Speaker 1: Welcome to Stuff you Should Know from how Stuff Works
Speaker 1: dot com. Hey, and welcome to the podcast. I'm Josh Clark,
Speaker 1: and there's Star Child Chuck Bryant, and there's Moon Rock
Speaker 1: Jerry Roland over there, and I'm just playing all Josh Clark.
Speaker 1: Like I said, but this is the Galactic Federation of
Speaker 1: Stuff you Should Know Episode of all Time. There was
Speaker 1: my all boy. Yeah, there you go. Chucklates to get
Speaker 1: nice and loaded when he talks about space stuff. Uh,
Speaker 1: here's something that I found helpful for me that I
Speaker 1: think it might help other dumb dumps, Like you're not
Speaker 1: a dumb dump. I like that trip. By the way,
Speaker 1: you click a circus peanut. It is circus peanut colored.
Speaker 1: Oh my god, that is circus peanut orange pent. Dude.
Speaker 1: I want to squeeze you do not um? All right,
Speaker 1: all right, you can squeeze you Ready for this? So
Speaker 1: if our solar system, which is the Sun and its
Speaker 1: orbiting planets, moons, dust, gas, a lot of dust and gas,
Speaker 1: solar system. Yeah, uh, if that was Let's say, if
Speaker 1: the Sun was the size of a grain of sand,
Speaker 1: then relatively our solar system would be like the size
Speaker 1: of our hand. With that at the center. And then
Speaker 1: if you extrapolate that, then our hand in relation to
Speaker 1: the Milky Way galaxy would stretch the length width of
Speaker 1: the United States and then keep going. Well, that's just
Speaker 1: one of you know, billions of galaxies in the universe
Speaker 1: if you go Solar system, galaxy, universe, and then so
Speaker 1: the universe would be like our the United States and Canada. Well,
Speaker 1: and I'm I am a dummy because I was like,
Speaker 1: and so let's stand in Lebanon, Kansas. Is as the
Speaker 1: geographic center not not as far as I recognize, But
Speaker 1: we're not at the geographic center of our solar system,
Speaker 1: is not the geographic center of the galaxy though, So
Speaker 1: I was wrong. No, there's a long history, by the way,
Speaker 1: it was beautiful. I love that, Thank you. Um, there's
Speaker 1: a long history of assuming that we are at the
Speaker 1: center of the universe, and then there's an equally almost
Speaker 1: equally long history of science proving that now we're absolutely not.
Speaker 1: And um, we finally figured out that we're about a
Speaker 1: quarter of the way between the galactic center and the
Speaker 1: edge of the Milky Way, and that checks out. So
Speaker 1: we're so we're nowhere near the center of the Milky Way. Well,
Speaker 1: because the center of the Milky Way is a supermassive
Speaker 1: black hole. The universe itself is expanding, and it's expanding
Speaker 1: faster than the speed of light, and galaxies are just
Speaker 1: caught up in the in the motion, going through the motions,
Speaker 1: and we're just here in this little rock called Earth
Speaker 1: trying to figure out what what in the age is
Speaker 1: going on? Yeah, during our you know, eighty to ninety
Speaker 1: years here. Yeah, we're so luckily though, we figured out
Speaker 1: how to encapsulate knowledge in the form of writing, so
Speaker 1: earlier generations can or later generations can build on the
Speaker 1: work of earlier generations, because we'd be toast if it
Speaker 1: all just got reset after everybody's lifetime and you couldn't say, oh,
Speaker 1: I've learned all this stuff. You know, people just keep
Speaker 1: discovering the same things, which would be great for that
Speaker 1: sense of discovery, but yeah, it wouldn't really help move
Speaker 1: our species forward now, And that's what we're all about here, right, Yeah,
Speaker 1: us and and the hubs um. So as far as
Speaker 1: what we know about galaxy is now compared to the
Speaker 1: very beginnings of this study. Of course, the Greeks were
Speaker 1: looking up at the sky a long time before we were,
Speaker 1: and they came up with this name galaxy's kuclose and
Speaker 1: it means milky circle. Yeah, and which guess which word
Speaker 1: we kept to describe galaxies, the milky not ku close.
Speaker 1: So when you're saying, like, looking at galaxy up there,
Speaker 1: you're saying, look at that milky up there. Oh right, right,
Speaker 1: ku closes circle. Yeah, I looked it up. I'm like,
Speaker 1: surely KU closes the milky one. But nope, no, surprising that.
Speaker 1: So but the Greeks were like, it looks like a
Speaker 1: milky circle, so we'll just go with that. Yeah. And
Speaker 1: they were onto some like kind of like everything they
Speaker 1: were doing back then, some stuff they got wrong, and
Speaker 1: we're kind of ahead of their time and they're thinking
Speaker 1: and other stuff they weren't quite right about because of technology.
Speaker 1: But Galileo did. He was He looked up and it's like, hey,
Speaker 1: that's a there's a bunch of stars up there. It
Speaker 1: ain't mile congregating for a reason. Yeah, And so we
Speaker 1: do pretty early on that, like we were in the
Speaker 1: midst of some sort of group of stars. But for
Speaker 1: most of the most of the era um where we
Speaker 1: were looking up at the sky, at least in the
Speaker 1: west I'm not sure about like the Muslim world. I
Speaker 1: know that they kind of had their own like track
Speaker 1: of astronomy and mathematics. It was, in many points in history,
Speaker 1: far more advanced than what the West was at. UM.
Speaker 1: But as far as the West is concerned, UM, they
Speaker 1: didn't understand that this group was anything less than the
Speaker 1: universe itself. They just looked out and they're like, well,
Speaker 1: there's the universe. Everything we're seeing is the universe, and
Speaker 1: that's all that there is. Not that Um. We possibly
Speaker 1: lived in what were later called by UM a guy
Speaker 1: named uh, I think Charles Messier who called them island
Speaker 1: island universes. No, I'm sorry, it was Harlow Shapley. In
Speaker 1: the early twentieth century. He started looking at some of
Speaker 1: these things and realized that they they had the same
Speaker 1: structure from that the Milky Way did we had kind
Speaker 1: of identified that we were in our own little galaxy,
Speaker 1: but that other stuff was beyond our own little galaxy,
Speaker 1: and that they were their own galaxies. And so these
Speaker 1: island universes came to be called milkies. Yeah, and so
Speaker 1: did you pronounce some Shapley, Yeah, there's an e that's
Speaker 1: not supposed to be in there because no one wants
Speaker 1: to be called Harlow Shapeley. I'm sure. Uh so he
Speaker 1: was actually right in this argument, right, this long standing
Speaker 1: um sort of disagreement but debate with Messi A no,
Speaker 1: Messi it was a couple hundred years before him. Well,
Speaker 1: but no, the whole argument though. I mean they didn't
Speaker 1: literally argue with each other because Messier was able to
Speaker 1: encapsulate his ideas in the form of writing. Yeah, but
Speaker 1: they had a long standing um again not to personal beef,
Speaker 1: but debate because we didn't have the technology to prove
Speaker 1: one or the other correct until Hubbs came along and
Speaker 1: in uh he basically said that Shapley was correct. Yeah,
Speaker 1: that that these little island universes weren't in the Milky Way.
Speaker 1: They were way far outside of the Milky Way. In
Speaker 1: the universe was astoundingly bigger than we we thought we
Speaker 1: previously imagined. So we mentioned Hubs, the hubs, Dr Hubble
Speaker 1: and it's awesome telescope, which did you know that's being replaced.
Speaker 1: I mean, I don't think they're gonna like destroy it,
Speaker 1: but surely not. It's being uh well, I guess sort
Speaker 1: of replaced by the James Webb space telescope. How do
Speaker 1: you mean being replaced, Like they're just gonna shoot it
Speaker 1: out of the sky with a space what I was saying,
Speaker 1: it out of field, destroy it. But it's being there's
Speaker 1: a new a new guy on the block, and everybody's
Speaker 1: hot and heavy, and his name is the James Webb Telescope,
Speaker 1: which will be I think now it's been pushed back
Speaker 1: to but this thing will supposed to be able to
Speaker 1: observe like the formation of galaxies pretty pretty much. The
Speaker 1: Hubble Telescope as it stands right now shows us I
Speaker 1: think back to like four million years after the Big Bang,
Speaker 1: which is astoundingly early in the universe's development. And the
Speaker 1: whole point of astronomy is what they're doing is looking
Speaker 1: back in time right the further away some object in
Speaker 1: the sky. Is what you're seeing then is what that
Speaker 1: object look like, say a billion or two billion, or
Speaker 1: ten billion years ago. And so you can take the
Speaker 1: structure of the object and compare it to objects that
Speaker 1: are much younger that we know of today. They're closer,
Speaker 1: and you can see how the universe has evolved, and
Speaker 1: we can learn, you know, figure out some of the
Speaker 1: mysteries of the universe, like where it came from, what
Speaker 1: its structure is like. Right, So if Hubble can if Hubble,
Speaker 1: that's great, great end of the world reference. But um,
Speaker 1: if Hubble can see back to four million years after
Speaker 1: the Big Bank, supposedly James Webb telescope can see back
Speaker 1: to like two hundred million years, that is a hair's
Speaker 1: breadth from the origin of the universe. Yeah, so it is.
Speaker 1: It's the big guy in town, the new sheriff. Yeah.
Speaker 1: I just don't want Hubs to get kicked to the curve.
Speaker 1: The James Wood telescope is gonna mush his face out
Speaker 1: of the way. Wait, you didn't say that James Wood's telescope.
Speaker 1: You would, You'd be like Trump forever the telescope full
Speaker 1: of right wing rage. Yeah, and very smart. I think
Speaker 1: he is the highest i Q of anyone in Hollywood. Really,
Speaker 1: he's like one sixthing. What he uh? Did you know
Speaker 1: that he supposedly tried to thwart the nine eleven hijacking? No? What,
Speaker 1: I think I need to look this up. Speaking from
Speaker 1: the top of my head, but I'm pretty sure that
Speaker 1: it is fact that he was on a flight with
Speaker 1: one of the ringleaders and was like this guy is
Speaker 1: on my flight and he's taken notes and something's fishy
Speaker 1: here and I'm going to report it. And that ended
Speaker 1: up being, you know, like Mohammed Atta or something. I
Speaker 1: gotta look that up because I'm truly like flying by
Speaker 1: the seat of my pants. But I think that's the
Speaker 1: true thing. He also made an appearance on The Simpsons.
Speaker 1: He was also the best part of the Stephen King
Speaker 1: anthology film Cat's Eye. I don't remember his is the
Speaker 1: man who tried to quit smoking? Is that what it
Speaker 1: was called? Yeah, you remember that? That was him. I
Speaker 1: don't remember James Witsby man. I think he was the
Speaker 1: guy that is trying to quit smoking under threat of
Speaker 1: violence to his family. Remember that. I haven't seen that
Speaker 1: in a while. I have to check that out. Sure
Speaker 1: it's being rebooted, all right, that's because it's space, alright.
Speaker 1: So the various shapes edwin the hubs. Hubble classified these
Speaker 1: uh and his Hubble sequence as elliptical, spiral, and irregular elliptical.
Speaker 1: I mean, we'll go into detail in these, but about
Speaker 1: six of all galaxies are elliptical roughly or so or spiral,
Speaker 1: which is us and then anywhere from one irregular. Yes,
Speaker 1: but elliptical, are there. There's a range of shape from circular,
Speaker 1: which is E zero, all the way up to EAT seven,
Speaker 1: which is the most elliptical, pretty much. Yeah, and you're like, okay, great,
Speaker 1: so all you need is elliptical, it's all galaxies are.
Speaker 1: But no, there's also something called spiral. And even though
Speaker 1: Hubble classified them by their shape, it's really they're more
Speaker 1: differentiated by their features and how bright right, right, they're bright.
Speaker 1: They have stars, bright stars, lots of hot gas. They
Speaker 1: tend to have arms that stretch out from them. Yeah. Like,
Speaker 1: if you looked at pictures of the Milky Way galaxy,
Speaker 1: it looks like a what does it look like like
Speaker 1: someone spinning an octopus? A bit of a whirlpool? Sure,
Speaker 1: it's spinning an octopus. I love that. Yeah, that was perfect.
Speaker 1: That's what I wish. That's what the Greeks had come
Speaker 1: up with instead of a Milky wayn't although they all
Speaker 1: they saw was like a strip of white light, and
Speaker 1: no one had any idea what the Milky Way looked
Speaker 1: like until the twentieth century, so they all, right, all
Speaker 1: these off the Greeks, everybody, I'm sorry, so, but spiral
Speaker 1: are the brightest, right, they're the brightest because they have
Speaker 1: the most bright stars um. Elliptical tend to sometimes not
Speaker 1: have any bright stars at all. UM. And then the
Speaker 1: other big difference between them is that elliptical are um
Speaker 1: are disordered and chaotic, whereas spiral are much more orderly.
Speaker 1: Where everything in the galaxy rotates in orbit around the
Speaker 1: galaxy center in the exact same way and for the
Speaker 1: exact same reasons that Earth rotates around the Sun, except
Speaker 1: in this rotation, our solar system takes about two d
Speaker 1: and thirty million years to make it all the way
Speaker 1: around the Milky Way, rather than one year around the Sun. Yeah,
Speaker 1: that's a big death. Yeah it is. And again with
Speaker 1: the size as illustrated at the onset, that might make
Speaker 1: a little more sense. Sure, the grain of sand in
Speaker 1: the palm palm in the middle of the United States,
Speaker 1: it's actually let's say the United States was that would
Speaker 1: place us like, I don't know what, Kentucky? What the
Speaker 1: center of the US? No, no, no, If the center
Speaker 1: of the U s is leban On, Kansas, what is
Speaker 1: in your book? I'll tell you. Got my own opinions
Speaker 1: on that. Just no credit to leban On, Kansas, I
Speaker 1: get it. Um I think it's actually a couple of
Speaker 1: miles from there, but I don't know where that would
Speaker 1: put us if we're in the like the what the
Speaker 1: a third of the way between the edge and I
Speaker 1: see what you're saying. If leban On, Kansas is the
Speaker 1: middle and you not though, but let's just for the
Speaker 1: sake of our in the east coast edge would the
Speaker 1: outer edge? What would that put us? Yeah, I think
Speaker 1: Kentucky is probably a pretty good roughly Kentucky or maybe
Speaker 1: East Tennessee or Middle Tennessee something like that. Yeah, somewhere between,
Speaker 1: just not in Memphis. Uh. Then the spirals are broken
Speaker 1: down and subdivided into other categories. Um normal spiral. That's
Speaker 1: where you have. That's sort of the classic disc shape
Speaker 1: that we're thinking of, right, Yeah, that's the other feature
Speaker 1: that they have is like a hump. They look like
Speaker 1: a ufolge if you looked at a spiral galaxy from
Speaker 1: the side especially, I guess in all right s A,
Speaker 1: I think in A. Yeah, that's the largest nuclear pulge.
Speaker 1: Nuclear bulges. So it's like great band name, it really is.
Speaker 1: But the bulge is like it's got a hump on
Speaker 1: the top and a hump on the bottom and then
Speaker 1: a disc of stuff in the middle like a UFO.
Speaker 1: That's what it looks like. Um, that's a that's a
Speaker 1: classic spiral galaxy, right, which would be the normal. Then
Speaker 1: they're the barred spiral that is has a disc shape
Speaker 1: as well, with a bright center as well. I don't
Speaker 1: get the difference then visually, so I think the difference is, Um,
Speaker 1: the disc shape is with the barred spiral, the center
Speaker 1: of it is drawn out so like in a in
Speaker 1: a normal spiral, it's just a nice circle in the center,
Speaker 1: a nice tidy sphere in the center, whereas in a
Speaker 1: barred spiral that sphere is pulled out into an elliptical
Speaker 1: it's self. So it's like a bar of light going
Speaker 1: through you know, the middle of the galaxy, and that's
Speaker 1: the galactic center and nucleus, all right. Uh. And then
Speaker 1: we have our irregular as the third type of galaxy shape. Uh.
Speaker 1: And these are very faint, very small Um, no bright center,
Speaker 1: no spiral arms, just losers of the loser galaxies. So
Speaker 1: they used to think that this was the evolution of galaxies,
Speaker 1: that the different galaxies was like, yeah, either it started
Speaker 1: as elliptical and then moved to um spiral or most
Speaker 1: likely vice versa. Now we found that's not the case
Speaker 1: at all. Interesting and they think probably you know, um,
Speaker 1: galaxies tend to start out as spiral galaxies, the ordered
Speaker 1: kind where everything's just going around nice and easy. Um,
Speaker 1: and that the reason we have elliptical galaxies, the disordered kind,
Speaker 1: is because a spiral merged with another spiral, which will
Speaker 1: it into later. Yeah, the collisions of galaxies, yeah, which
Speaker 1: I honestly didn't know that much about until this episode. Yeah,
Speaker 1: and it sounds a lot scarier than it is. Certainly
Speaker 1: not that scary, So don't be scared, everybody. You probably
Speaker 1: wouldn't even notice. You just have an extra son five
Speaker 1: billion years from there. I feel like we should take
Speaker 1: a break. I think we should too. We made it
Speaker 1: through page one, all right, we'll come back with page
Speaker 1: to right after this, alright, chuck. So we're talking spiral
Speaker 1: galaxies because that's what we care about, because that's what
Speaker 1: the Milky Way is. That's right. Um, it's a spiral
Speaker 1: bar galaxy to be particular. And so it's got that
Speaker 1: center hump the galactic disc, and the galactic disc is
Speaker 1: actually made up of a few different parts too. You've
Speaker 1: got the nucleus, which is the center. You've got the bulge,
Speaker 1: which you love the nuclear bulge like nine times already,
Speaker 1: and then the spiral arms. These are like um accumulations
Speaker 1: of stars, gas, dust, um, all sorts of stuff, planet,
Speaker 1: solar systems, all that, And that's where we are right.
Speaker 1: We're in a spiral arm. The Milky Way has four
Speaker 1: spiral arms, two major and two minor, and we're in
Speaker 1: a minor one Oriyan, which is still It's fine. We're
Speaker 1: in a minor arm, but it's the orion arm, which
Speaker 1: makes it pretty cool. So I guess it would not
Speaker 1: have been a octopus spinning. That would be eight arms.
Speaker 1: Well maybe we haven't discovered the other four yet, yes,
Speaker 1: or maybe we're just a ceiling fan. Maybe. So I
Speaker 1: like the spinning octopus the most. We need to get
Speaker 1: some more arms. Then, you know, you shouldn't need octopus.
Speaker 1: They're extraordinarily intelligent. Just y. I think we we've sung
Speaker 1: our octopus praises over the years. But do you you're
Speaker 1: you eating them those still, is what I'm saying. No,
Speaker 1: I don't need octopus. Yeah, did you give them up
Speaker 1: after our episode on it? Or yeah, we're on that
Speaker 1: time is it okay to eat squid inc pasta? Though
Speaker 1: squid they're stupid. Who cares about squid? I'll eat them
Speaker 1: all day long. Luckily, that's what most calamaria is, a
Speaker 1: squid or not even right? What is it? Then? In't
Speaker 1: there like a big calamari hoax going on? I can
Speaker 1: believe it's Some of that stuff is awfully rubbery. Yeah,
Speaker 1: I think that's the deal, all right. So back to
Speaker 1: the back to the shape of the galactic disc. There's
Speaker 1: also the globular cluster um these are above and below
Speaker 1: that disk, and then the halo, which is um hot
Speaker 1: gas we think, and that is that that sort of
Speaker 1: dim region that you see around the galaxy right when
Speaker 1: you think of like the Milky Way from all the
Speaker 1: pictures you've ever seen. What you're mostly thinking about is
Speaker 1: the galactic disc. Popular clusters nobody really thinks much about.
Speaker 1: But they're actually old super um, super burned out ancient
Speaker 1: clumps of stars that formed in like the early galaxy,
Speaker 1: that used up a bunch of stars, used up their
Speaker 1: fuel really quickly, and now they're just kind of like
Speaker 1: these dead balls that are in orbit around our galaxy
Speaker 1: and we actually can use them and the effect that
Speaker 1: our galaxy has on them. The title effects of gravity
Speaker 1: to figure out how much mass our galaxy has. Yeah,
Speaker 1: and you know gravity is what's holding all of this together.
Speaker 1: And you would think when you see it's something like
Speaker 1: the Milky Way galaxy. Uh, and you know gravity is
Speaker 1: dependent upon mass, that that center would be where all
Speaker 1: the masses. But that's not the case. It's a little
Speaker 1: bit opposite of what you might think. Yeah, that that
Speaker 1: um outer halo has about as much mass as the
Speaker 1: intergalactic disc um the counterintuitive. Yeah, and because that halo
Speaker 1: is made up mostly of gas and some dust um,
Speaker 1: it's actually orbiting or rotating at a different rate or
Speaker 1: different velocity I guess than the galactic disc. So there's
Speaker 1: actually torque that gets produced because the galactic disc is
Speaker 1: like dragging it along the arms. No, we found out recently,
Speaker 1: like within the last month or two. I believe that
Speaker 1: the actual the actual Milky Way galaxy is bent on
Speaker 1: the ants. Like so it looks like an s from
Speaker 1: the site, kind of like a sombrero with like the
Speaker 1: front up and the back down. That's what the milky is.
Speaker 1: Not an octopus, not the only fan. It's a crumpled sombrero,
Speaker 1: maybe a nacho sombrero like the one Homer Simpson war. Right,
Speaker 1: are the guys that make just wear the cowboy hat
Speaker 1: with a front brim turned up like the cook at
Speaker 1: the at the Cowboy camp. Sure, cookie cookie cook. Yeah.
Speaker 1: And galaxies are very very far apart from one another.
Speaker 1: The closest one to us, Uh, Andromeda is two point
Speaker 1: two million light years away from us. And uh that's
Speaker 1: a I mean, that's relatively close in the grand scheme,
Speaker 1: but that's also pretty far apart. So I want to
Speaker 1: there's this professor Barbara Ryden from Ohio State whose lecture
Speaker 1: we came across, and she like just nails this right.
Speaker 1: Two point two million light years is an astoundingly large distance, Right,
Speaker 1: but it's actually really close for a galaxy because galaxies
Speaker 1: are so huge. And the way that she put it,
Speaker 1: like if you took a pair of ping pongs and
Speaker 1: said one was balls ping pong balls, Yes, games of
Speaker 1: ping pong, and he took two games. If you took
Speaker 1: two ping pong balls and one was the Sun and
Speaker 1: one was a neighboring star to the Sun, Alpha Centauri, okay, uh,
Speaker 1: and you you put them relative to one another. Uh,
Speaker 1: the ping pong balls would be as far apart as Columbus,
Speaker 1: Ohio and Jacksonville, Florida. Okay, if you use ping pong
Speaker 1: balls to be Andromeda and the Milky Way, here we go.
Speaker 1: The distance would be three ft relative to one another. Interesting,
Speaker 1: it is interesting. Yeah, yeah, it's at least as interesting
Speaker 1: as your grain of singing in the palmyre this less
Speaker 1: than one big mac. Maybe I didn't get it across.
Speaker 1: Let me try another take. Okay, No, I thought it
Speaker 1: was great. Um they use Uh, well, we should talk
Speaker 1: about parsecs a little bit, just because of the Star
Speaker 1: Wars thing, because a parsk is a unit of distance
Speaker 1: that is three point to six light years. And you
Speaker 1: remember in Star Wars the famous line from Han Solo.
Speaker 1: Remember that he made the Kessel run in twelve parsecs. So,
Speaker 1: as a young dumb kid, I thought that meant, you know,
Speaker 1: like a parsak was like whatever, thirty seconds. So he
Speaker 1: did this thing in a matter of minutes. Uh. And
Speaker 1: then when I learned that it was a unit of
Speaker 1: distance in that time, I think a lot of people's
Speaker 1: inclination would be that that would be a mistake on
Speaker 1: the part of the writer of Star Wars. But Star
Speaker 1: Wars nerds are quick to point out that did no, no, no,
Speaker 1: he he did mean a unit of distance, but he
Speaker 1: actually skirted very close to a black hole on his
Speaker 1: Kessel run and he actually shortened the normally eighteen par
Speaker 1: sect route to twelve par secs. Wow, that's a big,
Speaker 1: big short cut. So he cut out. He basically took
Speaker 1: a shortcut. Yeah, not bad. Yeah, I'm just kind of
Speaker 1: wondering this is, you know, all after the fact, and
Speaker 1: they were like, oh, yeah, I think so. I got
Speaker 1: a lot going for them. So as far as formation
Speaker 1: and the galaxy, again, we're talking about going back further
Speaker 1: than we can see with our current telescopes, even even
Speaker 1: the web one upcoming. But we do have some pretty
Speaker 1: good guesses, um that after the Big Bang about fourteen
Speaker 1: billion years ago is when these galaxies formed from again
Speaker 1: just dust and gas, lots of hydrogen gas in the
Speaker 1: early universe. And yes, and the so from this expansion
Speaker 1: that took place, Um, there were parts of the universe
Speaker 1: that were less dense than other parts, and the denser
Speaker 1: parts slowed down the expansion enough to for some of
Speaker 1: this dust and gas to accumulate into balls, which uh,
Speaker 1: one of two ways. Either those balls formed the earliest stars,
Speaker 1: and then those stars started to to accumulate into a galaxy,
Speaker 1: which to me doesn't make sense because if stars are
Speaker 1: so far apart, how would they how would they have
Speaker 1: any effect on one another to form a galaxy? Probably
Speaker 1: not that. Instead, they think that the the clouds of
Speaker 1: dust and gas um formed like what's called the proto galaxy,
Speaker 1: and then from that more and more density was created,
Speaker 1: more and more gravity pushed more and more dust and
Speaker 1: gas together to form stars within this accumulation, which would
Speaker 1: be kind of like that um that uh disc, the
Speaker 1: gas disc that's flowing around the Milky Way. Yeah, and
Speaker 1: it's interesting. It just seems like so much happened because
Speaker 1: of um collapsing, things collapsing and on themselves. Yeah, yep,
Speaker 1: really interesting, it really is. I mean because and this
Speaker 1: is the whole reason why people study this stuff, is like,
Speaker 1: when you start to understand this, you can start to
Speaker 1: understand the very structure of the universe. And they've actually
Speaker 1: started to map this to where they can they can
Speaker 1: see where the dark matter is. Remember in that episode
Speaker 1: that we they started to map dark matter in the universe,
Speaker 1: and then also physical matter um and the map that
Speaker 1: they're created, it's it's it looks like a cobweb. There's
Speaker 1: lots of like um like spindle parts and thick clumps,
Speaker 1: and then parts where there's voids, and it looks unsettlingly
Speaker 1: like a close up of brain tissue of like neurons
Speaker 1: in a brain, like voids in between areas of matter.
Speaker 1: Really interesting. Um. So, we were talking about the the
Speaker 1: distance between galaxies being really large, and that is true,
Speaker 1: but also, like you said at the same time, galaxies
Speaker 1: himself are so large that they they do collide. I mean,
Speaker 1: should we go ahead and talk about that. I think
Speaker 1: it's inevitable. But when they do collide, it's not like, uh,
Speaker 1: everything within that galaxy so far apart. It's not like
Speaker 1: what you might picture in your head, which is planets
Speaker 1: and stars just smashing into each other all over the place. Right,
Speaker 1: But you would think so. But the distances between stars
Speaker 1: are so colossal that entire galaxies can just merge with
Speaker 1: one another without any Star collisions are virtually none. Now
Speaker 1: do they always merge or do sometimes they just kind
Speaker 1: of passed through one another and come out the other side.
Speaker 1: I think they can get both a little different there's
Speaker 1: definitely types of universes that passed within. Yes, yeah, that's
Speaker 1: all we're talking about right here, right now. Um, the
Speaker 1: galaxies passed close enough to one another but don't necessarily merge,
Speaker 1: but there their gravity still has an effect on one another.
Speaker 1: There's a pair of galaxies called the Mice where they've
Speaker 1: gotten close enough together that they've pulled stars toward one
Speaker 1: another and they each have tails. Now, um, there's a
Speaker 1: galaxy called the Cartwheel galaxy that a smaller galaxy passed
Speaker 1: through and apparently created ripples. So just like um, as
Speaker 1: as Professor Ryde and put it, just like you drop
Speaker 1: a stone into a pond, it creates ripples in the water.
Speaker 1: Those that other galaxy created ripples in this larger host universe.
Speaker 1: So there's other things that can happen besides just a
Speaker 1: straight up merger. But I think even in a merger,
Speaker 1: sometimes some of the stars shake loup and end up
Speaker 1: just they're they're out in space. Yeah that makes sense. Yeah, uh,
Speaker 1: and when they do uh come together or collide. They
Speaker 1: spiral galaxies generally, like the shape can change and they
Speaker 1: generally go to the elliptical side. So if you see
Speaker 1: a spiral galaxy like our own Milky Way, then chances
Speaker 1: are it has never been in such a collision. Yeah.
Speaker 1: They think that the spiral galaxies used to dominate. I
Speaker 1: think you said, like sixty of galaxies today are the
Speaker 1: elliptical ones, right, the disordered ones, And they think that
Speaker 1: spiral galaxies used to be the majority, but so many
Speaker 1: of them merged to become elliptical galaxy galaxies. That's what
Speaker 1: we see the most of now. Yeah. About what do
Speaker 1: they say about fifty of all galaxies at some point
Speaker 1: have been involved in a collision. Yeah, I saw as
Speaker 1: high as ninety in one place, and the Milky Way
Speaker 1: will at some point, right, Yeah, I mean there, it's
Speaker 1: kind of inevitable, isn't it. We're going to emerge with
Speaker 1: Andromeda and about five billion years. In about three billion years,
Speaker 1: we'll are We'll start affecting one another at the edges,
Speaker 1: will start pulling one another into each other, and then
Speaker 1: we'll eventually merge and become one called the milk Ameda Galaxy.
Speaker 1: Is that really what it's going to be called? Yeah,
Speaker 1: hopefully within five billion years will come up with a
Speaker 1: better name. Interesting um and drama see yeah, drama way
Speaker 1: the the and drama way and drama way good, yea,
Speaker 1: the androw way. It's definitely better than the milk Omeda. Yeah,
Speaker 1: but I mean we're not gonna be around our show
Speaker 1: will be I don't know, it's possible. What if this
Speaker 1: lived on billions of years from now. That's I mean,
Speaker 1: that's what we're doing, right, that's what we're hoping for.
Speaker 1: So uh. These galaxies um throughout the universe do exist
Speaker 1: in galactic clusters. They um they are drawn to one
Speaker 1: another by gravity. And we are in um what called
Speaker 1: a poor cluster, which is less than a thousand like
Speaker 1: way less Yeah, called the local group, and there's only
Speaker 1: fifty of us. That's a good local band name, too,
Speaker 1: I think. So it sounds like sort of a union group, yeah,
Speaker 1: or like the local forty one or whatever. If you're
Speaker 1: just playing for free beer, that's that's what you're doing
Speaker 1: with your band. Local groups should be the name of
Speaker 1: your band. That's great, that's pretty good. Uh. And then
Speaker 1: there are rich clusters, and there are more than a
Speaker 1: thousand in the rich clusters, right, and some some have
Speaker 1: way more than a thousand. There's one called the Virgo
Speaker 1: supercluster that has of these of galaxies all clustered together.
Speaker 1: So think about you've got a planets orbiting a star,
Speaker 1: solar system. Solar system is orbiting the center of the galaxy.
Speaker 1: Galaxies can orbit one another or at least have effects
Speaker 1: on one another's orbits. Everything clusters together in larger and
Speaker 1: larger amounts thanks to gravity. Once you pass a certain
Speaker 1: threshold old and electromagnetism and the strong and weak nuclear
Speaker 1: force or not like the dominant forces, gravity takes over
Speaker 1: and it does some interesting stuff to the structure, and
Speaker 1: it's driving astronomers batty. They're like, surely there is some
Speaker 1: rhyme or reason to this. There's some pattern to the
Speaker 1: there's gotta be there, like Jim Carrey in the number
Speaker 1: twenty three or something, you know. Um, And they think
Speaker 1: that if they can study the evolution of galaxies, they
Speaker 1: will be able to figure out the process that happens
Speaker 1: or what the ultimate point will be. Let's do let's
Speaker 1: take a break. We got more things, all right. So
Speaker 1: we've talked a lot about the distance between galaxies, but
Speaker 1: there's actually a name for that space in between galaxies
Speaker 1: and these clusters that we talked about, called the intergalactic medium.
Speaker 1: And uh, it is not empty. It's not just some void. Uh,
Speaker 1: And we don't know exactly what's going on in there,
Speaker 1: but we're studying it a lot. Um. They think that
Speaker 1: there's probably some gas, because I think that's the fault
Speaker 1: for everything in space, Like there's got to be some
Speaker 1: gas in there, and probably some dust, and a lot
Speaker 1: of it's super cold like you would expect. Yeah, this
Speaker 1: is what the strange thing is though, but some of
Speaker 1: it is really really hot. And did have they explained
Speaker 1: that yet? Now? No, they're just taking a step. It's
Speaker 1: a really neat age of discovery for astronomy, Like we're
Speaker 1: getting better and better at looking out into the universe,
Speaker 1: so we're finding out more and more. But just just
Speaker 1: because we get data back doesn't mean we can necessarily
Speaker 1: make heads or tails of it. Yeah, but yeah, there's
Speaker 1: there's hot sections of the inner interstellar void what's it
Speaker 1: called intergalactic medium and the intergalactic medium, and um which
Speaker 1: has kind of an interstilleroid. Sure, and but I can't
Speaker 1: start making up astronomy terms. I need to use the
Speaker 1: real one. Um. But there's also like in these hot pockets, right,
Speaker 1: there's some pepperoni and cheese in there that will take
Speaker 1: the roof clean off of your mouth. Um, there's hot
Speaker 1: metals which would also burn the roof of your mouth
Speaker 1: to a million degrees kelvin. Yeah, and I mean that
Speaker 1: is the difference to um from the cold um intergalactic
Speaker 1: medium about two degrees kelvin all the way to millions
Speaker 1: of degrees. Yeah, that's quite a span. And no idea
Speaker 1: why or what it's doing there, what's going to become
Speaker 1: of it or if it used to be something else.
Speaker 1: We just don't understand if it follows a pattern, and
Speaker 1: it seems to yeah for sure. Um. And thanks to
Speaker 1: Hubble too, we also have Hubble's law, which and it's
Speaker 1: so hard to believe he was doing all this in
Speaker 1: THEOD I know he was a boss. Yeah, like really really, Uh,
Speaker 1: that's that's amazing. He also wants beat up James Webb
Speaker 1: in a bar fight, which makes this whole telescope thing
Speaker 1: really ironic. But Helpal's law states this observation that he
Speaker 1: made way back when where and this is an actual
Speaker 1: graph of this relationship. But he basically was like, you
Speaker 1: know what, everything is moving away from us. Like every
Speaker 1: time I look at something through this telescope, it's everything
Speaker 1: is moving away and not only that, but the further
Speaker 1: way it is, the faster it's moving away, which is
Speaker 1: mind boggling. Yeah, because you can think, like, all right,
Speaker 1: the universe is expanding, so that's fine, everything's moving away
Speaker 1: from us. It also suggests that there's no center to
Speaker 1: the universe. This is where that comes from, because everything,
Speaker 1: no matter what direction you look in, it's moving away
Speaker 1: from us. You would think that, but doesn't that mean
Speaker 1: we're the center? Bite your tongue, um, But that's the
Speaker 1: cosmological principle that everything is expanding the entire universe, not
Speaker 1: everything in the universe is expanding within the uni the
Speaker 1: very universe itself is expanded, right, And since some things
Speaker 1: are moving away the further the further they are away,
Speaker 1: the faster they're moving away from us, that means that
Speaker 1: there's plenty of the universe that we will we can
Speaker 1: never possibly detect, because if even if we get up
Speaker 1: to the speed of light for travel, some parts of
Speaker 1: the universe, the furthest away parts are actually spreading at
Speaker 1: faster than the speed of light. So it is it
Speaker 1: was cosmically impossible for us to ever detect a large
Speaker 1: part of the universe, which is why when we're talking
Speaker 1: about the universe that we're talking about and observing. That's
Speaker 1: called the visible universe. But that's probably just a relatively
Speaker 1: small chunk of the universe itself, which might be infinite
Speaker 1: for all we know, and we may never know what
Speaker 1: the universe is really shaped, like, what it's made of,
Speaker 1: how big it is um because of this expansion that's
Speaker 1: actually speeding up and accelerating beyond our our ability to detected. Amazing,
Speaker 1: It's kind of sad in a way. Yeah, And eventually
Speaker 1: this is this is the most mind blowing thing I've
Speaker 1: ever heard. You're the expansion will accelerate so much that
Speaker 1: the moon will no longer be visible to us, like
Speaker 1: nothing will be visible to us. And on a long
Speaker 1: enough time scale, I believe you wouldn't even be able
Speaker 1: to detect your hand in front of your face if
Speaker 1: you could, if it was physically possible, because of that
Speaker 1: expansion of light. Right, So, the universe expanding is actually
Speaker 1: pulling light out of its out of the visible spectrum
Speaker 1: into a longer wavelength in what's called red shifting, because
Speaker 1: the red is the longer wavelength end of the visible spectrum.
Speaker 1: And so what Hubble did, what Hubble detected is called
Speaker 1: the red shift. Everything's moving away from us. Yeah, which
Speaker 1: we could observe because of X rays, right uh, because
Speaker 1: the infrared I think, Yeah, man, I know I love
Speaker 1: this stuff. Glad you do. I'm aroused. Oh goodness. Um So,
Speaker 1: I guess if you're aroused, we should talk about active
Speaker 1: galaxies because you know, I'm still waiting on my squeeze
Speaker 1: by the way, Oh you're peanut squeeze all right, just
Speaker 1: hang on. That's your little treat if we finished they
Speaker 1: if we um. So, if you're looking at a normal galaxy,
Speaker 1: let's say like the Milky Way, I guess all this
Speaker 1: light or most of it that you're seeing UM is
Speaker 1: pretty evenly distributed throughout that galaxy. Because it says, you know,
Speaker 1: the same those same galaxies that have the even distribution
Speaker 1: of light UM, they have looked at it through X
Speaker 1: ray and ultra violet and infrared, and it seems like
Speaker 1: they are giving off that energy from the nucleus. And
Speaker 1: that is the active galaxy okay, yeah, which is a
Speaker 1: very small percentage of the overall galaxy. Right. So the
Speaker 1: light and energy in a normal galaxy and non active galley, see,
Speaker 1: it's distributed evenly throughout, whereas in an active galaxy, all
Speaker 1: of that light and energy is coming from the center. Yeah,
Speaker 1: but they're I mean one of those like one how
Speaker 1: I was gonna say one percent. I don't know if
Speaker 1: I'm not you with the percentages, I know they're they're
Speaker 1: fairly rare from what we actually I didn't have a percentage,
Speaker 1: but it just has a very small percentage. Yeah, I
Speaker 1: think they've they've discovered like a couple of thousands so far,
Speaker 1: or less than less than half a million, less than
Speaker 1: a million, which is a very small amount. But the
Speaker 1: distinction between them and a regular galaxy is again, all
Speaker 1: of that light, all of that energy is coming from
Speaker 1: a very small portion of the galaxy rather than the
Speaker 1: galaxy as a whole putting out all this light and energy.
Speaker 1: This it's all concentrated in the middle. It's very weird.
Speaker 1: And upon closer inspection, these things that look as bright
Speaker 1: as you know, galaxies that are relatively close to us,
Speaker 1: we're finding are actually billions and billions and billions of
Speaker 1: miles light year I'm sorry, light years away from us.
Speaker 1: But they seem just as bright. Makes them super energetic.
Speaker 1: So they started to try to figure out what's going on,
Speaker 1: and they think that the culprit are super massive black
Speaker 1: holes at the center of these galaxies. Well, and that's
Speaker 1: what it's at the center of our own. I suspect
Speaker 1: there's a supermassive black hole at the center of every galaxy.
Speaker 1: That's my big prediction for for the second decade, the
Speaker 1: third decade of the century. We're going to figure that out. Okay, Um,
Speaker 1: if you're talking active galaxies, there are four classifications within
Speaker 1: that uh genre and uh they say that if it's
Speaker 1: basically it may not be structural. It might depend more
Speaker 1: on like the angle that we're viewing these things. Yeah,
Speaker 1: like they're all probably the same thing, right, But for
Speaker 1: that classification, it's the Seafort galaxies, radio galaxies, quasars and blazers. Yeah,
Speaker 1: and radio galaxy. I only ran across here. Everybody else
Speaker 1: just says it's Seafort, blazers and quasars. Yeah, radio galaxies
Speaker 1: point oh one percent of all galaxies. So I think
Speaker 1: freud Rinch has made that up. I think stock in
Speaker 1: radio galaxies or something, so he slipped it in. That's funny. Um,
Speaker 1: Carl Seafort coined the obviously in n the Seafort galaxies,
Speaker 1: and um, what's the deal with these. So let's see,
Speaker 1: the Seafort galaxy has no jets. So this is the
Speaker 1: thing about an active galaxy, and this is why they
Speaker 1: think there's a supermassive black hole at the center. They
Speaker 1: think that the accretion disc of gas and dust and
Speaker 1: everything that's just swirling circling the drain of the event
Speaker 1: horizon of the black hole. UM. As this gas and
Speaker 1: dust circles, friction develops, speed develops, and it gets so
Speaker 1: hot that some of that material doesn't get stuck in
Speaker 1: the black hole instead gets shot away above and below
Speaker 1: the black hole into jets that are so tall they're
Speaker 1: as tall as the galaxy is wide. They're just huge,
Speaker 1: huge energetic fountains of of just basically pure energy and
Speaker 1: um that's what causes this brightness that can be seen
Speaker 1: from so far away and depending on the angle of
Speaker 1: it relative to us, we've basically said it's a Seafort galaxy,
Speaker 1: which means that we're probably seeing it from the side,
Speaker 1: and so we can't see the jets because they're not
Speaker 1: pointed to us. And then there's blazars and quasars too,
Speaker 1: and in the case of the blaze, are that's looking
Speaker 1: basically straight on it that jet that you were talking
Speaker 1: about coming right at you, right at your face, looking
Speaker 1: down the barrel of a blazer. And then the quasars. Uh,
Speaker 1: we discovered those in the nineteen sixties. Um, they've discovered
Speaker 1: what like thirteen thousand, but they think there could be
Speaker 1: up to a hundred thousand. And these are billions of
Speaker 1: light years away from us, and these are the ones
Speaker 1: that are the most energetic of them all. Yeah. So
Speaker 1: if you look at a quasar something like that and
Speaker 1: the jets coming out of the quasar, what you're actually
Speaker 1: seeing is basically the most potent particle accelerator in the universe,
Speaker 1: just shooting those energetic particles into space. It's amazing. I
Speaker 1: can't imagine what it would be like to be anywhere
Speaker 1: near something like that. You die, yeah, but it's like
Speaker 1: you were just there in spirit or something, you know.
Speaker 1: Or if you could see it with a space telescope,
Speaker 1: that'd be great too. I'd settle for that for the
Speaker 1: James the James Woods space telecop What else you got? Oh,
Speaker 1: the Starburst galaxy thing at the end was kind of interesting. Yeah. This, Um,
Speaker 1: I just want to go on record is saying Starburst
Speaker 1: is one of the most beautiful words ever. You like that,
Speaker 1: I love it. Yeah, I like that too. Attached star
Speaker 1: or burst onto anything. Well, that's not true, because a
Speaker 1: fecal burst, fecal first star that sounds prettier than fecal burst,
Speaker 1: a fecal star, I sure, I guess. Yeah, it's just
Speaker 1: about everything sounds better than fecal burst. So um galaxy says,
Speaker 1: we know them have a very low rate of new
Speaker 1: star ours being formed, usually about one a year, but
Speaker 1: the star Wars galaxies produce more than a hundred a year,
Speaker 1: which is amazing. Yeah, it is compared to the rest,
Speaker 1: hundred times more amazing than a regular galaxy. That's true.
Speaker 1: They also think that they burn themselves out rather quickly,
Speaker 1: and that those might actually be the globular clusters that
Speaker 1: end up just kind of hanging around a real galaxy. Well,
Speaker 1: they say, the stars that burn the brightest. Yeah, like
Speaker 1: Jimi Hendrix. Yeah, the Seven Club, all globular clusters, starburst.
Speaker 1: That's it. That's it. If you want them more about galaxies, friends,
Speaker 1: there is a whole universe out there for you to
Speaker 1: go check out, and you can start on the internet,
Speaker 1: So go check it out there. Uh. And since I
Speaker 1: said something weird like that, it's time for listener mail.
Speaker 1: So in lieu of listener mail, okay, we uh, we
Speaker 1: got a lot of feedback on our stalker episode, which
Speaker 1: kudos to you, that's your idea, and they ended up
Speaker 1: being a really good episode, I think. Um, but we
Speaker 1: got a lot of emails from um, both men and
Speaker 1: women who had been victims of stalking. Some people who
Speaker 1: didn't even know they've been stocked until they listen to
Speaker 1: the episode you're like, oh, okay, I was stalked. Yeah,
Speaker 1: and some really just heartbreaking, scary, scary, in depth, long
Speaker 1: stories and we heard people who had to move and
Speaker 1: we're still in the midst of it. It's just awful.
Speaker 1: It's tough stuff. So we're not gonna read any of
Speaker 1: those because they are very personal stories and um, they're
Speaker 1: all anonymous, yeah, most most of them were. UM, but
Speaker 1: we just want to say thanks to everyone for being
Speaker 1: brave enough to share your story with us and just
Speaker 1: direct people to get help if you're being stalked. Uh.
Speaker 1: It is serious stuff and I hope that podcast really
Speaker 1: got that across. Yeah, And that was one thing almost
Speaker 1: universally that we heard was that like, thank you for
Speaker 1: saying like go find local help because it's out there,
Speaker 1: and that's a huge first step. Yeah, and a lot
Speaker 1: of these people, like just like we had talked about,
Speaker 1: kind of went through the batim steps of people at
Speaker 1: work thought I was just overreacting, and even my family
Speaker 1: thought I was blowing it out of proportion. Why didn't
Speaker 1: you press charges the first time? Do you wait for?
Speaker 1: You know that? Yeah, blaming the victim, basically all that stuff. So, uh,
Speaker 1: you can reach out to the Stalking Resource Center, the
Speaker 1: National Center for Victims of Crime. It's a good place
Speaker 1: to start. Um. There are plenty of it. Depending on
Speaker 1: what country you're from. There are different organizations to see
Speaker 1: one from the UK where you can report a stalker
Speaker 1: um and in fact, one of our listeners from the
Speaker 1: UK had a really hard time over there being taken seriously. Uh.
Speaker 1: And then there's also rain are AI n N who
Speaker 1: is in their twenty fi year and they have some
Speaker 1: good resources for you as well, So just check it
Speaker 1: out online. Nice work, Chuck, Nice work, Josh. All right, Well,
Speaker 1: thank you everybody who wrote in, And if you want
Speaker 1: to write in for a new reason, you can go
Speaker 1: to our website at stuff you Should Know dot com
Speaker 1: and check out the social links. I have a website
Speaker 1: to d Josh Clarkway dot com and you can send
Speaker 1: us all an email me, Chuck, Jerry, Everybody to Stuff
Speaker 1: podcast at how stuff works dot com. For more on
Speaker 1: this and thousands of other topics, visit how stuff works
Speaker 1: dot com. M