Latest / Daniel and Kelly’s Extraordinary Universe / Could black holes help form stars?

Transcript

Could black holes help form stars? · Daniel and Kelly’s Extraordinary Universe

• 0:08
  Speaker 1: Hey, hoorra, I have a visual challenge for you.
• 0:12
  Speaker 2: Ooh, I'm qualified for that.
• 0:13
  Speaker 1: So I'm thinking about how babies always seem cute. You know, kittens, puppies,
• 0:19
  Speaker 1: even little baby plants are cute.
• 0:20
  Speaker 2: Yeah, Candy and I, babies are cute.
• 0:22
  Speaker 1: So I'm wondering if we can apply to some of
• 0:24
  Speaker 1: that visual arts logic to physics. Can you think of
• 0:28
  Speaker 1: a way to make like a baby star look cute?
• 0:31
  Speaker 2: Oh? I thought you were gonna ask me if I
• 0:32
  Speaker 2: can make physicists look cute. The answer is no, that's impossible.
• 0:36
  Speaker 2: But what do you mean like the stars of babies.
• 0:38
  Speaker 1: Well, we say that they're born in stellar nurseries, and
• 0:42
  Speaker 1: we have you know, lullabys like Twinkle Twinkle, Little Star.
• 0:45
  Speaker 1: So how would we draw a baby star to make
• 0:48
  Speaker 1: it look cute?
• 0:49
  Speaker 2: Well, you know, maybe you can give it like a
• 0:51
  Speaker 2: plasma ribbon or have a burp little cute solar wind burps.
• 0:58
  Speaker 2: I wonder if that would make people go, oh, that
• 1:01
  Speaker 2: would be the plan. Or we should come up with
• 1:03
  Speaker 2: like an internet meme like baby star, baby Star Star
• 1:07
  Speaker 2: Star Sistar Star baby.
• 1:09
  Speaker 1: Star sounds like a viral TikTok video.
• 1:12
  Speaker 2: Bam, We're billionaires. Hi, I'm more ham Mad, cartoonist and
• 1:29
  Speaker 2: the creator of PhD comics.
• 1:31
  Speaker 1: Hi I'm Daniel. I'm a particle physicist and a professor
• 1:34
  Speaker 1: at UC Irvine, and I think the universe is beautiful,
• 1:38
  Speaker 1: but I'm not sure I would call it cute. Hmmm.
• 1:41
  Speaker 2: It's pretty cute, right, the way it all works together,
• 1:43
  Speaker 2: that's pretty like cute, but maybe like in an ironic sense,
• 1:47
  Speaker 2: like generalativity.
• 1:48
  Speaker 3: Oh that's cute. Oh like clever, yeah, clever. Yeah, yeah,
• 1:51
  Speaker 3: it's clever. I think it's more grand though, and dramatic
• 1:55
  Speaker 3: than cute. Cute makes me feel like we're minimizing it somehow.
• 1:59
  Speaker 2: M see what you mean. Yeah, but still it Maybe
• 2:01
  Speaker 2: it can be grand and cute. It can be cute
• 2:03
  Speaker 2: in a grand way.
• 2:04
  Speaker 1: Does anybody ever look at the Grand Canyon and say, ooh,
• 2:06
  Speaker 1: what a cute canyon.
• 2:09
  Speaker 2: Well, it maybe depends on your size, Like if you're
• 2:11
  Speaker 2: a giant, maybe the Grand Canyon looks cute to you. Yeah,
• 2:14
  Speaker 2: there you go. If you're the size of a galaxy,
• 2:16
  Speaker 2: maybe the universe would be cuter. Hmm.
• 2:19
  Speaker 1: So maybe astronomy and cosmology is grand and particle physics
• 2:22
  Speaker 1: is cute.
• 2:23
  Speaker 2: Yeah, Or maybe you're just too small.
• 2:26
  Speaker 1: I'm just trying to get you to call me cute.
• 2:28
  Speaker 1: That's the whole game here. I see it's not going
• 2:30
  Speaker 1: to happen though.
• 2:31
  Speaker 2: Oh that's cute, Daniel, right, success, But anyways, Welcome to
• 2:37
  Speaker 2: our podcast Daniel and Jra Explain the Universe, a production
• 2:40
  Speaker 2: of iHeartRadio.
• 2:41
  Speaker 1: In which we try to avoid getting too cute and
• 2:44
  Speaker 1: do dig deep into the mysteries of the universe. We
• 2:47
  Speaker 1: want to understand all of the grand questions of reality.
• 2:50
  Speaker 1: How does it all work, where does it all come from,
• 2:52
  Speaker 1: how big is it? And fundamentally, what are the rules
• 2:56
  Speaker 1: that decides what happens and what does not happen. We
• 2:59
  Speaker 1: cast our minds out into the universe to look at
• 3:01
  Speaker 1: all the crazy things that we observe black holes and
• 3:04
  Speaker 1: stars and galaxies and tiny little quirks and photons, to
• 3:09
  Speaker 1: try to understand how all of it comes together to
• 3:12
  Speaker 1: make our universe.
• 3:13
  Speaker 2: That's right, because it is a pretty adorable and cuggly universe.
• 3:16
  Speaker 2: And every episode we try to have a little meat
• 3:18
  Speaker 2: cute here between the universe and your mind.
• 3:21
  Speaker 1: We want you to look at the universe and understand
• 3:23
  Speaker 1: something about how it works and go aw, that's so cute,
• 3:27
  Speaker 1: or at least that's so clever.
• 3:29
  Speaker 2: It's a fine line between awe and awe, and you, well,
• 3:33
  Speaker 2: then you got to change one of the valves.
• 3:35
  Speaker 1: But it's true that we often look at the processes
• 3:38
  Speaker 1: in the universe or discover something that's happening out there,
• 3:40
  Speaker 1: and even if we don't say awe, we might say wow,
• 3:43
  Speaker 1: that's awesome, that's cute some at least, I mean the
• 3:48
  Speaker 1: sheer power and the magnitude of what's going on, like
• 3:50
  Speaker 1: at the heart of our star, or understanding the forces
• 3:54
  Speaker 1: involved in the energy scales of the formation of the
• 3:57
  Speaker 1: Solar system, or the black holes at the centers of galaxies.
• 4:01
  Speaker 1: It really makes you feel tiny. It makes you understand
• 4:03
  Speaker 1: that the universe operates at these grand scales that are
• 4:07
  Speaker 1: almost beyond our ability to understand, and yet here we
• 4:10
  Speaker 1: are on this tiny little rock trying desperately to understand it.
• 4:14
  Speaker 2: It's a pretty amazing universe, and one thing I think
• 4:16
  Speaker 2: a lot of people forget is that it's still happening
• 4:19
  Speaker 2: right now. I think to think of the universe as
• 4:21
  Speaker 2: super duper old and establish and fix out there in
• 4:24
  Speaker 2: the cosmos, but actually there's a lot going on right now,
• 4:26
  Speaker 2: including new stars being born.
• 4:29
  Speaker 1: Yeah, when you look up at the night sky, you think, oh,
• 4:31
  Speaker 1: this is the night sky. It's always been the night sky.
• 4:34
  Speaker 1: My great grandparents and my great Kirkirkirk grekork great grandparents
• 4:37
  Speaker 1: saw the same stars, and my grandchildren will see the
• 4:40
  Speaker 1: same stars. It feels immutable, feels unchanging. But we know
• 4:44
  Speaker 1: that the cosmos are dynamic. We know that things are
• 4:47
  Speaker 1: changing up there. It just happens sort of over deep
• 4:50
  Speaker 1: time instead of over the sort of minutes and days
• 4:53
  Speaker 1: and months that we are used to. But if you
• 4:55
  Speaker 1: look in the right places at the right times, you
• 4:57
  Speaker 1: can still see stuff happening and learn something about how
• 5:00
  Speaker 1: the universe works.
• 5:01
  Speaker 2: Yep, it happens over long stretches of times. But it's
• 5:03
  Speaker 2: also happening right now as we speak. There are probably
• 5:07
  Speaker 2: countless stars being born right now. There's a bunch of
• 5:10
  Speaker 2: baby stars out there in the night sky.
• 5:11
  Speaker 1: That's right. Stars are being born in stellar nurseries, and
• 5:15
  Speaker 1: stars are dying, exploding in supernovas, or just fizzling out.
• 5:19
  Speaker 1: Stars do not last forever, And what I think is
• 5:21
  Speaker 1: interesting is that we give them a life cycle as
• 5:23
  Speaker 1: if stars were alive. You know, they have a process
• 5:27
  Speaker 1: of formation and then dissipation or ending. But they're never
• 5:30
  Speaker 1: like life in the sense of the bile and just
• 5:32
  Speaker 1: think about it. But we talk about them being born.
• 5:35
  Speaker 2: And how do you know, Daniel, have you asked the star?
• 5:38
  Speaker 1: I have actually shouted at the Sun many times and
• 5:40
  Speaker 1: never heard a response.
• 5:41
  Speaker 2: Well, that could just be you, not the star.
• 5:44
  Speaker 1: Maybe I just don't speak sun ease or stella.
• 5:48
  Speaker 2: You need to get the right email address or a
• 5:50
  Speaker 2: toll freak number to call.
• 5:52
  Speaker 1: Maybe my accent is just terrible and I can't understand
• 5:54
  Speaker 1: what I'm saying.
• 5:55
  Speaker 2: Oh right, maybe you need to speak star ease.
• 5:57
  Speaker 1: In order to spark a conversation.
• 5:59
  Speaker 2: Yeah, and illuminating discussion about the life of stars.
• 6:04
  Speaker 1: But the formation of stars, how they operate internally, how
• 6:08
  Speaker 1: they die, These are still big questions in science. We
• 6:11
  Speaker 1: look out there in the universe and we see regions
• 6:13
  Speaker 1: where stars are being formed rapidly, in regions where galaxies
• 6:16
  Speaker 1: have quenched, where they are no longer making stars. This
• 6:20
  Speaker 1: is a really important thing to understand in the universe
• 6:22
  Speaker 1: because formation of stars is pretty basic to creating the
• 6:26
  Speaker 1: conditions for life. If we'd like to understand our very
• 6:29
  Speaker 1: very long term future in the universe, we need to
• 6:32
  Speaker 1: understand if more stars are going to be made for
• 6:34
  Speaker 1: us to eventually move to when ours fizzles out.
• 6:37
  Speaker 2: Yeah, there are a lot of amazing ways that stars
• 6:39
  Speaker 2: are being born out there, and every day we're also
• 6:42
  Speaker 2: discovering new ways that stars might be born out there.
• 6:44
  Speaker 2: And so today on the podcast, we'll be tackling the
• 6:46
  Speaker 2: question can black holes form stars?
• 6:55
  Speaker 1: I think this is a little bit of a rehabilitation
• 6:57
  Speaker 1: of the reputation of black holes.
• 7:00
  Speaker 2: Oh whoa, whoa, whoa, you just went deep there? What
• 7:02
  Speaker 2: what's wrong with black holes? Do they get canceled in culture?
• 7:06
  Speaker 1: I mean they're seen as destructive, right. They're like the
• 7:08
  Speaker 1: vacuum cleaners of the universe. They slop stuff up and
• 7:11
  Speaker 1: disappear it. They're not usually talked about. It's like part
• 7:14
  Speaker 1: of a process of rebuilding. They're like the end point
• 7:17
  Speaker 1: of the universe. Everything will finally end up inside some
• 7:20
  Speaker 1: vast black hole, separated by infinitely empty space. But instead
• 7:25
  Speaker 1: it might turn out that black holes have some positive
• 7:27
  Speaker 1: sides to it. Well.
• 7:28
  Speaker 2: As a person who cleans up the dishes and washes
• 7:30
  Speaker 2: them every night in my house, I would say that,
• 7:32
  Speaker 2: you know, props of the whoever is out there in
• 7:34
  Speaker 2: the universe cleaning things up and vacuuming all the all
• 7:38
  Speaker 2: the dirty dishes.
• 7:39
  Speaker 1: I mean, the universe is a bit of a mess,
• 7:40
  Speaker 1: but I don't want to see the whole thing just
• 7:41
  Speaker 1: like sucked up into a giant black hole. That would
• 7:44
  Speaker 1: seem kind of dull. You know. Sometimes you got to
• 7:47
  Speaker 1: embrace the mess.
• 7:48
  Speaker 2: That black holes were exciting, but you don't know what's
• 7:50
  Speaker 2: going on. Maybe there's a big party inside the black hole.
• 7:53
  Speaker 1: Maybe they're actually just a big mess. You know, we
• 7:55
  Speaker 1: thought they're cleaning things up, but it's sort of like
• 7:57
  Speaker 1: that closet you shove stuff in and if you went inside,
• 7:59
  Speaker 1: you'd be like, oh, oh no, this is a disaster.
• 8:01
  Speaker 2: But full of amazing things.
• 8:02
  Speaker 1: I'm sure that's right. You could learn so much about
• 8:05
  Speaker 1: the universe or that family by opening their closet slash
• 8:08
  Speaker 1: black hole.
• 8:09
  Speaker 2: But this is an interesting question, I think because we
• 8:11
  Speaker 2: don't often associate black holes with the formation of stars,
• 8:16
  Speaker 2: like usually maybe think of stars forming out there in
• 8:19
  Speaker 2: space and the emptiness of space in a big dust cloud.
• 8:21
  Speaker 2: But to think that it could maybe be born from
• 8:23
  Speaker 2: a black hole, or buy a black hole, or through
• 8:26
  Speaker 2: a black hole, it's pretty interesting to think.
• 8:28
  Speaker 1: About Yeah, it's a really fun counterintuitor topic, and I
• 8:30
  Speaker 1: recently read a paper exploring this and I thought this
• 8:33
  Speaker 1: would be fun to talk about.
• 8:34
  Speaker 2: Well, as usual, we were wondering how many people out
• 8:36
  Speaker 2: there had thought about the possibility of stars being born
• 8:40
  Speaker 2: from a black hole or buy a black hole, So
• 8:42
  Speaker 2: as usual, Daniel went out there into the wilds of
• 8:45
  Speaker 2: the Internet to ask people do you think black holes
• 8:48
  Speaker 2: can form from stars?
• 8:49
  Speaker 1: So thanks very much to the denizens of the wild
• 8:52
  Speaker 1: Internet who answer these questions for us. Everybody is welcome
• 8:55
  Speaker 1: to do so, don't be shy. Write to me two
• 8:57
  Speaker 1: questions at Daniel and Jorgeedon and I'll set you up.
• 9:01
  Speaker 2: Here's what people had to say.
• 9:02
  Speaker 4: I feel like they could definitely form some stars. You know,
• 9:05
  Speaker 4: they're stripping some material off of some stars, probably move
• 9:10
  Speaker 4: some material from that star over to this spot and
• 9:13
  Speaker 4: maybe becomes enough material to make a star.
• 9:16
  Speaker 2: Well maybe if they only if only hydrogen falls in
• 9:20
  Speaker 2: and they radiate away enough, most become a stag in.
• 9:23
  Speaker 5: I don't think that black holes can form stars directly,
• 9:28
  Speaker 5: but maybe they can form them indirectly, you know, since
• 9:32
  Speaker 5: they have such a strong pull of gravity, I'm sure
• 9:35
  Speaker 5: they have influences on the molecular clouds around them, and
• 9:40
  Speaker 5: maybe they can help stars form that way.
• 9:43
  Speaker 2: All right, some interesting possibilities here. Two out of three
• 9:47
  Speaker 2: people in the Internet think it's popple.
• 9:50
  Speaker 1: So boom, that's it. Question settled.
• 9:52
  Speaker 2: That's right. We all know how well polls work on
• 9:54
  Speaker 2: the Internet.
• 9:55
  Speaker 1: Hey, this was done by a scientist, so therefore it's scientific. Right.
• 9:59
  Speaker 2: Sure, that's cute.
• 10:01
  Speaker 1: It's not pretty, but it might be cute.
• 10:03
  Speaker 2: Yeah. So some people here thought that it wasn't possible
• 10:06
  Speaker 2: for stars to be born from black holes, and some
• 10:08
  Speaker 2: people thought maybe, like enough hydrogen falls in and or
• 10:11
  Speaker 2: it gets shut out, it maybe can become a star again.
• 10:14
  Speaker 1: Yeah, there's some really creative problem solving here. I love
• 10:16
  Speaker 1: hearing people use the physics in their minds to try
• 10:19
  Speaker 1: to tackle a new question. I mean, that's really what
• 10:21
  Speaker 1: physics is all about. It's a little set of tools
• 10:24
  Speaker 1: to try to answer questions about the universe. And everybody
• 10:27
  Speaker 1: who's doing that out there in their heads is doing physics.
• 10:30
  Speaker 1: You're all physicists deep down. I mean that as a compliment,
• 10:34
  Speaker 1: of course.
• 10:34
  Speaker 2: You mean, you're all cute on the outside, but physicists
• 10:36
  Speaker 2: on the inside. Is that what you're saying, which means
• 10:39
  Speaker 2: you're clever all the way through. All right, Well, let's
• 10:41
  Speaker 2: dig into this possibility of black holes forming stars, and
• 10:45
  Speaker 2: let's start with the basics. Let's talk about what a
• 10:47
  Speaker 2: black hole actually is.
• 10:48
  Speaker 1: So, boy, do I wish I knew what a black
• 10:50
  Speaker 1: hole actually is. You know, we tend to think of
• 10:53
  Speaker 1: it as like the endpoint of the life of a star.
• 10:56
  Speaker 1: You start with a big blob of stuff and gravity
• 10:59
  Speaker 1: pulls it together and you form a star and it
• 11:01
  Speaker 1: burns for a long time, and in burning, it helps
• 11:05
  Speaker 1: prevent further gravitational collapse. You know, gravity is always tugging
• 11:09
  Speaker 1: on this stuff. It's always pulling one bit of hydrogen
• 11:11
  Speaker 1: closer to another bit of hydrogen. But gravity is pretty weak,
• 11:15
  Speaker 1: so it has to sort of wait until all the
• 11:17
  Speaker 1: other forces have stopped working in the opposite direction. When
• 11:21
  Speaker 1: a star is burning, it's pushing energy out. It's like
• 11:24
  Speaker 1: blowing radiation out, and that prevents the star from collapsing further.
• 11:28
  Speaker 1: But that fire can't last forever, and eventually it burns
• 11:32
  Speaker 1: out and then gravity takes over and the whole thing collapses.
• 11:36
  Speaker 1: If you have enough mass and that initial clump of stuff,
• 11:38
  Speaker 1: you know, maybe more than forty times the mass of
• 11:41
  Speaker 1: our Sun, then it can collapse and form a black hole,
• 11:44
  Speaker 1: which is essentially the gravitational endpoint. When gravity's collapsed, everything
• 11:48
  Speaker 1: to be so dense that space is twisted and, as
• 11:51
  Speaker 1: you'd like to say, forms a hole, a place where
• 11:54
  Speaker 1: anything that goes in can never come out.
• 11:57
  Speaker 2: Now, just to tear, Not all stars end up. Dye
• 12:00
  Speaker 2: is a black hole, right, It has to be a
• 12:02
  Speaker 2: certain kind of star, and even if it does collapse,
• 12:05
  Speaker 2: they don't all form black holes, right. In fact, it's
• 12:08
  Speaker 2: kind of rare, right, Most stars just keep aching and
• 12:11
  Speaker 2: lead a long and pretty unexciting demise.
• 12:14
  Speaker 1: Yeah, that's right. And the endpoint of a star is
• 12:17
  Speaker 1: determined almost entirely by its initial amount of mass. So
• 12:20
  Speaker 1: if you don't have enough mass to even burn and
• 12:22
  Speaker 1: start fusion, then we call you like a brown dwarf
• 12:25
  Speaker 1: for a failed star. If you're a low mass star,
• 12:28
  Speaker 1: like less than eight times the mass of our Sun,
• 12:30
  Speaker 1: you don't form a black hole. It'll become a red giant,
• 12:33
  Speaker 1: and then maybe like a planetary nebula, at the core
• 12:36
  Speaker 1: will be something like a white dwarf, which will last
• 12:38
  Speaker 1: for a long time and eventually cool into a black dwarf,
• 12:41
  Speaker 1: but will not form a black hole. Only the larger
• 12:44
  Speaker 1: stars that have the capacity to become a black hole.
• 12:47
  Speaker 1: So bigger than like eight or ten times the mass
• 12:50
  Speaker 1: of our Sun, you end up as a red super giant.
• 12:53
  Speaker 1: And then you get these core collapse supernova And if
• 12:56
  Speaker 1: it has enough mass, if it started out with more
• 12:58
  Speaker 1: than forty times the mass of the Sun, it's almost
• 13:01
  Speaker 1: certainly going to end up being a black hole. But
• 13:03
  Speaker 1: you're right, those are rare because the most common type
• 13:05
  Speaker 1: of star in the universe are not the massive stars.
• 13:08
  Speaker 1: They're the little red dwarfs, stars that are cooler and
• 13:11
  Speaker 1: smaller than our star. Because the smaller the star, the
• 13:15
  Speaker 1: colder it is at it's core, and so the dimmer
• 13:17
  Speaker 1: it burns. So very big stars end up as black holes,
• 13:21
  Speaker 1: but they also don't last very long. Very small stars
• 13:24
  Speaker 1: are cooler but last longer. The smallest ones can burn
• 13:27
  Speaker 1: for billions and billions, maybe even trillions of years.
• 13:30
  Speaker 2: Yeah, like you said, it's rare, and only if it
• 13:32
  Speaker 2: has enough mass. But even if it has a lot
• 13:33
  Speaker 2: of mass and it collapses, well, I guess we're not
• 13:36
  Speaker 2: super duper sure that a black hole will form, right,
• 13:38
  Speaker 2: Like they could also form, like you said before, a
• 13:41
  Speaker 2: neutron star maybe, or we actually don't know. We've never
• 13:44
  Speaker 2: seen a black hole born out of a star.
• 13:46
  Speaker 1: So if you have like more than ten times the
• 13:48
  Speaker 1: mass of the Sun but less than forty times, you're
• 13:50
  Speaker 1: likely to make a neutron star, which is a very
• 13:53
  Speaker 1: very dense object filled with neutrons. But those neutrons are
• 13:57
  Speaker 1: resisting gravitational collapse. They're preventing it from becoming a black hole.
• 14:01
  Speaker 1: If it happens to eat some more mass and then
• 14:03
  Speaker 1: get over the mass threshold, then it can collapse into
• 14:06
  Speaker 1: a black hole. But if you have enough mass, it's
• 14:08
  Speaker 1: almost inevitable to become a black hole, at least if
• 14:11
  Speaker 1: black holes even exist. As you said, we're not even
• 14:14
  Speaker 1: really sure that black holes are black holes. The way
• 14:18
  Speaker 1: we think about them, we have a description of them
• 14:21
  Speaker 1: in general relativity, which uses a pure gravitational description and
• 14:25
  Speaker 1: ignores all the quantum mechanics and says that gravity will
• 14:27
  Speaker 1: pull everything together to this tiny dot a singularity at
• 14:31
  Speaker 1: the heart of these black holes and form an event
• 14:33
  Speaker 1: horizon around them. That's the general relativity view, and for
• 14:36
  Speaker 1: a long time that was basically the only idea out
• 14:38
  Speaker 1: there that could explain what we were seeing in the universe.
• 14:42
  Speaker 1: We saw these very dark, very dense blobs of matter
• 14:45
  Speaker 1: that we could only explain with black holes. Now though
• 14:48
  Speaker 1: we have other ideas. Maybe these are fuzzballs, maybe these
• 14:51
  Speaker 1: are dark stars, maybe these are something else entirely. Last
• 14:54
  Speaker 1: week we talked about balls of vacuum energy that could
• 14:57
  Speaker 1: look like black holes, So there's been a real flourishing
• 15:00
  Speaker 1: of ideas for what these things actually are.
• 15:02
  Speaker 2: Yeah, and also not all black holes come from stars,
• 15:05
  Speaker 2: right like, there are some black holes that may be
• 15:07
  Speaker 2: formed at the beginning of the universe, right from in
• 15:10
  Speaker 2: the Big Bang. And there's also kind of a mystery
• 15:12
  Speaker 2: how some black holes out there form, right like some
• 15:14
  Speaker 2: of the big ones in the middle of galaxies. Were
• 15:17
  Speaker 2: not quite sure how those started.
• 15:19
  Speaker 1: It's definitely a mystery how black holes the hearts of
• 15:21
  Speaker 1: galaxies started. We tend to have two categories of black holes.
• 15:25
  Speaker 1: The ones that came from like an individual star like
• 15:27
  Speaker 1: we just talked about, and then these mammoth black holes
• 15:30
  Speaker 1: we call them super massive black holes that the hearts
• 15:32
  Speaker 1: of galaxies that can have masses of millions or billions
• 15:35
  Speaker 1: of times the mass of the Sun. And these we
• 15:37
  Speaker 1: think are black holes in the same category as other things,
• 15:40
  Speaker 1: although some theories say there's something totally different. But you're right,
• 15:43
  Speaker 1: we don't understand how they got so big. If you
• 15:46
  Speaker 1: look back into the deep history of the universe, we
• 15:48
  Speaker 1: can see galaxies forming in like the first billion or
• 15:51
  Speaker 1: two billion years already having huge black holes at their centers,
• 15:55
  Speaker 1: and we don't understand how they got to be so big.
• 15:58
  Speaker 1: One theory, as you said, is prime ordial black holes,
• 16:01
  Speaker 1: that maybe black holes were made during the Big Bang,
• 16:04
  Speaker 1: before there actually even was matter, black holes were made,
• 16:07
  Speaker 1: and they may have served as like seeds for these
• 16:09
  Speaker 1: supermassive black holes. That's just one idea, but it's definitely
• 16:13
  Speaker 1: a big question mark how these black holes at the
• 16:15
  Speaker 1: hearts of galaxies formed. But you know, we have seen
• 16:18
  Speaker 1: black holes like in the act of feeding. Black holes
• 16:21
  Speaker 1: don't just have to form from like their initial star.
• 16:23
  Speaker 1: They can later on gobble up other stars and get bigger.
• 16:27
  Speaker 2: Well, So it's kind of like a weird cycle of
• 16:30
  Speaker 2: stellar life out there in the cosmus, right, Like some
• 16:32
  Speaker 2: black holes are born from stars, and then those black
• 16:36
  Speaker 2: holes and start eating up other stars.
• 16:38
  Speaker 1: Yeah, you might have a star that burns and would
• 16:40
  Speaker 1: eventually become a white dwarf, but it gets gobbled up
• 16:43
  Speaker 1: by a black hole, so it eventually ends up as
• 16:45
  Speaker 1: a black hole. It might not have had enough mass
• 16:47
  Speaker 1: to make a black hole on its own, but it
• 16:50
  Speaker 1: gets vacuumed up into a neighboring black hole. And this
• 16:53
  Speaker 1: is really dramatic and sort of amazing to watch.
• 16:55
  Speaker 2: Yeah, because we've actually seen this happen, right, Like we
• 16:58
  Speaker 2: have pictures of it.
• 16:59
  Speaker 1: Yeah, I've actually seen this happen. There's a great example
• 17:02
  Speaker 1: using X ray telescopes that watch this happen to a
• 17:05
  Speaker 1: black hole and another galaxy. Two hundred and fifty million
• 17:09
  Speaker 1: light years from Earth. There's a black hole in the
• 17:11
  Speaker 1: center of another galaxy. It has like ten million solar masses,
• 17:15
  Speaker 1: and they watched the star get too close and the
• 17:18
  Speaker 1: star was pulled apart by the gravity of the black
• 17:21
  Speaker 1: hole before it even went in. It like pulled it
• 17:23
  Speaker 1: apart into a long river of hot gas. Remember that
• 17:26
  Speaker 1: gravity does more than just tug on things. It can
• 17:29
  Speaker 1: also tear them apart because of the tidal forces.
• 17:32
  Speaker 2: Right, Because I guess the part of the star that's
• 17:34
  Speaker 2: closer to the black hole gets pulled faster or stronger,
• 17:37
  Speaker 2: and so then it starts to get stretched out, sort
• 17:39
  Speaker 2: of like if you're sucking up with a vacuum a
• 17:43
  Speaker 2: big pile of legos or something, it's going to break
• 17:45
  Speaker 2: up the cluster of legos.
• 17:47
  Speaker 1: Yeah, gravity pulls more strongly on things that are closer
• 17:50
  Speaker 1: to the source. And if gravity is really really powerful
• 17:53
  Speaker 1: and you have something big enough, then the force on
• 17:56
  Speaker 1: one side of it is pretty different from the force
• 17:58
  Speaker 1: and the other and that's effectively like gravity pulling that
• 18:00
  Speaker 1: thing apart. I mean, the Earth right now is pulling
• 18:03
  Speaker 1: on your body with a different force than it's pulling
• 18:05
  Speaker 1: on your head, and effectively, that's like the Earth trying
• 18:08
  Speaker 1: to pull the head off of your body. It's not
• 18:10
  Speaker 1: very powerful because Earth's gravity is pretty gentle and your
• 18:13
  Speaker 1: head is pretty close to your body, but if you
• 18:14
  Speaker 1: were a big enough object and close enough to a
• 18:16
  Speaker 1: very strong source of gravity, you'd be pulled apart. And
• 18:19
  Speaker 1: they saw this happen to a star. We've seen this
• 18:22
  Speaker 1: happen also to like comets that have entered the Solar System.
• 18:25
  Speaker 1: Common shoemaker levee got pulled apart into like twenty six
• 18:28
  Speaker 1: pieces by tidal forces. Anyway, this hot river of gas
• 18:31
  Speaker 1: was formed and then it fell into the black hole
• 18:34
  Speaker 1: and they could observe it due to this increase in
• 18:36
  Speaker 1: X ray emission from the accretion disk of the black hole.
• 18:40
  Speaker 1: The whole thing took like weeks to months to happen.
• 18:42
  Speaker 2: M that's pretty interesting. Do we have pictures of that?
• 18:45
  Speaker 2: Like if can you google that and find the pictures
• 18:48
  Speaker 2: of this star getting spaghetified?
• 18:50
  Speaker 1: We don't have cool images of that, unfortunately. We just
• 18:52
  Speaker 1: have like X ray telescope data that showed like rises
• 18:55
  Speaker 1: in X ray emissions as this hot gas enters the
• 18:58
  Speaker 1: accretion disk. We know that it happened. We could sort
• 19:01
  Speaker 1: of like watch it conceptionally, but we don't have like
• 19:03
  Speaker 1: pictures of it, and that would be awesome.
• 19:05
  Speaker 2: So then how do you know it's stretched down into
• 19:07
  Speaker 2: a long river of hot gas? You just think it
• 19:09
  Speaker 2: did well.
• 19:10
  Speaker 1: I mean, we have X ray data, and we have
• 19:12
  Speaker 1: X ray telescopes, but X ray telescopes don't have the
• 19:14
  Speaker 1: same kind of optics as like optical telescopes and the
• 19:17
  Speaker 1: same kind of resolution. They're more like particle detectors. You're
• 19:20
  Speaker 1: looking at a single stream of photons more than you're
• 19:23
  Speaker 1: like taking an image with high resolution.
• 19:26
  Speaker 2: So you're looking at like a pinpoint of an X
• 19:28
  Speaker 2: ray source and suddenly that X ray stars changed and
• 19:31
  Speaker 2: you're inferring that it means that the star got stretched out.
• 19:34
  Speaker 1: Yeah, exactly. And you used to see a star which
• 19:36
  Speaker 1: then disappeared, and you see this emission of X rays
• 19:38
  Speaker 1: very close to this black hole, and so you know,
• 19:40
  Speaker 1: there's a few steps of inference there. But people are
• 19:43
  Speaker 1: pretty convinced that this was a star getting eaten by
• 19:45
  Speaker 1: a black hole, or at least by something right, by something,
• 19:49
  Speaker 1: something very dense, and something very dark ended this star.
• 19:53
  Speaker 2: Something out there had star pasta for dinner. All right, Well,
• 19:58
  Speaker 2: that's a pretty quick primer on black holes, and now
• 20:01
  Speaker 2: let's get into how a black hole can form a star,
• 20:05
  Speaker 2: whether it can, and what would it mean. But first
• 20:08
  Speaker 2: let's take a quick break. Or we're answering the question
• 20:23
  Speaker 2: can black holes form stars? Now? Are these black holes
• 20:28
  Speaker 2: forming the stars like out of clay?
• 20:30
  Speaker 4: Like?
• 20:30
  Speaker 2: Are they molding the stars? Are they giving birth to
• 20:33
  Speaker 2: the stars? Are they making, you know, pulling a magic
• 20:36
  Speaker 2: trick making them appear out of nowhere?
• 20:38
  Speaker 1: Maybe they're just ordering them on Amazon like everybody else
• 20:40
  Speaker 1: around here?
• 20:41
  Speaker 2: Does that count as forming a star?
• 20:42
  Speaker 4: Though?
• 20:43
  Speaker 2: If I order order a toothpaste from Amazon, am i
• 20:47
  Speaker 2: making the toothpaste.
• 20:48
  Speaker 1: I don't know. But if I order a Christmas present
• 20:50
  Speaker 1: on Amazon and give it to my kids, you know,
• 20:52
  Speaker 1: they feel like it was from me, even if I
• 20:54
  Speaker 1: didn't make it myself.
• 20:55
  Speaker 2: Oh it's from you, but you didn't form the gift.
• 20:58
  Speaker 1: No, that's true. I did not build those earbuds myself.
• 21:01
  Speaker 2: There you go. Well, here the question is can a
• 21:03
  Speaker 2: black hole form a star? And I'm guessing maybe it's
• 21:05
  Speaker 2: like putting together some of the gas around or is it, like,
• 21:09
  Speaker 2: you know, is it happening when the the stuff is
• 21:12
  Speaker 2: falling into the black hole? What's going on here?
• 21:14
  Speaker 1: So so far we mostly think about black holes is
• 21:16
  Speaker 1: like the death of stars or eating other stars. To
• 21:20
  Speaker 1: understand how black holes can contribute to star formation, we
• 21:23
  Speaker 1: have to think a little bit and understand a little
• 21:25
  Speaker 1: bit about how stars are formed in the first place.
• 21:27
  Speaker 1: Like if you went out to build a star, You're like, oh,
• 21:30
  Speaker 1: Christmas is coming, I got to get my spouse something.
• 21:33
  Speaker 1: What should I do? I'm gonna build them a star?
• 21:35
  Speaker 1: How would you do it?
• 21:36
  Speaker 3: Right?
• 21:36
  Speaker 1: How do you make a star? Anyway? And it turns
• 21:38
  Speaker 1: out that star formation is a little bit more delicate
• 21:41
  Speaker 1: and difficult than you might imagine and I think all
• 21:45
  Speaker 1: you need is a big block of gas and eventually
• 21:47
  Speaker 1: gravity's going to pull it together. So you know, just
• 21:49
  Speaker 1: get a scoop a hydrogen, put it in space and
• 21:52
  Speaker 1: wait a few million years and there's your star. But
• 21:55
  Speaker 1: it's not so simple. You need sort of special conditions
• 21:58
  Speaker 1: for that gas in order to get it to collapse
• 22:01
  Speaker 1: and form a star.
• 22:02
  Speaker 2: Yeah, I know, we talked about this before. It's kind
• 22:04
  Speaker 2: of related to the temperature of the gas, right, and
• 22:08
  Speaker 2: also how much gas there is you need, like the
• 22:10
  Speaker 2: right amount of the right temperature.
• 22:12
  Speaker 1: Yeah, it depends a lot on the temperature and also
• 22:14
  Speaker 1: the metallicity. Remember, at the beginning of the universe, we
• 22:16
  Speaker 1: had basically just clouds of hydrogen. That's what was made
• 22:19
  Speaker 1: during the Big Bang, a little bit of helium and
• 22:21
  Speaker 1: a tiny little bit of heavier stuff, but almost entirely hydrogen.
• 22:25
  Speaker 1: So the first stars were all just hydrogen. Then the
• 22:28
  Speaker 1: hearts of those stars fusion makes heavier elements helium, lithium, carbon, oxygen, nitrogen,
• 22:33
  Speaker 1: et cetera, all that good stuff that makes up us
• 22:36
  Speaker 1: and ice cream and hamsters. So to form a star,
• 22:39
  Speaker 1: you need gas that's cold. As you said, it can't
• 22:41
  Speaker 1: be too hot because hot gas means the particles are
• 22:44
  Speaker 1: flying around at really high speeds. And you have to
• 22:46
  Speaker 1: remember that gravity is really really weak, so it can
• 22:49
  Speaker 1: only really pull together stuff if it's almost at rest.
• 22:53
  Speaker 1: If the gas is cold enough, you have a big
• 22:55
  Speaker 1: blob of hot gas, it'll just sit there forever without
• 22:58
  Speaker 1: forming a star. So you need that gas to be cold.
• 23:02
  Speaker 1: And it also depends on how much metal you have
• 23:04
  Speaker 1: and like how it's distributed.
• 23:06
  Speaker 2: Maybe not forever, Like eventually wouldn't hot the cloud of
• 23:09
  Speaker 2: gas cool down or eventually some of that energy might
• 23:13
  Speaker 2: you know, get canceled out or something.
• 23:15
  Speaker 1: Well, energy is concerned, right, so the energy can't just
• 23:17
  Speaker 1: go away and left literally by itself. I suppose it
• 23:21
  Speaker 1: would expand because there's empty space around it. So hot
• 23:25
  Speaker 1: gas will expand into empty space and that will cool
• 23:28
  Speaker 1: it down.
• 23:28
  Speaker 2: Yeah, but I guess I mean, like, wouldn't eventually the
• 23:31
  Speaker 2: gas particles hit each other and lose some of that energy? Right?
• 23:35
  Speaker 1: These clouds of gas are pretty dilute, so you can
• 23:37
  Speaker 1: model them as almost entirely collisionless, I'm pretty sure. So
• 23:40
  Speaker 1: what you really need to form a star is you
• 23:42
  Speaker 1: need this gas to be cold. We also need some
• 23:44
  Speaker 1: sort of seed, and that can come in the form
• 23:46
  Speaker 1: of like having a dense little blob of some metal,
• 23:49
  Speaker 1: you know, formed in the heart of another star and
• 23:51
  Speaker 1: then left out in the cosmos to seed another star,
• 23:55
  Speaker 1: or some sort of like shock wave sometimes like a
• 23:57
  Speaker 1: nearby supernova will give a little push to some of
• 23:59
  Speaker 1: these things and collapse them in a way that gets
• 24:02
  Speaker 1: gravity started. But it's got to be gentle. It can't
• 24:05
  Speaker 1: be too hard. If you shock these things too much,
• 24:07
  Speaker 1: then you're just heating up the gas. So you got
• 24:09
  Speaker 1: to like cool it down so it can coalesce and
• 24:11
  Speaker 1: give it like the right kind of nudge or give
• 24:14
  Speaker 1: it like the right seed to get that collapse started.
• 24:16
  Speaker 2: You also need the right amount of gas, right, Like,
• 24:19
  Speaker 2: if you have a small cloud of gas, it's going
• 24:22
  Speaker 2: to clump and maybe not clump and form the kind
• 24:24
  Speaker 2: of pressure you need to form a star. Right, You
• 24:27
  Speaker 2: need like a lot of gas so that you get
• 24:29
  Speaker 2: a big clump and then so that the clumps kind
• 24:32
  Speaker 2: of squeezes the stuff in the middle enough to be
• 24:35
  Speaker 2: ready for fusion.
• 24:36
  Speaker 1: Yeah, if your clumps are too small, you just get
• 24:38
  Speaker 1: a bunch of Jupiter's. You don't get real stars. And
• 24:41
  Speaker 1: the size of the clumps that tend to form does
• 24:43
  Speaker 1: depend on the metallicity. So in the very early universe,
• 24:47
  Speaker 1: we had big stars form huge clouds of hydrogen. But
• 24:49
  Speaker 1: later on in the universe, we had like more seeds,
• 24:52
  Speaker 1: more like little dots of metal in those clouds. So
• 24:54
  Speaker 1: you've got more stars, but they were smaller, and then
• 24:57
  Speaker 1: they tend to burn longer, and so they burn from
• 24:59
  Speaker 1: bi millions of years rather than just like a few
• 25:01
  Speaker 1: million years or tens of millions of years, like the
• 25:04
  Speaker 1: first generation of stars. So like the composition, so it's
• 25:07
  Speaker 1: sort of like cooking, you know, it's really dependent on
• 25:10
  Speaker 1: the temperature and the exact mixture of what you put
• 25:12
  Speaker 1: in there. You might get a bunch of really big stars,
• 25:15
  Speaker 1: or smaller stars, or just a bunch of jupiters, or
• 25:18
  Speaker 1: almost no stars at all, depending on the temperature of
• 25:21
  Speaker 1: your ingredients.
• 25:22
  Speaker 2: M All right, then that's generally how stars form. You
• 25:25
  Speaker 2: need a cloud of gas and then it has to
• 25:28
  Speaker 2: be the right conditions, has to be cold, and there
• 25:30
  Speaker 2: has to be a lot of it. And this happens
• 25:32
  Speaker 2: a lot in certain situations out there in the universe,
• 25:34
  Speaker 2: right like in dwarf galaxies.
• 25:36
  Speaker 1: Yeah, so lots of galaxies out there are forming stars,
• 25:39
  Speaker 1: and lots of galaxies out there are not forming stars.
• 25:42
  Speaker 1: We have some bigger galaxies and we have some smaller galaxies.
• 25:44
  Speaker 1: And when galaxies stop forming stars, we say that they
• 25:47
  Speaker 1: are quenched. And actually our galaxy, like the Milky Way
• 25:51
  Speaker 1: and Andromeda, we think are both starting to quench. They're
• 25:55
  Speaker 1: forming like maybe seven stars per year. The rate of
• 25:59
  Speaker 1: star formation in galaxies like ours is a lot less
• 26:02
  Speaker 1: than it was a billion years ago, for example. So
• 26:04
  Speaker 1: it's really interesting to look, as you say, at little galaxies,
• 26:08
  Speaker 1: like what we call dwarf galaxies. These are like little
• 26:11
  Speaker 1: mini galaxies that have not yet combined with other galaxies
• 26:14
  Speaker 1: in order to form mega galaxies. All the galaxies that
• 26:18
  Speaker 1: you see in the Milky Way, the Androma, all the
• 26:19
  Speaker 1: big ones are all just combinations of these little galaxies
• 26:23
  Speaker 1: that came together to form a big galaxy. So looking
• 26:25
  Speaker 1: at a dwarf galaxy is sort of like looking at
• 26:28
  Speaker 1: a baby galaxy.
• 26:29
  Speaker 2: All exactly thin, cute. You're kind of cute and fuzzy,
• 26:33
  Speaker 2: aren't they.
• 26:33
  Speaker 1: They are kind of cute and fuzzy. In fact, one
• 26:35
  Speaker 1: of the things that's fuzzy about them is what constitutes
• 26:38
  Speaker 1: a dwarf galaxy. Like some astronomers say, you know, a
• 26:41
  Speaker 1: few thousands to a few billions of stars can be
• 26:43
  Speaker 1: a dwarf galaxy. Others have a different definition. There's a
• 26:46
  Speaker 1: big argument about whether the large magallinic cloud, which is
• 26:50
  Speaker 1: a big blob of stuff orbiting the Milky Way, counts
• 26:53
  Speaker 1: as a dwarf galaxy or not. But there's a lot
• 26:56
  Speaker 1: of interesting physics happening in these dwarf galaxies. They're a
• 26:58
  Speaker 1: great place to learn about star formation and about black
• 27:02
  Speaker 1: holes and about how they might be connected.
• 27:05
  Speaker 2: Well, I guess, first of all, why is it the
• 27:07
  Speaker 2: dwarf galaxies have more stars being born than regular stars?
• 27:11
  Speaker 2: Are they denser? Are they just like a newer gas.
• 27:14
  Speaker 1: Maybe we're not exactly sure because we don't really understand
• 27:17
  Speaker 1: this quenching process. Some theories of why galaxies stop making stars,
• 27:22
  Speaker 1: and so why dwarf galaxies might still be making more
• 27:24
  Speaker 1: of them could be due to the black holes at
• 27:27
  Speaker 1: their center. These black holes don't just suck stuff up,
• 27:30
  Speaker 1: they also emit radiation. As they get really massive, they
• 27:33
  Speaker 1: generate a lot of heat in their accretion disk, which
• 27:36
  Speaker 1: shoots out a lot of X rays, which ends up
• 27:38
  Speaker 1: heating up the galaxy and preventing it from making stars.
• 27:41
  Speaker 1: The other thing that can stop these big galaxies from
• 27:44
  Speaker 1: making stars are the stars they have stars emit radiation. Also,
• 27:49
  Speaker 1: there's stellar wind right or super novas that from the
• 27:52
  Speaker 1: end of stars life cycles. These can also heat up
• 27:55
  Speaker 1: the stellar nurseries too much, so they're not really prime
• 27:58
  Speaker 1: for making stars anymore. Are too hot, and so these
• 28:01
  Speaker 1: dwarf galaxies don't have that as many stars and don't
• 28:04
  Speaker 1: have super big black holes at their hearts, so they
• 28:07
  Speaker 1: might be better places to make stars.
• 28:09
  Speaker 2: So the next time somebody asked me like, hey, are
• 28:10
  Speaker 2: you gonna have more kids, I can just say we're
• 28:12
  Speaker 2: quench we got too.
• 28:14
  Speaker 1: Hot, exactly. But this is sort of like the astronomical
• 28:19
  Speaker 1: equivalent of teenagers having kids, because now you're having like
• 28:22
  Speaker 1: dwarf galaxies making lots of stars in their stellar nurseries.
• 28:25
  Speaker 1: And there's one in particular that people are really interested
• 28:28
  Speaker 1: in with there's a black hole doing something very strange
• 28:31
  Speaker 1: and weird. It's a dwarf galaxy called Henise h e
• 28:35
  Speaker 1: Nize two Dash ten. It's about thirty million light years
• 28:39
  Speaker 1: away in the direction of the Pike Sis constellation, and
• 28:43
  Speaker 1: it's not that tiny. I mean, it's like a tenth
• 28:45
  Speaker 1: of the size of the Milky Way, but it has
• 28:47
  Speaker 1: a huge star formation rate. People think it's making stars
• 28:50
  Speaker 1: about ten times the rate of the large madell in
• 28:53
  Speaker 1: a cloud, even though it's about the same size.
• 28:56
  Speaker 2: Mmm. Interesting, So what explains why this galaxies making so
• 29:01
  Speaker 2: many stars?
• 29:01
  Speaker 1: It's not something that we understand all.
• 29:04
  Speaker 2: Right, then, how do black holes come into the picture?
• 29:06
  Speaker 2: How are we studying whether black holes can form stars?
• 29:09
  Speaker 1: So this dwarf galaxy is super interesting for a bunch
• 29:11
  Speaker 1: of reasons. One is just like to see the black
• 29:13
  Speaker 1: hole being formed, right, Dwarf galaxies are little galaxies, and
• 29:17
  Speaker 1: one question we have is like how do black holes
• 29:19
  Speaker 1: get formed? Do they start really big? Do they grow
• 29:21
  Speaker 1: with the galaxy? Are they coupled to cosmic acceleration? So
• 29:24
  Speaker 1: looking at the black hole, this dwarf galaxy is interesting
• 29:27
  Speaker 1: just from that point of view.
• 29:28
  Speaker 2: Oh wait, so this dwarf galaxy has a black hole
• 29:30
  Speaker 2: in the middle.
• 29:31
  Speaker 1: We know that we do think this dwarf galaxy has
• 29:33
  Speaker 1: a black hole. We didn't know if all dwarf galaxies
• 29:36
  Speaker 1: have black holes, but this one seems to have it.
• 29:38
  Speaker 1: The sort of distinctive radio and X ray emissions from
• 29:41
  Speaker 1: the heart of this dwarf galaxy that are consistent with
• 29:44
  Speaker 1: a black hole and like not consistent with other explanations
• 29:48
  Speaker 1: like X ray binaries or a supernova or something like.
• 29:53
  Speaker 2: At the center of this dwarf galaxy, you can tell
• 29:56
  Speaker 2: there's like you know, gas being maybe stretch out, and
• 30:00
  Speaker 2: as it falls into the black hole, you can see
• 30:02
  Speaker 2: signature X ray signals from it.
• 30:04
  Speaker 1: Yeah, exactly. You could see the radio and the X
• 30:07
  Speaker 1: ray emissions you would expect from the gas around the
• 30:10
  Speaker 1: black hole. You can also see something else. This gas
• 30:12
  Speaker 1: accretion disk is swirling around the black hole, and then
• 30:15
  Speaker 1: it's slamming into this other blob of gas basically into
• 30:19
  Speaker 1: a stellar nursery. So stellar nursery is just a big
• 30:22
  Speaker 1: blob of cold gas right where stars might be formed
• 30:25
  Speaker 1: if you get like the right seed to form, where
• 30:27
  Speaker 1: you get like the right supernova shockwave. And this black
• 30:30
  Speaker 1: hole is emitting a bunch of radiation and pushing gas
• 30:33
  Speaker 1: out also right as black holes sometimes do, and it's
• 30:37
  Speaker 1: slamming into this stellar nursery, but it's doing it kind
• 30:40
  Speaker 1: of gently.
• 30:41
  Speaker 2: Right.
• 30:41
  Speaker 1: Earlier, we talked about how super massive black holes might
• 30:44
  Speaker 1: stop stars from being formed by emitting really powerful radiation
• 30:48
  Speaker 1: that heats it up. This one is emitting radiation and
• 30:50
  Speaker 1: pushing the gas into the stellar nursery, but it's doing
• 30:53
  Speaker 1: it kind of gently. It's moving it like only a
• 30:56
  Speaker 1: million miles per.
• 30:57
  Speaker 2: Hour, a million miles per hour.
• 31:00
  Speaker 1: A million miles per hour, which is gentle compared to
• 31:02
  Speaker 1: the radiation from massive black holes, which can approach almost
• 31:06
  Speaker 1: the speed of light.
• 31:07
  Speaker 2: I'll try that excuse the next time I'm pulled over
• 31:09
  Speaker 2: for a speeding ticket. I was like, great, you know,
• 31:13
  Speaker 2: according to this, I was going really gently, more than gently.
• 31:17
  Speaker 1: You know, these super massive black holes have incredible jets
• 31:20
  Speaker 1: of gas. Some of them you can see from almost
• 31:22
  Speaker 1: across the galaxy. These jets that go up and down
• 31:25
  Speaker 1: from the poles of the black hole. They form these quasars,
• 31:28
  Speaker 1: and they're super bright emissions, and these enormous structures spew
• 31:32
  Speaker 1: out of these black holes. But this is a little
• 31:34
  Speaker 1: baby galaxy with a little baby black hole that's spewing
• 31:37
  Speaker 1: gas out, but only at a million miles per hour.
• 31:40
  Speaker 1: So it's slamming into this dense gas, and they think
• 31:43
  Speaker 1: that's what's actually sparking the birth of all of these stars.
• 31:47
  Speaker 2: All right, let me see if I got this straight,
• 31:49
  Speaker 2: there's a black hole in the center of this dwarf galaxy.
• 31:51
  Speaker 2: It's sucking in stuff. That's how we know it's there
• 31:54
  Speaker 2: because it's sucking in stuff and as the stuff falls in,
• 31:56
  Speaker 2: it creates a lot of energy. So now some of
• 31:59
  Speaker 2: that energy that it's releasing when it's sucking that stuff
• 32:01
  Speaker 2: in is being shut out and that's pushing another cloud
• 32:05
  Speaker 2: of gas into a third cloud of gas. Is that's
• 32:09
  Speaker 2: kind of what's happening, Like it's actually shooting radiation, not gas,
• 32:13
  Speaker 2: but that radiation is pushing one cloud of gas into
• 32:17
  Speaker 2: another cloud of gas around the black hole at a
• 32:19
  Speaker 2: million miles per second forever.
• 32:22
  Speaker 1: A million mile per hour. Burps of gas into the
• 32:25
  Speaker 1: stellar nursery are sparking the birth of new stars in
• 32:29
  Speaker 1: this dwarf galaxy.
• 32:30
  Speaker 2: But the gas is not coming from the black hole,
• 32:32
  Speaker 2: right The black hole is just pushing the gas that's
• 32:34
  Speaker 2: already there. Or is it like accelerating, you know, you
• 32:37
  Speaker 2: know what I mean, like slinging it around and then
• 32:39
  Speaker 2: pushing into a cloud of gas. Or is it just
• 32:42
  Speaker 2: emitting radiation and that's pushing one cloud into another cloud.
• 32:46
  Speaker 1: It's a little bit of both. The gas is heated
• 32:48
  Speaker 1: up from the radiation from the black hole, and that
• 32:50
  Speaker 1: helps it swirl around really really fast, and some of
• 32:53
  Speaker 1: it slams into this stellar nursery, this cocoon of gas
• 32:57
  Speaker 1: that exists already in the galaxy. And so it's just
• 33:00
  Speaker 1: like depositing a bunch of energy there, but doing it
• 33:02
  Speaker 1: gently enough not to overheat this nursery. It seems to
• 33:06
  Speaker 1: be like really right on the edge there.
• 33:08
  Speaker 2: But pushing it just enough so that it creates better
• 33:11
  Speaker 2: conditions for star formation. Is that the idea, like you're
• 33:14
  Speaker 2: like compressing the gas making it denser, or is it
• 33:17
  Speaker 2: that it's causing the ripples that you know you need
• 33:20
  Speaker 2: to like jump start a start.
• 33:22
  Speaker 1: Yeah, it could be either. We have lots of different
• 33:24
  Speaker 1: models of star formation. You know, imagine like taking something
• 33:28
  Speaker 1: and needing to compress it, but just enough, and if
• 33:30
  Speaker 1: you squeeze too hard, it's going to blow up essentially,
• 33:33
  Speaker 1: And so this is a really delicate operation. You know,
• 33:35
  Speaker 1: star formation is surprisingly fragile. It's incredible how many stars
• 33:39
  Speaker 1: have been born in the universe given how difficult it
• 33:42
  Speaker 1: is to arrange the conditions for stars to come together.
• 33:45
  Speaker 2: Mmmm. Interesting. All right, Well, let's dig into the details
• 33:48
  Speaker 2: of what's going on here and maybe what it means
• 33:51
  Speaker 2: about what we know about star formations and black holes.
• 33:55
  Speaker 2: But first, let's take another quick break. All right, we're
• 34:10
  Speaker 2: talking about black holes forming stars, and specifically there's a
• 34:16
  Speaker 2: dwarf galaxy nearby sort of nearby us called Henis, where
• 34:21
  Speaker 2: there seems to be a black hole in the middle
• 34:23
  Speaker 2: of that dwarf galaxy, but it's also got a lot
• 34:26
  Speaker 2: of gas around it, and somehow the black hole is
• 34:29
  Speaker 2: helping the cloud of gas form new stars, or at
• 34:32
  Speaker 2: least that's the idea, right mm hmm.
• 34:34
  Speaker 1: And one thing that's really fascinating about this black hole
• 34:37
  Speaker 1: is that it's not really at the center necessarily. These
• 34:40
  Speaker 1: dwarf galaxies are not as like organized as big old
• 34:44
  Speaker 1: galaxies that form really nice spirals. They're more like fuzzy blobs.
• 34:48
  Speaker 1: And the black hole here is not associated with like
• 34:51
  Speaker 1: any bulge or any other like well defined nucleus. You know.
• 34:55
  Speaker 1: The whole theory of like black hole formation is that
• 34:58
  Speaker 1: they're made from stars, and they live at the very center,
• 35:01
  Speaker 1: the dense place, and so they gobble up a bunch
• 35:03
  Speaker 1: of stars and get bigger and bigger and bigger. This
• 35:05
  Speaker 1: one's a bit of a puzzle because it's not sitting
• 35:07
  Speaker 1: at the center or like associated with the densest place
• 35:10
  Speaker 1: in this dwarf galaxy.
• 35:12
  Speaker 2: And you can actually look up a picture of this
• 35:14
  Speaker 2: dwarf galaxy, right, you spell it h E and I
• 35:18
  Speaker 2: ze two dash ten and there are pictures of it online, right.
• 35:22
  Speaker 1: Yeah, they're pictures of it, and you can see red
• 35:24
  Speaker 1: stars and blue stars and stripes of gas and all
• 35:28
  Speaker 1: sorts of stuff. It's a bit of a blob. I mean,
• 35:30
  Speaker 1: would you say this is a cute galaxy for Yeah?
• 35:32
  Speaker 2: Yeah, all babies are blobs. That's kind of what makes
• 35:35
  Speaker 2: them cute. You're blobby.
• 35:36
  Speaker 1: Some of them look sort of like Winston Churchill. I
• 35:38
  Speaker 1: don't know how cute that is, though. I mean, I'm
• 35:40
  Speaker 1: sure your babies are all cute, dear.
• 35:41
  Speaker 2: Listeners, and I'm sure all of you Winston Churchill's out
• 35:44
  Speaker 2: there are also cute.
• 35:48
  Speaker 1: How many Winston Churchills are listening to the podcast right now?
• 35:52
  Speaker 2: You never know. It's a big universe. You never know,
• 35:55
  Speaker 2: or you might be married to Winston Churchill, or maybe
• 35:57
  Speaker 2: you were married to Winston Churchill.
• 36:00
  Speaker 1: This is getting pretty surreal.
• 36:02
  Speaker 2: We just still want to insult any Winston Churchills or
• 36:04
  Speaker 2: any Winstons at.
• 36:05
  Speaker 1: All, or really anybody. We're not out to insult.
• 36:08
  Speaker 6: Anybody, especially not this galaxy, which is a cute little
• 36:12
  Speaker 6: dwarf galaxy, but doesn't sort of fit your mental image
• 36:15
  Speaker 6: of a galaxy because it's a little dwarf galaxy, right,
• 36:17
  Speaker 6: it hasn't it formed its big boy structure or it's
• 36:19
  Speaker 6: big girl structure.
• 36:21
  Speaker 1: And so it's a bit of a blob, and its
• 36:23
  Speaker 1: massive black hole is not like right at the heart
• 36:25
  Speaker 1: of it.
• 36:26
  Speaker 2: Now, is this a galaxy, this dwarf galaxy unusual or
• 36:30
  Speaker 2: is this just like one where we found that we
• 36:32
  Speaker 2: know for sure it has a black hole in it
• 36:34
  Speaker 2: and where we seeing some interesting star formation, or is
• 36:37
  Speaker 2: Henny's pretty typical of dwarf galaxies and we just happened
• 36:40
  Speaker 2: to pick this one because it's convenient to study.
• 36:43
  Speaker 1: I think it's the latter. It's one that we have studied,
• 36:45
  Speaker 1: people have identified the black hole in it. It's taken
• 36:48
  Speaker 1: a while to figure that out. There was like papers
• 36:50
  Speaker 1: for years about whether this is a black hole or
• 36:53
  Speaker 1: something else. It's not always easy to identify a black
• 36:56
  Speaker 1: hole in a distant galaxy, especially a dwarf galaxy. So
• 36:59
  Speaker 1: dwarf galaxies having always got as much attention as normal
• 37:02
  Speaker 1: big Mama and Papa galaxies have because they're harder to see,
• 37:06
  Speaker 1: you know, they're fainter. But recently we've understood that they're
• 37:08
  Speaker 1: really great laboratory for understanding the formation of galaxies and
• 37:13
  Speaker 1: dark matter and black holes. We had a whole episode
• 37:16
  Speaker 1: recently about the physics of dwarf galaxies, so it's really
• 37:19
  Speaker 1: just sort of like taking off. It's like a whole
• 37:21
  Speaker 1: new field within astronomy, the study of dwarf galaxies, and
• 37:24
  Speaker 1: so this is one of the first ones. We don't
• 37:26
  Speaker 1: really know the general properties of dwarf galaxies very well
• 37:29
  Speaker 1: because a lot of them are missing. You know, we
• 37:31
  Speaker 1: expect in our simulations to see lots and lots of
• 37:33
  Speaker 1: dwarf galaxies sometimes around big galaxies, and we don't see
• 37:36
  Speaker 1: very many. And we don't always know if that's because
• 37:39
  Speaker 1: our simulations are wrong, or we just can't see them
• 37:41
  Speaker 1: because they're so faint, or they're mostly dark matter or what. So.
• 37:45
  Speaker 1: Lots of big open questions about dwarf galaxies. This is
• 37:48
  Speaker 1: just one that we happen to study recently.
• 37:51
  Speaker 2: Okay, now, as you were saying, this black hole in
• 37:53
  Speaker 2: the middle of Hennis that the dwarf galaxy is spouting
• 37:56
  Speaker 2: out a jet of gas or a jet of radiation.
• 37:59
  Speaker 2: And sometimes black holes don't spout out radiation like that,
• 38:03
  Speaker 2: They just suck stuff in, and sometimes they shoot stuff
• 38:07
  Speaker 2: out so violently that it pushes everything away and disrupts
• 38:11
  Speaker 2: any possibility of stars forming. But this one seems to
• 38:14
  Speaker 2: be like just in the right Goldilogs situation here, where
• 38:17
  Speaker 2: it's shooting out radiation, but it's not doing it in
• 38:20
  Speaker 2: such a way that it disrupts things. In fact, it's
• 38:22
  Speaker 2: sort of doing it gently enough that it's maybe helping
• 38:26
  Speaker 2: more stars form in this dwarf galaxy. Do we know why,
• 38:29
  Speaker 2: We don't know why.
• 38:30
  Speaker 1: And in general, we'd like to understand more about how
• 38:33
  Speaker 1: black holes form in these galaxies and whether they are
• 38:36
  Speaker 1: linked to the mass of the galaxies. In lots of
• 38:39
  Speaker 1: cases we see a connection between the mass of the
• 38:41
  Speaker 1: black hole and the mass of the galaxy, where bigger
• 38:43
  Speaker 1: galaxies have bigger black holes, but also sometimes we don't
• 38:46
  Speaker 1: see a connection. And we've recently talked about a paper
• 38:49
  Speaker 1: that saw that black holes the hearts of galaxies grow
• 38:51
  Speaker 1: faster than the galaxies do, suggesting that they're maybe not
• 38:55
  Speaker 1: just eating mass that there's some other weird thing connected
• 38:57
  Speaker 1: to dark energy. Right, it's a big question of like
• 39:00
  Speaker 1: the relationship between the mass of a black hole and
• 39:03
  Speaker 1: the mass of the galaxy that it's in. It's not
• 39:06
  Speaker 1: something that we understand, especially for these super massive black holes,
• 39:10
  Speaker 1: these ones that are bigger than just like the endpoint
• 39:12
  Speaker 1: of a single star. So it's a great way to
• 39:14
  Speaker 1: study not just star formation, but also to understand how
• 39:17
  Speaker 1: black holes get their start, right, because again, this is
• 39:20
  Speaker 1: not a super massive galaxy with a super massive black hole,
• 39:23
  Speaker 1: and this is like looking back to its childhood to
• 39:25
  Speaker 1: understand how it got so big so fast.
• 39:28
  Speaker 2: We're looking at this baby galaxy as a way to
• 39:31
  Speaker 2: study baby galaxy development kind.
• 39:33
  Speaker 1: Of yeah, exactly. And this one is exciting because it
• 39:36
  Speaker 1: sort of hints towards this primordial black hole theory. You know,
• 39:40
  Speaker 1: this idea that maybe black holes, the ones become monsters,
• 39:42
  Speaker 1: that the hearts of galaxies didn't form the way we
• 39:45
  Speaker 1: described earlier, just like a single star that collapses and
• 39:47
  Speaker 1: then gradually eats stuff. Maybe they got a boost, they
• 39:50
  Speaker 1: got like a head start by being formed very early on,
• 39:53
  Speaker 1: before even hydrogen was formed. These primordial black holes which
• 39:57
  Speaker 1: then just grew rapidly. The idea here or is that
• 40:00
  Speaker 1: maybe that's the reason it's not like right at the
• 40:03
  Speaker 1: heart of the galaxy, where like there's the densest blob
• 40:05
  Speaker 1: of matter. Maybe that's why it's sort of like offset
• 40:08
  Speaker 1: a little bit, because it was seated by a primordial
• 40:10
  Speaker 1: black hole. Not just like the formation of a black
• 40:13
  Speaker 1: hole at the densest spot in the galaxy.
• 40:16
  Speaker 2: Already just moved to the suburbs, you know, for quieter light.
• 40:20
  Speaker 2: That's what makes it so gentle.
• 40:22
  Speaker 1: But this is a young black hole, right It's going
• 40:24
  Speaker 1: to want to be at the heart of the action.
• 40:25
  Speaker 1: It's going to move into the city, right where all
• 40:28
  Speaker 1: the clubs stay out.
• 40:29
  Speaker 2: I say that all young black holes are hipster black hole.
• 40:33
  Speaker 2: I thought Brooklyn was where it's at, not Manhattan.
• 40:35
  Speaker 1: I mean, maybe this is a black hole with an
• 40:37
  Speaker 1: old soul. I don't know.
• 40:38
  Speaker 2: Yeah, you go, But I guess the point is that
• 40:41
  Speaker 2: this black hole in this dwarf galaxy is actually helping
• 40:44
  Speaker 2: make stars, right Like, without this black hole, this dwarf
• 40:47
  Speaker 2: galaxy wouldn't be making as many stars. Now, is the
• 40:50
  Speaker 2: idea that this is happening all over the galaxy or
• 40:53
  Speaker 2: this is like a weird situation like, could it be
• 40:56
  Speaker 2: that our star was somehow aided by a black hole
• 40:59
  Speaker 2: or that black hole holes are helping stars form all
• 41:02
  Speaker 2: over the our galaxy and in other galaxies.
• 41:06
  Speaker 1: It's certainly possible, and what it does is paint a
• 41:08
  Speaker 1: picture of star formation is more complex than we previously imagined.
• 41:13
  Speaker 1: You know, we had a sort of simple model before
• 41:15
  Speaker 1: these clouds of gas which then collapse, and now we
• 41:17
  Speaker 1: understand that creating the conditions for a star formation is
• 41:20
  Speaker 1: tricky and lots of different processes out there in the
• 41:23
  Speaker 1: universe can play a role, probably more than just black
• 41:25
  Speaker 1: hole formation. Other things we haven't even thought about might
• 41:28
  Speaker 1: trigger star collapse or end star collapse. So this is
• 41:31
  Speaker 1: something that astronomers are really digging into in detail now,
• 41:34
  Speaker 1: finding regions of the universe where stars are being formed,
• 41:37
  Speaker 1: rapidly finding regions of the universe where stars are not
• 41:39
  Speaker 1: being formed, trying to understand all the effects at play.
• 41:43
  Speaker 1: And it's a very complex situation. It's not like the
• 41:45
  Speaker 1: kind of thing you can study in isolation and say
• 41:48
  Speaker 1: I'm just going to take a blob of gas and
• 41:50
  Speaker 1: think about how it works. It's something that really depends
• 41:52
  Speaker 1: on everything that's going on in the neighborhood. You know,
• 41:55
  Speaker 1: you have to understand not just nearby black holes emitting
• 41:58
  Speaker 1: radiation that might coax your stars to forming or might
• 42:01
  Speaker 1: quash their ability to form stars. You also have to understand,
• 42:04
  Speaker 1: like the dark matter halo for this galaxy, is the
• 42:08
  Speaker 1: dark matter halo getting too big so that it's pulling
• 42:11
  Speaker 1: in too much gas from the intergalactic medium, which then
• 42:14
  Speaker 1: like heats up all the gas in the galaxy and
• 42:17
  Speaker 1: make it stop forming stars. To understand how this works,
• 42:19
  Speaker 1: we're going to have to get almost everything right. And
• 42:22
  Speaker 1: that's the kind of problem that's really hard. You can't
• 42:24
  Speaker 1: like break it into pieces and isolate and think about
• 42:26
  Speaker 1: it all by itself. You really got to get lots
• 42:29
  Speaker 1: of different elements in place all at once. So it's
• 42:32
  Speaker 1: sort of like a big grand challenge for astronomy over
• 42:34
  Speaker 1: the next couple of decades.
• 42:37
  Speaker 2: I guess there's a lot going on here out there
• 42:39
  Speaker 2: in the universe, and there's a lot that could be
• 42:41
  Speaker 2: disrupting or influencing the formation of stars.
• 42:45
  Speaker 1: Yeah, exactly. And we're working on this sort of in
• 42:46
  Speaker 1: two directions. On one hand, we're like looking out there
• 42:49
  Speaker 1: to see what's going on, and on the other hand,
• 42:51
  Speaker 1: we're building models, we're doing calculations to predict what we
• 42:54
  Speaker 1: should see. Right, Scientias progresses along these two fronts, the
• 42:58
  Speaker 1: experimental or observational and the theoretical. Can we explain what
• 43:02
  Speaker 1: we are seeing? So people working on the theoretical side
• 43:04
  Speaker 1: have these models, these simulations where they build little galaxies
• 43:08
  Speaker 1: and watch them form and measure the star formation rate
• 43:11
  Speaker 1: and see if they get it right. But you can
• 43:12
  Speaker 1: never simulate an entire universe or even entire galaxy. These
• 43:15
  Speaker 1: simulations are always simplified. Sometimes they for example, like only
• 43:19
  Speaker 1: have one kind of matter, or they ignore the dark matter,
• 43:21
  Speaker 1: or they ignore the non dark matter, or they ignore
• 43:24
  Speaker 1: the supernovas. To add all those details, all those bells
• 43:27
  Speaker 1: and whistles into your simulation is really complicated. So at
• 43:30
  Speaker 1: first we were able to do it with sort of
• 43:31
  Speaker 1: simplified versions, But now what we're learning is we really
• 43:34
  Speaker 1: got to break out all the bells and whistles to
• 43:36
  Speaker 1: understand star formation. It's not something where you're going to
• 43:39
  Speaker 1: understand it with a simple model using only one component
• 43:42
  Speaker 1: of the universe. It's like a whole symphony of chaos
• 43:44
  Speaker 1: that sometimes come together to form just the right conditions.
• 43:48
  Speaker 2: And sometimes there's a lot of stuff out there that
• 43:50
  Speaker 2: you can't see, right, like these black holes. Maybe you
• 43:53
  Speaker 2: didn't know it was there before, or it could confirm
• 43:56
  Speaker 2: that it was there. And also things like dark matter
• 43:58
  Speaker 2: could be influenced things that you can get in a
• 44:00
  Speaker 2: way that you can't see, or maybe also dark energy.
• 44:03
  Speaker 1: Right, Yeah, And that's why these are such fun puzzles
• 44:05
  Speaker 1: because you work really hard to explain them using the
• 44:08
  Speaker 1: pieces that you do understand, but sometimes you just can't
• 44:11
  Speaker 1: and you're like, well, something else is going on. Maybe
• 44:13
  Speaker 1: we're missing a piece of the puzzle. There's something else
• 44:15
  Speaker 1: going on out there we haven't figured out yet that
• 44:17
  Speaker 1: we need to add to our description in order to
• 44:19
  Speaker 1: explain what we're seeing out there in the universe. So
• 44:22
  Speaker 1: that's why we chase these discrepancies so hard, because sometimes
• 44:25
  Speaker 1: the explanation is boring. It's like, oh, you're making this approximation,
• 44:28
  Speaker 1: but it's actually really important, so you can't make that approximation.
• 44:31
  Speaker 1: You got to really do it right. But sometimes the
• 44:33
  Speaker 1: answer is really exciting. It's like, oops, you missed something fundamental.
• 44:37
  Speaker 1: There's something really big, and this is a little thread
• 44:40
  Speaker 1: that unravels the whole story. So science is all about
• 44:43
  Speaker 1: chasing down these details and getting them right, not knowing
• 44:46
  Speaker 1: whether they're clues to a bigger mystery or just dotting
• 44:49
  Speaker 1: the I and crossing the T.
• 44:50
  Speaker 2: Yeah, and I guess it's important to sort of understand
• 44:53
  Speaker 2: how stars form out there in the whole universe, to
• 44:56
  Speaker 2: kind of maybe understand our own context, right, Like, was
• 44:59
  Speaker 2: our story formed in a really special or unlikely way?
• 45:03
  Speaker 2: Or are we just, you know, one of many many
• 45:05
  Speaker 2: stars out there that form in the regular way. That
• 45:07
  Speaker 2: would kind of tell us a little bit about how
• 45:10
  Speaker 2: likely it is that we're here and here to study
• 45:13
  Speaker 2: this kind of stuff.
• 45:13
  Speaker 1: Yeah, it's sort of incredible that stars form at all
• 45:16
  Speaker 1: in this universe. You know, so much has to go
• 45:18
  Speaker 1: right for stars to form, Otherwise the universe would have
• 45:21
  Speaker 1: just been dark forever. It's sort of incredible. And you're
• 45:25
  Speaker 1: right that our star is kind of unusual. Remember, most
• 45:27
  Speaker 1: of the stars out there in the galaxy are not
• 45:30
  Speaker 1: yellow stars like ours, they're cooler stars, they're red dwarf stars.
• 45:35
  Speaker 1: So our star already is a little bit unusual. And
• 45:37
  Speaker 1: of course, behind all of these questions, we're always wondering, like,
• 45:41
  Speaker 1: is our whole situation unusual? Is it really rare for
• 45:43
  Speaker 1: us to exist, or are we pretty common in the universe.
• 45:46
  Speaker 1: So understanding like how stars get formed in the first place,
• 45:49
  Speaker 1: and how you get bigger stars and little stars, that's
• 45:52
  Speaker 1: a whole other mystery. We don't even really understand this
• 45:54
  Speaker 1: initial mass function of the stars. How you get bigger
• 45:58
  Speaker 1: clumps and smaller clumps is part of the deeper question
• 46:01
  Speaker 1: to understand how we got here in the first place.
• 46:03
  Speaker 2: M All right, Well, at least if you don't figure
• 46:06
  Speaker 2: it out, it's not so bad at Lisia end up
• 46:08
  Speaker 2: with a lot of cute baby pictures to put up
• 46:10
  Speaker 2: on your fridge and your galactic fridge.
• 46:14
  Speaker 1: That's right. I wonder if there's a certain kind of
• 46:16
  Speaker 1: astronomer who likes babies, who tends to work on star
• 46:19
  Speaker 1: formation because they want to look inside the windows of
• 46:21
  Speaker 1: stellar nurseries.
• 46:23
  Speaker 2: You mean there are physicists who don't like babies.
• 46:25
  Speaker 1: There definitely are people out there who don't like babies.
• 46:28
  Speaker 2: Man, not everybody has the anti baby.
• 46:32
  Speaker 1: I don't know if anybody's anti baby. They might just
• 46:34
  Speaker 1: be like mutual on babies.
• 46:37
  Speaker 2: I see you're cool on babies exactly.
• 46:40
  Speaker 1: People. You know, I could take a baby or leave
• 46:42
  Speaker 1: a baby I'm not sure. Personally, I love babies, but
• 46:45
  Speaker 1: you know, not everybody out there feels that way anyway.
• 46:48
  Speaker 1: Star babies and galaxy babies are also super fun because
• 46:51
  Speaker 1: they teach us about where' staharson galaxies come from.
• 46:54
  Speaker 2: All right, Well, hopefully the next time you look up
• 46:56
  Speaker 2: at the night sky you get to see maybe the
• 46:58
  Speaker 2: birth of any star. It's possible to be looking other
• 47:01
  Speaker 2: and into space and then suddenly a new star is.
• 47:03
  Speaker 1: Born, because this guy and the cosmos in the universe
• 47:06
  Speaker 1: are constantly changing, and we are keeping our eyeballs on
• 47:09
  Speaker 1: it to learn as much as we can from everything
• 47:12
  Speaker 1: it does.
• 47:12
  Speaker 2: And if you remember anything from this conversation, just remember
• 47:16
  Speaker 2: Baby Star Stars, Stars and Stars Star Baby.
• 47:19
  Speaker 1: Start for his new viral hit.
• 47:22
  Speaker 2: We hope you enjoyed that. Thanks for joining us, See
• 47:25
  Speaker 2: you next time.
• 47:33
  Speaker 1: Thanks for listening, and remember that Daniel and Jorge Explain
• 47:36
  Speaker 1: the Universe is a production of iHeartRadio. For more podcasts
• 47:40
  Speaker 1: from iHeartRadio, visit the iHeartRadio app, Apple Podcasts, or wherever
• 47:45
  Speaker 1: you listen to your favorite shows.