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Speaker 1: What mysteries lie inside the Earth, inside stars, or at

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Speaker 1: the hearts of black holes? We always seem drawn to

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Speaker 1: cracking things open and looking for the surprises inside. We've

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Speaker 1: been walking around on this planet for hundreds of thousands

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Speaker 1: of years until recently had no idea what was hidden within?

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Speaker 1: Was it all just dirt? Is it hollow? Was Godzilla

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Speaker 1: sleeping in his lair down there? What about in the

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Speaker 1: hearts of stars? Science tells us that at their core

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Speaker 1: matter is incredibly dense, the fusion furnaces that illuminate the

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Speaker 1: universe and forge the heavy metals needed for life and podcasts.

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Speaker 1: But what if there was something else, even more exotic

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Speaker 1: in the hearts of stars? What if instead of iron

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Speaker 1: or nickel or even nuclear pasta, stars hearts might contain

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Speaker 1: the most mysterious objects in the universe holes? And what

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Speaker 1: if that could solve another longstanding cosmic mystery. Today on

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Speaker 1: the pod, we'll ask whether stars could have black holes

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Speaker 1: at their cores. Welcome to Daniel and Kelly's extraordinarily dense

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Speaker 1: but brilliant Universe.

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Speaker 2: Hello, I'm Kelly Wadersmith. I study parasites and space and

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Speaker 2: I love pizza. HM.

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Speaker 1: My name is Daniel I'm a particle physicist, and I'm

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Speaker 1: particularly particular about my pizza.

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Speaker 2: I remember you and I had a discussion once about

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Speaker 2: what we were like level twenty experts on, and you

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Speaker 2: said that you were like a level twenty expert on pizza.

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Speaker 2: And I'm embarrassed to say I couldn't figure out anything

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Speaker 2: to say that I was a level twenty expert on.

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Speaker 2: But anyway, you just visited Chicago, and so I have

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Speaker 2: to ask you a very important question, which city makes

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Speaker 2: the best pizza.

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Speaker 1: It's easy. New York obviously near pizza, hands down.

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Speaker 2: I'm so glad we can stay friends. I wasn't sure

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Speaker 2: if there's gonna be like a white chocolate dark chocolate

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Speaker 2: divide where I admit that I actually don't dislike white

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Speaker 2: chocolate that much and then you get upset and then

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Speaker 2: I pretend that I hate it. Moving forward, but yeah,

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Speaker 2: New York does have the best pizza.

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Speaker 1: It's similar to that, actually, because some people defend Chicago

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Speaker 1: pizza and it's a tasty thing, but it's not pizza. Yeah,

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Speaker 1: you know, it's like Mari Andara bathtub or something. I mean,

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Speaker 1: it's delicious and greasy and it's good, but it's not pizza. Yeah,

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Speaker 1: and when I gotta choose and I gotta make it myself,

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Speaker 1: I'm definitely making thin crust pizza, though with a little

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Speaker 1: bit more of a Neapolitan puffy crust around the edge.

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Speaker 2: Yeah. I love that all. I mean, I love all

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Speaker 2: kinds of pizza. But yeah, whenever I go to New York,

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Speaker 2: I've got to get some pizza.

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Speaker 1: And I don't know why they got to call it pizza,

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Speaker 1: you know, like they don't call the Chicago hot dog

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Speaker 1: like a taco, you know, like just call it its

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Speaker 1: own thing. Why we use this word pizza for something

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Speaker 1: which is to totally different from pizza.

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Speaker 2: I mean, it's got the same ingredients, but just in

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Speaker 2: different like depth. No you disagree, I don't know.

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Speaker 1: I recently tried Detroit Pizza, also quite tasty, very weird, delicious,

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Speaker 1: but still in my opinion, not pizza. But you know

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Speaker 1: that's semantic. It's all delicious combination of excellent ingredients. My

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Speaker 1: personal preference is the thin stuff. But you know, I

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Speaker 1: get why people like Chicago pizza.

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Speaker 2: We won't talk about pizza for that much longer because

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Speaker 2: we have important sites to get to you. But I

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Speaker 2: heard that Detroit Pizza is like in an like an

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Speaker 2: automotive pan of some sort, or like what is the

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Speaker 2: defining feature of Detroit pizza? Presumably you clean the pan first.

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Speaker 1: Detroit is also a deep dish kind of pizza. But

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Speaker 1: you have like sauce on the top in these rows

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Speaker 1: on top of the cheese, and you get this crispy

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Speaker 1: edge of cooks up if you do it right. Anyway,

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Speaker 1: it's quite good.

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Speaker 2: Okay, I should have eaten before we started recording this

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Speaker 2: because now I'm hungry.

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Speaker 1: But all right, but you know, if you eat too

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Speaker 1: much Chicago pizza or too much Detroit pizza, you risk

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Speaker 1: collapsing into a black hole.

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Speaker 2: Ah, that's where it was going. You got there first.

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Speaker 2: I was actually gonna like contribute a transition. But okay,

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Speaker 2: so today we're talking about black holes, all right, and

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Speaker 2: we are specifically talking about whether or not stars could

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Speaker 2: have black holes at their core. And I will be honest.

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Speaker 2: When you first sent this question to me, my thought was, well,

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Speaker 2: could a star exist if it had a black hole

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Speaker 2: in its core? It seems like the answer should be no.

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Speaker 2: And so let's see if our audience's guts had the

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Speaker 2: same response.

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Speaker 1: No matter what pizza they happen to be digesting.

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Speaker 2: We hope it's delicious no matter what it is.

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Speaker 3: I guess stuff in the core of a star could

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Speaker 3: get dance enough that it would turn into a black hole,

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Speaker 3: but maybe that will eventually end up extinguishing the star,

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Speaker 3: because I can see how the star could keep on

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Speaker 3: burning only with its alter or shell. So I guess

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Speaker 3: if that happens, it will be short lived and the

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Speaker 3: star will die and turn into a black hole.

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Speaker 4: I suspect a star can have a black hole for

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Speaker 4: a core as long as the star is both big

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Speaker 4: enough to survive then usual black hole formation and big

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Speaker 4: enough that the black hole's gravity doesn't affect the outermost

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Speaker 4: layers of the star.

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Speaker 2: I suspect not it would collapse the whole star material,

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Speaker 2: I think, into itself that's no longer being a star.

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Speaker 5: I think it's possible to have a black hole inside

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Speaker 5: the star in the core, because a black hole can

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Speaker 5: be small enough even for you to have it in

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Speaker 5: your hand, isn't it, And it would not.

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Speaker 3: Affect the surrounded Because it's more.

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Speaker 6: I don't believe a star could have a black hole core,

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Speaker 6: mainly because for want to fall in the first place,

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Speaker 6: a star would have to collapse, and if there was

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Speaker 6: such a condition where it did have a black hole

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Speaker 6: as its core, the gravitational force would pull in the

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Speaker 6: surrounding matter that makes up the star anyway, so it

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Speaker 6: could never be stable enough.

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Speaker 7: It seems possible, but then you'd have to ask how

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Speaker 7: did it get there and how does it stay there?

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Speaker 7: And I don't know how it would form, but for

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Speaker 7: it to stay there, the star around it would have

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Speaker 7: to be spinning very very fast so it doesn't get

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Speaker 7: pulled in, and I don't really know how that would

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Speaker 7: ever start happening.

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Speaker 2: Okay, so I'm feeling pretty good because a handful of

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Speaker 2: our audience members had the same feeling as I did.

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Speaker 2: And you know, I haven't gotten to the end of

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Speaker 2: the outline yet, so I don't know if I'm right

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Speaker 2: or if I'm wrong. It'll be an exciting journey that

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Speaker 2: we'll take together.

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Speaker 1: And these are great ideas. I like the way they're thinking.

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Speaker 1: But you know, it strikes me that a lot of

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Speaker 1: people think of black holes as like this infinitely powerful

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Speaker 1: thing that will suck in anything. But you know, we've

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Speaker 1: seen pictures of black holes, and we know what black

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Speaker 1: holes should look like out there in nature and they're

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Speaker 1: not totally by themselves. You can have stuff around the

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Speaker 1: black hole, Like the famous picture of a black hole

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Speaker 1: has a hot disk of gas right around it, because

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Speaker 1: the environment around a black hole is quite complex and

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Speaker 1: there's pressure out and gravitational attraction in, and so we're

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Speaker 1: going to learn it's not quite so simple. Yeah.

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Speaker 2: I was talking to Sarah Gallagher at Western University the

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Speaker 2: other day and she studies the gases that like emit

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Speaker 2: out of black holes, and I just kind of stared

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Speaker 2: at her for a second because I was like, I

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Speaker 2: didn't think anything could escape from black holes, and so

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Speaker 2: we had a fascinating conversation about how I was wrong.

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Speaker 1: Yeah, well, you're right that nothing can escape from a

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Speaker 1: black hole, but things can escape from the vicinity of

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Speaker 1: a black hole, right, And so it depends what you

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Speaker 1: count as the black hole. If it's a black hole,

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Speaker 1: plus it's accretion disk and all that stuff, then yeah,

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Speaker 1: it can emit, and they certainly do. We see quasars

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Speaker 1: from across the universe these incredibly bright emitters.

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Speaker 2: Okay, but I think we can all agree that nothing

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Speaker 2: escapes from the center of a black hole. So if

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Speaker 2: you are a star that has a black hole, in

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Speaker 2: your belly. It feels like that shouldn't work out. So

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Speaker 2: where do we start. What do we think stars have

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Speaker 2: at their center?

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Speaker 1: Yeah? Stars already super fascinating objects even without the black hole. Right,

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Speaker 1: It's incredible that these things exist. There are this delicate

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Speaker 1: balance between gravity and fusion. But they're also stable. They

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Speaker 1: can last for millions or billions, or we think sometimes

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Speaker 1: trillions of years. It's really incredible, and understanding what's going

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Speaker 1: on at their heart has taught us a lot about

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Speaker 1: the nature of physics and even chemistry.

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Speaker 6: Yeah.

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Speaker 2: I also had the urge to sort of spit and costs,

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Speaker 2: so I understand I'm.

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Speaker 1: Going to wipe my face before we go on. Yeah,

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Speaker 1: and also the distribution of stars that are out there,

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Speaker 1: the sizes, the colors, the ages tell us a lot

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Speaker 1: about the history of the universe. I love this about

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Speaker 1: science that you can piece together a whole history from

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Speaker 1: what you see around you. It's not just like does

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Speaker 1: this work, but it's like, how did we end up here?

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Speaker 1: Why do we have this arrangement of stuff? And that's

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Speaker 1: some other arrangement. There's so much information just encoded in

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Speaker 1: what's out there, So I love that we can dig

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Speaker 1: into it, and from that we've put together a pretty

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Speaker 1: good model for house stars form and what should be

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Speaker 1: at their center before we get into exotic black hole stars.

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Speaker 2: Yeah, I also love that kind of detective work into

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Speaker 2: the past, using science to understand things we couldn't have seen.

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Speaker 2: But okay, let's jump into stars. What should be in

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Speaker 2: the center of those stars.

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Speaker 1: So stars are basically just a scoop of universe, you know,

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Speaker 1: go all the way back to Big Bang, hot, dense

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Speaker 1: soup of stuff. It expands and therefore it cools, and

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Speaker 1: you get particles that form. You get electrons and quarks,

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Speaker 1: and then the quarks bind into protons, and then you

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Speaker 1: have protons and electrons in the universe. It keeps cooling,

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Speaker 1: and those electrons then get captured by the protons, and

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Speaker 1: so now you have hydrogen. And most of the universe

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Speaker 1: at the very beginning is hydrogen. It's like overwhelmingly hydrogen.

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Speaker 1: Tiny little bit of helium that forms because you can

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Speaker 1: actually have hydrogen fusion during the first few moments of

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Speaker 1: the universe to make a little bit of helium trace

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Speaker 1: anything else. So the universe is hydrogen, but it's not

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Speaker 1: perfectly smooth. The original quantum fluctuations in the early universe

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Speaker 1: lead to over densities in some places and under densities

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Speaker 1: in others, which gives gravity a handle to pull that

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Speaker 1: stuff together to make stars. And so you have these

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Speaker 1: big clouds of hydrogen. Some spots are little. They have

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Speaker 1: more gravity, they pull on more hydrogen, gives them more gravity,

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Speaker 1: gives them more hydrogen. You get this runaway effect, and

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Speaker 1: then you get a collapse. So the first stars we

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Speaker 1: think were mostly hydrogen and a little bit of helium.

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Speaker 2: And if you were explaining how black holes are formed,

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Speaker 2: would you have used all the same words or is

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Speaker 2: that a totally different process?

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Speaker 1: No, basically the same. But you need to get to

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Speaker 1: a critical density to form a black hole. And what

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Speaker 1: happens when a star is collapsing is that gravity isn't

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Speaker 1: the only game in town. You get to a certain

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Speaker 1: density at the core of the star and it ignites fusion.

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Speaker 1: So it's hot enough and it's dense enough that the protons,

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Speaker 1: which don't usually like to talk to each other because

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Speaker 1: they're both positively charged, are squeezed together close enough that

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Speaker 1: eventually they will fuse and they'll give you helium and

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Speaker 1: release some energy. So this is fusion. You get protons

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Speaker 1: fusing into helium and energy comes out, and that energy

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Speaker 1: pushes back out on the star. It's effectively a pressure outwards,

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Speaker 1: so you have gravity squeezing in and radiation pressure pushing out.

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Speaker 1: That's what keeps the star from collapsing into a black hole.

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Speaker 1: So you're right, black hole collapse very very similar, but

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Speaker 1: you don't get there in a star because of fusion.

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Speaker 1: Fusion keeps the universe from collapsing into black holes and

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Speaker 1: keeps it bright. Right without fusion, we wouldn't have light,

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Speaker 1: and the whole universe would be dark.

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Speaker 2: Thank you fusion. If only we could use it to

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Speaker 2: power our toasters, we'll get there one day.

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Speaker 1: And this is not the primary topic of today's episode,

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Speaker 1: but there is a theory that in the very very

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Speaker 1: early universe, there might have been enough over density, maybe

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Speaker 1: even before you formed all those protons to create primordial

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Speaker 1: black holes, which exist like before there are quirks and

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Speaker 1: protons and all sorts of stuff, so it's possible to

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Speaker 1: form black holes in the very very early universe. A

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Speaker 1: lot of people ask, like, if the universe was super dense,

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Speaker 1: why didn't the whole thing collapse into a black hole?

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Speaker 1: And the reason is that for a black hole to form,

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Speaker 1: you need density in one place relative to the density

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Speaker 1: around it. If everything is super dense, then nothing is

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Speaker 1: getting pulled. But if you happen to have once which

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Speaker 1: is super overdense, potentially you can have direct collapse into

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Speaker 1: a black hole in the early universe. But we're not

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Speaker 1: talking about that today. We're imagining what happens to normal stars.

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Speaker 1: So you get this collapse, you get fusion, and then

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Speaker 1: you have a balance. Gravity and radiation are doing this

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Speaker 1: delic balance and it can keep going for millions and

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Speaker 1: millions of years. And at the core you're manufacturing new elements.

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Speaker 1: So we're talking about what's at the core of stars. Well,

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Speaker 1: it starts out with just hydrogen, and then you get helium,

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Speaker 1: and if the star is big enough and massive enough,

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Speaker 1: it could also fuse that helium into heavier stuff. You

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Speaker 1: get carbon, you get neon, you get oxygen, and if

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Speaker 1: it's big enough and massive enough, you can get silicon.

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Speaker 1: You can get all the way up to nickel and

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Speaker 1: then to iron. So that's how we manufacture these elements.

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Speaker 1: They're made at the hearts of stars.

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Speaker 2: All right, Let's see if I can pass the qualifying exam

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Speaker 2: for my pod. If I remember correctly, the bigger the

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Speaker 2: elements that you're getting, the more like heat you're losing,

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Speaker 2: and over time that cools the star. Is that right?

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Speaker 1: Almost? No, Definitely, the spirit of it is right. You know,

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Speaker 1: up to a certain point, you are generating heat. So

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Speaker 1: before iron fusion creates heat, like when you go from

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Speaker 1: lighter elements to heavier elements, you release heat above iron

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Speaker 1: fusion costs heat, right, it takes energy, So it can

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Speaker 1: happen because there is energy there, but effectively cools the

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Speaker 1: star when you fuse iron nuclei together to make something

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Speaker 1: even heavier. And so that doesn't mean it doesn't happen,

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Speaker 1: but it means it effectively kills the star because now

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Speaker 1: the star is cooling down, and if it's cooling down,

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Speaker 1: it can't push back against gravity. And what do you

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Speaker 1: have is you start to have a gravitational collapse again,

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Speaker 1: and then you can form like a normal vanilla black hole,

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Speaker 1: like the kind that we have seen in our universe

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Speaker 1: where the whole star becomes a black hole. And we

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Speaker 1: talk about that a little bit more detail in a minute.

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Speaker 1: But there's another thing that we need to understand first

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Speaker 1: about normal stars, which is the limit on their size,

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Speaker 1: and the connection between the size and the age of

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Speaker 1: the star. You have the whole early universe, big cloud

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Speaker 1: of hydrogen, some clumps of which collapse to make stars.

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Speaker 1: And you might wonder, like, is there a limit to

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Speaker 1: the size of the star, Like can you just get

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Speaker 1: huge clouds that form together to make enormous mega stars?

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Speaker 1: And the answer is that there is kind of a

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Speaker 1: limit because the bigger the star, the higher the pressure

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Speaker 1: and the density and the temperature of the core, and

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Speaker 1: the faster fusion happens. Because fusion is very sensitive to

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Speaker 1: the temperature and the pressure. Like you increase the pressure

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Speaker 1: by a little bit, the rate of fusion increases very

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Speaker 1: very quickly. And so what happens if you have a

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Speaker 1: star that's too big is that the radiation pressure from

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Speaker 1: the fusion is so intense that actually blows the star apart.

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Speaker 1: It'll like rip apart the star and blow away its

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Speaker 1: outer layers so effectively, you can't get a star that's

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Speaker 1: like more than three hundred times the mass of our Sun.

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Speaker 1: It'll tear itself apart.

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Speaker 2: That would be a pretty epic way to go. I

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Speaker 2: think my new goal is to become super massive towards

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Speaker 2: the end of my life.

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Speaker 1: Blow yourself apart from the fusion that you're That's what

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Speaker 1: happens if you eat too much Chicago pizza.

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Speaker 2: Yeah, yeah, you gotta be careful. You gotta be careful.

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Speaker 1: And there's something else happening at the core of the star,

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Speaker 1: which is really crucial. You've made those elements, right, you've

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Speaker 1: made helium or iron or nickel or whatever. They're at

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Speaker 1: the core of the star. But when the star dies,

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Speaker 1: it goes supernova and it blows that material out into

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Speaker 1: the universe, and then those heavy metals become the seeds

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Speaker 1: of the next generation of stars. So when we start out,

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Speaker 1: we have a universe mostly filled with gas that makes

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Speaker 1: these really big stars, huge stars that don't last very long,

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Speaker 1: maybe a few million years because they're so big. But

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Speaker 1: the next generation it's different because now you have these

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Speaker 1: heavy seeds to start stars. You don't just have to

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Speaker 1: have a big hydrogen clump to start a big hydrogen star.

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Speaker 1: You have like a blob of iron over here and

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Speaker 1: some nickel over there, and those are excellent. It's seeding

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Speaker 1: new stars. So then the next generation of stars are

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Speaker 1: smaller because there's like more places to start, So the

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Speaker 1: big clouds of hydrogen breakup into more chunks, and because

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Speaker 1: they're smaller, they don't burn its hot and they ask longer.

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Speaker 1: So the second generation of stars that have more metals

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Speaker 1: in them last a lot longer than the first generation

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Speaker 1: and are also smaller.

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Speaker 2: That is beautiful, But my brain has gotten totally off

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Speaker 2: on a tangent imagining Kelly at the bend of her

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Speaker 2: life exploding into lots of little Kelly's, and that really

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Speaker 2: would be a great way to go.

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Speaker 1: Next generation of Kelly's will all be mini Kelly's. Yeah exactly,

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Speaker 1: that's right, that's right.

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Speaker 2: But at least there'll be more of them anyway. That

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Speaker 2: is beautiful that a giant star produces more stars.

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Speaker 1: Yeah, exactly. And in our universe we still have some

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Speaker 1: big stars, Like if you look at the star mass distribution,

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Speaker 1: mostly the stars in the universe are smaller, like our

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Speaker 1: star is on the heavier, larger side compared to the

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Speaker 1: average star. We may have yellow star, but most of

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Speaker 1: the stars out there are red dwarfs. They're smaller and colder,

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Speaker 1: and therefore they burn cooler than our star. So the

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Speaker 1: smaller the star, the cooler, the redder it is. The

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Speaker 1: bigger the star, the hotter and bluer.

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Speaker 6: It is.

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Speaker 1: So if you look out into the universe, you can

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Speaker 1: actually tell the age distribute of stars because the blue

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Speaker 1: stars disappear more quickly. So if you're like looking at

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Speaker 1: a part of the universe and there's a bunch of

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Speaker 1: blue stars, you know that stars have been formed there recently,

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Speaker 1: Whereas if you look at some corner of the universe

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Speaker 1: you're like, oh, it's all red stars, then you know

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Speaker 1: there have been no stars born recently. It's like a

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Speaker 1: retirement home versus a new subdivision or something.

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Speaker 2: But like, could you make a reasonable guess at star siblings,

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Speaker 2: Like this star exploded and produced these thirty stars in response.

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Speaker 1: You can understand stars siblings in the sense of like

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Speaker 1: you can estimate the age of a star from its neighbors, right, Like,

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Speaker 1: if there are no blue stars around, you can guess

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Speaker 1: that it's probably older, and if there's lots of blue

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Speaker 1: stars around, you can guess that it's probably younger. It's

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Speaker 1: really hard to trace back an individual star and say

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Speaker 1: this one was formed from the explosion of that earlier

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Speaker 1: star which no longer exists, and the other ones that

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Speaker 1: came from that star that's really tricky. And also it's

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Speaker 1: complicated because like our sun was formed from the remnants

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Speaker 1: of other stars, but not just one. Right, It's not

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Speaker 1: like one chunk of some other star landed in a

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Speaker 1: gas of high It's like a huge conglomeration of probably many,

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Speaker 1: many stars that all came together. So yeah, the family

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Speaker 1: tree gets pretty messy there. Yeah, it's like a big

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Speaker 1: orgy that happened to make our star.

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Speaker 2: Good. Good way to make this a non kid appropriate episode.

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Speaker 1: You can have totally family friendly orgies. You can have

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Speaker 1: like an orgy of pizza for example, right, sampling lots

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Speaker 1: of different pizzas.

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Speaker 2: Yeah, I'm not sure that you know what people usually

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Speaker 2: mean when they use that word, Daniel.

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Speaker 1: I know what people usually mean. I'm saying for folks

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Speaker 1: that they're listening with your kids, there's an explanation for you.

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Speaker 7: Yeah.

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Speaker 2: I hope they don't repeat it at school. All right, So,

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Speaker 2: should we talk about any other stars on our tour

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Speaker 2: of local Stars?

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Speaker 1: Yeah? So there are some really big stars in our universe,

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Speaker 1: and they're really fun to think about because the sizes

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Speaker 1: are just really incredible. A famous big star is Beetlejuice.

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Speaker 2: Beetlejuice is Oh, that's two, don't say it a third time.

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Speaker 1: That star is famous because it's in Orion and it

390
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Speaker 1: has a radius a thousand times that of our Sun. Wow,

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Speaker 1: Like the Sun is already enormous compared to Jupiter, which

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Speaker 1: is gigantic compared to the Earth. And now Beetle Juice,

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Speaker 1: it's showtime. It's a thousand times the radius, which means

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Speaker 1: a billion times the volume.

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Speaker 2: Holy cos it's just.

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Speaker 1: Hard to really wrap your mind around. If you put

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Speaker 1: it in our solar system, its edge would be at

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Speaker 1: the orbit of Jupiter, right, we would be inside Beetlejuice. Also,

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Speaker 1: it's a weird star because recently it's been seen to

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Speaker 1: be dimming, so it's like quite variable in ways people

401
00:19:33,600 --> 00:19:36,800
Speaker 1: don't understand, which some people think might mean it's about

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Speaker 1: to go supernova and there's interesting stuff happening at its core.

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Speaker 1: But again, we don't really understand the core of stars

404
00:19:42,359 --> 00:19:45,119
Speaker 1: in detail. It's so chaotic and difficult to describe with

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Speaker 1: simple equations and expensive to model with supercomputers. So it's

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Speaker 1: really an active area of research. But that's a really cool,

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00:19:52,320 --> 00:19:52,960
Speaker 1: really big star.

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Speaker 2: So my interest in a topic is directly proportional to

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Speaker 2: how much it impacts me. So if beetlejuice explodes, is

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Speaker 2: that going to be bad for me?

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Speaker 1: If beetlejuice explodes, it'll be dramatic and exciting, but probably

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Speaker 1: not super dangerous. It's six hundred and fifty light years away.

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Speaker 1: It's not the time of travel that keeps us safe.

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Speaker 1: It's not like, oh, it explodes, we have six hundred

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Speaker 1: and fifty years to do something about it. We won't

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Speaker 1: know it explodes until six hundred and fifty years after

417
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Speaker 1: it explodes, because that's when the signal is going to

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Speaker 1: arrive here on Earth. But because it's so far away,

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Speaker 1: the radiation it produces will be quite diluted. That radiation

420
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Speaker 1: is going to spread out in a huge sphere and

421
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Speaker 1: cover the inside of that sphere, and the Earth is

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Speaker 1: a tiny, tiny slice of that. So we're only in

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Speaker 1: danger to supernovas that are much closer than that.

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Speaker 2: Okay, that's good. I feel great. Now that I feel great,

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Speaker 2: Let's take a break, have some pizza, and when we

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Speaker 2: come back, we'll talk some more about some big stars

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Speaker 2: in our galaxy. All right, so I hope you had

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Speaker 2: some delicious New York style pizza. Let's go and talk

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Speaker 2: about yet another star in our galaxy? Which one are

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Speaker 2: we talking about next, Daniel?

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00:21:14,280 --> 00:21:16,639
Speaker 1: So the biggest star that we know about is a

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Speaker 1: star called Stephenson to eighteen. This one has twice the

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Speaker 1: radius of Beetlejuice. Right, Beetle Juice already a thousand times

434
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Speaker 1: the radius of the Sun. This one's twenty one hundred.

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Speaker 1: And it's so big that it's so hot. It's five

436
00:21:31,359 --> 00:21:35,600
Speaker 1: hundred thousand times brighter than the sun. Wow, Like, imagine

437
00:21:35,760 --> 00:21:40,080
Speaker 1: five hundred thousand suns in the sky. That's Stevenson two eighteen.

438
00:21:40,160 --> 00:21:41,199
Speaker 1: It's not kidding around.

439
00:21:41,400 --> 00:21:43,760
Speaker 2: So how is it that I have heard of Beetlejuice before,

440
00:21:43,800 --> 00:21:45,719
Speaker 2: but I haven't heard of Stevenson to eighteen.

441
00:21:45,960 --> 00:21:48,439
Speaker 1: Beetlejuice is a star in the sky, it's a constellation.

442
00:21:48,720 --> 00:21:52,520
Speaker 1: Stevenson to eighteen is much much further away. It's like

443
00:21:52,680 --> 00:21:56,920
Speaker 1: nineteen thousand light years away, so it's still in our galaxy,

444
00:21:56,920 --> 00:21:59,359
Speaker 1: but it's like a completely different arm so you can't

445
00:21:59,359 --> 00:22:02,000
Speaker 1: really see it with the naked eye. It's something we've discovered,

446
00:22:02,000 --> 00:22:03,919
Speaker 1: and there's still a lot of uncertainty about what we

447
00:22:03,960 --> 00:22:06,880
Speaker 1: know about it because it's so far away. But yeah,

448
00:22:06,920 --> 00:22:09,040
Speaker 1: it's a pretty dramatic star. And this is one of

449
00:22:09,040 --> 00:22:12,239
Speaker 1: the things I love about astrophysics and astronomy is like

450
00:22:12,440 --> 00:22:14,200
Speaker 1: the more you look out into the universe, the more

451
00:22:14,280 --> 00:22:16,639
Speaker 1: weird stuff you see that you can't explain, you know.

452
00:22:16,680 --> 00:22:20,359
Speaker 1: It's just like always a surprise when you build something new,

453
00:22:20,359 --> 00:22:22,280
Speaker 1: which is why I think we should have like ten

454
00:22:22,359 --> 00:22:25,080
Speaker 1: times as many space telescopes as we do and ground

455
00:22:25,119 --> 00:22:28,120
Speaker 1: telescopes and satellites, and like, wow, think about the things

456
00:22:28,119 --> 00:22:30,760
Speaker 1: we're missing in the universe just because we're not looking.

457
00:22:31,119 --> 00:22:33,480
Speaker 2: That's right, And we in more money for fish research too.

458
00:22:34,320 --> 00:22:37,719
Speaker 2: We're missing things we could be looking all over the place, guys,

459
00:22:37,840 --> 00:22:40,080
Speaker 2: and we're not looking. Enough more money for science.

460
00:22:40,359 --> 00:22:43,240
Speaker 1: Let's build a space telescope that's excellent at finding alien

461
00:22:43,280 --> 00:22:46,280
Speaker 1: fish on exoplanets. How about that? Is that a good compromise, Daniel?

462
00:22:46,359 --> 00:22:50,320
Speaker 2: I am so glad we found something we can agree on. Yes, amazing.

463
00:22:50,920 --> 00:22:53,800
Speaker 2: As long as those alien fish have alien parasites, I'm

464
00:22:53,800 --> 00:22:55,600
Speaker 2: one hundred percent in and I bet they.

465
00:22:55,520 --> 00:22:58,159
Speaker 1: Will, all right, excellent. I look forward to building that

466
00:22:58,200 --> 00:23:02,359
Speaker 1: telescope with you. Okay, it's slam dunk funding case for sure.

467
00:23:02,480 --> 00:23:04,639
Speaker 2: They can't turn us down, all right, So let's focus

468
00:23:05,280 --> 00:23:08,199
Speaker 2: away from fish unfortunately onto black holes. All right, so

469
00:23:08,240 --> 00:23:10,679
Speaker 2: let's go you. You told us that some of the

470
00:23:10,720 --> 00:23:13,680
Speaker 2: process for starting a star is similar to the process

471
00:23:13,720 --> 00:23:18,400
Speaker 2: for starting a black hole. Remind me where those processes diverge, please.

472
00:23:18,359 --> 00:23:20,639
Speaker 1: Yeah, So a lot of stars end up as black

473
00:23:20,640 --> 00:23:24,520
Speaker 1: holes because fusion can't last forever. Right, it's eating the

474
00:23:24,560 --> 00:23:28,000
Speaker 1: stars using the star as fuel. It's converting the light

475
00:23:28,040 --> 00:23:31,480
Speaker 1: stuff into heavy stuff, and eventually converts it into heavy

476
00:23:31,480 --> 00:23:34,160
Speaker 1: stuff that it can no longer burn. Like our sun

477
00:23:34,440 --> 00:23:37,439
Speaker 1: is hot enough to burn hydrogen, and near the end

478
00:23:37,440 --> 00:23:38,919
Speaker 1: of its life, it's going to be hot enough to

479
00:23:38,920 --> 00:23:42,480
Speaker 1: burn helium very very briefly. But anything heavier than that.

480
00:23:42,480 --> 00:23:45,280
Speaker 1: Our sun doesn't create the temperatures and the pressures and

481
00:23:45,280 --> 00:23:48,719
Speaker 1: the densities to fuse, and so anything else that it

482
00:23:48,760 --> 00:23:52,200
Speaker 1: makes is inert. It interferes with the process of the star.

483
00:23:52,720 --> 00:23:55,080
Speaker 1: And so that's why our sun, for example, is going

484
00:23:55,119 --> 00:23:58,639
Speaker 1: to get a core that's basically dead. It's not participating

485
00:23:58,640 --> 00:24:00,840
Speaker 1: in fusion anymore, and then fusions are going to move

486
00:24:00,880 --> 00:24:03,040
Speaker 1: to outer layers of the star, and that's why the

487
00:24:03,080 --> 00:24:04,920
Speaker 1: star puffs up near the end of its life. You hear,

488
00:24:04,960 --> 00:24:07,040
Speaker 1: like the sun is getting hotter and bigger and in

489
00:24:07,119 --> 00:24:09,280
Speaker 1: billion years it's going to be really big. And that's

490
00:24:09,359 --> 00:24:12,320
Speaker 1: true because the fusion is moving to the outer layers

491
00:24:12,320 --> 00:24:15,960
Speaker 1: where there still is hydrogen. But eventually the star accumulates

492
00:24:16,000 --> 00:24:19,800
Speaker 1: so much heavy inert stuff, stuff that can't participate in fusion,

493
00:24:20,160 --> 00:24:23,960
Speaker 1: that the star collapses. Gravity winds right, Eventually fusion just

494
00:24:24,040 --> 00:24:27,520
Speaker 1: peters out, and this collapse is really spectacular. You get

495
00:24:27,520 --> 00:24:30,520
Speaker 1: this pressure wave that goes into the star and then

496
00:24:30,560 --> 00:24:33,280
Speaker 1: it bounces back and comes out and explodes the star.

497
00:24:33,320 --> 00:24:35,159
Speaker 1: And that's where you get a supernova. Right, It's like

498
00:24:35,200 --> 00:24:37,520
Speaker 1: this shock wave that goes in and then out that

499
00:24:37,560 --> 00:24:43,160
Speaker 1: travels are like incredible velocities, really violent stuff, really amazing.

500
00:24:43,320 --> 00:24:45,399
Speaker 2: You sound like my daughter. She's really into violent stuff

501
00:24:45,440 --> 00:24:48,200
Speaker 2: right now. She also sounds very excited when she's fucking

502
00:24:48,200 --> 00:24:49,600
Speaker 2: about explosions and stuff.

503
00:24:50,200 --> 00:24:52,479
Speaker 1: Well, it's not that I want anybody start to blow up,

504
00:24:52,520 --> 00:24:56,160
Speaker 1: it's just the energy is just incredible. The numbers here

505
00:24:56,320 --> 00:24:59,440
Speaker 1: are just mind boggling. And then what happens at the

506
00:24:59,480 --> 00:25:01,639
Speaker 1: core of the star depends on the amount of mass,

507
00:25:02,000 --> 00:25:04,560
Speaker 1: So you get this really hot dense thing left over.

508
00:25:05,000 --> 00:25:07,280
Speaker 1: If it's not quite dense enough, it can form a

509
00:25:07,320 --> 00:25:10,480
Speaker 1: neutron star, which doesn't collapse into a black hole because

510
00:25:10,480 --> 00:25:13,560
Speaker 1: there's something else pushing back. Now, it's not fusion pressure.

511
00:25:13,640 --> 00:25:16,160
Speaker 1: Neutron star is a star, but there's no fusion happening.

512
00:25:16,440 --> 00:25:20,239
Speaker 1: It's just electron degeneracy pressure. Like the particles that are

513
00:25:20,240 --> 00:25:22,560
Speaker 1: in there, they're all fermions, which means they don't like

514
00:25:22,600 --> 00:25:24,960
Speaker 1: to be on top of each other the way electrons don't,

515
00:25:25,200 --> 00:25:28,600
Speaker 1: and that effectively creates a pressure. Like they can't squeeze

516
00:25:28,640 --> 00:25:32,080
Speaker 1: down and cool down into the lowest energy levels because

517
00:25:32,119 --> 00:25:34,640
Speaker 1: they can't be in the same energy levels, and so

518
00:25:34,680 --> 00:25:36,880
Speaker 1: they have to be in higher energy levels, which means

519
00:25:36,880 --> 00:25:39,800
Speaker 1: they keep some energy, they move around, they basically push back.

520
00:25:40,160 --> 00:25:42,560
Speaker 1: That's what degeneracy pressure is. People write in sometimes and

521
00:25:42,600 --> 00:25:46,160
Speaker 1: ask like what force is degeneracy pressure, or like why

522
00:25:46,160 --> 00:25:49,040
Speaker 1: does the universe keep particles from entering the same state?

523
00:25:49,400 --> 00:25:51,359
Speaker 1: You know, And there's no special force there. It's just

524
00:25:51,440 --> 00:25:54,520
Speaker 1: that the particles cannot be in the same state, and

525
00:25:54,600 --> 00:25:56,960
Speaker 1: so they stay in higher energy levels to avoid each other,

526
00:25:57,080 --> 00:26:01,399
Speaker 1: and that creates pressure. Effectively. Start doesn't collapse because of

527
00:26:01,480 --> 00:26:05,840
Speaker 1: quantum mechanics. But you know, eventually, if you have enough mass,

528
00:26:05,880 --> 00:26:08,320
Speaker 1: it can overcome that. It can push these things together,

529
00:26:08,400 --> 00:26:11,240
Speaker 1: so they're no longer really neutrons. Like they get smushed

530
00:26:11,240 --> 00:26:14,200
Speaker 1: together and their neutron this sort of goes away as

531
00:26:14,200 --> 00:26:17,120
Speaker 1: the quarks form this soup, and then the proto black

532
00:26:17,119 --> 00:26:19,600
Speaker 1: hole can collapse. So if you have enough pressure to

533
00:26:19,640 --> 00:26:23,080
Speaker 1: squeeze those neutrons out of their fermion states and form

534
00:26:23,119 --> 00:26:25,160
Speaker 1: a soup, you can form a black hole. And that's

535
00:26:25,160 --> 00:26:27,080
Speaker 1: when you get above this critical threshold.

536
00:26:27,160 --> 00:26:29,520
Speaker 2: Okay, So when we first started talking about fermions and

537
00:26:29,560 --> 00:26:31,480
Speaker 2: you said that they don't like to be near each

538
00:26:31,480 --> 00:26:33,920
Speaker 2: other the same way that electrons don't, I have been

539
00:26:33,920 --> 00:26:38,480
Speaker 2: thinking about fermions as something that was kind of electron adjacent,

540
00:26:38,520 --> 00:26:41,160
Speaker 2: and I forgot that fermions are more like neutrons.

541
00:26:41,480 --> 00:26:46,800
Speaker 1: Well, fermions are category particle. All matter are fermions, electrons, quarks, neutrons, protons,

542
00:26:46,840 --> 00:26:50,240
Speaker 1: they're all fermions. And fermions have this particular property that

543
00:26:50,280 --> 00:26:52,200
Speaker 1: you can't have two of them in the same quantum state,

544
00:26:52,280 --> 00:26:54,919
Speaker 1: which is why electrons, for example, are not all in

545
00:26:54,960 --> 00:26:58,600
Speaker 1: the lowest energy level around hydrogen. When the lowest energy

546
00:26:58,680 --> 00:27:00,560
Speaker 1: levels filled, the next one can't be there. It's got

547
00:27:00,600 --> 00:27:01,920
Speaker 1: to be in the next level, and then the next

548
00:27:02,000 --> 00:27:04,479
Speaker 1: level and then the next level. That's why electrons spread

549
00:27:04,520 --> 00:27:07,280
Speaker 1: out on the ladder of energy levels, one per level.

550
00:27:07,600 --> 00:27:09,800
Speaker 1: You know, there's like different spins you can have or whatever,

551
00:27:09,840 --> 00:27:12,080
Speaker 1: but they all have to be in a unique state,

552
00:27:12,119 --> 00:27:15,480
Speaker 1: which keeps the electrons effectively hotter. Right, If the electrons

553
00:27:15,480 --> 00:27:17,760
Speaker 1: could all collapse into the lowest energy level, they would

554
00:27:17,800 --> 00:27:20,479
Speaker 1: be cooler, but they're not, which keeps some electrons at

555
00:27:20,520 --> 00:27:23,000
Speaker 1: high energy. And that's the same thing that's happening in

556
00:27:23,040 --> 00:27:26,000
Speaker 1: the neutron star. The neutrons have to stay at higher

557
00:27:26,119 --> 00:27:29,080
Speaker 1: energy because they can't collapse all into the lowest energy state,

558
00:27:29,320 --> 00:27:32,040
Speaker 1: and that keeps the star hot, and that keeps pressure going.

559
00:27:32,680 --> 00:27:36,639
Speaker 2: Okay, and so when a big star collapses, presumably there's

560
00:27:36,720 --> 00:27:39,960
Speaker 2: still fermions around. But what you said was that the

561
00:27:40,000 --> 00:27:43,439
Speaker 2: black hole is so immense that it just squishes them

562
00:27:43,480 --> 00:27:47,080
Speaker 2: down anyway and overcomes their desire to remain in happy

563
00:27:47,080 --> 00:27:48,120
Speaker 2: states and push back out.

564
00:27:48,240 --> 00:27:52,600
Speaker 1: Yeah, exactly, because neutrons are fermions because they're combinations of quarks,

565
00:27:52,840 --> 00:27:55,480
Speaker 1: and so the rule still applies because you have fermions there.

566
00:27:55,840 --> 00:27:58,160
Speaker 1: But if you squeeze those quarks together, you can get

567
00:27:58,160 --> 00:28:00,480
Speaker 1: other states that are not fermions, and then it can

568
00:28:00,480 --> 00:28:03,199
Speaker 1: collapse them exactly. And the crucial thing to know for

569
00:28:03,240 --> 00:28:07,240
Speaker 1: our later discussion is that when this collapse happens, you

570
00:28:07,240 --> 00:28:09,359
Speaker 1: get a black hole. You get an enormous shockwave that

571
00:28:09,400 --> 00:28:13,359
Speaker 1: comes out right. This gravitational collapse produces an enormous shock wave,

572
00:28:13,600 --> 00:28:16,040
Speaker 1: and a black hole heats up everything around it. The

573
00:28:16,080 --> 00:28:19,080
Speaker 1: gravity the black hole is really intense. The accretion disc

574
00:28:19,160 --> 00:28:21,440
Speaker 1: the stuff around the black hole gets heated up by

575
00:28:21,440 --> 00:28:24,359
Speaker 1: the gravity of the black hole, and it radiates. This

576
00:28:24,480 --> 00:28:27,240
Speaker 1: is why black holes are so hot, because they heat

577
00:28:27,359 --> 00:28:30,280
Speaker 1: up everything around them, which then blows that stuff out.

578
00:28:30,440 --> 00:28:32,440
Speaker 1: So like, black holes is a limit to how fast

579
00:28:32,440 --> 00:28:35,040
Speaker 1: they can grow in the universe because they emit so

580
00:28:35,160 --> 00:28:38,520
Speaker 1: much radiation. They're pushing their food away from them. Yeah,

581
00:28:38,680 --> 00:28:40,400
Speaker 1: the more massive they get, the more they heat up

582
00:28:40,440 --> 00:28:43,160
Speaker 1: the stuff near them, which then blows the food away

583
00:28:43,200 --> 00:28:45,480
Speaker 1: from them. There's no theoretical limit to the size of

584
00:28:45,480 --> 00:28:47,600
Speaker 1: a black hole, but there's an effective limit to how

585
00:28:47,640 --> 00:28:51,240
Speaker 1: quickly they can grow because they push away their food.

586
00:28:51,480 --> 00:28:54,520
Speaker 2: Baffling. This blows my mind. I can't understand that behavior.

587
00:28:54,840 --> 00:28:58,520
Speaker 1: Yeah, and so these are normal stellar black holes, right,

588
00:28:58,680 --> 00:29:00,480
Speaker 1: These are black holes that form the end of the

589
00:29:00,520 --> 00:29:03,320
Speaker 1: life of a star. And so we call these small

590
00:29:03,360 --> 00:29:05,080
Speaker 1: black holes, even though they can be up to like

591
00:29:05,160 --> 00:29:07,280
Speaker 1: fifty or one hundred times the mass of the sun.

592
00:29:07,760 --> 00:29:09,959
Speaker 1: But there's another category of black holes that we need

593
00:29:10,000 --> 00:29:13,440
Speaker 1: to understand for today's episode, which are called super massive

594
00:29:13,560 --> 00:29:14,280
Speaker 1: black holes.

595
00:29:15,720 --> 00:29:16,600
Speaker 2: It's a great song.

596
00:29:18,800 --> 00:29:20,800
Speaker 1: And if I opened to Chicago Pizza doing, I would

597
00:29:20,840 --> 00:29:24,200
Speaker 1: call it super massive pizza because these are definitely like

598
00:29:24,240 --> 00:29:26,720
Speaker 1: a lot bigger. These are a few million to a

599
00:29:26,720 --> 00:29:29,680
Speaker 1: few billion times the mass of the sun. Wow, right,

600
00:29:29,720 --> 00:29:32,080
Speaker 1: like normal black holes, just one hundred times fifty times

601
00:29:32,120 --> 00:29:35,120
Speaker 1: the mass of the sun. This is millions or billions

602
00:29:35,200 --> 00:29:38,440
Speaker 1: of suns into a black hole. It's really incredible.

603
00:29:38,560 --> 00:29:41,560
Speaker 2: So how do you go from an exploding star to

604
00:29:41,720 --> 00:29:45,280
Speaker 2: something that's so much more massive than the star was initially?

605
00:29:45,600 --> 00:29:48,280
Speaker 1: Yeah, it's a good question, and people have been wondering

606
00:29:48,320 --> 00:29:51,800
Speaker 1: about this in particular for a long time, and they

607
00:29:51,800 --> 00:29:54,720
Speaker 1: asked exactly your question, and they did a bunch of simulations.

608
00:29:54,760 --> 00:29:57,120
Speaker 1: They thought, well, maybe you have early galaxies with early

609
00:29:57,200 --> 00:29:59,360
Speaker 1: stars and some of them formed black holes, and then

610
00:29:59,360 --> 00:30:02,680
Speaker 1: those black hole clump together and they just gather together

611
00:30:02,680 --> 00:30:04,920
Speaker 1: at the center, which makes sort of sense. And they

612
00:30:05,000 --> 00:30:08,280
Speaker 1: ran simulations, but those simulations do not describe what we

613
00:30:08,320 --> 00:30:11,400
Speaker 1: see like in those simulations, you do not get super

614
00:30:11,440 --> 00:30:14,360
Speaker 1: massive black holes. You get much smaller ones. But when

615
00:30:14,360 --> 00:30:16,680
Speaker 1: we look out into the universe, we can look really

616
00:30:16,720 --> 00:30:19,520
Speaker 1: far back in time at the formation of super massive

617
00:30:19,520 --> 00:30:21,760
Speaker 1: black holes and ask how long did it take in

618
00:30:21,800 --> 00:30:24,200
Speaker 1: the universe to form these black holes, And it didn't

619
00:30:24,240 --> 00:30:27,240
Speaker 1: take very long. We see super massive black holes at

620
00:30:27,280 --> 00:30:31,600
Speaker 1: the hearts of very very young galaxies much earlier than

621
00:30:31,640 --> 00:30:35,120
Speaker 1: we expect. So they're like super massive black holes that

622
00:30:35,160 --> 00:30:38,880
Speaker 1: are like thirteen billion years old, which is like about

623
00:30:38,880 --> 00:30:42,719
Speaker 1: a billion years after the universe began. You already have

624
00:30:43,240 --> 00:30:46,920
Speaker 1: black holes with like two billion solar masses. Nobody knows

625
00:30:46,960 --> 00:30:48,640
Speaker 1: how they got so big so fast.

626
00:30:49,000 --> 00:30:51,520
Speaker 2: So is that the answer, Like, we just we don't

627
00:30:51,520 --> 00:30:53,000
Speaker 2: know full step.

628
00:30:54,800 --> 00:30:56,960
Speaker 1: We don't know how super massive black holes have formed.

629
00:30:57,000 --> 00:31:00,479
Speaker 1: That is definitely a huge open question in astrophysics. There

630
00:31:00,480 --> 00:31:03,520
Speaker 1: are lots of crazy ideas out there. One of them

631
00:31:03,680 --> 00:31:06,320
Speaker 1: is the one I mentioned earlier, primordial black holes. People

632
00:31:06,320 --> 00:31:09,959
Speaker 1: thought maybe black holes formed in another special way, like

633
00:31:10,000 --> 00:31:13,400
Speaker 1: in the early universe there were already black holes formed

634
00:31:13,400 --> 00:31:17,240
Speaker 1: before even hydrogen, and so these guys were around to

635
00:31:17,320 --> 00:31:19,880
Speaker 1: see the formation of super massive black holes in the

636
00:31:19,960 --> 00:31:23,440
Speaker 1: universe perhaps, but nobody's ever seen a primordial black hole,

637
00:31:23,480 --> 00:31:26,440
Speaker 1: and we should have seen one if they existed, so

638
00:31:26,480 --> 00:31:29,560
Speaker 1: it's pretty hard to support that theory anymore. Although for

639
00:31:29,600 --> 00:31:31,920
Speaker 1: a while they were an exciting candidate for dark matter

640
00:31:32,000 --> 00:31:35,080
Speaker 1: because like, they're big, they're massive, they're dark. Maybe they

641
00:31:35,080 --> 00:31:38,080
Speaker 1: explain the missing matter, but again, we haven't seen them

642
00:31:38,120 --> 00:31:41,840
Speaker 1: and we should have. Another fun explanation for super massive

643
00:31:41,840 --> 00:31:44,640
Speaker 1: black holes came recently when people noticed that the rate

644
00:31:44,720 --> 00:31:48,280
Speaker 1: of super massive black hole formation, the rate of their growth,

645
00:31:48,720 --> 00:31:52,440
Speaker 1: seemed to link weirdly with the dark energy in the universe.

646
00:31:52,800 --> 00:31:54,640
Speaker 1: That like, the amount of dark energy in the universe

647
00:31:54,720 --> 00:31:57,520
Speaker 1: is increasing because the universe expands, and as it expands

648
00:31:57,600 --> 00:31:59,960
Speaker 1: makes more space than that space comes with more dark energy,

649
00:32:00,280 --> 00:32:03,240
Speaker 1: so the dark energy fraction is increasing as time goes on,

650
00:32:04,000 --> 00:32:06,920
Speaker 1: just like the super massive black hole mass is increasing.

651
00:32:07,080 --> 00:32:09,800
Speaker 1: They noticed a very tight correlation and they came up

652
00:32:09,800 --> 00:32:12,600
Speaker 1: with this theory, which went everywhere on social media when

653
00:32:12,600 --> 00:32:15,280
Speaker 1: it came out like last year or so, that maybe

654
00:32:15,440 --> 00:32:18,719
Speaker 1: super massive black holes are the source of dark energy.

655
00:32:18,880 --> 00:32:21,760
Speaker 1: That like, weirdly they're creating dark energy or they are

656
00:32:21,800 --> 00:32:25,320
Speaker 1: expanding the universe somehow. It's not a theory that's really

657
00:32:25,320 --> 00:32:28,640
Speaker 1: become mainstream. There's some questions and uncertainties about it. There's

658
00:32:28,640 --> 00:32:30,640
Speaker 1: a whole podcast episode about it. You should check it out.

659
00:32:30,720 --> 00:32:33,200
Speaker 1: But the point is that this is an open mystery.

660
00:32:33,640 --> 00:32:35,840
Speaker 1: How do you get black holes that are this big,

661
00:32:36,000 --> 00:32:38,400
Speaker 1: this massive in the early universe?

662
00:32:38,840 --> 00:32:40,800
Speaker 2: So how we how do? Real quick? Maybe you can

663
00:32:40,880 --> 00:32:43,560
Speaker 2: just tell me? So how does it get bigger and

664
00:32:43,600 --> 00:32:46,320
Speaker 2: more massive while also creating more dark energy?

665
00:32:46,520 --> 00:32:46,600
Speaker 1: Like?

666
00:32:47,280 --> 00:32:49,080
Speaker 2: Where is the energy for that coming from? You know what?

667
00:32:49,120 --> 00:32:51,240
Speaker 2: I'll listen to the episode. You didn't do that episode

668
00:32:51,240 --> 00:32:53,560
Speaker 2: with me? Right, and I've forgotten the answer? That was

669
00:32:53,560 --> 00:32:54,200
Speaker 2: one with Orgey.

670
00:32:54,400 --> 00:32:56,120
Speaker 1: Yeah, it's an episode I did with Jorgey quite a

671
00:32:56,120 --> 00:32:59,160
Speaker 1: while ago. It's a really fun idea, And there's two

672
00:32:59,160 --> 00:33:01,920
Speaker 1: things to understand that. One is that we do have

673
00:33:01,960 --> 00:33:05,080
Speaker 1: a theoretical model for black holes, like we can solve

674
00:33:05,120 --> 00:33:08,520
Speaker 1: the equations of general relativity for a black hole. But

675
00:33:08,600 --> 00:33:11,120
Speaker 1: there's a detail that's often left out when people say that,

676
00:33:11,280 --> 00:33:13,000
Speaker 1: which is that we only know how to solve these

677
00:33:13,040 --> 00:33:16,680
Speaker 1: equations for a black hole in an empty universe, Like

678
00:33:16,720 --> 00:33:19,240
Speaker 1: we can solve the equations for a super dense object

679
00:33:19,400 --> 00:33:22,840
Speaker 1: and nothing else. All right, but that's not our universe,

680
00:33:23,080 --> 00:33:26,840
Speaker 1: and more importantly, our universe is expanding, so we don't

681
00:33:26,880 --> 00:33:29,040
Speaker 1: know how to solve the equations for a black hole

682
00:33:29,120 --> 00:33:32,160
Speaker 1: in an expanding universe or a universe filled with stuff,

683
00:33:32,880 --> 00:33:36,120
Speaker 1: and so theoretically there is a question mark there, like

684
00:33:36,200 --> 00:33:38,560
Speaker 1: how do black holes form an expanding universe? What are

685
00:33:38,560 --> 00:33:41,040
Speaker 1: those rules? We don't really know because we don't understand

686
00:33:41,040 --> 00:33:44,120
Speaker 1: the solutions of general relativity. We basically only solved it

687
00:33:44,160 --> 00:33:47,040
Speaker 1: for a very few simple cases, like a black hole

688
00:33:47,080 --> 00:33:50,520
Speaker 1: in an empty universe or a universe filled with uniform dust.

689
00:33:50,800 --> 00:33:52,920
Speaker 1: We can't even solve it for like the Earth going

690
00:33:52,960 --> 00:33:54,640
Speaker 1: around the Sun. That's too hard.

691
00:33:54,800 --> 00:33:57,360
Speaker 2: Wow, what is it? All models are wrong? But some

692
00:33:57,400 --> 00:33:59,080
Speaker 2: models are useful? Are they are?

693
00:33:59,080 --> 00:33:59,280
Speaker 1: These?

694
00:33:59,280 --> 00:34:01,000
Speaker 2: These are still models, right?

695
00:34:02,360 --> 00:34:04,080
Speaker 1: Gr is still usable and we can do in americal

696
00:34:04,120 --> 00:34:07,200
Speaker 1: approximations a lot of times. But basically we don't understand

697
00:34:07,200 --> 00:34:10,880
Speaker 1: how black holes form in an expanding universe in theory.

698
00:34:11,440 --> 00:34:14,040
Speaker 1: And so these guys have an idea for what's inside

699
00:34:14,040 --> 00:34:16,600
Speaker 1: the black hole that inside the black hole is not

700
00:34:16,719 --> 00:34:20,920
Speaker 1: a singularity, but some weird vacuum energy that contributes to

701
00:34:20,960 --> 00:34:24,280
Speaker 1: the expansion of the universe, and like, hey, that's possible.

702
00:34:25,080 --> 00:34:27,640
Speaker 1: You know, it's a violation of general relativity, but we

703
00:34:27,680 --> 00:34:29,840
Speaker 1: know general relativity has to be wrong at some point,

704
00:34:30,360 --> 00:34:33,480
Speaker 1: and we don't understand how the expansion can be everywhere

705
00:34:33,520 --> 00:34:36,160
Speaker 1: if it's sourced from the black holes, So there's a

706
00:34:36,160 --> 00:34:38,960
Speaker 1: lot of open questions about that. You know, black holes

707
00:34:38,960 --> 00:34:40,759
Speaker 1: also are really big and massive, but there are a

708
00:34:40,840 --> 00:34:43,319
Speaker 1: tiny fraction of the mass of the universe, whereas dark

709
00:34:43,400 --> 00:34:46,120
Speaker 1: energy is like seventy percent of the energy in the universe,

710
00:34:46,560 --> 00:34:49,000
Speaker 1: So this doesn't really answer that. But the point is

711
00:34:49,040 --> 00:34:53,120
Speaker 1: that we still don't understand how super massive black holes form,

712
00:34:53,280 --> 00:34:56,680
Speaker 1: but they are out there in the universe. So there's

713
00:34:56,719 --> 00:35:00,160
Speaker 1: another really crazy and exciting theory that we'll talk about

714
00:35:00,200 --> 00:35:03,320
Speaker 1: after the break that might tell us what was inside

715
00:35:03,680 --> 00:35:24,600
Speaker 1: even bigger stars than we can imagine.

716
00:35:26,520 --> 00:35:28,960
Speaker 2: All Right, we're back and it's time for the big payoff.

717
00:35:29,960 --> 00:35:33,680
Speaker 2: Could black holes be inside of a star? Daniel?

718
00:35:33,960 --> 00:35:36,280
Speaker 1: So we talked about how stars form, and the crucial

719
00:35:36,320 --> 00:35:38,640
Speaker 1: things to remember there is that stars can't get too

720
00:35:38,640 --> 00:35:40,640
Speaker 1: big because they blow out their stuff, and if a

721
00:35:40,640 --> 00:35:43,560
Speaker 1: black hole forms, it blows stuff away from it also,

722
00:35:44,080 --> 00:35:46,319
Speaker 1: And then we talked about how we don't understand how

723
00:35:46,440 --> 00:35:49,319
Speaker 1: super massive black holes formed in the universe. So The

724
00:35:49,400 --> 00:35:51,680
Speaker 1: idea is bring these two things together and say, what

725
00:35:51,960 --> 00:35:54,920
Speaker 1: if there was a special kind of star in the

726
00:35:54,960 --> 00:35:59,560
Speaker 1: early universe that was so big, so massive that it

727
00:35:59,640 --> 00:36:02,120
Speaker 1: formed a black hole at its core, which ended up

728
00:36:02,120 --> 00:36:04,759
Speaker 1: being the seed for a super massive black hole, and

729
00:36:05,080 --> 00:36:08,080
Speaker 1: so big that it was protected against that shock wave

730
00:36:08,360 --> 00:36:10,719
Speaker 1: of blowing stuff out, so.

731
00:36:11,320 --> 00:36:14,160
Speaker 2: It would just be a star until the black hole

732
00:36:14,200 --> 00:36:14,640
Speaker 2: took over.

733
00:36:14,880 --> 00:36:16,560
Speaker 1: So let's walk through the life cycle of it, because

734
00:36:16,560 --> 00:36:18,760
Speaker 1: it's kind of crazy and kind of a fun theory.

735
00:36:19,120 --> 00:36:21,000
Speaker 1: So you start in the very early universe. Just like

736
00:36:21,040 --> 00:36:23,600
Speaker 1: we talked about before, everything is very dense, everything is

737
00:36:23,719 --> 00:36:26,359
Speaker 1: very hot, and you know, we have areas of over

738
00:36:26,400 --> 00:36:28,800
Speaker 1: density that are pulling stuff in. Something I should have

739
00:36:28,800 --> 00:36:31,040
Speaker 1: mentioned before, which I think is super cool, is that

740
00:36:31,080 --> 00:36:34,160
Speaker 1: it's not just over densities in the normal matter, not

741
00:36:34,280 --> 00:36:36,439
Speaker 1: just like, oh, here's a little bit more hydrogen. It's

742
00:36:36,480 --> 00:36:39,760
Speaker 1: actually over densities in the dark matter that are really important.

743
00:36:40,000 --> 00:36:42,719
Speaker 1: Because remember, dark matter is the dominant source of matter

744
00:36:42,760 --> 00:36:45,279
Speaker 1: in the universe. That's most of the matter. So if

745
00:36:45,320 --> 00:36:47,600
Speaker 1: you happen to have a clump of dark matter, then

746
00:36:47,600 --> 00:36:49,680
Speaker 1: the normal matter is going to get pulled towards that.

747
00:36:49,840 --> 00:36:54,360
Speaker 1: So dark matter actually controls where normal matter forms structure,

748
00:36:54,760 --> 00:36:56,000
Speaker 1: or you can think of it that way or the

749
00:36:56,040 --> 00:36:59,239
Speaker 1: other way, which is like normal matter tells us where

750
00:36:59,239 --> 00:37:01,680
Speaker 1: the dark matter is. It's like tracers. So if you

751
00:37:01,719 --> 00:37:03,200
Speaker 1: look at in the night sky and see a bunch

752
00:37:03,239 --> 00:37:04,959
Speaker 1: of stars, you know, oh, there's probably a big blob

753
00:37:05,000 --> 00:37:08,400
Speaker 1: of dark matter there. That's why stars formed there. Anyway,

754
00:37:08,520 --> 00:37:11,160
Speaker 1: that's super cool, But in the very early universe, we

755
00:37:11,200 --> 00:37:13,640
Speaker 1: didn't have metals to form these stars, right, So you

756
00:37:13,680 --> 00:37:16,200
Speaker 1: have either an over density of hydrogen or an overdensity

757
00:37:16,200 --> 00:37:19,520
Speaker 1: of dark matter. Pulls this stuff together. You get super massive,

758
00:37:19,640 --> 00:37:22,640
Speaker 1: short lived stars. And in the standard theory, remember that

759
00:37:22,719 --> 00:37:24,719
Speaker 1: if it gets too big, it gets too hot and

760
00:37:24,760 --> 00:37:27,440
Speaker 1: it blows that stuff away. But if the star is

761
00:37:27,520 --> 00:37:31,640
Speaker 1: big enough, like really enormous, not three hundred times the

762
00:37:31,719 --> 00:37:33,759
Speaker 1: mass of the sun, not a thousand times the mass

763
00:37:33,800 --> 00:37:36,560
Speaker 1: of the sun, We're talking millions of times of the

764
00:37:36,600 --> 00:37:38,480
Speaker 1: mass of the sun. If you happen to get a

765
00:37:38,480 --> 00:37:41,800
Speaker 1: blob of stuff together from a dark matter over density

766
00:37:42,040 --> 00:37:44,920
Speaker 1: and then try to collapse that gravitationally, the idea is

767
00:37:44,920 --> 00:37:47,319
Speaker 1: maybe something special happens at the core of the star,

768
00:37:47,800 --> 00:37:51,719
Speaker 1: and the star's mass protects it against the radiation. That's

769
00:37:51,760 --> 00:37:55,239
Speaker 1: coming out because gravity is just so overwhelming.

770
00:37:54,680 --> 00:37:55,799
Speaker 2: And it becomes black hole.

771
00:37:56,200 --> 00:37:58,760
Speaker 1: Yes, And so what happens is you have this huge

772
00:37:58,800 --> 00:38:01,920
Speaker 1: blob of stuff. We're talking about like a million times

773
00:38:01,960 --> 00:38:04,719
Speaker 1: the radius of the Sun, right, so like blow your

774
00:38:04,760 --> 00:38:06,880
Speaker 1: mind trying to hold this thing in your head. The

775
00:38:06,920 --> 00:38:09,680
Speaker 1: core gets hotter and gets denser, just like we talked

776
00:38:09,680 --> 00:38:12,600
Speaker 1: about before. But now there's enough gravitational pressure to turn

777
00:38:12,640 --> 00:38:15,480
Speaker 1: the core into a black hole. So you have this

778
00:38:15,680 --> 00:38:18,520
Speaker 1: enormous star and at the heart is this tiny but

779
00:38:18,680 --> 00:38:20,840
Speaker 1: very very dense black hole, like a few tens of

780
00:38:20,840 --> 00:38:27,160
Speaker 1: a kilometers across. How cute, How cute, but terrifying that's right. Now. Normally,

781
00:38:27,200 --> 00:38:28,920
Speaker 1: when you form a black hole or you have this

782
00:38:29,000 --> 00:38:32,239
Speaker 1: gravitational collapse of the core, you would get a shockwave

783
00:38:32,280 --> 00:38:34,279
Speaker 1: that would like tear the star apart, right, That's what

784
00:38:34,400 --> 00:38:37,720
Speaker 1: supernovas are in general. But this one is so massive

785
00:38:38,120 --> 00:38:40,960
Speaker 1: that the shockwave just like it just gets absorbed, right,

786
00:38:41,200 --> 00:38:43,440
Speaker 1: It doesn't get all the way to the outside. The

787
00:38:43,520 --> 00:38:47,080
Speaker 1: outside layers are squeezing back in. It's like you know,

788
00:38:47,200 --> 00:38:49,560
Speaker 1: a violent crowd or an English football game or something,

789
00:38:49,920 --> 00:38:52,720
Speaker 1: you know, squeezing back in. And so something else happens.

790
00:38:52,719 --> 00:38:54,840
Speaker 1: The outer layers of the star that are squeezing the

791
00:38:54,920 --> 00:38:58,760
Speaker 1: gas are forcing it into the black hole. Usually black

792
00:38:58,760 --> 00:39:03,160
Speaker 1: holes can grow only slowly because they're pushing their food away. Right, Well,

793
00:39:03,200 --> 00:39:05,320
Speaker 1: what if there's like a huge blob of gas on

794
00:39:05,360 --> 00:39:08,120
Speaker 1: the outside forcing it back. So now it's being force

795
00:39:08,200 --> 00:39:12,160
Speaker 1: fed gas even though the radiation pressure is pushing it away.

796
00:39:12,560 --> 00:39:14,839
Speaker 1: So now your black hole is growing pretty quickly as

797
00:39:14,880 --> 00:39:17,840
Speaker 1: it's like being force fed gas at the heart of

798
00:39:17,840 --> 00:39:21,040
Speaker 1: this star. So, yes, it is a star and there's

799
00:39:21,080 --> 00:39:23,040
Speaker 1: a black hole at its core, and the thing that

800
00:39:23,160 --> 00:39:26,439
Speaker 1: keeps it from blowing apart is its sheer mass. It's

801
00:39:26,480 --> 00:39:28,000
Speaker 1: too big to collapse.

802
00:39:28,400 --> 00:39:31,600
Speaker 2: Holy cow, I'm impressed. Okay, so it seems to me

803
00:39:31,680 --> 00:39:34,840
Speaker 2: that this process should pretty quickly result in the star

804
00:39:35,480 --> 00:39:37,840
Speaker 2: becoming a giant black hole. Is that the point you

805
00:39:37,880 --> 00:39:41,320
Speaker 2: can get black holes forming in the center of stars

806
00:39:41,400 --> 00:39:44,040
Speaker 2: before they're at their end of their life, and it

807
00:39:44,080 --> 00:39:45,759
Speaker 2: hastens the end of the life of the star.

808
00:39:46,120 --> 00:39:49,160
Speaker 1: Yeah, so eventually this thing will collapse. It can't last forever.

809
00:39:49,800 --> 00:39:51,959
Speaker 1: It's got a pretty good run though for the few

810
00:39:52,000 --> 00:39:55,120
Speaker 1: moments in the universe's history that it glows like it's

811
00:39:55,160 --> 00:39:57,960
Speaker 1: super duper bright. You know, we talked about fusion happening

812
00:39:57,960 --> 00:40:01,000
Speaker 1: more rapidly at high temperatures and pressures. So this one

813
00:40:01,080 --> 00:40:04,320
Speaker 1: single massive star with the black hole core would have

814
00:40:04,360 --> 00:40:07,640
Speaker 1: been about as bright as the entire galaxy. Wow, so

815
00:40:07,680 --> 00:40:10,239
Speaker 1: like really incredible. Essentially as bright as a supernova. A

816
00:40:10,280 --> 00:40:13,120
Speaker 1: supernova is also as bright as a galaxy. And so

817
00:40:13,200 --> 00:40:16,439
Speaker 1: the black hole is growing, the star is expanding, right,

818
00:40:16,440 --> 00:40:19,800
Speaker 1: Eventually the whole thing becomes thirty times the width of

819
00:40:19,840 --> 00:40:20,680
Speaker 1: our solar system.

820
00:40:20,760 --> 00:40:21,000
Speaker 4: Wow.

821
00:40:21,120 --> 00:40:23,680
Speaker 1: So we were talking beetle juice is like orbit and jube,

822
00:40:23,680 --> 00:40:26,200
Speaker 1: but wow, that's big. Yeah, this thing is monster as

823
00:40:26,320 --> 00:40:29,480
Speaker 1: compared to that, right, and then you get magnetic fields

824
00:40:29,480 --> 00:40:32,200
Speaker 1: which create radiation and quasar. It's just like we talk about.

825
00:40:32,440 --> 00:40:35,480
Speaker 1: But eventually the black hole grows so much that it

826
00:40:35,560 --> 00:40:38,719
Speaker 1: will tear the star apart because their radiation pressure from

827
00:40:38,760 --> 00:40:41,720
Speaker 1: the black hole is pushing out and that will eventually

828
00:40:41,800 --> 00:40:43,919
Speaker 1: take over because there's only so much star to eat.

829
00:40:44,080 --> 00:40:46,279
Speaker 1: And the thing that was keeping this stable was the

830
00:40:46,320 --> 00:40:49,000
Speaker 1: outer layers of the star. The more you eat the star,

831
00:40:49,280 --> 00:40:52,000
Speaker 1: the less protection you have. It's like you're eating your

832
00:40:52,000 --> 00:40:54,920
Speaker 1: own spaceship. Right, So it only lasts like ten million

833
00:40:55,000 --> 00:40:58,200
Speaker 1: years or so in the early universe. But what's left

834
00:40:58,280 --> 00:41:02,160
Speaker 1: over is a very massive black hole, much more massive

835
00:41:02,200 --> 00:41:04,680
Speaker 1: than you would expect from the death of a normal star.

836
00:41:05,239 --> 00:41:07,480
Speaker 1: And if you have a very massive black hole around

837
00:41:07,880 --> 00:41:10,719
Speaker 1: and other stars are forming nearby, you could imagine that

838
00:41:10,880 --> 00:41:13,880
Speaker 1: they would start orbiting that really massive black hole and

839
00:41:13,920 --> 00:41:16,520
Speaker 1: it could end up being the center of a galaxy.

840
00:41:16,800 --> 00:41:19,239
Speaker 2: Okay, so we've seen super massive black holes. Yeah, but

841
00:41:19,320 --> 00:41:22,800
Speaker 2: we have not seen this in the process of happening

842
00:41:22,800 --> 00:41:26,080
Speaker 2: because this would have happened so long ago. Exactly could

843
00:41:26,120 --> 00:41:28,560
Speaker 2: we still see this happening super far away, or this

844
00:41:28,600 --> 00:41:30,800
Speaker 2: happened so long ago that that light would have already

845
00:41:30,800 --> 00:41:31,960
Speaker 2: passed us or something.

846
00:41:34,200 --> 00:41:35,319
Speaker 1: Great question, we're going to.

847
00:41:35,320 --> 00:41:37,200
Speaker 2: Take away my pod in physics.

848
00:41:36,960 --> 00:41:40,280
Speaker 1: No, PD and physics come from asking sincere and curious

849
00:41:40,360 --> 00:41:43,040
Speaker 1: questions about the universe, not about being right. Okay, so

850
00:41:43,040 --> 00:41:46,040
Speaker 1: I never want to discourage somebody from thinking. And that's physics, right.

851
00:41:46,120 --> 00:41:47,880
Speaker 1: What you're doing right there is physics. You're like, this

852
00:41:47,920 --> 00:41:49,480
Speaker 1: is what I understand, this is what you're telling me.

853
00:41:49,520 --> 00:41:51,319
Speaker 1: How do I fit it together into a model in

854
00:41:51,360 --> 00:41:55,000
Speaker 1: my head? That's the essential step of doing science. And

855
00:41:55,200 --> 00:41:58,080
Speaker 1: so yeah, absolutely, you earn your PhD twice over ya.

856
00:41:58,320 --> 00:42:01,080
Speaker 1: The answer is if it happen in the early universe,

857
00:42:01,120 --> 00:42:03,160
Speaker 1: we should be able to see it because we could

858
00:42:03,200 --> 00:42:06,280
Speaker 1: just look further and further away. Because if it happened

859
00:42:06,280 --> 00:42:08,239
Speaker 1: a long time ago, we just need to look at

860
00:42:08,320 --> 00:42:11,120
Speaker 1: light that's been traveling since then, which means it's been

861
00:42:11,160 --> 00:42:14,560
Speaker 1: a really long distance and we can see pretty far back.

862
00:42:14,600 --> 00:42:16,600
Speaker 1: We can't see all the way back to that far

863
00:42:16,680 --> 00:42:19,040
Speaker 1: in the universe. The James Web space telescope can see

864
00:42:19,239 --> 00:42:22,480
Speaker 1: like formation of young galaxies, and that's helping us understand

865
00:42:22,800 --> 00:42:25,400
Speaker 1: the super massive black hole question. But we can't with

866
00:42:25,480 --> 00:42:28,359
Speaker 1: the James Web see that far back yet. But in

867
00:42:28,400 --> 00:42:31,200
Speaker 1: principle we could be able to write these things would

868
00:42:31,200 --> 00:42:33,520
Speaker 1: have been very bright even though they're super far away.

869
00:42:33,520 --> 00:42:36,319
Speaker 1: We might be able to make them out. The other

870
00:42:36,320 --> 00:42:38,799
Speaker 1: comment is like with the light from them have passed us,

871
00:42:39,080 --> 00:42:40,920
Speaker 1: that's true for some of them. Like if there was

872
00:42:41,000 --> 00:42:43,000
Speaker 1: one of these things at the heart of our galaxy

873
00:42:43,520 --> 00:42:45,640
Speaker 1: and it admitted a bunch of light, its light would

874
00:42:45,680 --> 00:42:47,480
Speaker 1: not be too far away for us to see. But

875
00:42:47,600 --> 00:42:49,400
Speaker 1: the universe just goes on and on and on, and

876
00:42:49,440 --> 00:42:52,520
Speaker 1: so there's always some more universe to send us light

877
00:42:53,200 --> 00:42:55,600
Speaker 1: that's just arriving now. So that's why we can see

878
00:42:55,600 --> 00:42:57,880
Speaker 1: the whole history of the universe from here if we

879
00:42:57,880 --> 00:42:59,160
Speaker 1: look further and further.

880
00:42:58,960 --> 00:43:03,239
Speaker 2: Away of today is fund more telescopes.

881
00:43:02,800 --> 00:43:06,080
Speaker 1: Yes, exactly, it's fun more telescopes because there are deep

882
00:43:06,120 --> 00:43:09,680
Speaker 1: mysteries here about how stars form and how matter works.

883
00:43:09,880 --> 00:43:12,759
Speaker 1: And you know, this is a fun theory because it

884
00:43:12,760 --> 00:43:15,560
Speaker 1: makes you think about huge stars and stars with exotic

885
00:43:15,600 --> 00:43:17,839
Speaker 1: cores in them and maybe something else is happening at

886
00:43:17,840 --> 00:43:20,680
Speaker 1: the hearts of stars or whatever, and because it solves

887
00:43:20,680 --> 00:43:23,400
Speaker 1: a mystery, but probably the answer is something else, something

888
00:43:23,480 --> 00:43:26,799
Speaker 1: even weirder than we have imagined. And so you know,

889
00:43:26,840 --> 00:43:29,239
Speaker 1: it's a useful exercise in physics to be like, what

890
00:43:29,320 --> 00:43:32,320
Speaker 1: about this? What about that? Could this even work? Very valuable,

891
00:43:32,640 --> 00:43:35,040
Speaker 1: but it's also just a useful exercise to go out

892
00:43:35,080 --> 00:43:37,640
Speaker 1: and look, you know, to ask the universe tell us,

893
00:43:37,840 --> 00:43:40,000
Speaker 1: show us what's going on out there. And then we

894
00:43:40,120 --> 00:43:42,480
Speaker 1: got to piece that together into our puzzle how the

895
00:43:42,560 --> 00:43:45,560
Speaker 1: universe works and maybe have one of those moments of

896
00:43:45,560 --> 00:43:48,000
Speaker 1: insight where we're like, oh, I get it, and it

897
00:43:48,080 --> 00:43:50,960
Speaker 1: clicks into place and you're like, yeah, Universe, you make

898
00:43:51,040 --> 00:43:51,520
Speaker 1: sense to me.

899
00:43:51,719 --> 00:43:54,440
Speaker 2: Oh. It's so nice to have those moments with your partner.

900
00:43:54,480 --> 00:43:56,879
Speaker 2: It's nice to have those moments with your universe as well.

901
00:43:57,960 --> 00:43:59,719
Speaker 1: Do you have a similar relationship with the universe as

902
00:43:59,719 --> 00:44:00,399
Speaker 1: you do with Zach.

903
00:44:00,880 --> 00:44:03,560
Speaker 2: Both of them surprise me from time to time. You know,

904
00:44:04,040 --> 00:44:06,000
Speaker 2: life should keep you on your toes.

905
00:44:07,280 --> 00:44:09,440
Speaker 1: I hope you keep building a husband telescope so you

906
00:44:09,440 --> 00:44:13,040
Speaker 1: can keep observing new surprises in your relationships.

907
00:44:13,040 --> 00:44:15,400
Speaker 2: Well, my training was an animal behavior, so I'm always

908
00:44:15,440 --> 00:44:18,279
Speaker 2: collecting data. I mess with him every once in a while.

909
00:44:18,320 --> 00:44:21,759
Speaker 2: I'll do things like see how close I have to

910
00:44:21,800 --> 00:44:24,840
Speaker 2: put the laundry bin to, like where he always throws

911
00:44:24,880 --> 00:44:27,560
Speaker 2: the clothes on the floor before they'll actually end up

912
00:44:27,560 --> 00:44:29,600
Speaker 2: in the bin? Like will he throw it if it's

913
00:44:29,640 --> 00:44:31,680
Speaker 2: just an inch out of where he usually throw it? Anyway,

914
00:44:31,840 --> 00:44:32,400
Speaker 2: I digress.

915
00:44:32,520 --> 00:44:34,879
Speaker 1: Do you need an IRB to do experiments on your husband?

916
00:44:34,920 --> 00:44:37,680
Speaker 2: Like, well, you know, I'm not really in academia right now,

917
00:44:37,800 --> 00:44:39,760
Speaker 2: and so don't tell Rice.

918
00:44:39,960 --> 00:44:44,359
Speaker 1: Okay, So was I gonna ask we were talking about

919
00:44:44,360 --> 00:44:45,800
Speaker 1: the black hole of Zack's laundry.

920
00:44:46,120 --> 00:44:52,240
Speaker 2: Oh God, that's actually a different topic. But okay, so.

921
00:44:51,640 --> 00:44:53,879
Speaker 1: We're supposed to keep this family friendly, all.

922
00:44:53,800 --> 00:44:56,320
Speaker 2: Right, all right, I'm back on track. I'm back on track. Okay,

923
00:44:56,520 --> 00:44:59,319
Speaker 2: so you hear this theory that you've just presented to us.

924
00:45:00,160 --> 00:45:02,680
Speaker 2: Do all the steps in this theory sound good to you?

925
00:45:02,760 --> 00:45:05,239
Speaker 2: Does this sound plausible? You said that it's probably something

926
00:45:05,280 --> 00:45:07,479
Speaker 2: else just because the universe is hard to figure out.

927
00:45:07,920 --> 00:45:10,479
Speaker 2: But is there any step in this process that makes

928
00:45:10,520 --> 00:45:12,560
Speaker 2: you feel like, I don't know, maybe not.

929
00:45:12,800 --> 00:45:15,840
Speaker 1: There's nothing about this that's obviously wrong, there's no red flags,

930
00:45:16,280 --> 00:45:18,680
Speaker 1: but there is a lot of speculation here, you know,

931
00:45:18,719 --> 00:45:21,560
Speaker 1: there's like, well, maybe this can survive that, and maybe

932
00:45:21,600 --> 00:45:24,560
Speaker 1: this happens and it gets force fed. But it's complicated,

933
00:45:24,640 --> 00:45:26,440
Speaker 1: Like what you would really need to do is to

934
00:45:26,480 --> 00:45:28,719
Speaker 1: model this, yeah, and not just be like more my

935
00:45:28,800 --> 00:45:31,719
Speaker 1: intuition says it's probably correct. You need to see what

936
00:45:31,800 --> 00:45:33,840
Speaker 1: it actually happened and put this thing into a computer.

937
00:45:34,320 --> 00:45:37,960
Speaker 1: But that's hard. You know, we have trouble modeling individual

938
00:45:38,000 --> 00:45:41,520
Speaker 1: stars turning into black holes and going supernova because you

939
00:45:41,560 --> 00:45:43,520
Speaker 1: need to keep track of so many particles and they're

940
00:45:43,640 --> 00:45:46,600
Speaker 1: very sensitive to the details we don't really understand, like

941
00:45:46,640 --> 00:45:48,640
Speaker 1: why does this star go supernova and that one doesn't.

942
00:45:48,680 --> 00:45:51,319
Speaker 1: It's not just a function of the mass, like it

943
00:45:51,360 --> 00:45:54,360
Speaker 1: requires some special circumstance to happen or to not happen,

944
00:45:54,760 --> 00:45:56,360
Speaker 1: and so there's probably just a lot of that, a

945
00:45:56,400 --> 00:45:58,879
Speaker 1: lot of details that need to be filled in, and

946
00:45:59,000 --> 00:46:01,480
Speaker 1: it's a lot of work. We should not only build

947
00:46:01,520 --> 00:46:03,879
Speaker 1: new telescopes, we should hire more scientists and give them

948
00:46:04,000 --> 00:46:04,960
Speaker 1: lots of computers.

949
00:46:05,160 --> 00:46:07,560
Speaker 2: Yes, amen, because you got to start somewhere, and ideas

950
00:46:07,680 --> 00:46:10,120
Speaker 2: like this help you identify the assumptions that you need

951
00:46:10,160 --> 00:46:12,919
Speaker 2: to be testing in order to move forward. So yeah,

952
00:46:13,080 --> 00:46:13,760
Speaker 2: very cool idea.

953
00:46:13,840 --> 00:46:15,560
Speaker 1: And if you discover, oh, this doesn't work, it's going

954
00:46:15,640 --> 00:46:18,680
Speaker 1: to give you another idea. And that's how we make progress. Yep. Right,

955
00:46:18,760 --> 00:46:22,040
Speaker 1: start out with terrible ideas that inspire less terrible ideas. Yeah,

956
00:46:22,120 --> 00:46:23,200
Speaker 1: dot dot dot science.

957
00:46:23,320 --> 00:46:26,120
Speaker 2: Yeah, I think the answer to my PhD work was no,

958
00:46:26,280 --> 00:46:30,120
Speaker 2: Kelly was wrong. But here's some other interesting stuff you

959
00:46:30,120 --> 00:46:31,840
Speaker 2: could ask exactly.

960
00:46:31,880 --> 00:46:34,359
Speaker 1: It's always fun follow up questions, that's right. And on

961
00:46:34,360 --> 00:46:36,880
Speaker 1: that note, if you have follow up questions from today's

962
00:46:36,880 --> 00:46:40,680
Speaker 1: episode or anything else you've heard about in physics, please

963
00:46:40,719 --> 00:46:44,399
Speaker 1: write to us. We would love to answer your questions physics, biology,

964
00:46:44,680 --> 00:46:47,040
Speaker 1: maybe even chemistry once in a while.

965
00:46:47,200 --> 00:46:48,920
Speaker 2: Pizza related questions.

966
00:46:48,719 --> 00:46:52,560
Speaker 1: Definitely, absolutely pizza related, especially the physics of pizza. No,

967
00:46:52,640 --> 00:46:55,600
Speaker 1: I guess pizza's mostly chemistry, isn't it anyway? Write to

968
00:46:55,680 --> 00:46:59,240
Speaker 1: us Questions at danieland Kelly dot org. We love hearing

969
00:46:59,239 --> 00:47:02,160
Speaker 1: from you, really do, and we really will write you back.

970
00:47:02,360 --> 00:47:14,240
Speaker 2: Enjoy your pizza. Daniel and Kelly's Extraordinary Universe is produced

971
00:47:14,239 --> 00:47:16,879
Speaker 2: by iHeartRadio. We would love to hear from you.

972
00:47:17,080 --> 00:47:20,000
Speaker 1: We really would. We want to know what questions you

973
00:47:20,200 --> 00:47:22,840
Speaker 1: have about this Extraordinary Universe.

974
00:47:22,960 --> 00:47:25,879
Speaker 2: We want to know your thoughts on recent shows, suggestions

975
00:47:25,880 --> 00:47:28,919
Speaker 2: for future shows. If you contact us, we will get

976
00:47:28,920 --> 00:47:29,319
Speaker 2: back to you.

977
00:47:29,600 --> 00:47:33,120
Speaker 1: We really mean it. We answer every message. Email us

978
00:47:33,160 --> 00:47:36,000
Speaker 1: at Questions at Danielankelly dot.

979
00:47:35,800 --> 00:47:37,680
Speaker 2: Org, or you can find us on social media. We

980
00:47:37,760 --> 00:47:41,640
Speaker 2: have accounts on x, Instagram, Blue Sky and on all

981
00:47:41,680 --> 00:47:43,960
Speaker 2: of those platforms. You can find us at D and

982
00:47:44,400 --> 00:47:45,400
Speaker 2: K Universe.

983
00:47:45,640 --> 00:47:47,200
Speaker 1: Don't be shy, write to us