Daniel and Jorge Explain the UniverseDaniel and Jorge explain how the theory of "Renormalization" tells us that we measure is different from what is real.
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Hey, Orge, remember a few weeks ago when we criticized Albert Einstein.
I remember you criticized Einstein.
Well, you know, he added a big fudge factor to his theory just to make it work.
Yeah, it was a pretty big fudge factor. I guess it was a little bit embarrassing for the old genius.
Yeah, it was sort of a universe sized fudge factor. Well, you know, turns out maybe I shouldn't have been so critical, because particle physics has some fudge factors of its own.
Article physicists shouldn't be throwing stones at glass theories.
That's right, we got some whoppers of fudgebacktors.
Are they Einstein size? Are they really big?
Well?
It does infinity count is really big?
Does nothing count as really small. I think so. I am more handwa, a cartoonist and the creator of PhD comics.
Hi. I'm Daniel, I'm a particle physicist, and I'd just like to point out that Jorge is not just a cartoonist. He also has a PhD from a famous university.
Oh, thank you. I'm glad you think it's a famous university. You being on the other side of the Bay Area.
It's famously the second best university in the Bay Area.
You enough to Santa Clara University. I think that's probably true. But welcome anyways to our podcast, Daniel and Jorge Explain the Universe, a production of iHeartMedia.
In which we take you on a tour of all the incredible, amazing bonker stuff in the universe, from tiny little particles that don't really spin to enormous galaxies that spin mysteriously.
Yeah. We go from the crazy maybe ideas that physicists have about the universe to the actual nitty gritty theories that they have.
Because everybody's curious about our universe, how does it work? What's really happening? The search for truth and understanding is as old as human consciousness, and here we take you on some of the last steps, and we try to bring you up to speed to what scientists are thinking right now. What model is in the head of particle physicists when they think about a particle. How does a cosmologist think about the whole universe?
Yeah, and are they right or are they just making it up as they go along?
And does it make any sense? And what does it mean if the universe doesn't actually make sense? Oh boy, Well, after today's episode you'll discover that it's all sort of monkers.
Well, these days, the universe doesn't seem to make a lot of sense. But fortunately that's what we're here for, and that's what physicists are here for, to try to put some order into the universe. And so today on the program, we'll be talking about a particular I don't know what would you call it? A hole in your theory of the universe or a hole in your theory of matter.
It's sort of like a shift in your perspective. We're used to thinking about particles in one certain way. What is their spin, what is their masks, what is their charge? But we discover that didn't really make a lot of sense. And what we had to do was think about particles in a totally different way.
I see. So when something's wrong or there's a big hole in it, you just call it you need to shift our perspective.
That's right. Let's just sweep all that under the rug and then call the rug our new idea. That's essentially what's happening here. But that's you know, that's an important part of physics. When you have a model and you push on it and push on it, you discover it doesn't actually quite work, and then you have to accept something counterintuitive, something new, a new perspective on the universe, but one that actually does work mathematically.
That's right, And so to be on the program, we'll be tackling the question what is renormalization.
Is it just a fancy physics word for making stuff up and pushing all the infinities under the carpet, or.
Are we going to talk about when things will go back to normal in this crazy world we live in right now? That's what I was hoping for when I saw the title, Daniel.
I would not rely on particle physics to make things normal. It reveals the bonkersness of the universe. It reveals how the universe is so hard to grasp, and we're in this constant journey of trying to map our understanding of the universe onto the microscopic to think about these little objects electrons and photons in terms of quantities that we find familiar, you know, mass or charge or spin. But it's a struggle.
I see. You have to sort of assume the opposite. When a particle physicist walks in, you're like, let's throw a nor normal outdoor. It's hard.
Buckle up and get ready for a journey to the weird because that's where we all live.
All right, Well, this is a pretty interesting idea, and it sort of has to do with your theories about particles and matter and that they sort of don't always work or there's holes about them.
Yeah, it's sort of akin to how if you try to describe particles in terms of particles like tiny little dots of stuff, that doesn't always work. Right. We see particles sometimes having properties like waves, right, they interfere, and so we have a broader sense of these things. They're not just little dots of stuff. They're these weird quantum mechanical objects. It can be like waves and like particles. So that's an example of how you might have to broaden your concept of a particle. And today we're gonna have to broaden it again, sort of in a different direction. I see, because the idea we had about particles carrying these little numbers with them doesn't actually quite work when you sit down to do them.
Well, man, I was just wrapping my head around that idea, Daniel. You're saying it doesn't apply or doesn't quite tell me what's happening in the universe.
Yeah, And you know what we do is we have this idea. We say, let's give these little dots in space, these labels, these numbers. We'll say charge minus one mass of whatever, spin of a half, and then let's see if it works. And when you run the numbers and try to compare it to what we see in experiments, it doesn't actually work. And it tells us something sort of deep and weird about what the particles are and what they aren't.
Oh, it sounds interesting and I want to know more. But first, as usual, Daniel went out there into the wilds of the Internet to ask people if they knew what renormalization was.
That's right, So thank you to everybody who volunteered to answer a random person on the internet questions.
So before you listen to these answers, think about it. Have you heard of the term renormalization or would you even know or guess what it could mean. Here's what people had to say.
Maybe something happened to you and you are becoming normal again.
I have no idea. I do not know, no clue. My guess would be to bring something back to normal after a change. I'm not sure.
When something goes normal again.
What happens if you don't know what any of the worlds. I really don't know.
It's not a term I've heard before. My guess is it has something to do with the phenomena of maintaining order in the universe.
We learned something new about space or so, whether that's on a cosmic scale or a particle scale, and we need to change our assumptions that go into our equations based on the new insight.
Well, it seems like some people are the same idea you did, hoping that you're going to go back normal.
I think getting back to normal is probably high on people's mind right now. But I like, yes, where the person just said doesn't mean becoming.
Normal, Well, I've never been normal so I can't really speak to that.
All right, Well, this sounds like a normal word, renormalization, but I'm guessing it has some pretty deep mathematical consequences here for particle physics.
Yeah, it comes from the word normalization, and normalization is just to make something normal. But in mathematics, when we say making something normal, we don't mean make it usual or typical, or you know, like when you were a kid. What we mean is we make it all add up to one or fix it to some specific.
Number, right, just sort of calibrate it almost in a way.
Yes, calibration exactly. And so renormalization is like oops, something went wrong and now we need to do it again. It's like, you know, you thought you had your speedometer working correctly on your ferrari, and then it turns out you were going one sixty when you thought you were only going eighty. So you got to recarry calendar, you got to renormal.
I see, make it normal again.
Yeah, make it normal again. Make it the old familiar ferrari or electric charge that you knew when you were a kid. Okay, And that's exactly the issue here is that we ran into a problem when we were trying to calculate the electric charge of the electron.
Hmmm, sounds pretty basic, isn't the electron something we've known for a long time and know what the charge is?
You think? So, right, it's sort of like how we defined electric charge. It's like, you know, Ben Franklin or whoever you know first identified this as moving charges, defined charges to be plus and minus and that's where the electron charge comes from. Right, It's the carrier of the minus one charge. It's like the definition of what the charge.
Is, right right, Oh, I see, so an electron has a negative charge.
Yeah, one, it's sort of the definition of charge.
What are the units electron?
Iss?
Well, you know it's defined in terms of coulombs, but it's a crazy number in terms of coulombs, and so we just in particle physics, we'd like to drop all the units and redefine everything, and so we just call it one E like one electron charge. That's the unit.
I see, all right, So it's kind of like the standard.
It's kind of like the standard. But the problem is if you say, okay, I have a little particle and I'm going to put a minus one charge on it, and then you'd put that into an experiment and try to measure the charge of it. You would actually measure zero. Like you shot other electrons at it, you would measure almost zero charge.
It sounds like a big area or you were expecting minus one and you get zero.
Yeah, So the electron can't have charge minus one because if it did, we would measure zero. And the reason is that the electron is never just by itself, right, It's not like a whole universe populated by just an electron. Instead, the electron is surrounded by space, and space is never empty. We've talked in this podcast a lot of times how space is not just the backdrop of the universe. It's this crothing quantum mechanical weirdness that can do stuff we don't understand, like expand and wiggle and stretch, And there are deep theories about space that people are working on. We talked about Steve Wolfram's idea about space and quantum foam space and.
Like it's a huge question mark. See, empty space is not empty. Empty space is not empty or spacey or space.
Is sometimes that space out when I think about it, but there is a lot of it. That's the one thing that's still true.
There's something to it, and somehow that's affecting what we measure about the electron.
Yeah, because space is filled with energy, and that energy can turn into virtual particles, particles that pop in and out of existence really briefly. And when that happens, usually you get a pair of the particles, like a plus one and a minus one that pop out together.
It has to balance out, Like you can't just introduce more negative charge into the universe. You kind of have to balance it out.
That's right.
There still follows some rules, right, Virtual particles are not a total free for all. They still have to observe the rules of the universe, and one of those is that the pluses and the minuses have to balance out, okay, And so essentially any electron is surrounded by a bunch of positive negative charged particles. So then the electrons field, the electric field that it creates, it pulls on the positive part of those virtual particles, and it pushes on the negative part of those virtual particles.
But they don't exist.
They do exist, though they do exist briefly, right and constantly is a frothing swarm of these particles. And so what it does is it like polarizes the vacuum. It pulls the positive part of these virtual particles closer, and it pushes the negative ones away, and it has the effect of essentially shielding the charge of the electron. Oh.
I see, but they don't exist though, do it? They actually pop into existence?
They do exist. They actually do pop into existence. Yeah, And you know, this is the kind of effect that's very familiar. Like the reason you can't use your cell phone inside an elevator is that electromagnetic field can't penetrate very well through metals because metals are filled with little charge carriers electrons, and when electric field passes through metal, the electrons will like rearrange themselves to cancel out any field. It's called a Faraday cage.
Okay, So then if you have an electron, it's going to pull these virtual plus particles to it, which then cancel it out. Is that kind of what you're saying. Yeah, But these for virtual particles are also like positrons or are they you know, imaginary? Are they actual like you know, ions or muons or what are they?
They're actually all kinds Because you can have any kind of virtual particle. You could have virtual particles that are pairs of electrons and positrons. Like you said, you could also create muons and anti muons. You can create quarks and anti quarks. You can create anything you like out of the vacuum as long as you observe the conservation laws, and the most likely you're going to create the lowest mass particles. So usually you're going to get things like electrons and positrons.
Okay, but they're sort of virtual because they're popping into existence and popping out of existence.
But there's enough of them and there's a constant popping in and out of existence that effectively they are real. They count as if they were there. And so what happens is that you shield the true charge of the electron. It reduces it. It like screens the charge sort of like if you want to know how cold it is in your freezer, but all you can do is measure on the outside. Well, you're not really measuring the true temperature inside your freezer, right, You're shielded by all the insulation, and so that's essentially what's happening here.
So then if all electrons then are shielded, how do they even work? Yeah, Like if I have two electrons in space and they're shielded, then they wouldn't repel each other.
That's true if the electrons charge is actually minus one, but it's not. That's the kicker, that's the renormalization. The charge we measure is minus one. Right, electrons do repel each other. You're right, electricity is real. Right, we're not repealing electricity to the.
End of the podcast, which is canceled the electricity.
Yeah, exactly. But what we've discovered is what we've been measuring for more than one hundred years is not the true charge of the electron. It's this shielded charge we're measuring the electron on the outside of the freezer. That charge is mine. What is the electron's true charge behind all that shielding. That was the new question.
Oh, I see it's in the freezer, and we didn't really know how cold it is or how electrically charged it is.
Yeah, and we sat down to do these calculations. We realized, wait, isn't there a big effect from this freezer, from this shielding, from the screening, from all these virtual particles. And people started to calculating and they realize, yeah, there is. So if electrons had charge actually minus one, we should be measuring zero charge in experiments, but obviously we're not. So they went back and they said, how much do we have to dial up the charge of the electron before we get a measured charge of minus one? So extrapolate through this cloud of particles and say, what's really going on in there?
So what we see of the electron, what we measure as its charge, is what we measure through the insulation, this virtual insallation that you're talking about.
That's right.
Oh, and so the question is what's the true value inside?
That's right. Let's pull back a layer of reality and say what is really happening.
Okay, it's not just minus too, I'm gonna.
Guess no, it's going to be totally unsatisfying and frustrating, like usual with particle physicism.
Great, well, I'm looking forward to it, Daniel. So let's get into it, and what does a real charge means of the for the electron and for mass and for the entire universe. But first, let's take a quick break.
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All right, so, an electron doesn't have the charge of an electron. Apparently depends what you mean by an electron. Up is not up, and the electron doesn't have the electron of an electron.
No, it's really it's about definitions, and that's where we're going to end up today is talking about like what it means to be an electron. Because the thing we measure, if you call that an electron, you know, some weird quantum dot with all of its shielding and fuzziness and virtual particles all around it. That thing has charged minus one. Right, But if you try to penetrate that cloud and say this bit at the core, the true electron, the fundamental electron. Because we're interested in understanding the deep nature of the universe, not like the effective, messy, sloppy things we can actually measure. We want to you know, penetrate all the way in and see what's really.
Happened to see. So I guess celebrity. You know, they're surrounded by all this hype and people and you never know really who they are on the inside. And so that's what we're doing today. We're peeling bag the layers of stuff to get a real sneak pick at the electron inside. That's right, So what is the real charge in of the elect.
When you get through the electrons entourage? What you discover urge is to make the measured charge minus one, you have to set the true charge. And particle physics we call this the bear charge. Like an electrono by itself to minus infinity.
Like what the bare minimum? You know, just a small thing like minus infinity.
I know. I remember learning about this and thinking, oh, renormalization. Okay, so you.
Gotta adjust the charge of the tweet. Yeah, maybe it's going to go down.
To one and a half or two or whatever, and then discovering you gotta go to minus infinity. What that doesn't even make any sense? That's great. You can't call that renormalization.
How can you say that an electron has a negative charge of negative infinity? What does it even mean?
It's hard to understand, and you know mathematically what's happening is that the more the electron is charged, the more it gets shielded. Like, the more powerful it charges, the more it polarizes the vacuum around it. If you crank it up to minus two, you don't get much measured charge. You gotta really crank it up incredibly just to get any measured charge because it works against you.
There's no limit to these virtual particles.
No, I mean space is full of them. And then what does it mean? Like whenever you discover an infinity in particle.
Physics, space is full up to infinity, Like if space has an infinite number of virtual particles all the time everywhere.
Yeah, an infinite number of virtual particles. That is true, it's not an infinite amount of energy. So there's an infinite number of virtual particles. The number of them increases as their energy decreases. So it's rare to get a high energy virtual particle or a high mass virtual particle. It's totally common to get an almost zero energy particle. I see, the smaller the energy, the higher the probability, and so as that goes to zero, you literally get infinite numbers of particles. But anytime you infinity in a particle physics, like you say, okay, this particle has minus infinity charge, that tells you you're doing something wrong, not just this particle.
I imagine it then applies to all particles.
Yep, this does actually apply to every single charge particle in the universe. That's right. So it's a pretty big problem. And you know, we should not be throwing stones at Einstein when it comes to like, you know, oh boy, making big corrections to basic facts about particles in the universe.
So my intuition tells me that it's it seems impossible, if not impossible, for every particle in the universe who have an infinite charge. So I guess, step me through what's going on, Like, where does our model of the universe break that we have to do this fudge?
If it is a fudge, No, it's it's sort of a fudge. But what you have to do is renormalize your theory of a particle, your idea of what a particle is. Like we've been thinking about an electron as a tiny individual dot, like a basic constituent, you know, mini lego brick out of which stuff in the universe is made out of right. But instead that doesn't physically make sense. It has to have negative infinity charge. Instead. You need to think about the electron, not by itself. The whole concept of an electron only makes sense together with this virtual swarm of particles. So that's not separate from the electron. It's not just an electron in the freezer. The freezer is part of the electron.
Icee hmmm. Just gonna pull back your definition and ignore what's inside of the freezer is kind of what you're saying.
That's right. It's like you say, hey, I'm not going to clean up my living room. Messiness is my new living room, and that's just you know, this is how I live now. This is the new clean. Right, that's renormalization.
Oh icy, Okay, god, got messiness is a new clean. Infinite particles is a new emptiness, and negative charge is it a new minus one?
That's right, and space is the nothingness. Trust me, this all makes sense?
Okay, got it? Got it? So I think that's kind of what you're saying is just ignore what's inside of the freezer and the don't open the freezer. Don't even think about what could be in there growing you know, who knows what. Just lock the freezer, throw away the key, and just deal with the freezer.
Yeah, And the thing to remember is that when you get an infinity to the answer to a physics question, it tells you that you're asking a question that doesn't really make sense or that isn't really logical. Here here's another simple example. Say you wanted to know what's the force on my head from all the stuff in the universe that's on my left. Well, the universe is infinite, then there's literally an infinite force of gravity and electromagnetism and all that stuff on your head from that side of the universe. Now there's a whole other side of the universe that also has an infinite force from the right side of the universe right, and they cancel each other out to get basically zero force. So asking that kind of question just means this an artificial distinction that you've introduced. The infinity comes only because the question you're asking doesn't really makes sense, like what is the left side of the universe or the right side of the universe. In the same way, trying to separate the electron from the rest of the universe and asking what is its charge? All by itself, that doesn't really make sense. You have to think about the electron as part of an interaction. I mean, the electron has interactions. It sends off photons constantly. It's not doesn't really make sense to sort of draw a dotted line just around it and say, only think about this bit.
I think I understood that a negative infinity amount. I feel like I feel like you're saying, does that's just ignore this little weird fact and just not think about it and just go with the flow.
No, don't ignore it, but just redefine the question you're asking. It's just like in Douglas Adams. You know, if you ask a question and get a nonsense answer, you have to go back and think about maybe I should ask a better question. In this context, asking what is the charge of the bear electron doesn't really make sense because that's not a physical thing. You'll never have a bear electron.
There'll never be an electron without its on.
That's right, only in a universe in which there is only electrons and there are no interactions at all, which can't exist.
So I guess you're saying that what's inside the freezer doesn't matter because we'll never open the freezer, or they'll never be something without a freezer, that's right, And we can't open the freezer. So even though you would predict that there's negative infinity charge inside of the freezer, that's probably not what's going on because we don't really know when we never will open that freezer.
Yes, except we have ways to partially crack open the freezer. Boy, Yeah, all right, because this is a virtual cloud of particles, right, and we can penetrate it. Like if you shoot an electron at another electron really hard, it'll get through more of that virtual cloud than if you shoot an electron at it really gently. And so it turns out that the harder you shoot one electron at another, the stronger the charge you measure. So the charge of the electrons on the energy of the particle you're using to measure it. So the electron doesn't just have a charge of minus one that you measure or minus infinity inside the freezer. The answer depends on how much you've cracked open the freezer.
How much the entourage gets out of the way or something.
Yes, so you can get through this virtual cloud of particles partially. You can never get all the way, but the more you probe in there, the stronger the charge of the electron that you measure. So it sort of is like a real physical thing.
You can poke it to freezer and kind of take a peek inside, and it does look like it's almost negative infinity. Is that kind of what you're saying.
Yeah, you can never get to negative infinity, but the higher energy you probe with, the stronger the charge you measure. And so that's also sort of like, you know, a bit of a brain scramble. You're used to thinking of the charge of the electron as a basic fundamental constant, right, Well, it turns out it's not constant. It depends on the energy at which you're probing the electron.
So the charge of an electron is not then one of the fundamental constants. No, it's not or basic constant. Not, And we talked about this on a podcast recently, how there's a different constant. It's called the fine structure constant. That includes the charge of the electron and the speed of light and planks constant because those things themselves are not actually fundamental constants. Only in combination. The ratio a special ratio of those things are fundamental constants. I see. So I guess what you're saying is, if I shoot an electron with a fast enough electron, I would maybe measure its charge to be negative infinity.
Yeah, it had to be an infinitely fast electron that you're shooting. But the faster the electron that you're using in your gun, the stronger the charge you measure on the electron.
Well, I feel like we're throwing infinities all around, so why not let's just throw an infinite number of infinitely fast electrons.
Now there's just no rules now, right, just like whatever anything can happen doesn't even matter, all right.
Well, yeah, that's pretty wild to know that the electron has this kind of hidden and maybe infinite charge. And so I guess the question is, how does that affect what we thought about the universe or how we look at things like mass or you know, ef egos am and all that stuff. So let's get into it. But first, let's take a quick break.
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All right, so apparently the electron has possibly a negative infinity charge if you can get to it, if you can get past the cloud of virtual particles that surrounded and protected and kind of shielded from the rest of the universe. And so that's a wild concept, Daniel, Now, what does it mean about what we know about the electron?
Well, it's not just the electron. Remember, all charge particles have the same property that they shield themselves. And what we're measuring is really the variable strength of the electromagnetic interaction. And the higher the energy you have, the stronger this interaction is. And so what it tells us is that the particle by themselves is unique. This bare particle, the stripped of all interactions, is not a physical thing that we should be thinking about. And we need to renormalize our idea and think about the particle together with its entourage. That really defines who it is. Because you know, if you met a celebrity without their entourage, they probably wouldn't seem that famous either, would they. It seemed normal and down to earth.
I don't know. You tell me you've met me in person, Daniel, What is that to you?
I had to fight my way through your entourage just to talk to you, all right.
So that's kind of what this renormalization means. It's like kind of like getting used to the entourage of particles.
And it doesn't just apply to the charge. It turns out that most of the fundamental characteristics of the particles have this same property that they have a measured value and then a weird sometimes non physical sort of bare true value.
I mean, like some of the other quantum charges like color and spin and things like that.
Just like that. Yeah, the strong nuclear f also has its strength vary with the energy of the particles that are shooting at it. But I think one of the weirdest things is the particle mass. Like we think about mass and sort of like a defining characteristic of a particle, like what's the difference between an electron and a muon while a muon is heavier. Right, we identify particles by their mass, But it turns out that what we measure when we measure the mass of the particle is not actually like the true fundamental mass of the particle. It's not the mass the particle would have if it was all by itself in the universe with no interactions.
Right, because instead of virtual particles that it interacts with, it interacts with something else, the Higgs field.
Right, that's right. All particles moving through the universe are interacting with all the quantum fields that are around them. And what happens when they interact is that you know, those fields emit little particles for them to interact with. And so you can imagine like an electron flying through the universe and it can emit a Higgs boson and then it can reabsorb that Higgs boson. That's effectively what's happening when and it's interacting with the Higgs field, it emits a virtual higgs boson and then reabsorbs it, and it can do that, or it can do admit two higgs bosons, or that higgs boson can split into other particles and then come back together. There's millions of different possible things that could happen as an electron is moving from A to B. And so we've talked before on the podcast about how the Higgs boson gives particles mass, and we say this field that fills the universe, and interacting with that field gives those particles masses. But we sort of got dot dotted over that critical bit, like how does interacting with a quantum field give a particle mass? What does that mean?
Right? Well, there's the analogy of like moving through a crowded party or something, right, Like you're trying to move, but the field is throwing particles at you, and you're throwing particles at it, and that's kind of what inertia sort of is.
That's exactly right. And if you want to go from A to B and you talk about a particle having mass, then it takes energy to speed it up. As it's going from A to B, it takes energy to slow it down and it turns out that's inertia, right, And that can be exactly modeled as a particle interacting with a field, because as it goes along, you can emit a particle, it can absorb a particle. There's all these complicated interactions that can happen, and those interactions have exactly the same effect as if you just gave a particle inertia sort of by hand. Those interactions all add up to create this effect that we describe as mass like. It's again, this is a separation between like our macroscopic observations of stuff and the microscopic explanation for what's really happening, And the macroscopic thing we're familiar with is like, hey, stuff seems to have inertia. You know, you push on a heavy rock, it takes a while to get it going. You're downhill from a heavy rock, you better move out of the way because it's hard to slow down, right, And that macroscopic property turns out to be explained by all the little particles inside it interacting with the Higgs.
Field with virtual particle, with.
Virtual particles exactly that it's the key.
Are you saying, sort of like all particles and it's not just their electrical charge. You're saying their mass is also kind of insulated by these virtual Higgs Boson clouds.
I'm saying that what we call an electron that has mass is actually an electron with a swarm of Higgs bosons around it. That's what it means for an electron to have mass, is that it's sort of clouded by the Higgs field, and so an electron moving through a universe with no Higgs field would have no mass. Right, So what we call the electron is not really just the electron. It's the electron surrounded by this swarm of virtual particles it's constantly interacting with. So in the same way we renormalized our concept of the electron as the electron surrounded by its virtual screen of particles shielding its charge, we also have to include for the electron when we think about its mass, we have to think about this virtual cloud of particles it's in interacting with, because that's where it.
Gets its mass. It's like kind of like what you're saying is that all of the these quantum fields in the universe are all sort of connected to each other, and so you can't really talk about one thing because it's it's all connected everything. Nothing can exist on its own.
That's right. We got pretty spiritual pretty quick there. Man.
Maybe it all is just renormaloss.
Past that do be over here, Man, I want to renormalize. Yeah, exactly. You got to smoke your banana peels. And you've got to understand that these particles they're not on their own. They're just fluctuations of quantum fields, and these fields are all interacting with each other. And so it doesn't really make physical sense to say, what is the mass of this one little particle, what is the charge of this one little particle? You got to think about it together.
In fact, you're sort of saying that particles don't have mass without the Higgs field, right.
That's exactly right. If there was no Higgs field, these particles would all have zero masses. And so the bare mass of these particles in the limit where you think about the minim interacting is zero. All the particles in the Standard model except for the Higgs boson, have bare mass of zero, and they all get their masses through this virtual swarm of craziness. I see. And it's not just actually through interacting with the Higgs. Like the electron also gets more mass because it emits photons. I know that's especially weird because photons have no mass.
Right, in addition to interacting with the Higgs, they get mass from photons.
That's right, they get mass from photons. And now if there wasn't the Higgs, the electrons would have no mass. But because they're the Higgs, photons can add mass to the electron. It's like multiplicative, like they make it have, you know, they multiply its mass by a certain factor. If it was zero, it'd stave zero. But since the electron gets some mass from the Higgs, the photons boost itase. Remember, mass is also related to energy in the sense what we're talking about is how the electron has a lot of self energy. It's constantly emitting and absorbing a swarm of photons, and those contribute to its effective mass, which is what in the end we measure. We only measure, you know, physical things. We can't actually measure true things about the electron if it was in the universe.
I feel like you guys wanted to call it naked charge, but you were but you sort of backtop. You're like, it's naked charge, but we can't call it naked charge. It's called bear charge and thus confusing everyone because they're like bears. What do you mean, like like a bear?
Yeah, exactly, it's one of the bear necessities, you.
Know, exactly all right, But then does the electron then have a constant mass or does it also vary like it's charged.
It also varies. Yeah, all these quantities actually vary with the energy you're using to probe it.
But last time we talked, that said the mass of the particles were constant in the universe.
No, you're totally right, And what we actually mean when we say those constants is we mean the strength of the interaction with those particles and the Higgs field. That's what controls the mass. But the mass that you measure an individual experiment does depend on the actual energy of that experiment.
Mm. Wow, So now we also have to redefine mass. Mass doesn't exist. It seems it's inside the freezer.
Yeah, everything's inside the freezer. This is something that helps you also understand how the universe could have been very different in its early years because in the very early moments of the universe, remember, things were hot and dense and nasty, and all the particles had a lot of energy. And all these forces charge, and the strong nuclear force and the weak nuclear force, all of them depend on the energy. And so back in the early days of the universe we think that maybe all the forces had the same strength, and that what's happened since then as things cooled down and things got slower and calmer, is that these things have different like variations with energy. You know, one of them drops really quickly as things go to low energy, another one drops really slowly. But back in the early days things were glorious and unified.
Back then things were normal. Then we denormalize kind.
Of, and now we got to renormalize.
You got to renormalize. But I have to say, none of this makes me feel normal at all. That you just told me that the electron doesn't have a charge and it doesn't have mass.
So it's not easy also for particle physics to accept this. There were a lot of years when after people made this discovery that you had these weird infinities in the theory, that they thought, well, the theory must just be wrong, right, there must be a problem with the theory. And then people realized, oh, well, you know, you just redefine what you mean by an electron and then you don't have to worry about those infinities. And a lot of people objected. They were like, you can't just do that. You can't just define your living room to be clean now. But if you don't have any better ideas, it turns out you can.
But it turns out you can. If yours is the only house in the universe and you're the only one person living there, you can define it however you want.
But then there was a guy Ken Wilson, who's sort of an underappreciated genius, who sort of made a deeper point about the whole nature of the universe, and he said, you know, nothing is really constant. Everything depends on energy. The physics you measure depends on the energy you're using to measure it. So it's totally natural for things to vary. In fact, the mistake was to expect anything to be constant. Oh so he'said the grandest renormalization of them all.
I see. Wow, he like dropped the mic. He's like, bam, I just redefined normal exactly. He redefined what success was. All right, Well, I think it's pretty interesting and mind blowing to think about what happens when you actually get down to that level. You know, when you try to get down to the zero size of the electron, what happens and how things kind of blow up mathematically?
Yeah, and will always struggle to explain the microscopic in terms of ideas we invented as macroscopic beings, and there's no guarantee that we're going to succeed. But when those ideas break down is when I think we get the greatest insights into what's really happening down there. We know that they're not really particles, they're not really waves, they're weird quantum fluctuations and fields, and they're not just isolated little dots. And so that's I think when physics has to confront our priors, our assumptions, our basic instincts and discover that they're wrong are when we can make a big step forward in our sort of intuitive understanding.
Well, thank you, Daniel. I feel like for the rest of today, I'm going to be thinking about naked electrons, naked higgs bosons.
This is all cleared by the Emtion Picture Association of America.
That's right, do this rated P for physics.
Some naked particles may appear.
All right, Well, we hope you enjoyed that discussion and learn a little bit more about what's really the charge of the electrons and what's really the massive things and what happens when you get down to where things are not normal.
That's right, and I hope that this podcast on renormalization has renormalized everybody else out there to be an at home particle physicist.
Thanks for joining us, see you next time.
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