Speaker 1: Welcome to Bedtime Astronomy. Explore the wonders of the cosmos
Speaker 1: with our soothing Bedtime Astronomie podcast. Each episode offers a
Speaker 1: gentle journey through the stars, planets, and beyond, perfect for
Speaker 1: unwinding after a long day. Let's travel through the mysteries
Speaker 1: of the universe as you drift off into a peaceful
Speaker 1: slumber under the night sky.
Speaker 2: Imagine just for a second, standing at the absolute edge
Speaker 2: of existence.
Speaker 3: Well, that is a pretty terrifying place to start, right.
Speaker 2: But just humor me. Here you are hovering just millimeters
Speaker 2: away from a boundary that is so profound and you know,
Speaker 2: so final that right before everything goes dark forever, the
Speaker 2: universe itself actually.
Speaker 3: Rings like a bell, a cosmic bell.
Speaker 2: Yeah, exactly, because it's basically a fundamental law of physics
Speaker 2: and well a massive pop culture cliche at this point
Speaker 2: that in the vacuum of space, no one.
Speaker 3: Can hear you scream because there's no air.
Speaker 2: Right, there is no medium for acoustic sound to travel through.
Speaker 2: Space is just this silent void. But there's this massive
Speaker 2: paradox sitting right at the center of modern astrophysics right now.
Speaker 2: Oh absolutely, we actually know that there is a way
Speaker 2: to quote unquote here the violent cataclysmic crash of two
Speaker 2: black holes colliding.
Speaker 3: Which is such a profound contradiction when you really think
Speaker 3: about it. I mean, we're talking about the darkest, most
Speaker 3: invisible objects in the universe. Yeah, and they are creating
Speaker 3: the most energetic outburst of noise imaginable, but not a
Speaker 3: sound moving through the air of course, right right, It's
Speaker 3: a sound moving through the very geometry of reality.
Speaker 2: Okay, So let's unpack this because what we are embarking
Speaker 2: on today is basically a journey to decode the loudest
Speaker 2: gravitational wave ever recorded by human beings.
Speaker 3: It really is a milestone.
Speaker 2: It is. Our mission here is to transport you, the listener,
Speaker 2: right to the edge of an event horizon during a
Speaker 2: cosmic collision, and we're gonna explore what this totally unprecedented
Speaker 2: signal tell us about, well, the most impenetrable boundary in
Speaker 2: the entire cosmos.
Speaker 3: And we really should establish right away that we aren't
Speaker 3: just talking about a loud noise in some abstract or
Speaker 3: you know, theoretical sense. Right when a signal of this
Speaker 3: magnitude hits our detectors, we're essentially unlocking space time's deepest secrets.
Speaker 3: We're peeling back the layers of physics that govern how
Speaker 3: the universe operates at its absolute extreme limits.
Speaker 2: The places where things get weird.
Speaker 3: Exactly, the places where our standard equations actually start to
Speaker 3: break down.
Speaker 2: So to really grasp the gravity of this, and yes,
Speaker 2: that pun is fully intended, nice, thank you, we have
Speaker 2: to look at the signal that started it all. This
Speaker 2: was basically a cosmic alarm bell ringing across the universe.
Speaker 2: The event is centered around a signal designated as GW
Speaker 2: two five zero one one.
Speaker 3: Fifteen, recorded just last year, right in twenty twenty five.
Speaker 2: YEP twenty twenty five by the two laser interferometer Gravitational
Speaker 2: Wave Observatories or you know LEGO as most people know
Speaker 2: it here in the United States. And the major our
Speaker 2: headline here is that it is the loudest binary black
Speaker 2: hole signal observed to.
Speaker 3: Date, which is staggering.
Speaker 2: It really is. I mean, we are talking roughly three
Speaker 2: times louder than the very first gravitational wave ever detected
Speaker 2: just a decade ago.
Speaker 3: In the concept of loudness and gravitational wave astronomy, it
Speaker 3: kind of requires us to completely discard our biological experience
Speaker 3: of hearing. Yeah, there are no sound waves right right.
Speaker 3: When astrophysicists say loud, they're actually referring to amplitude. Amplitude, okay, Yeah,
Speaker 3: gravitational waves are physical ripples in the actual fabric of
Speaker 3: space time. And you always hear people compare spacetime to
Speaker 3: a flat trampoline, which.
Speaker 2: Oh, the bowling ball on the trampoline analogy, Yes.
Speaker 3: And it is a terrible over used analogy that completely
Speaker 3: fails to capture the three dimensional nature of the universe.
Speaker 2: So what's a better way to picture it?
Speaker 3: Think of space time instead as a massive solid block
Speaker 3: of dense, clear gelatine.
Speaker 2: Okay, a giant block of cosmic jello. I can work
Speaker 2: with that, A.
Speaker 3: Giant block of cosmic jell exactly. So if you take
Speaker 3: two dense, heavy marbles and embed them deep inside that gelatin, right,
Speaker 3: and then you start spinning them around each other at
Speaker 3: a significant fraction of the speed of light, they are
Speaker 3: going to violently churn that material.
Speaker 2: Oh, I see.
Speaker 3: And when they finally smash together, that massive collision sends
Speaker 3: these severe pressure waves rippling outward through the gelatine in
Speaker 3: all three dimensions at once.
Speaker 2: Okay, So when those ripples finally reach Earth after traveling
Speaker 2: outward for you know, maybe billions of years, they are
Speaker 2: actually physically stretching and squeezing the space that we occupy.
Speaker 3: That's exactly what's happening.
Speaker 2: So, like, think about where you are sitting right now
Speaker 2: listening to this, as this specific wave passed through Earth,
Speaker 2: the room you're in, the chair you're sitting on, and
Speaker 2: literally your own body were physically stretched and squeezed, like
Speaker 2: oscillating back and forth.
Speaker 3: You were. But we do need to emphasize that this
Speaker 3: is on a microscopic.
Speaker 2: Scale, right, Nobody actually felt it.
Speaker 3: No, No, we are talking about distortions that alter the
Speaker 3: distance between here in the nearest star by roughly the
Speaker 3: width of a human hair.
Speaker 2: That is, I mean, that's almost impossible to even conceptualize.
Speaker 3: Or to bring it locally. It's like changing the length
Speaker 3: of logos four kilometer long vacuum tubes by just a
Speaker 3: fraction of the width of a single proton.
Speaker 2: Which honestly makes the engineering behind LIGO sound completely impossible.
Speaker 2: I mean, we aren't just talking about building a really
Speaker 2: big telescope here, not at all. These facilities they're in
Speaker 2: Washington State and Louisiana.
Speaker 3: Right, Yes, those are the two.
Speaker 2: They are shooting lasers down these four kilometer long vacuum tubes,
Speaker 2: bouncing them off perfectly suspended mirrors and basically measuring how
Speaker 2: long it takes for the light to return.
Speaker 3: And the precision required to pull that off is just
Speaker 3: difficult to overstate. I mean, to measure a distortion smaller
Speaker 3: than a proton. You have to isolate those mirrors from
Speaker 3: the seismic noise of the Earth itself.
Speaker 2: Right, because everything vibrates.
Speaker 3: Everything a truck driving down a highway miles away, or
Speaker 3: a wave crashing on some distant shoreline, even the microscope
Speaker 3: thermal vibrations of the actual atoms inside the mirrors themselves.
Speaker 2: Wait, really, the heat of the atoms in the mirror
Speaker 2: can mess up the reading.
Speaker 3: Well absolutely all that creates background noise. Yeah, so Lego
Speaker 3: has to mathematically and physically cancel out the ambient vibration
Speaker 3: of the entire planet just to hear the universe whisper.
Speaker 2: That is just wild. And you know, that rapid progression
Speaker 2: of our technological ability over just the last ten years
Speaker 2: is mind blowing to me.
Speaker 3: It's been incredibly fast.
Speaker 2: Like a decade ago, just confirming that these ripples existed
Speaker 2: at all. Was this monumental Nobel Prize winning priumph. And
Speaker 2: now just ten years later, we capture a signal three
Speaker 2: times as powerful, and we're using it as this incredibly
Speaker 2: precise surgical instrument to probe the black holes themselves well.
Speaker 3: And the amplitude is what allows for that surgical precision
Speaker 3: because it's louder, Right, A louder signal means that the
Speaker 3: stretching and squeezing of space time was significantly more pronounced.
Speaker 3: It implies immense energy, and crucially, it implies proximity.
Speaker 2: Proximity, so GW two five zero one one teen was
Speaker 2: close to.
Speaker 3: Us relatively speaking on a cosmic scale. Yes, it happened
Speaker 3: relatively close to us.
Speaker 2: Okay, let me throw out an analogy here to see
Speaker 2: if I'm visualizing the impact of this amplitude correctly. Sure
Speaker 2: it so if the first gravitational wave we detected a
Speaker 2: decade ago was kind of like feeling the faint rhythmic
Speaker 2: rumble of a distant train through the soles of your
Speaker 2: shoes while you're standing, I don't know, five miles away, Okay,
Speaker 2: is GW two five zero one to one tour more
Speaker 2: like standing right next to the tracks as a massive
Speaker 2: freight train blasts its horn and just rattles your ribcage.
Speaker 3: I like that. But let's actually take that train and
Speaker 3: analogy a step further. Okay, when you're five miles away,
Speaker 3: you really only feel the lowest, deepest base frequencies of
Speaker 3: that rumble.
Speaker 2: Right, Yeah, just the heavy vibrations exactly.
Speaker 3: The higher, more delicate frequencies, yeah, like the middle wheels
Speaker 3: clacking on the rails. Those are completely lost to the
Speaker 3: intervening distance and the soil.
Speaker 2: That makes sense.
Speaker 3: But by standing right next to the tracks, you don't
Speaker 3: just feel as stronger rumble. Your ear can suddenly pick
Speaker 3: up the complex, subtle harmonics of the machinery itself.
Speaker 2: Oh. I see. So the volume doesn't just make the
Speaker 2: main event easier to notice. The high volume actually allows
Speaker 2: us to hear entirely different layers of the collision.
Speaker 3: It unveils the harmonics. It's like in music, you know,
Speaker 3: a piano key doesn't just produce one pure mathematical tone
Speaker 3: when you strike it. It produces a fundamental frequency, but
Speaker 3: alongside dozens of overtones. These are higher, quieter frequencies resonating
Speaker 3: simultaneously and.
Speaker 2: That's what makes it sound like a piano and not
Speaker 2: a computer beep.
Speaker 3: Precisely, those overtones give the instrument its character. So in
Speaker 3: gravitational waves, the main roar is the bulk of the collision.
Speaker 2: The huge smash, But a profoundly.
Speaker 3: Loud signal like GW two five zero one fourteen has
Speaker 3: such an incredibly high signal to noise ratio that the
Speaker 3: faint overtones of the collision finally rise above the background
Speaker 3: static of the universe.
Speaker 2: Wow, which brings just a completely new layer of data
Speaker 2: to the table. We aren't just hearing this anymore. We're
Speaker 2: actually hearing the subtle vibrations of the new black hole
Speaker 2: settling down, Yes, the ring down, and that shifts our
Speaker 2: focus directly to the true protagonist of this whole cosmic drama,
Speaker 2: which is the event horizon, the point of no return exactly,
Speaker 2: this is the universe's ultimate point of no return. We
Speaker 2: know the basics, right, It's the boundary around a black
Speaker 2: hole where absolutely nothing, not even light, can escape. But
Speaker 2: for anyone familiar with the basic physics of gravity, the
Speaker 2: mechanics of this boundary get incredibly.
Speaker 3: Strange, oh very strange. And the strangeness really comes from
Speaker 3: the absolute finality of the universal.
Speaker 2: Speed limit the speed of light.
Speaker 3: Right, we know that as mass increases, the escape velocity,
Speaker 3: which is the speed required to break free of an
Speaker 3: object's gravitational pull, that increases too.
Speaker 2: Like how it's harder to launch a rocket from Jupiter
Speaker 2: than from.
Speaker 3: Earth exactly, and at a certain point of mass density,
Speaker 3: that required escape velocity hits exactly two hundred and ninety
Speaker 3: nine thousand, seven hundred and ninety two kilometers per.
Speaker 2: Second, which is the speed of light in a vacuum. Yes,
Speaker 2: and since Einstein equations dictate that nothing can travel faster
Speaker 2: than the speed of light, anything that crosses that mathematical
Speaker 2: boundary is just permanently trapped.
Speaker 3: It is a one way door in the universe information, matter, light,
Speaker 3: It goes in and it never comes out.
Speaker 2: Which presents a pretty profound paradox for observational astronomy, doesn't
Speaker 2: it a huge one? Because how do you observe an
Speaker 2: object that, by its very definition completely forbids observation. If
Speaker 2: no light, no radiation, and literally no information can cross
Speaker 2: from the inside of the event horizon to the outside universe,
Speaker 2: you're essentially trying to study a shadow by like turning
Speaker 2: off all the lights.
Speaker 3: Yeah, that paradox is really what trips up a lot
Speaker 3: of people when they first look at the data from
Speaker 3: GW two five zero one one day.
Speaker 2: I know, it tripped me up. I was like, if
Speaker 2: it's the ultimate trap, how did scientists witness it? We
Speaker 2: literally can't see the black hole itself.
Speaker 3: Well, the key is that we aren't seeing what comes
Speaker 3: out of it, because nothing does. Instead, we are witnessing
Speaker 3: the severe agonizing warping of the space time directly adjacent
Speaker 3: to the horizon and in the exact millisecond it is forming.
Speaker 2: Oh so it's the space around it.
Speaker 3: Yes. When two black holes merge, their individual event horizons deform,
Speaker 3: they stretch toward each other, and they finally fuse to
Speaker 3: form a single, larger and highly chaotic event horizon.
Speaker 2: Highly chaotic. So for a fraction of a second, this
Speaker 2: newly born remnant black hole is not a perfect sphere.
Speaker 3: Far from it. It is violently asymmetrical. Really, Oh yeah,
Speaker 3: it is wobbling, ringing, and shedding immense amounts of energy
Speaker 3: in the form of gravitational waves as it desperately attempts
Speaker 3: to settle down into a stable spherical state. Wow, it's
Speaker 3: that dynamic turbulent boundary the space time actively reacting to
Speaker 3: the violent birth of the horizon that we are observing.
Speaker 3: We are essentially catching the shadow just before the door
Speaker 3: slam shut forever.
Speaker 2: That is such a cool way to freeze it. Catching
Speaker 2: the shadow before the door slam shut, and the method
Speaker 2: scientists used to actually capture that fleeting moment before the
Speaker 2: eternal dark is just a brilliant piece of analytical detective work.
Speaker 3: It really is.
Speaker 2: And this research was led by doctor Lingsn and PhD
Speaker 2: candidate Neil Lou. They're over at OSGREV and the Australian
Speaker 2: National University, right.
Speaker 3: Yes, working with an international coalition spanning Canada, at the
Speaker 3: US and Spain.
Speaker 2: Just a massive global effort, and they managed to basically
Speaker 2: isolate the last sound these black holes made.
Speaker 3: And the secret to measuring this last sound lies in
Speaker 3: a very specific, notoriously elusive component of this signal called
Speaker 3: direct waves direct waves. Okay, yeah. Prior to this analysis,
Speaker 3: direct waves were theoretically understood but frankly impossible to extract
Speaker 3: from the noise. They were just buried exactly. But Neil
Speaker 3: Lu's new analytical framework essentially deciphered them. It pulled completely
Speaker 3: unique data from incredibly close to the event horizon.
Speaker 2: Okay, so let's dig into the how of that extraction.
Speaker 2: Because they couldn't just use like a standard audio filter
Speaker 2: to clean up the track. I was looking into the
Speaker 2: computational mechanics behind this, and the process of mathematical dissection
Speaker 2: is just staggering.
Speaker 3: It's intense.
Speaker 2: They had to rely heavily on something called numerical relativity, right.
Speaker 3: They did, And numerical relativity is basically the unsung hero
Speaker 3: of gravitational wave astronomy. Oh so well, Einstein's equations of
Speaker 3: general relativity. They are nonlinear partial differential.
Speaker 2: Equations, which means they're a nightmare to solve.
Speaker 3: They are famously brutally difficult to solve for decades, physicists
Speaker 3: could really only solve them for highly simplified, idealized scenarios.
Speaker 3: You cannot just write down the exact solution for two
Speaker 3: black holes merging.
Speaker 2: On a chop breaks mean a supercomputer.
Speaker 3: You need massive clusters of supercomputers running for months just
Speaker 3: to simulate a fraction of a second of a black
Speaker 3: hole merger.
Speaker 2: Months for a fraction of a second.
Speaker 3: Yes, the research team had to model millions of potential
Speaker 3: merger scenarios. They simulate the exact masses, the spins, and
Speaker 3: the orbital trajectories of the two black holes, and then
Speaker 3: the computer's crunch Einstein's equations to predict exactly what the
Speaker 3: main gravitational wave that dominant roar should look like.
Speaker 2: Okay, so if the main crash, the bulk collision is
Speaker 2: a deafening orchestral symbol smash happening right in front of you,
Speaker 2: these direct waves are like a tiny specific vibration of
Speaker 2: one single violin string happening at the exact same millisecond.
Speaker 3: That's a great way to picture it.
Speaker 2: So to find the violin string, they use the supercomputer
Speaker 2: to map out the exact acoustic profile of the symbol smash, right,
Speaker 2: and then they mathematically subtract it from the raw lego data.
Speaker 3: That's exactly what they do, but that subtraction requires an
Speaker 3: unprecedented level of precision. I can imagine if your numerical
Speaker 3: relativity model is off by even a fraction of a percent,
Speaker 3: the leftover data will just be statistical garbage.
Speaker 2: Oh, because you didn't subtract the right thing.
Speaker 3: Right. But by meticulously modeling and subtracting the dominant signal,
Speaker 3: which is the inspiral and the immediate merger. What they
Speaker 3: were left with was a tiny residual vibration, the ring.
Speaker 2: Down phase, the violin string.
Speaker 3: The direct waves, and the origin of those direct waves
Speaker 3: is really what makes them so and valuable to us.
Speaker 2: Why is that? Where do they come from?
Speaker 3: They don't come from the distant orbiting phase of the
Speaker 3: black holes. They are emitted right at the throat of
Speaker 3: the beasts. Wow. They carry the untainted fingerprint of the
Speaker 3: extreme gravity immediately adjacent to the newly formed event horizon.
Speaker 2: It's kind of like standing at a massive party with
Speaker 2: one hundred conversations happening, heavy music playing, glasses clinking, and
Speaker 2: you're trying to hear a specific whisper from across the
Speaker 2: room exactly except here, the team is filtering out the
Speaker 2: noise of the universe itself to hear a single whisper
Speaker 2: from billions of light years away.
Speaker 3: And the effort to isolate that single voice is driven
Speaker 3: by the totally unique physical environment it originates.
Speaker 2: From the event horizon itself.
Speaker 3: Yes, black holes are the ultimate extreme laboratories. They sit
Speaker 3: precisely at the intersection of our two most successful, yet
Speaker 3: fundamentally incompatible frameworks of physics.
Speaker 2: Oh right, general relativity and quantum theory exactly. This is
Speaker 2: where the physics gets incredibly tense because we have these
Speaker 2: two rule books. Right. General relativity is the master theory
Speaker 2: of the massive. It explains gravity orbits and the smooth,
Speaker 2: continuous fabric of space and time.
Speaker 3: Correct.
Speaker 2: But then we have quantum mechanics, which is the master
Speaker 2: theory of the microscopic. It explains atoms, subatomic particles, and
Speaker 2: it treats the universe as chunky like it's made of
Speaker 2: discrete packets.
Speaker 3: Of energy and under normal circumstances in the universe, those
Speaker 3: two rule books never have to speak to each.
Speaker 2: Other, right, because things are either huge or tiny.
Speaker 3: Exactly. You use relativity for stars and you use quantum
Speaker 3: mechanics for electrons. But at the event horizon of a
Speaker 3: black hole, the mass is so immense and the space
Speaker 3: it occupies is so compact that the gravity violently warps
Speaker 3: space time on a microscopic quantum level.
Speaker 2: It forces them together.
Speaker 3: It is the singular place in the cosmos where the
Speaker 3: rules of the massive crash headlong into the rules of
Speaker 3: the microscopic.
Speaker 2: So, okay, if these two frameworks fundamentally disagree on how
Speaker 2: the universe works. What does it actually mean for doctor
Speaker 2: Son and you'll lou to use these direct waves to
Speaker 2: test general relativity.
Speaker 3: Well, it's a huge deal.
Speaker 2: Are we essentially using this super loud gravitational wave to
Speaker 2: see if Einstein's equations finally break down? Like, are we
Speaker 2: trying to prove him wrong?
Speaker 3: We'll consider the implications of a breakdown. I mean, every
Speaker 3: single time physicists have tested general relativity over the last century,
Speaker 3: from the bending of starlight around the Sun to the
Speaker 3: time dilation in GPS satellite, it's always right. Einstein has
Speaker 3: been proven flawlessly correct every time. But theorists know the
Speaker 3: theory is incomplete.
Speaker 2: Because it produces infinities right right at the very center
Speaker 2: of a black hole.
Speaker 3: The singularity relativity predicts infinite density and infinite.
Speaker 2: Curvature, which doesn't make sense no.
Speaker 3: Because nature abhors in infinity and an infinity usually just
Speaker 3: means your math stopped working. Yeah, So theorists suspect that
Speaker 3: right at the boundary, right at the event horizon, general
Speaker 3: relativity might begin to fray, revealing subtle quantum effects.
Speaker 1: Oh.
Speaker 3: By isolating these direct waves, these little whispers from the
Speaker 3: absolute edge, the team is gathering the raw data needed
Speaker 3: to run the ultimate stress test. They are checking if
Speaker 3: Einstein's rulebook actually holds up under the most extreme pressure
Speaker 3: the universe can generate.
Speaker 2: Man that is fascinating. So to run those stress tests,
Speaker 2: the team had to pull incredibly specific measurements from that
Speaker 2: leftover whisper very specific. They had to essentially take the
Speaker 2: vitals of the newly born black hole, and the analysis
Speaker 2: of GW two five zero one one four allowed them
Speaker 2: to measure two fundamental properties of the remnant, its rotation
Speaker 2: frequency and its surface gravity.
Speaker 3: And those two properties basically define the entire existence of
Speaker 3: the remnant.
Speaker 2: And the remnant. Just to be clear, is the single
Speaker 2: black hole left behind after the chaotic fusion.
Speaker 3: Yes, And in that fusion process, a substantial percentage of
Speaker 3: the two parent black holes combined mass is converted instantaneously
Speaker 3: into pure energy.
Speaker 2: Oh, and that energy is the gravitational waves ligo detected.
Speaker 3: Exactly e equals ms squared. In its most violent form.
Speaker 2: The mass just turns into a ripple in space, right.
Speaker 3: And what remains after that burst is a new entity.
Speaker 3: And when we measure its rotation frequency, we are measuring.
Speaker 2: Its spin, because they spin.
Speaker 3: Black holes are rarely static stationary objects. I mean, almost
Speaker 3: everything in the universe possesses angular momentum. Stars spin, galaxy spin.
Speaker 3: When two massive black holes orbit each other e merge,
Speaker 3: all that tremendous orbital energy has to go somewhere. The
Speaker 3: law of conservation of angular momentum dictates that the rotational
Speaker 3: energy is inherited by.
Speaker 2: The remnant, meaning the resulting black hole can be spinning
Speaker 2: at like a significant fraction of the speed of light.
Speaker 3: Oh, absolutely speeds we can barely comprehend. And the second
Speaker 3: vital sign they measured the surface gravity. That requires a
Speaker 3: bit of a conceptual adjustment. Why is that Because, as
Speaker 3: we established earlier, a black hole doesn't have a physical
Speaker 3: solid surface, right.
Speaker 2: You can't land a rover on it. It's just a
Speaker 2: boundary exactly.
Speaker 3: The term gravity is really barred from planetary physics for
Speaker 3: a black hole. Surface gravity refers to the strength of
Speaker 3: the gravitational pull precisely at the mathematical boundary of the
Speaker 3: event horizon, just right at the edge. Right. It is
Speaker 3: a measure of how sharply, how steeply space time is
Speaker 3: curved exactly at the point of no return.
Speaker 2: You know, the mathematical reality here is actually stranger than
Speaker 2: fiction it usually is. I mean, think about it. We
Speaker 2: are taking the vitals, the spin, and the gravity of
Speaker 2: a completely invisible light trapping void sitting billions of light
Speaker 2: years away, purely by mathematically dissecting the invisible ripples it
Speaker 2: cast off during its birth.
Speaker 3: It is poetry, and those two properties give us a
Speaker 3: complete picture because a concept known as the no hair theorem.
Speaker 3: The no hair theorem, yes, it postulates that from the outside,
Speaker 3: an astrophysical black hole is incredibly simple. It has no
Speaker 3: complex identifying features. No hair.
Speaker 2: Oh, I get it.
Speaker 3: If you know it's mass and its spin, you know
Speaker 3: absolutely everything there is to know about its macroscopic state.
Speaker 3: It is fully identified.
Speaker 2: Okay, let's do it. So the basic definition is that
Speaker 2: a spinning black hole literally drags the fabric of space
Speaker 2: time nearby along with it, creating an environment where absolutely
Speaker 2: nothing can remain stationary relative to a distant observer. That's
Speaker 2: a definition, yeah, But to actually visualize that, I think
Speaker 2: we have to go back to our Gelatin analogy.
Speaker 3: Definitely. We intuitively think of space as a static, rigid
Speaker 3: stage where events happen like a three dimensional grid, right.
Speaker 2: Yeah, an empty room.
Speaker 3: But Einstein taught us that space time is a dynamic,
Speaker 3: tangible medium. So if you place a perfectly smooth, massive
Speaker 3: stationary ball in our block of clear gelatin, it just
Speaker 3: sits there. It displaces the material around it, but that's it.
Speaker 3: That is standard gravity.
Speaker 2: But if you start spinning that ball, the friction of
Speaker 2: the ball surface grips the gelatin, it doesn't just sit
Speaker 2: still anymore.
Speaker 3: The gelatin begins to swirl in a vortex around the
Speaker 3: spinning object.
Speaker 2: Like twisting a spoon and a bowl of honey.
Speaker 3: Yes, the material closest to the ball is dragged the fastest,
Speaker 3: and the effect tapers off the further way you get.
Speaker 2: But wait again. A black hole doesn't have a physical
Speaker 2: surface to create friction.
Speaker 3: And the beauty of general relativity is that it doesn't
Speaker 3: need one.
Speaker 2: It doesn't.
Speaker 3: No, the mass itself, just by twisting through the geometry
Speaker 3: of the universe, drags the coordinate system of space.
Speaker 2: Along with it the coordinate system itself.
Speaker 3: Yes, the swirling vortex of space time around a spinning
Speaker 3: mass is the lens thirring effect or frame dragging. The
Speaker 3: mathematical reference frame of space itself is literally being pulled
Speaker 3: into a whirlpool.
Speaker 2: Okay, let me push this to its logical extreme. To
Speaker 2: make sure I am truly grasping the physics here. Because
Speaker 2: this is wild, go for it. Say I have an
Speaker 2: indestructible spaceship. I have infinite fuel and infinite thruster power.
Speaker 3: Okay, a magical spaceship.
Speaker 2: Right, And I fly right up to this newly born,
Speaker 2: rapidly spinning black hole. And I cross into the region
Speaker 2: just outside the event horizon, which is an area called
Speaker 2: the ergosphere.
Speaker 3: Yes, the aerosphere.
Speaker 2: So I get there, and I fire my thrusters perfectly
Speaker 2: to hover in one exact mathematical coordinate. I am trying
Speaker 2: to stand completely still. Okay, do I stay still.
Speaker 3: If you do that, you are fighting a losing battle
Speaker 3: against the geometry of the universe.
Speaker 2: Really, even with infinite power.
Speaker 3: Even with infinite power inside the ergosphere, the frame dragging
Speaker 3: effect is so severe that space time itself is being
Speaker 3: dragged around the black hole faster than the speed of light.
Speaker 2: Wait wait, wait, nothing can move faster than light. That
Speaker 2: is the fundamental rule we just established for the event horizon.
Speaker 3: Ah, nothing can move through space faster than light, but
Speaker 3: space itself has no speed limit. Really, think about the
Speaker 3: expansion of the universe, the universe itself expands faster than light. Right, Okay,
Speaker 3: so in the ergosphere, the local space is swirling so
Speaker 3: violently that to remain stationary relative to me, Like if
Speaker 3: I'm an observer back on Earth watching your spaceship through
Speaker 3: a telescope, Yeah, to stay still relative to me, you
Speaker 3: would have to travel through your local space faster than
Speaker 3: the light just to hold your ground.
Speaker 2: Which is physically impossible.
Speaker 3: Exactly impossible. Therefore, even with your infinite fuel and your
Speaker 3: infinite thruster power, you are inevitably swept along in the
Speaker 3: cosmic whirlpool. To you, inside the cockpit of the spaceship,
Speaker 3: you might feel like you are pushing as hard as
Speaker 3: you can in one direction, you are burning fuel at
Speaker 3: maximum capacity. But to me looking at you from Earth,
Speaker 3: your spaceship is being irresistibly swept sideways in a cosmic hurricane.
Speaker 2: So you literally cannot stand still.
Speaker 3: You cannot stand still because the stillness of space no
Speaker 3: longer exists. There.
Speaker 2: Think about the absolute wildness of that concept. The very
Speaker 2: fabric of where you are is moving. It sounds like pure,
Speaker 2: unfiltered science fiction.
Speaker 3: It really does.
Speaker 2: But this is a measurable, mathematically proven reality happening in
Speaker 2: our universe right now. And the true triumph of the
Speaker 2: research led by doctor Son and Neil Lou is that
Speaker 2: their analytical technique actually allows us to e isolate the
Speaker 2: specific signatures of this frame dragging from those tiny direct waves.
Speaker 3: Yes, we are transitioning from merely cataloging the existence of
Speaker 3: black holes to actually charting the fluid dynamics of an
Speaker 3: invisible universe. We are mapping the whirlpools of space time
Speaker 3: with excruciating precision.
Speaker 2: It is truly staggering. So let's trace the arc of
Speaker 2: what we've explored today.
Speaker 3: It's been journey.
Speaker 2: We started with the sheer violence of GW two five
Speaker 2: zero one fourteen, a cosmic crash so massive it sent
Speaker 2: the loudest ripples ever recorded through the gelatin of space time.
Speaker 2: And we looked at how an international team of scientists
Speaker 2: used supercomputers and numerical relativity to mathematically subtract the deafening
Speaker 2: noise of that crash.
Speaker 3: Which revealed the tiny, hidden direct waves.
Speaker 2: Right and those faint, lingering vibrations allowed us to bypass
Speaker 2: the paradox of the event horizon. We use those whispers
Speaker 2: to measure the spin and surface gravity of a newborn.
Speaker 3: Remnant, taking the vitals of an invisible ghost.
Speaker 2: Exactly, and in doing so we uncover the reality of
Speaker 2: frame dragging, where the sheer rotational force of a black
Speaker 2: hole twists spacetime itself into a cosmic treadmill where nothing
Speaker 2: can ever stand still.
Speaker 3: It's beautiful.
Speaker 2: It really highlights the absolute beauty of human ingenuity. I mean,
Speaker 2: we are sitting here on a pale blue dot, orbiting
Speaker 2: a totally average star, yet with our minds, our supercomputers
Speaker 2: and you know, lasers shooting down four kilometer vacuum tubo.
Speaker 2: I forget the vacuum tubes, right, we can mathematically dissect
Speaker 2: the most extreme bizarre environments in reality.
Speaker 3: It is a remarkable perspective. The universe is incredibly vast
Speaker 3: and violently chaotic, yet it remains profoundly intelligible. It follows rules,
Speaker 3: It follows rules, and piece by piece, frequency by frequency,
Speaker 3: we are learning to read the rule book.
Speaker 2: Which leaves me with one final provocative thought for you
Speaker 2: to consider. We have established today that the event horizon
Speaker 2: is the ultimate eraser.
Speaker 3: Of information, the ultimate trap.
Speaker 2: It permanently swallows all light, sound and matter. Once something
Speaker 2: crosses that boundary, it is gone from the observable uth
Speaker 2: universe forever. Right yet, right before that eraser activates, right
Speaker 2: in the millisecond before the door slams shut for eternity,
Speaker 2: the violent collision broadcasts its most intimate secrets, its mass,
Speaker 2: its spin, its gravity across the cosmos via these gravitational
Speaker 2: direct waves.
Speaker 3: It's quite send off.
Speaker 2: The universe essentially screams its identity precisely at the moment
Speaker 2: of its erasure. Is this the universe is built in
Speaker 2: mechanism for ensuring that nothing is ever truly erased without
Speaker 2: living a trace. If the universe rings like a bell
Speaker 2: right before it goes dark, what other invisible boundaries are
Speaker 2: out there right now, just waiting for us to figure
Speaker 2: out how to listen.
Speaker 3: It is a beautiful contradiction to end on the darkness
Speaker 3: announces its arrival with absolute clarity.
Speaker 2: It truly does. Keep looking up and keep listening until
Speaker 2: next time.