Stuff You Should Know - How Galaxies Work

Episode Date: February 22, 2019

In the universe things tend to cluster. This means there’s a coherent structure to the universe and learning about clusters of stars – galaxies - helps us figure out what that structure is. Join Chuck and Josh on an amazing space voyage! Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

On the podcast, Hey Dude, the 90s called, David Lasher and Christine Taylor, stars of the cult classic show, Hey Dude, bring you back to the days of slip dresses and choker necklaces. We're gonna use Hey Dude as our jumping off point, but we are going to unpack and dive back into the decade of the 90s.

We lived it, and now we're calling on all of our friends to come back and relive it. Listen to Hey Dude, the 90s called on the iHeart radio app, Apple Podcasts, or wherever you get your podcasts. Hey, I'm Lance Bass, host of the new iHeart podcast, Frosted Tips with Lance Bass. Do you ever think to yourself, what advice would Lance Bass

and my favorite boy bands give me in this situation? If you do, you've come to the right place because I'm here to help. And a different hot, sexy teen crush boy bander each week to guide you through life. Tell everybody, ya everybody, about my new podcast and make sure to listen so we'll never, ever have to say. Bye, bye, bye.

Listen to Frosted Tips with Lance Bass on the iHeart radio app, Apple Podcasts, or wherever you listen to podcasts. Welcome to Stuff You Should Know from HowStuffWorks.com. Hey, and welcome to the podcast. I'm Josh Clark, and there's Star Child Chuck Bryant, and there's Moon Rock Jerry Rowland over there.

And I'm just playing old Josh Clark, like I said, but this is the galactic federation of Stuff You Should Know episode of all time. There's my tall boy. Yeah, there you go. Chuck likes to get nice and loaded when he talks about space stuff. Here's something that I found helpful for me

that I think might help other dumb dumps like me. You're not a dumb dump. I like that chirp, by the way. You look like a circus peanut. It is circus peanut colored, oh my God. That is circus peanut orange. 100% dude. I wanna squeeze you.

Do not. All right. All right, you can squeeze me. You ready for this? So if our solar system, which is the sun and it's orbiting planets, moons, dust, gas. Right. A lot of dust and gas. Rocks. Our solar system.

Yeah. Yeah. If that was, let's say if the sun was the size of a grain of sand, then relatively our solar system would be like the size of our hand, with that at the center. Wow. And then if you extrapolate that, then our hand in relation to the Milky Way Galaxy

would stretch the length width of the United States. Wow. And then. A lot of stuff like that. Oh, keep going Chuck. Well, that's just one of, you know, billions of galaxies in the universe. Right.

The solar system galaxy universe. And then so the universe would be like the United States and Canada. Well, and I am a dummy because I was like, and so let's stand in Lebanon, Kansas, because that's the geographic center. Not, not as far as I recognize. Well, but we're not at the geographic center of,

our solar system is not the geographic center of the galaxy though, so I was wrong. No, there's a long history. By the way, it was beautiful. I love that. Thank you. There's a long history of assuming that we are at the center of the universe.

And then there's an equally, almost equally long history of science proving that now, or absolutely not. And we finally figured out that we're about a quarter of the way between the galactic center and the edge of the Milky Way. Yeah, yeah. And that.

It checks out. So we're nowhere near the center of the Milky Way. Well, no, because the center of the Milky Way is a supermassive black hole. The universe itself is expanding, and it's expanding faster than the speed of light. And galaxies are just caught up in the motion, going through the motions.

And we're just here on this little rock called Earth trying to figure out what in the age is going on. Yeah, during our, you know, 80 to 90 years here. Yeah. We're so insignificant. Luckily though, we figured out how to encapsulate knowledge in the form of writing so earlier generations can, or later generations can build on the work

of earlier generations because we'd be toast. Sure. If it all just got reset after everybody's lifetime and you couldn't say, oh, I've learned all this stuff. Yeah. You know, people just keep discovering the same things, which would be great for that sense of discovery, but it wouldn't really help move our species forward.

No, and that's what we're all about here. That's right, right? Yeah. Us and the hubs. So as far as what we know about galaxies now, compared to the very beginnings of this study, of course, the Greeks were looking up at the sky a long time before we were,

and they came up with this name, galaxies cucklose, and it means milky circle. Yeah, and guess which word we kept to describe galaxies? The milky. Not cucklose? So when you're saying like, look at that galaxy up there, you're saying, look at that milky up there. Oh, right, right.

Cucklose's circle. Yeah. I looked it up, I'm like, surely cucklose is the milky one, but nope. Yeah, this is surprising. But the Greeks were like, it looks like a milky circle, so we'll just go with that. Yeah, and they were on to some,

like kind of like everything they were doing back then, some stuff they got wrong and were kind of ahead of their time and their thinking and other stuff they weren't quite right about because of technology. Right. But Galileo did, he looked up and it's like, hey, there's a bunch of stars up there. It ain't milk.

They're congregating for a reason. Yeah. And so we knew pretty early on that like we were in the midst of some sort of group of stars, but for most of the era where we were looking up at the sky, at least in the West, I'm not sure about like the Muslim world. I know that they kind of had their own like track

of astronomy and mathematics that was in many points in history far more advanced than what the West was at. But as far as the West is concerned, they didn't understand that this group was anything less than the universe itself. They just looked out and they're like, well, there's the universe. Everything we're seeing is the universe

and that's all that there is. Not that we possibly lived in what we're later called by a guy named, I think Charles Messier, who called them island universes. No, I'm sorry. It was Harlow Shapley in the early 20th century. He started looking at some of these things and realized that they had the same structure

from that the Milky Way did. We had kind of identified that we were in our own little galaxy, but that other stuff was beyond our own little galaxy and that they were their own galaxies. Right. And so these island universes came to be called milkies. Yeah. And so did you pronounce them Shapley?

Yeah, there's a E that's not supposed to be in there. Really? Because no one wants to be called Harlow Shapley. I'm sure. So he was actually right in this argument, right, this longstanding sort of disagreement, but debate with Messier. No, Messier was a couple of hundred years before him. Well, but no, the whole argument though,

I mean, they didn't literally argue with each other. Because Messier was able to encapsulate his ideas in the form of writing. Yeah, but they had a longstanding, again, not personal beef, but debate because we didn't have the technology to prove one or the other correct until hubs came along. And in 1924, he basically said that Shapley was correct.

Yeah, that these little island universes weren't in the Milky Way. They were way far outside of the Milky Way and the universe was astoundingly bigger than we thought we previously imagined. So we mentioned hubs, the hubs, Dr. Hubbell and his awesome telescope. Right.

Which did you know that's being replaced? I mean, I don't think they're gonna like destroy it, but surely not. It's being, well, I guess sort of replaced by the James Webb Space Telescope. How do you mean being replaced? Like they're just gonna shoot it out of the sky with a space laser?

Well, no, that's what I was saying. I doubt if they'll destroy it, but it's being there's a new guy on the block. Right, oh yeah. And everybody's hot and heavy for him. His name is the James Webb Telescope. Yes. I think now it's been pushed back to 2021.

Yeah. But this thing will supposedly be able to observe like the formation of galaxies. Pretty much the Hubbell Telescope as it stands right now shows us, I think back to like 400 million years after the Big Bang. Not bad. Which is astoundingly early in the universe's development.

And the whole point of astronomy is what they're doing is looking back in time, right? The further away some object in the sky is, what you're seeing then is what that object looked like, say a billion or two billion or 10 billion years ago. And so you can take the structure of the object and compare it to objects that are much younger that we know of today that are closer.

And you can see how the universe has evolved and we can learn, you know, figure out some of the mysteries of the universe, like where it came from, what its structure is. How we're all going to die. Right? So if Hubbell can see, if Hubbell, that's great, great end of the world reference by the way.

If Hubbell can see back to 400 million years after the Big Bang, supposedly James Webb Telescope can see back to like 200 million years. Oh really? And that is a hair's breadth. Sure. From the origin of the universe. So close.

Yeah. So it is, it's the big guy in town, the new sheriff. Yeah, I just don't want hubs to get kicked to the curb. The James Webb Telescope is going to mush his face out of the way. Wait, you didn't say the James Woods Telescope. Right. You would.

You'd be like Trump forever. The telescope full of right wing rage. Yeah. And very smart. I think he has the highest IQ of anyone in Hollywood. Really? Mm-hmm. Like 160 something.

What, did you know that he supposedly tried to thwart the 9-11 hijacking? No. What? I think, I need to look this up. Speaking from the top of my head. But I'm pretty sure that it is fact that he was on a flight with one of the ring leaders

and was like, this guy's on my flight and he's taken notes and something's fishy here and I'm going to report it. Really? And that ended up being, you know, like Muhammad Ata or something. Wow. I got to look that up because I'm truly like.

Wow. Flying by the seat of my pants. But I think that's a true thing. He also made an appearance on The Simpsons. He was also the best part of the Stephen King anthology film Cat's Eye. I don't remember his. As the man who tried to quit smoking.

Oh, Critter's Ink. Is that what it was called? Mm-hmm. Yeah. You remember that? I don't remember James Woodsby, man. I think he was the guy that was trying to quit smoking under threat of violence to his family.

Remember that? Yeah, that was a great one. I haven't seen that in a while. I'm going to have to check that out. Okay. I'm sure it's being rebooted. Boy, we are stalling. All right.

That's because it's space. All right. So the various shapes in 1936, Edwin the Hubs, Hubble classified these in his Hubble sequence as elliptical, spiral, and irregular, elliptical. I mean, we'll go into detail on these, but about 60% of all galaxies are elliptical,

roughly 20% or so are spiral, which is us. And then anywhere from one to 20, 25% are irregular. Yes. But elliptical are, there's a range of shape from circular, which is E0, all the way up to E7, which is the most elliptical. Pretty much, yeah. And you're like, okay, great.

So all you need is elliptical. That's all galaxies are. But no, there's also something called spiral. And even though Hubble classified them by their shape, it's really, they're more differentiated by their features. Yeah. Spirals bright. Right, right.

They're bright. They have stars, bright stars, lots of hot gas. They tend to have arms that stretch out from them. Yeah. Like if you've looked at pictures of the Milky Way galaxy, it looks like a, what does it look like? Like someone's spinning an octopus. A bit of a whirlpool.

Sure. Someone's spinning an octopus. I love that. Yeah. That was perfect. That's what the, I wish that's what the Greeks had come up with instead of a Milky Way.

I'm surprised they didn't. Although they, all they saw was like a strip of white light. No one had any idea what the Milky Way looked like until the 20th century. Yeah, that's true. So they, all right, all these off the Greeks, everybody, I'm sorry. So, but spiral are the brightest, right?

They're the brightest and they have the most bright stars. Right. Elliptical tend to sometimes not have any bright stars at all. And then the other big difference between them is that elliptical are disordered and chaotic, whereas spiral are much more orderly where everything in the galaxy

rotates in orbit around the galaxy center in the exact same way and for the exact same reasons that Earth rotates around the sun. Except in this rotation, our solar system takes about 230 million years to make it all the way around the Milky Way rather than one year around the sun. Yeah, that's a big diff. Yeah, it is.

And again, with the size as illustrated at the onset, that might make a little more sense. Sure. The grain of sand in the palm, that palm in the middle of the United States. Actually, let's say the United States was, that would place us like, I don't know, what, Kentucky? What, the center of the US?

No, no, no. The center of the US is Lebanon, Kansas. Not in my book. Our... What is in your book? I'll tell you later. Okay. I've got my own opinions on that.

Just no credit to Lebanon, Kansas. I get it. I think it's actually a couple of miles from there, but I don't know where that would put us. If we're on like the, what, the third of the way between the edge. Oh, I see what you're saying. If Lebanon, Kansas is the middle and, you know.

It's not though, but let's just, for the sake of our name, as it is. And the East Coast edge would be the outer edge. What would that put us on? Yeah, I think Kentucky's probably a pretty good... Roughly. Kentucky or maybe East Tennessee. Okay.

Or Middle Tennessee, something like that. Yeah. Somewhere between... Just not Memphis. No. Then the spirals are broken down and subdivided into other categories. Normal spiral, that's where you have,

that's sort of the classic disc shape that we're thinking of, right? Yeah. That's the other feature that they have is like a hump. They look like a UFO. A bulge. If you looked at a spiral galaxy from the side, especially, I guess, an S.A., I think an S.A.

Yeah. That's the largest nuclear bulge. All right. Nuclear bulges. So it's like... Great band name. It really is. But the bulge is like, it's got a hump on the top

and a hump on the bottom and then a disc of stuff in the middle. Like a UFO. That's what it looks like. Yeah. That's a classic spiral galaxy. Right, which would be the normal... Then there are the barred spiral.

That has a disc shape as well with a bright center as well. I don't get the difference then, visually. So I think the difference is the disc shape is with the barred spiral, the center of it is drawn out. Oh, okay. So like in a normal spiral,

it's just a nice circle in the center, a nice, tidy sphere in the center. Whereas in a barred spiral, that sphere is pulled out into an elliptical itself. So it's like a bar of light going through the middle of the galaxy and that's the galactic center nucleus. All right.

And then we have our irregular as the third type of galaxy shape. And these are very faint, very small, no bright center, no spiral arms. Just, you know... Losers. Yeah, sort of the loser of the three. Loser galaxies.

So they used to think that this was the evolution of galaxies, that the different galaxies was like... Oh, really? Yeah, either it started as elliptical and then moved to spiral or most likely vice versa. Now we found that's not the case at all. Interesting. I think probably galaxies tend to start out

as spiral galaxies, the ordered kind where everything's just going around nice and easy. And that the reason we have elliptical galaxies, the disordered kind is because a spiral merged with another spiral, which we'll get into later. Yeah, the collisions of galaxies. Yeah, which I honestly didn't know that much about until this episode.

Yeah, and it sounds a lot scarier than it is. It's really not that scary. So don't be scared, everybody. You probably wouldn't even notice. You just have an extra sun, five billion years from now. I feel like we should take a break. I think we should too. We made it through page one.

All right, we'll come back with page two right after this. ["Shining On The Face"] Shining on the face that you should know. On the podcast, Hey Dude, the 90s called David Lasher and Christine Taylor, stars of the cult classic show, Hey Dude, bring you back to the days of slip dresses and choker necklaces. We're going to use Hey Dude as our jumping off point,

but we are going to unpack and dive back into the decade of the 90s. We lived it, and now we're calling on all of our friends to come back and relive it. It's a podcast packed with interviews, co-stars, friends, and nonstop references to the best decade ever. Do you remember going to Blockbuster? Do you remember Nintendo 64?

Do you remember getting Frosted Tips? Was that a cereal? No, it was hair. Do you remember AOL Instant Messenger and the dial-up sound like poltergeist? So leave a code on your best friend's beeper because you'll want to be there when the nostalgia starts flowing. Each episode will rival the feeling

of taking out the cartridge from your Game Boy, blowing on it and popping it back in as we take you back to the 90s. Listen to Hey Dude, the 90s, called on the iHeart radio app, Apple Podcasts, or wherever you get your podcasts. Hey, I'm Lance Bass, host of the new iHeart podcast, Frosted Tips with Lance Bass. The hardest thing can be knowing who to turn to

when questions arise or times get tough, or you're at the end of the road. Ah, OK, I see what you're doing. Do you ever think to yourself, what advice would Lance Bass and my favorite boy bands give me in this situation? If you do, you've come to the right place because I'm here to help. This, I promise you.

Oh, God. Seriously, I swear. And you won't have to send an SOS because I'll be there for you. Oh, man. And so, my husband, Michael. Um, hey, that's me. Yep, we know that, Michael.

And a different hot, sexy teen crush boy bander each week to guide you through life, step by step. Oh, not another one. Kids, relationships, life in general can get messy. You may be thinking, this is the story of my life. Oh, just stop now. If so, tell everybody, yeah, everybody about my new podcast and make sure to listen so we'll never, ever have to say bye,

bye, bye, listen to Frosted Tips with Lance Bass on the I Heart Radio app, Apple podcast, or wherever you listen to podcasts. All right, Chuck. So we're talking spiral galaxies because that's what we care about because that's what the Milky Way is. That's right. It's a spiral bar galaxy to be particular.

And so it's got that center hump, the galactic disc. And the galactic disc is actually made up of a few different parts too. You got the nucleus, which is the center. You've got the bulge, which you love, the nuclear bulge. We've said bulge like nine times already. And then the spiral arms. These are like accumulations of stars, gas, dust,

all sorts of stuff, planets, solar systems, all that. And that's where we are. Right, we're in a spiral arm. The Milky Way has four spiral arms, two major and two minor. And we're in a minor one, Orion, which is still, it's fine. We're in a minor arm, but it's the Orion arm, which makes it pretty cool. Right.

So I guess it would not have been a octopus spinning. That would be eight arms. Well, maybe we haven't discovered the other four yet. Yes, or maybe we're just a ceiling fan. Maybe so. I like the spinning octopus the most. We need to get some more arms then. You know, you shouldn't eat octopus.

They're extraordinarily intelligent. Just FYI. I think we've sung our octopus praises over the years. But are you eating them, though, still, is what I'm saying? No, I don't eat octopus. OK. Me either. Yeah?

Did you give them up after our episode on it? Yeah, around that time. Is it OK to eat squid ink pasta, though? Squid. They're stupid. Who cares about squid? I'll eat them all day long. Luckily, that's what most calamari is, is squid.

Or not even, right? What is it then? Isn't there like a big calamari hoax going on? I can believe it. Some of that stuff is awfully rubbery. Yeah, I think that's the deal. All right, so back to the shape of the galactic disk. There's also the globular cluster.

And these are above and below that disk. And then the halo, which is hot gas, we think. And that is that sort of dim region that you see around the galaxy. Right, and when you think of the Milky Way from all the pictures you've ever seen, what you're mostly thinking about is the galactic disk. The globular clusters nobody really thinks much about.

But they're actually old, super burned out, ancient clumps of stars that formed in the early galaxy, that used up a bunch of stars, used up their fuel really quickly. And now they're just kind of like these dead balls that are in orbit around our galaxy. And we actually can use them in the effect that our galaxy has on them, the tidal effects of gravity,

to figure out how much mass our galaxy has. Yeah, and gravity is what's holding all of this together. And you would think when you see something like the Milky Way galaxy, and you know gravity is dependent upon mass, that that center would be where all the mass is. But that's not the case. It's a little bit opposite of what you might think.

Yeah, that outer halo has about as much mass as the intergalactic disk. Yeah, kind of counterintuitive. Yeah, and because that halo is made up mostly of gas and some dust, it's actually orbiting or rotating at a different rate or different velocity, I guess, than the galactic disk. So there's actually torque that gets produced,

because the galactic disk is dragging it along. Is that what makes the arms? No, we found out recently, within the last month or two, I believe, that the actual Milky Way galaxy is bent on the ends, like an S. So it looks like an S from the side, kind of like a sombrero with the front up and the back down. That's what the Milky Way is.

Not an octopus, not a ceiling fan. It's a crumpled sombrero, maybe a nacho sombrero, like the one Homer Simpson wore. Right, or the guys that make just wear the cowboy hat with the front brim turned up like the cook at the cowboy camp. Sure, cookie. Cookie.

Yeah, cookie. The cook. Yeah, and galaxies are very, very far apart from one another. The closest one to us, Andromeda, is 2.2 million light years away from us. And that's a, I mean, that's relatively close in the grand scheme, but that's also pretty far apart. So I want to, there's this Professor Barbara

Reiden from Ohio State whose lecture we came across, and she just nails this, right? 2.2 million light years is an astoundingly large distance. But it's actually really close for a galaxy, because galaxies are so huge. And the way that she put it, like, if you took a pair of ping-pongs and said one was- Ping-pong balls?

Ping-pong balls, yes. No, games of ping-pong if you took two games. If you took two ping-pong balls and one was the sun, and one was a neighboring star to the sun, Alpha Centauri. OK. And you put them relative to one another. OK. The ping-pong balls would be as far apart as Columbus, Ohio,

and Jacksonville, Florida. OK. If you use ping-pong balls to be Andromeda and the Milky Way, here we go. The distance would be three feet relative to one another. Interesting. It is interesting. Yeah, yeah.

It's at least as interesting as your grain of sand in the palm of your hand. I like it. That's less than one Big Mac. Maybe I didn't get it across. Let me try another take, OK? No, I thought it was great. OK.

They use, well, we should talk about Parsecs a little bit, just because of the Star Wars thing. Because a Parsec is a unit of distance that is 3.26 light years. OK. And you remember in Star Wars, the famous line from Han Solo, remember? No.

Then he made the Kessel run in 12 Parsecs. So as a young, dumb kid, I thought that meant, you know, like a Parsec was like whatever, 30 seconds. Right. So he did this thing in a matter of minutes. Right. And then when I learned that it was a unit of distance in that time, I think a lot of people's inclination

would be that that would be a mistake on the part of the writer of Star Wars. But Star Wars nerds are quick to point out that to no, no, no, he did mean a unit of distance. But he actually skirted very close to a black hole on his Kessel run. And he actually shortened the normally 18 Parsec route to 12 Parsecs.

Wow, that's a big, big shortcut. So he cut out, he basically took a shortcut. Right. Yeah, not bad. Yeah, I'm just kind of wondering if this is, you know, all after the fact. And they were like, oh, I thought it was. It's called shoe horning, I think.

Yeah, I think so. I got a lot going for them. So as far as formation in the galaxy, again, we're talking about going back further than we can see with our current telescopes, even the web one upcoming. But we do have some pretty good guesses that after the Big Bang about 14 billion years ago

was when these galaxies formed from, again, just dust and gas collapsing. Right, there was lots of hydrogen gas in the early universe. And helium. Yes, and so from this expansion that took place, there were parts of the universe that were less dense than other parts. And the denser parts slowed down the expansion

enough for some of this dust and gas to accumulate into balls, which went one of two ways. Either those balls formed the earliest stars, and then those stars started to accumulate into a galaxy, which to me doesn't make sense, because if stars are so far apart, how would they have any effect on one another to form a galaxy? Probably not that.

Instead, they think that the clouds of dust and gas formed at what's called a protogalaxy. And then from that, more and more density was created, more and more gravity pushed more and more dust and gas together to form stars within this accumulation, which would be kind of like that disk, the gas disk that's flowing around the Milky Way. Yeah, and it's interesting.

It just seems like so much happened because of things collapsing and on themselves. Gravity. Yeah. Yep. Really interesting. It really is. I mean, because, and this is the whole reason

why people study this stuff, is when you start to understand this, you can start to understand the very structure of the universe. And they've actually started to map this to where they can see where the dark matter is. Remember, in that episode, they started to map dark matter in the universe, and then also physical matter.

And the map that they're created, it looks like a cobweb. There's lots of spindly parts and thick clumps, and then parts where there's voids. And it looks unsettlingly like a close-up of brain tissue, of neurons in a brain, what the universe looks like. Voids in between areas of matter. Really interesting stuff. So we were talking about the distance between galaxies

being really large, and that is true. But also, like you said at the same time, galaxies themselves are so large that they do collide. I mean, should we go ahead and talk about that? I think it's inevitable. But when they do collide, it's not like everything within that galaxy is so far apart. It's not like what you might picture in your head, which

is planets and stars just smashing into each other all over the place. Right, which you would think so. But the distances between stars are so colossal that entire galaxies can just merge with one another without any star collisions or virtually none. Now, do they always merge, or do sometimes they just kind of pass through one another and come out the other side?

I think they can do both. A little different. There's definitely types of universes that pass within. Galaxies. Yes, yeah. That's all we're talking about right here right now. The galaxies pass close enough to one another,

but don't necessarily merge. But their gravity still has an effect on one another. There's a pair of galaxies called the mice, where they've gotten close enough together that they've pulled stars toward one another, and they each have tails now. There's a galaxy called the Cartwheel Galaxy that a smaller galaxy passed through and apparently

created ripples. So just like as Professor Reiden put it, just like you drop a stone into a pond, it creates ripples in the water. That other galaxy created ripples in this larger host universe. So there's other things that can happen besides just a straight up merger.

But I think even in a merger, sometimes some of the stars shake loose and end up just, they're out in space. Yeah, that makes sense. And when they do come together or collide, they spiral galaxies generally like the shape can change, and they generally go to the elliptical side. So if you see a spiral galaxy like our own Milky Way, then chances are it has never been in such collision.

Yeah, they think that the spiral galaxies used to dominate. I think you said like 60% of galaxies today are the elliptical ones, right? The disordered ones. And they think that spiral galaxies used to be the majority, but so many of them merged to become elliptical galaxies, that's what we see the most of now. Yeah, about, what do they say, about 50% of all galaxies

at some point have been involved in a collision. Yeah, I saw as high as 90% in one place. And the Milky Way will at some point, right? Yeah. I mean, it's kind of inevitable, isn't it? We're going to merge with Andromeda in about 5 billion years. In about 3 billion years, we'll start affecting one another at the edges.

We'll start pulling one another into each other, and then we'll eventually merge and become one called the Milka-Amada galaxy. Is that really what it's going to be called? Yeah. Hopefully within 5 billion years, they'll come up with a better name. Interesting.

Andromix-y. Yeah. Andromiway. The Andromaway. Andromaway, I like it. It's pretty good. Yeah. The Androway.

It's definitely better than the Milka-Amada. Yeah. But I mean, we're not going to be around. Our show will be. I don't know, it's possible. What if this lived on billions of years from now? I mean, that's what we're doing, right? That's what we're hoping for.

So these galaxies throughout the universe do exist in galactic clusters. They are drawn to one another by gravity. And we are in what's called a pore cluster, which is less than 1,000. Like way less. Yeah, called the local group. And there's only 50 of us.

That's a good local band name, too. I think so. It sounds like it's sort of a union group. Yeah. Or like the local 41 or whatever. If you're just playing for free beer, that's what you're doing with your band. Local group.

Local group should be the name of your band. That's a great name for it. That's pretty good. And then there are rich clusters. And there are more than 1,000 in the rich clusters. Right. And some have way more than 1,000. There's one called the Virgo Super Cluster that

has 2,500 of these galaxies all clustered together. So think about it, you've got planets orbiting a star, solar system. Solar system is orbiting the center of the galaxy. Galaxies can orbit one another, or at least have effects on one another's orbits. Everything clusters together in larger and larger amounts thanks to gravity.

Once you pass a certain threshold, and electromagnetism and the strong and weak nuclear force are not like the dominant forces, gravity takes over. And it does some interesting stuff to the structure. And it's driving astronomers batty. They're like, surely there is some rhyme or reason to this. There's some pattern to this. There's got to be.

They're like Jim Carrey in the number 23 or something. And they think that if they can study the evolution of galaxies, they will be able to figure out the process that happens. Or what the ultimate point will be. Are we done? Let's take a break. Oh, no, we got more. Yeah, we got more.

All right. Letting things with junk and junk. Shocking all the things that you should know. On the podcast, Hey Dude, the 90s called David Lasher and Christine Taylor, stars of the cult classic show Hey Dude. Bring you back to the days of slip dresses and choker necklaces. We're going to use Hey Dude as our jumping off point.

But we are going to unpack and dive back into the decade of the 90s. We lived it, and now we're calling on all of our friends to come back and relive it. It's a podcast packed with interviews, co-stars, friends, and nonstop references to the best decade ever. Do you remember going to Blockbuster? Do you remember Nintendo 64?

Do you remember getting Frosted Tips? Was that a cereal? No, it was hair. Do you remember AOL Instant Messenger and the dial-up sound like poltergeist? So leave a code on your best friend's beeper, because you'll want to be there when the nostalgia starts flowing. Each episode will rival the feeling

of taking out the cartridge from your Game Boy, blowing on it and popping it back in, as we take you back to the 90s. Listen to Hey Dude, the 90s, called on the iHeart radio app, Apple Podcasts, or wherever you get your podcasts. Hey, I'm Lance Bass, host of the new iHeart podcast, Frosted Tips with Lance Bass. The hardest thing can be knowing who to turn to when

questions arise or times get tough, or you're at the end of the road. OK, I see what you're doing. Do you ever think to yourself, what advice would Lance Bass and my favorite boy bands give me in this situation? If you do, you've come to the right place, because I'm here to help.

This, I promise you. Oh, god. Seriously, I swear. And you won't have to send an SOS, because I'll be there for you. Oh, man. And so will my husband, Michael. Um, hey, that's me.

Yep, we know that, Michael. And a different hot, sexy teen crush boy bander each week to guide you through life, step by step. Oh, not another one. Kids, relationships, life in general, can get messy. You may be thinking, this is the story of my life. Oh, just stop now. If so, tell everybody, yeah, everybody,

about my new podcast, and make sure to listen, so we'll never, ever have to say bye, bye, bye. Listen to Frosted Tips with Lance Bass on the iHeart radio app, Apple Podcasts, or wherever you listen to podcasts. All right, so we've talked a lot about the distance between galaxies, but there's actually a name for that space in between galaxies in these clusters that we talked about,

called the intergalactic medium. And it is not empty, it's not just some void. And we don't know exactly what's going on in there, but we're studying it a lot. They think that there's probably some gas, because I think that's the fault for everything in space. Right, there's gas in there. There's got to be some gas in there, and probably some dust.

And a lot of it's super cold, like you would expect. Yeah, this is what the strange thing is, though, but some of it is really, really hot. Right. And have they explained that yet? No. No? No.

They're just taking a stab. It's a really neat age of discovery for astronomy. Like, we're getting better and better at looking out into the universe. So we're finding out more and more, but just because we get data back doesn't mean we can necessarily make heads or tails of it. Yeah, that's true.

But yeah, there's hot sections of the interstellar void. What's it called? Intergalactic medium. The intergalactic medium. Yeah. And which is kind of an interstellar void. Sure. And I can't start making up astronomy terms.

I need to use the real ones. But there's also, like, in these hot pockets, right? There's some pepperoni and cheese in there that will take the roof clean off of your mouth. There's hot metals, which would also burn the roof of your mouth, too, a million degrees Kelvin. Yeah, and I mean, that is the difference, too, from the cold intergalactic medium about two degrees

Kelvin all the way to millions of degrees. Yeah. That's quite a span. Right. And no idea why, or what it's doing there, or what's going to become of it, or if it used to be something else. We just don't understand if it follows a pattern.

And it seems to. Yeah, for sure. And thanks to Hubble, too, we also have Hubble's Law, which, and it's so hard to believe he was doing all this in the 1920s. Dude, I know. He was a boss. Yeah, like, really, really, that's amazing. He also once beat up James Webb in a bar fight,

which makes this whole telescope thing really ironic. But Hubble's Law states this observation that he made way back when, where, and this is an actual graph of this relationship, but he basically was like, you know what? Everything is moving away from us. Like, every time I look at something through this telescope, everything is moving away.

And not only that, but the further away it is, the faster it's moving away. Which is mind-boggling. Yeah. Because you can think like, all right, the universe is expanding. So that's fine. Everything's moving away from us.

It also suggests that there is no center to the universe. This is where that comes from. Because everything, no matter what direction you look in, it's moving away from us. You would think that... But doesn't that mean we're the center? By your tongue. But that's the cosmological principle

that everything is expanding, the entire universe. Not everything in the universe is expanding within the universe. The very universe itself is expanding, right? And since some things are moving away, the further they are away, the faster they're moving away from us. That means that there's plenty of the universe

that we can never possibly detect. Because even if we get up to the speed of light for travel, some parts of the universe, the furthest away parts, are actually spreading at faster than the speed of light. Yeah, we can't catch up to it. So it is cosmically impossible for us to ever detect a large part of the universe. Which is why when we're talking about the universe

that we're talking about and observing, that's called the visible universe. But that's probably just a relatively small chunk of the universe itself, which might be infinite for all we know. And we may never know what the universe is really shaped like, what it's made of, how big it is, because of this expansion

that's actually speeding up and accelerating beyond our ability to detect it. Amazing. It's kind of sad in a way. Yeah. And eventually, this is the most mind-blowing thing I've ever heard, the expansion will accelerate so much that the moon will no longer be visible to us.

Like nothing will be visible to us. And on a long enough time scale, I believe you wouldn't even be able to detect your hand in front of your face if you could, if it was physically possible, because of that expansion of light. Wow. Right?

Yeah. So the universe expanding is actually pulling light out of the visible spectrum into a longer wavelength in what's called red shifting because the red is the longer wavelength end of the visible spectrum. Right. And so what Hubble detected is called the red shift.

Everything's moving away from us. Yeah, which we could observe because of X-rays, right? Because of infrared, I think. Oh, infrared? Yeah. Man. I know, I love this stuff. I'm glad you do.

I'm aroused. Oh, goodness. So I guess if you're aroused, we should talk about active galaxies because, you know. I'm still waiting on my squeeze, by the way. Oh, your peanut squeeze? All right, just hang on. Okay.

That's your little treat if we finish this. Okay. If we finish this. So if you're looking at a normal galaxy, let's say like the Milky Way, I guess, all this light or most of it that you're seeing is pretty evenly distributed throughout that galaxy because it says, you know, those same galaxies

that have the even distribution of light, they have looked at it through X-ray and ultraviolet and infrared and it seems like they are giving off that energy from the nucleus and that is the active galaxy. Okay, yeah. Which is a very small percentage of the overall galaxy.

Right, so the light and energy in a normal galaxy, a non-active galaxy, it's distributed evenly throughout. Whereas in an active galaxy, all of that light and energy is coming from the center. Yeah, but they're, I mean, what are those? Like one, how many percent? I was gonna say one percent. I don't know if that's right though.

I'm not sure what the percentage is. I know they're fairly rare from what we can do. Yeah, actually I didn't have a percentage, but it just says a very small percentage. Yeah, I think they've discovered like a couple thousand so far or less than half a million, less than a million, which is a very small amount. Yeah.

But the distinction between them and a regular galaxy is again, all of that light, all of that energy is coming from a very small portion of the galaxy. Rather than the galaxy as a whole putting out all this light and energy, this is, it's all concentrated in the middle. It's very weird. And upon closer inspection,

these things that look as bright as, you know, galaxies that are relatively close to us, we're finding are actually billions and billions and billions of miles light year, I'm sorry, light years away from us, but they seem just as bright, which makes them super energetic. So they started to try to figure out what's going on.

And they think that the culprit are super massive black holes at the center of these galaxies. Well, and that's what is at the center of our own. I suspect there's a super massive black hole at the center of every galaxy. That's my big prediction for the second decade, the third decade of the 21st century, we're gonna figure that out.

Okay, if you're talking active galaxies, there are four classifications within that genre. And they say that if it's basically, it may not be structural, it might depend more on like the angle that we're viewing these things. Yeah, like they're all probably the same thing. Right, but for that classification

is the Seaford galaxies, radio galaxies, quasars and blazars. Yeah, in radio galaxy, I only ran across here. Everybody else just says it's Seaford, blazars and quasars. Yeah, radio galaxies, 0.01% of all galaxies, so. I think Freud and Wrench just made that up. I think he has stock in radio galaxies or something.

So he slipped it in. That's funny. Carl Seaford coined the, obviously in 1943, the Seaford galaxies. And what's the deal with these? So let's see, the Seaford galaxy has no jets. Oh, right. So this is the thing about an active galaxy

and this is why they think there's a super massive black hole at the center. They think that the accretion disk of gas and dust and everything that's just swirling, circling the drain of the event horizon or the black hole. As this gas and dust circles, friction develops, speed develops and it gets so hot that some of that material doesn't get sucked

in the black hole, instead gets shot away above and below the black hole into jets that are so tall. They're as tall as the galaxy is wide. They're just huge, huge energetic fountains of just basically pure energy. And that's what causes this brightness that can be seen from so far away. And depending on the angle of it relative to us,

we've basically said it's a Seaford galaxy, which means that we're probably seeing it from the side. And so we can't see the jets because they're not pointed to us. And then there's blazars and quasars too. Yeah, in the case of the blazar, that's looking basically straight on it, that jet that you were talking about.

It's coming right at you. Right at your face. Looking down the barrel of a blazar. And then the quasars, we discovered those in the 1960s. They've discovered what, like 13,000, but they think there could be up to 100,000. And these are billions of light years away from us. And these are the ones

that are the most energetic of them all. Yeah. So if you look at a quasar or something like that and the jets coming out of the quasar, what you're actually seeing is basically the most potent particle accelerator in the universe. Just shooting those energetic particles into space. It's amazing.

I can't imagine what it would be like to be anywhere near something like that. You'd die. Yeah, but if you were just there in spirit or something. Sure. Or if you could see it with a space telescope. That'd be great too. I'd settle for that, for the James Woods space telescope.

What else you got? Oh, the starburst galaxy thing at the end was kind of interesting. Yeah, this, I just wanted to go on record as saying, starburst is one of the most beautiful words ever. You like that? And I love it. Yeah, I like that too.

Attach star or burst onto anything. Well, that's not true, because a fecal burst. A fecal burst or a fecal star. That sounds prettier than fecal burst. A fecal star, I sure, I guess, yeah. Just about everything sounds better than fecal burst. So galaxies, as we know them, have a very low rate of new stars being formed, usually about one a year.

But these starburst galaxies produce more than 100 a year, which is amazing. Yeah, it is. Compared to the rest. 100 times more amazing than a regular galaxy. That's true. They also think that they burn themselves out rather quickly, and that those might actually be the globular clusters

that end up just kind of hanging around a real galaxy. Well, they say the stars that burn the brightest. Yeah, like Jimi Hendrix. Yeah. The 27 Club, all globular cluster starbursts. That's it. That's it. If you want to know more about galaxies, friends,

there is a whole universe out there for you to go check out. And you can start on the internet, so go check it out there. And since I said something weird like that, it's time for listener mail. So in lieu of listener mail. Oh, okay. We got a lot of feedback on our stalker episode, which kudos to you, that was your idea.

Oh, thanks. And it ended up being a really good episode, I think. But we got a lot of emails from both men and women who had been victims of stalking. Some people who didn't even know they'd been stalked until they'd listened to the episode, they'd be like, oh, okay, I was stalked. Yeah, and some really just heartbreaking,

scary, scary, in-depth, long stories that we heard. People who had to move, people who were still in the midst of it, it's just awful. It's tough stuff. So we're not going to read any of those because they are very personal stories and... They're all anonymous. Yeah, most of them were.

But we just want to say thanks to everyone for being brave enough to share your story with us. And just direct people to get help if you're being stalked. It is serious stuff. And I hope that podcast really got that across. Yeah, and that was one thing almost universally that we heard was that, thank you for saying, go find local help because it's out there

and that's a huge first step. Yeah, and a lot of these people, just like we had talked about, kind of went through the verbatim steps of people at work thought I was just overreacting and even my family thought I was blowing it out of proportion. And then you press charges the first time.

Right. What did you wait for? Yeah, blaming the victim, basically. All that stuff. So you can reach out to the Stalking Resource Center, the National Center for Victims of Crime. It's a good place to start. There are plenty of it, depending on what country you're from.

There are different organizations. I see one from the UK where you can report a stalker. And in fact, one of our listeners from the UK had a really hard time over there being taken seriously. And then there's also Rain, R-A-I-N-N, who is in there 25th year and they have some good resources for you as well. Yeah.

So just check it out online. Nice work, Chuck. Nice work, Josh. All right, well thank you everybody who wrote in. And if you wanna write in for any reason, you can go to our website at stuffyshouldknow.com and check out the social links. I have a website too, thejoshclarkeway.com

and you can send us all an email, me, Chuck, Jerry, everybody to stuffpodcast at howstuffworks.com. For more on this and thousands of other topics, visit howstuffworks.com. On the podcast, hey dude, the 90s called David Lasher and Christine Taylor, stars of the cult classic show, hey dude,

bring you back to the days of slip dresses and choker necklaces. We're gonna use hey dude as our jumping off point, but we are going to unpack and dive back into the decade of the 90s. We lived it and now we're calling on all of our friends to come back and relive it. Listen to, hey dude, the 90s called

on the iHeart radio app, Apple podcasts, or wherever you get your podcasts. Hey, I'm Lance Bass, host of the new iHeart podcast, Frosted Tips with Lance Bass. Do you ever think to yourself, what advice would Lance Bass and my favorite boy bands give me in this situation? If you do, you've come to the right place

because I'm here to help. And a different hot, sexy, teen crush boy bander each week to guide you through life. Tell everybody, yeah, everybody, about my new podcast and make sure to listen so we'll never, ever have to say bye, bye, bye. Listen to Frosted Tips with Lance Bass on the iHeart radio app, Apple podcast,

or wherever you listen to podcasts.