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Speaker 1: Hey, Kelly, what's your favorite feature in the night sky? Mmmmm?

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Speaker 1: You know I like spotting the Orion constellation. Oh yeah,

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Speaker 1: what makes that one top your list? I like that

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Speaker 1: it's easy to spot. That makes it easier to point

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Speaker 1: it out to my kids. And you know, since it's

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Speaker 1: so easy to find, I'd like to imagine that, like,

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Speaker 1: even as the Earth has changed for thousands of years,

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Speaker 1: other people have been able to find it as well,

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Speaker 1: and that pulls us together. Mmm. And it's nice to

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Speaker 1: think about the sweep of history. But you know that

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Speaker 1: constellations aren't forever, right? Oh? What is that our fault?

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Speaker 1: Did humans manage to ruin the sky and the planet?

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Speaker 1: Nothing to do with us this time? But you know

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Speaker 1: the sky is in motion. A t Rex looking up

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Speaker 1: at this guy probably never saw the Orion constellation. Well,

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Speaker 1: you know what, that's okay, because their little arms would

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Speaker 1: have been too short to point it out to their

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Speaker 1: t rex kids. Anyway, I can't tell what you're pointed to. Mom. Hi,

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Speaker 1: I'm Daniel I'm a particle physicist and a professor at

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Speaker 1: UC Irvine. And I'm Kelly Weener Smith. I'm a parasitologist

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Speaker 1: and an adjunct professor with Rice University, and even though

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Speaker 1: I'm technically also a professor of astronomy, I've never really

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Speaker 1: been that into constellations. And you know what, neither have

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Speaker 1: I Ryan Ryan and the Big Dipper are one of

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Speaker 1: the two that I'm able to name. When I was

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Speaker 1: really young, I like looking up at this guy and

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Speaker 1: seeing the stars, of course, and who can't help but

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Speaker 1: look for patterns. But I remember as a kid discovering

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Speaker 1: that the constellations are sort of artificial. You only see

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Speaker 1: those patterns in the sky because of where the Earth

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Speaker 1: happens to be. Some of those stars are like really

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Speaker 1: close to us, and some of them are really far away.

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Speaker 1: It's not like an inherent part of the sky or

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Speaker 1: the universe. Anybody looking at the sky from another perspective

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Speaker 1: would see something totally different. And I think it wasn't

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Speaker 1: until college that I realized, like, oh, constellations are not

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Speaker 1: like a helpful astronomy thing. They're just a human pattern

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Speaker 1: finding thing. It was kind of weirdly disappointing, I know,

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Speaker 1: and it sort of encourages the false impression that the

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Speaker 1: sky is two dimensional, that you're like looking at a screen.

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Speaker 1: I think it's much more thrilling to look up at

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Speaker 1: the night sky and see it in three D, to

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Speaker 1: imagine that some of these things are much deeper and

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Speaker 1: some are much closer than the others. Instead of looking

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Speaker 1: at an image, it makes you feel like you're looking

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Speaker 1: at a view, like the best view in the cosmos. Yes,

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Speaker 1: I remember. Also when I was in college, I got

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Speaker 1: to look through a giant telescope at sort of part

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Speaker 1: of a constellation, and it kind of blew my mind

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Speaker 1: that in all of the stories that I was able

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Speaker 1: to see, they were like, you know, clusters are swirling

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Speaker 1: things happening in between there, and they were sort of

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Speaker 1: part of the constellation too, and like, ah, it's I

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Speaker 1: don't even know what the point was, but it just

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Speaker 1: sort of the closer you look, the more surprising it is.

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Speaker 1: So even though I was disappointed at first to learn

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Speaker 1: that constellations are sort of a pattern finding thing, the

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Speaker 1: closer you look and the more you learn, the like

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Speaker 1: more exciting it gets, indeed, and so welcome to the podcast.

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Speaker 1: Daniel and Jorge explain the Universe, in which we try

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Speaker 1: to take a closer look as possible into the very

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Speaker 1: nature of this crazy universe. We zoom in on the

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Speaker 1: tiniest details and try to understand how quantum particles really move,

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Speaker 1: what is really going on, and we zoom out to

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Speaker 1: the biggest, deepest, oldest, most dramatic questions of the universe.

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Speaker 1: How old is everything, how does it all work? What's

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Speaker 1: going on up there in the night sky. We take

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Speaker 1: all of that and we try to explain all of

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Speaker 1: it to you. And as you may have, guest Horrie

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Speaker 1: isn't with us today, he's on a brake, and so

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Speaker 1: we're very glad to have with us one of our

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Speaker 1: favorite guest hosts, Kelly. Kelly, thanks for joining us today. Thanks.

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Speaker 1: I love being here. I always love it when Jorge

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Speaker 1: takes a break and I get to geek out with you. Well,

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Speaker 1: today we're gonna be talking about one of the most

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Speaker 1: accessible things in physics and astronomy, a place where a

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Speaker 1: lot of people get attracted to the big questions of

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Speaker 1: the universe, and that's just looking up at the night

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Speaker 1: sky and seeing the stars. I think everybody who has

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Speaker 1: questions about the universe, everybody who wonders what's out there,

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Speaker 1: probably got started by just looking up and seeing those

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Speaker 1: twinkling lights and wondering what it all means and So

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Speaker 1: what part of the night sky are we going to

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Speaker 1: focus on today? Today? I want to talk about the

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Speaker 1: illusion that is the night sky. On one hand, we

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Speaker 1: say that the night sky seems like it's two dimensional,

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Speaker 1: but really it's three D. And it takes this sort

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Speaker 1: of mental exercise to unhook yourself from the illusion that

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Speaker 1: it's a screen and to remember that it's a deep,

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Speaker 1: deep view that you're looking across billions of miles of

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Speaker 1: empty space. But there's another illusion of the night sky,

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Speaker 1: and that's that it seems to be sort of static,

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Speaker 1: that it seems to be fixed. And it's true that

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Speaker 1: a thousand years ago astronomers looked up at the same

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Speaker 1: night sky that we see, and in a thousand year

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Speaker 1: as astronomers will still be looking at basically the same

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Speaker 1: night sky. But that's because the time scales for the

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Speaker 1: nights guy and for the Solar system and for the

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Speaker 1: universe are just much much longer than we tend to

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Speaker 1: think about in human history, and that on those long

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Speaker 1: time scales, the universe is actually quite chaotic. So like

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Speaker 1: a thousand years ago, was it a little bit different?

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Speaker 1: And that's how we know it's way different, like a

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Speaker 1: billion or a million years from now, or do we

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Speaker 1: know that some other way exactly? The night sky is

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Speaker 1: changing very slowly, So if you have very precise measurements

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Speaker 1: of where all the stars were, you could see those

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Speaker 1: things in action. But mostly we understand the night sky

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Speaker 1: is dynamic because we understand the processes behind it. We

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Speaker 1: know that these stars are in motion. We see these

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Speaker 1: crazy effects. We see snapshots of all these processes back

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Speaker 1: through time, because the further we can look out into

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Speaker 1: the universe, the further back in time we see. And

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Speaker 1: so we can see things happening to other galaxies and

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Speaker 1: other stars, galaxies, colliding stars swirling around each other, all

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Speaker 1: sorts of crazy stuff is happening out there. It's sort

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Speaker 1: of like we are in the middle of a white

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Speaker 1: water rapids, but we're just looking at things in super

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Speaker 1: slow motion, so it seems like nothing's happening, right, So

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Speaker 1: can we go from like this more sort of abstract,

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Speaker 1: grandiose discussion to like a more concrete example, So, like,

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Speaker 1: what's happening with the Hyades Cluster. That's right, it's been

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Speaker 1: in the news recently. There's a blob of stars out

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Speaker 1: there called the Hyades Cluster, and astronomers have discovered that

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Speaker 1: something quite dramatic is going on to this cluster. So

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Speaker 1: on today's episode, let's talk about what's happening to the

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Speaker 1: Hyades Cluster. And before you get too worried, you know,

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Speaker 1: this is a group of stars out there. They don't

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Speaker 1: have emotions or feelings, so you don't have to worry

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Speaker 1: about them too much. Although I guess if there are

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Speaker 1: aliens out there, you know, living on planets in this cluster,

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Speaker 1: what's happening to the cluster could be disrupting their lives.

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Speaker 1: So now I'm worried. So yeah, actually I changed my mind.

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Speaker 1: You should totally be worried about those aliens. I'm having

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Speaker 1: a bit of an existential crisis now, and so as usual,

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Speaker 1: I went out there into the Internet to ask people

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Speaker 1: if they knew what was happening to the Hyades Cluster,

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Speaker 1: and I should have asked them how they felt about it.

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Speaker 1: But if you are interested in participating for future episodes

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Speaker 1: of the podcast and lending your voice to these questions

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Speaker 1: and hearing your voice on the podcast, please don't be shy.

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Speaker 1: Just right to me two questions, add Daniel and Jorge

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Speaker 1: dot com. So before you listen to these answers, think

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Speaker 1: to yourself, do you know what's going on to the

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Speaker 1: high these cluster. Here's what people had to say. If

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Speaker 1: it's a stock cluster, then it could be spinning itself

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Speaker 1: a pot or flinging stuff out of it. Or if

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Speaker 1: it's a galaxy cluster them maybe it's uh combining galaxies

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Speaker 1: together or just again flinging them out of each flinging

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Speaker 1: them away from each other. I have never heard of

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Speaker 1: the Hyades cluster, and I'm not even sure i'm pronouncing

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Speaker 1: it correctly. The Hayvis cluster, if I remember correctly, is

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Speaker 1: a star cluster quite close to us, or maybe even

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Speaker 1: the closest one. And if I'm correct, it's falling apart

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Speaker 1: or dissipating, or at least it's the stars are not

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Speaker 1: staying together in the cluster as they are, But I'm

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Speaker 1: not sure what the reason for that is anymore. I'm

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Speaker 1: not sure what's happening to it, but I really hope

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Speaker 1: it's okay. I'm again not sure I know that much

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Speaker 1: that this cluster is the closest one to us or

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Speaker 1: to the Sun, but haven't actually heard what's happening to it,

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Speaker 1: so I'm not sure. I assume this has to do

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Speaker 1: with a constellation of stars not in our galaxy to

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Speaker 1: my knowledge, but should be outside of our galaxy, and

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Speaker 1: clearly it is, since you're asking a question, it is

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Speaker 1: clearly an interaction or something that has not been observed

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Speaker 1: by humans before. So breaking the mold pussy? Is it

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Speaker 1: moving towards another cluster creating a giant explosion in space?

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Speaker 1: I think that the Hades clusters all dying out. I

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Speaker 1: think it's a clusters does and to go off of

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Speaker 1: the name Hades, I think they're all going to the underworld.

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Speaker 1: May be confusing the Hyades cluster with another one, but

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Speaker 1: I think that's a youngish cluster where a lot of

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Speaker 1: the dust and such from formation has already been you

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Speaker 1: accumulated or blown off, and now the stars are moving apart.

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Speaker 1: Their answers were a nice mix of, you know, honestly

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Speaker 1: admitting that they don't know what's going on to one

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Speaker 1: person who was maybe having a bit of an existential crisis,

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Speaker 1: really hoping that the Hyades cluster was okay. But since

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Speaker 1: nobody like seemed to have gotten it totally right, can

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Speaker 1: you explain to us what what is it? Right? So,

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Speaker 1: the Hyades cluster is something that astronomers call an open cluster.

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Speaker 1: This is basically a group of stars that formed together.

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Speaker 1: I think this is really interesting because I think it

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Speaker 1: gives you a window and understanding how and when and

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Speaker 1: where stars are formed. People might imagine that the stars

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Speaker 1: just sort of like pop into existence in random places

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Speaker 1: in the universe, but there's really actually a lot more

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Speaker 1: structure and pattern to it than that. And star clusters

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Speaker 1: are these groups of stars that all formed together and

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Speaker 1: give us an opportunity to study exactly how and when

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Speaker 1: stars are formed. And if they're still in the cluster,

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Speaker 1: does that mean it's a younger group of stars. Does

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Speaker 1: the clustering tell you something about age? It does, and

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Speaker 1: it tells you something about mass, So you have to

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Speaker 1: go back to the original blob of stuff that formed

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Speaker 1: this cluster. Remember that most stars are formed from like

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Speaker 1: huge clouds of gas and dust and left over remnants

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Speaker 1: from other stars. You know, we're like fourteen billion years

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Speaker 1: into the history of the universe that have already been

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Speaker 1: generations of stars that burned for millions or billions of

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Speaker 1: years and then exploded and sent their shrapnel, their dust,

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Speaker 1: their compost out into the universe. To see new generations

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Speaker 1: of stars. So you have this sort of like raw

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Speaker 1: material floating out there, but it doesn't always just necessarily

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Speaker 1: like come together into a star. There's nobody out there

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Speaker 1: like scooping up huge blobs of hydrogen to form stars.

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Speaker 1: Something has to happen to make those stars formed, to

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Speaker 1: make this huge cloud of gas and dust actually coalesced

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Speaker 1: into these burning, bright blobs. So what happens. So it's

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Speaker 1: fascinating because two things have to happen. One is the

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Speaker 1: blob has to get cold, like you think of stars

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Speaker 1: is like obviously really really hot. But in order for

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Speaker 1: them to come together, gravity has to pull those things together,

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Speaker 1: and it can't do that if the particles inside it

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Speaker 1: are moving really really fast. So if you have like

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Speaker 1: a cloud of really really hot gas, it's never going

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Speaker 1: to form a star if it can't cool down somehow.

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Speaker 1: Those particles have to slow down because remember that gravity

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Speaker 1: is really weak. It's the weakest force in the universe

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Speaker 1: by huge number. It's much much weaker than magnetism or electricity.

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Speaker 1: So for a star to form, gravity has to be

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Speaker 1: able to gather together those tiny little particles, and that

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Speaker 1: can only happen if the particles are really slow moving.

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Speaker 1: So you have some big cloud of gas and dust,

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Speaker 1: it needs a way to cool down, like radiating off

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Speaker 1: its energy, sending photons out into deep space. That gives

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Speaker 1: you the raw material that gravity can then use to

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Speaker 1: form those stars. But usually these clouds are not just

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Speaker 1: like enough cloud to make one star. There are enough

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Speaker 1: cloud to make hundreds or thousands of stars all at

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Speaker 1: the same time. So I'm having a little trouble wrapping

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Speaker 1: my head around this. So when you say cool down,

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Speaker 1: you mean like cool for a star but still ridiculously hot,

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Speaker 1: or is it like actually cool, no, really cool even

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Speaker 1: for you Like these are freezing, freezing cold clouds of

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Speaker 1: gas and dust. They need to be moving very slowly

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Speaker 1: for gravity to take over. So we say two things

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Speaker 1: have to happen. One is they need to be cooled down,

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Speaker 1: not like thousands of degrees Calvin, but you know, much

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Speaker 1: smaller values, actually cold values. And then you need gravity

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Speaker 1: to be sort of like get a foothold to like

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Speaker 1: make these clouds collapse into a cluster of stars. And

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Speaker 1: for that to happen, either you need like one blob

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Speaker 1: that's extra dense and it starts to gather the other

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Speaker 1: ones because it has stronger gravity. Than anything else around it,

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Speaker 1: or you have some external event, like a supernova nearby

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Speaker 1: sends a shock wave, and that can trigger the collapse

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Speaker 1: because it sort of pushes a bunch of particles into

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Speaker 1: another bunch of particles and then they have more density

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Speaker 1: than everything else around them. So you need like a

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Speaker 1: cold cloud of gas. It's like the raw ingredients, you know,

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Speaker 1: like when you make a recipe and they say, like,

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Speaker 1: you know, use chilled butter or whatever. It's important for

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Speaker 1: the texture of your pie that you start with cold butter. Right,

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Speaker 1: You're not gonna get your lamonation in your flaky crust.

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Speaker 1: In the same way, you need to start with like

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Speaker 1: cold gas for your stars, and then you need to

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Speaker 1: trigger that lapse somehow. So it's this two step process

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Speaker 1: of forming new stars and so the one once you

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Speaker 1: get that you know the right pieces of the recipe

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Speaker 1: so you can make your cosmic pie. What does it

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Speaker 1: end up looking like? Like what kind of stars do

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Speaker 1: you make? And how big is the product? It depends

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Speaker 1: a lot on exactly how much metal there is in

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Speaker 1: this cloud. The universe started out with only hydrogen and

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Speaker 1: helium and very very tiny amounts of everything else, and

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Speaker 1: astronomers called everything above helium a metal, like I know,

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Speaker 1: biologists and chemists had their own definition of metals, but

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Speaker 1: for astronomers, anything above helium they call the metal. And

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Speaker 1: so you know, I don't know what they call heavy

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Speaker 1: metal music, but you know, probably anything with a beat

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Speaker 1: to it. Do astronomers listen to heavy metal? I guess

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Speaker 1: some of them must. Almost everything is heavy metals for astronomers.

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Speaker 1: And if your cloud has more heavy metals in it,

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Speaker 1: heavier elements carbon, oxygen, nitrogen, even iron, then it's easier

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Speaker 1: for it to coalesce, and so you get reasonably sized stars.

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Speaker 1: If you have really really big clouds without any heavy metals,

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Speaker 1: and it's harder for it to sort of cool down

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Speaker 1: and to coalesce, and so you get really big stars.

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Speaker 1: You get these huge clouds, and so we think like

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Speaker 1: the first population of stars ever reformed in the universe

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Speaker 1: were probably like enormous mega stars for that reason, whereas

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Speaker 1: in later clouds of gas and dust that had these

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Speaker 1: like smaller pockets of metals in them, they formed these

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Speaker 1: points for the stars to form, and so you've got

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Speaker 1: a larger number of sort of reasonably sized stars, you know,

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Speaker 1: stars like half to ten times the mass of our sun,

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Speaker 1: and do these stars are these stars that will last

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Speaker 1: for a long time. There's a really close connection. They're

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Speaker 1: actually the bigger the star, the greater the gravitational pressure.

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Speaker 1: Once it does start to burn, the higher the temperature,

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Speaker 1: and the faster it burns through its fuel. That's why

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Speaker 1: that first generation of stars that had almost no metals

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Speaker 1: in them, only lasted a few hundred million years, whereas

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Speaker 1: the second generation of stars, some of those are still

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Speaker 1: around there more than ten billion years old, and the

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Speaker 1: smaller ones might even burn for trillions of years. So

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Speaker 1: the smaller the star at the longer the lifetime. And

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Speaker 1: the thing to realize is that these stars are not

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Speaker 1: just formed one at a time. Right, you have a

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Speaker 1: huge cloud of gas and dust, and so a bunch

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Speaker 1: of stars are formed together. And so earlier you asked

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Speaker 1: me like, well, how long do these clusters last? And

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Speaker 1: so it depends on how many stars you get into

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Speaker 1: that cluster. So if you get like a huge cloud

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Speaker 1: of gas and dust that gives you like thousands and

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Speaker 1: thousands of stars, then those stars which are formed together

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Speaker 1: will hang out together for quite a long time. A

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Speaker 1: smaller cloud which gives you fewer stars like you know,

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Speaker 1: ten or maybe a hundred. They don't have the gravitational

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Speaker 1: strength to resist the rest of the galaxy, and they

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Speaker 1: mostly just end up going their own way. I have

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Speaker 1: been in some social groups like that. So typically these

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Speaker 1: clusters can last, you know, millions or hundreds of millions

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Speaker 1: of years. Scientists are really surprised if they see a

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Speaker 1: cluster that's like a billion years old, because it's hard

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Speaker 1: for these clusters to resist like the tug of the

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Speaker 1: rest of the galaxy, which tends to sort of pull

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Speaker 1: them apart. Do they all stick around for about the

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Speaker 1: same amount of time because they started at the same

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Speaker 1: amount of time, or do some of them disappear at

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Speaker 1: different rates? Well, the stars inside the cluster can be

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Speaker 1: of varying sizes, and so because some of them are bigger,

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Speaker 1: they burn brighter, they burn bluer, they tend to disappear.

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Speaker 1: So as you're looking in older cluster, you tend to

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Speaker 1: see fewer blue stars in them and more of the

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Speaker 1: red stars and the yellow stars. So an older cluster

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Speaker 1: tends to have like more yellow and red stars. One

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Speaker 1: weird thing is that they have been looking at open

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Speaker 1: clusters and globular clusters, which are similar and even larger,

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Speaker 1: and they see something really weird, which that they see

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Speaker 1: a bunch of bright blue stars even inside these clusters

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Speaker 1: that are supposed to be pretty old, where all the

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Speaker 1: blue stars should have already burned up. WHOA, So why

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Speaker 1: do we think that they're sticking around? Scientists aren't sure,

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Speaker 1: of course, but that's what makes it exciting. They call

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Speaker 1: these things blue stragglers. And one idea, which I think

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Speaker 1: is really fun, is that these blue stragglers might be

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Speaker 1: new combinations of old stars. Like maybe you had a

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Speaker 1: couple of stars that are red or yellow and are

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Speaker 1: burning happily and planning to burn for billions of years,

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Speaker 1: but then they merge. They smashed together, they like gravitationally

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Speaker 1: bound to each other. Maybe they were in a binary

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Speaker 1: system to start with, and they just sort of like

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Speaker 1: fall into each other and become a big hot star. WHOA,

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Speaker 1: So I wonder like the social media and that galaxy,

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Speaker 1: is it like benefer when Ben Affleck and Jennifer what

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Speaker 1: Lopez come together? You know, these stars have names that combine.

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Speaker 1: I don't know, but instellar marriages. There are no divorces,

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Speaker 1: right once you get gravitationally married to each other. I

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Speaker 1: don't know how you can get separated again. You better

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Speaker 1: like each other. So you've mentioned an open cluster, and

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Speaker 1: I think I also heard you say globular cluster? Are

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Speaker 1: there clothes clusters? How many kinds of clusters do we have?

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Speaker 1: You know, if astronomical names made sense, then yes, there

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Speaker 1: would be open clusters and close clusters, globular clusters, and

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Speaker 1: I guess non globular clusters. But no, these things come

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Speaker 1: from history of people noticing, just as you were saying earlier,

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Speaker 1: they would like zoom in on a star and then discover,

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Speaker 1: way a second, that's not a star, that's actually a

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Speaker 1: bunch of stars and a little cluster. That's why it

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Speaker 1: looked a little bit like a hazy blob instead of

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Speaker 1: a bright pinpoint. And as we study these things, we

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Speaker 1: discover that these categories, which is sort of historical based

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Speaker 1: on who found them and what they called them, might

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Speaker 1: actually just sort of sit in a spectrum. That the

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Speaker 1: difference between an open cluster, you know, which tends to

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Speaker 1: have tens of thousands of stars, and a globular cluster

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Speaker 1: that has like a hundred thousand stars might just be

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Speaker 1: the size that there might be like clusters of stars

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Speaker 1: of all sizes, and we just sort of like found

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Speaker 1: a few here and found a few there and gave

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Speaker 1: them different names, when really it's just like a smooth

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Speaker 1: spectrum and there's no like fundamental difference. But that's something

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Speaker 1: astronomers are studying, like the concept of this open cluster

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Speaker 1: and is it different from a globular cluster and how

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Speaker 1: does it all fit together in the sort of history

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00:19:51,000 --> 00:19:53,960
Speaker 1: of the galaxy is an exciting area of research right now.

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Speaker 1: It's got to be a tough thing to study, but

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Speaker 1: I found it really fascinating because it gives you like

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Speaker 1: a hint as to what's going on in the Ga galaxy.

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Speaker 1: You know, it's not like we just got these stars

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Speaker 1: and they're gonna be burning. We're making new stars, like

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00:20:05,600 --> 00:20:08,679
Speaker 1: right now, like everyday, new stars are being formed. And

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Speaker 1: these clusters are especially fascinating because not only do you

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Speaker 1: have stars in there, but they still have clues in

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Speaker 1: the structure of the cluster about the thing that made them,

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Speaker 1: this huge cloud which formed them. And so I think

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Speaker 1: these clusters are super fascinating because there's sort of like

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Speaker 1: little mini sub galaxies within the galaxy. They give you

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Speaker 1: a clue as like the texture of the galaxy and

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Speaker 1: it's particular history that is so cool. So do we

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Speaker 1: have a sense for like what kind of things you

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Speaker 1: most commonly find at the center of the clusters? How

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Speaker 1: many of these have we've been able to study in detail? Well,

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Speaker 1: you know, these things are not made that often. There's

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Speaker 1: like one of these open clusters we think formed every

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Speaker 1: few thousand years in the Milky Way, so like it's

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Speaker 1: not like they're always popping into the night sky. But

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Speaker 1: because the Milky Way is pretty old, there are a

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Speaker 1: bunch of them. And we've identified more than a thousand

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Speaker 1: open clusters just in our galaxy, but we think there

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Speaker 1: are lots and lots more so we've they're all over

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Speaker 1: the place. A thousand that's a pretty nice data set

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Speaker 1: to work with. Yeah, it's something that you can you

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00:21:05,080 --> 00:21:07,159
Speaker 1: really use to study because you're going to see them

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Speaker 1: at all different points in their history. Recently, foreign clusters,

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Speaker 1: clusters that are just falling apart, all sorts of stuff.

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Speaker 1: Of course, the one that astronomers really like to study

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Speaker 1: is the one that's closest to the Earth, and is

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Speaker 1: that the Hyades cluster. That is all right now that

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Speaker 1: everybody's excited to learn about the Hyades Cluster. Let's wait

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Speaker 1: and take a break to hear from our sponsors. All right,

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Speaker 1: the moment you've all been waiting for, we're back. Let's

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Speaker 1: hear about the Hyades Cluster. So you were just telling

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Speaker 1: us that it is the closest of the clusters. So

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Speaker 1: if I look out in the night sky, where should

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Speaker 1: I be looking if I want to be looking in

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Speaker 1: the right direction to find the Hyades cluster. The Hyse

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Speaker 1: Cluster is actually part of a constellation. So if you

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Speaker 1: know that Horace constellation, the Face of the Bull, you know,

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Speaker 1: then there's this part of that constellation that's sort of

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Speaker 1: like a v The High These Cluster is part of that.

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Speaker 1: Another part of that constellation is sort of a famous

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Speaker 1: star called Aldera Bond, which I think is famous maybe

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Speaker 1: just because it sounds like the name of a planet

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Speaker 1: in Star Wars, but it's also one of the brightest

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Speaker 1: stars in the night sky. And so would we be able,

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Speaker 1: like if we were looking at the Tourist constellation, would

431
00:22:25,680 --> 00:22:29,439
Speaker 1: we see something kind of fuzzy or would it just

432
00:22:29,480 --> 00:22:31,399
Speaker 1: sort of look like a point. Well, it's about a

433
00:22:31,480 --> 00:22:34,879
Speaker 1: hundred and fifty three light years away, which means that

434
00:22:34,920 --> 00:22:37,560
Speaker 1: it's pretty far away, right, it's not that close, and

435
00:22:37,600 --> 00:22:39,879
Speaker 1: so to the naked eye it just looks like a point.

436
00:22:40,040 --> 00:22:41,959
Speaker 1: But if you have a strong enough telescope, you can

437
00:22:42,040 --> 00:22:43,760
Speaker 1: zoom in on it and you can tell that's not

438
00:22:43,920 --> 00:22:47,320
Speaker 1: just a star, it's actually a cluster of stars. It

439
00:22:47,359 --> 00:22:50,439
Speaker 1: doesn't take that powerful a telescope. So if you have

440
00:22:50,480 --> 00:22:53,000
Speaker 1: a pretty good telescope in your backyard, zoom in on

441
00:22:53,040 --> 00:22:55,000
Speaker 1: the high these cluster and you can see it looks

442
00:22:55,040 --> 00:22:57,200
Speaker 1: like a bit of a fuzzy blob, and that's how

443
00:22:57,200 --> 00:22:59,800
Speaker 1: it was discovered to be a cluster. How wide is this?

444
00:23:00,359 --> 00:23:03,560
Speaker 1: So the thing is about sixty light years across, right,

445
00:23:03,560 --> 00:23:05,919
Speaker 1: and so it's a hundred fifty three light years away

446
00:23:05,920 --> 00:23:07,720
Speaker 1: and sixty light years across. So that gives you a

447
00:23:07,720 --> 00:23:11,000
Speaker 1: sense for like how broad this thing is relative to

448
00:23:11,040 --> 00:23:14,040
Speaker 1: its distance, And that means that it's large enough and

449
00:23:14,119 --> 00:23:17,440
Speaker 1: close enough that we can actually measure its distance directly

450
00:23:17,840 --> 00:23:21,399
Speaker 1: using parallax. Remember that the distance two stars can be

451
00:23:21,520 --> 00:23:24,880
Speaker 1: hard to estimate because you can't necessarily tell the difference

452
00:23:24,880 --> 00:23:28,800
Speaker 1: between a star that's really bright and far away or

453
00:23:28,840 --> 00:23:31,280
Speaker 1: a star that's not so bright and closer up. They

454
00:23:31,320 --> 00:23:33,240
Speaker 1: look the same in the night sky, but we have

455
00:23:33,280 --> 00:23:36,000
Speaker 1: all these cool techniques for measuring how far away a

456
00:23:36,080 --> 00:23:38,920
Speaker 1: star is from, like looking at type one a supernova

457
00:23:38,960 --> 00:23:41,520
Speaker 1: for stars and other galaxies, just seeing if they're near

458
00:23:41,560 --> 00:23:44,800
Speaker 1: one of these variable stars, these sephids, or if they're

459
00:23:44,840 --> 00:23:47,800
Speaker 1: close enough, we can see how the star moves in

460
00:23:47,840 --> 00:23:50,760
Speaker 1: the night sky as the Earth goes around the Sun,

461
00:23:51,080 --> 00:23:52,720
Speaker 1: because as the Earth goes around the Sun, you get

462
00:23:52,720 --> 00:23:55,960
Speaker 1: a slightly different view of the night sky. And for

463
00:23:56,000 --> 00:23:58,480
Speaker 1: stars that are close enough, it's sort of like opening

464
00:23:58,480 --> 00:24:01,520
Speaker 1: and closing one eye and looking at your finger. You've

465
00:24:01,520 --> 00:24:04,200
Speaker 1: got a different view of that finger, and your brain

466
00:24:04,240 --> 00:24:07,560
Speaker 1: actually automatically uses that binocular information to give you a

467
00:24:07,600 --> 00:24:10,520
Speaker 1: sense for how far away something is. So Hyades is

468
00:24:10,560 --> 00:24:12,360
Speaker 1: close enough that we can do that. We can use

469
00:24:12,400 --> 00:24:15,320
Speaker 1: parallax to measure how far away it is. Interesting, and

470
00:24:15,320 --> 00:24:16,639
Speaker 1: of course you know now that you've mentioned that I

471
00:24:16,680 --> 00:24:18,600
Speaker 1: have to be blinking and looking at my finger in

472
00:24:18,600 --> 00:24:21,520
Speaker 1: this room by myself. So we talked a little bit

473
00:24:21,560 --> 00:24:24,399
Speaker 1: ago about how you need something in the center to

474
00:24:24,600 --> 00:24:28,160
Speaker 1: pull the cloud together. Do we know what is pulling

475
00:24:28,200 --> 00:24:31,760
Speaker 1: things together in the Hyades cluster? So probably all of

476
00:24:31,800 --> 00:24:35,800
Speaker 1: those gravitational centers then became stars, right, So you have

477
00:24:35,880 --> 00:24:38,199
Speaker 1: this like big cloud of gas and dust that forms it,

478
00:24:38,359 --> 00:24:41,159
Speaker 1: and then you need these seeds, these gravitational seeds to

479
00:24:41,280 --> 00:24:44,720
Speaker 1: pull stuff together. Each of those are the progenitors of

480
00:24:44,760 --> 00:24:46,800
Speaker 1: a star, and so what you end up with instead

481
00:24:46,800 --> 00:24:48,800
Speaker 1: of a big cloud of gas and dust, is then

482
00:24:48,880 --> 00:24:51,560
Speaker 1: just a bunch of stars. And interestingly, all the gas

483
00:24:51,560 --> 00:24:55,159
Speaker 1: and dust that didn't get gathered into a star gets

484
00:24:55,320 --> 00:24:58,640
Speaker 1: blown out of the cluster because of the radiation from

485
00:24:58,640 --> 00:25:01,359
Speaker 1: those stars. So sort of like musical chairs, like you

486
00:25:01,440 --> 00:25:03,399
Speaker 1: gotta find a star to join, and if you don't,

487
00:25:03,760 --> 00:25:06,480
Speaker 1: then the radiation just like blows you away and you're

488
00:25:06,520 --> 00:25:11,440
Speaker 1: alone forever. You're just floating out there destined to be

489
00:25:11,640 --> 00:25:14,240
Speaker 1: you know, in some next generation of stars, maybe the

490
00:25:14,280 --> 00:25:16,440
Speaker 1: fourth or the fifth time around, you'll win the game

491
00:25:16,480 --> 00:25:19,200
Speaker 1: of musical stars and you'll get to burn brightly in

492
00:25:19,240 --> 00:25:21,480
Speaker 1: the universe. I don't know though, if gas really wants

493
00:25:21,520 --> 00:25:23,159
Speaker 1: to be part of a star and get fused into

494
00:25:23,240 --> 00:25:26,000
Speaker 1: something heavy, or if it's happy just the way it is. Well,

495
00:25:26,040 --> 00:25:28,160
Speaker 1: some of us are loaners, and so you know, I'm

496
00:25:28,160 --> 00:25:30,720
Speaker 1: glad there's lots of options out there for the dust particles,

497
00:25:30,720 --> 00:25:32,439
Speaker 1: and I hope they'll get what they want. I like

498
00:25:32,520 --> 00:25:37,119
Speaker 1: the introvert extrovert theory of gas. That's nice. Well, I

499
00:25:37,119 --> 00:25:41,560
Speaker 1: study animal behavior. So, so about how many stars are

500
00:25:41,640 --> 00:25:44,560
Speaker 1: in this particular cluster. So the high these clusters sort

501
00:25:44,560 --> 00:25:46,800
Speaker 1: of like a big spherical blob, and right now it

502
00:25:46,880 --> 00:25:49,760
Speaker 1: has hundreds of stars in it. And as we said earlier,

503
00:25:49,800 --> 00:25:52,400
Speaker 1: probably all these stars around the similar age, and they

504
00:25:52,440 --> 00:25:54,800
Speaker 1: come from the same cloud and so that the same

505
00:25:54,840 --> 00:25:58,960
Speaker 1: sort of chemical makeup. And interestingly, we think, based on

506
00:25:59,040 --> 00:26:02,439
Speaker 1: the light that comes from these stars, that there's more

507
00:26:02,480 --> 00:26:05,119
Speaker 1: metals in those stars than there is in sort of

508
00:26:05,119 --> 00:26:08,840
Speaker 1: our stellar neighborhood. So you told us that astronomers think

509
00:26:08,880 --> 00:26:12,479
Speaker 1: anything more than helium is a metal, right, So that

510
00:26:12,560 --> 00:26:14,960
Speaker 1: might not mean what I think it means. Does that

511
00:26:15,080 --> 00:26:18,280
Speaker 1: just mean it has less helium and hydrogen? Yeah, when

512
00:26:18,280 --> 00:26:21,400
Speaker 1: a star is formed, it's usually it is mostly hydrogen

513
00:26:21,480 --> 00:26:24,119
Speaker 1: and helium, and that's really what the star starts to burn,

514
00:26:24,560 --> 00:26:28,359
Speaker 1: because stars are factories for turning helium and hydrogen into

515
00:26:28,480 --> 00:26:31,920
Speaker 1: heavier elements. But of course they often come with some

516
00:26:32,080 --> 00:26:35,160
Speaker 1: left over remnants of previous stars, and at the beginning

517
00:26:35,160 --> 00:26:37,840
Speaker 1: of a star's lifetime, those heavy elements just sort of

518
00:26:37,880 --> 00:26:40,480
Speaker 1: hang out and get hot. If the star burns long

519
00:26:40,600 --> 00:26:43,639
Speaker 1: enough so that they can fuse those heavier elements. Then

520
00:26:43,680 --> 00:26:46,800
Speaker 1: eventually they can participate in the star itself. One thing

521
00:26:46,840 --> 00:26:49,280
Speaker 1: we can do is we can measure the emissions from

522
00:26:49,280 --> 00:26:51,360
Speaker 1: those elements. We can look at a star, we can

523
00:26:51,400 --> 00:26:54,920
Speaker 1: see in what frequencies it's sending us light, and that

524
00:26:55,000 --> 00:26:58,199
Speaker 1: those frequencies tell us what the star is made out of,

525
00:26:58,480 --> 00:27:01,720
Speaker 1: because different elements glow with different colors. Like if you

526
00:27:01,720 --> 00:27:04,560
Speaker 1: remember middle school chemistry, you probably got to put like

527
00:27:04,720 --> 00:27:07,280
Speaker 1: weird chemicals and a bunsen burner and see the flame

528
00:27:07,320 --> 00:27:11,560
Speaker 1: turn green or blue or whatever. Chemistry. That's part of chemistry,

529
00:27:11,640 --> 00:27:13,760
Speaker 1: you know, the whiz bang factor. And so we can

530
00:27:13,760 --> 00:27:15,600
Speaker 1: do the same thing with stars. You say, oh, this

531
00:27:15,640 --> 00:27:18,159
Speaker 1: one is burning green, that has more copper in it. Whatever.

532
00:27:18,400 --> 00:27:21,000
Speaker 1: And so this tells you, like the particular context of

533
00:27:21,040 --> 00:27:23,879
Speaker 1: the neighborhood wherever the high these cluster was when it

534
00:27:23,920 --> 00:27:27,320
Speaker 1: was born, happen to have more medals in it because

535
00:27:27,480 --> 00:27:30,400
Speaker 1: it just happened to have like more compost from other

536
00:27:30,560 --> 00:27:33,480
Speaker 1: stars that had blown up and spread those medals into

537
00:27:33,520 --> 00:27:37,679
Speaker 1: the universe. Interesting, I'm trying to figure out a hippie

538
00:27:37,760 --> 00:27:40,880
Speaker 1: joke or something about composting, but it's just not it's

539
00:27:40,920 --> 00:27:43,560
Speaker 1: not coming together. It's a cycle of life or something,

540
00:27:43,640 --> 00:27:46,280
Speaker 1: or the cycle of star life. Yes, the cycle of

541
00:27:46,320 --> 00:27:48,359
Speaker 1: star life. And as you look at these clusters, you

542
00:27:48,359 --> 00:27:51,760
Speaker 1: can also compare them to the other clusters nearby, and

543
00:27:51,800 --> 00:27:53,760
Speaker 1: I can tell you more of like the story of

544
00:27:53,800 --> 00:27:55,800
Speaker 1: what happened. I feel like this is sort of like

545
00:27:55,920 --> 00:27:59,320
Speaker 1: space archaeology, you know, wondering like how did this form

546
00:27:59,359 --> 00:28:01,400
Speaker 1: and what was going on here? While the high these

547
00:28:01,400 --> 00:28:05,320
Speaker 1: cluster is near another cluster where there similarly difficult to

548
00:28:05,400 --> 00:28:08,000
Speaker 1: pronounce a name. It might be Presepi, but it has

549
00:28:08,160 --> 00:28:11,760
Speaker 1: similar metallicity and it's sort of moving in the same direction.

550
00:28:12,240 --> 00:28:14,720
Speaker 1: So they might have been formed together like one big

551
00:28:14,800 --> 00:28:18,359
Speaker 1: mega cluster and then gotten split up by title forces,

552
00:28:18,400 --> 00:28:21,560
Speaker 1: by the gravitational forces of the Milky Way, into two

553
00:28:21,560 --> 00:28:23,679
Speaker 1: separate clusters. Or they could have just come from the

554
00:28:23,720 --> 00:28:26,720
Speaker 1: same neighborhood which had like the same sort of leftover

555
00:28:26,800 --> 00:28:30,199
Speaker 1: bits of stars. But all these things are remnants, you know,

556
00:28:30,240 --> 00:28:32,280
Speaker 1: sort of like when you see a church and it's

557
00:28:32,320 --> 00:28:34,960
Speaker 1: built on top of the foundations of something else, which

558
00:28:35,000 --> 00:28:36,840
Speaker 1: is built on top of the foundations of something else.

559
00:28:36,920 --> 00:28:40,240
Speaker 1: It's like ten layers deep of human history. There that's

560
00:28:40,240 --> 00:28:41,800
Speaker 1: sort of what we're looking at when we're looking at

561
00:28:41,800 --> 00:28:46,320
Speaker 1: the stars. There's so many generations of cosmic dramatic history,

562
00:28:46,480 --> 00:28:48,760
Speaker 1: and yet you have to try to disentangle it from

563
00:28:49,080 --> 00:28:51,600
Speaker 1: light years away. It remains amazing to me that we

564
00:28:51,640 --> 00:28:53,560
Speaker 1: know anything at all about the night sky. And you

565
00:28:53,600 --> 00:28:56,160
Speaker 1: asked a really interesting question earlier about how we can

566
00:28:56,240 --> 00:28:58,680
Speaker 1: know that these things are happening because we're seeing them

567
00:28:58,760 --> 00:29:01,760
Speaker 1: in slow motion. I think that's a really important question,

568
00:29:01,760 --> 00:29:03,840
Speaker 1: because you're right. We can't like look at one star

569
00:29:04,040 --> 00:29:06,680
Speaker 1: and see its whole life cycle and say, Okay, we

570
00:29:06,720 --> 00:29:08,600
Speaker 1: saw it get born, and we saw burn, and we

571
00:29:08,640 --> 00:29:10,719
Speaker 1: saw it die. All we can do is look at

572
00:29:10,760 --> 00:29:12,880
Speaker 1: lots of different examples. It's sort of like if you

573
00:29:12,880 --> 00:29:15,080
Speaker 1: look at a town and you see there are kids,

574
00:29:15,200 --> 00:29:17,320
Speaker 1: and there are teenagers, and there are grown ups, and

575
00:29:17,320 --> 00:29:19,239
Speaker 1: there are people who are old and dying, and then

576
00:29:19,280 --> 00:29:21,880
Speaker 1: you can sort of put together the lifespan of a human,

577
00:29:22,160 --> 00:29:24,400
Speaker 1: even though you don't ever get to see a human

578
00:29:24,640 --> 00:29:27,720
Speaker 1: go through the whole cycle just from one snapshot. That's

579
00:29:27,720 --> 00:29:29,560
Speaker 1: sort of what we're doing in the night sky. We

580
00:29:29,600 --> 00:29:31,959
Speaker 1: don't get to see a star's entire life cycle, and

581
00:29:32,000 --> 00:29:35,080
Speaker 1: we definitely don't get to see an open clusters entire cycle.

582
00:29:35,240 --> 00:29:37,400
Speaker 1: But we can sort of put the story together by

583
00:29:37,440 --> 00:29:39,200
Speaker 1: looking at lots of them. And as you said earlier,

584
00:29:39,240 --> 00:29:41,320
Speaker 1: there's like more than a thousand of them, So that

585
00:29:41,400 --> 00:29:43,840
Speaker 1: gives us a pretty good picture what's going on in

586
00:29:44,000 --> 00:29:47,680
Speaker 1: terms of the dynamics. And so when these clusters go away,

587
00:29:48,320 --> 00:29:51,200
Speaker 1: do they go away because the stars die, or do

588
00:29:51,280 --> 00:29:53,880
Speaker 1: they go get pulled aparts and sort of spread out

589
00:29:53,920 --> 00:29:56,480
Speaker 1: in the night sky? What what happens to these clusters

590
00:29:56,480 --> 00:29:58,920
Speaker 1: as time goes on. It depends a little on the age.

591
00:29:59,280 --> 00:30:01,720
Speaker 1: Sometimes of the cluster lasts a long time. Then the

592
00:30:01,760 --> 00:30:04,440
Speaker 1: stars can live their whole life in the cluster and

593
00:30:04,520 --> 00:30:06,640
Speaker 1: never have to leave. But the rest of the Milky

594
00:30:06,640 --> 00:30:09,680
Speaker 1: Way is tugging on these things. Remember that there's rarely

595
00:30:09,720 --> 00:30:12,680
Speaker 1: strong gravitational forces from the center of the Milky Way.

596
00:30:12,800 --> 00:30:15,320
Speaker 1: All of these stars, they're not just hanging out in space.

597
00:30:15,480 --> 00:30:19,120
Speaker 1: They're zooming through space because they're whirling around the galaxy,

598
00:30:19,200 --> 00:30:21,880
Speaker 1: which is spinning. That means that there's a very strong

599
00:30:21,960 --> 00:30:25,080
Speaker 1: gravitational force towards the center of the galaxy, but their

600
00:30:25,160 --> 00:30:27,840
Speaker 1: velocity keeps them from falling into it, sort of like

601
00:30:27,880 --> 00:30:30,120
Speaker 1: the way the Earth doesn't fall into the Sun because

602
00:30:30,120 --> 00:30:33,120
Speaker 1: it's moving so fast, and so these stars are getting

603
00:30:33,120 --> 00:30:35,600
Speaker 1: pulled on by the gravity of the Milky Way, but

604
00:30:35,680 --> 00:30:38,000
Speaker 1: doesn't pull on all of them equally. Some of them

605
00:30:38,000 --> 00:30:39,840
Speaker 1: are closer to the center and some of them are

606
00:30:39,920 --> 00:30:43,640
Speaker 1: further from the center, so they're effectively getting pulled apart,

607
00:30:43,960 --> 00:30:46,600
Speaker 1: and we call it tidal forces. Anytime gravity is pulling

608
00:30:46,640 --> 00:30:49,320
Speaker 1: on one part of something with a different force than

609
00:30:49,360 --> 00:30:51,720
Speaker 1: it pulls on the other part of it, effectively it's

610
00:30:51,760 --> 00:30:55,400
Speaker 1: pulling it apart. So we call those tidal forces. And

611
00:30:55,440 --> 00:30:57,400
Speaker 1: the Milky Way is doing that to the open cluster,

612
00:30:57,520 --> 00:30:59,520
Speaker 1: just like us doing it to everything else. Is trying

613
00:30:59,520 --> 00:31:03,240
Speaker 1: to basically pull it apart. So if you we're living

614
00:31:03,280 --> 00:31:06,320
Speaker 1: on a habitable planet and it could be anywhere in

615
00:31:06,320 --> 00:31:09,400
Speaker 1: the Solar System, would you not want your habitable planet

616
00:31:09,440 --> 00:31:12,000
Speaker 1: to be in a cluster because it's getting pulled on

617
00:31:12,200 --> 00:31:14,960
Speaker 1: a lot, and you'd be more likely to, I don't know,

618
00:31:15,000 --> 00:31:17,120
Speaker 1: get thrown out of whack. Or is it not more

619
00:31:17,200 --> 00:31:20,360
Speaker 1: chaotic there than other places? These things are denser than

620
00:31:20,440 --> 00:31:22,760
Speaker 1: other places, So the rest of the Milky Way sort

621
00:31:22,800 --> 00:31:25,120
Speaker 1: of less dense in terms of stars, like in our

622
00:31:25,160 --> 00:31:27,360
Speaker 1: neighborhood of the Milky Way, it's like one star every

623
00:31:27,400 --> 00:31:31,120
Speaker 1: three or four cubic light years, so not very dense,

624
00:31:31,440 --> 00:31:34,200
Speaker 1: whereas in the center of a globular cluster, for example,

625
00:31:34,400 --> 00:31:36,840
Speaker 1: there's like one star every cubic light year, so they're

626
00:31:36,920 --> 00:31:39,960
Speaker 1: much closer to each other. Normally, that doesn't really affect

627
00:31:40,000 --> 00:31:42,160
Speaker 1: you because like that's still really far away, like a

628
00:31:42,240 --> 00:31:45,720
Speaker 1: light year is a big distance. However, it really can

629
00:31:45,800 --> 00:31:48,880
Speaker 1: affect you because if stars are near each other, they

630
00:31:48,880 --> 00:31:52,400
Speaker 1: can perturb each other's Solar system. So, for example, if

631
00:31:52,440 --> 00:31:55,840
Speaker 1: another star came close to our Sun, it might knock

632
00:31:55,960 --> 00:31:59,200
Speaker 1: some things in the or cloud out. This this huge

633
00:31:59,320 --> 00:32:02,680
Speaker 1: cloud of lillions of icy objects orbiting really far from

634
00:32:02,680 --> 00:32:05,040
Speaker 1: the Sun. If one of them gets knocked out of orbit,

635
00:32:05,240 --> 00:32:08,080
Speaker 1: you can fall into the Solar system and become a comet.

636
00:32:08,240 --> 00:32:14,080
Speaker 1: And sometimes those things smack into planets, causing catastrophes. Yeah,

637
00:32:14,120 --> 00:32:17,320
Speaker 1: so it's not great actually to have neighbors. You want

638
00:32:17,360 --> 00:32:19,360
Speaker 1: to live out in the middle of nowhere, and this

639
00:32:19,440 --> 00:32:22,040
Speaker 1: neighbors maybe getting a little bit too close. We should

640
00:32:22,080 --> 00:32:26,760
Speaker 1: see if they're following all the h O rules exactly.

641
00:32:26,880 --> 00:32:28,760
Speaker 1: Probably they're coming up and they're saying, hey, you'r or

642
00:32:28,880 --> 00:32:30,640
Speaker 1: cloud is out of whack, and you're like, hey, that's

643
00:32:30,640 --> 00:32:32,680
Speaker 1: because you came too close. Get out of here. It's

644
00:32:32,680 --> 00:32:36,160
Speaker 1: your phone. You're gonna have to pay for the property

645
00:32:36,240 --> 00:32:39,280
Speaker 1: damage if a comet gets too close, exactly. And so

646
00:32:39,400 --> 00:32:41,600
Speaker 1: living in the center of a stellar cluster and open

647
00:32:41,640 --> 00:32:45,280
Speaker 1: cluster or a globular cluster probably not great for life

648
00:32:45,280 --> 00:32:48,200
Speaker 1: because you could probably get more common bombardments. Got it.

649
00:32:48,200 --> 00:32:50,959
Speaker 1: It's a dangerous place out there on long time scales.

650
00:32:51,440 --> 00:32:54,480
Speaker 1: So what is Hyades is history? How old is it

651
00:32:54,600 --> 00:32:56,800
Speaker 1: and is it breaking up a lot right now or

652
00:32:56,880 --> 00:32:59,080
Speaker 1: is it still pretty well held together so high these

653
00:32:59,080 --> 00:33:02,480
Speaker 1: we think is around six hundred million years old, which

654
00:33:02,520 --> 00:33:05,040
Speaker 1: is pretty old for one of these clusters. We think

655
00:33:05,080 --> 00:33:08,040
Speaker 1: that usually these clusters only last for like fifty to

656
00:33:08,200 --> 00:33:11,320
Speaker 1: a hundred million years before basically they get pulled apart

657
00:33:11,520 --> 00:33:14,440
Speaker 1: and they just become dissolved into the background structure of

658
00:33:14,480 --> 00:33:16,720
Speaker 1: the Milky Way. So this one is pretty old, which

659
00:33:16,760 --> 00:33:20,520
Speaker 1: means probably it started out really big and really massive,

660
00:33:20,880 --> 00:33:22,360
Speaker 1: and while we're looking at is sort of like the

661
00:33:22,440 --> 00:33:26,320
Speaker 1: leftover bits. What's been able to resist those tidal forces

662
00:33:26,560 --> 00:33:30,080
Speaker 1: for six hundred million years. That's incredible because that's not

663
00:33:30,160 --> 00:33:33,600
Speaker 1: just a little bit longer than usual. That's longer than usual.

664
00:33:33,640 --> 00:33:36,160
Speaker 1: So we've got a thousand data points. Is six hundred

665
00:33:36,200 --> 00:33:39,240
Speaker 1: million years old and extreme value? Are we lucky to

666
00:33:39,280 --> 00:33:41,960
Speaker 1: live next to this extreme open cluster? Or is there

667
00:33:42,000 --> 00:33:44,520
Speaker 1: a lot of variability around that fifty to one hundred

668
00:33:44,560 --> 00:33:47,080
Speaker 1: million years? There is a lot of variability, though they

669
00:33:47,080 --> 00:33:50,280
Speaker 1: tend to peek at much smaller values, so six hundred

670
00:33:50,320 --> 00:33:52,440
Speaker 1: is pretty rare that we have seen some up to

671
00:33:52,520 --> 00:33:55,760
Speaker 1: like maybe a billion if they're really really massive. But

672
00:33:55,800 --> 00:33:57,960
Speaker 1: this suggests the high these is definitely on the more

673
00:33:58,120 --> 00:34:01,920
Speaker 1: massive end of clusters. All right, Well, so we opened

674
00:34:02,000 --> 00:34:05,280
Speaker 1: by saying what's happening to Hyades? Which suggests that something

675
00:34:05,360 --> 00:34:08,479
Speaker 1: interesting is happening to Hyades. So let's make everybody wait

676
00:34:08,960 --> 00:34:11,080
Speaker 1: when we take a break before we get back to

677
00:34:11,080 --> 00:34:26,759
Speaker 1: the big question. And we're back. So, now that we've

678
00:34:26,760 --> 00:34:30,040
Speaker 1: all learned about Hyades background, we all, you know, are

679
00:34:30,080 --> 00:34:32,839
Speaker 1: sort of emotionally attached to it. But you told us

680
00:34:32,880 --> 00:34:34,879
Speaker 1: that something is happening to it, which we all hope

681
00:34:34,920 --> 00:34:38,440
Speaker 1: is nothing bad. What is happening to Hyades? So what

682
00:34:38,520 --> 00:34:40,799
Speaker 1: you usually happens to these clusters is that they get

683
00:34:40,840 --> 00:34:43,760
Speaker 1: pulled apart by the galaxy, right and usually tidal forces

684
00:34:43,800 --> 00:34:46,279
Speaker 1: have a very distinctive effect on something. They tend to

685
00:34:46,320 --> 00:34:49,520
Speaker 1: pull it apart into long strands, and so you get

686
00:34:49,560 --> 00:34:52,640
Speaker 1: like a forward tail and a trailing tail instead of

687
00:34:52,640 --> 00:34:55,080
Speaker 1: just being a blob that like pulls the closer bits

688
00:34:55,200 --> 00:34:58,160
Speaker 1: harder and doesn't pull on the back bits as hard.

689
00:34:58,320 --> 00:35:00,239
Speaker 1: So it gets sort of like stretched out. You get

690
00:35:00,280 --> 00:35:03,480
Speaker 1: these really long tails, and so that's what typically happens

691
00:35:03,520 --> 00:35:06,520
Speaker 1: to these clusters. They get stretched out and eventually dispersed.

692
00:35:06,680 --> 00:35:09,520
Speaker 1: And so people have been studying the high these cluster

693
00:35:10,080 --> 00:35:13,279
Speaker 1: and they see these tails, but one of these tails

694
00:35:13,480 --> 00:35:16,279
Speaker 1: is missing. The trailing tails seems to sort of have

695
00:35:16,360 --> 00:35:19,920
Speaker 1: been like chopped off. WHOA where did it go. It's

696
00:35:19,960 --> 00:35:22,000
Speaker 1: like finding a lizard in nature and be like, oh,

697
00:35:22,080 --> 00:35:24,040
Speaker 1: somebody took a bite out of this one, right right,

698
00:35:24,080 --> 00:35:27,000
Speaker 1: the predator got him. Yeah. And so what that means

699
00:35:27,160 --> 00:35:30,480
Speaker 1: is that there's something big out there that's disrupting this thing.

700
00:35:30,520 --> 00:35:34,040
Speaker 1: It's not just the normal process of the galaxy tearing

701
00:35:34,040 --> 00:35:37,600
Speaker 1: this thing apart gently. Something sort of more brutal is happening.

702
00:35:37,960 --> 00:35:40,719
Speaker 1: And I say more brutal as a direct quotation from

703
00:35:40,760 --> 00:35:43,799
Speaker 1: one of these astronomy papers I read. And when astronomers say,

704
00:35:43,880 --> 00:35:45,960
Speaker 1: you know who are used to like stars burning and

705
00:35:46,000 --> 00:35:49,200
Speaker 1: exploding and supernovas. When they say something's brutal, you know,

706
00:35:49,239 --> 00:35:52,239
Speaker 1: it's pretty severe. I'm scared. What is the brutal thing

707
00:35:52,280 --> 00:35:55,120
Speaker 1: that's happening? Do they know? We don't know exactly because

708
00:35:55,120 --> 00:35:57,480
Speaker 1: all we can do is measure the gravity, right. What

709
00:35:57,560 --> 00:35:59,919
Speaker 1: we know is that these things are disrupted by grab,

710
00:36:00,360 --> 00:36:02,839
Speaker 1: of course, the gravity of the galactic center. But here

711
00:36:02,840 --> 00:36:06,440
Speaker 1: there's some new source of gravity. Something else is tugging

712
00:36:06,440 --> 00:36:09,200
Speaker 1: on this thing, and it's like slurred up the tail

713
00:36:09,320 --> 00:36:11,799
Speaker 1: of this cluster, it's like gobbled it up. And so

714
00:36:11,840 --> 00:36:16,360
Speaker 1: there's some massive invisible structure out there that's tearing the

715
00:36:16,400 --> 00:36:19,080
Speaker 1: high these cluster apart. So why don't the clumps get

716
00:36:19,160 --> 00:36:22,200
Speaker 1: like pulled away and then form something bigger? Where where

717
00:36:22,200 --> 00:36:24,960
Speaker 1: are they going? Yeah, that's a great question. It depends

718
00:36:25,040 --> 00:36:27,120
Speaker 1: on the sort of the shape of this new thing

719
00:36:27,200 --> 00:36:29,799
Speaker 1: that's pulling on them. It's possible that it's just sort

720
00:36:29,800 --> 00:36:31,839
Speaker 1: of like yanks them out, and they get tossed out

721
00:36:32,040 --> 00:36:35,000
Speaker 1: because of their high velocity, into some new direction and

722
00:36:35,040 --> 00:36:39,440
Speaker 1: they can't necessarily like coalesce around this new heavy, invisible object.

723
00:36:39,719 --> 00:36:42,560
Speaker 1: But in order to tear this thing apart. It needs

724
00:36:42,600 --> 00:36:45,880
Speaker 1: to be some object that has like ten million times

725
00:36:45,920 --> 00:36:48,760
Speaker 1: the mass of the Sun, so it's much more massive

726
00:36:48,800 --> 00:36:51,440
Speaker 1: than the entire cluster, and we can't see it, and

727
00:36:51,480 --> 00:36:53,600
Speaker 1: we can't see it directly. When we look, we don't

728
00:36:53,640 --> 00:36:56,839
Speaker 1: see anything there, and that of course suggests that it

729
00:36:56,920 --> 00:37:00,960
Speaker 1: might be something really fascinating, like you know, a supermassive

730
00:37:01,000 --> 00:37:04,359
Speaker 1: black hole that somehow escaped its galaxy and it isn't

731
00:37:04,400 --> 00:37:08,319
Speaker 1: surrounded by you know, glowing accretion disks and other stars.

732
00:37:08,440 --> 00:37:11,479
Speaker 1: Or it could be like a huge blob of dark matter.

733
00:37:11,920 --> 00:37:14,600
Speaker 1: WHOA which one do we think it is? Are those

734
00:37:14,640 --> 00:37:17,839
Speaker 1: equally plausible? I think it's more likely to be dark matter,

735
00:37:17,920 --> 00:37:19,800
Speaker 1: although you know, it's a bit of a catch all.

736
00:37:20,040 --> 00:37:23,040
Speaker 1: Like every time we say, oh, there's gravity, and we

737
00:37:23,080 --> 00:37:26,040
Speaker 1: can see the gravitational effects because we see it tugging

738
00:37:26,120 --> 00:37:29,799
Speaker 1: on the stars, we don't see anything there. Then we say, okay,

739
00:37:29,840 --> 00:37:32,399
Speaker 1: there's some invisible matter, and it's easy to say, well,

740
00:37:32,440 --> 00:37:34,520
Speaker 1: that must be dark matter, sort of like the go

741
00:37:34,680 --> 00:37:38,239
Speaker 1: to explanation for a black hole to be like ejected

742
00:37:38,239 --> 00:37:40,880
Speaker 1: from its galaxy or to lose all of its stars.

743
00:37:41,000 --> 00:37:43,480
Speaker 1: That could happen. Also, if you get two galaxies that

744
00:37:43,640 --> 00:37:46,360
Speaker 1: merge and then one of them gobbles all these stars

745
00:37:46,440 --> 00:37:48,440
Speaker 1: and the other ones sort of orbit each other for

746
00:37:48,480 --> 00:37:50,799
Speaker 1: a while, but then one of them gets ejected. But

747
00:37:50,840 --> 00:37:53,120
Speaker 1: it's much less likely to happen. So I think dark

748
00:37:53,160 --> 00:37:56,040
Speaker 1: matter is the sort of current best explanation that we

749
00:37:56,040 --> 00:37:59,280
Speaker 1: don't have any direct evidence that it is dark matter. Okay,

750
00:37:59,320 --> 00:38:01,239
Speaker 1: how do we know any of this? Yeah, we can

751
00:38:01,320 --> 00:38:04,120
Speaker 1: only see this stuff because of the gravitational effects, right,

752
00:38:04,160 --> 00:38:06,360
Speaker 1: So what we do is we look at the path

753
00:38:06,480 --> 00:38:09,600
Speaker 1: of all of these stars really, really carefully and really

754
00:38:09,640 --> 00:38:12,640
Speaker 1: accurately in order to try to understand these dynamics. And

755
00:38:12,719 --> 00:38:16,680
Speaker 1: we're actually entering a really exciting era in astronomy where

756
00:38:16,680 --> 00:38:19,880
Speaker 1: we're getting much more precise pictures of what's going on

757
00:38:19,960 --> 00:38:22,200
Speaker 1: in the Milky Way. We talked earlier about how we

758
00:38:22,239 --> 00:38:23,759
Speaker 1: look at the stars is sort of like a two

759
00:38:23,800 --> 00:38:25,719
Speaker 1: D screen in the sky. It takes it sort of

760
00:38:25,760 --> 00:38:29,080
Speaker 1: like mental gymnastics to remember that it's three dimensions. Well,

761
00:38:29,160 --> 00:38:32,360
Speaker 1: recently we've launched some telescopes that really help us build

762
00:38:32,400 --> 00:38:34,719
Speaker 1: that three D map of the Milky Way. This is

763
00:38:34,760 --> 00:38:37,759
Speaker 1: this thing called the Gaia satellite, whose entire job is

764
00:38:37,880 --> 00:38:41,680
Speaker 1: essentially just to map the Milky Way really really precisely.

765
00:38:41,880 --> 00:38:44,239
Speaker 1: Is that a NASA project or did somebody else launch it?

766
00:38:44,680 --> 00:38:47,200
Speaker 1: That's from the European Space Agency, so thanks to our

767
00:38:47,239 --> 00:38:50,360
Speaker 1: European colleagues, and they launched it in two thousand thirteen.

768
00:38:50,520 --> 00:38:53,200
Speaker 1: Has two really powerful telescopes on it, and so what

769
00:38:53,239 --> 00:38:55,000
Speaker 1: it does is it focuses on a star and it

770
00:38:55,040 --> 00:38:57,440
Speaker 1: can measure the brightness of the star. But because has

771
00:38:57,480 --> 00:39:00,440
Speaker 1: two telescopes, it can also do parallax. It sort of

772
00:39:00,480 --> 00:39:02,719
Speaker 1: sort of like looking at the sky with binoculars. So

773
00:39:02,760 --> 00:39:06,480
Speaker 1: it measures the angular precision, the distance, and the brightness

774
00:39:06,600 --> 00:39:10,160
Speaker 1: really really accurately. And it also measures the velocity of

775
00:39:10,200 --> 00:39:12,840
Speaker 1: those stars. Because we can look at the spectrum of

776
00:39:12,880 --> 00:39:15,160
Speaker 1: the light that comes from the stars, we can say

777
00:39:15,200 --> 00:39:18,680
Speaker 1: what frequency are the photons that come from those stars,

778
00:39:19,000 --> 00:39:21,440
Speaker 1: and based on this frequency, we can measure the speed

779
00:39:21,560 --> 00:39:24,600
Speaker 1: of the stars from the Doppler shift on those photons.

780
00:39:25,040 --> 00:39:27,480
Speaker 1: Stars that are moving away from us really really fast

781
00:39:27,640 --> 00:39:30,160
Speaker 1: tend to be more red shifted. Stars that are moving

782
00:39:30,200 --> 00:39:33,239
Speaker 1: towards us get blue shifted. So as a result, we

783
00:39:33,280 --> 00:39:35,960
Speaker 1: can build this incredible map of the Milky Way with

784
00:39:36,120 --> 00:39:39,319
Speaker 1: really high precision. So having two telescopes helps us do

785
00:39:39,360 --> 00:39:42,880
Speaker 1: all of that. Are these two telescopes like Hubble sized

786
00:39:43,160 --> 00:39:46,360
Speaker 1: or much smaller. They're not nearly Hubble sized. Remember, anything

787
00:39:46,400 --> 00:39:48,600
Speaker 1: that we launched in the space is sort of limited

788
00:39:48,600 --> 00:39:50,920
Speaker 1: because you can only fit an object of a certain

789
00:39:50,960 --> 00:39:53,719
Speaker 1: size into our rocket. Unfortunately, so neither of them are

790
00:39:53,800 --> 00:39:57,000
Speaker 1: Hubble class telescopes. But together they can really make this

791
00:39:57,160 --> 00:40:00,160
Speaker 1: very accurate map of the universe. And it's not just

792
00:40:00,239 --> 00:40:02,520
Speaker 1: a three D map. It's sort of like a four

793
00:40:02,640 --> 00:40:05,879
Speaker 1: D map because not only do you know where all

794
00:40:05,920 --> 00:40:08,600
Speaker 1: the stars are now, but you can tell where they

795
00:40:08,640 --> 00:40:11,600
Speaker 1: are going. Right, You can tell their velocity, which tells

796
00:40:11,640 --> 00:40:14,600
Speaker 1: you something about their direction. And that's really exciting because

797
00:40:14,600 --> 00:40:17,200
Speaker 1: it gives you this picture of the Milky Way as

798
00:40:17,239 --> 00:40:19,799
Speaker 1: that dynamic entity. Right. It's like looking at all the

799
00:40:19,840 --> 00:40:22,840
Speaker 1: water droplets in that white water river and knowing which

800
00:40:22,880 --> 00:40:25,640
Speaker 1: direction they're going, and also gives you a sense for

801
00:40:25,719 --> 00:40:28,719
Speaker 1: like the snapshot that we have of this crazy chaotic

802
00:40:28,760 --> 00:40:32,120
Speaker 1: galaxy that's swirling around us. That is incredible. And so

803
00:40:32,200 --> 00:40:35,839
Speaker 1: it's been out there for less than a decade, but like,

804
00:40:35,960 --> 00:40:38,680
Speaker 1: you know, eight years or something, how many stars has

805
00:40:38,680 --> 00:40:41,000
Speaker 1: it mapped so far? It has a map of a

806
00:40:41,040 --> 00:40:45,560
Speaker 1: billion stars. It's incredible, and it's you know, it's really

807
00:40:45,560 --> 00:40:48,200
Speaker 1: a new era of astronomy. And every time I talk

808
00:40:48,280 --> 00:40:51,000
Speaker 1: to astronomers about what they're doing, they're always talking about

809
00:40:51,040 --> 00:40:52,960
Speaker 1: this data set. You know, they can use this to

810
00:40:53,000 --> 00:40:56,400
Speaker 1: measure things they could never measure before, to observe effects

811
00:40:56,400 --> 00:40:58,440
Speaker 1: that they could never study before. You know, I know

812
00:40:58,560 --> 00:41:00,919
Speaker 1: people here you see Irvine that are studying like how

813
00:41:00,960 --> 00:41:04,040
Speaker 1: often do we get asteroids impacting on the Earth and

814
00:41:04,160 --> 00:41:07,520
Speaker 1: can we tell if that's because other stars come nearby?

815
00:41:07,600 --> 00:41:09,719
Speaker 1: And they can use this guy a data set to

816
00:41:09,920 --> 00:41:12,200
Speaker 1: like look at the history of stars. So this one's

817
00:41:12,239 --> 00:41:14,239
Speaker 1: going in that direction. It must have come by our

818
00:41:14,239 --> 00:41:16,600
Speaker 1: solar system a few million years ago. It's kind of

819
00:41:16,640 --> 00:41:19,880
Speaker 1: really interesting studies. And so it's it's like we've been

820
00:41:19,920 --> 00:41:21,960
Speaker 1: looking at a flat screen and now we're getting like

821
00:41:22,000 --> 00:41:24,640
Speaker 1: the four D picture of the galaxy. We've got our

822
00:41:24,680 --> 00:41:27,760
Speaker 1: three D goggles and we're ready. And so it sounds

823
00:41:27,760 --> 00:41:30,520
Speaker 1: like these data are just available to anyone and will

824
00:41:30,560 --> 00:41:33,279
Speaker 1: be available a thousand years later when people want some

825
00:41:33,400 --> 00:41:36,360
Speaker 1: like background data to work with. Yeah, because it's the

826
00:41:36,560 --> 00:41:38,360
Speaker 1: s A, it means that it's available so and we

827
00:41:38,400 --> 00:41:40,399
Speaker 1: can go and download the data and analyze it. And

828
00:41:40,440 --> 00:41:43,799
Speaker 1: get in your computer a four D picture of the galaxy.

829
00:41:43,920 --> 00:41:46,799
Speaker 1: And that's how we're making these really interesting discoveries, like

830
00:41:46,920 --> 00:41:49,200
Speaker 1: looking at the high these cluster and be like, oh,

831
00:41:49,320 --> 00:41:52,520
Speaker 1: something is chomping on this tail. Is that something where

832
00:41:52,560 --> 00:41:54,239
Speaker 1: like if you knew where to look in the night sky,

833
00:41:54,360 --> 00:41:56,279
Speaker 1: you could pull up the e s A data and

834
00:41:56,280 --> 00:41:59,560
Speaker 1: you could see a tail sort of disappearing. That's exactly

835
00:41:59,640 --> 00:42:02,239
Speaker 1: what happened. And then so these astronomers that made this discovery,

836
00:42:02,480 --> 00:42:04,279
Speaker 1: that's just what they did. They looked at the guide

837
00:42:04,360 --> 00:42:06,919
Speaker 1: data for the Hyades cluster and they tried to find

838
00:42:06,960 --> 00:42:09,760
Speaker 1: these tails, and they noticed that this backwards tail was missing.

839
00:42:10,120 --> 00:42:12,799
Speaker 1: And there's no like really big cloud of gas or

840
00:42:12,840 --> 00:42:17,280
Speaker 1: other star cluster nearby that could provide this dramatic gravity.

841
00:42:17,360 --> 00:42:19,879
Speaker 1: And so it's cool because you can think about these

842
00:42:19,920 --> 00:42:22,319
Speaker 1: stars is sort of like tracers. You know, there's a

843
00:42:22,320 --> 00:42:25,200
Speaker 1: lot more going on in the galaxy than just the

844
00:42:25,200 --> 00:42:27,759
Speaker 1: things we can see, but the stars are affected by

845
00:42:27,760 --> 00:42:30,440
Speaker 1: those because of the gravity of the rest of the galaxy.

846
00:42:30,520 --> 00:42:32,280
Speaker 1: So you can think of the stars is like giving

847
00:42:32,360 --> 00:42:35,000
Speaker 1: us a sense for the currents of mass that are

848
00:42:35,040 --> 00:42:37,960
Speaker 1: flowing through the galaxy and anytime they're moving in a

849
00:42:38,000 --> 00:42:41,239
Speaker 1: way that we don't understand that tells you there's something there.

850
00:42:41,480 --> 00:42:43,880
Speaker 1: So is this like I guess my question was more like,

851
00:42:43,960 --> 00:42:45,919
Speaker 1: is this like Google Maps where I can just sort

852
00:42:45,960 --> 00:42:48,839
Speaker 1: of like plup my little guy down wherever I want

853
00:42:48,880 --> 00:42:50,839
Speaker 1: in space? Or is it? Is it more of like

854
00:42:51,000 --> 00:42:53,239
Speaker 1: an Excel sheet with zeros and ones and you need

855
00:42:53,280 --> 00:42:55,200
Speaker 1: to know what you're looking for to see that there's

856
00:42:55,239 --> 00:42:57,799
Speaker 1: a tail there. Yeah, it's more like an Excel sheet.

857
00:42:57,840 --> 00:42:59,879
Speaker 1: You have to be a little bit familiar with data

858
00:43:00,000 --> 00:43:02,080
Speaker 1: ealysis techniques to get a handle on it. I don't

859
00:43:02,080 --> 00:43:05,279
Speaker 1: think they have yet like a Google galaxy, but that

860
00:43:05,280 --> 00:43:07,880
Speaker 1: would be pretty awesome. You can zoom through the galaxy

861
00:43:07,920 --> 00:43:10,000
Speaker 1: and look at all the stars. Yeah, that would be great,

862
00:43:10,080 --> 00:43:11,920
Speaker 1: and then we can see, you know, what aliens are

863
00:43:11,920 --> 00:43:15,240
Speaker 1: watering their law on today. That sounds great, but whatever

864
00:43:15,280 --> 00:43:17,640
Speaker 1: is happening to these stars is pretty dramatic. And you know,

865
00:43:17,719 --> 00:43:19,920
Speaker 1: if these stars are getting yanked out of this cluster,

866
00:43:20,320 --> 00:43:22,920
Speaker 1: it's a pretty serious force. And so the dynamics of

867
00:43:22,920 --> 00:43:26,040
Speaker 1: what's happening there could be very dramatic. For those solar systems.

868
00:43:26,160 --> 00:43:28,680
Speaker 1: They could get like briefly very close to each other

869
00:43:28,719 --> 00:43:31,680
Speaker 1: and both like induce lots of common rains on the

870
00:43:31,719 --> 00:43:34,279
Speaker 1: inner planets in their solar systems, or even lose some

871
00:43:34,400 --> 00:43:36,759
Speaker 1: of their planets if they get close enough each other

872
00:43:36,800 --> 00:43:39,200
Speaker 1: to like steal planets from each other. So next time

873
00:43:39,280 --> 00:43:41,560
Speaker 1: you're looking up at the night sky, remember that you're

874
00:43:41,560 --> 00:43:43,960
Speaker 1: not looking at a flat screen. You're looking at a

875
00:43:44,120 --> 00:43:49,640
Speaker 1: four dimensional view, a huge three D starscape that's evolving

876
00:43:49,719 --> 00:43:53,319
Speaker 1: in time, that's crashing and smashing and flowing and doing

877
00:43:53,360 --> 00:43:55,640
Speaker 1: all sorts of crazy things. And now we have a

878
00:43:55,640 --> 00:43:58,600
Speaker 1: pretty good picture for what's out there and where it's going.

879
00:43:59,040 --> 00:44:00,759
Speaker 1: Kid one is going to have a long lesson the

880
00:44:00,800 --> 00:44:03,600
Speaker 1: next time we look at the Ryan, just be glad

881
00:44:03,640 --> 00:44:09,279
Speaker 1: your arms are long enough to point it out. I

882
00:44:09,360 --> 00:44:11,719
Speaker 1: am all right. Thanks for joining us, everybody, and thank

883
00:44:11,760 --> 00:44:14,560
Speaker 1: you Kelly for guest hosting today. Thanks for a fun afternoon.

884
00:44:14,719 --> 00:44:17,040
Speaker 1: Have a good one, Daniel, alright, tune in next time.

885
00:44:17,120 --> 00:44:27,719
Speaker 1: Thanks everybody, thanks for listening, and remember that Daniel and

886
00:44:27,800 --> 00:44:31,120
Speaker 1: Jorge Explain the Universe is a production of I Heart Radio.

887
00:44:31,360 --> 00:44:34,120
Speaker 1: For more podcast for my Heart Radio, visit the I

888
00:44:34,280 --> 00:44:37,960
Speaker 1: Heart Radio app, Apple Podcasts, or wherever you listen to

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00:44:38,040 --> 00:44:39,000
Speaker 1: your favorite shows.