Speaker 1: Hey, Orge, you work with a lot of scientists. Who
Speaker 1: is the brightest one you've ever interviewed?
Speaker 2: Well, I have made a lot of Nobel Prize winners.
Speaker 2: They're all pretty humble, but yeah, generally they're pretty sharp
Speaker 2: at that level, you know, beams of light or shooting
Speaker 2: out of their eyes. They have an ore of genius.
Speaker 1: So do you think when you're talking to a scientists
Speaker 1: you can predict if they're going to be a future
Speaker 1: Nobel Prize winner?
Speaker 2: If I could, that would be awesome. I could probably
Speaker 2: make a lot of money that way. Aren't there betting
Speaker 2: pools for Nobel Prize winners?
Speaker 1: If there are, you probably qualify as insider information.
Speaker 2: Well, good thing, I'm not a betting person. Hi am
Speaker 2: Jorhem Makartudas and the author of All of Great Big Universe.
Speaker 1: Hi. I'm Daniel. I'm a particle physicist, a professor at
Speaker 1: U c Irvine, and I actually do have a tiny
Speaker 1: slice of a Nobel Prize.
Speaker 2: Ooh, what does that mean, Like they shaved off a
Speaker 2: piece of the metal or something.
Speaker 1: No, I'm one of a large group of collective winners
Speaker 1: of the Nobel Prize. Oh. Several years ago they gave
Speaker 1: the Nobel Peace Prize to the European Union, and that's
Speaker 1: back when Britain was a member, and I'm a citizen
Speaker 1: of the UK, so I'm not sure if I lost
Speaker 1: it during Brexit, but I was briefly one five hundred
Speaker 1: millionth of a Nobel Prize winner.
Speaker 2: Oh, I see you and all Europeans have won the
Speaker 2: Nobel Prize. Well technically you're not part of Europe, so yeah,
Speaker 2: I think you did lose it.
Speaker 1: I used to round that up to one Nobel Prize.
Speaker 1: Now I guess I got to round it down to
Speaker 1: zero to zero.
Speaker 2: I think you could have rounded it down to zero
Speaker 2: before you know, one fortieth million probably maybe count to zero.
Speaker 1: Well to me, one five hundred billion was pretty different
Speaker 1: from zero, but I take your point.
Speaker 2: But anyways, Welcome to our podcast Daniel and Jora Explain
Speaker 2: the Universe, a production of iHeartRadio.
Speaker 1: In which we think everybody deserves a prize for their
Speaker 1: curiosity about the universe. We're here to stimulate that curiosity,
Speaker 1: to encourage it, and to go with you on the
Speaker 1: journey of exploration of understanding the universe. We think, we hope,
Speaker 1: we believe that the universe out there can be understood
Speaker 1: and deserves to be understood, and that everything that scientists
Speaker 1: have figured out so far and that they're puzzling over
Speaker 1: currently deserves to be explained to you.
Speaker 2: That's right. We're here to illuminate the darkest corners of
Speaker 2: science and take you on a trip to the bright
Speaker 2: future of our understanding of how things work and why
Speaker 2: things are the way they are.
Speaker 1: We want to understand everything here on Earth, how water flows,
Speaker 1: how mountains form the history of life, but we also
Speaker 1: want to understand our vast cosmos, what's happening in the
Speaker 1: dark deep reaches of space. How did the universe get
Speaker 1: to look the way that it does. One of the
Speaker 1: most powerful forces operating on galaxies and stars and galactic
Speaker 1: clusters out there, shaping the entire structure of space, time
Speaker 1: and the universe. And to do that we have to
Speaker 1: look out into the night sky and gather messages that
Speaker 1: are coming here from the rest of the universe.
Speaker 2: Yeah, because the cosmos is vast and mostly dark, with
Speaker 2: lots of empty space, but there are some bright spots
Speaker 2: out there making the universe visible to us and giving
Speaker 2: us information about what's out there in the farthest reaches
Speaker 2: of existence.
Speaker 1: Though very few humans have actually left the surface of
Speaker 1: the Earth for significant periods of time and entered even
Speaker 1: our space neighborhood. We have a pretty good understanding of
Speaker 1: what's going on in the rest of our galaxy, the
Speaker 1: structure of galaxies beyond that, and all of that comes
Speaker 1: from gathering that information that's beamed to us from the
Speaker 1: rest of the universe. Imagine if instead the universe was
Speaker 1: totally dark, we would have no idea what was out there.
Speaker 1: We're grateful that at least some little fraction of it
Speaker 1: is shown brightly and letting us know what it's up to.
Speaker 2: Yeah, there are things happening all over the universe creating light,
Speaker 2: blasting it out into the universe, but some of them
Speaker 2: are maybe a little bit stronger than others.
Speaker 1: That's right. We have a whole series of episodes about
Speaker 1: the darkest things in the universe, dark matter, and the
Speaker 1: mysteries of the missing gravity. But today in the podcast,
Speaker 1: we're going to go in exactly the opposite direction.
Speaker 2: So to On the podcast, we'll be tackling the question
Speaker 2: what was the brightest explosion ever seen?
Speaker 1: And was it that moment when Jorge finally understood particle physics?
Speaker 1: Boom mind a blown as it happened. I'm anticipating it. Man,
Speaker 1: we're building up to it.
Speaker 2: Has that even happened for you?
Speaker 1: You know, there's that old quote, if you think you
Speaker 1: understand quantum field theory, then you don't understand quantum field theory.
Speaker 1: So it's a matter of degrees.
Speaker 2: I think, yeah, yeah, it's a dimmer setting the light
Speaker 2: bulb of quantum physics. But yeah, there are explosions happening
Speaker 2: all over the universe, and some of them are incredibly bright,
Speaker 2: and some of them are less bright. But maybe we
Speaker 2: haven't seen all of them. Maybe there are some that
Speaker 2: we have managed to see out there.
Speaker 1: Something that's wonderful about exploring the universe is being shocked
Speaker 1: by the scale of it. Learning how deep the history
Speaker 1: of time is, not thousands of years, not millions of years,
Speaker 1: but billions of years, Learning how large the universe is,
Speaker 1: how many billions of light years across stuff has spread out.
Speaker 1: These enormous scales that shock our understanding also serve to
Speaker 1: give us a better context for our existence. Turns out,
Speaker 1: the Earth and the Milky Way are a tiny little
Speaker 1: speck of dust in the vast cosmos, But there are
Speaker 1: other dimensions to be shocked in the sun you think
Speaker 1: is quite bright, it turns out the universe gets much
Speaker 1: much much brighter than that.
Speaker 2: Yeah, the universe never sees us to make us all
Speaker 2: feel tiny and insignificant and short lived compared to the
Speaker 2: scale of the cost and its existence. But as you said,
Speaker 2: there are things that maybe would even shock of physicists
Speaker 2: about how bright they are.
Speaker 1: Absolutely, and today we're going to be learning about the
Speaker 1: brightest of all time what physicists called the boat the
Speaker 1: boat boat.
Speaker 2: The biggest of all time, the brightest of all time.
Speaker 1: Not the banana East of all time, the amazing.
Speaker 2: Of all time. So, as usual, we were wondering how
Speaker 2: many people out there had thought about this question about
Speaker 2: what is the brightest explosion ever seen in the universe.
Speaker 2: So Daniel went out there as usual to ask people
Speaker 2: this question.
Speaker 1: Thanks very much to everybody who plays for this segment
Speaker 1: of the podcast, and if you'd like to hear your
Speaker 1: voice for future episodes, please don't be shy. We would
Speaker 1: love to add you to our group. Write to me
Speaker 1: two questions at Daniel and Jorge dot com to volunteer,
Speaker 1: or send me questions or send me ideas or pictures
Speaker 1: of your cats, whatever, we love to hear from listeners.
Speaker 2: And today, Daniel, what are our players playing for?
Speaker 1: They're playing for the recognition of having their voice on
Speaker 1: the podcast. Their friends and relatives will all be jealous.
Speaker 2: They'll be brightly jealous.
Speaker 1: They're playing for the biggest banana of all time.
Speaker 2: So think about it for a second. What do you
Speaker 2: think is the brightest explosion ever seen? Here's what people
Speaker 2: had to say.
Speaker 3: I am going to say that is a supernova explosion,
Speaker 3: either that or the source of whatever gamma ray bursts are.
Speaker 4: The biggest explosion ever seen would have to be the
Speaker 4: Big Bang, although there was nobody around to see it.
Speaker 4: We can still see the cosmic microwave background radiation, so
Speaker 4: we still can see it. But that's not.
Speaker 1: Really bright anymore. So I don't know.
Speaker 4: This is You got me in a quandary here, So
Speaker 4: it's probably a supernova.
Speaker 5: I would imagine the Big Bang was pretty bright, and
Speaker 5: then maybe gamma ray burse but maybe something to do
Speaker 5: with merging black holes or merging neutron stars. I guess
Speaker 5: bright doesn't necessarily have to be in our visible spectrum.
Speaker 2: All right. A couple of answers, kind of a trick
Speaker 2: answers here the Big Bang was maybe the biggest explosion.
Speaker 2: You can't argue with that.
Speaker 1: You can't actually argue with that. I don't think of
Speaker 1: the Big Bang as an explosion. I think of it
Speaker 1: as an expansion.
Speaker 2: Oh, I see, you're gonna use grammar to disqualify their answer.
Speaker 1: I know, words meanings, words having meanings are so annoying.
Speaker 2: I know it did just all be bath right, But
Speaker 2: I mean, you do call it the Big Bang? I mean,
Speaker 2: yourself are saying it's a bang.
Speaker 1: Well, you know, there's that famous story about how the
Speaker 1: Big Bang was not named by anybody who actually believed
Speaker 1: in the Big Bang, but by proponents of the steady
Speaker 1: state theory.
Speaker 2: Physicistal call it the Big Bang?
Speaker 1: Right, who still call it the Big Bang? Yes?
Speaker 2: Absolutely, they don't call it the Big Stretch or the
Speaker 2: Big Expansion.
Speaker 1: I think we should call it the Big Stretch. I
Speaker 1: think that's a much better name. Absolutely.
Speaker 2: Maybe we should amend the title of this episode to
Speaker 2: what was the biggest explosion besides the Big Bang?
Speaker 1: The brightest explosion? Though? Yeah, good question. I'm not sure
Speaker 1: how you measure the brightness of the Big Bang.
Speaker 2: Now, the way we phrased this question, what was the
Speaker 2: brightest explosion ever seen. Are we only counting the ones
Speaker 2: that we've seen or that we think happened, or is
Speaker 2: that the same, Well, we're.
Speaker 1: Only going to talk about the ones that we've seen.
Speaker 1: But as soon as you've seen something extraordinarily bright, it
Speaker 1: means that there's something out there capable of making very
Speaker 1: very bright explosions, and it's very unlikely you've seen the
Speaker 1: brightest one. So it's like discovering a unicorn. You figure, ooh,
Speaker 1: there are probably other unicorns in the forest, maybe even
Speaker 1: with longer horns. So we could only talk about the brightest.
Speaker 1: That suggests that there are very likely even brighter explosions
Speaker 1: out there we haven't seen.
Speaker 2: But that's an assumption, right, I mean, there could just
Speaker 2: be one unicorn out there in the universe.
Speaker 1: Oh absolutely, it's a statistical statement. But yes, as soon
Speaker 1: as you discover one unicorn, you figure, like, well, probably
Speaker 1: had parents, maybe it had siblings. You know, there are
Speaker 1: probably other unicorns out there, but it could be the
Speaker 1: sole unicorn, you know, created by a random collection of
Speaker 1: quantum fluctuations. That's also a possibility, even.
Speaker 2: If it's unlikely, it could be the unicorn of unicorn spottings.
Speaker 1: Yeah, we could sell it for a billion dollars. That
Speaker 1: should be our startup. My startup idea is give me
Speaker 1: a billion dollars. I will make you a unicorn, and
Speaker 1: then it'll be a unicorn startup.
Speaker 2: You would only make one unicorn, otherwise it's not worth much.
Speaker 1: Yeah, but if you only have one, you can set
Speaker 1: the price, right. I mean, I'm not an economist, but.
Speaker 2: I think that's how economy worries. Sure, well that's our problem.
Speaker 1: We're selling shares in our unicorns, folks, unicorns singular.
Speaker 2: But anyways, it's an interesting question. The brightest explosion ever seen?
Speaker 2: And so Daniel steps through, what are some things that
Speaker 2: can cause explosions in the universe?
Speaker 1: Well, first, I think it's useful to think about brightness,
Speaker 1: Like what do we mean by brightness? Obviously you're very bright,
Speaker 1: All of our listeners are very bright, our children are
Speaker 1: very bright. But when we talk about brightness in an
Speaker 1: astronomical setting, what we mean is like how many photons
Speaker 1: are arriving from it to Earth. And it used to
Speaker 1: be that astronomy only really dealt with photons. We had
Speaker 1: telescopes that could see photons. We used our eyeballs. These days, though,
Speaker 1: we have other devices like particle detectors and gravitational wave
Speaker 1: detectors that can see other kinds of messengers from astronomical events.
Speaker 2: Now, would brightness and photons be the best way to
Speaker 2: measure the energy of an explosion? Like, could there be
Speaker 2: an explosion that maybe you know, throws up part other
Speaker 2: kinds of particles more than photons or neutrinos or something
Speaker 2: like that that might have more energy but be less
Speaker 2: bright or there's like a pretty good indication of the energy.
Speaker 1: No, different astronomical events have a different fraction. They are
Speaker 1: energy produced in photons, in neutrinos, or in gravitational waves.
Speaker 1: So the best way to do astronomy they call these
Speaker 1: days multi messenger astronomy, where you're looking for photons and
Speaker 1: you're looking for particles, and you're looking for gravitational waves.
Speaker 1: It's the best way to get a handle on what happened.
Speaker 1: For example, when we look at neutrons star collisions, you
Speaker 1: can sometimes see a gravitational wave and also see light
Speaker 1: from the collision. But sometimes like supernova, can release huge
Speaker 1: amounts of energy just in neutrinos, because when the neutrinos
Speaker 1: are produced in the supernova, they're not reabsorbed, they just
Speaker 1: fly right out because the supernova itself, though it's super dense,
Speaker 1: is also transparent to those neutrinos, whereas photons get reabsorbed.
Speaker 1: So definitely there are things that are brighter in neutrinos
Speaker 1: than in photons. So that makes it very, very complicated.
Speaker 1: I think today, let's just focus on the photons.
Speaker 2: Okay, let's just focus on the photons, because my eyeballs
Speaker 2: can neutrinos.
Speaker 1: Yet, you'd have to have eyeballs the size of swimming pools.
Speaker 2: Oh, Daniel, that's very flattering. Thank you you saying my
Speaker 2: eyes are endless pools of.
Speaker 1: Of chlorinated water.
Speaker 2: Yeah, of physics detection technology.
Speaker 1: Yes, you're like an anime character with big eyes.
Speaker 2: Yeah, yeah, there you go.
Speaker 1: And the other issue with brightness is that it depends
Speaker 1: a little bit on where you are, Like you could
Speaker 1: have a really bright source, but it's really really far
Speaker 1: away and so its appears quite dim. Like when quasars
Speaker 1: were first discovered, they were quite bright in the sky,
Speaker 1: and then we discovered, oh my gosh, they're also super
Speaker 1: dup far away, which means at their source they're extraordinarily bright.
Speaker 1: So what astronomers typically do is define brightness by how
Speaker 1: bright something would seem if you were one AU away
Speaker 1: from it. If you were, like the distance the Earth
Speaker 1: is from the Sun away from that object, how bright
Speaker 1: would it be.
Speaker 2: That's what an AU is, right, It's like an earth
Speaker 2: distance from the Sun.
Speaker 1: Yeah, exactly, all right.
Speaker 2: So step us through, like how bright are things in
Speaker 2: the night sky?
Speaker 1: Yeah? So if you define the Sun as brightness of one,
Speaker 1: then you can look at things like some of the
Speaker 1: biggest stars that are out there, Like the biggest brightest
Speaker 1: star ever discovered. It's three hundred and fifteen solar masses.
Speaker 1: It's got the amazing name of R one three six
Speaker 1: a one, and it's eight point three million times brighter
Speaker 1: than the Sun. Like, if you took that star. What, Yeah,
Speaker 1: you took that star and put it in our solar
Speaker 1: system and looked up at the sky, it would be
Speaker 1: eight point three million times as intense as the Sun.
Speaker 2: Wow, you would need eight point three layers of sunblock
Speaker 2: just to walk out into the Sun.
Speaker 1: Eight point three million, Yes, it's million, yes, exactly. So
Speaker 1: that's the brightest star in the universe. And already that
Speaker 1: gives you a sense of like, wow, this stuff in
Speaker 1: our neighborhood not really that bright when we're talking about
Speaker 1: like Hall of Fame brightness.
Speaker 2: Wouldn't this star be huge or is it still a
Speaker 2: small star?
Speaker 1: So it's very large. It's right up on the edge
Speaker 1: of the biggest star you can have around three hundred
Speaker 1: and fifteen solar masses. Because bigger stars have a higher
Speaker 1: temperature at their core, so they burn hotter and faster.
Speaker 1: They don't last very long typically, and they also produce
Speaker 1: an enormous amount of radiation which pulls the star apart.
Speaker 1: Stars are actually a delicate balance between the radiation pressure
Speaker 1: from fusion and the gravitational pressure inwards from all of
Speaker 1: that mass. So it's sort of incredible that so many
Speaker 1: stars are stable for millions and billions of years. These
Speaker 1: guys essentially tear themselves apart. Anything bigger than that can't
Speaker 1: really last very long. So this is the brightest star
Speaker 1: I ever seen.
Speaker 2: Could you even stand at one AU away from the star,
Speaker 2: would you be inside the star?
Speaker 1: You wouldn't be inside the actual edge of the star.
Speaker 1: Its radius is like forty three times the radius of
Speaker 1: the Sun, so it's much much denser than our Sun.
Speaker 1: But it's nowhere near an AU for example.
Speaker 2: And why is it brighter. Is it just the more
Speaker 2: dense so there's more fusion going on.
Speaker 1: Yeah, fusion is very nonlinear, and so because you have
Speaker 1: so much more mass and it's more dense, then it's
Speaker 1: much hotter. The pressure and temperature at the core is
Speaker 1: much greater. And remember that while there's fusion happening at
Speaker 1: the core of our star, it's still pretty inefficient, Like
Speaker 1: most of the hydrogen in the star is not fusing,
Speaker 1: because fusion is a hard thing to make happen. You
Speaker 1: got these two protons, you're trying to squeeze them together.
Speaker 1: There are electromagnetic forces are trying to push them apart.
Speaker 1: Most of the time in the Sun, protons don't fuse.
Speaker 1: But the higher the temperature and the higher the pressure,
Speaker 1: the more often you do get fusion happening. And so
Speaker 1: the fusion is just much more efficient at the heart
Speaker 1: of this star, which keats the whole thing up and
Speaker 1: makes it brighter.
Speaker 2: WHOA, but you said they don't last pretty long.
Speaker 1: Yeah, these stars last for like millions of years, whereas
Speaker 1: smaller stars like hours less billions and red dwarfs can
Speaker 1: last even longer, maybe even up to trillions of years.
Speaker 1: We're not sure because the universe is kind of young
Speaker 1: compared to the expected lifetime of some of these stars.
Speaker 2: Now, is that as bridess it gets out there in space.
Speaker 1: That's not even close to how bright things get. That's
Speaker 1: the brightest star we've seen. But stars are not bright
Speaker 1: compared to like the radiation emission at the hearts of galaxies.
Speaker 1: Big galaxies have big black holes at their centers, and
Speaker 1: their enormous gravity creates a lot of high temperature and
Speaker 1: high pressure in the accretion disk around the black hole.
Speaker 1: So the black hole, of course is black. Maybe this
Speaker 1: hawking radiation, but that would be very, very dim. But
Speaker 1: because it has so much gravitational energy, there's a big
Speaker 1: swirling mass of stuff around the black hole, and that
Speaker 1: is so hot it's emitting a lot of radiation. That
Speaker 1: radiation then gets guided by the magnetic field of the
Speaker 1: black hole up and down the poles, sort of the
Speaker 1: same way that like the Aurora Borealis guides charged particles
Speaker 1: to the north pole and the south pole. Here, the
Speaker 1: magnetic field of the quasar creates two beams of particles
Speaker 1: when shooting up the north pole and when shooting down
Speaker 1: the south pole, and that's what a quasar is that's
Speaker 1: also called an active galactic nucleus WHOA.
Speaker 2: So it creates a jet of particles or light for both.
Speaker 1: If you look at pictures of galaxies with jets, these
Speaker 1: jets can be enormous. They can be even much longer
Speaker 1: than the galaxy itself. The power of the hearts of
Speaker 1: these galaxies is really incredible. And there's an enormous amount
Speaker 1: of photons also emitted here because this is just like
Speaker 1: hot particles, and hot particles emit photons.
Speaker 2: Because I guess it can't guide the photons to the
Speaker 2: North pole and South poles, but it guides other particles
Speaker 2: and in those particles are what emit the brightness the light.
Speaker 1: Yeah, exactly. And anytime you have charge particles changing direction,
Speaker 1: like an electron flies to a magnetic field and bends,
Speaker 1: how does it bend. It has to bend by emitting
Speaker 1: a photon. So you have accelerating charged particles, you're going
Speaker 1: to get lots and lots of photons, like in the
Speaker 1: particle colliders like the Large Hadron Collider or the Large
Speaker 1: Electron positron Collider. One of the biggest challenges is that
Speaker 1: these particles are bending with magnets and constantly losing energy
Speaker 1: to radiation, and so that's why you get so many photons.
Speaker 2: H all right, I have more questions about this quasar
Speaker 2: and about maybe what could be even brighter than a quasar.
Speaker 2: So let's set the dimmer too high on those questions.
Speaker 2: But first let's take a quick break. All Right, we're
Speaker 2: talking about the brightest explosion ever seen, and Daniel, you
Speaker 2: were saying, a quasar has many times more brightness than
Speaker 2: the brightest star that we know about.
Speaker 1: Yeah, quasars in the sky are like bafflingly bright. It
Speaker 1: was a huge mystery for a long time before we
Speaker 1: even knew that there were black holes in the hearts
Speaker 1: of galaxies. People saw these sources in the sky and
Speaker 1: they calculated the distance and then they were like, oh
Speaker 1: my gosh, it's already brightened the sky and it's super
Speaker 1: duper far away. Because quasars tend to be formed in
Speaker 1: the early universe and not recently, so all the quasars
Speaker 1: we see are like really far across the universe. And
Speaker 1: so you do that calculation, you discover that like, wow,
Speaker 1: quasars are trillions of times brighter than the sun. Trillions trillions. Yeah,
Speaker 1: there's one called three C two seven three is the
Speaker 1: brightest quasar we know officially, and it's four trillion times
Speaker 1: brighter than the sun. Like, if you were one AU
Speaker 1: away from it, it would be equivalent to having four trillion suns.
Speaker 2: But only if you're one AU at the north or
Speaker 2: south poles.
Speaker 1: Right, Yes, exactly, if you're at the horizontal or you're
Speaker 1: a little bit tilted away from it, then it's less bright.
Speaker 2: Now does that technically count as an explosion?
Speaker 3: Though?
Speaker 1: I don't think it counts as an explosion because it's constant,
Speaker 1: but it is super duper bright, and.
Speaker 2: It's super directed too, right, Like you said, it's not
Speaker 2: like it's not an explosion going in all directions. It's
Speaker 2: more like a laser.
Speaker 1: Yeah, it's more like a laser like a pencil beam,
Speaker 1: which is actually really useful, and we can use these
Speaker 1: quasars not just to understand the early universe, but also
Speaker 1: to understand what's between us and the quasars. There's lots
Speaker 1: of studies where people examine the light from quasars and
Speaker 1: they use it as a probe of all the the
Speaker 1: material between us and the quasar, for example, the dark
Speaker 1: matter density and the gravitational lensing that happens along the way.
Speaker 1: They're really useful. Sometimes a quasar can get even brighter
Speaker 1: due to relativistic effects. These quasars are called blazars. If
Speaker 1: the quasar is moving towards us, then its light is
Speaker 1: enhanced by relativistic effects and it can seem even brighter
Speaker 1: than a quasar.
Speaker 2: Wait, a blazar is a quasar that's moving towards us.
Speaker 2: It's not just a quasar with a nice jacket on.
Speaker 2: Is that what you mean, Like, it's a quasar moving
Speaker 2: towards us.
Speaker 1: Well, a blazar is a quasar. It's not. It doesn't
Speaker 1: have to be just moving towards us, but it's pointed
Speaker 1: like directly at the Earth. We can see these quasars
Speaker 1: even if they're not directly at us, because we can
Speaker 1: see their jets and the light emitted. But if they
Speaker 1: are actually pointed directly at us, then we call them
Speaker 1: a blazar.
Speaker 2: Wait, that's the only difference is that it's pointing at us.
Speaker 1: Yeah, blazars are quasars that are basically pointing right at
Speaker 1: the Earth.
Speaker 2: And you need a whole new name for that.
Speaker 1: Well, you know, it's historical. People see the things in
Speaker 1: the sky. They don't always understand the connections between them.
Speaker 1: It's like, why do we even have constellations? You could say, hey,
Speaker 1: now we know that like stars and constellations, some of
Speaker 1: them are super close and some of them are across
Speaker 1: the galaxy. Why do we group them together? It's historical?
Speaker 1: You know, people have called that ursa minor for a
Speaker 1: long time, so we're gonna keep doing it.
Speaker 2: M So, blazar, then, is a quasar that's pointing at us? Now,
Speaker 2: is it brighter than four trillion times brighter than the sun.
Speaker 1: Yeah, the brightest blazar is three hundred trillion times brighter
Speaker 1: than the sun. So we're talking about a factor of
Speaker 1: one hundred boost when a quasar is pointed right at us.
Speaker 2: So this is if we're one au at the north
Speaker 2: and south pole of a quasar, Yeah, three hundred trillion
Speaker 2: times more than brighter than the sun. But if we're
Speaker 2: not in the north and south pole, you're saying it's
Speaker 2: more like four trillion times.
Speaker 1: Yeah, exactly, And so not recommended to do any sunbathing
Speaker 1: on the north or south pole of a blazar.
Speaker 2: Well, as you have three hundred trillion layers of some.
Speaker 1: Block also known as like three light years of lead
Speaker 1: still might not be enough.
Speaker 2: Now, that sounds pretty intense. But if we're counting beams,
Speaker 2: I wonder like, is it brighter than the brightest laser
Speaker 2: we've made here on Earth.
Speaker 1: It's much brighter than the brightest laser. Yes, I mean,
Speaker 1: if you were one AU from the brightest laser, you
Speaker 1: would not think it's very bright. Even a laser is
Speaker 1: pretty colimated. It's going to spread out, and an AU
Speaker 1: is a large distance.
Speaker 2: But in terms of intensity per you know, area, is
Speaker 2: it as intense or more intense?
Speaker 1: These blazers are much more intense than any source on
Speaker 1: Earth at one au. Yes, but these are constant things, right.
Speaker 1: Blazer is key pumping out, so I don't know if
Speaker 1: it really counts as explosions. And the brightest thing in
Speaker 1: the universe is actually not something that's constant.
Speaker 2: So then we are disqualifying quasars and blazers from being
Speaker 2: the boats.
Speaker 1: We don't even need to disqualify them. They don't even qualify.
Speaker 2: We're seeking their chances of being the boat.
Speaker 1: Yeah, we're going to torpedo them, but even if we didn't,
Speaker 1: they still wouldn't qualify because the brightest thing in the
Speaker 1: universe isn't explo and it's also much brighter than the
Speaker 1: most constant thing in the universe, which are blazers.
Speaker 2: WHOA all right, what are these things that are brighter
Speaker 2: than a blazer? Is it a dinner jacket?
Speaker 1: Are I don't know if it's white tie or black time?
Speaker 3: Right?
Speaker 2: Which is brighter? It's a glittery on the disco jacket.
Speaker 1: Oh, sparkle tie. Yeah. The brightest explosion in the universe,
Speaker 1: and also the brightest thing we've ever seen, is a
Speaker 1: gamma ray burst. These are sort of mysterious and enormous
Speaker 1: bursts of gamma rays. Gamma rays are just very high
Speaker 1: energy photons that we see sometimes in the night sky.
Speaker 2: Well, meaning like we have gamma ray antenna and gamma
Speaker 2: rays are just a kind of light, right, like it's
Speaker 2: a high frequency light.
Speaker 1: Yeah, Gamma rays are very very high energy.
Speaker 3: You know.
Speaker 1: Photons exist all across the electromagnetic spectrum. Some of them
Speaker 1: we call in the visible range. Some are very long
Speaker 1: wavelength and infrared or radio waves. But these are just
Speaker 1: artificial divisions above the visible We have ultraviolet and then
Speaker 1: X rays and the gamma rays. But again these are
Speaker 1: just like historic dotted lines we've put on the electromagnetic spectrum.
Speaker 1: There's nothing above gamma rays. So gamma rays include everything
Speaker 1: above X rays and then out to infinite energy.
Speaker 2: Whoa, So we have these antennas out there on Earth
Speaker 2: like in the tech gamma rays, and sometimes we get
Speaker 2: these burds coming from space, like these huge kind of
Speaker 2: waves of gamma rays.
Speaker 1: Yeah, exactly. And it's fascinating history because this is something
Speaker 1: that really benefits from the Cold War. Like in the
Speaker 1: second half of last century, the United States military was
Speaker 1: really curious whether the Soviet Union was doing atmospheric nuclear
Speaker 1: testings before it was ruled out. So they built satellites
Speaker 1: and all sorts of technologies to try to detect nuclear testing.
Speaker 1: And sure they found some, I guess, but they also
Speaker 1: spotted these weird bursts in the sky of gamma rays
Speaker 1: that they didn't understand that were not coming from below,
Speaker 1: they were coming from above. That's how gamma ray bursts
Speaker 1: were first discovered. I love when we spend money on
Speaker 1: the military, we accidentally end up doing science.
Speaker 2: Are you making a case for more military spending.
Speaker 1: I don't think military spending is a very efficient way
Speaker 1: to do science. I'm just grateful when sometimes that money
Speaker 1: turns out to be useful for science as well.
Speaker 2: Hey, I see, it's a win. It's a win for everyone.
Speaker 1: Yeah, I'll take it. I mean, the military budget totally
Speaker 1: dwarfs the science budget. But anyway, that's a topic for
Speaker 1: another time.
Speaker 2: How bright are these gammay bursts?
Speaker 1: Some of them are crazy, crazy bright. Like we've seen
Speaker 1: gamma ray bursts that are a million trillion times brighter
Speaker 1: than the sun, like a quadrillion times brighter than the sun.
Speaker 2: So yeah, in terms of how bright we think they
Speaker 2: are at the source, you're on Earth. We don't get
Speaker 2: a million trillion times more gamma rays than the sun.
Speaker 1: Yes, that's right. We were all killed several years ago
Speaker 1: due to the gamma ray burst. We're just now catching up. No,
Speaker 1: this is at the source absolutely. Fortunately for us, they're
Speaker 1: quite distant, so when they get here on Earth, there's
Speaker 1: a few very high energy gamma rays, but we're not
Speaker 1: all fried.
Speaker 2: But so, how do we know how far they are?
Speaker 2: Like we're just getting a blip on our antennas, Like,
Speaker 2: how do we know like how far away they came from?
Speaker 1: Yeah, it's a good question. We're not exactly sure because
Speaker 1: for many of them, you look in the night sky
Speaker 1: where they came from and there's like nothing there. It's
Speaker 1: not like you can point to and say, oh, it
Speaker 1: came from this star that went supernova, or it came
Speaker 1: from that galaxy. Like you look at the sky, you're like, oh,
Speaker 1: here's a huge source of gamma rays. There's nothing in
Speaker 1: the night sky there that we can see. It must
Speaker 1: mean that there's something extraordinarily distant. So there's a lot
Speaker 1: of uncertainty on the inherent brightness of these things.
Speaker 2: A huge amount of uncertainty, right, Like, it could be
Speaker 2: something closed that's dim, or it could be something really
Speaker 2: far that's super duper bright. How do you tell the difference, Well.
Speaker 1: It's definitely not something close and dim. Right. If it
Speaker 1: was something close, we would see it, because these things
Speaker 1: are very very bright. It could be something close that's
Speaker 1: dim most of the time and occasionally bright. But yet
Speaker 1: there is uncertainty on the distance to these.
Speaker 2: Things, meaning like the range goes from sixty what to
Speaker 2: a million trillion times brighter than the sun.
Speaker 1: Yeah, we don't know exactly how far they are. All
Speaker 1: of the gamma ray bursts we've seen have originated from
Speaker 1: outside the Milky Way galaxy, which means that they're very
Speaker 1: far away, but there's a huge range there, right, they
Speaker 1: could be a neighboring galaxy, that could be a very
Speaker 1: very distant galaxy at the edge of the universe.
Speaker 2: And we think they came from outside the Milky Way
Speaker 2: because when we pinpoint where they came from, we don't
Speaker 2: see anything that we think is in the Milky Way.
Speaker 1: Yeah, exactly. And we think these things are extraordinarily bright.
Speaker 1: And any gamma ray burst in the Milky Way that's
Speaker 1: actually pointed towards Earth would probably fry the Earth. And
Speaker 1: there are some theories about how, like some mass extinctions
Speaker 1: might have occurred due to gamma ray bursts in the
Speaker 1: Milky Way, for example. But yeah, these things we think
Speaker 1: are extraordinarily bright. I mean, it's hard to get your
Speaker 1: mind around these numbers. It's easier if you express it,
Speaker 1: like in terms of how much energy the Sun puts out.
Speaker 1: So for example, our Sun in its entire lifetime will
Speaker 1: put out as much energy as is in one of
Speaker 1: these gamma ray bursts for one second, So like a
Speaker 1: second of gamma ray bursts is ten billion years of
Speaker 1: the Sun. WHOA, we think, Yeah, we think there is
Speaker 1: definitely a lot of uncertainty here.
Speaker 2: I mean, it sounds like a huge amount of absurdity, right,
Speaker 2: How do we know how far away it is?
Speaker 1: Yeah, we don't know. We can say sort of like
Speaker 1: lower limits because we know the nearest neighborhood and we
Speaker 1: can tell that there's nothing there that's generating these things.
Speaker 1: You know, there's a lot of fuzziness in some general
Speaker 1: arguments there. But yet take these numbers definitely with a
Speaker 1: big grain of salt.
Speaker 2: And you said it was a mystery for a long time,
Speaker 2: meaning that we still don't know what makes these bursts.
Speaker 1: We still don't really understand it. Yeah, we have some theories.
Speaker 1: It turns out the gamma ray bursts come in two categories,
Speaker 1: is like shorter ones and longer ones. The shorter ones
Speaker 1: last for like seconds or tens of seconds, and the
Speaker 1: longer ones last for like minutes. So that seems like
Speaker 1: probably there are two different things going on there, and
Speaker 1: there are theories. The leading theory is that short gamma
Speaker 1: ray bursts might come from merging neutron stars like we
Speaker 1: talked about. You know, neutron stars are these very dense
Speaker 1: objects that the end of life of large stars not
Speaker 1: so big that they become a black hole and not
Speaker 1: so small they become a white dwarf, but having enough
Speaker 1: mass to become very dense neutron stars, and often these
Speaker 1: stars are in binary systems and then at the end
Speaker 1: of their life they're orbiting and eventually they collapse and
Speaker 1: fall into each other. And these are incredibly powerful events.
Speaker 1: They generate gravitational waves, they generate the conditions needed to
Speaker 1: make like gold and platinum and all the heavy nuclei
Speaker 1: in the universe, just like supernova, and also generate very
Speaker 1: high energy gamma rays.
Speaker 2: Would they also generate regular light like visible light or
Speaker 2: would they maybe only generate gamma rays, and that's why
Speaker 2: we don't see them with the naked eye.
Speaker 1: Yeah, we definitely see neutron star collisions, and we've seen some.
Speaker 1: We've also correlated some with gravitational waves. But you know,
Speaker 1: there's lots of different varieties of these things, different masses
Speaker 1: of neutron stars, and the collision themselves can happen in
Speaker 1: lots of different ways. So we've seen neutron star collisions
Speaker 1: that haven't caused huge gamma ray bursts, but there's a
Speaker 1: speculation that sometimes neutrons our collisions might cause these incredibly
Speaker 1: bright gamma ray bursts. But it's not something we understand
Speaker 1: very well. Even the heart of a single neutron star
Speaker 1: is not something we understand. Like, what is the state
Speaker 1: of matter under these incredible densities? Is it a quark,
Speaker 1: gluon plasma? Is it some other state of matter? Is
Speaker 1: it nuclear pasta? We have a whole episode about this question.
Speaker 1: We're really just the very beginning of the ability to
Speaker 1: think about these things coherently. And then take two neutron
Speaker 1: stars that are swirling around each other, and the dynamics
Speaker 1: of that and the relativity. It's really just sort of
Speaker 1: beyond our ability to calculate in a robust manner. And
Speaker 1: so there's a lot of sort of theoretical questions about
Speaker 1: whether those even could cause gamma.
Speaker 2: Ray bursts, meaning they might not even be bright enough,
Speaker 2: or they might not be enough to generate the kinds
Speaker 2: of bursts we think we're seeing.
Speaker 1: Yeah, it's the leading theory, but it's definitely far from proven.
Speaker 2: All right, let's begin more into what could be causing
Speaker 2: these gamma ray bursts, and then we'll get to the
Speaker 2: boat the brightest of all time. But first let's take
Speaker 2: another quick break. All right, we're hopping on a boat here,
Speaker 2: Daniel trying to find the brightest of all time, the
Speaker 2: brightest explosion of.
Speaker 1: All time, right, yes, exactly.
Speaker 2: It's the biggest exploding boat.
Speaker 1: Yeah, and it's really wonderful. I love the experience of
Speaker 1: just being overwhelmed by stuff that happens in the universe.
Speaker 1: Really stretches your mind to even try to conceive of
Speaker 1: these incredible events. You know, it makes everything that happens
Speaker 1: here on Earth just seem inconsequential. Yeah.
Speaker 2: I mean for it to have been so bright that
Speaker 2: even though it's super duper duper far away, we're still
Speaker 2: seeing it here on Earth. It's pretty amazing, right, I mean,
Speaker 2: I'm sure the rest of the universe is also seen it.
Speaker 1: Yeah, exactly. And unless this is the unicorn of unicorns,
Speaker 1: it means that's probably even brighter stuff out there that
Speaker 1: we're missing.
Speaker 2: Oh, maybe it is the unicorn making this.
Speaker 1: Yeah. Maybe it's the collision of two unicorns when they
Speaker 1: cross their horns. Maybe that's what happens.
Speaker 2: Yeah, yeah, Or it's a unicorn farting.
Speaker 1: Let's keep it clean for the families out there.
Speaker 2: It's something wrong with farts. Everybody farts, even unicorns.
Speaker 1: This is not a fart podcast. Folks, we're talking about
Speaker 1: bright explosions, not stinky ones.
Speaker 2: But you did say these things are really fart away.
Speaker 1: They are. They are mind blowingly far away exactly. So
Speaker 1: we have the short gamma ray bursts that are probably
Speaker 1: emerging neutron stars, and then we have these longer gamma
Speaker 1: ray bursts, which just means that we see photons for longer,
Speaker 1: like a last four minutes instead of seconds. And the
Speaker 1: leading theory here is supernova collapse. That when supernova's collapse
Speaker 1: sometimes they create these very bright bursts of photons. Not
Speaker 1: always like we see supernovas that don't cause gamma ray bursts,
Speaker 1: but sometimes we think like there's a jet of matter
Speaker 1: ejected from the supernova, Like the collapse isn't completely symmetric,
Speaker 1: and this jet of matter sort of like a blazar
Speaker 1: or a quasar, can accelerate particles and generate enormous bursts
Speaker 1: of very very intense light.
Speaker 3: Hm.
Speaker 2: Does that mean we have to disqualify supernova from our
Speaker 2: category here because a burst is not sort of going
Speaker 2: in all directions.
Speaker 1: No, I think it's fine. I don't think there's a
Speaker 1: reason to disqualify it just because it's focused, you know,
Speaker 1: I think it's still it's bright and it's an explosion,
Speaker 1: so yeah, I think it qualifies as one of the
Speaker 1: brightest explosions.
Speaker 2: M it's more of a float, like the focused, focusedly
Speaker 2: bright of all time. All right, So those are leading theories,
Speaker 2: but we're not sure. It seems you're saying maybe even
Speaker 2: a supernova emerging neutron stars might not be powerful enough
Speaker 2: to generate the kinds of gamma ray burst we're seeing.
Speaker 1: Yeah, exactly. And you know, this is the exciting edge
Speaker 1: of astronomy when we see stuff in the night sky
Speaker 1: we can't quite explain. We're not sure if it's like
Speaker 1: a weird, extreme version of something we've already seen, or
Speaker 1: if it's something totally new kind of thing out there
Speaker 1: in the universe we've never considered. And that's definitely happened, right.
Speaker 1: I think about the first time we discovered supernova or
Speaker 1: black holes or quasars. All these things were discoveries of
Speaker 1: something new out there in the universe, a whole new
Speaker 1: category of things the universe can do. So we don't
Speaker 1: really know if gamma ray bursts represent that, or if
Speaker 1: they represent like the extreme edge of some kind of
Speaker 1: thing we're familiar with.
Speaker 2: Yeah, it's pretty exciting. So is that then the brightest
Speaker 2: thing we've seen explode out there in the universe.
Speaker 1: So the brightest thing we've ever seen in the universe
Speaker 1: is a gamma ray burst, and it's one that just
Speaker 1: happened last year. Like the record was set in October
Speaker 1: twenty twenty three.
Speaker 2: Ooh, was there a celebration, was Thinkinness World Record official
Speaker 2: there at the telescope.
Speaker 1: I think that everybody was too stunned, Like this is
Speaker 1: something just crazy bright, brighter than anything we've ever seen
Speaker 1: by like a big factor. This is one hundred times
Speaker 1: brighter than any other gamma ray burst we've ever seen,
Speaker 1: which remember is already like quadrillions of times brighter than
Speaker 1: the sun.
Speaker 2: Wow, that's incredible. But then do we know how far
Speaker 2: away this one was? Like maybe it was dimmer than
Speaker 2: the ones before, it was just closer.
Speaker 1: They think this one might just be closer. They actually
Speaker 1: have a candidate to where it might have come from,
Speaker 1: which is a galaxy only two and a half billion
Speaker 1: light years from Earth, and so it might be why
Speaker 1: it seemed brighter here and it seemed like the jet
Speaker 1: might be like pointed right at us. That's sort of
Speaker 1: one theory for why this one was so bright. But
Speaker 1: you know, we have this telescope orbiting Earth. It's called
Speaker 1: the Fermi LAT and it's excellent finding gamma rays, really
Speaker 1: high energy photons. It's kind of like a particle detector
Speaker 1: in space. So I think it's pretty cool. Like photons
Speaker 1: enter the telescope and it's not like a telescope like
Speaker 1: Hubble where you have lenses and optics. Instead, it converts
Speaker 1: the photon into electron and positron then attract those particles,
Speaker 1: so it's sort of like a very high energy particle detector.
Speaker 1: And this thing was totally overwhelmed, Like it was just
Speaker 1: flooded with higher energy photons than it had ever seen before.
Speaker 2: Wow, Like it maxed out the sensor.
Speaker 1: Yes, exactly, it saturated that eyeball in space. It was
Speaker 1: totally overwhelmed, and not just our sensors, like the ionosphere,
Speaker 1: this part of the atmosphere of the Earth. The whole
Speaker 1: thing swelled up for several hours. This is the kind
Speaker 1: of thing that happens when like we got a big
Speaker 1: solar flare, like when the Sun burps out an enormous
Speaker 1: number of particles towards the Earth at the ionosphere response,
Speaker 1: but this is something that happened like billions of light
Speaker 1: years away and it still made the Earth like a
Speaker 1: little swollen and inflamed.
Speaker 2: WHOA, Now, how do we know where it came from?
Speaker 1: We don't know exactly, but there's sort of a candidate
Speaker 1: galaxy in that direction to people think maybe it came
Speaker 1: from there. But you know, this is all very speculative.
Speaker 1: You can't really tell me, like.
Speaker 2: How do we triangulate where it came from?
Speaker 1: Oh, we can measure the direction of these photons, Like
Speaker 1: for me, lat is a detector, and so we can
Speaker 1: see the trajectory of the particles that come from the photon.
Speaker 1: So we can reconstruct the direction of these photons.
Speaker 2: What do you mean we can see the direction? How
Speaker 2: do we do that?
Speaker 1: Well, the photon turns into an electron and positron pair,
Speaker 1: and those carry the momentum of the original photon. And
Speaker 1: then we have layers of detector. So we have like
Speaker 1: ten or one hundred layers that detect the motion of
Speaker 1: the particles that come from the photon, and then we
Speaker 1: can reconstruct that track and it points back to where
Speaker 1: it came from.
Speaker 2: Oh, I see, it's like a sort of like a cake,
Speaker 2: you know, like if you stick your finger in a cake,
Speaker 2: you can sort of trace which direction the finger was poking.
Speaker 1: Yeah, imagine like a hundred layer cake and you like
Speaker 1: shoot a bullet through it, and then you'll take slices
Speaker 1: of that cake and you traced where that bullet hole was.
Speaker 1: You could figure out what direction the bullet came from.
Speaker 2: Yeah, there you go. Just don't eat the bullet.
Speaker 1: I was going to go with a JFK analogy, but
Speaker 1: I decided to go with cakes.
Speaker 2: GOTFK, We got the boat.
Speaker 1: The mystery gamma ray burst came from the direction of
Speaker 1: the Texas school Book Depository. It's all a big conspiracy theory.
Speaker 2: Yeah, yeah, it's a cosmic conspiracy theory. All right. So
Speaker 2: this was detected just last year and who detected it?
Speaker 1: So it was detected all over the Earth. It was
Speaker 1: seen by Fermi Laugh which is a big collaboration of
Speaker 1: scientists from across the world. It was also seen by
Speaker 1: the Large High Altitude Air Shower Observatory in China, and
Speaker 1: then there was a Russian facility that saw it also.
Speaker 1: And this observatory in China is only for very very
Speaker 1: high energy photons and they only ever seen a few
Speaker 1: photons very high energy, and this time they saw five
Speaker 1: thousand photons just from this one gamma ray burst. It's
Speaker 1: like ten times as many as they've ever seen in
Speaker 1: the entire history of the entire detector. They saw in
Speaker 1: this one day. This one period lasted about seven minutes long.
Speaker 2: Wait weaning that it was visible to the naked eye,
Speaker 2: or you could only see it in gammorrays.
Speaker 1: You could only see it in gammorys. You cannot see
Speaker 1: gamma rays with the naked eye. They're way too high energy.
Speaker 1: And one of the most interesting and weird things about
Speaker 1: this gamma raburse if not just the intensity, like the
Speaker 1: number of photons, but the energy of each individual photon.
Speaker 1: So this thing also set a record as sending the
Speaker 1: highest energy photon ever seen. This one photon had eighteen
Speaker 1: terra electron bolts, which is like much more energy than
Speaker 1: protons have the Large Hadron collider. And yes, it means
Speaker 1: it's a very very high frequency, very short wavelength. This
Speaker 1: is the highest energy photon ever seen by a factor
Speaker 1: of four. So like, this thing is really far out
Speaker 1: there on the tails.
Speaker 2: We wouldn't it mean that it's really close, right, because
Speaker 2: then don't photons kind of get stretched out as they
Speaker 2: go further out in space.
Speaker 1: Absolutely, it's very weird for a super high energy photon
Speaker 1: to come from really far away for two reasons. One
Speaker 1: is you're right, if it's coming from really far away,
Speaker 1: then as the universe expands, those photons get stretched out,
Speaker 1: they get red shifted right, so they get lower energy,
Speaker 1: which means originally had even more energy. The other reason
Speaker 1: is that the universe is actually not very transparent to
Speaker 1: super high energy photons. As particles get really really high energy,
Speaker 1: they start to interact with the cosmic microwave background radiation
Speaker 1: like protons and other cosmic ray particles. If they're super
Speaker 1: high energy, they'll collide with the photons from the cosmic
Speaker 1: microwave background the remnants of the Big Bang, and interact
Speaker 1: and disappear. The same thing is true with super duper
Speaker 1: high energy photons interact with those photons from the CMB.
Speaker 1: So we shouldn't be able to see photons from really
Speaker 1: really far away because they should get absorbed by the universe.
Speaker 1: So here we're seeing a super high energy photon from
Speaker 1: what seems like really really far away. It's very weird.
Speaker 2: So we can trace where the burths came from and
Speaker 2: when we look in that direction, we see some galaxy
Speaker 2: where maybe it came from. That's why you think it
Speaker 2: came from that gux.
Speaker 1: But that's very speculative. It's like, yeah, it's in the
Speaker 1: same direction in the sky, right, and that's the first
Speaker 1: thing we see there. That doesn't mean it came from that.
Speaker 1: I could have come from behind that. There could be
Speaker 1: something else between us and there. All right, we're really
Speaker 1: limited by our vantage point.
Speaker 2: Like it could be an alien in between us and
Speaker 2: this galaxy with like a laser pointer that shoots lighting
Speaker 2: the gama right direction and they're just messing with us.
Speaker 1: Yeah. Absolutely, it could be or you know, it could
Speaker 1: be that it just came from something else and it
Speaker 1: happened to land here on Earth. This one special photon
Speaker 1: happened to land here on Earth at the same time
Speaker 1: as this gamma ray burst, right.
Speaker 2: That could have been random, or maybe it's not random.
Speaker 2: What if it's like a phone.
Speaker 1: Call, it's like a voicemail. It's like in your hotel
Speaker 1: room when you ignore that blipp you're like, it's an emoji.
Speaker 2: It's a text message that says you up.
Speaker 1: Wow, It's a late night booty call from aliens.
Speaker 2: Hopefully not a booty call ye, hopefully to science call
Speaker 2: family friendly.
Speaker 1: But you know, there's a lot of really interesting science
Speaker 1: that could be done with this, because again, people don't
Speaker 1: understand how a photon with that much energy could travel
Speaker 1: that far across space. One fun paper I read suggests
Speaker 1: that maybe it wasn't a photon the whole time. Maybe
Speaker 1: it converted to this weird theoretical particle called an axion.
Speaker 1: There's this idea that maybe axion particles are the dark matter,
Speaker 1: and they couple a little bit to photons, and so
Speaker 1: photons can sometimes turn into axions. There's a set of
Speaker 1: experiments called light shining through walls where people look for
Speaker 1: photons penetrating stuff that photons shouldn't be able to penetrate
Speaker 1: by turning briefly or for a while into axions and
Speaker 1: then converting back into photons when they come near the Earth,
Speaker 1: for example, and hit our magnetic field. So some people
Speaker 1: argue that this might be evidence that this photon turned
Speaker 1: into an axion, flew across the universe, and then came
Speaker 1: back into photon modes so we could see it.
Speaker 2: WHOA, that's a little too convenient, though, isn't it.
Speaker 1: It's just hard to explain that we have no actual
Speaker 1: explanation for this photon. There is no way we should see.
Speaker 1: It's like an impossible photon. I mean, the most boring
Speaker 1: explanation for the crazy photon is that it's a mistake
Speaker 1: that we don't know how to measure the energy of
Speaker 1: particles with super duper high energy, because remember, we're always
Speaker 1: reconstructing these things. This is an air shower observatory, which
Speaker 1: means you're not seeing the original photon. You're seeing the
Speaker 1: particles that turned into when it's slammed into the atmosphere
Speaker 1: and created this cascade of particles that are shining and
Speaker 1: flashing light.
Speaker 2: Meaning it could have been something else, not a photon.
Speaker 1: It could have been something else not a photon, or
Speaker 1: it could have been something with lower energy. You know,
Speaker 1: the uncertainty on this resolution is significant. We should also
Speaker 1: say the Russian observatory reported an even higher energy photon
Speaker 1: two hundred and fifty terra electron bolts, like more than
Speaker 1: ten times the energy of this one scene in China.
Speaker 1: But the truth is nobody believes them. They're like, yeah, no,
Speaker 1: you guys messed up.
Speaker 2: Let me get this straight. We don't know what cost
Speaker 2: this burst. We don't know where it is exactly. We
Speaker 2: don't even know if it is a burst.
Speaker 1: We know it's a gamma y burst. It was very,
Speaker 1: very intense, but it has a special photons in it
Speaker 1: that really raise some questions. Maybe we've mismeasured them, or
Speaker 1: maybe they're evidence of axion, dark matter, or something else happening.
Speaker 1: But there's a lot of uncertainty in these things, and
Speaker 1: you know, the frustrating thing in astronomy is you can't
Speaker 1: control these experiments, Like if this was something you were
Speaker 1: doing in your lab, in your basement, or even if
Speaker 1: a large hadron collider, so you could say, let's do
Speaker 1: it again and check. But these are just things we're
Speaker 1: lucky or unlucky enough to see in the sky and
Speaker 1: have to wait for it to happen again before we
Speaker 1: can convince ourselves it's real.
Speaker 2: I wonder then we should maybe retitle the episode, because
Speaker 2: really we're just talking about the brightest flash we've ever seen.
Speaker 2: We don't even know if it came from an explosion
Speaker 2: or an alien laser or an alien phone call.
Speaker 1: Right, yeah, or space unicorn farts.
Speaker 2: Yeah, absolutely, yeah, a very focused space unicorn part.
Speaker 1: Maybe they are the aliens woo, I'm unifying the theories.
Speaker 2: That's how they make phone calls to their fart network,
Speaker 2: in which case it is sort of technically a booty call.
Speaker 1: People are doing a lot of work to try to
Speaker 1: understand this better. They're trying to see, like was there
Speaker 1: a jet of material that was emitted. By looking at
Speaker 1: the spectrum of light that comes in the gamma ray burst,
Speaker 1: they can try to get a sense for like what
Speaker 1: was in that jet? Was it wide, was it narrow?
Speaker 1: Did they have the kind of material we expect from
Speaker 1: a collapsing star? What can we learn about the origin star?
Speaker 1: Maybe there was something weird about the star that collapsed
Speaker 1: that generated this incredibly bright source of light. And so
Speaker 1: there's a lot of sort of conflicting studies still about this.
Speaker 1: Some people say the jet was really really narrow, that's
Speaker 1: why I was bright. Another study said no, actually the
Speaker 1: jet looks like it was wider. But you know, there's
Speaker 1: a lot of questions. This is early days in understanding this.
Speaker 1: But unless we're lucky enough to see a brighter one,
Speaker 1: this is going to be a boat for a while.
Speaker 2: Is it possible also that maybe it was like focus
Speaker 2: somehow right, because isn't there a sort of lensing out
Speaker 2: there by dark matter or maybe other things? Could something
Speaker 2: have lensed this light to make it seem more intense.
Speaker 1: Mm hm, that's certainly a possibility. There's some really cool
Speaker 1: studies to try to understand how much dark matter there
Speaker 1: is between us and any point in the sky by
Speaker 1: looking for evidence of lensing. We don't see lensing evidence
Speaker 1: in this distribution, but it's certainly possible. We don't have
Speaker 1: a great map of where the dark matter is in
Speaker 1: the universe, and you know, that's a fundamental limitation to
Speaker 1: looking at the universe only from the surface of one planet.
Speaker 1: Anytime you get a photon, you don't exactly know where
Speaker 1: it came from, what happened to it along the way.
Speaker 1: You have to try to untangle all of these mysteries simultaneously, right,
Speaker 1: how much dust is there between us and there? How
Speaker 1: much dark matter is there? How much is the universe stretching?
Speaker 1: Is that even? Is that isotropic? Because there are other
Speaker 1: weird stuff going on simultaneously. We have to try to
Speaker 1: unravel these mysteries to explain this incredible mosaic we see
Speaker 1: in the night sky.
Speaker 2: Amazing, but I guess maybe the overall message is that
Speaker 2: we've seen something that is brighter than what we thought
Speaker 2: was possible, and it's pretty incredible that we're still doing that, right,
Speaker 2: We're seeing things we didn't think could exist before.
Speaker 1: Yeah, and it's stunned astronomers. I mean, astronomers are used
Speaker 1: to big numbers about the universe, but even this one
Speaker 1: sort of like you can tell, it rocked them back
Speaker 1: on their heels. Well.
Speaker 2: Wait, it is shocked, even the bright ones exactly.
Speaker 1: Eric Urns is an astronomer who studies this kind of stuff, said, quote,
Speaker 1: the energy of this thing is so extreme that if
Speaker 1: you took the entire Sun and you converted all of
Speaker 1: it into pure energy, it still wouldn't match this event.
Speaker 1: There's just nothing comparable.
Speaker 2: Yeah, that's incredible. Yeah, unless you consider farting unicorns in
Speaker 2: this case, anything's possible. All right. Well, it's an interesting
Speaker 2: exploration of a new universal or at least local world
Speaker 2: record of the brightest flash we've seen and its mysteries.
Speaker 1: And one thing we do know is that the universe
Speaker 1: contains enduring mysteries. And the more we look out there
Speaker 1: in the universe, the more we understand and the more
Speaker 1: we are shocked by what's out there?
Speaker 2: Yeah, and the more that we need bright people like
Speaker 2: maybe you out there to figure out.
Speaker 1: Mister he's talking to you, folks, guys, not to me.
Speaker 2: We hope you enjoyed that. Thanks for joining us, See
Speaker 2: you next time.
Speaker 1: For more science and curiosity, come find us on social
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Speaker 1: and now TikTok. Thanks for listening, and remember that Daniel
Speaker 1: and Jorge Explain the Universe is a production of iHeartRadio.
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