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: Picture this it is. It's September twenty twenty three.
Speaker 3: Right.
Speaker 2: You are just going about your normal day, maybe pouring
Speaker 2: a cup of coffee, sitting in traffic, just taking.
Speaker 3: A breath, a completely ordinary Tuesday, exactly.
Speaker 2: But right at that exact moment, high above our heads,
Speaker 2: NASA's Fermi satellite registers an event in the cosmos so
Speaker 2: staggeringly powerful that, for a brief, just a fleeting fraction
Speaker 2: of a second, a single explosion outshines entire galaxies.
Speaker 3: It's almost hard to wrap your head around the scale
Speaker 3: of it.
Speaker 2: It really is talking about a concentrated burst of light
Speaker 2: that dwarfs the combined output of billions of stars billions,
Speaker 2: and it gets registered in the astronomical community as GRB
Speaker 2: two three zero nine zero six A, which.
Speaker 3: Is a highly peculiar immensely violent class of phenomena.
Speaker 2: Right, a short gamma ray burst. So okay, let's unpack
Speaker 2: this because trying to mentally process an explosion that outshines
Speaker 2: a galaxy, it requires looking at the actual mechanics of
Speaker 2: what triggers it.
Speaker 3: And the culprits. In this case, we're two neutron.
Speaker 2: Stars, dead crushed remnants of massive stars.
Speaker 3: Exactly stars that spiral together and collided hundreds of millions
Speaker 3: of years ago.
Speaker 2: We are going to map out exactly how an explosion
Speaker 2: of that magnitude happens. But more importantly, we're going to
Speaker 2: look at how this distant, chaotic violence is fundamentally connected
Speaker 2: to the jewelry.
Speaker 3: You wear and the iron and the blood flowing through
Speaker 3: your veins right now.
Speaker 2: Yeah, So, just starting with the sheer physics of what
Speaker 2: the Fermi satellite recorded that day.
Speaker 3: It really challenges our everyday understanding of scale. I mean,
Speaker 3: to get a blast that outshines of galaxy, you need
Speaker 3: a mechanism that converts mass into energy with terrifying.
Speaker 2: Efficiency, right, And that is where the neutron stars come in.
Speaker 3: Because we aren't talking about active fusing stars like our sun.
Speaker 3: We were looking at the absolute extreme limit of material density, the.
Speaker 2: Very limit before black hole.
Speaker 3: Forms, precisely when a giant star dies and its core collapses.
Speaker 3: That gravitational crush is so intense that electrons and protons
Speaker 3: are physically forced together.
Speaker 2: They just get mashed into neutrons.
Speaker 3: We'll mashed together to become neutrons, and the result is
Speaker 3: a sphere maybe ten or twelve.
Speaker 2: Miles across, basically the size of a small city.
Speaker 3: A small city, yeah yeah, but it contains the mass
Speaker 3: of an entire sun.
Speaker 2: Which is wild like a single teaspoon of neutrons star
Speaker 2: material would weigh what billions of tons?
Speaker 3: Billions of tons just one teaspoon, So hundreds of millions
Speaker 3: of years ago, two of these ultra dense remnants found
Speaker 3: themselves locked in a decaying orbit.
Speaker 2: Just circling each other.
Speaker 3: Circling, spiraling toward each other, accelerating to a significant fraction
Speaker 3: of the speed of.
Speaker 2: Light until they ultimately collided.
Speaker 3: In that kinetic impact and the resulting instantaneous release of
Speaker 3: high energy radiation that is what washed over the Fermi
Speaker 3: satellite in twenty twenty three.
Speaker 2: Just visualizing a city sized atomic nucleus crashing into another
Speaker 2: one at near light speed, it is.
Speaker 3: The ultimate cosmic hammer and anvil.
Speaker 2: Yeah, that's a perfect way to put it. But the
Speaker 2: blast didn't happen in a vacuum, which brings us to
Speaker 2: the actual location of the collision.
Speaker 3: The cosmic crime scene.
Speaker 2: Right, the cosmic crime scene, because this wasn't some localized
Speaker 2: event in our own galactic backyard, not at all. The
Speaker 2: environment where this happened is a faint galaxy situated inside
Speaker 2: a much larger group of galaxies, and it's a staggering
Speaker 2: eight point five billion light years away from us.
Speaker 3: The eight point five billion year travel time provides really
Speaker 3: essential context here because think about it, the Earth itself
Speaker 3: is only about four point five billion years old.
Speaker 2: So this light was already on its way.
Speaker 3: The high energy photons from this gamma ray burs had
Speaker 3: already been traveling through the void of space for four
Speaker 3: billion years before our solar system even coalesced from a cloud.
Speaker 2: Of dust, before there was even an Earth to eventually
Speaker 2: hit exactly.
Speaker 3: But locating an event that far back in time and
Speaker 3: that far away in space is an incredibly difficult piece
Speaker 3: of astronomical detective work.
Speaker 2: Because Fermi just gives you the general area right right.
Speaker 3: FORMI is a fantastic instrument for detecting gamma rays. But
Speaker 3: gamma rays are notoriously hard to focus. They don't bounce
Speaker 3: off traditional mirror. This blast tree through art They blastraight through.
Speaker 3: So SERMI can tell us that a massive burst happened,
Speaker 3: and it can give us a general patch of.
Speaker 2: Sky, but it can't pinpoint the exact street address.
Speaker 3: No, it's too wide of a net.
Speaker 2: It's kind of like hearing a sonic boom.
Speaker 3: Oh, that's a great analogy.
Speaker 2: You know, a jet just broke the sound barrier somewhere overhead,
Speaker 2: but you can't point to the exact cubic meter of
Speaker 2: air it happened in just by the sound alone. You
Speaker 2: have to look for the contrail.
Speaker 3: That is exactly it. And finding that cosmic contrail required
Speaker 3: bringing in two two vastly different observational tools.
Speaker 2: NASA's Chandra X ray Observatory and the Hubble Space Telescope.
Speaker 3: Right now, Hubble operates heavily in the visible and near
Speaker 3: infrared spectrum. It excels at showing us the architecture of
Speaker 3: the universe.
Speaker 2: The shapes and structures of the galaxies themselves.
Speaker 3: Yes, but to connect the gamma ray bursts to a
Speaker 3: specific galaxy astronomers.
Speaker 2: Needed Chandra because of the afterglow.
Speaker 3: Decisely after the initial gamma ray flash subsides the explosion
Speaker 3: leaves behind a feeding after glow of lower energy light,
Speaker 3: particularly X rays.
Speaker 2: And astronomy professor Jane Charlton highlighted a really critical reality
Speaker 2: about the specific observation he did. She said that without
Speaker 2: the incredibly precise X ray imaging capabilities of the Chandra observatory,
Speaker 2: this faint host galaxy would have been completely missed.
Speaker 3: Because without the X ray data, you just have a
Speaker 3: picture of thousands of distant galaxies.
Speaker 2: From Hubble, just a sea of smudges, a sea.
Speaker 3: Of smudges, and absolutely no way to know which one
Speaker 3: hosted the explosion. You need Chan to find the glowing
Speaker 3: embers to narrow it down right. What's fascinating here is
Speaker 3: how relying on a single observational method leaves you blind
Speaker 3: to the actual mechanics of the universe.
Speaker 2: You need the layered approach exactly.
Speaker 3: By layering the data, taking the high energy X ray
Speaker 3: pinpoint from Chandra and overlaying it onto the deep optical
Speaker 3: field captured by Hubble, astronomers could drop a literal pin
Speaker 3: on a map eight point five billion light years away.
Speaker 2: They found the host galaxy.
Speaker 3: We found it. But more importantly, Hubble's optical data revealed
Speaker 3: that this galaxy wasn't just sitting in isolation.
Speaker 2: It belongs to a larger group it does.
Speaker 3: And that entire group is currently in the middle of
Speaker 3: a massive, chaotic cosmic merger.
Speaker 2: A galactic pile up. Which is wild because when we
Speaker 2: think of galaxies, we usually picture these serene, majestic pinwheels,
Speaker 2: just slowly rotating in.
Speaker 3: The dark like our own Milky Way looks in artistic renderings, right.
Speaker 2: But the environment where this burst happened is the total
Speaker 2: opposite of serene. These galaxies are actively colliding.
Speaker 3: Their gravitational fields are interacting in real time.
Speaker 2: They are ripping material away from each other, and all
Speaker 2: that turbulence is stirring up massive, massive amounts of new
Speaker 2: star formation.
Speaker 3: And within this chaotic wreckage, astronomers isolated the exact location
Speaker 3: of the.
Speaker 2: Blast inside a structure known as a tible tale a
Speaker 2: tidle tail. Yes, so walk us through what a tidal
Speaker 2: tale actually is physically in the middle of a multi
Speaker 2: galaxy merger.
Speaker 3: To understand a title tale, we really have to look
Speaker 3: at the fluid mechanic of gravity on a massive scale. Galaxies,
Speaker 3: you have to remember, are predominantly empty space.
Speaker 2: Just populated by billions of stars.
Speaker 3: Stars, and vast reservoirs of coal, gas, and dust. So
Speaker 3: when two galaxies pass close to one another, they don't
Speaker 3: usually crash like solid objects.
Speaker 2: They don't just smashed together like rocks.
Speaker 3: No, Instead, their gravitational fields interlock. But gravity follows the
Speaker 3: inverse square.
Speaker 2: Law, meaning its strength drops off exponentially with distance.
Speaker 3: Exactly so, the side of a galaxy see that is
Speaker 3: closest to the intruding galaxy feels a vastly stronger gravitational
Speaker 3: pull than the side facing away.
Speaker 2: It's a differential pole, differential poll. Yeah, it's like taking
Speaker 2: two massive balls of taffy and bring them close together.
Speaker 2: The edges closest to each other grab on, and as
Speaker 2: the bodies continue their momentum, those edges get stretched out
Speaker 2: into long, stringy lines of sugar connecting the two main pieces.
Speaker 3: That is a brilliant way to visualize it.
Speaker 2: Only in this case, the taffy is made of millions
Speaker 2: of stars in interstellar gas, and the strings are hundreds
Speaker 2: of thousands of light years long.
Speaker 3: The taffy analogy perfectly captures the sheer stretching force involved.
Speaker 3: That differential gravitational pull literally strips the outer layers of
Speaker 3: the galaxies away, just heels it off, peels it off,
Speaker 3: drawing out these immense, sweeping ribbons of material into intergalactic space.
Speaker 3: Those ribbons are the tidal tails.
Speaker 2: The elongated shrapnel of a galactic interaction.
Speaker 3: And importantly, those tails are absolutely packed at the cold
Speaker 3: gas and dust that was formally just floating in the
Speaker 3: outer disks of the galaxy.
Speaker 2: So it's yanked out and funneled.
Speaker 3: Funneled into these narrow streams, and as it does, the
Speaker 3: gas violently compresses.
Speaker 2: And when you compress cold gas in space, you basically
Speaker 2: build a cosmic pressure cooker.
Speaker 3: You certainly do.
Speaker 2: The density spikes, the temperature rises, and you trigger a
Speaker 2: massive wave of new star formation, which brings us to
Speaker 2: a specific sequence of events proposed by researcher Simone di Quiara.
Speaker 3: Dikiara's timeline is fascinating.
Speaker 2: Yeah. He laid out this seven hundred million year timeline
Speaker 2: that connects the grand macro scale of this galaxy collision
Speaker 2: directly down to the microscale of those two neutron stars colliding.
Speaker 3: The timeline he outlines is a perfect demonstration of stellar
Speaker 3: evolution accelerated by a chaotic environment.
Speaker 2: So the clock starts roughly seven hundred million years before
Speaker 2: the gamma raypors.
Speaker 3: Right, the galaxies get emerged, the tidal forces stretch out
Speaker 3: the taffy, and a resulting compression in the tidal tail
Speaker 3: triggers the starburst phase.
Speaker 2: Just a massive ignition.
Speaker 3: Millions of new st ignite almost simultaneously within this ribbon
Speaker 3: of debris. But the key here is the type of
Speaker 3: stars being born.
Speaker 2: The compression favors a specific kind.
Speaker 3: The intense compression in a tidal tale heavily favors the
Speaker 3: creation of incredibly massive stars. We are talking O type
Speaker 3: and B type stars that are dozens of times more
Speaker 3: massive than our Sun.
Speaker 2: And the rule with stars is the bigger they are,
Speaker 2: the harder they fall, and the.
Speaker 3: Faster they burn through their fuel.
Speaker 2: Right, a star like our Sun might sip its hydrogen
Speaker 2: for ten billion years, but these massive giants born in
Speaker 2: the tidal tail, they are burning through their nuclear fuel
Speaker 2: at a ridiculous rate.
Speaker 3: They live fast and die young. Astronomically speaking, their life
Speaker 3: spans are mere.
Speaker 2: Blips, just a few million years.
Speaker 3: Within a few million years, these hyper massive stars exhaust
Speaker 3: the hydrogen in their cores, the outward pressure of nuclear fusion.
Speaker 2: Drops, and gravity takes over.
Speaker 3: The star can no longer support its own immense weight
Speaker 3: against the crush of gravity. The core collapses in a
Speaker 3: fraction of a second.
Speaker 2: And the outer layers rebound in a catastrophic supernova explosion.
Speaker 3: Leaving behind the crushed neutron star core we discussed earlier. Now,
Speaker 3: because stars often form in.
Speaker 2: Pairs, binary systems, yes.
Speaker 3: Binary systems, you frequently end up with two massive stars
Speaker 3: orbiting each other that both go supernova.
Speaker 2: Assuming the explosions don't just kick them apart entirely.
Speaker 3: Exactly, assuming they stay gravitationally bound, you are left with
Speaker 3: a compact binary.
Speaker 2: System, two dead neutron stars orbiting a common center of mass,
Speaker 2: just floating inside this tidal.
Speaker 3: Tail, orbiting in the dark.
Speaker 2: So the tidal tale essentially acts as a hyper efficient
Speaker 2: factory for producing pairs of dead neutron stars.
Speaker 3: A factory build from galactic wreckage.
Speaker 2: But they don't just immediately crash into each other. According
Speaker 2: to Dickyar's timeline, they spend hundreds of millions of years
Speaker 2: in a kind of agonizingly slow death spiral. Right, how
Speaker 2: does a binary pair of dead stars eventually close the distance?
Speaker 2: I mean, in a vacuum, shouldn't they just orbit forever?
Speaker 3: If we relied strictly on Newtonian physics, they would orbit forever.
Speaker 3: But in the realm of extreme gravity, Einstein's general relativity
Speaker 3: takes over.
Speaker 2: Okay.
Speaker 3: As these two incredibly dense masses orbit each other, they
Speaker 3: accelerate through the gravitational field, which creates ripples in the
Speaker 3: actual fabric.
Speaker 2: Of space time gravitational waves.
Speaker 3: Yes, gravitational waves. You can think of gravitational waves as
Speaker 3: a mechanism that physically bleeds kinetic energy away from the
Speaker 3: binary system, like friction almost sort of. Yes, As energy
Speaker 3: is radiated away into space, the orbit shrinks. It is
Speaker 3: a slow, relentless process.
Speaker 2: So for hundreds of millions of years, they bleed.
Speaker 3: Energy, spiraling closer and closer, faster and faster, until the
Speaker 3: orbit decays completely.
Speaker 2: And that is the climax of the seven hundred million
Speaker 2: year journey. The compact binary star merger. You touch the
Speaker 2: system violently, shares a part, and it triggers the massive
Speaker 2: short gamma ray bursts that Fermi saw in twenty twenty three.
Speaker 3: If we connect this to the bigger picture, Dikyure's hypothesis
Speaker 3: really redefines how we view the life cycle of a galaxy.
Speaker 3: How so well, the tidal interactions aren't merely the setting
Speaker 3: for this event. The gravitational disruption is the direct trigger.
Speaker 2: It's a chain reaction exactly.
Speaker 3: The chaotic merger forces the compression. The compression forces the
Speaker 3: massive star birth. The massive stars rapidly die to leave
Speaker 3: neutron stars, and the neutron stars decay into a catastrophic merger.
Speaker 2: The largest structures in the universe. Colliding galaxies are directly
Speaker 2: responsible for generating the most concentrated microscopic points of extreme energy.
Speaker 3: It is the ultimate cosmic domino effect.
Speaker 2: That is just incredible. But the final massive explosion, the merger,
Speaker 2: it doesn't just produce a blinding flash of light and
Speaker 2: then fade into history.
Speaker 3: No, it leaves a very permanent mark.
Speaker 2: That collision fundamentally alters the chemistry of the universe around it,
Speaker 2: because when those two neutron stars slam together, the physics
Speaker 2: get so extreme that they create a phenomenon called a killinova.
Speaker 3: A killinova, yes.
Speaker 2: And a killinova is basically the universe's premiere heavy metal forge.
Speaker 3: The term forge is incredibly accurate. There when we observe
Speaker 3: killinova emissions, we are seeing the brightly glowing, rapidly expanding
Speaker 3: halo of radioactive material ejected during.
Speaker 2: The collision, just blasting our words.
Speaker 3: And to understand why this is a forge, we have
Speaker 3: to look at how elements are created in.
Speaker 2: The first place, like in normal stars.
Speaker 3: Right, normal stars synthesize light elements hydrogen and helium, helium
Speaker 3: into carbon, oxygen all the way up to iron.
Speaker 2: But iron is the wall, right, the dead end.
Speaker 3: Iron is the absolute limit for normal stellar fusion. Fusing
Speaker 3: iron requires more energy than it releases, so a normal
Speaker 3: star just stops there.
Speaker 2: So to get past iron to create elements heavier than iron,
Speaker 2: like gold, platinum, or uranium, you need something way more intense.
Speaker 3: You need an environment with an overwhelming abundance of free
Speaker 3: neutrons and incomprehensible energy.
Speaker 2: Because neutrons have no electrical charge. Exactly, if you try
Speaker 2: to mash to positively charged atomic nuclei together, they just
Speaker 2: repel each other. But a neutron you can just slip
Speaker 2: right past the defenses and bury itself in the nucleus.
Speaker 3: That is the core mechanism of what astrophysicists call the
Speaker 3: rapid neutron capture process the R process. The R process.
Speaker 3: During the fraction of a second when the two neutron
Speaker 3: stars collide, the environment is flooded with a density of
Speaker 3: free neutrons that exists almost nowhere else in the universe.
Speaker 2: Just a total deluge of neutrons.
Speaker 3: Atomic nuclei are bombarded with these neutrons so rapidly that
Speaker 3: they capture them before they even have a chance to
Speaker 3: undergo radioactive decay.
Speaker 2: So the nucleus just balloons in size.
Speaker 3: It balloons, becomes highly unstable, and then finally decays into
Speaker 3: a stable, incredibly heavy element.
Speaker 2: And the kilinova is the site of this R process.
Speaker 3: The explosion creates elements like gold and platinum, and the
Speaker 3: kinetic force of the blast physically scatters them outward into
Speaker 3: the surrounding interstellar medium.
Speaker 2: Which actually solves a massive puzzle in astronomy too. It
Speaker 2: really does, because for years astronomers looking at interacting galaxies
Speaker 2: notice something strange. They were seeing heightened levels of heavy
Speaker 2: elements like gold and platinum, specifically located in the halos.
Speaker 2: The chaotic outer fringes of these merging galaxies, and it
Speaker 2: did make sense, right, Why is the heavy stuff floating
Speaker 2: way out in the cosmic suburbs exactly?
Speaker 3: And the observation of GRB two three zero nine zero
Speaker 3: six A within a tidal tail provides a highly elegant,
Speaker 3: observable solution to that mystery.
Speaker 2: It's the smoking gun.
Speaker 3: It is the interacting galaxies draw out the tidal tails
Speaker 3: into the outer halos. The tails greed the massive stars.
Speaker 3: The stars leave the neutron binaries, the binaries merge into kilnova.
Speaker 2: And there are process sprays those newly forged heavy elements
Speaker 2: directly into that outer galactic envelope.
Speaker 3: The environment forces the creation of the forge, exactly where
Speaker 3: we see the resulting metals.
Speaker 2: Here's where it gets really interesting, because we've been talking
Speaker 2: about galaxies eight point five billion light years away, but
Speaker 2: this cosmic alchemy is intimately tied to you, the listener,
Speaker 2: very intimately tied. Professor Jane Charlton reviewed the data from
Speaker 2: this event and noted that it gives us a rare
Speaker 2: glimpse into how destruction acts as a catalyst for creation.
Speaker 3: The universe doesn't just destroy, it aggressively.
Speaker 2: Recycled, aggressively recycles.
Speaker 3: I love that the recycling process is really the foundation
Speaker 3: of our physical reality. We tend to view massive cosmic
Speaker 3: explosions as endpoints, the death of stars right game over,
Speaker 3: But chemically speaking, they are seeding mechanisms.
Speaker 2: Think about the gold right here on Earth, like if
Speaker 2: you are wearing a gold ring right now, or just
Speaker 2: holding a smartphone that relies on trace amounts of gold
Speaker 2: and its microchips.
Speaker 3: Earth didn't make that gold, no, and our.
Speaker 2: Sun cannot make that gold. Every single atom of gold
Speaker 2: on this planet was forged in the rare process of
Speaker 2: a kilinovo.
Speaker 3: Which is astonishing to think about.
Speaker 2: Billions of years ago, somewhere in the cosmos, neutron stars
Speaker 2: smashed into each other, and the shrapnel from that distant
Speaker 2: violence eventually drifted into the cloud of gas that formed
Speaker 2: our solar system.
Speaker 3: You are interacting with the wreckage of a cosmic collision
Speaker 3: on a daily basis.
Speaker 2: And it goes deeper than the metal in your phone.
Speaker 2: It goes straight into your biology.
Speaker 3: Yes, Charlton made a point to connect this astrophysical process
Speaker 3: to the very physiological mechanisms keeping us alive.
Speaker 2: The heavier elements in our bodies.
Speaker 3: Particularly iron. Iron has an extraordinary origin It is the
Speaker 3: central atom in the heme group of hemoglobin.
Speaker 2: The protein in red blood cells that binds to oxygen.
Speaker 3: Exactly when you take a breath, oxygen from your lungs
Speaker 3: binds to the iron in your blood to be transported
Speaker 3: to every cell in your body. Without that specific atomic structure,
Speaker 3: respiration as we know it completely fails.
Speaker 2: And the origin of that iron.
Speaker 3: It was synthesized in the cores of dyeing massive stars
Speaker 3: just before they went supernova. The current estimate is that
Speaker 3: the iron coursing through your veins right now is an
Speaker 3: amalgamation of material forged in the explosive depths of roughly
Speaker 3: ten thousand different massive stars in the Milky Way's history.
Speaker 2: The human body is essentially a mosaic constructed from the
Speaker 2: remains of ten thousand dead stars. It is every time
Speaker 2: your heart pumps, you were relying on heavy elements that
Speaker 2: were forged in a pressure cooker billions of years before
Speaker 2: Earth even existed.
Speaker 3: Ten thousand stars had to live, burn fiercely, and detonate
Speaker 3: violently just to see the gas cloud that would eventually
Speaker 3: allow you to exist.
Speaker 2: It completely reframes how you look at the night sky.
Speaker 2: It's not just an empty void with pretty lights. It
Speaker 2: is the active machinery that manufactured the chemistry required for
Speaker 2: complex life, and.
Speaker 3: The timescale required for that machinery to operate is deeply humbling.
Speaker 3: The universe operates with a profound patience.
Speaker 2: Hundreds of millions of years just for.
Speaker 3: The initial galaxies to interact. Then it took millions of
Speaker 3: years for the massive stars to form and die, hundreds
Speaker 3: of millions more for the neutron binaries to decay and merge,
Speaker 3: scattering their payload.
Speaker 2: Just a slow, methodical process.
Speaker 3: Then it took billions of years for that scattered stardust
Speaker 3: the iron the goal the carbon to coalesce in the
Speaker 3: interstellar medium, collapse into a protoplanetary disk and form the Earth.
Speaker 2: And then billions of years of biological evolution on top
Speaker 2: of that.
Speaker 3: For organisms to develop the complex metabolic pathways to actually
Speaker 3: utilize that iron for respiration. We are the beneficiaries of
Speaker 3: a supply chain that has been running for billions of years.
Speaker 2: But even with all of these profound connections and everything
Speaker 2: we have deduced from the light of GRB two three
Speaker 2: zero nine zero six A, the cosmos isn't handing over
Speaker 2: all its secrets.
Speaker 3: No, it never does.
Speaker 2: There is still a significant amount of ambiguity surrounding this
Speaker 2: specific event. The detective work is far from over.
Speaker 3: The nature of observational astronomy is that every answer refines
Speaker 3: our models, but it also exposes the limitations of our
Speaker 3: current instruments.
Speaker 2: And in the case of this specific burst, the most
Speaker 2: pressing unsolved mystery is its exact.
Speaker 3: Redshift, which translates to its exact distance.
Speaker 2: Right. Our current spectroscopic data places it at an estimated
Speaker 2: eight point five billion light years away, but the host
Speaker 2: galaxy is so incredibly faint and the data is noisy
Speaker 2: enough that there is a margin of error.
Speaker 3: A fairly significant one.
Speaker 2: Because redshift is essentially how we measure distance in an
Speaker 2: expanding universe.
Speaker 3: Right. That's right.
Speaker 2: As light travels toward us over billions of years, the
Speaker 2: actual fabric of space is stretching, which stretches the light waves,
Speaker 2: shifting them toward the red end of the spectrum.
Speaker 3: The red or the light the farther it traveled.
Speaker 2: But if a galaxy is barely a smudge on Hubble's lens,
Speaker 2: getting a clean read on that stretched light is really tough,
Speaker 2: and if the current estimates are off, this explosion might
Speaker 2: be even further away than we think.
Speaker 3: Precisely, if the actual red shift is on the higher
Speaker 3: end of the possible spectrum, it would significantly push back
Speaker 3: the distance in the timeline, making it much older. It
Speaker 3: would make GRB two three zero nine zero six A
Speaker 3: one of the most distant and therefore one of the
Speaker 3: earliest short gamma ray bursts ever recorded in human history.
Speaker 2: Meaning we are looking at the r process heavy element
Speaker 2: forge operating incredibly early in the universe's lifespan.
Speaker 3: Which raises an important question, but the future of our
Speaker 3: open servational infrastructure. Well, we've pushed Chandra and Hubble to
Speaker 3: their absolute limits to find this one bullet hole.
Speaker 2: We need better eyes.
Speaker 3: Exactly. While Chandra and Hubble have defined a generation of astrophysics,
Speaker 3: they simply cannot resolve the faint spectroscopic signatures of galaxies
Speaker 3: at the very edge of the observable universe with the
Speaker 3: precision we now require.
Speaker 2: So what's the next step.
Speaker 3: To lock down the true distance of this burst and
Speaker 3: to deeply map the tidal structures of these ancient galactic mergers.
Speaker 3: We are entirely dependent on next generation observatories.
Speaker 2: Like the James Web Space telescope.
Speaker 3: Instruments operating with the infrared sensitivity of JWST, combined with
Speaker 3: proposed future high energy X ray probes, will be required
Speaker 3: to really dissect the chemistry of these distant chaotic environments.
Speaker 2: We are always building a bigger lens to see a
Speaker 2: little deeper into the dark.
Speaker 3: Always.
Speaker 2: But here is the ultimate twist to this entire story.
Speaker 2: We've been looking outward this whole time, studying this chaotic
Speaker 2: galactic merger eight point five billion light years away, analyzing
Speaker 2: the tidal tales and the Kilanova forges right. But the
Speaker 2: physics we are observing out there are eventually coming for us.
Speaker 3: Yes they are.
Speaker 2: Professor Charlton reminded us of a very sobering fact. Having
Speaker 2: neighbors in the universe is common. Galaxies are highly social,
Speaker 2: they cluster, and our.
Speaker 3: Own Milky Way galaxy has a very massive.
Speaker 2: Neighbor, the Andromata galaxy.
Speaker 3: It is the closest major spiral galaxy to our own,
Speaker 3: located approximately two point five million light years away.
Speaker 2: Which seems far, but on a cosmic scale, it's right
Speaker 2: next door.
Speaker 3: It's right next door. If you look at it in
Speaker 3: the night sky today, it appears as a faint, stable
Speaker 3: smudge of light, but the gravitational dynamics between the Milky
Speaker 3: Way and Andromeda are already locked in.
Speaker 2: The gears are turning.
Speaker 3: The two galaxies are gravitationally bound, and they are currently
Speaker 3: accelerating toward one another.
Speaker 2: The space between us is shrinking every second.
Speaker 3: As Charlton pointed out, living in a galactic group is standard,
Speaker 3: but undergoing a major merger is a completely transformative event.
Speaker 3: The Milky Way, that event is an absolute certainty.
Speaker 2: It is a cosmic inevitability. In roughly four to five
Speaker 2: billion years, the Milky Way and Andromeda are going to collide.
Speaker 3: And as we've learned from studying GRB two three zero
Speaker 3: nine zer six A, galaxies don't just gently bump into
Speaker 3: each other.
Speaker 2: No, they don't. When Andromeda arrives, our serene spiral structure
Speaker 2: is going to be completely obliterated. The exact same chaotic
Speaker 2: physics we just mapped out eight point five billion light
Speaker 2: years away are going to happen right here in our
Speaker 2: local space.
Speaker 3: The parallels to our future are undeniable. It's going to
Speaker 3: be a mess, a spectacular mess. As the two immense
Speaker 3: dark matter halos and stellar disks intersect, the differential gravitational
Speaker 3: forces will tear both galaxies apart the night.
Speaker 2: Sky from Earth, assuming the Earth still exists in some form,
Speaker 2: would be totally unrecognizable.
Speaker 3: Completely alien. Massive tidle Tales will be violently drawn out
Speaker 3: from the Milky Way and Andromeda, stretching hundreds of thousands
Speaker 3: of light years into the intergalactic medium.
Speaker 2: Just massive ribbons of taffy of taffy.
Speaker 3: Yes, the interstellar gas within our galaxy will be subjected
Speaker 3: to immense shock waves in compression.
Speaker 2: And we know exactly what happens when you compress gas
Speaker 2: In a title Tale, the cosmic pressure cooker turns on
Speaker 2: exactly the Milcomeata merger is going to ignite a furious
Speaker 2: firestorm of new star formation. Millions of massive O type
Speaker 2: and B type stars will burn fast, go supernova, and
Speaker 2: populate our newly formed Title Tales with a massive new
Speaker 2: generation of dead neutron stars.
Speaker 3: The cycle will repeat itself flawlessly over the subsequent hundreds
Speaker 3: of millions of years. Those local binary neutron stars will
Speaker 3: bleed their orporal energy via gravitational waves. It will spiral inward,
Speaker 3: and eventually our newly merged galaxy will be lit up
Speaker 3: by a series of short gamma ray bursts and killinova.
Speaker 2: Explosion, setting off the forge again.
Speaker 3: And our process will activate in our own cosmic backyard,
Speaker 3: heavily enriching the local environment with a massive influx of
Speaker 3: newly forged heavy elements.
Speaker 2: Fresh gold, fresh platinum, whole new batch. So what does
Speaker 2: this all mean for you? It means that you aren't
Speaker 2: just a passive observer sitting on a rock in a
Speaker 2: static universe, not at all. You are an active participant
Speaker 2: in an incredibly violent, incredibly beautiful cycle of cosmic recycling.
Speaker 2: The iron currently binding the oxygen in your blood is
Speaker 2: the direct physical evidence of ancient stellar destruction.
Speaker 3: We exist because stars die.
Speaker 2: We are walking, talking proof that destruction is the absolute
Speaker 2: prerequisite for creation, and knowing that our entire galaxy is
Speaker 2: destined for a cataclysmic collision just proves that the mechanics
Speaker 2: of the universe never stop.
Speaker 3: It is a profound realization that the violent processes we
Speaker 3: observe in the deepest reaches of space are the exact
Speaker 3: same processes that engineered our present reality, and.
Speaker 2: They are the exact same processes that will dictate our
Speaker 2: distant future.
Speaker 3: The universe is a continuous engine of transformation, and that.
Speaker 2: Leads to a thought. I want to leave you with
Speaker 2: a concept to just sit with and mull over long
Speaker 2: after you finish listening. We know, as a matter of
Speaker 2: measurable physics that the iron pumping through your veins right
Speaker 2: now was forged in the violent deaths of ten thousand
Speaker 2: ancient stars ten thousand stars. And we know with absolute
Speaker 2: gravitational certainty that in four to five billion years, our home,
Speaker 2: the Milky Way, will be violently torn apart and smashed
Speaker 2: into andromedal. The skies will blaze with new star formation,
Speaker 2: monumental tidle tales will whip across the dark, and an
Speaker 2: entirely new generation of heavy elements will be forcefully scattered into.
Speaker 3: The void, seating the next generation.
Speaker 2: So, when our galaxy is finally destroyed and completely remade
Speaker 2: by that future collision, what entirely new, unfathomable forms of creation,
Speaker 2: what strange new chemistry, or perhaps even what unimaginable new
Speaker 2: forms of life might eventually be catalyzed by our own destruction.
Speaker 2: Sai