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What Are Quantum Fields? · Daniel and Kelly’s Extraordinary Universe

• 0:06
  Speaker 1: Hey, Daniel, you know how in science fictions are all
• 0:09
  Speaker 1: kinds of fields. You mean like big expansive lawns. No,
• 0:13
  Speaker 1: I mean like force fields or energy fields. Oh my god,
• 0:17
  Speaker 1: you know none of that is real, right? What the
• 0:21
  Speaker 1: force from Star Wars is not real? None of it. Absolutely,
• 0:25
  Speaker 1: none of that is real. Wait? Wait, what about like
• 0:27
  Speaker 1: energy fields? Those are real? Right? Energy fields are not real.
• 0:31
  Speaker 1: But there's something that's even weird or even cooler that
• 0:36
  Speaker 1: is real. Wait, cooler than star wars. Cooler than star
• 0:39
  Speaker 1: Wars are quantum fields. And that's a thing that is
• 0:43
  Speaker 1: real and is everywhere in the universe. I don't believe it.
• 0:46
  Speaker 1: I think you just made it up. We physicists did,
• 0:48
  Speaker 1: in fact, invent quantum fields. But it turns out because
• 0:51
  Speaker 1: it accurately predicts what happens in the universe, it might
• 0:54
  Speaker 1: just be real. Is that like field of dream Like
• 0:56
  Speaker 1: if you think of it, people will believe it. That's right,
• 0:59
  Speaker 1: quantum fields of quantum dreams. That's basically what being a
• 1:02
  Speaker 1: physicist is all about, having quantum dreams. And you're the
• 1:05
  Speaker 1: Kevin Costner in the situation him and I'm Daniel, and
• 1:27
  Speaker 1: welcome to our podcast. Daniel and Jorge explain the universe.
• 1:30
  Speaker 1: This is Daniel and Jorge. This is the podcast you're
• 1:33
  Speaker 1: looking for exactly um. Yeah. On this podcast, we try
• 1:39
  Speaker 1: to talk to you about everything in the universe. Things
• 1:41
  Speaker 1: that are big, things that are small, things that are
• 1:43
  Speaker 1: invisible but fill the entire universe, things that are everywhere,
• 1:48
  Speaker 1: things you had no idea existed, but determine everything about
• 1:52
  Speaker 1: your existence that's right. Today on the podcast, we'll talk
• 1:55
  Speaker 1: about quantum fields. What are they? Where are they? Who
• 2:04
  Speaker 1: are they? What are they good for? Absolutely nothing? Say
• 2:07
  Speaker 1: it again. Is it's just a family whose last name
• 2:10
  Speaker 1: is field, or it's a bunch of discrete playing fields
• 2:16
  Speaker 1: somewhere quantum fields, you're gonna have one field, you can
• 2:18
  Speaker 1: have two fields. You can't have two and a half fields.
• 2:20
  Speaker 1: They're quantized, but once you enter, you don't really know
• 2:22
  Speaker 1: where you're going or where you are now. A quantum
• 2:27
  Speaker 1: field theory is something you hear about, you might have heard.
• 2:30
  Speaker 1: It's part of modern physics. It's a theory that people
• 2:33
  Speaker 1: use to do calculations. It's really awesome, it's impressive. But
• 2:37
  Speaker 1: what isn't What is a quantum field? What is the
• 2:40
  Speaker 1: theory of quantum fields? What relationship does that have to
• 2:42
  Speaker 1: you or the rest of your life or anything at all. Well,
• 2:45
  Speaker 1: it's more than just a part of modern physics. It's
• 2:47
  Speaker 1: kind of like the foundation of our theory about the universe. Right,
• 2:52
  Speaker 1: that's right. It's kind of like the language of physics currently.
• 2:55
  Speaker 1: You know, it's quantum field theory is to modern physics
• 2:58
  Speaker 1: the way like English is to Shakespeare. You know. We
• 3:01
  Speaker 1: use the tools of quantum field theory to try to
• 3:03
  Speaker 1: talk about what's going on in the universe, and it's
• 3:05
  Speaker 1: remarkably successful. It's incredibly successful. When you guys want to
• 3:10
  Speaker 1: use pig latin, I thought that was the We only
• 3:12
  Speaker 1: do that when you come by, Jorge to try to
• 3:13
  Speaker 1: confuse you. Um. But it's like the foundation of modern physics.
• 3:18
  Speaker 1: And it's also super duper accurate. Like you guys are
• 3:22
  Speaker 1: pretty sure is it the right way to describe the universe? Yeah, Well,
• 3:27
  Speaker 1: on one hand, it's super duper accurate. Like we can
• 3:29
  Speaker 1: predict the way particles interact with fields, and we can
• 3:33
  Speaker 1: make predictions out to lots of decimal places, and then
• 3:36
  Speaker 1: we can go out and measure how those particles interact
• 3:38
  Speaker 1: with the fields, and it turns out those predictions are
• 3:40
  Speaker 1: correct to like one in millions and millions. So you know,
• 3:44
  Speaker 1: you have, on one hand, like a theoretical calculation that
• 3:47
  Speaker 1: you've written downs is like an idea that predicts an experiment,
• 3:50
  Speaker 1: and then you go out and you check it with
• 3:52
  Speaker 1: a super precise experiment and get the same answer, and uh,
• 3:56
  Speaker 1: you know it's so accurate that you think maybe this
• 3:58
  Speaker 1: is the true story of the universe. It's not just
• 4:01
  Speaker 1: like human ideas. This is like revealing the source code
• 4:05
  Speaker 1: kind of thing. So you're pretty close to saying quantum
• 4:08
  Speaker 1: fields are true. They're they're like the truth of the universe. Yes,
• 4:12
  Speaker 1: that's except that we also know they can't be the
• 4:15
  Speaker 1: final answer. Oh yeah, well well we'll get into it.
• 4:20
  Speaker 1: But I will admit I don't have a clear idea
• 4:22
  Speaker 1: of what a quantum field is um and we were
• 4:25
  Speaker 1: wondering how many of you out there had some ideas
• 4:28
  Speaker 1: about what it would be. So, as usual, I walked
• 4:30
  Speaker 1: around the u C Irvine campus and I asked a
• 4:32
  Speaker 1: bunch of very friendly, very accommentating, very willing to answer
• 4:35
  Speaker 1: random questions you see, Irvine undergrads, and I asked them
• 4:39
  Speaker 1: what is quantum field theory? Here's what people had to say.
• 4:43
  Speaker 1: I have no idea, but I have heard of before.
• 4:45
  Speaker 1: All right, Um, it's probably really to quantum mechanics UM.
• 4:52
  Speaker 1: I'm not sure exactly what it is, but I think
• 4:56
  Speaker 1: it describes the different factor of fields that you use
• 5:00
  Speaker 1: in quantum mechanics. UM. Maybe the way cell atomic particles
• 5:07
  Speaker 1: instracted with one another cool um, similar to quantum mechanics chemistry.
• 5:12
  Speaker 1: I don't know what it is, but I've heard of it.
• 5:14
  Speaker 1: It's something to do with general relativity. Is it trying
• 5:17
  Speaker 1: to marry that together with quantum theory? Are the waves
• 5:22
  Speaker 1: involved and residents of particles? Something like that? Maybe? All right,
• 5:29
  Speaker 1: some pretty pretty good answers. I feel like, though the
• 5:32
  Speaker 1: word quantum just give it away, you know, asked what
• 5:36
  Speaker 1: is the quantum Google book, you can just say, oh,
• 5:39
  Speaker 1: I think it's related to quantum particles, right, and you
• 5:41
  Speaker 1: would be sort of right, yeah, but that's not really
• 5:43
  Speaker 1: an answer, right, you know. Um? And and we know
• 5:47
  Speaker 1: one of those answers is actually not from a UC
• 5:49
  Speaker 1: Irvine undergraduate. That's from a fellow who wrote in and
• 5:53
  Speaker 1: said that he was disappointed with the quality of the
• 5:56
  Speaker 1: answers that the undergrads were giving. He thought he could
• 5:59
  Speaker 1: do better. So I said, all right, here's the next
• 6:03
  Speaker 1: question from the next podcast. Don't do any research and
• 6:06
  Speaker 1: record your answer. And he wrote back a very humbled
• 6:09
  Speaker 1: email and he said, Okay, you're right. It's harder than
• 6:11
  Speaker 1: I thought it was, but he was still willing to
• 6:14
  Speaker 1: do it, so I thought that was totally awesome. So
• 6:16
  Speaker 1: he sent us. He sent us his description of quantum
• 6:18
  Speaker 1: field theory. Do you think that we think in society
• 6:21
  Speaker 1: today we think for smarter than we are because we
• 6:23
  Speaker 1: have Google at our fingertips. You know, I feel like
• 6:27
  Speaker 1: you know everything because we kind of do. If we
• 6:29
  Speaker 1: just give us a second to tap it on our phones,
• 6:31
  Speaker 1: it's easier to access information. But sometimes that makes me
• 6:33
  Speaker 1: feel less smart because I feel like I have less
• 6:36
  Speaker 1: information actually in my head and I'm relying more and
• 6:39
  Speaker 1: more on these facilities that are outside my brain. You
• 6:42
  Speaker 1: know this, Even though the cognitive connection between me and
• 6:44
  Speaker 1: Google keeps increasing, I don't feel like that makes me smarter.
• 6:47
  Speaker 1: It just makes me plus Google smarter. What what about
• 6:52
  Speaker 1: the day that you get you connect your phone through
• 6:54
  Speaker 1: your brain or something, then you're sort of technically as
• 6:56
  Speaker 1: smart as Google. The day that I become Google. That's
• 7:02
  Speaker 1: the singularity, the Google's singularity. Yeah, we all connect our brains,
• 7:05
  Speaker 1: we all become one mega consciousness. The Google were smoking
• 7:08
  Speaker 1: over there today, Jorge, I want some pass that over.
• 7:11
  Speaker 1: It's the googlarity, the Google larity. I look forward to that.
• 7:16
  Speaker 1: But well, we know they're related to quantum theory, quantum
• 7:20
  Speaker 1: field um. So let's let's let's break it down. First
• 7:23
  Speaker 1: of all, what is a field to a physicist? Right? So,
• 7:26
  Speaker 1: a field is just it's like a fluid that feels
• 7:29
  Speaker 1: all of space. It's like it's something that's everywhere and
• 7:34
  Speaker 1: everywhere in space. You have a number, right, And it
• 7:36
  Speaker 1: comes from things like the electromagnetic field. People were puzzling
• 7:40
  Speaker 1: a hundred years or so ago, like how do to
• 7:42
  Speaker 1: magnets push each other apart without touching? Right? There was
• 7:46
  Speaker 1: this action at a distance mystery like that's sort of spooky,
• 7:49
  Speaker 1: like a yeah, right are they? How are they actually
• 7:52
  Speaker 1: pushing each other apart? You know? And this really puzzled
• 7:55
  Speaker 1: physicists for a while, and they came up with this
• 7:57
  Speaker 1: idea of a field, the idea that each magnet has
• 7:59
  Speaker 1: a magnetic field. It's this invisible thing that surrounds it,
• 8:03
  Speaker 1: which will push on any other magnet that enters that
• 8:06
  Speaker 1: magnetic field. Right, and the magnetic field is strongest near
• 8:09
  Speaker 1: the source of the magnet and then it drops off
• 8:12
  Speaker 1: just as you would expect because the magnet super far
• 8:14
  Speaker 1: away won't feel anything. And just came because they noticed
• 8:17
  Speaker 1: that how one magnet pulls or pushes on another sort
• 8:21
  Speaker 1: of depends on where you put them relative to each other, right,
• 8:25
  Speaker 1: Like where you put it around the other other one,
• 8:27
  Speaker 1: that's right. And so they came up they said, well, wait,
• 8:29
  Speaker 1: maybe every magnet generates in space this invisible thing. We'll
• 8:34
  Speaker 1: call it a magnetic field, and that's the thing that
• 8:36
  Speaker 1: does the pushing. And sort of a mystery that came
• 8:40
  Speaker 1: up immediately was like is the field a real thing?
• 8:43
  Speaker 1: Is it actually they're a physical thing that's that exists
• 8:46
  Speaker 1: in the universe, Like does it have substance and can
• 8:49
  Speaker 1: you play baseball on it? Or is it just a
• 8:51
  Speaker 1: way that we calculate things, you know, just like a
• 8:53
  Speaker 1: tool in our minds to help us understand things, Like
• 8:58
  Speaker 1: is it a thing like you said, it could be
• 9:00
  Speaker 1: like a fluid, or it could just be like a
• 9:03
  Speaker 1: mathematical construct exactly exactly. And that's the questions people are
• 9:06
  Speaker 1: still grappling with, right. One philosophical problem was how can
• 9:10
  Speaker 1: things that are not touching push and pull on each other?
• 9:12
  Speaker 1: And they answer that with okay, we just invent fields
• 9:15
  Speaker 1: all right? Now the question is our fields a real
• 9:17
  Speaker 1: thing or are they something else? You know, that's the
• 9:20
  Speaker 1: joy of philosophies that every time you answer a question,
• 9:22
  Speaker 1: it just creates another question which is just as deep.
• 9:25
  Speaker 1: But what do you mean by a field is like
• 9:28
  Speaker 1: a number? Because the way I learned about it in
• 9:31
  Speaker 1: engineering is that a field is basically something that gives
• 9:34
  Speaker 1: you a number depending on where you stand or where
• 9:37
  Speaker 1: you are in space. That's right, Every point in space
• 9:40
  Speaker 1: has a number associated with it with each field. So
• 9:43
  Speaker 1: for example, the magnetic field from a magnet, there's a
• 9:46
  Speaker 1: strength of that field. There's a field strength and every location.
• 9:49
  Speaker 1: So as you're saying, you can ask what is the
• 9:51
  Speaker 1: field strength here right next to the magnet and you
• 9:53
  Speaker 1: get a number. What is the field strength way over there,
• 9:56
  Speaker 1: far away from the magnet, and you get a smaller number.
• 9:58
  Speaker 1: So the magnetic fiel field has a number at every
• 10:01
  Speaker 1: point in space. And you can have different kinds of
• 10:03
  Speaker 1: fields you can feel that just have a number. Those
• 10:05
  Speaker 1: are called scale or fields. That's just a fancy way
• 10:07
  Speaker 1: of saying a number, or you can have vector fields.
• 10:10
  Speaker 1: You can have a field where at every point you
• 10:12
  Speaker 1: have an arrow that points in a certain direction. It's
• 10:15
  Speaker 1: like kind of like, are you saying it's a field
• 10:17
  Speaker 1: that's kind of like a map, like it tells you
• 10:19
  Speaker 1: what is it every position in space? Yeah? Or a
• 10:22
  Speaker 1: map is kind of like a field actually, um, yeah, exactly.
• 10:27
  Speaker 1: So you can think of for like a map is
• 10:28
  Speaker 1: how much magnetic field is there here? How much magnetic
• 10:31
  Speaker 1: field is there there? And you know everywhere in space
• 10:34
  Speaker 1: there is magnetic field and easither you're strong or it's weak. Right,
• 10:37
  Speaker 1: it can be if you're talking about like ordinary classical
• 10:39
  Speaker 1: fields like from a hundred and fifty years ago, then
• 10:41
  Speaker 1: they can be zero. Right, No magnets means there's a
• 10:44
  Speaker 1: field there, but the field value is zero. So the
• 10:48
  Speaker 1: question is is a field just like a map that
• 10:51
  Speaker 1: we hold in our hands it tells these things? Or
• 10:53
  Speaker 1: are we actually living on a map? Right? Like is
• 10:56
  Speaker 1: a field a real thing of substance? Yeah? And the
• 10:59
  Speaker 1: answer that question is we have no idea. And it's
• 11:02
  Speaker 1: sort of a philosophical question more than a scientific one. Right.
• 11:05
  Speaker 1: If you have a calculational tool a field that lets
• 11:09
  Speaker 1: you predict the outcome of experiments and that works really
• 11:12
  Speaker 1: really well. Doesn't matter if it's really physically true the
• 11:16
  Speaker 1: thing that's happening, um or just or just a the
• 11:19
  Speaker 1: way do you do these calculations? What's the difference? Right? Um?
• 11:24
  Speaker 1: You know, if we weren't here with those fields exist, right, well,
• 11:27
  Speaker 1: that's not really a question you can answer because if
• 11:29
  Speaker 1: we weren't here, there'd be nobody to answer the question
• 11:31
  Speaker 1: or do the experiment, right. So they're really tricky little
• 11:35
  Speaker 1: philosophical puzzles. And that's a whole area of philosophical exploration
• 11:39
  Speaker 1: that I'm totally not qualified to talk about, but I
• 11:42
  Speaker 1: often do anyway that do. That's the basis of our
• 11:46
  Speaker 1: entire podcast. That's the field of our podcast. Now, you know,
• 11:49
  Speaker 1: there's a huge conflict between philosophers of science and physicists
• 11:55
  Speaker 1: who think there's philosophers of science and spout off glibly
• 11:59
  Speaker 1: sometimes um an uninformed way in front of mass audiences
• 12:03
  Speaker 1: and then get taken down by actual philosophers of science.
• 12:08
  Speaker 1: So that's a common mistake to make, which is why
• 12:10
  Speaker 1: I wanted to put that qualifier out there. In the
• 12:12
  Speaker 1: world economic war kind of between the pilosophers and physicists
• 12:18
  Speaker 1: who venture into philosophy. Yes, exactly, exactly right. And there
• 12:23
  Speaker 1: are some physicists who really have learned about philosophy and
• 12:25
  Speaker 1: can speak knowledgeably about it. And then there are others
• 12:27
  Speaker 1: who think they can speak knowledge of me about it
• 12:29
  Speaker 1: but don't actually know anything. It sounds like an exciting fight,
• 12:32
  Speaker 1: ironically speaking. All right, so, um, so that's a field.
• 12:40
  Speaker 1: That's kind of what it is. It's kind of like
• 12:41
  Speaker 1: a map of space that tells you something. Um, And
• 12:46
  Speaker 1: then you can have particles in these fields, right, Like
• 12:49
  Speaker 1: a particle is part of the field, or something can
• 12:51
  Speaker 1: be on the field. Yes. One of the most interesting
• 12:53
  Speaker 1: thing about field theories or theories of fields is it
• 12:57
  Speaker 1: tells you that particles are not the most basic thing
• 12:59
  Speaker 1: in the universe. The particles are, in fact, just vibrations
• 13:03
  Speaker 1: of the field. Like particles are a real thing. Right,
• 13:06
  Speaker 1: We feel them, we see them, we are them. But
• 13:08
  Speaker 1: this tells us what they where they come from? Right
• 13:10
  Speaker 1: the rules. It tells us that if you want to
• 13:12
  Speaker 1: understand how particles move, you really have to understand these fields,
• 13:16
  Speaker 1: because the particles are just vibrations in those fields, but
• 13:21
  Speaker 1: vibrations of what of the fields? Right, Like the fields
• 13:25
  Speaker 1: are you know, a thing and they vibrate, which means
• 13:28
  Speaker 1: they have energy, right, and localized excitations of these fields. Right.
• 13:33
  Speaker 1: Imagine for example, a big rubber sheet that fills the
• 13:36
  Speaker 1: universe right, totally flat, but you could um poke it
• 13:40
  Speaker 1: and send a wave through it, right, and that wave
• 13:43
  Speaker 1: can travel. It's energy that's traveling by oscillating this field.
• 13:47
  Speaker 1: And that's what particles are. There are oscillations in fields.
• 13:50
  Speaker 1: But if I poke a sheet, it'll sort of dissipate,
• 13:53
  Speaker 1: It'll go outwards and dissipate. A particle kind of likes
• 13:57
  Speaker 1: to stay in one place. Well, I don't know what
• 13:58
  Speaker 1: particles like. You've done any interviews with particles, and you
• 14:01
  Speaker 1: can um, there's lots of waste of vibrated sheet, right,
• 14:07
  Speaker 1: you can vibrted sheet, so you get a localized packet
• 14:10
  Speaker 1: that's traveling. Right. It's easier to think about, for example,
• 14:12
  Speaker 1: in one dimension, like instead of a sheet, think of
• 14:14
  Speaker 1: a rope. Like if I'm holding a rope and you're
• 14:16
  Speaker 1: holding a rope, I can wiggle it to send you
• 14:19
  Speaker 1: like a little wiggle along the rope, so you can
• 14:21
  Speaker 1: get a message. Right, And you're saying a particle is
• 14:24
  Speaker 1: one of these wiggles. A particle is a localized excitation
• 14:28
  Speaker 1: of the quantum field exactly. And the crazy thing is
• 14:31
  Speaker 1: every particle has its own field. So like in the universe,
• 14:35
  Speaker 1: everywhere there's an electron field, and everywhere there's an electron
• 14:39
  Speaker 1: that's the electron field wiggling, wiggling, And there's also a
• 14:43
  Speaker 1: um cork field, right, an upcork field. Everywhere there's an
• 14:46
  Speaker 1: upcork The upcork field is wiggling. Like a particle is
• 14:49
  Speaker 1: something that's causing the field to vibrate or it's like
• 14:52
  Speaker 1: it is the vibration of the field. It is the
• 14:55
  Speaker 1: vibration exactly, That's what it is. Yeah, And so that's
• 14:59
  Speaker 1: what we're all made out of. Like you and I
• 15:01
  Speaker 1: are made out of protons and quirks and electrons, and
• 15:04
  Speaker 1: so we're all just like massive collections of little vibrations.
• 15:08
  Speaker 1: That's right. It's all actually vibrations. Man, those dudes, that's
• 15:11
  Speaker 1: not a vibrations were everything they were right in exactly.
• 15:17
  Speaker 1: And so for if you like to think of yourself
• 15:19
  Speaker 1: as made of particles, and you wonder like, well, what
• 15:21
  Speaker 1: are the particles made out of? Right, I mean, they
• 15:23
  Speaker 1: might be made out of smaller and smaller particles. But
• 15:25
  Speaker 1: at some point you get down to the smallest particle
• 15:27
  Speaker 1: and what's that particle made out of? And you think, oh,
• 15:29
  Speaker 1: universe stuff. Well, it turns out the universe stuff might
• 15:32
  Speaker 1: be quantum fields, right, that it's the quantum fields that
• 15:35
  Speaker 1: are oscillating that make a particle. Okay, So that's a
• 15:38
  Speaker 1: definition of a quantum field. It's it's the stuff of
• 15:41
  Speaker 1: the universe. We're done. Yeah, So a field is just
• 15:44
  Speaker 1: like a fluid field space. It could doesn't have to
• 15:46
  Speaker 1: become quantum. It could be like electromagnetic or in any
• 15:49
  Speaker 1: kind of field. But a quantum field is a field
• 15:52
  Speaker 1: that describes the motion of a quantum object, like a particle.
• 15:55
  Speaker 1: And so since we're dealing with particles and they move
• 15:58
  Speaker 1: really fast and they have quantum entical properties, we deal
• 16:01
  Speaker 1: with quantum fields. Okay, So a quantum field is what
• 16:06
  Speaker 1: describes the things that we're made out of, right, because
• 16:09
  Speaker 1: we're all made out of quantum particles, that's right, And
• 16:12
  Speaker 1: every particle that makes us up is actually just a
• 16:14
  Speaker 1: vibration of one of those fields, you know. And it's
• 16:17
  Speaker 1: a really different way to look at the universe. Like
• 16:19
  Speaker 1: when physicists started and they were thinking about quantum mechanics.
• 16:22
  Speaker 1: They were thinking about, like what happens to a particle?
• 16:25
  Speaker 1: You know what, what is this electron story? It starts
• 16:28
  Speaker 1: off over here and then it goes off over there.
• 16:30
  Speaker 1: And that's the way we're used to do in physics, right,
• 16:32
  Speaker 1: Like you think about a ball, what happens to this
• 16:35
  Speaker 1: ball as it rolls down the hill. It's very natural
• 16:37
  Speaker 1: to sort of follow the story of the ball. So
• 16:40
  Speaker 1: we tried to do that with us, follow the story.
• 16:41
  Speaker 1: The electron problem is quantum particles don't behave like that,
• 16:45
  Speaker 1: Like they don't have a path, right, It's not like
• 16:47
  Speaker 1: you're here and then you're here and then you're here.
• 16:50
  Speaker 1: Is all this uncertainty, But more than that, they're being
• 16:53
  Speaker 1: destroyed and created all the time. Like an electron doesn't
• 16:56
  Speaker 1: just fly through space. It flies through space, it turns
• 16:59
  Speaker 1: into aton and something else, then it turns back into
• 17:01
  Speaker 1: an electron, and then it creates this other thing which
• 17:03
  Speaker 1: exists for a bill of second and then comes back.
• 17:05
  Speaker 1: This is like frothing mass of stuff that's happening. And
• 17:09
  Speaker 1: the quantum mechanics we first developed couldn't describe that at
• 17:12
  Speaker 1: all because it was very difficult to describe the creation
• 17:14
  Speaker 1: or destruction of particles. So you sort of like reboot
• 17:18
  Speaker 1: your thinking completely and say, let's ignore the story of
• 17:21
  Speaker 1: one particle and just think about like the particles in general. Right,
• 17:25
  Speaker 1: let's think about all the particles. It's just like vibrations
• 17:28
  Speaker 1: of this sheet that fills the universe. And then we
• 17:30
  Speaker 1: don't have to worry about the story of particle A
• 17:32
  Speaker 1: and the story of particle B. Because, um, you're saying
• 17:36
  Speaker 1: an electron. If you think of it as a thing,
• 17:39
  Speaker 1: and that thing disappears and turns into something else, then
• 17:42
  Speaker 1: you're left wondering what happened to that thing? Yeah, Like
• 17:44
  Speaker 1: Kevin the electron, what is his story? He disappeared and
• 17:47
  Speaker 1: he came back. Is it's still Kevin? Right, Like in
• 17:50
  Speaker 1: the quantum field theory version, Like all the electrons are
• 17:53
  Speaker 1: Kevin because all the electrons are the same, right, Every
• 17:55
  Speaker 1: electron is identical. Right, there's no difference between this electron
• 17:58
  Speaker 1: and that electron. Where all Kevin, we're all made out
• 18:02
  Speaker 1: of Kevin. Turns out that's the answer to the life,
• 18:04
  Speaker 1: the universe and everything. Kevin. There's like twelve Kevin's listening
• 18:07
  Speaker 1: to this, going, I knew it. I hope we have
• 18:11
  Speaker 1: more than twelve Kevin's listening to this. Well, let's get
• 18:14
  Speaker 1: a little bit deeper into it. But first let's take
• 18:16
  Speaker 1: a quick break. Okay, so you're saying that the universe
• 18:32
  Speaker 1: is not empty. It's like it's filled with these quantum
• 18:36
  Speaker 1: fields that just kind of permeate everything. And they might
• 18:40
  Speaker 1: be imaginary or they might be real things, but they
• 18:42
  Speaker 1: premiate the entire universe. And we, like particles us matter,
• 18:47
  Speaker 1: are just kind of like um little vibrations in these fields,
• 18:51
  Speaker 1: that's right. And they lay on top of each other, right,
• 18:53
  Speaker 1: Every point in space can have an electron field and
• 18:57
  Speaker 1: an upcork field, and a down cork field, and a
• 18:59
  Speaker 1: Higgs boson on field and electromagnetic field. We have lots
• 19:02
  Speaker 1: of different kinds of fields, and you know, it might
• 19:05
  Speaker 1: turn out eventually that we figure out how they're all
• 19:07
  Speaker 1: really just part of one big field. But right now,
• 19:09
  Speaker 1: we have lots of different kinds of fields that all
• 19:11
  Speaker 1: sort of lay on top of each other. They're all
• 19:13
  Speaker 1: the same size, or all the size of the universe.
• 19:15
  Speaker 1: Every piece of space has all these fields, and some
• 19:18
  Speaker 1: of them are zero ish, you know, they're low, and
• 19:20
  Speaker 1: some of them have energy in them, which is why
• 19:22
  Speaker 1: you have the electron here. So if you have like
• 19:24
  Speaker 1: an electron on your left, that means the electron field
• 19:27
  Speaker 1: is excited there. And if you have an upcork on
• 19:29
  Speaker 1: your right, it means the upcork field is excited there
• 19:31
  Speaker 1: and the electron field is not. Right. But and they
• 19:34
  Speaker 1: can sort of talk to each other, right, Like an electron,
• 19:37
  Speaker 1: you could have a little vibration in the electron field
• 19:39
  Speaker 1: and then suddenly that disappears and it gets transferred to
• 19:43
  Speaker 1: a different field and becomes a different particle exactly. And
• 19:46
  Speaker 1: those are the forces. So quantum field theory can describe matter.
• 19:49
  Speaker 1: That's what we've been talking about. They could also describe
• 19:51
  Speaker 1: the forces like the electromagnetic field is a way for
• 19:54
  Speaker 1: charge particle fields to interact with each other. Right, you
• 19:57
  Speaker 1: have one electron over here, another electron over there. How
• 20:00
  Speaker 1: do they talk to each other? Well, turns out the
• 20:02
  Speaker 1: electron field and the photon field interact, and so one
• 20:06
  Speaker 1: electron can talk to another electron by shooting a ripple
• 20:09
  Speaker 1: through the photon field, which is like sending a photon
• 20:12
  Speaker 1: between one electron and the other through another field. Yes, exactly,
• 20:16
  Speaker 1: the fields coupled to each other, they interact otherwise would
• 20:19
  Speaker 1: be pretty boring universe, and in these fields fill the
• 20:22
  Speaker 1: entire universe. So are they related to space, like if
• 20:25
  Speaker 1: if space grows, these fields grow as well. Yes, exactly,
• 20:29
  Speaker 1: it's a basic part of space, right, you can't have
• 20:31
  Speaker 1: space without these fields. As far as we know. There's
• 20:34
  Speaker 1: no fieldless part of space, and every part of space
• 20:37
  Speaker 1: has these fields. It's like there's a hum at every
• 20:40
  Speaker 1: point in the universe. There's no quiet place in the
• 20:42
  Speaker 1: universe exactly. And you might be thinking, well, what if
• 20:45
  Speaker 1: you have an empty space, maybe all the fields are
• 20:46
  Speaker 1: just zero. Right, Well, that's the fascinating thing about quantum fields,
• 20:50
  Speaker 1: right because uncertainty principle, because there's a maximum amount of
• 20:54
  Speaker 1: information you can have. You can't have quantum field to
• 20:57
  Speaker 1: be exactly at zero. There's a minimum amount of inner
• 21:00
  Speaker 1: g they have to have, so they can bubble and
• 21:02
  Speaker 1: slosh in a way that gives you that uncertainty. Wait wait, wait, um,
• 21:06
  Speaker 1: there's there's kind of like an inherent energy in these
• 21:09
  Speaker 1: quantum fields. That's right, Like they're positive. I guess they're
• 21:12
  Speaker 1: they're not zero exactly. You can't have quantum fields exactly
• 21:16
  Speaker 1: at zero, and so there's always some energy there and
• 21:20
  Speaker 1: this is the energy of empty space, right, and that
• 21:23
  Speaker 1: energy means you have energy and you can create an
• 21:25
  Speaker 1: electron and depositron which then annihilate themselves back into a
• 21:29
  Speaker 1: photon or back into something else. So this energy is
• 21:32
  Speaker 1: always bubbling and frothing. And I feel like this kind
• 21:35
  Speaker 1: of makes it kind of makes anything possible. Right like before,
• 21:39
  Speaker 1: when you when you were is there something specific you
• 21:41
  Speaker 1: want to do? Accomplish with the punting field, you wanted
• 21:44
  Speaker 1: to do your dishes, get away with something I wanted
• 21:45
  Speaker 1: to get away with, or or imagine that I can
• 21:47
  Speaker 1: do you No, What I mean is in the sense
• 21:52
  Speaker 1: that before, if you were keeping track of all particles,
• 21:54
  Speaker 1: like if I was made out of the Kevin particles,
• 21:56
  Speaker 1: then there's sort of no way for me to suddenly
• 21:59
  Speaker 1: disappear and a you're over there. But now, because everything
• 22:02
  Speaker 1: is a quantum field, I could choose magically for some reason. Rights,
• 22:08
  Speaker 1: It's not like because we have quantum fields, there are
• 22:10
  Speaker 1: no rules, right, There are specific rules for how quantum
• 22:14
  Speaker 1: fields interact with each other and and how things propagate
• 22:17
  Speaker 1: through quantum fields, and you know, so we still have
• 22:20
  Speaker 1: laws of physics. It's not like we're tossing the laws
• 22:22
  Speaker 1: out the window and you do whatever you like. The
• 22:24
  Speaker 1: parents are out of town, right um, there's it's just
• 22:27
  Speaker 1: another way of looking at the universe. Okay, all right,
• 22:29
  Speaker 1: I guess what I mean is, you know stuff can
• 22:31
  Speaker 1: appear out of nowhere with these quantum fields. Yes, okay,
• 22:34
  Speaker 1: it's certainly true that a lot of your intuition is wrong,
• 22:37
  Speaker 1: and the quantum fields tell us that crazy things could happen,
• 22:40
  Speaker 1: And then we do the experiments and it's right, right,
• 22:42
  Speaker 1: quantum quantum field theory seems to be correct. It's a
• 22:49
  Speaker 1: pretty interesting view of the universe. You know, we think
• 22:51
  Speaker 1: of it as big and empty, but really there's sort
• 22:54
  Speaker 1: of like a like a little froth in the background
• 22:56
  Speaker 1: where a little like simmering bubbling. Yeah, exactly, there's no
• 22:59
  Speaker 1: place that's actually empty. Either's energy everywhere, and it's it's
• 23:03
  Speaker 1: filled with possibilities literally, and it's a it's a fascinating
• 23:06
  Speaker 1: way to look at the universe, and it's led to
• 23:08
  Speaker 1: a lot of insights. I mean, just like this mathematical
• 23:11
  Speaker 1: way of thinking about things has revealed things about the
• 23:14
  Speaker 1: universe we didn't know. For example, like what like the
• 23:18
  Speaker 1: Higgs boson. The Higgs boson was just an idea. Right
• 23:22
  Speaker 1: fifty years ago, Peter Higgs and several others said, huh,
• 23:25
  Speaker 1: what if there was another field? We'll call it the
• 23:27
  Speaker 1: Higgs field conveniently, And you know, where did you get
• 23:31
  Speaker 1: this idea? Where did this idea come from? Right? Who
• 23:33
  Speaker 1: wouldn't want to postulate a field that fills the universe?
• 23:36
  Speaker 1: And it is named after themselves? Right? Do you think
• 23:38
  Speaker 1: he named it after himself or people named it after him? Oh,
• 23:41
  Speaker 1: there's a whole controversy there about who named the Higgs fields,
• 23:45
  Speaker 1: And it comes down to um who submitted a paper first,
• 23:49
  Speaker 1: and whether a paper is dated based on the submission
• 23:53
  Speaker 1: date or the acceptance dage. You know, I mean like,
• 23:56
  Speaker 1: did Higgs write in his paper I'm going to call
• 23:58
  Speaker 1: this the Higgs field or did you say it's the
• 24:00
  Speaker 1: age or b? And then that somebody said, oh, that's
• 24:03
  Speaker 1: the field Higgs was talking about. Yes, somebody later referred
• 24:06
  Speaker 1: to it as the Higgs field because Higgs paper has
• 24:09
  Speaker 1: the earliest date on it. But he actually submitted his
• 24:12
  Speaker 1: paper after some other folks. Their paper had a later
• 24:16
  Speaker 1: date on it because the paper had the acceptance date
• 24:18
  Speaker 1: on it, not the submission date. So somebody later gave
• 24:21
  Speaker 1: Higgs credit, maybe inappropriately. Okay, so you're saying that these
• 24:25
  Speaker 1: fields are not just kind of need to think about,
• 24:28
  Speaker 1: but they've actually led to real discoveries and real understanding
• 24:32
  Speaker 1: of the universe. Yeah. It was a guy named Steve
• 24:34
  Speaker 1: Weinberg who read Higgs paper. He was looking at these
• 24:37
  Speaker 1: fields and he was thinking, thinking, there's a mystery here,
• 24:40
  Speaker 1: there's a pattern here that doesn't quite work, and that
• 24:43
  Speaker 1: comes from trying to unify the fields. We've talked on
• 24:45
  Speaker 1: other podcasts about how the electromagnetic field and the weak
• 24:49
  Speaker 1: nuclear field, Right, those two forces are actually parts of
• 24:53
  Speaker 1: the same thing, and they're very similar. But the difference
• 24:56
  Speaker 1: is that the photon, the thing that moves the electromagnetic field,
• 24:59
  Speaker 1: has no mass, right, It's it's massless. And the thing
• 25:03
  Speaker 1: that moves the weak nuclear force are the w n
• 25:06
  Speaker 1: z bosons. They're really heavy. So Weinberg was like, if
• 25:09
  Speaker 1: these are two parts of the same thing, how come
• 25:12
  Speaker 1: one has no mass and the other one has a
• 25:14
  Speaker 1: huge amount of mass? Right? What could do that mathematically?
• 25:17
  Speaker 1: Like theoretically, how could you make that happen? And the
• 25:22
  Speaker 1: what he found was the simplest way to do that,
• 25:24
  Speaker 1: the easiest, the clearest, like the without adding the minimal
• 25:27
  Speaker 1: number of moving pieces was to add one more field.
• 25:30
  Speaker 1: And so he read that paper by Higgs and he thought, Aha,
• 25:34
  Speaker 1: that is just the field we need. So he said,
• 25:38
  Speaker 1: if you add this field, and it explains this mystery
• 25:40
  Speaker 1: why photons have no mass and why the w z
• 25:43
  Speaker 1: have a lot of mass, But it, you know, creates
• 25:45
  Speaker 1: another field that feels the universe. So let's go see
• 25:48
  Speaker 1: if that's real. And but what's interesting is that there
• 25:51
  Speaker 1: were other people positing other fields, right, Like, he wasn't
• 25:55
  Speaker 1: the only one. He wasn't the only one. Other people
• 25:57
  Speaker 1: had similar ideas, and then there are other totally competing ideas,
• 26:00
  Speaker 1: you know, for ways to solve that mystery with other
• 26:02
  Speaker 1: different fields. Yeah, exactly. So like I could say, hey,
• 26:05
  Speaker 1: there's a horhe field that permius everything. Yeah, you could,
• 26:08
  Speaker 1: and I would be a physicist. Boom, you're a physicist
• 26:13
  Speaker 1: right here today on the podcast and deputize you. Yeah. Alright,
• 26:17
  Speaker 1: So if you wanted to propose a field, they would
• 26:19
  Speaker 1: have to solve a problem, right, like why this field
• 26:21
  Speaker 1: and not some other fields? And you'd have to provide
• 26:24
  Speaker 1: a way for us to check, like what in what
• 26:26
  Speaker 1: experiment could we see the Jorge particle, right, which is
• 26:30
  Speaker 1: an excitation of the Jorge field, right, and the same
• 26:33
  Speaker 1: as the Higgs boson is an excited state of the
• 26:36
  Speaker 1: Higgs field. Right. You have to provide some way for
• 26:39
  Speaker 1: us to do that, and Peter Higgs did. He's like, oh, well,
• 26:41
  Speaker 1: if you smash protons together this energy, you should see
• 26:44
  Speaker 1: a certain number of Higgs particles. All right, So, um,
• 26:47
  Speaker 1: i'll table that for my next career after we have
• 26:50
  Speaker 1: a podcast host in a world where cartoonists try to
• 26:54
  Speaker 1: be physicists. Before we keep going, let's take a short break. Um, okay.
• 27:12
  Speaker 1: So yeah, it's it's like it's like, really the basic
• 27:14
  Speaker 1: theory of everything, you know, matter, light, forces, energy, any
• 27:20
  Speaker 1: kind of everything out there, we describe it using quantum fields.
• 27:25
  Speaker 1: Almost everything is there? Yeah? Is there something we don't
• 27:27
  Speaker 1: describe with quantum fields? Yeah, And it's always the same thing.
• 27:31
  Speaker 1: It's the black sheep of physics. It's gravity. It's quantum
• 27:35
  Speaker 1: field theory describes matter, it describes electromagnetism, it describes the
• 27:39
  Speaker 1: weak nuclear force, it describes the strong nuclear force. It
• 27:43
  Speaker 1: even can incorporate special relativity, meaning we understand what happens
• 27:47
  Speaker 1: when electrons go super duper fast close to the speed
• 27:49
  Speaker 1: of light. Right, But quantum field theory is easiest when
• 27:54
  Speaker 1: space is flat. I mean, we can do quantum field
• 27:57
  Speaker 1: theory and curved spaces, but it gets really nasty in space.
• 28:00
  Speaker 1: Getting curved is exactly what general relativity says will happen.
• 28:04
  Speaker 1: So what quantum field you're saying, don't work in space
• 28:09
  Speaker 1: that is not flat, like, it only works in flat space.
• 28:13
  Speaker 1: Not exactly. We can do it, but it's not easy.
• 28:16
  Speaker 1: It's not a lot of fun. Why not? Why not? Um,
• 28:21
  Speaker 1: it's a no, it's a great question. It's a great question.
• 28:24
  Speaker 1: So the issue is more about figuring out how to
• 28:26
  Speaker 1: get quantum field theory, to explain that curvature, to generate
• 28:29
  Speaker 1: that curvature, to get a quantum field theory description of
• 28:32
  Speaker 1: how space gets curved. Like, I like your space curves
• 28:36
  Speaker 1: or contracts. What does that do to the quantum field?
• 28:39
  Speaker 1: Doesn't it just squishes it or bends it? Oh? Yeah,
• 28:42
  Speaker 1: you're right, it just squishes it. Thanks. We just solve
• 28:44
  Speaker 1: that problem, all right, Um, check that off the list
• 28:47
  Speaker 1: of modern physics mysteries. Nobel Prize please, Yeah, the squish function.
• 28:50
  Speaker 1: We'll decide this function. Um. I think also the larger
• 28:53
  Speaker 1: problem is that we don't know how to describe gravity
• 28:57
  Speaker 1: in terms of a quantum field. Right, electromagna autism and
• 29:00
  Speaker 1: all these other forces we can describe as oscillations in
• 29:03
  Speaker 1: the field. Right, and that fields associated with its own particle.
• 29:06
  Speaker 1: The photon is is the particles is associated with the
• 29:09
  Speaker 1: field for electromagnetism, the gluon is the particle associated with
• 29:13
  Speaker 1: the field. For the strong nuclear force. We have never
• 29:16
  Speaker 1: been able to describe gravity in terms of a quantum field,
• 29:19
  Speaker 1: like a gravitational field field space and has a particle
• 29:23
  Speaker 1: associated with the graviton. We try to do that. We
• 29:27
  Speaker 1: try to do those theories and write them down, but
• 29:29
  Speaker 1: you get crazy answers, you get infinities where you should
• 29:31
  Speaker 1: get reasonable numbers, and just doesn't work on and so
• 29:34
  Speaker 1: even if you came up with the gravity quantum field
• 29:37
  Speaker 1: and the graviton, it's still you're saying by itself, it's
• 29:41
  Speaker 1: not consistent even in flat space. That's right, it's um.
• 29:45
  Speaker 1: We can't make those theories work. I mean, people have tried,
• 29:47
  Speaker 1: and people are trying, and they're writing down theories of
• 29:49
  Speaker 1: quantum um gravity, but those theories don't make testable predictions
• 29:53
  Speaker 1: that make sense. You know, They predict infinities. You know,
• 29:55
  Speaker 1: what is the force between these two particles? Infinity? How
• 29:58
  Speaker 1: much mass does this thing have? Infinite? So it makes
• 30:02
  Speaker 1: predictions which your nonsense, and we haven't been able to
• 30:04
  Speaker 1: fix them mathematically. What if it does have infinite masks?
• 30:08
  Speaker 1: No wonder, I feel so sluggish today, I have infinite masks.
• 30:12
  Speaker 1: Um alright, So quantum fields they PerMIATE everything. They describe
• 30:21
  Speaker 1: everything that we know about almost except gravity, except gravity,
• 30:25
  Speaker 1: and and and they're amazingly accurate, like you're you're telling
• 30:29
  Speaker 1: me earlier. They can predict things up to like ten
• 30:33
  Speaker 1: decimal places. Yes, exactly, it's super accurate. Like if you
• 30:37
  Speaker 1: exclude gravity, we can do these experiments and we can
• 30:40
  Speaker 1: check them and we get bang on the right answer
• 30:42
  Speaker 1: to as far as we can measure. You know, it's
• 30:44
  Speaker 1: a kind of thing that makes me wonder if we
• 30:46
  Speaker 1: really have pulled back the curtain of nature and seeing
• 30:49
  Speaker 1: the way the world really works. You know, yeah, yeah,
• 30:52
  Speaker 1: that sort of makes me all wonder. You know, if
• 30:54
  Speaker 1: this is the way the universe works? What makes these fields? Like,
• 30:58
  Speaker 1: what's what's their origin? Where do they come from? You
• 31:01
  Speaker 1: just never satisfied, are you, Jorge? We explain matter in
• 31:04
  Speaker 1: terms of particles. We explained particles in terms of fields,
• 31:06
  Speaker 1: But you're like, I want more. What makes up the fields? Yeah?
• 31:11
  Speaker 1: How far? How far does the rabbit hole go? Yeah?
• 31:14
  Speaker 1: I mean we've explained the way matter works in terms
• 31:16
  Speaker 1: of particles, and particles work in terms of fields and so,
• 31:18
  Speaker 1: and then of course the next natural question is you
• 31:21
  Speaker 1: know what makes the fields? Are the fields actually just
• 31:24
  Speaker 1: something else? Right? Uh, the wiggling of strings or you know,
• 31:29
  Speaker 1: the dancing of tiny puppies or something. We don't know,
• 31:32
  Speaker 1: and we don't know. If we get that answer, if
• 31:33
  Speaker 1: there's not another question behind it, right, it goes even deeper.
• 31:37
  Speaker 1: Is there an end of this rabbit hole? We have
• 31:38
  Speaker 1: no idea. Frankly, I hope not. I think the answer
• 31:41
  Speaker 1: is clear. It's made to Glorian's obviously making absolutely. Yeah,
• 31:47
  Speaker 1: that was definitely a documentary. So you know, the next
• 31:52
  Speaker 1: time you are out walking around in the world and
• 31:54
  Speaker 1: you look up at the sky and you are amazed
• 31:56
  Speaker 1: at how beautiful things are, remember that deep down underneath
• 31:59
  Speaker 1: it's a hot, sasty, frothing mess of quantum fields, oscillating
• 32:02
  Speaker 1: and interacting and bouncing against each other and doing crazy
• 32:06
  Speaker 1: calculations just to make your everyday world work for you. Yeah,
• 32:10
  Speaker 1: I like to think of it more as happy fields,
• 32:12
  Speaker 1: maybe not so like nasty What if they're happy fields? Happy?
• 32:16
  Speaker 1: What's happy about these fields? They're like zinging and zinging
• 32:19
  Speaker 1: and interacting with each other, and they're like never resting,
• 32:21
  Speaker 1: you know, they're they're not like slow lingorious lazy fields.
• 32:26
  Speaker 1: You know, these are hyper fields. But it's interesting. I
• 32:29
  Speaker 1: think it sort of makes me think that maybe in
• 32:32
  Speaker 1: a way, we are all connected, you know, if we're
• 32:34
  Speaker 1: all just vibrations in these mysterious quantum fields of stuff,
• 32:42
  Speaker 1: we're all sort of part of all We're all connected,
• 32:44
  Speaker 1: you know, we're all part of part of the same
• 32:46
  Speaker 1: stuff that the universe is made out of. That's right, Me,
• 32:49
  Speaker 1: you and Kevin, who are all really the same, all
• 32:52
  Speaker 1: the Kens, all of them, all the Kevin's, We are
• 32:55
  Speaker 1: all the Kevin's. Basically, that's my new religion, the Church
• 32:58
  Speaker 1: of Kevin to the Church of the Flying Kevin Monster.
• 33:02
  Speaker 1: Now we are all oscillations in the same universe expanding fields.
• 33:06
  Speaker 1: That is true. All right, Well, I hope you enjoyed
• 33:09
  Speaker 1: that quantum field discussion. Thanks for tuning in, And if
• 33:12
  Speaker 1: you have some crazy concept in physics you'd like us
• 33:15
  Speaker 1: to break down, send it to us at Feedback at
• 33:18
  Speaker 1: Daniel and Jorge dot com. Or if your name is Kevin,
• 33:21
  Speaker 1: we have reserved an email address for you, which is
• 33:24
  Speaker 1: Kevin at Daniel and Jorge dot com. That's right, and
• 33:28
  Speaker 1: if you have secrets to the universe, Kevin, please send
• 33:31
  Speaker 1: them to us at that address. See you next time.
• 33:34
  Speaker 1: Thanks for listening. If you still have a question after
• 33:45
  Speaker 1: listening to all these explanations, please drop us a line.
• 33:48
  Speaker 1: We'd love to hear from you. You can find us
• 33:50
  Speaker 1: at Facebook, Twitter, and Instagram at Daniel and Jorge that's
• 33:54
  Speaker 1: one word, or email us at Feedback at Daniel and
• 33:58
  Speaker 1: Jorge dot com. One