Latest / Daniel and Kelly’s Extraordinary Universe / New discoveries in our cosmic neighborhood

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New discoveries in our cosmic neighborhood · Daniel and Kelly’s Extraordinary Universe

0:08
Speaker 1: Hey, or hey, do you know what our cosmic addresses? Yeah,
0:12
Speaker 1: it's a one universe lane, isn't it. Well, that's where
0:15
Speaker 1: you can send us all your gifts of presence and bananas.
0:18
Speaker 1: I mean, that's how the aliens know where to find,
0:20
Speaker 1: is right, that's true. But I actually don't need a
0:22
Speaker 1: lot of bananas delivered in the mail, So let's not
0:25
Speaker 1: encourage people to send us any fresh fruit. No, no,
0:28
Speaker 1: I think you know what you mean, Like our address
0:29
Speaker 1: like in the universe, Like if we're here on Earth
0:32
Speaker 1: around our star about halfway down the Milky Way. Yeah,
0:35
Speaker 1: that's enough to get your mail delivered to your house.
0:38
Speaker 1: But like, what about the rest of our cosmic context?
0:42
Speaker 1: I mean, like what's the equivalent of our city or
0:44
Speaker 1: zip code? Yeah, And it turns out that we're part
0:46
Speaker 1: of a cluster called the Local Group sounds local, and
0:50
Speaker 1: then zooming out a little bit where the suburbs of
0:53
Speaker 1: an even bigger cluster called Virga, and then part of
0:56
Speaker 1: a super cluster of a hundred thousand galaxies called Lena Kia.
1:01
Speaker 1: And then you know, that's actually about as far as
1:03
Speaker 1: we've mapped. Wait, we don't know where we live exactly
1:06
Speaker 1: in the universe. We don't know, So if you want
1:08
Speaker 1: to order alien bananas, you just gotta put a question mark.
1:12
Speaker 1: Gonna throw up a flare. I am more handy cartoonists
1:29
Speaker 1: and the creator of PhD comics. Hi, I'm Daniel. I'm
1:33
Speaker 1: a particle physicist, and I don't like Earth bananas, but
1:36
Speaker 1: I'd be willing to try alien bananas. Really, how do
1:40
Speaker 1: you know they're not going to be worse? You don't know.
1:43
Speaker 1: But that's the joy of exploration. I want to land
1:46
Speaker 1: on a new planet, to see the new kinds of life,
1:48
Speaker 1: the new kinds of animals and critters, and taste any
1:50
Speaker 1: new potentially delicious fruits. Well, you're welcome to be humanity's taste.
1:55
Speaker 1: I guess to make sure it's all right, somebody's gotta
1:59
Speaker 1: do it. I'll probably come down with the alien banana flu.
2:02
Speaker 1: But welcome to our podcast Daniel and Jorge Explain the Universe,
2:05
Speaker 1: a production of My Heart Radio in which we don't
2:08
Speaker 1: take any actual trips out into the universe, but a
2:11
Speaker 1: mental journey through all the amazing questions and discoveries, all
2:15
Speaker 1: the things science has figured out and the things that
2:18
Speaker 1: science is still working on. We think that curiosity belongs
2:21
Speaker 1: to everybody, and that you are questions are as fascinating
2:24
Speaker 1: and as important as those that scientists are working on
2:28
Speaker 1: right now. Yeah, because it is a huge universe out there,
2:31
Speaker 1: with a lot of places to explore and a lot
2:34
Speaker 1: of things to discover, and a big question is how
2:36
Speaker 1: do we fit into all of this? What is our
2:40
Speaker 1: place in the universe? And how do we fit into
2:43
Speaker 1: this giant cosmic ballet of stars and galaxies and dust.
2:48
Speaker 1: And it's sort of an extension of exploration that humans
2:51
Speaker 1: have been doing basically forever, since we wondered what was
2:55
Speaker 1: over that hill, what's past that mountain, what's over that ocean?
2:59
Speaker 1: And modern day explorers might wonder like, well, is there
3:02
Speaker 1: anything left for me to look for? Thanks to Google
3:06
Speaker 1: Earth and satellite technology, we basically know where all the
3:09
Speaker 1: mountains are and all the little islands you can name
3:11
Speaker 1: after your chihuahua. But it turns out there's a lot
3:15
Speaker 1: of exploration left to do. Yeah, is there an equivalent
3:17
Speaker 1: of Google Universe? Google? Get on it now. Yet it's
3:20
Speaker 1: mostly a big question mark. But you can look at
3:24
Speaker 1: maps of our cosmic neighborhood to see what's around us,
3:28
Speaker 1: what's nearby? If you just google large scale structures of
3:31
Speaker 1: the universe. Wow, does it tell you how much each
3:33
Speaker 1: galaxy is worth? Can you figure out the perse square
3:37
Speaker 1: light here value? You know, even just our solar system
3:40
Speaker 1: is worth like a gazillion dollars because of all the
3:42
Speaker 1: platinum and gold and stuff that you can find in aster.
3:46
Speaker 1: So it's basically just infinite. Well, we are still learning
3:49
Speaker 1: about the basics of where we are in the universe
3:52
Speaker 1: and what's kind of around is and so a big
3:55
Speaker 1: question is, you know, what can we find? What interesting
3:58
Speaker 1: things are there in our very own neighborhood here in
4:01
Speaker 1: the universe, And it's not something that we can easily
4:04
Speaker 1: explore in person. In the old days of exploration, you
4:08
Speaker 1: would hop in a ship and you would land on
4:10
Speaker 1: foreign shores and you would wonder who else was living
4:13
Speaker 1: there and what kind of fruits did they enjoy. But
4:15
Speaker 1: these days it's not so easy. The distances are vast,
4:18
Speaker 1: the technology is still so primitive. But we have other
4:21
Speaker 1: ways of exploring the universe. You mean, we don't have
4:24
Speaker 1: those warp drives and teleportation devices yet. Well, you know,
4:27
Speaker 1: I sent them to the Daniel and Jorge Engineering department.
4:29
Speaker 1: So I'm just waiting for the prototype to come back
4:34
Speaker 1: last engineer in our team here. But yeah, you're right,
4:37
Speaker 1: it is kind of interesting that we have to explore
4:40
Speaker 1: the universe from here. From Earth using telescopes, we can
4:43
Speaker 1: actually like go out that far because some of the
4:45
Speaker 1: things that we can see are hundreds or millions of
4:49
Speaker 1: light years away, like the pretty much we might never
4:52
Speaker 1: see them in person. That's right, most of these things
4:54
Speaker 1: we will never see in person. And most of these
4:57
Speaker 1: things that we're looking at, they don't exist right now
5:00
Speaker 1: on the way that we are seeing them, right, we
5:02
Speaker 1: are seeing old light that comes to us from them.
5:05
Speaker 1: So what's actually happening now out there is not what
5:09
Speaker 1: we are seeing. Yeah, So astronomers are out there looking
5:12
Speaker 1: and exploring and checking out what's around us, and recently
5:15
Speaker 1: there's been an incredible discovery. Just this past summer, astronomers
5:20
Speaker 1: discovered a whole new thing pretty close to our corner
5:25
Speaker 1: of the universe here, and it's huge. It's basically the
5:28
Speaker 1: biggest thing anybody has ever found, and it's shockingly large
5:33
Speaker 1: and shockingly close. It's basically a literal mind exploder. So
5:37
Speaker 1: today on the podcast, we'll be asking the question what
5:44
Speaker 1: is the South Pole Wall and why did they give
5:48
Speaker 1: it such a ridiculous name south? But yeah, it's a
5:51
Speaker 1: little confusing because is it a pole or is it
5:53
Speaker 1: a wall? Is it a wall of poles? Is it
5:58
Speaker 1: a wall around the South Pole? I guess it's south,
6:00
Speaker 1: but south relative to who, Well, you have a very
6:03
Speaker 1: northern bias, right, You tend to view the earth is up,
6:06
Speaker 1: north is up, and so you know, maybe that gives
6:09
Speaker 1: you a clue. I was born in the equator, so, Daniel,
6:11
Speaker 1: I'm pretty agnasting. I think maybe this time you can
6:14
Speaker 1: rag on after physicists and how they name things, and
6:17
Speaker 1: as particle physicists can get a break for a weekend
6:20
Speaker 1: for once. Yeah, and also, who's paying for this wallt Daniel?
6:25
Speaker 1: The Aliens are definitely paying for the wall, yeah, with
6:29
Speaker 1: the tariffs. But yeah, so they discovered something huge and enormous.
6:33
Speaker 1: I mean, it's like you said, it's the biggest thing
6:35
Speaker 1: pretty much ever discovered. Is that true. Yeah, it's in
6:38
Speaker 1: the top five biggest things we know about in the universe,
6:42
Speaker 1: and of the top five, it's the closest one. So
6:46
Speaker 1: it's really kind of amazing that we haven't seen this before,
6:49
Speaker 1: that we didn't even know about it before. It really
6:51
Speaker 1: it makes me feel like, you know, cartographers in the
6:55
Speaker 1: fifteen hundreds drawing maps to the Earth and like leaving
6:58
Speaker 1: out America. You know, like how could to be so
7:00
Speaker 1: ignorant of like an enormous continent that's honestly not that
7:04
Speaker 1: far away. It'd be like discovering a whole wall of
7:07
Speaker 1: poles in your backyard and you're like, where did that
7:09
Speaker 1: come from? That's right, I didn't order this online. Yeah,
7:14
Speaker 1: so it's a new discovery. It's huge, it's very close.
7:18
Speaker 1: But we're wondering how many people out there know about
7:21
Speaker 1: this south Pole Wall and whether it was discovered recently. So,
7:25
Speaker 1: as usual, Daniel went out there and ask people on
7:28
Speaker 1: the internet if they knew what is the south Pole Wall?
7:31
Speaker 1: So thanks to everybody who volunteered to share their baseless
7:35
Speaker 1: and uninformed speculation with us for our podcast. And if
7:39
Speaker 1: you would like to be a victim War Future podcast
7:41
Speaker 1: to share your unprepared thoughts on difficult questions in physics,
7:46
Speaker 1: please write to us two questions at Daniel and Jorge
7:49
Speaker 1: dot com. Think about it for a second. Do you
7:51
Speaker 1: know what the south Pole Wall is? Here's what people
7:54
Speaker 1: had to say. Does that have something to do with
7:56
Speaker 1: flat earther theory, it's all a man made will but
8:00
Speaker 1: around South Pole to stop animals or in shooters from
8:04
Speaker 1: coming in as a way to preserve this out pole.
8:06
Speaker 1: Maybe it's some sort of electromagnetic barrier, not just an
8:11
Speaker 1: obvious structure, something to do with like a magnetic like
8:17
Speaker 1: the Earth's magnetic field, some sort of barrier for particles
8:22
Speaker 1: in the sun from the sun. Maybe it's related somehow
8:25
Speaker 1: to the like Aurora borealis and southern lights. The South
8:31
Speaker 1: Pole Wall is a ice fault formation that is incredibly
8:40
Speaker 1: difficult to traverse on foot or sled or with dogs.
8:46
Speaker 1: I have no idea. I am guessing that it is
8:50
Speaker 1: a wall, either physical or metaphorical, located in the South Pole.
8:56
Speaker 1: The first thing that comes into mind is a big
8:58
Speaker 1: rule of ice in the South Pole, like the one
9:00
Speaker 1: phone Game of Thrones. I'm not sure, but I believe
9:03
Speaker 1: there are some I don't know if they're called caverns
9:06
Speaker 1: or cliffs or something like that, but I believe there's
9:09
Speaker 1: some impediment in our way to get to the uh,
9:12
Speaker 1: to travel freely to the South Pole where the ice
9:15
Speaker 1: is all right. It sounds like nobody knew well. I
9:19
Speaker 1: think this is a real commentary on the name of
9:22
Speaker 1: this thing, right, because everybody keyed in on south Pole
9:25
Speaker 1: and wall, right, And I like how somebody said it
9:29
Speaker 1: was like Game of Thrones, although that wall wasn't the North.
9:32
Speaker 1: That's right, Maybe it's the equivalent. Maybe it's for like
9:35
Speaker 1: the penguin zombie. Well, we physicists, we do like having
9:38
Speaker 1: symmetry in the universe. So if there's going to be
9:40
Speaker 1: a wall in the north, there should be a wall
9:42
Speaker 1: in the south, because otherwise you gotta ask why what's
9:44
Speaker 1: special about North? Right? Yeah, winter is coming? Is there
9:49
Speaker 1: another version of our universe out there in the multiverse
9:52
Speaker 1: in which summer is coming? Well, technically, if it's a
9:55
Speaker 1: south Pole wall, it would come in our summer, which
9:58
Speaker 1: is winter for them. The beauty and power of symmetry
10:01
Speaker 1: once again displayed. But I guess maybe the takeaway here
10:04
Speaker 1: is that not a lot of people had heard of it,
10:06
Speaker 1: which means it didn't make the news that much. Maybe
10:10
Speaker 1: that's right. Most of our listeners are pretty up on
10:12
Speaker 1: the cosmic news here. Yeah, I think it just didn't
10:14
Speaker 1: fall into people's brains. It's an incredible discovery. It's something
10:18
Speaker 1: that's fascinating and something it tells us about where we
10:21
Speaker 1: live in the universe, but it doesn't really actually change
10:24
Speaker 1: your day to day life. So maybe people just heard
10:27
Speaker 1: about it and filed it away. But honestly, I think
10:30
Speaker 1: we should pin most of the blame on the name
10:31
Speaker 1: of this thing. Wow, I can't disagree with you more,
10:36
Speaker 1: Daniel about the naming of things. Finally we're agreeing about
10:40
Speaker 1: how the name. All right, let's let's not keep people
10:43
Speaker 1: in suspense here. So what is the South Pole Wall, Daniel?
10:47
Speaker 1: And when was it discovered? So? The South Pole Wall
10:49
Speaker 1: is an incredibly huge and immensely vast, gargantuan wall of galaxies.
10:56
Speaker 1: I remember that galaxies are not just sprinkled everywhere through space.
11:01
Speaker 1: Our Earth goes around our Sun, which is the core
11:03
Speaker 1: of our solar system, which is one of many solar
11:06
Speaker 1: systems in our galaxy. But those galaxies are not just
11:09
Speaker 1: everywhere in space, sprinkled randomly. They tend to clump together
11:13
Speaker 1: into clusters of galaxies, and those clusters of galaxies form
11:18
Speaker 1: structures we call superclusters. And then those superclusters are not
11:22
Speaker 1: just sprinkled everywhere. They tend to form these enormous structures,
11:26
Speaker 1: these walls, these filaments, these sheets that surround incredible voids
11:31
Speaker 1: in which there are no stars, no galaxies, no planets,
11:34
Speaker 1: no people, no podcasts. Yeah, it's weird to think of
11:37
Speaker 1: space being not random, you know what I mean, Like
11:41
Speaker 1: we're just still looking at the nights guy and seeing
11:44
Speaker 1: stars kind of sprinkled kind of randomly and evenly. But
11:47
Speaker 1: actually the universe has a lot of structure, like, it
11:51
Speaker 1: has a lot of things in it, Like everything's kind
11:54
Speaker 1: of organized in the way. That's right, Things are organized,
11:56
Speaker 1: and it's gravity that's doing the organizing. Gravity is very
12:00
Speaker 1: gently but very gradually pulling things together and clumping them.
12:04
Speaker 1: And it's kind of incredible that gravity is the thing
12:07
Speaker 1: doing this job. Because of all the forces we are
12:09
Speaker 1: aware of, the strong force, the weak force, electromagnetism, gravity,
12:14
Speaker 1: Gravity is the weakest, and not by a little bit,
12:17
Speaker 1: but like by tens of orders of magnitude. But it's
12:22
Speaker 1: also the only one that can't be like balanced out.
12:25
Speaker 1: Electromagnetism can be neutralized with positive and negative forces, but
12:29
Speaker 1: gravity always pulls. It can't push, so eventually everything else
12:33
Speaker 1: gets balanced out. Is just gravity left over to sweep
12:36
Speaker 1: stuff together into stars and planets and galaxies and superclusters.
12:41
Speaker 1: And then these incredibly immense voids and walls and filaments.
12:45
Speaker 1: And that's essentially where the exploration is today, is figuring
12:48
Speaker 1: out like where is our cluster and our supercluster in
12:52
Speaker 1: this larger structure, what's around us? Right? Yeah, And what's
12:56
Speaker 1: kind of cool too is that these giants, you know,
12:59
Speaker 1: super ginormous structures, they're all kind of evidence of the
13:03
Speaker 1: quantum fluctuations right at the very beginning of the universe. Right,
13:08
Speaker 1: there's sort of like the wrinkles or the fingerprints of
13:11
Speaker 1: quantum randomness and structure that was in the early universe.
13:15
Speaker 1: That's exactly right. Gravity has essentially just exaggerated initial little
13:20
Speaker 1: over densities. If you had only gravity in the universe
13:24
Speaker 1: was totally smooth, you wouldn't get any sort of structure
13:27
Speaker 1: at all, because gravity would pull equally on everything in
13:30
Speaker 1: all directions, and you wouldn't get any clumping. You need
13:33
Speaker 1: some sort of initial clumping to get things started and
13:37
Speaker 1: form this runaway effect where gravity makes things heavier and
13:40
Speaker 1: then pulls harder, and then makes things heavier which pulls harder.
13:44
Speaker 1: And you're right in the very beginning what this comes from,
13:46
Speaker 1: our little tiny quantum fluctuations in the very first moments
13:50
Speaker 1: of the universe, and basically everything's been derivative from that.
13:54
Speaker 1: It's like we had one idea very early on sketch
13:57
Speaker 1: the doodle, and everything else is just derived from that.
14:00
Speaker 1: And it's amazing. Do you think that you can go
14:01
Speaker 1: from like a quantum fluctuation is something that huge sort
14:07
Speaker 1: of like you know, like a little baby scar that
14:09
Speaker 1: you had as a baby, you still have it as
14:11
Speaker 1: an adult. And let's give people a sense for like
14:13
Speaker 1: how big we're talking about. These structures are like billions
14:17
Speaker 1: of light years wide. These are not little things. There's
14:20
Speaker 1: not like one galaxy, two galaxies. Remember each galaxy already
14:24
Speaker 1: is an incredibly enormous thing. But we're talking about bubbles
14:28
Speaker 1: and sheets that are billions of light years on a side,
14:31
Speaker 1: and that all comes from tiny quantum fluctuations expanded rapidly
14:36
Speaker 1: during inflation. Yeah, because you know, I guess like one
14:40
Speaker 1: galzi is a hundred thousand light years, and so if
14:42
Speaker 1: you put like thousands of them together, then it's literally
14:45
Speaker 1: billions of light years. It's billions of light years, meaning
14:48
Speaker 1: if you're going at the speed of light, it still
14:50
Speaker 1: takes you a billion years to go from one side
14:52
Speaker 1: to the other. And so you can imagine the whole
14:55
Speaker 1: universe is sort of like a big pile of bubbles,
14:58
Speaker 1: like a big quantum foam that was inflated from the
15:01
Speaker 1: early universe to this incredibly vast quantum foam. And we've
15:05
Speaker 1: recently discovered that we're essentially living on the edge of
15:09
Speaker 1: one of those bubbles. And we're now looking around us.
15:12
Speaker 1: We're like, oh, look, there's a bubble over there. There's
15:14
Speaker 1: a bubble over there. But we're really just beginning to
15:17
Speaker 1: map the universe to understand what is our cosmic neighborhood.
15:21
Speaker 1: We're seeing edges of bubbles here and bubbles merging over there,
15:25
Speaker 1: and so it's like it's early days, you know, we
15:27
Speaker 1: have only just begun to explore. Yeah, and so tell
15:30
Speaker 1: me about this wall that we just found. This wall,
15:33
Speaker 1: the South Pole wall. You said it's a ginormous. When
15:35
Speaker 1: you say ginormous, is that the technical term or is
15:38
Speaker 1: there a number associated? The technical term actually is huge jungis.
15:43
Speaker 1: But this one is a billion and a half light
15:47
Speaker 1: years wide. Right, So you shoot a photon, you press
15:51
Speaker 1: the button on your laser on one side of the thing.
15:53
Speaker 1: You wait a billion and a half years before across
15:57
Speaker 1: it to the other side. And that's only the part
16:00
Speaker 1: of it that we've seen so far. It could go
16:02
Speaker 1: on more. Yeah, astronomers are not even sure that we've
16:04
Speaker 1: seen all of it. So it's a structure of galaxies basically. Right,
16:09
Speaker 1: it's not like a row of stars. It's like a
16:12
Speaker 1: row of galaxies and they're all sort of like sprinkled
16:15
Speaker 1: in a wall or or what's going on. That's right,
16:17
Speaker 1: it's actually a row of clusters of galaxies. Clusters of
16:22
Speaker 1: galaxies are grouped together. They're gravitationally bound. There there's enough
16:26
Speaker 1: gravity between galaxies to sort of hold them together into objects.
16:30
Speaker 1: That's why we call them a cluster. We don't just
16:32
Speaker 1: like artificially draw a line and say this is a cluster,
16:35
Speaker 1: that's a cluster. We look for things that are holding
16:38
Speaker 1: themselves together gravitationally. So this is a wall of clusters
16:41
Speaker 1: of galaxies, and we call it a wall because it's
16:43
Speaker 1: much wider and longer than it is thick, sort of
16:47
Speaker 1: like our galaxy. Right, our galaxy is flat, it's like
16:50
Speaker 1: a hundred thousand light years across and a thousand light
16:54
Speaker 1: years thick, and these things have sort of similar dimensions.
16:56
Speaker 1: There are much much wider and longer than they are thick.
17:00
Speaker 1: So we called them a wall. Now do you call
17:02
Speaker 1: them Do you group them together because they're close to
17:05
Speaker 1: each other, or because they're actually kind of gravitationally affecting
17:09
Speaker 1: each other, or bound together they are gravitationally holding themselves together.
17:13
Speaker 1: Remember that the whole universe is expanding. Everything is moving
17:16
Speaker 1: away from everything else. That's because space between objects is
17:20
Speaker 1: getting bigger. We don't understand it. It's this thing called
17:23
Speaker 1: dark energy that's just inflating all of space and increasing
17:26
Speaker 1: the distances between everything. But if stuff is near enough
17:30
Speaker 1: to each other and has enough mass, it can resist that.
17:33
Speaker 1: It can be gravitationally bound. Like our solar system. Dark
17:37
Speaker 1: energy is increasing the space between the Earth and the Sun,
17:41
Speaker 1: but gravity of the Sun holds the Earth in place
17:44
Speaker 1: so that distance doesn't change. So our solar system is
17:47
Speaker 1: gravitationally bound. Our galaxy is gravitationally bound. It's small enough
17:51
Speaker 1: and compact enough that on that scale, gravity wins. And
17:54
Speaker 1: that's true also on the scale of clusters, and it's
17:57
Speaker 1: sort of true on the scale of super clusters. Clusters
18:01
Speaker 1: of clusters, people argue about whether they're actually gravitationally bound.
18:05
Speaker 1: Are they going to hold together in the long term
18:08
Speaker 1: future of the universe, or is dark energy gonna win
18:11
Speaker 1: and tear on them apartment. That's sort of on the edge, right,
18:14
Speaker 1: because I guess if expansion is fascin enough or big enough,
18:17
Speaker 1: it would even rip our solar system. But I guess
18:19
Speaker 1: we're we're lucky that it's not. That's right, We're lucky
18:21
Speaker 1: that it's not. But we're living in a fascinating moment
18:24
Speaker 1: in the universe where gravity has had time to build
18:27
Speaker 1: galaxies and clusters, and now superclusters have sort of formed
18:31
Speaker 1: and maybe gravitationally bound, but it's not clear if gravity
18:35
Speaker 1: will have time to build those together and really hold
18:38
Speaker 1: them together and then build super duper clusters, or whether
18:41
Speaker 1: dark energy will tear them apart. So we're living at
18:44
Speaker 1: this fascinating moment in the history of the universe. That's
18:47
Speaker 1: why there is a maximum size to an object in
18:50
Speaker 1: the universe, because any bigger than that, gravity hasn't had
18:53
Speaker 1: time to sort of pull it together. And so we're
18:56
Speaker 1: really looking at the biggest things in the universe. It's
18:59
Speaker 1: sort of incredible, right. So we found this giant wall,
19:01
Speaker 1: and so a big question I have is how did
19:03
Speaker 1: we find it and why didn't we see this earlier?
19:07
Speaker 1: If it's so big? So let's get into that. But
19:09
Speaker 1: first let's take a quick break. All right, Daniel, we're
19:24
Speaker 1: talking about the South Pole Wall, which is I guess,
19:29
Speaker 1: is that where the anti Santa Claus lives? Is that
19:33
Speaker 1: defense that it put around into health village? That's right,
19:38
Speaker 1: it's his first line of defense against folks coming to
19:41
Speaker 1: trying to steal their Christmas presents earlier. He's not as
19:44
Speaker 1: or she's not as jolly as the North Pole Santa Claus. No,
19:46
Speaker 1: there's South Pole boiling oil, and there's archery, and it's
19:50
Speaker 1: all sorts of stuff. Just just leave them alone. But anyways,
19:54
Speaker 1: they found this summer a giant wall of galaxies called
19:58
Speaker 1: the South Pole Wall, and it's huge. It's one and
20:00
Speaker 1: have billion light years wide. And Daniel, this seems like
20:04
Speaker 1: a big thing that we should have seen earlier, but
20:06
Speaker 1: we didn't. So I guess what's the history of finding this?
20:09
Speaker 1: How do we find it? And why didn't we see
20:11
Speaker 1: it before? We didn't see it before because it's not
20:14
Speaker 1: easy to spot. We can't actually see it very well
20:17
Speaker 1: because there's something in the way and that's the rest
20:20
Speaker 1: of our galaxy. If you look out into the sky,
20:24
Speaker 1: mostly you're seeing stars, and those stars are other stars
20:28
Speaker 1: in our galaxy. But remember the galaxy is much wider
20:31
Speaker 1: than it is thick, So in most directions you're looking
20:35
Speaker 1: out through a little bit of our galaxy and then
20:37
Speaker 1: out into deep space where you can see other galaxies
20:40
Speaker 1: and stuff. But if you look in just the right direction,
20:42
Speaker 1: then you're looking through the galaxy. And on a really
20:45
Speaker 1: dark night you can see this. You can see the
20:47
Speaker 1: Milky Way, which is the plane of the rest of
20:50
Speaker 1: the galaxy, and it looks much brighter and sort of
20:52
Speaker 1: more smeared out than individual stars because it's a huge
20:56
Speaker 1: number of stars that are further away there on the
20:59
Speaker 1: other side of the Milky Way, and so they sort
21:01
Speaker 1: of add up to this milky spread. And it's hard
21:04
Speaker 1: to see things on the other side of this plane
21:07
Speaker 1: of the Milky Way because there are so many stars
21:10
Speaker 1: and gas and dust in our way. Yeah, we're in
21:13
Speaker 1: the way of our view, kind of kind of like
21:14
Speaker 1: the back of your head. Yeah, the rest of the galaxy.
21:17
Speaker 1: And so they called it the South Pole Wall because
21:20
Speaker 1: if you're standing on Earth, it's sort of in the
21:23
Speaker 1: direction that the South Pole points. That is, the south
21:26
Speaker 1: pole of Earth sort of points towards the center of
21:29
Speaker 1: the galaxy. Not exactly, but you know, close enough, close
21:33
Speaker 1: enough for astronomical naming committees apparently. Yeah. Yeah, it is
21:38
Speaker 1: pretty amazing to think that we can see the Milky Way, right.
21:41
Speaker 1: I mean, it looks like a fuzzy cloud, but it
21:43
Speaker 1: really it's like millions of stars kind of all kind
21:46
Speaker 1: of joining their light together and causing this glow. Yeah,
21:49
Speaker 1: it's billions of stars. Right. The Milky Way has more
21:52
Speaker 1: than a hundred billion stars in it, and the center
21:55
Speaker 1: of the Milky Ways, where most of them are. There's
21:57
Speaker 1: also a lot of gas and dust, so it's just
21:59
Speaker 1: very difficult to see through the center of the Milky Way.
22:02
Speaker 1: Astronomers called this whole region of the sky the Zone
22:06
Speaker 1: of Avoidance. It sounds like something from a video game,
22:09
Speaker 1: but it basically means look somewhere else because this part
22:12
Speaker 1: is hard. Don't look here, you're not gonna be able
22:15
Speaker 1: to see much. Yeah, and so we can't actually see
22:17
Speaker 1: most of the South Pole wall in the visible light.
22:20
Speaker 1: We can't just like look at and say, oh, there's
22:22
Speaker 1: a galaxy. There's a galaxy. There's a galaxy, otherwise we
22:26
Speaker 1: would have spotted it earlier. You know. It was like
22:28
Speaker 1: in the nineteen eighties people started to understand that we
22:31
Speaker 1: could make a huge three D map of our universe
22:35
Speaker 1: and that it had interesting things to look at, and
22:37
Speaker 1: that's when we discovered the first of these voids and walls,
22:41
Speaker 1: and so now it's you know, forty years later, we're
22:43
Speaker 1: finally figuring out one of the biggest structures was hiding
22:46
Speaker 1: right behind the bulge of the Milky Way. It is
22:49
Speaker 1: sort of fascinating that, you know, from our little point
22:53
Speaker 1: on Earth, just sitting in the spherical ball and looking
22:56
Speaker 1: out at the stars, we can get a three D
22:59
Speaker 1: D view of things, right, because when you look at
23:02
Speaker 1: the night sky it looks kind of like two D,
23:04
Speaker 1: like all the stars are painted on the ceiling. But
23:06
Speaker 1: somehow we're able to get a three D view of
23:09
Speaker 1: what's going on out there, to the point where you know,
23:12
Speaker 1: we can make out these super cluster structures. Yeah, it's incredible,
23:16
Speaker 1: because of course you're right, we do see it two
23:18
Speaker 1: D image, right, We can't resolve distance. We don't know
23:21
Speaker 1: necessarily how far a star is, and this ambiguity there
23:25
Speaker 1: when you look at one individual star, you don't know
23:28
Speaker 1: is it's super bright but very far away, or not
23:31
Speaker 1: that bright and kind of close up. So for a
23:34
Speaker 1: long time, that was a big puzzle in astronomy, is
23:37
Speaker 1: how to measure the distance two stars. We had a
23:40
Speaker 1: whole fun podcast episode just on that topic, and it
23:43
Speaker 1: turns out that it depends on how far away it is.
23:46
Speaker 1: If it's really close by, you can use the equivalent
23:49
Speaker 1: of sort of like opening one eye and closing the
23:52
Speaker 1: other one and seeing how the image changes to see
23:55
Speaker 1: how far away it is. As the Earth goes around
23:57
Speaker 1: the Sun, you get two images of the star, and
24:00
Speaker 1: if it's further away, you have to rely on these
24:02
Speaker 1: super clever little stars, these variable stars, whose brightness is
24:07
Speaker 1: connected to how fast they pulse. And then if they're
24:10
Speaker 1: really far away, then you have to use type one
24:12
Speaker 1: a supernova, which is sort of a standard candle. We
24:15
Speaker 1: know how bright they are because the physics constrains them
24:17
Speaker 1: to only be a certain brightness, and so we can
24:20
Speaker 1: tell how far away they are. So we have this
24:22
Speaker 1: sort of cosmic distance ladder, but that only works for
24:25
Speaker 1: things we can see. Yeah, so the Milky Way is
24:28
Speaker 1: kind of standing in the way of a huge part
24:31
Speaker 1: of our field of view. It's blocking it, but somehow
24:34
Speaker 1: we were able to see through it is to find
24:36
Speaker 1: this South Pole wall. So how do we look through
24:39
Speaker 1: the Milky Way? Well, again, the answer is gravity. Gravity
24:43
Speaker 1: is like the most important thing astronomically. It basically controls
24:46
Speaker 1: the whole universe. And in this case, what we did
24:49
Speaker 1: is we measured how fast some galaxies were moving and
24:52
Speaker 1: in what direction to make a sort of cosmic map
24:56
Speaker 1: of the flow of galaxies, and then we use that
24:59
Speaker 1: to figure out, like, well, where is there stuff? Because
25:03
Speaker 1: gravity affects how things move. So we started from understanding
25:07
Speaker 1: how galaxies are flowing, and then we look for sort
25:10
Speaker 1: of like blobs, like discontinuities, like oh, everything is clustering
25:14
Speaker 1: over here, there must be something there, or these guys
25:17
Speaker 1: are flowing fast, and then we expected so they must
25:19
Speaker 1: be pulled on by something. From the velocity of galaxies,
25:23
Speaker 1: you can infer where the mass is. But wait, our
25:27
Speaker 1: galaxies moving that fast, and we as humans and in
25:31
Speaker 1: such a short period of time, can tell they're moving
25:34
Speaker 1: because like, if I look at the stars, they don't
25:36
Speaker 1: look like they're moving. That's right. We are not watching
25:39
Speaker 1: galaxies move and like clocking them. It's not like Usain Bolt,
25:42
Speaker 1: where we measure a distance and measure of time and
25:45
Speaker 1: then use that to measure the velocity. Instead, we're looking
25:48
Speaker 1: at the light from those stars and we're seeing how
25:50
Speaker 1: the light from the stars is shifted in frequency because
25:54
Speaker 1: like the Doppler effect, if something is moving away from you,
25:57
Speaker 1: then light from it will get shifted to longer wavelengths
26:00
Speaker 1: so gets stretched out. And something is moving towards you,
26:04
Speaker 1: light from it will get shifted to shorter wavelengths to
26:06
Speaker 1: get blue shifted. And so we can measure the light
26:09
Speaker 1: from these stars and we can see hasn't been shifted
26:12
Speaker 1: away from what we expect because we we know what
26:15
Speaker 1: the light from these stars, from these galaxies should look like.
26:17
Speaker 1: Because stars around the universe are all the same, they
26:20
Speaker 1: admit from hydrogen and from sodium in various lines. We
26:23
Speaker 1: can see those lines get shifted, so we can measure
26:26
Speaker 1: the velocity of all of these galaxies. So we have
26:28
Speaker 1: this huge catalog of thousands of thousands of galaxies and
26:32
Speaker 1: we know in which direction they're moving. But wait, I
26:35
Speaker 1: thought the shifting of light only works if it's moving
26:38
Speaker 1: away or towards you. How do you tell if it's
26:40
Speaker 1: moving to the right or to the left, or up
26:42
Speaker 1: or down. That's true. The red shift and blue shift
26:45
Speaker 1: measures the velocity along a line from us to them,
26:48
Speaker 1: and sort of the radial velocity, and so you have
26:51
Speaker 1: to use other tricks to try to sort of guess
26:54
Speaker 1: and construct from the motion of all the galaxies nearby
26:58
Speaker 1: what these sort of three D map is. But you're right,
27:00
Speaker 1: we don't really know a lot about this sort of
27:02
Speaker 1: transverse motion of these galaxies. So everything we know is
27:07
Speaker 1: is just from that velocity towards or away from us,
27:09
Speaker 1: that's right, and we're we're sort of guessing about everything
27:12
Speaker 1: else guessing. You can see these things moving over short
27:15
Speaker 1: periods of time, so you have some idea, but they
27:18
Speaker 1: are really far away, so it's very difficult to measure
27:20
Speaker 1: those distances. And also how do we know where they
27:24
Speaker 1: are how far away they are? Don't we need like
27:26
Speaker 1: a supernova to happen in them before we know, or
27:29
Speaker 1: do we have supernova from each of those thousands of galaxies,
27:31
Speaker 1: we have supernova that go out really, really far. That's
27:35
Speaker 1: the nice thing about type one A supernova is they're
27:37
Speaker 1: they're super bright and they're basically in every galaxy, but
27:41
Speaker 1: we don't have one. We haven't seen one necessarily in
27:44
Speaker 1: every galaxy. But we have ideas for where other things are,
27:47
Speaker 1: so we can place them sort of in a ladder,
27:49
Speaker 1: and we have the most information about the closest things.
27:52
Speaker 1: And so that's why we're starting to map the structure
27:55
Speaker 1: of the universe. And we're beginning from the nearby neighborhood.
27:58
Speaker 1: That's where we can see for examples, to sephids in
28:00
Speaker 1: some of these galaxies and type of a supernova. We
28:03
Speaker 1: definitely have the most information about the local neighborhood. All right,
28:07
Speaker 1: So then step us through, how do we find the
28:08
Speaker 1: South Pole Wall. Did we, you know, gain some sort
28:12
Speaker 1: of new trick to look through the milky way or
28:15
Speaker 1: we just got better at it and suddenly it popped up.
28:17
Speaker 1: It's just sort of like being careful and finally analyzing
28:20
Speaker 1: the hard bit of the data. You know, if you're
28:23
Speaker 1: doing science, you get a bunch of data and the
28:25
Speaker 1: first thing you do is you eat the ice cream
28:27
Speaker 1: off the top, right, And I said, well, here's the
28:29
Speaker 1: easy question to answer, the most exciting one. You do that,
28:33
Speaker 1: and people have found cool stuff. They found the Sloane
28:35
Speaker 1: Great Wall, which is as big as the South Pole Wall,
28:39
Speaker 1: but it's further away and it's easier to spot. So
28:42
Speaker 1: they found other structures. But then people started to get
28:45
Speaker 1: more comprehensive about their search, and so they looked through
28:48
Speaker 1: sort of some gaps, and they noticed there was a
28:50
Speaker 1: gap in our cosmic neighborhood where we didn't understand what
28:53
Speaker 1: was going on. That's because it was behind this zone
28:56
Speaker 1: of avoidance. So they decided to look like, well, what
28:59
Speaker 1: is there, and they combined data from a bunch of
29:02
Speaker 1: different surveys slowing Digital Sky Survey and lots of other
29:06
Speaker 1: surveys to make one sort of mega database of all
29:09
Speaker 1: the galaxies called cosmic flows. And so they analyzed this
29:14
Speaker 1: hard bit and they noticed that galaxies between us and
29:18
Speaker 1: this region, we're moving away from us faster than you
29:21
Speaker 1: would expect from just dark energy, and the galaxies past
29:26
Speaker 1: this region we're moving away from us more slowly than
29:29
Speaker 1: you would expect. And so that's suggest right there that
29:31
Speaker 1: there's some like big blob of some moving together. There's
29:35
Speaker 1: some gravity. They're holding it together, pulling on galaxies between
29:39
Speaker 1: us and this blob and slowing down galaxies that are
29:42
Speaker 1: past the blob. We saw like this giant, like if
29:46
Speaker 1: you're looking at it on a on a radar, you
29:48
Speaker 1: would see like a like a flock of birds kind
29:51
Speaker 1: of all moving together away from us. Yeah, exactly. So
29:54
Speaker 1: you put together where all these galaxies are and how
29:57
Speaker 1: fast they're moving away from us, and the only way
29:59
Speaker 1: to explore in the velocities of these galaxies. They call
30:02
Speaker 1: this peculiar velocity, velocity other than the velocity of the
30:06
Speaker 1: expansion of the universe. The only way to explain this
30:09
Speaker 1: peculiar velocity, such a quaint term peculiar, is in like local,
30:13
Speaker 1: you know, like as in our velocity and not somebody else's.
30:17
Speaker 1: They didn't want to go with weird or or local
30:20
Speaker 1: velocity or something anyway. The only way to explain this
30:23
Speaker 1: peculiar velocity is to say, well, there must be something
30:26
Speaker 1: big there, some new source of gravity. And this is
30:29
Speaker 1: not the first time that we've used gravity to deduce
30:33
Speaker 1: the presence of something. Remember our podcast episode about the
30:36
Speaker 1: Great Attractiveate. That's some other like incredible source of gravity
30:41
Speaker 1: that's similarly tugging on stuff and changing the peculiar velocities.
30:45
Speaker 1: So we know that there must be something there, all right,
30:48
Speaker 1: So we saw something big out there but we can
30:52
Speaker 1: we see it directly, like can we see the glow
30:55
Speaker 1: from it, or we can only see the gravity of it.
30:57
Speaker 1: We can only see the gravity from most bit little
31:00
Speaker 1: bits of it sort of peek out the sides of
31:03
Speaker 1: the zone of avoidance. Then you can't spot it. And
31:06
Speaker 1: then they actually went back through old surveys to say,
31:09
Speaker 1: shouldn't we have seen this before? And it turns out
31:12
Speaker 1: that you can see sort of edges of it in
31:15
Speaker 1: previous astronomical surveys, and so people have been sort of
31:18
Speaker 1: like known to look for it and and have been paying
31:20
Speaker 1: more attention. They could have discovered this like ten twenty
31:23
Speaker 1: years ago. They saw like the edges of it, the
31:26
Speaker 1: edges of it sort of peek out past the zone
31:28
Speaker 1: of avoidance. The bulk of it, though, is basically invisible
31:32
Speaker 1: to us in terms of electromagnetic radiation that we can't
31:36
Speaker 1: see it via radio waves, are infrared or anything because
31:39
Speaker 1: it has to pass through the galaxy. So it's only
31:41
Speaker 1: gravitational information that we have about most of it. But
31:44
Speaker 1: that's pretty good, Like if you look up this paper,
31:47
Speaker 1: they're pretty good three D map of the density of
31:50
Speaker 1: this thing that shows you like where the galaxies are
31:53
Speaker 1: and where they aren't. It's a fascinating structure. All right,
31:55
Speaker 1: Let's get into the shape of this South Pole Wall
31:57
Speaker 1: and why it's important that we found it. But first
32:00
Speaker 1: let's take another quick break. All right, Daniel, we're talking
32:15
Speaker 1: about the wall south, the Southern Wall that the first
32:20
Speaker 1: man built, or the first Aliens built, I guess to
32:23
Speaker 1: keep out the alien zombies. You know, I'm just kidding.
32:26
Speaker 1: We found a giant galactic structure, or a structure of
32:30
Speaker 1: galaxies kind of pointing if you look south of the
32:33
Speaker 1: Earth towards the South Pole and keep going past the
32:36
Speaker 1: Milky Way out there in space, and it's huge. It's
32:39
Speaker 1: one and a half billion light years wide. And what
32:42
Speaker 1: does it look like, Daniel? Is it like literally a wall,
32:45
Speaker 1: or like a sheet or just like a giant lump.
32:49
Speaker 1: This looks like a giant cosmic banana. You're just saying that, Daniel,
32:55
Speaker 1: just saying that. It really does look like a huge banana.
32:58
Speaker 1: What do you mean, like like it's curved. If you
33:01
Speaker 1: look at this thing from the paper, it's sort of
33:02
Speaker 1: long and narrow, and it even has like a little
33:04
Speaker 1: thing sticking up at the top that could be like
33:06
Speaker 1: you know, where it's peeled off the giant cosmic banana
33:09
Speaker 1: tree man. So are you saying it looks delicious, is
33:12
Speaker 1: what you're saying. I'm saying you've got to be hungry
33:15
Speaker 1: to eat this thing as well. It's huge and it
33:18
Speaker 1: has a lot of potassium, a lot. I'm not joking
33:21
Speaker 1: that it looks like a banana. But you know, it's
33:23
Speaker 1: sort of like staring at clouds. You can see whatever
33:25
Speaker 1: shape you want, and so I guess I just had
33:27
Speaker 1: bananas on the brain in my mind. It's not as
33:29
Speaker 1: much of a wall as is sort of like a
33:31
Speaker 1: vast tube, but it's definitely big, and it's incredible because
33:35
Speaker 1: it's it's also telling us not just where the stuff
33:39
Speaker 1: is that we can see where the galaxies and the
33:41
Speaker 1: stars and maybe the aliens and their bananas are. It's
33:44
Speaker 1: also a map of the dark matter. What what do
33:47
Speaker 1: you mean? Well, remember that stuff in the universe is
33:50
Speaker 1: not sprinkled at randomly, right, It's clumped together based on
33:53
Speaker 1: the gravitational over densities from the early universe. But most
33:57
Speaker 1: of the stuff in the universe is not the kind
33:59
Speaker 1: of stuff that we can see. It's dark matter. There's
34:02
Speaker 1: five times as much invisible mysterious matter that's affected by gravity.
34:07
Speaker 1: As the kind of matter that we're familiar with and
34:10
Speaker 1: the kinds of matter that we can see tend to
34:13
Speaker 1: line up with the dark matter. Both of them are
34:16
Speaker 1: affected by gravity and they pull on each other. So actually,
34:19
Speaker 1: when you look at stars in the sky, they're telling
34:21
Speaker 1: you where the dark matter is, because dark matter has
34:25
Speaker 1: created these like gravitational wells for stars and galaxies to
34:29
Speaker 1: fall into into form. So the light matter, the normal matter,
34:33
Speaker 1: is sort of like lights showing you where the dark
34:36
Speaker 1: matter is. I mean, but we think right like, you're
34:39
Speaker 1: assuming that where there are stars, there is dark matter.
34:43
Speaker 1: I mean you're assuming like it's the same kind of
34:46
Speaker 1: concentration or ratio between dark matter and regular matter as
34:50
Speaker 1: we have. Yes, and that's something that we've seen. We've
34:52
Speaker 1: measured in lots of different galaxies and we see some
34:55
Speaker 1: variation there. There are some galaxies with more dark matter
34:58
Speaker 1: or less dark matter, and we don't full understand that
35:00
Speaker 1: at all, but roughly we can say that there's a
35:03
Speaker 1: five to one relationship between dark matter and normal matter,
35:06
Speaker 1: and certainly on distances this large enormous supercluster sized structures,
35:12
Speaker 1: we expect the dark matter to have formed these structures
35:15
Speaker 1: like they just would not have formed without the dark matter.
35:17
Speaker 1: You run a simulation the universe without the dark matter,
35:20
Speaker 1: you just don't get structures like this this early in
35:23
Speaker 1: the universe. I feel like you're almost telling me that
35:25
Speaker 1: the you know, basically most of the universe is dark matter,
35:29
Speaker 1: and it's clumping and doing its own thing, and really
35:32
Speaker 1: the stars the bright stuff. Us, we're really just kind
35:34
Speaker 1: of like the bling, you know, like we're just here
35:37
Speaker 1: to tell everyone where the dark matter is. Yeah, we're
35:40
Speaker 1: like those birds that ride on the back of rhinoceroses
35:43
Speaker 1: and sort of like pick the worms off of them.
35:45
Speaker 1: That's us. Yeah, I mean, call us the bling, call
35:47
Speaker 1: us the worm eating birds. Whatever you like. Where the
35:50
Speaker 1: frosting on the cupcake. Yeah, kind of right. I mean
35:52
Speaker 1: when you when you talk about the structure of the universe,
35:55
Speaker 1: it's really the dark matter structure we're just hanging on. Yeah,
35:58
Speaker 1: we call it normal matter because we're used to it,
36:01
Speaker 1: but it's actually pretty unusual in the universe. It's just
36:04
Speaker 1: five percent of the energy in the universe is devoted
36:08
Speaker 1: to making me and you and cosmic bananas. So that's
36:11
Speaker 1: why it's fascinating to sort of use this light matter,
36:14
Speaker 1: this luminous matter to tell us what's actually going on
36:17
Speaker 1: in the universe, and gravity is really the key there.
36:20
Speaker 1: It tells us where the dark matter is. It's also
36:23
Speaker 1: telling us about the balance between the dark matter holding
36:26
Speaker 1: stuff together and dark energy trying to tear it apart.
36:30
Speaker 1: Except that here we can't actually see the galaxies in
36:33
Speaker 1: the stars in the light right like we can only
36:35
Speaker 1: see the gravity, which means maybe this whole wall is
36:38
Speaker 1: just a giant wall of dark matter. We don't really know, right,
36:41
Speaker 1: that's true, We don't really know. Although on the bits
36:44
Speaker 1: of it that we do see, the edges of the
36:46
Speaker 1: banana that stick out past the zone of avoidance, we
36:49
Speaker 1: can't see luminous stars there. So it would be pretty
36:52
Speaker 1: weird to find a massive dark matter wall, But that
36:56
Speaker 1: would be pretty awesome and gives a sense of how
36:58
Speaker 1: big this thing is, Like how any galaxies are in
37:01
Speaker 1: this giant wall? Or like how many stars? Do you
37:03
Speaker 1: have a sense? It's trillions and trillions of stars, you know,
37:07
Speaker 1: it's thousands and thousands of galaxies, and each galaxy has
37:10
Speaker 1: billions of stars, and we don't know how big this
37:14
Speaker 1: thing is. The thing that's incredible to me is that
37:16
Speaker 1: before we discovered this, we had sort of a gap
37:19
Speaker 1: in our understanding of the cosmic neighborhood right around this spot, right,
37:23
Speaker 1: and people like, well, we don't know what's there, probably
37:25
Speaker 1: nothing interesting. And then they found this great wall and
37:28
Speaker 1: it's basically completely fills that gap. You know, it's like
37:32
Speaker 1: it couldn't have been any bigger. You know, there's like
37:35
Speaker 1: a little spot you haven't checked and you open up
37:37
Speaker 1: the door and it turns out it's totally full of stuff.
37:41
Speaker 1: We have this giant gap that looks like a banana,
37:43
Speaker 1: but we don't know what's inside. Oh wait, it is
37:45
Speaker 1: a giant banana. The giant banana. And you know, it's
37:49
Speaker 1: really important that we understand the shape of the universe
37:53
Speaker 1: around us. It really is telling us about how the
37:55
Speaker 1: universe was formed, because it tells us about how this
37:58
Speaker 1: structure has made and it's telling us about the future
38:01
Speaker 1: of the universe. Is telling us, is dark matter gonna
38:04
Speaker 1: win and hold this stuff together? Is dark energy gonna
38:07
Speaker 1: win and tear this stuff apart? You know, we think
38:10
Speaker 1: about this stuff on really long time scales, billions of years,
38:14
Speaker 1: but it's really sort of frothing and dynamical. This is
38:17
Speaker 1: sort of like if you watch froth forming or water boiling,
38:20
Speaker 1: but you just watch the first like two milliseconds of
38:23
Speaker 1: the movie. We're basically two milliseconds into the movie of
38:26
Speaker 1: the universe, of this frothing, bubbling boiler, trying to understand
38:30
Speaker 1: the forces at play. Wow, you mean, like we don't
38:32
Speaker 1: know who's gonna win at the end, but we're still
38:35
Speaker 1: figuring that out looking at the things around us. Yeah, well,
38:38
Speaker 1: we know that dark energy, if it continues as it
38:41
Speaker 1: has been, is gonna eventually tear things apart, but we
38:44
Speaker 1: don't know where those fractures are going to happen exactly.
38:47
Speaker 1: Like how much will gravity get to clump together to
38:50
Speaker 1: form structures that will be impervious to dark energy, and
38:53
Speaker 1: then dark energy will just increase the distance between them.
38:56
Speaker 1: How big will those objects be? We don't really know.
38:59
Speaker 1: It depends sort of delicately on how much dark matter
39:02
Speaker 1: and how much dark energy there is. I mean, like, well,
39:04
Speaker 1: the universe is expanding, but the stuff in it could
39:06
Speaker 1: hold together. Potentially, the stuff and it probably will hold together.
39:09
Speaker 1: Our galaxy will hold together, Our cluster of galaxies probably
39:13
Speaker 1: will hold together. Will our superclusters survive or be torn apart?
39:17
Speaker 1: By dark energy. We don't really know will these walls
39:20
Speaker 1: and filaments be pulled apart. Are they even gravitationally held
39:24
Speaker 1: together today? Or are they just sort of near each other.
39:27
Speaker 1: These are the questions we don't know the answer to.
39:29
Speaker 1: It's like a cosmic battle between the two greatest forces
39:32
Speaker 1: in the universe, and we're basically right in the middle
39:35
Speaker 1: of We're just here on the back of the rhinoceros
39:37
Speaker 1: picking worms, looking at it like eating popcorn, but instead
39:41
Speaker 1: of popcorn, it's it's worm. That's right. Hey, look this
39:43
Speaker 1: worm looks like a banana. Al right, Well, it's pretty
39:48
Speaker 1: amazing that we are still discovering things that are that big.
39:52
Speaker 1: Like you know, if I look at into the sky,
39:54
Speaker 1: how big is this giant wall, Daniel? Is it like
39:57
Speaker 1: like an inch or like a centimeter, or like a
39:59
Speaker 1: whole foot as a fracture of the night sky? If
40:01
Speaker 1: you held, I think a banana at arms length. It's
40:04
Speaker 1: about that big. No, that's too much of a coinci is, Danny.
40:09
Speaker 1: It goes from the constellation Perseus in the northern hemisphere
40:13
Speaker 1: to the constellation APUs. I can't pronounce this one in
40:16
Speaker 1: the far south, so it is really pretty big. And
40:19
Speaker 1: the incredible thing is that it's twice as close as
40:22
Speaker 1: the Sloan Great Wall, right, this long great Wall, just
40:24
Speaker 1: as big discovered decades ago. This thing is twice is close,
40:28
Speaker 1: which should make it more obvious. But you know, there's
40:31
Speaker 1: just so much we still don't know about, the pretty local,
40:35
Speaker 1: large scale structure and sort of the grand scheme of
40:38
Speaker 1: things in our neighborhood. It's amazing. It's amazing. It's almost
40:41
Speaker 1: like we're, you know, explorers. Only a thousand years ago.
40:44
Speaker 1: We didn't know that America was there, or you know,
40:47
Speaker 1: Australia was there. Probably I know how many incredible opportunities
40:50
Speaker 1: were there to discover things, you just have to hop
40:52
Speaker 1: in a boat and sail for a few days. If
40:54
Speaker 1: you had known where to look, discovery is easy. And
40:57
Speaker 1: that's the situation we're in today. We're looking around us
41:01
Speaker 1: and we just don't know what's out there. There could
41:02
Speaker 1: be incredible, mind blowing surprises if we just look a
41:06
Speaker 1: little further or look in the places that have been
41:08
Speaker 1: hard to look at so far. Are definitely surprises out there.
41:12
Speaker 1: And then remember we've only mapped a tiny little dot
41:15
Speaker 1: of the universe. When we talked about like our Solar
41:18
Speaker 1: System being a tiny fraction of the Milky Way, which
41:20
Speaker 1: is a tiny fraction of our cluster. If you look
41:23
Speaker 1: out even further, it just goes on and on and on,
41:26
Speaker 1: and what we've mapped is a tiny fraction of just
41:29
Speaker 1: the observable universe. So most of it is a huge
41:33
Speaker 1: cosmic question. It could be maybe an infinite question mark.
41:36
Speaker 1: It could be an infinite question mark, And it could
41:39
Speaker 1: be that we just have sort of bubbles and walls
41:42
Speaker 1: and voids that go on forever. But it could also
41:44
Speaker 1: be that once you get a sense of those bubbles
41:47
Speaker 1: and voids, that you see a larger pattern and that
41:49
Speaker 1: could tell you something about the early universe and this
41:52
Speaker 1: quantum foam that generated all of this structure. Or it
41:55
Speaker 1: could be that at that level it's mostly random. We
41:58
Speaker 1: just don't know the answer. Like that's a pretty big
42:01
Speaker 1: question to not know the answer to. And maybe once
42:03
Speaker 1: we figure out our address, we can finally get those
42:06
Speaker 1: deliveries from the Amazon aliens. That's right, and I want
42:10
Speaker 1: them in thirty minutes by drone from across the universe,
42:14
Speaker 1: same century delivery. I'll pay extra for that, all right, Well,
42:19
Speaker 1: we hope you enjoyed that and you've got a little
42:21
Speaker 1: bit of a better sense of where we are in
42:23
Speaker 1: the universe and what's out there for us to discover.
42:26
Speaker 1: Thanks for listening, See you next time. Thanks for listening,
42:37
Speaker 1: and remember that Daniel and Jorge Explain the Universe is
42:40
Speaker 1: a production of I Heart Radio. For more podcast from
42:43
Speaker 1: My Heart Radio, visit the I Heart Radio Apple Apple Podcasts,
42:47
Speaker 1: or wherever you listen to your favorite shows. M