Latest / Daniel and Kelly’s Extraordinary Universe / Can brains spontaneously form in space?

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Can brains spontaneously form in space? · Daniel and Kelly’s Extraordinary Universe

0:08
Speaker 1: Hey, Orgey, did you ever think about the odds of
0:11
Speaker 1: you existing? My existence is pretty odd. So well, I'm
0:19
Speaker 1: sure that you exist right now, but you know, go
0:21
Speaker 1: back a hundred years. What are the chances that everything
0:24
Speaker 1: would align to make or hey, oh man, I I
0:28
Speaker 1: think I'm pretty special, so probably pretty low. Exactly, so
0:33
Speaker 1: many things had to happen in just the right way
0:36
Speaker 1: for you to be here, right It seems astronomical that
0:39
Speaker 1: I would be here, Yes, and yet you are here.
0:42
Speaker 1: So sometimes unlikely things actually do happen. Maybe a hundred
0:47
Speaker 1: years from now, you'll be listening to David and Juan
0:50
Speaker 1: explain the universe instead. I am more Hammond cartoonists and
1:09
Speaker 1: the creator of PhD comics. Hi, I'm Daniel. I'm a
1:12
Speaker 1: particle physicist, and I like to think about really unlikely events.
1:16
Speaker 1: Oh yeah, like us getting a podcast. Yeah, or two
1:20
Speaker 1: protons colliding to make a Higgs boson, which happens like
1:24
Speaker 1: one in a trillion collisions. But those are important, right,
1:27
Speaker 1: Like when it happens, it's a pretty big deal. Exactly
1:30
Speaker 1: when it happens, it's exciting. It teaches us something about
1:33
Speaker 1: the universe, and also thinking about these rare things, thinking
1:36
Speaker 1: about the extremely unlikely events tells us something about like
1:41
Speaker 1: the nature of the universe, what's possible and what's actually
1:44
Speaker 1: zero percent possible? Does it also sort of teach a
1:47
Speaker 1: little bit about perseverance, like if you try enough times,
1:52
Speaker 1: you should eventually be able to do anything. Yeah, And
1:54
Speaker 1: it helps to persevere because our collider operates at like
1:58
Speaker 1: millions of times a second, so you don't have to
2:00
Speaker 1: wait that long to get a trillion tries. Are you
2:03
Speaker 1: saying that your collider misses several million times a second? No,
2:07
Speaker 1: it makes collisions every time. It's just those collisions are
2:10
Speaker 1: usually boring. Not much exciting happens on your average collision
2:14
Speaker 1: at the LHC. I see, so it basically it has
2:17
Speaker 1: like a zero point zero zero zero zero zero zero
2:20
Speaker 1: one RBI. Yeah, exactly. We actually throw away most of
2:25
Speaker 1: the data from the large age on collider because it's boring.
2:28
Speaker 1: But anyways, welcome to our Unlikely podcast. Daniel and Jorge
2:31
Speaker 1: Explain the Universe, a collection of I Heart Radio in
2:34
Speaker 1: which we focus on that tiny little bit of the
2:37
Speaker 1: universe that's amazing, that's exciting, that's wondrous, that's confusing. We
2:41
Speaker 1: talk about all the things that are out there in
2:43
Speaker 1: the universe that you want to fit into your brain.
2:46
Speaker 1: You'd like to understand how neutron stars work, you want
2:48
Speaker 1: to know how the galaxy formed. You want to understand
2:51
Speaker 1: it from particles all the way up to superclusters of galaxies.
2:55
Speaker 1: So you've come to the right place because we take
2:57
Speaker 1: the entire universe and explain all of it to you.
3:00
Speaker 1: Because it is a pretty huge universe. I mean, it's fast,
3:03
Speaker 1: and it's full of stuff in it and energy, and
3:06
Speaker 1: it seems like there are amazing things happening and existing
3:10
Speaker 1: all over the place, and makes you wonder how likely
3:13
Speaker 1: it is for them to be there or not. Yeah, exactly,
3:16
Speaker 1: And we can't go to all those places, and we
3:18
Speaker 1: can't even see all of those places, so sometimes we're
3:22
Speaker 1: limited to like mental explorations, to take journeys in our
3:25
Speaker 1: mind and wonder, like, is it possible that somewhere out
3:28
Speaker 1: there there's another planet with similar kinds of people on it,
3:31
Speaker 1: listening to a even funnier podcast, and wonder what their
3:34
Speaker 1: names are? But yeah, it's sort of like taking a
3:37
Speaker 1: mental vacation, except you actually do it for work. It's
3:40
Speaker 1: like you take a mental work trip. Yeah, it's called
3:43
Speaker 1: the thought experiment. How do you expense that in your accounting? Unfortunately,
3:47
Speaker 1: they're mostly free, right, there's no plane tickets, there's no
3:50
Speaker 1: risk of catching a virus. It's a great way to
3:53
Speaker 1: do some work. Can you fly first class? Though? Is
3:55
Speaker 1: that allowed in your government grant? They have to say
3:57
Speaker 1: it uncomfortably while you have your thought experiments. Oh, that's
4:00
Speaker 1: the best part is that it looks exactly like you're
4:02
Speaker 1: taking a nap. So if I remember caught by my
4:04
Speaker 1: department chair napping on my couch, I'll just say no, No,
4:07
Speaker 1: I was doing thought experiments. I was working. I was
4:10
Speaker 1: having physics dreams. I guess that counts rights work for you. No, No,
4:16
Speaker 1: it's a real privilege to get to like think about
4:18
Speaker 1: the nature of the universe for your job. So I
4:21
Speaker 1: definitely religion enjoy that. Well, it is a crazy universe,
4:24
Speaker 1: which I guess requires some crazy thinking to understand it,
4:28
Speaker 1: explore it, and come up with interesting explanations for it. Absolutely,
4:32
Speaker 1: we like to do these crazy thought experiments. And you know,
4:35
Speaker 1: I was thinking about the kinds of things we think
4:37
Speaker 1: about happening in the universe, crazy shock waves and all
4:41
Speaker 1: sorts of bizarre stuff. And I got an email from
4:43
Speaker 1: a listener just yesterday who asked me this funny related question.
4:47
Speaker 1: This is Dev Candlewall, and he says, what do you
4:51
Speaker 1: think is the scariest thought in the universe? So I
4:54
Speaker 1: was wondering what you thought about that whorehead the scariest
4:58
Speaker 1: thought in the universe? Ah, like the one that would
5:02
Speaker 1: shock people the most. Yeah, exactly what did you reply?
5:06
Speaker 1: I said, I would ask Korge next time we record
5:09
Speaker 1: a podcast. Let's see, let's see that the universe will
5:12
Speaker 1: run out of bananas, a zero banana universe. I don't
5:16
Speaker 1: think that's possible quantum mechanically. Well, there you have it.
5:19
Speaker 1: I can sleep easier at night, or I can take
5:22
Speaker 1: naps much more comfortably now, all right, So there you go, Dev,
5:24
Speaker 1: you don't have to worry about scary universes. Quantum mechanics
5:27
Speaker 1: protects the number of bananas in the universe. So we
5:30
Speaker 1: got another interesting question from a listener, this time about
5:33
Speaker 1: a pretty crazy thought experiment. Yeah, that's right. We're always
5:37
Speaker 1: getting questions from listeners who are thinking themselves about crazy
5:41
Speaker 1: stuff in the universe and wanted to hear us chat
5:43
Speaker 1: about it. So here's a really fun question we got
5:46
Speaker 1: from Roselle Santos hiding and I have a question about
5:51
Speaker 1: Boltzmann brains. I read that there are hypothetical self aware
5:54
Speaker 1: disembodied brings floating around in the universe. But why would
5:58
Speaker 1: serious physicists hype the size about disembodied breeds floating around
6:02
Speaker 1: in the universe. It sounds both shocking and absurd to
6:06
Speaker 1: me that I'm excited to know more about it. I
6:08
Speaker 1: love the pod. Thank you. Wow, that was a pretty
6:14
Speaker 1: interesting question. There so much the pokemon a physicists, I know.
6:18
Speaker 1: I love that she assumes that there are serious physicists
6:21
Speaker 1: out there. Yeah, there's a difference. Like there's two kinds, right,
6:26
Speaker 1: There's the clowney kind, and then there's the serious kind.
6:29
Speaker 1: You know, the kind of words both ties and the
6:31
Speaker 1: kinds of were both ties with colors in it, right,
6:34
Speaker 1: the kind of do actual work and the kind of
6:36
Speaker 1: just do podcast with cartoonists. It's now, those are the
6:41
Speaker 1: seriously cool physicists, right. That's why I'm wearing my clown
6:44
Speaker 1: shoes over here. But thank you roself for sending in
6:47
Speaker 1: this question, and thank you to all our listeners who
6:49
Speaker 1: send those questions. So it's cool to get ideas from you. Absolutely,
6:53
Speaker 1: and this sounds like a ridiculous and absurd idea, but
6:57
Speaker 1: it's actually a very useful and powerful tool in cosmology.
7:01
Speaker 1: Thinking about this question about brains forming in space, I
7:05
Speaker 1: see it's a serious question. It's a serious question about
7:09
Speaker 1: a silly idea. That's my favorite kind. So to be
7:13
Speaker 1: on the program, we'll be asking the question can a
7:20
Speaker 1: brain spontaneously form out in space? What? What does this
7:27
Speaker 1: even mean? Like a brain just suddenly appears completely out
7:31
Speaker 1: of the blue. Well, you can't just like violate the
7:33
Speaker 1: laws of physics and just like appear out of nothing.
7:36
Speaker 1: You have to find a way in the laws of
7:38
Speaker 1: physics for a brain to like self assemble out of
7:41
Speaker 1: the stuff that already exists, or for particles to fluctuate
7:45
Speaker 1: out of the vacuum and come together into a brain.
7:47
Speaker 1: I agree with Rosel, this sounds both shocking and absurd
7:50
Speaker 1: to me. How can you be serious about this? You
7:52
Speaker 1: can quantify it, right, you can lay down exactly the
7:55
Speaker 1: probability for this to happen or not happen. All right,
7:58
Speaker 1: So the idea is that as the kind it's called
8:01
Speaker 1: the Boltzman brain. Yeah, it's the Boltsman brain. Is named
8:03
Speaker 1: after Ludwig Boltzman. Who first thought about weird probabilities, because
8:07
Speaker 1: he was one of the pioneers of statistical mechanics, which
8:10
Speaker 1: thought about entropy in terms of like microscopic little particles.
8:14
Speaker 1: So it's not his brain. It's like he came up
8:16
Speaker 1: with this idea of hypothetical brain. He actually didn't come
8:20
Speaker 1: up with this specific idea of Folks later realized that
8:24
Speaker 1: this is an outcome of some of his arguments. But
8:26
Speaker 1: yet all goes back to the question of, like, what
8:29
Speaker 1: universe do we live in? Do we understand it is
8:32
Speaker 1: the universe that we're looking at, one that we expect
8:34
Speaker 1: to see, how unlikely is it? And if the universe
8:37
Speaker 1: is unlikely, does that mean that we're totally wrong about
8:39
Speaker 1: what we're actually looking at. Wow, some pretty big ideas
8:43
Speaker 1: there to be fit into a little brain. So I
8:47
Speaker 1: guess the basic concept is that you know, the universe
8:50
Speaker 1: is crazy. There are things popping into existence all the
8:52
Speaker 1: time and forming and bumping into each other, and so
8:55
Speaker 1: what are the chances that suddenly things would just form
8:59
Speaker 1: a brain out and space? Right? That's right, like for
9:01
Speaker 1: a long time, for momentarily or does it matter, Yeah,
9:04
Speaker 1: it would be momentarily. And then the question of you know.
9:06
Speaker 1: How long it survived depends on you know it. Does
9:09
Speaker 1: it also fluctuate in new existence with the body around
9:12
Speaker 1: it and with a planet around it? Or is it
9:14
Speaker 1: just like literally a brain out in space, which, as
9:17
Speaker 1: you suspect, wouldn't last very long. He would turn into
9:20
Speaker 1: brainsical pretty quickly there. Unless it forms in the middle
9:24
Speaker 1: of a sun. That would be tragic, roasted toasted brain.
9:27
Speaker 1: Maybe that's the scariest thought in the universe. Oh man,
9:30
Speaker 1: that your brain, like who exists for a second in
9:33
Speaker 1: the sun before you do? And that start it's pretty bright. Actually,
9:38
Speaker 1: well it's a pretty crazy question, pretty serious but crazy question.
9:41
Speaker 1: And we were wondering, as usual, how many people out
9:44
Speaker 1: there had heard of this idea, this hypothetical brain, or
9:47
Speaker 1: even think that it is likely. So, as usual, Daniel
9:50
Speaker 1: went out there into the internet to ask people what
9:53
Speaker 1: are the chances that a brain would spontaneously form in space?
9:59
Speaker 1: And so, as usual will I'm deeply, deeply grateful to
10:02
Speaker 1: those of you who volunteered to answer random questions and
10:06
Speaker 1: lend your unprepared thoughts to the podcast. If you'd like
10:10
Speaker 1: to volunteer in the future, please I encourage you. You
10:12
Speaker 1: get to hear your own voice on the podcast, and
10:15
Speaker 1: trust me, it's fun. So right to me two questions
10:18
Speaker 1: at Daniel and Jorge dot com. There's a whole protocol, right,
10:21
Speaker 1: like you ask people to not read the question, but
10:24
Speaker 1: start recording, and then you ask them to read the
10:26
Speaker 1: question right, and then they have to answer yeah, exactly,
10:29
Speaker 1: no googling. I'm trying to capture the same energy and
10:31
Speaker 1: spirit that we had when I was just walking around
10:33
Speaker 1: campus at you see ir run before the world sort
10:36
Speaker 1: of shut down and those folks didn't get like a
10:38
Speaker 1: chance to look on their phones to go think about
10:40
Speaker 1: it or ask their favorite physicists. Because the goal here
10:42
Speaker 1: is just to get a sense for like, hey, what
10:44
Speaker 1: do people know? What do people understand already? Because you know,
10:47
Speaker 1: we're trying to teach this stuff to you guys out there,
10:49
Speaker 1: and we want to get a sense for what level
10:51
Speaker 1: to pitch it at the people run away from you.
10:53
Speaker 1: Also on internet, do they call campus police? Also, they
10:59
Speaker 1: don't give me as many weird looks on the internet
11:01
Speaker 1: as they did in real life, which is kind of
11:03
Speaker 1: surprising that you know, of they're probably rolling their eyes,
11:08
Speaker 1: you never know. Well, I hope they have fun with it.
11:10
Speaker 1: At least. But anyways, think about it for a second.
11:12
Speaker 1: Do you think a brain could spontaneously form out in space?
11:15
Speaker 1: Here's what people have to say. That's a really interesting question.
11:19
Speaker 1: I think I've heard of it before. It's maybe the
11:21
Speaker 1: Boltzmann brain. My understanding is that if the universe is infinite,
11:28
Speaker 1: then such a brain has to form somewhere at some time.
11:33
Speaker 1: But I still find that really hard to believe. I
11:37
Speaker 1: don't know how many random atsoms if there's like an
11:42
Speaker 1: infinite supply, then well, it also depends on what type
11:47
Speaker 1: of brain. So I have had something um less complex,
11:52
Speaker 1: like the brain of an aunt. I'm guessing maybe one
11:56
Speaker 1: in ten to the five, but it was more sophisticated.
12:00
Speaker 1: It like a human rain. Maybe you wanted into the fifty. Um.
12:04
Speaker 1: I don't have a real basis for these gisses, so
12:09
Speaker 1: I think that the chances of a brain spontaneously forming
12:13
Speaker 1: from random atoms is not that low. I could totally
12:17
Speaker 1: see it happening because atoms are the building blocks for matter.
12:22
Speaker 1: So um, if it didn't happen already, I could definitely
12:27
Speaker 1: see it happening in the future. Oh my god. Uh well,
12:33
Speaker 1: I would never say that absolutely, there's no chance for
12:39
Speaker 1: that to happen. But even if it would happen, where
12:45
Speaker 1: would this form and how long would last? Um? But
12:53
Speaker 1: it's interesting. Chances are I don't think it matters, uh
13:01
Speaker 1: to calculate the chances, but for sure there are some chances.
13:07
Speaker 1: I finally got a question I know the answer to.
13:09
Speaker 1: I just finished reading Brian Green's Until the End of Time,
13:13
Speaker 1: and I know that a Boltzman brain could form within
13:17
Speaker 1: ten to the ten to something years, which is at
13:22
Speaker 1: least less than the amount of time left in the universe.
13:27
Speaker 1: So people are pretty skeptical. Well, I was surprised a
13:30
Speaker 1: lot of people knew what you were talking about. They're like, oh, yeah,
13:32
Speaker 1: the Boltzman brain. Of course, who doesn't know about the
13:36
Speaker 1: Boltzman brain. Well, we got smart, well educated listeners, and
13:39
Speaker 1: you know, Boltzman brain is a thing that's been sort
13:42
Speaker 1: of bouncing around for quite a few decades. And people
13:45
Speaker 1: seem pretty open to the idea, right, Like they didn't
13:48
Speaker 1: think like, no way, Yeah, they're more open to it
13:50
Speaker 1: than you or when you heard about it a minute ago.
13:54
Speaker 1: I am maybe odd about these odds. All right, So
13:57
Speaker 1: it's a pretty interesting idea. So tell us an, you know,
14:00
Speaker 1: what are the chances that a brain would spontaneously appear,
14:03
Speaker 1: and how would it happen? Yeah, well, the odds are
14:07
Speaker 1: very very very very very very small, but technically not zero.
14:12
Speaker 1: You know, there is the possibility for particles in space
14:16
Speaker 1: to sort of bump into each other and assemble into atoms,
14:21
Speaker 1: and those atoms could assemble into molecules, which could assemble
14:24
Speaker 1: into cells, which could assemble into a brain. Like, there's
14:27
Speaker 1: nothing in the laws of physics actually preventing that from happening,
14:31
Speaker 1: which means the probability is non zero, but of course
14:35
Speaker 1: very unlikely. Do you need the atoms to have been
14:38
Speaker 1: formed already, Like do you need carbon atoms or are
14:40
Speaker 1: you talking about particles at the like the cork level,
14:43
Speaker 1: Like corks suddenly become you know, protons and neutrons just
14:47
Speaker 1: the right you know, ratio, and then those become carbon
14:49
Speaker 1: and potassium and oxygen and and suddenly everything like just
14:54
Speaker 1: poofs into existence. Or do you do you mean like assembled, Well,
14:56
Speaker 1: I guess you could actually just poof into existence. That
15:00
Speaker 1: been less likely, right, all that stuff to just like
15:02
Speaker 1: fluctuate out of the vacuum instantaneously. I think it's more
15:06
Speaker 1: likely for you to fluctuate the essential components out of
15:10
Speaker 1: the vacuum, you know, for a photon to turn into
15:13
Speaker 1: a pair of quarks and anti quark, or for photon
15:16
Speaker 1: to turn into electron oppositron, and for those particles to
15:19
Speaker 1: assemble into atoms and then molecules and then cells. So
15:24
Speaker 1: I think that's probably more likely than the actual massive
15:27
Speaker 1: quantum fluctuation of a whole brain. But don't you need
15:30
Speaker 1: like a supernova sometimes to assemble some of these particles
15:33
Speaker 1: or do me like they maybe come into existence with
15:36
Speaker 1: that kind of energy. Yeah, well, you can build these
15:39
Speaker 1: things out of anything. Typically they are made, you know,
15:42
Speaker 1: in the cores of suns or in supernovas or neutron
15:45
Speaker 1: star collisions. But that's not the only way you can
15:48
Speaker 1: make them, right. We can also make them here on
15:50
Speaker 1: Earth in collisions of particles. So yeah, you can make
15:53
Speaker 1: them in other ways. There's no law of physics requiring
15:56
Speaker 1: you to have a supernova in order to make uranium
15:59
Speaker 1: or phosphorus or whatever it is. So like you're saying,
16:02
Speaker 1: like it's not just a brain, then it could be
16:03
Speaker 1: anything like a cow or a perfect diamond could just
16:07
Speaker 1: suddenly poof out of existence, Yeah, exactly, or you know,
16:10
Speaker 1: like a banana the size of a school bus or whatever.
16:13
Speaker 1: Could a million dollars just suddenly appear in my hands,
16:15
Speaker 1: and instead of you know, admitting that I stole it,
16:18
Speaker 1: I could just say that it was a quantum fluctuation.
16:21
Speaker 1: I'm just you know, hypothetically speaking, it's called the Boltsmann heist,
16:26
Speaker 1: the Boltzmann alibi. I think technically speaking, that's well beyond
16:29
Speaker 1: reasonable doubt. But it's not impossible. Yes, absolutely you should
16:33
Speaker 1: try that defense, and then I'll come visit you in
16:35
Speaker 1: prison and bring you some bananas. But what if I
16:38
Speaker 1: bring a serious physicist with me to testify. I don't
16:43
Speaker 1: know any song, so I can't recommend one for you.
16:47
Speaker 1: I only know the podcasting kind, all right, So let's
16:50
Speaker 1: put my legal troubles aside here. So that's how it
16:52
Speaker 1: would happen. It would happen like you know, particles would
16:55
Speaker 1: appear out of the vacuum or get transformed from light
16:58
Speaker 1: or something, and then they would has happened to assemble
17:01
Speaker 1: into a brain with like thoughts and a personality in
17:04
Speaker 1: it already, or like a blank brain with thoughts and
17:06
Speaker 1: a personality and memories, right, because your memories are just
17:11
Speaker 1: a reflection of the sort of physical state of your brain.
17:14
Speaker 1: And so for example, somebody who thinks they are you
17:18
Speaker 1: could assemble out there in space. Right, you could make
17:21
Speaker 1: a whorehe brain out there which would have thought that
17:23
Speaker 1: it lived your whole life. It is that like, maybe
17:26
Speaker 1: I am a Boltzmann brain, maybe you are a Boltzman
17:29
Speaker 1: brain exactly. And so we use this as a probe
17:33
Speaker 1: to like think about the likelihood of various cosmological theories
17:37
Speaker 1: of the universe. And one standard is like, does your
17:41
Speaker 1: theory predict that there are more Boltzmann brains than actual
17:45
Speaker 1: real people out there, you know, thinking and breathing. So
17:49
Speaker 1: it sort of is a way for us to think
17:51
Speaker 1: about the origins of the universe. And you know what's
17:54
Speaker 1: likely and unlikely to have happened. And you know, we
17:57
Speaker 1: can actually put a number on this probability, probability to
18:01
Speaker 1: have a brain assemble out there in space. Really you
18:04
Speaker 1: can quantify this crazy probability. Well, people have quantified it,
18:08
Speaker 1: you know, they've gone through the argument and thought about
18:11
Speaker 1: how many particles and what are the chances for this
18:13
Speaker 1: to happen and that to happen for them to assemble,
18:16
Speaker 1: And you know, the point is you get a number
18:18
Speaker 1: which is really really small. It says that it should
18:20
Speaker 1: happened about once every ten to the ten to the
18:25
Speaker 1: fifty years. That means if you wait a number of years,
18:28
Speaker 1: which is ten with ten to the fifty zeros in
18:31
Speaker 1: front of it, you should get a Boltsman brain. That's insane.
18:34
Speaker 1: It's like ten to the zeros to tend to be
18:38
Speaker 1: ten with fifty zero's past it. Wow, that is a
18:41
Speaker 1: really big number and much older than the age of
18:44
Speaker 1: the universe, right, like the age of the universe, it
18:46
Speaker 1: just tend to the eight or nine. Yeah, exactly, we're
18:49
Speaker 1: fourteen billion years so, like you know, tend to the ten.
18:52
Speaker 1: So basically, it's a pretty low probability for one to
18:56
Speaker 1: have happened so far in our universe if the universe
19:00
Speaker 1: is only fourteen billion years old, if you believe that,
19:03
Speaker 1: if that's true, or if the universe is only going
19:05
Speaker 1: to be fourteen billion years old, but I who knows,
19:07
Speaker 1: maybe it will have a long, crazy life exactly. And
19:10
Speaker 1: so the point is that it's very very unlikely. But
19:13
Speaker 1: it's sort of like a standard, like your theory the
19:15
Speaker 1: universe should not predict something like this happening because that
19:18
Speaker 1: seems pretty absurd and unlikely, but I guess the point
19:21
Speaker 1: is that the probably is not zero, Like it's possible
19:25
Speaker 1: for a brain to appear out of the blue, even
19:27
Speaker 1: if the probability is small, Like you can roll a
19:30
Speaker 1: pair of snake eyes on a pair of dye. It's unlikely,
19:33
Speaker 1: but it does. It could happen on your first roll. Yeah, exactly,
19:36
Speaker 1: and in some way, like everything that is happening was
19:40
Speaker 1: very unlikely, like the chances of me existing are almost zero.
19:45
Speaker 1: In the same way, so many things have to happen
19:47
Speaker 1: just right for me to exist, and yet here I am.
19:51
Speaker 1: I do exist. So some things, even though they're vastly improbable,
19:55
Speaker 1: do actually happen. All right, Well, let's think about why
19:58
Speaker 1: we think about this crazy scenario and what it has
20:01
Speaker 1: to do with the Big Bang and explaining what happened.
20:05
Speaker 1: But first, let's take a quick break. All right, we're
20:21
Speaker 1: talking about Boltman's brains and big bangs, about of bees today.
20:27
Speaker 1: Boltsman sounds like an ad for I don't know, a
20:34
Speaker 1: mattress store by your space brains. Come on down to
20:37
Speaker 1: Boltsman's brains and you're bananas. All right, Well, this is
20:43
Speaker 1: a crazy scenario. The idea that you know, a brain
20:45
Speaker 1: could spontaneously form out in space out of random particles
20:49
Speaker 1: popping into existence. They could assemble into something that thinks
20:53
Speaker 1: and has the exact same memories as you, and that
20:56
Speaker 1: could maybe, for like a second, think that it is you, right,
20:59
Speaker 1: because this brain would be alive for you know, a
21:02
Speaker 1: little bit of time, right, Yeah, exactly. The brain would
21:04
Speaker 1: survive for a little bit of time long enough to think, Wow, look,
21:08
Speaker 1: I'm a brain. I think I understand the universe, or
21:11
Speaker 1: I'm gonna go get a banana or whatever. And you know,
21:14
Speaker 1: if you're living in the moment right now, you don't
21:16
Speaker 1: know that you're not a Boltzman brain, you know, then
21:19
Speaker 1: and about to disintegrate, you could be right, like everything
21:22
Speaker 1: that's happened to you before it could just be an
21:24
Speaker 1: implanted memory. Yeah exactly, Nothing that you have fought in
21:28
Speaker 1: the past could be real. Wow, all right, Well this
21:31
Speaker 1: is super highly unlikely to the tune of one intent
21:35
Speaker 1: to the tent to the fifty. But it's not zero
21:38
Speaker 1: the probability, which means that if the universe is infinite,
21:41
Speaker 1: it's happening all the time now right there are brains
21:43
Speaker 1: popping out into existence everywhere. Yeah, exactly. If the universe
21:48
Speaker 1: is infinite in extent, right, spatially infinite, it goes on
21:51
Speaker 1: forever with an infinite amount of stuff and totally random
21:56
Speaker 1: initial conditions, and then everything that is possible is happening,
22:01
Speaker 1: even if it's very very unlikely. So that means that
22:03
Speaker 1: somewhere out there right now, if the universe is infinite
22:07
Speaker 1: and totally random and the initial conditions, there is a
22:09
Speaker 1: Boltman brain appearing and thinking that it's me. And so
22:13
Speaker 1: this whole wild idea has a lot to do it.
22:15
Speaker 1: As you were saying, thinking about probability in the universe
22:19
Speaker 1: and what are the chances of things happening, and specifically
22:22
Speaker 1: kind of like how you compare that to the Big Bang,
22:25
Speaker 1: because the Big Bang is also pretty unlikely. The Big
22:28
Speaker 1: Bang is very unlikely exactly. And you know, the current thinking,
22:31
Speaker 1: of course, is that the universe started about fourteen billion
22:35
Speaker 1: years ago, and we think that because we look at
22:37
Speaker 1: the expansion of the universe and we track it back
22:39
Speaker 1: and we look at like the oldest things in the
22:42
Speaker 1: universe and they seem to be about that age, and
22:44
Speaker 1: so there seems to have been this special moment early
22:47
Speaker 1: in the universe. But you know, we don't know what
22:49
Speaker 1: comes before the Big Bang. We don't know what caused
22:53
Speaker 1: the Big Bang. So while our universe seems to have
22:55
Speaker 1: come from a very special state fourteen billion years ago,
22:59
Speaker 1: we really know very very little about the origins of
23:02
Speaker 1: that state, what created it, what caused it, if anything,
23:05
Speaker 1: if it even means anything to say this something before
23:08
Speaker 1: the Big Bang. You know, we have lots of different theories,
23:10
Speaker 1: and some of them say that there is nothing before
23:13
Speaker 1: the Big Bang, that's face in time, didn't even exist,
23:15
Speaker 1: and other theories that say, you know, maybe there was
23:18
Speaker 1: something before the Big Bang. We talked about pen roses
23:20
Speaker 1: conformal cosmology that talked about the universe continuing to expand
23:25
Speaker 1: like flower pedals upon flower pedals. So the point is
23:28
Speaker 1: we don't know it all about what happened before the
23:30
Speaker 1: Big Bang, which means that the universe could have existed
23:33
Speaker 1: before it could have gone on basically infinitely into the past,
23:37
Speaker 1: or a very long time into the past, or maybe
23:40
Speaker 1: I guess the interesting and alternative is that maybe the
23:42
Speaker 1: universe just popped out of existence out of the blue,
23:45
Speaker 1: just like one of these Boltzmann brains. Right, that's one idea,
23:49
Speaker 1: and this is sort of the direction that Boltzman was
23:51
Speaker 1: going when he was thinking about entropy and probability. As
23:55
Speaker 1: he was developing his theories in the late eighteen hundreds,
23:58
Speaker 1: he realized that the second law of thermodynamics that tells
24:01
Speaker 1: you that entropy is always increasing, that things basically tend
24:04
Speaker 1: towards equilibrium, that our universe is sort of tending towards
24:09
Speaker 1: a state where everything is going to be equally spread out,
24:11
Speaker 1: and they call this the heat death of the universe.
24:14
Speaker 1: He realized that if the universe goes on for a
24:16
Speaker 1: very very long time, and this is sort of the
24:19
Speaker 1: eventual end of the universe, that the universe would spend
24:22
Speaker 1: most of its time as the heat death universe. Like,
24:25
Speaker 1: eventually you get to the equilibrium, and then you just
24:27
Speaker 1: stay there forever and ever and ever for the whole
24:30
Speaker 1: life cycle of the universe. And so he realized that
24:33
Speaker 1: it's kind of weird to not be at that point.
24:36
Speaker 1: It's sort of strange and very unlikely, almost vanishingly unlikely,
24:40
Speaker 1: that we're in a moment that's not at maximal entropy, right.
24:43
Speaker 1: It's it's like, it's weird that there was so much
24:45
Speaker 1: stuff kind of condensed in one place that would eventually
24:48
Speaker 1: expand and explode into planets and people and bananas. Yeah, exactly.
24:53
Speaker 1: And so his solution to this sort of paradox to
24:56
Speaker 1: thinking like, if the universe just trends towards maximum entropy
25:00
Speaker 1: all the time, then it should basically always be a
25:02
Speaker 1: maxim of entropy. His solution was like, well, maybe there
25:05
Speaker 1: are fluctuations. Maybe you can get the universe into this
25:09
Speaker 1: like totally smooth state, but then randomly in some corner
25:12
Speaker 1: or the universe, boom, it fluctuates to a lower entropy situation.
25:16
Speaker 1: And so in his thinking, because entropy was statistical, it's
25:20
Speaker 1: it's like property that came out of the motion of
25:22
Speaker 1: the little particles inside it, not absolute that you could
25:25
Speaker 1: get like little deviations, little moments when you break this
25:29
Speaker 1: second law of Thuring dynamics, where things get a little
25:31
Speaker 1: bit lower entropy. So, for example, he imagined, maybe the
25:34
Speaker 1: universe is this vast pool that's in the heat death.
25:37
Speaker 1: It's totally in equilibrium, but then a galaxy fluctuates out
25:41
Speaker 1: of existence, and that's us. So he imagined that our
25:44
Speaker 1: entire existence might be this like fluctuation out of equilibrium
25:50
Speaker 1: of an otherwise like vast universe that's just sort of
25:53
Speaker 1: like smooth and featureless, like you're a bubble in your
25:56
Speaker 1: peanut butter or something. Well, that's a very humble analogy
26:02
Speaker 1: for our entire galaxy. But we're not just one galaxy.
26:06
Speaker 1: We can count trillings of galaxies out there. So it's
26:08
Speaker 1: the idea that all of those streelings of galaxies are
26:10
Speaker 1: just like a again, like a bubble in a in
26:13
Speaker 1: a jar of peanut butter. Well, Boltzman was thinking about
26:15
Speaker 1: this before we really understood the context of our universe
26:19
Speaker 1: at all. This is the late eighteen hundreds, before people
26:21
Speaker 1: even understood that there were other galaxies. That wasn't until
26:24
Speaker 1: later when Hubbles saw those galaxies and realized while the
26:27
Speaker 1: universe is much bigger than we ever imagined, and it's expanding.
26:31
Speaker 1: So it makes Boltsman's strategy that's like, well we could
26:35
Speaker 1: just fluctuate a galaxy out of equilibrium much more difficult
26:38
Speaker 1: because now you have to fluctuate like the whole universe.
26:41
Speaker 1: You have to take like the Big Bang and say
26:44
Speaker 1: this entire Big bang, this like moment of crazy high density,
26:47
Speaker 1: which led to, as you say, our entire universe with
26:50
Speaker 1: galaxies and superclusters. That whole thing was a fluctuation, And
26:55
Speaker 1: that's when the problem of Boltzmann brains arose because people realized,
26:58
Speaker 1: you know what, that seems pretty unlikely. It's much more
27:01
Speaker 1: likely to just fluctuate a brain. I mean, now, fluctuating
27:05
Speaker 1: a whole universe out of equilibrium seems much much less
27:09
Speaker 1: likely than just fluctuating one brain, which seems like pretty
27:12
Speaker 1: reasonable in comparison. Is the idea that, like the universe
27:15
Speaker 1: as we see it now suddenly appeared, or that the
27:18
Speaker 1: Big Bang initially is one of these bubbles in the
27:21
Speaker 1: peanut butter, you know what I mean? Like, is the
27:24
Speaker 1: idea that we sort of like popped into existence the
27:26
Speaker 1: way it is now with the galaxies moving at just
27:29
Speaker 1: the right speeds and everything moving away from each other coincidentally,
27:34
Speaker 1: Or is the idea that the maybe the Big Bang
27:37
Speaker 1: was sort of the this bubble forming. The idea is
27:40
Speaker 1: that the Big Bang was this bubble forming, right. That's
27:42
Speaker 1: the concept of this kind of cosmology. It's not that
27:46
Speaker 1: we're all being fooled and thinking that the universe existed
27:49
Speaker 1: and then it just actually popped into existence right now
27:52
Speaker 1: with this apparent history. It's that the Big Bang itself
27:55
Speaker 1: was a fluctuation that the vaster universe is this ocean
27:58
Speaker 1: of equilibrium at of which fluctuated this crazy condition, this
28:03
Speaker 1: crazy low entropy state, which was the Big Bang, And
28:06
Speaker 1: then physics sort of rolls forward the way we expected
28:09
Speaker 1: and the way we've observed, and all of our experiments
28:11
Speaker 1: are honest and actually have measured the history of the universe.
28:15
Speaker 1: But this is an argument that's used to criticize that idea,
28:18
Speaker 1: say that idea is so ridiculous and so absurd and
28:22
Speaker 1: so unlikely, that it's more likely that you have this
28:25
Speaker 1: other absurd scenario that we're all just Boltsman brains floating
28:28
Speaker 1: in space. I guess you're saying that the universe is
28:30
Speaker 1: so unlikely that it's more likely then that we are
28:35
Speaker 1: all just all came into existence yesterday. That's the Boltsman
28:40
Speaker 1: brain argument exactly. Says that if you believe that, then
28:43
Speaker 1: you should also accept the possibility of Boltzmann brains. And
28:47
Speaker 1: in an universe that has lived for a very very
28:49
Speaker 1: long time, there'll be lots of Bolsman brains, and the
28:52
Speaker 1: probability that you're not a Boltsman brain but like an
28:55
Speaker 1: actual brain, seems very vanishing lee small, and so they're
29:00
Speaker 1: for most likely we're all boltspan brains. Daniel, Are you
29:02
Speaker 1: saying that there's a possibility that the Bible is right
29:07
Speaker 1: and that actually it's more likely than your current theories
29:10
Speaker 1: of physics? Is that what you're saying, Daniel? Can I
29:14
Speaker 1: get you on the record to say that. You cannot
29:17
Speaker 1: get me on the record to say that. You know,
29:19
Speaker 1: this is one method that's used to sort of critique
29:22
Speaker 1: this kind of cosmology, this particular idea that the Big
29:26
Speaker 1: Bang was a low entropy fluctuation. It can be criticized
29:30
Speaker 1: by this kind of argument. But you know, as we
29:32
Speaker 1: can dig into in a minute, there also criticisms of
29:35
Speaker 1: this argument, like you know, the boltspen brain argument itself,
29:38
Speaker 1: like does it really hold up as a way to
29:41
Speaker 1: evaluate the likelihood of the Big Bang as a fluctuation? Oh?
29:45
Speaker 1: I see, we're still in thought experiment mode. It's not
29:48
Speaker 1: that just because the Big Band is less likely that
29:51
Speaker 1: than the idea that we're all just made yesterday. That's
29:54
Speaker 1: not a good argument. We're still in thought mode. Yeah,
29:57
Speaker 1: we're still in thought mode. And you know, just being
30:00
Speaker 1: unlikely is in devastating. As we said, unlikely things do happen,
30:04
Speaker 1: and so it certainly is possible that something unlikely happened,
30:07
Speaker 1: and we're here anyway, that the reason, for example, that
30:11
Speaker 1: we are here asking questions about why this unlikely thing
30:14
Speaker 1: happened is because the unlikely thing happened, and otherwise they
30:17
Speaker 1: wouldn't be anybody to ask these questions. So that's, for example,
30:20
Speaker 1: one way out of this predicament. All right, well, let's
30:23
Speaker 1: dig into what is wrong with this argument and why
30:27
Speaker 1: it's maybe not possible for brains to spontaneously form out
30:31
Speaker 1: of the blue, and most important, what does it all mean.
30:34
Speaker 1: But first, let's take another quick break. All right, we're
30:50
Speaker 1: talking about spontaneous brains, and sometimes I have spontaneous thoughts.
30:54
Speaker 1: That's not the same thing, Daniel. Right now, all your
30:58
Speaker 1: spontaneous thoughts are gold. The Boltzman brains are just brains
31:01
Speaker 1: goles out there in space. That's right. That's what I'm
31:03
Speaker 1: doing when I'm napping. I'm just making gold. It's called cartoons.
31:08
Speaker 1: And you know, people out there might be thinking, hold
31:10
Speaker 1: on a second, I'm pretty sure I'm not a Boltzman brain.
31:14
Speaker 1: How can these folks be telling me I'm likely to
31:16
Speaker 1: be a Boltzmann brain? Because like you look down and
31:19
Speaker 1: you have arms, right, and legs and how could that
31:22
Speaker 1: possibly be a Boltzman brain? But you only have memories
31:25
Speaker 1: and electrical impulsis in your brain telling you that you
31:28
Speaker 1: have arms and legs. But maybe those formed out of
31:30
Speaker 1: the bluetooth. Yeah, maybe they did. And you know, you
31:33
Speaker 1: can take that direction, you can say, well, you only
31:35
Speaker 1: have memories of them. But you can also go the
31:37
Speaker 1: other direction, and you could say, well, you know, let's
31:40
Speaker 1: just not consider only Boltman brains. Let's consider Boltzmann people.
31:44
Speaker 1: You know, like, if you're gonna fluctuate a brain out
31:45
Speaker 1: of the vacuum, and it is basically almost impossibly unlikely,
31:49
Speaker 1: why don't you just go whole hog and make a
31:51
Speaker 1: whole person, you know, arms and legs and everything, Well,
31:54
Speaker 1: the full Boltzman. Think of Boltzmann booties and it's full
31:59
Speaker 1: fund a bolt and a Boltzman elbows, right, yeah, And
32:05
Speaker 1: you know this is all in comparison to fluctuate in
32:08
Speaker 1: entire universe out of the vacuum, and so compared to that,
32:11
Speaker 1: like everything is basically free. Even if you add like
32:14
Speaker 1: a Boltzman room around your Boltsman body, even a Boltzman town,
32:17
Speaker 1: it's still much more likely than fluctuating the entire universe. Really,
32:22
Speaker 1: like and you can expand that to the Earth, like
32:24
Speaker 1: the whole Earth produced profit existence with photons coming out
32:28
Speaker 1: of just the right way for us to think that
32:30
Speaker 1: there's a larger universe. Yes, yes, exactly, And that's still
32:35
Speaker 1: more likely than the Big Bang. That's more likely than
32:37
Speaker 1: fluctuating the whole Big Bang. And this was the criticism
32:39
Speaker 1: of Boltzman's arguments. You know, Boltzman's like, just fluctuated galaxy,
32:43
Speaker 1: No big deal, folks, and people like, actually, that is
32:46
Speaker 1: a pretty big deal. Fluctuating a brain is unlikely, and
32:49
Speaker 1: that's much more likely. And so you know, as a
32:51
Speaker 1: way to critique either fluctuating like a Boltzmann galaxy out
32:54
Speaker 1: of the vacuum or fluctuating the whole universe, this is
32:57
Speaker 1: just a way to point out that that's all seems really,
33:00
Speaker 1: really really unlikely. But I guess the core argument, though,
33:03
Speaker 1: is still valid. Isn't it that it is more likely
33:06
Speaker 1: for us to have suddenly appeared six thousand years ago
33:09
Speaker 1: than through a big bang fourteen billion years ago if
33:12
Speaker 1: you think that the Big Bank comes from a low
33:14
Speaker 1: entropy fluctuation. Yeah, and again we're not just talking about
33:17
Speaker 1: like the creation of the universe in general. We're talking
33:20
Speaker 1: about this one idea that the Big Bang is this fluctuation, right.
33:24
Speaker 1: There are other ideas of how the Big Bank came
33:26
Speaker 1: about or how the universe was formed that are not
33:29
Speaker 1: this one particular cosmology, But this one is susceptible to
33:33
Speaker 1: this criticism of Boltzmann brains. It's only if you think
33:36
Speaker 1: that the universe itself fluctuated out of the blue. But
33:39
Speaker 1: there's other ideas. Maybe the universe didn't fluctuate out of
33:43
Speaker 1: the blue, maybe it came from something else. Yeah, exactly.
33:46
Speaker 1: There are lots of other theories for where the universe
33:48
Speaker 1: came from, you know, and like they're all improbable and
33:51
Speaker 1: probably wrong. We talked about them on the podcast before.
33:55
Speaker 1: You know, maybe there was a whole universe before and
33:57
Speaker 1: there was a big crunch, or maybe base just started
34:01
Speaker 1: at that moment and we don't understand how and why
34:03
Speaker 1: and it doesn't even make any sense to ask that question.
34:06
Speaker 1: Or maybe there's an inflating eternal universe where this sort
34:10
Speaker 1: of weird infloton field then decays into the kind of
34:13
Speaker 1: stuff which can create a big Bang. So, you know,
34:16
Speaker 1: none of these things are like well formed theories that
34:18
Speaker 1: anybody really believes. They're all just sort of still at
34:21
Speaker 1: the level of intellectual playgrounds, because we're at that point
34:24
Speaker 1: where were like throwing stuff off the wall and see
34:26
Speaker 1: which brains stick to it. You know, which peanut butter
34:29
Speaker 1: makes any sense at all? Maybe the universe is almond butter, right,
34:35
Speaker 1: or it's got a peanut allergy. But yeah, right, and
34:38
Speaker 1: that's been the problem the whole time. You know, I
34:40
Speaker 1: guess what you're saying is that there might be other explanations,
34:43
Speaker 1: but for them to be scientific, wouldn't they at the
34:45
Speaker 1: core be sort of random events? Right? Otherwise, what what
34:50
Speaker 1: else is there besides a random event? Sorry? Are you
34:55
Speaker 1: saying that every idea is just a random event? I
34:57
Speaker 1: mean you can't actually like think hard about things and
35:00
Speaker 1: come up with good ideas well in terms of the
35:02
Speaker 1: origin of the universe, right, like, maybe the universe came
35:05
Speaker 1: from another universe, but where did that universe come from?
35:07
Speaker 1: And then at infinitum and eventually you sort of come
35:10
Speaker 1: to a probability argument, right, Well, maybe, I mean you
35:14
Speaker 1: might come to a single possibility. It could be that
35:18
Speaker 1: you discover that the laws of physics can only work
35:21
Speaker 1: in one way, and the universe could have only started
35:24
Speaker 1: in one way and be self consistent. It certainly is
35:27
Speaker 1: possible to reveal that the universe has to be a
35:31
Speaker 1: certain way because the laws only work. For example, if
35:34
Speaker 1: that happens, and that that, I think is sort of
35:36
Speaker 1: the hope and the goal that we'll get back to
35:38
Speaker 1: the very beginning of stuff and we'll realize, oh, this
35:40
Speaker 1: is the only way that makes sense, and so that
35:43
Speaker 1: must be why it is this way. But we have
35:45
Speaker 1: no guarantee. It could be an infinite ladder of questions
35:49
Speaker 1: leading to questions leading to questions. We have no guarantee
35:52
Speaker 1: we're ever going to make sense of it. That's making
35:54
Speaker 1: my bols my brain hurt a little bit, and that's
35:57
Speaker 1: not just because I'm in the middle of the sun
35:59
Speaker 1: or days. So I guess. Then let's get back to
36:02
Speaker 1: this question. Then are we a Boltzman brain and my
36:05
Speaker 1: Bolthman brain? How can I be sure that I'm not?
36:08
Speaker 1: You can't actually be sure that you're not a Boltman brain,
36:11
Speaker 1: But you can use your brain to sort of reason
36:14
Speaker 1: your way out of it, right. You can make arguments
36:17
Speaker 1: that convince you that you're probably not a Boltzmann brain.
36:20
Speaker 1: And this is you know, some good arguments out there.
36:23
Speaker 1: One of my favorites comes from Sean Carrol. Right, Sean
36:27
Speaker 1: Carroll thinks about this stuff pretty deeply, and you know,
36:30
Speaker 1: he points out that if you're a Bolthman brain, that
36:33
Speaker 1: means that most of the things you think are not
36:36
Speaker 1: based in reality. They're like false memories that are implanted
36:40
Speaker 1: in your brain when your Boltman brain assembled. Right, you
36:42
Speaker 1: didn't actually go to that elementary school, you didn't actually
36:47
Speaker 1: marry that person. That's all just fake memories. Right. Wait, wait, wait, wait,
36:51
Speaker 1: he's saying that we are that or we're not that.
36:54
Speaker 1: He's saying if you're a Boltzman brain, then all of
36:56
Speaker 1: your memories and all of your thoughts are false right there,
36:59
Speaker 1: just assembled randomly. They're not based on real experiences, real
37:03
Speaker 1: inside into a real universe. And that includes the idea
37:07
Speaker 1: of Boltzmann brains. So if you're a Bolsman brain, then
37:11
Speaker 1: you shouldn't trust any of your ideas, including the idea
37:14
Speaker 1: of Boldsman brains. What that's not right? Just because I'm
37:19
Speaker 1: dreaming or because I'm an illusion doesn't mean that there
37:22
Speaker 1: aren't real things that could exist outside of me. Right,
37:26
Speaker 1: that's right. Yeah, but your thought about Boltzmann brains could
37:29
Speaker 1: have not come from a careful analysis of the universe
37:32
Speaker 1: and it's likelihood. It could just be like I'm made
37:34
Speaker 1: up crazy idea and planting your brain because you know,
37:38
Speaker 1: it just happened to come that way when the particles
37:40
Speaker 1: assembled themselves out there near Alpha Centauri. It could have.
37:43
Speaker 1: But it also could be the opposite, right. It could
37:46
Speaker 1: be that it is true. It could be that it's true, right,
37:48
Speaker 1: but you have no basis for believing that it's true
37:50
Speaker 1: just because you're thinking it, right, I mean, he says,
37:53
Speaker 1: if you reason yourself into believing that you live in
37:56
Speaker 1: such universe with Bolsman brains, you have to conclude the
38:00
Speaker 1: have no justification for accepting your own reasoning because the
38:04
Speaker 1: reasoning and Boltman brains is by definition unreliable. They're not
38:08
Speaker 1: doing any reasoning, they just like have ideas. And I
38:10
Speaker 1: think you're saying that the argument against this crazy idea
38:14
Speaker 1: is that if you are like a spontaneous brain that
38:16
Speaker 1: formed with all these crazy thoughts in it, then you
38:19
Speaker 1: can't really say anything about reality, Like maybe all of
38:22
Speaker 1: what you think are the laws of physics could just
38:25
Speaker 1: be some kind of sort of bogus random assembly of
38:28
Speaker 1: molecules in your head. Yeah, you can't like at the
38:31
Speaker 1: same time, conclude that you live in like a randomly
38:34
Speaker 1: fluctuating universe creating brains, and believe that you have good
38:37
Speaker 1: reason for listening to those brains. Well you could, but
38:40
Speaker 1: you just wouldn't be a serious train. You'd be a
38:43
Speaker 1: brain cast exactly. So he says that the whole idea
38:47
Speaker 1: is what he calls cognitively unstable, that if you believe
38:50
Speaker 1: in it, that gives you reason to not believe in it. Right,
38:53
Speaker 1: And so it says the whole thing sort of falls apart. Well,
38:55
Speaker 1: it doesn't fall apart, it just makes it questionable, right,
38:58
Speaker 1: but it's good still be true, right, you have anything
39:01
Speaker 1: could still be true. That's a low standard. Remember we're
39:03
Speaker 1: using this idea is a way like probe the likelihood
39:06
Speaker 1: of a cosmological theory, of saying could the universe be
39:09
Speaker 1: this way? And the argument is if your theory the
39:12
Speaker 1: universe suggests there are more Boltman brains than not, then
39:15
Speaker 1: you're not really going to believe in it. And this
39:17
Speaker 1: is just a way of saying, you know, okay, Bollsman
39:19
Speaker 1: brains are bad, but you know, you can be pretty
39:21
Speaker 1: confident that you're not a Boltswin brain. If you're forming
39:24
Speaker 1: like well thought out, coherent ideas. What if Einstein was
39:27
Speaker 1: a Baltzmann brain and he happened to be right? Yeah? Maybe?
39:32
Speaker 1: And you know you have to also wonder, like, should
39:34
Speaker 1: you listen to your own ideas? Right? If the universe
39:37
Speaker 1: is filled with bullspin brains, probably more of those Bollsman
39:40
Speaker 1: brains are not very clever. Then there are Bollsman brains
39:44
Speaker 1: that are like Einstein, right, Which means that you're probably
39:47
Speaker 1: not Einstein, which makes you wonder, life, should you be
39:51
Speaker 1: listening to your own thoughts about the universe. I don't know.
39:53
Speaker 1: It's the most insulting thing I've heard from me, Daniel.
39:56
Speaker 1: You still, I'm probably not Einstein. I mean, Einstein was
40:00
Speaker 1: and smart enough to come up with your peanut butter analogy.
40:02
Speaker 1: I got that on him. Yet, maybe I'm smarter than Einstein.
40:06
Speaker 1: Maybe you're right, Maybe I'm not Einstein. Maybe I'm better
40:10
Speaker 1: at cartooning than eight Stein. Yeah, I'm sure that's true.
40:13
Speaker 1: This is part of that counterpoint that you were talking
40:15
Speaker 1: about that you mentioned, is this idea that there could
40:18
Speaker 1: be Boltman brain, but there may not necessarily be smart
40:22
Speaker 1: Boltzmann brains. Yeah, exactly, So we could be a bunch
40:25
Speaker 1: of Bolsman brains, so to fool on ourselves into believing
40:28
Speaker 1: some silly argument about the origin the universe because we're
40:30
Speaker 1: not a wave, so we could be Boltman brains foolishly
40:34
Speaker 1: thinking that bolts when brains are possible. Yes, but then
40:39
Speaker 1: we would be right if that's true. You might have
40:43
Speaker 1: to be a dumb Boltmann brain to believe the dumb
40:45
Speaker 1: Boltman brain idea doesn't make any sense. You just proved yourself.
40:51
Speaker 1: Oh man, it's confusing, all right, Well, then what's the
40:55
Speaker 1: other alternative? I guess if the universe is not a
40:58
Speaker 1: random fluctuation, you know, there are sort of two other alternatives.
41:02
Speaker 1: One is to accept that maybe the universe was a
41:05
Speaker 1: really unusual, unlikely fluctuation, and then just to say that's okay, Like,
41:10
Speaker 1: sometimes really rare things do happen, even like unfathomably rare,
41:15
Speaker 1: like an entire big bang coming into existence out of
41:19
Speaker 1: thermal equilibrium. Sometimes they do happen. And this is what
41:22
Speaker 1: we were talking about before. It's the anthropic principle. It
41:24
Speaker 1: says that it's okay for unlikely things to happen if
41:28
Speaker 1: they're necessary for you to be here to ask questions
41:31
Speaker 1: about how unlikely they are. Maybe the universe is infinite
41:36
Speaker 1: and this kind of stuff almost never happens. But in
41:39
Speaker 1: the places where it's not happening, there's nobody noticing. There's
41:42
Speaker 1: nobody asking like, hey, how come we didn't get a
41:44
Speaker 1: big bang over here. It's only in the places where
41:47
Speaker 1: you do have a big bang and then people to
41:49
Speaker 1: ask these questions that you ask these questions. So it's
41:51
Speaker 1: like me saying, what's the probability of me existing? I
41:55
Speaker 1: can't rule out my own existence by arguing that I'm
41:58
Speaker 1: unlikely because I did happen. Right. It's like you're a
42:01
Speaker 1: pair of snake eyes and a pair of die right,
42:04
Speaker 1: Like you're two ones, and you're thinking, like, oh my god,
42:07
Speaker 1: what that's crazy that I exist? But you don't know
42:10
Speaker 1: if the universe, you know, through the paradise bazillion times
42:13
Speaker 1: before you existed. Yeah, exactly. And I don't really like
42:17
Speaker 1: that argument that much. It feels to me like sort
42:19
Speaker 1: of a cop out. It says, there's no answer. Stop
42:22
Speaker 1: asking questions. You know, there's no reason for this very
42:26
Speaker 1: unlikely thing. And in science it might be true. But
42:29
Speaker 1: in science we've made a lot of good progress by
42:32
Speaker 1: looking at weird stuff and going hmm, that's weird. I
42:35
Speaker 1: wonder if there's more to the story, And that's usually
42:38
Speaker 1: the way we pull on threads and unravel something deep
42:41
Speaker 1: and true and interesting about the universe. So can't disprove
42:43
Speaker 1: the anthropic argument. But it's sort of like it doesn't
42:46
Speaker 1: give you anywhere else to go. There's nothing deeper you
42:49
Speaker 1: can do after you answer a question that way, So
42:52
Speaker 1: it's not really very satisfying. I'd like to keep digging. Well,
42:54
Speaker 1: you could keep asking like who through the die right,
42:58
Speaker 1: or like how does the die throwing work? That would
43:00
Speaker 1: explain and and it'd be interesting to look into. Yeah, absolutely,
43:04
Speaker 1: but it doesn't answer the question of like, why is
43:06
Speaker 1: our seemingly impossibly unlikely universe exists? He says, well, it
43:11
Speaker 1: just kind of does. Well, I think that's a perfectly
43:12
Speaker 1: good reason. I mean, I tell it to my kids
43:14
Speaker 1: all the time, just because why can't you watch more TV?
43:18
Speaker 1: Just because because Daddy needs you to go to bed?
43:22
Speaker 1: Because my Baltzman brain says so, because my baltmonan gratest tired.
43:27
Speaker 1: I guess the idea is that maybe our universe did
43:29
Speaker 1: come out of this super crazy, unlikely event, But that
43:32
Speaker 1: doesn't mean that within it you can have these crazy
43:35
Speaker 1: Balthman brains floating in it. Yeah, And I think the
43:37
Speaker 1: other sort of category of answers is to say, all right,
43:40
Speaker 1: you're right Boltzmann brains suggest that the universe as a
43:44
Speaker 1: low entropy fluctuation is super unlikely. So let's focus on
43:48
Speaker 1: other cosmologies, other ideas for how the universe started that
43:52
Speaker 1: don't require it to have existed forever and then fluctuate
43:56
Speaker 1: into a big bang. Things that where the universe actually
43:59
Speaker 1: did start for billion years ago, or there's some other
44:02
Speaker 1: mechanism for creating the Big Bang other than it's just
44:05
Speaker 1: like weird random, super low entropy fluctuation. All right, I
44:09
Speaker 1: guess maybe we just have to keep our fingers crossed.
44:12
Speaker 1: Then it's that kind of the general approach here that
44:15
Speaker 1: there's a lot we don't know, and we don't know
44:17
Speaker 1: what these actual probabilities are. Yeah, and this is just
44:20
Speaker 1: a fun way to sort of like explore these ideas
44:23
Speaker 1: and to think about the consequences. You know, we have
44:26
Speaker 1: such an incredible lack of knowledge about the early universe
44:29
Speaker 1: and such an incredible variety of kind of bonkers ideas
44:33
Speaker 1: for how it could have come about that it's useful
44:36
Speaker 1: to like come up with these arguments to evaluate them,
44:38
Speaker 1: because we can't like go back in time and see
44:40
Speaker 1: what actually happened, or journey around the whole universe and
44:43
Speaker 1: gather the data we need. So until then we just
44:45
Speaker 1: are stuck here on Earth in our brains, whites and
44:48
Speaker 1: brains or cham brains or Boltsman brains, thinking about the
44:52
Speaker 1: origin of the universe and convincing ourselves that maybe we're
44:54
Speaker 1: making progress. Yeah, that's a good point, David, you just
45:00
Speaker 1: woke me up from my nap. I was doing some
45:02
Speaker 1: thought experiments. David and Klan nap their way through the universe.
45:06
Speaker 1: We could replace ourselves and none of the other Bolsman
45:09
Speaker 1: brains would notice the difference. Maybe our Bolzman listeners would notice.
45:13
Speaker 1: All right, Well, we hope that gave you as much
45:15
Speaker 1: of a Boltzmann headache and it did for me, and
45:18
Speaker 1: that it maybe helped you think about what's like the
45:21
Speaker 1: out there in the universe and whether or not it's
45:24
Speaker 1: all even real. Thanks for joining us, See you next time.
45:35
Speaker 1: Thanks for listening, and remember that Daniel and Jorge explained.
45:38
Speaker 1: The Universe is a production of I Heart Radio or
45:41
Speaker 1: more podcast for my Heart Radio, visit the I heart
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45:47
Speaker 1: favorite shows.