Latest / Daniel and Kelly’s Extraordinary Universe / Listener Questions 32: Particles, particles, particles!

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Listener Questions 32: Particles, particles, particles! · Daniel and Kelly’s Extraordinary Universe

• 0:08
  Speaker 1: Hey, ho, hey, you ready for this? I don't know.
• 0:11
  Speaker 1: I had kind of a big lunch. Let me guess
• 0:14
  Speaker 1: what you had for lunch. Oh, well, that's not hard.
• 0:16
  Speaker 1: I always have cereal. But which kind of cereal though? Mm?
• 0:21
  Speaker 1: Something made out of protons, neutrons, and electrons, maybe clothes.
• 0:26
  Speaker 1: I had a new cereal called neutrinos. Now I'm just kidding.
• 0:29
  Speaker 1: Let's just regular atom based cereal. How did you know? Well,
• 0:32
  Speaker 1: you know you gave me a massive hint telling me
• 0:35
  Speaker 1: it was a heavy lunch, right right, and only things
• 0:38
  Speaker 1: with protons, neutrons, and electrons have mass. That's right. Maybe
• 0:43
  Speaker 1: you should try something lighter, like a photon based meal. Hmm.
• 0:47
  Speaker 1: It sounds like a brilliant and delicious idea good for
• 0:51
  Speaker 1: my diet. Hi am or hand made cartoonists and the
• 1:08
  Speaker 1: co author of Frequently Asked Questions about the Universe. Hi,
• 1:11
  Speaker 1: I'm Daniel. I'm a particle physicist and a professor at
• 1:14
  Speaker 1: u C Irvine, and I'm pretty glad that I can't
• 1:17
  Speaker 1: eat photons. Well, how do you know? Have you tried?
• 1:20
  Speaker 1: Could you taste it? Then? Have you shown a flashlight
• 1:23
  Speaker 1: down your throat? I think they do that at the
• 1:25
  Speaker 1: doctors all the time, so I think you have eaten photons. Yeah, well,
• 1:28
  Speaker 1: but if I lay down in the sun for a nap,
• 1:30
  Speaker 1: for example, I still sometimes wake up hungry. Maybe you
• 1:33
  Speaker 1: shouldn't put on sun block the no photon diet, But
• 1:37
  Speaker 1: I mean, do you nap with your mouth open? Though?
• 1:40
  Speaker 1: Have you tried that? I have not tried napping with
• 1:42
  Speaker 1: my mouth open. But I was imagining that maybe humans
• 1:45
  Speaker 1: would evolve to photosynthesize, so we could just like absorb
• 1:49
  Speaker 1: photons as well walk around or lay in the sun.
• 1:52
  Speaker 1: Oh wow, it's pretty cool. Yeah, we could all be
• 1:54
  Speaker 1: green with envy and photosist. It would be pretty hard
• 1:57
  Speaker 1: to go on a diet, though, I guess you'd have
• 1:59
  Speaker 1: to like walk around with an umbrella. You could sell
• 2:01
  Speaker 1: a diet sunblock, I guess, or paracel would be like
• 2:05
  Speaker 1: a new fashion accessory for the super thin. Stay thin
• 2:08
  Speaker 1: and pale. But welcome to our podcast. Daniel and Jorge
• 2:10
  Speaker 1: explain the Universe, a production of I Heart Radio, in
• 2:13
  Speaker 1: which we don't eat the photons, but we do gobble
• 2:16
  Speaker 1: of all of the information provided to us by the
• 2:19
  Speaker 1: particles in the universe. We are made of particles. Everything
• 2:23
  Speaker 1: around us is made of particles. And in their incredible dance,
• 2:26
  Speaker 1: they convey to us everything that is happening out there.
• 2:30
  Speaker 1: They tell us about the fundamental nature of the universe
• 2:32
  Speaker 1: at the smallest scales, and they come together to describe
• 2:35
  Speaker 1: the sweeping motions of enormous galaxies and the dance of
• 2:39
  Speaker 1: galactic clusters as they get pulled apart by dark energy.
• 2:43
  Speaker 1: Everything around us is made of particles, and all of
• 2:45
  Speaker 1: our understanding of it is stored in particles in our brain. Yeah,
• 2:49
  Speaker 1: because it is a tasty and brilliant universe full of
• 2:52
  Speaker 1: amazing thanks to discover full of information beaming down to
• 2:56
  Speaker 1: us from the light of stars and planets and nebulas.
• 3:00
  Speaker 1: They're in the cosmos, ready for us to digest and
• 3:03
  Speaker 1: absorb all of those amazing knowledge nutrients from the universe.
• 3:07
  Speaker 1: And the most amazing thing about the particles that make
• 3:09
  Speaker 1: up your brain is that they are curious about all
• 3:12
  Speaker 1: the other particles. These particles want to understand those particles,
• 3:17
  Speaker 1: and that bubbles up in the form of questions, Questions
• 3:20
  Speaker 1: that we ask about the nature of the universe around us.
• 3:23
  Speaker 1: Questions we ask ourselves, Questions we ask our friends, Questions
• 3:27
  Speaker 1: we whisper to ourselves quietly at night when we stare
• 3:29
  Speaker 1: up at the stars and questions we send to podcast hosts. Yeah,
• 3:33
  Speaker 1: the world is full of questions. Everyone has questions. It's
• 3:36
  Speaker 1: kind of an inherent part of being human, and in
• 3:38
  Speaker 1: this podcast we like to answer some of those questions.
• 3:41
  Speaker 1: Most of the time, at least we like to ask them.
• 3:43
  Speaker 1: We don't always answer them. I guess we answer them
• 3:46
  Speaker 1: as best as we can. Some of these things are tough.
• 3:49
  Speaker 1: Explaining concepts in an understandable way, which are often just
• 3:52
  Speaker 1: described mathematically can be a real challenge, but we do
• 3:55
  Speaker 1: our best to boil it down to the essential ideas.
• 3:58
  Speaker 1: I guess saying I don't know is also answer, So
• 4:00
  Speaker 1: technically we we do answer every question. Yeah we have
• 4:04
  Speaker 1: no idea is a valid answer to not just a
• 4:06
  Speaker 1: good book. Absolutely. And sometimes when I'm posed with an
• 4:09
  Speaker 1: especially difficult conceptual question like can you make me understand
• 4:13
  Speaker 1: why X, y Z happens? I'll walk the hallways here
• 4:16
  Speaker 1: you see I, and I'll ask the theorists, why do
• 4:18
  Speaker 1: you think this happens? Why do you think that happens?
• 4:20
  Speaker 1: You have an intuitive understanding of this, And often I'll
• 4:23
  Speaker 1: get very different ideas and sometimes conflicting accounts for why
• 4:27
  Speaker 1: things happen, which just tells you that even the experts
• 4:30
  Speaker 1: don't always deeply understand the why right right because the
• 4:34
  Speaker 1: X and the Z are easier or what? Because sometimes
• 4:38
  Speaker 1: the A, B, C s are easier than the X, Y, Z,
• 4:40
  Speaker 1: so they do come first, I guess. But it's not
• 4:43
  Speaker 1: just the scientists and the physicists of the world that
• 4:46
  Speaker 1: ask questions. Everybody asked questions. Everyone looks up at the stars,
• 4:49
  Speaker 1: at the sky that things around and and they wonder
• 4:51
  Speaker 1: what's going on? How does it all work? They do,
• 4:53
  Speaker 1: and especially our listeners are curious folks. We hope that
• 4:57
  Speaker 1: you are listening to the podcast because you wonder about
• 5:00
  Speaker 1: the nature of the universe, and because you want to
• 5:03
  Speaker 1: understand it. You want to do more than just here
• 5:06
  Speaker 1: an explanation. You want those pieces to fit together in
• 5:09
  Speaker 1: your mind in a way that you can manipulate it.
• 5:11
  Speaker 1: You can rotate it and probe it from different angles
• 5:14
  Speaker 1: and make sure that it sort of hangs together. And
• 5:16
  Speaker 1: when it doesn't, we encourage you to write to us
• 5:18
  Speaker 1: so we could help you fill in those gaps. So
• 5:20
  Speaker 1: today on the podcast, we'll be tackling listener questions number
• 5:29
  Speaker 1: thirty two. Oh my goodness, we don't thirty two of
• 5:32
  Speaker 1: these listener question episodes, so we have We get lots
• 5:34
  Speaker 1: and lots of listener questions. Many of them come to
• 5:37
  Speaker 1: our email address two Questions at Daniel and Jorge dot
• 5:40
  Speaker 1: com and we answer all of them. So if you
• 5:43
  Speaker 1: have a question, please don't be shy. But sometimes we
• 5:46
  Speaker 1: got a question which I think will be really fun
• 5:48
  Speaker 1: to talk about or is quite tricky and requires me
• 5:51
  Speaker 1: to do a little bit of background research, and for
• 5:53
  Speaker 1: those we ask people to send in some audio so
• 5:55
  Speaker 1: we can talk about it on the podcast Interesting. And
• 5:57
  Speaker 1: So if this is our thirty second listener Questions episode
• 6:01
  Speaker 1: and we do about three questions and episode, that means
• 6:03
  Speaker 1: we're close to like a hundred questions. I mean, one
• 6:06
  Speaker 1: of you, anyone sending the question in now could be
• 6:09
  Speaker 1: the one hundred listener question we answer on the podcast. Wow,
• 6:13
  Speaker 1: are we going to give away a prize? Yes, a
• 6:15
  Speaker 1: possible answer. I think we should at least shower them
• 6:19
  Speaker 1: in digital confetti or something, send them a gift or
• 6:22
  Speaker 1: an emoji COMPETI instead of a gift, you just got
• 6:27
  Speaker 1: a gift. There you go leave out the tea. They
• 6:31
  Speaker 1: get a gift or a Jif we do love answering
• 6:33
  Speaker 1: questions from listeners, and today we have some pretty interesting
• 6:36
  Speaker 1: questions in that they're all about particles and kind of
• 6:41
  Speaker 1: about masks. It seems we are you feeling in a
• 6:43
  Speaker 1: kind of particle mood or do you think these questions
• 6:45
  Speaker 1: just all came in at the same time. Now, these
• 6:47
  Speaker 1: questions are not sorted by when they arrive. I try
• 6:50
  Speaker 1: to group them together, so the concepts are a little
• 6:52
  Speaker 1: bit related. So we do a batch about black holes,
• 6:54
  Speaker 1: and a batch about particles, and a batch about how
• 6:57
  Speaker 1: physics might kill you, so we can dive a little
• 6:59
  Speaker 1: bit were into the topic. Al right, Well, today we
• 7:02
  Speaker 1: have three particularly particle ly questions, some of them about
• 7:06
  Speaker 1: virtual particles, about particles that may or may not exist,
• 7:10
  Speaker 1: and also about what kind of particle light is. And
• 7:13
  Speaker 1: so our first question comes from Carter, who wants to
• 7:16
  Speaker 1: know about all the other particles in existence. Hi, this
• 7:20
  Speaker 1: is Carter, and my question for you is why do
• 7:23
  Speaker 1: particles other than the electron, the electron, neutrino, and the
• 7:28
  Speaker 1: up and down corks exist if we only need those
• 7:31
  Speaker 1: four particles to build up the world around us. Awesome question,
• 7:35
  Speaker 1: Thank you, Carter. It's amazing to me that you have
• 7:38
  Speaker 1: a question like that. Absolutely. Carter is twelve years old
• 7:41
  Speaker 1: and he's already at the forefront of particle physics asking
• 7:44
  Speaker 1: questions we don't know the answers to. Yeah. I think
• 7:46
  Speaker 1: when I was twelve, I was mostly just wondering what
• 7:49
  Speaker 1: I was going to have for lunch that day. I
• 7:52
  Speaker 1: think when I was twelve, I was watching the movie
• 7:54
  Speaker 1: Stand by Me over and over every single day for
• 7:57
  Speaker 1: a summer. I mean, the one where they find a
• 7:59
  Speaker 1: dead body. I don't know why I watched that every
• 8:03
  Speaker 1: single day for a summer, but I remember there was
• 8:04
  Speaker 1: a summer where I watched that in the morning and
• 8:06
  Speaker 1: then I wrote computer programs in the afternoon. Unlike that
• 8:09
  Speaker 1: was my summer. Wow, it sounds like you've got a
• 8:12
  Speaker 1: lot of sunlight, or or at least light from your
• 8:15
  Speaker 1: monitor exactly. The Carter apparently is thinking about the nature
• 8:19
  Speaker 1: of the universe and how it comes together and why
• 8:21
  Speaker 1: there are weird particles out there. Yeah, because, as he said,
• 8:24
  Speaker 1: we only sort of need a certain number of particles
• 8:26
  Speaker 1: to make the things around us. Like everything we can
• 8:29
  Speaker 1: see and touch and stand on and look up at
• 8:31
  Speaker 1: this guy at it's pretty much made out of only
• 8:34
  Speaker 1: three particles, right, I mean, he mentioned the fourth, but
• 8:36
  Speaker 1: most of the things that are made out of three particles. Yeah,
• 8:39
  Speaker 1: he's right that the things that we are made out
• 8:41
  Speaker 1: of technically are just three particles. But as we'll talk about,
• 8:45
  Speaker 1: the other particles do play a role in determining the
• 8:48
  Speaker 1: nature of our universe. It would be quite different if
• 8:51
  Speaker 1: those particles didn't exist. All right, Well, maybe let's rebuild
• 8:55
  Speaker 1: things a little bit. So why is it that everything
• 8:58
  Speaker 1: that we're made out of is only made out of
• 9:00
  Speaker 1: three particles? So everything that we are made out of
• 9:02
  Speaker 1: is made of atoms. Right, if you zoom in really,
• 9:05
  Speaker 1: really far, you see that your hand and the table
• 9:08
  Speaker 1: next to you, and the lama that maybe you wrote
• 9:11
  Speaker 1: to work on this morning are all made out of molecules,
• 9:14
  Speaker 1: which are built out of atoms from the periodic table,
• 9:17
  Speaker 1: everything around us, right, All the kinds of matter that
• 9:20
  Speaker 1: you're familiar with are made out of atoms. This excludes,
• 9:23
  Speaker 1: of course, dark matter, which is some other weird kind
• 9:25
  Speaker 1: of stuff that's part of the universe but we don't
• 9:28
  Speaker 1: understand at all. So all this sort of familiar kind
• 9:30
  Speaker 1: of matter, the kind of stuff you can see and
• 9:32
  Speaker 1: taste and eat, is made out of atoms. And those
• 9:35
  Speaker 1: atoms are made out of electrons, and then in the
• 9:37
  Speaker 1: nucleus there are protons and neutrons. Inside the protons and
• 9:42
  Speaker 1: neutrons are quarks. Protons and neutrons are made out of
• 9:45
  Speaker 1: two different kinds of quarks. Two ups and a down
• 9:49
  Speaker 1: make a proton, two downs and and up make a neutron.
• 9:53
  Speaker 1: So out of up corks, down corks, and electrons you
• 9:55
  Speaker 1: can build basically any atom, and from that you can
• 9:58
  Speaker 1: build any chemical, and from that you and build anything.
• 10:01
  Speaker 1: And the thing that's incredible to me is that it's
• 10:03
  Speaker 1: not just that all the stuff around us has made
• 10:06
  Speaker 1: out of these three particles. It's also made out of
• 10:09
  Speaker 1: these three particles in the same relative abundances, Like a
• 10:14
  Speaker 1: kilogram of lava and a kilogram of kitten have the
• 10:18
  Speaker 1: same number of each kinds of these particles inside of them.
• 10:21
  Speaker 1: It's just the arrangements that are different between them. Interesting. Yeah,
• 10:24
  Speaker 1: it's amazing that you can reduce the almost seemingly infinite
• 10:28
  Speaker 1: variety of stuff in the universe into three things. And
• 10:31
  Speaker 1: like you said, it's amazing that it's just all about
• 10:33
  Speaker 1: the arrangement. Although I think you said it's all kind
• 10:35
  Speaker 1: of the same proportion is that really true? Like a
• 10:37
  Speaker 1: cloud of hydrogen doesn't have the same number or proportion
• 10:40
  Speaker 1: of particles as like lava does it it almost does. Hygrogen,
• 10:44
  Speaker 1: of course, mostly has just protons in it, though there
• 10:46
  Speaker 1: are forms of hydrogen that also have a neutron, and
• 10:49
  Speaker 1: most atoms have an equal balance between protons and neutrons.
• 10:53
  Speaker 1: So most of the stuff out there in the universe
• 10:54
  Speaker 1: has the same number of protons and neutrons in it,
• 10:58
  Speaker 1: and that means the same number of upcore and down
• 11:00
  Speaker 1: corks inside. You're right that most of the universe is hydrogen,
• 11:03
  Speaker 1: which means that most of it are protons, which means
• 11:06
  Speaker 1: that there are more up corks out there than down corks.
• 11:09
  Speaker 1: The stuff that we're made out of, the stuff that
• 11:10
  Speaker 1: we interact with, is mostly not hydrogen. I mean, I
• 11:13
  Speaker 1: don't know if you're having hydrogen for lunch, for example,
• 11:15
  Speaker 1: but if you're having things made out of more complicated atoms,
• 11:18
  Speaker 1: then mostly it's an equal number of protons and neutrons,
• 11:21
  Speaker 1: which means an equal number of up corks and down corks.
• 11:24
  Speaker 1: I do have a lot of gas right now, but
• 11:25
  Speaker 1: I don't think it's hydrogen um. But that's that's interesting.
• 11:29
  Speaker 1: I haven't thought about it before that there are maybe
• 11:31
  Speaker 1: more up quarks in the universe and down courts. Yes,
• 11:33
  Speaker 1: there definitely are, because the universe is mostly hydrogen out there,
• 11:37
  Speaker 1: like it started out as mostly hydrogen, and it's still
• 11:40
  Speaker 1: mostly hydrogen. Even though stars have been working furiously to
• 11:43
  Speaker 1: make heavier elements in their cores, and it's been billions
• 11:47
  Speaker 1: and billions of years, they really only made a little
• 11:49
  Speaker 1: bit of a dent. So most of the matter out
• 11:52
  Speaker 1: there in the universe, the visible matter of our kind,
• 11:54
  Speaker 1: is hydrogen, just as a caveat. Remember that there's five
• 11:58
  Speaker 1: times as much dark matter as any kind of atomic
• 12:01
  Speaker 1: matter out there in the universe. So anytime we're talking
• 12:04
  Speaker 1: about this, we're only talking about the fraction of atomic
• 12:06
  Speaker 1: matter in the universe. And that's all made out of
• 12:09
  Speaker 1: atoms by definition, right, because we are talking about matter particles, right,
• 12:13
  Speaker 1: there are other particles besides matter particles, that's right, And
• 12:16
  Speaker 1: so the up cork, the down cork, and the electron
• 12:19
  Speaker 1: these are particles we call fermions. There spin one half particles.
• 12:23
  Speaker 1: But as you say, there are other particles out there
• 12:25
  Speaker 1: in the universe, and there's a different kind of particles.
• 12:27
  Speaker 1: Their particles. We call force particles. These are bosons. For example,
• 12:32
  Speaker 1: what holds the proton together. It has three corks inside
• 12:35
  Speaker 1: of it. They're tied together by gluons. So gluons are
• 12:38
  Speaker 1: inside the proton, and they're just as much part of
• 12:41
  Speaker 1: the proton as the corks are. They're just sort of
• 12:44
  Speaker 1: like less long lived. There's a huge swarm of gluons
• 12:48
  Speaker 1: inside the proton. In fact, most of the mass of
• 12:51
  Speaker 1: the proton is not the corks, it's the gluons. So
• 12:54
  Speaker 1: it's like you have these three very light corks held
• 12:57
  Speaker 1: together by an incredibly massive ocean and the gluons. But
• 13:01
  Speaker 1: each individual gluon doesn't last very long, right, right. It's
• 13:05
  Speaker 1: kind of like my when my kids make a craft,
• 13:06
  Speaker 1: it's like it's mostly hot glue, a mess of hot
• 13:10
  Speaker 1: with some you know, popsicles things holding it the glue together. Yeah,
• 13:15
  Speaker 1: So most of the energy inside the proton, which is
• 13:19
  Speaker 1: what contributes to its mass, is due to the gluons.
• 13:22
  Speaker 1: So you know, can you say that the proton is
• 13:24
  Speaker 1: made partially of gluons, Yes you can, but you can't
• 13:27
  Speaker 1: like point to a gluon and say this is the
• 13:30
  Speaker 1: gluon inside the proton because they're constantly just getting passed
• 13:33
  Speaker 1: back and forth between the corks. Whereas the corks you
• 13:36
  Speaker 1: can say, here's an upcork, I see where it is.
• 13:38
  Speaker 1: It's this same upcork. It's been part of the proton
• 13:41
  Speaker 1: for a long time. It's a stable state, right right.
• 13:43
  Speaker 1: So we're all made out of up and down quirks
• 13:46
  Speaker 1: and electrons, and you're saying that we also sort of
• 13:48
  Speaker 1: need the particles that glue things together and then keep
• 13:52
  Speaker 1: them together. But I wonder if Car's question was more
• 13:54
  Speaker 1: about the other matter particles that have mass but that
• 13:57
  Speaker 1: don't form the things that we're made out of. You know,
• 14:00
  Speaker 1: it thinks like the top cork and the extra corks
• 14:03
  Speaker 1: and the other metrinos and the extra electrons. Right, yes, So,
• 14:06
  Speaker 1: just to complete the story of the force particles, there's
• 14:10
  Speaker 1: not just the gluons. Of course, there are photons inside
• 14:12
  Speaker 1: of us. There are Higgs bosons that give mass to
• 14:15
  Speaker 1: the particles. There are weak bosons like the W and
• 14:18
  Speaker 1: D c. All these things are playing part of this
• 14:20
  Speaker 1: dance of how those matter particles are fitting together. But
• 14:24
  Speaker 1: you're right, there are other matter particles, and I think
• 14:26
  Speaker 1: these are probably the ones that he was referring to.
• 14:28
  Speaker 1: Because it's not just the electron. The electron has a
• 14:31
  Speaker 1: heavy cousin called the muan, and it has an even
• 14:33
  Speaker 1: heavier cousin called the tao. And that's true of all
• 14:37
  Speaker 1: of these fermions. The up coork has two heavy cousins,
• 14:40
  Speaker 1: the charm and the top. The down cork has too
• 14:42
  Speaker 1: heavy cousins, the strange and the bottom. And you know
• 14:45
  Speaker 1: a fundamental question, which is, I think basically what Carter
• 14:48
  Speaker 1: was asking is why do these exist? Why are they there?
• 14:52
  Speaker 1: Why isn't there just a single generation? Or why if
• 14:55
  Speaker 1: we have other particles, are they not totally different? Why
• 14:58
  Speaker 1: are they so similar? Basically tweaked copies of this first generation.
• 15:03
  Speaker 1: The short answer to that is the title of our
• 15:05
  Speaker 1: great book, which is, we have no idea sort of
• 15:07
  Speaker 1: why it is that way. We can't say the universe
• 15:10
  Speaker 1: has to be this way. What we can say is
• 15:13
  Speaker 1: that if the universe wasn't this way, it would look
• 15:15
  Speaker 1: very different. That is, we would notice if you like
• 15:18
  Speaker 1: deleted them from nature. Right. Well, it's kind of interesting
• 15:21
  Speaker 1: that you would ask, or that anyone would ask that question, right,
• 15:24
  Speaker 1: I mean, we know these sort of heavy cousin versions
• 15:27
  Speaker 1: of the electron and the courts exist because they can
• 15:30
  Speaker 1: be made in a particle collider, for example. Right, that's
• 15:33
  Speaker 1: how we know they exist. Tanky exist even though you
• 15:35
  Speaker 1: don't see them around very much. Yeah, So by exist
• 15:38
  Speaker 1: we mean they're part of the laws of the universe,
• 15:41
  Speaker 1: not necessarily that there are any in existence at any moment, right,
• 15:44
  Speaker 1: And so they can exist. And so the question I
• 15:47
  Speaker 1: guess is like, why is it that they can exist
• 15:49
  Speaker 1: if we don't see them around us very much? Right?
• 15:52
  Speaker 1: Because everything we know that I think that things are
• 15:55
  Speaker 1: made out of around us are just the basic electron
• 15:58
  Speaker 1: and up and down courts. Why can these other heavier
• 16:01
  Speaker 1: particles exist? Yeah, And there's lots of really fascinating angles
• 16:04
  Speaker 1: they're One is like, if there are these heavier particles,
• 16:08
  Speaker 1: why do we only see the lighter ones? Why are
• 16:10
  Speaker 1: the lighter ones the only ones that seem to be around.
• 16:13
  Speaker 1: And the answer to that is that nature doesn't like
• 16:15
  Speaker 1: heavy stuff. It tends to spread out the energy, so
• 16:18
  Speaker 1: the heavy ones are short lived. They tend to decay
• 16:21
  Speaker 1: into the lighter ones. So if you made a bunch
• 16:24
  Speaker 1: of all the different kind of particles, including the heavy
• 16:26
  Speaker 1: ones and the light ones, the heavy ones would very
• 16:29
  Speaker 1: quickly just turn into the lighter ones. Like the top
• 16:31
  Speaker 1: cork doesn't last for very long and last for like
• 16:33
  Speaker 1: ten of the mine is twenty three seconds before it
• 16:36
  Speaker 1: turns into a bottom cork, and then the bottom cork
• 16:38
  Speaker 1: decays into a strange cork, which decays then into a
• 16:41
  Speaker 1: down cork for example. And so these things just don't
• 16:44
  Speaker 1: last very long. That's why they're not around. But the
• 16:48
  Speaker 1: deeper question, which I think you're asking, is like why
• 16:51
  Speaker 1: can they exist at all? Why are they on the menu?
• 16:54
  Speaker 1: And why three generations? And why not too? And why
• 16:56
  Speaker 1: not four? Right? I think that's the deeper question you're asking. Yeah, well,
• 16:59
  Speaker 1: I think they're both deep questions, right, like why can
• 17:02
  Speaker 1: they exist? Yes, first of all, and also why is
• 17:05
  Speaker 1: it that right now we only see one time? I mean,
• 17:07
  Speaker 1: those are two big questions, right. Well, the answer to
• 17:11
  Speaker 1: why can they exist is really just a flat out
• 17:13
  Speaker 1: we don't know. We don't know if the universe has
• 17:16
  Speaker 1: to be this way. To answer the question why can
• 17:19
  Speaker 1: they exist? You have to think like what kind of
• 17:20
  Speaker 1: answer would be satisfactory? And one kind of answer would
• 17:24
  Speaker 1: be to say this is the only way the universe
• 17:26
  Speaker 1: could exist, like mathematically would be inconsistent or just wouldn't
• 17:30
  Speaker 1: make sense or doesn't hang together. There's no other way
• 17:33
  Speaker 1: for it to be than to have three generations. We
• 17:36
  Speaker 1: don't think that's true right now, Like we could imagine
• 17:39
  Speaker 1: a universe without those things. It would still have laws
• 17:42
  Speaker 1: of physics which functioned well and would make sense. It
• 17:45
  Speaker 1: would just be quite different, like it would look very
• 17:47
  Speaker 1: different from our universe. But that doesn't mean that it
• 17:49
  Speaker 1: couldn't exist. And maybe out there, somewhere in the multiverse
• 17:52
  Speaker 1: it does. There are universes with one generation or seven
• 17:55
  Speaker 1: generations or seven thousand generations. The short answer is this
• 17:59
  Speaker 1: is just a number three, and we don't know why
• 18:01
  Speaker 1: three and why not one. It's not something in the
• 18:04
  Speaker 1: equations of math of the universe said that that maybe
• 18:07
  Speaker 1: tell you why they have to exist, like just to
• 18:10
  Speaker 1: make things click or something. Not Right now, right now,
• 18:12
  Speaker 1: it's just descriptive, you know. We don't understand it, sort
• 18:16
  Speaker 1: of the way like we used to not understand why
• 18:18
  Speaker 1: there were so many atoms, like why isn't there just hydrogen?
• 18:21
  Speaker 1: Why are these other weird atoms also out there? These
• 18:23
  Speaker 1: other elements? Now we do understand it. We understand that
• 18:27
  Speaker 1: those things emerge from how smaller pieces come together and
• 18:30
  Speaker 1: create these other opportunities. So it's possible that these other
• 18:34
  Speaker 1: generations are like that, that they're all made out of
• 18:36
  Speaker 1: some smaller bits. Electrons and quarks are not the smallest
• 18:40
  Speaker 1: things in the universe. There are even smaller things squiggles
• 18:42
  Speaker 1: or squaggles or whatever. And the way that squiggles and
• 18:45
  Speaker 1: squaggles come together make all these various options. We don't
• 18:48
  Speaker 1: know that that's true right now. We're just in the
• 18:50
  Speaker 1: descriptive phase. We see these particles, we catalog them, we
• 18:53
  Speaker 1: describe their interactions. We don't know whether they emerge from
• 18:56
  Speaker 1: something deeper, which determines this structure we see, right And
• 19:00
  Speaker 1: the other question is why do we only see the
• 19:02
  Speaker 1: lighter particles now, Because I think we've talked about this before,
• 19:05
  Speaker 1: that like maybe in the early universe there were the
• 19:07
  Speaker 1: conditions for the heavier particles to exist. They were like
• 19:10
  Speaker 1: back then it was common to have those larger, heavier particles,
• 19:13
  Speaker 1: but just right now you don't see them. Yeah. The
• 19:16
  Speaker 1: short answer is that the universe is cold and old.
• 19:19
  Speaker 1: So back when the universe was young and hot, then
• 19:22
  Speaker 1: there was enough energy density to create these particles. All
• 19:25
  Speaker 1: the time, they still decayed that these particles are very
• 19:28
  Speaker 1: short lived. The heavy ones they turned into the lighter particles.
• 19:31
  Speaker 1: That's just the natural way of the universe. Energy density
• 19:34
  Speaker 1: spreads out right, second law of thermodynamics. But back then
• 19:37
  Speaker 1: there was enough energy to constantly just be creating the
• 19:39
  Speaker 1: amount of the vacuum. So the universe was a hot
• 19:41
  Speaker 1: soup of all of these particles, and there was so
• 19:43
  Speaker 1: much energy that didn't really matter which ones had mass
• 19:46
  Speaker 1: and which ones didn't, because there was much more energy
• 19:48
  Speaker 1: around than any of the mass of these particles. So
• 19:51
  Speaker 1: they were all very very fast moving particles. But as
• 19:54
  Speaker 1: the universe cooled down, it basically wasn't capable of making
• 19:57
  Speaker 1: these particles on its own anymore, and all the heavy
• 20:00
  Speaker 1: ones decayed into the lighter ones, and then it's just
• 20:02
  Speaker 1: capable of keeping the lighter ones around making those And
• 20:05
  Speaker 1: now the universe is very cold and very old, and
• 20:08
  Speaker 1: so the only way you can make these heavy particles
• 20:11
  Speaker 1: now is to artificially recreate those conditions by, for example,
• 20:15
  Speaker 1: slamming two protons together to create a dot of very
• 20:18
  Speaker 1: high energy density. And that's exactly how we discover that
• 20:22
  Speaker 1: these particles still can exist in our universe, even though
• 20:25
  Speaker 1: they don't very often naturally, right, And so that's kind
• 20:27
  Speaker 1: of the answer for why we don't see them around anymore, right,
• 20:30
  Speaker 1: is that they die right, and they've all died out basically, right,
• 20:35
  Speaker 1: Like maybe the early universe had a bunch of them,
• 20:37
  Speaker 1: but they're like, you know, I'm done, I'm out. Yeah, Well,
• 20:40
  Speaker 1: it's just not hot enough to make those anymore. And
• 20:43
  Speaker 1: you know, there are conditions naturally that will create them,
• 20:45
  Speaker 1: like when protons hit the upper atmosphere at very very
• 20:48
  Speaker 1: high energy cosmic rays from space, they also create these particles,
• 20:52
  Speaker 1: So it's not just a large hadron collider capable of
• 20:54
  Speaker 1: making these conditions. It does occur naturally. But when they do,
• 20:58
  Speaker 1: they decay away very very quickly, so you don't find
• 21:00
  Speaker 1: like a pile of top corks lying around. You can
• 21:02
  Speaker 1: dig into the Earth to find them. And it's fascinating
• 21:05
  Speaker 1: that some of these things are stable and some of
• 21:07
  Speaker 1: them are not, right, Like, we don't have the conditions
• 21:09
  Speaker 1: to make iron, for example, here on Earth, but iron
• 21:12
  Speaker 1: is stable. Once you've made it in the heart of
• 21:14
  Speaker 1: a star, you can take it out of that and
• 21:17
  Speaker 1: bury it in a planet and you'll sit there for
• 21:19
  Speaker 1: billions of years. Top corks are not like that they're
• 21:21
  Speaker 1: not stable, so you make them in the early universe.
• 21:24
  Speaker 1: You can't then just find hunks of top corks lying
• 21:26
  Speaker 1: around all right. Well, then I guess maybe to extend
• 21:29
  Speaker 1: Carter's question, then, like if the universe couldn't make these
• 21:33
  Speaker 1: heavier particles besides the electron up and down corks, if
• 21:37
  Speaker 1: it was maybe impossible, or if they didn't exist with
• 21:40
  Speaker 1: the universe, Notice, would it be any different than it
• 21:43
  Speaker 1: is right now? Yeah? You might wonder like would the
• 21:45
  Speaker 1: only difference be for particle physicists creating these collisions at
• 21:48
  Speaker 1: the large adron collide or would anybody else? Notice would
• 21:51
  Speaker 1: the universe be any different? Well, apparently we don't sort
• 21:53
  Speaker 1: of need them to have the world around is right now, right,
• 21:55
  Speaker 1: because they don't exist right now right, You don't see
• 21:58
  Speaker 1: a lot of them around, So why we need them?
• 22:01
  Speaker 1: I guess it's probably Cardis's question. Yeah, so we actually
• 22:04
  Speaker 1: do need them. They do play a role, Like there's
• 22:07
  Speaker 1: not enough energy to make them actually exist, but virtual
• 22:10
  Speaker 1: versions of themselves can exist. They can like participate in
• 22:14
  Speaker 1: interactions even if they can't ever exist on their own,
• 22:18
  Speaker 1: And that's important because they do end up playing a role.
• 22:20
  Speaker 1: For example, the Higgs boson itself has a bunch of mass,
• 22:24
  Speaker 1: and that mass comes from interacting with not just the
• 22:27
  Speaker 1: particles that do exist, but all the particles that can
• 22:30
  Speaker 1: possibly exist. So if those other particles, the top cork
• 22:33
  Speaker 1: and the bottom cork, weren't on the menu, the Higgs
• 22:36
  Speaker 1: boson would have a very different mass and it would
• 22:39
  Speaker 1: behave differently, right, So that would change how everything operated,
• 22:42
  Speaker 1: well not just the Higgs, but basically every other particle
• 22:45
  Speaker 1: would weigh the same or have a different mass. Yeah,
• 22:48
  Speaker 1: it would change how the Higgs field is balanced, and
• 22:50
  Speaker 1: so that would change the mass of all of the particles.
• 22:52
  Speaker 1: And so it's a very sort of delicate Rube Goldberg machine,
• 22:55
  Speaker 1: you know, it all sort of hangs together in this
• 22:57
  Speaker 1: very complex way. It also it affect how the universe
• 23:01
  Speaker 1: had evolved from the very early stages. You know, we
• 23:04
  Speaker 1: think that in the very beginning of the universe, matter
• 23:07
  Speaker 1: and antimatter were made in the same proportions. Now, of course,
• 23:10
  Speaker 1: it's almost all matter. We don't understand very well why
• 23:13
  Speaker 1: that is, but the hints we have suggest that it
• 23:16
  Speaker 1: has to do with these other weird particles like strange
• 23:19
  Speaker 1: quirks and bottom quirks that they don't have symmetries that
• 23:22
  Speaker 1: there's a difference between particles made of strange quirks and
• 23:25
  Speaker 1: anti strange quirks, for example, that the universe prefers for
• 23:29
  Speaker 1: those to decay into matter rather than antimatter. It's not
• 23:32
  Speaker 1: something we've totally solved, but we think these other generations
• 23:34
  Speaker 1: play a big role in that. So they weren't around,
• 23:38
  Speaker 1: then there might just be a perfect balance between matter
• 23:40
  Speaker 1: and antimatter, which would have all just annihilated into photons
• 23:43
  Speaker 1: and the universe would just be light. There would be
• 23:45
  Speaker 1: no matter left over. It sounds like either way we
• 23:48
  Speaker 1: just all weigh a little less. We'd all be brighter too. Well,
• 23:53
  Speaker 1: all right, well, I think that answers Carter's question. Why
• 23:55
  Speaker 1: do particles other than the electron nutrina up and down quarks?
• 23:58
  Speaker 1: Is this we don't know, but definitely the universe would
• 24:01
  Speaker 1: be a lot different, And if they didn't exist, we
• 24:04
  Speaker 1: probably wouldn't be around to ask this question. That's right.
• 24:07
  Speaker 1: But maybe one day we will peer inside the electron
• 24:09
  Speaker 1: in the cork and we will understand why they exist
• 24:12
  Speaker 1: and why their cousins exist. So future generations of podcast
• 24:16
  Speaker 1: listeners might be asking questions about why those little squiggles
• 24:20
  Speaker 1: and squaggles again. It could be Carter. He could become
• 24:23
  Speaker 1: a particle physicist. Do it, Carter? His parents are going, no,
• 24:27
  Speaker 1: what have you done? I bet they prefer a particle
• 24:30
  Speaker 1: physicists to a cartoonist. I mean, some cartoonists are pretty rich.
• 24:33
  Speaker 1: I don't know any of them, but I hear some
• 24:35
  Speaker 1: of them are pretty rich. Yeah, we'll have Mac Crowning
• 24:38
  Speaker 1: on the podcast. All right, well, awesome questions. Thank you, Carter.
• 24:41
  Speaker 1: So let's get to some of our other questions about
• 24:43
  Speaker 1: particles from listeners. But first let's take a quick break.
• 24:58
  Speaker 1: All right, we're answering this and her questions, and today's
• 25:01
  Speaker 1: theme is particles and mass and little tiny things in
• 25:04
  Speaker 1: the universe. We're drilling down to the core questions about
• 25:08
  Speaker 1: the universe, like how do you pronounce Matt Groening's name anyway?
• 25:12
  Speaker 1: Groaning graining. I've never interested. And so our next question
• 25:15
  Speaker 1: comes from Ricky from New Zealand. Hi, guys, my name
• 25:18
  Speaker 1: is Rookie from New Zealand. I've been listening to the
• 25:21
  Speaker 1: podcast for a few months and they're really enjoying it.
• 25:23
  Speaker 1: So I think seems that I have a question about light.
• 25:26
  Speaker 1: I was wondering how it would have affected the growth
• 25:30
  Speaker 1: of the universe and how it would affect our everyday
• 25:34
  Speaker 1: life now if light had any form of mass to it.
• 25:38
  Speaker 1: I think you great question, Thank you, Ricky. I think
• 25:41
  Speaker 1: his question is how would the universe be different if
• 25:44
  Speaker 1: light had mass? And I guess specifically, like, how would
• 25:48
  Speaker 1: it have developed differently and how would it be different
• 25:51
  Speaker 1: for us today if it had mass. Yes, this is
• 25:54
  Speaker 1: a super fun question, and it led me down a
• 25:56
  Speaker 1: little rabbit hole of reading thinking about why is it
• 25:59
  Speaker 1: any way that the photon has no mass? And do
• 26:02
  Speaker 1: we actually know that the photon has no mass? What? Okay?
• 26:07
  Speaker 1: First of all, most people think the photon or light
• 26:10
  Speaker 1: has no mass. That's right, And in our current theory
• 26:13
  Speaker 1: it has no mass, like the standard model of particle
• 26:15
  Speaker 1: physics assigns it to be exactly zero mass. But that's
• 26:19
  Speaker 1: the theoretical description, right. You can also go out in
• 26:21
  Speaker 1: the universe and you can ask, well, can we measure
• 26:24
  Speaker 1: the mass of light? Can we do experiments to tell
• 26:26
  Speaker 1: us whether light has any mass? And you know, experiments
• 26:30
  Speaker 1: are always a little bit fuzzy, and there's always statistical
• 26:33
  Speaker 1: fluctuations or a limit to your sensitivity and So a
• 26:37
  Speaker 1: really fine question to ask is like, well, how do
• 26:39
  Speaker 1: we know that light has no mass? Interesting, nobody's trying
• 26:42
  Speaker 1: to weigh it, I guess, But isn't it impossible for
• 26:45
  Speaker 1: light to have mass? Like then it can go as
• 26:48
  Speaker 1: fast as the speed of light. Right, then you would
• 26:50
  Speaker 1: have to change the name of the speed of light. Yeah,
• 26:52
  Speaker 1: that's right. If light had mass, then it wouldn't act
• 26:55
  Speaker 1: the way we describe it. You know, all the properties
• 26:58
  Speaker 1: we talk about for light, that it moves at the
• 27:00
  Speaker 1: maximum speed of the universe, that it can't have a
• 27:02
  Speaker 1: rest frame. All of these things require it to not
• 27:05
  Speaker 1: have mass. That doesn't mean that it doesn't have mass, right,
• 27:09
  Speaker 1: that's just like our description of the universe as light
• 27:12
  Speaker 1: with zero mass in it. You can also ask the
• 27:14
  Speaker 1: question like, does our description of the universe require light
• 27:17
  Speaker 1: to have zero mass? Could you have a universe where
• 27:20
  Speaker 1: light does have mass? Is it necessary, as we were
• 27:23
  Speaker 1: talking about earlier, for light to have no mass or
• 27:26
  Speaker 1: why does our universe give mass? No light? But I
• 27:31
  Speaker 1: thought in our theories that if something had mass and
• 27:34
  Speaker 1: if it was going at the speed of light, it
• 27:36
  Speaker 1: would need infinite energy. That's right, So if light has mass,
• 27:40
  Speaker 1: then it wouldn't be moving at the maximum speed of
• 27:42
  Speaker 1: the universe, what we're currently calling the speed of light.
• 27:46
  Speaker 1: But you can devise theories of the universe where light
• 27:48
  Speaker 1: does have mass and then doesn't move at that maximum speed. Oh,
• 27:53
  Speaker 1: we could have a universe where there was a maximum speed,
• 27:56
  Speaker 1: but light wouldn't move at that speed exactly like you
• 27:58
  Speaker 1: can just give mass to light and the universe would
• 28:01
  Speaker 1: still work. Yeah. In fact, we don't even really know
• 28:04
  Speaker 1: why our universe doesn't give any mass to light. You know,
• 28:08
  Speaker 1: the mass of the other particles, like the W and
• 28:10
  Speaker 1: the Z. These come from the Higgs boson, But the
• 28:13
  Speaker 1: W and the Z are really very very similar to
• 28:16
  Speaker 1: the photon, and in the very early universe they all
• 28:19
  Speaker 1: had no mass. And then the Higgs field settled into
• 28:22
  Speaker 1: its weird value and it gave mass to the W
• 28:25
  Speaker 1: and to the Z and zero to the photon. You
• 28:28
  Speaker 1: might ask like, why zero. Well, the answer is, we
• 28:31
  Speaker 1: don't know. It's sort of unexplained. It could have given
• 28:34
  Speaker 1: some mass to the photon, but it didn't, and if
• 28:37
  Speaker 1: it had, then our universe would be a little bit different.
• 28:40
  Speaker 1: But we don't know why the Higgs boson gives the
• 28:42
  Speaker 1: photon zero mass. It doesn't have to. It's like a parameter.
• 28:46
  Speaker 1: We seem to be at or very near zero for
• 28:48
  Speaker 1: the photons mass, but it could have been different. Is
• 28:52
  Speaker 1: it that the Higgs field just ignores the photon, like
• 28:55
  Speaker 1: it just doesn't interact with it, or it doesn't interact.
• 28:58
  Speaker 1: It's just the signs of value of zero mass to it.
• 29:00
  Speaker 1: It definitely interacts with it. You know, the photon is
• 29:02
  Speaker 1: part of the electroweak theory where you can bind electromagnetism
• 29:06
  Speaker 1: where the photon operates, and the weak force where you
• 29:09
  Speaker 1: have the WS and disease. So in the early universe,
• 29:11
  Speaker 1: the photon, the two WS, and disease, they're like a
• 29:14
  Speaker 1: gang of four. They're all very related. They're part of
• 29:16
  Speaker 1: this larger group. And the Higgs comes along and it
• 29:19
  Speaker 1: picks three of the mountain says, you guys all get
• 29:21
  Speaker 1: a mass and photon you get none. And you're saying
• 29:23
  Speaker 1: that we don't actually know if light has zero math
• 29:26
  Speaker 1: like nobody has ever measured it. Where I guess we've
• 29:29
  Speaker 1: never measured that something can go faster than light. Would
• 29:32
  Speaker 1: that tell us that light has math? Like if we
• 29:34
  Speaker 1: ever measure something going faster than light, maybe that means
• 29:38
  Speaker 1: that the maximum of the universe is higher than the
• 29:40
  Speaker 1: speed of light, and light maybe has some mass exactly.
• 29:43
  Speaker 1: We have definitely tried to measure the mass of light,
• 29:46
  Speaker 1: and every experiment is consistent with light having no mass.
• 29:50
  Speaker 1: So you know, this is sort of a theoretical exercise.
• 29:52
  Speaker 1: The best description of the universe that we see around
• 29:54
  Speaker 1: us is one where light has no mass. Don't be
• 29:56
  Speaker 1: confused about that. We're not saying the light might have mass,
• 29:59
  Speaker 1: or we think it does have mass. We're just saying
• 30:02
  Speaker 1: there's not necessarily any a priori reason for it to
• 30:05
  Speaker 1: not have mass. But it's the best description of what
• 30:07
  Speaker 1: we see out there. And so we can do a
• 30:09
  Speaker 1: bunch of experiments to try to measure the mass of light.
• 30:12
  Speaker 1: And if light had a lot of mass, it would
• 30:14
  Speaker 1: be obvious, right, it would look very different, things would
• 30:16
  Speaker 1: travel faster than it. Right. The most sensitive experiment, the
• 30:20
  Speaker 1: best way to see if light has even a tiny
• 30:22
  Speaker 1: little bit of mass, is to look at the Sun's
• 30:25
  Speaker 1: magnetic field and how the solar wind moves through it.
• 30:29
  Speaker 1: Because remember, photons are part of the electromagnetic field, and
• 30:32
  Speaker 1: so if light had even a little bit of mass,
• 30:35
  Speaker 1: it would change how electromagnetic fields propagate through the universe.
• 30:39
  Speaker 1: There would be a little bit weaker if light had
• 30:41
  Speaker 1: a little bit of mass. So the Sun's magnetic field
• 30:43
  Speaker 1: is like the biggest electromagnetic effect in our neighborhood, and
• 30:47
  Speaker 1: so it's the most sensitive test. So by looking at
• 30:50
  Speaker 1: the Sun's magnetic field, we can tell that light if
• 30:53
  Speaker 1: it has any mass, it's an incredibly small value. I see.
• 30:57
  Speaker 1: I think you're saying that according to the state Rea's
• 31:00
  Speaker 1: light could have mass. But according to our measurements, we
• 31:04
  Speaker 1: think light has no mass exactly. There's a parameter in
• 31:06
  Speaker 1: the theory that could give mass to light. We set
• 31:09
  Speaker 1: that parameter to zero because that's the value that's most
• 31:12
  Speaker 1: consistent with all of the experiments. All of our descriptions
• 31:15
  Speaker 1: of the universe as we see today are consistent with
• 31:18
  Speaker 1: light having zero mass. All right, well, now let's get
• 31:20
  Speaker 1: to Ricky's question. How would the universe be different if
• 31:24
  Speaker 1: light had mass? So the universe would look pretty different,
• 31:27
  Speaker 1: But it depends on how much mass light had. You know,
• 31:31
  Speaker 1: if light had a lot of mass, then everything would
• 31:33
  Speaker 1: be very, very different because it would make the electromagnetic
• 31:37
  Speaker 1: force quite different. You know, the electromagnetic force is very powerful.
• 31:40
  Speaker 1: It is much more powerful than the weak force. But
• 31:43
  Speaker 1: that's because the photon has no mass and the weak
• 31:46
  Speaker 1: bosons do have mass. Wait, how does having mass make
• 31:49
  Speaker 1: the force weaker? Well, you know there's a connection between
• 31:51
  Speaker 1: these forces and the particles, right, So the electromagnetic force
• 31:55
  Speaker 1: comes from the photon. The photon is the thing that
• 31:57
  Speaker 1: does the job of the electromagnetic force. And so if
• 32:00
  Speaker 1: the photon was massive, it couldn't do his job as well.
• 32:03
  Speaker 1: It would move more slowly, it would cost more energy
• 32:06
  Speaker 1: to make it. This kind of stuff just like the
• 32:08
  Speaker 1: way the weak force does. Because the particles that transmit
• 32:11
  Speaker 1: the weak force, the W and Z particles, they're also heavy, right,
• 32:14
  Speaker 1: like when you get two magnets together, or like what
• 32:17
  Speaker 1: keeps your atoms together in your body is the electromagnetic force,
• 32:21
  Speaker 1: and so it's the photon is sort of like the
• 32:23
  Speaker 1: transmitter of that force, right, And so I guess if
• 32:27
  Speaker 1: that transmitter had mass, it would just be sluggish, right,
• 32:31
  Speaker 1: or it would sort of disappear more easily. Yeah, it
• 32:33
  Speaker 1: would be like shorter range, you know, it wouldn't have
• 32:36
  Speaker 1: as far an impact. Like the weak force right now
• 32:39
  Speaker 1: is basically like the electromagnetic force, but with heavy photons, right,
• 32:43
  Speaker 1: so what would happen if the photon had passed. Electromagnetism
• 32:47
  Speaker 1: would be a lot more like the weak force. It
• 32:48
  Speaker 1: would be much weaker, it would have shorter range. It's
• 32:52
  Speaker 1: like instead of email communications between people right now, we
• 32:54
  Speaker 1: would be back to like stone tablet kind of right,
• 32:58
  Speaker 1: like in the way that things communicate had a lot
• 33:00
  Speaker 1: of mass to them. Uh, you know, the society wouldn't
• 33:04
  Speaker 1: function as as quickly, right, Yeah, it would be very different.
• 33:08
  Speaker 1: And also light wouldn't be as long lived. Right If
• 33:10
  Speaker 1: lighthead mass, he could decay into other particles. Right now,
• 33:15
  Speaker 1: we're very privileged because the photon created billions of years
• 33:18
  Speaker 1: ago and super far away can travel through the universe
• 33:21
  Speaker 1: basically forever until it hits something like maybe it hits
• 33:24
  Speaker 1: the James web Space telescope and we get to see
• 33:26
  Speaker 1: a really old distant galaxy. That's because that photon is stable.
• 33:30
  Speaker 1: It's because the photon is massless. If the photon had mass,
• 33:34
  Speaker 1: then along the way he could like turn into other stuff.
• 33:36
  Speaker 1: It could decay into lighter particles depending on how much
• 33:40
  Speaker 1: mass it had, and so the universe wouldn't be as visible.
• 33:43
  Speaker 1: M Like if I sent you a stone tablet email
• 33:46
  Speaker 1: it might break along the way, or most likely will
• 33:48
  Speaker 1: break along the way, right, almost certainly, Yeah, ZS and
• 33:53
  Speaker 1: w's created by distant galaxies don't get here. They turn
• 33:56
  Speaker 1: into other stuff and fizzle out, and so we don't
• 33:59
  Speaker 1: see them. We see photons from those galaxies because they're massless,
• 34:02
  Speaker 1: because they're stable, so they can fly forever. All right,
• 34:05
  Speaker 1: I'll cancele my news startup idea stone mail. It's probably
• 34:10
  Speaker 1: very secure though, right do encrypted is in cuneiform, and
• 34:13
  Speaker 1: I think it probably doesn't rock alright. So then if
• 34:18
  Speaker 1: if the light had mass, then the electromagnetic force would
• 34:22
  Speaker 1: be a lot weaker, shorter range. How would that affect
• 34:25
  Speaker 1: the universe? Well, first of all, you can do really
• 34:27
  Speaker 1: fun experiments in that case, because you could like catch
• 34:29
  Speaker 1: up to photons. You could be in their reference frame.
• 34:33
  Speaker 1: You could have photons that are at rest. You could
• 34:35
  Speaker 1: like have a pile of photons. You know, we don't
• 34:38
  Speaker 1: know what a photon looks like right now. A photon
• 34:42
  Speaker 1: you only see it if it hits your eye. Photon
• 34:44
  Speaker 1: passing by you, you can't see, right, You can't ever
• 34:47
  Speaker 1: catch up to a photon. But if photons had mass,
• 34:50
  Speaker 1: then they could be at rest and so you could
• 34:52
  Speaker 1: like hang out with a photon, So that would be
• 34:55
  Speaker 1: pretty different. You know, nes like us who are curious
• 34:57
  Speaker 1: about what particles are like quite differ. Well, although can
• 35:00
  Speaker 1: we do we know what an electron looks like? What
• 35:03
  Speaker 1: does an electron look like? What does an electron look like?
• 35:05
  Speaker 1: You know, whatever it does to a photon that bounces
• 35:07
  Speaker 1: off of it. So, yeah, you have to probe these
• 35:09
  Speaker 1: things with something. So what would you probe light with
• 35:13
  Speaker 1: more light? You could probe it with electrons. You could
• 35:15
  Speaker 1: use a scanning electron microscope to look at photons at rest. Interesting,
• 35:19
  Speaker 1: all right, so we could maybe get a closer look
• 35:22
  Speaker 1: at light if it was moving slower because it had mass.
• 35:25
  Speaker 1: How else would things to be different? What Ricky was
• 35:27
  Speaker 1: also asking about how it would affect the evolution of
• 35:29
  Speaker 1: the universe. You know, we know that very early on
• 35:33
  Speaker 1: in the universe there was this plasma of all sorts
• 35:35
  Speaker 1: of crazy goop. There were photons, there are particles, there
• 35:38
  Speaker 1: was dark matter and all it was sort of oscillating
• 35:40
  Speaker 1: back and forth and slashing in and out and made
• 35:43
  Speaker 1: all of these acoustic ripples. And the rate of those
• 35:46
  Speaker 1: ripples and how things were slashing back and forth depend
• 35:49
  Speaker 1: on the fraction of dark matter and normal matter and photons,
• 35:53
  Speaker 1: and so that would all be different if photons had mass,
• 35:56
  Speaker 1: because it would affect the gravity of that situation, and
• 35:59
  Speaker 1: so it would affect how those things are slashing. And
• 36:01
  Speaker 1: that slashing is very important because it ends up controlling
• 36:04
  Speaker 1: where the dark matter pooled together, which turns out to
• 36:07
  Speaker 1: influence how galaxies form. So the whole structure of the
• 36:10
  Speaker 1: universe could be very different if you tweak those initial
• 36:13
  Speaker 1: ingredients even a little bit. Well, how would the start
• 36:16
  Speaker 1: to be different, Like would we be more dark matter
• 36:19
  Speaker 1: ish or would mass? Would we have black holes earlier?
• 36:24
  Speaker 1: You know what would be different about how it looks.
• 36:26
  Speaker 1: So part of this slashing has to do with dark
• 36:29
  Speaker 1: matter pulling things in and then photons pushing things back out.
• 36:32
  Speaker 1: That's why we get these like ripples, these oscillations, and
• 36:36
  Speaker 1: so photons aren't as powerful if they have mass. If
• 36:39
  Speaker 1: they contribute to pulling things in rather than pushing things out,
• 36:43
  Speaker 1: then things would oscillate differently. And those oscillations are were
• 36:46
  Speaker 1: caused sort of the pattern of galaxies that we see today,
• 36:49
  Speaker 1: And so we'd have galaxies that like different distances from
• 36:52
  Speaker 1: each other right now, because those oscillations are were caused
• 36:55
  Speaker 1: galaxies to form like here and not there, and so
• 36:58
  Speaker 1: the overall large structure of the galaxies would definitely be different.
• 37:02
  Speaker 1: You might also get different size pools of dark matter,
• 37:06
  Speaker 1: which would make different size galaxies. But I have to
• 37:08
  Speaker 1: like run a bunch of really complicated stimulations to know
• 37:11
  Speaker 1: for sure. I see, like maybe the universe would be
• 37:14
  Speaker 1: good clustered together more, or maybe it might be sparser
• 37:17
  Speaker 1: or something like that. It's all very very delicate recipe,
• 37:21
  Speaker 1: you know, sort of like a souffle. You change the
• 37:23
  Speaker 1: ingredients a very small amount and it can come out
• 37:26
  Speaker 1: quite different. That's why I don't like baking or cooking,
• 37:29
  Speaker 1: just stressful. Well, I'm glad you weren't in charge of
• 37:33
  Speaker 1: baking the universe. Yeah, you don't want to be in
• 37:35
  Speaker 1: charge of baking anything much less everything everything. But I guess,
• 37:41
  Speaker 1: you know, being selfish, how would it affect me of
• 37:43
  Speaker 1: lighthead mass? Right? Because I think the electromagnetic force really
• 37:46
  Speaker 1: basically controls everything about me, right, Like, it's not just
• 37:49
  Speaker 1: magnets and light, it's also like chemical bonds, and why
• 37:53
  Speaker 1: even the electrons sticks to the nucleus of an atom,
• 37:56
  Speaker 1: and why atoms stick together. All. It's all because of photons, right,
• 38:00
  Speaker 1: and the electromagnetic force. Chemistry is basically just the dance
• 38:04
  Speaker 1: of electrons and photons, right as those charges make atoms stable,
• 38:08
  Speaker 1: and then those atoms formed together to make molecules and
• 38:11
  Speaker 1: all sorts of chemistry of life. And so you're really
• 38:13
  Speaker 1: changing the very basic rules of those structures. You know,
• 38:16
  Speaker 1: It's like you're taking away some of the crucial lego
• 38:19
  Speaker 1: pieces for building things and you're replacing them with something else,
• 38:22
  Speaker 1: something much much weaker. And so it might be that,
• 38:25
  Speaker 1: you know, you just can't get atoms as stable with energy.
• 38:28
  Speaker 1: Levels of atoms would definitely be different, which would lead
• 38:30
  Speaker 1: to totally different chemistry, and it might also be interesting,
• 38:34
  Speaker 1: It might also be delicious, but it would definitely be
• 38:36
  Speaker 1: unrecognizable from our world. Well, I think maybe a cool
• 38:41
  Speaker 1: question to ask is, like, what if I had to
• 38:43
  Speaker 1: switch in front of me that had like, uh, the
• 38:45
  Speaker 1: mass with the photon, and I just said, hey, don't
• 38:47
  Speaker 1: touch it, don't touch it. Yeah, that's what I mean. Like,
• 38:51
  Speaker 1: what if suddenly we had the world we have right now,
• 38:54
  Speaker 1: but all of a sudden the photon had masks, but
• 38:56
  Speaker 1: we all just kind of like dissolve explode, you know,
• 39:00
  Speaker 1: trying too much. What do you think? I think we
• 39:02
  Speaker 1: were probably just sort of like drift off into a gas.
• 39:04
  Speaker 1: You know. I think that a lot of our bodily
• 39:06
  Speaker 1: consistency depends on all these bonds holding themselves together, and
• 39:09
  Speaker 1: those bonds suddenly get weaker by a significant amount than Yeah,
• 39:13
  Speaker 1: you basically just like sublimate into a gas. You mean,
• 39:16
  Speaker 1: like in the Avengers and Finny War, like, we just
• 39:19
  Speaker 1: all turned to ash. Yes, maybe that's how Fanas did it. Yeah,
• 39:23
  Speaker 1: maybe that's how it did it. Yeah, that's how he
• 39:26
  Speaker 1: did it. Oh, man, you knew he was a particle physicist, right,
• 39:30
  Speaker 1: he had that evil gleam in his eye. That's right,
• 39:34
  Speaker 1: that's how it works. You snapped your fingers and you
• 39:36
  Speaker 1: can change the universe. That's that's what physics gives you
• 39:39
  Speaker 1: the power to do. Yeah. And so we think that
• 39:41
  Speaker 1: our photons probably have zero mass. If they do have mass,
• 39:45
  Speaker 1: it's something smaller than ten to the twenty six of
• 39:47
  Speaker 1: the mass of the electron. Right, So it's a very
• 39:50
  Speaker 1: very very small value. But we can't actually say for
• 39:52
  Speaker 1: sure it's zero, and the theory would allow for it
• 39:55
  Speaker 1: to be non zero. Interesting, but I guess if it
• 39:59
  Speaker 1: did have a little bit of man as, everything might
• 40:01
  Speaker 1: be okay because we're still here. Yeah, you could have
• 40:03
  Speaker 1: like almost zero, very very close to zero, like zero
• 40:07
  Speaker 1: point zero, and then a hundred zeros and then a one,
• 40:09
  Speaker 1: and the universe wouldn't be very different. We wouldn't be
• 40:12
  Speaker 1: able to tell the difference. All right, Well, I think
• 40:14
  Speaker 1: that answer is Ricky's question. The universe would be pretty
• 40:18
  Speaker 1: different depending on how much mass the photon would have
• 40:21
  Speaker 1: in this scenario. If we had a lot of mass
• 40:23
  Speaker 1: um this would be super duper different and not the same.
• 40:28
  Speaker 1: But maybe it has a little bit of mass, it
• 40:29
  Speaker 1: would still be okay and we would still be here.
• 40:32
  Speaker 1: And so Ricky, please don't build a device that gives
• 40:35
  Speaker 1: photons in the universe mass, or if you do, don't
• 40:37
  Speaker 1: press the button. That's right, dude, don't put on the
• 40:39
  Speaker 1: Infinity Gauntlet. Leave it where it is, or at least
• 40:43
  Speaker 1: take out the physics stone, because that's the that's the
• 40:45
  Speaker 1: one that causes all the trouble. All right, Well, let's
• 40:47
  Speaker 1: get to our last question about virtual particles. But first
• 40:51
  Speaker 1: let's take another quick break. All right, we're taking listener
• 41:07
  Speaker 1: questions about particles in this episode, and our last question
• 41:11
  Speaker 1: comes from Anthony, who is a question about virtual particles. Hello,
• 41:16
  Speaker 1: Daniel and Jorge. Ever since I heard your episode on
• 41:19
  Speaker 1: virtual particles recorded back in I've had a question in
• 41:23
  Speaker 1: the back of my mind from your explanations on the subject.
• 41:26
  Speaker 1: I've understood that virtual particles are ephemeral and they don't
• 41:29
  Speaker 1: last long, and that their mass may fluctuate. But that
• 41:33
  Speaker 1: still means that at any given point in time there
• 41:35
  Speaker 1: must be myriad virtual particles in the universe. Someone must
• 41:39
  Speaker 1: have surely estimated their combined mass. What does it add
• 41:42
  Speaker 1: up to. Does the mass of all the virtual particles
• 41:45
  Speaker 1: in the universe get counted as ordinary matter? And if not,
• 41:49
  Speaker 1: could it account for the elusive dark matter or some
• 41:52
  Speaker 1: portion thereof Thank you alright, awesome question from Anthony about
• 41:57
  Speaker 1: virtual particles and possibly as an explanation of dark matter.
• 42:02
  Speaker 1: Do you think he's cracked the big mystery? No, you
• 42:06
  Speaker 1: could have been a little genter there. Sometimes you just
• 42:10
  Speaker 1: got to give a clear and chris answer. Oh man,
• 42:14
  Speaker 1: I don't think that dark matter has made out a
• 42:17
  Speaker 1: virtual part of Well, I'm still reading for your Anthony.
• 42:19
  Speaker 1: Need to worry. We'll try to make it work here
• 42:22
  Speaker 1: on the podcast. You know, you gotta understand how often
• 42:24
  Speaker 1: people write to me and say, oh, by the way,
• 42:27
  Speaker 1: I don't really understand ABC, and could that be the
• 42:30
  Speaker 1: dark matter? It's just basically like the end of almost
• 42:33
  Speaker 1: every question we get, really, well, maybe one of them
• 42:35
  Speaker 1: might be true one day, Yeah, they might. Absolutely, isn't
• 42:38
  Speaker 1: that possible? Absolutely, And encourage people to keep thinking about
• 42:40
  Speaker 1: it because someday somebody will figure it out. Hey, Daniel,
• 42:43
  Speaker 1: I don't understand pink hamsters. Could that be the cost
• 42:46
  Speaker 1: of dark matter in the universe? No, man, you're like
• 42:52
  Speaker 1: the Simon Cowell here of physics today. Harsh, harsh, people
• 42:56
  Speaker 1: want answers. All right, So the question was about virtual
• 42:59
  Speaker 1: part articles and whether maybe physicists have forgotten to take
• 43:04
  Speaker 1: into account their mass and their effect in the universe.
• 43:07
  Speaker 1: So step us through what is a virtual particle? First
• 43:10
  Speaker 1: of all, so a virtual particle is shocker, sort of
• 43:13
  Speaker 1: badly named. It's not really a particle in the way
• 43:16
  Speaker 1: that we are thinking about particles. You know, what is
• 43:20
  Speaker 1: a particle? A particle is like a wiggle in a field.
• 43:24
  Speaker 1: So the electron, for example, is a wiggle in the
• 43:27
  Speaker 1: electron field is a field for every particle that's out there.
• 43:31
  Speaker 1: The electron field, the upcork field, the down cork field,
• 43:33
  Speaker 1: the electromagnetic field. All these things are fields, and they
• 43:37
  Speaker 1: can wiggle in this interesting and particular way. We have
• 43:39
  Speaker 1: like a little packet of energy which is self sustaining
• 43:42
  Speaker 1: and moves through the field the way you can take,
• 43:45
  Speaker 1: for example, a rope and you can tweak it so
• 43:47
  Speaker 1: that you have like a standing way which moves down
• 43:50
  Speaker 1: the rope. Right. So particles are these sort of special
• 43:53
  Speaker 1: oscillations of these fields in a way that lets them
• 43:56
  Speaker 1: like move through the field. So that's what a particle is.
• 44:00
  Speaker 1: I see, there's sort of like a wiggle that doesn't
• 44:03
  Speaker 1: just dissipate in the in a quantum field in the universe.
• 44:06
  Speaker 1: Do we know why some wiggles stay around and some
• 44:09
  Speaker 1: wiggles don't. So we have this whole episode recently about
• 44:12
  Speaker 1: what is a particle and it gets kind of philosophical
• 44:15
  Speaker 1: and of some folks think that particles are just these
• 44:18
  Speaker 1: wiggles in fields, and the ones we define to be
• 44:20
  Speaker 1: particles are the ones that do stay around, right, that
• 44:24
  Speaker 1: they have this capacity for the energy to slide around
• 44:27
  Speaker 1: in this particular way. So the way the energy moves
• 44:30
  Speaker 1: through these fields is governed by the wave equation, just
• 44:33
  Speaker 1: like with any other kind of wave, right like in
• 44:36
  Speaker 1: the water or on a string. This is mathematical equation
• 44:39
  Speaker 1: that tells you what are the possible solutions. And there
• 44:42
  Speaker 1: are some solutions to those equations that are self sustaining,
• 44:46
  Speaker 1: you know that where the energy just flows in this
• 44:48
  Speaker 1: particular way so it maintains itself, it doesn't spread out, right,
• 44:51
  Speaker 1: I'm thinking maybe like the if you think about a
• 44:54
  Speaker 1: field a quantum fields, like a big sheet that you have,
• 44:57
  Speaker 1: maybe and if you have it out there in the
• 45:00
  Speaker 1: win and kind of holding it up, the wind will
• 45:03
  Speaker 1: make it kind of ripple all over the place. But
• 45:04
  Speaker 1: every once in a while you might see like a
• 45:06
  Speaker 1: little like a bump in that sheet that tend to
• 45:10
  Speaker 1: forms and then can move it across the sheet. That's
• 45:12
  Speaker 1: kind of what a particle is, right m And so
• 45:15
  Speaker 1: any situation where you have a self sustaining wave that
• 45:18
  Speaker 1: moves across and sort of keeps its coherence, that's what
• 45:21
  Speaker 1: you call a particle. And if it does that, then
• 45:24
  Speaker 1: it has special properties, like you can talk about it
• 45:26
  Speaker 1: having a certain mass because it has motion, and you
• 45:29
  Speaker 1: can describe the motion, you know, in terms of like
• 45:32
  Speaker 1: a force having been applied and getting acceleration, and so
• 45:35
  Speaker 1: there's a concept of mass of this particle has all
• 45:37
  Speaker 1: sorts of properties that we tend to attribute to the
• 45:40
  Speaker 1: kind of stuff we find. Familiar things around us have mass,
• 45:44
  Speaker 1: So these ripples in these fields have these properties, like
• 45:46
  Speaker 1: a specific mass which is related to their energy, etcetera, etcetera,
• 45:49
  Speaker 1: all the things we tend to think of as particles.
• 45:52
  Speaker 1: So that's what a particle is. A virtual particle is
• 45:55
  Speaker 1: something different. A virtual particle is like a different kind
• 45:58
  Speaker 1: of wiggle in this field. It's one that's not self sustaining.
• 46:02
  Speaker 1: It's usually caused by the presence of other particles. For example,
• 46:07
  Speaker 1: an electron is a self sustaining wiggle in the electron field,
• 46:11
  Speaker 1: but it creates wiggles in the electromagnetic field, right because
• 46:14
  Speaker 1: electrons have charge, and that's what it means to have charge,
• 46:18
  Speaker 1: is that you create wiggles in the electromagnetic field. So
• 46:21
  Speaker 1: an electron whizzing around the universe is making ripples in
• 46:25
  Speaker 1: the electromagnetic fields around us, which means in some sense,
• 46:29
  Speaker 1: it's making virtual particles in that field, which we call
• 46:33
  Speaker 1: virtual photons. So virtual particles are like non self sustaining
• 46:38
  Speaker 1: ripples in a field mostly caused by the presence of
• 46:41
  Speaker 1: other particles. Wait what Okay, First of all, you're saying
• 46:46
  Speaker 1: that an electron can cause a ripple in the photon
• 46:50
  Speaker 1: field that is not a photon, but it does create photons, right,
• 46:54
  Speaker 1: like the presence of an electron talking to maybe another
• 46:57
  Speaker 1: electron does create ripples in the electromagnetic field, which we
• 47:01
  Speaker 1: call photons. But you're saying you can also make ripples
• 47:04
  Speaker 1: that are not photons. You can make ripples that are
• 47:07
  Speaker 1: real photons, Like an electron can radiate a photon which
• 47:10
  Speaker 1: you could hit your eyeball and you can see it.
• 47:12
  Speaker 1: It's a real photon, propagates through the universe with what
• 47:15
  Speaker 1: we think is zero mass and follows all those rules.
• 47:18
  Speaker 1: Electrons can also create all sorts of other ripples in
• 47:21
  Speaker 1: the electromagnetic field, you know, just sort of like sloshy,
• 47:24
  Speaker 1: messy ripples that don't coalesce to be a self sustaining packet.
• 47:28
  Speaker 1: And we call all those ripples virtual particles. It would
• 47:31
  Speaker 1: have been better if we've given them a different name,
• 47:33
  Speaker 1: because there really are sort of different category of thing,
• 47:36
  Speaker 1: but some people think of them as all part of
• 47:38
  Speaker 1: a larger spectrum of phenomenon. So they call these real
• 47:41
  Speaker 1: particles versus virtual particles. I see, and I guess the
• 47:44
  Speaker 1: big difference is that virtual particles don't last or something. Right,
• 47:48
  Speaker 1: They're not sort of cohesive packages like the regular particles
• 47:51
  Speaker 1: they are. They are ripples in the quantum fields. But
• 47:54
  Speaker 1: maybe there are sort of like like messy ripples, like
• 47:58
  Speaker 1: just the little tiny random fluctuations. Yeah, they don't last.
• 48:01
  Speaker 1: They dissipate, They tend to spread out, and if the
• 48:04
  Speaker 1: source of them disappears, then they disappear. But doesn't take
• 48:07
  Speaker 1: energy to make them. It does take energy absolutely, and
• 48:10
  Speaker 1: so the source of them is putting some energy from
• 48:12
  Speaker 1: its field into the target field. So, for example, electrons
• 48:16
  Speaker 1: do give up energy into virtual photons, right, Those virtual
• 48:20
  Speaker 1: photons capture some of that energy, right, But then they
• 48:22
  Speaker 1: turn into other stuff. Those virtual photons turned into other fields.
• 48:25
  Speaker 1: So just slashes through the universe. It's not in a coherent,
• 48:29
  Speaker 1: self sustaining packet. Wait what so then an electron flying
• 48:32
  Speaker 1: through the universe will eventually slow down. Well, an electron
• 48:35
  Speaker 1: to transmit any energy into the photon field, it has
• 48:37
  Speaker 1: to decelerate or accelerate as to change its energy, so
• 48:41
  Speaker 1: it would slow down. But electron just flying constant velocity
• 48:44
  Speaker 1: doesn't slow down and doesn't create any virtual photons. Only
• 48:47
  Speaker 1: when it accelerates does it create any real or virtual photons.
• 48:51
  Speaker 1: That's when it changes the electromagnetic field. Flying with constant
• 48:55
  Speaker 1: velocity doesn't change in the field. But I guess maybe
• 48:58
  Speaker 1: they take away talking about these pacific is that a
• 49:00
  Speaker 1: virtual particle is just like the random wiggle in the
• 49:03
  Speaker 1: quantum fields. Right, well, it's a little bit different than
• 49:06
  Speaker 1: maybe I wonder if Anthony is maybe thinking of maybe
• 49:09
  Speaker 1: a different kind of virtual particle. Like they say that
• 49:11
  Speaker 1: when a particles sort of exist, there's also like other
• 49:16
  Speaker 1: particles popping in and out around it, right, isn't it.
• 49:19
  Speaker 1: Isn't that something they also call virtual particles, Like when
• 49:21
  Speaker 1: you calculate the massive a particle, you have to calculate
• 49:24
  Speaker 1: all of the possible particles and maybe popping in and
• 49:27
  Speaker 1: out of existence around it too. Yeah. Yeah, And so
• 49:30
  Speaker 1: you could ignore virtual particles completely and you could say, look,
• 49:33
  Speaker 1: it's just particles and there are fields, and instead of
• 49:37
  Speaker 1: thinking about virtual particles, you just think about the fields.
• 49:39
  Speaker 1: Like when the electron moves through the universe, it's interacting
• 49:42
  Speaker 1: with the photon field, and don't try to call those
• 49:44
  Speaker 1: things particles. Just think about them as fields. And so
• 49:46
  Speaker 1: what you were just talking about is how particles interact
• 49:49
  Speaker 1: with the fields that are around them. Like we were
• 49:51
  Speaker 1: saying earlier, the fact that the top corks can exist
• 49:54
  Speaker 1: changes how Higgs bosons moved through the universe because they
• 49:57
  Speaker 1: talked to virtual top corks. Or another way to say
• 50:00
  Speaker 1: that is that they interact with the top cork field
• 50:03
  Speaker 1: that is out there in the universe, even if there
• 50:06
  Speaker 1: are no real top corks existing in the universe. So
• 50:09
  Speaker 1: every bit of space is filled with these quantum fields,
• 50:13
  Speaker 1: and those fields the top cork field. The field is
• 50:15
  Speaker 1: there even if there are no top corks in it, right,
• 50:18
  Speaker 1: And so the electron field is there even if there
• 50:21
  Speaker 1: are no electrons in it. So the universe is filled
• 50:23
  Speaker 1: with these fields, which you could also call virtual particles, right.
• 50:27
  Speaker 1: You could think of these fields is just like a
• 50:29
  Speaker 1: swarm of very low energy virtual particles. It's sort of
• 50:32
  Speaker 1: mathematically equivalent, whether you think about them in terms of
• 50:35
  Speaker 1: the fields or some over lots and lots of virtual particles. Okay,
• 50:39
  Speaker 1: but I think that maybe the takeaway is that we
• 50:41
  Speaker 1: have quantum fields out there and they do wiggle maybe
• 50:44
  Speaker 1: and sometimes not in super permanent particle ways. They do
• 50:49
  Speaker 1: sort of wiggle which maybe have energy in their wiggles.
• 50:52
  Speaker 1: And so I think maybe Anthony is asking, like, you know,
• 50:55
  Speaker 1: there are all these fields out there, they're wiggling and
• 50:57
  Speaker 1: have energy, um doesn't maybe add mass to the universe
• 51:01
  Speaker 1: because energy in a field is sort of like having
• 51:05
  Speaker 1: mass and the universes, and like, what's the relationship between
• 51:08
  Speaker 1: these wiggles and do they actually have mass? It's a
• 51:12
  Speaker 1: great question, right, And so you can think about empty
• 51:14
  Speaker 1: space and what's going on there, and there are these
• 51:16
  Speaker 1: fields which you can all think about. Is like particles. Now,
• 51:19
  Speaker 1: do virtual particles have mass? You know, particles themselves have
• 51:23
  Speaker 1: a specific mass because of the way they move through
• 51:25
  Speaker 1: the universe. Virtual particles don't really have a well defined mass,
• 51:29
  Speaker 1: But do they have mass? If you want to think
• 51:31
  Speaker 1: about them in terms of the particle framework, then they
• 51:33
  Speaker 1: can have mass, and those masses can be any value.
• 51:36
  Speaker 1: You know, you can have virtual photons that have a
• 51:39
  Speaker 1: huge amount of mass. You can have virtual topquorks with
• 51:42
  Speaker 1: a very tiny amount of mass, but those only really
• 51:44
  Speaker 1: exist in our calculations. Virtual particles are not things you
• 51:47
  Speaker 1: can ever see or observe they're only like the way
• 51:51
  Speaker 1: other particles talk to each other, which I think is
• 51:53
  Speaker 1: why it's maybe more natural to think about them instead.
• 51:55
  Speaker 1: And just in terms of fields, they're just really the
• 51:57
  Speaker 1: way that two particles talk to each other. But technically, mathematically,
• 52:01
  Speaker 1: these particles do have mass, but you can never observe
• 52:04
  Speaker 1: these particles. You can never interact with them. You can
• 52:06
  Speaker 1: only interact with real particles, not with virtual particles. But
• 52:10
  Speaker 1: isn't But I guess we were calling virtual particles wiggles
• 52:13
  Speaker 1: in these these fields, right, So the universe has fields,
• 52:16
  Speaker 1: there are random non particle wiggles in them, and so
• 52:20
  Speaker 1: maybe Anthony's wondering, like, do these random wiggles have mass,
• 52:23
  Speaker 1: and could that mass maybe account for dark matter? These
• 52:26
  Speaker 1: random wiggles do have energy, right, And all the fields
• 52:28
  Speaker 1: that are out there in the universe have energy because
• 52:30
  Speaker 1: quantum fields can never be at zero. That's why we
• 52:33
  Speaker 1: talk of sometimes about virtual particles popping out of the vacuum,
• 52:36
  Speaker 1: because there isn't really zero energy vacuum out there. There's
• 52:40
  Speaker 1: energy out there, but mostly it's potential energy. These fields
• 52:43
  Speaker 1: have non zero potential energy, and potential energy actually has
• 52:47
  Speaker 1: the opposite effect of mass. Potential energy can create a
• 52:51
  Speaker 1: repulsive force in the universe. It contributes, for example, potentially
• 52:55
  Speaker 1: to the dark energy of the universe. So Anthony's onto something.
• 52:59
  Speaker 1: He's just maybe the wrong dark gossip here. Is that
• 53:02
  Speaker 1: what you're saying, Yeah, and we know the universe is accelerating,
• 53:05
  Speaker 1: and one way to describe that acceleration is to say,
• 53:08
  Speaker 1: maybe the universe is filled with a bunch of potential
• 53:10
  Speaker 1: energy that's causing that. Because in general relativity, if your
• 53:14
  Speaker 1: space is filled with a field with potential energy that
• 53:18
  Speaker 1: can cause repulsion, might explain inflation the early universe, It
• 53:21
  Speaker 1: might explain dark energy. Problem is that if we look
• 53:24
  Speaker 1: out into the universe and measure the potential energy of
• 53:27
  Speaker 1: all the fields we think are out there, it doesn't
• 53:29
  Speaker 1: explain the dark energy that we see. So we have
• 53:33
  Speaker 1: accounted for the potential energy of the fields that we see,
• 53:36
  Speaker 1: but it doesn't explain the acceleration. It's off by a
• 53:38
  Speaker 1: factor of like ten to the one hundred. I see
• 53:42
  Speaker 1: a little bit off, a little bit off. What about
• 53:45
  Speaker 1: Anthony's question here where he asked, what is the combined
• 53:48
  Speaker 1: mass of virtual particles in the universe? I would say
• 53:50
  Speaker 1: that doesn't really have a solid answer. You know, because
• 53:53
  Speaker 1: the virtual particles don't really have a well defined mass,
• 53:56
  Speaker 1: so it really could be anything at any moment. Oh interesting,
• 54:00
  Speaker 1: but in a particular spot, maybe you know, a virtual
• 54:03
  Speaker 1: particle could have any mass. But maybe he's wondering if
• 54:06
  Speaker 1: overall in the universe, as an average, if you take
• 54:09
  Speaker 1: the average of all virtual particles everywhere, or at least
• 54:12
  Speaker 1: in like a giant space, the size of a galaxy,
• 54:14
  Speaker 1: is that also fluctuating or do you think it has
• 54:17
  Speaker 1: some sort of like standing mass to that average. You know,
• 54:20
  Speaker 1: ripples and and wiggles in the fields. The way I
• 54:23
  Speaker 1: think about it is that that's just the potential energy
• 54:26
  Speaker 1: of those fields, right. Sometimes that potential energy gets momentarily
• 54:30
  Speaker 1: converted into virtual particles, But it's really just another way
• 54:33
  Speaker 1: of thinking about the field as having potential energy is
• 54:36
  Speaker 1: having capacity to interact with the stuff around it. So
• 54:40
  Speaker 1: I don't really think about as having like real actual mass.
• 54:43
  Speaker 1: But you just said that that that virtual particles are
• 54:45
  Speaker 1: sort of created and popped into existence. But those virtual
• 54:50
  Speaker 1: particles don't have mass, Well, they don't have mass in
• 54:52
  Speaker 1: the same way that real particles do. Like, what does
• 54:54
  Speaker 1: mass mean? It means how particles propagate through the universe,
• 54:57
  Speaker 1: and virtual particles don't propagate through the universe the same
• 55:00
  Speaker 1: way real ones do. Also, Remember, and now we're talking
• 55:03
  Speaker 1: about like the mass from particles. We don't even understand
• 55:07
  Speaker 1: how gravity works when it comes to particles. So if
• 55:10
  Speaker 1: you're talking about like the gravitational impact of individual quantum particles,
• 55:14
  Speaker 1: that's a question for quantum gravity anyway. All right, well,
• 55:17
  Speaker 1: then I guess how would you summarize his question? The
• 55:20
  Speaker 1: answer to his question like, do virtual particles have mass
• 55:23
  Speaker 1: and can they add up to something? Or? I mean,
• 55:25
  Speaker 1: I feel like your answer is very kind of theoretical,
• 55:27
  Speaker 1: and it seems to be depending on how you look
• 55:29
  Speaker 1: at things in the universe. What would be a more
• 55:31
  Speaker 1: direct answer for Anthony? I think maybe the Christmas answer
• 55:34
  Speaker 1: is no, no, that virtual particles don't have mass. No,
• 55:37
  Speaker 1: the virtual particles aren't the dark matter. They're are contributing
• 55:40
  Speaker 1: to the mass of the universe. I think the clearest
• 55:42
  Speaker 1: way to think about it is the virtual particles are
• 55:45
  Speaker 1: not particles the way you are thinking about tiny little
• 55:48
  Speaker 1: bits of stuff. Instead, just think about them as fields
• 55:50
  Speaker 1: filling the universe. There are these quantum fields out there
• 55:53
  Speaker 1: capable of doing stuff, and they are affecting the overall
• 55:57
  Speaker 1: flow in shape of the universe, but in the opposite
• 55:59
  Speaker 1: way of mass. We think they're probably contributing to the
• 56:02
  Speaker 1: expansion of the universe rather than pulling stuff together. Mm
• 56:05
  Speaker 1: I see, okay, I think maybe then what you're saying
• 56:08
  Speaker 1: is that virtual particles maybe even have not only do
• 56:12
  Speaker 1: they not have mass in the same way that particles do,
• 56:15
  Speaker 1: but maybe they have kind of negative matter, or they
• 56:17
  Speaker 1: contribute negative mass to the universe, as maybe you can tell.
• 56:20
  Speaker 1: I'm not a fan of the picture of virtual particles.
• 56:23
  Speaker 1: I prefer to think about fields as ways to interact
• 56:26
  Speaker 1: between particles rather than virtual particles. But you know, mathematically
• 56:30
  Speaker 1: they are equivalent. But I think they raise a whole
• 56:32
  Speaker 1: bunch of questions that you can't really answer because particles
• 56:35
  Speaker 1: is sort of the wrong word to describe them. I see.
• 56:37
  Speaker 1: So we'll just tell Anthony to rephrase this question in
• 56:40
  Speaker 1: terms of quantum fields, and maybe you'll be in a
• 56:43
  Speaker 1: better mode to answer this one. Quantum fields don't contribute
• 56:49
  Speaker 1: to the dark matter, Anthony. We think they might contribute
• 56:52
  Speaker 1: to dark energy, but we don't really understand by how much.
• 56:55
  Speaker 1: But it is interesting. I mean, I can see how
• 56:58
  Speaker 1: I think it could have reached that conclusion. Right. You
• 57:00
  Speaker 1: learn about one thing and then you learn about something
• 57:02
  Speaker 1: else and you're like, oh, wow, that makes sense to me.
• 57:04
  Speaker 1: They're related. I wonder if they are, right, Like, it's
• 57:07
  Speaker 1: all right to wonder these things, right, Oh? Absolutely. And
• 57:10
  Speaker 1: sometimes two big mysteries are the answers to each other, right,
• 57:14
  Speaker 1: like why does this happen over there? Why does that
• 57:16
  Speaker 1: happen over there? Oh? It turns out you were thinking
• 57:18
  Speaker 1: about these things as disconnected, but there are actually two
• 57:21
  Speaker 1: parts of the same coin. So I absolutely encourage people
• 57:23
  Speaker 1: to think about how part of one mystery might be
• 57:26
  Speaker 1: the answer to another. And also don't insult physicist by
• 57:29
  Speaker 1: asking if maybe they miss something. That's one lesson we've
• 57:32
  Speaker 1: learned today. No, I don't feel insulted at all. And
• 57:36
  Speaker 1: I love all of the questions, and I encourage people
• 57:39
  Speaker 1: to think broadly and write every question they have. Please
• 57:42
  Speaker 1: send us your questions two questions at Daniel and Jorge
• 57:45
  Speaker 1: dot com. Great, well, those are our three questions about
• 57:48
  Speaker 1: particle physics and Daniel as a particle physicists. UM must
• 57:51
  Speaker 1: be pretty exciting to have people ask you questions about
• 57:54
  Speaker 1: the field you're study. It's super fun. I love thinking
• 57:56
  Speaker 1: about this stuff, and I love that other folks, not
• 57:59
  Speaker 1: just article physicists, are interested in these questions. You know,
• 58:02
  Speaker 1: it's easy to look up at the night sky and
• 58:04
  Speaker 1: think about astronomy and ask questions about stars and galaxies.
• 58:07
  Speaker 1: But it's also possible to look just down at your
• 58:09
  Speaker 1: hand and the ground below your feet and all of
• 58:12
  Speaker 1: the matter that's around us and wonder like, what makes
• 58:14
  Speaker 1: that up? What are the rules of it. That's what
• 58:17
  Speaker 1: got me into particle physics, and I think that's pretty accessible. Yeah,
• 58:20
  Speaker 1: and it's pretty amazing to think that. You know, we
• 58:21
  Speaker 1: have this intuitive view of our our intuitive sense of
• 58:24
  Speaker 1: the universe as being these kind of you know, giant
• 58:26
  Speaker 1: pool table with builder balls bouncing around. But as you
• 58:30
  Speaker 1: drill down into these small sizes, Uh, there's all kinds
• 58:32
  Speaker 1: of weird things happening. Absolutely, And sometimes we understand that
• 58:36
  Speaker 1: only in terms of the mathematical description, which amazingly works
• 58:40
  Speaker 1: so well and predicts the results of our experiments. We
• 58:42
  Speaker 1: don't always have a deep intuitive understanding of it. And
• 58:46
  Speaker 1: that's because things at the smallest level really are very
• 58:49
  Speaker 1: different from our intuition. To build an intuitive understanding usually
• 58:53
  Speaker 1: means explaining the unknown in terms of the known. But
• 58:56
  Speaker 1: here the unknown is so radically different than the known
• 58:59
  Speaker 1: that it's really hard and sometimes to describe it in
• 59:02
  Speaker 1: terms of familiar concepts. So if you hear me struggling
• 59:05
  Speaker 1: and you hear Jorge persisting and asking the same question
• 59:07
  Speaker 1: until we get an answer that you guys can understand,
• 59:10
  Speaker 1: that's because sometimes it's just hard to translate these ideas
• 59:13
  Speaker 1: from mathematics to intuition. Right right, we need to spend
• 59:15
  Speaker 1: a summer in front of a computer coding so that
• 59:18
  Speaker 1: we can beam the best right into our listeners paint
• 59:23
  Speaker 1: that picture in their brain. I've had many moments in
• 59:26
  Speaker 1: science where I said, I don't understand this, but I'm
• 59:28
  Speaker 1: just going to follow the math because the math works.
• 59:31
  Speaker 1: It will give me a prediction. It gives me the
• 59:32
  Speaker 1: answer I need. I don't really intuiteally understand it, Daniel,
• 59:36
  Speaker 1: the mass is telling me that you send me a
• 59:37
  Speaker 1: check for a hundred thousand dollars. Uh. And sometimes being
• 59:41
  Speaker 1: asked to explain it, to really to teach it in
• 59:43
  Speaker 1: a class or to talk about in a podcast, forces
• 59:46
  Speaker 1: me to think about it again and dive deeper for
• 59:48
  Speaker 1: an intuitive explanation which helps me understand it. Better cool. Well.
• 59:51
  Speaker 1: Thank you to all the people who send these questions.
• 59:54
  Speaker 1: We love to answer them here on the podcast, and
• 59:57
  Speaker 1: we hope that all of you out there enjoyed us
• 59:59
  Speaker 1: talking about at these questions and maybe or maybe not
• 1:00:02
  Speaker 1: answering them, certainly doing our best. We hope you enjoyed that.
• 1:00:06
  Speaker 1: Thanks for joining us, See you next time. Thanks for listening,
• 1:00:17
  Speaker 1: and remember that Daniel and Jorge Explain the Universe is
• 1:00:19
  Speaker 1: a production of I Heart Radio. For more podcast from
• 1:00:23
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• 1:00:27
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