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What are the basic constants of the Universe? · Daniel and Kelly’s Extraordinary Universe

0:09
Speaker 1: Or Hey, what's your favorite number? Well, I like all numbers.
0:12
Speaker 1: I try not to discriminate between numbers, but you know,
0:14
Speaker 1: I think since I was little, I've always liked the
0:16
Speaker 1: number four. Number four. Why is that that's a lot
0:19
Speaker 1: less than the number of bananas in a bunch for example? Well,
0:23
Speaker 1: I think I liked it because when I was literally
0:25
Speaker 1: kind of blew my mind that, you know, four was
0:27
Speaker 1: two plus two and it was two times two, and
0:30
Speaker 1: it was two to the two, and so I just
0:32
Speaker 1: thought that was like amazing, Right, it's pretty two two.
0:35
Speaker 1: What about you, what is your favorite number? Oh, that's easy.
0:37
Speaker 1: It's got to be forty two, because forty two. It's
0:41
Speaker 1: the answer to everything. So maybe that should be our
0:43
Speaker 1: podcast title. Forty two explains the universe forget about those
0:47
Speaker 1: two guys. I guess we could stretch that to forty
0:49
Speaker 1: five minutes, right, The answered everything is just forty two.
0:52
Speaker 1: Every episode would be forty two minutes long, and we'd
0:57
Speaker 1: have forty two good jokes. They would cancel it after
1:00
Speaker 1: forty two episodes, and I hope we have forty two
1:05
Speaker 1: million listeners. Hi am more hand made cartoonists and the
1:22
Speaker 1: creator of PhD comments, Hi, I'm Daniel Whitzen. I'm a
1:25
Speaker 1: particle physicist, and I'm a co author of our book
1:28
Speaker 1: We Have No Idea, a Guide to the Unknown Universe,
1:32
Speaker 1: and which we talk about all the amazing open mysteries
1:35
Speaker 1: of the universe, all the things science has figured out,
1:38
Speaker 1: and all the things science has not figured out. It's right,
1:41
Speaker 1: there are a lot of books out there about all
1:42
Speaker 1: the things we know about the universe, but ours is
1:44
Speaker 1: about all the things we don't know. And believe it
1:47
Speaker 1: or not, we filled the whole book with things we
1:50
Speaker 1: don't know. And it's not just what Jorge and I
1:52
Speaker 1: don't know about the universe, which is a lot, but
1:54
Speaker 1: it's about what science in general. We try to speak
1:56
Speaker 1: for humanity and bring you to the forefront of human knowledge,
2:00
Speaker 1: to delve into the deepest questions about the biggest things
2:03
Speaker 1: in the universe, i e. The entire universe, Because it
2:06
Speaker 1: turns out there's a lot that scientists don't know about
2:09
Speaker 1: this great, big and complex and beautiful universe, including sometimes
2:13
Speaker 1: things about numbers. Yeah, because one way to tear the
2:16
Speaker 1: universe apart is to sort of take it apart literally physically,
2:20
Speaker 1: and say I am made of bits. What are those
2:23
Speaker 1: bits made out of what are those bits made out of?
2:25
Speaker 1: And then you can drill down to the sort of
2:27
Speaker 1: the the core bit, the fundamental element of the universe.
2:31
Speaker 1: But there's another way to look at the universe, another
2:33
Speaker 1: way to think about it, and that's more mathematical, to
2:36
Speaker 1: think about what are the basic numbers? Like if you
2:40
Speaker 1: had a theory of the universe, what numbers would appear
2:43
Speaker 1: in it? Yeah, Like if you had an equation that
2:45
Speaker 1: just describes everything in the universe, would it have any
2:49
Speaker 1: numbers in it or not? Or just symbols or concepts?
2:52
Speaker 1: And what would those numbers be, right? And why would
2:55
Speaker 1: they be those numbers and not other numbers? I like
2:58
Speaker 1: to think about some he's sitting at a control panel
3:01
Speaker 1: for the universe. Maybe the universe is a simulation and
3:03
Speaker 1: somebody up there has knobs and they're twiddling it. And
3:06
Speaker 1: you know, as you change those knobs, the universe looks different.
3:09
Speaker 1: And so our job is to measure the value of
3:12
Speaker 1: those knobs and then to ask, like why this value
3:15
Speaker 1: not something else could have been anything? Are these two
3:17
Speaker 1: knobs actually connected? Is there just one big knob? Yeah?
3:21
Speaker 1: Like why are our podcast always about forty five minutes?
3:24
Speaker 1: Is there a universe in which our podcasts are shorter
3:26
Speaker 1: or longer. That's as long as we can be funny.
3:30
Speaker 1: For after that it just trails off. Yeah. In fact,
3:34
Speaker 1: even the number of knobs that the universe might have
3:36
Speaker 1: would be significant, Like if the universe had seven knobs
3:39
Speaker 1: versus three knobs, that would be pretty significant and would
3:42
Speaker 1: tell you a lot about whoever or whatever made this universe. Yeah,
3:46
Speaker 1: and this is a deep question, not just of science,
3:49
Speaker 1: but also of philosophy. If you think the goal of
3:51
Speaker 1: science is to reveal the truth about the universe, then
3:54
Speaker 1: you have to be prepared to answer the question what
3:57
Speaker 1: does that truth mean or does it inform us? Right?
4:00
Speaker 1: If you're going to ask a question, you better know
4:02
Speaker 1: how to interpret the answer, which is of course the
4:04
Speaker 1: underlying joke behind forty two. Those folks that build a
4:07
Speaker 1: huge planet sized computer to figure out the answer to life,
4:09
Speaker 1: the universe and everything and then have no idea what
4:12
Speaker 1: it means. You think they know there's a universe out
4:14
Speaker 1: there in which there Douglas Adam wrote the same book
4:17
Speaker 1: but used the number forty one, or and there are
4:22
Speaker 1: jokes are all about that number. I don't know. I'd
4:25
Speaker 1: love to read an interview with him about how he
4:27
Speaker 1: chose that number, because it's achieved such cultural prominence. You know,
4:31
Speaker 1: they did a survey of like all the numbers that
4:33
Speaker 1: appear in Python code on GitHub, and they plotted the distribution,
4:38
Speaker 1: and there's a big spike at forty two. People just
4:40
Speaker 1: like use it as an arbitrary number all the time.
4:44
Speaker 1: Maybe it's not a coincidence, or you know, maybe it
4:47
Speaker 1: is a basic number that just pops up. It's the
4:50
Speaker 1: number of neurons that work in an average person's head. Maybe. Yeah,
4:54
Speaker 1: So this is an interesting concept to think about the
4:56
Speaker 1: constants of the universe. And so today on the episode,
4:58
Speaker 1: we'll be asking the question what are the basic constants
5:06
Speaker 1: of the universe? And are they even constants? And why
5:10
Speaker 1: do physicists keep calling things constant when they don't know
5:12
Speaker 1: if they are. Why can't they be consistent about it
5:15
Speaker 1: or at least conscientious, Right, It seems like a constant
5:19
Speaker 1: annoyance to have to recalibrate my meaning of words when
5:23
Speaker 1: I talk to physicists. Yeah, and I don't think it's
5:25
Speaker 1: even a conscious thing. You know, we talk about constants,
5:28
Speaker 1: we really mean numbers. But then there's a question, you know,
5:30
Speaker 1: are these numbers actually constant. Are they changing? How could
5:33
Speaker 1: we tell if they were changing? What if two of
5:35
Speaker 1: them are changing at the same time, would we even notice?
5:38
Speaker 1: These are really fun, interesting questions, and they really go
5:41
Speaker 1: deep into the nature of the universe itself. You know,
5:43
Speaker 1: we have these basic laws that describe sort of how
5:46
Speaker 1: things interact. But then they're just seemed to be numbers
5:49
Speaker 1: that determine, you know, the relative power, like why is
5:52
Speaker 1: the gravitational force so much weaker than the other forces?
5:55
Speaker 1: You know, why our stars so far apart. There's has
5:59
Speaker 1: to be something to say at these scales to determine
6:01
Speaker 1: why the universe turned out this way and not other ways. Daniel,
6:04
Speaker 1: I feel like this baby. This question assumes that there
6:07
Speaker 1: are basic constants in the universe. Do we know for
6:09
Speaker 1: sure that there are constants in the universe? Is it
6:11
Speaker 1: may be just something that we haven't discovered or something Well,
6:15
Speaker 1: we have constants that we've measured and we do not
6:18
Speaker 1: know how to derive them, and we'll get into the
6:20
Speaker 1: definition of what it means to be a basic constant.
6:23
Speaker 1: Um there used to be more right, and sometimes we discover, oh,
6:26
Speaker 1: this thing that we thought was fundamental turns out to
6:29
Speaker 1: just be a combination of these other numbers, and so
6:31
Speaker 1: we don't need it. Sometimes, like a basic number is
6:33
Speaker 1: just a combination of other numbers, just a combination to
6:36
Speaker 1: other numbers. So what we're looking for is the minimal set, right,
6:38
Speaker 1: We want the smallest number of constants, just like we
6:41
Speaker 1: want the smallest number of physical laws. We don't want
6:44
Speaker 1: to describe five thousand forces. We wanted to have one
6:47
Speaker 1: force that describes everything. All the features of electromagnetism. We've
6:51
Speaker 1: tied them up so nicely into a few equations with
6:54
Speaker 1: a small number of numbers in them. So we're always
6:56
Speaker 1: working to reduce the number of ideas and then the
6:59
Speaker 1: number of parameters of those ideas. And we're not talking
7:02
Speaker 1: about things like pie or e, right, which are sort
7:05
Speaker 1: of mathematical or geometric constants in the universe. We're talking
7:09
Speaker 1: more about physical constants, right, Yeah, things that you have
7:12
Speaker 1: to measure, right, not just geometrical stuff that you could
7:15
Speaker 1: calculate without having access to the universe. Things you have
7:18
Speaker 1: to go out and actually measure. Because things like pie
7:20
Speaker 1: and e are like sort of like basic constants in mathematics,
7:24
Speaker 1: you know, which is sort of abstract. We're talking about
7:27
Speaker 1: the constants in the universe that seemed to be there
7:30
Speaker 1: that sort of define how things work. Yes, things that
7:33
Speaker 1: if you change them, the nature of the universe would change.
7:37
Speaker 1: Things would be different. You wouldn't have chemistry anymore, or
7:39
Speaker 1: you wouldn't have stars, or you'd have more stars, or
7:42
Speaker 1: you know, if different forces would be more powerful, or
7:46
Speaker 1: we'd be made out of different kinds of particles. You know,
7:48
Speaker 1: this kind of stuff that fundamentally changed our description of
7:51
Speaker 1: the universe. But you're right, we don't know how many
7:53
Speaker 1: constants we actually need right now. We need quite a
7:57
Speaker 1: few to describe in the number. But if we had
7:59
Speaker 1: the ultimate theory, how many constants would it happen? It
8:02
Speaker 1: maybe one, maybe five, maybe ten, Maybe you have pie
8:04
Speaker 1: number of constants. What does that even mean? It means
8:09
Speaker 1: I just blew your mind, Daniel. Well, you know we
8:11
Speaker 1: talked about how in Steven Wolfram's world there are two
8:13
Speaker 1: point seven dimensions, so maybe you can have three point
8:16
Speaker 1: one four numbers. Me and Stephen Wolfram are at the forefront. Well,
8:21
Speaker 1: I pulled our listeners who are willing to participate in
8:24
Speaker 1: virtual person on the street interviews and ask them this
8:27
Speaker 1: question about the basic constants of the universe. And if
8:30
Speaker 1: you would like to participate in these virtual person on
8:33
Speaker 1: the street interviews, just right to us two questions at
8:36
Speaker 1: Daniel and Jorge dot com. And you can also display
8:39
Speaker 1: your knowledge or lack thereof on the podcast. So think
8:42
Speaker 1: about it for a second. If someone asked you, what
8:45
Speaker 1: are the basic constants of the universe? What would you answer?
8:48
Speaker 1: Here's what people had to say this one. It's easy.
8:51
Speaker 1: I don't know the gravitational constant and Avogadro constant. Other
8:56
Speaker 1: than light speed, I would say that pie and oiler's
8:59
Speaker 1: number also constants of the universe. At It's just like
9:02
Speaker 1: things that we've measured. Well, I don't know. Well, they
9:07
Speaker 1: gave us one hint of the speed of light, but
9:09
Speaker 1: I think based on other podcasts that I've listened to
9:12
Speaker 1: and learned from them, I think entropy might be a constant.
9:16
Speaker 1: Gravity is a constant. And my last guest would be
9:21
Speaker 1: maybe thermodynamics. I think physics, the you know, the standard
9:26
Speaker 1: model of physics as we know it is constant. Right,
9:29
Speaker 1: coals one equals one um? What else equals one pie?
9:35
Speaker 1: There's Avogadro's number from ancient chemistry, listens plank mass, plank,
9:41
Speaker 1: lenks um, Boltzman's constant reintropy. I think there was a
9:49
Speaker 1: Daniel Why I explained the universe episode onto my dynamics.
9:52
Speaker 1: I mentioned that the gravitational constant, elementary charge, the exponent
9:59
Speaker 1: of the radius, the radius squared, and uh Gaussian formula,
10:04
Speaker 1: and probably, I guess also called Maxwell's equations, death and taxes.
10:10
Speaker 1: And there's also the charge of an electron and um
10:16
Speaker 1: maybe the mass of the part of fundamental particles that
10:21
Speaker 1: have mass. I know there are several constants in the universe,
10:24
Speaker 1: however I can't remember most of them. The ones I
10:27
Speaker 1: do remember are the speed of light, the gravitational constant,
10:32
Speaker 1: and planks constant. Alright, some pretty good answer, is man?
10:36
Speaker 1: Some of these I've never even heard of. Death and taxes?
10:38
Speaker 1: You never heard it before? You know, what are taxes?
10:41
Speaker 1: I don't understand. Is that what I keep playing any
10:44
Speaker 1: letters in the midid Do you live in the sovereign
10:47
Speaker 1: state of Jorge? Maybe I'll ask my accountant. But you know,
10:50
Speaker 1: a lot of people are are talking about real physical
10:53
Speaker 1: things like light speed and soul and entropy and the
10:57
Speaker 1: speed of light. Yeah, people are saying things that are
11:00
Speaker 1: sort of parameters of physical theories. But these are not.
11:04
Speaker 1: Actually the basic constants that physicists talk about the speed
11:08
Speaker 1: of light, planks constant, the gravitational constant. They seem basic,
11:12
Speaker 1: but they're actually susceptible to sort of arbitrary definitions because
11:16
Speaker 1: they're expressed in terms of human units. Oh, I see,
11:19
Speaker 1: Meaning that, for example, the speed of light could be
11:22
Speaker 1: a constant, but the constant wouldn't be three hundred thousand
11:25
Speaker 1: meters per second, yeah, because that's subject to units. Yeah,
11:29
Speaker 1: so let's get into that, Like what do we mean
11:31
Speaker 1: by a basic physical constant? And one important thing is
11:34
Speaker 1: that it should be dimensionless, like it shouldn't have units.
11:38
Speaker 1: It shouldn't be expressed in terms of like furlongs per fortnite,
11:42
Speaker 1: you know, or gallons per second or something. It should
11:44
Speaker 1: just be a pure number, like a pure number without unit,
11:48
Speaker 1: without units, like is a number without units, pies a
11:51
Speaker 1: number without units. But it's not a physical constant because
11:53
Speaker 1: it doesn't need to be measured with experiment, right, you
11:55
Speaker 1: can do it in a simulation or on the computer
11:58
Speaker 1: or something. But we're talking about physical instance that have
12:00
Speaker 1: to be measured, and those are things like we'll get
12:02
Speaker 1: into the whole list, but you know, things like the
12:05
Speaker 1: mass of a particle relative to the mass of another particle,
12:08
Speaker 1: like ratios, like ratios, which wouldn't change if you suddenly
12:12
Speaker 1: change what it means if you change, like from English
12:14
Speaker 1: units to international unit exactly. And there's two important reasons
12:18
Speaker 1: why you have to use numbers without units. The first
12:21
Speaker 1: is you want to look at the number and know
12:23
Speaker 1: what it means, and it doesn't mean anything if it's
12:26
Speaker 1: relative to some stick in Paris, or you know the
12:29
Speaker 1: length of somebody's foot a hundred years ago. Right. If
12:33
Speaker 1: you're interested in knowing a number, then you don't want
12:35
Speaker 1: to express in terms of human units because it's totally arbitrary,
12:38
Speaker 1: and you could change that number. It could be a
12:40
Speaker 1: hundred eighties six thousand miles per second or three times
12:43
Speaker 1: ten meters per second. Like, you can't look at the
12:46
Speaker 1: number and say it means anything if it's defined relative
12:49
Speaker 1: to something totally arbitrary. You need a basic constant to
12:51
Speaker 1: feel classic, like not subject to the whims of man
12:55
Speaker 1: and what they consider foot. That's right, And it's more
12:58
Speaker 1: than just you know, having an maturity standard. You also
13:02
Speaker 1: need the basic constants to be dimensionless so that you
13:05
Speaker 1: can tell if they're changing, if they're changing, then you
13:07
Speaker 1: can tell what's changing. I see, you don't want a
13:10
Speaker 1: meter to be, you know, the length of a length
13:14
Speaker 1: of putty, because the length of putty might change. That's right,
13:17
Speaker 1: of the length of putty might change. But also like
13:20
Speaker 1: you know, say you're interested in the question, you know,
13:22
Speaker 1: does the speed of light change? Right? This is a
13:25
Speaker 1: question you see in science all the time. It turns
13:27
Speaker 1: out it doesn't actually have the meaning that you think
13:30
Speaker 1: it does when you drill down into it, because it's
13:32
Speaker 1: so subject to human conventions. Depends on how you're defining units.
13:36
Speaker 1: And in fact, in Night three we change what we
13:39
Speaker 1: meant by the speed of light. Really, yeah, the speed
13:42
Speaker 1: of light change in after three, it doesn't make any
13:47
Speaker 1: sense to measure the speed of light. And that's because
13:50
Speaker 1: before nine eight three, we defind the meter to be
13:53
Speaker 1: the length of some rod in Paris, and the second
13:56
Speaker 1: to be um you know, ten trillion oscillations of C
13:59
Speaker 1: C and one thirty three. So we had the meter
14:01
Speaker 1: and we had the second, and then you could go
14:03
Speaker 1: out and you could measure the speed of light. You
14:05
Speaker 1: could say, how far did a beam of light go
14:07
Speaker 1: in ten seconds? And I'll measure that distance with my
14:11
Speaker 1: ruler from Paris or my copy of it, and get
14:13
Speaker 1: a number. Cool. But then a bunch of people got
14:17
Speaker 1: together and decided that will keep the second as like
14:20
Speaker 1: you know, the number of oscillations of set three. But
14:23
Speaker 1: then we're going to fix the speed of light. We're
14:25
Speaker 1: going to define it to be something. So we just
14:28
Speaker 1: pick a number. We say it's two point nine nine
14:30
Speaker 1: whatever times ten per second. Okay, So once you do that,
14:35
Speaker 1: you don't have to define the meter anymore. It's already
14:38
Speaker 1: defined by the other constants. Right, You've got time, and
14:42
Speaker 1: you've got speed because you have the speed of light.
14:45
Speaker 1: So a meter then is just defined as how far
14:48
Speaker 1: light goes in a certain tiny fraction of a second.
14:52
Speaker 1: So the meter is now defined to be a fraction
14:54
Speaker 1: of a light second. Right. Light seconds are the reference
14:58
Speaker 1: for distance now the under mental way we measure distance
15:01
Speaker 1: to the universe instead of that crazy rod in Paris,
15:05
Speaker 1: and we're used to measuring distances in terms of time,
15:08
Speaker 1: like a light year is a unit for distance to
15:12
Speaker 1: the stars. Right, that's familiar. Well, a meter is now
15:15
Speaker 1: just a tiny bit of a light second. It's not
15:17
Speaker 1: defined anymore by a rod in Paris. It's measured by
15:21
Speaker 1: how far light goes in that tiny slice of a second. Yeah,
15:25
Speaker 1: we flipped it. And so now you ask, well, a
15:28
Speaker 1: meter is now measured instead of the speed of light
15:30
Speaker 1: being measured. Isn't even time variable? You know, according to relativity?
15:35
Speaker 1: You know how close you are to a gravitational object,
15:38
Speaker 1: you know, like, isn't even the oscillations of of season
15:41
Speaker 1: one thirty three also may be subject to you know, relativity. Yeah, absolutely,
15:46
Speaker 1: And that's why you want to focus on dimensionless constants, right.
15:50
Speaker 1: But the point here, the point I was trying to make,
15:52
Speaker 1: is that, like you can't even tell in this example
15:56
Speaker 1: if the speed of light is changing, or you know,
15:58
Speaker 1: the length scale the uni verse itself is changing. It
16:01
Speaker 1: depends on if you're defining the speed of light to
16:03
Speaker 1: be fixed and measuring the meter relative to that, or
16:06
Speaker 1: you're defining the meter to be fixed and measuring the
16:09
Speaker 1: speed of light relative to that. So the way to
16:11
Speaker 1: figure out if the universe is changing, if the physics
16:14
Speaker 1: of the universe are changing in time or static, which
16:17
Speaker 1: is really what we're trying to get at, where we
16:19
Speaker 1: measure these numbers and see if they're changing, is to
16:22
Speaker 1: define only dimensionless numbers, numbers without any units because they're
16:25
Speaker 1: not subject to any of these totally arbitrary definitions. All right,
16:30
Speaker 1: So that's kind of what a basic constant is. It's
16:33
Speaker 1: a number that defines some kind of ratio about physical
16:36
Speaker 1: things in the universe, which may be there at the
16:38
Speaker 1: end when we discover the equation of the universe. Yeah,
16:41
Speaker 1: and I really like thinking about this this way, like
16:43
Speaker 1: thinking about measuring distances in terms of times. You know,
16:48
Speaker 1: it makes a lot of sense when you think about,
16:50
Speaker 1: you know, measuring distances to stars in terms of the
16:53
Speaker 1: speed of light um and it just shows you that
16:55
Speaker 1: all these numbers we measure, like the speed of light,
16:58
Speaker 1: they're really just ways to convert between meters and seconds.
17:01
Speaker 1: They're just like translations between arbitrary human conventions. So they're
17:05
Speaker 1: not actually fundamental. The things that are fundamental are things
17:08
Speaker 1: we'll talk about, you know, a little bit. But yes,
17:10
Speaker 1: we're looking for sort of a minimal list of dimensionless
17:14
Speaker 1: quantities which would change the world if if they changed, right,
17:18
Speaker 1: So let's maybe get into what is that minimal list
17:21
Speaker 1: of basic constants in the universe and what we know
17:24
Speaker 1: about them so far. But first let's take a quick break,
17:40
Speaker 1: all right, Daniel, we're talking about this constant topic that
17:44
Speaker 1: keeps coming up in physics, which is constants and what
17:48
Speaker 1: is and what isn't changing about the universe? And are
17:51
Speaker 1: there constants in the basic equation of the universe? And
17:54
Speaker 1: there are how many? And what are they? And let's
17:58
Speaker 1: just get out of the way. It's probably forty two,
18:00
Speaker 1: but you know, we still have to check. Well, forty
18:03
Speaker 1: two would be wonderful because it'd be kind of a
18:05
Speaker 1: good joke, but it would also be kind of disappointing
18:08
Speaker 1: because forty two is a big number. You're never happy, Daniel.
18:12
Speaker 1: All answers have both good and bad consequence. I'm constantly disappointed. Now.
18:17
Speaker 1: What we're looking for. What we'd love is to have
18:19
Speaker 1: a small number of constants, because that would tell us
18:22
Speaker 1: that we're close, right like the way we're trying to
18:24
Speaker 1: boil down the universe to one particle and one rule,
18:28
Speaker 1: that tells you something deep about the universe. If your
18:31
Speaker 1: list of particles and your list of rules about how
18:33
Speaker 1: they interact is fifty pages long, it tells you you're
18:36
Speaker 1: not really close to the answer. So we want to
18:38
Speaker 1: get down to a small number of constants because we
18:40
Speaker 1: think those are probably fundamental. We want to look at
18:43
Speaker 1: those and say, you know, the theory of the universe
18:46
Speaker 1: has the number seven in it. What does that mean?
18:48
Speaker 1: Why is the universe seven? Ish? You know, why seven
18:52
Speaker 1: and not six? And we're looking for that moment where
18:54
Speaker 1: we get to ask that philosophical question about the universe.
18:57
Speaker 1: And you can't really do that if you suspect your
19:00
Speaker 1: list of numbers is sort of an artifact of not
19:02
Speaker 1: having gotten there yet. Do you think maybe the last
19:05
Speaker 1: number in the universe. Do you think it's an integer
19:08
Speaker 1: like a whole number, or do you think it's gonna
19:10
Speaker 1: be some weird numbers? I don't know. You know a
19:12
Speaker 1: lot of particle theorists like numbers that are close to one.
19:16
Speaker 1: They think all the numbers and there should just be one.
19:19
Speaker 1: They're like, we got one, we don't need anymore. Yeah,
19:22
Speaker 1: And they wonder when they find a number that's not one.
19:24
Speaker 1: You know, they see things and like, well, why is
19:28
Speaker 1: electromagnetism so much stronger than the weak force? And why
19:31
Speaker 1: is it so much stronger than gravity? And they have
19:33
Speaker 1: these numbers and that reflect the relative strength of those forces,
19:36
Speaker 1: and they wonder, why is it not one? They look
19:38
Speaker 1: for symmetry and simplicity, so anytime they see a number
19:41
Speaker 1: that's not one, they get suspicious because they think maybe
19:44
Speaker 1: there's a reason, maybe there's a simpler way to express things,
19:46
Speaker 1: where all these things are just one. And that's how
19:48
Speaker 1: they conduct your social life too. They're like, there's more
19:50
Speaker 1: than one people here, what's going on? This is not
19:53
Speaker 1: what I ordered? They have one friend at a time,
19:57
Speaker 1: you know, one friend at a time. It's like of
20:00
Speaker 1: one else is apparently that's right. So we are not
20:03
Speaker 1: there yet. We are not down to one constant. In fact,
20:06
Speaker 1: we sort of have an embarrassing number of constants so far.
20:09
Speaker 1: We have twenty six basic constants of the unit. Twenty six.
20:13
Speaker 1: Oh man, that seems like a significant number in itself,
20:16
Speaker 1: seems like a special number because it's what two times thirteen, Yeah,
20:19
Speaker 1: and thirteen is the prime number. Yeah, but that means
20:22
Speaker 1: twenty six isn't right, so it's much less exciting. Alright,
20:26
Speaker 1: what do you mean? We have twenty six constants? Meaning
20:28
Speaker 1: in all of physics and all of the equations that
20:30
Speaker 1: we currently have about the universe, there twenty six numbers
20:34
Speaker 1: that you can't break down anymore or that are not
20:37
Speaker 1: related to each other. If you wrote down the whole
20:39
Speaker 1: standard model of particle physics, and you have to put
20:42
Speaker 1: all the numbers into all the four strengths and all
20:44
Speaker 1: the mass particles and all the way things change to
20:46
Speaker 1: each other. There are a lot of numbers in there,
20:48
Speaker 1: like thousands of thousands of numbers, but most of those
20:51
Speaker 1: numbers come from other numbers, Like how long does the
20:54
Speaker 1: muan live? That's a number, but you can calculate that
20:58
Speaker 1: based on the muan mass and the elect on mass
21:00
Speaker 1: and the fourth strength between them. And so if you
21:02
Speaker 1: boil it down to the minimal set of numbers that
21:05
Speaker 1: you needed to find all those other numbers, right, the
21:08
Speaker 1: ones that, according to our understanding currently are the knobs
21:12
Speaker 1: of the universe, then you get twenty six. Like I
21:14
Speaker 1: toss a ball up into the air and catch it,
21:16
Speaker 1: you can maybe derive that time using other numbers. Yeah, exactly.
21:20
Speaker 1: If I know the mass to the electron relative to
21:22
Speaker 1: the gravitational constant and stuff like that, I can derive
21:25
Speaker 1: most of physics from just a few numbers. All right, Well,
21:29
Speaker 1: then let's let's talk numbers. Danuel, What what are these
21:31
Speaker 1: twenty six? Break it down for us. What are these
21:33
Speaker 1: twenty six apparently basic constants of the universe that we
21:37
Speaker 1: have right now. Yeah, So there are sort of three categories.
21:41
Speaker 1: One is like the strength of forces, another is the
21:44
Speaker 1: masses of particles and how they mix, and then there's
21:48
Speaker 1: the cosmological constant and its own category. The first ones
21:52
Speaker 1: are really really interesting, and these are the fourth ones.
21:54
Speaker 1: The most important one, the one that you hear about
21:56
Speaker 1: a lot and I think reveals a lot about what
21:58
Speaker 1: we mean by a engineless physical constant. Is this one
22:02
Speaker 1: called the fine structure constant. Fine structure constant, all right,
22:07
Speaker 1: I'm intrigued. It's a weird name. It's called the fine
22:10
Speaker 1: structure constant because it comes from when people were trying
22:13
Speaker 1: to understand the nature of the atom and the structure
22:17
Speaker 1: of the spectra that it emitted. And so what it
22:19
Speaker 1: really reveals sort of the strength of the electromagnetic force.
22:23
Speaker 1: And so this number here tells you about the power
22:26
Speaker 1: of electromagnetism as probed by the internals of the atom,
22:30
Speaker 1: but it turns out to be a fundamental number of
22:32
Speaker 1: the universe. What does it mean? Is it like how
22:35
Speaker 1: how attracted an electron is to a proton or something
22:38
Speaker 1: like that. Yeah, it's something like the probability for an
22:42
Speaker 1: electron to emit a photon, and that number is a
22:46
Speaker 1: vacuum or um. Will electrons only emit photons inside electromagnetic fields,
22:51
Speaker 1: of course, And that number everyone knows that. And that
22:55
Speaker 1: number turns out to be one over one thirty seven.
22:58
Speaker 1: What exact one over one thirty seven, not exactly. For
23:02
Speaker 1: a long time people thought it was exactly one over
23:04
Speaker 1: on seven, and there was a big mystery in physics
23:07
Speaker 1: like why that number. And Richard Feynman likes to say
23:09
Speaker 1: that if you were a physicist and you were ever
23:11
Speaker 1: like stranded in a foreign city, you just hold up
23:14
Speaker 1: a piece of cardboard that says one over seven on it,
23:17
Speaker 1: and some other physicists will see that and know that
23:19
Speaker 1: you're a physicist, come rescuing. It's like a code. I'm
23:23
Speaker 1: not sure if you're stranded in a city you want,
23:26
Speaker 1: what you need is a physicist to rescue you. But
23:29
Speaker 1: you know, let's leave that aside. And um. Alright, So
23:32
Speaker 1: one of these constants of the universe is kind of
23:35
Speaker 1: how likely an electron is to admit a photon. Yeah,
23:38
Speaker 1: it's like the probability for an electron to emit a photon,
23:42
Speaker 1: and it's it's actually expressed in terms of other numbers
23:46
Speaker 1: that you will find familiar. Like the way you calculated
23:49
Speaker 1: is the charge of the electron squared divided by planks
23:55
Speaker 1: constant h bar times the speed of light, and so
23:59
Speaker 1: it has all these other of familiar things built into it.
24:02
Speaker 1: But when you put all those things together, the units cancel,
24:05
Speaker 1: Like you get up a number that has no units
24:08
Speaker 1: in it, And that means something really really deep. Um,
24:10
Speaker 1: what do you mean? What I mean is that it
24:12
Speaker 1: tells you something about the importance of the speed of light.
24:15
Speaker 1: It tells you, for example, that the speed of light
24:17
Speaker 1: is not actually a fundamental constant. That if you change
24:20
Speaker 1: the speed of light, but then you also change these
24:23
Speaker 1: other numbers inside the fine structure constant to keep the
24:26
Speaker 1: fine constructure constant the same, you would not be able
24:29
Speaker 1: to tell the difference. The universe would work the same way.
24:32
Speaker 1: As long as you keep these numbers the same, then
24:35
Speaker 1: you can change the speed of light and the strength
24:37
Speaker 1: electromagnetic force, and you could not do an experiment that
24:40
Speaker 1: showed that anything had change, Like it doesn't have any
24:42
Speaker 1: consequences anywhere else in the universe. That's right. When if
24:45
Speaker 1: you change the speed of light, Wooden, you we know
24:47
Speaker 1: it is like, oh, it takes longer for light to
24:50
Speaker 1: come to us from the sun. If you only change
24:52
Speaker 1: the speed of light, which means that you're effectively changing
24:55
Speaker 1: the fine structure constant, then yes. But if you change
24:57
Speaker 1: the speed of light and you also change like the
25:00
Speaker 1: charge of the electron or planks constant, or you manipulated
25:04
Speaker 1: these things in such a way to keep the fine
25:06
Speaker 1: structure constant the ratio of these things the same, then
25:09
Speaker 1: you could not tell the difference. It's like, Okay, distance
25:12
Speaker 1: now means something different. But you know, the electromagnetic force
25:16
Speaker 1: is now stronger. So what are you using to measure distance.
25:20
Speaker 1: You're using you know, the photons admitted by electrons or something.
25:24
Speaker 1: So you cannot devise an experiment that is sensitive to
25:27
Speaker 1: changes of just planks constant or just the speed of light. Um,
25:32
Speaker 1: if you keep the fine structure constant fixed, somebody could
25:36
Speaker 1: change these things and nobody in the universe would even notice.
25:40
Speaker 1: Nobody in the universe could even notice, you know. Imagine
25:42
Speaker 1: a simpler example, like, I feel like, I feel like
25:44
Speaker 1: this is a conspiracy. Suddenly I feel nervous. It's about
25:48
Speaker 1: our world is relative to our units. Imagine, for example,
25:51
Speaker 1: somebody came in and change the universe so that now
25:55
Speaker 1: every distance was doubled. This distance between all particles was doubled. Suddenly,
26:00
Speaker 1: could you notice? Well? Sure, but not if then they
26:03
Speaker 1: also increase the power of all the forces so that
26:05
Speaker 1: things didn't seem as far, and they increase the maximum
26:09
Speaker 1: speed you could go. Right, then it would take you
26:12
Speaker 1: just as long to get from here to work, and
26:15
Speaker 1: your rulers would also change, right, so you would say, oh,
26:18
Speaker 1: I'm still the same high as that was yesterday. It's
26:20
Speaker 1: like if somebody just scaled up the universe, but they
26:22
Speaker 1: made sure that everything worked same, would we even notice? Exactly? Like,
26:26
Speaker 1: could somebody bottle up the whole universe into a little
26:28
Speaker 1: bottle and then made sure that all the knobs were
26:31
Speaker 1: also changed that we wouldn't notice the difference. It could happen.
26:34
Speaker 1: It could happen. And that's why we focus on these
26:36
Speaker 1: dimensionless quantities, because you can't change those without changing the physics.
26:41
Speaker 1: You can change the things that they express, you know,
26:43
Speaker 1: this fine structure constant. You can change the dimension full
26:46
Speaker 1: of the unit quantities inside them. But if you change
26:50
Speaker 1: these fine structure constants, then there's no way to hide
26:52
Speaker 1: that they do seem like basic constants of the university.
26:56
Speaker 1: They do. And it's like a basic ratio of the universe,
26:58
Speaker 1: you know, just like pies, like the ratio of you know,
27:01
Speaker 1: the radius and the circumference. This is like the basic
27:04
Speaker 1: ratio of matter and how it moves in the world.
27:07
Speaker 1: And now I'm gonna disappoint you because it turns out
27:09
Speaker 1: it's not actually constant. No. No, but it's not that
27:13
Speaker 1: it's not constant in time. It's really weird and we're
27:16
Speaker 1: gonna dig into this next week when you talk about renormalization.
27:19
Speaker 1: But it depends on how fast you're going when you
27:22
Speaker 1: measure it. Isn't that what I brought up earlier, like
27:24
Speaker 1: relativity special relativity. Yeah, it's actually it's more about the
27:28
Speaker 1: momentum you have relative to the thing that you're measuring,
27:31
Speaker 1: rather than actual velocity. You just can't admit I was right,
27:34
Speaker 1: You're always right, or hey, that's one constant of the
27:37
Speaker 1: universe relatively speaking. All right, So that's that's a good flavor.
27:41
Speaker 1: I think that gives us a good flavor for what
27:43
Speaker 1: these constants mean. And it blows my mind that there
27:47
Speaker 1: are twenty six of these that we think we know
27:49
Speaker 1: about twenty six things that can't change or could change
27:52
Speaker 1: internally but we wouldn't notice. Yeah, all right, Well, let's
27:55
Speaker 1: get into the other kinds of constants in the universe
27:58
Speaker 1: that we have and what they mean and whether or
28:01
Speaker 1: not there are more of them. But first let's take
28:03
Speaker 1: another quick break. All right, then, we're talking about the
28:18
Speaker 1: basic constants of the universe that are not constant, but
28:22
Speaker 1: we think are sort of constant consistently. Well, that's one
28:24
Speaker 1: thing we don't know, right. We measure this thing, we've
28:27
Speaker 1: measured a lot of different times, over many different years,
28:30
Speaker 1: and we do not see it changing in time, and
28:32
Speaker 1: so we say, maybe this is constant, and it's just
28:36
Speaker 1: like the rest of science. We have no reason to
28:38
Speaker 1: believe that you do an experiment today and you do
28:40
Speaker 1: experiment in a week, you should get the same answer
28:42
Speaker 1: in the same conditions. But it seems to be true.
28:44
Speaker 1: We live in an empirical universe where you can repeat experiments,
28:48
Speaker 1: and it seems like these numbers are fixed. We may discover,
28:52
Speaker 1: if we keep doing science over a thousand years or
28:54
Speaker 1: a million years, that they're very slowly varying, and that
28:57
Speaker 1: would be fascinating, But so far they do seem constant.
29:00
Speaker 1: All right, And so you're telling me that physicists have
29:03
Speaker 1: twenty six of these constants, and some of them are
29:05
Speaker 1: related to like how particles interact with each other and
29:08
Speaker 1: how attracted they are to each other, but some of
29:11
Speaker 1: them are also related to their masses. So tell me
29:13
Speaker 1: about this, yea. So we have to the determine the forces.
29:16
Speaker 1: One is the fine structure constant that tells you about electromagnetism.
29:19
Speaker 1: There's a second one which tells you about the strong
29:21
Speaker 1: nuclear force. But then most of these constants actually relate
29:25
Speaker 1: to the particles, and that's because we just don't know
29:28
Speaker 1: why the particle masses are what they are. Like, we
29:31
Speaker 1: have twelve matter particles that make up the standard model.
29:35
Speaker 1: There are six kinds of quirks up down, charm strange
29:40
Speaker 1: top bottom. Those are six different particles with six different masses.
29:44
Speaker 1: And then there's six leptons, electrons, muans, towels, and their
29:49
Speaker 1: three neutrinos. So those are twelve particles and we do
29:53
Speaker 1: not know why they have the masses they do. We
29:55
Speaker 1: can't predict it, we can't calculate it. We don't even
29:57
Speaker 1: see a pattern. And so we just have to put
30:00
Speaker 1: one parameter when to mention this constant for each one.
30:03
Speaker 1: You wish they were related, but so far they don't
30:06
Speaker 1: seem to be. Yeah, we wish that. You know, the
30:08
Speaker 1: muon was twice the mass of the electron and the
30:11
Speaker 1: towel was four times the mass or there was some relationship,
30:15
Speaker 1: so you could only fix one number that would determine
30:17
Speaker 1: all the rest of them, and also that would give
30:19
Speaker 1: us some insight to like why are there these other
30:21
Speaker 1: particles and why are they heavier and stuff like that,
30:24
Speaker 1: But we see no pattern at all. There's a huge range.
30:27
Speaker 1: The electron is super duper light, the neutrinos are even lighter.
30:31
Speaker 1: The top cork is like enormously heavy relative to all
30:35
Speaker 1: the other ones. So there are some very general rough patterns,
30:38
Speaker 1: but really nothing we can put our finger on. So
30:40
Speaker 1: it's the masses of these particles. And I guess the
30:42
Speaker 1: question is how do you measure these masses? Is it
30:44
Speaker 1: like how much they weigh when you put them on
30:46
Speaker 1: a scale in Paris, or you know, it more like
30:50
Speaker 1: if you push a towel particle, how much does it move?
30:53
Speaker 1: What he called the mass of these particles. Yeah, so
30:55
Speaker 1: here we're talking about the rest mass, right, which means
30:57
Speaker 1: how much energy it has essentially when it's at rest,
31:00
Speaker 1: when you're in its reference frame, and it's hard to
31:03
Speaker 1: measure because particles are very very small and their masses
31:06
Speaker 1: are very very light. And so what we do instead
31:09
Speaker 1: is we wait for one of these things to decay,
31:11
Speaker 1: for example, and we measure the energy of the particles
31:15
Speaker 1: that come out. So if a massive particle turns into
31:19
Speaker 1: massless particles, then the mass of the original particle gets
31:22
Speaker 1: turned into energy of those massless particles. We measure those
31:25
Speaker 1: energies like the photons, etcetera. Then we can measure the
31:29
Speaker 1: mass of the original particle, and so we can do
31:32
Speaker 1: things like that, but it gets harder. The particles that
31:33
Speaker 1: don't do that, like the electron stable, so there you
31:37
Speaker 1: have to do things like put it in a magnetic
31:39
Speaker 1: field and see how much it bends, because that's partially
31:42
Speaker 1: determined by its mass. I guess it would be route
31:44
Speaker 1: just to ask him what the mass. They don't like
31:47
Speaker 1: to talk about it constantly, but they have to be
31:50
Speaker 1: dimensionless numbers. And so what you could do is, because
31:52
Speaker 1: I'm gonna fix the mass of the electron, and I
31:54
Speaker 1: would measure everything relative to the mass of the electron.
31:57
Speaker 1: But then the electron mass then is still a dimension
31:59
Speaker 1: full number. And so what we do is we set
32:02
Speaker 1: all these things relative to the gravitational constant big G,
32:06
Speaker 1: which has the same units of mass, and so all
32:09
Speaker 1: these things are relative to big G. Big G meaning
32:12
Speaker 1: like nine eight per second square. No, that's little little
32:15
Speaker 1: G is But just you said louder, little G is
32:20
Speaker 1: the force of gravity at the surface of the Earth, right,
32:23
Speaker 1: And that's a number that's important to us, irrelevant, but
32:26
Speaker 1: definitely not a constant of the universe. It just depends
32:29
Speaker 1: on the size of the Earth and how much mass
32:30
Speaker 1: it is, and this kind of stuff. Big G is
32:33
Speaker 1: the number that goes inside Newton's equation and then later
32:36
Speaker 1: also in Einstein's field equations for gravity that determines the
32:40
Speaker 1: strength of the gravitational force. It's more basic. It's more basic, yeah,
32:44
Speaker 1: and it should be true all over the universe. And
32:47
Speaker 1: so we measure the mass of these particles relative to
32:49
Speaker 1: that because usually what you're interested in is actually the
32:52
Speaker 1: ratio of inertial mass two forces, right, like how much
32:56
Speaker 1: gravity are you putting on this thing? How much is
32:58
Speaker 1: it going to accelerate? That depends on how much mass
33:01
Speaker 1: it has, and so we measure these things relative to
33:04
Speaker 1: big g also to keep them dimensionless. And so it
33:06
Speaker 1: seems that we have twelve particles and their masses. That
33:10
Speaker 1: seems to be basic about the universe. And are these
33:12
Speaker 1: constants sort of like define structure constant where I could,
33:15
Speaker 1: you know, change the mass of an electron and I
33:17
Speaker 1: wouldn't notice. Now, if you change the fine structure constant,
33:20
Speaker 1: you would definitely notice. But if you change one of
33:22
Speaker 1: the numbers inside of it, you you might not notice.
33:24
Speaker 1: So as long as it's a constant, then we would
33:26
Speaker 1: have noticed. Yeah. And so if you change the mass
33:28
Speaker 1: of the electron, for example, and made it heavier than
33:30
Speaker 1: the muan, then a lot of things would change, because
33:33
Speaker 1: then the electron wouldn't be stable anymore. It could decay
33:37
Speaker 1: into muans. And then maybe our atoms would we have
33:40
Speaker 1: muans in them instead of electrons, right, we'd be muonic
33:44
Speaker 1: matter instead of electronic matter. But what you're I guess
33:47
Speaker 1: what you're saying is that the speed of light could change.
33:49
Speaker 1: But as long as you change everything else, we wouldn't notice.
33:52
Speaker 1: And as long as you also don't change the masses
33:54
Speaker 1: of the particles, yeah, but if you change these massive
33:56
Speaker 1: the particles relative to the gravitational constant, you'll definitely notice,
34:00
Speaker 1: and especially if you change their relative orders, you know,
34:03
Speaker 1: because there's a hierarchy there, and if you change those
34:06
Speaker 1: things then we will definitely notice. It would change the
34:08
Speaker 1: way physics and chemistry works. All right, Okay, we have
34:11
Speaker 1: twenty six constants. Two of them are about the forces
34:13
Speaker 1: of the universe, twelve are about the masses of the particles,
34:18
Speaker 1: and some of them are also sort of related to
34:20
Speaker 1: how particles mixed together. Right, and then we have the
34:24
Speaker 1: cosmological constants, which we talked about in a previous episode. Yeah,
34:29
Speaker 1: and so all the other ones relate to the particles
34:31
Speaker 1: and how they mix and and all of that stuff.
34:33
Speaker 1: There's three more for the force particles Higgs, W, and Z,
34:37
Speaker 1: and then eight for how the particles turn into each
34:39
Speaker 1: other and how often it happens. But then you write
34:42
Speaker 1: the big one, the one at the end, is the
34:44
Speaker 1: cosmological constant. That's the one that tells us how fast
34:48
Speaker 1: the expansion of the universe is accelerating, or if it's
34:51
Speaker 1: accelerating at all, and it determines like the overall shape
34:55
Speaker 1: of the universe. But you guys, don't go in between here,
34:59
Speaker 1: it's either but little tiny particles or the entire universe.
35:03
Speaker 1: It turns out little tiny particles determine the entire universe.
35:07
Speaker 1: Do you think maybe the cosmological constant is related to
35:10
Speaker 1: something about particles? It could be right. People have tried
35:12
Speaker 1: to calculate it. They say, let's try to predict the
35:15
Speaker 1: cosmological constant. If it's in fact just the energy of
35:18
Speaker 1: empty space, like the vacuum of empty space it becomes,
35:21
Speaker 1: for example, from the Higgs Boson field, then we should
35:24
Speaker 1: be able to calculate it. And they've tried. But the
35:26
Speaker 1: number they get is different from the number we measure
35:30
Speaker 1: by ten to the hundred and twenty a little bit.
35:33
Speaker 1: We're not even close. Yeah, we're not even close to
35:35
Speaker 1: getting that one right. But we'd love to. You're right,
35:37
Speaker 1: we'd love to be able to derive this number from
35:39
Speaker 1: the other numbers, because then we could take it off
35:41
Speaker 1: our list and we'd be down to a thin and
35:43
Speaker 1: trim twenty five numbers, and you would make a little
35:46
Speaker 1: bit of progress in the constant define the universe. All right, Well,
35:50
Speaker 1: we uh, there are twenty six right now that physicists
35:53
Speaker 1: can't break down anymore. And is that it do you
35:55
Speaker 1: think maybe there are more? Do you think there should
35:57
Speaker 1: be less? Are you guys aiming to collect more? Are
36:00
Speaker 1: or to you know, do some spring cleaning and get
36:03
Speaker 1: rid of some of these. I think there should definitely
36:05
Speaker 1: be a fewer, right, we should have one number, maybe
36:08
Speaker 1: maybe even zero. I'd love a theory the universe that
36:10
Speaker 1: has zero numbers. Yeah, well, zero numbers in terms of physics,
36:14
Speaker 1: but maybe like if you can get it to come
36:16
Speaker 1: down to a mathematical constant, then that would be cool,
36:19
Speaker 1: that's what you mean, right, Yeah, maybe you could have
36:20
Speaker 1: pie and E and I and there. It would be
36:22
Speaker 1: cool if there are no physical parameters in the fundamental theory.
36:26
Speaker 1: But we're sort of working in the other direction right now, Like,
36:29
Speaker 1: if anything, we're moving in the direction of adding more numbers.
36:32
Speaker 1: Because this theory we've been talking about, the standard model
36:36
Speaker 1: that describes the universe, we know, doesn't actually describe everything
36:40
Speaker 1: in the universe, and so as we add to it
36:42
Speaker 1: to describe those other bits, were just figuring out that
36:45
Speaker 1: we're gonna need more numbers. Yeah, because it turns out
36:47
Speaker 1: that apparently the standard model only covers about five percent
36:52
Speaker 1: of the entire universe, right, Yeah, And you know, it's
36:55
Speaker 1: a staggering achievement so far. But there's a lot of
36:57
Speaker 1: stuff out there it does not describe. And so what
37:00
Speaker 1: about dark matter? For example, if dark matter is fifty
37:04
Speaker 1: kinds of particles and we don't understand why they are
37:07
Speaker 1: fifty and why they all have different masses, Boom, that's
37:09
Speaker 1: fifty more numbers right there, or maybe could have one number,
37:12
Speaker 1: or I wonder if it could help you cancel some
37:14
Speaker 1: of your numbers. Dark matter has the same structure as
37:17
Speaker 1: normal matter, and now we understand the masses because we
37:20
Speaker 1: see more of the pattern and it reveals itself and
37:22
Speaker 1: we get some insights and it helps us figure it out.
37:25
Speaker 1: That's why we're always struggling to attack the parts of
37:27
Speaker 1: the universe we don't understand, because they could be the
37:30
Speaker 1: puzzle piece that lets us see the whole picture. And so, yeah,
37:34
Speaker 1: there could be more out there, because there's a lot
37:36
Speaker 1: of the universe we don't know about. And you're also
37:40
Speaker 1: telling me that they're not really Maybe even constants, like
37:43
Speaker 1: maybe the mass of the electron could be changing, is
37:45
Speaker 1: that possible, or you know, this fine structure constant could
37:48
Speaker 1: also be different, not just in time, but in different
37:51
Speaker 1: parts of the universe. Yeah, we don't know if these
37:53
Speaker 1: things are constant in space and in time. It's sort
37:56
Speaker 1: of like a hypothesis. It's the simplest description so far,
38:00
Speaker 1: because we haven't seen them change, and they seem really
38:02
Speaker 1: basic and fundamental. But because we don't know where they
38:05
Speaker 1: come from and why they're important, why we have this
38:08
Speaker 1: set not a smaller set, we can't say anything about
38:11
Speaker 1: whether they really are constant. It's just an observation. It's
38:15
Speaker 1: like if you live in l A. And you go
38:16
Speaker 1: outside and you're like, hey, every day is sunny. Well,
38:19
Speaker 1: that doesn't mean it's gonna be sunny every day. There
38:21
Speaker 1: might be a reason why it's sunny or in l
38:22
Speaker 1: A than it is in New York, but unless you
38:25
Speaker 1: understand the reason for it, you can't really make an
38:27
Speaker 1: accurate prediction. But you know, I like looking forward to
38:30
Speaker 1: the end days when we have that theory and we're
38:32
Speaker 1: looking at it and we're asking questions about what those
38:35
Speaker 1: numbers mean. So I went around and I did a
38:37
Speaker 1: little informal survey in my department. I asked some of
38:40
Speaker 1: the particle theorists. I said, how many numbers do you
38:43
Speaker 1: expect to see in a theory of everything expect to
38:46
Speaker 1: be or want there to be. I think, I think,
38:51
Speaker 1: isn't it the same seem you know, you're asking whether
38:56
Speaker 1: they expect to be disappointed? Essentially? Yeah, kind of. So
38:59
Speaker 1: what did they say? How many numbers did they predict
39:02
Speaker 1: our final theory of the universe will have? I was surprised.
39:05
Speaker 1: I was expecting them to say one number, and that
39:08
Speaker 1: numbers shouldn't be one or close to one one number
39:11
Speaker 1: one quantity, Yeah, exactly, but they really didn't know. They said,
39:14
Speaker 1: you know, could be one number, could be seven numbers.
39:17
Speaker 1: You know, they expected to be smallish, you know, maybe
39:19
Speaker 1: less than ten numbers, but they wouldn't give a firm prediction.
39:23
Speaker 1: And then I asked them, well, what do you expect
39:24
Speaker 1: those numbers to look like? Like? Should they be huge
39:26
Speaker 1: numbers or small numbers? Should they all be close to
39:29
Speaker 1: one and one of them? A friend of mine, Tim Tait,
39:31
Speaker 1: sort of blew my mind, and he said, it doesn't
39:33
Speaker 1: really matter if it's close to one, because close to
39:36
Speaker 1: one is just relative to the integers, and who knows
39:38
Speaker 1: if like equally spaced numbers one unit apart means anything anyway.
39:43
Speaker 1: So he's like thinking about like whether integers are a
39:46
Speaker 1: kind of unit. But yeah, exactly, questioning the nature of
39:50
Speaker 1: numbers themselves. Yes, yes, And you know, it doesn't even
39:54
Speaker 1: make sense to have mathematics in terms of equally space numbers,
39:58
Speaker 1: because you know, the numbers were all there. Just declaring
40:01
Speaker 1: these equally space numbers to be meaningful, you know, it's
40:04
Speaker 1: sort of a human convention. Let's just throw everything out
40:06
Speaker 1: the door, Daniel, numbers don't mean anything. Distance, the word constant, Yeah,
40:10
Speaker 1: that doesn't mean anything. Well, that's why we try to
40:13
Speaker 1: drill down, because we try to peel away the human
40:15
Speaker 1: bias and look at the universe the way it actually is,
40:18
Speaker 1: which is why you know, I like stories about alien
40:21
Speaker 1: scientists where the aliens don't have differentiated bodies that they're
40:26
Speaker 1: like part of some larger mass, and so they never
40:29
Speaker 1: come up with this idea of integers because they never
40:31
Speaker 1: count like me and you and indistinct objects, and they
40:35
Speaker 1: aren't linked to this kind of assumption in their mathematics,
40:38
Speaker 1: and that makes them think differently about the universe. And
40:40
Speaker 1: that's what we're trying to do here, not specifically meet
40:43
Speaker 1: those weird aliens, but get out of our human bias
40:47
Speaker 1: and think about the universe as close to objectively as
40:50
Speaker 1: we can, right, Yeah, I think the lesson here is
40:53
Speaker 1: don't go to a physics theorist if you want the
40:55
Speaker 1: concept simplified. That's what I'm here for. I'm trying to
40:59
Speaker 1: filter the sixth theory for everybody. All Right, Well, that
41:04
Speaker 1: was a pretty cool discussion. I feel like it's amazing
41:08
Speaker 1: to think that there are constants that you know, kind
41:10
Speaker 1: of define our universe and that maybe in another universe
41:13
Speaker 1: those numbers are different and they're having different discussions about
41:16
Speaker 1: the whole thing. Yeah, And it could be that we
41:18
Speaker 1: get down the theory of everything and it has a
41:20
Speaker 1: few numbers in it, and we wonder, like why those numbers,
41:22
Speaker 1: And you know, it could be that those numbers are
41:25
Speaker 1: just an accident that there are zillions universes and they're
41:27
Speaker 1: all set randomly, or it could be that, you know,
41:30
Speaker 1: they were set for some other reason, or it could
41:32
Speaker 1: be that they could only be those numbers. It will
41:36
Speaker 1: be a fascinating moment when if we finally get there,
41:39
Speaker 1: there could be no answer. You're preparing to be disappointed.
41:43
Speaker 1: I'm always looking forward to the future the universe, expecting
41:46
Speaker 1: it to be chock full of insights and discoveries. And
41:49
Speaker 1: mind blowing revelations. That's why I'm helping out. You're a
41:52
Speaker 1: constant optimist, and yeah, exactly so far, I've revealed exactly
41:57
Speaker 1: zero truths about the universe in my professional career, but
42:00
Speaker 1: I am optimistic. Hey, zero is a basic constantly the universe.
42:05
Speaker 1: You know, Douglas Adam would be proud today. Zero What
42:08
Speaker 1: I've accomplished today, the number of pairs of pants I
42:11
Speaker 1: put on today. Well, we hope you guys enjoyed that.
42:16
Speaker 1: Thank you for joining us, and think about whether the
42:19
Speaker 1: universe around you is constant and what that means. See
42:22
Speaker 1: you next time. Thanks for listening, and remember that Daniel
42:32
Speaker 1: and Jorge Explain the Universe is a production of I
42:35
Speaker 1: Heart Radio. For more podcasts for my Heart Radio, visit
42:38
Speaker 1: the I Heart Radio Apple Apple Podcasts, or wherever you
42:42
Speaker 1: listen to your favorite shows.