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What is the Cosmological Constant? · Daniel and Kelly’s Extraordinary Universe

0:08
Speaker 1: Daniel, what happens if you have a great new physics theory?
0:12
Speaker 1: I mean just really beautiful, gorgeous, perfect explains almost everything.
0:17
Speaker 1: This sounds great so far, but I knew it was
0:21
Speaker 1: a butt coming. But it's wrong about one thing. Well,
0:24
Speaker 1: is it like a little thing? Yeah, just a little
0:26
Speaker 1: thing called the whole universe? All right? Well, is it
0:29
Speaker 1: like just a little bit wrong? It's wrong by about
0:32
Speaker 1: the size of the whole universe. Doesn't sound like such
0:35
Speaker 1: a great theory. But you know there's always a fix.
0:38
Speaker 1: Oh yeah, what's that? Well, engineers would love it. We
0:40
Speaker 1: just add a fudge factor. And here's how safety factors
0:43
Speaker 1: not fudge factors. But that's it. Really. Just put a
0:46
Speaker 1: big number in it and you can fix it. Step one,
0:49
Speaker 1: put in a big number. Step two, give it a
0:51
Speaker 1: fancy sounding name. Hi. I'm Orge I'm a cartoonists and
1:11
Speaker 1: the creator of PhD comics. Hi. I'm Daniel Whiteson. I'm
1:14
Speaker 1: a particle physicist, and I have never fixed a theory
1:18
Speaker 1: with a fudge factor, and not yet, Daniel, how about
1:20
Speaker 1: a podcast? Have you faced the podcast? I've never fudged
1:23
Speaker 1: the physics on this podcast, but I've also never come
1:27
Speaker 1: up with my own theory of the universe. Have you
1:29
Speaker 1: had fudge while you were recording this podcast? My theory
1:32
Speaker 1: is that fudge is the basic element of the universe
1:34
Speaker 1: because it brings joy, and in the end, what's life
1:37
Speaker 1: about other than beauty and joy and in chocolate obviously,
1:41
Speaker 1: But welcome to our podcast Daniel and jrge Explained the Universe,
1:44
Speaker 1: a production of I Heart Radio, in which we compare
1:47
Speaker 1: the universe to various snack foods, delicious and dark and
1:51
Speaker 1: dense sometimes but with all the stuff that's happening out
1:55
Speaker 1: there in this crazy world. We want to take you
1:56
Speaker 1: on a tour of the grandest, deepest, most amazing but
2:00
Speaker 1: yet strangely accessible questions of the universe. Right, we want
2:04
Speaker 1: to take your mind and have it go on a
2:05
Speaker 1: trip out into the far reaches of the cosmos and
2:09
Speaker 1: to think about what it is that we're all doing here,
2:12
Speaker 1: and how did this crazy universe come to be and
2:14
Speaker 1: why is it the way it is. That's right, because
2:16
Speaker 1: the universe belongs to all of us, and wondering and
2:19
Speaker 1: being curious about the universe is as old as being human.
2:22
Speaker 1: And we think that everybody should understand what scientists are
2:25
Speaker 1: thinking about, what the deepest questions are and what scientists
2:28
Speaker 1: are pretty clueless about and only pretend to think they
2:31
Speaker 1: understand anything about. Physicists fudge things. Sometimes that's right, and
2:37
Speaker 1: not little questions, and not by a little bit. Sometimes
2:40
Speaker 1: we need a really really massive fudge, really big bowl
2:44
Speaker 1: of fudge. Hey, you know on a bad day that
2:46
Speaker 1: sometimes that's all that makes you feel like, that's pretty
2:48
Speaker 1: good about it? Right now? Yeah, I wouldn't mind swimming
2:51
Speaker 1: in a swimming pool full of fudge. All right, we'll
2:53
Speaker 1: wipe that mental image, folks and replace it with questions
2:56
Speaker 1: about the universe, so to be on the program. We'll
2:58
Speaker 1: be talking about what such fudge fact about the universe
3:02
Speaker 1: that physicists have come up with. And this comes up
3:05
Speaker 1: a lot in discussions about the entire universe and the
3:08
Speaker 1: theories that underlied, like general relativity and dark energy. That's right,
3:12
Speaker 1: and this is one of my favorite topics in physics
3:15
Speaker 1: because it's a topic where we are absolutely sure that
3:18
Speaker 1: we are in the beginning days of understanding. Like if
3:21
Speaker 1: you go back and read in history about people thinking
3:23
Speaker 1: about the nature of reality and our things made out
3:26
Speaker 1: of atoms or made out of fire and water, it
3:28
Speaker 1: feels like man, they had some pretty crazy ideas back then.
3:32
Speaker 1: They had no idea what they were doing, right, While
3:34
Speaker 1: there are fields of physics where we are also just
3:37
Speaker 1: starting out having all sorts of crazy ideas, which physicists
3:41
Speaker 1: in ten fifty or a hundred years will look back
3:43
Speaker 1: and snortal act. Yeah, and this one's particularly interesting because
3:47
Speaker 1: it all sort of comes down to a number. Would
3:49
Speaker 1: you say it's the biggest number in physics. It's definitely
3:52
Speaker 1: the wrongest number in physics, the wrongest and the biggest. Man.
3:57
Speaker 1: One of the weird things about this number is why
3:59
Speaker 1: it's so small. We think it should be a lot bigger,
4:01
Speaker 1: and it turns out to be kind of small, and
4:03
Speaker 1: we don't understand that. I see it's a small number numerically,
4:07
Speaker 1: but I'm saying, like, in terms of significance, it's a
4:09
Speaker 1: huge number. It's a little number with big significant the
4:12
Speaker 1: biggest slice of the fudge pie of the universe. To
4:15
Speaker 1: be on the program, we'll be talking about what is
4:23
Speaker 1: the cosmological constant? All right? So this was a question
4:27
Speaker 1: that was sent to us by someone from Belgium. So
4:30
Speaker 1: this is Pascal asking what is the cosmological constant? Hi,
4:34
Speaker 1: Danielle and Hockett. I have a nagging question about the
4:38
Speaker 1: cosmological constant. I understand that Anstein introduced the cosmological constant
4:43
Speaker 1: in the field equation because he thought that this would
4:46
Speaker 1: make the universe static, but in fact, the presence of
4:49
Speaker 1: the cosmological constant in the field equation actually shows that
4:53
Speaker 1: the universe is expanding. So that's why he said that
4:56
Speaker 1: this was the biggest mixtake of his life, which, by
4:59
Speaker 1: the way, shows one more time how brilliant it was.
5:01
Speaker 1: Even when he was making you mistake, it turns out
5:03
Speaker 1: that it was right. So my question is, how does
5:06
Speaker 1: the presence of the cosmological constant in the fit equations
5:10
Speaker 1: show that the universe is expanding? And more deeply, where
5:14
Speaker 1: did this cosmological constant come from? Who quoten quote invented it?
5:19
Speaker 1: Thank you so much for your podcasts and cheers from Belgium.
5:22
Speaker 1: All right, cheers, Pascal. Thanks for sending in that question,
5:25
Speaker 1: and I think it's awesome that it's a question that's
5:27
Speaker 1: nagging up, a question that next you also, Daniel doesn't
5:30
Speaker 1: keep you open, Oh my gosh, the history and future
5:33
Speaker 1: fate of the universe totally keeps me up at night.
5:35
Speaker 1: I mean, that's like the biggest question in physics. You know,
5:39
Speaker 1: literally literally the biggest question in physics. Are we living
5:42
Speaker 1: in the space that's going to be crunched? Are we
5:44
Speaker 1: exploding out into the heat death of the universe? What
5:47
Speaker 1: is the shape, the size and nature the dynamics of
5:50
Speaker 1: the universe, like thought of as a whole object. It's
5:53
Speaker 1: it's incredible that humans can even consider things so vast
5:57
Speaker 1: in our tiny little minds and sort of comes down
5:59
Speaker 1: to one number almost, it seems to come down to
6:02
Speaker 1: one number, a number we had to insert into the
6:03
Speaker 1: equations to explain what we see. And you know, the
6:07
Speaker 1: reason I love this topic is because not only do
6:10
Speaker 1: we have fresh new ideas for how to explain what
6:13
Speaker 1: we see, but our understanding of what we're seeing has
6:15
Speaker 1: also changed. You know, a hundred years ago, we thought
6:18
Speaker 1: there was just one galaxy in the universe, and then
6:21
Speaker 1: we discovered their other galaxies and they're zooming away from us.
6:24
Speaker 1: And then we discovered, oh my gosh, the things are
6:26
Speaker 1: expanding even faster and faster. So like, only twenty years
6:29
Speaker 1: ago did we figure out that there was this weird
6:31
Speaker 1: thing called dark energy tearing our universe apart. And now
6:35
Speaker 1: we're struggling to explain it. So, yeah, it's a big knack.
6:38
Speaker 1: It's dark energy, just fudge. Maybe something to think about.
6:42
Speaker 1: Fudge energy would have been a energy energy, the quantum
6:45
Speaker 1: fudge energy. The number is called the cosmological constant. And
6:48
Speaker 1: so as usual, we were wondering how many people out
6:50
Speaker 1: there and know what this term means and where it
6:53
Speaker 1: came from. So as usual, Daniel went out and asked
6:56
Speaker 1: people on the street what is the cosmological constant? And
6:59
Speaker 1: before you listen to these answers, think about it for
7:01
Speaker 1: a second. If someone asked you what it is, would
7:04
Speaker 1: you know what to say. Here's what people had to say.
7:06
Speaker 1: I have no idea what it is. The idea that
7:10
Speaker 1: there's one constant that explains all the others, so we
7:12
Speaker 1: don't have to have like forty two to explain all
7:14
Speaker 1: the different little stuff. I think, So I have no clue.
7:17
Speaker 1: Does that I mean it has something to do with light?
7:20
Speaker 1: Maybe I don't know that's a cosmological constant, so I
7:24
Speaker 1: would say it's something to do with the creation of
7:27
Speaker 1: life or um. The long those line is probably like
7:31
Speaker 1: a number like Dealer's constant or something. Some some mathematical
7:35
Speaker 1: things it's some sort of scale factor. Uh. I guess
7:40
Speaker 1: it's the best way to describe it. No, if you
7:43
Speaker 1: had to guess like movement, something like that, something that's
7:46
Speaker 1: more fixed and something that throughout time they've seen constantly.
7:51
Speaker 1: There heard of it, but I can't remember right now.
7:55
Speaker 1: I believe that refers to Einstein's whoopsie and which had
8:00
Speaker 1: to add a factor to an equation to account for
8:03
Speaker 1: either the repulsion or attraction that would actually make the
8:08
Speaker 1: evolution of the universe's topology. I guess you must say
8:12
Speaker 1: um stable or not stable. I know I'm getting that
8:15
Speaker 1: little right. It's also synonymous these days with dark matter,
8:18
Speaker 1: I think, or the effect of dark matter. You guess,
8:21
Speaker 1: something to do with how the universe expense. Okay, something
8:27
Speaker 1: about the shape of the cosmos. I'm not sure, all right,
8:31
Speaker 1: some pretty good answers out there. Yeah, some people are
8:33
Speaker 1: pretty close, and then some other people sort of grasping at,
8:36
Speaker 1: you know, broad things, because it's it sounds broad and consequential, right, cosmologicalsmologically, Yeah,
8:43
Speaker 1: it's not like it's not like the local neighborhood constant
8:45
Speaker 1: or sofa my sofa constant. You know, it's like it's
8:52
Speaker 1: it's going for the it's going for the fences, cosmological cost,
8:55
Speaker 1: it's a dramatic name. What do you think about the name?
8:57
Speaker 1: You approve, Well, let me see what it is. You
8:59
Speaker 1: know it is? It is it cosmological and insignificance. I
9:03
Speaker 1: think you'll find that it is. My guess is that
9:06
Speaker 1: it's not even a constant there, Like you guys got
9:09
Speaker 1: even that part of the name wrong. That's a good guess.
9:13
Speaker 1: And you know, it's a kind of thing where you
9:14
Speaker 1: think it's a constant, You call it a constant, then
9:16
Speaker 1: you discover hopes it's changing, and you still call it
9:19
Speaker 1: a constant. The only thing that's constant is the name.
9:24
Speaker 1: The only thing that isn't changing about it. But it
9:26
Speaker 1: is sort of a pretty big topic, and it all
9:29
Speaker 1: sort of originated with Einstein, right, This is something Einstein
9:33
Speaker 1: came up with kind of by accident. So tell us
9:36
Speaker 1: about the history. And this is something you have to
9:38
Speaker 1: understand the history of it. And Pascal's question really goes
9:40
Speaker 1: to that you have to understand sort of where Einstein's
9:43
Speaker 1: mind was when he was trying to explain the universe.
9:46
Speaker 1: And you're right, it began with Einstein, but really it
9:49
Speaker 1: was Einstein building on what Newton did. This was like
9:52
Speaker 1: in nineteen fifteen around right, Yeah, this is the early
9:55
Speaker 1: nineteen hundreds, and Einstein was trying to understand the universe
9:58
Speaker 1: and its shape and how and how gravity works because
10:02
Speaker 1: he had gotten these ideas from Newton that everybody else
10:05
Speaker 1: had that gravity is something where two objects with mass
10:08
Speaker 1: pull on each other. And he didn't like this idea,
10:11
Speaker 1: and he tried to come up with a more general
10:14
Speaker 1: idea for what gravity might be, and he reimagined gravity completely, right.
10:18
Speaker 1: His idea of gravity was not that gravity is like
10:21
Speaker 1: a force or two objects pull on each other, but
10:24
Speaker 1: that it's sort of the effect of mass on space itself.
10:28
Speaker 1: So space is no longer just like a backdrop. It's
10:31
Speaker 1: not like an emptiness on which things happen. It's a
10:34
Speaker 1: dynamical part of the universe. Meaning you put mass into space,
10:38
Speaker 1: space changes, right, And so he imagined gravity as a
10:42
Speaker 1: bending of space. Any local density of energy will bend
10:46
Speaker 1: space around it, changing the shape of the universe. And
10:49
Speaker 1: this idea sort of came up from the equations, right,
10:51
Speaker 1: Like if you sort of look at the equations of
10:53
Speaker 1: gravity and things moving because of gravity, you can sort
10:56
Speaker 1: of look at the equations into ways as a as
10:59
Speaker 1: a force or as a as a kind of a
11:01
Speaker 1: bending of space. Right. It's not like he suddenly came
11:03
Speaker 1: up with this idea. Well. I think it had a
11:05
Speaker 1: complex history and it required him to merge some ideas
11:08
Speaker 1: or mathematics that had recently been developed. But I think
11:11
Speaker 1: it's a pretty big conceptual shift to say gravity is
11:14
Speaker 1: not just a force between two objects, like electromagnetism, but
11:18
Speaker 1: it's something conceptually very different. It's a changing of the
11:21
Speaker 1: shape of space itself. I think that's sort of mind bending,
11:24
Speaker 1: the way you know, the mind bending to think about
11:25
Speaker 1: space and bending. Right. And so he came up with
11:28
Speaker 1: this idea and it worked really well for lots of
11:31
Speaker 1: things that he was able to recover Newton's theory from it.
11:33
Speaker 1: He showed that thinking about gravity in this way gave
11:36
Speaker 1: the same predictions that Newton gave. Right. It didn't mean
11:39
Speaker 1: apples should fall differently from trees, right, because Newton's theory
11:43
Speaker 1: sort of worked, right, It's been tested a lot of
11:45
Speaker 1: ways and even explained the motion of the planets mostly right.
11:49
Speaker 1: And so it's important when you come up with like
11:50
Speaker 1: a deeper theory that it still explains all the stuff
11:53
Speaker 1: that Newton had gotten right. Right in einsience theory, the
11:56
Speaker 1: apple doesn't fall from the tree. It just sort of
11:59
Speaker 1: rides down own the space time, or it sits in
12:02
Speaker 1: the same spacetime. Yeah, it's surfs, right, it's surfs on space.
12:06
Speaker 1: But the motion is the same. Right, Einstein doesn't predict
12:09
Speaker 1: that you'd see anything different from when an apple falls.
12:12
Speaker 1: But then it did make small differences in predictions for
12:15
Speaker 1: like how mercury moved. Really, yeah, that's the procession of mercury.
12:19
Speaker 1: And so he proved that his idea was right and
12:21
Speaker 1: the Newton's idea was wrong. But then he took the
12:24
Speaker 1: idea even bigger. He said, all right, if we think
12:26
Speaker 1: about this, what does that mean for the whole universe? Right?
12:29
Speaker 1: Can I understand what that means for like everything? He
12:31
Speaker 1: also swung for the fences. Yeah, he went cosmologically saying, hey,
12:34
Speaker 1: it predicts his apple. Let's go for the universe. And
12:38
Speaker 1: you only have to think about it for a moment
12:39
Speaker 1: to realize, Well, if the Sun bends space or the
12:43
Speaker 1: Earth moves around it, right, that means that mass and
12:45
Speaker 1: energy is bending space sort of towards itself. Then what's
12:49
Speaker 1: going to happen when you have a lot of masks,
12:51
Speaker 1: like a universe sized blob of mass. Well, it's going
12:55
Speaker 1: to cause things to contract, right, it's going to cause
12:58
Speaker 1: things to contract. What do you mean, like it under
13:01
Speaker 1: its own weight. Yeah, the gravity of all the stuff
13:03
Speaker 1: in the universe should pull all the stuff together. Right.
13:06
Speaker 1: If you're Einstein, you think, okay, I have an empty universe.
13:09
Speaker 1: Space is flat. Then I add galaxies and stars and
13:12
Speaker 1: gas and dust. What should happen, Well, space will bend
13:15
Speaker 1: in a way to pull all that stuff eventually together.
13:17
Speaker 1: And so in Einstein's universe, originally all that stuff should compact,
13:21
Speaker 1: should fall into itself, and eventually create you know, like
13:24
Speaker 1: a huge black hole. But do you need Einstein's gravity
13:28
Speaker 1: formulation that way? Can what a Newton also predicted, everything
13:31
Speaker 1: would just pull on itself and class Oh yeah, that's
13:33
Speaker 1: a great question. Right now. In Newton's universe, you don't
13:37
Speaker 1: necessarily get a collapse. I mean, you have gravity and
13:41
Speaker 1: it's pulling stuff together. But in Newton's universe, space is flat,
13:45
Speaker 1: and so it's possible for stuff to be arranged in
13:47
Speaker 1: a way that's sort of stable in static like the
13:50
Speaker 1: way that our planets orbit the Sun and don't collapse
13:53
Speaker 1: the way our galaxy doesn't collapse because it's spinning. And
13:56
Speaker 1: in Newton's time, remember they only knew about our galaxy,
13:59
Speaker 1: that know about other galaxies out there, so even this
14:02
Speaker 1: concept of the larger universe was not around. But for Einstein,
14:07
Speaker 1: space can bend, and so even if things are in
14:09
Speaker 1: stable orbits like they are here, they would still eventually collapse.
14:13
Speaker 1: In fact, Einstein's calculations were done assuming that everything was
14:17
Speaker 1: smoothly distributed, So even in the universe where gravity would
14:21
Speaker 1: all cancel out like that, even in that scenario he
14:24
Speaker 1: predicted that everything would collapse. So in Newton's universe things
14:28
Speaker 1: could be arranged stable so they don't collapse, or Einstein,
14:32
Speaker 1: without the cosmological constant, predicted everything would eventually collapse. But
14:36
Speaker 1: that's a problem, right, This prediction, this consequence of his
14:39
Speaker 1: theory or consequence of gravity, that the universe should be
14:42
Speaker 1: like falling in on itself, is not what Einstein thought
14:45
Speaker 1: was happening at the time, because back then, if you
14:47
Speaker 1: looked out into the sky, things look pretty static, right,
14:51
Speaker 1: nothing that nothing looks like it's trunching together. Yeah, back
14:53
Speaker 1: in niften or so, people thought the universe was static,
14:57
Speaker 1: that the stars are just hanging there in space and
14:59
Speaker 1: there was no rel of motion, and things were just
15:01
Speaker 1: sort of fixed. They've been that way forever, they would
15:04
Speaker 1: be that way forever. Things look pretty peaceful. Yeah, And
15:06
Speaker 1: so when Einstein came up with this theory and it
15:10
Speaker 1: predicted that the universe should be falling in and itself,
15:12
Speaker 1: he thought, oh, there must be something wrong, something must
15:17
Speaker 1: be wrong with the universe or with his equations. Well,
15:21
Speaker 1: he didn't doubt that the universe was static. He tried
15:23
Speaker 1: to fudge his equations. He says, all right, well, if
15:27
Speaker 1: the universe is not collapsing in itself, then I need
15:29
Speaker 1: something to prevent it from collapse, something to push in
15:33
Speaker 1: the other direction to keep its static, to balance. Because
15:36
Speaker 1: if you apply his theory to the universe or just
15:38
Speaker 1: really it doesn't have to be the universe, right, it
15:40
Speaker 1: had just any collection of mass back at least in
15:43
Speaker 1: the way that they thought space and mass was like
15:47
Speaker 1: back then. Then that's sort of inevitable, right, if you
15:49
Speaker 1: have gravity, everything's gonna come crunching down together. So he's like, wait,
15:52
Speaker 1: that's not happening. So therefore I'm going to fudge my equation. Yeah,
15:55
Speaker 1: he fudged it. He said, all right, so what I
15:58
Speaker 1: need is something to balance gravity. So he has this
16:00
Speaker 1: equation which predicts the basically the velocity how things will
16:05
Speaker 1: move through space based on the matter and energy density.
16:08
Speaker 1: And he just added another number with a minus sign
16:11
Speaker 1: to to balance it out, to balance it out, to
16:13
Speaker 1: make it match the idea of a universe that's not collapsing. Yeah,
16:17
Speaker 1: he said, if there's some effect on gravity from mass
16:21
Speaker 1: and energy, what if there's something else which is pushing
16:24
Speaker 1: back something else which provides a counterbalancing influence so that
16:29
Speaker 1: there is no overall gravity and so and so this
16:31
Speaker 1: is his famous fudge factor, right, And did he call
16:34
Speaker 1: it the cosmological concept or was that name given to
16:37
Speaker 1: it afterwards? He called it the cosmological concept. He named
16:40
Speaker 1: it capital lambda, and he chose this minus sign. And
16:44
Speaker 1: there's no explanation for It's not like it comes from anything.
16:47
Speaker 1: It's not like there's a bottoms of physics reason why
16:50
Speaker 1: it should exist. It was really just added to try
16:54
Speaker 1: to describe the universe that he was seeing interesting, all right,
16:56
Speaker 1: And so this number has been described as sinds biggest blunder.
17:01
Speaker 1: And so let's get into whether or not it was
17:03
Speaker 1: a blunder or not and what that means. But first
17:05
Speaker 1: let's take a quick break. All right, Daniel, did Einstein
17:21
Speaker 1: commit a blunder or not when he introduced the cosmological
17:25
Speaker 1: constant in his equations? What do you think? I think
17:27
Speaker 1: it totally is a blunder, because well, it didn't even
17:31
Speaker 1: really solve his problem. Like the problem he had was
17:34
Speaker 1: that gravity was pulling in and he needed something to
17:37
Speaker 1: be sort of pushing out. But the way he described it,
17:41
Speaker 1: it was a very delicate balance, like he needed this
17:43
Speaker 1: number to be exactly the right thing so that the
17:47
Speaker 1: effect or gravity from mass would be balanced by the
17:49
Speaker 1: effect of gravity from this weird cosmological constant. But it
17:53
Speaker 1: doesn't work unless they're exactly balanced. But I guess why
17:56
Speaker 1: do you call it a blunder? I mean, I just
17:57
Speaker 1: think he's just being a good scient doesn't be like, oh,
18:00
Speaker 1: I need something. I'm trying to a word with these
18:01
Speaker 1: equations to make them fit when I'm observing. Therefore, I'm
18:04
Speaker 1: going to add this. It's not like he maybe thought
18:07
Speaker 1: something wrong, did he know? But my complaint is that
18:09
Speaker 1: it doesn't even really work, Like if you actually had
18:12
Speaker 1: a universe like that, then it wouldn't be static because
18:16
Speaker 1: any little extra pocket of mass that was over dense,
18:19
Speaker 1: like you know, a solar system whatever, would start this
18:22
Speaker 1: runaway effect because it's not stable, like an extra pocket
18:25
Speaker 1: of mass very quickly generates extra gravity and overcomes this
18:28
Speaker 1: cosmological constant. And so while he wouldn't have like everything
18:32
Speaker 1: drawing into the center, there would be lots of little collapses. Oh,
18:36
Speaker 1: I see, his theory doesn't even really predict a static universe.
18:39
Speaker 1: I see you're saying, putting it into the same equations
18:42
Speaker 1: that he had before made a balance. But it's like
18:45
Speaker 1: a super precarious and technically it only works if matters
18:50
Speaker 1: totally evenly distributed through the universe and there's no extra
18:53
Speaker 1: little spots of extra density, and if there are, then
18:57
Speaker 1: those very rapidly coalesced. In collection doesn't know what happened.
19:00
Speaker 1: The galaxies are in galaxies and planets really just like
19:03
Speaker 1: small concentrations with mass, and so he's not describing what's happening, right,
19:08
Speaker 1: He's trying to describe what he thought was happening, which
19:10
Speaker 1: is a stable universe. But his description doesn't even lead
19:14
Speaker 1: to a stable universe. You mean the whole equations wrong,
19:17
Speaker 1: not just that constant. Yeah, I don't think the equation
19:20
Speaker 1: is he put it together describes the static universe that
19:22
Speaker 1: he was trying to describe, all right, So how did
19:24
Speaker 1: they know it was a blunder? Well, I think it's
19:26
Speaker 1: the blunder because it doesn't even describe the universe he
19:29
Speaker 1: thought he was describing. But then it turns out that
19:32
Speaker 1: the universe is different from what he thought, that the
19:34
Speaker 1: universe is not static, right, that the universe he was
19:37
Speaker 1: trying to describe suddenly shifted from under his feet, right,
19:40
Speaker 1: because we now know that the universe is expanding, right,
19:43
Speaker 1: that's right. Later on in the nineties, they discovered that
19:46
Speaker 1: galaxies are actually moving apart from each other, that's right. Hubble,
19:49
Speaker 1: building on work of various other people, discovered that there
19:52
Speaker 1: are other galaxies out there and they're really far away,
19:55
Speaker 1: and they're moving away from us faster and faster. So
19:58
Speaker 1: he discovered that the universe not static, that it's expanding.
20:02
Speaker 1: And so this would have blew up Einstein's idea because
20:05
Speaker 1: he had worked carefully to add this number to his
20:07
Speaker 1: equations to describe a static universe, and then it turns out, oops,
20:10
Speaker 1: the universe not well, his problem was that he called
20:14
Speaker 1: it a constant. Right if he had called it not,
20:17
Speaker 1: or is it that they even did, the whole math
20:19
Speaker 1: equation is wrong. I know. The problem is not that
20:21
Speaker 1: he called it a constant that we can talk about
20:23
Speaker 1: later about whether we think it's varying in time. The
20:26
Speaker 1: problem is that he put this number in to fudge
20:29
Speaker 1: his equation to describe a static universe, which is not
20:32
Speaker 1: our universe. Okay, so we we don't live in a
20:35
Speaker 1: static universe. Therefore any equation that assumes that is wrong.
20:39
Speaker 1: That's right. And so then Einstein abandoned the cosmological constant,
20:43
Speaker 1: and he never actually said it was his greatest blunder.
20:46
Speaker 1: But after that he was definitely not a fan of it.
20:48
Speaker 1: You know, he thought it was He was not well motivated,
20:51
Speaker 1: and you sort of putting it in by hand, and
20:53
Speaker 1: it doesn't come from anything. It doesn't really make sense.
20:55
Speaker 1: I see. Well, he was pretty cool about it. Then
20:58
Speaker 1: he didn't try to like hang onto it. And this
21:00
Speaker 1: party is a little bit confusing because you might think, well,
21:03
Speaker 1: Einstein put the cosmological constant in to prevent the universe
21:07
Speaker 1: from collapsing in his model, but then he discovers the
21:10
Speaker 1: universes expanding? How does he get rid of the cosmological constant? Right,
21:14
Speaker 1: just put another number in it, a plus number. Well,
21:18
Speaker 1: the cosmological constant already was pushing in that direction, right,
21:21
Speaker 1: the cosmological constant. He had kept the universe from collapsing.
21:25
Speaker 1: It was a positive repulsive force. Did you just make
21:28
Speaker 1: that number bigger and will explain expansion? Right? And so
21:32
Speaker 1: down the road, in order to explain expansion, accelerating expansion,
21:35
Speaker 1: we're gonna have to make that number bigger. But what
21:37
Speaker 1: Einstein did was get rid of it, right, not make
21:40
Speaker 1: it bigger, but he just made it zero. He's like, oh,
21:42
Speaker 1: this is wrong, and that seems confusing, right, because then
21:46
Speaker 1: there are two things to keep in mind here at once,
21:49
Speaker 1: the expansion, which is like a velocity, and then the
21:52
Speaker 1: change in expansion, which is like an acceleration. Just like
21:55
Speaker 1: in your car, you have a certain velocity and then
21:57
Speaker 1: the engine or breaks gives you accelerating aation to change
22:01
Speaker 1: that velocity. Now, the cosmological constant is more like the engine.
22:05
Speaker 1: It gives acceleration to the expansion, either positive or negative. Now,
22:09
Speaker 1: Einstein had originally assumed that the expansion velocity was zero,
22:13
Speaker 1: that we lived in a static universe, and so he
22:16
Speaker 1: set the cosmological constant to zero to also gave no acceleration.
22:21
Speaker 1: So what Hubble discovered is that the expansion velocity was positive.
22:25
Speaker 1: Hubble didn't measure the acceleration. He couldn't, so Einstein at
22:29
Speaker 1: that point knew that his no expansion, no acceleration description
22:32
Speaker 1: was wrong. Now, when Einstein tossed out the cosmological constant,
22:37
Speaker 1: it gave him a universe with negative acceleration because gravity
22:40
Speaker 1: was collapsing it, but it could still have positive expansion
22:44
Speaker 1: velocity at that moment. It's sort of like driving at
22:47
Speaker 1: high speeds at the same time as hitting the brakes
22:49
Speaker 1: to slow you down. So no cosmological constant means negative acceleration,
22:54
Speaker 1: which would eventually turn the universe's expansion around into a collapse.
23:00
Speaker 1: But Einstein was more giving up on the whole idea
23:02
Speaker 1: using the cosmological constant to get balanced and get zero
23:05
Speaker 1: acceleration and zero velocity. So the cosmological constant um tells
23:12
Speaker 1: you how how fast the expansion is changing. Yeah, okay,
23:16
Speaker 1: And so by making it zero than Einstein thought that
23:19
Speaker 1: he was saying, okay, it's expanding, but it's not accelerating,
23:22
Speaker 1: it's not getting faster and fast. So Einstein's vision, I
23:24
Speaker 1: think was the universe is expanding right now, but I'm
23:27
Speaker 1: gonna get rid of the cosmological constant, which means that
23:29
Speaker 1: expansion is decreasing. And so in the future Einstein thought
23:33
Speaker 1: expansion would slow down, stop and eventually universe would still collapse.
23:37
Speaker 1: Can't this Einstein guy get anything right? I mean, but
23:41
Speaker 1: that he was kind of wrong about that too, right,
23:42
Speaker 1: because later on, more recently, we discovered that the universe
23:46
Speaker 1: is expanding faster and faster and faster. That's right, Hubble
23:49
Speaker 1: was right, the universe is expanding, and the question was
23:53
Speaker 1: is that expansion slowing down quickly or is that expansion
23:55
Speaker 1: slowing down slowly? And we went out to measure it,
23:59
Speaker 1: and this covered that neither of those are true. Right,
24:02
Speaker 1: That the expansion is accelerating, that it's going faster and
24:06
Speaker 1: faster every year, right, And we figured this out by
24:09
Speaker 1: watching supernova's explode, which is let us understand how far
24:13
Speaker 1: away things are and how fast they're moving away from us.
24:16
Speaker 1: And we reconstructed this sort of history of the speed
24:19
Speaker 1: the things are moving away from us, and that told
24:21
Speaker 1: us that things are moving away from us faster and
24:23
Speaker 1: faster every year. And so not only is hubble saw
24:27
Speaker 1: is the universe expanding, but that expansion is getting faster
24:30
Speaker 1: every year. Right. We We've had podcast episodes about this,
24:33
Speaker 1: about the the idea that the universe is kind of exploding. Yeah,
24:37
Speaker 1: the universe is sort of being torn apart, and it's
24:39
Speaker 1: going through puberty or something. The most precise way to
24:42
Speaker 1: think about it, I think, is that space is expanding, right,
24:45
Speaker 1: We're creating new space between us and other galaxies. Right.
24:49
Speaker 1: And a very common question from listeners is, if space
24:53
Speaker 1: is being created between us and other galaxies, why isn't
24:55
Speaker 1: it being created between us and the Sun, or between
24:58
Speaker 1: me and you, or between in his banana, and and
25:01
Speaker 1: it is. It's just that we're getting pulled together by gravity,
25:03
Speaker 1: that's right. It is. It's being created equally everywhere. That's
25:06
Speaker 1: why it's a cosmological constant. It's constant in space. Everywhere
25:10
Speaker 1: in space is being stretched the same way. But as
25:13
Speaker 1: you say, the Earth is holding you onto it, and
25:16
Speaker 1: the Sun is holding us by its gravity, and our
25:19
Speaker 1: galaxy is holding itself together even even like the air
25:21
Speaker 1: inside of your mouth. Right now, is literally expanding, is
25:25
Speaker 1: literally expanding. Yeah, everyone's brain is literally exploding right now,
25:30
Speaker 1: not just because of us, that's right. And we call
25:32
Speaker 1: this dark energy, right, but it's just physics shorthand for
25:36
Speaker 1: we have no clue what's going on. This is, you know,
25:40
Speaker 1: something we observe. We see that the universe is expanding,
25:43
Speaker 1: and this is something we only discovered years ago. It's
25:47
Speaker 1: mind blowing to realize that before that we were ignorant
25:50
Speaker 1: of this really basic fact about our own EXAs well.
25:53
Speaker 1: So I guess my question now is, then, is dark
25:56
Speaker 1: energy related to the cosmological constant? You're sort of making
25:59
Speaker 1: it sound like it's the same thing. Like what Einstein
26:02
Speaker 1: was missing in his equation was the idea of dark
26:05
Speaker 1: energy and that maybe this constant is related to it
26:08
Speaker 1: or or is it totally separate. It's related to it,
26:11
Speaker 1: and you know, the idea is you see something out
26:13
Speaker 1: there in the universe, something you don't understand, which is
26:16
Speaker 1: like the universe is expanding and that expansion is accelerating.
26:19
Speaker 1: That's dark energy, just the observation that the expansion is accelerating.
26:24
Speaker 1: No cosmological constant idea involved. Yet there's several possible explanations
26:29
Speaker 1: for dark energy, one of which is the cosmological constant. Right,
26:33
Speaker 1: how do you describe it? You want physics equations that
26:35
Speaker 1: describe it so you can understand it, so you can
26:37
Speaker 1: predict it. So you need to somehow describe it. And
26:41
Speaker 1: so one way to describe that is to take Einstein's
26:44
Speaker 1: field equations, which are awesome, and put the cosmological constant
26:48
Speaker 1: back in, back in. So he put it back in.
26:51
Speaker 1: He had taken it out, and now everyone is saying, no, no, wait,
26:54
Speaker 1: don't take it out. It actually helps us understand what's
26:57
Speaker 1: what's happening. That's right, and you need to put it
26:59
Speaker 1: back in and put it back in larger than he did. Right.
27:02
Speaker 1: He put it back in to try to balance the
27:04
Speaker 1: universe on a knife edge to keep it static, and
27:07
Speaker 1: then he pulled it out again. He's like, oh, the
27:08
Speaker 1: universe is not static. I'll just let it collapse in
27:10
Speaker 1: the future. Now we gotta put it back in and
27:13
Speaker 1: crank it up so that it's accelerating the expansion to
27:16
Speaker 1: the un Everyone's like, more fudge, Put more fudge in.
27:19
Speaker 1: Don't put it in the fridge, just pour the whole
27:22
Speaker 1: thing in. That's right. He put in some fudge. Then
27:24
Speaker 1: he took the fudge out, and now we've doubled the fudge.
27:27
Speaker 1: That's nice double fudge. It's a double fudged universe. Maybe
27:30
Speaker 1: ein Steins Blunder was just picking the wrong ice cream flavor.
27:33
Speaker 1: You never know. Alright, let's get into whether or not
27:36
Speaker 1: this cosmological fudge constant is real and what that means
27:41
Speaker 1: for the fate of the universe. But first let's take
27:44
Speaker 1: a quick break. All right, we're talking about the cosmological
28:00
Speaker 1: sin and we're talking about how it's something that Einstein
28:02
Speaker 1: put in, then took out, and then people put back
28:05
Speaker 1: in because it explains how the universe can be expanding
28:08
Speaker 1: faster and faster. So it's kind of a real thing
28:12
Speaker 1: because we're seeing it. But Daniel explain to us what
28:15
Speaker 1: it actually is and like physically what it means, and
28:19
Speaker 1: and how does it explain how the universe is expanding. Yeah,
28:21
Speaker 1: so nobody knows the answer to any of those questions,
28:23
Speaker 1: so we could just end the podcast, right, Well, then,
28:26
Speaker 1: thank you very much, we'll end the podcast. It's a
28:28
Speaker 1: fascinating question and it's something physicists or thinking about a lot,
28:31
Speaker 1: and it's worth understanding what physicists do not yet understand.
28:36
Speaker 1: And the first thing to know sort of the mechanics
28:38
Speaker 1: of it, like how did he put it in? Well,
28:40
Speaker 1: the the equations for john relativity are very complicated, but
28:43
Speaker 1: you can solve them in some sort of simplifying assumptions
28:46
Speaker 1: and you get like two equations, one that gives you
28:48
Speaker 1: the expansion of the universe, the other that gives you
28:51
Speaker 1: the acceleration. And if you look at those equations you
28:53
Speaker 1: can google them later, you see that there's a term
28:55
Speaker 1: there for mass and energy and that has one effect,
28:58
Speaker 1: and he just literally put in a number with an
29:01
Speaker 1: opposite sign to balance it. And so it's something Einstein's
29:06
Speaker 1: description of mathematically would be something which has the opposite
29:09
Speaker 1: gravitational effect of mass in it, and you have to
29:11
Speaker 1: put it in a certain sort of solution of the equation. Yeah,
29:14
Speaker 1: you have to put it into the equations in a
29:16
Speaker 1: certain place, because it's not in like equals semc squared.
29:18
Speaker 1: That's not where it is. It's somewhere else in the equation.
29:21
Speaker 1: That's right, that's not the that equal s mc squared
29:23
Speaker 1: is not part of Einstein's field equations for general relativity,
29:27
Speaker 1: And so it goes into those field equations, and and
29:30
Speaker 1: this is what we do in physics. We're like, all right,
29:32
Speaker 1: this model, these equations describe what we see. Then what
29:36
Speaker 1: does that mean? Right? The next step is interpretation, like
29:39
Speaker 1: why is it like this and not something else? What
29:41
Speaker 1: does that tell us about the universe that we need
29:44
Speaker 1: this number here? Okay? So yeah, he people agree he
29:47
Speaker 1: put it in the right place, but they don't agree
29:49
Speaker 1: that it's actually a constant. Is it? Well, we don't know.
29:51
Speaker 1: And the way you can interpret it sort of physically
29:54
Speaker 1: is to think about it like maybe it's the energy
29:57
Speaker 1: of empty space, right, because if space itself has some
30:02
Speaker 1: energy inherent in it, then it could have this effects. Right,
30:05
Speaker 1: So we're like searching for a physical explanation and this
30:09
Speaker 1: could be totally wrong, right, This could be like, you know,
30:11
Speaker 1: maybe the universe is made out of air, fire and water.
30:14
Speaker 1: Could be that level of idea which peoples scots. But
30:17
Speaker 1: we're just groping around in the dark here, and and
30:21
Speaker 1: this is what we came up with. What you came
30:22
Speaker 1: up with was that space is not space, and emptiness
30:25
Speaker 1: is not empty. Noess, there's actually something in not an
30:29
Speaker 1: empty space. There's something in empty space, and it's important
30:32
Speaker 1: that this gets something really big, right if you think
30:35
Speaker 1: of it as the energy of empty space, not as
30:38
Speaker 1: something in space. Then as the universe expands, As space expands,
30:44
Speaker 1: you get more space, you get more of this stuff. Right,
30:47
Speaker 1: Because say you have like a cube of space and
30:50
Speaker 1: it has two hydrogen molecules in it, and then it expands, right, Well,
30:54
Speaker 1: you still only have two hydrogen molecules in it. So
30:57
Speaker 1: the density of stuff in the universe is decreased, so
31:00
Speaker 1: the gravitational effect of that stuff has decreased, but the
31:03
Speaker 1: cosmological constant, the energy of empty space, is constant. So
31:07
Speaker 1: you get twice as much space, you have twice as
31:09
Speaker 1: much of this mysterious dark energy. It kind of sounds
31:12
Speaker 1: like magic, Like you're like the you know, like the
31:15
Speaker 1: total energy in the universe. You're just it just bubbles
31:18
Speaker 1: up from like an infinite fountain. Yeah, it's pretty weird.
31:21
Speaker 1: And gradually it's sort of takes over, Like as the
31:24
Speaker 1: universe expands, you get more dark energy, and so the
31:27
Speaker 1: fraction of the energy of the universe that's in dark
31:29
Speaker 1: energy just grows and grows and grows and grows, and
31:32
Speaker 1: eventually it's going to be totally dominant. Does that mean
31:36
Speaker 1: that the energy of the universe is not being concerned. Well,
31:39
Speaker 1: that's a whole other question. It's a great question. It's
31:41
Speaker 1: pretty complicated. I think we should dive into that and
31:42
Speaker 1: a whole other podcast. But the brief answer is that
31:46
Speaker 1: the energy the universe might just be zero. So where's
31:48
Speaker 1: all this new energy coming from. It's a lot of
31:50
Speaker 1: negative energy in the universe that's bound up in gravitational interactions,
31:54
Speaker 1: and so this new energy can be balanced by negative
31:58
Speaker 1: energy of the gravitational interaction. That's uh, oh I see
32:02
Speaker 1: when you create something, Oh I see, Like if you're
32:04
Speaker 1: creating space between you and me, there's energy being created
32:07
Speaker 1: by the space, but we're also sort of storing it
32:10
Speaker 1: in the gravitational potential. Energy between negative energy in our
32:14
Speaker 1: gravitational potential, because you need to add energy to free us.
32:18
Speaker 1: Like if you have Daniel and Jorge orbiting each other,
32:21
Speaker 1: we're bound together gravitationally. Then in order to make a
32:25
Speaker 1: free Daniel and a free Johe, you need to add
32:27
Speaker 1: energy to the system to pull it apart. Yeah, so
32:30
Speaker 1: that means that that has negative energy. But it's weird
32:34
Speaker 1: that the universe kind of wants that it wants to
32:36
Speaker 1: free you, Daniel, why why didn't want what doesn't it
32:40
Speaker 1: wanted to come to me? I don't know. I don't
32:42
Speaker 1: know why the universe wants what it wants, But it's
32:44
Speaker 1: it's weird to think about dark energy because it feels
32:47
Speaker 1: like a strange coincidence, Like we are living at a
32:49
Speaker 1: time when right now dark energy is about seventy percent
32:52
Speaker 1: of the universe. We know eventually it's going to take over,
32:55
Speaker 1: So why is it that we happen to live at
32:57
Speaker 1: this time when like matter is thirty scent and dark
33:00
Speaker 1: energy matter and radiation and all that stuff ist and
33:04
Speaker 1: dark energy is sevent It feels like sort of a
33:06
Speaker 1: weird balance. Really why? I mean like if we were
33:10
Speaker 1: if the human race had come up a billion years ago,
33:12
Speaker 1: we might be asking the same question, like, oh, why
33:14
Speaker 1: is it six But if you look at the history
33:18
Speaker 1: of the universe over a trillion years, only the very
33:20
Speaker 1: first blip is going to have any sort of balance
33:23
Speaker 1: between matter and dark energy. Most of it will be
33:26
Speaker 1: dominated by dark energy. So even before us, you know,
33:29
Speaker 1: the dark energy is the future, not the past, I guess.
33:31
Speaker 1: I mean, like we're wondering why it is the way
33:34
Speaker 1: it is like that now, But if we had been
33:36
Speaker 1: born a billion years before, wouldn't it also be odd?
33:39
Speaker 1: It would also be odd. Yeah, it's weird to find
33:41
Speaker 1: two things in balance that won't stay in balance. Right.
33:44
Speaker 1: We don't think that there's anything that's keeping dark energy
33:47
Speaker 1: in balance with these other forces. Eventually it will take over,
33:51
Speaker 1: and so it's just sort of weird to be alive
33:53
Speaker 1: in a moment when it hasn't yet taken over because
33:55
Speaker 1: most of the history of the universe. In the future
33:57
Speaker 1: it will be in charge, but in the past there's
34:00
Speaker 1: less or more less less because the universe is getting
34:04
Speaker 1: more and more diluted, and so dark energy is growing
34:07
Speaker 1: in important Okay, all right, so these are all related
34:10
Speaker 1: to each other. The cosmological constant, the energy of empty space,
34:14
Speaker 1: and dark energy. Are these all different names for the
34:16
Speaker 1: same thing? Or I guess help me understand why we
34:19
Speaker 1: have three names for it. Yeah, there's sort of three
34:21
Speaker 1: layers of ideas there, and there's one more layer we
34:23
Speaker 1: should be into. The dark energy is the description of
34:27
Speaker 1: the accelerating expansion in the universe that's like experimental something
34:31
Speaker 1: is out there doing this, as we call it dark energy.
34:34
Speaker 1: The cosmological constant is an attempt to describe dark energy
34:38
Speaker 1: using gravity, say well, maybe it's just a feature of gravity, right, Oh,
34:42
Speaker 1: it could not be. It could not be, could be
34:44
Speaker 1: something totally different. We could not need a cosmological constant.
34:47
Speaker 1: And there's something that's probably different going on. Really, Oh
34:50
Speaker 1: I see, I get it all right, Yeah, yeah, there
34:52
Speaker 1: are other explanations for dark energy that don't involve the
34:55
Speaker 1: cosmological constant. So the cosmological constant could still be zero,
34:58
Speaker 1: like Einstein said, it coulds zero out here. See, you
35:02
Speaker 1: guys were calling him a blunderer, and you don't even know.
35:06
Speaker 1: I'm gonna I'm gonna go switch you over to t
35:07
Speaker 1: mind Stein here and say maybe I'm gonna keep with him.
35:10
Speaker 1: I think that's bananas. And the cosmological constants an attempt
35:13
Speaker 1: to describe that, right, And then we go and say, well,
35:15
Speaker 1: how can we explain the cosmological constant? If it exists,
35:18
Speaker 1: if it's real, if it's there, what could be creating it?
35:22
Speaker 1: This energy of empty space is an attempt to calculate
35:25
Speaker 1: what the cosmological constant should be. Oh, I see, it's
35:29
Speaker 1: a theory. It's a hypothesis built on a hypothesis of
35:32
Speaker 1: a hypothesis, and because maybe it would work like if
35:35
Speaker 1: you if you then sat down and said, all right,
35:37
Speaker 1: what is the energy of empty space? And can I
35:40
Speaker 1: calculate it? And if I get the right number, if
35:42
Speaker 1: I get the number that actually measuring out there in
35:44
Speaker 1: the universe, that suggests that I'm right right, Okay. So
35:47
Speaker 1: they sat down and they said, all right, how much
35:50
Speaker 1: energy do we expect there to be an empty space?
35:53
Speaker 1: And you can calculate this because we know that there
35:55
Speaker 1: are quantum fields out there in empty space, like the
35:57
Speaker 1: Higgs field, which is not a zero. When the Higgs
36:00
Speaker 1: field is at its lowest level, it's not at zero.
36:04
Speaker 1: And we talked about this in another podcast. What would
36:06
Speaker 1: happen if the Higgs field collapse down to zero and
36:09
Speaker 1: destroy the universe. So we're we're lucky, We're happy that
36:12
Speaker 1: the Higgs field is not at zero. But then if
36:14
Speaker 1: you add up all the energy you think is stored
36:16
Speaker 1: in the Higgs field and various other fields, you get
36:18
Speaker 1: a number, and you compare that number to the number
36:21
Speaker 1: that we measure for the cosmological constant, and they're different.
36:26
Speaker 1: I see. So this idea that there's energy everywhere is
36:29
Speaker 1: not unusual. You're saying that all of the quantum fields
36:32
Speaker 1: have energy in them, and you're saying that they actually
36:36
Speaker 1: have too much energy. Yeah, the number you get is
36:38
Speaker 1: too big by a factor of ten to the one
36:41
Speaker 1: hundred and twenty. Maybe Higgs is fudging it too, you know,
36:47
Speaker 1: Higgs flavored fudge what that means? But could it be awesome?
36:50
Speaker 1: Maybe like a field that we don't know about. Is
36:53
Speaker 1: that possible to or like thinking like you know, maybe
36:56
Speaker 1: these fields are leaking or something. Yeah, exactly. People say, well,
36:58
Speaker 1: maybe there's another field there we haven't discovered, and it
37:01
Speaker 1: happens to cancel all the other ones to give us
37:04
Speaker 1: a really tiny number. And that's weird, right, Like, it's
37:08
Speaker 1: weird if these two things balance each other to a
37:11
Speaker 1: hundred and twenty decimal places to give us the number
37:14
Speaker 1: the reasure, let's call it the fudge field, the fudge field.
37:18
Speaker 1: And so that's not very satisfying, right, And then other
37:20
Speaker 1: people say, well, who cares about those other fields? It
37:23
Speaker 1: doesn't even have to be a field, doesn't even have
37:24
Speaker 1: to be the energy of empty space. It can just
37:26
Speaker 1: be a basic number of the universe, like maybe it's
37:30
Speaker 1: just a parameter of the universe like a remainder or
37:33
Speaker 1: just like a speed of light, you know, or the
37:36
Speaker 1: planks constant. You know. Maybe there's just a number and
37:39
Speaker 1: it's part of the universe. Yeah, yeah, exactly. And people
37:43
Speaker 1: don't like that answer either, because then well why this
37:46
Speaker 1: number and not any other number? And to answer that
37:49
Speaker 1: you have to go multiverse, which is also unsatisfying. I
37:52
Speaker 1: feel like we're stagging crazy hypothetical ideas one and top
37:56
Speaker 1: of the other. How deep does this go, Daniel? This
37:58
Speaker 1: is about as deep as it goes. Once you get
38:00
Speaker 1: to the anthropic principle and the multiverse, you really can't
38:02
Speaker 1: go deeper into the scientific bologna. You gotta throw your
38:05
Speaker 1: heads up and be like, that's just the way it is. Folks.
38:07
Speaker 1: Well you're drowning and scientific bologna at that point. So
38:10
Speaker 1: we're out of fudge. That's it. We filled the pool
38:13
Speaker 1: with fudge and we're in the deep end. Now, Well,
38:15
Speaker 1: what is this anthropic principle? I think it means that
38:19
Speaker 1: things are just the way they are, and we think
38:21
Speaker 1: it's weird only because we happen to exist. Yeah. It
38:23
Speaker 1: says when you have a random number, you can't explain.
38:26
Speaker 1: It says, well, maybe there's an infinite number of universes,
38:29
Speaker 1: and each one has a different random number, and only
38:32
Speaker 1: in the universes where that random number happens to be
38:34
Speaker 1: what it is, so that you can't have intelligent life?
38:37
Speaker 1: Do you have intelligent life asking why is that number?
38:40
Speaker 1: What I see? There are other universes where this cosmological
38:45
Speaker 1: constant is different, but there's nobody around to ask the question. Yeah,
38:49
Speaker 1: if on those other universes the cosmological constant was some
38:52
Speaker 1: crazy big number and the universe just like exploded in
38:55
Speaker 1: the first bill a second and no interesting structure formed,
38:58
Speaker 1: and you didn't get you know, awesome podcasts asking about
39:01
Speaker 1: the nature of the universe, or maybe there are universes
39:04
Speaker 1: where you know that there are the two guys having
39:07
Speaker 1: a podcast. They're wondering, I wonder why pie is seven
39:10
Speaker 1: point six. They must live in a different geometrical space then,
39:14
Speaker 1: But yeah, and I find that answer totally unsatisfying because
39:18
Speaker 1: it's kind of like saying there is no answer, stop asking,
39:22
Speaker 1: And that's not who I am. You know, I'm always
39:24
Speaker 1: asking questions. I always want to dig deeper. I just
39:27
Speaker 1: want to know why. You're like, I'm sure Einstein was wrong.
39:29
Speaker 1: I know it. I'm pretty sure Einstein was wrong. I
39:33
Speaker 1: have to go on team not Einstein. Oh I see
39:36
Speaker 1: anti Einstein. Oh man. I mean I'm pro Eenstein in general,
39:40
Speaker 1: but in this one, I don't think you guys right?
39:42
Speaker 1: All right, well, I think that clears it up a
39:44
Speaker 1: lot for me. How all these things are related. Um,
39:47
Speaker 1: so let me try to recap then. So we know
39:49
Speaker 1: the universe is expanding, and we call that dark energy.
39:53
Speaker 1: We know the universe expanding, and its expansion is accelerated, right,
39:56
Speaker 1: It's getting faster and faster, and we don't know what
39:59
Speaker 1: it is in any of our equations. We just call
40:01
Speaker 1: it dark energy, and so we have a theory about
40:03
Speaker 1: what it could be, and maybe it's due to gravity,
40:06
Speaker 1: and so that's where the cosmological constant comes in. And
40:10
Speaker 1: then we don't have a good explanation for the cosmological constants,
40:13
Speaker 1: so we just poured a lot of fudge in it
40:14
Speaker 1: and then call it. Call it the energy of not energy.
40:19
Speaker 1: And that's right, the fudge of empty space. All right? Well, um,
40:25
Speaker 1: and I think it's been pretty interesting that to think
40:27
Speaker 1: about these huge questions about the universe, you know, and
40:29
Speaker 1: how how ay we don't know what's going on and
40:32
Speaker 1: be how you know, even people like Einstein are sort
40:35
Speaker 1: of grasping it strong sometimes. That's right, And we made
40:38
Speaker 1: a little bit of fun of science here for having
40:40
Speaker 1: silly ideas. But you know, this is how real science
40:43
Speaker 1: gets done. When you're on the forefront of human ignorance,
40:45
Speaker 1: you try crazy stuff and you say, well, maybe it's
40:48
Speaker 1: something like this. Can we make this work? Can we
40:50
Speaker 1: make that work? Because you know, the universe is ridiculous,
40:53
Speaker 1: and so no ridiculous ideas should be discarded because it
40:56
Speaker 1: might be correct, it might be accurate, it might describe
40:59
Speaker 1: our ridiculous reality. This is the best we can do, folks.
41:03
Speaker 1: It's a process, right, you want to join in the fun,
41:05
Speaker 1: Go study physics, that's right. If you've ever done any writing,
41:08
Speaker 1: you know the rough draft is always pretty roub. And
41:11
Speaker 1: that's where we are now. All right, Well, thank you
41:15
Speaker 1: very much to Pascal for asking this question, and we
41:17
Speaker 1: hope that helps you sleep a little bit better at night.
41:20
Speaker 1: That's right, And remember that the biggest questions in the universe,
41:23
Speaker 1: about the biggest universe out there are still unsolved, which
41:26
Speaker 1: means you might be the person to figure them out.
41:29
Speaker 1: Thanks for joining us. See you next time before you
41:39
Speaker 1: still have a question after listening to all these explanations,
41:42
Speaker 1: please drop us a line. We'd love to hear from you.
41:45
Speaker 1: You can find us on Facebook, Twitter, and Instagram at
41:48
Speaker 1: Daniel and Jorge That's one Word, or email us at
41:51
Speaker 1: Feedback at Daniel and Jorge dot com. Thanks for listening
41:55
Speaker 1: and remember that Daniel and Jorge Explain the Universe is
41:58
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