Latest / Daniel and Kelly’s Extraordinary Universe / Listener Questions #9

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Listener Questions #9 · Daniel and Kelly’s Extraordinary Universe

0:06
Speaker 1: Are adams mostly empty space? What kind of host should
0:10
Speaker 1: a parasite chase?
0:11
Speaker 2: Do other particles travel at the speed of light? Why
0:15
Speaker 2: is dark chocolate better than white?
0:18
Speaker 1: Biology? Physics, archaeology, forestry. Thankfully no one asked about chemistry.
0:24
Speaker 2: But whatever question keeps you up at night, Daniel and
0:26
Speaker 2: Kelly's answer will make it right.
0:28
Speaker 1: Welcome to Another Listener's Questions episode on Daniel and Kelly's
0:32
Speaker 1: Extraordinary Universe. Hello, I'm Kelly Waiter Smith. I study parasites
0:50
Speaker 1: and space.
0:51
Speaker 2: Hi. I'm Daniel. I'm a particle physicist. I study particles
0:54
Speaker 2: and the spaces between them.
0:56
Speaker 1: Ah well, one of the first questions that we have
0:58
Speaker 1: today is about ball, which makes me wonder. You know,
1:02
Speaker 1: usually when you think about scientists, be they ecologists or physicist.
1:06
Speaker 2: I'm about to make a family inappropriate balls joke, Kelly, Oh.
1:09
Speaker 1: No, no, okay.
1:12
Speaker 2: I just felt like the audience was like, uh, oh,
1:14
Speaker 2: where are we going with this?
1:15
Speaker 1: This is a joke about sports.
1:17
Speaker 2: Oh my goodness, sports balls?
1:20
Speaker 1: Yeah, go ahead, Oh my goodness, There's.
1:22
Speaker 2: Never been an inappropriate joke about balls and sports. You
1:25
Speaker 2: know what, I.
1:27
Speaker 1: Feel like you're pigeonholing me here. Daniel and I've got
1:30
Speaker 1: a lot more range than you're giving me credit for.
1:32
Speaker 2: I'm just looking out for the audience. You know, their
1:34
Speaker 2: kids in the backseat listening to this, and I just
1:36
Speaker 2: want to make sure this joke is clean or anyway,
1:39
Speaker 2: go ahead, tell us about sports balls.
1:41
Speaker 1: And it's not even a joke. It's a question how
1:43
Speaker 1: you've raised all the expectations. So my question is, you know,
1:45
Speaker 1: usually when you think about scientists, you don't immediately think, oh, wow,
1:49
Speaker 1: they're great at sports, although many of us are. So
1:52
Speaker 1: are there any sports where being a physicist would give
1:55
Speaker 1: you an advantage? Now there is a all right clean question, Daniel.
2:01
Speaker 1: I'll point out it is.
2:02
Speaker 2: A very clean question, yes, very family appropriate. But not
2:06
Speaker 2: an easy question, you know, because I feel like sports
2:10
Speaker 2: don't rely on calculations. You might think, oh, you're playing baseball,
2:14
Speaker 2: you want to calculate to the trajectory of the pitch
2:16
Speaker 2: so it gets exactly in the right spot. But nobody
2:19
Speaker 2: has time for that. All this stuff is intuitive, you know,
2:21
Speaker 2: it's all muscle memory. It's amazing that your brain can
2:24
Speaker 2: do that all so fast. It's got this heuristic physics
2:27
Speaker 2: engine inside of it. It's just like almost instantly tells
2:31
Speaker 2: you exactly how to kick the ball so it goes
2:33
Speaker 2: exactly where you want it to go, though of course
2:36
Speaker 2: it's not that easy. But does being a physicist help
2:39
Speaker 2: you in any sport? I don't think the answer is yes.
2:42
Speaker 2: The only thing I can imagine is that being a
2:44
Speaker 2: physicist might make it more enjoyable to be a sports fan,
2:49
Speaker 2: because you have the science to know, like how difficult
2:52
Speaker 2: something is, Like to accelerate a baseball at t one
2:54
Speaker 2: hundred miles an hour. That's tough, to put enough spin
2:57
Speaker 2: on a soccer ball so that it goes around the defenders,
3:00
Speaker 2: like that's some serious work. So you know, maybe, if anything,
3:04
Speaker 2: it helps you appreciate the sports.
3:06
Speaker 1: I like that. I do feel like in general, science
3:08
Speaker 1: makes me appreciate just about everything about the world more.
3:12
Speaker 1: And you know, I've talked to people who are like, well,
3:13
Speaker 1: why does it increase your joy to know the chemical
3:17
Speaker 1: reaction that makes firefly butts glow? And I'm like, I
3:20
Speaker 1: don't know. Just the fact that nature came up with
3:22
Speaker 1: that makes it even more wonderful and amazing. And anyway,
3:25
Speaker 1: science makes everything better.
3:26
Speaker 2: Science does make everything better. I was just visiting some
3:29
Speaker 2: folks at teen Harvard and talking to them about the
3:32
Speaker 2: value of science in society. I was talking to a
3:35
Speaker 2: young guy and he was making the argument that science
3:38
Speaker 2: has its own value. You know, people often say science
3:42
Speaker 2: has value because it develops technology and changes our lives,
3:45
Speaker 2: and that's all true, but I could see that he
3:47
Speaker 2: was trying to express something deeper, which is that, like,
3:50
Speaker 2: science makes the universe more wonderful and our experience of
3:53
Speaker 2: it deeper and more pleasurable, in the same way that
3:56
Speaker 2: like art does. You know, what value does art add
3:59
Speaker 2: to society? Adds to the experience of being human and science,
4:02
Speaker 2: though it does have these spinoffs, I think it also
4:05
Speaker 2: deepens our appreciation of the universe just in and of itself,
4:09
Speaker 2: the same way that art does. And I really respect that.
4:12
Speaker 2: I think that a lot, but I think it's not
4:13
Speaker 2: often said that really science has its own intrinsic value
4:17
Speaker 2: to humanity.
4:18
Speaker 1: Yeah, I agree. I study galls, which are these growths
4:20
Speaker 1: on trees and they can take lots of different shapes,
4:22
Speaker 1: but insects live inside of them, and every once in
4:24
Speaker 1: a while you'll see an insect come out of them
4:26
Speaker 1: that's like iridescent and just absolutely gorgeous, and it's so
4:30
Speaker 1: small that if you don't get it under a microscope,
4:32
Speaker 1: you don't get to see how gorgeous it is. But
4:34
Speaker 1: nature has all.
4:35
Speaker 2: Of this tiny but fabulous.
4:37
Speaker 1: It is tiny but fabulous. There's so much about the
4:39
Speaker 1: world that we don't even know yet. Some of these
4:41
Speaker 1: insects that emerge, they haven't even been described by science yet,
4:45
Speaker 1: and they're gorgeous. There's just so much cool stuff happening
4:48
Speaker 1: in nature. We don't even know all about it. And
4:50
Speaker 1: the more science teaches us, the more amazing it is.
4:52
Speaker 2: All right, well, though it might get us even further
4:55
Speaker 2: off track. I have a philosophy of biology question. I
4:58
Speaker 2: always wondered about that. I I now want to ask
5:00
Speaker 2: you because you brought it up essentially, And that's why
5:03
Speaker 2: do we find nature beautiful? Like? Do you think it's
5:07
Speaker 2: possible that we could have evolved on a planet and
5:10
Speaker 2: been like, Eh, it's kind of ugly here. Does every
5:14
Speaker 2: species love the vistas and the fabulousness of the critters
5:19
Speaker 2: on their planets? Are their aliens out there that are
5:21
Speaker 2: like an Our whole planet's kind of brown? And but
5:23
Speaker 2: you know, if you evolved on Mars, you'd be like, wow,
5:26
Speaker 2: look at the glorious red.
5:28
Speaker 1: That's a great question I don't know the answer to.
5:31
Speaker 2: I'm glad that we do enjoy the beauty of nature.
5:34
Speaker 2: I mean it would suck, yeah, right. I wondering if
5:37
Speaker 2: there's like a reason for that, if it's evolutionary, if
5:40
Speaker 2: it's just luck, or if the universe is just inherently beautiful,
5:44
Speaker 2: or if it's something about us. Then humans just like
5:47
Speaker 2: to find beauty and things.
5:48
Speaker 1: I mean, so I'm just a bitballing here. I don't
5:50
Speaker 1: know that there's a solid final answer here, but I mean,
5:53
Speaker 1: I think all animals are to some extent queued into
5:56
Speaker 1: the things that other animals are doing around them, because
5:58
Speaker 1: you need to like make sure, you know, get eaten,
6:00
Speaker 1: you need to find the food you're going to eat.
6:02
Speaker 1: So I think we're all paying attention to whatever degree
6:06
Speaker 1: our sensory systems will allow us to. But do we
6:09
Speaker 1: find it beautiful? I just don't know how we could
6:12
Speaker 1: even ask that. I mean, when you see a dog
6:14
Speaker 1: playing in the snow, do they think that's beautiful or
6:18
Speaker 1: do they think that's fun?
6:19
Speaker 2: I think it's beautiful. How much fun we're having that
6:22
Speaker 2: makes me happy? Yeah, it's incredible. I think this connects
6:25
Speaker 2: to the whole philosophy of consciousness discussion we have with
6:28
Speaker 2: Megan Peters recently about the nature of your experience, what
6:31
Speaker 2: it's like to be you or an alien or a dog,
6:34
Speaker 2: and how little we understand about that. So maybe someday
6:37
Speaker 2: the cognitive scientists will be able to answer that question,
6:39
Speaker 2: but not today.
6:40
Speaker 3: That's right.
6:41
Speaker 1: We'll have to get Megan Peters back on the show
6:43
Speaker 1: in a couple of years and she'll give us the answer.
6:45
Speaker 2: But in the meantime, we do have some questions from
6:48
Speaker 2: listeners that might actually have answers, or at least we're
6:51
Speaker 2: going to do our best to provide the answers, and
6:52
Speaker 2: then we're going to check in with the listeners to
6:54
Speaker 2: see whether or not we have satisfied their curiosity or
6:58
Speaker 2: just inflamed it further.
6:59
Speaker 1: And it's part of two. So let's listen to the
7:00
Speaker 1: first question.
7:02
Speaker 4: Since every atom is mostly empty space, and we know
7:07
Speaker 4: how much matter there is in the universe, how big
7:11
Speaker 4: would a ball be if we made one only out
7:13
Speaker 4: of the protons, neutrons, and electrons, and we just eliminated
7:16
Speaker 4: the empty space. Would that fit in my trunk?
7:20
Speaker 2: All right? What do you think of this question from Martin?
7:22
Speaker 2: Is this the kind of thing you think about also
7:24
Speaker 2: keeps me up at night.
7:26
Speaker 1: Well, you know it's why. Actually, the more you and
7:27
Speaker 1: I talk, the more interested I am and what the
7:30
Speaker 1: right way is to visualize an atom, Because you know,
7:33
Speaker 1: the more we talk, the more clear it is to
7:34
Speaker 1: me that the sort of diagrams that I saw in
7:36
Speaker 1: my science textbook is no longer how we think about it.
7:39
Speaker 1: And so well, I haven't personally thought of this question
7:43
Speaker 1: prior to hearing it. I'm excited to hear the answer.
7:46
Speaker 2: Yeah, And I'm excited to talk about it because this
7:48
Speaker 2: isn't the kind of thing you hear about in popular
7:50
Speaker 2: science all the time. It's like a g whiz fact.
7:53
Speaker 2: The atom is all filled with empty space that I
7:56
Speaker 2: think is cool to say, but if you dig into
7:58
Speaker 2: it doesn't really have a lot of meaning. Actually misleads
8:00
Speaker 2: people into the nature of these quantum particles and the
8:03
Speaker 2: atom rather than giving them any clarity. So I'm actually
8:06
Speaker 2: looking forward to the chance to unpack it and give
8:09
Speaker 2: people a clearer sense for what's going on inside the atom.
8:13
Speaker 1: Can I ask a question that we'll test how well
8:15
Speaker 1: I've been listening in the past, Yes, Oh boy, All right,
8:18
Speaker 1: here we go. Historically, when I've done this, I've usually
8:21
Speaker 1: embarrassed myself. But I'm moving forward anyway.
8:23
Speaker 2: So that's what I'm hoping for here.
8:24
Speaker 1: Yeah, well, you know I aim to please. Okay, So
8:27
Speaker 1: in the past we've talked about how, you know, particles
8:29
Speaker 1: aren't like points, they're like waves, and so you know,
8:33
Speaker 1: if you're thinking about empty space, is there less empty
8:36
Speaker 1: space because it's not points, it's waves and those waves
8:38
Speaker 1: take up a lot of space inside the atom, or
8:42
Speaker 1: you know, you can think of those waves as filling
8:44
Speaker 1: a lot of the atom. Is that part of the
8:46
Speaker 1: answer or did Kelly totally miss the point again?
8:49
Speaker 2: No, that's totally part of the answer. You shouldn't be
8:52
Speaker 2: thinking these particles as just point particles. In some of
8:55
Speaker 2: our calculations, it's convenient to do that, and when it
8:58
Speaker 2: doesn't matter, we do it. But when you do zoom
9:01
Speaker 2: in on these things, it doesn't make sense to think
9:03
Speaker 2: of them as points but little distributed wave packets. And
9:07
Speaker 2: the answer has a couple more wrinkles to it. One
9:10
Speaker 2: is like, well, what does it mean to have the
9:11
Speaker 2: size of a particle? What are we talking about here?
9:14
Speaker 2: Do particles have a surface? The way he's imagining packing
9:18
Speaker 2: these things together where the surface is touched. And then
9:20
Speaker 2: also is the space in the atom even empty at all?
9:24
Speaker 2: And the answer is no, But let's just talk about
9:27
Speaker 2: the first one. Because this idea of like taking the
9:30
Speaker 2: particles and making a ball of just them with no
9:33
Speaker 2: empty space packing them together really leans on your mental
9:37
Speaker 2: image of particles as balls that you could like squeeze
9:40
Speaker 2: together so the surface is touch Like if you have
9:42
Speaker 2: a pile of tennis balls, you can think about how
9:44
Speaker 2: to pack them into an object, right, So they're touching,
9:47
Speaker 2: they're squeezed in together, and it's actually a really interesting
9:50
Speaker 2: mathematical problem, like how many spheres can you pack into
9:53
Speaker 2: a cube. It's hard and it's fascinating. It's complicated, but
9:56
Speaker 2: it requires these things to have a specific shape, right.
10:00
Speaker 2: Packing tennis balls requires them to have a surface, a
10:02
Speaker 2: well defined point where the tennis ball ends and the
10:04
Speaker 2: new one can start. And usually you think about these
10:07
Speaker 2: things as rigid and because tennis balls you could squeeze,
10:09
Speaker 2: but imagine like a perfectly rigid sphere, it has an
10:12
Speaker 2: edge to it, a surface, right, And we think about
10:15
Speaker 2: stuff as having surfaces because we live in a world
10:18
Speaker 2: where they seem to you put your butt in the chair,
10:21
Speaker 2: there's a contact between the surface of your butt and
10:23
Speaker 2: the surface of the chair, and your butt doesn't phase
10:25
Speaker 2: through the chair, and you can say where one starts
10:27
Speaker 2: and the other one ends. Right. So in our classical
10:30
Speaker 2: macroscopic world, this makes a lot of sense to have
10:33
Speaker 2: a surface and to pack things together. And now we're
10:36
Speaker 2: trying to take that and apply it to quantum particles,
10:39
Speaker 2: protons and neutrons and electrons, and that only works if
10:42
Speaker 2: they also have a well defined surface, if you can
10:45
Speaker 2: even talk about what it means for them to have
10:47
Speaker 2: a size.
10:48
Speaker 1: And I feel like the answer is that it doesn't
10:50
Speaker 1: make sense because of the wave stuff we were talking about.
10:53
Speaker 2: It doesn't make sense because of the wave stuff. But
10:55
Speaker 2: even more deeply, it doesn't make sense because the size
10:58
Speaker 2: of an object depends on how you poke it. Unfortunately,
11:02
Speaker 2: so in our macroscopic world, the reason when you poke
11:05
Speaker 2: the wall your finger doesn't go through it is that
11:08
Speaker 2: there are forces there. There's like a mesh of atoms
11:10
Speaker 2: in the wall and a mesh of atoms in your finger,
11:12
Speaker 2: and those things are repelling each other electromagnetically, right, So
11:16
Speaker 2: that's what defines the surface, is these charge particles repelling
11:19
Speaker 2: each other. Okay, so think about an electron. Right, take
11:24
Speaker 2: an electron and poke it with another electron. What happens, Well,
11:27
Speaker 2: it gets repelled because like charges repel each other. Right, Well,
11:30
Speaker 2: what happens if you poke it with a neutrino? Phases
11:33
Speaker 2: right through because the electron and the neutrino don't interact.
11:36
Speaker 1: So then the point is that you can't find the
11:38
Speaker 1: exterior of the electron because it just goes through and
11:42
Speaker 1: you don't see where they bounce off. If that's where
11:44
Speaker 1: you're going, why can't you just define the outside of
11:46
Speaker 1: electron by what it does when you throw another electron
11:49
Speaker 1: at it?
11:50
Speaker 2: You could, and that works if you're just packing electrons. Right,
11:53
Speaker 2: The answer depends And this is also even true for
11:55
Speaker 2: like macroscopic objects. Take for example, the Earth. Right, where's
11:59
Speaker 2: the edge of the Earth. Well, I don't know. I
12:02
Speaker 2: mean the atmosphere peters out and it's kind of gradual,
12:05
Speaker 2: and so like what happens if you shoot a rock
12:08
Speaker 2: at the Earth. It also depends on the size of
12:10
Speaker 2: the rock. Right, does it bounce off the atmosphere, does
12:12
Speaker 2: it penetrate the atmosphere? Does it destroy the earth? The
12:15
Speaker 2: same thing is true if you shoot charged particles at
12:17
Speaker 2: the Earth, so like where you would say the edge
12:20
Speaker 2: of the Earth is depends on how you probe it.
12:23
Speaker 2: What finger you are using. Are using a finger that's
12:25
Speaker 2: electrically charged, are using a finger that's only charged in
12:28
Speaker 2: the weak force, are using something that has no charge
12:30
Speaker 2: at all? Like, it depends on how you probe it. Unfortunately,
12:34
Speaker 2: and you might think, oh, this is nippicking. Can't you
12:37
Speaker 2: just choose a definition. You can choose a definition, but
12:39
Speaker 2: I just want to highlight that, like, these quantum objects
12:42
Speaker 2: don't have a well defined surface the way classical objects
12:45
Speaker 2: do because classical objects only interact with the electromagnetism, right,
12:49
Speaker 2: All these other charges are essentially irrelevant. That's why it
12:52
Speaker 2: seems like you have a simple, crisp definition of an
12:54
Speaker 2: edge for a ball or a shoe or the wall.
12:58
Speaker 2: But for quantum objects, they have all these other kinds
13:00
Speaker 2: of interactions. So it really depends on how you're poking them.
13:03
Speaker 2: And if we're going to pack protons and neutrons and
13:05
Speaker 2: electrons together, we have all those charges at.
13:08
Speaker 1: Work, all right, Yeah, this stuff is complicated. When you
13:10
Speaker 1: go to space conferences, you could talk to space geeks
13:12
Speaker 1: for like literally days about the definition of where space
13:15
Speaker 1: starts and where Earth ends or begins. But okay, so
13:18
Speaker 1: we've been talking about how you measure how big things
13:20
Speaker 1: are and why that's complicated. Have scientists to some extent
13:24
Speaker 1: agreed on how big any of the particles are electrons, protons, neutrons,
13:29
Speaker 1: or do we just have no definition for any of them?
13:31
Speaker 2: No, we have some definitions, and of course the answer
13:35
Speaker 2: is it depends.
13:36
Speaker 1: Aha, just like ecology, I know, you're no better.
13:40
Speaker 2: Literally, there's a twenty page paper just on this question
13:43
Speaker 2: how do we define the size of a proton? Because
13:46
Speaker 2: people have come up with a bunch of different ways
13:48
Speaker 2: to do it, like shoot this thing at it and
13:50
Speaker 2: measure at what angle it starts to change its deflection,
13:53
Speaker 2: et cetera, et cetera. There's a few different ways, and
13:56
Speaker 2: there's a whole paper trying to like harmonize them into one.
14:00
Speaker 2: But the answer is it's not simple to define the
14:02
Speaker 2: size of a proton. Basically, though, what you do is
14:06
Speaker 2: you shoot electrons at the proton, and you shoot it
14:09
Speaker 2: at various angles, and you see the deflection and like,
14:12
Speaker 2: at some point, basically the electron gets gently deflected and
14:15
Speaker 2: then suddenly it starts to get more dramatically deflected, like
14:18
Speaker 2: it's bouncing back right, there's more of a collision there.
14:21
Speaker 2: And you can measure the size of a proton like
14:24
Speaker 2: this is different than what happens with an electron. Electron
14:28
Speaker 2: is either a fundamental and a point particle or it's
14:31
Speaker 2: just really really small. We can't tell the difference right now.
14:34
Speaker 2: We're gonna have a whole episode soon about like probing
14:36
Speaker 2: the inside of the electron. The electron is so small
14:39
Speaker 2: that we can't measure its size, but the proton is
14:42
Speaker 2: definitely bigger than the electron. We can roughly measure its size,
14:45
Speaker 2: and you know, people argue about the exact definition, but
14:49
Speaker 2: roughly it's ten to the minus fifteen meters. It's really
14:53
Speaker 2: really really tiny thing.
14:54
Speaker 1: Yeah, okay, so now we have a handwavy guess for
14:59
Speaker 1: how big proton is. But that's only one of the
15:02
Speaker 1: three things we need to pack together. So where do
15:03
Speaker 1: we go from here?
15:04
Speaker 2: Yes, so now trying to imagine taking these objects and
15:07
Speaker 2: trying to make a ball out of them. So you know,
15:10
Speaker 2: Martin's question is basically, take all the protons and neutrons
15:13
Speaker 2: and neutrons in the universe and squeeze them together with
15:17
Speaker 2: no empty space. How big is that? Right? So can
15:20
Speaker 2: you pack that stuff together? Well, you can pack protons
15:23
Speaker 2: and neutrons together, right, And that's what the nucleus is,
15:26
Speaker 2: a bunch of protons and neutrons packed together. Right, And
15:29
Speaker 2: so far we've seen ones with you know, hundreds of nucleons.
15:33
Speaker 2: Definitely not you know, ten to eighty like we have
15:35
Speaker 2: in the universe. But in principle, you can pack these
15:38
Speaker 2: things together. And for example, the hearts of neutron stars
15:41
Speaker 2: are a bunch of these things just all squeeze together.
15:45
Speaker 2: So that's definitely possible. But again, you're not packing them
15:48
Speaker 2: like tennis balls. The distance between these things is not
15:50
Speaker 2: the physical edge of them, but it's where those bonds determine.
15:54
Speaker 2: They're happy to be, right, because you squeeze them together
15:57
Speaker 2: enough and they change into something else. Like he squeeze
15:59
Speaker 2: to newrons together, you're going to form something that's not
16:02
Speaker 2: a neutron. Like actually, at the heart of neutron stars,
16:04
Speaker 2: they're not neutrons anymore. They form this weird new state
16:07
Speaker 2: of matter called nuclear pasta, which is nearly as delicious
16:11
Speaker 2: as it sounds.
16:12
Speaker 1: Do you physicists work hungry? All the time, and is
16:14
Speaker 1: that how we came up with spaghetification and stuff like this.
16:18
Speaker 2: You know, if you read papers about the hearts of
16:20
Speaker 2: neutrons starts, they have these figures showing these like weird
16:23
Speaker 2: sheets of matter and they're like, this is nuclear lasagna,
16:26
Speaker 2: and if you keep squeezing it you get like nuclear
16:28
Speaker 2: RIGATONI and like it's really regular areas.
16:32
Speaker 1: I'm on board. That sounds great, But.
16:33
Speaker 2: The point is you're not just squeezing them together based
16:36
Speaker 2: on this radius. There are bonds here, and the balance
16:39
Speaker 2: of these forces determine how you could actually pack them together. Now,
16:43
Speaker 2: try to add some electrons, right, Martin wants us to
16:45
Speaker 2: squeeze in all the particles. So you might think, well, well,
16:48
Speaker 2: how close could you really bring electrons to these particles. Well,
16:52
Speaker 2: the answer is the hydrogen atom. That's what the hydrogen
16:55
Speaker 2: atom is. It's the closest you can bring an electron
16:58
Speaker 2: to be happy near a proton and a neutron. It's
17:01
Speaker 2: already in its minimum state. You can't localize electrons more
17:06
Speaker 2: than that because of the Heisenberg uncertainty principle. Their really
17:10
Speaker 2: tiny mass means a small uncertainty in their momentum means
17:13
Speaker 2: a huge uncertainty in their velocity. So basically, you can't
17:18
Speaker 2: bring electrons closer to protons and neutrons than they already
17:21
Speaker 2: are the most of the universe. Right, And you might think, okay,
17:25
Speaker 2: but I'm doing this mental thought exercise where I'm bringing
17:28
Speaker 2: them together to touch their surfaces. No, they don't have surfaces, right.
17:31
Speaker 2: The concept of a surface should be replaced in your
17:34
Speaker 2: mind with like the forces between these things. How happy
17:37
Speaker 2: are they to come close together?
17:39
Speaker 1: Okay, so say you squish everything together and the forces
17:44
Speaker 1: get as close as they're comfortable getting together. I know
17:47
Speaker 1: that when you answer a question, you go big or
17:50
Speaker 1: you go home. So you've done this calculation.
17:53
Speaker 2: This is just one more thing I want to say
17:54
Speaker 2: before we get there, which is I think this also
17:57
Speaker 2: should change your view of the atom. Like if you're
17:59
Speaker 2: thinking about the atom as these tiny little dots orbiting
18:03
Speaker 2: with mostly empty space, remember that these dots are where
18:06
Speaker 2: they are because it's a balance of the forces, which
18:09
Speaker 2: means is a lot of energy being exchanged constantly. So
18:12
Speaker 2: if you like the particle picture of forces, that like
18:15
Speaker 2: the way things indirect or electromagnetically is by exchanging photons,
18:18
Speaker 2: you should take your mental image that's like filled with
18:21
Speaker 2: darkness between all these particles and replace it with like
18:24
Speaker 2: a blinding ocean of photons. And the center of the
18:28
Speaker 2: atom is not empty. It's a sea of frothing energy, right,
18:32
Speaker 2: and so it's not really empty in any sense. But yeah,
18:35
Speaker 2: let's take Martin's question at face value. We know you
18:38
Speaker 2: can't treat these things as tiny balls, but let's try, right, So,
18:42
Speaker 2: ignoring the balance of the forces, let's just assume that
18:45
Speaker 2: the proton is a hard little sphere like a billiard ball,
18:48
Speaker 2: with a radius of ten to the minus fifteen meters.
18:51
Speaker 2: Then you can calculate its volume, and that would be
18:54
Speaker 2: ten to the minus forty five meters cubed roughly. Now,
18:58
Speaker 2: there's a lot of protons in the universe. We estimate
19:01
Speaker 2: is about ten to the eighty protons in the observable universe.
19:05
Speaker 2: We don't know how big the full universe is, but
19:07
Speaker 2: the sphere that we can observe, we know it's volume,
19:10
Speaker 2: we know its density, we know how much matter there is.
19:14
Speaker 2: So that's a number we can calculate, and that's a
19:16
Speaker 2: really really big number. It's like nobody can hold that
19:19
Speaker 2: number in their mind. But fortunately our mathematics can describe it.
19:23
Speaker 2: So take ten to the eighty tiny little balls, each
19:26
Speaker 2: of which has this tiny little volume, and you pack
19:29
Speaker 2: it together and you end up with something whose volume
19:32
Speaker 2: is really quite large. It's ten to the thirty five
19:35
Speaker 2: cubic meters. And it's flobergasting to think about, because you're
19:40
Speaker 2: taking these objects whose individual volumes are ten of the
19:43
Speaker 2: minus forty five cubic meters, and you end up with
19:46
Speaker 2: a total volume of ten to the thirty five. And
19:50
Speaker 2: the reason that number still ends up so big is
19:52
Speaker 2: just the sheer number of protons in the universe is
19:55
Speaker 2: just such a big number that, even though they're so tiny,
19:59
Speaker 2: they add up to make a really big ball. It's
20:01
Speaker 2: not easy to visualize ten to the thirty five cubic meters.
20:05
Speaker 2: But that's a sphere whose radius is about a trillion meters,
20:10
Speaker 2: which is like seven au or about fifteen hundred times
20:13
Speaker 2: the radius of the Sun. So if you did this,
20:16
Speaker 2: took all the protons in the universe and like centered
20:18
Speaker 2: them in the center of the Solar System, it would
20:21
Speaker 2: be a sphere whose edge was between Jupiter and Saturn's orbit.
20:25
Speaker 1: Oh my gosh, that was a great question, Martin. There
20:30
Speaker 1: was so much unpacked there, So.
20:31
Speaker 2: No, Martin, you can't put it in your trunk. Ah
20:34
Speaker 2: un THISUS. Martin's got a really big truck.
20:36
Speaker 1: Yeah, it makes some really big trucks in the US.
20:40
Speaker 2: It makes it ridiculously big trucks that are good of
20:44
Speaker 2: running over pedestrians or hauling the universe. All right, Martin,
20:48
Speaker 2: let us know what you think of our answer.
20:50
Speaker 4: That was absolutely fantastic.
20:52
Speaker 2: Thank you so much.
20:53
Speaker 4: Not only did it answer my question, but it also
20:55
Speaker 4: answered twenty other questions I.
20:57
Speaker 2: Didn't even know I had.
20:59
Speaker 4: And my original question actually came up because it was
21:02
Speaker 4: moving apartments. So now I know that with my van,
21:06
Speaker 4: I guess I'd have to do at least four drives
21:09
Speaker 4: round trip if I wanted to move the universe. So
21:12
Speaker 4: thank you very much.
21:30
Speaker 1: All right. Next up, we have a biology question from Ricky.
21:35
Speaker 3: I've been trying to figure out the way to even
21:37
Speaker 3: phrase this question for a long time. When you have
21:41
Speaker 3: a carnivore, they tend to run down the sick, the weak,
21:46
Speaker 3: and the elderly. But argument says they prefer an elephant
21:52
Speaker 3: in its prime if they could get it. So my
21:54
Speaker 3: question is parasites, how opportunistic are they? Is there a
21:59
Speaker 3: level of health that they tend to be looking for.
22:02
Speaker 3: Do they want to go after the healthiest or do
22:05
Speaker 3: they tend to infect the sick, the young, and the elderly.
22:11
Speaker 1: Oh, this is a fun question.
22:13
Speaker 2: Mmmmm. I was hoping you'd react that way.
22:16
Speaker 1: Well, you know, it has parasites in it, so I'm
22:17
Speaker 1: immediately excited about it.
22:19
Speaker 2: So glad you're excited about this question. Help me understand
22:22
Speaker 2: Ricky's question. Is he saying that carnivores tend to eat
22:26
Speaker 2: the sick and the weak and the elderly because those
22:29
Speaker 2: are the ones they can catch. But if they have
22:30
Speaker 2: their druthers, they would rather eat a big, meaty specimen
22:34
Speaker 2: in its prime because it's more food, or because it's
22:36
Speaker 2: healthier and therefore were going to be better food. Is
22:38
Speaker 2: that the idea?
22:39
Speaker 1: I think that is the idea. I can understand the
22:43
Speaker 1: motivation here that a carnivore probably would like to have
22:46
Speaker 1: the largest packet of food possible, and an animal that's
22:50
Speaker 1: easy to catch could be an animal that's sick, so
22:52
Speaker 1: the quality of the meat could be lower. But I
22:54
Speaker 1: think in general animals are quite happy to go for
22:58
Speaker 1: the sick, the elderly, the babies like whatever they're able
23:01
Speaker 1: to catch, because you know, taking down an elephant in
23:03
Speaker 1: his prime is dangerous for for example, a lion that
23:06
Speaker 1: could get stopped to them. And so for a lot
23:08
Speaker 1: of reasons, I think animals tend to go for whatever
23:11
Speaker 1: prey they can catch. And this is something that parasites
23:14
Speaker 1: actually take advantage of. So, for example, there is a
23:17
Speaker 1: tapeworm parasite called Aconococcus granulosis and it infects moose and
23:22
Speaker 1: it lives in the moose lungs and it replicates and
23:26
Speaker 1: produces this giant, fluid filled sack. It's kind of like
23:29
Speaker 1: a tumor, and inside the sack there's all these baby parasites.
23:32
Speaker 1: But having a huge sack in your lungs makes it
23:35
Speaker 1: harder to run away from wolves, and so these animals
23:37
Speaker 1: get debilitated, they are sick, it's hard for them to
23:40
Speaker 1: get away from wolves, and so wolves end up catching
23:43
Speaker 1: these moose and then they end up eating the parasites
23:46
Speaker 1: while they're eating the moose and they get infected.
23:48
Speaker 2: Is that good for the parasites or not good for
23:50
Speaker 2: the parasites.
23:51
Speaker 1: That is great for the parasites. So these tapeworms need
23:54
Speaker 1: to get from the moose to the wolves to complete
23:58
Speaker 1: their life cycle. Wow, yeah, it's incredible. When they're in
24:01
Speaker 1: the wolves, they often don't seem to cause that much damage.
24:04
Speaker 1: And frequently when you get these parasites that have to
24:07
Speaker 1: go from a prey to a predator and they get
24:10
Speaker 1: transmitted by the predator eating the prey, the predators when
24:13
Speaker 1: they harbor the parasites don't tend to be that debilitated.
24:17
Speaker 1: It seems like the parasites tend to live. For example,
24:20
Speaker 1: in their gut they produce eggs, and when you're in
24:23
Speaker 1: what's called the definitive host, which is where you find
24:25
Speaker 1: a mate, you produce eggs that pass like with the
24:28
Speaker 1: host feces out into the environment again. And so if
24:30
Speaker 1: that predator is eating a lot, pooping a lot, going
24:33
Speaker 1: all over the place, then your eggs are transmitted everywhere,
24:36
Speaker 1: and so they tend to not damage this particular host
24:40
Speaker 1: in the life cycle. But then when you get into
24:42
Speaker 1: a host that needs to get eaten by the predator,
24:44
Speaker 1: you do often see those kinds of hosts getting debilitated
24:48
Speaker 1: or messed up in some way by the parasites because
24:51
Speaker 1: that facilitates transmission.
24:53
Speaker 2: So let's see if I understand these things end up
24:55
Speaker 2: in a moose, and they want the moose to get
24:57
Speaker 2: caught by wolves, so they end up in the low lungs,
25:00
Speaker 2: slowing the moose down. Wait, hold on, nerdy question. Plural
25:04
Speaker 2: of moose is mease? I don't know, mices, moses, moses, mooses,
25:11
Speaker 2: I'm not sure. So they slow the moose down and
25:13
Speaker 2: then the wolf eats them gets the parasite, which is
25:16
Speaker 2: what the parasite wants. But somehow the parasite manages to
25:19
Speaker 2: not slow down the wolf because it wants the wolf
25:22
Speaker 2: to be healthy. How does it manage to end up
25:24
Speaker 2: in the moose lungs the mease lungs, but not in
25:28
Speaker 2: the wolf lungs? Does it know when it is in
25:30
Speaker 2: wolf or moose? It does taste the flesh and like
25:33
Speaker 2: this tastes wolfy well, so when.
25:35
Speaker 1: It's in the moose, it makes the fluid filled sex.
25:37
Speaker 1: I don't know how it knows that it's in the moose,
25:40
Speaker 1: but there might be some sort of cues that tell
25:42
Speaker 1: it what host it's in.
25:43
Speaker 2: I feel like if I was injected in a random animal,
25:45
Speaker 2: I could tell the difference between a moose and a wolf.
25:47
Speaker 2: But maybe not.
25:48
Speaker 1: I really doubt it. I mean, maybe it takes longer
25:51
Speaker 1: to pass through an herbivores digestive system than a carnivores,
25:55
Speaker 1: so maybe you could track how long it took before
25:57
Speaker 1: you were pooped out. How would you tell the difference, Daniel.
25:59
Speaker 2: I mean they taste different, right, like ones a predator
26:02
Speaker 2: ones an herbivore. I'm pretty sure if you put like
26:04
Speaker 2: a moose steak and a wolf steak in front of me,
26:07
Speaker 2: I could taste the difference.
26:08
Speaker 1: Yeah, but you're not eating steaks of the different animals
26:11
Speaker 1: for comparison, they're blind inside of an animal's gut.
26:14
Speaker 2: Yeah, but I'm eating it right, Like, how are these
26:15
Speaker 2: things surviving?
26:17
Speaker 5: Uh?
26:17
Speaker 1: They are sort of absorbing nutrients across their skin. They're
26:21
Speaker 1: not sampling the steak.
26:24
Speaker 2: I mean, I understand they're not going to be like
26:26
Speaker 2: having a baked potato and a one sauce or whatever.
26:29
Speaker 2: But they are interacting with They're eating nutrients from this animal,
26:32
Speaker 2: so that information is there. I don't know parasites are
26:35
Speaker 2: sophisticated enough to tell the difference, but it's possible in.
26:38
Speaker 1: Principle, right, Yeah, Yeah, And I think there are some
26:40
Speaker 1: cues that parasites can use to figure out what host
26:43
Speaker 1: they're in. But also, you know, just because of the
26:45
Speaker 1: way things often happen in nature, there's like a cycle
26:48
Speaker 1: to what host you can expect you're gonna find yourself
26:50
Speaker 1: in next. Like, if you are in a moose's lung,
26:52
Speaker 1: you're probably not going to end up in the moose's
26:54
Speaker 1: lungs again, because moose don't tend to eat each other's lungs.
26:57
Speaker 1: But you are pretty likely to end up in a
27:00
Speaker 1: wolf gut, for example.
27:02
Speaker 2: So it could just be first host, second host.
27:03
Speaker 1: It might not even know, yeah, right, just working through
27:06
Speaker 1: its life cycle, and it doesn't form those fluid filled
27:09
Speaker 1: sacs in wolves. It's just they find mates, they make eggs,
27:13
Speaker 1: and the eggs pass into the environment, and then the
27:15
Speaker 1: moose accidentally eats the eggs and that's how they get infected.
27:18
Speaker 2: Man, it's good to be a wolf. But I think
27:20
Speaker 2: that Ricky's question is essentially about choosing the host, right,
27:23
Speaker 2: So in this case, they debilitate the host. But do
27:27
Speaker 2: they want to start from a healthy moose or do
27:29
Speaker 2: they not care? Are they happy to get into a
27:31
Speaker 2: moose that's about to get gobbled by a wolf anyway?
27:33
Speaker 2: Does it matter whether the moose is healthy or not?
27:35
Speaker 1: But I think Ricky's question is do parasites try to
27:39
Speaker 1: choose the host that they end up in.
27:41
Speaker 2: I think Ricky's question is do they care about the
27:44
Speaker 2: health of the host the same way that carnivores are
27:47
Speaker 2: choosing the sick and the feeble and easy to catch.
27:51
Speaker 2: Do parasites care about the health of the host that
27:52
Speaker 2: they're infecting.
27:53
Speaker 1: I don't have a lot of choice, and so so
27:56
Speaker 1: for a kind of caucus granulosis, I don't think it
27:58
Speaker 1: has a preference for the host that it's in, as
28:00
Speaker 1: long as it can debilitate that host and get it
28:02
Speaker 1: eaten by wolves. You maybe don't want to infect a
28:06
Speaker 1: host that is like super sick and is about to
28:08
Speaker 1: die tomorrow, because after a parasite infects a host, it
28:12
Speaker 1: takes days to weeks before it's mature enough that it
28:15
Speaker 1: could survive jumping to the next host, and so they
28:18
Speaker 1: probably don't want the host to die immediately. But in general,
28:21
Speaker 1: most parasites don't have a lot of choice because parasites
28:25
Speaker 1: aren't very mobile. You might think back to are we
28:28
Speaker 1: called it dirt worms, but these are the geo helmets,
28:31
Speaker 1: the nematodes that live in the soil. And when we
28:34
Speaker 1: were talking about that parasite. We were talking about how
28:36
Speaker 1: the hookworms need to burrow through the feet, burrow through
28:39
Speaker 1: the skin to get into their hosts. They can't be
28:42
Speaker 1: very choosy. They like move away from the feces and
28:44
Speaker 1: then they just have to wait and hope something steps
28:47
Speaker 1: on them. And so if like, these feet are stinky,
28:49
Speaker 1: I'd rather not infect this person. Like, they don't have
28:51
Speaker 1: a choice. They take what they.
28:52
Speaker 2: Can, not having a choice and not having a preference
28:57
Speaker 2: or different things. Right the way we were talking about
28:59
Speaker 2: appreciation nature, it might be that they don't have a
29:02
Speaker 2: choice and end up in whatever moose. But there are
29:04
Speaker 2: some moose that they're like, mmm, this is a primo moose. Yeah,
29:07
Speaker 2: I'm really loving this one. Other ones are like, man,
29:09
Speaker 2: this moose kind of sucks.
29:10
Speaker 1: Like and there's some moose that probably have better immune
29:13
Speaker 1: systems than others. And so if you're going to try
29:15
Speaker 1: to infect a moose, you'd rather have the moose that's
29:17
Speaker 1: immune system isn't going to slow your growth. They don't
29:21
Speaker 1: really get like a choice, you know, they don't get
29:23
Speaker 1: like a platter with five different moose and they get
29:25
Speaker 1: to pick which moose looks the most delicious. You know,
29:27
Speaker 1: like when you go to the seafood store and you're like,
29:29
Speaker 1: I want that lobster. They don't get to pick.
29:32
Speaker 2: But if we invited it on the podcast, it might
29:34
Speaker 2: still have an opinion.
29:35
Speaker 1: Sure, yeah, I mean, you know, maybe we all have opinions.
29:39
Speaker 2: Do but we don't have that. Instead, we have the
29:41
Speaker 2: president of the hell Menothological Society of Washington speaking for
29:46
Speaker 2: all parasites.
29:47
Speaker 1: Yeah. I don't know that I get to speak on
29:49
Speaker 1: behalf of the parasite.
29:50
Speaker 2: But you are, you're telling us what they prefer.
29:52
Speaker 1: I'm telling you they might have preferences, which is hedging
29:55
Speaker 1: my best even more. But and then when we were
29:57
Speaker 1: talking about the dirt worms, we also talked about whipworms
29:59
Speaker 1: and and they get into hosts when their eggs are
30:03
Speaker 1: accidentally consumed, and there too, they don't have a choice,
30:06
Speaker 1: like they just get eaten by whoever they get eaten by,
30:08
Speaker 1: and then they got to make the best out of
30:09
Speaker 1: the situation that they're in. There are trematods, So these
30:13
Speaker 1: are if you've heard of schistosomiasis or liver flukes, there's
30:16
Speaker 1: some trematode diseases that are bad in like Asia and Africa.
30:20
Speaker 1: We don't have too many to worry about here. Swimmers itch.
30:22
Speaker 1: Have you ever heard of swimmers?
30:23
Speaker 5: Itch?
30:24
Speaker 2: Sounds uncomfortable.
30:25
Speaker 1: It is uncomfortable. So the idea with trematods is that
30:28
Speaker 1: they typically start in snails. They often castrate the snail
30:32
Speaker 1: and they reproduce asexually, so they make tons and tons
30:35
Speaker 1: and tons of these free swimming infectious stages that leave
30:39
Speaker 1: the snail and they go off in search of something else.
30:41
Speaker 1: Swimmers itch is when you get these free swimming stages
30:44
Speaker 1: that are going off in search of a bird to
30:47
Speaker 1: infect snacks, but they accidentally hit you and they've taken
30:52
Speaker 1: what they can get. Maybe they can't tell the difference,
30:54
Speaker 1: but they burrow into you and then your immune system
30:56
Speaker 1: kills them almost immediately. But then you get this horrible
30:59
Speaker 1: itch afterwards because you have an immune reaction to it
31:02
Speaker 1: for some reason.
31:02
Speaker 2: Because it's called swimmers ith, I'm imagining this itch is
31:05
Speaker 2: in a very uncomfortable place.
31:06
Speaker 1: Oh geez, Daniel, you just keep bringing the conversation back there.
31:09
Speaker 1: But it could be there. But my colleagues and I
31:12
Speaker 1: usually get it on like our calves because we're in
31:14
Speaker 1: salt marshes and it's yeah, don't worry don't worry. That's
31:18
Speaker 1: free swimming stage of the parasite. Depending on the species
31:21
Speaker 1: that you're looking at, they often have strategies to try
31:24
Speaker 1: to get closer to where their hosts usually hang out.
31:27
Speaker 1: So if they're leaving a snail and hoping to infect
31:30
Speaker 1: a fish, some of them will respond by swimming towards
31:33
Speaker 1: whatever light source you give them, so they're trying to
31:35
Speaker 1: swim up to the water surface where they're more likely
31:37
Speaker 1: to encounter certain kinds of fish. But once they encounter
31:40
Speaker 1: a fish, they'll take what they can get. They're not
31:43
Speaker 1: choosy because literally two thousand of these free swimming stages
31:47
Speaker 1: of trematade called you Up work as California Asis. It's
31:49
Speaker 1: the one that I studied for my PhD. Two thousand
31:52
Speaker 1: of them leave the snail every day like that's how
31:55
Speaker 1: many need to be made in the hopes that some
31:57
Speaker 1: of them encounter a fish. Because there's a low probability game,
32:00
Speaker 1: so in general, there's not a lot of evidence of choosiness.
32:04
Speaker 1: They're not very mobile. They don't have a chance to
32:07
Speaker 1: be choosy. But parasitoid wasps can be a little bit
32:10
Speaker 1: more mobile. So parasitoid wasps lay their eggs in some insect,
32:14
Speaker 1: and then their eggs consume the inside of the insect
32:17
Speaker 1: and then burst out of it when they're done. This
32:19
Speaker 1: is yeah, it's super creepy. There's some evidence that some
32:23
Speaker 1: parasitoid wasps can tell if a for example, caterpillar has
32:28
Speaker 1: already had eggs laid in it, and then they'll go
32:31
Speaker 1: off in search of another one because they don't want
32:33
Speaker 1: their offspring to have to compete with like older wasp
32:36
Speaker 1: babies that are already starting to eat the caterpillar from
32:38
Speaker 1: the inside. So there's some choosiness in the more mobile parasites,
32:42
Speaker 1: but in general they don't get a chance to.
32:44
Speaker 2: Do much choosing all right, So to some of the
32:46
Speaker 2: answer for Ricky, I think that there are some outcomes
32:50
Speaker 2: for the parasite that are better, Like if they get
32:53
Speaker 2: into a healthy host, it lasts long enough for them
32:56
Speaker 2: to do their whole life cycle dance. But they don't
32:59
Speaker 2: get choices. Often, unlike carnivores, they can't pick who they're
33:03
Speaker 2: going to chase. After though if we invited them on
33:05
Speaker 2: the podcast, they might still have thoughts about where they
33:07
Speaker 2: ended up. We don't know what is it like to
33:10
Speaker 2: be a parasite nobody knows.
33:11
Speaker 1: Maybe you should be president of the Helmetological Society of
33:15
Speaker 1: Washington because you're doing a great job speaking for the parasites.
33:18
Speaker 2: No, no, no, no, I want to be a philosopher
33:21
Speaker 2: of parasitology. I don't think that exists. We just invented
33:24
Speaker 2: a new academic field today.
33:25
Speaker 1: Oh my goodness. There's probably no funding for it, unfortunately,
33:29
Speaker 1: but I hope we're wrong about that. But well, let's
33:31
Speaker 1: see if Ricky would like to fund a new position
33:33
Speaker 1: for the philosopher of parasitology.
33:35
Speaker 2: And if I'm wrong and you are a philosopher of parasitology,
33:39
Speaker 2: we want to hear from you right to us. Please
33:41
Speaker 2: two questions at Damilankelly dot org.
33:45
Speaker 1: And while we're waiting for that email to come in,
33:47
Speaker 1: let's see what Ricky thought of the answer.
33:49
Speaker 6: First of all, it is obviously my fault because I
33:53
Speaker 6: knew what question I asked, and then I was like, oh,
33:55
Speaker 6: I'll listen to your answer while I'm having lunch. But
33:58
Speaker 6: that aside, which was to on me, Thank you Daniel
34:02
Speaker 6: for bringing it back. My real question was about preference.
34:06
Speaker 6: If there were the ability to infect an quote unquote
34:12
Speaker 6: ideal host, what would that look like, and I think
34:15
Speaker 6: you really got there, especially with the mobile ones with
34:19
Speaker 6: the parasitoid wasps, which are a big thing for me
34:22
Speaker 6: as a farmer. And also I have two useless philosophy
34:26
Speaker 6: degrees and I'm considering pursuing this third one. Thanks and
34:30
Speaker 6: thank you Kelly for going into such incredible nerdy detail
34:34
Speaker 6: for me.
34:52
Speaker 1: All Right, for our next question, we have a question
34:55
Speaker 1: from Wendy.
34:58
Speaker 5: Hey, I'm Wendy. Came from my I have a question
35:01
Speaker 5: about the speed of light. The speed of light is
35:05
Speaker 5: something really fundamental, I think, because both light and gravity
35:09
Speaker 5: waves travel at that speed. Does every force carrier travel
35:13
Speaker 5: at the speed of light? And if that's the case,
35:16
Speaker 5: it's not the speed of light. Isn't it the speed
35:20
Speaker 5: of the universe?
35:21
Speaker 2: Thanks so much, And Wendy asks a really deep, really
35:25
Speaker 2: basic question about the nature of the universe and motion
35:29
Speaker 2: at the speed of light and why do we call
35:31
Speaker 2: it the speed of light? Anyway? All sorts of stuff
35:34
Speaker 2: connected here that I hear a lot of people puzzling about,
35:37
Speaker 2: and that I still puzzle about because the nature of
35:39
Speaker 2: the universe and transmission of information is not something we
35:42
Speaker 2: have fully understood, even if we do have a great
35:46
Speaker 2: mathematical framework for describing it.
35:48
Speaker 1: Well, let's start from the beginning. Does every force carrier
35:51
Speaker 1: travel at the speed of light? I'm gonna guess the
35:54
Speaker 1: answer is it depends. No, no, no, we.
36:00
Speaker 2: Are watering down the crispness of physics today. Right, you
36:03
Speaker 2: are right. The answer is it depends. But it depends
36:06
Speaker 2: very precisely on something, which is whether the force carrier
36:09
Speaker 2: has mass. You see, things that have mass cannot travel
36:13
Speaker 2: at the speed of light. Never ever, Ever, they can
36:16
Speaker 2: approach the speed of light. You can keep pushing them
36:18
Speaker 2: and pushing them and pushing them. They will ask them talk.
36:20
Speaker 2: They get closer and closer to the speed of light
36:22
Speaker 2: relative to something. But things that have mass cannot travel
36:25
Speaker 2: at the speed of light. It would take infinite energy. Sorry, sorry,
36:30
Speaker 2: both exactly. Keep pushing though, keep pushing. And for those
36:34
Speaker 2: of you out there thinking, don't things traveling near the
36:36
Speaker 2: speed of light also gain mass and become infinitely massive?
36:40
Speaker 2: The answer to that is no, they just have infinite energy.
36:43
Speaker 2: And we have a whole episode talking about whether potatoes
36:45
Speaker 2: turned into black holes need the speed of light. Check
36:47
Speaker 2: that out if you're interested in the question of relativistic mass.
36:51
Speaker 2: But the issue here is whether something has mass. So
36:53
Speaker 2: things that do have mass can never travel at the
36:56
Speaker 2: speed of light relative to anybody, whereas things that don't
36:59
Speaker 2: have mass are always moving at the speed of light
37:02
Speaker 2: for everybody. So when he asks, does every force carrier
37:06
Speaker 2: travel at the speed of light? It depends on whether
37:09
Speaker 2: they have mass. So let's quiz Kelly, what are they
37:12
Speaker 2: some force carriers?
37:14
Speaker 1: The electromagnetic field?
37:16
Speaker 2: Yeah, and what is the particle associated with that electron? No,
37:19
Speaker 2: the photons?
37:19
Speaker 1: Ohton, Yeah, that's what I said.
37:21
Speaker 2: Yes, So the photon is the particle that transmits the
37:25
Speaker 2: electromagnetic force. Like when two electrons are repelling each other,
37:29
Speaker 2: what's happening there? Will electrons cause ripples in the electromagnetic
37:34
Speaker 2: field because they have a charge, And check out our
37:36
Speaker 2: episode on weak Harper charge to get like a deeper
37:39
Speaker 2: understanding of what charge is. But essentially, it's a coupling
37:41
Speaker 2: between two fields. And so two electrons nearing each other
37:45
Speaker 2: are both causing these ripples and the electromagnetic field and
37:48
Speaker 2: those ripples push on each other. And so you can
37:50
Speaker 2: think about it from the field perspective, or you can
37:52
Speaker 2: think about it from the particle perspective and say, those
37:55
Speaker 2: ripples in the electromagnetic field, those are photons, and so
37:58
Speaker 2: what's happening when the elect trans come near each other
38:01
Speaker 2: as they are exchanging photons. That's what's meant by a
38:03
Speaker 2: force carrier, the particles associated with the field that transmits
38:08
Speaker 2: that force. So for the electromagnetic force, it's the electromagnetic
38:12
Speaker 2: field and the force carrier is the photon and photons
38:15
Speaker 2: they are massless, and so they do move at the
38:18
Speaker 2: speed of light. Now, other forces have different fields and
38:23
Speaker 2: different force carriers. So for example, the strong force.
38:25
Speaker 1: Is that the one with the colors, Yes.
38:27
Speaker 2: Exactly, the strong force. The charge there is not a
38:30
Speaker 2: plus or minus. It's a red, green or blue, which
38:33
Speaker 2: is really weird. And there's a bunch of gluon fields.
38:36
Speaker 2: There's eight gluon fields, and each field carries two colors,
38:40
Speaker 2: not just one, so it can be like red, anti
38:42
Speaker 2: green or something crazy. And these gluons are also massless.
38:46
Speaker 2: So gluon fields transmit information at the speed of light
38:50
Speaker 2: as well. So that's two force carriers that do travel
38:53
Speaker 2: at the speed of light. And gravitational waves also move
38:57
Speaker 2: at the speed of light. Now, gravitational waves not technically
39:00
Speaker 2: a force carrier. They are ripples. In the gravitational field
39:04
Speaker 2: created by the acceleration of masses. But information in gravity
39:07
Speaker 2: does travel at the speed of light. And we don't
39:09
Speaker 2: know what a force carrier is for gravity because we
39:11
Speaker 2: don't have a theory of quantum gravity, so we don't
39:13
Speaker 2: know like, are there gravitons, etcetera, et cetera. But gravitational
39:17
Speaker 2: waves definitely travel at the speed of light. But other
39:20
Speaker 2: force carriers do have mass. So, for example, the weak force,
39:24
Speaker 2: it's all messed up because of the Higgs boson. Higgs
39:27
Speaker 2: comes in and it makes the W and the Z
39:29
Speaker 2: have mass, whereas the photon doesn't. Makes a big mess
39:33
Speaker 2: of the weak force. So these things are quite massive.
39:36
Speaker 1: I'm just gonna go ahead and interject that I'm not
39:38
Speaker 1: the one who added fuzziness to physics.
39:41
Speaker 2: It was Higgs.
39:42
Speaker 1: Yeah, it was Higgs. Go ahead, tell me more about this.
39:45
Speaker 2: Yeah. So the W and the Z bosons are really
39:47
Speaker 2: quite massive. The w's mass is like eighty times the
39:51
Speaker 2: mass of a proton and the Z is like ninety times.
39:54
Speaker 2: These are super duper massive particles. And it's one reason
39:56
Speaker 2: why the weak force is so weak, because it's force
39:59
Speaker 2: carriers are so massive. They don't travel at the speed
40:02
Speaker 2: of light, and they're very unstable. They decay very quickly
40:05
Speaker 2: into other stuff. And so these force carriers that W
40:08
Speaker 2: and Z do not travel at the speed of light,
40:11
Speaker 2: so it depends on whether they're massless.
40:14
Speaker 1: Okay, so we've answered the first part of the question
40:16
Speaker 1: that no, every force carrier does not travel at the
40:19
Speaker 1: speed of light. Okay, So where do we go from there?
40:22
Speaker 2: Yeah, and so she's asking, like, why do we call
40:24
Speaker 2: it the speed of light if other things travel at
40:27
Speaker 2: that same speed. It's not special to photons, And she's right,
40:31
Speaker 2: photons are the first thing we saw that was massless
40:34
Speaker 2: that traveled at the maximum speed of the universe, and
40:37
Speaker 2: so it really is the maximum speed of information in
40:40
Speaker 2: the universe, and all massless things can travel at this
40:43
Speaker 2: massless speed and have to travel at this massless speed.
40:47
Speaker 2: So yeah, it's the speed of information or the speed
40:49
Speaker 2: of causality, or the speed of the universe. You could
40:52
Speaker 2: also call it the speed of gluons. Right. We call
40:56
Speaker 2: it the speed of light because light was the first
40:58
Speaker 2: thing we discovered that mood at this so it's just
41:01
Speaker 2: sort of historical, but it's also really fascinating, like philosophically,
41:05
Speaker 2: why the universe has a maximum speed, and why it's
41:09
Speaker 2: this number and why it means that all observers have
41:13
Speaker 2: to see massless things moving at this speed.
41:15
Speaker 1: So, first of all, I think I prefer speed of
41:17
Speaker 1: the universe. I don't know, that sounds more epic. But why, yeah,
41:21
Speaker 1: why is this the speed of the universe?
41:23
Speaker 2: Yeah, nobody knows currently, we don't even know if there
41:26
Speaker 2: is an explanation. One possibility is that it comes out
41:30
Speaker 2: of the way space is built. You know, space could
41:33
Speaker 2: be quantized. It could be a bunch of pixels and
41:36
Speaker 2: these pixels could interact with each other through quantum entanglement,
41:39
Speaker 2: and that's how space is woven together from a bunch
41:41
Speaker 2: of like little space pixels, and that the speed of
41:44
Speaker 2: information is connected to that entanglement, and so it could
41:48
Speaker 2: come out of some deeper understanding of space. That's just
41:51
Speaker 2: a speculation currently, we don't know. Currently, it's just a
41:53
Speaker 2: number that we measure, and it could be anything. It
41:56
Speaker 2: could be twice as big, it could be half as big.
41:59
Speaker 2: And it's important number because it really determines what it's
42:02
Speaker 2: like to be in the universe. Like, on one hand,
42:05
Speaker 2: having the speed of light be as small as it
42:07
Speaker 2: is relative to the size of the universe means we
42:10
Speaker 2: can't see that far right, Like the whole regions of
42:12
Speaker 2: the universe we can't even see because in the fourteen
42:15
Speaker 2: billion years of its history, life hasn't had time to
42:17
Speaker 2: get here. Imagine if the speed of light was a
42:20
Speaker 2: thousand or a billion times higher, we could see so
42:23
Speaker 2: much further into the universe, and the information in our
42:27
Speaker 2: neighborhood wouldn't be as out of date. That would be amazing.
42:30
Speaker 2: The other hand, there'd be downsides also, like the fact
42:34
Speaker 2: that the speed of light is not infinite protects us
42:37
Speaker 2: from alien death rays. For example, you know, if an
42:41
Speaker 2: alien shoots a death ray at Earth from Andromeda, that's
42:45
Speaker 2: a few million light years away. We got a few
42:47
Speaker 2: million years before it comes here, So that's cool. If
42:50
Speaker 2: the speed of light was like instantaneous or much much higher,
42:54
Speaker 2: then we would be vulnerable to alien death rays in
42:56
Speaker 2: a much bigger volume. So it isolates us in a
42:58
Speaker 2: protective way.
42:59
Speaker 1: No time to get our affairs together.
43:01
Speaker 2: Yeah, exactly, exactly. Talk to your parasites, get everything in order.
43:06
Speaker 2: Are your parasites in your will? Have you figured out
43:08
Speaker 2: all that out? Kelly?
43:09
Speaker 1: You know I don't have a will. Yet. Oh no,
43:12
Speaker 1: I know, that's like literally on my to do list
43:15
Speaker 1: for this week, but I'll make sure someone good gets
43:18
Speaker 1: my parasites.
43:19
Speaker 2: Yeah, so it's really fascinating. We don't know the answer.
43:23
Speaker 2: It's possible that the value of the speed of light
43:26
Speaker 2: is determined by some deeper physics we don't know yet,
43:29
Speaker 2: or it's possible it's just like a random number and
43:32
Speaker 2: when the universe cools and settles, it turns out to
43:35
Speaker 2: be this number. And in the multiverse, different universes have
43:38
Speaker 2: different values of this number. We don't know the answer
43:41
Speaker 2: to that, but it is fascinating and it's something I
43:43
Speaker 2: hear a lot of people sort of misunderstanding when they're
43:46
Speaker 2: writing to me and asking questions about it. You know,
43:49
Speaker 2: for example, there is this constant question like what is
43:51
Speaker 2: it like to be a photon? You know, do photons
43:54
Speaker 2: experience time in the universe that we've talked about that
43:57
Speaker 2: I think reveals a sort of misunderstanding about the nature
44:00
Speaker 2: of these massless objects and their velocity.
44:04
Speaker 1: Well, let's see if you've cleared this all up for Wendy.
44:07
Speaker 5: Thank you so much for your lucid and straightforward answer
44:11
Speaker 5: about the speed of force carriers. I also appreciated your
44:15
Speaker 5: elaboration on the speed of the universe why it is
44:19
Speaker 5: what it is, which is also a question I've pondered.
44:23
Speaker 5: Of course, I'm left wondering about why the weak force
44:26
Speaker 5: is so different from the strong force gravity and electromagnetism.
44:32
Speaker 5: Why it froze out of the electroweak force as the
44:34
Speaker 5: universe cooled. But that's another question altogether. Thanks again.
44:41
Speaker 1: All right, well, thank you so much to everyone who
44:43
Speaker 1: submitted questions, and we are looking forward to hearing your questions.
44:47
Speaker 1: You can write us at questions at Danielankelly dot org
44:51
Speaker 1: and we will definitely write you back, either with an
44:53
Speaker 1: answer if we know it right away, or if you've
44:55
Speaker 1: kind of stumped us, or it's a question we get often,
44:58
Speaker 1: we'll answer it on the show.
45:00
Speaker 2: Right as family friendly questions, Kelly doesn't have to cringe
45:03
Speaker 2: when I'm responding to them.
45:05
Speaker 1: You know, Daniel, I feel like you took family friendly
45:07
Speaker 1: topics and sort of morph them into something not family friendly,
45:10
Speaker 1: so I don't think our listeners can win.
45:14
Speaker 2: I have a special gift to that.
45:18
Speaker 1: You would have thought that the co host with the
45:19
Speaker 1: last name wider Smith would.
45:20
Speaker 2: Have that gift. There you go, that was you, and
45:24
Speaker 2: that was all you.
45:26
Speaker 1: We're a good team, all right, everybody, Until next time.
45:28
Speaker 2: Thanks for listening.
45:36
Speaker 1: Daniel and Kelly's Extraordinary Universe is produced by iHeart Reading.
45:40
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45:43
Speaker 2: We want to know what questions you have about this
45:46
Speaker 2: Extraordinary Universe.
45:48
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45:51
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45:54
Speaker 1: back to you.
45:54
Speaker 2: We really mean it. We answer every message. Email us
45:58
Speaker 2: at questions at Daniel and Kelly dot org.
46:01
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46:03
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46:10
Speaker 2: Op chaye right to us.