not only did it not drop, it significantly increased.
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  Speaker 1: Wow.
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  Speaker 3: Up to a certain point, it dipped slightly, but as
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  Speaker 3: he kept climbing higher into this freezing sky, the radiation
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  Speaker 3: levels rose to several times what they were down at
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  Speaker 3: sea level.
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  Speaker 2: It's like hiking up a mountain to escape a flood,
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  Speaker 2: only to find out the water is actually getting deeper
• 3:33
  Speaker 2: and deeper the higher you go.
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  Speaker 3: That's a great way to put it.
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  Speaker 2: You'd realize pretty quickly it's not a flood bubbling up
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  Speaker 2: from the ground at all. It's a torrential downpour coming
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  Speaker 2: from the sky.
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  Speaker 3: And that is exactly what Hess realized. It totally defied
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  Speaker 3: all expectations of where the source of background radiation should be. Right.
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  Speaker 3: He correctly deduced that this highly penetrating radiation was actually
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  Speaker 3: entering our atmosphere from outer space.
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  Speaker 2: Which is just wild to think about for 1912.
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  Speaker 3: Oh, it fundamentally changed our entire understanding of the universe.
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  Speaker 3: It eventually earned him the Nobel Prize in physics in 1936.
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  Speaker 2: Okay, so what exactly is raining down on us then?
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  Speaker 2: If I hold my hand out in this cosmic storm
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  Speaker 2: right now, what is actually passing through it?
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  Speaker 3: Well, the initial particles that hit the top of our
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  Speaker 3: atmosphere are incredibly fast-moving nuclei.
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  Speaker 2: Okay.
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  Speaker 3: Mostly we're dealing with protons, which are just the nuclei
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  Speaker 3: of hydrogen atoms, right? And they are traveling at blistering speeds.
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  Speaker 2: Like almost light speed.
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  Speaker 3: Exactly. But the really fascinating part happens when they hit
• 4:34
  Speaker 3: our atmosphere.
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  Speaker 2: The shit?
• 4:35
  Speaker 3: Yes. When a proton slams into, say, a nitrogen or
• 4:41
  Speaker 3: oxygen atom high above the Earth, the sheer violence of
• 4:44
  Speaker 3: that impact converts energy into entirely new mass.
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  Speaker 2: So it's not just breaking pieces off.
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  Speaker 3: No, it creates a cascade. A shower of secondary particles
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  Speaker 3: that harbor entirely new fleeting times of exotic matter.
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  Speaker 2: We're talking about antimatter.
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  Speaker 3: Antimatter, yeah. And exotic subatomic particles like muons, pions, and kaons.
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  Speaker 2: Okay, wait. Muons, pions, and kaons. I've heard those terms
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  Speaker 2: thrown around in physics before, but what are they actually doing?
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  Speaker 1: Well.
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  Speaker 2: Like, are they just shattered pieces of the original atom?
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  Speaker 3: Not exactly. Like, they aren't just broken pieces. They are
• 5:17
  Speaker 3: newly forged entities. Oh, I see. Think of Einstein's E
• 5:21
  Speaker 3: equals mc squared.
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  Speaker 2: Energy equals mass.
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  Speaker 3: Right. The kinetic energy of the collision is so incredibly
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  Speaker 3: high that it literally materializes into these exotic particles.
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  Speaker 2: That is mind-blowing.
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  Speaker 3: Yeah. Pions and kaons, for instance, are made up of
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  Speaker 3: quarks and antiquarks.
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  Speaker 2: Okay.
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  Speaker 3: They're incredibly unstable and only exist for a tiny fraction
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  Speaker 3: of a second before decaying into other particles.
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  Speaker 2: Just a flash.
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  Speaker 3: Exactly. But their brief existence in these cosmic showers... actually
• 5:47
  Speaker 3: provided physicists with the very first glimpses of these fundamental particles.
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  Speaker 2: Oh, because this was way before we had, you know,
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  Speaker 2: particle accelerators on Earth to make them ourselves.
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  Speaker 3: Exactly. The atmosphere was our first particle collider.
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  Speaker 2: OK, so where are the original fast moving protons coming from?
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  Speaker 2: Like what kind of engine out in deep space is
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  Speaker 2: firing these things at us?
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  Speaker 3: Oh, they originate from some of the most violent, extreme
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  Speaker 3: places in the entire universe.
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  Speaker 2: Like what?
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  Speaker 3: We're talking about the aftermath of massive exploding stars. Supernovae.
• 6:19
  Speaker 2: Oh, wow. Like the Crab Nebula.
• 6:21
  Speaker 3: Yeah, exactly like the Crab Nebula. The shock waves from
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  Speaker 3: those explosions can accelerate protons for thousands of years. And
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  Speaker 3: the highest energy cosmic rays. Those are likely ejected from
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  Speaker 3: the accretion disks of supermassive black holes.
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  Speaker 2: So the center of distant galaxies.
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  Speaker 3: Right, acting like unimaginably powerful cosmic slingshots.
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  Speaker 2: It's just incredible to think that the debris from a
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  Speaker 2: black hole millions of light years away is essentially washing
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  Speaker 2: over us right now.
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  Speaker 3: It really connects you to the cosmos.
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  Speaker 2: It does. But, you know, beyond the profound nature of that,
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  Speaker 2: why does this matter for the average person? Because you
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  Speaker 2: mentioned earlier that we actually use these cosmic rainstorms as
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  Speaker 2: practical tools.
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  Speaker 3: We do. Because these particles are raining down at a constant,
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  Speaker 3: fairly predictable rate, They interact with our environment in ways
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  Speaker 3: that we can measure.
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  Speaker 2: And utilize. Yes.
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  Speaker 3: For example, back in the mid-20th century, we realized we
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  Speaker 3: could use the byproducts of these cosmic rays for radiocarbon dating.
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  Speaker 2: Okay, I know radiocarbon dating is how we figure out
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  Speaker 2: the age of ancient artifacts, like bones or wooden tools.
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  Speaker 3: Exactly.
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  Speaker 2: But how do cosmic rays actually drive that process?
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  Speaker 3: It all comes down to a very specific interaction high
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  Speaker 3: in the atmosphere.
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  Speaker 2: Okay.
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  Speaker 3: So when a cosmic ray hits an atom, it often
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  Speaker 3: knocks loose neutrons.
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  Speaker 2: Just stray neutrons floating around.
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  Speaker 3: Right. And those stray neutrons drift around and occasionally bump
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  Speaker 3: into a nitrogen-14 atom.
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  Speaker 2: Which is the most abundant gas in our atmosphere.
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  Speaker 3: Exactly. And when that happens, the neutron knocks a proton
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  Speaker 3: out of the nitrogen atom, which effectively transforms it into carbon-14.
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  Speaker 2: Which is a radioactive isotope of carbon.
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  Speaker 3: You got it.
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  Speaker 2: Okay. So the space rain is literally manufacturing this Special
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  Speaker 2: radioactive carbon high in the sky. Yep. But how does
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  Speaker 2: that get into an ancient artifact?
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  Speaker 3: Well, that newly forged carbon-14 mixes with oxygen to become
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  Speaker 3: carbon dioxide.
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  Speaker 2: Oh, and plants absorb carbon dioxide.
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  Speaker 3: During photosynthesis, yeah. And then animals eat the plants. Right.
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  Speaker 3: So you, me, every living thing on Earth has a
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  Speaker 3: very specific, consistent ratio of radioactive carbon-14 in our bodies
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  Speaker 3: right now.
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  Speaker 2: And it's constantly replenished while we're alive because we keep eating.
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  Speaker 3: Exactly.
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  Speaker 2: Exactly.
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  Speaker 3: But the exact moment a plant or animal dies, it
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  Speaker 3: completely stops taking in new carbon-14.
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  Speaker 2: And because carbon-14 is radioactive, it slowly decays over time.
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  Speaker 3: Precisely. It decays back into nitrogen at a known rate.
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  Speaker 2: So by measuring how much carbon-14 is left in, say,
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  Speaker 2: an ancient bone or a piece of charcoal.
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  Speaker 3: Archaeologists can calculate a highly accurate timeline of exactly when
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  Speaker 3: that organism died.
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  Speaker 2: That revolutionized archaeology.
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  Speaker 3: It did. And it is entirely powered by this unseen
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  Speaker 3: cosmic storm.
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  Speaker 2: That is just brilliant. But you also mentioned muons earlier,
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  Speaker 2: those exotic particles created in the shower.
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  Speaker 3: Right, the muons.
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  Speaker 2: I read that geologists and archaeologists are actually using muons
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  Speaker 2: to look inside solid structures.
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  Speaker 3: Yes. This is a really cool technique called muography. Muography. Yeah.
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  Speaker 3: So out of all the particles created in a cosmic
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  Speaker 3: ray shower, muons are the ones most likely to actually
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  Speaker 3: reach the ground.
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  Speaker 2: Because they're heavier.
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  Speaker 3: Exactly. You can think of a muon essentially as a
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  Speaker 3: heavier cousin of the electron.
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  Speaker 2: Okay.
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  Speaker 3: It has the same negative electrical charge, but it is
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  Speaker 3: about 200 times more massive.
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  Speaker 2: So why does being heavy make it useful for looking
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  Speaker 2: inside things?
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  Speaker 3: It's all about its sheer momentum. Normal electrons get stopped
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  Speaker 3: very easily by solid matter. You know, they bump into
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  Speaker 3: the atoms of a wall and just get absorbed or deflected.
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  Speaker 2: They can't get through.
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  Speaker 3: But a muon, because it is 200 times heavier and
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  Speaker 3: traveling near the speed of light, it acts like a
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  Speaker 3: heavy bowling ball rolling through a field of pins.
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  Speaker 2: It just plows straight through.
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  Speaker 3: It plows straight through. It can penetrate hundreds of meters
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  Speaker 3: of solid rock before finally losing its energy.
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  Speaker 2: So it's essentially acting like a giant naturally occurring X-ray.
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  Speaker 3: Exactly. So geologists will place these muon detectors around the
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  Speaker 3: base of an active volcano.
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  Speaker 2: Oh, wow.
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  Speaker 3: Yeah. And because the muons are constantly falling from the sky,
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  Speaker 3: they pass straight through the mountain.
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  Speaker 2: And then hit the detectors on the other side. Right.
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  Speaker 3: So by measuring how many muons make it through to
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  Speaker 3: the detectors, geologists can map the internal density of the volcano.
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  Speaker 2: Because solid rock absorbs more muons, but an empty liquid
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  Speaker 2: magma chamber lets more muons pass through.
• 10:42
  Speaker 3: Exactly.
• 10:42
  Speaker 2: And archaeologists have done the exact same thing with the
• 10:45
  Speaker 2: Egyptian pyramids.
• 10:45
  Speaker 3: They have. By placing muon detectors inside the lower known
• 10:50
  Speaker 3: chambers of the Great Pyramid of Giza, they just looked upward.
• 10:54
  Speaker 2: Just waited for the cosmic rain. Yep.
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  Speaker 3: They mapped the dense stone blocks and a few years
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  Speaker 3: ago actually discovered a previously unknown massive hidden void deep
• 11:03
  Speaker 3: inside the pyramid.
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  Speaker 2: Just by analyzing the variations in this cosmic muon rain.
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  Speaker 3: Just from the rain.
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  Speaker 2: That's incredible. But, okay, if these cosmic rays are so useful, right,
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  Speaker 2: and we understand enough about them to date, fossils, and
• 11:16
  Speaker 2: x-ray pyramids, why are scientists still so obsessed with studying
• 11:21
  Speaker 2: their origins? I mean, it feels like we have a
• 11:23
  Speaker 2: pretty good handle on them.
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  Speaker 3: Well, we have a good handle on the secondary particles.
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  Speaker 2: The rain that reaches the ground. Exactly.
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  Speaker 3: The real mystery lies in the initial impact. The primary
• 11:34
  Speaker 3: cosmic rays themselves.
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  Speaker 2: The ones hitting the top of the atmosphere.
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  Speaker 3: Right. The highest energy cosmic rays carry more kinetic energy
• 11:40
  Speaker 3: than a baseball thrown by a major league pitcher.
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  Speaker 2: Wait. entirely contained within a single subatomic particle.
• 11:47
  Speaker 3: Yes, a single particle. And we still don't fully understand
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  Speaker 3: the exact mechanics of how the universe accelerates particles to
• 11:54
  Speaker 3: those extremes or exactly what those primary particles are even
• 11:57
  Speaker 3: composed of at the very highest energies.
• 12:00
  Speaker 2: So how do we even try to answer that?
• 12:02
  Speaker 3: Traditionally, we look up. We use these enormous observatories like
• 12:05
  Speaker 3: the Telescope Array Project in the high desert of Utah.
• 12:08
  Speaker 2: Oh, in Utah. Yeah.
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  Speaker 1: Yeah.
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  Speaker 3: It is a massive network of over 500 specialized surface
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  Speaker 3: detectors spread across hundreds of square miles of empty land.
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  Speaker 2: That's huge.
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  Speaker 1: It is.
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  Speaker 3: And they are paired with fluorescence detectors, which are essentially
• 12:24
  Speaker 3: specialized cameras that look at the night sky.
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  Speaker 2: What are they looking for? Like a flash of light? Yes.
• 12:29
  Speaker 3: When a high-energy particle slams into the atmosphere, the resulting
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  Speaker 3: shower of particles excites the nitrogen gas in the air.
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  Speaker 2: Okay.
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  Speaker 3: And that causes it to emit this very faint blue
• 12:40
  Speaker 3: ultraviolet glow.
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  Speaker 2: Like a spark in the sky.
• 12:43
  Speaker 3: Exactly. It's incredibly faint, lasting only a few billionths of
• 12:46
  Speaker 3: a second. But the cameras out in Utah act together
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  Speaker 3: as one giant telescope to catch those faint flashes, tracing
• 12:54
  Speaker 3: the path of the shower as it moves through the atmosphere.
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  Speaker 2: I mean, that sounds like an incredible engineering feat, but
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  Speaker 2: there has to be a catch.
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  Speaker 3: There is.
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  Speaker 2: If we have hundreds of square miles of sensors looking
• 13:04
  Speaker 2: at the sky, why is there still a mystery?
• 13:06
  Speaker 3: Because there is a critical, unavoidable flaw in this traditional method.
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  Speaker 3: Even with the best cameras in the world, we cannot
• 13:13
  Speaker 3: see the exact moment the initial particle hits the very
• 13:16
  Speaker 3: top of the atmosphere.
• 13:17
  Speaker 2: Oh, because it's too high up.
• 13:19
  Speaker 3: The air is simply too thin up there to produce
• 13:22
  Speaker 3: enough light for us to see. We only catch the cascade,
• 13:25
  Speaker 3: the resulting shower of particles, after it has already started
• 13:29
  Speaker 3: spreading out and descending.
• 13:30
  Speaker 2: So we are seeing the aftermath of the subatomic car crash.
• 13:35
  Speaker 2: But not the crash itself.
• 13:36
  Speaker 3: Precisely. We only see the debris. So to actually understand
• 13:40
  Speaker 3: the birth of the storm.
• 13:41
  Speaker 2: To decode what that initial primary particle was.
• 13:44
  Speaker 3: Exactly. Scientists have to rely on complex computer models. They
• 13:49
  Speaker 3: feed the debris data into a simulation. And the computer
• 13:52
  Speaker 3: works backward to estimate the mass and energy of the
• 13:55
  Speaker 3: original particle.
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  Speaker 2: But wait, if we can't actually see the initial impact
• 13:59
  Speaker 2: and we're completely relying on simulations to tell us what happened. Mm-hmm.
• 14:02
  Speaker 2: Aren't scientists kind of just guessing at this point?
• 14:05
  Speaker 3: Wow.
• 14:05
  Speaker 2: Like, why should we trust these computer models?
• 14:07
  Speaker 3: And that is the exact problem the physics community has
• 14:10
  Speaker 3: been wrestling with for years. You see, the different computer
• 14:13
  Speaker 3: models wildly disagree with each other.
• 14:16
  Speaker 2: Wildly. But why do they disagree? Shouldn't physics, math just be,
• 14:20
  Speaker 2: you know, universal?
• 14:22
  Speaker 3: The math is universal, but our understanding of the forces
• 14:25
  Speaker 3: involved at those specific extreme energies is incomplete. When particles
• 14:30
  Speaker 3: collide at near light speed... They interact primarily through the
• 14:34
  Speaker 3: strong nuclear force, which is the force that binds the
• 14:37
  Speaker 3: nucleus of an atom together.
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  Speaker 2: Okay, sure.
• 14:40
  Speaker 3: Down here on Earth, we understand how the strong force
• 14:42
  Speaker 3: behaves at lower energies. But these cosmic rays hit with
• 14:46
  Speaker 3: energies far beyond what we typically observe.
• 14:48
  Speaker 2: So the models are basically taking our low energy knowledge
• 14:51
  Speaker 2: and trying to extrapolate it out to high energy extremes.
• 14:54
  Speaker 3: Exactly. And different physicists make different theoretical assumptions about how
• 14:59
  Speaker 3: particles will behave in those extreme conditions, which leads to
• 15:02
  Speaker 3: divergent models.
• 15:03
  Speaker 2: So like one model might say a shower was caused
• 15:06
  Speaker 2: by a heavy iron nucleus. And another model looking at
• 15:09
  Speaker 2: the exact same data might say it was caused by
• 15:12
  Speaker 2: a lighter hydrogen proton.
• 15:13
  Speaker 3: That's exactly what happens. And if you don't know whether
• 15:16
  Speaker 3: you are looking at hydrogen or iron, you can't trace
• 15:19
  Speaker 3: the particle back to its origin.
• 15:21
  Speaker 2: Because iron suggests one type of cosmic event. And hydrogen
• 15:25
  Speaker 2: suggests another.
• 15:26
  Speaker 3: Right. It creates this massive bottleneck in high-energy astrophysics.
• 15:31
  Speaker 2: So what do you do? If the models disagree, and
• 15:35
  Speaker 2: we obviously can't physically strap a microscope to the very
• 15:38
  Speaker 2: edge of Earth's atmosphere to watch the collision happen live,
• 15:42
  Speaker 2: how do we break the tie?
• 15:43
  Speaker 3: In physics, when observation and simulation hit a wall, you
• 15:47
  Speaker 3: turn to experimentation.
• 15:48
  Speaker 2: Okay.
• 15:48
  Speaker 3: If you cannot go up to the edge of the
• 15:50
  Speaker 3: atmosphere to study the cosmic rainstorm up close... you have
• 15:53
  Speaker 3: to figure out a way to build that exact rainstorm
• 15:56
  Speaker 3: down here on Earth.
• 15:57
  Speaker 2: Which means we need a particle accelerator.
• 15:59
  Speaker 3: Yes.
• 15:59
  Speaker 2: And specifically, the Large Hadron Collider at CERN in Switzerland.
• 16:03
  Speaker 3: Correct. In July of 2025, physicists pulled off a truly
• 16:06
  Speaker 3: groundbreaking experiment at CERN.
• 16:08
  Speaker 2: Okay, walk me through this.
• 16:09
  Speaker 3: Researchers like Jesse Liu and Lydia Beresford successfully advocated to
• 16:13
  Speaker 3: take the world's most powerful particle accelerator and temporarily reconfigure
• 16:18
  Speaker 3: it to simulate cosmic rays.
• 16:20
  Speaker 2: Wait, how does that work? I know the Large Hadron
• 16:22
  Speaker 2: Collider usually smashes protons into other protons to look for
• 16:26
  Speaker 2: things like the Higgs boson.
• 16:28
  Speaker 3: Right.
• 16:28
  Speaker 2: How do you reconfigure it to make a sky in
• 16:30
  Speaker 2: a tube?
• 16:31
  Speaker 3: By changing the ingredients of the collision.
• 16:33
  Speaker 2: Okay.
• 16:33
  Speaker 3: To recreate a cosmic ray hitting the atmosphere, you need
• 16:36
  Speaker 3: a proxy for the cosmic ray and a proxy for
• 16:39
  Speaker 3: the atmosphere.
• 16:40
  Speaker 2: So it's a casting call for the universe. What do
• 16:42
  Speaker 2: they use?
• 16:42
  Speaker 3: The proton beam plays the role of the cosmic ray
• 16:45
  Speaker 3: shooting in from deep space.
• 16:47
  Speaker 2: Naturally.
• 16:48
  Speaker 3: But for the atmosphere, they needed something different. Our atmosphere
• 16:52
  Speaker 3: is largely composed of nitrogen and oxygen. Right. So the
• 16:56
  Speaker 3: Sohn scientists introduced a beam of oxygen atoms into the accelerator.
• 17:01
  Speaker 2: Hold on. How do you accelerate an oxygen atom to
• 17:03
  Speaker 2: the speed of light? It's a gas. You can't just
• 17:07
  Speaker 2: pump air into a vacuum tube and push it, right?
• 17:09
  Speaker 3: No, you definitely can't. It requires an incredibly complex pre-acceleration process.
• 17:14
  Speaker 3: All right. You start with oxygen gas, but you have
• 17:17
  Speaker 3: to strip away all of the electrons orbiting the oxygen
• 17:20
  Speaker 3: atoms using intense electric fields.
• 17:22
  Speaker 2: Leaving just the nucleus. Yes.
• 17:25
  Speaker 3: Naked, positively charged oxygen nuclei.
• 17:28
  Speaker 2: Ah, and because they now have a strong electrical charge.
• 17:31
  Speaker 3: You can use the massive, superconducting magnetic fields of the
• 17:35
  Speaker 3: Large Hadron Collider to grip those nuclei and push them
• 17:39
  Speaker 3: faster and faster around the 27-kilometer underground ring.
• 17:44
  Speaker 2: That is wild. So you have a beam of protons
• 17:46
  Speaker 2: going one way and a beam of stripped oxygen nuclei
• 17:50
  Speaker 2: going the other way, both approaching the speed of light.
• 17:52
  Speaker 3: Exactly. And for the very first time in a laboratory setting,
• 17:56
  Speaker 3: scientists steered those two beams to cross and collide.
• 18:00
  Speaker 2: And what happened?
• 18:01
  Speaker 3: When the protons smashed into the oxygen nucleus, the immense
• 18:05
  Speaker 3: kinetic energy of the impact instantly converted into a brilliant
• 18:09
  Speaker 3: spray of entirely new particles.
• 18:11
  Speaker 2: Just like in the atmosphere.
• 18:12
  Speaker 3: Yes. They flawlessly recreated the exact mechanics of the very
• 18:17
  Speaker 3: first milliseconds of a cosmic rainstorm.
• 18:20
  Speaker 2: That is just staggering. They literally bottled the violent energy
• 18:23
  Speaker 2: of a black hole inside a tunnel under the Swiss-French border.
• 18:26
  Speaker 3: It's a profound achievement.
• 18:27
  Speaker 2: But, okay, even if you successfully smash them together, this
• 18:30
  Speaker 2: microscopic explosion is happening in a fraction of a second.
• 18:33
  Speaker 2: How do you actually record and measure something that fast
• 18:36
  Speaker 2: and that small?
• 18:37
  Speaker 3: That is where the ATLAS experiment comes in.
• 18:39
  Speaker 2: ATLAS? Yes.
• 18:40
  Speaker 3: ATLA is one of the massive particle detectors built around
• 18:44
  Speaker 3: a collision point on the Large Hadron Collider ring. It
• 18:48
  Speaker 3: is an instrument the size of a literal football field,
• 18:51
  Speaker 3: buried roughly 100 meters underground.
• 18:53
  Speaker 2: Wait, how does something the size of a football field
• 18:55
  Speaker 2: capture a subatomic particle?
• 18:57
  Speaker 3: It uses layers upon layers of highly specialized technology arranged
• 19:01
  Speaker 3: in concentric cylinders around the collision point.
• 19:03
  Speaker 2: Like an onion?
• 19:04
  Speaker 3: Yeah, like a giant high-tech onion. But at its core,
• 19:08
  Speaker 3: closest to where the impact happens... It uses a massive
• 19:11
  Speaker 3: array of silicon pixel sensors.
• 19:13
  Speaker 2: Silicon sensors. Wait, is that basically the same technology that's
• 19:16
  Speaker 2: in a smartphone camera?
• 19:17
  Speaker 3: Conceptually, yes.
• 19:18
  Speaker 2: Really?
• 19:19
  Speaker 3: Yeah. In your phone's camera, a photon of light hits
• 19:23
  Speaker 3: a silicon pixel, knocks an electron loose, and creates a
• 19:26
  Speaker 3: tiny electrical signal that the phone registers as a piece
• 19:29
  Speaker 3: of the image.
• 19:30
  Speaker 2: Okay.
• 19:31
  Speaker 3: The inner tracker of the ATLA's detector works on a
• 19:34
  Speaker 3: very similar principle, just scaled up to an incomprehensible degree
• 19:37
  Speaker 3: of complexity and speed. When the subatomic particles fly outward
• 19:41
  Speaker 3: from the proton-oxygen collision, they pass through these silicon wafers.
• 19:46
  Speaker 3: And as a charged particle pushes through the silicon, it
• 19:50
  Speaker 3: knocks electrons loose, creating a tiny electrical hit.
• 19:54
  Speaker 2: So as a particle travels outward through the concentric layers,
• 19:58
  Speaker 2: it's basically leaving a connect-the-dots trail of electrical signals.
• 20:01
  Speaker 3: Precisely. By connecting those dots, scientists can map the exact
• 20:05
  Speaker 3: trajectory of the particle.
• 20:06
  Speaker 2: That's amazing.
• 20:08
  Speaker 3: Furthermore, because the entire detector is based in a massive
• 20:11
  Speaker 3: magnetic field, the path of the particle curves.
• 20:14
  Speaker 2: Oh, because of the charge. Right.
• 20:16
  Speaker 3: And by measuring exactly how much it curves, scientists can
• 20:19
  Speaker 3: calculate the particle's momentum and precisely identify what kind of
• 20:23
  Speaker 3: particle it is.
• 20:24
  Speaker 2: And ATLAs isn't just doing this once or twice. I mean,
• 20:26
  Speaker 2: when the collider is running, it's capturing an unbelievable amount
• 20:29
  Speaker 2: of data. I saw that the high-speed camera setup at
• 20:32
  Speaker 2: the heart of ATLAs can take more than 200 million
• 20:35
  Speaker 2: photos or, you know, collision events instantly. In a single day.
• 20:38
  Speaker 3: Yes. The data generation is so immense that they actually
• 20:41
  Speaker 3: have to use supercomputers to filter out the noise in
• 20:44
  Speaker 3: real time, only saving the most significant collisions.
• 20:48
  Speaker 2: 200 million. That's insane.
• 20:50
  Speaker 3: But the sheer volume of data is exactly what we
• 20:52
  Speaker 3: needed to solve the mystery.
• 20:54
  Speaker 2: So that brings us to the ultimate payoff. Yes. We
• 20:56
  Speaker 2: built a football field-sized camera. We spent millions to accelerate
• 21:01
  Speaker 2: naked oxygen atoms to the speed of light. And we
• 21:03
  Speaker 2: took billions of pictures of this tiny artificial sky. What
• 21:08
  Speaker 2: did we actually learn? Like, did it solve the argument
• 21:11
  Speaker 2: between the computer models?
• 21:13
  Speaker 3: It did something better than just settle an argument. It
• 21:15
  Speaker 3: provided hard empirical truth. The results of this proton oxygen
• 21:20
  Speaker 3: run were recently published in physical review letters, and they
• 21:23
  Speaker 3: represent a massive leap forward for particle physics.
• 21:27
  Speaker 2: How so?
• 21:28
  Speaker 3: By analyzing the images, the physicists were able to count
• 21:30
  Speaker 3: exactly how many particles were created in these specific collisions,
• 21:34
  Speaker 3: and they measured the precise energies at which those particles
• 21:36
  Speaker 3: flew outward.
• 21:37
  Speaker 2: And how did that compare to what the computer models
• 21:40
  Speaker 2: were guessing before?
• 21:41
  Speaker 3: Well, because they were observing this directly in a controlled lab,
• 21:44
  Speaker 3: rather than trying to infer it from faint flashes in
• 21:47
  Speaker 3: the Utah night sky, they measured the properties of these
• 21:50
  Speaker 3: interactions with more than 10 times the precision of the
• 21:53
  Speaker 3: old computer models.
• 21:54
  Speaker 2: 10 times the precision? Yes. That's not just a minor tweak.
• 21:58
  Speaker 2: That's like taking off a blindfold.
• 22:00
  Speaker 3: It is entirely transformative. This high precision data from CERN
• 22:05
  Speaker 3: acts as a Rosetta Stone for astrophysicists. We now have
• 22:09
  Speaker 3: a ground truth measurement of exactly how a proton interacts
• 22:12
  Speaker 3: with an oxygen atom at these extreme energies.
• 22:15
  Speaker 2: So scientists can now take this ground truth math from
• 22:18
  Speaker 2: Switzerland and plug it directly into the computer models they
• 22:22
  Speaker 2: use for the telescope array out in Utah.
• 22:24
  Speaker 3: Exactly. By updating the models with this empirical data, the
• 22:28
  Speaker 3: disagreements between the simulations will just evaporate.
• 22:30
  Speaker 2: Wow.
• 22:31
  Speaker 3: We will finally be able to look at the secondary
• 22:33
  Speaker 3: particle showers hitting the ground and pinpoint with high confidence
• 22:37
  Speaker 3: whether the primary cosmic ray that started it all was
• 22:40
  Speaker 3: a light hydrogen proton or a heavy atomic nucleus.
• 22:43
  Speaker 2: Which ultimately tells us where they came from.
• 22:45
  Speaker 3: Yes. It officially bridges a major historical gap.
• 22:49
  Speaker 2: Between the microscopic and the cosmic.
• 22:51
  Speaker 3: Exactly. It renews the link between particle physics, the study
• 22:56
  Speaker 3: of the incredibly small and high energy astrophysics, the study
• 22:59
  Speaker 3: of the incredibly massive, Right. By understanding the exact composition
• 23:03
  Speaker 3: of these cosmic rays, we are drawing a new map
• 23:06
  Speaker 3: to track down the most extreme violent events in the universe,
• 23:10
  Speaker 3: tracing the subatomic debris all the way back to the
• 23:12
  Speaker 3: black holes and exploding stars that fired them at us.
• 23:15
  Speaker 2: It is profound to think that by bringing the cosmos
• 23:19
  Speaker 2: down into a laboratory and smashing it apart, we are
• 23:23
  Speaker 2: quite literally reconstructing the origins of the universe using its
• 23:26
  Speaker 2: fundamental building blocks.
• 23:28
  Speaker 3: It's human curiosity at its absolute best.
• 23:30
  Speaker 2: It really is. But as we wrap this up, there
• 23:33
  Speaker 2: is one final thought that keeps lingering in my mind.
• 23:36
  Speaker 3: What's that?
• 23:36
  Speaker 2: Well, we established right at the start of our conversation
• 23:39
  Speaker 2: that these particles are passing through your body right now,
• 23:43
  Speaker 2: every single second.
• 23:44
  Speaker 3: Raining down constantly.
• 23:46
  Speaker 2: And we know that they carry the chaotic high-speed energy
• 23:48
  Speaker 2: of exploding stars. We know they are heavy and fast
• 23:52
  Speaker 2: enough to be used to map dense, solid rock inside
• 23:56
  Speaker 2: active volcanoes. And we know they can penetrate the heavy
• 23:59
  Speaker 2: stone of ancient pyramids.
• 24:01
  Speaker 3: Oh, I see where you're going with this.
• 24:02
  Speaker 2: Knowing all of that, knowing that this relentless cosmic rainstorm
• 24:06
  Speaker 2: is shooting right through our biology, right through our very
• 24:09
  Speaker 2: cells every day of our lives, it makes you wonder.
• 24:13
  Speaker 3: It does.
• 24:14
  Speaker 2: What tiny unseen impacts are these relentless cosmic rainstorms having
• 24:18
  Speaker 2: on the human body over the course of a lifetime?
• 24:21
  Speaker 3: That's a fascinating question.
• 24:22
  Speaker 1: Right.
• 24:23
  Speaker 2: Could these subatomic collisions be driving subtle genetic mutations? Are
• 24:27
  Speaker 2: they a hidden variable in the long, slow march of
• 24:30
  Speaker 2: human evolution itself?
• 24:31
  Speaker 3: It's very possible.
• 24:32
  Speaker 2: It is definitely something to ponder the next time you
• 24:34
  Speaker 2: step outside, feel the sun on your face, and look
• 24:36
  Speaker 2: up at a seemingly empty sky.