Daniel and Jorge Explain the UniverseWhy do scientists think there might be a wispy mysterious particle? And why did they give it such a silly name?
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Hey, Daniel, if you ever discovered a particle, what would you name it?
Oh?
I feel a little bit put on the spot.
He had no pressure. I mean, you wouldn't just name it the White Son or the White Sonino, the Danielino.
Well, you know, over the course of these podcasts, I've come to get a feeling of, I don't know, judgment from you by the quality of particle names. So I guess I feel some responsibility to, like, do it ride and meet your high standards.
Oh well, I'm glad. I'm doing my bid to make physics better, do you know. I just hope you don't give it a silly name, you know, like a random.
Name like a squigglyon or something.
Yeah, no, nose quiglyons. That would be a silly name.
Well, I promise to do my best. I won't like name it after a random laundry detergent or something.
All right, if you do that, this podcast is over. Hi am Jorge. I'm a cartoonist and the creator of PhD Comics.
Hi I'm Daniel. I'm a particle physicist who has never discovered a particle.
At least one that nobody else has discovered.
That's right. I've found particles this morning when I had breakfast, and I plan to find some more for lunch. But they're all your every day running the mill quirks and electron Yeah.
I find out particles all the time. In my billy button. That's probably not a picture we want to paint this early in the episode.
That's probably what dark matter is, Jorge, It's just your belly button lint.
Oh yeah, my billy win is full of dark matter and dark energy and physicists also can't explain it. But welcome to our podcast, Daniel and Jorge Explain the Universe, a production of iHeartRadio.
In which we try to tackle the biggest questions in the universe. What is dark matter? What is everything made out of? What is that weird thing in Hoorge's belly button, and we try to do it in a way that educates you and entertains you along the way.
Yeah, and we like to talk about not just the science and what we know about the universe and what we don't know, but we also kind of like to talk sometimes about the process of science, like how are things discovered or what are scientists thinking about or what are they looking for?
That's right because the forefront of science, the edge of human curiosity, it belongs to everybody, and we want you to know what are scientists thinking about, what are they wondering about, what do they not know, and what are they doing to figure it out? How do we go from clueless to slightly clued in, slightly less clueless, diminishing cluelessness. That'll be the title of my autobiography.
Yeah, we like to kind of stand at the precipice of ignorance. I'd like to call it, like, we're right at the edge of what scientists know and don't know and what they're discovering right now at the moment.
Do you think we're in danger of falling into that precipice or we're pushing it back?
I think it's possible to go a little bit too deep into the rabbit hole here of what we don't know in physics.
Just following up on your metaphor there, does that make the rabbit is the ignorance or rabbits are ignorant?
Well, I don't want to insult any rabbits.
We're definitely pro rabbit on this podcast.
We are we like rabbits here. But well, you know, one question is that you know, there are all these particles out there in the universe, and there's a whole bunch of particles we've discovered in the universe, and so the kind of the question is like, how do people find new particles? How do you physicists discover them?
Yeah, there's sort of two big ways to do. It. Is to look at the list of particles we have now and say it doesn't seem complete. We need another one. And this is the case when we talked about the top quark, for example, we had a nice little pattern of particles with a missing square in it. There was one particle that didn't have a partner and everything else was paired off, so we thought there must be one there. And sometimes more abstractly, we say there's just a larger pattern that would make sense if we added one more particle. I see, that's how the Higgs Boson was discovered. For example.
Do you're seeing particle physics? It's kind of like pokemon collecting or baseball card collecting.
Yeah, except we can't trade. You know, if the aliens come, maybe we could trade our discoveries for theirs.
Right, Oh my goodness, your nerve brains just exploded.
I'll give you a Higgs Boson for the dark matter. Please do you have dark matter? We want dark matter?
Boy? That would be a that does sound kind of like fun. You know, you can get together at the neighborhood and you exchange what do you know about the universe?
Yeah, I'm looking forward to that party. But there's a whole other way to discover particles, which is just to sort of stumble across them, to like find them in nature and see them and go what's that and then figure out sort of how does it fit into the larger puzzle where does this go? How to be connected? And we haven't done too much of that recently. Mostly we've been predicting particles and then find out.
Oh, I see, so how would you stumble upon a particle, like you're running the collider or any kind of collider, and then suddenly you see something you weren't expecting.
Yeah, precisely. This is how muons were discovered. For example, they had big blocks of photographic materials up on the tops of mountains and they saw these streaks of particles going through them, and the particles weren't consistent with electrons or anything else, and so they said, well, this must be some new particle we haven't seen before. And colliders are actually the best place to discover a new unexpected particle because you smash the protons together and you get this little blob of energy which can turn into anything. Anything the universe is capable of making, and so it could just pop out some crazy new particle you've never seen without you knowing that it exists. You don't have to know it's there in order to find it. That's the amazing thing about exploring the universe with colliders.
You'd be like, who ordered that? Exactly where that goes?
That's exactly literally what they said when they heard about the Mewan, and they said, what, we don't need that, That doesn't make any sense. Go take that somewhere else.
Well, we've had several episodes where we talk about the discovery and the search for different particles. We had one about the top core and the electron and all these other particles. And so today we'll tell the story of another particle, one that was proposed almost forty years ago and that we are still looking for.
That's right, This is a particle which may or may not exist, and if it does exist, it may simultaneously solve two of the biggest problems in particle physics.
Wow.
And weirdly, it's a particle almost nobody outside the field has even heard of. Wow.
Well, I guess we don't know if it exists, and so if it doesn't exist, we have to erase this podcast episode. Daniel or.
No, we get paid either way, it doesn't really matter.
Okay, I forget about that. Well apparently has the one of the sitiest names in the history of.
Particle Yes, I'm looking forward to hearing your reaction to how this particle was named. It ends up with a really pretty cool name. But the reason for that name is is really pretty ludicrous and whimsical.
Oh man, I am not looking forward to that. But anyway, so today on the podcast, we'll be asking the question, what is the most important particle you've never heard of? This is like a trendy band that everyone should listen to but nobody knows about.
Yeah, this is the particle your teenager knows about but you are clueless about.
It's super hot. On TikTok, you're like, what what is TikTok?
That's precise it. You don't even know the name of the social media app on which this particle is cool. That's how uncool you are. No, but it is. It is a really cool name. Like I like the sound of the name of this particle. It's this particle is called the axion.
That does sound pretty cool.
It does sound pretty cool. What does it evoke in your mind?
Like a robot or you know, like like axes? Maybe. Unfortunately, the word for armpit in Spanish is kind of close to it, so it is making me think a little bit of ar pits, but we won't go there.
The arm piton Wow, that is unfortunate. It makes me think of sort of like double edged axes being thrown in space along three different axes, you like the X and Y ax in your y ax and your.
Z throwing an X an ax around I don't know.
I don't know, but it is a cool name. It's fun to say. It's got that same sound in there.
Yeah, I think as long as it sounds like a transformer, it sounds I think cool. In physics, you know synchrotron, graviton, megatron.
The stron is not a particle, though the awesome tron. There you go, that be the name of a particle. Some of you may have heard about the new interesting axion result from the Xenon experiment. Now today we'll be talking about the axion more generally, but we're going to dig into the Xenon solar axion question in a dedicated episode coming very soon. But as usual, I was curious, what did people know about the axion? Is this something people actually have heard of or is this something that only the cool kids on physics TikTok know about it?
And so as Daniel went out there into the wilds of the Internet to ask people what they know about the axion particle.
So thank you to everybody who volunteered to answer random Internet questions and sending in your responses. If you'd like to participate in random person on the street Internet questions, then please write to us at questions at Daniel and Jorge dot com.
So before you hear these answers, think about it for a second. If someone asks you if you knew what the axion particle was, what would you say. Here's what people had to say.
I think, and this is a way to classify particles like they can be axion, some boat zones, and it has to do with them, for example, having mass or not.
I don't know. I guess axiom axis.
Would it perhaps be some sort of particle that other particles turn around?
I have no idea, But since it sounds like the word axel, I'm going to guess it has something to do with joining other particles together.
I have no idea.
I don't know.
I think that's to do with what dark matter is made of. I believe there are two options, are axioms or whimps. Honestly, I have no idea. Because it has the word ion in it, maybe it's some kind of ion.
I've got no idea.
I never heard about something called axion.
Yeah, of course, that's an elementary particle of an action figure the Caveman scientists.
In your book discussing what the most fundamental particle of a stone axe would be.
I assume it's not a standard particle.
Maybe it's more like strange matter.
All right, not a lot of positive recognition there. I like the one that said it's an action figure or it's related to an action figure.
Yeah, the fundamental element of an action figure. That makes a lot of sense.
Well, if it does exist and it is part of nature, it could be part of all action figures.
It could be. And the other great idea was that maybe it's related to axels, so maybe like joined particles together. This is some really creative responses here. I'm impressed.
Or maybe they were thinking like axel rose and like, oh my god, some roses fan, in.
Which case the axion's career has to also be in the dust.
Yeah, they better get on that physics TikTok right away through some silly dances.
But it did seem like none of these folks had heard of this particle or really had any clue about its incredibly important role in particle physics.
Oh man, well, I would count myself among those numbers. I had no idea what this and have no idea what this particle is before you sent me the outline for today's episode. But let's get into it, Daniel, what is the axion? It sounds kind of important but maybe not yet discovered.
Yeah, the axion particle is totally theoretical, so we do not know if it's part of our universe at all. It may just be an idea in people's minds. And remember there have been a lot more ideas than actual particles. And sometimes these ideas are beautiful, they make perfect sense, and when the physicist has them, they go, Wow, everything is connected and this is the way the universe works. But then you go and you ask the universe like is it real? And the uver says, nice idea, but no, isn't.
That kind of strange? I feel like that's almost like trying to discover new animals by thinking of them before you actually find them. It's like, oh, what if there's an animal with a dut bill, but then at a dinosaur neck, and then butterfly wings, and then you go out looking for them. Wouldn't that be kind of not productive?
Yeah? Well, but to stretch the you know, mixed metaphor of our rabbit holes here, it's more like that you see evidence for this animal, It's like, what's eating all the deer? And you know, I see all these strange footprints, and maybe that would be explained if there was this new predator out there I'd never seen before. And so you're trying to like tie up loose ends and complete the picture by suggesting an explanation. And that's exactly what the Axion and a lot of other theoretically motivated particles do, is they sort of try to tie together what we see in a smaller, more compact explanation.
It's just been a pretty horrible picture of this animal, Daniels, because they're not eating deer. Oh my goodness, it's like a wolf man sharp edges. You're trying to go for a cool animal exactly wolf for the duck bill and butterfly wings. Yeah, that does sound pretty cool.
That does not pretty cool. I want to see that animal. If it exists, and you can name it.
We'll call it the Action.
We already use that name for something else. That would be so confusing.
But what if you find the animal first? Right, Like, what if you find the animal and call it the axion before you cover this particle?
I think we've already used up the name though. That's sort of like, you know how the space force television show on Netflix has trademarked the term space force before the actual US Space Force got around doing it.
Oh that's a problem.
That's a problem, yeah exactly. Anyway, back to particle physics, the axion, if it exists, is a lot like a photon, but it doesn't have zero mass. It has a super tiny, little wispy mass, really a massive photon. Yeah, but it's not very massive, like the mass if it has some is like two hundred billionth of the mass of the electron, which is already one of the lightest particles.
So it's like a light light particle. It's like light light exactly.
It's very light, light light.
But not quite light, not quite light. So it's not coke zero.
It's like coke light, yeah, exactly, it's that coke with a tiny little bit of real sugar in it.
All right, So, and why did somebody come up with.
This, Well, they came up with it to sort of answer the biggest problem in physics that nobody ever heard of, which is we're looking at the way that interactions happen in physics, and we noticed something weird, something that we cannot explain, and so it's sort of thought up to explain this other mystery the same way you know, you might hypothesize wolves if you see your deer missing. This is sort of like hypothesizing the axion to explain this other problem, which is called the strong CP problem.
Interesting, and now is its official title, the biggest problem NODI has ever heard of? Like, do you guys talk about it that way?
Yeah, it's sort of a famous problem that nobody really has any answer to except the axion. And so that's why people think the axion might really be real. And then we'll talk later in the program about how it could also simultanecly solve another huge problem interesting, which makes the axion sort of a sexy particle right now. But it was originally dreamed up to solve this other problem called the strong CP problem.
Okay, so what's the strong CP problem.
So this problem has to do with basically, why does the strong force not break some symmetries In particle physics, we have all these symmetries like charge symmetry and paroity symmetry and time symmetry. These symmetries tell us whether something works the same when you flip it the other way. Like if we say something could happen to an electron, we ask, well, can the same thing happen to a positron, which is the opposite charge version of it. Because we like symmetries in particle physics, we like the smallest set of rules, so we don't want a different set of rules for electrons and for positrons, for example.
So it's kind of like, you know, like if two negative electrons propel each other, you can ask, like, two positive electrons propel each other too, and if they do, then that means it's like symmetric.
That's right, it's symmetric in charge. If you flip the charge and you get the same thing, then it's symmetric in charge. And so we call that C for charge symmetry, and we ask that question about everything, and electromagnetism is charge symmetric. Everything that happens in electromagnetism would happen the same way if you flipped all of the charges, not just one, but all of the charges, Okay, And then the second one is called P for parody violation, and that says would the same thing happen if you did it in the mirror. So, if you like set up some particle experiment, or particle decays to two other ones, or two particles collide into each other or whatever. And then you put that experiment in front of a mirror. The thing that happens in the mirror is not exactly the same as the thing that's happening in real.
Life, Like it's flipped in one dimension.
Yeah, a mirror will flip like the Z axis for example, the axis perpendicular to the mirror, but not the other two. So, for example, if you hold up your left hand in front of a mirror, then it looks like your right hand doesn't look like your left hand, and so your hand has parody. It's not parody symmetric, right, because it doesn't look the same in the mirror.
It doesn't look the same, but like a ball does sort of look like a perfectly round ball with no drawings or features on it does is parody symmetric because it looks the same in.
The mirror exactly. So for a long time, this is this thought that all of particle physics was charged symmetric and parody symmetric because it just sort of made sense, right, and physicists liked to do that. They say the universe is beautiful and natural and so it should follow this.
Rule, right, Like, it'd be weird if the electron looked like my right hand in front of the mirror.
Or if you had electrons for hands, that would also be weird, but for different reasons. And for a long time, everybody assumed that everything followed all these rules. And then in the fifties people realized, oh, nobody'd ever actually checked this. For the weak force, we had a whole episode we dug into how the weak force actually violates parody. Interesting, Yeah, if you have a reaction in the mirror, it looks different than the reaction you're having like in your actual laboratory.
And when we're talking about these these are particles, right, so they don't have features like hands, but they'll do things like they'll turn a certain way in a magnetic field. They'll they'll react a certain way when they hit something else.
Right. Yeah, the experiment that discovered the violation of parody did just that. It like takes a bunch of nuclei, aligns them in a magnetic and then watches the direction that they emit electrons. Is it like in the same direction as the magnetic field or backwards? And so that's a fascinating experiment that if you're interested in you should dig into that whole podcast episode. But for a while, people thought, okay, parody is violated by the weak force. What about the combination of charge and parity? So put it in the mirror and flip the charge, so that says, will an electron look the same if you put it in the mirror and turn it into a positron? M I see. And then we discovered that the weak force actually violates this also, so we call this CP. If an interaction or a particle physics thing that happens violates CP, it means that it doesn't look the same when you flip the charge and put it in the mirror.
So the weak force violates parody, and it also violates charge and parity.
That's right now. It violates parody big time. It's like a really big violation. And that was a Nobel prize. And then people thought, well, it must then preserve CP. It must be that parody is violated, but the combination of these two things is still preserved. Then they discovered that they violates CP and that was another Nobel prize. Oh man, so that's the weak force, So we force violates CP, and that was sort of surprising. But then people realized, well why not, I mean, why shouldn't these things violate CP. They looked at the way that we write down these interactions and the way we understand these theories, and we say, well, it's actually totally natural for them to violate CP. So like the theorists went from that's impossible, that's absurd, to actually it makes perfect sense.
All right, Well, it sounds like there's a lot going on with the weak force here that it violates all kinds of symmetries, and so let's talk about some of the other forces and how that could maybe lead people to come up with a brand new particle called the axion. But first, let's take a quick break.
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All right, I know we're talking about a potentially existing particle with a cool name called the axion, and you're telling me that it's definitely related to this idea of the CP problem, which is like a problem in theoretical physics about the symmetry of particles and whether or not they act the same way in all kinds of situations. And so we talked about how the weak force doesn't follows parity or charge parity symmetry and so, and that's now become the normal. Before we give them people a nobl price, we're figuring that out. But now it's like, okay, that's the way.
That's right. We realize that it's actually not outrageous for the weak force to violate CP. And then we looked at the other forces. We said, you know, the same thing that allows the weak force to violate CP, why doesn't it also allow the strong force to do it? Like the strong force could also violate CP. No big deal, that's the sort of same freedom inside it. It also interacts with quarks, which is what the weak force does when it violates parody. And so people thought, oh, well, the strong force, maybe that also violates CP.
But it doesn't.
But it doesn't. And we've made really really precise measurements of this, like crazy precise measurements, and so the strong force observes CP sort of for no good reason. Interesting.
So, like, if you try the strong force, it seems to be symmetric.
It follows the rules.
It's like, it follows the rules. It's the good is in physics.
Yeah, it's like if you were watching people drive down the highway and every single one of them was driving exactly at the speed limit, no higher, no lower, to like one billion of a mile per hour, you'd be like, that's weird.
That would be suspicious.
Precisely, and you'd wonder like, oh, maybe there's a speed trap out there or something like that, or their engines are fixed or something. You'd look for a reason, right, or they're all using cruise control. Yeah, precisely, and it's automated by the government or something. And so that's what makes us wonder. We see this parameter in the strong force that would very naturally allow for the strong force to violate CP, but it doesn't. It's like this angle that would allow it is set to exactly zero, and that seems weird. It seems like it needs an explanation. And that's the strong CP problem is why doesn't the strong force violate CP.
It's called I just got it, Daniel. It's called the strong CP problem because it applies to the strong force.
That's right, not because it's a strong problem.
Yeah, well you don't have Some problems are called like the you know, like in a I don't know.
The hard problem of consciousness, et cetera.
Yeah, or in computer science, and they're like a you know, strong there's.
The strong anthropic principle and the weaknthropic principle.
Yeah, there you go. Yeah, I'm not crazy.
That those exist. But that doesn't mean you're not crazy.
Okay, Right, it's not an exclusionary all right. So it's this strong ce people, but it's not actually a problem. It's more like it's like a strong why does it follow the rules?
Yeah?
Question, it's not really a problem, right, Like it's not causing any problem. It's just something that's it's hard to understand why it doesn't break the rules.
Yeah, it's not going to like fundamentally rip the universe apart or something. It's not going to bring the apocalypse upon us or anything. We don't have to call Bruce Willis. It's not that kind of problem. It's the why does this work that way when it doesn't have to? You know, it's it's strange, right, And anytime you see something unexplained and weird, a pattern you don't understand and physics, you've got to ask why, and you've got to think, is there a simpler explanation? Is there something that's making this happen?
So people, I guess, had to think up this question, right because before you thought that was totally normal. It was following the rules, but now it's weird. Suddenly became weird that it was following the rule.
Yeah, exactly. Once we realized the rules could be broken, we thought, hey, how come everybody's been breaking the rules? Right? Why is the strong force over there being so nice?
What you can drive as fast as you want in the highway? Why is everyone driving under the speed limit?
Yeah? The weak force is like driving the wrong way, it's driving any speed, it's driving the middle of the night, it's like going off road. And the strong force is like driving Miss Daisy right down the right in the correct lane.
Oh Man, all right, so that's weird. And so people started asking this question in the seventies.
Yeah, it was in the seventies that people came up with maybe the first answer to this question. People started asking this question basically after CP violation was discovered, which is, you know, just a few years earlier, and then people came up with this explanation and it's from Roberto Pecci and Helen Quinn. It was a nineteen seventy seven and of course their answer is is let's think up a new quantum field that fills the whole universe, Like that's the go to course.
Let's just add more things to the zoo, I know.
And it feels complicated, right, it feels counterintuitive, like we're trying to simplify things, and to simplify things we have to add a new complicated bit. Like yeah, that's all right, that seems counterintuitive. But it's like say you're trying to describe how an engine worked and you were missing the pistons. You'd be like, well, this doesn't really make sense. I'm gonna add one more piece. Oh look, it all clicks together now it makes sense. And so sometimes you have to add one missing piece in order to make the whole machine work, or you're understanding of the machine work at least, right.
Well, I imagine it's weird because you know, really, you guys are sort of just looking at some equations on a page, right, But it's like, oh, I if I could add just one number here would work. But really you're like you're adding a whole new field to the entire universe just by putting that number.
Some of us experimentalists do more than just look at pencil and paper, you know, we actually go out and smash particles and try to make this stuff.
Oh sorry, yeah, you also look at computer screens.
That's right. That is fundamentally different. Okay. My wife used to always tease me that my research was just quote on the computer and therefore wasn't real research.
I see, you don't mix chemicals, or you don't have to wear a lab code.
I'm not wearing a lab code, So how can it be science? Right exact?
I mean you can, but it's just strictly cosmetic.
That's right. And so they thought of this field and they said, well, what if there's this new field that fills up all of space and it's connected to the same field that controls the strong force. This field of quantum chromodynamics, the field of the gluons, these particles that mediate the strong force, and what if it talks to those, It like interacts with those, and it basically keeps it in line. And so there's this new field created in a very early universe with everything else, and it sort of pushes the strong force in the direction of having no CP violation.
I see, but not the other forces, like it only somehow affects the strong force.
That's right, it only affects a strong force. And it was created just with everything else. And then in the first sort of few moments of the universe, it pushed the strong force towards having a zero value for this angle that controls the CP violation, So not instantaneously like there may be in like a bill a second there in the very early universe where the strong force could violate CP. But then it was sort of like pushed in line by this other field.
Really, but I guess my question is why do you need this special field. Couldn't you just say that the strong force that's the way it is, like it was born with this angle. Why do you need to bring in like a field that accellent in and then somehow disappears.
Yeah, you could go with the non answer right to say, you know, physics doesn't have explanations, so stop asking questions. You know, like the numbers just are what they are. It's not really satisfying. You wonder like why is it this and not that? Especially when the numbers are a simple value. I mean, if the number is like zero point four, two, one, seven, you wonder what it is. But when the number is like zero or one, it hints at something else happening. It hints at something else controlling it. Just like seeing those people drive down the street at all the same speed, you wonder what's doing it?
But I guess you know, like how does it adding a whole new field help? Because if we add a whole new field, then you have to ask why does that field exist?
Yeah, exactly, just like you have to ask why do the pistons exist in the engine. But if you think them up, it does simplify all the parts working together in the way that you observe. And so they thought up this field and they're trying to make it as simple as possible and very naturally connected to the strong force, and in that connection between the strong force, and this new field forced the strong force sort of automatically to have zero CP violation. It's sort of like transforming one question into another. You're saying, you know, why is this angle? Zero gets transformed into why does this field exist? Sure?
Okay, and that's I guess that's a more comfortable question for you, guys, because.
Because we like fields, man.
Because then do without you be out of a job.
Well, also, the field is something we could discover, right, and so if this field exists, we can go out and find it, and then you can ask, Okay, why does that field exist? Why do we need all these fields? Is it part of some larger strategy? I don't know, but it is something that we can test.
It's fine, right, as opposed to like just some weird property of the strong force.
Yeah, you can measure this property the strong force all day long and say zero. That doesn't help you understand why it happens if it If it can transform into it's forced to happen because this field exists, and we can prove that field exists, then we can start to think about the larger puzzle and like, well, why this field and does this mean other fields have to exist, and what does this tell us about the pattern of all the fields, which is sort of the larger mission of particle physics is to understand how all the fields fit together into one.
And I guess it's not totally crazy because that's how they discovered the Higgs boson, right, Like you thought of a field to patch something in your theories, and then you found the particle that belonged to that field. So it's all a sort of been buttoned up.
Yeah, exactly. The question there was like, why does the photon have no mass and these other particles do have masks? Can you explain that? And some people were like, hey, just accept it, move on, man, but Higgs was like, no, I'm going to create a new field that explains it. And he was right. And so now we can of course ask the question like why is there a Higgs field dot? Do we get to get on to the next question. And so just like that, this new field creates a new particle, and that new particle is something we could discover, all right.
And so there's a fun story and by fun I mean crazy story about how it was name how they name Axion came about. So tell us the story.
So it's it's sort of funny for two reasons. First of all, Petchy and Quinn, who thought of this field, forgot to name the particle. Like they came up with this field, and of course, naturally if the field exists, then it's possible for the field to get like an excited bundle of energy, which we call a particle. But they didn't name the particle. So another physicist came along, Frank Wilchik, who's famous and he won a Nobel Prize for understanding how quarks interact with each other with a strong force. He decided to name it. He's like, well, let's think about this field and how we might see it. And of course he thought about the particle and then he had to give it a name.
No, how he got to name it, but the particle already had parents. How can you just go in and like, name somebody else's kids.
Say you met a family and they didn't give their kid a name, you would probably come up with a nickname for it, right. You wouldn't want to say that kid's name.
No, I would tell the parents to give him a name. I would ask the parents what do they call? What do they say when they want the kid to come over.
Well, then you are more modest than Frank Wilcheck, which is true for almost all of humanity anyway.
Oh my goodness. So wait, but did they name did Pesci and Helen Quinn name the field at least? Or did they just say like a field?
Yeah, a field? They just gave it a mathematical symbol, right. They didn't give a name to the particle that comes from it, And so you know, if Frank Wilcheck had been less modest, he would have called it the Pechy Quinn particle or something.
For the field, or what Frank will Check called the field.
Yeah, well now it's called the Axion field.
Oh man, he totally took it over.
He totally took it over. And on top of that, he gave it a totally ridiculous name, like Axion is a cool name. But he got the idea when he was grocery shop.
Oh no, what happened.
He was in the aisle for laundry detergent and he saw this laundry detergent called Axion detergent booster, and he thought Axion, that's kind of a cool name.
Oh no, well he was what was he thinking? Like this particle that I'm earthsurping and stealing from this. Other other physicists would clean everything up pretty well. So, hey, laundry deterg makes perfect sense.
It's a physics booster, so we need a detergent booster. Yeah. So somebody in some marketing department created the name for this laundry detergent, which ended up naming a theoretical particle.
But didn't they copyright it? Can you do that?
That's a great question. Can you name a particle after like a copyright? Can you name a particle like the Nintendo switch particle?
Yeah, or the Netflix particle?
Can you do that? You know, that's a question for our legal department, for the physics lawyers. You stumped me on that one. That's through the physics lawyers, of whom I am not one. And you know, there was competition. There were other famous Nobel Prize winning physicists like Stephen Weinberg. He wanted to call it the Higgs lit because he thought, oh this is he reminds me a little bit of the Higgs boson, So he wanted to call it THEGGS.
You were gonna say you wanted to name it clorox or Kleenex.
Or the Taido particle no, and axion sort of stuck. And you know, these things are not fair, and they're not always done the right way. Like we talked about how quarks are named quarks because a famous physicist came up with the name, even though a young physicist came up with the name aces before that and it was sort of buried in obscurity. These things are not always done correctly.
They're not always given to the people who to the parents.
You mean, that's right, Yeah, it's not always fair. It's just sort of like what people end up calling something.
All right, Well, let's let's get into why this accion is super duper cool and why we think it could be real. But first, let's take a quick break.
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Right, Daniel, we're talking about the Axion and it got its name from a laundry detergent, which is I guess not too surprising in physics, because you know, I'm not impressed by the general imagination and naming things.
But it is a cool sounding name at least, you know it satisfies your transformer principle.
Well, well, why didn't'd you steal Megatron's name? You know, Optimus Prime?
Yeah, maybe they had better lawyers, right, the detergent companies lawyers are not as good as the Transformers.
As the has Bro Yeah, that is a little bit scarier. All right. So you're telling me that this particle is cool because it would answer the question of why a strong force does not violate some of these symmetry conditions in the universe and that, But it could also be cool because it explained another big problem.
Yeah, there's another big problem in particle physics, which is where is all the stuff? Right? We know that most of the stuff in the universe is not made of quarks and electrons or any other kind of familiar matter. It's made of this new thing that we call dark matter, even though we don't really know what it is. And just like with the other sort of physics mysteries, we see evidence for it and how galaxy spin and how light bends through space, but we don't know what it is and what it's made out of. So it's one of the biggest pressing questions in particle physics or I think in modern science. Right, what is eighty percent of the matter of the unit?
What is dark matter?
Right?
And so it could be axios, it could be laundry detergent, it.
Could be exactly the dark matter could be scrubbing the universe.
Oh no, it seems ironic that dark matter would be something that's supposed to get the stains out.
Yeah, precisely. Well, it satisfies a lot of the requirements you need for dark matter. Doesn't interact with normal matter, so we wouldn't have seen it. That's what makes it dark. It has some mass to it, although it's very very light. So if it were dark matter, you would need like a ridiculous number of these things. You need like two hundred billion just to make the mass of one electron and we need enough to make five times as much mass as everything in the universe. And so like, if axioms are the dark matter and they are real, then we are swimming and swimming in bajillions of axioms all the.
Time, meaning that if these particles exist and they explain this strong force problem, they could also be there, but we wouldn't see them, like they don't interact with the electromaggots, and of course.
That's right, they don't interact with electromagnetism, and they do connect to the strong force, but only in this way that they make the strong force not violate.
Seen.
The field also has some other super duper heavy particles in it that do interact with a strong force, but they're so heavy that they essentially don't exist, and so we don't have to worry about them. And so effectively, axions are totally inert except for the fact that they have a small mass. And so if they have this mass, then they contribute to gravity. And that's what dark matter is. It's something mysterious out there that's adding gravity to the universe, and so it could be the.
Acts all right, Well, would that be sort of a coincidence that we have this particle and it just so happens to fill in the blank for dark matter.
It would be amazing, Like, who wouldn't want to solve two big problems in physics at once? Right? You think of this particle to solve one problem, and boom, it turns out to solve the other problem at the same time. You can collect two Nobel Prizes in one trip. Wow, I mean that sounds pretty Do.
You get two?
Like?
Do you get two in the same ceremony? I wonder.
I think you have to come back the next year. I'm not sure, but that's attractive. But it also makes you a little suspicious, Like we thought this particle up to explain the strong CP problem, and then we have this other problem. We're going to try to sort of squeeze this particle into solving the dark matter problem. It actually sort of reflects something else about the dark matter problem, which is that we're getting a teen c bit desperate. Like we thought we would have figured out dark matter by now. We had better ideas for what dark matter could be, these weekly interacting massive particles stuff like that, and none of that has really panned out, and so now we're sort of like dragging along the bottom of the barrel looking for other ideas that might explain dark matter, and so that sort of led to a resurgence and interest in the axions. People think, wait a second, what about axions? Maybe those could be the dark matter.
Like so desperate, you're reaching for the non brand bunge of deterge.
What you're saying, that's exactly where we are.
And it could also make you solve another big problem, right.
It could solve another big problem. There was a really fascinating paper out there last year that talked about those first few moments in the universe when this field was created and it forced the strong field to not violate CP. And it turns out when it did that, it had sort of two directions. It could go sort of like imagine a marble in an upside down hat and it's rolling towards the bottom, and that's how it forces the strong force to not violate CP. But if instead of just rolling strength down, what if it had like a little bit of a kick, so it sort of went around in a circle and then relaxed to the center. Then it could have done it clockwise or counterclockwise. Oh boy, it's like another symmetry it's another symmetry. And it turns out if it goes clockwise, then the universe is filled with matter, and if it goes counterclockwise, the universe is filled with anti matter.
Oh.
What it's like flipping a coin of antimatter.
Yes, and that's a big question in physics. It's like, why is the universe made out of matter and not antimatter? And we don't know. And it feels like a coin was flipped, and it could be that this was the coin.
Oh, it was a laundry detergient coin that determined the entire universe.
Yeah, and so the axion could solve this other problem also, So it really could be key to a lot of these big, big mysteries in particle physics.
And I guess you're because I imagine you were saying, this is not the only idea, Like, this is not the only field or particle that people have dreamed of, but this one is somehow more attractive because it sort of makes more sense.
Well, because the other ones have been sort of ruled out. You know, you have your first idea, you go look for it, the experiment says no, sorry, Then you go for your second idea. You know, and you just keep looking through ideas until you find one that the universe says yes to. Wow, and so that sort of led to a resurgence. And you know, also theoretical physics, there are trends, there are fads. People get excited about an idea and they work on it furiously, and then they get bored with it. Somebody else comes up with a new idea, and so the idea sort of have cycles. You know, people get bored of an idea, put it aside, and then twenty years later, some new young woman says, hey, I have found a new way to use this old idea, and everybody get excited about it again. It's a human endeavor, all right.
So then the axion is trending, is what you're saying, Like it's having a popular a surgeon popularity. And so I guess the question is is it real? Like does it actually exist? And can I find it in places not in my laundry detergent aisle at my grocery store.
Well, we don't know, but there are experiments out there to look for it, sort of two different categories of experiments that both use magnetic fields. The idea is that the axion is still sort of like a photon, and it doesn't interact with photons normally. But it turns out that if you put the axion into a super duper strong magnetic field, then sometimes it will turn into photons.
What ye wait, a magnetic field can cause particles to change.
Yes, the magnetic field will change the way the particles interact. Right, it has energy in it. And if those particles can feel photons in any sort of way, then they can get enhanced and they can change the way they decay. And so the axion, if it's in a chamber that sort of resonates with it, and it's that chamber is filled with magnetic field, and this magnetic field is like one hundred and fifty thousand times the strength of the Earth's magnetic field, then it could sometimes turn into like little microwave photons. So they have this cavity up in the University of Washington where they have very cold and they have a very powerful magnetic field, and they're just listening for a little microwave blip.
Woh.
So we can't see them, but they might turn into things.
We can see them precisely in these weird conditions, in very strange, very strong conditions, they might turn into photons.
Really, you can predict that with the equations.
The equations say should happen if you get the magnetic field at the right frequency and you get it down to cold enough conditions and they've been running it for a while and they haven't seen them, but they're sort of like tuning the magnetic field, like are they over here? Are they over there? And so far they haven't seen anything, but it's sort of getting more and more powerful the.
Device pretty cool. So that's one way. What's the other way that we might see them.
The other way is sort of the opposite is to try to turn light into axions. Like instead of having axion turn into photons, turn that around, take a beam of light and try to turn it into axions by putting.
The light like make light disappear, yes.
And so this experiment is called light shining through walls because you basically have a wall and a really strong magnetic feel and then a beam of light and the idea is maybe the light will turn into axions which can then pass through the wall with no problem, which will then turn back into light. And so you can sort of like have your light, you know, pass through the wall by phase through the wall, by becoming an axion as it's going through the wall.
I feel like you're getting to the point where you're like, we need ideas, or what's what's this? Is this a comic book? What where's the superhero that can go through walls? Oh? That sounds like a great idea.
Yeah, well it's pretty cool because if we figured it out, then we could actually build beams of light that go through. So it's also sort of a cool experiment because you just need like a light beam and a wall and then you just look for light making it through the wall. Right, So it's pretty dramatic.
When you see something like a magical X rays.
Yeah, yeah, turning light in X rays making them penetrate just like X ray to do. And it's pretty fun, you know, to see these experiments. These are clever ideas, These are wacky ideas, and personally, I never expect these experiments to actually discover the axion.
What isn't this your field?
This is my field? Yes, but the axion has always seemed sort of, I don't know, out there to me, like too crazy an idea. This she feels like a little bit out there in left field.
Like it's too su sutsy.
Yeah, it's a little too sudsy. Like I read this interview with Helen Quinn, one of the two people who came up with the original idea, and even she's a little amused that this idea still.
Likes Really, She's like, I don't know what all the fuzz is about.
Yeah. There, quote from her is Roberto and I spent a few months cooking up this theory, and now the experimentalist has spent forty years looking for it.
She's laughing at you, Daniel, It's like she's amused by you.
The whole thing was a joke to begin with. What do you guys do in wasting your time?
You're like, that's why we didn't give it a name. It was all a big practical joke, the whole thing, and then we planted the detrogent for Frank Wiltrick to find it.
Yeah, using their time travel device, right.
Their magical X ray light.
But it's fun, and you know, sometimes an idea can begin from a silly place, right, just exploring, just futzing around with the math, and then turn into something real. I mean, if the axion is real and it solves these big open questions in physics. Then that would have been a productive few months cooking up that crazy theory.
The productive forty years because you know, like it's almost like the Higgs boson, right, you predicted it and like forty years later they found it.
Yeah, it took almost fifty years to find the Higgs. So sometimes you come up with a theory for a particle that's really really hard to find. It's not always easy to go and just like look for this thing. Even if you know what it's supposed to do and how it's supposed to look, creating those conditions to find it is not always easy, especially if it's elusive. I mean, if it's the dark matter, then it's been hiding for a long time.
Yeah, and the stakes are pretty high, Like, if you find it, it would explain so many things, including dark matter and antimatter and strong CP problem.
Yeah, it would really close off a lot of big open questions in physics. So from that point of view, I sort of hope it is real because they would be a fascinating inside into the universe. And then, like as always with physics, we get to ask the next question, like, all right, well, why is there an axion? What does that mean? Is there another axion?
You know?
Is the whole spectrum of axion particles? And so the questions never really end, right.
I wonder if there are lawyers at the Axion Corporation they're like just waiting for you guys to discover it to give them that marketing boost in popular culture.
Or that's when they're going to see it, right there you.
Go, they're going, they're waiting, like, we own this, you can. You can't make X rays light special laser beams without us.
That's right. We demand you pack up all your axions and boxes and send them to us immediately.
Yeah, all right, well, I think as usual, this just points to the things we don't know and how you know, science is actively still trying to explain the universe.
That's right. And then one hundred years we could look back and think, what was it like before physics knew about the axion particle or the chlorox particle or whatever it is we're going to discover in twenty years, But before we know it, it's just an idea. It feels very different to be on the ignorance side of a discovery than on the knowledge side.
Just never know what could turn out to be true.
That's right, because the universe is no strangers to weirdness.
All right, Well, we hope you enjoyed that. And the next time you're going down the grocery store faundry detergent aisle, look around. You might discover a new particle that explains the universe. So keep your eyes open.
Or at least discover a cool name for somebody else's good idea.
There you go, Thanks for joining us, See you next time.
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 ap 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 elect your cars. Visit you as Dairy dot COM's last sustainability to learn.
More our iHeartRadio Music Festival for a sentate by Capital One Coming Back to Las Vegas twenty first, a weekend full of superstar performances asap Rocky Banks, Sean came Mei Laka Bail Tojika Zuliva, When Stefani Hoosier, Keith Urban, New Kids on the Block, Paramore Shaboozi, The Black Crows, The Weekend, Thomas Red, Victoria Monette, Coldplay Is, Chris Martin, had More, Stream Live Holy on Hulu.
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Hi, I'm David Eagleman from the podcast Inner Cosmos, which recently hit the number one science podcast in America. I mean neuroscientists at Stanford and I've spent my career exploring the three pound universe in our heads.
Join me weekly to explore the relationship.
Between your brain and your life.
Because the more we know about what's running under the hood be or we can steer our lives. Listen to Inner car with David Eagelman on the iHeartRadio app Apple Podcasts or wherever you get your podcasts,
