Daniel and Jorge Explain the UniverseThis mysterious particle is part of our Universe, but not part of the atom
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Hey, Jorgey, do you have a lot of cousins in your family?
Yeah, I've got a few. I have maybe over thirty six cousins, maybe around that number.
Wow, that's a big family. Well, would you be surprised to discover, sort of late in life a brand new cousin you'd never even heard of before.
That would be pretty amazing, kind of weird, I guess, but maybe, yeah, I would be surprised, all right.
And then what if that cousin turns out to be exactly like you, like, look like you in every single way.
Okay, Yeah, that's getting kind of weird.
All right. And then what if this cousin looks exactly like you, except they are two hundred times more.
Massive Dan Dan do Hi, I'm Jorge. I'm a cartoonist and the creator of PhD Comics.
Hi, I'm Daniel. I'm a particle physicist, and I do not have thirty six cousins.
Welcome to our podcast, Daniel and Jorge Explore Your Family Tree.
In which we examine all the amazing and fascinating things about the universe, about the big things, the small things, and about how things are related to each other.
Yeah, so no, that's not the name of our podcast. It's actually Daniel and Jorge Explain the Universe, a production of iHeartRadio, in which.
We do examine crazy things about the universe and we try to make them relatable. We try to present them in a way that you can understand them. So they connect to topics that matter to you.
Yeah, in a way, we do sort of explore the family tree of the universe. You know, how you came to be here, what sort of pairings and fusions occurred for you to be here in this universe? Appreciating it and listening to funny podcasts.
Yeah, I think one of the reasons people are in just did in the origins of the universe and the creations of our cosmosis because they want to understand how we got here and what it means. In the same way people explore their family tree. They want to know where did my family come from, what stories are in our past, what is my personal context? And also I think it's a useful way for us to sort of organize our thoughts. You know, when we think about the universe in terms of particles, we sometimes think about how those particles are related to each other, Like do particles have families?
Yeah? And I think you know, every part of anyone's family tree or origin tree kind of tells you a little bit of the story of the whole thing, right, like how you came to be, how things work and how things move about in life.
And other ways your life could have gone like, if you have a very successful cousin that's a gazillionaire, then you know you wonder, hmm, could I have made different choices and been a gazillionair Or if be people's paths in life diverge.
Yeah, or if you are that bazillion er cousin, then good for you. Please these contact as we would love to take your donations.
That's right, it'd be awesome to have at least one gazillionaire listener. Who is our richest listener? That's a good question.
Episode To prove it, you have to send us a check. Whoever sends is the biggest check that doesn't bounds. When's this little plaque here that I am I'm just now putting together?
It's made of platinum?
Right, Yeah, well it's going to be once we get those checks.
Yes, you'll get a drawing of a plaque that's made of platinum.
Oh my gosh, even more valuable from a well known internet cartoonist.
Exactly. But we do try to understand the world around us, and sometimes that means putting things in context and understanding what are the patterns, what are the structures there, and what clues do those patterns give? Us about the sort of fundamental nature of the universe.
Yeah. So today on the podcast, we'll be talking about a particle in nature that is maybe not the most famous one and maybe not the most well known one or consequential in your existence, but which does I think tell you a little bit about and told humanity a little bit about how the universe works.
Yeah, this is the non gazillionaire cousin. This is the cousin that ended up maybe sleeping under the overpass and wearing funny clothes to the family reunion.
Oh, I feel bad for this particle.
Now, this particle doesn't need your help. It's very massive.
Yes, In today's episode, we'll be talking about the muon Electron's mysterious, lesser known, much more massive cousin.
And I'm biased, of course, because I'm a particle physicist, but I think it's really fascinating to think about how we know each particle is there. We talk about the standard model of particle physics sometimes, but that's a theoretical construct that's like our idea for how these particles might relate to each other. And that's fascinating and we'll dig into all that. But I think it's also really important to remember each of these were discovered. There is a story behind each particle. Humanity didn't know it existed and then boom, some experiment revealed it. And on the podcast, we've talked about the first discovery of the particle, how the whole concept of a particle was created, the electron. Then we talked about how we know the photon is a thing, how we know it's really a particle, the photo electric effect, And so now we're going to take the next step and talk about the discovery of the muon.
Yeah, because you know, I think that every particle tells a story, you know, and also every story is made out of particle. So there's kind of this really weird confusing loop there.
Yeah, this is like the Superhero Origin story particle version.
Yeah. So the muon is not a name that rolls off the tongue. Makes me think of maybe cows muons, maybe.
Muon muon mew off, muon mew off. I was thinking sort of a karate kid thing there.
Oh, it's back to the eighties references.
Yeah, back to the eight references. And it's funny actually because the name muon is totally inappropriate. We'll dig into it later, But they named it before they discovered it because they thought it was going to be a different particle, and then they sort of changed the name later. It's not a great history for naming particles.
Oh boy, my favorite topic in science.
Yeah, and so I was wondering, how much do people know about Muon's. Is it a famous particle or is it sort of the darker cousin of the electron that nobody really knows about. Hasn't gotten the same Instagram attention.
The black sheep, the goateea wearing particle of the family tree.
Now you're setting it up to be like the grumpy particle. It's going to come in with some evil plan to finally get its revenge, and it's.
You already made this particle, the homeless particle that lives under a bridge.
So yeah, that was the sad particle that deserves our love and compassion, not the one that's been plotting its victorious return to the center of attention.
Well, you never know what these particles, you know, Physics is full of surprises.
There is a lot of drama. But as usual, I walked around and I asked people if they knew what the muon was and how we knew it was a thing.
Yeah, So before you listen to these answers, think about it for a second. If someone asks you what a muon is, would you know what it is? Have you heard it before? Here's what people had to say.
I'd say, it's a unit of measure.
It's like one of the fundamental elements or particle of what makes up everything.
A mew on.
Now, I believe this to be the name of a sub atomic particle.
Luons muon's uh, shoot, I don't remember what classification they fall on her as far as the naming conventions.
Fundamental particle some sort. It's real small sub atomic particles, kind of resemed what it does. How do we know muons exist? Particles? So what's your opinion of these answers today?
Pretty good? It sounds like most people have heard it or I heard of the word before, you know, very only a few people said never heard.
Of it mm hmmm, or think it was a unit of measure, like you know, how much water? Would you like, I'll have seven muons of water.
I wonder that if you pronounced it correctly, maybe they knew about it, but just under a different pronunciation.
You think I'm mispronouncing the name of Muon.
I don't know. I mean, what's the correct way? Is it Muon or Muon?
Like?
And you're making it sound like a Disney movie, like, Oh, my favorite Disney princess is Mulan.
My favorite Disney prince is Muon Muan.
Oh. That is a great way, though, to get more attention for particles in the mainstream. We should get Disney to name the next Disney princess after a particle.
Mm why not? Why it could be the next Pixar movie. What it's like. What's the emotional roller coaster right of being a fundamental particle of nature?
Yeah? So much to explore there, and I expect that we will be getting checks from Pixar when they make a billion dollar movie out of it. But I was impressed with these answers, though, I want to pick a bone about one thing. People say, yes, it's a fundamental particle, totally cool. People also say it's a sub atomic particle or it's one of the fundamental particles that make up everything. And that's really a key idea that I think people have not understood about muons, that you can be a tiny particle and not be subatomic not be part of the atom.
Oh, I see, sub atomic doesn't just mean it's smaller than atom. You're saying that, it means that you're part of the atom.
Remember, fundamental particles have no size there dots, They are zero volumes, so they're all smaller than the atom in that sense. So being fundamental guarantees you to be smaller than the atom. I think to me, sub atomic means it's part of the atom, like you break it up and you find it inside the atom.
Okay, so we'll get into that, but let's break it down for people. For us, what is a muon and why does it sound like an electron? You know it ends with on but maybe but it's not the electron.
Yeah, but it really is related to the electron. It's sort of like the electron's cousin. And by that I mean that it's identical to the electron in so many ways. It has the same electric charge, it has the same interactions with matter, like it interacts via the weak force and via the electromagnetic force, but it doesn't feel the strong force just like the electron. It has a neutrino, just like the electron has its neutrino. So in so many ways, it's exactly the same as the electron. Sound like when you discover a new particle and it's totally different, like a quark or a glu on, it's just completely different from the electron. This one is very very similar to the electron. It's like weirdly similar, but then with one important difference.
Okay, so it's a particle. Let's start down.
It's not a cow, it's not a Disney princess.
So it's a particle, meaning like it's a it's one of these things that you see in nature in the universe, like things that pop up and you can touch them, and and it's a thing.
Yes, muons are a thing. They are a little thing. There are particles, and they are little dots of matter. They have mass and they have charge and they interact.
Okay, so it's a particle like the electron. But you're saying and you say, it's a cousin of the electron, not that they share like not that their parents were siblings, but just like in the sense that it's very similar to the electron.
Yeah, when we organize our knowledge, we look for patterns, we look for similarities. Right like when we were one hundred years ago, when the state of knowledge about the universe was the periodic table. We didn't just have like a pile of different elements and say here's an element. There's an element. We said, oh, look, this one is similar to that one. They're both really active, or these are really similar because they're both really inactive, or this one weighs a tiny bit more than that one. We notice patterns. We put those patterns together in the same way. We're looking for patterns in the fundamental particles. So we try to figure out which ones are related to each other. And we have only a few handles on each particle. It's only like a few things we can know about a particle.
Right, And so is this a particle that we can see in our everyday lives, like is it floating around? Does it move around wires and electri electricity like the electron? Or is this kind of a weird one of those weird particles? And you know you don't ever actually.
See Yeah, you don't see the muon because it doesn't last for very long. It lives for two point two microseconds and then it turns into an electron and some neutrinos, but they are actually everywhere. There's ten thousand muons going through a square meter of Earth every minute, So there's lots of muons everywhere, but you just can't really see them very easily because they don't last very long.
Wait wait, I mean, how can they be everywhere but also only last two point two microseconds? Does that mean that they're constantly coming into existence, lasting for two point two microseconds and then disappearing and breaking up or what does that mean? How can they be all around is but also evaporating at the same time.
Well, there's two things going on there. One is right, they're being created when particles hit the atmosphere. So protons hit the atmosphere and they create a shower of particles, some of which include muons, and those muons fly along a little bit, but they don't last very long, just two point two microseconds, and then they turn into electrons. But they last for two point two microseconds according to their clocks. Because they move really fast, there's a relativistic time dilation, so they're according to us that two point two microseconds takes longer to click, and so for us it can take like seconds or minutes for muons to decay.
Oh but for them. If you were sitting on top of the muon, mm hmm, it would only last You would only be alive for two point two microseconds.
Yeah, that's the half life of a muon. So muon is not stable. It's not like an electron. It can just sit there for eons and eons and just be itself. A muon is a heavy particle, and heavy particles like to decay into lighter particles. In this case, the muon turns into an electron very quickly according to its clock.
Oh, I see the ones that we see, the ones coming from the Atmosphe are moving fast, so they last longer. But if I just created a muon here in front of me, it would last only for two point two microseconds, and it's not going anywhere.
Mm hmm. If you could break muons in your oven, you take them out of the oven two point two microseconds later, boom they turn into election.
Yeah. Yeah, gotta eat them up real quick.
Exactly. They're like making fortune cookies or.
Toss them really fast, have them pop out of toaster really fast, in which case it would last longer.
Technically, right, that's true, Yeah, exactly. Somebody could shoot muons into your mouth and it would last long enough to get there. I wouldn't recommend that though, that's not a suggestion for something somebody should do. And actually two point two microseconds is kind of a long time for a particle that's this massive to last mm.
So what does it mean that it disappears or breaks up like it's just unstable, like it just it's made out of other things and it breaks up, or it literally just kind of evaporates into energy and that energy turns into something else.
Yeah, that's a great question. These are fundamental particles, so they're not made up of anything else. As far as we know. The muon turns into the electron. It's not like it has an electron inside of it, and it breaks up into an electron and other stuff it converts. It goes from a muon, it turns via the weak force into a W particle and a neutrino, and then the W particle turns into an electron and another neutrino. So the muon turns into an electron and two different neutrinos, but it didn't have those bits inside of it. Remember, particle physics is like alchemy. We can convert one kind of matter into another kind of matter.
Okay, so it's it doesn't break apart, it's just somehow it's very existence. The universe sort of doesn't like it, like it it can It just ceazes to exist and in favor of other things existing instead of it.
Yeah, and this is true for every particle that is pretty massive. The universe doesn't like massive particles. It's like putting a particle on the top of a hill. Eventually it's going to roll down. And so the muon is like the at the top of the hill, and the electron is rolling down to the bottom of the hill. Eventually the mion is going to turn into the electron. And every particle in nature that can do this does this. The only reason the electron doesn't is that there's no lighter particle for it to turn into.
Oh, and that's why we are able to exist, because yes, the universe does seem to like electrons and quarks, which make us up, and so that's why we're stable. But if we were made out of neons, we would disappear pretty quickly.
Yes, exactly. We are made up of the lightest particles out there, up quarks and down quarks. Of the lightest quarks electrons of the lightest version of that kind of particle called e lepton. So the matter that makes us up that stable is made out of stuff that can't turn into lighter stuff because there is no lighter stuff for it to turn into.
Right, Yeah, there's nothing for it to turn into, so we stay where we are. But a meon is heavy and could turn into something else.
So it does precisely. And for those of you wondering, like, well, what about a photon, Why can't an electron turn into a photon. A photon is massless, Well, remember that there are rules about how these things happen, and one of those rules is conservation of electric charge. An electron has a minus one charge, so it can't turn into a photon, which has zero charge, because you'd have to somehow disappear that charge. The only way for that to happen is for an electron to hit a plus one positron and then they can turn into a photon together. But for a particle to just spontaneously decay, it has to convert to another particle that has all the same sort of quantum mechanical numbers.
Okay, so the meuon is the electron's massive cousin or massive sort of like alternate universe version of the electron.
Right, Yeah, it's two hundred times the mass of the electron. It's really really massive.
That's a lot. It's like two hundred meters crunch into the same meat.
Yes, exactly. It's like if you met another version of you, but you weren't bigger, you were denser or something. You're two hundred times as much mass, but still fundamental.
And it doesn't hang around existence very long. It usually breaks up into or not breaks up, but it turns into lighter particles, so we don't really seed around that much. But still it's sort of an important part of the universe, and it seems that it's a important part of the universe and also tells us a lot about the mysteries of how everything is put together.
Yeah, and it actually lasts a long time for a heavy particle. Other particles that are heavy, like the Higgs boson, they decay much more quickly. They decay in like ten to the minus twenty seconds, whereas this one decays very slowly. It's just two point two microseconds. And the reason is that it decays via the weak force, which is very weak to the weaker the force, the longer it takes for that decay to happen.
All right, let's get into that a little bit more, and also how it was discovered and why it is such an important particle. But first, let's take a quick break.
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All right, so the muon decays by the weak force? What does that mean? How can something decay via a force? Like the force makes a decay?
Yeah, the force sort of provides the avenue for the decay to happen. Like, how does a muon turn into an electron just and just roll down a hill and say, hey, now I'm an electron. It has to there has to be an interaction there. And so what happens is the muon turns into a W particle and a neutrino in the W particle, remember, is the particle of the weak force. It's like the weak force version of the photon. And so that's what we mean when we say it uses the weak force to decay. It just just spontaneously happened. Something has to sort of carry that information, something has to make it happen. It's like a reaction, and that reaction always includes one of the forces. And in this case, it uses the weak force.
Right, and that weak force came out of just its own energy.
It uses the mass. Right. The muon has a huge amount of energy in it because it has so much mass, and that mass is turned into the energy of the electron and the neutrinos that come out of it. So yeah, the weak force turns the mass of the muon into very small masses of these other particles and gives them a lot of energy.
Right, and it ends up as an electron and two neutrinos precisely. All right, Well, tell us Daniel, how was it discovered and why is this an important particle?
Well, it was discovered initially in cosmic rays. People saw these particles just sort of shooting from the sky, and they didn't understand what was making them, and they thought, oh, well, you know, we found a few particles, so these are probably electrons. This is you know, in the early nineteen hundreds, we didn't have a really deep understanding of how particles work. We didn't have a good bench of particles, and so people thought, you know, everything they saw they thought in terms of the particles at the time. So they have to sort of wind your mind back to what we knew at the time. Back then, we knew about protons, we knew about neutrons, we knew about electrons, and so people saw these particles shooting from the sky. They didn't know what made them, but what they saw was that they penetrated really far into matter, much more than electrons could.
We saw the actual muons, the not what it looks like after it decays or turns into something else, like we actually you can actually see and feel the muons.
You can't really feel them, but you can make particle detectors that can detect them. You can actually do this in your garage using something called a cloud chamber. They were able to see them using detectors that they put together. And these detectors were like a cubic piece of film, like remember the old way films worked, where like light was exposed on the film. You didn't have a digital camera or anything.
And that made some kind of chemical change. You're saying, you can make like a solid cube of this.
Yeah, you just take a solid cube of it, You leave it up on a mount and you leave it there for like six months, and then you cart it back down, or you ask your grad students to do that. Then you slice it into pieces and then you can develop each of those. And what you do is you see all the particles that shot through it in those six months, and so they can see and when they did this, they saw all these particles shooting through this film and they were surprised at how far they were going because electrons shouldn't get that far. Electrons penetrate in a little bit and then they stop. But these particles were shooting all the way through.
It's kind of like a bull in a china shop, you know, versus like a mouse in a china shop.
Yeah, And they didn't understand that. They thought, well, you know, are there two kinds of electrons are there. Sometimes electrons can penetrate really far. It was really a puzzle at the time.
What made them think it was an electron. Why couldn't it be like a some kind of new atom or something.
We did know it had negative charge, and so I think that's what made people think it was more likely to be an electron or something like an electron than something positive like inside the nucleus. And remember, at the time, we only knew basically about protons, neutrons, and electrons, and so everything we saw where like all of a sudden, having this imagination that we could explain everything in the universe in terms of these particles. And it was a great success of the particle model at the time, right, like everything could be built out of protons, neutrons, and electrons. What a wonderful simplification. And so when we first saw these particles that penetrated really far, we thought, well, it must be one of those, right, But it was not. It was not. And people were able to later produce it in the laboratory using collisions and all sorts of other stuff, and they discovered that if you put it in a magnetic field, it didn't bend as much as an electron, and that's when they decided, you know what, this must be a different kind of thing. It's like a new version of the electron, a different flavor of the electron, because it must be more massive, which is why it doesn't bend inside the magnetic.
Field as much, reflected as much because it has so much mass. It just has more inertia.
Precisely, it takes a stronger magnetic field to bend a muon than it does for an electron. And this was kind of a scandal in particle physics at the time.
Scandal.
Yeah, people were upset. They were like, what a muon? Who ordered that? Like, we don't need this. We get out of here with your ridiculous new particle. We have this beautiful description of the universe. We don't want more particles.
Up until then, everything that you knew about helped make the universe. It's kind of what you're saying, like everything you knew about had a purpose.
Yeah, we had taken apart the stuff around us and found the basic building blocks, and then we didn't. Some people were like, I don't want to hear stories about other building blocks that could be out there. It just sort of confuses the issue, right, it's a shift in the question not just what we made out of, but what is the basic organizing principle of the universe. It shows you all of a sudden that there's a larger question you didn't even think to ask.
It's like you find something that you don't know what to do with it, Like it doesn't help you with what you knew about how things work.
Yeah, you're putting together jigsaw puzzle and all of a sudden, somebody hands you like a really big piece that just doesn't fit, and you're like, what I didn't ask for, that I don't need, That doesn't help me with my problem, Like, well, but okay, but this piece is here and it's not going away.
Right, Yeah, And so it makes you think that maybe there's another puzzle, or that the puzzle is bigger than you think it is.
Yes, all of a sudden you realize this is a three dimensional puzzle and you've been only playing on two dimensions, and it just blows your mind. And so that's it's sort of an earthquake, an intellectual earthquake through the field at the moment. But also it's a great opportunity. Those are the kind of discoveries that make you realize, Wow, there's a whole larger question to ask, and there's a whole world of answers out there. And of course now we know there's not just the mew on, this also the tao, which is the even heavier version of it, and then every particle has these cousins. Yeah.
I like how this counts as a scandal in physics, Like was it on the front page of the Daily Physics News or the National Inquiring Inquirer of physics newspapers?
People have to all the tabloids.
People had to give testimony about this, and there were.
You know, physicists are not that exciting, so we just got to create drama wherever we can see. There was even more drama because some people had predicted the existence of a particle sort of similar to this.
Hmmm, what do you mean predicted like just just guessing.
Yeah. Well, there was a famous physicist named Yukaba the Genius and won a Nobel Prize for all sorts of fascinating stuff, and he was trying to understand the strong force. He was like, okay, the weak force, we have that one. We have the photon for the electromagnetism, but what mediates the strong force? And he did some calculations that he thought, hmm, I bet there's a particle out there about two hundred times the mass of the electron and it mediates the strong force, all right, So that's his prediction, right, And back in the day, physics would just make predictions like here's my idea and here's what I predict.
Like we need this for this for what we know to make sense.
Yeah, just like with the Higgs boson, Peter Higgs said, this doesn't make sense to me, but if you look at the universe in a new way, then it makes more sense. And this new way predicts a new particle, so you can test my theory. So that was what Yukawa did, and he predicted a new particle about two hundred times the mass of the electron. Then they found this particle and Yukawa was like, whoo, I was right. But it turns out this particle has nothing to do with this strong force at all. So it's just like a coincidence, right, And he still got the Nobel Prize. He still got the Nobel Prize, but not for this and not for this one. But he's sort of the reason why this particle has a strange name.
Oh really, he was a fan of cows.
I don't know if he liked Kobe Beef, you know, the guy's Japanese or anything, but he you know, we had the electron, which is really really light, and we had the proton, which is like two thousand times the mass of the electron, and he predicted a particle sort of at an intermediate mass, and so he wanted it called like the you know, the mesotron something where mazo means like middle, and so that was the sort of the origin of this, like, let's call these particles here, you know, in this mass region, we'll call the meso particles.
Wow, what don't you have to call it the messo on or meson on or I feel like, just to be consistent here.
And then later people were like, well, it's not just really have anything to do with these other particles that we found in the same mass, but we'll just keep calling it the muon anyway.
Right, I bet you wanted to call it the meon.
Yeah, I'm so smart on.
Yeah, but this is where like, come on, dude.
But it's a it's a fascinating moment in physics because.
Like the or the yuon is themeon, how about we call it the miuon done compromise.
That's exactly how these decisions get made, and that's why we have such terrible names for particles.
Yeah, so, but now it's so it's not a well known thing, like everyone knows about muon's. Do they know that they're there? And you can study them? You can, you can. They're going through our bodies right now at ten thousand times per minute.
Yeah, ten thousand muons per square meter per minute. And you're right. At first it was totally exotic and what is this weird thing? And now we know it's a relative of the electron, but also created another field, which is cosmic ray physics. It was the first cosmic ray scene. And at first people weren't sure, like where are these particles coming from? We know they're coming down from the sky, but are they made in the sky or whatever? And people did all these crazy experiments, like balloon experiments where they shot detectors up into the atmosphere with balloons and discovered that the higher up you go, the more muons there are, and that tells you that like muons are being created in the upper atmosphere, and then they're decaying as they sort of come down to Earth. And finally people put together this picture that like particles were hitting the top of the atmosphere and creating these showers of particles, and we were just sort of picking up the little last bits of the fireworks as they hit the surface.
Right. I bet they'd also try to shoot a cout to the moon. That's really inspiration.
Well, you know how the Russians put a dog in one of their first attempts to go to space. I won't comment as to whether particle physicists ever used a weather balloon to launch a cow.
Yeah, they're like, we gotta up those Russians a dog. Anyone can launch a dog into space. Law.
This is this is well before the space race. This is the cow race. But I love thinking about what it must have been to be a physicist at that time and to it like crack open a whole new era of discovery by by you know, putting photographic plates up on mountains and just seeing like what's up there. There's so many amazing things to discover. Someone like new world were opened up. They discover that all this invisible stuff is happening around us. That's really wonderful to sort of like crack open a new way of looking at the universe.
Yeah, all right, let's get into the last bit here, which is what does the muon teaches? What does it tell us about how the universe is put together? But first, let's take another quick break.
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All right, Danio, So the muon is a thing. It's there. It's super massive. It looks just like the electron. We can feel it. It's going through us right now. Why is it there? That's the question that maybe a lot of people have. I mean, we don't need the muon to make iPhones or pizzash, So why is it there?
Is that the standard upon which we judge things. Now, if you don't need you for iPhones or pizzas, you don't need to exist.
What else is there? Daniel?
That's my whole life basic. I just keeps No. It's a good question. It's a question i'd like to know the answer to. Why does the muon exist? The short version of the answer is the title of a great book I read last year. It's called we have No Idea? Because we really do have no idea Why the muon is there?
Doesn't seem to be used for anything, is what you're saying. Like the trinos, I think, also are there, but we don't know why why they're there? Right?
Yeah, neutrinos and muons and many of the other particles are not part of the atom. You know, build them. You don't use them to build up the stuff that we're familiar with, but they sort of can exist. They're on nature's menu. You might ask the same question about like some of the really heavy elements, like why is plutonium a thing? Well, it turns out you can assemble protons and neutrons and electrons in this way that's stable and hangs out and it does this is funny thing.
We call it plutonium, and plutonium also decays, right, it like breaks up. This one actually breaks up into other things. But it's also kind of ephemeral, like it's only there for so long before it becomes something else.
Precisely, and in the same way, we organize our list of particles, and we wonder, like, why are these there? What does this tell us about? Maybe one deeper layer of reality, Like maybe the muons and the electrons are made out of smaller particles, and these are just like different ways to assemble those little internal bits, right, And there's a few ways to assemble them, the way that there's a few ways to assemble protons and neutrons to get different elements. Maybe there's a few ways to assemble these little tinyons. One way is to get an electron, and other ways to get a muon, other ways to get a tao, which is the third member of that family. We just don't know. We know it's a clue though, right, It's a tantalizing clue that there's something going on here. We just don't know what it means.
It's a clue as to some sort of a hint that there's some sort of rule for how electrons exist, Like if you can make an electron that's heavier, maybe that tells you something about what makes an electron an electron.
Precisely, and why there are three of them tells you something about how that rule has to play out. Because there's three electrons, the electron, the muon, and the towel. There's three neutrinos. There's also three upquarks. There's three down quarks. Like there's something really fundamental going on there we just don't understand. But it seems like an obvious clue. You know. It's like you're doing your jigsaw puzzle and then you find this other weird piece. It turns out, oh, that piece fits into a different jigsaw puzzle you didn't even know about. And you know, it's as you start to get this larger picture.
Right, or you find it like all of your pieces have three sides to them, then you start thinking, you know, whoever made this puzzle, if it was made by somebody had a thing for threes.
Yeah, the universe has a thing for threes, and we don't know why that is. The muon was our first clue that particles have copies at all. And now it turns out every particle has three copies, and so that's a huge open question. Is a kind of question people are going to look back in one hundred years and be like, man, that was so obvious. Why couldn't they figure it out? If I was a physicist in twenty nineteen, I would totally figured it out. But it's not so easy when you don't know the answer when you have to come up with it. But it's important for people to understand. You know, it's not part of the stuff that we are made of, but it does answer this larger questions like what is the sort of context of everything. That's why we're trying to figure out like what are all the particles? Because the more particles you put into this table, the more clues we get as to what the rules are for making this table. And then maybe we can peel back a layer and show how this table is put together, right.
Or I guess maybe a question I would have is how do you even know it's a separate thing? Like why isn't it just called the heavy electron? Could it just be an electron that just gets a lot of mass added on to it somehow through energy or something.
That's a deep question and goes sort of to like what do we call a particle. Part of the identity of the particle is its mass. Like that's how we identify what particle we're talking about. We measure the mass and we say, well, if it has this mass, it's an electron. It's sort of semantics, but it's it's what we mean by an electron. We mean quantum dot in space that has these properties, and one of those is the mass. Oh I see, and there are only a few. It's not like this. It's there's a knob. You can't have halfway between an electron and muon this like the electron mass, the muon mass, the tau mass. There's some notches there.
Right, And so this was the first particle that kind of we found outside of the ones that make up atoms. Is that what you're saying that this was the first one that was weird?
Yeah, precisely, it's weird and cute. I'm glad you're finally putting positive attributes on the on the muon, you know, trying to make it.
I said weird. I didn't say cue. I think somebody has a particle fetish, and it's not the cartoonist.
Yes, well, maybe the particle physicist has a particle fetish. I will totally own up to that. I love you particles.
I think we all love particles by necessity. We can't live with that.
You just like particles when they make up pizza and iPhones, though otherwise you don't care about them. You objectify particles and cartoonists cartoonists.
Well, I think this particle is interesting in that it also kind of hints, you know, the universe is full, is full of these small little details that people can explain right now and then maybe tell us a little bit about that there are other mysteries yet to discover.
Yeah, and you know, the story of how the muon was discovered is also motivational. Right, People saw this weird stuff in these pictures, and they could have just shrugged it off. They could have been like, I don't know, electrons are doing some weird that day, whatever, But instead of cracked open this whole other mystery. And we're still doing that. We still don't totally understand the muon. One thing we'd like to understand is the muon's magnetic field.
Oh, it's odd. It has a weird magnetic field.
Yeah, these particles, remember, have quantum spin, so they're doing something we like spinning. That's giving them each a little magnetic field because they have electric charge and spinning charges get magnetic fields. But when we predict the magnetic field of the muon from what we know about it, and then we go when we measure the magnetic field, it's a little bit different. It's not exactly right, and that little difference we could say, Hmm, I don't know, shrug it off. Maybe meuon is doing some weird that day, or it could be a clue. It could be that the muon is like interacting with new weird heavy particles we haven't even seen before. It could be the first evidence that there are more particles out there that we haven't yet discovered. And also they help us unravel ancient mysteries, like maybe you heard about how muons are used to take a picture of the inside of pyramids.
What do you mean, like we can make a neon viewer like like meon glasses.
No, we can use muons to like X ray a pyramid. Because what happens is muons, the sizillian muons shooting from the sky through everything. And if you take a muon detector and you put it on the other side of something, you can tell sort of the density of that thing, because muons will penetrate air differently than they'll penetrate rock, for example. And so you take a lot of muan you shoot them through something, you can tell whether that thing is fill, is hollow or not hollow. And so they did this recently by looking at muons that went through the Great Pyramids, because we're curious, like what's inside the Great Pyramid, but you don't want to take it apart, and so they use it basically to X ray the Great Pyramids.
Like you put a detector underneath the pyramid or or what.
Yeah, you take the detectors as far underneath the pyramids as you can in some of those rooms that do exist. And you know, you can't build an X ray gun the size of the pyramids. But the sky is a muon gun, right, The sky is shooting muons at us all the time.
The sky is a muon gun.
Oh my god, yeah, yeah, put on your tin hats, folks, because the sky really is shooting particles.
That sounds like I need like a lead titanium hed not a tin head.
Maybe you know, maybe the Pharaohs had the right idea. Maybe that's why they have those really weird headdresses.
Hmmm. Well, that's what I was going to ask, is how do you know what neons look like after they go through Aliens? There are alies inside the pyramid you wouldn't know.
Wow. I was so ready with an answer to that question until you went to Aliens, and now I'm totally at a lost.
That's why I'm here, Daniel, to ask the tough questions that are on everyone's minds.
Joking aside, they did find something inside the pyramids. They think they may have found a new empty room inside the pyramids that they didn't know about before, because the way the Muon's full of cows before the cows are the Aliens actually to wrap it all up.
Then we're in deep trouble when their overlord's coming and they're like, what are you guys doing.
And they say, welcome to our our leader, King Muon the first, the first first of his name. No, they found that inside the Great Pyramid there may be a new hollow section that nobody knew about before, and it's only thanks to muons that we were able to muon x ray the Pyramids.
M a new on chamber they phone.
Thanks thanks to me on Yes. So it may not be inside your iPhone and it may not be inside your pizza, but it does help unravel ancient mysteries about ancient civilizations.
All right, Well, with that, we will wrap it up and we hope you enjoyed that little discussion about this unknown but super massive and mysterious part of the universe.
Part of our family of cousins, particles, big, small, massive or not. We love you all, at least I do.
Thanks for tuning in. See you next time.
Before you still have a question after listening to all these explanations, please drop us a line. We'd love to hear from you. You can find us on Facebook, Twitter, and Instagram at Daniel and Jorge That's one word, or email us at Feedback at Danielandjorge dot com. Thanks for listening and remember that Daniel and Jorge Explain the Universe is a production of iHeartRadio. For more podcasts from iHeartRadio, visit the iHeartRadio app, Apple Podcasts, or wherever you listen to your favorite shows. When you pop a piece of cheese, into your mouth. You're probably not thinking about the environmental impact, but the people in the dairy industry are. That's why they're working hard every day to find new ways to reduce waste, conserve natural resources, and drive down greenhouse gas emissions. How is US dairy tackling greenhouse gases? Many farms use anaerobic digestors to turn the methane from manure into renewable energy that can power farms, towns, and electric cars. Visit you as dairy dot COM's Last Sustainability to learn more.
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