How was antimatter discovered?

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Speaker 1: Hey, or Hey, did you know that there are physics truthers? What? I know there are particle theorists, but I didn't know there are conspiracy theorists. The conspiracy theorists some of them don't believe that antimatter is a real thing, so they're anti antimatter. All matter matters. What do they just think that you made up this concept of antimatter? Yeah, it turns out a lot of people don't think antimatter is real. They don't believe in it. Well, maybe they just need proof, you know, maybe they're not crazy, they're not bananas. Well it turns out the proof is bananas. Who are bananas antimatter? No, but it turns out bananas produce antimatter. Hi am Jorge, I'm made particle physicist, and I'm Daniel. I'm a cartoonist, but I'm not the author of PhD comics. And those are the anti versions of the real us. The host of this podcast, Daniel and Jorge explain the universe de production of My Heart Radio. Although since you've been listening to me talk and talk and talk for all these years, by now you're basically a particle physicist. That's right. I feel like I talked to you more than you probably talked to your grad students, so probably should give me a PhDs. Don't tell my grad students that do you allow them to hear hear this podcast? Do you let them out of their basement every once in a while. I'm curious if they listen. I think I've mentioned it to them. Actually, some of them appear in our interviews from time to time. Oh, I see people who can't. That's right. I wonder if it's extra stressful for them if they say no, Are you going to judge them based on what they know or don't know? No, I think it's extra stressful if they say yes, and then I asked them a particle physics question they really should know the answer to. Then they're on the spot, and you have them on tape. I have them on tape exactly, but the podcast universe to listen, that's right. But the goal of this podcast is not just to embarrass my graduate students and put them on the spot, but to teach all you people out there about the amazing universe of particles and stars and bananas that we all get to live in. That's right, All the things that exist out there in the universe and all the things that maybe don't exist or that exist in a constant state of denial, that's right, or things that currently only exist in the minds of particle theorists, ideas about what the universe might be like that we don't know if they are real, right, because even the things that might not be real tell us a little bit about how things really are and why they are there where they are right, that's right. And in physics we have this sort of cycle of people making predictions and saying, what if the universe works this way, and then people going out to check and say, hey, it turns out you were wrong. Go back to the drawing board. And there are many many beautiful theories out there that people came up with that they were convinced we're real, but then we're confronted by the evidence that they're not. That's right. There are conspiracy theorists. Even in physics. There are people who are skeptical about the things that physicists have found. Right, even physicists themselves who are skeptical, Well, it's our job to be skeptical, but we like to think that's sort of a reason skepticism. You know, when presented with the evidence, we don't come up with an even more elaborate conspiracy theory to deny it. We accepted, we move on. But it's true that some of these ideas that are in the minds of physicists, they can be kind of hard to accept, and some people still out there think that they're just ideas, that they're not actually real, right, because it's kind of an interesting cycle in physics where you might see something in nature and then you come up with the theory, and then you do an experiment that validates or disproves this theory, and then you come up with more theories, and so it's like this weird and interesting loop, and so it's hard to tell sometimes where ideas come from. Yeah, especially in particle physics, we seem to obscolet between two modes. One is where theorists are leading the field, where they have ideas for what they think is happening in the universe, and then experimentalists have to go out and basically check those ideas. And the other mode is where experimentalists are taking the lead, where we're out there finding crazy stuff nobody understands and theorists are scrambling to keep up to explain all the bizarre stuff that we've uncovered. So what do you think it's that determines who's taking the lead. Is it like just who has more free time in their hands to play around and discover things, or who's more suspicious of the other. It's just up to nature. It's just up to how much stuff there is to discover. You know, in the fifties and sixties, they were discovering a new particle every time they turned on the accelerator. They called it the era of the particle zoo. Whereas these days it's like decades between particles, and that gives the theorists a lot out of time to be creative, to come up with new ideas, to say, maybe it's this, maybe it's that, because we don't have anything to sort of constrain them right now, we're in a really fury driven mode of the field. Is there a song for the particles? I feel like there should be a song particles, particle zoo doing the things particles do. There you go wow on the spot, jingle making that's right by. They might be particle physicists PhD and jingle engineering, granted, but it's interesting history right in the fifties, we were discovering new particles nobody understood. And in the very early days of particle physics, like the first particle was discovered, right, that wasn't predicted, it was discovered, and then the photon was like thought up to explain an experiment that people had seen. So the very beginning it was driven by experiments. But these days, of course it's driven more my theory. And so today we'll be talking about one such thing that has been seen or had that some people have seen in nature and physics, but maybe some physicists don't really believe that it exists. Oh, I think most physicists believe it, but I just wonder about the general public. Oh so it's just, um, you say true things, you mean physicists or people? I mean people, because physicists or not people. Is that what you're saying. You just trapped me. You totally led me into a trap there, Daniel, Are you a person or a physicist? Take one? No, I think that you know, this is really fascinating because it's one of the first things that was ever predicted before it was seen. This is the first time somebody said, maybe this crazy new thing does exist out there. In the universe, somebody go look and sort of sort of the dawn of the New era. And it's taken a long time for people to believe that it's real, and some people out there still don't. So I guess at some point this was a topic where some people thought it was true, but a lot of physicists maybe didn't think that we would see it or that it would be proven to exist. That's right. Between the prediction and its discovery. It was contentious, and it's a pretty interesting topic because it talks about a huge part of the universe that is both intriguing and super dangerous. Yeah, and fascinating. And you hear all about it in popular culture, like it's everywhere. It's even in Dan Brown novels, so you know it's got to be cool. Oh man, it must be true then if it's a Dan Brown never Yeah, I think those are all heavily researched. The Da Vinci particle. All right, Well, so today on the podcast, we'll be asking the question, how do we know antimatter is a thing or an anti thing? What's the correct way to how do we know antimatter is not a thing? Or how do we not know that antimatter isn't not a thing? That's put it more more negative, No, I and anti that kind of use of language, Daniel. I think that often the history of particle physics and the topic of particle physics is framed from a theoretical point of view, like what is our understanding of the particles? That it's out there? And that's cool, But for me, I'm an experimentalist. I want to know, like, how do we know these things? Like you say, these particles exist, how do we know that it's real? What experiment? What? What the thing happened that proved to us that it had to be there, that it's part of the universe. So we did a podcast episode about how do we know even particles exist? About the electron and how do we know photons exist in this kind of stuff? And and why are their muans? And so this is sort of in that series of like telling people about the moment when we confronted something that proved to us that this new thing had to be a part of our universe. Yeah, and so antimatter is a is a word or two words put together, and we kind of know it's a thing, but we were wondering how much people out there know about it, or that they know that it is a thing and not just one of those crazy physics ideas that are floating around. Yeah. So I went around and my goal was to ask people if they knew how anti matter was discovered. But I had to back up because it turns out a lot of people didn't even know that anti matter actually had been discovered, so they didn't know that it was a thing. Yeah, that was so surprising to me. But listen to these interviews and thinks to yourself, do you know how we discovered antimatter? Here's what people had to say. I know about about it, I don't know how they discovered it now, No, I don't have heard of it, and like science fiction and stuff, um, but I don't know how the logistics of it would even be possible. So I'm not too sure. But I know, like the phrase I've heard it like a lot of is it a real thing or just science fiction? I like, it's kind of like theory, So it's not too sure. I think they are because I read it something about it keeping the universe from expanding too fast? So how do we know anti matter is a real thing? Like? How was it discovered. I don't know exactly, but my best guess is that that it could be shown through like how the universe expands. But it seems like it's being limited by a certain the end. It's predicted to the antimatter Right now, it's all theoretical, isn't I don't like, have we actually done anything with like large hangar clider as far as any matter? Yeah, I'm not sure. I don't know. I don't know what that means for now. It's it is just an idea surreal thing. Okay, how do we know it exists? By calculation? To make your to accommodate the amount of our understanding of matter in the universe? Do you think matter? I thought there was some anti matter dirt matter connection, Okay, not that I'm aware of. Don't know. Don't antimatter Well, it's like I'm kind of doesn't exist. I mean, if it were. No, wait, because it goes to show that I know nothing about particle physics. But there's something. I mean, listen to my podcast for office. I would love to listen to your podcast, and I'm sure that that there's something I would learn from it. Antimatter is a real thing as a it's a counterpart to a regular matter rights. How do we know it exists because to create matter, you have to also create antimatter, and it's been a proven reaction, and we know that it exists despite not being able to necessarily detect. I have not heard of that term actually, all right, So it sort of seems like people are skeptical about it, or they weren't. Not a lot of people seem sure that it is a thing, Like they talk about it like it's a theoretical thing, or it's not proven, or it's an idea. Maybe actually I just realized maybe it's because it's in a Dan Brown novel and they thought, oh well, then it must be b Yes, thank you, Dan Brown. And that should be called like anti science communication anti science. I don't think he claims to be a scientist or claims to be a work of nonfiction. No, But you know, when he made that movie, of course, we're referring to Angels and Demons, Dan Brown's novel about an anti matter bomb, in which the science is mostly right actually about antime matter. But when they made yeah they did, um yeah, yeah, the science in there's is mostly correct. But they made that movie. They filmed it actually where I was working at the time, because I was at Sern and they were filming the movie at Stern and uh, and then I wanted to get a camera. What's that did you get? Did you get a camera? Next? With Tom Hanks? Only the most v I P of v I P has got to give Tom Hanks a tour. So I was like, not even in the top five list of people who would get to have lunch with Tom Hanks, unfortunately, But now now you now you would be making the top Yeah, I'm really moving up. But the cool thing was when I watched the movie, they had taken our like normal boring workspaces, which which is basically just a bunch of computers and screens, and they had science fictioned it up, so people had like cool heads of displays and like fancy interfaces with their computers, las, lasers and scanning devices. And I thought, that looks pretty cool. We should upgrade the way our office works to look like the movie. You're like taking your pocket and looking at a metal key. You're like reality versus world. But it was cool to see what like Hollywood's best designers would do with my office. Pretty cool, all right, So it seems like people are not quite sure that it's real. They think it's maybe theoretical. Do you think maybe they were confusing antimatter with other things like dark matter or yes, absolutely, I hear that a lot. Actually, I think that people know that there's something out there is a miss dearious counterpart to matter. And it turns out there's sort of a few mysterious counterparts to matter. Right, there's this whole antimatteric thing. It's dark matter that there's super particles, and so there's antimatters, there's quasi matter, there's matter, there's exotic matter. You know, yeah, I know that's a real potentially could be a thing thing. Splatter matter, there's mats matter, and now you're making me matter matter um. And so there's sort of a lot of different ideas to keep track of. And so if you're not like a particle physicists like you are, then maybe it's hard to keep your finger on which ones are real and which ones are theoretical. Right, And I have to say, antimatter does sound a little ridiculous, does it. It sounds very like nineties fifties science fitching. It's antimatter, it's like matter, but it's anti The whole concept is absurd, right, But as we said on this podcast, absurdity is no obstacle to reality. Right. Turns out the universe is kind of bonkers. Yeah, I feel that way every time I read the news every morning these days. It used to be just physics, and now it's also politics. Is bomb beers. But anyways, um so yeah, let's talk about anti matter. And we have a whole episode about anti matter. If you scrolled through our archive, you can find that episode and learn a little bit more about it. But here we'll just kind of go over quickly about what it is and how it's not actually dark matter. That's right. Antimatter is not dark matter. It's a whole other, enormous, fascinating puzzle about the universe. Anti matter is a statement about particles and patterns. It's noticing that particles come in pairs. And so some of the particles that we've discovered, the electron, the muan, the corks, there's another particle that looks just like them, except it's the opposite in a couple of ways. And so, for example, the electron is a particle. We know it, we love it, we're made of it. It's in ice cream. And there's this other particle called the positron, which is just like the electron accepted, has a positive charge instead of a negative charge. It has other negative things about it, right, like the opposite spin or the opposite quantum color, and other kinds of charges, right that are different. Some of the other charges for the for the forces are opposite. The electron actually doesn't have a color because it's doesn't feel the strong force, but it has the same mass and spin. So the positron are the same in mass and quantum spin. They're both spin one half, and they have exactly the same mass as far as we know, but they have the opposite electric charge. And so you might just say like, oh, well, it's just a different particle, and it is. It's a different particle, but there's definitely a relationship there. So we group them together. And this is what we do all the time in physics, and especially in particle physics, is we're looking for patterns. We're looking for, you know, relationships that help us simplify. We're looking for symmetries that give us insight. And so it's interesting not just because the electron has this weird partner particle, But so does the muan, and so do all the quarks, right, and and we call it matter and antimatter because the ones we call matter are the ones that make of most of the things we see. A round is right, like positrons and anti mu as an anti quarks. I'm not made of any of these things. I'm made out of the regular versions, the provisions. That's right, you're made of the regular versions. But you're right also that we call them regular versions because they're familiar. They're like the first ones we encountered, because they make up the world we know, and so there's nothing anti about the other ones. They're just sort of not the first ones we found. Maybe maybe a different word might be like mirror matter or symmetric matter that's actually already taken. There's a whole other theory about mirror matter we can talk about another time. But it's a crowded field of terrible names for particles, and you're running out of English words to append to your existing physics concepts. Banana matter taken. Banana matter is not even an idea yet, not until this podcast comes out. Is banana matter not ever a phrase anybody's effer Herd in their mind. But it's fascinating because it seems to be like a thing. It's like a symmetry in the world, you know, like a lot of these particles which exist, there is also this other one of them in the same way that we notice that electrons and muans and taws have a relationship, right, They all have the same electric charge and the same weak interaction, and they're organized in a similar way, but they have different masses. So it's like these different directions along which patterns sort of form. All these particles are kind of different versions of each other, Like one of them has a little bit of this more, or this one has the opposite of that more. But they're all sort of particles that we know and love because some of them make us who we are, that's right, And we're tempted to define one of them is like the normal one. But again that's just the first one we discovered. It's like, you know, what's real chocolate, dark chocolate or white chocolate. You know, maybe if you grew up in a family or white chocolate was the first thing you ate, then dark chocolate would seem to be like the anti chocolate, do you right? Yeah, that I think we should we should do that, just call it anti chocolate. Um. And and and remember also the antimatter is has positive mass, right as far as we oh, it's made of the same kind of stuff, and so it is antimatter because it has the opposite charge. And if you collide matter and antimatter, they interact and turned into light and turned into energy. But in that sense, they're just more matter. It's just you know, they have this relationship. We could have called it something other than antimatter. We could have called it, called it oppositely charged matter, or something that's a little bit longer to fit into it didn't focus group as well. Yeah, alright, so that's what antimatter is. And there's this whole mystery about how most of the universe seems to be matter and not antimatter, which we got into into in our last podcast about antimatter. But in this case, this one is more about how we discovered it and how we know that it actually is a thing. Right, that's right. The history of antimatter is like almost a hundred years old now, um, it's sort of surprising, but positrons, the first antimatter particle ever discovered, were found You know in nineteen thirty two, so we've known about them for a long long time, which kind of surprised me that people still don't necessarily believe that they're a thing or are aware that it's a thing, because it's been a thing for decades. People, Right, Well, I think antimatter is anti celebrating birthdays, so that's probably why maybe nobody has noticed. But let's get let's get into whether or not antimatter really is real or theoretical, and how we know that it's real or anti real, whatever the case may be. But first let's take a quick break, all right, Daniel, So antimatter is real, whereas an anti real or anti fake, which makes it real. I'm so confused. It's really really anti anti real. So yes, it's real. That did not help. Okay, So it's real in the sense that not only can it exist in theory, but you can actually like see and touch antimatter. You can see in touch antimatter. I don't recommend actually touching any antimatter because it's quite reactive. But it is a thing. And you know, there's sort of two ways something can be a thing. One is it's in the list of particles that can exist in the universe, like the potential particles, and the other is that it's actually made, that it really exists. You can imagine a universe where that's cold and dead and the only thing in it our photons, for example, and you could in theory and that universe have electrons. It just don't exist. Right, So one thing is like being on the list of potential particles, the other is actually existing an antimatter is both, but started off on the theoretical list and then people actually found it. You mean, people looked at the equations of the universe at the time and they said, you know, we have a little pocket here where there could be like an electron with a positive charge. Like, there's nothing that would prevent the equations from making this real. So you're saying that's one way that something can be real if it's there, if the equations point to it as being possible. Yeah, and more than just the equation saying it's possible, you could prove that it exists. But it doesn't have to always actually exist, you know, like the Higgs boson, right, the Higgs boson. We know it it's a thing, but it doesn't actually like get created very often you know you have you have specially need very special circumstances to actually make one. So it's sort of like knowing that the recipe works and actually making the cake. Right, It's like unicorns can exist, but maybe they're just technically aren't in right now the unicorns, what's the difference here, Daniel? But and the matter is real. It occurs naturally in cosmic rays. You don't actually need like a particle collider or special physics lab to make it. It's created in collisions in the atmosphere. Um, every time you have rate, you active decay, you can create antimatter. Sometimes these decays will create anti neutrinos or anti electrons or stuff like this. Really in our atmosphere, we're getting rained down. Wait, it's it's like regular matter is coming from the Sun as cosmic rads hitting the atmosphere, and then in those collisions you're saying antimatter is produced. That's right. Antimatter and matter can turn into each other, right. Um Photons, for example, can turn into a pair at an electron and apositron one is matter? What is antimatter? All you have to do is follow the rules of physics, which say, like conserve electric charge. But if you have photons, they can turn into matter and antimatter. So you have in the atmosphere because of cosmic rays, you have all these crazy complicated, high energy collisions, and some of those just turned into antimatter particles. Does that mean we're constantly and currently being rained down upon by antimatter? Absolutely? It is antimatter rain. I think that is a song by Prince wasn't it? Yeah, anti Prince Um. But the wait I thought it was dangerous. How can I be getting rained on by antimatter and not exploding like you said I would? It is dangerous in high quantities, but there's not that much antimatter, Just like you know, there's radiation coming from the upper atmosphere all the time, and radiation is also dangerous. You know, protons and muans that go through your body have the opportunity to damage your DNA, but there's not that much of them, And so the higher you go up in the atmosphere, the more there there is just particle radiation, and some of that is antimatter. So what happens if a positron hits your arm, Well, it encounters an electron and it turns into a photon. That photon has the energy that's the equivalent twice the mass of the electron because all that mask got turned into a photon. But that's not that much, so you know, you one photon gets created. Should I be wearing anti sunscreen? Then said, there's no sunscreen. You can wear it to protect your things that matter or just antimatter. Just make me glow in a way that's desirable. Antimatter. It gives you an anti tan, So actually what you want to do? Yeah, you do look brighter, I guess in a way, so it's almost like you're The amazing thing about antimatter, though, is that it is really energy dense because it converts all of the masses inside of it into energy. So if you had, for example, like a raisin's worth of antimatter, which is a lot more than one positron, right it's ten to the twenty three particles or something, then that would be as much energy as a nuclear bomb exploding. But again that's a much bigger dose. And in the atmosphere you get you know, a few few positrons at a time, and it's not just the atmosphere. Your favorite snack actually is an antimatter of factory. What. Yeah, a random banana has potassium in it. As we've mentioned before, potassium is unstable and it decays radioactively and produces one positron every seventy five minutes. One positron, Like a sitting banana will shoot out a positron or does it get caught by the other you know, banana electron banana on. It depends. I guess where it gets produced. If it's produced in the skin to the banana, it will shoot out into the air. But of course positrons don't last very long because they interact with electrons. But yeah, your favored fruit, whether it's sitting on the table or you know, in a high speed banana accelerator or whatever you do with your bananas, produces about one positron every seventy five minutes. It doesn't get stopped by the peel electrons electron. Yeah, if it's produced in the center of the banana, then it could. But if it's produced near the edge, and then you could make it out of the banana into the air. Well, maybe that's where I get my superpowers. Dan, You get antimatter, you get that banana's proportional strength. Yeah, there you go. I can make anyone slip and fall. That's superpower. I can't make anyone uncomfortable with my ban ant a chewing. All right, Well, let's just slide on past that discussion. Yeah, alright, So antimatter is real. It is a thing. It's all around this. In fact, you're probably baild in antimatter even though you maybe didn't know it um. And you can also like make it in a lab, right, like a certain you guys have been making anti protons and anti hydrogen for a while, like you have an antimatter of factory there. Yeah, that's right, And the reason is that we're curious about it. We're curious about like how symmetric our matter and antimatter. You know, For example, can you make an anti proton and pair it with an anti electron to get anti hydrogen? Does chemistry work for antimatter? You know? Can you get enough of it to test its gravitational properties? We don't even know if antimatter feels gravity the way matter does, or or if it feels like anti gravity because you just never made enough of it. Really, the equations don't tell you whether it should have mass or anti mass. Yeah, because it's really hard to measure the gravitational force on a particle because it hardly has any mass. And in the history of particle physics, we've made something like twenty nanograms of anti matter ever total, and so it's pretty hard to measure the gravitational effect of such a tiny scrap. But you have made anti protons and anti hydrogen, which is pretty cool, right. It's like a hydrogen, but the complete opposite. Yeah, And as far as we can tell, it works exactly the same way as a hydrogen atom. So they get into a bound state, they can get excited, they emit photons. It's exactly the same. So it's super fascinating either to learn that they're different or to learn that they're the same, you know, and it brings up all sorts of interesting questions like why why is there antimatter? It seems like such an interesting clue, Like why does universe have this weird reflection? You know, it has all these reflections. I love all these symmetries and particle physics, but each one should tell us something about the universe. They're a big, deep clue that says, here's something fastening that's going on. We just don't know what it means, well, you know, some people are just really contrarian, you know, and to mabe, the universe is just just being anti anti for no reason other than to just be anti. But if it, But if antimatter exists, then why aren't there other sort of reflections? You know, Why can't you have all the same particles but with different spin. Oh well that's supersymmetry, you know, why this reflection not other reflections? Anyway, it's kind of stuff that makes me wonder do you think it's these other mirror images exist? Do you think they would have better names in physics, like actually good ones because they're to be the opposite. Well, they can't have much worse names. So there you go. All right, Well it does exist. It's real. You can we can make it in the lab. It's my banana makes it on a daily basis. And there are still a lot of open questions about anti matter. So now let's talk about how it was discovered, because that's a pretty interest seeing story as well, and what it could mean for the future of the universe. But first, let's take another quick break. Okay, Daniel, So how is antimatter discovered? Were they not looking for it and found it that would be a great story. No, and that matter is sort of a theoretical triumph because it happened actually very similarly to the joke you made earlier, or the comments you made earlier about people sort of noticing a gap in the equations. What happened was the Paul Drac who's famous theorist of around the beginning of when quantum mechanics was was being formed, he was taking the Shortinger equation, the equation that describes the motion of particles, and he was trying to make it work for really fast moving particles. He was trying to fold in relativity and quantum mechanics, which amos is very hard to do, but he was able to actually unify um, quantum mechanics, and special relativity the laws that tell you what happens when things move really really fast. So he came up with Yeah, he came up with a new equation. It's called the Dirac equation, and it's like the relativistic version of the Shortinger equation. Shortinger equation tells you what happens for quantum particles that are not moving that fast. The direct equation tells you what happens when quantum particles are moving fast enough that relativity kicks in. So he had this awesome equation already a triumph, right, and it turned out to be true. Right, This theory is as far as you know now. Yeah, and that's amazing, right, direct unified special relativity and quantum mechanics. And remember we've never successfully unified quantum mechanics and general relativity theory by like bending space. That's still like to be done. So folks out there looking to make a big impact on physics that's been an open problem for a hundred years TVD to be discovered. That's right. But then Derek looked at this equation. He's like, this is something weird about this equation. He noticed that the equation worked for a negatively charged particles like electrons, but it would also work for positively charged particles. They thought, that's interesting. Did did the equations have a pocket or like an empty space for an anti electron? Or he just figured out that this equation that we think describes the universe could also work for something that looks like an anti electron. Yeah, it's an equation with two solutions, just like you find all the time and equations that have like squares in them, like X squared equals nine, while there's a solution there, right, X equals three, But there's another solution X equals minus three, right, because minus three ties minus three is also plus nine. Yeah, exactly. And so he noticed that his equation described electrons as we know them, but it also described something else, something we hadn't seen before, another particle with positive charge. And it's for exactly that reason that there's a squared in his equation, and it allows for you know, particles of either charge to satisfy his equations. And so he predicted that this would work for an anti electron. But did he predicted for other anti matter particles or just just for the anti electron? Oh? Yeah, the story gets exciting, But first he started small. He's like, you know what, I think this is real? And I wonder like what went through his head there? What makes him think, Oh, that's not just a mathematical oddity. I've discovered something about the universe. Because a lot of times we have equations that describe things and we just sort of toss out solutions and say they're not physical, Like if you're talking about, you know, how a ball moves through the air, you have a parabola. And sometimes there are non physical solutions to those equations, and you say, oh, those don't make sense because they required the ball to move through the ground or something. But he thought, no, this is real. It's kind of like if you said that the number of cookies that I have times a number of cookies you have equals nine. You wouldn't say we both both have minus three cookies. That wouldn't that want to be a serious solution, because let's face it, we always have cookies. Yeah, you impose a physical requirement there at least zero cookies. Right, there's no such thing as a negative cookie. And but Dirac was like, you know what, what if negative you can count it as a negative. If I eat your cookies, then maybe you have negative cookies. I don't know. I would have a very negative reaction. Sure. I think there's probably a whole course in philosophy on theory of negative cookies, the ethical ramifications of less than zero cookies. Yeah, anti ethics or anti pastry. But he predicted it. He was balls, and he said, I believe in myself, I believe in my equation. I think this thing is real. So he predicted his way before iPhones or the internet. Yeah, he couldn't have just googled for it or asked Siri if this is real. He made a prediction. And he's sort of famous for being, you know, a bit of an odd guy. You know, he probably fit in well on the Big Bang theory. It had a lot of self confidence, but maybe not a lot of social skills. He made the claim that these equations work for an anti electron, so therefore there must be an anti electron. Is that is? That? Was that his big leap there? That was his big leap. He says, I've discovered this equation, and the equation is fundamental to the universe and it describes something happening that we haven't seen. So I think it's happens right, even though we haven't we haven't seen it because we haven't looked for it. This equation allows for it to happen. So let's go see if it does happen. Was that a shift in physics as well? You know, people thinking that well, if the if the math predicts it, then it must be real. You know, like that's a big leap to think about that. It's a big leap. It takes a lot of ego but it was the first time a particle had been predicted. Yeah. Before that, every particle discovered had been discovered first and then explained. It's like, oh, look who we found How does that make sense? Let's try to stitch together a theory that that accommodates it. It's like in baseball, it's like calling your shot run than just hitting a home run. You're like, I'm gonna hit a home run and it's the land right over there. Well, I guess he had a history. Maybe he had up to that point, there was a history where they had discovered particles and then they found out the math fits it. So then this, in this case, the math fitted and so he probably thought, well then it must exist. Yeah, And it didn't take long for him to be proved. Right. He was a babe ruth of physics. Yeah, and he gets better. So it was just a few years later a guy at cal Tech named Carl Anderson. He actually found the first positron, and like we were talking about, he found it in cosmic rays. He just saw one flying through the air. And what made him think it was a positron or an anti electron? Was he looking for it? Or I guess maybe his setup could only work for an anti electron. No, he was looking just to study cosmic rays, which were fairly new discovery at the time. The whole idea that there were these particles being rained on us from the upper atmosphere was sort of new, and he was using a pretty cool device. At the time, the first cosmic rays were discovered basically by huge cubic blocks of film that they had to slice up and analyze later. But he wanted some real time. He wanted to see these things in real time, so he used this thing called the cloud chamber, which is basically a box of glass that you can see into and then you fill it with air which is supersaturated with water, and when a particle goes through it that has a charge, it will cause droplets along its path, and so you see are these like little drops of water appear as a particle flies through it. You can actually build the cloud chamber in your garage. Yeah. It creates like a trail of bubbles as it goes through. Not bubbles, there's there's something else called the bubble chamber. This creates a trail of water droplets and you can see them, and they have them in a lot of science museums you can see like muans flying through them, and so he had seen muans and people have seen electrons and stuff like this. But then he put it in a magnetic field, and the magnetic field bends the path of this particle, and the magnetic field will bend a positive particle differently than it bends a negative particle cool and so that this was just a few years after direct So he did he know about directs prediction or did he discover it kind of independently. Now, he definitely knew about directs prediction. It was an idea that was out there, so it helped him sort of interpret his data. And what he saw was, of course, a bunch of electrons. Electrons are much more common in the atmosphere than positrons. But then he saw this one track, this track that curved the wrong way, and he said, what's that? You know? And he could tell the mass of the particle by how much it curved, and you could tell the charge of it by the direction of its curve. So he knew, for example, it wasn't a proton, because the proton is much heavier and would have curved less. So curved just like an electron except the other way, except the direction. Yes, And this is amazing to me because these days, to discover something, you don't just need one example. You can't be like, hey, look here's the Higgs boson. We found it, and here's the picture of it. You know, um, we need like five examples or something to show statistically that it really exists. Really, he claimed his discovery with and equals one data points and equals one. It was so conclusive. Nothing we knew of could make that data. He didn't even wait to get another one. No, he didn't even wait to get another one. And you can see like that is famous data. You can google for it and see like his original data that proved the discovery of the positive. Sure he didn't he didn't get at least two. He didn't wait a little bit and got another one. Maybe he got some backup data, but you know that's all he needed. That that convinced everybody. I'm still convinced by one image. Yeah, and um, and so he discovered that was ninety two. And then the next year Dirac wins the Nobel Prize for predicting antimatter. Did Carl and Anderson also get it? Or just the just the rack in nineteen thirty three, but then Anderson wanted three years later sort of in a combined Nobel Prize for cosmic rade discoveries. But my favorite bit of this story is that Dirac, you know, he was a heavy guy, and he made of this bold prediction and then it actually had come true. So then you know he like called his shot at like babe Ruth. So then in his acceptance speech where he's like, you know, at the Nobel Prize ceremony getting the Nobel Prize from the King of Sweden, in that speech he predicts another particle. He like doubles down. He's like, I predict a million dollars in my bank account tomorrow. He predicted the anti proton. He was like, well, if the electron has an anti particle, why not the proton? So he predicted it. Oh wow. And then when he got the Nobel price for that one, did he also make another prediction in the next speech, like, how when did you stop? It's still going on? Actually, I see he's still making predictions. He's like, and the next election will be won by Hey, doubling down works for you, right, you just keep doubling down. And the exponentially you get more and more Nobel prizes. Yeah, yeah, alright cool. So that's how the antimatter, the first antimatter particle was discovered, and since then we've we've seen antimatter particles all over the place and for all kinds of particles to write, that's right. And these days in particle collisions we can very easily make anti electrons, which are positrons, and anti muons, and we've seen antiquarks and all sorts of crazy stuff. There are some antiparticles we haven't seen yet. Oh really, they're still hiding or there's still we just haven't bothered. Well, no, there's some some that are still hiding. For example, anti neutrinos. Like we know neutrinos are a thing. What we don't know is if there are anti neutrinos. I mean we talk about it, but we don't really know if anti neutrinos are just the same thing as neutrinos because they have no electric charge. Yeah, how can you be anti nothing? Yeah? Well, for example, the photon is its own antiparticle, or you could say it doesn't have an antiparticle. So we don't know if neutrinos are in that category of particles that don't would have antiparticles, or if they're in the category of particles like electrons and do have antiparticles, like asking who who is the anti version of Switzerland and sucerand is neutral? So nobody and everybody precisely. So people are trying to figure out do neutrinos have antiparticles or are they just themselves? Um, all sorts of stuff, And then people are doing more and more experiments to make antimatter and try to study its chemical properties. We'd love to see, like more than just anti hydrogen. We'd love to see you know, anti water and all sorts of crazy stuff. But I guess the point is that it does exist, and that it is something that was predicted by the physics, by the equations first, and then we went out and found it, and now there's in controvertible proof that it does exist, that antimatter can exist, does exist, even if we don't know exactly where it is in the universe. That's right. Even though it's been featured in the Dan Brown novel, it is really out there, and it's a triumph in the theoretical physics to sort of notice these patterns in the universe and assume that the universe might follow those patterns, right to say, we think the universe makes sense, and if we can figure out the rules that describe it, then maybe we can use that to predict things in the universe we've never even seen. Right, what a crazy step forward. Yep, it's not a conspiracy theory. It's a conspiracy fact. We have a picture of it from that says that it's true, so it must be true. It's out there, it's in you, it's in me, it's in jogees bananas, So get used to it, folks. All right, Well, we hope you enjoyed that and got to learn a little bit more about the anti universe out there, the antihistory of physics, or the physics of antihistory, or the history of anti physics. Well, you've definitely convinced me. Daniel am definitely pro anti matter. Now, thanks everyone for tuning in. Before you still have a question after listening to all these explanations, please drop us the 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 Daniel and Jorge dot com. Thanks for listening and remember that Daniel and Jorge Explain the Universe is a production of I heart Radio. For more podcast from my heart Radio, visit the i heart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.