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Scientists Build a Tiny Magnet to Hunt Dark Matter · 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: By all the laws of physics, um, The Milky Way
• 0:30
  Speaker 2: should just be tearing itself apart right now.
• 0:32
  Speaker 3: It really should.
• 0:33
  Speaker 2: Like the outer stars of our galaxy are spinning at
• 0:35
  Speaker 2: this extreme velocity. And mathematically speaking, they should just be
• 0:39
  Speaker 2: flung outward into the void.
• 0:41
  Speaker 1: Right.
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  Speaker 3: The centrifugal force of that spin is just way too high.
• 0:44
  Speaker 2: Exactly. It far outweighs the gravitational pull of all the
• 0:48
  Speaker 2: visible matter holding it together. I mean, every star, every nebula,
• 0:53
  Speaker 2: every speck of dust we can see with our most
• 0:56
  Speaker 2: powerful telescopes, It simply does not have enough mass to
• 0:59
  Speaker 2: keep this galactic merry-go-round intact.
• 1:03
  Speaker 3: Which is kind of terrifying when you think about it.
• 1:05
  Speaker 3: It is.
• 1:06
  Speaker 2: The only reason you, our planet, and this entire solar
• 1:08
  Speaker 2: system haven't been scattered into deep space is because of
• 1:11
  Speaker 2: this invisible glue binding the galaxy together. And, you know,
• 1:15
  Speaker 2: we call it dark matter.
• 1:16
  Speaker 3: Yeah, and it remains the most glaring omission in our
• 1:18
  Speaker 3: understanding of the universe. I mean, dark matter is basically
• 1:21
  Speaker 3: the architectural foundation of the cosmos.
• 1:23
  Speaker 2: The scaffolding.
• 1:24
  Speaker 3: Exactly, the scaffolding. It dictates where galaxies form, how they cluster,
• 1:29
  Speaker 3: and why they don't just rip themselves to shreds. Without it,
• 1:33
  Speaker 3: the universe as you and I currently experience it simply
• 1:35
  Speaker 3: cannot exist.
• 1:36
  Speaker 2: But there's a catch.
• 1:37
  Speaker 3: A huge catch. While we can observe its gravitational effects
• 1:41
  Speaker 3: on this massive galactic scale, we have absolutely no idea
• 1:44
  Speaker 3: what this invisible substance actually is.
• 1:47
  Speaker 2: Right. And today, we are crossing into a completely radical
• 1:51
  Speaker 2: new frontier in the hunt for this missing piece of
• 1:54
  Speaker 2: the universe. Because for decades, the search for dark matter
• 1:57
  Speaker 2: has looked a very specific way.
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  Speaker 3: Lots of massive underground tanks.
• 2:01
  Speaker 2: Oh yeah, giant tanks of liquid xenon, huge particle colliders.
• 2:05
  Speaker 2: But physicists are starting to suspect they might have been
• 2:08
  Speaker 2: searching in the wrong place entirely.
• 2:09
  Speaker 3: Or at least looking for the wrong kind of particle.
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  Speaker 2: Exactly. So we are going to look at how this tiny, floating, magnet-like,
• 2:17
  Speaker 2: literally no bigger than a single grain of sand, is
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  Speaker 2: currently being used to search for some of the heaviest
• 2:22
  Speaker 2: invisible matter in existence.
• 2:24
  Speaker 3: The contrast in scale there is just staggering to me.
• 2:28
  Speaker 3: We are deploying microscopic engineering to unravel the largest macro
• 2:31
  Speaker 3: structures in existence.
• 2:33
  Speaker 2: It's wild.
• 2:34
  Speaker 3: Because understanding what physically constitutes that invisible blue. Well, it's
• 2:39
  Speaker 3: the linchpin to understanding the evolution of the universe from
• 2:43
  Speaker 3: the Big Bang right up to the present moment.
• 2:45
  Speaker 2: So to grasp why a floating grain of sand might
• 2:48
  Speaker 2: somehow outsmart these billion dollar underground detectors. We kind of
• 2:52
  Speaker 2: have to look at this massive paradigm shift happening in
• 2:55
  Speaker 2: theoretical physics right now.
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  Speaker 3: The shift in how we think about the size of
• 2:59
  Speaker 3: dark matter. Yeah.
• 3:01
  Speaker 2: For a very long time, scientists built their experiments assuming
• 3:04
  Speaker 2: dark matter particles were incredibly light. They calibrated everything to
• 3:08
  Speaker 2: look for particles with masses roughly in the neighborhood of
• 3:11
  Speaker 2: standard visible atoms.
• 3:13
  Speaker 3: And that was a completely logical starting point. The physics
• 3:16
  Speaker 3: community just naturally assumed the dark sector of the universe
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  Speaker 3: would mirror the scale of the visible sector.
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  Speaker 2: Makes sense, right.
• 3:23
  Speaker 3: Most of those traditional massive underground detectors were engineered specifically
• 3:27
  Speaker 3: to catch WIMPs.
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  Speaker 2: Weakly Interacting Massive Particles.
• 3:31
  Speaker 3: You got it. And those fall right into that lighter
• 3:34
  Speaker 3: atomic mass range.
• 3:35
  Speaker 2: Okay, let's unpack this with a fishing analogy. You build
• 3:38
  Speaker 2: a net for the kind of fish you actually know exist, right?
• 3:40
  Speaker 1: Obviously.
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  Speaker 2: But there is this growing consensus, led by researchers like
• 3:46
  Speaker 2: Andrew Long, suggesting this assumption is just fundamentally flawed.
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  Speaker 3: Completely flawed, yeah.
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  Speaker 2: Theoretical models are now pointing toward the possibility that dark
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  Speaker 2: matter particles aren't the mass of an atom at all.
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  Speaker 2: They could be immensely, almost incomprehensibly heavier.
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  Speaker 3: We are talking about a single invisible fundamental particle that
• 4:05
  Speaker 3: possesses the mass of an entire living biological cell.
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  Speaker 2: Wait, an entire cell? Just one particle?
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  Speaker 3: Just one particle. And that leap in scale, it really
• 4:14
  Speaker 3: cannot be overstated. I mean, a single human biological cell...
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  Speaker 3: contains trillions of atoms.
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  Speaker 2: Trillions? Trillions.
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  Speaker 3: So suggesting that a solitary dark matter particle might weigh
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  Speaker 3: as much as trillions of atoms packed together, that completely
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  Speaker 3: upends all the traditional search parameters. Yeah, Christopher Tunnell, he's
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  Speaker 3: an associate professor of physics and astronomy at Rice University,
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  Speaker 3: and he helped lead this new experimental research. He pointed
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  Speaker 3: out that traditional detectors simply don't have the architectural sensitivity
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  Speaker 3: to register something that heavy.
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  Speaker 2: I can imagine traditional physicists might find that shift a
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  Speaker 2: bit hard to swallow. Like if you've spent 40 years
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  Speaker 2: of your career and billions of dollars in funding building
• 4:55
  Speaker 2: these elaborate fine mesh nets to catch microscopic plankton. Right.
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  Speaker 2: It has to be so jarring to hear a new
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  Speaker 2: generation of theorists come in and say, actually, the target
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  Speaker 2: is the size of a blue whale. And it's just
• 5:08
  Speaker 2: swimming right through your net, tearing it to shreds without
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  Speaker 2: you even noticing.
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  Speaker 3: It's a tough pill to swallow, definitely.
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  Speaker 2: But that brings up a glaring mechanical question for me.
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  Speaker 2: If this invisible stuff is so incredibly massive, why hasn't
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  Speaker 2: it been easier to spot? You'd think a heavy particle
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  Speaker 2: would leave a much bigger footprint.
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  Speaker 3: Well, the difficulty there comes down to a basic principle
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  Speaker 3: of local density.
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  Speaker 2: Okay, how so?
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  Speaker 3: So in our galactic neighborhood, the total overall mass of
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  Speaker 3: dark matter is a relatively fixed number. We know this
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  Speaker 3: because we can literally measure its gravitational pull on our
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  Speaker 3: solar system. Right, the total weight is a known factor. Exactly.
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  Speaker 3: So if you take that fixed total mass and you
• 5:48
  Speaker 3: suddenly decide that the individual particles making it up are
• 5:51
  Speaker 3: trillions of times heavier, then mathematically there must be vastly
• 5:56
  Speaker 3: fewer of those particles passing through our region of space. Ah,
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  Speaker 3: I see.
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  Speaker 2: Because if the total weight of the invisible pie is
• 6:01
  Speaker 2: the same, but you suddenly make the slices a trillion
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  Speaker 2: times bigger, you get way fewer slices.
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  Speaker 3: Basic division, yeah. Instead of this constant torrential downpour of
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  Speaker 3: microscopic atomic particles raining through the Earth every second, You
• 6:14
  Speaker 3: might only have a handful of these massive cell-sized particles
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  Speaker 3: passing through a given area over the course of a
• 6:19
  Speaker 3: whole month. Oh, wow. So they're incredibly rare. Extremely rare.
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  Speaker 3: And traditional detectors require frequent, repeated collisions to separate a
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  Speaker 3: dark matter signal from just random background radiation. So when
• 6:31
  Speaker 3: the particles are this rare, that traditional methodology completely breaks down.
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  Speaker 2: Which brings us to the trap they built at Race University.
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  Speaker 2: Because you can't just build a bigger net for these massive,
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  Speaker 2: rare particles. You need an entirely different mechanism.
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  Speaker 3: A completely new approach.
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  Speaker 2: And the solution they engineered is just a genuine marvel.
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  Speaker 2: It revolves around a permanent magnet about the size of
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  Speaker 2: grain of sand.
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  Speaker 3: The physical detector itself is remarkably simple, honestly. But the
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  Speaker 3: environment they create around it, that is where the breakthrough happens.
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  Speaker 3: They take this tiny magnet and they levitate it above
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  Speaker 3: a superconductor.
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  Speaker 2: I want to pause on the superconductor, actually, because we
• 7:10
  Speaker 2: throw that word around a lot in sci-fi, but the
• 7:12
  Speaker 2: reality of how it works is essential here.
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  Speaker 3: Yeah, it's not just magic.
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  Speaker 2: Right. A superconductor isn't just a powerful magnet pushing back.
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  Speaker 2: When certain materials get cold enough, they undergo this quantum
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  Speaker 2: phase transition where they expel all magnetic fields from inside themselves.
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  Speaker 3: That phenomenon is known as the Meissner effect. So when
• 7:30
  Speaker 3: the tiny permanent magnet is placed over the superconductor, the
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  Speaker 3: superconductor actively rejects the magnet's magnetic field lines.
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  Speaker 2: It's basically creating a perfect invisible magnetic mirror.
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  Speaker 3: Exactly. The magnetic force pushes back against gravity with absolute perfection,
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  Speaker 3: locking that little grain of sand in a state of
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  Speaker 3: stable levitation.
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  Speaker 2: So it is hovering without touching any physical surface. There
• 7:54
  Speaker 2: is no string, no pedestal, no contact whatsoever.
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  Speaker 3: Nothing. And that achieves a state of virtually zero physical friction.
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  Speaker 2: Which is crucial. It is.
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  Speaker 3: But eliminating physical friction is only half the battle. They
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  Speaker 3: also have to eliminate thermal friction. So to do that,
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  Speaker 3: the entire apparatus is sealed in a chamber and cooled
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  Speaker 3: down to just fractions of a degree above absolute zero.
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  Speaker 2: Absolute zero being the theoretical limit where all atomic movement
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  Speaker 2: simply ceases to exist. Everything just freezes. Right.
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  Speaker 3: Because temperature at a fundamental level is really just a
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  Speaker 3: measurement of how violently atoms are vibrating. Heat is microscopic motion.
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  Speaker 2: So if it's warm, things are moving. Yeah.
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  Speaker 3: If you leave a detector at room temperature... The atoms
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  Speaker 3: inside that detector are violently vibrating. They're jittering around and
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  Speaker 3: creating an enormous amount of what physicists call thermal noise.
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  Speaker 2: It is like the difference between trying to detect a
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  Speaker 2: pebble dropping into a boiling, churning cauldron of water versus
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  Speaker 2: detecting that same pebble dropping into a perfectly still, frozen,
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  Speaker 2: glass-like pond.
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  Speaker 3: That's a great analogy.
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  Speaker 2: Like in the boiling water, the splash is completely lost
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  Speaker 2: in all that chaos. But in the frozen pond, the
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  Speaker 2: tiniest ripple is instantly visible.
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  Speaker 3: Exactly. By dropping the temperature to near absolute zero, they
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  Speaker 3: effectively freeze out all that thermal noise. You now have
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  Speaker 3: a frictionless object touching nothing with almost zero internal atomic jitter.
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  Speaker 2: And the resulting sensitivity is breathtaking. The researchers can monitor
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  Speaker 2: the position of this levitating grain of sand so precisely
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  Speaker 2: that they can detect a physical displacement of about 100th
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  Speaker 2: the width of a single atom.
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  Speaker 3: 100th the width of an atom. It's almost hard to comprehend.
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  Speaker 2: The level of precision is terrifying, to be honest. If
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  Speaker 2: the goal is to detect an incredibly rare, weak interaction
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  Speaker 2: from a dark matter particle that ignores almost all ordinary matter,
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  Speaker 2: you obviously need that sensitivity.
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  Speaker 3: You do.
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  Speaker 2: But it creates a monumental problem. If a sensor can
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  Speaker 2: register a shift smaller than an atom, it feels like
• 9:53
  Speaker 2: an errant sound wave or a truck shifting gears on
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  Speaker 2: a highway two towns over, or even just a slight
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  Speaker 2: change in the building's air pressure would send this thing
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  Speaker 2: completely off the chart.
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  Speaker 3: Oh, absolutely. The background noise of the Earth itself becomes
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  Speaker 3: the biggest obstacle. Every seismic tremor, every passing vehicle, every
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  Speaker 3: footstep in the laboratory building, it all registers as a
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  Speaker 3: massive event to a sensor this delicate.
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  Speaker 2: So how do they deal with that?
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  Speaker 3: Well, this forces the researchers to fundamentally change both their
• 10:22
  Speaker 3: listening strategy and their schedule.
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  Speaker 2: Let's talk about that listening strategy, because it hinges entirely
• 10:27
  Speaker 2: on what they expect this heavy particle to do. I
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  Speaker 2: know past experiments using levitating sensors were actually looking for
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  Speaker 2: ultralight dark matter, not the heavy stuff.
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  Speaker 3: That's right.
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  Speaker 2: And ultralight particles operate more like a wave, so they
• 10:39
  Speaker 2: would supposedly hit the detector continuously, creating this gentle, repeating hum.
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  Speaker 3: And if you are looking for a repeating hum, you
• 10:48
  Speaker 3: have a massive advantage. You can observe the data over
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  Speaker 3: a long period, and the random chaotic background noise will
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  Speaker 3: eventually average out.
• 10:55
  Speaker 2: Leaving behind that persistent repeating wave signal.
• 10:59
  Speaker 3: Exactly. But as we established with the density mechanism earlier,
• 11:03
  Speaker 3: ultra-heavy dark matter particles are incredibly rare. You are not
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  Speaker 3: going to get a steady hum. You're going to get
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  Speaker 3: one isolated interaction.
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  Speaker 2: Zhuhang Qin, a postdoctoral researcher on the project, described it
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  Speaker 2: as waiting for, quote, very small knocks.
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  Speaker 3: Just a single knock.
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  Speaker 2: Right. A single massive particle flies through the Earth, grazes
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  Speaker 2: the atomic structure of the hovering magnet, delivers one microscopic impulse,
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  Speaker 2: and then just vanishes back into the void.
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  Speaker 3: And the challenge of modern physics is isolating that single knock.
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  Speaker 2: Right.
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  Speaker 3: How do you distinguish one legitimate atomic scale tap from
• 11:35
  Speaker 3: the dark universe from, say, the random vibration of an
• 11:39
  Speaker 3: air conditioning unit kicking on upstairs?
• 11:41
  Speaker 2: Right. And their solution to the human noise problem was
• 11:44
  Speaker 2: incredibly pragmatic. They gathered continuous data for about a month,
• 11:48
  Speaker 2: but they entirely discarded the daytime data for their most
• 11:51
  Speaker 2: rigorous analysis.
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  Speaker 3: They isolated their search to the dead of night.
• 11:55
  Speaker 2: Yeah, they had to wait for the human world to
• 11:58
  Speaker 2: physically go to sleep, for the traffic to die down,
• 12:01
  Speaker 2: the construction to stop, the daily seismic rumble to just
• 12:04
  Speaker 2: quiet down so they could listen.
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  Speaker 3: And there is a really profound symmetry to where this
• 12:10
  Speaker 3: nighttime observation took place, because this specific research was conducted
• 12:14
  Speaker 3: alongside colleagues in Leiden in the Netherlands.
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  Speaker 2: A city with a very deep history when it comes
• 12:20
  Speaker 2: to the dark universe.
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  Speaker 3: Oh, totally. Leiden is where the very concepts of missing
• 12:25
  Speaker 3: mass first took root. Back in the early 20th century,
• 12:29
  Speaker 3: astronomers working there, like Jan Oort, they were looking at
• 12:32
  Speaker 3: the movement of stars in our local galactic neighborhood.
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  Speaker 2: And they realized something was off.
• 12:37
  Speaker 1: Right.
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  Speaker 3: They realized the stars were moving much faster than the
• 12:40
  Speaker 3: visible mass of the galaxy should allow. That was the
• 12:43
  Speaker 3: first observational hint. that the universe was heavier than it appeared.
• 12:46
  Speaker 2: And now, nearly a century later, scientists in that exact
• 12:50
  Speaker 2: same city are sitting in the dark, watching a hovering
• 12:53
  Speaker 2: grain of sand at absolute zero, trying to catch a
• 12:56
  Speaker 2: physical piece of the ghost that their predecessors first noticed.
• 13:00
  Speaker 3: It's quite poetic.
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  Speaker 2: It really is. So, we have the ultimate frictionless trap,
• 13:05
  Speaker 2: cooled to the edge of physics, monitored in the silence
• 13:08
  Speaker 2: of the night, waiting for a single cell-sized ghost to knock.
• 13:12
  Speaker 2: a whole month of data collection, filtering, and analysis. The
• 13:16
  Speaker 2: big question, the combination of all this extreme engineering, what
• 13:20
  Speaker 2: did the data actually show?
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  Speaker 3: The data showed a flat line. They found zero NOx.
• 13:24
  Speaker 2: Absolutely nothing. No interactions. No ultra-heavy dark matter detected.
• 13:28
  Speaker 3: Zero evidence of an ultra-heavy dark matter particle interacting with
• 13:32
  Speaker 3: a magnetic sensor.
• 13:33
  Speaker 2: Now, for anyone outside of the scientific community, putting all
• 13:36
  Speaker 2: of that genius and effort into a machine only to
• 13:39
  Speaker 2: find a complete absence of a signal Sounds like a
• 13:42
  Speaker 2: crushing failure.
• 13:42
  Speaker 3: It does sound like a bummer.
• 13:43
  Speaker 2: But in quantum mechanics and cosmology, a definitive nothing is
• 13:47
  Speaker 2: actually a massive analytical weapon.
• 13:49
  Speaker 3: Well, without a doubt, a null result is often the
• 13:52
  Speaker 3: most powerful tool we have for advancing our understanding. It
• 13:56
  Speaker 3: allows physicists to systematically eliminate false theories. In this field,
• 14:00
  Speaker 3: researchers rely on a concept called parameter space.
• 14:03
  Speaker 2: Okay, the best way I can visualize parameter space is
• 14:07
  Speaker 2: to think of it like the ultimate game of Clue.
• 14:10
  Speaker 2: But instead of crossing off suspects and rooms, you are
• 14:13
  Speaker 2: crossing off potential realities.
• 14:15
  Speaker 3: That's a fun way to look at it.
• 14:16
  Speaker 2: You have this massive theoretical map plotting out all the
• 14:20
  Speaker 2: possible masses a dark matter particle could have on one
• 14:24
  Speaker 2: axis and all the possible ways it might physically interact
• 14:27
  Speaker 2: with ordinary matter on the other axis.
• 14:30
  Speaker 3: And because the Rice University team knows exactly how sensitive
• 14:34
  Speaker 3: their trap is, down to the fraction of an atom,
• 14:37
  Speaker 3: the fact that it did not trigger... allows them to
• 14:39
  Speaker 3: impose incredibly strict new boundaries on that map.
• 14:43
  Speaker 2: So they can confidently tell the theoretical physics community, well,
• 14:47
  Speaker 2: if dark matter was this specific mass and interacted with
• 14:50
  Speaker 2: this specific strength, our magnet would have moved. It didn't. Therefore,
• 14:53
  Speaker 2: dark matter does not exist in this configuration.
• 14:56
  Speaker 3: Exactly. You were systematically cornering the ghost. And the sheer
• 14:59
  Speaker 3: amount of the map they were able to cross off
• 15:01
  Speaker 3: with this single experiment is astounding. The researchers stated they
• 15:04
  Speaker 3: explored nine orders of magnitude in dark matter mass.
• 15:08
  Speaker 2: Nine orders of magnitude.
• 15:09
  Speaker 3: Which is a difficult concept to visualize, but it represents
• 15:13
  Speaker 3: a colossal expansion of our search capabilities.
• 15:15
  Speaker 2: Let's ground that in reality. An order of magnitude is
• 15:19
  Speaker 2: a factor of 10. So if a traditional dark matter
• 15:22
  Speaker 2: experiment is like thoroughly searching a one square foot patch
• 15:25
  Speaker 2: of grass in your backyard, expanding that search by nine
• 15:28
  Speaker 2: orders of magnitude isn't just searching the whole yard. It
• 15:32
  Speaker 2: is the equivalent of scaling up that search to cover
• 15:35
  Speaker 2: the entire surface area of the Earth and then some.
• 15:38
  Speaker 3: It's massive.
• 15:39
  Speaker 2: They probed a vast, previously untouched expanse of reality.
• 15:43
  Speaker 3: They really did. They were able to rule out particles
• 15:45
  Speaker 3: approximately 10 million times heavier than those studied in any
• 15:50
  Speaker 3: previous levitation experiment.
• 15:51
  Speaker 2: 10 million times. Wow.
• 15:53
  Speaker 3: Dorian Amaral, a former postdoctoral researcher on the project, highlighted
• 15:57
  Speaker 3: why this specific null result is so groundbreaking. Because it
• 16:01
  Speaker 3: wasn't just about having a heavy sensor.
• 16:02
  Speaker 2: It was the combination.
• 16:04
  Speaker 1: Right.
• 16:04
  Speaker 3: It was the unprecedented combination of three factors. A sensor
• 16:08
  Speaker 3: massive enough to interact with a heavy particle, a frictionless
• 16:12
  Speaker 3: environment sensitive down to the atomic level, and a stable
• 16:15
  Speaker 3: listening period lasting an entire month.
• 16:17
  Speaker 2: And that specific combination of mass, sensitivity, and time allowed
• 16:23
  Speaker 2: them to completely gut the middle range of this new
• 16:27
  Speaker 2: parameter space. It narrows down the potential hiding spots for
• 16:30
  Speaker 2: ultra-heavy dark matter.
• 16:32
  Speaker 3: Yes, but the hunt obviously doesn't stop with one null result.
• 16:36
  Speaker 3: They didn't catch a signal this time, which means the
• 16:38
  Speaker 3: next step is upgrading the trap.
• 16:40
  Speaker 2: So what does that look like?
• 16:42
  Speaker 3: Well, the roadmap for the future of this experiment involves
• 16:44
  Speaker 3: pushing these physical extremes even further. The researchers plan to
• 16:48
  Speaker 3: drive the temperature even closer to the absolute zero limit,
• 16:51
  Speaker 3: squeezing out whatever tiny bit of microscopic thermal noise remains
• 16:55
  Speaker 3: in the system.
• 16:55
  Speaker 2: Okay, colder is better.
• 16:57
  Speaker 3: And they also intend to extend the data collection period
• 16:59
  Speaker 3: from one month to potentially an entire year.
• 17:02
  Speaker 2: Wait, but dropping the temperature and waiting longer doesn't solve
• 17:06
  Speaker 2: the fundamental problem of the Earth vibrating. Like, a truck
• 17:09
  Speaker 2: driving by a year from now is still going to
• 17:12
  Speaker 2: shake a colder magnet.
• 17:13
  Speaker 3: That is the most elegant part of their proposed upgrade.
• 17:16
  Speaker 2: Oh.
• 17:16
  Speaker 3: Instead of relying on a single hovering magnet, the next
• 17:19
  Speaker 3: iteration of the experiment will levitate an entire array... of
• 17:23
  Speaker 3: several magnets simultaneously, all within the same super cool chamber.
• 17:28
  Speaker 2: Oh, that completely solves the background noise issue. It's a
• 17:32
  Speaker 2: physical filter.
• 17:33
  Speaker 3: Exactly.
• 17:33
  Speaker 2: Because if a seismic tremor rolls through the laboratory or
• 17:36
  Speaker 2: a heavy truck rumbles down the street, that acoustic wave
• 17:39
  Speaker 2: is going to hit the entire chamber at once. Every
• 17:42
  Speaker 2: single magnet in the array will twitch at the exact
• 17:45
  Speaker 2: same moment in the exact same direction.
• 17:47
  Speaker 3: It is a mechanism called common mode noise rejection. Because
• 17:50
  Speaker 3: a dark matter particle is infinitesimally small in volume, even
• 17:54
  Speaker 3: if it is incredibly heavy, a single particle passing through
• 17:57
  Speaker 3: the chamber would logically only collide with one of the
• 17:59
  Speaker 3: magnets in the array.
• 18:00
  Speaker 2: It's the ultimate lie detector for quantum physics. If all
• 18:04
  Speaker 2: the magnets shake, it's just the Earth settling. But if
• 18:07
  Speaker 2: one solitary magnet in the array suddenly shifts a hundredth
• 18:11
  Speaker 2: of an atom to the left while the others remain
• 18:13
  Speaker 2: perfectly frozen in place.
• 18:15
  Speaker 3: But then you have isolated the NOC. You have definitively
• 18:18
  Speaker 3: captured the physical signature of the invisible universe momentarily brushing
• 18:23
  Speaker 3: against our own.
• 18:24
  Speaker 2: That is incredible.
• 18:26
  Speaker 3: It really is. Identifying where dark matter is not hiding
• 18:29
  Speaker 3: is the only logical path we have to eventually cornering
• 18:32
  Speaker 3: where it actually resides. It is the scientific method scaled
• 18:36
  Speaker 3: up to the cosmos.
• 18:37
  Speaker 2: So to pull all these threads together, we live in
• 18:39
  Speaker 2: a spinning galaxy that defies the visible laws of physics,
• 18:42
  Speaker 2: bound tightly by an invisible glue. And for a long time,
• 18:45
  Speaker 2: we were stubbornly looking for atomic-sized dust.
• 18:48
  Speaker 3: Very stubbornly.
• 18:48
  Speaker 2: But by daring to ask if that invisible glue might
• 18:51
  Speaker 2: be made of exceedingly rare, incredibly massive particles, particles the
• 18:55
  Speaker 2: weight of entire living cells, we force a complete mechanical
• 18:59
  Speaker 2: reinvention of how we observe the universe.
• 19:01
  Speaker 3: Yeah. We moved from giant vats of liquid underground to
• 19:06
  Speaker 3: a perfectly still, frictionless grain of sand hovering at absolute zero,
• 19:10
  Speaker 3: waiting in the silence of the night for a single
• 19:13
  Speaker 3: microscopic tap.
• 19:15
  Speaker 2: It completely dismantles our intuition about reality.
• 19:17
  Speaker 3: It serves as a stark reminder that the universe operates
• 19:20
  Speaker 3: on a scale and with mechanics completely detached from what
• 19:24
  Speaker 3: our human senses can perceive.
• 19:25
  Speaker 2: Which leads to a final thought that completely reframes how
• 19:28
  Speaker 2: we look at the night sky.
• 19:29
  Speaker 3: I love this part.
• 19:30
  Speaker 2: If dark matter, the substance making up the vast, overwhelming
• 19:34
  Speaker 2: majority of mass in our galaxy, is potentially composed of
• 19:37
  Speaker 2: fundamental particles that are already the mass of a biological cell,
• 19:42
  Speaker 2: what does that imply about the invisible universe?
• 19:44
  Speaker 3: It's a huge question.
• 19:45
  Speaker 2: Because in our visible reality, when matter gets complex and
• 19:49
  Speaker 2: heavy enough to form biological cells, it creates life, ecosystems,
• 19:53
  Speaker 2: and immense structural diversity. So if the fundamental building blocks
• 19:57
  Speaker 2: of the dark sector are already that massive and complex,
• 20:00
  Speaker 2: could the dark matter landscape be as intricate and varied
• 20:03
  Speaker 2: as the visible universe?
• 20:04
  Speaker 3: Mind-blowing. Right.
• 20:05
  Speaker 2: Are we just floating through an invisible, massively structured ecosystem?
• 20:10
  Speaker 2: that passes cleanly through our own every single second. It
• 20:13
  Speaker 2: is definitely something for you to seriously ponder the next
• 20:16
  Speaker 2: time you look up at the spinning stars.