Daniel and Kelly’s Extraordinary Universe - What is Mirror Matter?

Episode Date: September 1, 2020

It's not anti-matter, or supersymmetric matter, but yet another way our familiar particles might be reflected, and could explain a deep mystery of the Universe. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

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Brought to you by the American Lung Association and the Ad Council. Hey, Daniel, I have a question. Do particles have families? Oh, yeah. Actually, each particle has a whole set of relatives. Really? So who is the electron's closest cousin? Well, the positron is kind of like the electron's evil twin.

Ooh, does it have like a twirly mustache? Or... It's got a goateeat. Where is the opposite color clothes? Yeah, and then it's got the muon, which is like it's heavier cousin. It's more massive cousin. Like it's more fit, like it's bulky, or does it just sit around and eat bananas? Nobody knows, nobody knows.

And then the electron even has like hypothetical relatives. What? You mean like long-loss relatives? Yeah, like there might be a super symmetric version of the electron. We call it the selectron. That sounds like a great superpower. I'd love to select my own relatives. Hi, I'm a cartoonist and the creator of PhD comics.

Hi, I'm Daniel. I'm a particle physicist, and there is no super symmetric version of me. Is there an asymmetrical version of you? I don't know. But if there was a super symmetric version, it would be the Daniel or the Danielino. The Daniel Tron. I'm sure you would come up with an awesome name for that version of Daniel. Welcome to our podcast, Daniel and Jorge Explain the Universe, a production of IHard Radio. In which we take you on a mental tour of everything that's amazing, that's wonderful, that inspires your curiosity. Everything that makes you wonder, how does that work?

Why is it like that? Why isn't it some other way? We take the whole universe and try to break it down into tiny little pieces and explain them to you. And we try to take you in a tour. of all the things that are out there, all the amazing and incredible types of objects like black holes and neutron stars and all of the incredible and mysterious particles that are out there and that might be out there.

That's right, because part of the journey of understanding the universe is thinking about what's there and what might be there. What would make more sense if the universe had it in it? What do we need to add to our vision of the universe to make it make more sense? What puzzle pieces are we missing? Because that's how a scientist explorer, right, Daniel? That's how we kind of probe the unknown. We sit around and we think, well, I guess you guys sit around with some coffee.

And you try to think of what could be out there. What would make sense in terms of what the equations predict and what the data suggests and try to think about what we can discover out there in the universe. Yeah, there's sort of two ways to make big discoveries in physics. One is like try to anticipate them. to look at the pattern of what we know and say, what's missing? Would this make more sense if we had another piece? Like if you were doing a puzzle and you fill the whole thing in and it's one piece missing,

you're going to go out and look for that one piece and you know sort of what to look for you, have expected it. The other way to make discoveries just to like go out there as an explorer and see what you find. And maybe you're running to something amazing you didn't expect. That's also fun. But there's a lot of times that we can't just do that. We don't have necessarily the way to explore. We have to think about it in advance.

and try to figure out in advance, what is it we should be looking for? I usually find my puzzle pieces in between my couch cushions or under the table. I borrowed a bunch of puzzles from some friends, and I put the first one together, and it was missing a piece. And it had an extra piece from another one of the puzzles.

What? I think your friends are trying to drive you crazy. I think so, because then the next puzzle was the same. So by the time I think it was the next puzzle, I had this like two extra random pieces and two puzzles each missing a piece. And it wasn't symmetric? Like one piece was missing from the other one? No, it was like a cycle.

It was like you have to finish all six to finish any of them. It was torture. I think they're trying to gaslight you in the puzzle version of gaslighting. Trying to puzzle light you then. Yeah, exactly. But you know, I have to take issue with what you said earlier that physicists, when we try to have ideas, we sit around and think about stuff. Why is that you think about it?

It's just like sitting around. These days I try to do my things. thinking while I'm active. I'm going for a walk to think about stuff. I'm doing jumping jacks to think up new theories. Oh, I thought you were going to complain that you actually lie down when you think for physics. Is that how you get your creative ideas, curl up under the desk or something? My best ideas come when I have my feet up for sure. Poster definitely leads to creativity. Yeah, so we know a lot about the universe and we know a lot of the particles that are out there that make up matter, that might make up matter,

and that make up other things that maybe are not as useful to the universe. But there are also a lot of missing pieces in the universe. There's a lot of empty places in our ideas of particles and matter that could be filled by new particles. That's right, because when we look at the particles, we don't just want to make a list and say, here are all the particles in the universe, we're done.

We want to understand that we want to fit them together into patterns, because those patterns are clues, clues that will lead us to be able to pull back a layer of reality and see what's underneath those particles, what are the tiny, even smaller particles that make them up all the way down to the smallest bits of the universe. So the way to do that is to organize our knowledge and look for holes. For example, before we discovered the top cork, we had five corks and they fit together in two pairs plus one lonely bottom cork, and we thought, where's the partner for the bottom cork? It must be out there.

And we went and looked for it and found it. So this strategy of organizing our knowledge and looking for holes and gaps and symmetries is a really productive way to find new things. And so to the end of the program, we'll be talking about one such set of holy particles that might exist and that might answer a lot of questions

about our understanding of the universe. So we'll be asking the question. What is? is mirror matter. And why is it so hard to say? It is a little hard to say. I feel a little tongue-tight. You say mirror matter.

Well, you know, there's a whole sociological question we'll dig into later about why mirror matter is not so popular among theoretical physicists. But one answer might be that it's just kind of hard to say. Do you think that matters? It's more fun to say dark matter, anti-matter than mirror matter. Don't use alliteration when you come when you, when you, discover something new and amazing in physics. Is that what you're saying?

And ours. Ours are just hard to say. They're a horror. They're a horrible choice. Exactly. Is that why particle physics has some problems there? Yeah, I think so. All right.

So as usual, Daniel went out there into the wilds of the internet to ask if people were familiar with this idea of mirror matter. So thanks to everybody who sent in their speculations about what mirror matter might be, If you'd like to speculate on a future topic of one of our podcast episodes, please write to us to Questions at danielandhorpe.com. We'd love to have you participate. So think about it for a second before you listen to these answers. If someone asks you, what is mirror matter?

Or ask you how to pronounce it for that matter, what would you say? Here's what people had to say. Something that reflected like a positron versus, you know, it's kind of the opposite of each of the particles. that we have. I can only guess by the name. Probably it's the matter that imitates the matter that comes close to or gets in contact with.

I have no idea. So there are two things that come to my mind immediately. The first one is antimatter. But I think that this answer is too straightforward. So I don't think this is the right answer to your question. So the second thing that comes to my mind, that's super symmetry. I assume that mirror matter talks about particle physics, and I don't know a whole lot about it, but from what I know, I think mirror matter wants to kind of explain why the weak force

is the only one that does not respect the mirror reflection symmetry. That sounds made up. Sounds like something I'd hear on Star Trek. but I'm going to go with, it relates to supersymmetry. Those are words I've heard before. I would guess that mirror matter is matter with the opposite handedness. Mirror matter is maybe matter with particles of opposite spin in charge. I'm immediately thinking of antimatter, but I'm presuming it's something different.

All right. I like the Star Trek reference. Maybe we should be writing for Star Trek. Star Trek, Daniel. Star Trek is just stealing from reality, you know. Reality is so weird that inspires hilarious fiction. But people seem to have sort of the idea that it's like matter, but it's somehow their mirror image. So I guess it is a pretty good name, kind of. Like there's some kind of idea about symmetry and handedness and spin. And there seem to be a general understanding that there are these symmetries, that everything we know could be reflected. There could be a whole other set of stuff in exactly the way that the area is antimatter. Now, we'll talk in a

moment about what mirror matter is. It's not the same thing as antimatter, but it does share that thing in common, that it's a reflection of the particles we know. It tells us something about the symmetries that are built into the universe. The idea is that there's potentially more than one of these reflections. You have the reflection of all the matter particles into anti-matter particles, and you can also have the reflection potentially of matter particles into these mirror matter particles. So it's in the same sort of family of ideas, but it's just a different kind of reflection. Man, I feel like we're living in a house of mirrors or a universe of mirrors. It's crazy and it's amazing. And it blows my mind how many of these reflections there are. Because, you know,

we talk about antimatter. We will talk about mirror matter. But then there are also these particle families like the electron is not just reflected into the muon. It's reflected into the muon and the tau. And so the whole structure that we understand of the universe of particle physics is really built around all these symmetries and reflections. I mean, that's what we're trying to do is organize these things into patterns and the look at the patterns and say, what does that pattern mean about the universe? It means that maybe you shouldn't have decorated your whole universe with mirrors, perhaps. You know, who did, right? Who put up all these mirrors, right? This place is like a crazy fun house. Why is it so hard to understand? No, it's.

It's fascinating. You know, just like you can ask the question, you know, why is there no antimatter left in the universe? You can ask the question like, well, why do we have antimatter at all, right? Why is there this symmetry? What does it mean about the universe that there seems to be this balance in the list of particles, but not in their actual, you know, existence? Right.

And so people also mentioned the idea of supersymmetry, but mirror matter is not related to super symmetry, right? That's right. Super symmetry is yet another hypothetical reflection that looks to try to build. the symmetry into the universe, it says, we have some particles called fermions that make up matter particles and other particles called bosons that make up forces like photons and Z bosons. What if each of those has a corresponding particle on the other side? Every fermion has some boson that corresponds to it.

So the electron has a selectron and the muon has a smuon. And then every boson, like the photon, has a fermion partner. So the photon would have a photino and the W particle would have a we know. for example. And so that again just reflects the whole set of standard model particles over into a new set of hypothetical particles that we have not yet discovered and are not the same as antimatter and not the same as mirror matter. It's just another kind of reflection that tells you about how we're always looking for symmetries

in the universe. But this one seems to claim the mantle of mirror matter. Like it just grabs that word and says, I'm the mirror type of matter. Yeah, exactly. And it's mostly championed by like one guy in Australia. What? Wait, this is a major physics theory that has the support of exactly one physicist. Not exactly one physicist, but, you know, not that many physicists believe in mirror matter.

Although other people have ideas that are very similar to mirror matter that just don't call it that. So maybe it's just a naming issue. People are like, we hate that name. We're going to come up with a similar idea and call it something else. Yeah, you were telling me that this idea also has other names like Alice Matters or Shadow Matter. Yeah, that's all the same one idea with several different potential names. So I guess, you know, the community around Miramatter was trying out a few things to see what would stick. And I guess Mirror Matter is the most popular.

I kind of like Alice Matter because it has the like literary reference to it. Oh, I like Shadow Matter. Sounds like something out of Dungeons and Dragons. You're going to roll a dye and try to use your Shadow Matter sword. Yeah, the shadow mage uses a shadow matter sword, of course. I think it's too similar to dark matter, you know, because then people are like, well, if you put matter in the shadows, does it become dark matter? You know, it's very confusing. All right, well, let's jump right into it, Daniel.

Let's answer the question. What is mirror matter? I'm guessing it has to do, it's sort of like super symmetric matter, but maybe you're saying it's a different kind of mirror? Yeah, it's a different kind of mirror. So whenever we create a new set of hypothetical particles to back. the particles we have, it's because we see an imbalance. We see something asymmetric and we wonder, why do we have positive charge particles and not negative, for example?

Or, you know, why do we have fermion matter and boson forces, not the opposite? So in this case, we've created a whole new set of particles, the mirror particles, to try to balance the parity asymmetry of the universe, the symmetry about being reflected in the mirror. Does the universe look the same when you reflect it in the mirror? And we've talked on the podcast several times about how our universe seems, to be weirdly left-handed, like some parts of the standard model, the forces that are involved, like to only talk to particles that are left-handed and not right-handed. And that's weird.

I guess it all sort of goes back to the concept of particles and matter having like properties or valleys of things, like charge or color or what's the other one? Spin. Spin. Flavor. Spin, flavor. They have all these properties. And so, and really in the math, you can just just flip them and such a particle could still exist. Like mathematically, you can flip these things even though you may not necessarily see them in nature, right? That's kind of the idea is that particles have these properties and you can flip some of them and sometimes you see particles that have them and sometimes you don't see particles

that have them. Yeah, that's exactly right. We look at the structure of our theory and we wonder if it's symmetric. We're like, well, what happens if you flip all these things? You know, if you flip the charges from positive to negative or you, you flip everything for the minus z axis to the positive x axis or you run time backwards and all these things we wonder like is our theory symmetric and so as you say you can take this set of particles and you can say well do we have the opposite set in this sense or in this other sense

or in this third sense do we have the opposite set you know do they exist and if not then why not because that tells you something about the universe right like why do we only have negatively charged electrons and not positively charged electrons you know positrons and so It's interesting because you feel like there must be a reason. We like to think that the universe should be symmetric because that makes sense. Because if it's asymmetric, then like, who made that choice, right? Why matter or not antimatter? Did somebody flip a coin?

Is it totally random? And we don't like that in physics. We don't like things that don't have explanations. So we'd like things to be symmetric because then they don't need explanations. So we take our theory, we look for all the things that are asymmetric and then we try to fill in those holes. But I guess, you know, why do physicists have a preference for? symmetry. Like, couldn't you ask the same question? Like, who made the universe symmetric? Like, if the universe was symmetric, wouldn't you ask the same question? That's a great question. And that

really goes to philosophy. And it's a question of what's simple. You know, when we look at a physics theory, we have questions about it. And when we compare two different physics theories, we want the one that's simpler, that needs, like, less explanation and fewer ideas. And that's sort of, you know, we don't know why the universe is that way, but it does seem to work that way. That simpler ideas seem to work best. And so I would just ask fewer questions about a theory that was symmetric than a theory that was asymmetric because a theory that's symmetric, you're right.

There's no reason why the universe has to be symmetric, but it just seems to make more sense intuitively or aesthetically. But, you know, that's not a scientific feeling at all. That's sort of like a philosophical or personal aesthetic feeling. Yeah, that's what I mean. It's like if one of your kids was really well-behaved and the other one was a lot of trouble, you'd be like, yep, that makes sense in the universal cosmic balance sense. I think there is something there, though, because if the universe is asymmetric,

there are lots of ways it could be asymmetric, but there's only really one way to be symmetric. And so if you're asymmetric and you're asymmetric in one particular way, then you have to wonder why. Are we living in a multiverse where every choice for that asymmetry is made? Are there other universes out there that are anti-matter instead of matter, for example? Or are we living in a simulation where this was decided by the people who ran the simulation? It's just sort of unsatisfying to not have an explanation if there are lots of options. Whereas if there's only one option, then that's just the option.

You can ask, like, why is there only that option? And that's a deeper question. Like, if both your kids are well-behaved, you'd be suspicious. I'd give my wife credit if that was the case. But fortunately, we don't live in that universe. All right. Well, okay, so mirror matter then is a matter that also breaks one of these symmetries in nature that you have. And it's sort of related to the weak force, right? Mm-hmm. I find it a little confusing to think about parity because it's hard to think about whether it matters if you're reflected in the mirror, whether the universe prefers right-handed or left-handed. Now, it's the same basic concept, but I think it's easier to think about whether it matters if you rotate your experiment, whether the universe... has a preferred direction, which seems obviously crazy.

Imagine you throw a ball and it follows some law of physics, right? Parabola goes up and it comes down. Now you watch that same ball toss, but now you're standing on your head. It looks a little different, right? Because you've rotated yourself, but the same laws apply. Like you can still apply the laws of physics to the ball moving. It shouldn't matter if you're standing on your head. Right, except that now down means up and up means down.

Yeah, exactly. You have to put some minus signs in there, but the same laws do apply. Now, you don't see exactly the same thing. Like, it looks different if you're standing on your head, but the same rules apply. And so parody is sort of like that. Like, if you reflect something into the mirror, do the same rules apply or not? And people for a long time thought, well, of course, like, just because you're doing it in the mirror, the same rules should apply.

Like, it would be nonsense if our universe was somehow left-handed and it looked different in the mirror and like the mirror was right-handed. It would be weird. It would be weird. And people just assumed for like, you know, as long as people had this idea until about 50 years ago, people assumed the universe was symmetric in the mirror. But if you didn't experiment, it would look the same in the mirror. That, you know, that the mirror is that in the mirror world, the same laws of physics would apply.

Now, we can't actually go to the mirror world. We can't do the mirror experiment, right? The idea is we do experiments in our universe and then we think about what they would look like in the mirror world. We imagine that all the experiments we do in our universe would look the same in the mirror world. But the universe is a little bit weirder than that, right? The universe is super duper weird, in fact. And it was about 50 years ago that people realized, you know, we never actually checked to see if this is true for all the different kinds of interactions. They had checked for the strong force.

They had checked for electromagnetism. And parody was preserved. Like everything made perfect sense. But nobody had actually checked for the weak interactions. And then one summer, people wrote this paper realizing, wow, nobody's ever checked this one thing. Somebody should do it. And the paper came out. And then over Christmas vacation, a scientist at Columbia, the famous professor, C.S. Wu, she did the experiment.

And she set up a system that would look different in the mirror. And so they broke the mirror. And that was seven years of seven decades of bad physics luck. Is that kind of what happened? Yeah, exactly. All right. Let's jump into the details here about the weak force and symmetry. and left and right-handedness.

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or wherever you get your podcast. All right, we're talking about Mirror Matter. And this is not related to how I look like in the morning when I look in the mirror, Daniel. That's right. No physics could explain that. This relates to how particles look in the mirror because particles, as weird as they are, they have this bizarre property that they're either left-handed or right-handed. And, of course, particles don't have hands, right?

But they do have a property which gets inverted in the mirror sort of the way that left-handedness and right-handedness does. And that's when you compare the direction they spin with the direction they're moving. And because clockwise spin in the mirror still looks clockwise, whereas moving in the mirror can get flipped in the other direction. So a left-handed particle looks like a right-handed particle in the mirror. And a right-handed particle in our universe looks like a left-handed particle in the mirror. Right. It's kind of like the mnemonic, you know, like when you use your hand,

like you point your thumb one way and then you curl your fingers and that, that's sort of like a handedness kind of thing for particles, right? Like the thumb could be pointing to where it's going, and the curl of your finger points to how it's spinning. And so when you look in the mirror, that looks not the same. That's right. And that tells you if a particle is left-handed or right-handed. Is it moving in the same direction as its spin vector is pointing,

or is it moving in the opposite direction? And in a mirror, a left-handed particle is turned into a right-handed particle. Now, the weird thing is that the weak force, the weak nuclear force only interacts with left-handed particles. It totally ignores right-handed particles. That's the big asymmetry that the force ignores these other particles? It doesn't interact with them at all. You know how some forces interact with some particles and not others,

like the strong nuclear force doesn't interact with electrons. Electrons just totally ignore the strong force. Oh, I see. It just doesn't apply to that. It just doesn't apply. So there are actually two kinds of electrons. There's the left-handed electron or the right-hand electron. The weak force only interacts with left-handed electrons.

It doesn't interact with right-handed electrons at all. Wait, do right-handed electrons exist? Are they out there flying around, ignoring the weak-force? Absolutely, all the time. There are left-and-right-handed electrons, and only left-handed electrons interact with the weak force. And that's what causes this parity asymmetry. In the mirror, the weak force interacts with right-handed electrons, but in our universe, it only talks to left-handed particles,

neutrinos, electrons, and quarks. That is so bizarre. It's really weird. It's a huge asymmetry, and it's not like a little asymmetry, like it talks to left-handed particles more than right-handed particles. It's complete asymmetry. It only ever talks to left-handed particles, never to right-handed particles. What?

If I threw a right-handed electron, like, nothing would stop it in terms of the Strong force? In terms of the weak force. It just flies through. Oh, sorry, the weak force? Yeah, that's right. But you don't really notice that because the weak force is super weak. And right-hand electrons still feel electromagnetism, right?

The photons. It's biased, but it's a weak bias. That's right. And so most of the interactions work with both of them. But the weak force only talks to the left-handed particles. And that's why, for example, we've never seen a right-handed neutrino. Because neutrinos only feel the weak-for. And so the only way to talk to neutrinos is through the weak force, but the weak force doesn't

talk to right-handed particles, and so we've never seen a right-handed neutrino. Wow. It's not just that it has a bias against the electron being right-handed. It has a bias against any particle being right-handed. That's right-handed. There are two kinds of every particle. This is the left-handed kind and the right-handed kind, and the weak-force only talks to left-handed quarks to left-handed electrons, left-handed muons, left-handed neutrinos.

It never talks to right-handed anybody. It kind of makes me wonder if there's a right-handed weak force. Have you guys thought about that? Like, maybe there are two forces. And that's the genesis of the idea for mirror matter. This kind of asymmetry. It's me and the guy from Australia. No, but that's exactly it.

This kind of asymmetry makes you wonder, is there something out there to balance it, right? That was exactly the thought you just had live right here on the program. And that's the whole motivation for this entire program of physics is can we find something else out there to balance it? You didn't like that asymmetry and you're like, let's fill in that gap. Let's balance the universe. And that's exactly what we're trying to do with mirror matter. Yeah, because I believe in cosmic justice, Daniel. And so there's sort of two different sets of ideas there. One is a minimal idea and say, well, can we restore the

balance by saying, well, maybe there is a right-handed neutrino out there. We've just never seen it because we can't interact with it with our weak force. So maybe there's a right-hand a neutrino and then like some other version of the weak force that's biased in the other way, like a W prime boson and a Z prime boson. And that's a cool idea and that would restore some balance. I mean, it would mean that the universe is sort of cracked in half, right? It's not really symmetric. It's sort of like cracked in half and we have two different pieces and we happen to be

on the left-handed part of it. But mirror matter takes a step further and it says instead of just adding a right-handed neutrino and a new force to talk to it, let's copy all of the particles. So let's take the electron and make a mirror electron. And let's take the quarks and make mirror corks. And let's have a whole new set of forces, a mirror strong force, a mirror weak force,

a mirror electric force. And in that whole mirror, then parity is violated in the opposite direction. So rather than just adding the minimal pieces to our standard model to balance parity, reflect the whole thing. And just have the whole thing be balanced in the other direction.

But wait, I thought that right-handed electrons did exist. Right-hand electrons do exist, yeah. And so this idea would say, well, let's make mirror electrons, and you'll have both left and right-handed mirror electrons, right? And we have left-handed neutrinos, so this would make right-handed mirror neutrinos. Oh, I see. It's like a whole different, it's like a whole new set of two hands. Yeah, exactly.

It's like you got one family, you know, where. where everything is balanced except the neutrino is only left-handed. And instead of just inviting one more neutrino that's right-handed, invite a whole other family. Except they have a right-handed neutrino. It's more like in our family, we only like the kids that are left-handed. And instead of making up, because we have kids that are left-hand, right, I'm so confused. We have kids that are right-handed. We just don't like him.

And so to balance it out, maybe there's another family out there down the street that that has right and left-handed kids, but they have a different bias. Different preference. They make different parenting mistakes that balance are parenting mistakes. They're terrible in a whole mirror

symmetric way. That's right. The universe doesn't care if you make parenting mistakes as long as somebody else is making the opposite one. That's the physics approach to parenting. Symmetry is restored

and all is good. Oh, man. Love to see. I maybe wouldn't love to see Yeah, things work in your house, and Daniel. But there's some fascinating twists there. Like, one of them is gravity is not mirrored. If there is a graviton, this particle that transmits gravity in a quantum theory of gravity,

it would not be mirrored. There would not be like a mirror graviton. It's like it sits at the edge of the mirror or something. Yeah, because it sits at the mirror line. Yeah, because gravity is how we bend space and there's only one space. We think that our particles and the mirror particles live in the same space. if they had their own graviton, they'd have to have their own space,

and that would be weird. And so, yeah, it sits on the mirror itself. Okay, so the idea of mirror matter then is that there's a whole set of matter particles that are mirrored somehow in this bias that the weak force has, and there's a whole different weak force that has a different bias. Yeah. If you built that parity violation experiment, Dr. Wu's experiment out of mirror matter and did the experiment,

you would get the opposite result. I guess my question is, where is all this mirror matter? Like, is it on top of us? Is it next to us? Is it kind of like a parallel universe kind of thing? Well, we don't know if it exists, first of all. And if it does exist, it'd be very hard to see. And so in that respects, it's sort of similar to dark matter

because we suspect we might only have gravitational interactions with it, that we'll talk in a moment about other ways we might probe it. And so it could be right here on top of us without us interacting with it. Remember that the universe is filled with all sorts of invisible stuff that you cannot sense, like all the neutrinos that are flying through you right now that you don't interact with, all the dark matter that surrounds the earth and fills your room that you can't see or touch or interact with. So it's possible to share space physically overlap with other kinds of matter if you do not interact with them. And mirror matter, if it exists, we may only interact with it gravitationally,

which is very, very weak, which means essentially we wouldn't sense it. And so if there is mirror matter, it could be right here on top of us. But it could also be out there in the universe separated from us. Well, I guess, yeah, I guess like dark matter and neutrinos, they're all sitting on top of us, but we don't feel them. Maybe there's a whole bunch of right-handed laws and right-handed matter that's sitting on top of us too. Yeah, there could be a right-handed Jorge doing a right-handed podcast right now.

Doing it the right way. And we'd feel left out, exactly. Wow. All right. So I guess my question is, like, why wouldn't our weak force with the left-handed bias interact with the left-handed mirror matter? Do you know what I mean? Like if in my house, I only like my left-handed kids, wouldn't I like the right-handed kids in the other house? Well, first of all, I hope that either all your kids are left-handed or they don't listen to this podcast. But you're right, but our forces don't interact with those particles at all. So those particles don't carry like electric charge. They carry mirror electric charge. And they interact with like the mirror photon with mirror electromagnetism.

And so, yeah, you might ask like, why do you need to create all these particles? Why don't you just add a right-handed neutrino? And I think that's one of the biggest sort of theoretical criticisms of this idea is that it's too much. You don't need all this extra stuff. It just seems like too much of a copy. But the reason to do it, remember, is to try to restore symmetries, to try to say, well, let's have balance in the universe. And then you might ask, but, you know, we're not really balanced.

We have like two pieces cracked in half that sort of complement each other, but we're living on one half of it, right? It's not like the universe has this symmetry, sort of broken. And we see that a lot in particle physics that we see symmetries that have been broken. And we think that these symmetries are fundamental, that they like exist. in the early parts of the universe when everything was hotter, when the universe, when different effective laws of physics were taking place. And then as the universe cooled, it's sort of like cracked the way, you know,

ice can crack as it freezes or things can crack as a change phase. Or like we, everything fell to one side of the mirror, kind of, or got trapped inside. Yeah, and we ended up trapped in one side of the mirror, and that there's other particles that got trapped on the other side. And so these are what we call broken symmetries. We think that they do reflect something. deep that's happening in the universe, but that they got broken. And we actually see examples of those, like the Higgs boson is a broken symmetry. Like the Higgs boson unifies the weak force and

electromagnetism. And it says that the photon is actually part of the electroweak force. It should go along with the W bosons and the Z boson. But when the universe was cooling, the Higgs sort of got stuck in a weird spot and it gave all this mass to the W and Z and none to the photon. It broke that symmetry. And so in the same way, symmetries that existed in the early hot universe can be broken as sort of the phase of the universe changes. You know, universe doesn't go from like liquid to gas, but as it cools, different physics sort of takes over. And so we think that that might have broken. So that's another explanation for the asymmetry that wouldn't require this whole new universe sitting on top of us that we can't see or touch. That would explain why this symmetry

exists sort of at higher level. It's like, you know, yeah, we still have any symmetry here today, but we think that maybe there was a symmetry early in the universe, that the other half exists. It explains why the symmetry was broken at some point. All right. So it sounds like a pretty amazing and incredible concept. I guess the question now is how do we verify if it's true?

How do we know it's real? And how do we look for these mirror particles? I guess we can't just look in the mirror, Daniel. Oh my God, nobody thought of that. go do that right now. Hold on. Nobel Prize right here. Mirror. What's the mirror of a Nobel Prize? It's the Loban Prize. Yeah. Do you have to pay a million dollars for that one? That's why nobody accepts it. All right, let's get into how we look for a mirror matter. But first, let's take a quick break. Your entire identity has been fabricated.

Your beloved brother goes missing without a trace. You discover the depths of your mother's illness the way it has echoed and reverberated throughout your life, impacting your very legacy. Hi, I'm Danny Shapiro. And these are just a few of the profound and powerful stories I'll be mining on our 12th season of Family Secrets. With over 37 million downloads,

we continue to be moved and inspired by our guests and their courageously told stories. I can't wait to share 10 powerful new episodes with you, stories of tangled up identities, concealed truths, and the way in which family secrets almost always need to be told.

I hope you'll join me and my extraordinary guests for this new season of Family Secrets. Listen to Family Secrets Season 12 on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. I had this overwhelming

sensation that I had to call her right then. And I just hit call. Said, you know, hey, I'm Jacob Schick. I'm the CEO of One Tribe Foundation. And I just wanted to call and let her know there's a lot of people battling some of the very same things you're battling. And there is help out there. The Good Stuff Podcast Season 2 takes a deep look into One Tribe Foundation, a non-profit

fighting suicide in the veteran community. September is National Suicide Prevention Month. So join host Jacob and Ashley Schick as they bring you to the front lines of One Tribe's mission. I was married to a combat army veteran, and he actually took his own life to suicide. One tribe saved my life twice. There's a lot of love that flows through this place, and it's sincere. Now it's a personal mission. I don't have to go to any more funerals, you know.

I got blown up on a React mission. I ended up having amputation below the knee of my right leg and a traumatic brain injury because I landed on my head. Welcome to Season 2 of the Good Stuff. Listen to the Good Stuff podcast on the IHeart Radio app, Apple Podcast, or wherever you get your podcast. Hello, it's Honey German. And my podcast, Grasas Come Again, is back. This season, we're going even deeper

into the world of music and entertainment with raw and honest conversations with some of your favorite Latin artists and celebrities. You didn't have to audition? No, I didn't audition. I haven't audition in, like, over 25 years. Oh, wow. That's a real G-talk right there.

Oh, yeah. We've got some of the biggest actors, musicians, content creators, and culture shifters sharing their real stories of failure and success. You were destined to be a start. We talked all about what's viral and trending with a little bit of chisement, a lot of laughs, and those amazing Vibras you've come to expect.

And of course, we'll explore deeper topics dealing with identity, struggles, and all the issues affecting our Latin community. You feel like you get a little whitewash because you have to do the code switching? I won't say whitewash because at the end of the day, you know, I'm me. But the whole pretending and coat, you know, it takes a toll on you. Listen to the new season of Grasasas Come Again

as part of My Cultura Podcast Network on the IHartRadio app, Apple Podcasts, or wherever you get your podcast. All right, Daniel, sir, there might be a whole mirror universe of mirror electrons and quarks and particles and also forces.

There might be a whole universe of mirror forces like the opposite electromagnetic force and opposite strong force sitting right on top of us right now acting and ignoring us basically. Yeah, and they might even have like better snacks than we have. Yeah, all the bananas would be curved the other way.

They would actually be tasty. But you would still hate it though. Mirror Daniel probably would hate it, yeah. Yeah, yeah, yeah. All right, I guess that other question is how do we look for mirror matter if it does exist and how could we ever, you know, confirm the existence of something we can't see or touch?

It's pretty tough. In the sort of cleanest version of the idea, we can only interact with mirror matter through gravity. And so in that sense, we can only look for its effects on a gravitational scale, which means, like, looking for it the way we look for dark matter. Because gravity is kind of like the one thing in common we have with mirror matter. Like it's like a two vent diagrams that touch at a point.

Yeah, it's the only way that we can interact with it. And so to discover something, to prove that it exists, to understand it, we need to be able to interact with it. There could be all sorts of crazy stuff happening right here on top of us. But if it doesn't interact with us, then we could never discover it. But we think that gravity is sort of universal. Everything that has mass feels gravity. That's like another way that gravity is super weird and amazing.

But so we might have to just use gravity to study it. And then there's the natural question of like, well, if there's all this weird stuff out there that we can't see and gives us extra gravity. Maybe it's not like dark matter. Maybe it is dark matter. That's what I was about to ask, Daniel. It feels like the perfect conspiracy theory. But this guy in Australia has cracked open. People always write in and try to connect the mystery of dark matter with other mysteries. Is dark matter like antimatter? Is dark matter this? Is dark matter that? And it's super fun. It's fascinating because wouldn't it be awesome to like crack two mysteries simultaneously, right, to solve two big questions of physics at once.

This seems really tantalizing, right? Because you just told me that there might be a whole universe of matter out there that we can't see your touch, but that influences us gravitationally. And that sounds like exactly like dark matter. Yeah, well, do you want the good news first or the bad news? I want the news that gives me the Nobel Prize. Okay. Well, then here's the good news. And you should go off on your trip to get the Nobel Prize before you hear the bad news in this case. The good news is that you can use dark matter detectors to look for this kind of stuff and that there is a detector out there. It's called the Dama experiment. It's in Italy. And it's actually had a very strong signal for dark matter for like more than 10 years.

We're going to do a whole episode on why nobody believes that Dama detected dark matter, despite their amazing evidence for a dark matter. And nobody's been believing their signal. They have this very clear signal that looks like it should be dark matter, but nobody else sees it like other dark matter experiments don't see the same thing and they should but this guy in Australia has this explanation he's like oh well maybe that's because um those dark other dark matter experiments are only sensitive to heavier versions of mirror matter and this one experiment in italy is different from all the other ways in in such a way that makes it sensitive to mirror matter so he thinks that this dama experiment might actually be a signal of dark matter and a signal that

Dark matter is mirror matter. Is this one of the ones that, you know, has like a huge vat of some noble gas sitting around waiting for things to ping, ping it? Yeah, it's sort of similar. It's a slightly different setup, which is why it's a little bit different. And we'll dig into the details on another episode. But they have this signature that most of the people in the community think probably isn't dark matter, but, you know, they believe it.

And their experiment is different from other experiments. And so they try to find, like, a reason why only they would see this. thing that other experiments don't see. And they're saying it could also be mirror matter, meaning that they're both the same thing. Yeah. And so Bob Foote in Australia, he wrote this paper saying, aha, maybe this explains why Dahma is seeing this weird signal,

and it's a discovery of mirror matter. So that was pretty exciting for a few minutes. But somebody found an error. Well, it's a little bit unlikely because we know that dark matter, if it exists, is cold, right? It's not fast moving. It tends to poke around the universe. It doesn't zip around.

Whereas mirror matter, if it's real, and it really is a mirror of everything we know, should have similar properties to our matter. There should be relativistic elements of it. And so already we think like, well, mirror matter doesn't really fit the same profile of dark matter. What we know about dark matter doesn't really mimic everything we know about the standard model. It seems like it should be heavier and slower. Mirror matter is too hot for dark matter. That's right, exactly.

Everybody looks better in the mirror, right? Everyone looks hotter, yeah. Well, but I guess, I mean, are you saying that dark matter is significantly colder in general than we are? Yes, absolutely. Oh, I see. Yeah, and then the other thing is that that was 15 years ago. And since then, there have been a lot more experiments looking for dark matter and cross-checking the DOM experiment. And if mirror matter was making a significant,

in the DOM experiment, we would have seen it in some of these other experiments, CDMS and Xenon. It's not as special anymore. Yeah. So there was a brief window when the experiments

looked like they might support this crazy idea, and that was exciting for a few minutes, but it sort of fell apart. All right. So not a lot of support experimentally for this idea. Are there any other ways

that we could find mirror matter? Well, the other things we could do gravitationally are trying to look for its effects, you know, astronomically because it might be that mirror matter isn't like diffused and spread out the way dark matter is. It really does have interactions that can form interesting structures. Like there could be mirror stars out there. There could be mirror galaxies and mirror planets,

right? And so that could be exciting. Would we be able to see them? Do they still spit out, photons or do they spit out mirror photons? They spit out mirror photons only for the mirror astronomers to write mirror papers about and win mirror Nobel Prizes. But, But, of course, we might be able to see their effects gravitationally. But, you know, these are not studies where you're, like, looking for individual particles of mirror matter, but you're, like, looking for distortions in cosmic gravitational fields. You know, we talked on the podcast before about weird gravitational anomalies in the universe like the great attractor, a strange source of localized gravity somewhere beyond the Milky Way

that we can't explain in terms of the stuff that we see. So that's the kind of thing that you might try to explain. using like mirror galaxies. Oh, but I guess at the mirror, at the galaxy level, it's sort of maybe indistinguishable from dark matter, maybe. Yeah, except that dark matter tends to clump with normal matter. Dark matter, normal matter tend to overlay each other. In fact, the reason you have normal matter where it is is because there's dark matter

there like pulling it together. So then are you saying that there could be a mirror planet, like right now in our solar system, spin around our sun, We just can't see it, but we might feel it gravitationally. Is that kind of the idea? That's kind of the idea. I mean, I never thought about it in terms of like a whole mirror planet in our solar system. That's pretty awesome.

And I'm right now writing that down for an idea for a science fiction novel, which somebody should write. That's pretty cool. I was more thinking about like entire mirror galaxy separated from ours. But no, you're right. I mean, if our matter feels gravity, it could pull on this stuff. And so our sun could have a mirror planet surrounding it. And in fact, Bob Foote from Melbourne, claims that some weird things in the solar system

support the existence of mirror matter. Ah, like there could be mirror asteroids kind of in how all of the things in our solar system move around. Yeah, and he's looked at some like craters on some things in the solar system and claimed that they can't be explained using normal impacts from normal asteroids. You would need a mirror asteroid to explain it.

And I'm pretty skeptical of that thing. There's like shards of glass everywhere and you're like, it has to be a mirror collision. I'm pretty skeptical of that because, you know, mirror objects wouldn't collide with normal objects the normal way, right? They don't feel electromagnetism or the strong force. So they would mostly just pass through each other and affect each other just gravitationally. So you can't really have like impact sites or collisions in that same way. You can only feel a gravitational tug.

So that would be pretty spectacular, but I'm not sure I buy that argument. All right, but it sounds like a pretty interesting idea. And again, I think it really taps into again this whole feeling that maybe there's a whole universe out there that's kind of on top of us, but maybe unreachable. You know, all these ideas are fascinating for that reason. And this idea may be wrong or maybe right, but it's definitely true that there is stuff out there that we don't understand, that there's a whole invisible universe of stuff going on that if we could tap into it and figure it out, would give us a sense of context, you know, like which part of the puzzle are we in? It's like when you're doing a puzzle and you're just working on a tiny little bit and you don't even really know like, where does this go? Is this part of that foot or is this part of the person's face?

That's where we are in physics. We have no idea where our little piece fits in. We know that the puzzle is huge and we've only tapped into a little bit of it. And so there's this temptation. It'll be like, well, maybe this fits over here. Maybe this is other part over there. And so it's definitely a good idea to look for weirdnesses in what we see and try to reflect it into the larger context. I think that's definitely a good way forward.

I'm not sure about this particular theory, but, you know, I'm definitely a fan of this kind of idea. I like what you did there, Daniel. He said, reflected. I reflected on that joke for a while. All right. Well, hopefully that will get everyone to think a little bit about all of these amazing symmetries we have and all of the amazing asymmetries that we have in our universe. Because, you know, there has to be kind of a reason for these weird, unexplained patterns in our universe. That's right. And anybody out there could be the person who figures it out. We joke around a little bit about how there's just one guy in Australia, but you know, it only takes one person to have an idea and to change the world. And for that to be correct, Einstein was just one guy. You know, Maxwell was just one guy. All these people who contributed to science, they had an idea and they propagated it forward. And so that could be Bob Foote in Australia or it could be you or it could be your kids. So everybody out there should be thinking deeply about the universe. and try to understand the whole context of our lives. Yeah, so all of you thinking about physics, look in the mirror

and raise your right hand or your left hand and help us figure all of this stuff out. Well, we hope you enjoyed that. Thanks for joining us. See you next time. Thanks for listening. And remember that Daniel and Jorge Explain the Universe is a production of Eye Heart

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