Speaker 1: Welcome to Bedtime Astronomy. Explore the wonders of the cosmos
Speaker 1: with our soothing Bedtime Astronomi 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: Welcome to the deep Dive. Today, we're looking at something
Speaker 2: that feels like it's straight out of science fiction. We
Speaker 2: might be at the end of a hunt that's been
Speaker 2: going on for what nearly one hundred years, the search
Speaker 2: for dark matter.
Speaker 3: It's the biggest piece of the cosmic puzzle, and it's
Speaker 3: been missing this whole time. We're talking about the invisible structure,
Speaker 3: the scaffolding that holds literally everything together, and for decades
Speaker 3: it's just been well, a number in an equation, a
Speaker 3: gravitational ghost.
Speaker 2: That's such a good way to put it. And our
Speaker 2: mission today is to really get into a new fine
Speaker 2: that is so specific, so tantilizing that it has the
Speaker 2: entire physics community buzzing.
Speaker 3: It really does.
Speaker 2: We're going to be unpacking the work of Professor Tomanoy
Speaker 2: Totani from the University of Tokyo using data from NASA's
Speaker 2: Fermi gamma rayse based telescope, and the claim is huge.
Speaker 2: They think they may have finally seen it, or at least.
Speaker 3: Seen its fingerprint. It's direct signature. We're going to connect
Speaker 3: the dots today from the abstract theories of the nineteen
Speaker 3: thirties all the way to this cutting edge space telescope
Speaker 3: data from twenty twenty five.
Speaker 2: And we're using the study itself as our guide, the
Speaker 2: one published in the Journal of Cosmology and Astroparticle.
Speaker 3: Physics, exactly because this isn't just about finding something new.
Speaker 3: If this is right, it's the discovery of a brand
Speaker 3: new fundamental particle, something that would force us to rewrite
Speaker 3: the standard model of particle physics.
Speaker 2: Okay, so let's unpack that. If this really is the
Speaker 2: smoking gun, it means that eighty five percent of all
Speaker 2: the matter in the universe is made of stuff that
Speaker 2: is fundamentally different from anything we have ever seen or cataloged.
Speaker 3: Right, the implications are just staggering.
Speaker 2: So we have to approach this with, you know, a
Speaker 2: lot of critical thinking. We need to understand not just
Speaker 2: what they found, but why on Earth it's taken us
Speaker 2: this long to get even a glimpse of it.
Speaker 3: Precisely, to really appreciate what a massive claim this is,
Speaker 3: you have to understand the decades of frankly frustration and
Speaker 3: dead ends, and that journey starts way back at the beginning.
Speaker 3: Why did we even think this invisible stuff existed in
Speaker 3: the first place.
Speaker 2: Okay, so let's set the scene. We're in the nineteen thirties.
Speaker 2: Our understanding of the universe is still pretty new, but
Speaker 2: it's built on these pillars of classical mechanics. You know,
Speaker 2: Newtonian gravity, right, And.
Speaker 3: The assumption was simple. What you see is what you get.
Speaker 3: If you want to know the mass of a galaxy,
Speaker 3: you just add up all the light from the stars,
Speaker 3: estimate the mass of the gas and dust.
Speaker 2: And that's your total mass. That tells you how much
Speaker 2: gravity it has exactly.
Speaker 3: And this is where the Swiss astronomer Fritz Zwicki comes in.
Speaker 3: He was this brilliant though apparently very cantankerous scientists.
Speaker 2: I heard that.
Speaker 3: Yeah, he was studying a huge collection of galaxies called
Speaker 3: the Coma cluster, and he was trying to measure how
Speaker 3: fast the galaxies inside it were moving around.
Speaker 2: So he's basically timing the speed of this giant cosmic dance.
Speaker 3: A very very fast dance. As it turned out, he
Speaker 3: did the math based on all the light coming from
Speaker 3: the cluster, all the visible matter, the galaxies should have
Speaker 3: been moving at a certain speed, but what he actually measured.
Speaker 2: Was just wrong. They were moving too fast.
Speaker 3: Way too fast, so fast in fact, that the gravity
Speaker 3: from all the visible stars and gas wasn't nearly strong
Speaker 3: enough to keep them from flying away.
Speaker 2: Wait, so, based on the laws of physics, the entire
Speaker 2: coma cluster should have just disintegrated.
Speaker 3: It should have flown apart billions of years ago. The
Speaker 3: galaxies were moving with so much energy that the cluster's
Speaker 3: own gravity couldn't possibly hold them in orbit. It was
Speaker 3: a massive paradox.
Speaker 2: So Zwicki had a choice. Either Newton's laws of gravity
Speaker 2: are completely wrong, or there's a whole lot of mass
Speaker 2: in that cluster that he just can't see.
Speaker 3: And that's the conclusion he came to. He was confident
Speaker 3: in his measurements. He reasoned there had to be some
Speaker 3: other source of gravity, an enormous amount of unseen matter
Speaker 3: holding it all together. He called it dunkle material, dark matter.
Speaker 2: And people didn't exactly jump on board with this idea,
Speaker 2: did they.
Speaker 3: Oh, not at all. He was largely ignored, even ridiculed.
Speaker 3: The idea that maybe ninety percent of the universe was
Speaker 3: made of some invisible, unknown substance was just too radical.
Speaker 3: People thought, you know, it must be an error in
Speaker 3: his calculations, or some dust were not accounting for.
Speaker 2: Just a weird anomaly exactly.
Speaker 3: The idea was just shelved for decades. It was a
Speaker 3: theory way ahead of its time.
Speaker 2: But the evidence didn't go away. In fact, it came
Speaker 2: back with a vengeance in the nineteen seventies with astronomers
Speaker 2: like VERA. Rubin and Kent Ford.
Speaker 3: And that was the pivot, That was the moment this
Speaker 3: went from a weird idea to a fundamental problem in physics.
Speaker 3: Reuben and Ford weren't looking at giant clusters. They were
Speaker 3: looking at individual spiral galaxies like our own Milky.
Speaker 2: And they were measuring how fast the stars were rotating
Speaker 2: around the center of the galaxy.
Speaker 3: Right, and you'd expect something similar to our solar system.
Speaker 3: Mercury moves really fast, Earth is a bit slower, and
Speaker 3: Neptune way out of the edge is just crawling along.
Speaker 3: The further you get from the central mass, the slower
Speaker 3: you go.
Speaker 2: But that's not what they found in galaxies.
Speaker 3: Not even close. They found that the stars way out
Speaker 3: on the fringes of the spiral arms were moving just
Speaker 3: as fast as the stars near the core. The rotation
Speaker 3: curves were flat, which is impossible unless unless there's a
Speaker 3: huge invisible halo of mass surrounding the entire visible galaxy,
Speaker 3: extending far beyond the stars. Its gravity is what's keeping
Speaker 3: those outer stars in their high speed orbits, stopping them
Speaker 3: from flying off into space.
Speaker 2: So after forty years, Zwicki was vindicated. This wasn't just
Speaker 2: a quirk of the Coma cluster. It was everywhere. Every
Speaker 2: galaxy seemed to be embedded in this massive, invisible halo
Speaker 2: of dark matter.
Speaker 3: It went from being a curiosity to a cosmic necessity.
Speaker 3: And that raises the billion dollar question that physicists have
Speaker 3: been wrestling with ever since. If this stuff makes up
Speaker 3: eighty five percent of all matter, why can't we see it?
Speaker 3: Why is it so incredibly elusive?
Speaker 2: And the answer gets down to the fundamental forces of nature.
Speaker 2: It's all about what it doesn't do.
Speaker 3: It's all about the electromagnetic force. That's the force that
Speaker 3: governs light, electricity, magnetism, basically everything that makes matter visible
Speaker 3: and interactive particles interact with photons, which are particles of light.
Speaker 2: They can absorb light, reflect it, emit it.
Speaker 3: But dark matter particles, whatever they are, they just don't
Speaker 3: seem to play that game. They have no electric charts.
Speaker 3: They just ignore light completely.
Speaker 2: So a particle of dark matter could pass right through you,
Speaker 2: right through the Earth, without hitting a single thing. It's
Speaker 2: completely transparent, which.
Speaker 3: Makes it invisible to every telescope we've ever built. We
Speaker 3: only know it's there because we can feel its gravity.
Speaker 3: We're trying to study a ghost.
Speaker 2: So if you can't study it with light, you have
Speaker 2: to find another way. You have to hope it interacts
Speaker 2: with one of the other fundamental forces, even if it's
Speaker 2: just a tiny, tiny bit.
Speaker 3: And that's exactactly the strategy that led scientists to the
Speaker 3: leading theory, to the whimp hypothesis.
Speaker 2: Okay, so if dark matter ignores the electromagnetic force, scientists
Speaker 2: had to place a bet which of the other forces
Speaker 2: might give us a clue, and they landed on the
Speaker 2: weak nuclear force.
Speaker 3: That's right, And this led to the dominant candidate for
Speaker 3: what dark matter could be for a long long time.
Speaker 3: The WIMP. It stands for a weekly interacting massive particle.
Speaker 2: And it wasn't just a random guess, right. This idea
Speaker 2: came out of other bigger theories in particle physics.
Speaker 3: Exactly. It emerged naturally from theories like supersymmetry, which proposed
Speaker 3: that every known particle has a heavier super partner. The
Speaker 3: lightest of these super partners would be stable massive and
Speaker 3: would interact via the weak force. It was a perfect
Speaker 3: dark matter candidate just waiting to be discovered.
Speaker 2: So let's break down the name weekly interacting Why is
Speaker 2: that part so important?
Speaker 3: Well, the weak nuclear force is one of the four
Speaker 3: fundamental forces, but as its name suggests, it's incredibly feeble
Speaker 3: and only works over very short distances. It governs things
Speaker 3: like radioactive decay.
Speaker 2: So if dark matter particles interact through that force, it
Speaker 2: would explain why they're so hard.
Speaker 3: To detect, it would. It means they would stream through
Speaker 3: normal matter through us through planets almost all the time
Speaker 3: without ever hitting anything. An interaction would be an incredibly
Speaker 3: rare event. It solves the elusiveness problem perfectly.
Speaker 2: Okay, so that's the weekly interacting part. What about massive.
Speaker 3: That's crucial for a couple reasons. First, they need to
Speaker 3: be massive enough to clump together under gravity and form
Speaker 3: those giant halos around galaxies that we see the effects
Speaker 3: of light. Particles wouldn't do that.
Speaker 2: And the second reason, the second.
Speaker 3: Reason is key for actually finding them. If they are massive,
Speaker 3: say hundreds of times heavier than a proton, it gives
Speaker 3: us something to look for. It gives us Einstein's famous
Speaker 3: equation E equals mc square.
Speaker 2: Ah. Okay, mass can be converted into energy, and this
Speaker 2: brings us to the really clever part of the whole search,
Speaker 2: the annihilation sign.
Speaker 1: Right.
Speaker 3: If trying to catch a single wimp is nearly impossible,
Speaker 3: what if we could see what happens when two of
Speaker 3: them collide? Okay, the theory predicts that WIMPs are their
Speaker 3: own antiparticles. So when two WIMPs zipping around in the
Speaker 3: dense center of a galaxy happen to crash into each.
Speaker 2: Other, they annihilate. They just vanish, poof.
Speaker 3: They're gone. But their mass can't just disappear. It gets
Speaker 3: converted instantaneously into a shower of pure energy, and that.
Speaker 2: Energy creates other particles that we can detect exactly.
Speaker 3: It produces a whole cascade of familiar standard model particles.
Speaker 3: The heavier the original wimp, the more energy is released,
Speaker 3: and the heavier the particles that are created, things like
Speaker 3: quarks or even w and z bosons.
Speaker 2: Now those are heavy unstable particles. They don't stick around
Speaker 2: for long.
Speaker 3: Do they not at all. They decay almost instantly, and
Speaker 3: in that decay process, in that chain reaction, they produce
Speaker 3: the final stable thing we can actually look for.
Speaker 2: From Earth gamma race, high energy, high.
Speaker 3: Energy gamma rays. That's the smoking gun. The whims disappear,
Speaker 3: they create these heavy unstable particles, and those particles immediately
Speaker 3: fall apart and release a flash of gamma ray light.
Speaker 2: And the beauty of this is that the energy of
Speaker 2: that gamma ray is directly connected to the mass of
Speaker 2: the original wimp that started the whole thing.
Speaker 3: That's the fingerprint. It's a direct line. If you can
Speaker 3: measure the precise energy of the gamma ray, you can
Speaker 3: calculate the mass of the dark matter particle that created it.
Speaker 3: It's no longer a ghost. It has a specific measurable property.
Speaker 2: So the whole strategy for the last few decades has
Speaker 2: been find the place where dark matter is densest, point
Speaker 2: a gamma ray telescope at it and look for a
Speaker 2: specific spike of energy that can't be explained by anything else.
Speaker 3: That's the game plan in a nutshell. And there's one
Speaker 3: place in our neighborhood that is by far the most
Speaker 3: promising hunting.
Speaker 2: Ground, the center of our own galaxy, the Milky Way.
Speaker 3: All the models show that our galaxy is sitting inside
Speaker 3: this enormous, sort of football shaped halo of dark batter,
Speaker 3: and the density of that halo gets highigher and higher
Speaker 3: the closer you get to the galactic core.
Speaker 2: More density means more whimps packed into a smaller.
Speaker 3: Space, which means a much higher chance that two of
Speaker 3: them will actually collide and annihilate. It's the brightest spot
Speaker 3: on the dark matter map.
Speaker 2: But it's also an incredibly messy and violent place. Astronomically speaking,
Speaker 2: You've got a supermassive black hole, exploding stars, pulsars, all
Speaker 2: sorts of things throwing out high energy radiation.
Speaker 3: And that's the monumental challenge. How do you listen for
Speaker 3: the faint, specific whisper of dark matter annihilation amidst the
Speaker 3: deafening roar of a thousand other cosmic fireworks going off
Speaker 3: at the same time. That was the problem Professor Tatani's
Speaker 3: team had to solve, and solving that problem required an
Speaker 3: instrument built for exactly this purpose. The data that Tatani's
Speaker 3: team analyzed came from NASA's Fermi Gamma ray space telescope.
Speaker 3: It's been orbiting Earth for years, mapping the sky in
Speaker 3: the highest energies of light, so let's.
Speaker 2: Get right to it. The team sifts through all this
Speaker 2: data from the Galactic Center, What specific signal did they
Speaker 2: make managed to pull out of all that noise?
Speaker 3: After a very very careful analysis, they isolated a gamma
Speaker 3: ray signal with a remarkably specific energy. The photons they
Speaker 3: found were clocked at twenty gig electron vaults.
Speaker 2: Okay, twenty gv let's ground that number for a second.
Speaker 2: We hear these terms, but what does twenty billion electron
Speaker 2: vaults actually mean? How energetic is that?
Speaker 3: It's immense? For perspective, the light our eyes can see
Speaker 3: has an energy of maybe two or three electron vaults.
Speaker 3: A medical X ray might be a few thousand. We're
Speaker 3: talking about photons that are billions of times more energetic
Speaker 3: than visible light.
Speaker 2: So it's an extremely high energy.
Speaker 3: Signature, an incredibly high energy signature, And that's the first clue.
Speaker 3: An energy that high can really only come from a
Speaker 3: very energetic event, like the annihilation of a really massive particle.
Speaker 3: The more mass you start with, the more energy you
Speaker 3: get out.
Speaker 2: So the energy level is the first perfect match. But
Speaker 2: the second clue, and maybe this is even more important,
Speaker 2: was the signal shape and location.
Speaker 3: Absolutely, if this was just say a pulsar, a spinning
Speaker 3: neutron star, you'd expect to see a single bright point
Speaker 3: of light. But that's not what they saw.
Speaker 2: What did they see.
Speaker 3: Tatani described it as a distinct halo like structure. It's
Speaker 3: not a point. It's a diffuse glow that's brightest toward
Speaker 3: the galactic center but extends outward, fading gradually.
Speaker 2: That's the clincher, isn't it. That shape is a dead
Speaker 2: ringer for the theoretical models of the dark Manner halo itself.
Speaker 3: It's an almost perfect spatial match. You have a signal
Speaker 3: with the right energy showing up in the right place
Speaker 3: and distributed in the right shape. When you line all
Speaker 3: three of those up, the odds of it being some
Speaker 3: random astronomical objects start to drop very very quickly.
Speaker 2: The observational data is lining up with the theoretical profile
Speaker 2: of a wimpiss. So let's talk about that profile. What
Speaker 2: does a twenty GF gamma ray tell us about the
Speaker 2: wink that made it?
Speaker 3: Well, this is where it gets really exciting for the
Speaker 3: particle physicists. You can work the map backwards. A gamma
Speaker 3: ray with twenty gv of energy would be produced by
Speaker 3: the annihilation of WIMPs that each have a mass of
Speaker 3: roughly five hundred times the mass of a.
Speaker 2: Proton proton masses. Now is that significant in the grand
Speaker 2: scheme of all the theories out there? Where does a
Speaker 2: five hundred proton mass particle fit?
Speaker 3: It's extremely significant because it starts to narrow things down.
Speaker 3: For a long time, many of the most popular theories,
Speaker 3: especially those connected to supersymmetry, were predicting much heavier WIMPs,
Speaker 3: maybe thousands of times the mass of a proton.
Speaker 2: So this is actually on the lighter side of what
Speaker 2: people were expecting.
Speaker 3: It is. A wimp with about five hundred times of
Speaker 3: proton's mass is still very heavy, but it falls into
Speaker 3: a specific window that a lot of previous searches might
Speaker 3: have overlooked. It immediately forces theorists to look at a
Speaker 3: different set of models. Any new theory of dark matter
Speaker 3: now has to be able to produce a particle with
Speaker 3: this specific mass. It's a hard data point.
Speaker 2: So you had the energy peak at twenty gv, but
Speaker 2: not just a single spike, right, The annihilation should produce
Speaker 2: a whole spectrum of energies.
Speaker 3: Yes, and that's another crucial piece of the puzzle. The
Speaker 3: overall shape of the energy signal they found, not just
Speaker 3: the peak, also aligns incredibly well with the spectrum you'd
Speaker 3: expect from whimps of this mass annihilating into other particles
Speaker 3: like bottom quarks for example.
Speaker 2: It's the whole package. Yeah, the energy, the shape, the spectrum,
Speaker 2: it all fits.
Speaker 3: It's a remarkably coherent picture.
Speaker 2: But as we said, the galactic center is chaos. How
Speaker 2: did they convince themselves and how do they convince the
Speaker 2: rest of the world that this isn't just some other
Speaker 2: weird thing that also happens to produce twenty jv gamma
Speaker 2: rays is.
Speaker 3: The most difficult part of the analysis, and it's what
Speaker 3: makes this claim so credible. They had to systematically rule
Speaker 3: out everything else pulsars have the wrong energy spectrum. Cosmic rays.
Speaker 3: Hanging gas clouds produce gamma rays, but again the shape
Speaker 3: in the spectrum don't match this halo.
Speaker 2: And their main strategy was to look just outside the
Speaker 2: very center right to avoid the worst of the noise.
Speaker 3: Exactly, they deliberately cut out the data from the central
Speaker 3: galactic plane itself, because it's just saturated with radiation from
Speaker 3: known sources. They focused on the extended diffuse glow around
Speaker 3: that noisy core.
Speaker 2: So they looked at the subtle glow in the back range,
Speaker 2: not the bright fireworks in the foreground.
Speaker 3: Right, and by doing that, they isolated a signal that is,
Speaker 3: in their words, not easily explained by any of the
Speaker 3: usual suspects. When you've ruled out every known possibility, the
Speaker 3: one that remains, no matter how extraordinary, starts to look
Speaker 3: pretty compelling.
Speaker 2: And the most compelling explanation left on the table is
Speaker 2: the annihilation of a five hundred proton mass dark matter particle.
Speaker 3: It all points in that direction, the energy, the distribution,
Speaker 3: the frequency, it all converges on that one whim model.
Speaker 2: Okay, so this is the moment everything pivots. If this
Speaker 2: signal holds up to scrutiny. If this really is wimp annihilation,
Speaker 2: then we're not talking about a theory anymore.
Speaker 3: We're talking about a real physical particle. As Professor Totwani
Speaker 3: himself said, this would mark the first time humanity has
Speaker 3: seen dark matter.
Speaker 2: And that leads directly to the massive consequences for physics
Speaker 2: for the Standard model.
Speaker 3: The Standard Model of particle physics has been unbelievably successful,
Speaker 3: describes all the known particles, all the forces, but it
Speaker 3: has these two huge glaring holes in it. It can't
Speaker 3: explain gravity, and it has absolutely nothing to say about
Speaker 3: dark matter.
Speaker 2: So if this WIMP is real, it is by definition
Speaker 2: a new particle. It's something that exists outside that beautiful
Speaker 2: established framework.
Speaker 3: It's the first definitive piece of evidence that the Standard
Speaker 3: Model is incomplete. This wimp. It's massive, it interacts with
Speaker 3: the weak force, but it just doesn't fit anywhere on
Speaker 3: the current chart of quarks and leftones. It's like finding
Speaker 3: a new continent on a map you thought was finished.
Speaker 2: It means you have to draw a new map.
Speaker 3: You have to expand the theory. It means there's an
Speaker 3: entire dark sector of particles and forces that we've been
Speaker 3: totally oblivious to it fundamentally changes our definition of what
Speaker 3: matter even is.
Speaker 2: But a claim that big one that rewrites the textbooks
Speaker 2: requires an unbelievable amount of proof. This is where the
Speaker 2: scientific community goes from excitement to intense skepticism.
Speaker 3: And rightly so. The urgeon of proof is an enormous So.
Speaker 2: What does that verification process actually look like? It can't
Speaker 2: just be one team's analysis.
Speaker 3: No, absolutely not. There are two main lines of attack here.
Speaker 3: First is independent verification. Other teams of physicists around the
Speaker 3: world need to take the exact same public data from
Speaker 3: the Fermi telescope and run their own completely independent analysis, using.
Speaker 2: Their own methods, their own code, to see if they
Speaker 2: find the same thing exactly.
Speaker 3: Can they filter out the background noise in their own
Speaker 3: way and still pull out that same twenty gv halo.
Speaker 2: That's step one, and what's step two.
Speaker 3: Step two is finding the signal somewhere else. Finding it
Speaker 3: once in a very messy place is fantastic, but finding
Speaker 3: the exact same signal in a completely different, much cleaner
Speaker 3: environment that would be undeniable.
Speaker 2: This is the wimprerun you mentioned. Yeah, you need to
Speaker 2: find a cosmic clean room, a place that's packed with
Speaker 2: dark matter but doesn't have all the other astrophysical fireworks
Speaker 2: going off.
Speaker 3: And we know exactly what to look for. Those The
Speaker 3: perfect targets are the dwarf galaxies that or our own
Speaker 3: Milky Way.
Speaker 2: Why are they so perfect for this.
Speaker 3: Because they are completely dominated by dark matter. They have
Speaker 3: very few stars, so they're very dim, but they have
Speaker 3: a huge amount of mass for their size. Their mass
Speaker 3: to light ratio is off the.
Speaker 2: Charts, and crucially, they're quiet.
Speaker 3: They're very quiet. They don't have supermassive black holes at
Speaker 3: their centers, they're not forming lots of new stars, they
Speaker 3: don't have the chaos of the Milky Way's core. They
Speaker 3: are almost pure, clean laboratories for studying dark matter.
Speaker 2: So if you point the Fermi telescope at one of
Speaker 2: these dwarf galaxies and you see that same twenty gv
Speaker 2: gamma ray signal.
Speaker 3: Then you've got it. That's the nail on the coffin.
Speaker 3: Because you've now seen the exact same fingerprint from the
Speaker 3: exact same particle in two radically different environments. The odds
Speaker 3: of that being a coincidence are practically zero.
Speaker 2: That would be the moment you can confidently say you've
Speaker 2: discovered the dark matter particle.
Speaker 3: That's what would provide the overwhelming evidence. And Professor Totani
Speaker 3: himself points this out. He says, detecting the signal from
Speaker 3: dwarf galaxies would provide even stronger evidence that the gamma
Speaker 3: rays originate from dark matter. We're all basically waiting for
Speaker 3: that confirmation.
Speaker 2: Now. It's just an incredible journey. You go from Fritz
Speaker 2: Wicki nearly a century ago, just looking at fuzzy smudges
Speaker 2: of light moving too fast, to today where we're pinpointing
Speaker 2: the energy signature of their invisible components colliding.
Speaker 3: It's a beautiful example of how theory and observation work
Speaker 3: together over decades. It shows that sometimes the biggest discoveries
Speaker 3: aren't about seeing something totally unexpected, but about finally building
Speaker 3: the tools to see something we knew deep down had
Speaker 3: to be there all along.
Speaker 2: All right, So let's wrap up this deep dive and
Speaker 2: boil it down to the key takeaways, the things you
Speaker 2: should remember from this whole incredible story.
Speaker 3: First, it all started with gravity. Zwiki in the nineteen
Speaker 3: thirties saw that galaxies were moving too fast, which meant
Speaker 3: there had to be a huge amount of invisible or
Speaker 3: dark matter, providing the extra gravitational glue.
Speaker 2: Second, the main theory to explain this was the WIMP,
Speaker 2: the weekly interacting massive particle, and the key idea is
Speaker 2: that when two whimps collide, they annihilate and produce a
Speaker 2: detectable flash of high energy gamma rays.
Speaker 3: Third, that's the breakthrough. Professor Totani's team, using data from
Speaker 3: the Fermi telescope, found a signal that fits that description perfectly,
Speaker 3: a diffuse halo of gamma rays right at twenty gv
Speaker 3: near the galactic center.
Speaker 2: And that signal is consistent with a WIMP that has
Speaker 2: a mass about five hundred times that of a proton,
Speaker 2: a signal that can't be easily explained away by any
Speaker 2: other known astronomical source.
Speaker 3: And if this gets confirmed, it's the first time we've
Speaker 3: ever seen dark matter, and it proves the existence of
Speaker 3: a new particle beyond the standard model. It literally changes physics.
Speaker 2: And finally, the next crucial step is verification. Scientists are
Speaker 2: now looking for that exact same twenty gv signature in
Speaker 2: the clean, quiet environments of dwarf galaxies. If they find
Speaker 2: it there, it's case closed.
Speaker 3: So for you, the listener, You're now completely up to
Speaker 3: speed on what could be one of the biggest scientific
Speaker 3: revolutions of our lifetime. This isn't just an actandemic paper.
Speaker 3: It is fundamentally redrawing the map of our universe.
Speaker 2: Which brings us to our final provocative thought. If we
Speaker 2: are just now, after one hundred years, finally confirming the
Speaker 2: existence of the stuff that makes up eighty five percent
Speaker 2: of all matter, It makes you wonder, doesn't it.
Speaker 3: It really does.
Speaker 2: If that much of the universe was completely invisible to
Speaker 2: us until now, what else is out there? What other particles,
Speaker 2: what other forces might be lurking just beyond the reach
Speaker 2: of our current technology, just waiting for the next Zwiki
Speaker 2: or the next Fermi telescope to bring them into the light.
Speaker 3: The invisible universe might be far stranger and more complex
Speaker 3: than we can even begin to imagine.
Speaker 2: A truly mind bending thought. Thank you so much for
Speaker 2: joining us on this deep dive into one of the
Speaker 2: Cosmos' greatest mysteries. Keep asking questions and we'll see you
Speaker 2: next time.
Speaker 1: The Steam.
Speaker 3: School stas SA