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Speaker 1: Hey, Daniel, what keeps you up at night? Oh? I

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Speaker 1: worry about a lot of things. Financial crises, my kids

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Speaker 1: growing up to be just like me, all sorts of stuff.

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Speaker 1: I worry about that too for them. You worry about

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Speaker 1: my kids growing up to be just like me. We

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Speaker 1: can't have more of him in the world, Okay, But

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Speaker 1: like on a galactic scale, on a universe scale, what's

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Speaker 1: something we should be concerned about. Well, we do have

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Speaker 1: a lot of things look forward to in terms of

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Speaker 1: our galaxy. If we survived the Sun exploding and the

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Speaker 1: waters the Earth boiling off, then we have something pretty

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Speaker 1: dramatic to look forward to, which is that our galaxy,

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Speaker 1: the Milky Way, is going to collide with their nearest

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Speaker 1: neighbor and Dromeda. Meaning right now, there's an entire galaxy

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Speaker 1: Drameda heading towards us at this very moment. That's right.

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Speaker 1: It's like somebody shot it at us with a slingshot

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Speaker 1: and it's zooming right towards us, and it's going to

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Speaker 1: hit us smack on him. And I'm Daniel, and this

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Speaker 1: is our podcast. Daniel and Jorge explained the universe on

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Speaker 1: the episode. Today, we're going to talk about what will

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Speaker 1: happen when galaxies collide. Is this something we should all

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Speaker 1: be worrying about our packing our bags, about building our

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Speaker 1: underground shelters or are we all screwed? Or is it

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Speaker 1: just going to be like a big nothing? How much

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Speaker 1: should I pack? You should definitely be stalking lentils no

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Speaker 1: matter what. Lentils are a good investment for any of

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Speaker 1: these end of the world. Not just beans, no, no, lentils.

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Speaker 1: I mean lentils are kind of lego for a galactic emergency.

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Speaker 1: That's the that's the one to go with. Yeah, absolutely,

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Speaker 1: I would. I would invest in lentils heavily. And it's

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Speaker 1: not just because I happened to purchase lentils just before

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Speaker 1: we recorded this podcast and I'm trying to drum up

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Speaker 1: the lentil futures, you know. I'm I'm sincerely worried about

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Speaker 1: our listeners, and I encourage you all to go out

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Speaker 1: there in stockpi lentils. Well that's a whole hill of

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Speaker 1: beans worth of advice right there, that's right. And so

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Speaker 1: this is the question and today's podcast, what will happen

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Speaker 1: when our galaxy, the Milky Way, collides with the neighboring galaxy?

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Speaker 1: And this question I love not just because it's huge

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Speaker 1: and dramatic and galactic and all this sort of stuff,

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Speaker 1: but because it was suggested by one of our listeners.

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Speaker 1: That's right. It's Blake from Australia who listens to this

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Speaker 1: podcast on her commute to work every day. That's right.

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Speaker 1: And she didn't tell us what she uses to commute.

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Speaker 1: Maybe she rides in a beautiful pickup truck, maybe she's

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Speaker 1: in the back of a limo, maybe rides kangaroo who knows,

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Speaker 1: that's right, with a really nice sound system. Yeah, but

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Speaker 1: she has some interesting feedback for us about our podcast. Right,

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Speaker 1: what did she say? Yeah, she said that she likes

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Speaker 1: listening to me explain things, but she also likes when

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Speaker 1: you interrupted me. She said that often you interrupt me

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Speaker 1: just the same moment when she has a question and

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Speaker 1: you pose the same question that was bouncing around in

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Speaker 1: her head that she was shouting at her limo sound

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Speaker 1: system or kangaroo speakers or whatever it is she us

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Speaker 1: going to listen to. And so I was glad for that,

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Speaker 1: because you know, I like when you interrupt me. Also

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Speaker 1: it breaks the flow and it keeps me from just

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Speaker 1: droning on and on and on. So Thank you Blake

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Speaker 1: for suggesting this topic, and thank you Orge for occasionally interrupting. Yeah, no,

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Speaker 1: I'm happy to be rude. It seems to come naturally. Yeah, yeah,

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Speaker 1: And so that's the topic of today's podcast, And we

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Speaker 1: thought first before we dove into it, we would walk

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Speaker 1: around like we usually do and ask people, are you

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Speaker 1: worried about a galactic collision? What do you think will

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Speaker 1: happen when our galaxy collides with a neighboring galaxy? So

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Speaker 1: put that image in your mind to giant galaxies, full

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Speaker 1: stars running into each other. What do you think is

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Speaker 1: going to happen? Here's what people had to say, big explosion.

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Speaker 1: We'd probably all die. It is going to be mostly

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Speaker 1: nothing because of all the empty space around the world,

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Speaker 1: although there will be some crushes and so on in

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Speaker 1: the way. Okay, probably somewhere between a glacial, slow event

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Speaker 1: that we won't even notice and nothing at all. Maybe

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Speaker 1: leaning towards nothing at all. I think it would probably

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Speaker 1: be a big explosion with something pretty crazy happening. All right,

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Speaker 1: That was a little anti climatic. People seem to have

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Speaker 1: very low expectations of this event. What do you mean

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Speaker 1: It seems like half of the people are like it's

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Speaker 1: gonna be nothing, and the other half of like big explosions,

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Speaker 1: we're all gonna die. Well, why do you why do

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Speaker 1: you think Blake asked this question? Do you think there's

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Speaker 1: something she's concerned about or is something she's curious about?

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Speaker 1: You know? I think Blake is probably deciding whether or

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Speaker 1: not to stock up on lentils. You know, Um, she's

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Speaker 1: probably right now, story she asked. I think it's part

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Speaker 1: of just trying to be a sort of a citizen

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Speaker 1: of the larger universe, you know, wondering where we stand

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Speaker 1: and trying to think bigger than just our planet, you know,

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Speaker 1: because there's so much going on out there, it's so

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Speaker 1: easy to just walk around on the surfaces planet never

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Speaker 1: really look up and remember that there is an enormous

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Speaker 1: amount of stuff happening out there, And then you wonder like, well,

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Speaker 1: how is that relevant to me? And is he going

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Speaker 1: to ruin my life? Or can I go on ignoring it? Um? So,

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Speaker 1: I think maybe she was just sort of thinking into

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Speaker 1: the deep future and wondering like, how long can this

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Speaker 1: whole ridiculous, beautiful thing we call life on Earth go on? Right?

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Speaker 1: Is it going to change from how it is now, right, Yeah,

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Speaker 1: exactly do I need to change the way I live?

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Speaker 1: Does it affect any decision making? On the other hand,

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Speaker 1: it could be that Blake, like many people, is just

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Speaker 1: a thinker and likes to think about these scenarios, and

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Speaker 1: she probably heard that the Milky Way will collide with

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Speaker 1: Andromeda and wonder like, what's that going to be? Like?

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Speaker 1: You know this this this is the other side of

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Speaker 1: me that likes to smash stuff together. I mean, I'm

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Speaker 1: a particle physicist, but then we have the whole universe

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Speaker 1: to play with, right, and so you might wonder, like

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Speaker 1: what happens when planets collide, what happens when solarcisms? Like

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Speaker 1: oh my gosh, what if we could build a galaxy

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Speaker 1: collider and shoot them against each other and smash them

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Speaker 1: into each other? Right, So it just comes out of

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Speaker 1: like a curiosity to see stuff break by smashing it together. Yeah, well,

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Speaker 1: let's let's take it step back and just kind of

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Speaker 1: think about why even galaxies would collect, Like is this

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Speaker 1: a relevant question that is something that happens a lot

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Speaker 1: galaxies colliding, or is it something that's incredibly rare. It

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Speaker 1: turns out galaxies colliding happens all the time. It's like

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Speaker 1: a totally natural thing. And our galaxy. Yeah, not only

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Speaker 1: will our galaxy collide with and John Day in a

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Speaker 1: few billion years, it's currently colliding with other smaller galaxies.

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Speaker 1: That what Yeah, we're in a collision right now. Yeah,

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Speaker 1: that's right. And remember that the galactic time scales are

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Speaker 1: very different. You know, the galaxy takes about two hundred

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Speaker 1: million years just to rotate once, to go around once. Yeah,

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Speaker 1: so one galactic year is two hundred million earth years.

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Speaker 1: But it looks so swirly. It looks you know, you

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Speaker 1: know what I mean, Like it looks like it's in motion,

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Speaker 1: but it's actually it is. It is in motion, it's

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Speaker 1: just very slow, right, And so all these things are

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Speaker 1: dancing around each other and sometimes they bump into each other.

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Speaker 1: And the thing I think is amazing is that, you know,

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Speaker 1: until like a hundred years ago, we didn't even know

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Speaker 1: there were other galaxies. Like we looked up at the

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Speaker 1: night sky and we saw stars, and we thought, oh,

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Speaker 1: there's just stars that go on forever. At the universe

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Speaker 1: is just filled with stars. The universe is just like

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Speaker 1: a giant MESSI pinpoints, right, just stars. Yeah, yeah, like

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Speaker 1: somebody had scattered stars across the cosmos, right, And it

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Speaker 1: was Hubble, the guy for whom the telescope and the

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Speaker 1: constant are named. He's the guy who figured out, oh,

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Speaker 1: some of those things that are really far out there

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Speaker 1: are not stars. There are other galaxies. Right, So there's

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Speaker 1: the universe is filled with other galaxies. And of course

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Speaker 1: there are more galaxies than stars, and and then each galaxy,

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Speaker 1: of course, contains hundreds of billions of stars, and so

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Speaker 1: the numbers pretty quickly blow your head up before you

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Speaker 1: can understand them. But the point I wanted to make

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Speaker 1: was that we didn't realize there were galaxies until recently,

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Speaker 1: and now we're realizing that galaxies are in motion relative

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Speaker 1: to each other, and they're moving. Like the these galaxies

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Speaker 1: that we see out there in the sky, they're not

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Speaker 1: just like hanging there in space never to change, right,

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Speaker 1: They are moving their dynamic things, and they're constantly in motion,

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Speaker 1: and they have huge gravitational attraction. Well, let's break it down.

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Speaker 1: What exactly is a galaxy? I mean, I know it's

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Speaker 1: like kind of like a collection of stars, but you

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Speaker 1: know what, why do stars clump together like that? First

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Speaker 1: of all? And what makes a galaxy special? Like, why

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Speaker 1: is it more than just a clump of stars. Well,

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Speaker 1: what makes our galaxy special is that you're in it. Horse.

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Speaker 1: There's no other galaxy that features such a good looking,

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Speaker 1: funny cartoonists, meet me and lentils. We make it, make

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Speaker 1: it habitable, right, Okay, so what's the recipe for a galaxy? Right? Well,

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Speaker 1: the thing that the galaxies have the most of, remember,

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Speaker 1: is dark matter. In general, there's about five times as

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Speaker 1: much dark matter as there is any other kind of matter,

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Speaker 1: you know, the stuff that makes up gas and dustin

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Speaker 1: stars and people and cartoonists and and and ice cream.

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Speaker 1: So it's mostly dark matter. So that's the stuff we

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Speaker 1: can't see your touch. I mean, we did a whole

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Speaker 1: podcast episode on dark matter, but it just in case

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Speaker 1: somebody didn't listen to it. Um, it's like this weird

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Speaker 1: invisible dark gravity thing that's hanging out every galaxy has,

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Speaker 1: that's right. Yeah, we call it dark and matter because

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Speaker 1: we can't see it. So it's dark and we know

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Speaker 1: it gives gravity, so therefore it's matter and the crazy

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Speaker 1: things that until you know, a few decades ago, we

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Speaker 1: didn't even know it existed. And now we know that

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Speaker 1: galaxies are mostly made up of this stuff. Right. So

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Speaker 1: number one ingredient when you want to make a galaxy

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Speaker 1: is you have to have dark matter. It's like five

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Speaker 1: times more than the stars, right, yeah, exactly, Like a

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Speaker 1: galaxy is basically a clump of dark matter with a

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Speaker 1: few sprinkles of stars in it. That's right. Yeah. If

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Speaker 1: a galaxy was a cupcake, right, the dark matter would

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Speaker 1: be the chocolate cake, and you know there everything else

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Speaker 1: would be the frosting and the sprinkles. The gas and

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Speaker 1: the dust would be the frosting. The stars would be

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Speaker 1: the sprinkles on top. Oh I see, Okay, that's kind

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Speaker 1: of the right proportions. Yeah, something like that. Um, So

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Speaker 1: you start with big blob of dark matter and that's

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Speaker 1: most of it, and then after that you have huge

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Speaker 1: amounts of gas and dust, right, And that's the stuff

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Speaker 1: that's left over from the Big Bang or left over

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Speaker 1: from stars exploding, and those the ingredients you need to

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Speaker 1: make planets and stars and all sorts of stuff that

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Speaker 1: you're familiar with, right. And so you have dark matter,

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Speaker 1: you have gas, you have dust, you have planets and

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Speaker 1: stars and black holes right, Like there's just a little

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Speaker 1: black hole sprinkled throughout throughout probably, But there's a huge

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Speaker 1: giant black hole at the center of every galaxy. That's right.

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Speaker 1: I can't believe I forgot the black hole. The black

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Speaker 1: hole at the center of almost every galaxy is huge.

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Speaker 1: It's like, you know, millions of solar masses and it's

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Speaker 1: sitting there at the center of the black hole, and

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Speaker 1: it's it's got a lot of stuff to it also, right,

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Speaker 1: it carries a lot of mass and so it contributes.

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Speaker 1: So that's what a galaxy is. And you know, a

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Speaker 1: galaxy couldn't really form without all those elements, Like you

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Speaker 1: couldn't really have a galaxy without dark matter because dark

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Speaker 1: matter provides the gravitational attraction to suck all this stuff together.

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Speaker 1: You know, they do these simulations of the universe. They say,

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Speaker 1: what would the universe look like if you never had

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Speaker 1: dark matter in it? And it would take a lot

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Speaker 1: longer for galaxies to form because dark matter has pulled

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Speaker 1: all this stuff together. It's like it's made a you know,

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Speaker 1: like a well in the rubber sheet of the universe,

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Speaker 1: so everything rolls together more closely. Okay, so that's a

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Speaker 1: that's a galaxy. It's a black hole surrounded by dark

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Speaker 1: matter and sprinkles of stars and gas and dust and

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Speaker 1: lintels and lintels exactly yes, And so they're not just

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Speaker 1: hanging out in space. They're moving around. That's right there.

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Speaker 1: Each one is spinning, right, which is why you see

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Speaker 1: a lot of them having these these spiral features. Each

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Speaker 1: one is spinning, and then they're also moving around each other.

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Speaker 1: They have gravity and they're moving around each other, and

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Speaker 1: they have these Each galaxy is a member of a

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Speaker 1: cluster of galaxies, and so these guys are orbiting the

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Speaker 1: center of the cluster. And then the clusters are members

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Speaker 1: of superclusters. So these things have a lot of gravitational

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Speaker 1: interactions everywhere. It's like a system of galaxy. They all

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Speaker 1: interact with each other, and they all spin around their

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Speaker 1: common center of mass exactly right, And they're all spinning

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Speaker 1: around that center. So it's sort of like a big

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Speaker 1: slow motion tornado. Right you looked at it. If you

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Speaker 1: looked at it really really slow, you're like, oh, nothing's

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Speaker 1: really moving. I mean, I guess a little bit, but

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Speaker 1: you you you watch it at natural speed of tornado,

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Speaker 1: and obviously it's going really fast, and so a galaxy

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Speaker 1: is that's sort of that same way. The gather system

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Speaker 1: of galaxies is sort of that same way, but they're

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Speaker 1: all moving around each other and then occasionally, you know,

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Speaker 1: they bump into each other. Wow, that's so weird to

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Speaker 1: think that gravity works the way like we are, you know,

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Speaker 1: moving around the center of the Earth. The Earth is

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Speaker 1: moving around our solar system, around the center of gravity,

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Speaker 1: which is mostly the Sun, but the Sun is also

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Speaker 1: we were moving around the center of gravity of the galaxy,

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Speaker 1: and the galaxy is also moving around the center of

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Speaker 1: gravity of its cluster of galaxies. That's right, Yeah, and

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Speaker 1: on and on and on like a bunch of nested

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Speaker 1: Russian dolls, you know, until you get to the biggest

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Speaker 1: structures in the universe, you know, which are the superclusters,

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Speaker 1: and then the filaments of superclusters, and beyond that, we

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Speaker 1: don't know anything about whether there are bigger and bigger structures.

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Speaker 1: That's as far as we've seen. So we're moving around

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Speaker 1: and sometimes these two two galaxies can just run into

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Speaker 1: each other. In the giant, vastness of space, all these

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Speaker 1: moving galaxies can sometimes cross pass right. Yeah. And there's

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Speaker 1: another thing I want to say about that before we

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Speaker 1: talk about what actually happens, which is that it's incredible

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Speaker 1: to me that gravity is the force that's dominant on

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Speaker 1: these scales, right, Like, that's the thing that's controlling how

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Speaker 1: galaxies form and how they dance around each other, and

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Speaker 1: that's pulling them all the way through the universe and

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Speaker 1: forming these crazy structures. It's all gravity, right. But gravity

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Speaker 1: is the weakest force of nature. It's weaker than electromagnetism,

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Speaker 1: it's weaker than any of the nuclear forces. It's pathetically weak,

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Speaker 1: but it's the only one that operates on these huge scales,

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Speaker 1: and it can't be balanced out. And so because it's

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Speaker 1: only an attractive force, there's no repulsive version of it.

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Speaker 1: And so that's why, like on these huge scales, gravity

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Speaker 1: is the thing that dominates. Gravity determines the structure the

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Speaker 1: Solar system, the structure the galaxy, the structure of the clusters.

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Speaker 1: Gravity sort of winds in the end. It's like, you know,

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Speaker 1: revenge of the nerd forces, Right, It's the weakest force

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Speaker 1: in the end controls the universe. It's like slow and

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Speaker 1: steady wins the race. It's the turtle of forces. Yeah, Anyway,

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Speaker 1: we need to do a whole other podcast on why

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Speaker 1: gravity is so weird and weak and whatever, and we're

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Speaker 1: into that. Okay, so we have a cult clusters and

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Speaker 1: galaxies are moving around space and sometimes they collide. So yeah,

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Speaker 1: let's talk about what actually happens when two of these

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Speaker 1: things collide. But first let's take a quick break. All right.

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Speaker 1: So we're sitting in a galaxy and we are moving

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Speaker 1: inside of this galaxy, and this galaxy is moving in space.

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Speaker 1: But there's another galaxy nearby called the Andromeda galaxy, and

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Speaker 1: it's kind of an interset course with us, right, like

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Speaker 1: we're going to run into it in about four and

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Speaker 1: a half billion years. Yeah, not kind of. They've measured it.

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Speaker 1: They can measure the velocity of Andromeda relative to us,

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Speaker 1: and they can see that it's getting closer and closer

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Speaker 1: every year, and they can also measure the lateral velocity,

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Speaker 1: like is it going to shoot by us or just

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Speaker 1: or come right at us? And after for a while

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Speaker 1: they weren't sure. They were like, oh, it's heading our way,

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Speaker 1: but it could miss, you know, like every time they

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Speaker 1: say there's an asteroid coming within, you know, a certain

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Speaker 1: thousands of miles of the Earth, and usually it misses.

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Speaker 1: For a while, they weren't sure, but now they're pretty

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Speaker 1: certain they've taken enough measurements, they've seen it move, and

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Speaker 1: they can project confidently that these two things are going

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Speaker 1: to collide. Also, Andromeda and Milky, we have a lot

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Speaker 1: of gravity, and so you don't have to aim perfectly

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Speaker 1: to get a collision, right, They're gonna um pull each

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Speaker 1: other closer and closer. They want to collide, you know,

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Speaker 1: you know what I mean, Like, it's not like a

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Speaker 1: random asteroid. It's like we're we're pulling towards each other. Yeah, well,

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Speaker 1: I don't know if you can really say they want Like,

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Speaker 1: do you understand the psychology of the galaxy? Do you you

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Speaker 1: know what galaxy wants in life? You know, Hey, galaxy

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Speaker 1: have feelings, right, I think I read that science fiction

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Speaker 1: novel right where every galaxy is actually a living thing

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Speaker 1: and we're just like the tiny moats on the on

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Speaker 1: an island of red blood cells instead of galaxy. Anyway, Yeah,

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Speaker 1: so you don't have to shoot perfectly, and they're gonna collide.

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Speaker 1: So to think about what happens in the collision, you

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Speaker 1: probably think about each individual piece separately, Like we're a

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Speaker 1: cluster of things. Like a galaxy is not a solid object.

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Speaker 1: It's like a word almost like a cloud of things,

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Speaker 1: right is that kind of way? Mean? Yeah, yeah, exactly.

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Speaker 1: And you know, imagine two crowds right passing into each other,

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Speaker 1: and like one gets off the train and one's coming

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Speaker 1: down the stairs and they pass each other in the platform.

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Speaker 1: What's going to happen, Well, it depends on how they interact, right,

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Speaker 1: and how dense they are. So we can start with

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Speaker 1: something and the obvious parts, like the stars. Okay, so

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Speaker 1: you might think, oh my gosh, there's a hundred billion

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Speaker 1: stars coming right at us. That's going to be a

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Speaker 1: big deal. Is that the right size? Like it isn't

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Speaker 1: drama about the same size as the Milky Way. Actually

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Speaker 1: I think it's bigger than the Milky Way. But you know,

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Speaker 1: factors of ten here are not important. Um, so it's

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Speaker 1: hundreds of billions of stars, and each star, of course

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Speaker 1: is really big. And you might think, while they're heading

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Speaker 1: right at us, you know, this is gonna be a

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Speaker 1: big deal, But remember that the stars are really far apart. Also, like,

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Speaker 1: galaxies are huge, not just in terms of the number

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Speaker 1: of stars, in terms of the amount of space they

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Speaker 1: take up. And you know, you look around you in

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Speaker 1: our galaxy, there aren't that many stars nearby, right, and

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Speaker 1: the closest stars are light years away. I like this

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Speaker 1: crowd analogy that's pretty interesting. Like we're a crowd of

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Speaker 1: people getting off the subway. There's a crowd of people

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Speaker 1: coming down the stairs to get on the subway. It's

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Speaker 1: going to be a disaster potentially. Potentially, But if it's

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Speaker 1: not rush hour and the crowds are pretty light, you know,

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Speaker 1: there's like enough space the two crowds can just pass

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Speaker 1: right through each other. Like if the stairways and the

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Speaker 1: hallways are huge and people are pretty spread out, it

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Speaker 1: may not be like a riot, you know, it may

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Speaker 1: just be like a busy intersection. Right, It's like two

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Speaker 1: people leaving Yankee Stadium at the same time as as

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Speaker 1: somebody else's trying to come in. Like there's plenty of exits,

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Speaker 1: nobody's gonna bump into each other, right, And that's sort

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Speaker 1: of the case with stars. I read this one comparison

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Speaker 1: where if you imagine the stars the size of a

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Speaker 1: ping pong ball on average, the nearest stars three kilometers away, right,

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Speaker 1: So like if you were going to throw a ping

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Speaker 1: pong ball into a cloud of ping pong balls, where

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Speaker 1: the spaces between them were three kilometers away. You'd be

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Speaker 1: lucky if you hit anything, right, even if you were trying.

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Speaker 1: Oh I see, Okay, So our galaxy is actually pretty sparse,

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Speaker 1: meaning the stars are pretty far apart from each other.

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Speaker 1: We're not sort of clumped together. Yeah, exactly, and astronomically speaking,

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Speaker 1: astronomically speaking, and so there's gonna be very few or

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Speaker 1: probably zero direct collisions. You know, where one star like

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Speaker 1: actually slams into another one, you get stellar explosions. I mean,

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Speaker 1: that would be pretty awesome. I would pay for front

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Speaker 1: road seat, but I think it's pretty unlikely that's going

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Speaker 1: to happen. But you know, there's a hundred billion stars

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Speaker 1: running into a hundred billion other stars. Surely some of

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Speaker 1: them are going to hit head on, isn't it. Aren't they?

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Speaker 1: I mean, there's always a non zero probability, and you

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Speaker 1: could get lucky you're unlucky, depending on which which outcome

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Speaker 1: you're rooting for. But if they're diffuse enough, right, they're

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Speaker 1: they're far enough apart, then then all of them could

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Speaker 1: pass through without hitting. I mean, I think probably the

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Speaker 1: most likely scenarios that maybe you get one. The stars

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Speaker 1: also don't have to hit directly to affect each other. Right.

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Speaker 1: Each one is a big blob of mass, which means

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Speaker 1: it has gravity, and so they can jostle each other.

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Speaker 1: I mean, if another star came by and near our

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Speaker 1: Solar System and pass nearby, it could affect the orbits

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Speaker 1: of all the planets, like nudge a planet out of orbit.

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Speaker 1: Didn't have to hit the star directly head on or

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Speaker 1: to affect our lives. It could maybe pull us out

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Speaker 1: of orbit or sunk us into that other star. That's right, Um,

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Speaker 1: it could it could steal planets right exactly. Or um,

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Speaker 1: one of our planets could get ejected out of the

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Speaker 1: Solar System right, or it could even kick our star

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Speaker 1: out of the galaxy. Our star is in orbit around

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Speaker 1: the center of the galaxy, right, and if it comes,

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Speaker 1: if another star comes near enough, it could get pulled

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Speaker 1: and so that it gets you out of that orbit, right.

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Speaker 1: And orbit is sort of a delicate thing. You have

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Speaker 1: to be the right radius and the right velocity for

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Speaker 1: it all to work and start going to fast and

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Speaker 1: you each escape velocity. And our star could even get

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Speaker 1: kicked out of the galaxy. So we could be you know,

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Speaker 1: sort of evicted from the Milky Way, floating in intergalactic space,

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Speaker 1: just our star with the planets and everything. Oh, I see.

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Speaker 1: So when two galaxies collided, it's not it's not we

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Speaker 1: don't have to worry about things running into each other.

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Speaker 1: But it is going to be pretty chaotic, right, Like,

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Speaker 1: suddenly there's going to be you know, twice the number

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Speaker 1: of stars, and that's just going to change everything, right, yeah, exactly,

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Speaker 1: So things that definitely get mixed up. The stars won't

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Speaker 1: necessarily smash into each other, but it definitely mix each

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Speaker 1: other up and disturb each other. So are they are

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Speaker 1: these two messages going to kind of go towards each other,

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Speaker 1: makes a little bit and then keep going, or are

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Speaker 1: they you know, slamming to each other and then become

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Speaker 1: this giant mega galaxy. It depends a little bit on

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Speaker 1: their relative velocity. If they're going fast enough relative to

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Speaker 1: each other, then they'll pass through each other, right, But

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Speaker 1: if if they're not, and it doesn't seem like they are,

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Speaker 1: the most like scenario is that they merge, that they

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Speaker 1: come together and there's a little bit of slashing or whatever,

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Speaker 1: but eventually becomes one big galaxy. But wait, what does

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Speaker 1: that mean? It's like the other stars and from the

424
00:21:07,040 --> 00:21:08,800
Speaker 1: other galaxy. They're gonna come, but then they're going to

425
00:21:08,960 --> 00:21:10,560
Speaker 1: kind of go pass us a little bit, and then

426
00:21:10,600 --> 00:21:12,480
Speaker 1: they're gonna get pulled back in kind of thing like

427
00:21:12,520 --> 00:21:15,040
Speaker 1: it's gonna like a giant jelly out in space, like

428
00:21:15,080 --> 00:21:16,920
Speaker 1: it's going to go move, you know what I mean,

429
00:21:16,920 --> 00:21:18,960
Speaker 1: but in slow motion, yeah, or sort of like things

430
00:21:18,960 --> 00:21:21,320
Speaker 1: getting flushed down the toilet. You know, they come closer

431
00:21:21,320 --> 00:21:23,800
Speaker 1: and closer and closer and circle each other faster and faster.

432
00:21:26,040 --> 00:21:29,520
Speaker 1: You know, where we might circle each other, the two galaxies, Yeah,

433
00:21:29,520 --> 00:21:31,400
Speaker 1: and sort of a wall being on top of each other,

434
00:21:31,480 --> 00:21:34,639
Speaker 1: you know, so coming together pass a little the centers

435
00:21:34,680 --> 00:21:36,720
Speaker 1: of mass might pass a little bit and then turn

436
00:21:36,760 --> 00:21:39,159
Speaker 1: and come the other direction and spin it faster and

437
00:21:39,160 --> 00:21:41,600
Speaker 1: faster until the center is a massive line. So being

438
00:21:41,640 --> 00:21:44,359
Speaker 1: flushed down the toilet. That doesn't doesn't sound pleasant. Like

439
00:21:44,400 --> 00:21:46,480
Speaker 1: that doesn't sound like it's going to be easy, do

440
00:21:46,520 --> 00:21:47,800
Speaker 1: you know what I mean? Like, it doesn't sound like

441
00:21:47,840 --> 00:21:51,720
Speaker 1: it's going to uh leave us unscathed. It might, though,

442
00:21:51,760 --> 00:21:53,800
Speaker 1: you know, our sun could be totally fine, and it

443
00:21:53,800 --> 00:21:56,320
Speaker 1: could be that the planets are not distorted, their orbits

444
00:21:56,320 --> 00:21:58,360
Speaker 1: are not distorted, and we could just have a front

445
00:21:58,440 --> 00:22:01,000
Speaker 1: row seat to a pretty amazing event. And the other

446
00:22:01,040 --> 00:22:03,040
Speaker 1: thing is that we see this happening all the time.

447
00:22:03,080 --> 00:22:05,320
Speaker 1: Like you look out into space with the hubble zoom

448
00:22:05,320 --> 00:22:08,120
Speaker 1: in on other galaxies. There's lots of galaxies out there,

449
00:22:08,119 --> 00:22:10,760
Speaker 1: and lots of them are in state various stages of emerging.

450
00:22:11,119 --> 00:22:14,080
Speaker 1: And you can see galaxies that are just starting to merge.

451
00:22:14,280 --> 00:22:16,240
Speaker 1: You can see galaxies that have been merging for a

452
00:22:16,280 --> 00:22:19,280
Speaker 1: billion years. You can see galaxy that obviously merged a

453
00:22:19,320 --> 00:22:22,200
Speaker 1: long time ago. And there's sort of like an uncomfortable

454
00:22:22,240 --> 00:22:25,119
Speaker 1: blob of two galaxies, like one spiral arms sort of

455
00:22:25,200 --> 00:22:27,400
Speaker 1: knocked off over here and there's another one over there.

456
00:22:27,440 --> 00:22:30,080
Speaker 1: And so we have a lot of catalogs of examples

457
00:22:30,080 --> 00:22:32,119
Speaker 1: of galaxies that have mergy. That's how we know so

458
00:22:32,200 --> 00:22:33,760
Speaker 1: much about it. Yeah, if you look at there's a

459
00:22:33,800 --> 00:22:36,320
Speaker 1: bunch of crashes that you can study. Yeah, exactly. So

460
00:22:36,359 --> 00:22:38,680
Speaker 1: you want to know what galaxy collisions look like, you

461
00:22:38,720 --> 00:22:40,760
Speaker 1: don't have to build a galaxy collider. This is one

462
00:22:40,840 --> 00:22:43,320
Speaker 1: thing I love about astronomy. You have to google. You

463
00:22:43,320 --> 00:22:48,920
Speaker 1: can just that's right, cosmic googling, otherwise known as telescopes. Um.

464
00:22:48,960 --> 00:22:51,160
Speaker 1: You just look out into space and eventually you will

465
00:22:51,200 --> 00:22:53,600
Speaker 1: see that thing happening, like you want to imagine some

466
00:22:53,680 --> 00:22:56,000
Speaker 1: crazy scenario, or this kind of galaxy hits that kind

467
00:22:56,000 --> 00:22:58,240
Speaker 1: of galaxy, and then from behind comes a third one

468
00:22:58,480 --> 00:23:00,679
Speaker 1: that's happening somewhere out there there and you just need

469
00:23:00,760 --> 00:23:02,879
Speaker 1: to find it and watch it. And so that's the

470
00:23:02,920 --> 00:23:05,920
Speaker 1: amazing thing about astronomy is that all these cosmic experiments

471
00:23:05,920 --> 00:23:09,560
Speaker 1: are happening. We just need to look for them. Okay,

472
00:23:09,560 --> 00:23:12,080
Speaker 1: well we process that. Let's say, let's take a quick break,

473
00:23:24,640 --> 00:23:27,000
Speaker 1: all right, So that's what might happen to the stars

474
00:23:27,000 --> 00:23:29,160
Speaker 1: in the galaxy. What's going to happen to all these

475
00:23:29,160 --> 00:23:33,720
Speaker 1: other parts of the galaxy when these two galaxies collide, right?

476
00:23:33,720 --> 00:23:35,480
Speaker 1: And I like that we started with the stars because

477
00:23:35,480 --> 00:23:37,160
Speaker 1: that's like the most important thing to us, because we're

478
00:23:37,200 --> 00:23:40,280
Speaker 1: sort of staro centric, right, because we think stars are

479
00:23:40,400 --> 00:23:42,320
Speaker 1: most the most important element of the galaxy. But the

480
00:23:42,359 --> 00:23:45,199
Speaker 1: biggest element of the galaxy, remember, is dark matter. And

481
00:23:45,240 --> 00:23:46,879
Speaker 1: so you might ask, well, what's going to happen to

482
00:23:46,920 --> 00:23:49,719
Speaker 1: all our dark matter? And just like with the stars,

483
00:23:49,760 --> 00:23:53,440
Speaker 1: what what happens there depends on how much it interacts. Currently,

484
00:23:53,480 --> 00:23:56,000
Speaker 1: we don't really know anything about how much dark matter interacts.

485
00:23:56,040 --> 00:23:58,919
Speaker 1: We know that it doesn't interact with normal matter. We

486
00:23:59,080 --> 00:24:00,919
Speaker 1: think it doesn't interact with itself, or if it does,

487
00:24:00,960 --> 00:24:03,640
Speaker 1: it doesn't interact very strongly and so, but it does

488
00:24:03,720 --> 00:24:07,119
Speaker 1: have gravitational attraction. So if the galaxies are are going

489
00:24:07,160 --> 00:24:09,399
Speaker 1: to hit each other and they're not moving too fast

490
00:24:09,400 --> 00:24:12,320
Speaker 1: that they just basically pass right through each other, then

491
00:24:12,359 --> 00:24:14,840
Speaker 1: the gravity from dark matter is going to affect the

492
00:24:15,000 --> 00:24:17,680
Speaker 1: gravity from the other galaxies dark matter just the same

493
00:24:17,720 --> 00:24:19,960
Speaker 1: way the stars are, and the two will sort of

494
00:24:20,080 --> 00:24:23,760
Speaker 1: merge eventually become one big dark matter halo. And it's

495
00:24:23,760 --> 00:24:25,520
Speaker 1: the kind of thing I would love to watch, but

496
00:24:25,720 --> 00:24:27,679
Speaker 1: you can't really see the dark matter. It could be

497
00:24:27,720 --> 00:24:30,199
Speaker 1: just another version of the cluster of stars. You know.

498
00:24:30,320 --> 00:24:33,320
Speaker 1: It's like one blob goes into the other blob and

499
00:24:33,359 --> 00:24:35,840
Speaker 1: then they kind of slash around and then just becomes

500
00:24:35,840 --> 00:24:38,280
Speaker 1: a bigger blob. Yeah, you can think of the stars.

501
00:24:38,400 --> 00:24:41,359
Speaker 1: It's sort of like a collisionless liquid, right, It's like

502
00:24:41,400 --> 00:24:44,040
Speaker 1: a you have a liquid of stars that don't interact

503
00:24:44,080 --> 00:24:45,880
Speaker 1: with each other the same way the dark matter does.

504
00:24:45,920 --> 00:24:49,040
Speaker 1: So dark matter in stars are basically operating this under

505
00:24:49,040 --> 00:24:51,639
Speaker 1: the same principles. The only relevant interaction that we know

506
00:24:51,640 --> 00:24:54,320
Speaker 1: about is gravity, So everything we said about stars is

507
00:24:54,359 --> 00:24:56,480
Speaker 1: also going to affect the big blobs of dark matter.

508
00:24:56,680 --> 00:24:59,880
Speaker 1: The dark matter is much more continuous. We think it's smooth.

509
00:25:00,000 --> 00:25:01,960
Speaker 1: It's not like there's just dots of it here and there.

510
00:25:02,320 --> 00:25:04,840
Speaker 1: But because it hardly interacts with each other, it doesn't

511
00:25:04,880 --> 00:25:08,280
Speaker 1: matter if it rams smack into itself. Right, It mainly

512
00:25:08,320 --> 00:25:11,560
Speaker 1: affect is gravitational. It may not interact with itself. It

513
00:25:12,080 --> 00:25:15,040
Speaker 1: could just pass by itself and not really kind of

514
00:25:15,119 --> 00:25:20,480
Speaker 1: explode or collide or do anything besides pull itself gravitationally. Yeah, exactly.

515
00:25:20,640 --> 00:25:22,280
Speaker 1: And we don't even know what dark matter is made out,

516
00:25:22,359 --> 00:25:24,399
Speaker 1: so we can't say things like dark runner particles can

517
00:25:24,440 --> 00:25:26,400
Speaker 1: do this. Dark matter as far as we know, it's

518
00:25:26,440 --> 00:25:30,720
Speaker 1: just smooth, collisionless blob of something. And we know it

519
00:25:30,760 --> 00:25:33,399
Speaker 1: has gravitational interactions, and that's really about all we know

520
00:25:33,440 --> 00:25:35,840
Speaker 1: about it. So we think that that that's what's going

521
00:25:35,880 --> 00:25:38,560
Speaker 1: to happen. And you know, we've seen dark matter in

522
00:25:38,600 --> 00:25:41,760
Speaker 1: these gravitational collisions and we see that it basically sticks

523
00:25:41,760 --> 00:25:45,119
Speaker 1: with the galaxies, right, it sticks with the stars. Okay,

524
00:25:45,160 --> 00:25:47,719
Speaker 1: so then the last part is the black hole at

525
00:25:47,720 --> 00:25:50,080
Speaker 1: the center of each galaxy. What no, no, don't forget

526
00:25:50,080 --> 00:25:52,760
Speaker 1: the dust, right, this gas dust, which a lot of

527
00:25:52,760 --> 00:25:55,160
Speaker 1: people overlook, and this is actually the most exciting part

528
00:25:55,240 --> 00:26:00,560
Speaker 1: because the dust is the most the coolest part. That's

529
00:26:00,560 --> 00:26:02,679
Speaker 1: how you know you're listening to a nerdy podcast and

530
00:26:02,680 --> 00:26:06,399
Speaker 1: they get excited about dust. Oh my god. You know

531
00:26:06,520 --> 00:26:09,520
Speaker 1: if if for those people who are like expecting dramatic

532
00:26:09,560 --> 00:26:12,399
Speaker 1: events and explosions, this is where you get them. Okay,

533
00:26:12,440 --> 00:26:16,879
Speaker 1: because dust is not diffuse, right's spread everywhere, Like you

534
00:26:16,920 --> 00:26:19,160
Speaker 1: have a big blob of dust. It's not like little

535
00:26:19,160 --> 00:26:22,080
Speaker 1: clusters of mass the way stars are. It's a huge

536
00:26:22,200 --> 00:26:25,879
Speaker 1: extended blob of dust. And when it smashes into another

537
00:26:25,920 --> 00:26:29,080
Speaker 1: blob of dust, you're going to get fireworks. Like those

538
00:26:29,320 --> 00:26:31,680
Speaker 1: clouds of dust interact with each other the way dark

539
00:26:31,720 --> 00:26:36,000
Speaker 1: matter doesn't. And they're um spread everywhere the way stars aren't,

540
00:26:36,280 --> 00:26:39,120
Speaker 1: and so you get huge collisions. And what happens when

541
00:26:39,160 --> 00:26:41,560
Speaker 1: you compress gas and dust. What happens when you collide

542
00:26:41,720 --> 00:26:44,480
Speaker 1: huge blobs of gas and dust is you get more

543
00:26:44,520 --> 00:26:47,240
Speaker 1: dense and then you get stars. And so you could

544
00:26:47,240 --> 00:26:51,159
Speaker 1: see like new stars being born where these two huge

545
00:26:51,280 --> 00:26:55,359
Speaker 1: clouds of gas and dust being into each literally like fireworks.

546
00:26:55,440 --> 00:27:00,080
Speaker 1: Like that's right, cosmic fireworks. I mean, what's more are

547
00:27:00,119 --> 00:27:03,240
Speaker 1: dramatic and what's a better cosmic firework than seeing stars

548
00:27:03,320 --> 00:27:05,280
Speaker 1: be born? Yeah, so this one is going to be

549
00:27:05,359 --> 00:27:08,280
Speaker 1: like to you know, you know, two liquids kind of

550
00:27:08,359 --> 00:27:10,040
Speaker 1: running into each other. It is going to be kind

551
00:27:10,040 --> 00:27:12,720
Speaker 1: of dramatic, you know, like it is going to be

552
00:27:12,800 --> 00:27:19,520
Speaker 1: like with the sound effects and everything in space. No, yeah, exactly,

553
00:27:19,520 --> 00:27:21,480
Speaker 1: It's just like two water balloons hitting each other. Right,

554
00:27:21,680 --> 00:27:24,119
Speaker 1: You're gonna get an initial shop wave. And you know,

555
00:27:24,160 --> 00:27:26,439
Speaker 1: you don't get stars born when you fire water balloons

556
00:27:26,440 --> 00:27:28,480
Speaker 1: at each other because the density isn't great enough obviously,

557
00:27:28,760 --> 00:27:30,640
Speaker 1: But yeah, you're gonna get a shock wave. You're gonna

558
00:27:30,640 --> 00:27:32,920
Speaker 1: get friction between the fluids, and you're going to get

559
00:27:32,920 --> 00:27:36,240
Speaker 1: stars being born. It's gonna be pretty dramatic. So you

560
00:27:36,240 --> 00:27:37,960
Speaker 1: don't want to be there. You don't want to want

561
00:27:37,960 --> 00:27:40,720
Speaker 1: to But we are, aren't We surrounded by gas clouds

562
00:27:40,720 --> 00:27:42,959
Speaker 1: and stuff? Oh? I think you need denser stuff. I mean,

563
00:27:43,000 --> 00:27:45,840
Speaker 1: the milky wave definitely has big clouds of gas and dust.

564
00:27:46,600 --> 00:27:48,840
Speaker 1: Oh I see, But when those clouds running to the

565
00:27:48,880 --> 00:27:51,520
Speaker 1: other clouds, then that's where this stuff happens. But we're

566
00:27:51,520 --> 00:27:55,639
Speaker 1: not necessarily sitting in one of those clouds. That's right, yeah, okay,

567
00:27:58,760 --> 00:28:01,320
Speaker 1: the last element is the black hole, right, and so

568
00:28:01,560 --> 00:28:03,720
Speaker 1: our galaxy is a huge black hole the center, and

569
00:28:03,720 --> 00:28:05,680
Speaker 1: the other guy, almost every other galaxy is a huge

570
00:28:05,680 --> 00:28:08,520
Speaker 1: black hole of the center. And there it's gonna be

571
00:28:08,640 --> 00:28:12,280
Speaker 1: mostly dominated by gravity, right, because they're gonna pull each

572
00:28:12,320 --> 00:28:15,320
Speaker 1: on each other really hard, and they're gonna pass by

573
00:28:15,359 --> 00:28:17,320
Speaker 1: each other a little bit, perhaps because they're probably not

574
00:28:17,400 --> 00:28:20,000
Speaker 1: gonna hit dead on and then they're gonna swing around.

575
00:28:20,040 --> 00:28:22,600
Speaker 1: They're gonna pull on each other, so they'll probably be

576
00:28:22,640 --> 00:28:24,800
Speaker 1: you know, some sort of a near miss, and then

577
00:28:24,840 --> 00:28:27,600
Speaker 1: they'll turn around and come back. And then they'll just

578
00:28:27,640 --> 00:28:30,720
Speaker 1: circle each other faster and faster and faster. And if

579
00:28:30,760 --> 00:28:33,480
Speaker 1: you remember the episode we did on gravitational waves, or

580
00:28:33,680 --> 00:28:36,320
Speaker 1: if you've heard about the discovery of gravitational waves, you

581
00:28:36,359 --> 00:28:38,760
Speaker 1: know that what happens when black holes get close to

582
00:28:38,760 --> 00:28:40,600
Speaker 1: each other as they start to circle each other faster

583
00:28:40,640 --> 00:28:44,080
Speaker 1: and faster, until eventually they spend really really fast and

584
00:28:44,080 --> 00:28:46,520
Speaker 1: the distance get closer and closer and closer, and then

585
00:28:46,520 --> 00:28:48,880
Speaker 1: they merge and they become one enormous black hole. They

586
00:28:48,960 --> 00:28:52,080
Speaker 1: like eat each other, right, But and it's not a

587
00:28:52,080 --> 00:28:54,880
Speaker 1: peaceful event it's like a pretty violent thing, right, Like

588
00:28:55,040 --> 00:28:58,920
Speaker 1: they've been super super fast, there's energy spewed out everywhere,

589
00:28:58,960 --> 00:29:03,360
Speaker 1: and then suddenly have these huge cataclysmic gravitational waves. Oh yeah,

590
00:29:03,360 --> 00:29:05,960
Speaker 1: when black holes fight, it's a big mess. Absolutely. You

591
00:29:05,960 --> 00:29:09,120
Speaker 1: don't want to be anywhere near that because huge amounts

592
00:29:09,120 --> 00:29:11,760
Speaker 1: of radiation, not just gravitational waves. Right, yeah, you make

593
00:29:11,800 --> 00:29:14,160
Speaker 1: gravitational waves, which are pretty awesome from a physics point

594
00:29:14,160 --> 00:29:16,520
Speaker 1: of view, but you know, these things tear up into

595
00:29:16,600 --> 00:29:19,160
Speaker 1: each other and amid huge amounts of radiation, and so

596
00:29:19,200 --> 00:29:20,720
Speaker 1: you don't want to be anywhere near that. Yeah, I

597
00:29:20,760 --> 00:29:23,520
Speaker 1: mean that that's gonna like sterilize life on any nearby

598
00:29:23,560 --> 00:29:26,080
Speaker 1: star system for sure. But anyway, there probably isn't any

599
00:29:26,120 --> 00:29:28,320
Speaker 1: life in the center of art galaxy for that same

600
00:29:28,360 --> 00:29:31,080
Speaker 1: reason that the galactic black hole is already emitting huge

601
00:29:31,080 --> 00:29:33,560
Speaker 1: amounts of life killing radiation, so you don't want to

602
00:29:33,560 --> 00:29:35,600
Speaker 1: get too close anyway. It's like the eye of a storm.

603
00:29:35,680 --> 00:29:38,800
Speaker 1: There's nothing living in the middle of it, that's right.

604
00:29:38,840 --> 00:29:40,840
Speaker 1: I don't know if it's calm inside the black hole.

605
00:29:41,000 --> 00:29:42,800
Speaker 1: That we did a whole episode actually on what it's

606
00:29:42,800 --> 00:29:44,680
Speaker 1: like to be inside a black hole. So you guys

607
00:29:44,680 --> 00:29:46,600
Speaker 1: should go listen to that. But yeah, it's a it's

608
00:29:46,640 --> 00:29:48,719
Speaker 1: everything is swirling around that central black hole. And so

609
00:29:48,760 --> 00:29:51,720
Speaker 1: probably what will happen is they'll merge and the new milk,

610
00:29:51,840 --> 00:29:54,840
Speaker 1: the new galaxy. I wonder what that galaxy would be called. Actually,

611
00:29:55,160 --> 00:29:57,760
Speaker 1: how would you combine and Rameda in the Milky Way,

612
00:29:57,880 --> 00:30:04,280
Speaker 1: like Drama Dinky Way, milk milk Drameda, I don't know,

613
00:30:04,640 --> 00:30:09,160
Speaker 1: and ramedaway the Andromeda Away. There you go, the Andromeda Way. Yeah,

614
00:30:09,200 --> 00:30:14,120
Speaker 1: the new galaxy would have a huge, super duper massive

615
00:30:14,120 --> 00:30:16,760
Speaker 1: black hole at its center. Yeah, and so I think

616
00:30:16,760 --> 00:30:19,200
Speaker 1: that basically sums it up. You'd have the black holes

617
00:30:19,200 --> 00:30:24,320
Speaker 1: will probably emerge huge violent eruption of radiation there gas

618
00:30:24,320 --> 00:30:26,600
Speaker 1: and the dust would have a lot of friction caused

619
00:30:26,680 --> 00:30:31,520
Speaker 1: caused star formation, big explosion, bigion work, Yeah, exactly. Friction, Yeah,

620
00:30:31,640 --> 00:30:33,200
Speaker 1: just all the kind of stuff you expect to see

621
00:30:33,200 --> 00:30:38,520
Speaker 1: in the next Transformers movie. And then stuff. He'll be there,

622
00:30:38,560 --> 00:30:42,080
Speaker 1: He'll be there everything. If there's money to be made,

623
00:30:42,160 --> 00:30:46,240
Speaker 1: he'll be there. Um. And then the stars and the

624
00:30:46,360 --> 00:30:48,920
Speaker 1: dark matter will just have a gravitational effect, but they'll

625
00:30:49,040 --> 00:30:52,040
Speaker 1: know eventually settle down and in a few more billion years,

626
00:30:52,520 --> 00:30:55,040
Speaker 1: the new galaxy will have its own shape. It will

627
00:30:55,080 --> 00:30:57,640
Speaker 1: sort of settle into its own new shape. But it

628
00:30:57,720 --> 00:31:00,280
Speaker 1: kind of sounds like every part will do something. Friend,

629
00:31:00,360 --> 00:31:01,880
Speaker 1: do you know what I mean? Yeah, they will because

630
00:31:01,880 --> 00:31:04,600
Speaker 1: they follow different rules, right, they interact differently and so

631
00:31:04,880 --> 00:31:07,000
Speaker 1: but so, then kind of the nice structure we have

632
00:31:07,080 --> 00:31:09,760
Speaker 1: now is going to be pretty much obliterated right when

633
00:31:09,760 --> 00:31:11,680
Speaker 1: it we're just with the other one. Yeah, exactly. You

634
00:31:11,720 --> 00:31:14,000
Speaker 1: shouldn't count on your real estate being the same value.

635
00:31:14,120 --> 00:31:18,440
Speaker 1: After the galaxy collision, Everything's going to be shook up, right, Absolutely,

636
00:31:18,880 --> 00:31:21,480
Speaker 1: it's going to be disrupt the entire Both galaxies gonna

637
00:31:21,480 --> 00:31:26,400
Speaker 1: be totally disrupted. Fireworks collisions. But you're saying it's possible

638
00:31:26,440 --> 00:31:29,160
Speaker 1: we may survive it, right, that it's possible nothing will

639
00:31:29,280 --> 00:31:31,560
Speaker 1: actually happen to our solar system. I think that's the

640
00:31:31,600 --> 00:31:33,560
Speaker 1: most likely outcome. Yeah, is it will just be sort

641
00:31:33,560 --> 00:31:37,160
Speaker 1: of interesting likely, Yeah, most likely most likely thing. I mean,

642
00:31:37,200 --> 00:31:39,960
Speaker 1: we're a star. We were basically part of our star,

643
00:31:40,120 --> 00:31:41,760
Speaker 1: right you think of the Solar system is just one

644
00:31:41,760 --> 00:31:44,200
Speaker 1: big blob, And the most likely thing is that nothing

645
00:31:44,240 --> 00:31:46,560
Speaker 1: gets close enough to disrupt our orbit around the star.

646
00:31:47,080 --> 00:31:49,120
Speaker 1: And you know what, even if our star gets like

647
00:31:49,240 --> 00:31:52,760
Speaker 1: ejected from the galaxy. So what we don't need the galaxy.

648
00:31:53,280 --> 00:31:55,120
Speaker 1: We could live just fine, just a star with a

649
00:31:55,120 --> 00:31:57,320
Speaker 1: bunch of planets in the middle of intergalactic space. We

650
00:31:57,360 --> 00:31:59,960
Speaker 1: don't need anything else. We just never start to provide

651
00:32:00,320 --> 00:32:03,200
Speaker 1: energy for life. So so we don't mean just in

652
00:32:03,240 --> 00:32:05,000
Speaker 1: the same way we're talking about the beginning of the episode,

653
00:32:05,040 --> 00:32:07,040
Speaker 1: like you don't really notice what's going out in space

654
00:32:07,080 --> 00:32:10,520
Speaker 1: because you don't usually have to. And if all those

655
00:32:10,640 --> 00:32:12,800
Speaker 1: if all those stars disappeared and all we and we

656
00:32:12,800 --> 00:32:15,440
Speaker 1: were in the middle of intergalactic space, it wouldn't change

657
00:32:15,480 --> 00:32:17,640
Speaker 1: your life at all. You would still still need to

658
00:32:17,640 --> 00:32:19,920
Speaker 1: stock up on lentils for the coming Apoco lips. You know,

659
00:32:20,160 --> 00:32:22,080
Speaker 1: it wouldn't save you or change your plans at all.

660
00:32:22,360 --> 00:32:24,560
Speaker 1: You wouldn't mind getting kicked out of town like that.

661
00:32:24,560 --> 00:32:27,320
Speaker 1: That's kind of what it would feel like, like the

662
00:32:27,360 --> 00:32:29,680
Speaker 1: whole town, our whole town. We just get kicked out,

663
00:32:29,720 --> 00:32:31,680
Speaker 1: you know, and we just go on living the way

664
00:32:31,840 --> 00:32:35,160
Speaker 1: what we did before. But things will definitely change for

665
00:32:35,240 --> 00:32:38,600
Speaker 1: us even if we survived it's galactic collision, the night

666
00:32:38,680 --> 00:32:41,840
Speaker 1: sky will look very different. I mean, as Andromeda approaches

667
00:32:41,920 --> 00:32:44,280
Speaker 1: in the next few billion years, it will grow in

668
00:32:44,320 --> 00:32:47,360
Speaker 1: the sky and eventually look really big. And then after

669
00:32:47,480 --> 00:32:49,400
Speaker 1: the collision, right when things have settled down, the night

670
00:32:49,480 --> 00:32:51,440
Speaker 1: sky would look totally different because all the stars will

671
00:32:51,480 --> 00:32:53,600
Speaker 1: have been rearranged and we won't see that band in

672
00:32:53,640 --> 00:32:56,160
Speaker 1: the milky Way anymore. Well, that makes me feel better.

673
00:32:57,600 --> 00:32:59,320
Speaker 1: I was sweating. I was sweating what was gonna happen

674
00:32:59,360 --> 00:33:01,000
Speaker 1: for and I have been years from now. But now

675
00:33:01,800 --> 00:33:04,320
Speaker 1: now I feel better and I and I hope Blake

676
00:33:04,360 --> 00:33:06,360
Speaker 1: you also feel a little bit better. Yeah, that's right, Bake,

677
00:33:06,400 --> 00:33:08,720
Speaker 1: chill out, don't worry about it. Um, you have nothing

678
00:33:08,760 --> 00:33:16,400
Speaker 1: to worry about. I think it's fun to think about

679
00:33:16,560 --> 00:33:19,320
Speaker 1: things happening deep into the future, and also even further

680
00:33:19,360 --> 00:33:22,120
Speaker 1: into the future. You know, the universe has been around

681
00:33:22,120 --> 00:33:25,200
Speaker 1: fourteen billion years, right, and that's just sort of like

682
00:33:25,520 --> 00:33:28,120
Speaker 1: the initial bits, not before we get to the interesting part.

683
00:33:28,600 --> 00:33:30,160
Speaker 1: But it could be they were not even at the

684
00:33:30,240 --> 00:33:33,160
Speaker 1: interesting part. You know. Thinking about galaxies in this way

685
00:33:33,240 --> 00:33:36,840
Speaker 1: reminds you that they're spinning their dynamic, they're swirling around

686
00:33:36,840 --> 00:33:39,360
Speaker 1: each other. What's going to happen? We don't know, right,

687
00:33:39,600 --> 00:33:43,000
Speaker 1: they could continue to swirl and form crazy new structures

688
00:33:43,000 --> 00:33:45,400
Speaker 1: that know, the universe has never seen before. Because there

689
00:33:45,440 --> 00:33:48,240
Speaker 1: hasn't been time to make them. And so this is

690
00:33:48,240 --> 00:33:49,880
Speaker 1: the kind of thing makes me think about the universe,

691
00:33:49,920 --> 00:33:53,160
Speaker 1: like on the trillion or two trillion life year cycle,

692
00:33:53,240 --> 00:33:56,960
Speaker 1: Like if life is still around ten trillion years into

693
00:33:56,960 --> 00:33:59,280
Speaker 1: the history of the universe, they'll think about these first

694
00:33:59,320 --> 00:34:03,520
Speaker 1: few moments of lactic formation as you know, almost irrelevant,

695
00:34:03,680 --> 00:34:07,400
Speaker 1: just like just warming up. The best maybe yet to come. Now,

696
00:34:08,239 --> 00:34:10,960
Speaker 1: that's right. I'm an optimistic person, so I'm always hoping

697
00:34:11,000 --> 00:34:14,200
Speaker 1: that the best thing is yet to come. Exactly well, great, um,

698
00:34:14,280 --> 00:34:16,280
Speaker 1: thank you so much Bla for sending us this question.

699
00:34:16,680 --> 00:34:19,319
Speaker 1: We really enjoyed answering it. That's right. And check out

700
00:34:19,360 --> 00:34:22,080
Speaker 1: our book called We Have No Idea. It's a guide

701
00:34:22,080 --> 00:34:24,520
Speaker 1: to the unknown questions of the universe, all the things

702
00:34:24,520 --> 00:34:26,759
Speaker 1: that physics wants to know the answer to but really

703
00:34:26,800 --> 00:34:30,160
Speaker 1: hasn't got a clue about. And thanks for listening. Yeah,

704
00:34:30,440 --> 00:34:32,799
Speaker 1: and if you're hungry or want to stuck up, just

705
00:34:32,840 --> 00:34:39,000
Speaker 1: don't forget to get Daniel's Spicy lentils, now available at

706
00:34:39,040 --> 00:34:49,320
Speaker 1: your local grocery store. If you still have a question

707
00:34:49,320 --> 00:34:52,759
Speaker 1: after listening to all these explanations, please drop us a line.

708
00:34:52,800 --> 00:34:54,960
Speaker 1: We'd love to hear from you. You can find us

709
00:34:54,960 --> 00:34:58,759
Speaker 1: at Facebook, Twitter, and Instagram at Daniel and Jorge That's

710
00:34:58,800 --> 00:35:02,200
Speaker 1: one Word, or smail us at Feedback at Daniel and

711
00:35:02,400 --> 00:35:12,359
Speaker 1: Orge dot com. H m hm