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What are fermi bubbles? · Daniel and Kelly’s Extraordinary Universe

0:08
Speaker 1: If I told you that today we're talking about bubbles,
0:11
Speaker 1: what comes to mind? I'm thinking of bathtime. Are you
0:15
Speaker 1: in the bath as we're recording this. I'm just worried.
0:17
Speaker 1: I listened to the Higgs boson. I think that rubber
0:20
Speaker 1: duck ees might destroy the universe. All right, well, I
0:24
Speaker 1: want you to think bigger than just your bathtube. Okay,
0:27
Speaker 1: like those hula hoop bubbles that you make with your
0:30
Speaker 1: kids in this classic bath that's the right direction. But
0:34
Speaker 1: go bigger, bigger than that. Then you've got to be
0:37
Speaker 1: talking about like our atmosphere or something as a huge
0:40
Speaker 1: bubble around the whole ward, even bigger. Can a bubble
0:44
Speaker 1: be that pig? Can you even think about a bubble
0:48
Speaker 1: that big? Or is it gonna blow your mind? Hi?
1:06
Speaker 1: This is Daniel. I'm a particle physicist and the co
1:09
Speaker 1: author of the book We Have No Idea, A Guide
1:12
Speaker 1: the Unknown Universe. My other co host and co author
1:16
Speaker 1: is Jorge cham, a cartoonist and a friend of mine.
1:19
Speaker 1: Jorge is not here today, so we have a guest host,
1:22
Speaker 1: Professor Matt Georgianni of the University of Maryland. Say Hi
1:26
Speaker 1: to everybody. Matt, Hello, everybody. Yeah, I'm Matt Georgiohnny, And
1:29
Speaker 1: I'm a biologist, so I don't know anything about physics
1:33
Speaker 1: unless it makes animals. Biology is basically just big physics, though,
1:38
Speaker 1: isn't it It is? I mean, it's biologist what physicists
1:41
Speaker 1: which they could study to lay the gauntlet down. Now, Wow,
1:47
Speaker 1: I thought you were admitting that biology is nothing but
1:50
Speaker 1: an emergent phenomenon of physics. But now it seems you're
1:53
Speaker 1: trying to turn the tables on me. It won't be
1:55
Speaker 1: the first time, So tell everybody a little bit about yourself, Matt.
1:58
Speaker 1: Why are you a biologist? What do you study? What
2:00
Speaker 1: do you find fascinating? I loved mathematics early on, in
2:04
Speaker 1: in high school and in college, but I got really taken.
2:08
Speaker 1: Loved is in past tense. I loved, I still love,
2:11
Speaker 1: But I got really taken with evolution. And I loved
2:14
Speaker 1: how big, you know, animals evolved into different shapes and beings,
2:19
Speaker 1: and how all of life on Earth came to be.
2:21
Speaker 1: And I just find it utterly fascinating. You mean the
2:24
Speaker 1: theory of evolution, right, the theory of evolution, yes, but
2:28
Speaker 1: what a wonderful theory right up there with the theory
2:31
Speaker 1: of gravity. Two of my favorite theory. Oh snap, snap,
2:34
Speaker 1: all right, I will I'll take that blow touchet. So
2:37
Speaker 1: do you study evolution in your research? I do. I
2:40
Speaker 1: study rattlesnake venom actually, and how that has evolved across
2:45
Speaker 1: different types of snakes. Wow? So how many years until
2:49
Speaker 1: humans evolve venom that we can squirt out of our teeth? Man?
2:52
Speaker 1: I am keep waiting. Every day I check my teeth
2:54
Speaker 1: and I haven't done it yet. What do you mean waiting?
2:56
Speaker 1: If anybody's going to develop that technology, it's going to
2:59
Speaker 1: be you. We are waiting for you to develop it. Matt. Well,
3:03
Speaker 1: I'm working on it. I'll get there. Have you tried
3:05
Speaker 1: getting bitten by a radioactive rattlesnake? I feel like now
3:09
Speaker 1: this is why I called you. Now I can finally
3:12
Speaker 1: complete my research. Al Right, Well, I want authorship or
3:15
Speaker 1: at least acknowledgement on the paper where you announced that.
3:18
Speaker 1: Give me my first bite? How about that? That's a deal.
3:21
Speaker 1: That's a deal. All right? Well, welcome you are our
3:23
Speaker 1: co host today our guest host on the podcast Daniel
3:26
Speaker 1: and Jorge explain the Universe featuring Today Matt Georgianni. So
3:30
Speaker 1: I guess it's Daniel and Matt explained Daniel and Jorges
3:33
Speaker 1: universe or I'm not sure what the temporary name should be,
3:37
Speaker 1: or maybe I can just work up what you guys explain.
3:40
Speaker 1: That's right. Daniel tries to explain the universe and Matt
3:42
Speaker 1: confuses everybody. That's right. And our podcast is a production
3:46
Speaker 1: of I Heart Radio. Today we're gonna be talking about
3:49
Speaker 1: all those amazing things that you do go into science
3:51
Speaker 1: to discover. You went into science to talk to discover
3:54
Speaker 1: evolution and unravel the secrets of the history of life.
3:56
Speaker 1: And I went into physics to reveal a deeper truth
3:59
Speaker 1: about the nature of the universe. And as always when
4:02
Speaker 1: you jump into something scientific, you never know what you're
4:05
Speaker 1: going to discover. And today's episode is going to be
4:07
Speaker 1: all about that, about unexpected discoveries. What's the most interesting
4:11
Speaker 1: or famous unexpected discovery in biology or in rattlesnake venom.
4:16
Speaker 1: I can only say that one of the things about
4:17
Speaker 1: biology is that we as we keep discovering things, we
4:21
Speaker 1: the conclusion is always that everything is way more complicated
4:25
Speaker 1: than we ever thought it was. Oh, I see, so
4:27
Speaker 1: we're like, hey, we evolved from primates. There must be
4:30
Speaker 1: a straight, dotted line between us and some common ancestor
4:33
Speaker 1: of chimps, and then we dig up a bunch of
4:35
Speaker 1: fossils and they don't make a nice dotted line. I
4:38
Speaker 1: think human evolution is one of these great cases where
4:41
Speaker 1: we did kind of think maybe there would be a
4:43
Speaker 1: sort of simple line, and all we keep learning is
4:46
Speaker 1: that populations of early humans and different hominids were intermingling
4:51
Speaker 1: and mixing, and that the modern human that we that
4:54
Speaker 1: what we envision is actually this really complex mixture of
4:58
Speaker 1: a bunch of different populations of humans and early humans
5:02
Speaker 1: and we're just way more complex than we ever thought
5:05
Speaker 1: we were. And do you think that's like a really
5:08
Speaker 1: fun moment when you're, you know, digging up a skeleton
5:11
Speaker 1: that doesn't look anything like the one you expected to find,
5:14
Speaker 1: because that opens the doors to crazy new ideas. Or
5:17
Speaker 1: do you think it's like frustrating. We're like, look, I
5:19
Speaker 1: just got to graduate, I want to write this paper,
5:21
Speaker 1: and now this data doesn't make any sense to me.
5:24
Speaker 1: I think it it's a little of both. I think
5:26
Speaker 1: the first time you realize it's not the answer you expected,
5:29
Speaker 1: you think, oh great, I was really hoping I could
5:32
Speaker 1: wrap this up, and then your mind starts to click
5:35
Speaker 1: and you start to think of all the other new
5:37
Speaker 1: questions you suddenly have, and then all of a sudden,
5:39
Speaker 1: the world just becomes that much bigger. And that's that's
5:42
Speaker 1: really a fun moment. Yeah, And I think there's an
5:44
Speaker 1: analogy there. I think like the progress of science in
5:46
Speaker 1: general is something like the weird, complicated mess of human evolution.
5:51
Speaker 1: You know, we make progress in this direction, and we
5:53
Speaker 1: got to back up and go this other way, and
5:54
Speaker 1: then we stumble across this thing, and then the end
5:57
Speaker 1: we draw some conclusions based on this big mess combination
6:01
Speaker 1: of ideas, this population of discoveries. Yeah. And so today
6:04
Speaker 1: on the podcast, we'll be talking about an amazing discovery
6:08
Speaker 1: that was made very recently, within the last ten years, uh,
6:11
Speaker 1: something which totally changes what we know about the very
6:14
Speaker 1: galaxy we live in. I love that physics is still
6:16
Speaker 1: discovering things. You thought physics was used up like a
6:19
Speaker 1: hundred years ago, But I thought that Einstein and Newton
6:22
Speaker 1: had figured it all out. No, No, not at all.
6:27
Speaker 1: So today on the podcast, we'll be answering the question
6:34
Speaker 1: what are the FIRMI bubbles? When we're talking about bubbles,
6:38
Speaker 1: we're not talking about Matt having a soapy bath, or
6:41
Speaker 1: making Hulaho bubbles, or even the bubble of our atmosphere.
6:45
Speaker 1: We're talking about something on an enormous scale, something basically
6:48
Speaker 1: the size of the galaxy that was only recently discovered,
6:52
Speaker 1: and we talked about recently on a podcast about how
6:54
Speaker 1: stuff at the center of the galaxy is still a
6:57
Speaker 1: huge mystery. Like, we know there's a big black hole there.
7:00
Speaker 1: We have lots of questions about black holes. There's a
7:02
Speaker 1: bunch of stuff swirling around that black hole, and questions
7:05
Speaker 1: about how those black holes were made and all sorts
7:07
Speaker 1: of stuff. It's a big, messy swarm of goop there
7:10
Speaker 1: in the middle of the galaxy. And even Gwyneth Paltrow
7:13
Speaker 1: can't give us any insight. Yeah, yeah, well maybe she's
7:18
Speaker 1: in this Fermi bubbles that we'll see. That's right. And
7:21
Speaker 1: so today we're gonna be talking about an amazing discovery
7:23
Speaker 1: that they made recently. They found these huge blobs of
7:26
Speaker 1: gas they're like basically the size of the galaxy, and
7:29
Speaker 1: they called them the Fermi bubbles. And before we dig
7:32
Speaker 1: into talking about what they are and what they mean
7:34
Speaker 1: and what they might reveal about the nature of our
7:36
Speaker 1: galaxy and the universe in general. I was wondering had
7:40
Speaker 1: anybody heard of this? Because in my field and physics,
7:43
Speaker 1: everybody knows about it because it's a big discovery made
7:45
Speaker 1: pretty recently. Somebody was recently awarded a big prize for it.
7:49
Speaker 1: But I wasn't sure if it had sort of penetrated
7:51
Speaker 1: into the cultural Zeite guys to people who have been
7:54
Speaker 1: talking about this, and so I walked around campus at
7:57
Speaker 1: U C Irvine and I asked people, Hey, have you
7:59
Speaker 1: ever heard of the Fermi bubbles? Do you know what
8:01
Speaker 1: they are? Before you listen to these answers, think to yourself,
8:04
Speaker 1: do you know what the Fermi bubbles are? If I
8:05
Speaker 1: had asked you randomly on the street, what would you
8:08
Speaker 1: have said. This is actually my favorite part of your podcast,
8:10
Speaker 1: when we're asked to just quietly listen, think, think about
8:14
Speaker 1: our own answer. I love it, and I'm never right,
8:17
Speaker 1: so I love It's a good time. All right, Well,
8:20
Speaker 1: listen to these answers and hear what people had to say.
8:23
Speaker 1: Have you ever heard of the Fermi bubbles? No? No, no, no, no,
8:29
Speaker 1: I have not known. I've heard the name, but I
8:31
Speaker 1: the definition escapes me. All right, Matt, what did you
8:35
Speaker 1: think of people's responses. I have to say that I
8:38
Speaker 1: also had not heard of Fermi bubbles and I wasn't
8:40
Speaker 1: really aware of them. I know who for Me is
8:42
Speaker 1: because I was in Chicago, However, I didn't really know
8:45
Speaker 1: what these were. And it seems like the people on
8:47
Speaker 1: her mind did not really know much about him either. No,
8:50
Speaker 1: pretty much nobody had ever heard of them. You hear
8:52
Speaker 1: some clever guesses, right, people like, oh, I think I
8:55
Speaker 1: know who for Me is, or you know, maybe there's
8:58
Speaker 1: some connection to particle physics with the chamber. That was clever,
9:01
Speaker 1: But basically zero percent of these people had ever heard
9:04
Speaker 1: of the Fermi bubbles. And God, that blows me away
9:07
Speaker 1: because we're making these huge discoveries. This is like when
9:10
Speaker 1: we talked about on the podcast about the hexagon on Saturn.
9:14
Speaker 1: You know, everybody has heard of Jupiter's red spot, obvious thing,
9:17
Speaker 1: fascinating mystery, but very few are Almost nobody had heard
9:21
Speaker 1: of the fact that there's a huge hexagon on the
9:23
Speaker 1: top of Saturn. Like, people just don't know that there
9:25
Speaker 1: are these big mysteries out there, these recent discoveries, and
9:29
Speaker 1: so um I hope at least after today people will
9:32
Speaker 1: know a little bit about what the formy bubbles are,
9:34
Speaker 1: why they're such a fascinating discovery. All right, so we'll
9:37
Speaker 1: dig into what the formy bubbles are, but first let's
9:39
Speaker 1: take a quick break, okay, Daniel. So now I've got
9:55
Speaker 1: some questions, right, So what I've done is I've looked
9:57
Speaker 1: at a picture at Google search where Fernie bubbles. Is
10:01
Speaker 1: that how you biologists do research or just type stuff
10:03
Speaker 1: into Google? The world of the answers are pretty much
10:06
Speaker 1: already out there, so I so I'm looking at these
10:09
Speaker 1: Fermi bubbles, and what I'm seeing is this really great
10:12
Speaker 1: picture of our galaxy, the Milky Way galaxy, and I
10:16
Speaker 1: see two big purple bubbles I guess that are extending
10:19
Speaker 1: out from the plane perpendicular to the plane of our
10:23
Speaker 1: hard spinning disk. So I guess I can start with
10:27
Speaker 1: my first questions, which is what am I looking at? Yeah,
10:30
Speaker 1: it's amazing you visualize the galaxy. Most people think of
10:33
Speaker 1: something pretty flat like a disc. It's got these swirling
10:36
Speaker 1: arms of stars and that's correct, right. But in this
10:39
Speaker 1: image that we're looking at, and that I hope that
10:41
Speaker 1: the folks out there have a chance to Google if
10:43
Speaker 1: they're not currently driving, you see these huge balls, these
10:46
Speaker 1: big purple balls. And the most important thing for people
10:48
Speaker 1: to know is these things are basically the same size
10:51
Speaker 1: of the galaxy. There like twenty five thousand light years
10:55
Speaker 1: above and below the galaxy. They're basically the biggest feature
10:59
Speaker 1: of our galaxy, and nobody even knew they existed until
11:03
Speaker 1: ten years ago. Right, the disc becomes this, uh, this
11:06
Speaker 1: little belt that are of all the galaxy has, yeah, exactly,
11:10
Speaker 1: all the planets, all of life, all of the stars
11:12
Speaker 1: are kind of like the feature around the balls. I
11:15
Speaker 1: know exactly. It's like we are the side note to
11:18
Speaker 1: this enormous feature. Right, And for those of you who
11:20
Speaker 1: don't know, the whole galaxy in the Milky Way galaxy
11:23
Speaker 1: is about a hundred thousand light years across, So to
11:26
Speaker 1: have something that's fifty tho light years wide, that's a
11:29
Speaker 1: pretty big feature, right, that's maybe the dominant thing. Um.
11:33
Speaker 1: And so there are these two giant blobs and they're
11:35
Speaker 1: basically circular, also, like they're tight at the at the
11:38
Speaker 1: center of the galaxy and then they sort of expand
11:40
Speaker 1: out and then taper off a little bit. So they
11:42
Speaker 1: look basically like two huge basketballs um one above and
11:46
Speaker 1: one below. The galaxy touching right there at the center
11:49
Speaker 1: of the galaxy, or if I tried my belt really tight,
11:53
Speaker 1: not my waist. Okay, I just got a very disturbing
11:56
Speaker 1: mental image. Let's let's pack that out. And there's very
12:02
Speaker 1: beautiful And there's two of them, right, there's the north
12:04
Speaker 1: one in the south one, and they're about the same size.
12:07
Speaker 1: Right there, there is there's a lot of symmetry here,
12:10
Speaker 1: So let's just start with what are they made of?
12:13
Speaker 1: We don't even know the answer to that question. We
12:15
Speaker 1: think that maybe they're made of some sort of hot gas,
12:19
Speaker 1: which in this case basically means protons. Right, Remember that gas.
12:23
Speaker 1: Most of the gas in the universe is hydrogen, which
12:25
Speaker 1: is a proton and an electron, but a lot of
12:27
Speaker 1: it is hot, which means it's I and I, so
12:29
Speaker 1: the electron has escaped, so basically just protons. So one
12:32
Speaker 1: idea is maybe it's just a huge number of protons.
12:35
Speaker 1: And and the thing to know is, like it would
12:38
Speaker 1: be a huge number of protons. Like if you took
12:40
Speaker 1: all those protons and like use them to build stars,
12:43
Speaker 1: which is something our galaxy is good at, you could
12:45
Speaker 1: make two million stars. Right, This is not a small
12:49
Speaker 1: amount of gas. So one idea is maybe they're protons.
12:53
Speaker 1: The other idea is that maybe they're electrons. Right, maybe
12:55
Speaker 1: they're like really fast moving, zippy electrons. And I think
13:00
Speaker 1: the thing to understand is is what we're looking at.
13:03
Speaker 1: What we're seeing, of course, is light. Right, we have
13:05
Speaker 1: a telescope out in space that can see these things,
13:08
Speaker 1: so we're seeing photons from these objects. Right. You know,
13:12
Speaker 1: when we see like stars that are really far away,
13:14
Speaker 1: we're not seeing the star. We're seeing the life from
13:16
Speaker 1: that star. So things that we only see things that
13:19
Speaker 1: give off light. Right, there could be something out there
13:21
Speaker 1: like a big black rock or a black hole. We
13:24
Speaker 1: wouldn't see it because it's not giving off any photons.
13:26
Speaker 1: So how did we just discover this? Then? I know, right,
13:29
Speaker 1: how did we not see this before? Well, the story
13:32
Speaker 1: is that, you know, we didn't have a telescope that
13:35
Speaker 1: could see these things before. People I think imagine that
13:38
Speaker 1: we've looked out into the universe, that we've basically seen
13:41
Speaker 1: the whole universe. But that's not true, right, We've looked
13:44
Speaker 1: at a very tiny fraction of the universe. Just recently,
13:47
Speaker 1: we had an episode about like how many stars have
13:49
Speaker 1: we seen in the sky? And we talked about how
13:51
Speaker 1: the Hubble, which can see really deep into the universe,
13:54
Speaker 1: has only looked at a tiny patch of the sky.
13:56
Speaker 1: Most of the sky has not even been examined by Hubble,
13:59
Speaker 1: and you could look out there and find this crazy,
14:02
Speaker 1: amazing stuff nobody's ever seen before. There could be huge
14:05
Speaker 1: surprises there. So I think the lesson is like every
14:07
Speaker 1: time we turn on a new astronomical device, we see
14:11
Speaker 1: crazy stuff that we didn't expect because the universe is
14:13
Speaker 1: filled with crazy stuff and we just got open lots
14:16
Speaker 1: of new kinds of eyes. And the key is not
14:18
Speaker 1: that we're it's not that we're not pointing in the
14:20
Speaker 1: right direction. If that we're not looking with the right
14:22
Speaker 1: or we're not using all the wavelengths or something, yeah, exactly.
14:26
Speaker 1: So this this these things are called Fermi bubbles because
14:29
Speaker 1: they were discovered by the Fermi telescope, which is named
14:32
Speaker 1: after Enrico Fermy. So it's a bit of a you know,
14:35
Speaker 1: double misdirection there. People thought Fermi might have discovered these things,
14:38
Speaker 1: but now the telescope named after him discovered it. So
14:41
Speaker 1: I think it's cool he sort of gets credit for
14:43
Speaker 1: stuff he didn't discover, because, like you know, if you
14:47
Speaker 1: become a famous scientist and then they name something after
14:50
Speaker 1: you and then that device is used to discover stuff,
14:52
Speaker 1: you get like secondary credit for it. I think that's
14:54
Speaker 1: pretty cool. But yeah, that telescope was the first one
14:56
Speaker 1: that could see these photons. These are very high energy
14:59
Speaker 1: gam raise like above fifty or a hundred giga electron volts,
15:04
Speaker 1: and we just didn't have a great space telescope that
15:06
Speaker 1: could see these things before. And so essentially the first
15:09
Speaker 1: time they build one of these things, put it in
15:11
Speaker 1: space and then looked out into the universe with it,
15:14
Speaker 1: they spotted these things. It was pretty quick, like it
15:16
Speaker 1: only took a couple of years of data before they
15:18
Speaker 1: noticed these things. So we just hadn't been looking at
15:20
Speaker 1: the right energies before. So there are more of them,
15:23
Speaker 1: Well there's the our galaxy has only these two. Yeah,
15:25
Speaker 1: there's the one, the north one and the South one.
15:28
Speaker 1: And there's a lot of really weird things about them.
15:30
Speaker 1: Like if you look at the picture, you notice there's
15:32
Speaker 1: like a really strong cut off, Like they're not these
15:35
Speaker 1: like amorphous blobs. They're not like, you know, sort of
15:38
Speaker 1: gradually fading out. They're pretty crisp, like the edges are
15:42
Speaker 1: kind of sharp, right, And that's really interesting because they're
15:45
Speaker 1: trying to understand, like what are these things made of,
15:47
Speaker 1: like you were asking, and so either their protons or
15:51
Speaker 1: their electrons or you know, they could always be something
15:53
Speaker 1: totally weird and different. But the thing that's happening is
15:56
Speaker 1: that you know, there's photons out there all over the universe,
15:59
Speaker 1: is caused a gray background and and and other sort
16:02
Speaker 1: of soft photons, and then these really high energy particles,
16:05
Speaker 1: the protons or the electrons in these bubbles. What they
16:08
Speaker 1: do is they basically give those photons a boost, like
16:12
Speaker 1: they interact with those photons, and the photons like get
16:15
Speaker 1: pushed and then they become really high energy gamma rays
16:18
Speaker 1: and they come to Earth. And that's what we're seeing.
16:21
Speaker 1: So we're not literally seeing the gas or the photo
16:24
Speaker 1: or the electrons directly. We're seeing the photons that got
16:27
Speaker 1: boosted by those high energy particles in these bubbles. So
16:30
Speaker 1: it's almost like this little chamber that's everything that comes
16:33
Speaker 1: into its shooting it out or it's a I guess
16:36
Speaker 1: that's the high energy part of it. Yeah, exactly, it's
16:39
Speaker 1: like a little accelerator, right, everything that comes in gets
16:42
Speaker 1: zoomed out and that's what we're seeing. We're seeing that
16:44
Speaker 1: photons in this region of space are getting pushed, are
16:47
Speaker 1: getting boosted up to some really high energy. And that's
16:50
Speaker 1: the mysteries, like what why are these things here, what
16:53
Speaker 1: are they doing, what's causing it? Where do they come from?
16:56
Speaker 1: And do we think it's a cloud of gas or
16:58
Speaker 1: is it like a bubble with a perimeter than a
17:00
Speaker 1: hollow center. Now that's really interesting things that it seems
17:03
Speaker 1: to be sort of smooth. It's not like there's an
17:05
Speaker 1: edge like a bubble right where it. Mostly it's happening
17:08
Speaker 1: on the edge um And it's also not really much
17:10
Speaker 1: more intense closer to the center of the galaxy. We
17:13
Speaker 1: see the same intensity basically all the way across it,
17:16
Speaker 1: which is really hard to explain physically. Like we'll talk
17:19
Speaker 1: later about the possible things that could have made these things,
17:21
Speaker 1: but none of those hypotheses explain what we see because
17:24
Speaker 1: none of them can generate a bubble that's smooth all
17:28
Speaker 1: the way through it. It's really weird. I can't believe
17:30
Speaker 1: you're gonna make me wait for an answer. Okay, Matt,
17:33
Speaker 1: at least you have to listen to the rest of
17:34
Speaker 1: the podcast. You're on the podcast, don't tune out? Should
17:39
Speaker 1: I tell everybody to skip forward ten minutes? Now, let's
17:43
Speaker 1: not do that. This might be one of these moments, right,
17:46
Speaker 1: So when these things were first discovered, can actually what
17:49
Speaker 1: was it like? If it was recent, then what was
17:51
Speaker 1: it like in the physics community. It was a big surprise,
17:54
Speaker 1: right because the Fermi telescope was not launched to find
17:58
Speaker 1: the Fermi bubbles because nobody knew the over there. It's
18:00
Speaker 1: one of these moments when you build a device to
18:02
Speaker 1: look for something and you find something totally different, you know.
18:05
Speaker 1: A famous example is like the cosmic microwave background. These
18:09
Speaker 1: guys built a radio telescope to do radar testing and
18:13
Speaker 1: listen to other stuff from the universe, and they found
18:15
Speaker 1: this weird buzz background that they couldn't explain, and it
18:18
Speaker 1: turned out to be this amazing discovery cosmic marcroway background.
18:22
Speaker 1: We got a podcast schedule for that next week, I think.
18:24
Speaker 1: And this is the kind of thing that happens a lot.
18:26
Speaker 1: You build a new instrument, you look out in the universe.
18:28
Speaker 1: Do you expect to see something? You see something totally different.
18:31
Speaker 1: So this one was designed basically to discover dark matter
18:35
Speaker 1: I mean, it also has other intentions. But in my community,
18:38
Speaker 1: we're most interested in the Fermi telescope because it could
18:40
Speaker 1: see dark matter, and you might wonder, like, how can
18:43
Speaker 1: you see you dark matter? Right? And the idea is
18:46
Speaker 1: that dark matter could bounce into other dark matter and annihilate,
18:50
Speaker 1: and maybe sometimes that would produce photons and you could
18:53
Speaker 1: see those. So this device, the Fermi telescope, it's basically
18:57
Speaker 1: it's like a big particle detector in space. You could
19:00
Speaker 1: see high energy photons. It turns them into electrons and positrons,
19:04
Speaker 1: splits them and then it can measure their energy. And
19:07
Speaker 1: so essentially it's like looking out into space with a
19:10
Speaker 1: very very high energy light. Right. You know, the Hubble,
19:13
Speaker 1: for example, looks at visible light um, but this looks
19:16
Speaker 1: at really really high energy photons. Did they think there
19:19
Speaker 1: would be anything near the center of the galaxy like
19:21
Speaker 1: this above and you know above and below it, Yeah,
19:24
Speaker 1: great question. There was another instrument recently called w MAP,
19:28
Speaker 1: and it's a sort of like a fuzz. They called
19:29
Speaker 1: it the w MAP haze above and below the center
19:32
Speaker 1: of the galaxy, and it was more in the radio waves,
19:35
Speaker 1: and nobody understood what that was either, and so these
19:38
Speaker 1: guys were interested, like, well, let's look at that, but
19:40
Speaker 1: let's also they were looking more specifically at the center
19:43
Speaker 1: of the galaxy to try to understand whether they could
19:45
Speaker 1: see a signal of dark matter from there. And you know,
19:48
Speaker 1: when you do that, you've got to understand the day
19:49
Speaker 1: that you have to say, like, what are we seeing
19:51
Speaker 1: to make sure we understand what we can see so
19:53
Speaker 1: then we can look for the thing we're looking for.
19:55
Speaker 1: It's like, you know, you gotta understand the backgrounds before
19:57
Speaker 1: you can look for your signal. But they couldn't. They
20:00
Speaker 1: were like, what is this you know, yeah, yeah, And
20:04
Speaker 1: it's one of those moments where they're like it's an
20:05
Speaker 1: obstacle because they wanted to answer this other science question.
20:09
Speaker 1: But then potentially that obstacle is a whole new avenue
20:12
Speaker 1: for discovery. And so they released this paper. It was
20:15
Speaker 1: kind of a bombshell. People were like, what are you
20:18
Speaker 1: telling me that the galaxy is a totally different shape
20:20
Speaker 1: than the one we always imagine and always draw, Like
20:23
Speaker 1: this this huge new structure which basically changes the way
20:26
Speaker 1: you should think about the shape of the galaxy. Right,
20:29
Speaker 1: So it was a pretty big deal. Did you find
20:31
Speaker 1: it annoying because you were really hoping to know about
20:33
Speaker 1: dark matter, and now all of a sudden, its that
20:35
Speaker 1: you knew that everyone was going to be focused on
20:37
Speaker 1: these bubbles. Yeah, why can't we just turn those bubbles
20:40
Speaker 1: off so we can get back to the dark matter studies?
20:42
Speaker 1: Somebody get rid of them? Yeah, exactly, No, it's it's um.
20:46
Speaker 1: It's frustrating in that respect. It does obscure the dark
20:49
Speaker 1: matter signal a little bit. But it's also fascinating because
20:53
Speaker 1: every time you see something that you don't understand, something
20:56
Speaker 1: that you don't expect, it's a clue, right, It's a
20:58
Speaker 1: clue that tells you where to look for a new answer,
21:01
Speaker 1: where to find something new, because by definition, if you
21:04
Speaker 1: didn't expect it, it means there's something either a new
21:06
Speaker 1: kind of object out there in the universe or something
21:10
Speaker 1: you knew about doing something weird, right, like, oh, I
21:12
Speaker 1: didn't know that stars could do that, or I didn't
21:14
Speaker 1: know black holes could make this kind of feature. So
21:17
Speaker 1: you're you're guaranteed to learn something new. So presumably this
21:20
Speaker 1: is going to teach us a lot about black holes, presumably, right,
21:23
Speaker 1: since near the center of our galaxy and I knew
21:26
Speaker 1: you were either you were either going to go for
21:28
Speaker 1: black holes or for aliens, right, because most of your
21:31
Speaker 1: go to explanations for weird stuff in space. Hey, well
21:37
Speaker 1: you know aliens is my go to explanation. When we
21:39
Speaker 1: don't understand something, you would always explain it using intelligent life, right. Um. Yeah,
21:44
Speaker 1: so let's talk about that. Let's dig into like what
21:47
Speaker 1: these might be, how we might explain it, what the
21:49
Speaker 1: various ideas are, and why none of them actually work.
21:52
Speaker 1: But let's take another break. Why are they the center
22:07
Speaker 1: of our galaxy? Is that is that important? It's definitely
22:10
Speaker 1: a clue, right. We think that they must have been
22:12
Speaker 1: generated by something at the center because they're touching sort
22:15
Speaker 1: of the disc of the milky way only there at
22:18
Speaker 1: the center. So they must be related to something crazy
22:21
Speaker 1: happening at the center of the galaxy. And remember that
22:24
Speaker 1: the center of our galaxy we have a really big
22:25
Speaker 1: black hole, and so you might think maybe like it's
22:29
Speaker 1: a burp, right, maybe the black hole like ate something
22:32
Speaker 1: really big. And remember when things get sucked into blood, Yeah,
22:37
Speaker 1: it's a galactic black hole. Belch indi indigestion from the
22:41
Speaker 1: black hole. Because remember when black holes eat something, things
22:44
Speaker 1: don't just like trip and fall into the black hole
22:46
Speaker 1: and they're totally gone. They swirl around the black hole
22:49
Speaker 1: because they still have anglar momentum. They get torn up
22:52
Speaker 1: into pieces, and most of it goes in the black hole,
22:54
Speaker 1: but some of it gets flung out, right, it gets
22:56
Speaker 1: shot out from the black hole. And so you see
23:00
Speaker 1: black holes eat something big. Often there's like a big
23:02
Speaker 1: jet of gas or something that gets admitted. So you
23:06
Speaker 1: like to think maybe what's remarkable here too, is that
23:09
Speaker 1: I often think of the sci fi black holes where
23:12
Speaker 1: you're looking at the black hole and the spaceships circling
23:15
Speaker 1: and about to fall into it. And I often think
23:18
Speaker 1: of then, for some reason, black holes as being one sided.
23:21
Speaker 1: But I guess when I see these two bubbles and
23:23
Speaker 1: the symmetry here, it really tells me more that the
23:26
Speaker 1: black hole exists potentially as a disk, I guess, and
23:30
Speaker 1: it's belching out of both ends. Well, remember, black holes
23:33
Speaker 1: are not like like Looney Tunes black holes right where
23:36
Speaker 1: anybody can roll them up and drag them around. They're
23:39
Speaker 1: spoil this for me, all right, you're a biologist, you're
23:43
Speaker 1: allowed to have a totally unreliable, No, black hole is
23:48
Speaker 1: more like a sphere, right, it's a it's not even
23:51
Speaker 1: really a hole. It's a dense blob of stuff, right,
23:53
Speaker 1: So it's more like a really black rock, you know.
23:56
Speaker 1: But you can fall into it from any direction, so
23:59
Speaker 1: you're right, it's it's um not preferring the north or
24:02
Speaker 1: the south side of the galaxy. Either way, it's happy
24:04
Speaker 1: to gobble stuff from either direction. You would expect of
24:06
Speaker 1: the black hole created some sort of feature, it would
24:09
Speaker 1: appear in the north and the south. And in fact,
24:11
Speaker 1: some galaxies do have features, like they have these jets
24:14
Speaker 1: of material that gets shot out exactly in these directions,
24:17
Speaker 1: like one north and one south right from the center
24:20
Speaker 1: of the galaxy. But those look very different. Those are
24:22
Speaker 1: really colimnated. They're long, they're thin, they're about the same size,
24:26
Speaker 1: but they don't look anything like this. And most importantly,
24:29
Speaker 1: they're really intense close to the black hole, and then
24:31
Speaker 1: they sort of spread out and slowed down, which is
24:33
Speaker 1: what you'd expect. But these bubbles they don't look like that. Right,
24:37
Speaker 1: Like we were saying before, they have these crisp edges
24:40
Speaker 1: and they're smooth, they like look the same on the
24:42
Speaker 1: very top of the very farthest part from the center
24:45
Speaker 1: of the galaxy, as they do close to the center
24:47
Speaker 1: of the galaxy and in the middle, So that seems
24:50
Speaker 1: like an important clue about how they were made or
24:52
Speaker 1: what made them. Right, they don't look like they're spewed
24:55
Speaker 1: out from the center in that way. I mean, it
24:57
Speaker 1: really seems like I think the image it also invokes
24:59
Speaker 1: is on huge bubble that's been cinched in the middle,
25:02
Speaker 1: presumably because of it's the spinning of the Milky Way.
25:06
Speaker 1: But I guess that would make you think that the
25:07
Speaker 1: center should be more dense as well. Yeah, yeah, precisely,
25:12
Speaker 1: that would. You would see a density there from the
25:14
Speaker 1: from the cinching, right, So, but we don't know what
25:16
Speaker 1: made it. We don't know. And you know, other galaxies
25:19
Speaker 1: have jets, but the Milky Way doesn't have jets, right,
25:21
Speaker 1: it doesn't have these huge jets. It spewed out, so
25:24
Speaker 1: though maybe it did in the past. Right, we don't
25:26
Speaker 1: really know what the history of the Milky Way is.
25:28
Speaker 1: We can't look back in time at it and understand
25:31
Speaker 1: if it had jets in the past. But this can't
25:33
Speaker 1: really be explained by the same mechanism that creates those
25:36
Speaker 1: galactic jets. And then given our perspective on the arm
25:40
Speaker 1: of the Milky Way. Would we be able to see
25:42
Speaker 1: if a big bubble was shutting out towards us. Are
25:46
Speaker 1: you worried in the same way. I don't know if
25:49
Speaker 1: we're in a bubble or not. When I listened to
25:52
Speaker 1: the news, they tell me I'm in a bubble, but
25:54
Speaker 1: I don't know if that is here. You're you're in
25:57
Speaker 1: a biology bubble. You're a rattlesnake bubble. Um, No, we are.
26:01
Speaker 1: We're in an arm in the Milky Way. So we're
26:02
Speaker 1: not in the middle of one of these bubbles. We
26:04
Speaker 1: are separated from it. So you know, you can take
26:06
Speaker 1: off your tinfoil hat. You do not need protection. I
26:08
Speaker 1: just yeah, but we would be able to tell if
26:10
Speaker 1: it was like so, the bubbles only extend sort of
26:13
Speaker 1: perpendicular to the plane of the desk of the Milky Way. Yes,
26:17
Speaker 1: now that we have this FIRMI telescope, we can see
26:19
Speaker 1: these bubbles. We can see where they are, and we
26:21
Speaker 1: can see where they aren't. And we are not in
26:23
Speaker 1: a bubble. And we can also point this telescope but
26:27
Speaker 1: other galaxies and be like, hold on, if our galaxy
26:29
Speaker 1: has these bubbles, you know, does every galaxy have bubbles UM,
26:33
Speaker 1: And we don't know the answer to that question yet
26:35
Speaker 1: because these bubbles are a little bit tricky to see,
26:38
Speaker 1: Like first of all, you need this telescope and you
26:40
Speaker 1: need a bunch of data because the picture you might
26:42
Speaker 1: see if you Google, that's after like years of data
26:45
Speaker 1: and background subtraction. It's not this kind of thing you
26:47
Speaker 1: can see with the naked eye in five seconds of data.
26:50
Speaker 1: And the and the other galaxies are really far away.
26:53
Speaker 1: So we've pointed it at in drama and we've looked
26:56
Speaker 1: for these bubbles, but we just can't tell if they
26:57
Speaker 1: exist in other galaxies or not. So we just we
27:01
Speaker 1: don't know the answer to that question. In fact, we
27:02
Speaker 1: haven't so we haven't seen any of them or No,
27:06
Speaker 1: there are other galaxies that are much bigger that have
27:08
Speaker 1: really big black holes and they have jets, and some
27:11
Speaker 1: of them have like bubble like features, but they're not
27:14
Speaker 1: the same as these kind of bubbles. They're like lower
27:16
Speaker 1: energy photons and also they're much much bigger UM. So
27:20
Speaker 1: we've never seen a galaxy like this one before UM.
27:23
Speaker 1: But again we don't know if there are other galaxies
27:25
Speaker 1: out there like this one because we only recently discovered
27:28
Speaker 1: the ones that are like around the corner, so the
27:30
Speaker 1: ones that are in another galaxy really far away will
27:32
Speaker 1: be harder at a spot. So that's you know, for
27:34
Speaker 1: future astronomers to discover. Now, are future astronomers looking in
27:39
Speaker 1: one direction or another? Yeah, future astronomers want to look everywhere, right,
27:43
Speaker 1: because the universe is jammed full of crazy stuff. And
27:47
Speaker 1: you know, the next person who's trying to answer this question,
27:49
Speaker 1: are there Fermi bubbles and another galaxy? They're probably gonna
27:52
Speaker 1: find something else weird and crazy and get distracted and
27:55
Speaker 1: never answer that question because they're gonna be studying, you know,
27:57
Speaker 1: the Fermi bicycle or the you know, whatever next crazy
28:01
Speaker 1: thing they find out. There probably more hexagons, but there
28:05
Speaker 1: must certainly be scientists now that are looking for these right,
28:09
Speaker 1: Oh absolutely yeah. Um. They announced this paper and there
28:15
Speaker 1: was some folks at m I t Um, Tracy Slatcher
28:18
Speaker 1: and Dunk Dug finkbiner Um at Harvard and other folks
28:22
Speaker 1: and people have been following up, and people are looking
28:24
Speaker 1: for these things at other galaxies. Um. And people are
28:27
Speaker 1: also spending a lot of time having fun coming up
28:30
Speaker 1: with various ideas to explain it. One of my favorite
28:32
Speaker 1: is this starburst hypothesis. They think that maybe is your
28:39
Speaker 1: mouth watering right now? All right, and we're gonna charge
28:42
Speaker 1: starburst for this plug, right anyways, Uh, the idea is
28:47
Speaker 1: that maybe ten million years ago, the Milky Way went
28:51
Speaker 1: through a period of star formation because a bunch of
28:54
Speaker 1: gas slammed into another bunch of gas. And when gas
28:57
Speaker 1: creates these collisions, you get these density that you get
28:59
Speaker 1: these becaus of density, and that's how stars formed. And
29:03
Speaker 1: maybe when those stars were formed, that kind of event
29:05
Speaker 1: could have also jetted out a bunch of gas in
29:08
Speaker 1: either direction. It could have been these big gas outflows
29:11
Speaker 1: from a big burst of star formation, you know, and
29:14
Speaker 1: that would have happened like ten million years ago. Hold on,
29:18
Speaker 1: you said ten million years ago. Ten million years ago,
29:21
Speaker 1: and remember that's nothing. It's it's like avolution standard that
29:26
Speaker 1: I know. There were things and people crawling around on
29:28
Speaker 1: Earth right at the time that this happened. And remember
29:31
Speaker 1: that there were rattlesnakes biting things. Years ago is recent, yea,
29:38
Speaker 1: even in biological time scale. And remember the galaxy is
29:41
Speaker 1: super old. It's almost as old as the universe. It's
29:44
Speaker 1: thirteen billion years old. So this is a very new feature.
29:47
Speaker 1: And we also don't know how long it's gonna last.
29:49
Speaker 1: Maybe it'll dissipate and in a few million years it
29:52
Speaker 1: will be gone right in our and our could just
29:55
Speaker 1: be a blip. It could just be a blip, right,
29:57
Speaker 1: something we tell our grandkids about, you know, when I
29:59
Speaker 1: was had we had these big bubbles and shut up, grandpa,
30:04
Speaker 1: or one of many blips. This might be a feature
30:07
Speaker 1: that's happened for the entire lifestyle life of the galaxy. Yeah,
30:13
Speaker 1: and um, none of these explanations, like the gas outflows
30:16
Speaker 1: from star formation or the black hole burps or you
30:19
Speaker 1: know anything else, none of them explained this really weird
30:22
Speaker 1: feature that the bubbles are smooth, right, All of those
30:26
Speaker 1: hypotheses predict something more intense close to the center and
30:29
Speaker 1: then sort of fading out. So the real answer is
30:32
Speaker 1: something that nobody's thought of yet. The real answer is
30:34
Speaker 1: something that some future scientists will discover. And you know,
30:38
Speaker 1: it could be something really deep, like there's a new
30:40
Speaker 1: kind of object there and then in the middle of
30:42
Speaker 1: the black hole or in the middle of the galaxy,
30:45
Speaker 1: or it could be like you know, very rarely black
30:48
Speaker 1: holes have indigestion and fared out. These weird bubbles and
30:51
Speaker 1: you know, we just happened to see one, in which case,
30:53
Speaker 1: like how weird and lucky that our galaxy did this,
30:55
Speaker 1: like right now basically, but if these bubbles are smooth,
30:58
Speaker 1: it makes me it makes it hard to believe that
31:00
Speaker 1: there is emitting out almost from this black hole. Is
31:03
Speaker 1: it possible that these bubbles are pulling being pulled into
31:08
Speaker 1: the galaxy from elsewhere? WHOA, that is such a good idea.
31:11
Speaker 1: I'm going to write that down and take credit for it. Good.
31:15
Speaker 1: We expect nothing less. You're so smart. It's like you
31:18
Speaker 1: got bitten by our radioactive rattlesnake or something. I'm beginning
31:22
Speaker 1: to feel it now. No, that's a great question. But
31:25
Speaker 1: then wherever they have come from? Right, Like, maybe if
31:28
Speaker 1: they're sucking up something um from the outside, then they
31:32
Speaker 1: have to be a symmetric source, right, you need something
31:34
Speaker 1: on the north and the south to get to create
31:38
Speaker 1: these bubbles from outside the galaxy. That seems pretty unlikely
31:41
Speaker 1: because they're so symmetrically the same size on both side. Sure, yeah,
31:46
Speaker 1: I don't understand it. I just have to pose the ideas.
31:51
Speaker 1: You are supposed to explain it, all right, Well, on
31:54
Speaker 1: our the biology version of this podcast. I'm gonna expect
31:56
Speaker 1: some answers from you, all right, Well, so this has
31:59
Speaker 1: been very informative, and I have to say, physics, you're
32:03
Speaker 1: doing a good job. But I think, you know, these
32:05
Speaker 1: are kind of amazing. I think it's amazing that we
32:07
Speaker 1: have these new, i mean really young clouds of gas
32:12
Speaker 1: that are just essentially stopped at the center of our unit,
32:15
Speaker 1: our center of our galaxy. The fact that we don't
32:19
Speaker 1: know what they are, I think it's just fascinating. The
32:21
Speaker 1: fact that the science behind it is only not even
32:24
Speaker 1: ten years old is is really fascinating. So it seems
32:27
Speaker 1: like the kind of thing that we might actually get
32:29
Speaker 1: some really cool answers for in the near future. Yeah,
32:33
Speaker 1: twenty years from now, people to look back and they're
32:35
Speaker 1: going to know the answer, hopefully, and uh, it's gonna
32:37
Speaker 1: seem obvious to them, right whereas right now we're standing
32:40
Speaker 1: at the forefront of human ignorance, not knowing where it's
32:43
Speaker 1: going to lead. But the favorite place to stand, Well,
32:48
Speaker 1: the my favorite thing about this kind of thing is
32:50
Speaker 1: that it's a hint, right, It's a hint about how
32:53
Speaker 1: many more amazing discoveries there are out there. If every
32:56
Speaker 1: time we open a new kind of eyeball into the universe,
32:59
Speaker 1: we see some thing crazy and unexpected. That tells you
33:02
Speaker 1: that there's a lot more crazy stuff out there waiting
33:05
Speaker 1: to be discovered. And so we should build as many
33:08
Speaker 1: kinds of scientific eyeballs as we can, especially astronomical ones,
33:13
Speaker 1: because there's so much out there in the universe waiting
33:16
Speaker 1: for us to find it and to go. What the
33:19
Speaker 1: f is that more eyeballs is absolutely what we need,
33:24
Speaker 1: all right, Get on at physicists, engineers, more telescopes now, yeah,
33:29
Speaker 1: and I don't mean rattlesnakes with more eyeballs, they have plenty.
33:32
Speaker 1: What I'm talking about is news scientific instruments. All right.
33:36
Speaker 1: Thanks everyone for tuning in. That was our podcast about
33:38
Speaker 1: the mystery of the Fermi bubbles. If you have something
33:41
Speaker 1: you'd like us to rattle on about ignorantly, then please
33:44
Speaker 1: send us a suggestion to feedback at Daniel and Jorge
33:47
Speaker 1: dot com. Or if you have a question about something
33:50
Speaker 1: random about physics. We answer all of our listener emails.
33:53
Speaker 1: Send it to questions at Daniel and Jorge dot com.
33:57
Speaker 1: Thanks Matt for joining us on today's podcast. Thank you,
34:00
Speaker 1: it's been marvelous al right, So go all right, Mrs Nasal,
34:07
Speaker 1: go off and solve your rattlesnake venom problem. And we
34:09
Speaker 1: don't want to hear back from you until it's done.
34:11
Speaker 1: Will you solve these problems? Sounds good? Thanks everyone for
34:14
Speaker 1: tuning in. If you still have a question after listening
34:24
Speaker 1: to all these explanations, please drop us the line. We'd
34:27
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34:30
Speaker 1: and Instagram at Daniel and Jorge that's one word, or
34:34
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34:38
Speaker 1: Thanks for listening, and remember that Daniel and Jorge explained.
34:41
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