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What is the Space Roar? · Daniel and Kelly’s Extraordinary Universe

• 0:08
  Speaker 1: Hey, Daniel, do you ever think we should explore the
• 0:10
  Speaker 1: universe with all five senses? Well, I'm definitely a fan
• 0:14
  Speaker 1: of looking out into space. Yeah, but we have other senses.
• 0:17
  Speaker 1: Have you thought about what space smells like? Well, astronauts
• 0:21
  Speaker 1: report that space smells a little bit like a barbecue.
• 0:25
  Speaker 1: Really does it taste like barbecue? Also, I don't know,
• 0:28
  Speaker 1: maybe frozen barbecue, I guess. Well, I hope it doesn't
• 0:31
  Speaker 1: feel like barbecue. Space is not that saucy it turns
• 0:35
  Speaker 1: out or sound like barbecue. That would just be the
• 0:37
  Speaker 1: sound of aliens preparing their barbecue grills. Well, I just
• 0:41
  Speaker 1: hope we're not on the menu. Talk about first contact first,
• 0:46
  Speaker 1: of course, of course I am more handmade cartoonists and
• 1:04
  Speaker 1: the creator of PhD comics. Hi, I'm Daniel. I'm a
• 1:07
  Speaker 1: particle physicist, and I do love me a barbecue. So
• 1:10
  Speaker 1: it really smells like barbecue space? It does. Actually, we
• 1:13
  Speaker 1: had to listener question recently about what space smells like.
• 1:16
  Speaker 1: And they're a bunch of really interesting organic molecules out
• 1:19
  Speaker 1: there in space that like cling to space suits and
• 1:22
  Speaker 1: then release themselves when you come back inside, And they
• 1:25
  Speaker 1: smell like sometimes like sulfur, sometimes like barbecue. What does
• 1:28
  Speaker 1: it mean? Like the astronauts would go out into space
• 1:31
  Speaker 1: on a spacewalk and then when they come in they
• 1:33
  Speaker 1: smell like barbecue. Yeah, exactly, when they open up their
• 1:36
  Speaker 1: helmets again after they've come back in, the stuff that's
• 1:38
  Speaker 1: stuck to their space suit now goes up their nostrils
• 1:41
  Speaker 1: and it smells a little bit like barbecue. Guess technically
• 1:44
  Speaker 1: barbecues are part of the universe. So yeah, the universe
• 1:47
  Speaker 1: does smell like barbecue, as it does smell like other things.
• 1:50
  Speaker 1: Our barbecue universe. Welcome to our podcast Daniel and Jorge
• 1:54
  Speaker 1: Explain the Universe, a perlection of I Heart Radio in
• 1:57
  Speaker 1: which we use all sorts of absurd food analogy used
• 2:00
  Speaker 1: to explain to you what the universe is like. Is
• 2:03
  Speaker 1: it goopy and saucy? Is it chewy and stringy? Can
• 2:06
  Speaker 1: you bite right through it? But really, we want to
• 2:08
  Speaker 1: make sure that you understand the nature of the universe,
• 2:12
  Speaker 1: the things that scientists are thinking about, the things that
• 2:15
  Speaker 1: we are mentally chewing on, and the things we have
• 2:17
  Speaker 1: not yet been able to digest. That's right because even
• 2:20
  Speaker 1: analogies are part of the universe, and so it's a
• 2:24
  Speaker 1: broad topic that we are discussing here Daniel and Jorge
• 2:27
  Speaker 1: explain bad analogies with other worse analogies. Yeah, it feels
• 2:32
  Speaker 1: like we just be compounding the problem there. But it
• 2:35
  Speaker 1: is a pretty interesting universe out there, and there's a
• 2:38
  Speaker 1: lot going on. Like if you just sit there in
• 2:41
  Speaker 1: space and you float, you can smell things, you can
• 2:43
  Speaker 1: feel things, I'm sure radiation hitting you, and you can
• 2:45
  Speaker 1: see definitely a lot out there in the universe. Absolutely,
• 2:49
  Speaker 1: and we are continuing to invent new ways to interrict
• 2:52
  Speaker 1: with our universe. And basically every time we do, we
• 2:56
  Speaker 1: find something shocking, we discover something else out there the
• 3:00
  Speaker 1: universe we didn't even know existed. Yeah, I mean, we're
• 3:03
  Speaker 1: just sitting here in one corner of the Milky Way,
• 3:05
  Speaker 1: which is sitting in one corner of the observable universe,
• 3:08
  Speaker 1: and we're getting a lot of signals from everywhere. Basically,
• 3:11
  Speaker 1: anything that gives up light, we get that light, and
• 3:13
  Speaker 1: we detected with our telescopes and our antennants. Exactly we
• 3:17
  Speaker 1: are drowning and information from the universe, much of which
• 3:20
  Speaker 1: we didn't even know existed until recently. For example, most
• 3:24
  Speaker 1: of astronomy has been done using visible light. Light that
• 3:27
  Speaker 1: you can see with your eyes and even maybe enhanced
• 3:30
  Speaker 1: with telescopes, but there are really interesting signals in X
• 3:33
  Speaker 1: rays and on the other side of the spectrum down
• 3:36
  Speaker 1: to radio waves, you can also look at all the
• 3:38
  Speaker 1: particles that are washing over us, neutrinos and other crazy
• 3:42
  Speaker 1: sources of information about what's going out there in the universe.
• 3:45
  Speaker 1: And recently we added gravitational waves to our toolkit for
• 3:50
  Speaker 1: listening to the universe. And each of these tells us
• 3:53
  Speaker 1: something different about the nature of the universe because different
• 3:55
  Speaker 1: stuff out there emits in different ways. Some of it
• 3:58
  Speaker 1: gives off light, some radio waves, some gravitational waves. Each
• 4:02
  Speaker 1: one can tell us something different about what's out there
• 4:05
  Speaker 1: in the universe. What sense would you use, Daniel to
• 4:07
  Speaker 1: describe detecting gravitational waves, Like, what what sense do you
• 4:11
  Speaker 1: need to detect gravity? Do you feel it? Do we
• 4:14
  Speaker 1: hear it, do we see it? You would feel it
• 4:16
  Speaker 1: technically because it's a space quake, right, It's like a
• 4:19
  Speaker 1: shaking of space itself. Space contracts, it expands into wiggles,
• 4:24
  Speaker 1: So that's really what's happening. And a lot of science
• 4:27
  Speaker 1: communication about gravitational waves, though they talk about listening to
• 4:31
  Speaker 1: the universe they talk about like the chirp of black holes.
• 4:35
  Speaker 1: I think that's a tiny bit confusing because we're not
• 4:38
  Speaker 1: using our ears to hear these things. We're not getting
• 4:41
  Speaker 1: sound waves from gravitational waves. What they've done is taken
• 4:45
  Speaker 1: the frequency of those waves, transform them into sound waves,
• 4:48
  Speaker 1: and then listen to them. We're feeling the gravitational waves. Yeah.
• 4:52
  Speaker 1: I like thinking about gravitational waves as the shaking of space.
• 4:56
  Speaker 1: All right, Well, there are a lot of things out
• 4:58
  Speaker 1: there giving of a light and signals and gravity, and
• 5:01
  Speaker 1: for the most part we sort of know where it's
• 5:04
  Speaker 1: coming from over or what's making these signals. But sometimes
• 5:07
  Speaker 1: there are surprises. There are almost always surprises, and a
• 5:10
  Speaker 1: lot of times these things are picked up by accident.
• 5:13
  Speaker 1: Somebody develops a new kind of antenna or a new
• 5:16
  Speaker 1: kind of telescope and looks out of the universe the
• 5:18
  Speaker 1: first time, maybe looking for one thing and finding something
• 5:21
  Speaker 1: totally different, and then puzzling over and wondering like, huh,
• 5:24
  Speaker 1: what's making all that light or emitting all that radiation?
• 5:28
  Speaker 1: And those are fascinating clues that tell us about something
• 5:31
  Speaker 1: new out there in the universe, or something we knew
• 5:33
  Speaker 1: about that's doing something we didn't know about. Yeah, and
• 5:36
  Speaker 1: there is one particular signal out there that is basically
• 5:40
  Speaker 1: all around us. You can hear it in every direction,
• 5:42
  Speaker 1: but we don't know what's making it. It's sort of
• 5:44
  Speaker 1: this weird, unexplained phenomenon exactly, and it's also got a
• 5:49
  Speaker 1: hilarious name to it. Oh does it in physics? How surprising?
• 5:54
  Speaker 1: I'm shocked, hilarious and some ways misleading? Well do they?
• 6:00
  Speaker 1: On the podcast will be tackling the question what is
• 6:07
  Speaker 1: the space roar now, Daniel? Is it like a roar
• 6:10
  Speaker 1: like a lines war or is it more like a
• 6:13
  Speaker 1: cat's meo like rare like is the universe caddie or
• 6:18
  Speaker 1: is it you know, not had its morning coffee yet?
• 6:20
  Speaker 1: What is the universe's attitude exactly? Does the universe need
• 6:24
  Speaker 1: to go to therapy? Like, dude, chill out, somebody give
• 6:26
  Speaker 1: the universe some valium? What's definitely cool and chill We've
• 6:30
  Speaker 1: I think we've established that. Does it got kind of
• 6:33
  Speaker 1: hot sometimes? Yeah? Exactly. Roar is a pretty funny name. Really.
• 6:37
  Speaker 1: I would have called this the space hiss, the space
• 6:40
  Speaker 1: his his yeah, exactly, like the space buzzes. Yeah, the
• 6:44
  Speaker 1: space buzz That would have been a great name for it,
• 6:46
  Speaker 1: the space hum um. That makes it sound like alien music,
• 6:51
  Speaker 1: you know, like Gregorian alien chance, the space whistle while
• 6:55
  Speaker 1: you work. Yeah, exactly. I think all of those would
• 6:58
  Speaker 1: have been more accurate name than the space raw. Now
• 7:03
  Speaker 1: I see now you're calling it. I would spell that
• 7:06
  Speaker 1: differently than r O A r oh. Yeah, that's more
• 7:08
  Speaker 1: like the space meal. Yeah. But anyways, it is a thing,
• 7:12
  Speaker 1: the space roar, and it's kind of a big mystery
• 7:15
  Speaker 1: in physics, and we were wondering how many people out
• 7:17
  Speaker 1: there knew what it was or had heard of it
• 7:20
  Speaker 1: or been I don't know the subject of its attitude.
• 7:24
  Speaker 1: So thanks to everybody who's willing to guess at the
• 7:27
  Speaker 1: true nature of something poorly named by astronomers. If you
• 7:31
  Speaker 1: were willing to participate for a future episode, please write
• 7:34
  Speaker 1: to me. Two questions at Daniel and Jorge dot com.
• 7:37
  Speaker 1: I like how you just totally through astronomers under the
• 7:40
  Speaker 1: bus there. You could have said physicists. You definitely specifically
• 7:44
  Speaker 1: said astronomers there. Yeah. Well, I feel like they are
• 7:46
  Speaker 1: the target of your criticism more often than other kind
• 7:49
  Speaker 1: of physics. Mr particle man, are you serious? Yeah? We
• 7:55
  Speaker 1: got strange names. We got charming names. But you know,
• 7:59
  Speaker 1: astronomer is there. Maybe let's call them more creative with
• 8:02
  Speaker 1: their names. Remember that whole episode about space centaurs. Let's
• 8:06
  Speaker 1: not hear me raw about this topic any longer. Alright,
• 8:10
  Speaker 1: let's not hiss about it all right? Well, as usual,
• 8:12
  Speaker 1: Daniel went out there and ask people what they thought
• 8:14
  Speaker 1: the space roar was. To think about it for a second.
• 8:17
  Speaker 1: If someone ask you, what would you say? How would
• 8:20
  Speaker 1: you answer? Here's what people had to say, saying, as
• 8:23
  Speaker 1: it's called aurora, I imagine Scott to do with sound waves,
• 8:26
  Speaker 1: and I think they might come from all directions in space.
• 8:30
  Speaker 1: The space roar sort of reminds me of a tiger
• 8:34
  Speaker 1: or Allian. But in our universe, I think that the
• 8:38
  Speaker 1: space roar could be like an explosion. Maybe it could
• 8:42
  Speaker 1: be compared to the Big Bang, and maybe this explosion
• 8:45
  Speaker 1: was the beginning of something. I don't know if it
• 8:48
  Speaker 1: could have been the beginning of a galaxy. The spice role,
• 8:52
  Speaker 1: I'm fairly certain is aliens. Probably it can only be
• 8:58
  Speaker 1: radio waves since nobody can scream with us, who wouldn't
• 9:03
  Speaker 1: hear it? Because you avoids, the sound cannot travel, So
• 9:07
  Speaker 1: the space road can be in radio We always talk
• 9:11
  Speaker 1: about light and energy being transmitted through space, but a
• 9:15
  Speaker 1: lot of what happens in the universe also produces or
• 9:18
  Speaker 1: could produce sound if there was something to convey that sound.
• 9:22
  Speaker 1: So is this some sort of accumulation of that? I
• 9:25
  Speaker 1: have no idea, all right, I like this idea of
• 9:28
  Speaker 1: a space tiger or a space lion when alien space tiger? Yeah,
• 9:34
  Speaker 1: that was basically your answer. Yeah, and some people assume
• 9:36
  Speaker 1: it has something to do with radio waves or at
• 9:39
  Speaker 1: least some sort of waves that we're getting out there
• 9:42
  Speaker 1: from the universe. Yeah, totally solid response there. Yeah, but
• 9:45
  Speaker 1: technically can you get sound from space? I know in
• 9:48
  Speaker 1: space no one can hear you scream. But is that
• 9:50
  Speaker 1: because you're wearing a helmet or because you can't transmit sound? Right,
• 9:54
  Speaker 1: Anything where you describe something we get from space in
• 9:58
  Speaker 1: terms of a sound is usually playing the same trick
• 10:01
  Speaker 1: we talked about with respect to gravitational waves, where you're
• 10:04
  Speaker 1: getting some other kind of wave and all waves have
• 10:06
  Speaker 1: a frequency, and then you transform that wave into a
• 10:10
  Speaker 1: sound wave so you can listen to it. This is
• 10:12
  Speaker 1: no different than like taking radio waves or X rays
• 10:16
  Speaker 1: from space which you can't see visually, and then just
• 10:19
  Speaker 1: shifting them in the spectrum so that you can see
• 10:22
  Speaker 1: them like a false color image. So no, you can't
• 10:24
  Speaker 1: actually hear any sounds from space because sounds are mechanical waves.
• 10:30
  Speaker 1: They require like air shifting or something banging into something else.
• 10:34
  Speaker 1: So we can't hear anything technically from space, right. But
• 10:38
  Speaker 1: space isn't completely empty, is right. It's not a perfect vacuum.
• 10:41
  Speaker 1: There's a little bit of gas and hydrogen everywhere, isn't there? No, exactly,
• 10:45
  Speaker 1: there are some particles out there, and so you can
• 10:48
  Speaker 1: imagine there are some like waves in the solar wind,
• 10:51
  Speaker 1: for example, oscillations that happened, like the sun has a
• 10:54
  Speaker 1: period of eleven years, where like there's lots of ups
• 10:57
  Speaker 1: and downs in the radiation it emits. So you can
• 11:00
  Speaker 1: imagine waves propagating in that medium, and perhaps you can
• 11:04
  Speaker 1: imagine actually listening to them. So yeah, there are ways
• 11:07
  Speaker 1: you're right for sound to propagate through not totally empty space.
• 11:11
  Speaker 1: But space is also not empty in another way. We
• 11:13
  Speaker 1: always talk about space being filled with quantum fields, and
• 11:17
  Speaker 1: those fields can propagate waves, and for example, that's what
• 11:20
  Speaker 1: a photon is. It's a wave in the electromagnetic field
• 11:23
  Speaker 1: in otherwise empty space m sounds good, so they can
• 11:28
  Speaker 1: hear you scream in space from radiation burning. Probably if
• 11:32
  Speaker 1: you scream in light, then yes, people can hear you scream.
• 11:35
  Speaker 1: All right, So there's this big mystery in physics called
• 11:38
  Speaker 1: the space roar. Now, Daniel step us through this. What
• 11:41
  Speaker 1: is the space war? The space roar is a totally weird,
• 11:45
  Speaker 1: unexplained source of radio from space, And that's why they
• 11:50
  Speaker 1: call it the space roar because it comes in the
• 11:53
  Speaker 1: radio spectrum, which is a spectrum where we often listen to. Right,
• 11:56
  Speaker 1: you might even be hearing this podcast on the radio,
• 11:59
  Speaker 1: which means it's and transmitted using radio waves. So because
• 12:03
  Speaker 1: we associate radio waves with sound often, I think that's
• 12:07
  Speaker 1: why I got this name, the space roar. But basically
• 12:10
  Speaker 1: it's unexplained source of radio waves from space, I guess,
• 12:13
  Speaker 1: meaning that if you turn on your radio, you would
• 12:16
  Speaker 1: technically be able to listen to this roar, right, yeah, exactly,
• 12:19
  Speaker 1: it is coming in through the radio waves. You need
• 12:22
  Speaker 1: a radio antenna. And remember that radio waves are just
• 12:26
  Speaker 1: another part of the electromagnetic spectrum. All of these are photons.
• 12:30
  Speaker 1: You could call all of it light if you want,
• 12:32
  Speaker 1: but they're all just part of the same wiggling of
• 12:35
  Speaker 1: electromagnetic fields. In the center of the spectrum, there's visible light.
• 12:38
  Speaker 1: Above that there's UV light, and then X rays. Below it,
• 12:42
  Speaker 1: there's infrared light, and below that are radio waves. So
• 12:45
  Speaker 1: radio waves are just photons with a very very long wavelength.
• 12:49
  Speaker 1: And you know, as we were saying earlier, for centuries,
• 12:51
  Speaker 1: people were doing astronomy only by looking at visible light,
• 12:55
  Speaker 1: the light you could see with your eyes, and of
• 12:57
  Speaker 1: course there's a lot of fascinating information about stars and
• 12:59
  Speaker 1: the universe you can see you just with your eyes
• 13:01
  Speaker 1: or gathering more of those visible moutons into a telescope.
• 13:05
  Speaker 1: But in the ninet thirties it was this amazing discovery
• 13:08
  Speaker 1: that you could actually listen to the sky using radio
• 13:11
  Speaker 1: waves also, and that there was a huge source of
• 13:14
  Speaker 1: radio waves coming to us from space. How did we
• 13:17
  Speaker 1: discover that it wasn't through like actual radios. No, it
• 13:20
  Speaker 1: was a really interesting accidental discovery by this guy Jansky.
• 13:24
  Speaker 1: He was hired by the Bell Telephone Company. They wanted
• 13:27
  Speaker 1: to beam radio signals across the Atlantic, and they were
• 13:30
  Speaker 1: worried that thunderstorms would generate radio interference, so they hired
• 13:34
  Speaker 1: him to like listen to the radio spectrum carefully and
• 13:37
  Speaker 1: see if you could understand these forms of interference. So
• 13:40
  Speaker 1: he built basically a huge radio telescope, the first radio telescope,
• 13:43
  Speaker 1: just to gather radio waves, and he heard a lot
• 13:46
  Speaker 1: of stuff that he couldn't explain as coming from Earth. Interesting,
• 13:51
  Speaker 1: totally unintended, totally unintended. It was like a fascinating little
• 13:55
  Speaker 1: piece of science. He heard this weird hiss he couldn't explain,
• 13:58
  Speaker 1: and actually he discovered that it was related with the
• 14:00
  Speaker 1: rotation of the Earth, which is how he knew it
• 14:03
  Speaker 1: wasn't coming from the Earth. It's like seeing something in
• 14:06
  Speaker 1: the sky. You see it once a day, so you
• 14:08
  Speaker 1: know that, like as the Earth is turning, it's appearing
• 14:11
  Speaker 1: in the sky. But he was looking at the sky
• 14:13
  Speaker 1: in a different spectrum, right, He was looking at the
• 14:15
  Speaker 1: sky in the radio waves, and what he was actually
• 14:19
  Speaker 1: listening to was radio emissions from the center of the galaxy.
• 14:23
  Speaker 1: And so here was like a whole new way to
• 14:25
  Speaker 1: listen to this guy to look out at the universe.
• 14:28
  Speaker 1: Nobody ever thought that there are natural sources of radio
• 14:32
  Speaker 1: waves out there in the universe, and by listening to
• 14:34
  Speaker 1: them we could tell what's going on. And the whole
• 14:37
  Speaker 1: field is hilarious sort of because nobody really did anything
• 14:40
  Speaker 1: about it until at ten years later, when this guy
• 14:43
  Speaker 1: outside Chicago built the world's first radio telescope by himself
• 14:47
  Speaker 1: in his backyard, and he was basically the only radio
• 14:50
  Speaker 1: astronomer in the world for about ten years. A pioneer,
• 14:55
  Speaker 1: A pioneer absolutely in his backyard. This thing is huge.
• 14:59
  Speaker 1: It's one of these big dishes. So Jansky's first one
• 15:02
  Speaker 1: was just like a string of antennas on a big
• 15:04
  Speaker 1: wheel that he could turn and then whever. He built
• 15:07
  Speaker 1: the first dish to sort of like concentrate radio waves
• 15:10
  Speaker 1: and collect them together. And that's the sort of radio
• 15:13
  Speaker 1: dish that we have now. Like Arisibo until recently was
• 15:15
  Speaker 1: a big radio telescope, and we have other big radio telescopes.
• 15:19
  Speaker 1: You can see them. They are these huge dishes, and
• 15:21
  Speaker 1: they have to be big because radio has very long wavelengths, right.
• 15:25
  Speaker 1: I guess it's sort of like you know, maybe astronomers
• 15:27
  Speaker 1: at the time we're still busy trying to figure out
• 15:29
  Speaker 1: what they were seeing in the visible light spectrum, and
• 15:32
  Speaker 1: so nobody thought to look in other wavelengths. Yeah, exactly.
• 15:35
  Speaker 1: There's still plenty of astronomy to do invisible lights. People
• 15:38
  Speaker 1: are still doing it now, but you know, there's a
• 15:40
  Speaker 1: lot of spectra out there, and the universe looks different
• 15:43
  Speaker 1: at different spectrum. You know, different things glow at different temperatures.
• 15:46
  Speaker 1: Some things are very bright in the UV and very
• 15:49
  Speaker 1: dark in the visible light, or they're very strong radio
• 15:51
  Speaker 1: emitters and they're very quiet and invisible, and so it's
• 15:54
  Speaker 1: sort of like looking at the universe in color instead
• 15:57
  Speaker 1: of in black and white. You can see different things
• 16:00
  Speaker 1: light up in different things being dark at different frequencies,
• 16:03
  Speaker 1: and so it's sort of like extra colors to the universe.
• 16:06
  Speaker 1: It's really a great way to sort of understand what's
• 16:08
  Speaker 1: out there, right right. It's a great romantic line. And
• 16:11
  Speaker 1: hear you're glowing in the X rayspector, all right, So
• 16:15
  Speaker 1: that was a bit his that he heard back then.
• 16:18
  Speaker 1: But now we're hearing a roar and it's sort of
• 16:21
  Speaker 1: unexplained to what's the history of this roar when we
• 16:24
  Speaker 1: first started listening to it or seeing and who did it.
• 16:27
  Speaker 1: So there's an experiment developed called the arcade instrument. Arcade
• 16:31
  Speaker 1: is one of these tortured acronyms that stands for absolute
• 16:34
  Speaker 1: radiometerr for cosmology, astrophysics, and diffuse emission. But it's basically
• 16:39
  Speaker 1: a really sensitive radio antenna attached to a balloon and
• 16:43
  Speaker 1: it goes up into the atmosphere and it listens to
• 16:46
  Speaker 1: radio waves. And they're trying to really accurately measure these
• 16:49
  Speaker 1: sources of radio waves because they want to understand things
• 16:52
  Speaker 1: like the very early universe. They want to listen to
• 16:55
  Speaker 1: the cosmic background radiation and detect to see if, like
• 16:58
  Speaker 1: the first stars in the univer gave it a little
• 17:00
  Speaker 1: bit of hot spots here and there. So they launched
• 17:03
  Speaker 1: this probe something like ten fifteen years ago, and it
• 17:06
  Speaker 1: was one of the most sensitive probes to radio waves,
• 17:09
  Speaker 1: and they heard this crazy hiss that they couldn't explain. Wow,
• 17:13
  Speaker 1: where did they launch it? Was this one of these
• 17:15
  Speaker 1: like antarctic balloons or was it outside Chicago, also the
• 17:18
  Speaker 1: epicenter of radio astronomy. It was launched from a spot
• 17:21
  Speaker 1: in Texas. NASA has a scientific balloon facility there, and
• 17:25
  Speaker 1: this thing is not just like a normal balloon. It's
• 17:27
  Speaker 1: one of these like massive weather balloons, and as it
• 17:30
  Speaker 1: goes up it gets really really big. And this thing
• 17:32
  Speaker 1: went up to thirty seven kilometers above the Earth's surface.
• 17:37
  Speaker 1: All right, So then they send out this balloon and
• 17:39
  Speaker 1: they I guess we're able to point it. Can they
• 17:41
  Speaker 1: pointed around, and that's when they heard this roar. They
• 17:44
  Speaker 1: can't point it. It just sort of like floats around.
• 17:47
  Speaker 1: They don't steer it. But it has a bunch of
• 17:49
  Speaker 1: antennas on it, so you can get directional information about
• 17:52
  Speaker 1: the signals you're picking up based on like when they
• 17:54
  Speaker 1: arrive at the instruments. It's sort of like parallax or
• 17:57
  Speaker 1: like binocular vision, and so they and tell where things
• 18:01
  Speaker 1: are coming from. And so you know, they saw a
• 18:03
  Speaker 1: lot of the expected stuff in the radio. You can
• 18:05
  Speaker 1: see the Sun, you can see the galactic center, you
• 18:08
  Speaker 1: can see Jupiter, you can see other galaxies that are
• 18:12
  Speaker 1: putting out radio waves, and that's sort of what they expected.
• 18:15
  Speaker 1: But they also found this sort of like overall signal,
• 18:18
  Speaker 1: this uniform HIS that nobody had ever heard before, and
• 18:22
  Speaker 1: it's much much stronger than anything they expected. Interesting. All right,
• 18:27
  Speaker 1: let's getting too a little bit more in detail of
• 18:29
  Speaker 1: this his, and then let's talk about where it could
• 18:32
  Speaker 1: be com firm and what it could be. But first
• 18:34
  Speaker 1: let's take a quick break. All right, we're talking about
• 18:48
  Speaker 1: the space roar, a mysterious signal that the arcade instrument
• 18:54
  Speaker 1: detected on a balloon kilometers up in the sky. Now, Daniel,
• 18:59
  Speaker 1: this is different than the cosmic microwave background radiation, right,
• 19:02
  Speaker 1: the CMB r F. That's right, This is different from
• 19:05
  Speaker 1: the CMB. No are we're not living in the marvel universe.
• 19:10
  Speaker 1: The CNB does emit in the radio. Right. Part of
• 19:13
  Speaker 1: the CMB is in the radio spectrum. It's a bit
• 19:16
  Speaker 1: of confusing terminology here because sometimes waves in this part
• 19:19
  Speaker 1: of the spectrum are called radio sometimes they're called microwaves.
• 19:23
  Speaker 1: Through the same thing. Essentially, anything longer than a millimeter
• 19:26
  Speaker 1: you could call a radio wave, or you could call
• 19:28
  Speaker 1: it a microwave. So you could also call it the
• 19:30
  Speaker 1: cosmic radio background m So it is sort of like
• 19:35
  Speaker 1: the cosmic microwave background, but it's just at a different wavelength. Yeah, exactly.
• 19:39
  Speaker 1: They were looking for at the slightly longer wavelength portion
• 19:42
  Speaker 1: that's not as well studied. Because what they wanted to
• 19:44
  Speaker 1: understand was can they see like the heat the light
• 19:47
  Speaker 1: put out from some of the first stars in the universe,
• 19:50
  Speaker 1: which would have emitted in the radio. That was sort
• 19:53
  Speaker 1: of their scientific goals, like measure this part of the
• 19:56
  Speaker 1: spectrum really really accurately, and then study it for hints
• 20:00
  Speaker 1: about the formations of the first stars, which they hoped
• 20:02
  Speaker 1: would leave a little fingerprint on this part of the universe. Oh,
• 20:05
  Speaker 1: I see. They sent that Bluna up to study the
• 20:08
  Speaker 1: CMB specifically, but in the radio wave wavelength, Yeah, exactly,
• 20:12
  Speaker 1: and to study sort of the longer tails of the CNB,
• 20:16
  Speaker 1: which people haven't studied as precisely using like Kobe and
• 20:20
  Speaker 1: Plunk and w MAP and those other satellites. So it
• 20:22
  Speaker 1: has a slightly different sensitivity than other instruments. So sort
• 20:26
  Speaker 1: of the first time people looked with this precision at
• 20:29
  Speaker 1: this part of the spectrum. All right, So then I
• 20:32
  Speaker 1: guess they expected to hear like a background his but
• 20:35
  Speaker 1: what they found was not quite what they were expecting
• 20:38
  Speaker 1: to find. Yeah, they expected to find the CMB, as
• 20:41
  Speaker 1: we talked about, that's part of the spectrum. They also
• 20:43
  Speaker 1: expected to hear sort of like a diffuse background, you know,
• 20:46
  Speaker 1: like all the galaxies that are out there they admit
• 20:48
  Speaker 1: in the radio, especially if they have a strong black
• 20:51
  Speaker 1: hole at their center, they're gonna be giving off a
• 20:53
  Speaker 1: lot of radio waves, So you expect sort of just
• 20:55
  Speaker 1: like a diffuse source of noise out there in the
• 20:58
  Speaker 1: universe in radio waves. But they heard this hiss. That's
• 21:02
  Speaker 1: not The CMB comes at a different wavelength, and it's
• 21:05
  Speaker 1: much much stronger than what you would expect just from
• 21:08
  Speaker 1: like all the galaxies emitting. It's like six times larger
• 21:12
  Speaker 1: than what we can explain. Wait, why can it be
• 21:15
  Speaker 1: the CMB. Well, we know the CMB pretty well. The
• 21:18
  Speaker 1: CMB is what you expect from like a two point
• 21:20
  Speaker 1: seven degree kelvin black body emitter, So we know it's
• 21:23
  Speaker 1: spectrum and we know it's intensity. And this is just
• 21:26
  Speaker 1: much bigger than the CMBs. That's not consistent with what
• 21:29
  Speaker 1: you would expect from the CMB, I see, And it's
• 21:32
  Speaker 1: much bigger than what you would expect from just a
• 21:35
  Speaker 1: general like din of the universe, like the general radio
• 21:38
  Speaker 1: wave background of the universe. Yeah, exactly. And it's the
• 21:42
  Speaker 1: most sensitive instrument in this area. And it also has
• 21:45
  Speaker 1: an absolute calibration, which is the reason we first heard it.
• 21:48
  Speaker 1: Most of the radio balloons and other things listening to
• 21:51
  Speaker 1: this part of the spectrum before would always just do
• 21:53
  Speaker 1: a relative calibration that would like listen to two points
• 21:56
  Speaker 1: and look, for example, at radio from the center of
• 21:59
  Speaker 1: the galaxy relative to just sort of like an average direction.
• 22:02
  Speaker 1: So previous experiments couldn't detect like an overall background noise
• 22:06
  Speaker 1: because they were always like measuring relative to the background noise.
• 22:09
  Speaker 1: This is the first experiment that can actually measure the
• 22:12
  Speaker 1: background noise itself because it has an absolute calibration on it.
• 22:16
  Speaker 1: And so this is the first time we realized that
• 22:18
  Speaker 1: the background noise that Din you were talking about is
• 22:20
  Speaker 1: just much larger than what we can explain. You know,
• 22:23
  Speaker 1: It's like if you walked into a room expecting there
• 22:26
  Speaker 1: to be ten people in there, but instead there's the
• 22:28
  Speaker 1: noise from sixty people. You're like, where's all this noise
• 22:30
  Speaker 1: coming from? Mysterious Yes, something out there in the universe,
• 22:36
  Speaker 1: like this one. They calibrated by I guess shielding it
• 22:39
  Speaker 1: completely or just having like knowing their instruments so much
• 22:42
  Speaker 1: that they know what no radio emissions would sound like
• 22:46
  Speaker 1: this thing they shielded. They cool it down to two
• 22:49
  Speaker 1: point seven degrees kelvin using super fluid liquid helium, which
• 22:54
  Speaker 1: is pretty awesome, and then they also have a device
• 22:56
  Speaker 1: on there which gives out a known signal, so like
• 22:59
  Speaker 1: it has its own little calibrator on it, which they
• 23:01
  Speaker 1: can calibrate absolutely, like they know what they should be
• 23:04
  Speaker 1: hearing from this, So rather than just using the sky
• 23:07
  Speaker 1: to calibrate where you're sensitive to background noise in the sky,
• 23:10
  Speaker 1: they have their own little calibration source. This is like
• 23:13
  Speaker 1: a little add on thing they did to make it
• 23:15
  Speaker 1: more sensitive so they could like calibrate it more precisely.
• 23:18
  Speaker 1: And what they discovered is like, oops, the background from
• 23:20
  Speaker 1: the sky was much bigger than what everybody had thought,
• 23:23
  Speaker 1: and nobody had been sensitive to it before because nobody
• 23:26
  Speaker 1: else had done their own calibration. I see now, is
• 23:29
  Speaker 1: this coming from a particular direction or it's like it's
• 23:31
  Speaker 1: coming from everywhere. It seems to be coming from everywhere, right,
• 23:35
  Speaker 1: It's really weird. It comes from all directions and we
• 23:39
  Speaker 1: don't know yet, like is it coming from our galaxy
• 23:42
  Speaker 1: or is it coming from other galaxies. It's really confusing.
• 23:47
  Speaker 1: If it was coming from other galaxies, to be pretty surprising,
• 23:49
  Speaker 1: wouldn't it, because they're so far away that that signal
• 23:52
  Speaker 1: should be pretty weak by the time it gets here,
• 23:54
  Speaker 1: So it would be a pretty big source at those galaxies.
• 23:57
  Speaker 1: It would be you know, some of those galaxies really
• 24:00
  Speaker 1: pump out radio waves all galaxies put out radio for example,
• 24:03
  Speaker 1: like Andromeda, it puts out ten to the thirty two watts.
• 24:08
  Speaker 1: Like that's just a huge number. It's hard to wrap
• 24:10
  Speaker 1: your mind around. You know, your light bulb was like
• 24:13
  Speaker 1: fifty watts or a hundred wats. Andromeda puts out ten
• 24:16
  Speaker 1: to the thirty two watts, you know, and it's all noise.
• 24:19
  Speaker 1: It's not even like playing good music or anything. But
• 24:22
  Speaker 1: that's actually a fairly quiet galaxy. Some of the galaxies
• 24:25
  Speaker 1: out there, like Signus A, it puts out a million
• 24:29
  Speaker 1: times as much radio energy. So these galaxies, you're right,
• 24:32
  Speaker 1: they're really far away, they're millions of light years away,
• 24:35
  Speaker 1: but they're still very loud in the radio, which just
• 24:38
  Speaker 1: tells you how intense they are. Could those be the
• 24:41
  Speaker 1: source of this space war? Are well, that was the
• 24:43
  Speaker 1: first ideas that people thought, Oh, well, you know, maybe
• 24:46
  Speaker 1: the galaxies are louder than we thought, but we can
• 24:49
  Speaker 1: listen to the individual galaxies. We can tell basically how
• 24:52
  Speaker 1: loud galaxies are. In order to explain it with galaxies,
• 24:55
  Speaker 1: you need to just like add more galaxies because you
• 24:58
  Speaker 1: need this like diffuse emission not just from individual galaxies,
• 25:02
  Speaker 1: but there sort of isn't enough space to add more galaxies.
• 25:05
  Speaker 1: Like if you just said, what if there are a
• 25:06
  Speaker 1: bunch of galaxies out there we didn't know about somehow,
• 25:09
  Speaker 1: then you'd have to like pack them into the universe
• 25:11
  Speaker 1: like sardines. And so you can't really explain this just
• 25:14
  Speaker 1: by like adding more galaxies. M So it can't be galaxies.
• 25:19
  Speaker 1: Could it be something specific, like you know that just
• 25:22
  Speaker 1: happens to be like a like a pulsar aimed at
• 25:24
  Speaker 1: us or something like that, or a quasar. It's coming
• 25:26
  Speaker 1: from all directions, right, So what you need is like
• 25:29
  Speaker 1: a very large population of something, all of which is
• 25:33
  Speaker 1: emitting these sources and emitting sort of like noise to write,
• 25:37
  Speaker 1: like not any frequencies in specific. Yeah, well down here
• 25:40
  Speaker 1: in the radio. But exactly, it's not like a spike.
• 25:42
  Speaker 1: It's not like a very narrow peak. And you know,
• 25:44
  Speaker 1: and maybe we should talk about like why things emit
• 25:47
  Speaker 1: radio because that helps us understand what it is that's
• 25:50
  Speaker 1: generating this sound. All right, Yeah, what makes things emit
• 25:53
  Speaker 1: radio waves? Well, we have a few sort of categories
• 25:56
  Speaker 1: of things that can make radio waves. One is just
• 25:58
  Speaker 1: things being hot. You know, everything in the universe gives
• 26:01
  Speaker 1: off radiation. It's called black body radiation depending on your temperature,
• 26:05
  Speaker 1: and things that are really hot give off higher frequency radiation,
• 26:08
  Speaker 1: you know, for example, like X rays and ultra violet
• 26:11
  Speaker 1: light from really really hot things. Things like the sun
• 26:14
  Speaker 1: give off in the visible spectrum. Things like cool clouds
• 26:18
  Speaker 1: of gas and dust give off in the infrared. But
• 26:21
  Speaker 1: things also emit in the radio. So like big dark
• 26:24
  Speaker 1: dust clouds out there in space that are really pretty cold,
• 26:27
  Speaker 1: they glow in the radio spectrum. That's one source of
• 26:31
  Speaker 1: radio waves. Another source comes from just like magnetic fields,
• 26:35
  Speaker 1: charge particles. When they move to a magnetic field, they
• 26:38
  Speaker 1: get bent, like for example, when the solar wind hits
• 26:41
  Speaker 1: the Earth's magnetic field, you get the Northern lights. Right.
• 26:44
  Speaker 1: The particles are emitting light when they bend, because anything
• 26:48
  Speaker 1: that accelerates, anything that turns in a magnetic field has
• 26:51
  Speaker 1: to give off a photon to do that, and if
• 26:53
  Speaker 1: things have the right speed, then those photons are radio waves.
• 26:57
  Speaker 1: And so if you have charged particles moving through a
• 26:59
  Speaker 1: magnetic field, you're gonna get photons, and sometimes those photons
• 27:03
  Speaker 1: are radio waves. But maybe my favorite stories of radio
• 27:07
  Speaker 1: waves is that it turns out that there are sort
• 27:09
  Speaker 1: of natural molecular lasers out there in space, natural molecular lasers, yeah, exactly.
• 27:15
  Speaker 1: You know, a laser works when you have light passing
• 27:18
  Speaker 1: through a resonant cavity as material in it that can
• 27:20
  Speaker 1: sort of amplify it. And we don't want to go
• 27:22
  Speaker 1: in detail into the physics of lasers, but there are
• 27:25
  Speaker 1: sometimes out there in space these dense pockets of molecular clouds,
• 27:29
  Speaker 1: and if life passes through them at the right frequency,
• 27:32
  Speaker 1: it can become a mazer, which is basically a laser,
• 27:35
  Speaker 1: but in the microwave spectrum. And remember microwaves and radio
• 27:38
  Speaker 1: waves basically the same thing. And so sometimes out that
• 27:41
  Speaker 1: there are these basically radio lasers just sort of naturally occurring. Wow,
• 27:46
  Speaker 1: so there could those be what's causing these space war No,
• 27:49
  Speaker 1: we don't think those things happen often enough to explain
• 27:52
  Speaker 1: the space roar, and there wouldn't be coming in every direction.
• 27:54
  Speaker 1: Those things typically come from like dense clouds inside our
• 27:58
  Speaker 1: Milky Way. But these emissions don't would follow the pattern
• 28:01
  Speaker 1: of the Milky Way, right, Like, they don't lie along
• 28:05
  Speaker 1: the plane of the Milky Way. Remember, the Milky Way
• 28:07
  Speaker 1: is a flat disk, and so if these things were
• 28:10
  Speaker 1: coming from our galaxy from something in our galaxy. You
• 28:13
  Speaker 1: would expect it to be like in the disk of
• 28:15
  Speaker 1: the galaxy, and that when you pointed your intent is
• 28:17
  Speaker 1: away from the galaxy, it would get fainter, but it doesn't.
• 28:21
  Speaker 1: It seems to be in every direction. So either the
• 28:23
  Speaker 1: Milky Way has some like new structure in it that
• 28:27
  Speaker 1: tends to be like a spherical halo around us that's
• 28:30
  Speaker 1: meeting this, or it's coming from somewhere outside the galaxy.
• 28:35
  Speaker 1: Like it doesn't seem to get louder when you sort
• 28:37
  Speaker 1: of listen towards the center of the galaxy. It's like
• 28:40
  Speaker 1: pretty even all around this. It's pretty even in every direction.
• 28:43
  Speaker 1: And that's why they call it this space roar, because
• 28:45
  Speaker 1: it's just like filling space with this sound right right.
• 28:49
  Speaker 1: Trying to make a statement, but to me, it's really
• 28:53
  Speaker 1: exciting because it's like a puzzle. It's like something out
• 28:56
  Speaker 1: there is giving off this radiation and we don't have
• 28:59
  Speaker 1: an explanation for it, and that tells us that it
• 29:01
  Speaker 1: has to be something new, and we're about to learn
• 29:03
  Speaker 1: something new about the universe. Something in the universe has
• 29:07
  Speaker 1: been screaming at us forever and we only recently heard it.
• 29:10
  Speaker 1: And so that to me is exciting because it makes
• 29:12
  Speaker 1: us be creative about what could possibly be out there.
• 29:16
  Speaker 1: Is it's something we're familiar with that screaming in a
• 29:18
  Speaker 1: way we didn't expect, Or is it something totally new
• 29:22
  Speaker 1: out there that's creating this crazy radiation? Right? And I
• 29:25
  Speaker 1: guess they're pretty sure it's not a technical issue, right, Like,
• 29:28
  Speaker 1: they've calibrated this pretty good. They have calibrated this pretty good. Exactly.
• 29:32
  Speaker 1: They were really surprised to see this, and so they
• 29:34
  Speaker 1: spent a long time. This is not like an aha
• 29:36
  Speaker 1: moment one evening. You know, they did this flight in
• 29:38
  Speaker 1: over the last several days, but they spent months and
• 29:41
  Speaker 1: months and months analyzing this data, removing background noises, removing
• 29:46
  Speaker 1: other background noises, checking for sources of mistakes and uncertainty,
• 29:50
  Speaker 1: and calibration and cross checking and redouble cross checking, because
• 29:54
  Speaker 1: you know, it takes a lot of guts to publish
• 29:56
  Speaker 1: a paper like this to say there's something we don't
• 29:58
  Speaker 1: understand in our ata. Your fear at night when you
• 30:01
  Speaker 1: wake up in the the middle night you're like, wait a second,
• 30:03
  Speaker 1: did I remember to check for this thing? Is that
• 30:05
  Speaker 1: you overlooked something simple that you're making a mistake. It's exciting,
• 30:09
  Speaker 1: right to say we found something new we don't understand,
• 30:11
  Speaker 1: but it's also a little terrifying. So they definitely crossed
• 30:15
  Speaker 1: their tea s and dot of their eyes. These are
• 30:17
  Speaker 1: very careful folks, especially this one, because the discovery is
• 30:20
  Speaker 1: not very specific, right. I mean they're basically saying, hey,
• 30:22
  Speaker 1: we're getting a lot more noise in our instrument than
• 30:25
  Speaker 1: we think we should, which normally just means that you
• 30:27
  Speaker 1: you're not doing it all right, right, But here they're
• 30:30
  Speaker 1: saying that this could be something new in the universe. Yeah,
• 30:33
  Speaker 1: they're pretty sure this is actual signal from space and
• 30:36
  Speaker 1: not just an artifact of their instrument. And you know,
• 30:39
  Speaker 1: this is a very carefully engineered instrument, like they are
• 30:42
  Speaker 1: flying liquid helium up in a balloon, like they spent
• 30:45
  Speaker 1: a lot of time designing this thing. I read the
• 30:47
  Speaker 1: design paper and it's very detailed. These folks definitely did
• 30:50
  Speaker 1: their homework, and so I certainly believe that this is
• 30:54
  Speaker 1: a signal from space, which now lets us wonder about
• 30:56
  Speaker 1: you know, what is it? You know, another aspect of
• 30:58
  Speaker 1: writing a paper like this when you see a new
• 31:01
  Speaker 1: signal from space, because you're sort of putting it out there,
• 31:03
  Speaker 1: and you're not naming the source of it. You'd love
• 31:06
  Speaker 1: to see a new signal from space and at the
• 31:09
  Speaker 1: same time explain it because you're like, wow, look a
• 31:11
  Speaker 1: new signal and we discovered something. To here's the explanation.
• 31:15
  Speaker 1: That would be like a complete scientific story. Instead, you
• 31:17
  Speaker 1: just sort of published the experiment and then go, I
• 31:19
  Speaker 1: don't know, and then everybody gets to play with it.
• 31:22
  Speaker 1: But it sort of opens the door for somebody else
• 31:24
  Speaker 1: to come in and explain your discovery, right right, Yeah,
• 31:28
  Speaker 1: it's very open and collaborative. That's pretty cool. Alright, So
• 31:32
  Speaker 1: it can be other galaxies because there aren't enough galaxies
• 31:35
  Speaker 1: to make up this background roar, and it's it's probably
• 31:38
  Speaker 1: not a magnetic field or the cosmic microwave background radiation.
• 31:43
  Speaker 1: So the question is what could it be. Let's talk
• 31:45
  Speaker 1: about that, But first let's take a quick break. All right,
• 32:00
  Speaker 1: we're talking about the space roar or rower otherwise known
• 32:05
  Speaker 1: as the cosmic radio background always kind of yeah, part
• 32:10
  Speaker 1: of it exactly. Yeah, yeah, So we tacked off a
• 32:12
  Speaker 1: couple of things that it can't be can be galaxies,
• 32:15
  Speaker 1: it can't be magnetic fields potentially, so what could it be?
• 32:18
  Speaker 1: Daniel Well as usual, we have a spectrum of possibilities
• 32:21
  Speaker 1: ranging from like pretty boring to totally bonkers slash exciting.
• 32:26
  Speaker 1: I'm gonna guess we're gonna start with the boring and
• 32:28
  Speaker 1: build up to the bonkers one. Absolutely, so sort of
• 32:32
  Speaker 1: the most boring explanation is that maybe there are just
• 32:35
  Speaker 1: more magnetic fields than we thought. Remember, when charge particles
• 32:39
  Speaker 1: fly to magnetic fields, they bend, and bending means acceleration,
• 32:43
  Speaker 1: and when any charged particle accelerates, it has to give
• 32:45
  Speaker 1: off a photon. That's just basic conservation of momentum. You
• 32:49
  Speaker 1: can't move in one direction without pushing something else off
• 32:51
  Speaker 1: the other direction, and that's usually a photon. So if
• 32:54
  Speaker 1: magnetic fields out there are stronger than we thought they were,
• 32:58
  Speaker 1: then there's gonna be more of this kind of radiation
• 33:00
  Speaker 1: from charged particles then we thought. And if they're sort
• 33:03
  Speaker 1: of everywhere, then charged particles everywhere are going to be
• 33:06
  Speaker 1: basically roaring at us. And remember, we did an episode
• 33:09
  Speaker 1: about whether or not space itself is magnetized, because we've
• 33:14
  Speaker 1: been discovering as we've been trying to measure magnetic fields
• 33:17
  Speaker 1: through the universe, that magnetic fields are kind of everywhere,
• 33:20
  Speaker 1: Like there's definitely one from the Earth and the Sun
• 33:23
  Speaker 1: and Jupiter, and even our galaxy has a magnetic field.
• 33:26
  Speaker 1: But recently we discovered that there are magnetic fields between
• 33:29
  Speaker 1: galaxies and between galaxy clusters, and there might even be
• 33:33
  Speaker 1: magnetic fields out there in the huge voids where there's
• 33:36
  Speaker 1: just nothing. So it might just be that space has
• 33:40
  Speaker 1: more magnets than we thought, which leads to more particles
• 33:43
  Speaker 1: of roaring at us. Right, Maybe the universe it's just
• 33:45
  Speaker 1: more attractive than we thought. Yeah, it has a certain
• 33:49
  Speaker 1: glow to it, basically, right, Yeah, exactly more active than
• 33:52
  Speaker 1: we thought, you know, and it's more magnetic. There's more
• 33:54
  Speaker 1: things that you can't really quite see that are happening
• 33:57
  Speaker 1: in there. And you know, you need to and redients
• 34:00
  Speaker 1: to make a roar from magnetic fields. You need the
• 34:02
  Speaker 1: magnetic field, and then you also need the particles. And
• 34:05
  Speaker 1: as you were saying, space is not empty, right, There
• 34:07
  Speaker 1: particles everywhere, even between galaxies. In fact, like something like
• 34:12
  Speaker 1: half of the stuff in the universe is the intergalactic plasma,
• 34:15
  Speaker 1: this stuff between galaxies. So there are a lot of
• 34:19
  Speaker 1: particles out there flying through these magnetic fields, and if
• 34:21
  Speaker 1: they are larger than we expect, that could be the
• 34:24
  Speaker 1: source of the space roar, right, but do we know
• 34:26
  Speaker 1: what's causing these magnetic fields or what would cause the
• 34:29
  Speaker 1: magnetic fields to be that's wrong for it to generate
• 34:32
  Speaker 1: this roar. We definitely do not know the source of
• 34:34
  Speaker 1: these magnetic fields, which is sort of like awesome and crazy.
• 34:38
  Speaker 1: That's something that's basic as like the magnetic field of
• 34:40
  Speaker 1: the universe can't be explained. People are talking about like
• 34:43
  Speaker 1: weird unknown mechanisms inside galaxies or between galaxies. But my
• 34:48
  Speaker 1: favorite possible explanation for what's causing these magnetic fields is
• 34:52
  Speaker 1: that maybe they are primordial, maybe they date from the
• 34:55
  Speaker 1: origin of the universe itself. That when the universe was created,
• 34:59
  Speaker 1: some energy just sort of like slipped into a magnetic
• 35:02
  Speaker 1: field and then got stuck there. So it's like leftover
• 35:05
  Speaker 1: energy from the Big Bang captured in the magnetic field
• 35:09
  Speaker 1: still around. I see it's in the DNA of the universe. Yeah,
• 35:13
  Speaker 1: it could be. It could be. People have forever assumed
• 35:16
  Speaker 1: the default configuration should be like no magnetic field, no stuff,
• 35:20
  Speaker 1: no moving charges, no magnets, no magnetic field. But it
• 35:23
  Speaker 1: might just be that the baseline situation for the universe
• 35:26
  Speaker 1: is to have magnetic fields in it. So if you
• 35:29
  Speaker 1: find that stuffing interesting, check out our whole episode about
• 35:32
  Speaker 1: is space magnetized? All right, And that's a vanilla explanation
• 35:38
  Speaker 1: that some other universe is inherently magnetic to a super
• 35:42
  Speaker 1: high degree than we thought was possible. What's our next possibility?
• 35:45
  Speaker 1: Next possibility is stuff happening. You know, we talked about
• 35:49
  Speaker 1: that's a technical term, stuff happening. Isn't that just the
• 35:54
  Speaker 1: column definition of physics. Physics stuff happens. Yeah, but in
• 35:58
  Speaker 1: this case it'd be exciting stuff of happen physics, Exciting
• 36:02
  Speaker 1: stuff happens. Yes, it's exciting. Stuff is happening out there
• 36:05
  Speaker 1: in the universe. And in this case it might be
• 36:07
  Speaker 1: galaxies dancing around each other and eventually merging. You know,
• 36:11
  Speaker 1: these galaxies are sources of radio because their black holes
• 36:15
  Speaker 1: and because the big clouds of gas and dust that
• 36:17
  Speaker 1: are in them. And it might be that when galaxies
• 36:20
  Speaker 1: merge that that merging forms some turbulence, and that turbulence
• 36:25
  Speaker 1: sort of like gets these clouds of gas and dust
• 36:28
  Speaker 1: to emit in the radio waves louder than they otherwise would.
• 36:31
  Speaker 1: And so it could be that there's part of this
• 36:34
  Speaker 1: process of galaxy merging that we don't quite yet understand. Oh,
• 36:38
  Speaker 1: I see, it could be something normal happening, but that
• 36:41
  Speaker 1: when it happens at an extreme level, we just don't
• 36:44
  Speaker 1: have a good model for it. So maybe that's what's
• 36:46
  Speaker 1: generating these waves. Yeah, instead of having more galaxies out there,
• 36:50
  Speaker 1: the same number of galaxies, but have them do something
• 36:53
  Speaker 1: different from what we expected. So maybe there's more of
• 36:56
  Speaker 1: these mergers happening than we thought, where the mergers are
• 36:58
  Speaker 1: more turbulent than we thought, and that's what's giving off
• 37:01
  Speaker 1: this roar. So not new stuff, but old stuff doing
• 37:04
  Speaker 1: new and exciting things, teaching old galaxies and new tricks physics.
• 37:09
  Speaker 1: Stuff happens in any ways, all right, So it could
• 37:13
  Speaker 1: be merging galaxies. Well what else could it be. It
• 37:16
  Speaker 1: could also just be something new out there in the
• 37:18
  Speaker 1: universe that's giving off radio emissions that's not on our
• 37:21
  Speaker 1: list of things we understand. You know. It could be
• 37:24
  Speaker 1: not stars, It could be not the centers of galaxies.
• 37:28
  Speaker 1: It could be you know, not black body emission. It
• 37:30
  Speaker 1: could be some new source of radio emission that we
• 37:34
  Speaker 1: somehow have missed all this time. Yeah, we somehow have missed,
• 37:37
  Speaker 1: and people have even connected it. For example, to our
• 37:40
  Speaker 1: favorite universe mystery, which is dark matter. I hate. It
• 37:44
  Speaker 1: might be that dark matter is out there and that
• 37:47
  Speaker 1: it can annihilate with itself. Remember, dark matter, we know
• 37:51
  Speaker 1: is something massive that's out there, but we don't really
• 37:53
  Speaker 1: know what it's made out of. One hypothesis for dark
• 37:57
  Speaker 1: matter is that it's the really heavy particles that mostly
• 38:00
  Speaker 1: just sit around and do nothing. But it's sort of
• 38:02
  Speaker 1: hard to explain how you get dark matter and how
• 38:05
  Speaker 1: you have the amount of dark matter that we have
• 38:07
  Speaker 1: in the universe if there's no way for dark matter
• 38:09
  Speaker 1: to be created or for it to annihilate itself. So
• 38:12
  Speaker 1: people have thought of this idea that maybe dark matter
• 38:14
  Speaker 1: sometimes bumps into itself and then annihilates, just like particle antiparticle.
• 38:19
  Speaker 1: Maybe there's dark matter anti dark matter, and sometimes it
• 38:23
  Speaker 1: bumps into itself and then turns into for example, normal
• 38:26
  Speaker 1: matter like electrons and positrons. I see. So maybe all
• 38:31
  Speaker 1: this dark matter, because there's a lot of dark matter
• 38:33
  Speaker 1: in the universe, maybe that's what's causing this glow. That's
• 38:35
  Speaker 1: the idea, and that would make sense because dark matter
• 38:38
  Speaker 1: is pretty diffused out there. We're sort of surrounded by
• 38:41
  Speaker 1: it in a halo and in our galaxy. That would
• 38:44
  Speaker 1: sort of make sense. That would make a lot of sense.
• 38:46
  Speaker 1: So in more detail, the mechanism is that these dark
• 38:48
  Speaker 1: matter particles annihilate and then create these electrons and positrons.
• 38:53
  Speaker 1: But because dark matter is heavy, like it's much heavier
• 38:55
  Speaker 1: than electrons or positrons, these particles would be created with
• 38:59
  Speaker 1: sort of a lot of energy. They'd be flying through
• 39:01
  Speaker 1: the universe and when they hit magnetic fields they would
• 39:04
  Speaker 1: bend and then they would give off some radio waves.
• 39:06
  Speaker 1: And so it could be as you say that this
• 39:09
  Speaker 1: is sort of a signal of a lot of dark
• 39:11
  Speaker 1: matter surrounding the galaxy and giving off these electrons and
• 39:15
  Speaker 1: positrons which then roar at us. Dark matter we know
• 39:19
  Speaker 1: there's five times as much of it as normal matter,
• 39:21
  Speaker 1: and as you say, it's not spread through the galaxy
• 39:24
  Speaker 1: in the same way the normal matter is. It tends
• 39:26
  Speaker 1: to make up this big halo it surrounds everything, and
• 39:29
  Speaker 1: it's fluffy and diffuse, it's not as clumped, and so
• 39:32
  Speaker 1: that would be a good explanation. Wow, So basically dark
• 39:35
  Speaker 1: matter would not be dark, that's what you're saying. You
• 39:37
  Speaker 1: would have to rename it, or would you continue with
• 39:40
  Speaker 1: this incorrect name. It would still be darker, it just
• 39:42
  Speaker 1: wouldn't be quiet, right, to be like screaming matter. See
• 39:45
  Speaker 1: now you're mixing the metaphors there, Daniel. It's giving up light,
• 39:49
  Speaker 1: but you're saying it's not quiet. It's so much fun
• 39:53
  Speaker 1: to mix your metaphors and put silly names on things.
• 39:56
  Speaker 1: I see why astronomers are tempted. I see you just
• 39:59
  Speaker 1: threw them under the bus again. No, and now I'm
• 40:02
  Speaker 1: joining them. I'm saying, you know what, I get it
• 40:04
  Speaker 1: all right. So it could be dark matter. That would
• 40:06
  Speaker 1: be pretty exciting and pretty far out there. But it
• 40:09
  Speaker 1: gets been wilder, it gets even wilder. I was reading
• 40:12
  Speaker 1: some sort of bonkers ideas that there could be alternate
• 40:15
  Speaker 1: universes out there, right. This is like the multiverse theory,
• 40:18
  Speaker 1: the idea that our universe is not the only universe
• 40:21
  Speaker 1: as out there, there are other universes out there, and
• 40:24
  Speaker 1: that these universe sort of echo with ours, and there
• 40:27
  Speaker 1: are even ways for our universe to communicate with those universes,
• 40:30
  Speaker 1: for like radiation to slip from our universe to their universe.
• 40:34
  Speaker 1: And there's this crazy idea, this fredkin Wolf fram automaton,
• 40:39
  Speaker 1: which spreads across multiple universes that like lives in more
• 40:42
  Speaker 1: than one universe and gives off radio signals, and so
• 40:46
  Speaker 1: the idea is like, maybe this could be evidence of
• 40:49
  Speaker 1: other universes. WHOA, yeah, like you're seeing like the shadow
• 40:53
  Speaker 1: or the glow of other universes that are sort of
• 40:56
  Speaker 1: on top of ours, right, yeah, exactly, And I don't
• 40:59
  Speaker 1: want to be too click baby, Like this is total
• 41:01
  Speaker 1: speculation and it's not a prediction. Like if this is
• 41:04
  Speaker 1: an idea that had been invented before we heard it,
• 41:06
  Speaker 1: and somebody said, I think there are multiverses out there,
• 41:09
  Speaker 1: and you can prove it if you hear this particular thing,
• 41:12
  Speaker 1: go out and look for it, and then we found it.
• 41:14
  Speaker 1: That would be convincing. But you know, once you see
• 41:16
  Speaker 1: it and you don't know how to explain it, and
• 41:18
  Speaker 1: then later you cook up a crazy multiverse explanation for it,
• 41:22
  Speaker 1: it's sort of less convincing as an explanation. It's always
• 41:24
  Speaker 1: more impressive to predict something than to postdict something. Right,
• 41:29
  Speaker 1: But isn't that technically the same thing, Daniel. It's like
• 41:32
  Speaker 1: it just depends on the order in which you do it,
• 41:34
  Speaker 1: but it's still the same sort of connection, right, I
• 41:36
  Speaker 1: don't know I think the order sort of matters, Like
• 41:38
  Speaker 1: you know, naming lottery numbers after they've picked the lotteries
• 41:41
  Speaker 1: a lot easier than before. Right, it's sort of the
• 41:44
  Speaker 1: same deal like telling the past. It's a lot easier
• 41:47
  Speaker 1: than telling the future. So I think order matters. Yeah, right, right,
• 41:51
  Speaker 1: But I guess what I mean is that they could
• 41:52
  Speaker 1: still be right. Just because they came up with it afterwards.
• 41:55
  Speaker 1: Doesn't mean that they're wrong. Absolutely. They could still be right, absolutely,
• 41:58
  Speaker 1: But it's not really like is for their theory. You know,
• 42:01
  Speaker 1: it's not that hard to come up with a theory
• 42:03
  Speaker 1: that describes what you see. What's hard is to come
• 42:05
  Speaker 1: up with a simple theory that explains what you see,
• 42:08
  Speaker 1: which means it's capable of making predictions. That's what science
• 42:11
  Speaker 1: is about, and it's predicting the future, not just describing
• 42:14
  Speaker 1: the past. So you're right, we can't rule out this idea.
• 42:17
  Speaker 1: The only way to rule it out as to do
• 42:18
  Speaker 1: future experiments to compare against their predictions. So it could
• 42:21
  Speaker 1: totally be that we live in a multiverse and that
• 42:23
  Speaker 1: the space war is you know, a sound from these
• 42:26
  Speaker 1: other universes or radio emissions from these common overlapping elements
• 42:30
  Speaker 1: of our universes could totally be but you know, I
• 42:33
  Speaker 1: don't oversell it right, right, I wonder if it could
• 42:36
  Speaker 1: it be something more mundane, like could it just be
• 42:38
  Speaker 1: I don't know, like radaways coming from our technology, Like
• 42:42
  Speaker 1: could it be just human noise? Or I guess you
• 42:44
  Speaker 1: would hear it only coming from Earth. Yeah, exactly, it's
• 42:46
  Speaker 1: not connected to the Earth, right. It seems to be
• 42:49
  Speaker 1: coming from every direction and it's independent of the orientation
• 42:53
  Speaker 1: of the Earth. And also one of the reasons they
• 42:55
  Speaker 1: launched this thing on a balloon was just sort of
• 42:57
  Speaker 1: trying to get away from earth bound sources of noise.
• 43:00
  Speaker 1: You know, the Earth is very loud in their radio
• 43:03
  Speaker 1: these days because there's so many cell phones and radio
• 43:06
  Speaker 1: emitters are basically everywhere. A good place to do radio
• 43:09
  Speaker 1: astronomy is like on the dark side of the Moon
• 43:12
  Speaker 1: because it's shielded from the Earth, but it's kind of
• 43:14
  Speaker 1: hard to get there. So launching a balloon into space
• 43:17
  Speaker 1: is a good way to sort of insulate yourself away
• 43:19
  Speaker 1: from a lot of sources of earthbound noise. Well, I
• 43:22
  Speaker 1: think I got a Daniel, what is it? I think
• 43:24
  Speaker 1: it's cell phone signals from aliens. Like we just happened
• 43:27
  Speaker 1: to be in the middle of a couple of you know,
• 43:30
  Speaker 1: intergalactic alien cell phone towers, and that that's what we're
• 43:33
  Speaker 1: listening to. I can't believe nobody else has suggested that idea, Right,
• 43:38
  Speaker 1: it's obvious, and I came up with it before getting
• 43:41
  Speaker 1: in my hands into the data, so technically accounts. Well,
• 43:44
  Speaker 1: then the question is, why are these aliens roaring at
• 43:47
  Speaker 1: each other? Like what's going on? Can't you guys just
• 43:49
  Speaker 1: calm it down? You know, what's the cosmic equivalent of
• 43:52
  Speaker 1: like knocking on your ceiling with the broomstick. Well, they're
• 43:56
  Speaker 1: just talking on the phone, exchinging emojis and and memes,
• 43:59
  Speaker 1: and you know, we just don't know how to decode it.
• 44:01
  Speaker 1: That's all. Well, we're busy here trying to listen to
• 44:03
  Speaker 1: the origins the universe and understand, you know, the heating
• 44:06
  Speaker 1: of the first stars, and they're just like chatting with
• 44:08
  Speaker 1: each other and we can't make out these cosmic signals. Yeah. Yeah,
• 44:12
  Speaker 1: Well that's what life is all about, learning to live
• 44:15
  Speaker 1: with your neighbors, your fellow sentien beaks. All right, So
• 44:19
  Speaker 1: it's a big mystery in astronomy and physics. There's this
• 44:23
  Speaker 1: big roar. So it's still a mystery. And so what
• 44:26
  Speaker 1: are people doing about it than you? Well, of course
• 44:27
  Speaker 1: they are proposing new projects, spend more money to gather
• 44:31
  Speaker 1: more data. There's this plan for a new version of
• 44:33
  Speaker 1: the Arcade experiment that's gonna be much bigger. It's gonna
• 44:36
  Speaker 1: have five hundred gallons of liquid helium, which is going
• 44:39
  Speaker 1: to allow it to be even colder and say more sensitive,
• 44:43
  Speaker 1: like more data. Maybe we can look for some variations.
• 44:46
  Speaker 1: Maybe we can see if it's a little bit stronger
• 44:48
  Speaker 1: in one part of the sky than somewhere else. So
• 44:50
  Speaker 1: that's one possibility that we could just sort of like
• 44:52
  Speaker 1: get more resolution on the problem that might give us
• 44:55
  Speaker 1: a clue. We also have ground based instruments, and now
• 44:58
  Speaker 1: that Arisibo is in the past, unfortunately, that's the most
• 45:01
  Speaker 1: powerful radio telescope in the world is in Green Bank,
• 45:05
  Speaker 1: West Virginia, which is the beautiful instrument. You should google
• 45:07
  Speaker 1: it and check this thing out and you can make
• 45:09
  Speaker 1: very precise maps of the skies and these radio frequencies.
• 45:12
  Speaker 1: Again to look for patterns, right, because even the costing
• 45:15
  Speaker 1: microwave background has patterns to it, right, and those patterns
• 45:19
  Speaker 1: are important. There's a huge amount of information encoded in
• 45:23
  Speaker 1: those patterns. So we're just the very beginning of understanding
• 45:26
  Speaker 1: this other map of the sky and what's in it
• 45:28
  Speaker 1: and what it means. Cool alright, So maybe expect more
• 45:31
  Speaker 1: in the coming years. But in the near future it's
• 45:34
  Speaker 1: going to be a big mystery. We are bathed in mystery.
• 45:37
  Speaker 1: There's a huge source of rad of waves that is
• 45:40
  Speaker 1: coming from all over space, and we don't know what
• 45:42
  Speaker 1: it is. Yeah, we won't know for a little while
• 45:44
  Speaker 1: until we hear more rare in the meantime, Universe, we
• 45:47
  Speaker 1: hear you, We hear you roaring, We respect you, we
• 45:51
  Speaker 1: get it. May chill out a little bit, exactly. We're
• 45:54
  Speaker 1: doing our best to figure out what you're roaring is
• 45:56
  Speaker 1: all about. Maybe it's the universe hitting the brewstick and
• 45:59
  Speaker 1: we're seeling at us because we're being too noisy exactly.
• 46:02
  Speaker 1: Maybe we should learn to shut up too many podcasts.
• 46:04
  Speaker 1: And on that note, thanks for listening to this one,
• 46:07
  Speaker 1: Thanks for joining us, See you next time. Thanks for listening,
• 46:17
  Speaker 1: and remember that Daniel and Jorge explained. The Universe is
• 46:20
  Speaker 1: a production of I Heart Radio. For more podcast from
• 46:23
  Speaker 1: my Heart Radio, visit the i Heart Radio app, Apple
• 46:27
  Speaker 1: Podcasts or wherever you listen to your favorite shows,