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Did our Universe evolve? · Daniel and Kelly’s Extraordinary Universe

0:00
Speaker 1: Hi, it's Jorge and Daniel here. And this holiday season,
0:03
Speaker 1: if you're looking for a gift for yourself, for a friend,
0:06
Speaker 1: or for your your family, why not get him the
0:09
Speaker 1: Gift of Answers about the Universe. To check out our
0:11
Speaker 1: new book Frequently Asked Questions about the Universe, you can
0:14
Speaker 1: find details at Universe f a Q dot com. Thanks
0:18
Speaker 1: for supporting the podcast. Happy holidays everyone, Hey or hey?
0:31
Speaker 1: Do you think that our universe is well suited to us?
0:35
Speaker 1: I don't know. I mean, some of it seems so
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Speaker 1: staggeringly beautiful to our eyes, you know, like stars, the galaxies,
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Speaker 1: even like the drama of the black holes. That's true,
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Speaker 1: it's definitely something we can appreciate, but also sometimes seems
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Speaker 1: like the universe is kind of alien to us. I
0:52
Speaker 1: think the universe is here first, so technically we are
0:54
Speaker 1: the eighteen Yeah, but you know, sometimes the way that
0:56
Speaker 1: it works is so bizarre and so strange that I
0:59
Speaker 1: wonder if we're ever going to understand it, if our
1:02
Speaker 1: minds are suited to it, maybe that's what makes it
1:05
Speaker 1: especially suited to us. What do you mean? You know,
1:08
Speaker 1: it's like the perfect puzzle to keep us entertained. For
1:10
Speaker 1: attorney it's like that toy you put in front of
1:12
Speaker 1: a toddler. Why you need to get some work done.
1:14
Speaker 1: It's like the TV for human toddlers. Maybe Steve Jobs
1:17
Speaker 1: created the universe. Hi, I'm poor Hammad, cartoonists and the
1:35
Speaker 1: creator of PhD comics. Hi I'm Daniel. I'm a particle physicist,
1:39
Speaker 1: and I'm constantly amazed at the strangeness and the bonkers
1:43
Speaker 1: nous of the universe that we live in. Do you
1:46
Speaker 1: think the universe is bonkers? Like it is bonkers or
1:49
Speaker 1: it was made bonkers or made by a bonkers I
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Speaker 1: won't speak to the mind of the creator if one exists,
1:55
Speaker 1: but it does continue to astound me how strange and
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Speaker 1: how weird the univer is, and the fact that it
2:01
Speaker 1: is weird, that it seems strange, that it's counter to
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Speaker 1: our expectations because we are part of the universe, So
2:07
Speaker 1: why doesn't it feel intuitive to us? Well, you know
2:09
Speaker 1: what I always say, if your expectations are not being met,
2:12
Speaker 1: maybe you should change your expectations, Daniel, I should try
2:15
Speaker 1: the Scandinavian approach. Just expect to be disappointed all the
2:18
Speaker 1: time and then be pleased when you're not, or expect
2:21
Speaker 1: to be surprised. You know, it's only weird because you
2:23
Speaker 1: think it's weird because it doesn't mean but really, really,
2:28
Speaker 1: the universe was here first, so that's true. Maybe the
2:30
Speaker 1: universe thinks we're weird. We are kind of bonkers after all.
2:34
Speaker 1: Welcome to our bonkers podcast. Daniel and Jorge Explain the Universe,
2:37
Speaker 1: a production of I Heart Radio in which we have
2:40
Speaker 1: no idea what the universe thinks of us, but we
2:43
Speaker 1: do dive deep into what human minds think about the universe,
2:46
Speaker 1: the questions we have about the way it works. At
2:49
Speaker 1: the tiniest scale of frothing buzzing quantum particles to the
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Speaker 1: very biggest scale of galaxy formations and the entire fate
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Speaker 1: of the universe. We question the very nature of reality,
3:00
Speaker 1: peel it back to see what's going on underneath, and
3:02
Speaker 1: we explain all of it to you, at least as
3:05
Speaker 1: far as we understand. Yeah, because it is a pretty
3:08
Speaker 1: big universe, and there's a lot that seems very puzzling
3:10
Speaker 1: and perplexing to us. It's, you know, wonderful and amazing
3:14
Speaker 1: and beautiful it seems sometimes but also a little bit
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Speaker 1: terrifying and powerful and sometimes even dangerous. It sometimes seems
3:21
Speaker 1: amazing that we even live here. You know, we could
3:23
Speaker 1: have been wiped out by a supernova nearby, or could
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Speaker 1: be that with small changes in the nature of the particles,
3:29
Speaker 1: we couldn't have had the chemistry we need for life
3:31
Speaker 1: to happen. Sometimes it seems like a lot of things
3:33
Speaker 1: had to go just right for us to evolve and
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Speaker 1: to survive. Yeah, and if we hadn't been here, who
3:39
Speaker 1: would be asking these questions? Daniel, That's the main question.
3:42
Speaker 1: Probably some better looking, smarter version of us. If that's yeah, impossible,
3:49
Speaker 1: but we just disproved that theory or improbable at least.
3:53
Speaker 1: But yeah, it is a pretty amazing universe. And sometimes
3:55
Speaker 1: you have to wonder, like, how did it come to
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Speaker 1: be like that? And how coming it came to be?
4:00
Speaker 1: And we are here and we are looking at it
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Speaker 1: and wondering how it works. That's right, and that is
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Speaker 1: one of the deepest questions in physics. We are often
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Speaker 1: asking how do things work? What's going on with these particles?
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Speaker 1: But underlying that there is a question standing in the
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Speaker 1: wings waiting for an answer, and that question really is
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Speaker 1: why this universe? Why is the universe of this one
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Speaker 1: and not some other one? Could it have been a
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Speaker 1: different universe, or is this the only possible way for
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Speaker 1: universe to exist? What does it mean that we ended
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Speaker 1: up in this universe? Well, for thankful that we are
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Speaker 1: in this universe, I guess, or that this universe is
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Speaker 1: here for us. But to understand these questions sometimes you
4:36
Speaker 1: kind of have to look outside of physics to think
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Speaker 1: about the new ways in which you might answer these
4:40
Speaker 1: types of queries. That's right, And when we look to biology,
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Speaker 1: for example, we find a very compelling and very powerful,
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Speaker 1: very broadly useful argument for understanding why creatures exist and
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Speaker 1: have certain traits. When we look at, for example, the
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Speaker 1: beaks of birds and ask like, why do they have
4:55
Speaker 1: that shape? We get the answer when we look at
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Speaker 1: the nuts they eat or they bug that they have
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Speaker 1: to pick up. They seem to be very well suited
5:03
Speaker 1: to their environment and for a reason. Yeah, So to
5:06
Speaker 1: be on the podcast really asking the question is the
5:13
Speaker 1: universe the result of natural selection? All right? We're asking
5:19
Speaker 1: some big questions. Did they hear? I know that's sort
5:21
Speaker 1: of mind blowing to imagine, Like the universe is a
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Speaker 1: bird on an island somewhere picking on bugs. I thought
5:27
Speaker 1: we were the birds, aren't we the birds. I think
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Speaker 1: we might be the bugs and or the nuts, like
5:33
Speaker 1: the nuts are we're wondering how some some things are
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Speaker 1: are suited to eat us. No, we are the birds,
5:39
Speaker 1: and when physics is the nuts and we're trying to
5:40
Speaker 1: crack it open. Oh boy, I'm getting lost in these
5:43
Speaker 1: analogies here. I know I'm driving you nuts, But it
5:46
Speaker 1: is a fun idea to wonder if the universe could
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Speaker 1: have been other ways, and if the universe that we
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Speaker 1: ended up when is this way because of some sort
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Speaker 1: of process that guides the formation of universes to end
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Speaker 1: up at one that sort of works. WHOA you mean
6:01
Speaker 1: like the evolution of universe is multiple universes over countless time,
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Speaker 1: somehow changing and evolving. Yeah, that's the idea. We have
6:12
Speaker 1: talked about multiverses and many times on this podcast. But
6:15
Speaker 1: this is sort of like a different take. Instead of
6:17
Speaker 1: imagining the universe is actually many universes all sort of
6:20
Speaker 1: rolled up into one grand idea, this is like maybe
6:23
Speaker 1: our universe is in competition with other universes on some
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Speaker 1: sort of like meta universe playing field. WHOA like an
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Speaker 1: African savannah but for universes. And then there's some kind
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Speaker 1: of predator, some universe predator, some universe eating. I think
6:38
Speaker 1: I saw that on an episode of the new show
6:39
Speaker 1: Look what can eat an entire universe? Exactly right, and
6:43
Speaker 1: so maybe Marvel got it right. As usual, they can
6:46
Speaker 1: do no wrong. Well, this is a kind of a
6:49
Speaker 1: mind bogging question, big ideas here, and so we were
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Speaker 1: wondering how many people out there had thought about the
6:55
Speaker 1: universe as evolving and or as being the result of
6:58
Speaker 1: something like natural select. So Daniel went out there as
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Speaker 1: usual and ask people on the internet what they thought
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Speaker 1: of this question. That's right, and so thank you to
7:06
Speaker 1: everybody who's willing to entertain my crazy questions without the
7:09
Speaker 1: opportunity to think about it or to prepare. If you'd
7:13
Speaker 1: like to participate for a future episode, we would love
7:15
Speaker 1: to hear your voice on the podcast. Just to write
7:17
Speaker 1: us an email, no special equipment required. Shoot us an
7:20
Speaker 1: email two questions at Daniel and Jorge dot com. So
7:24
Speaker 1: think about it for a second. If someone asked you
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Speaker 1: what is cosmological natural selection? What would come to mind
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Speaker 1: in your brain? Here's what people had to say. I'm
7:34
Speaker 1: gonna say those bodies orbiting around a star that have
7:41
Speaker 1: the most stable gravitational orbits last the longest. Every star
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Speaker 1: for itself, may the strongest in the universe survive and
7:51
Speaker 1: the weakest universal objects becomes space test well, I guess
7:55
Speaker 1: planet stars, gallessies, etcetera. Survival of the fittest would apply
8:00
Speaker 1: to another star is more likely to pass on positive traits.
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Speaker 1: Does that have an influence on the next generation stars.
8:10
Speaker 1: Maybe it's a theory that explains why there are no
8:13
Speaker 1: medium sized black holes by using an analogy from evolution.
8:17
Speaker 1: Maybe there were some conditions in the environment that made
8:19
Speaker 1: them go extinct, while the supermassive black holes with you
8:23
Speaker 1: today lived on and appropriated. Assuming that's the thing they
8:26
Speaker 1: can do, all right. Nobody said in African Savannah with
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Speaker 1: the universes, nobody talked about something eating universes. It's a
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Speaker 1: pretty crazy idea to encapsulate in just three words, cosmological
8:38
Speaker 1: natural selection. So we didn't give them a whole lot
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Speaker 1: to go on. It seems like people didn't trigger something
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Speaker 1: big in their heads. Like most people stuck to stars
8:45
Speaker 1: or galaxies as maybe evolving, but nobody thought about the
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Speaker 1: universe evolving. It's sort of too crazy, you know, it's
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Speaker 1: sort of too big an idea to even leap to
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Speaker 1: from this concept. It's sort of bold. But you know,
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Speaker 1: I like that. I like that about bold ideas. Like
8:59
Speaker 1: for as you hear about someing, you think, what, that's great.
9:02
Speaker 1: Hold on a second, maybe that makes a little bit
9:04
Speaker 1: of sense. That's the nice thing about crazy, big ideas.
9:07
Speaker 1: I guess. You know, even ideas like the multiverse, at
9:10
Speaker 1: some point, you know, seem crazy and insane, and but
9:13
Speaker 1: now people seem to kind of accept it, and some
9:16
Speaker 1: people even assume it's true, like people like Marvel. That
9:20
Speaker 1: you can't necessarily turn that around. Just because some ideas
9:23
Speaker 1: which now make a lot of sense once seemed crazy
9:26
Speaker 1: doesn't mean that every crazy seeming idea will eventually make sense,
9:30
Speaker 1: right right, right. Sense only works one way, It only
9:33
Speaker 1: makes sense, it makes sense one way. There are a
9:35
Speaker 1: lot of crazy seeming ideas that we don't talk about
9:37
Speaker 1: it anymore because they still seem crazy right the whole,
9:40
Speaker 1: Like the universe is like turtles and turtles all the
9:44
Speaker 1: way down on top of some elephants or something that
9:48
Speaker 1: also seemed bonkers. But that doesn't mean it's true. Yeah, exactly,
9:52
Speaker 1: it's gotta have some legs, it's got to solve some problems,
9:54
Speaker 1: it's got to open up avenues for exploration, and it's
9:57
Speaker 1: got to sort of hang together mathematically. Well, I mean,
10:00
Speaker 1: turtles do solve all problems you think about it, and
10:03
Speaker 1: they have legs and they do have legs. Yeah, although
10:05
Speaker 1: they do it kind of slowly, so I mean we're
10:07
Speaker 1: still waiting for those turtles. All right, Well, to step
10:09
Speaker 1: us through this, Daniel, this big idea, what is the
10:12
Speaker 1: cosmological natural selection? So cosmological natural selection is a really
10:16
Speaker 1: fun creative idea by a physicist named Lee Smollen, a
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Speaker 1: theoretical physicist, and it's in solution to what physics calls
10:25
Speaker 1: a fine tuning problem, which is just a fancy way
10:28
Speaker 1: of saying, like, why is the universe the way that
10:31
Speaker 1: it is, because it seems like it could have been
10:34
Speaker 1: lots of other ways. So before we dig into how
10:37
Speaker 1: he tries to answer that question, let's make sure we
10:40
Speaker 1: have like a good grasp on what the question is.
10:42
Speaker 1: What is the problem we're trying to solve. Why is
10:44
Speaker 1: the tricky to understand that the universe is this way
10:46
Speaker 1: and not some other way? Right? Because you know, as physicist,
10:49
Speaker 1: you've been sort of drilling down on the equations that
10:52
Speaker 1: make the universe work, and at some point you come
10:54
Speaker 1: upon something that you're like, you can't explain, like it
10:57
Speaker 1: just seems to be the way it is, because it
10:59
Speaker 1: seems to be the way it is, Like you can't
11:01
Speaker 1: really explain why pious three point one four or the
11:04
Speaker 1: cosmological constant is is X. Right, that's exactly right. You know.
11:08
Speaker 1: The grand goal of physics is to summarize everything we see,
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Speaker 1: all phenomena, all matter, all energy, all forces in terms
11:16
Speaker 1: of one concept, you know, like maybe a single equation
11:19
Speaker 1: that we could write onto a T shirt. And so
11:21
Speaker 1: we've made a lot of progress there. We have a
11:23
Speaker 1: few equations. They don't quite fit onto a T shirt,
11:26
Speaker 1: but they're kind of beautiful and compact, and you know,
11:28
Speaker 1: they describe a portion of the universe that we understand
11:31
Speaker 1: that we've explored. Well, it depends on the size of
11:33
Speaker 1: your your T shirt. Just get a bigger T shirt,
11:36
Speaker 1: Like I said, just adjust your expectations of what a
11:38
Speaker 1: T shirt uh is or how many people can fit in.
11:42
Speaker 1: It might solve your problem. That's right. If we go
11:44
Speaker 1: to micro font and then it's no problem. We can
11:46
Speaker 1: describe the whole universe on a T shirt. But currently
11:49
Speaker 1: we have this model of particles and their interactions. We
11:52
Speaker 1: call it the standard model, and as you say, there
11:54
Speaker 1: are parts of it that we don't understand, you know,
11:56
Speaker 1: not just the structure, but there's lots of questions about
11:58
Speaker 1: the structure of you know, like why are their copies
12:01
Speaker 1: of these particles electron, Muan, Tau, but also just we
12:04
Speaker 1: find numbers in these equations, and those numbers have no
12:08
Speaker 1: explanation that we can find. They are just numbers, and
12:11
Speaker 1: the theory doesn't tell us what those numbers have to be.
12:13
Speaker 1: We have to go out and measure them. One of
12:15
Speaker 1: these numbers, for example, as you say, is the cosmological constant,
12:19
Speaker 1: this rate at which the universe seems to be expanding.
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Speaker 1: We don't know why that number is what it is.
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Speaker 1: We have no theoretical prediction for what it should be.
12:27
Speaker 1: It's just like a placeholder, like a parameter. It's sort
12:29
Speaker 1: of like you're in the control panel for the universe
12:32
Speaker 1: and it just has these knobs. You know. The structure
12:35
Speaker 1: of the universe is this control panel, and you could
12:37
Speaker 1: turn the values of these parameters up or down and
12:40
Speaker 1: maybe get different universes that follow the same basic laws
12:43
Speaker 1: of physics. But you know, with different settings on those knobs, right,
12:46
Speaker 1: they seem like arbitrary, like somebody came in before you
12:49
Speaker 1: and adjusted to those dials, and then you came in
12:52
Speaker 1: and you're like, why did you set these dials? Yes, exactly,
12:54
Speaker 1: we have no explanation and for why these numbers are
12:56
Speaker 1: where they are. And you might be tempted to think
12:58
Speaker 1: about numbers like this speed of light because we don't
13:01
Speaker 1: know why the speed of light is the speed of light,
13:03
Speaker 1: you know, why isn't it not faster or slower. It's
13:06
Speaker 1: a little tricky because the speed of light has units
13:09
Speaker 1: on it, right, it's meters per second. So the actual
13:12
Speaker 1: number there depends on the units you choose. If you
13:15
Speaker 1: change the meter or change the second, you get a
13:17
Speaker 1: different number. So physicists like to focus on dimensionless numbers.
13:20
Speaker 1: You can rearrange all these constants of the universe in
13:24
Speaker 1: ratios and whatever to get rid of the units in
13:26
Speaker 1: unit with pure numbers numbers that just are. And you know,
13:29
Speaker 1: if all those numbers were one, we'd be like, cool,
13:33
Speaker 1: that makes sense. Where if all those numbers were ten
13:35
Speaker 1: or something, it would make sense. But they're all really different.
13:37
Speaker 1: Some of them are really small, some of them are
13:39
Speaker 1: really large, and we just have no explanation for them. So,
13:41
Speaker 1: as you say, they seem kind of arbitrary, and we wonder,
13:44
Speaker 1: you know, like could they be different? Could you have
13:47
Speaker 1: had another universe with different values of those numbers? And
13:50
Speaker 1: we think through like what the physics could be like.
13:52
Speaker 1: But the physics would be really really different in the
13:54
Speaker 1: universe would be totally different from the one we see.
13:57
Speaker 1: And so we wonder, like, why are these values what
14:00
Speaker 1: they are? They seem to be sort of just right
14:02
Speaker 1: to give us the universe that we have. So these
14:05
Speaker 1: are like ratios, I imagine it would be like saying,
14:08
Speaker 1: what is the rate at which the universe is expanding?
14:10
Speaker 1: It's like, you know, there's seven point four seven percent
14:14
Speaker 1: and so that's that's a dimensionless constant to write a percentage.
14:17
Speaker 1: So is that what you mean? Like ratios of like
14:18
Speaker 1: the number of so and so particles through so and
14:21
Speaker 1: so other particles. Yeah, that kind of thing. So one
14:24
Speaker 1: of the most important dimensionless constant is called the fine
14:26
Speaker 1: structure constant. It includes the speed of light and the
14:30
Speaker 1: charge of the electron and planks constant. And if you
14:33
Speaker 1: change that number, then physics changes because that affects like
14:36
Speaker 1: how strongly. Electrons and pausit trying to repel each other,
14:39
Speaker 1: and you know the distances at which things feel these
14:42
Speaker 1: kinds of forces. Other important ones are ratios of the
14:45
Speaker 1: masses of the particles, like why is the muan so
14:48
Speaker 1: much heavier than the electron? Why is the top corks
14:51
Speaker 1: so much heavier than everything else? You know, if you
14:54
Speaker 1: change those numbers, you also really change how physics work,
14:57
Speaker 1: you know, like what if the electron wasn't the light
15:00
Speaker 1: just leapt on? What if we had muans in our
15:02
Speaker 1: bodies instead of electrons because muans were lighter mass, Like
15:05
Speaker 1: that would really change everything, right, But you're you're really
15:08
Speaker 1: sort of asking two questions, right, aren't you. Like you're asking,
15:11
Speaker 1: for example, in the case of the electron, like what
15:13
Speaker 1: is the mass of the electron the way it is?
15:15
Speaker 1: And also why is the mass of the other cousins
15:19
Speaker 1: of the electron you know a certain number of times
15:22
Speaker 1: dead mass with the electron? Yeah, exactly. And so there's
15:24
Speaker 1: lots of different ways you're going to arrange these things.
15:26
Speaker 1: But fundamentally, we're looking at a set of numbers, and
15:29
Speaker 1: those numbers control the way the universe is, and we
15:32
Speaker 1: don't know why those numbers are what they are, and
15:36
Speaker 1: you know, as you said earlier, one possible explanation is,
15:39
Speaker 1: we know if those numbers were different, who would be
15:42
Speaker 1: here asking that question? And that's a popular answer, and
15:46
Speaker 1: it goes by the name of the anthropic principle. It
15:48
Speaker 1: just says that if the numbers were different, you wouldn't
15:50
Speaker 1: get humans and you wouldn't get intelligence, and nobody would
15:53
Speaker 1: be asking. So only in a universe where things happen
15:56
Speaker 1: to work in just this way do you have people
15:58
Speaker 1: to ask that question? So you want to ask that
16:00
Speaker 1: question when it's possible, And that's sort of like a
16:03
Speaker 1: circular explanation, but a lot of people like that answer.
16:05
Speaker 1: Sort of like my kids asking why is our house
16:07
Speaker 1: designed that way? It's like they are just born into
16:10
Speaker 1: the house. Been born in a different house, they would
16:12
Speaker 1: be asking a different question about that house. Yeah. Or
16:15
Speaker 1: it's like kids asking, you know, why am I here?
16:18
Speaker 1: Why was I created? And not some other kid? You know, like, well,
16:21
Speaker 1: if I had had a different kid, because you know,
16:23
Speaker 1: you've been conceived in a different moment, that kid might
16:25
Speaker 1: be asking the same question, or you know, have different
16:28
Speaker 1: interests or whatever, ask a different question. Right, Basically, you
16:31
Speaker 1: want to tell your kids they're not special. Of course,
16:35
Speaker 1: my kids are special. Everybody else kids I don't know about. Yeah,
16:39
Speaker 1: it sounds like anthropic parenting. And my complaint with this
16:44
Speaker 1: is that it's sort of like giving up. It's sort
16:46
Speaker 1: of like saying there is no explanation, look no further,
16:49
Speaker 1: Whereas what I like in science is when you're always
16:52
Speaker 1: trying to dig deeper. You're always saying, there must be
16:55
Speaker 1: a reason for this to happen. Let's look deeper, because
16:57
Speaker 1: it's possible that there is a deeper sir. Right, We
17:00
Speaker 1: certainly don't have the final theory of physics. We know
17:04
Speaker 1: that our description of particles and their interactions is flawed
17:07
Speaker 1: and limited, because we know, for example, it breaks down
17:09
Speaker 1: if you have really really high energies. Our theory just
17:12
Speaker 1: doesn't work. And so we know we need some sort
17:14
Speaker 1: of deeper theory. And so maybe you know there is
17:17
Speaker 1: some deeper explanation one we just haven't found yet, that
17:19
Speaker 1: explains these values and says these values have to be
17:22
Speaker 1: certain numbers, like, there's not arbitrary. It only works if
17:26
Speaker 1: they are these numbers. We just don't quite see the
17:28
Speaker 1: full picture yet, And so I don't like the entropic answer,
17:31
Speaker 1: because I always want to strive for that deeper understanding, right,
17:34
Speaker 1: Like maybe you'll dig deeper into the equations and find
17:37
Speaker 1: that if the electron had half the mass that it
17:39
Speaker 1: does right now, it just doesn't make for a logical
17:42
Speaker 1: universe or like a universe dead. You know, it gives
17:45
Speaker 1: you tupiles to equal seven, Like that's what you want.
17:47
Speaker 1: You wanted to boil it down to one question and say, look,
17:49
Speaker 1: if you change this, then you wouldn't it wouldn't logically work, right,
17:53
Speaker 1: because that's kind of the only alternative when you say,
17:55
Speaker 1: like it's think things have to be a certain way,
17:57
Speaker 1: like not being able to be a certain way mean
18:00
Speaker 1: that it would be illogical. Yeah, And people are looking
18:03
Speaker 1: for a theory of the universe that's self consistent, right,
18:06
Speaker 1: So the sort of philosophical implication there is that only
18:09
Speaker 1: self consistent universes can exist. And so maybe there's a
18:13
Speaker 1: reason why those other values of those numbers make for
18:16
Speaker 1: some inconsistency, and there you need to have some sort
18:20
Speaker 1: of physics principle we haven't yet discovered, right that shows
18:23
Speaker 1: us why those things would be inconsistent, you know, And
18:26
Speaker 1: we don't have that, but we can sketch the sort
18:28
Speaker 1: of like rough idea. You know, maybe for example, string
18:31
Speaker 1: theory is correct, and at the basic level the universe
18:34
Speaker 1: are these little, tiny vibrating strings and they can only
18:37
Speaker 1: vibrate in certain ways and because of their basic fundamental nature,
18:41
Speaker 1: and that leads to certain properties that we then measure,
18:44
Speaker 1: you know, at our scale, which have to come out
18:46
Speaker 1: this certain way, and that you just can't have an
18:48
Speaker 1: electron with a different charge, and you can't have them
18:50
Speaker 1: you want with four times as much mass as the electron.
18:53
Speaker 1: You have to have the numbers that we have now,
18:56
Speaker 1: and it comes out of some deeper logic that we
18:58
Speaker 1: just don't know yet. So we don't have that theory yet,
19:00
Speaker 1: but you know, you can imagine that kind of theory existing, right.
19:03
Speaker 1: But that is still satisfy you though as a physicist,
19:06
Speaker 1: like did you say, Well, that's just the way the
19:07
Speaker 1: universe is, and it has to be that way because
19:10
Speaker 1: of the way the universe is. I'll never be satisfied,
19:12
Speaker 1: absolutely not when we get that answer that explains all
19:15
Speaker 1: the mysteries we see today. There will just always be
19:17
Speaker 1: more questions. And that's what I don't like about the
19:19
Speaker 1: anthropic principle because it stops you from asking that next
19:22
Speaker 1: round of questions, whereas I feel like science is this
19:25
Speaker 1: cycle of digging every deeper into the most basic questions.
19:27
Speaker 1: And you know, even if we exhaust physics and we
19:30
Speaker 1: get just one single theory that describes the whole universe,
19:33
Speaker 1: will always have philosophy because we can always ask like, well,
19:35
Speaker 1: what does it mean? Man? What does it mean? And
19:39
Speaker 1: that's one potential way to answer why the universe is
19:43
Speaker 1: the way it is, Why those numbers are all the
19:44
Speaker 1: way that the numbers that they are. Maybe there's some
19:47
Speaker 1: asked yet to be discovered, you know, equation or theory
19:50
Speaker 1: that explains them all that makes them want to be
19:52
Speaker 1: those numbers or makes them have to be those numbers.
19:55
Speaker 1: But then there's another theory about what could explain them, right, Yeah,
19:58
Speaker 1: And another way to approach this problem is to say,
20:01
Speaker 1: maybe the values aren't arbitrary, maybe they are random, Like
20:06
Speaker 1: maybe it's possible to have different universes with different values,
20:10
Speaker 1: and all the universes would all the different values exist.
20:14
Speaker 1: This is the multiverse explanation to say that maybe all
20:17
Speaker 1: those possible universes are out there with these different values
20:20
Speaker 1: of the parameters, and there's different physics in each one,
20:23
Speaker 1: and this just happens to be the one that we
20:24
Speaker 1: are in, right. It's like you walk into a control room.
20:27
Speaker 1: You see all the knobs turning to a certain number
20:29
Speaker 1: for all the values of the universe, and you're like,
20:31
Speaker 1: why are they like this? And the answer is sort
20:33
Speaker 1: of like, well, that's because there's another control room next
20:36
Speaker 1: to you with the value said a little bit different,
20:38
Speaker 1: and next to that one is another control with the
20:40
Speaker 1: value said a little bit different at up to infinity.
20:43
Speaker 1: That's sort of an explanation, and it doesn't answer questions like,
20:46
Speaker 1: you know, well, who chooses those values? Or is it
20:49
Speaker 1: truly random like quantum mechanically random, or is it like
20:52
Speaker 1: systematic where you get one universe for every possible value?
20:56
Speaker 1: Are there an infinite number of them? There's so many
20:58
Speaker 1: questions opened up by that, and unfortunately, it's pretty difficult
21:02
Speaker 1: to probe that kind of theory, like where do you
21:04
Speaker 1: go from here? You know, if those universes exist or not?
21:07
Speaker 1: You know, can we ever discover them? No? Can we
21:09
Speaker 1: interact with them? No? So can we prove fundamentally that
21:13
Speaker 1: they exist? Folks like Sean Carroll would argue that you
21:16
Speaker 1: can sort of implicitly prove they exist if you demonstrate
21:20
Speaker 1: that it's the only way to make sense of the universe,
21:23
Speaker 1: that our theory of physics requires that they exist, and
21:27
Speaker 1: it's the only theory that you can develop. It's a
21:30
Speaker 1: bit weaker than actually finding them and exploring them. But
21:34
Speaker 1: you know, it's an argument to suggest that the multiverse
21:36
Speaker 1: might be real because I guess that would sort of
21:38
Speaker 1: explain why we have the one we have is that
21:40
Speaker 1: it's just like a random role to die, although you
21:43
Speaker 1: could you make the argument that you know, the universe
21:46
Speaker 1: only role to die ones like does it have to
21:48
Speaker 1: roll to die an infinite number of times? It's a
21:50
Speaker 1: great question and one it's hard to probe. But what
21:52
Speaker 1: we can do is look at the numbers that we
21:54
Speaker 1: have and ask are they likely? Is this a likely arrangement?
21:58
Speaker 1: And here we're get into really fuzzy territory. But physicist
22:01
Speaker 1: look at the numbers we have and they feel weird
22:03
Speaker 1: about them. They're like, the cosmological constant is very small,
22:07
Speaker 1: and these other numbers seem kind of large, and why
22:10
Speaker 1: is gravity so so weak? And you know why all
22:13
Speaker 1: the forces have such a different strengths, And they make
22:15
Speaker 1: these really handwavy arguments that suggest that the numbers we
22:19
Speaker 1: have are somehow improbable or unnatural, and it's more likely
22:24
Speaker 1: to get a different set of values, and that makes
22:25
Speaker 1: our universe seems sort of like weird on this like
22:29
Speaker 1: multiverse landscape. And I don't know if that's an argument
22:32
Speaker 1: against the multiverse exactly, but it suggests that you might
22:35
Speaker 1: need some sort of mechanism to explain why we have
22:38
Speaker 1: these numbers. And if this is the only one, then
22:41
Speaker 1: you know, the universe are really unlucky or lucky, depending
22:44
Speaker 1: on your point of view. I think that the universe
22:46
Speaker 1: is totally lucky to have us, at least you, Daniel.
22:48
Speaker 1: At least we're lucky to have you. All right, Well,
22:51
Speaker 1: we have this big question about why the universe is
22:53
Speaker 1: the way it is. There are some theories, but they
22:55
Speaker 1: are a little bit unsatisfying, and so there's sort of
22:58
Speaker 1: a new or emerging idea that's is really interesting and
23:02
Speaker 1: it's all about evolution. So let's get into that. But
23:05
Speaker 1: first let's take a quick break. All right, Daniel, what
23:20
Speaker 1: does it all mean? Man? Why are we here? Why
23:23
Speaker 1: is the universe way it is? What does it seem
23:25
Speaker 1: so suited to us? For us to be comfortable in
23:27
Speaker 1: our houses. Here having a conversation about the way it works. Yeah, exactly.
23:31
Speaker 1: Maybe we are just the beaks of those birds, perfectly
23:35
Speaker 1: evolved to fit into the trees and grab out those grubs.
23:38
Speaker 1: And you know, that's the inspiration, is that we see
23:41
Speaker 1: in biology that it's not random that animals are well
23:45
Speaker 1: suited to their environments, that they're very fine tuned, right,
23:48
Speaker 1: And they're fine tuned for a reason. There's a mechanism there.
23:51
Speaker 1: Natural selection operates by enhancing those that are well suited
23:55
Speaker 1: right and killing off those that are not, And so
23:57
Speaker 1: you're more likely to end up with ers that are
24:00
Speaker 1: well suited to the environment. So the environment then shapes
24:03
Speaker 1: the nature of the critters. And so the idea was,
24:06
Speaker 1: take that and can we use that to explain sort
24:09
Speaker 1: of how we find the universe to be fine tuned?
24:11
Speaker 1: Is there some mechanism we can use to explain how
24:14
Speaker 1: the universe itself selected these values? So in this analogy,
24:19
Speaker 1: in this idea to explain why the universe is the
24:21
Speaker 1: way it is, somehow like the universe has been evolving
24:25
Speaker 1: in some environment and it's sort of arranged itself or
24:28
Speaker 1: it came to be the way it is now because
24:31
Speaker 1: of some natural selection process that that's kind of the idea, right, Yeah,
24:35
Speaker 1: But it's not being selected for us or for physics
24:39
Speaker 1: that makes sense, or for physicists or for cartoonists. Is
24:42
Speaker 1: being selected for universes with lots of black holes in it? What? Yeah?
24:49
Speaker 1: So the basic idea is maybe universes can give birth
24:53
Speaker 1: to other universes by creating new universes inside their black holes,
24:58
Speaker 1: and that would tend to give you lots of universes
25:01
Speaker 1: that have lots of black holes in them. You would
25:03
Speaker 1: ended with more universes that have lots of black holes
25:06
Speaker 1: than universes that don't have lots of black holes. And
25:09
Speaker 1: so maybe our universe is fine tuned to have the
25:12
Speaker 1: sets of parameters you would need to give you universes
25:15
Speaker 1: with lots of black holes. WHOA, Okay, I feel like
25:19
Speaker 1: you just introduce a lot of crazy ideas here, Like,
25:21
Speaker 1: first of all, like universe giving birth to other universes,
25:24
Speaker 1: don't you need to universes? Is this a mono biological birth?
25:30
Speaker 1: What do you call those animals that can just split
25:32
Speaker 1: off and just butt off? A sexual reproduction? Yes, that's right, yes? Right?
25:37
Speaker 1: Is the universe a sexual Yeah? It could be that
25:40
Speaker 1: universe is reproduce in lots of different ways. We're open
25:43
Speaker 1: minded on this podcast, but the idea is not totally bonkers.
25:46
Speaker 1: It comes from the recognition that there's a connection between
25:50
Speaker 1: what happens inside a black hole and what happens at
25:53
Speaker 1: the beginning of our universe, and that connection is a singularity. Right.
25:57
Speaker 1: We know that our universe started with a singularity that's
26:00
Speaker 1: this crazy dense moment when the universe is like infinitely
26:04
Speaker 1: dense and then expanded out really rapid that we call
26:06
Speaker 1: that the Big Bang. And we know that there's a
26:08
Speaker 1: singularity at the heart of black holes, or we think
26:11
Speaker 1: there is according to general relativity. And so this idea says, like,
26:15
Speaker 1: maybe every singularity at the heart of a black hole
26:18
Speaker 1: is actually a singularity to create a new universe. WHOA,
26:23
Speaker 1: But then I guess. So then the idea is that
26:25
Speaker 1: the universe that is created inside of a black hole
26:28
Speaker 1: exists within the black hole, or does it grow out
26:30
Speaker 1: and take over its parent universe exists within the black hole.
26:34
Speaker 1: So the idea is that instead of imagining inside a
26:37
Speaker 1: black hole, you have like a dead singularity that's just
26:40
Speaker 1: like super dense point that instead you have something dynamic
26:43
Speaker 1: that it's a bounce instead of like just to collapse
26:46
Speaker 1: into a singularity that matter collapses, you get this moment
26:50
Speaker 1: of great density, and then you get a new expanding
26:53
Speaker 1: region of space time within the black hole and never escapes.
26:57
Speaker 1: You can't see it from the outside of the black hole,
26:59
Speaker 1: but that maybe inside black holes we have this region
27:02
Speaker 1: of expanding space time began with the singularity of infinite density,
27:06
Speaker 1: just like our universe, and so it's sort of like
27:09
Speaker 1: this bounce moment where it collapses into a singularity and
27:12
Speaker 1: then starts expanding out again, expanding but still inside of
27:15
Speaker 1: the black hole, still inside the it's like a little
27:18
Speaker 1: bubble inside of the black hole of regular space. And
27:21
Speaker 1: this sort of connects to an idea we talked about
27:23
Speaker 1: recently about whether black holes actually are black holes, and
27:26
Speaker 1: we talked about how these objects, whatever they are, are
27:29
Speaker 1: in regions of very warped space time, which means that
27:32
Speaker 1: their time slows down dramatically. So when you're looking at
27:35
Speaker 1: a black hole, instead of looking at something which is
27:37
Speaker 1: sort of like a dead singularity, you might be looking
27:40
Speaker 1: at something dynamic which is collapsing and then going to
27:43
Speaker 1: bounce back. But it's just super duper slowed down, so
27:46
Speaker 1: that what takes micro seconds and its time takes billions
27:49
Speaker 1: or trillions of years for us. So this is sort
27:51
Speaker 1: of a similar idea to say, maybe black holes are
27:53
Speaker 1: not just like static little dense objects collecting more mass,
27:57
Speaker 1: but there are this bounce where you come to a
27:59
Speaker 1: point a great density and then start expanding out into effectively,
28:03
Speaker 1: what's a new universe inside each black hole? WHOA, But
28:07
Speaker 1: then wouldn't that mean that each universe is like bounded
28:11
Speaker 1: or finite, you know, like it has a limited amount
28:14
Speaker 1: of energy to it, whereas you know, it seems like
28:16
Speaker 1: our universe has almost it looks almost infinite, and it
28:19
Speaker 1: has almost infinite amount of energy. How did all this
28:22
Speaker 1: stuff that we're living in come from, like a tiny
28:24
Speaker 1: black hole for example? Yeah, exactly. That would mean that
28:27
Speaker 1: there is a bound on the universe, But we don't
28:29
Speaker 1: know if our universe is bounded. With some of our
28:31
Speaker 1: theories of cosmology suggests that it should be infinite. It
28:34
Speaker 1: would be most natural if it were infinite, but we
28:37
Speaker 1: just don't know that, and we can only see a
28:39
Speaker 1: limited part of the universe. The portion of the universe
28:42
Speaker 1: we can see now is about ninety three billion light
28:44
Speaker 1: years wide, and we just don't know what's beyond that.
28:47
Speaker 1: And we also know that our universe is expanding, and
28:49
Speaker 1: the mechanism for that is totally unexplained. So it is
28:53
Speaker 1: possible that our entire universe is inside some like mega
28:57
Speaker 1: black hole that's just unimaginably wide. Okay, So then the
29:00
Speaker 1: idea is that in our universe, or basically any universe,
29:03
Speaker 1: whenever there's a black hole, it's sort of creating a
29:06
Speaker 1: whole new kind of universe, and those new universes are
29:10
Speaker 1: the same or slightly different than the parent universe. They're
29:13
Speaker 1: slightly different. So when you create a new universe inside
29:16
Speaker 1: a black hole somehow, and this is like where the
29:19
Speaker 1: magic happens, the laws of physics tweak a little bit,
29:22
Speaker 1: like that process of bending space time and that singularity
29:26
Speaker 1: somehow changes the fundamental constants of that universe a little bit.
29:30
Speaker 1: And this part of the theory is extremely fuzzy because
29:33
Speaker 1: like we don't have a mechanism to understand how that
29:35
Speaker 1: might happen. It's just like a what if. And so
29:38
Speaker 1: in that way, you can sort of like explore different
29:41
Speaker 1: possible universes. You can in one universe create lots of
29:44
Speaker 1: babies with different sort of properties, the same way that
29:47
Speaker 1: in natural selection, if a spider has a thousand offspring
29:51
Speaker 1: and they're all a little bit different than the ones
29:53
Speaker 1: that are best suited to survival, will continue. So in
29:56
Speaker 1: this model, you create lots of baby universes in law
30:00
Speaker 1: two black holes and the ones that are more likely
30:02
Speaker 1: to create more black holes within them. So now black
30:05
Speaker 1: holes within black holes are more likely to create more universes, right,
30:11
Speaker 1: and so you can just call those black holes turtles,
30:13
Speaker 1: and it is sort of turtles all the way. Now,
30:16
Speaker 1: I think a big question here is you know, like
30:19
Speaker 1: in natural selection and regular biological evolution, you have DNA,
30:22
Speaker 1: and that makes sense that like your DNA changes a
30:25
Speaker 1: little and then your kids carry on that DNA that's
30:27
Speaker 1: changed a little bit. But like you said, there's sort
30:29
Speaker 1: of no known way in which like that new universe
30:34
Speaker 1: we will have different constants, right, Like, like why would
30:37
Speaker 1: it have different constants if it's being born in the
30:40
Speaker 1: in the universe with certain laws and certain constants. Yeah, absolutely,
30:43
Speaker 1: that's not something we understand. And you're right, Like for
30:46
Speaker 1: natural selection, we understand the mechanism of it, right, you
30:49
Speaker 1: have the genetic code which is then modified. And so
30:52
Speaker 1: in this case we have no explanation for how that happens,
30:55
Speaker 1: no mechanism for it. You know, maybe the fundamental constants
30:59
Speaker 1: of the universe are ord in some deep process and
31:02
Speaker 1: the creation of a singularity disturbs that process. Really just speculating,
31:06
Speaker 1: and the theory itself has not been fleshed out. We
31:08
Speaker 1: don't have any sort of like DNA like mechanism that
31:12
Speaker 1: explains where these parameters are like stored and how they
31:15
Speaker 1: might be modified by a singularities. Really just speculation, But
31:19
Speaker 1: you know, physics works this way. Sometimes we're like, let's, uh,
31:22
Speaker 1: you know, put a bunch of dots down, and we'll
31:23
Speaker 1: come back later and connect to those dots. But let's
31:25
Speaker 1: see how far we can get with sort of a
31:27
Speaker 1: string of big ideas, and you know, we'll circle back
31:30
Speaker 1: and filling some of the crucial details later. All right, Well,
31:33
Speaker 1: so then the basic ideas that you know, our universe
31:35
Speaker 1: makes a whole bunch of black holes, and each of
31:38
Speaker 1: those black holes has a universe, and some of the
31:40
Speaker 1: our baby universes make more black holes, and some of
31:43
Speaker 1: them don't make a lot of black holes, and so
31:45
Speaker 1: the ones that make more black holes are then going
31:48
Speaker 1: to have their own kid universes who are also good
31:51
Speaker 1: at making black holes, and some of them will make
31:53
Speaker 1: more black holes. And eventually, don't you get to a
31:55
Speaker 1: universe that's all black holes. And that's the idea that
31:58
Speaker 1: this process is more like to give you universes that
32:01
Speaker 1: are likely to have black holes, and so you should
32:05
Speaker 1: end up with universes where the numbers are fine tuned
32:08
Speaker 1: to sort of maximize black holes. And so that's the
32:12
Speaker 1: argument at least Moan makes is he says, I'm looking
32:15
Speaker 1: at the parameters, and it seems to me like if
32:17
Speaker 1: you change some of these parameters, you end up with
32:19
Speaker 1: fewer black holes in the universe. And so maybe our
32:22
Speaker 1: universe is sort of like at the maximum black holiness. Oh,
32:27
Speaker 1: I see, that's the idea that somehow, maybe we're at
32:31
Speaker 1: the maximum black hole capacity, Like this is the most
32:34
Speaker 1: that any universe can make of black holes. That's sort
32:37
Speaker 1: of the argument, and we'll talk later about whether that's
32:39
Speaker 1: actually true. But you know, it's got to maximize something,
32:41
Speaker 1: and it's interesting this idea that it doesn't maximize us, right.
32:44
Speaker 1: I like this idea because it's not anthrocentric. It's not
32:47
Speaker 1: like the universe was created for us. It's like, oh,
32:50
Speaker 1: it turns out we're a byproduct of the universe being
32:53
Speaker 1: optimized for something totally different, which is production of black holes.
32:57
Speaker 1: And that's pretty cool. And you know, it's interesting how
32:59
Speaker 1: many black holes there are right there, black holes everywhere.
33:01
Speaker 1: Every galaxy is a super massive black hole in it.
33:04
Speaker 1: Stars are collapsing in the black holes all the time.
33:06
Speaker 1: It does seem like the fate of our universe, as
33:09
Speaker 1: you say, is to end up as a huge string
33:11
Speaker 1: of black holes. And so it does kind of feel
33:14
Speaker 1: like we are a maximal black holiness and we should
33:17
Speaker 1: rename the podcast to maximal black Holiness. That has a
33:20
Speaker 1: better ring to it. Maybe. All right, well, let's get
33:23
Speaker 1: into what does it all mean, man, and is this
33:26
Speaker 1: theory right or is it totally bonkers? But first let's
33:29
Speaker 1: take another quick break. All right, we are talking about
33:45
Speaker 1: cosmological natural selection, the idea that the universe somehow evolved
33:50
Speaker 1: to be the way it is and that's why it
33:51
Speaker 1: is the way it is. We talked about how maybe
33:54
Speaker 1: the universe is the way it is because we're at
33:56
Speaker 1: like optimal black hole making capacity of the universe, and
34:00
Speaker 1: so that's why the universe is the way it is
34:02
Speaker 1: and not some other way. Yeah. So I so I
34:05
Speaker 1: question was, why do we think that we're an optimal
34:07
Speaker 1: maximal black holiness or black hole making capacity, Like couldn't
34:11
Speaker 1: it feels like there's a lot of rooms still left
34:13
Speaker 1: in the universe for to make more black holes? Yeah,
34:15
Speaker 1: how would you make our universe black holier? I don't know,
34:18
Speaker 1: I just poke a bunch of holes in it, you know,
34:21
Speaker 1: Like why not? Like could in the universe be such
34:23
Speaker 1: a way that they pop up more randomly or something.
34:26
Speaker 1: It's really interesting to think about. And you know, it
34:28
Speaker 1: takes some of these parameters like the mass of the
34:31
Speaker 1: strange cork for example, you know, relative to the mass
34:34
Speaker 1: of the other corks. It's interesting because that actually does
34:37
Speaker 1: help determine the number of black holes in our universe
34:40
Speaker 1: because it creates an opportunity for matter to form something
34:43
Speaker 1: that's not a black hole, that's a neutron star. Like
34:46
Speaker 1: if you have not enough stuff in your star, then
34:49
Speaker 1: sometimes when it collapses, it doesn't form a black hole.
34:52
Speaker 1: Instead it forms a neutron star. And it forms a
34:55
Speaker 1: neutron star because gravity isn't powerful enough to overcome the
34:59
Speaker 1: nuclear force. Is that are preventing the collapse, and that's
35:02
Speaker 1: partially controlled by the mass of the strange cork. You know,
35:05
Speaker 1: what happens inside a neutron star is not something that
35:07
Speaker 1: we understand very well. It's the strong force at work,
35:10
Speaker 1: zillions of bluons back and forth all the time. But
35:13
Speaker 1: these things are very sensitively dependent on the masses of
35:16
Speaker 1: the corks that are involved. And so, for example, if
35:19
Speaker 1: you increase the strange cork mass, if we were in
35:21
Speaker 1: a universe where the strange cork mass was larger than
35:25
Speaker 1: those forces would be more powerful and lots more stars
35:28
Speaker 1: would collapse into neutron stars instead of black holes. So
35:31
Speaker 1: you tweak this parameter, you get fewer black holes in
35:34
Speaker 1: our universe. But then wouldn't that work the other way
35:37
Speaker 1: to like, if you decrease the strange cork mass, and
35:40
Speaker 1: you would get more black holes. So why isn't the
35:43
Speaker 1: mass of the strange cork smaller if we are an
35:46
Speaker 1: optimal black hole making capacity? And that's one of the
35:50
Speaker 1: main criticisms. Lee Smolin came up with this argument, and
35:53
Speaker 1: he suggested that a lot of these parameters are tuned
35:56
Speaker 1: for black holes. But then other people came and looked
35:58
Speaker 1: at these parameters, like, actually, it's not that hard to
36:01
Speaker 1: make universes that are black holier Joe Silka, famous astronomer,
36:05
Speaker 1: tweaked the parameters and he came up with a universe
36:07
Speaker 1: that could make ten thousand times more black holes than
36:11
Speaker 1: our universe. And you know, number one is you decrease
36:14
Speaker 1: the strange cork mass, and number two is you crank
36:16
Speaker 1: up the strength of gravity. Right, so it tends to
36:18
Speaker 1: collapse things faster. You don't want to crank it up
36:21
Speaker 1: too much, right, You want a large number of black holes,
36:23
Speaker 1: not just like a single black hole. So you've gotta
36:26
Speaker 1: left stuff spread out a little bit and then collapse
36:28
Speaker 1: into a lot of black holes. M oh, I see
36:32
Speaker 1: you're saying things are being like this for a number
36:34
Speaker 1: of black holes, not like, let's make a giant black hole,
36:37
Speaker 1: because if you do, then that means you only have
36:39
Speaker 1: one offspring. Kind of That's right. As fun as that sounds,
36:42
Speaker 1: let's make a giant black hole, it's maybe not the
36:44
Speaker 1: best plan if your goal is to have lots and
36:47
Speaker 1: lots of baby universes, not just one mega baby, right,
36:51
Speaker 1: But I guess you also don't want to have you know,
36:53
Speaker 1: lots and lots of or like an infinite number of
36:55
Speaker 1: tiny baby black holes right or small tiny sort of
36:59
Speaker 1: easy to evapp for a black holes, you want like
37:01
Speaker 1: a good number of significant black holes as your children exactly.
37:04
Speaker 1: If your black holes are too small, then they will evaporate,
37:07
Speaker 1: as you say, because black holes are not completely black,
37:09
Speaker 1: they give off a little bit of energy, and they
37:12
Speaker 1: give off more energy the smaller they are, so smaller
37:15
Speaker 1: black holes are more likely to evaporate away into nothingness.
37:19
Speaker 1: So you need to be big enough that they can
37:21
Speaker 1: be sustained that they can keep gobbling things. So you
37:24
Speaker 1: don't want one mega black hole, you don't want an
37:26
Speaker 1: infinite number of tiny ones. There is a little bit
37:28
Speaker 1: of a balancing act to play there. So the basic
37:31
Speaker 1: ideas that maybe all those control maps in the universe,
37:33
Speaker 1: all those numbers that we can't explain, are the way
37:36
Speaker 1: they are because somehow they maximize the universe's conditions for
37:42
Speaker 1: making the right, the most and best kind of black
37:44
Speaker 1: holes exactly. And that doesn't argue that the universe has
37:48
Speaker 1: to be maximized for black holiness, to suggest that there
37:51
Speaker 1: are lots of universes out there, but there are more
37:54
Speaker 1: that are close to this maximum because they tend to
37:56
Speaker 1: produce more. And so if you're gonna randomly choose among
37:59
Speaker 1: uni versus to be in that you're more likely to
38:02
Speaker 1: end up in the universe that's closer to the maximum.
38:05
Speaker 1: Oh I see, yeah, because I was wondering, like in
38:07
Speaker 1: this idea of the universe evolving or universe is evolving,
38:10
Speaker 1: there's no natural selection process really, right, There's no like
38:14
Speaker 1: predator killing off weak universes or you know, something destroying
38:18
Speaker 1: the universes that don't make a lot of black hole.
38:20
Speaker 1: It's more like you're more represented in the population of
38:24
Speaker 1: all the universes that exist if you're good at making
38:27
Speaker 1: black holes. Yeah, everybody can make as many babies as
38:30
Speaker 1: I can, and then it's just a race to have
38:31
Speaker 1: the most babies. Nobody's eating anybody else's babies. But if
38:35
Speaker 1: you're gonna randomly pick somebody to be you're gonna end
38:38
Speaker 1: up in a family that makes more babies. Right, So
38:41
Speaker 1: there's like an infinite savannah out there in some universe Africa.
38:45
Speaker 1: There are no predators. You know, you can multiply as
38:48
Speaker 1: you see fit. But the animals or universes that are
38:50
Speaker 1: good at multiplying, they're just gonna be more overrepresent they're
38:53
Speaker 1: going to basically take over the savannah, right, this infinite savannah.
38:56
Speaker 1: And so then that means that we are if we
38:59
Speaker 1: are going to this in the universe, we're more likely
39:01
Speaker 1: to exist in the universe that's good at making baby
39:04
Speaker 1: black holes. That's the argument. And you know, there's a
39:06
Speaker 1: lot of steps there and a lot of questions, but
39:08
Speaker 1: it's sort of the structure of it interesting. So then
39:12
Speaker 1: it's still sort of tentative. And so what are some
39:14
Speaker 1: criticisms I guess, or what does it all means do
39:16
Speaker 1: to have any interesting implications if it were true? Yeah,
39:18
Speaker 1: there aren't criticisms of it. People argue that we're not
39:21
Speaker 1: actually that close to maximum black hole production, as I say,
39:25
Speaker 1: people to tweak the parameters and done some simulations and
39:28
Speaker 1: suggested that you could get many, many more black holes
39:32
Speaker 1: than you have in our universe. And you know, the
39:34
Speaker 1: thing about this argument is that it's impossible to disprove
39:36
Speaker 1: that way. You could say, oh, well, this is the
39:38
Speaker 1: way the universe works. We're just a little bit unlucky.
39:40
Speaker 1: We're close to the maximum, we're not necessarily at the maximum.
39:44
Speaker 1: We're gonna get the best parents have pretty pretty good
39:46
Speaker 1: parents we're not in the biggest family, but you know,
39:49
Speaker 1: we're not doing too bad. But it does definitely weaken
39:52
Speaker 1: the argument. It would be a more compelling argument if
39:54
Speaker 1: we were like right at the maximum and you have
39:57
Speaker 1: this good argument to suggest that certain values of all
39:59
Speaker 1: these univer as parameters overwhelmed everything else, than so the
40:02
Speaker 1: universe should be totally dominated by numbers very very close
40:06
Speaker 1: to the optimal values. So that's not exactly the case. Well,
40:09
Speaker 1: I guess that counter argument to that counter argument is that, like,
40:12
Speaker 1: maybe we don't really know if we are optimized for
40:15
Speaker 1: optimal black hole of production. Maybe we are, which just
40:17
Speaker 1: don't understand the universe well enough to say, like, no,
40:20
Speaker 1: this is this is the best number of black holes.
40:23
Speaker 1: If we had ten thousand more black holes, you know,
40:25
Speaker 1: the universe wouldn't be sustainable, or those black holes wouldn't
40:28
Speaker 1: be good enough to make other universes, do you know
40:30
Speaker 1: what I mean? That's certainly a good point. We don't
40:32
Speaker 1: know how to stimulate the whole history of the universe
40:34
Speaker 1: and accurately predict the number of black holes, so these
40:36
Speaker 1: simulations are approximations, and there's lots we don't understand about
40:39
Speaker 1: the evolution of the universe, big deals about you know,
40:42
Speaker 1: what is dark matter and how the universe is expanding
40:45
Speaker 1: and why and when. So there's definitely a lot of uncertainty,
40:48
Speaker 1: they're sure. And this also has consequences about the like
40:51
Speaker 1: the faith of the universe, right, like maybe that means
40:53
Speaker 1: that the universes don't implode eventually. Yeah, and this idea
40:57
Speaker 1: is not Actually that new sort of been developing over
40:59
Speaker 1: a few gades, and it was sort of more in
41:02
Speaker 1: vogue when people thought that the universe was going to
41:05
Speaker 1: end in a big crunch, when we thought that maybe
41:08
Speaker 1: gravity was so powerful that it was going to bring
41:10
Speaker 1: the whole universe back together into another singularity that like
41:14
Speaker 1: inside black holes, you have this like cycling bounce theory
41:18
Speaker 1: a singularity and then expanding space time like a big
41:21
Speaker 1: bang and then come back to a singularity. Because people
41:23
Speaker 1: like this idea that every universe starts with a singularity
41:26
Speaker 1: and ends with a singularity that connects it to like
41:29
Speaker 1: what's happening inside a black hole. But now we know
41:31
Speaker 1: that the universe is less likely to do that because
41:33
Speaker 1: we discovered twenty years ago that the universe is expanding
41:36
Speaker 1: and that expansion is accelerating, so it seems like a
41:38
Speaker 1: big crunch is less likely to be in our future,
41:41
Speaker 1: so that takes a little bit of the shine off
41:43
Speaker 1: of this theory. You know, more likely in the future
41:46
Speaker 1: of our universe is not one big crunch, but as
41:49
Speaker 1: we said earlier, lots and lots of very widely distributed
41:53
Speaker 1: black holes, as each sort of local clump of gravitationally
41:57
Speaker 1: dominated matter falls into a mega black hole which is
42:00
Speaker 1: super separated from all the other clumps of matter which
42:03
Speaker 1: is falling into their own black holes. So you end
42:05
Speaker 1: up with like a universe with lots and lots of
42:07
Speaker 1: black holes in it and nothing else. I see. You're saying,
42:10
Speaker 1: like this new theory, but natural selection assumes kind of
42:13
Speaker 1: a bouncy universe. But we are not seeing that the
42:15
Speaker 1: universe is bouncing. We've seen that it's expanding forever. It's
42:18
Speaker 1: expanding forever. Yeah, and we are going to end up
42:21
Speaker 1: with more singularities in our future because of all these
42:23
Speaker 1: black holes, but not like one meta singularity that pulls
42:26
Speaker 1: it all together again. But that's not actually critical. That's
42:29
Speaker 1: not a fatal flaw because you don't have to assume
42:31
Speaker 1: that inside every black hole is a universe that's going
42:33
Speaker 1: to bounce. You can just assume that you create a
42:35
Speaker 1: new universe, and whatever happens inside the universe happens inside
42:38
Speaker 1: that universe, even if it means creations of lots of
42:41
Speaker 1: different black holes inside that black hole universe. So that's
42:44
Speaker 1: not a fatal flaw, right right. What happens in a
42:46
Speaker 1: black hole stays in the black hole. That's definitely true.
42:50
Speaker 1: More concerning is that, you know, we don't understand what
42:54
Speaker 1: the implications are for like black hole mergers. We see
42:57
Speaker 1: black holes gobbling up each other, like fouring a mega
43:00
Speaker 1: black hole as they combine, and that probably happened even
43:04
Speaker 1: for things like the black hole the center of our galaxy,
43:07
Speaker 1: because our galaxy is likely the product of the collision
43:09
Speaker 1: of several galaxies, each of which had their own black hole.
43:12
Speaker 1: So Sagittarius A at the center of our galaxy probably
43:16
Speaker 1: is the result of several black holes. But if each
43:18
Speaker 1: one had a universe inside of it, what happens when
43:21
Speaker 1: they emerged the universes collide, you get some other crazy
43:24
Speaker 1: thing happening. They would have different laws of physics inside
43:28
Speaker 1: each black hole. So like, do you have some sort
43:30
Speaker 1: of like how Senate Reconciliation Committee where you negotiate with
43:33
Speaker 1: the new laws of physics are and we know that
43:36
Speaker 1: always goes smoothly and perfectly. That's right. You know, black
43:39
Speaker 1: holes default on their dead limit, et cetera. And so
43:42
Speaker 1: that's not something that's understood. And again this is because
43:45
Speaker 1: this came about before we understood how often that happened.
43:48
Speaker 1: When LEGO turned on and we saw black hole collisions,
43:50
Speaker 1: we discovered, Wow, black holes are colliding and merging all
43:53
Speaker 1: the time. It's not rare. So it's sort of a
43:55
Speaker 1: new thing to face for this theory. Right, Well, we
43:57
Speaker 1: don't know what happens, but that's not necessarily an argument
44:00
Speaker 1: against this idea, right, Like, maybe you can merge universes
44:03
Speaker 1: that that are different, or maybe they annihilate each other
44:06
Speaker 1: and they form a new universe, like you, you don't
44:08
Speaker 1: know it yet, right, We just don't know. It's an
44:10
Speaker 1: open question because we don't understand the mechanism for like
44:13
Speaker 1: storing and changing these parameters. We don't understand what would
44:16
Speaker 1: happen if two universes with different values of these parameters
44:19
Speaker 1: came into contact somehow. And well, there's also the other
44:23
Speaker 1: question of like you're sort of assuming that all of
44:25
Speaker 1: these universes that are making more universes. Do you all
44:28
Speaker 1: work with the same laws. We just can't explain the
44:32
Speaker 1: parameters of those laws. But it assumes one set of
44:34
Speaker 1: laws for all universes in this giant savannah exactly, and
44:38
Speaker 1: we don't understand that structure at all. It's like saying, well,
44:41
Speaker 1: all right, I'm explaining why the control panel is set
44:44
Speaker 1: this way, but like, who built the control panel? Why
44:46
Speaker 1: do you have this many parameters? Why are there twenty
44:49
Speaker 1: six parameters and not one? Why have any parameters at all?
44:53
Speaker 1: Can't you imagine other universes without parameters? So it doesn't
44:56
Speaker 1: answer that deeper question. And that's what I find frustrating
44:58
Speaker 1: about a lot of these explanations is that they don't
45:00
Speaker 1: go all the way I want to go all the
45:02
Speaker 1: way to explaining the universe down to know numbers. You
45:06
Speaker 1: mean us a giant savannah full of infinite universes having
45:09
Speaker 1: baby black holes. That's not hardcore enough for you, Like,
45:12
Speaker 1: do you want to go more extreme than that? I mean,
45:15
Speaker 1: it's extremely imaginative and it's evocative mentally, but it doesn't
45:19
Speaker 1: really answer questions, you know, because it doesn't let you
45:22
Speaker 1: grasp of those things and and ask deeper questions, you know,
45:25
Speaker 1: about like this, like why are there all these parameters?
45:28
Speaker 1: You know it's a limitation of the theory, but couldn't
45:30
Speaker 1: you also apply the same idea though, to this idea
45:33
Speaker 1: of laws, like maybe when you make a new baby
45:35
Speaker 1: black hole universe, the laws also changed a little bit,
45:38
Speaker 1: not just the parameters, and so then you also have
45:40
Speaker 1: natural selection of physical laws. All right, I'm gonna call
45:43
Speaker 1: that the smoll en cham theory of the universe done.
45:47
Speaker 1: Noble Prize. Here's my address. You win one black hole, sir,
45:51
Speaker 1: I get half of a Nobel prize. I'll share with Sleep.
45:54
Speaker 1: I've mentally at least more than before. I'll be happy
45:56
Speaker 1: to share it with him. All right, that sounds like
45:58
Speaker 1: a plan. All right, Well, that's the idea, and there's
46:01
Speaker 1: something also about the timing of it that's complicated, right, Yeah,
46:04
Speaker 1: It's hard to really think about the timing because you
46:07
Speaker 1: need to think about like the framework in which this happens.
46:10
Speaker 1: Like we're arguing that these universes would create more universes
46:15
Speaker 1: with more black holes in them. But you know, if
46:18
Speaker 1: you think about how long it takes our universe to
46:20
Speaker 1: make black holes, it's like millions or billions of years.
46:23
Speaker 1: We do see black holes having formed in the early universe,
46:26
Speaker 1: like after a few hundred million years or maybe a
46:29
Speaker 1: billion years, but that's kind of a long time. Imagine
46:32
Speaker 1: you had other universes that very rapidly formed a smaller
46:36
Speaker 1: number of black holes. They would then create their babies
46:39
Speaker 1: when they were very very young, and so even if
46:41
Speaker 1: they're not creating as many black holes per universe, they're
46:45
Speaker 1: reproducing so quickly that they in the end there are
46:48
Speaker 1: more of those universes than ones with more black holes
46:51
Speaker 1: in them, just because they had babies sooner than everybody else. Yes,
46:56
Speaker 1: but you know that depends on this idea of like clocks,
46:58
Speaker 1: Like are the clocks and universe really sink to the
47:01
Speaker 1: clocks in that universe? When did this whole process start?
47:04
Speaker 1: Is there really sort of like a timing for the
47:07
Speaker 1: meta universe. It's sort of fuzzy, right, because, as we've
47:10
Speaker 1: talked about the at time sort of slows down as
47:13
Speaker 1: your approach a black hole, right like when you bend
47:15
Speaker 1: gravity that much, time works totally different. Are you Are
47:18
Speaker 1: we saying that time works the same inside of the
47:21
Speaker 1: black hole. We don't know what's going on inside a
47:23
Speaker 1: black hole, right, And this theory would suggest that time
47:25
Speaker 1: inside the universe, that space time is expanding inside that
47:29
Speaker 1: universe instead of just being like twisted by the singularity.
47:32
Speaker 1: But this is a question about like whether you have
47:34
Speaker 1: some meta clock that's you know, is counting like how
47:37
Speaker 1: long you've taken to create babies, and that like the
47:41
Speaker 1: clocks inside the universe are sort of somehow connected to
47:43
Speaker 1: this concept of how many universes there are and how
47:46
Speaker 1: long it's taken to make those universes. I think what
47:49
Speaker 1: you're saying is that evolution is complicated, right, It's not
47:51
Speaker 1: just about optimal solutions, like in and in the animal world,
47:55
Speaker 1: you know, we're not necessarily the most the most perfect
47:58
Speaker 1: animal out We're just happened to be the best animal
48:01
Speaker 1: that seems to have survived the most, right, Like, like
48:04
Speaker 1: there's still a question of why we have toes, Like
48:06
Speaker 1: nobody knows why we have toes, but we're there. They're
48:09
Speaker 1: there because you know, something needs to collect lint, I
48:12
Speaker 1: guess or you know, the idea is that we're not
48:14
Speaker 1: necessarily optimized. We just got here first. Yeah, we're the
48:17
Speaker 1: product of our specific history and you know, and wild
48:20
Speaker 1: biologists look to explain toes physicist look to explain theories
48:24
Speaker 1: of everything, which are also toes. Yeah, there you go.
48:28
Speaker 1: So are we Is this the pinky toe of the
48:30
Speaker 1: universe or is this the big toe? Oh, it's definitely
48:33
Speaker 1: it's the big toe. It's one megato. It's the meta too,
48:36
Speaker 1: it's the alpha toe. All right. Well, I think the
48:40
Speaker 1: main takeaway here is that we we don't know why
48:42
Speaker 1: the universe is the way it is, Like, we have
48:45
Speaker 1: really no idea, and so we're open to any crazy idea,
48:48
Speaker 1: even like giant savannahs full of competing universes. We really
48:51
Speaker 1: are at the beginning of our exploration of all these
48:54
Speaker 1: crazy ideas, at the point where we really should take
48:56
Speaker 1: seriously concept that seem bonkers, that seem at first is
49:00
Speaker 1: like what that's insane? It might actually make sense and
49:03
Speaker 1: it might actually describe our reality. Yeah, And I think
49:06
Speaker 1: it points to also how much there is still to
49:09
Speaker 1: discover about the universe. Right like any kids listening or
49:11
Speaker 1: any young aspiring physicists listening to this, or any old
49:15
Speaker 1: help physicist to like who aspire to make a big
49:17
Speaker 1: break there that you could sort of focus on these
49:20
Speaker 1: big questions and there's still a lot to explain about
49:22
Speaker 1: why things are the way they are. That's right, and
49:24
Speaker 1: I hope it's the young physicists to figure it out
49:26
Speaker 1: because I gotta go take a nap. But why do
49:30
Speaker 1: you have to take a nap, Daniel? Why do you
49:31
Speaker 1: have to take a nap now and not not a later?
49:34
Speaker 1: Or why in your couch and not in your futon.
49:36
Speaker 1: There's a fundamental parameter of the universe, the number of
49:39
Speaker 1: naps per physicists. I see. It's the big end. Nobody
49:42
Speaker 1: understands it. And is it dimensionless or or do you
49:44
Speaker 1: sleep forever? Or is there a set amount of time
49:47
Speaker 1: that you are units of time that do you sleep for?
49:49
Speaker 1: I sleep in many dimensions? All right, Well, we hope
49:52
Speaker 1: you enjoyed that and made you think about why we
49:54
Speaker 1: are here and why we are in this universe, which
49:57
Speaker 1: seems pretty good. But who knows. Maybe it's not subot well,
50:00
Speaker 1: maybe we are in the pink toe of all the universites.
50:02
Speaker 1: Whatever universe it is, I like it. Thanks for joining us,
50:06
Speaker 1: see you next time. Thanks for listening, and remember that
50:16
Speaker 1: Daniel and Jorge explained the universe is a production of
50:19
Speaker 1: I Heart Radio or more podcast from my Heart Radio.
50:22
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50:26
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