Can you communicate with neutrinos?

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Speaker 1: Hey, Katie, are you reading anything good right now? Yeah, I'm actually on like a multi year journey of reading the Earth Sea books. They're really good. And did you read them with photons? Yeah? I guess that's a very particle physics way of asking if I read it with my eyeballs? And yes, yes I do. I read it with photons that go into my eyeballs. And so are you not a fan of audio books for example? No, I I do actually like audio books, but yeah, I like to read with my eyeballs and my earballs. And how about Brail. Do you know anyone who can read with their fingerballs? I don't, but I would love to learn it's it seems fascinating. I wonder how different it would be to experience a book with smell or with taste. Well, do you remember scratch and sniff? It's been a long time since I read a textbook with scratch and sniff. I would love to smell outer space because I've heard it smells kind of funky. Hi. I'm Daniel. I'm a particle physicist and a professor at UC Irvine, and I've never eaten a physics book. I am Katie. I am the host of a animal biology podcast. And I have sometimes nibbled on the corners of a physics textbook, And how does physics taste? Taste kind of like cellulose that has been converted into readable format. Well, maybe you should print it on the surface of a cake, like frosting, and that would be tastier. In fact, I should make that assigned reading from my next class cake printed textbooks. I wish you could learn by printing textbook pages on a cake and eating it. And welcome to the podcast. Daniel and Jorge explain the Universe production of I Heart Radio, in which we serve up the entire universe as a slice of delicious knowledge. We try to bake all of the ingredients that make up this amazing cosmos, the quarks, the gluons, whatever is smaller and underneath, which weaves together to make our incredible reality, all the way up to the largest portions of galaxies and superclusters. We love the way it's all come together into this delicious and amazing and totally crazy universe, and we love sharing all of it with you because we think everybody deserves a delicious bite of the universe. Do physicists like to celebrate discoveries by bringing in like cookies and naming them things after the universe, like quais our crunch and so on. You know, at certain we often have cakes to celebrate things. You know, just finished a big piece of the detector, or wow, this multimillion dollar apparatus actually worked, or you know, we started up the exil orator and didn't create a black hole. Yeah, let's have a cake. I think maybe it's just part of the European culture, something the wheel in a cake often for these celebrations. I like that. I like that scientists are being motivated with cake, not to start a new black hole. It's good, keep the cake coming and joking aside. I think there's a real connection between our senses and our knowledge of the universe, because philosophically, everything that we know about the universe, while it might sit in our heads as a sort of theoretical mathematical framework, it's all informed by things that we saw or tasted or touched or smelled or nibbled on. Our window to the universe is through our senses, and often in science we are using our photons and we are using our ears, but we do have more senses to detect the universe, and we know that the universe out there is more than we do sense. Yeah, it's like every sense we have is a little porthole into the universe, and it varies from person to person like some people have, you know, like different kind of senses, are different strengths with different senses, but each sense it's like one method of reaching out to the universe and letting it kind of come into your little private world that is your own brain. Yeah, and we build this little mental model of the universe in our brain that's informed by our senses. But we also know that our senses are not a complete picture of everything that's out there. I mean even just think about the photons that you can see with your eyeballs, where you can only see the visible part of the spectrum, right, that's why we call it visible. But there are other kinds of photons out there there, ultraviolet photons whose frequency is too high for your eyeballs to see. There are infrared photons whose wavelengths are too long for you to see. The universe would look very different if you could see those. And we as humans have built technological eyeballs that allow us to see out into space and look at the universe in these other wavelengths to James Web Space telescope. Example is in the infrared those pictures you see of the James Webb. You couldn't see those with your eyeballs if you went out into space and stared out in those directions, because the photons that are hitting the James Web Space telescope would be ignored by your eyeball. So all those pictures are colors shifted. They take the photons that land in the telescope and they change their frequencies so that you can see. It's sort of like taking music that only dogs can hear and shifting it into a lower spectrum so that the human ear can hear it. I've been wanting to do that because I know my dog is probably listening to some dog music and not letting me in on it. But when you said the thing about like, you know, we can't see u V, of course, that's like for for human beings, our eyes are not naturally capable of seeing UV light, although there are a lot of animals that can see UV light. In fact, humans actually seem more like the exception in terms of not being able to see UV. But there are rare cases in which humans can see u V and that is when people have eye surgery, and UV light can actually trigger the rods and cones on the on our corneas, but it can't get through like the lens. And so if you have some kind of surgery where there they are removing that sort of top layer of your lens, it can actually get through your I hit the back of your eye. And people can actually see UV light occasionally, like after getting eye surgery, because they'll replace the lens with sort of like an artificial lens that helps you focus on the image, but it is different a different material than our natural biological lenses. And so people can actually see UV and they describe it as this like sort of purply light, but of course they can only describe it using words that exist in the English language. That we're made by humans that can't see UV lights, so it's very hard to know what exactly they're seeing, but it is really fascinating. And there's this theory that Monet had because he had a cataracts later in life and he had a sort of rudimentary cataract surgery that he actually saw UV light and that's why some of his later paintings were so violent and vibrant with Purple's. Wow, incredible. There are people out there who can see our invisible universe. I would love to be able to do that. I have this sense that we are walking around almost blind, that there's so much information out there about the universe that we are not absorbing that doesn't inform our mental models, that leaves us sort of ignorant. I recently read Ed Young's book about Animal Senses, and we recently had on the podcast Aria Kurshionbaum Zoologists talking about the different kinds of senses that animals have. And I was amazed learning about, for example, fish that can directly sense electric fields and birds that can sense magnetic fields with their eyeballs, And I wonder, like, what's that like to be able to say it's a magnetic fields. What does it feel like? Yeah? I mean it's so interesting. So with fish that can sense electric fields, like one of my favorite ones is the elephant nose fish. It's an amazing looking fish because it has this long protrusion on its lower jaw that looks like this really long nose. It's not actually a nose, but um it's called a Schnauzen organ, which I love. I just love that name so much. Are you want to take that it's real? I do sometimes wonder because I read these papers and maybe someone just like decided I'm going to start calling it a schnauz a organ starting now, put it in their paper and hopes no one notices. Uh, but yeah, this fish is covered in electra receptors. But not only that, it can generate a weak electric field with its tail. With this special electric organ in its tail, that's like these modified muscle cells, because when our muscle cells act debate, they actually produces very weak electrical pulse, which actually some animals can use to detect your movement by sensing your muscles. And when our muscle cells activate, there's that that electrical pulse. But this fish is organ creates a stronger electrical pulse, and so it basically forms this like field around itself of weak electric force. And then when that weak electric force hits something like an obstacle or prey or another fish, the schnells and organ and other electro receptors on its body receives sort of this bounce back information of like this electric field got disturbed. There's something over here. And if you think about it, it's similar to how bets will be able to sense their environment through um a location where they're sending out instead of an electric field, they're sending out sort of a sonar sound field that bounces back to them and they receive that. It's incredible because when it really comes down to it, things have to bounce into us for us to receive them. And so with humans, with our sight and our smell, and I suppose also touch and hearing, things are actually bouncing into us, even though sometimes it doesn't feel that way. But the difference is that typically we don't produce a field, so we don't like unlike these fish that produce an electric field or bats that produce sort of this sound wave, we typically don't do that. Where we produce, we don't shoot out photons from our eyes and have them bounce back at us. We just received photons that bounce into our eyes. Some of us are so brilliant that we do glow, actually, Katie, but I think that's really fascinating what you brought up about echolocation. One of my favorite bits in ed Young's book is when he talks about dolphins that can echolocate. Not only, of course, can they navigate, but they can identify objects in echolocation. And he talked about an experiment where dolphins they're shown an object while they're mindfolded, so they can only sense its shape using echolocation, and then the dolphins can recognize the same object on a TV screen using their eyeballs, which tells you that they have like a mental model of this object that they're comparing across different senses. Right, It's like somebody gives you a shape and you're not to touch it, and then later you have to identify it just by looking at them. That gives me a little bit of a window and like what it's like to be a dolphin, which is really to me the philosophically fascinating question of what it's like to have these other senses, to be able to see the universe in other terms, because so much of what we do in physics is explain the unknown in terms of the known, just as you were saying describing the ultra violet in terms of what you do know words for like violet. Right, But if we had other senses, if we we had evolved with the ability to detect other kinds of particles neutrinos or dark matter or something else. We might have a whole different experience of living in this universe and vocabulary for explaining it and exploring it. It might be uch easier to talk about the nature of the universe if we only had evolved one or two more senses. Dangity. So biology is the reason physics is hard. That's my main point. I apologize, I guess, yeah, no, it is. It is really interesting to think about how different the human experience would be if we did have different senses, which could have been very possible given how different the senses are of so many different animals, even ones close to us, like dogs, who are very smell based, but they're they're like our buddies, there are friends, and so we have this sense of like we're very emotionally are are kind of emotional connection to dogs. We can really relate to them, but they have this whole kind of hidden communication of smells that goes far far beyond our ability, Like we can smell things, but it's so far beyond our ability to distinguish smells. It's sort of like, you know, the difference UH envisioned between like an aunt and like a you know, an eagle, and so we'd love to understand what it's like to be an aunt or an eagle or a dog. But beyond that, we also wonder what would we like to see the universe in terms of other particles, not just photons and not just phonons, not just touching stuff, but to see some of the truly invisible parts of the universe. And we know from our particle physics experiments that there are other particles out there flowing through us and over us right now, rich with information about the universe. We're talking about the almost invisible particle, the neutrino. What would it be like to have a neutrino schnauzen an organ which could detect neutrinos? And I swear I didn't make that up, you know, that's in the literature. No, I totally just made that. From what I know about languages, is like in Italian, anything with eno usually means like small, like bambino is like a baby, and you know, newts or like seems to come from neutral. So the name neutrino, to my ears and to my brain means a teeny tiny neutral thing. Yeah, that's exactly right. It was actually named by an Italian, of course, for it was actually discovered, it was hypothesized and named to be a tiny, little neutral particle. And so today on the podcast, we're gonna be talking about whether we can use those particles to learn more about the universe and to actually talk to each other. So on the episode today we'll be asking the question can you communicate with new trinos? And is this new plan going to cost be more money than T mobile? That's right, you're now going to have something else to pay your new trino bill every single month. Fortunately, new trinos are everywhere. They surround us. They're produced in the Sun. There are a hundred billion neutrinos passing through every square centimeter of the surface of the Earth every second, So that's a hundred billion, two hundred billion, eight more seconds, and there's a trillion neutrinos that have passed through your fingernail. And that just gives you a sense of the scale of how much we do not see about the universe, how many ways the universe can do stuff that we don't participate in. Because for our ancestors, it just was not an evolutionary advantage to build internal neutrino detectors. And you might think, well, it's too difficult, it's too subtle a thing for evolution to master. But remember that evolution has figured out how to sense the Earth's magnetic field using chemical reactions in the eyeballs of birds, or how the chemistry happens depends on the external magnetic field. So evolution, if there's an advantage, is capable of developing very very sensitive detectors to all sorts of weird physical phenomena. I mean, even our own eyeballs. The fact we can see we can maybe take for granted. But the fact we can have such a sharp image from being able to have a photon hit a protein structure and change its shape that sends a signal to a nerve is incredible. I mean, it's that to me. If some alien that had no eyeballs and no vision, like was told that you could sense the world and photons hitting a protein, they'd go like, no, that's absurd. Yeah. We talked about that in a really fun episode about how the human eye is sensitive to individual photons and not just that you can respond really quickly. These little protein machines change configuration when a photon hits them and then they switch back and they're ready for another photon like very soon afterwards, so that not only can you see the world if it's very dim, you can also see very fast moving things. It's a really an incredible piece of technology. So kudos to biology and evolution. And maybe in another billion years are neutrino Schnelzen's will evolve, so we can smell neutrinos in the universe. One can only hope. But until then it's the physicists who are in the lead, because we have detected the existence of these ghostly particles and we have studied them, and they're a fascinating window into the nature of reality because these particles are produced everywhere in the universe, but they hardly ever interact, but they do sort of hold a place in the periodic table of the fundamental particles, the basic organizing system of the universe as we know. It's so far and so now that physics has revealed to us the existence of these other particles, naturally the engineers are wondering what are they good for? Can we do something with them? Is it possible to do something with neutrinos that we couldn't do with photons, and so I was wondering if people thought it was possible to use new trinos to communicate, for example, to stream movies while you're deep underground. Perhaps, so I went out there into the Internet and tapped our cadre of volunteers who answer these random questions without a chance to prepare, to give you a sense for what other people out there are thinking about these questions. And if you'd like to participate for a future episode, please don't be shy. Everybody's welcome. Just right to me two questions at Daniel and Jorge dot com and I'll set you up. So before you hear these answers, think for a second, what do you think is it possible to communicate with new tri trinos. Here's what everybody had to say. It is possible to send messages with neutrinos. Even saw a movie that everybody was trying to send messages to stock market the fastest possible. At the end of the movie that was this is what they this guy was thinking about, to send messages with neotrinos that would go through the curvature of Earth. You just go and pass by it and this will get you the fastest message ever from point to point. So I think some future tech could develop that could allow us to communicate with neutrinos. But I do remember from a past episode that you mentioned a neutrino could pass through a mile or a light year long break of lead and only half interactions, so even if you could communicate, you might not want to stream with it. I don't even remember what neutrinos are from college or your podcast, so I have no idea. Well, since neutrinos don't interact with other types of matter, I don't think you can use them for communicycation because I think the reason why electromagnetic waves can carry and um as supposed to transmit information is that because they can interact with I don't know, antennae and stuff. I'm gonna say we can't communicate with neutrinos just based on I guess what I would define communication itself as, which I think applies sentience of some kind, like like a knowing exchange of information between at least two different beings. And I don't really see neutrinos a sentience, so I don't really see how they can communicate with us. I'm trying to think of what movie the first respondent mentioned that they saw a movie where someone wanted to send messages as fast as possible. I guess using neutrinos. Yeah, it's interesting because if you want to send messages as fast as possible, obviously the speed of light is as fast as possible, and photons travel at the speed of light, so you know, fiber optics are pretty good. Maybe they have the impression that neutrinos could somehow travel faster than the speed of light, or maybe like because neutrinos can go through stuff, right. Neutrinos can, in fact and go through a lot of mostly because the universe is transparent to them. They don't really interact with this stuff, so they just like fly through it. So maybe even if they're not as fast as the speed of light, they can get through things better, so like they won't be blocked by things until you receive them. Oh, that's a good point. If you want to send a message from here to Beijing, for example, you could send it through the Earth rather than having to go along the surface of the Earth. That would save you a few nano seconds. Your email arrives first to Beijing before everybody else, your new tree mail. I guess neutron mail. Wasn't that something or was that proton I don't know, man, proton mail is still a thing. I think it's for the super security conscious people. Yeah, well they should do neutrino mail. I'd sign up for that. You have a lot of emails. You just can't see them. You just can't see them so like normal email. So neutrinos are teeny tiny neutral particles that can sort of like like they seem so ethereal. I need a little more help sort of understanding something that's essentially like a tiny ghost. It's really fun to think about neutrinos. They're one of my favorite particles. Let's start with this description used of tiny. What do we mean when we say neutrinos are tiny? Are they like smaller than other particles? If you put a neutrino next to an electron, like which one would be smaller. We don't really have a sense for the size of these particles, if you'd like to think about them as like tiny little balls of stuff. In our theory, we treat them all as point particles. Corks and electrons and neutrinos really have essentially zero volume in our theory. That's not because we know they have zero volume. We just treat them that way because we don't know what's inside. Realistically, it's probably the case that all of these particles are made of something even smaller that we just can't see yet. But it's whatever it is, it's so small that we can treat them as if they have no size. But the neutrino is tiny compared to the electron and the other particles in sort of another way, not in literal volume, but in mass. The mass these neutrinos is something just above zero. We know it's not zero, but we also know it's very very small. There are many orders of magnitude less massive than the electron and the corks, so in that sense they are tiny. Wow, And electrons and corks are pretty tiny as well. So at a certain point of tininess, it's hard for me to even conceive of the tininess of a thing As it gets smaller and smaller. It's kind of like when you try to think of infinity. It's really hard. It's just like when you try to think of something getting so tiny, my brain can't process it well. You can use Italian as a bridge. There. You can say you have tiny and then you have tiny no, or you do Spanish right tinito or or whatever piccolino. People also talk about neutrinos as tiny because they can go through matter, and I think people have the impression that neutrinos sort of like wiggle their way through the gaps in stuff. Like if you have a huge sheet of lead, a neutrino can pass right through it, and you might wonder, like, how does it get through the lead? Is it's so small that it can like find its way through the holes in the lattice? Well, its size there again isn't helping it because technically it's just as small as an electron. But if you shot an electron at a wall of lead, the electron would interact with all the other particles there. So what happens, For example, when you push against the wall, why doesn't your hand go through it. It's not because the particles in your hand are too big to get through the wall. It's because the particles in the wall are pushing back against the particles in your hand. The particles in the wall feel the electromagnetic force, and so does your hand. But the neutrino doesn't. It has zero charge. That's why it's neutral. So when it hits the wall, it ignores the electrons and it ignores the corks. It doesn't interact with them using electromagnetism at all. So it's sort of like the way glass is transparent to some photons, because those photons don't interact with the atoms in the glass because they don't have the right energy level, so they can't interact, and so they just fly right through. I sometimes I want to be like a neutrino when I'm just not really in a good mood and I'm walking through town and like, I love people and I love to say hi to people, but there are days, you know, there are days where I want to be a little neutrino just passing through and not interacting with anyone. And I think that's an interesting handle on this question of like what's really out there in the world. You use mostly photons and your sense of touch to get a sense of what's out there, but you're really building a picture of the world that depends on the force that you were talking about electromagnetism. Mostly, if you were to explore the universe like a neutrino that didn't sense that, then all that stuff would be invisible to you, and you would have a very different sense of like what is out there in the universe. Neutrinos can interact with stuff, they're not completely sterile or inert, but they only interact via the weak force, which is much much weaker than all the other forces. Okay, so what is a weak force then? Right? So we have four fundamental forces in the universe that we're aware of. Right, there's the strong force. Every particle that has what we call color, like corks and gluons, interact with the strong force. This is what holds the nucleus together. And electrons and photons don't have the strong force. They don't have color. So not every particle out there feels this force. And it's really interesting to me that in our sort of table of particles, some of them feel some forces and some of them just don't. And we don't know why. Are like, why doesn't the electron feel the strong force? We don't know, it just doesn't. Why do we use the term color to describe that the particles that do have the strong force because we like confusing people by reusing words that have other meanings. No, it's an analogy. It's because the strong force is very different from the other forces in that it has three kinds of charges instead of two. Electromagnetism has positive and negative. The strong force has three kinds of charges, and if you combine them all together you get something neutral. And that reminds people sort of how you can combine three different colors to get white. And so the sort of mathematical structure of the charges of the strong force is sort of similar to the way we think about color, and so that's what we do in physics a lot. If you're like, oh, this reminds us of this other thing. It's not perfect and Orge wouldn't be happy with it, but we're going to use this word anyway. Well, I'm not Orges, but I'm also not happy with it. So here we are. So that was the strong force and electromagnetism. Only things that have electric charge feel electromagnetism. There's sort of a chicken and egg thing, right, We might say, like, why do some particles have charged to feel electromagnetism. That's sort of what charge is. We call things charged if they feel electromagnetism. If they don't feel it, we call them not charged. So in one sense, having charged just means you feel electromagnetic fields and not having charge means you don't. It's not like the same kinds of particles will very about whether they have electromagnetism. It's always specific particles that either do or don't. All electrons have electromagnetism, right, Yes, all electrons have the same charge, which is really interesting and might wonder like why are there not different kinds of electrons, And yeah, we don't know. We think they're all just different ripples in the same quantum field for electrons, so in some sense they're all like part of the same universe spanning electron. But there are other particles like neutrons and photons that don't have electric charge, so they sort of see the universe differently. And neutrinos are fascinating because they don't have the strong force, so they don't have color, they don't interact with gluons. They also don't have electric charge, so they don't interact with the electromagnetic force. They only have the weakest of all the forces. Everything else they just idore. And the weak force is something that like all particles kind of have, but it's not as well understood, like what is actually going on. Yes, the weak force is fascinating because it's the only force we know of that every single particle in the universe feels, except maybe dark matter. We don't know if dark matter is a particle and what it is exactly, and we don't think it actually feels the weak force. But all the particles that we know about that we've discovered, the w z, the quarks, the electro on, all of those feel the weak force, and so it seems like really important. It's like very universal, but it's also super duper weak. It's like ten thousand times weaker than electromagnetism. So interesting. And that's not the Vanderwals force. That's that's weak of electromagnetism. Or is Vanderwals force actual weak force? I think the Vanderwall's force is just a manifestation of electromagnetism in certain arrangements. But hey, you know that's chemistry, So we need to get a chemical expert in here. This isn't a chemistry podcast, all right, Well, we want to dive more into the mysteries of the neutrinos and avoid talking about chemistry. But first let's take a quick break. No chemistry allowed. He heard it here first, folks. All right, we're back and we're talking about the mysteries of the universe and specifically, and we are wondering about neutrinos and if we can use them to see the universe in a different way and to build new technology to use them to talk to other humans. So we've talked about how neutrinos they basically can just move through the universe without interruption, not because like they can wiggle through the gaps and say atoms or something, but because they simply do not interact with a lot of the forces in the universe, so they only have the weak force effect on them, which I guess, based on its name, I'm going to guess it's not too strong. And so you're putting a lot of faith there in physicist ability to name things accurately. You guys did name like a force color uh, without it actually being about being colorful, but some strange you're just trying to confuse us at this point. Yeah, Well, I think the thing to take away about this question of neutrinos is in the weak force is that what's opaque and what's transparent in the universe is not universal. It's not like you have some blob of stuff, and every particle is going to see it as opaque or every particle is going to pass right through it without interacting. It depends on the particle and it depends on the energy. Like when we look out into the universe, even with photons, we can see different things in the infrared and in the ultra violet because some stuff out there will block photons only of certain energies, so really long wavelength is better, and like seeing through dust clouds which would otherwise block things, our atmosphere mostly blocks ultra violet, so if you want to UV telescope, it's got to be out there in space because our atmosphere is like a solid wall for ultraviolet photons. So that shows you how even the same particle of different energies will see different objects as transparent meaning they can fly through it, or opaque meaning they're blocked and they interact. So it's really microphysically speaking all about the interactions. And for neutrinos they hardly interact with anything, so almost the entire universe is transparent to them. You say they hardily interact with anything, is the only interactions through this very weak force are there? Like specific situations in which the neutrino will actually react to something. It's just through the weak force. And in order for a neutrino to interact, they have to encounter another particle which feels the weak force. Now, every particle does, but imagine you have a sheet of matter in front of you and a neutrino is approaching an electron, for example. Is a chance of the neutrino interacting with that electron, but it's really really small. So it's like the universe rolls to die, but it's like a ninety seven million sided die and only one number results in a hit. So how many electronics do you have to go by before on average, you're gonna hit one like million. That's why neutrinos can go through like a light year thick wall of lead and have a fifty percent chance of interacting, which means half of them go through and ignore it completely. Like a light year of lead is not a small amount of material to pass through, right now, that seems a pretty yeah. So these are really the most introverted particles in the universe. Absolutely they are, but there are a lot of them out there right They're produced in the sun. They are a byproduct of fusion, an enormous amount of the energy produced by the Sun comes out not in photons but in new trinos, and we just mostly ignore it, just like flies right by us. It's the kind of thing that makes me wonder why evolution didn't pick up on it, because you know, it took evolution like how many years, like a billion years to figure out how to eat photons, how to grab all this energy which was around, not just to see them, right, eyeballs are different from photosynthesis, to capture this energy. Well, there's also a huge amount of energy in new trinos. Imagine if you could eat new trinos, you just like walk around all day and get energy without doing anything. You could take naps and fuel up, right, It's like charging your batteries. Yeah, I mean it's It is a funny thing about evolution because it's like evolution doesn't really have a plan. It can't think in these clever ways like an engineer might think we should do something thing like this because it's a good idea. Here's an available resource for us to exploit, whereas evolution just blunders its way into managing to work out. So like if if something some little protein strand manages to survive and copy itself. There it is. That's evolution, and that's about it. I get the point that I can't expect the universe to be sitting at its drawing table and thinking what's the way that we could figure out to detect neutrinos or to capture their energy. But it just feels like, if there's so much energy out there that's available, if some chemical reaction turns out to be sensitive to it in some subtle way, there'll just be a river of energy that you could tap into. And it's incredible to me that in billions of years, nothing on Earth has evolved the ability to capture or interact with neutrinos. Yeah, I mean, I guess how do we even know that's true? That nothing can detect or use the energy from neutrinos? How do we even detect neutrinos using scientific instruments? Hey, that's a great point. You're right. There could be micro ups out there right now gobbling neutrinos and we don't even know about it. We should have invited them on the podcast to speak up. I mean, we try to always talk about both sides of every issue. No jokes aside that is a really good point, but no spin zone except for the up or down spin um. But you're right, and it's tricky, right, It's not easy to see neutrinos. Neutrinos were theorized. The idea for them came about in the first half of last century because we saw beta decay, we saw radioactive decay, and the energy didn't add up. There was like more energy and momentum in the initial state and then in the final state, and we thought that those things were conserved. And so people thought, well, either energy and momentum isn't conserved in the universe, which would be weird, or there's something out there, something invisible, something little and neutral, that's carrying away this momentum. So it was named before we actually saw it, and then it was so difficult to see because they are so shy that it took decades for people to develop the detection technologies to see neutrinos. The basic principle there is to get a huge which vat of some kind of liquid and put it underground so it's shielded so you don't think anything else is going to bump into that liquid. And you choose a kind of liquid so that if a neutrino bumps into one of your electrons, it makes like a little flash of light. And then you put an underground for like years, and you count the number of flashes that you see, and you figure out how many flashes you can explain by other stuff like radioactive decay in the rock nearby, or muans that happen to have penetrated, and you convince yourself that you've seen more than can be explained through other sources. And that was basically the discovery of the neutrino. But it took building enormous detectors, like many tons of weird liquid underground, not the kind of thing you expect, you know, some critter crawling along a leaf to be able to develop I know some other weird liquids that you need to use to be able to draw introverted particles out of their shells. But that is really interesting. So we know that they exist, or at least we guess that they exist due to how they represent at a sort of mathematical conundrum. And then we were able to detect them using these just like a law of large numbers. I guess some of these new trinos are by you know, a very low chance of ever, you know, sort of bonking into anything with the weak force. But then they do occasionally, and so we see that. So I guess how do we go from there to actually being able to reliably detect these because being able to like or or being able to communicate with them. Because it's one thing to be able to buy chance once in a while catch one that bumps into these vats of liquid, and it's an entirely other thing to be able to reliably sort of have this like stream of information that comes from new trinos. Yeah, and if folks are interested in more details about how the new Trino was discovered, is actually Professor's here at you see Irvine who won the Nobel Prize for it a few decades ago. And so we have a whole episode about how the new trino was discovered and the clever techniques that were used to see them. So go check that out. But your question is a good one, is that how do we actually use this for communication? Remember that all communication microphysically is about interactions. It's about particles. Like you were saying earlier, when you see something, you're receiving particles in your eyeball. When you hear something. You're receiving sound waves, which are just pressure waves in the electromagnetic structure of the air. Right, it's air molecules bumping into other air molecules and using their electromagnetic interaction to push on each other. But some people could also think about those just as sound waves, which we sometimes call phonons, which you can think of a sort of a quasi particle. And you know, when you send an email to your friend in China, for example, that gets transmitted digitally, right, those are electrical pulses, So in the end, those are also photons. So every kind of communication involves particles, right, involves communicating somehow by sending information via particles. And that makes you wonder, now you've discovered a new kind of particle in the world, a new trino that has different capacities and different weaknesses and strengths and other particles, whether it's possible to also send information using this new kind of particle, right, because the like basically for communication, you need something to receive that particle, and once it receives it, you need to be able to process that, causing a chain reaction in that receptor to like a nerve or two. If it's a non biological thing to something that will record it. So if we think about it, those big vats of fluid deep underground, or like a very very rudimentary, huge eyeballs that can only detect things in a very simple way, which is like when you actually look at some of our the earlier versions of eyeballs in our more flat worm esk ancestors, it really is like these kinds of things of like, oh, is it there or isn't it there? Did a photon bond into it or didn't it and give us sort of like that very limited amount of information. But yeah, in order for it to actually to be able to communicate better with these neutrinos, we need to have more interactions. I would think, Yeah, you're right, these vats of liquid underground are basically primitive engineered neutrin no schnauzen. Right, there are a technological version of what biology has so far as we think, maybe failed to develop. And you're right that if you want to send complicated information, you need to be able to detect these things reliably. But fundamentally, the underlying principle is use particles to communicate, and that's the basic building block of it. From there you can build a more complicated things. Right if you and your friend are using flashlights to flash to each other across the street when your little kids, you can start out just flashing your flashlights and say look, I'm here, and then you can develop some code like this kind of flash means this, and that kind of flash means that, And then you can develop some alphabet from which you can make almost any kind of communication. And you know, basically, from there you're inventing the Internet. Now go back and do it. At the heart of it all is the ability to send and receive particles, and so that's sort of the fundamental bit. And listeners out there who are interested in quantum mechanics might be wondering, what about quantum entanglement. Isn't it possible to send information using quantum entanglement when you collapse one particle and one part of the universe which collapses another particle somewhere else without sending particles in between. Check out our podcast episode about quantum entanglement and communication. It is possible to entangle particles that are very very far from each other, like maybe if I have an electron and Katie has an electron, we can create them in such a way that we know there's spins have to be the opposite. So if I look at my electron, I can see, oh, it's spin up. That means Katie's must be spinned down. Or if Katie looks at her electron and says hers, the spin up means mine must be spinned down. And there's a weird thing that happens there, which is my electron could be up or down and Katie's could be up or down. And as soon as one of us looks at ours, the other one's collapses. And that happens instantaneously across space. But it can't be used to send any information. I can't control my electron to make it spin down so to make Katie spin up. And Katie can't even tell whether I've collapsed my electron or not. All she can do is look at hers and see is it up or down? And I can do the same. So kartum entanglement it feels like a way to get around this and send information without sending particles. But actually you can't can't send any information using quantum entanglement. Unfortunately, I see, because there's no way to like know that you have like a basketfull of up particles, and then as soon as you look at the entangled particle to see what kind it is, then it's already collapsed the wavelength of the other one, and so there's no no way to then like communicate with the other person with it. I can't change the states of your particles from up or down. I can make your particles collapse, but there's no way for you to know that I've made your particles collapse. When you look at your particle, you don't know if has already been collapsed or if you are collapsing. It unfortunate. A lot of folks writing with that idea, they're like, what if I have a bunch of particles here, and you have a bunch of particles there, and I collapse, mind, and you can see that they're collapsed, and that we can use that at the basis for communication. But there's a flaw there because if I collapse my particle, you can't tell that yours has also been collapsed, even though we think it has been. So it's very tantalizing. But back to neutrinos, you might also wonder, like why would we want to use neutrinos to communicate like photons are pretty good, right, Well, that listener who commented about sending things faster than light is making a good point, because you know, photons are blocked by things. If you want to communicate with China, you do need to go mostly along the surface of the Earth, not through it, whereas neutrinos can go through other kinds of stuff, right. And this is also useful to astronomers because it allows us to see things in the universe that would otherwise be blocked the way we use infrared light to see through dust clouds. Neutrinos can get through stuff which otherwise is totally opaque to all photons, and so being able to see the universe in neutrinos it's like another window into the universe. You can see things you otherwise couldn't. One example is that we can see the inside of supernovas. Supernovas the cataclysmic death of stars. Right, things explode and it's very furious, and it sends out an enormous amount of light. It actually sends out more energy in neutrinos than in photons, and the neutrinos see the star that's exploding as transparent, so neutrinos from the heart of the supernova just fly right out and come to Earth and we can detect them, whereas photons created at the heart of the supernova get reabsorbed by all that other stuff that's part of the supernova exploding, so they can sort of like X ray supernovas to see stuff. So we're actually already using neutrinos to communicate or at least receive information from the universe. Yeah, the universe is using neutrinos to communicate with us at least right it's sending those messages all the time in terms of neutrinos, and we've seen supernovas with neutrinos. You can also see the Sun in new trinos. You should google this. It's super cool. You can see the Sun through the Earth. This experiment in Japan's Supercamioconda is another one of these huge vats of liquid. They can see neutrinos and when the Sun is on the other side of the Earth, when it's the middle of the night in Japan, they can see neutrinos that come through and interact with the Earth and then hit their detector, so they can see the Sun is still there even though it's nighttime, they can like check to make sure the Sun has not exploded. So that would be a useful technology for birds for when you throw a blanket over their cage, you're like, up, Sun's gone, must be nighttime. And you know, we're also wondering what's out there in the universe, and we're looking for alien life, for example, mostly in terms of electromagnetic radiation. We should also be aware that maybe aliens like to speak in neutrino Maybe they're sending us weird new trino pulses and they're screaming at us, but we just haven't been paying attention. So it's definitely something worth listening to. Would we know how to send out neutrinos like from our like, say we wanted to send aliens a message, Could we like shoot out some new trinos or is that something only the Sun has kind of gotten down to a science. That's a great question, and let's dig into whether we can produce messages using new trinos and then read them back. But first let's take another quick break. Okay, I'm going to check for aliens during the break. All Right, we're back, and we're wondering if Katie got any new treemail about aliens or from aliens. Yes, yeah, I got a new treat mail that said, great offer. Just send money the horsehead nebula and we will make a transfer to your bank account. And so I've done it. Okay, you built a huge catapult, for example, and launched gold coins in datospace, just throwing dollars and coins up at the air, hoping the alien AMers got it. Well, your beams of gold coins are one thing. But on this podcast today, we're talking about creating beams of neutrinos and using that to pass information. You asked a great question just before the break, whether we humanity has the technology to create neutrino beams and use that to encode information. The answer is yes, actually we can. We know how to build beams of neutrinos. Yeah, gasps, because like you said earlier, that neutrinos are made in the sun, so it seems like it would be kind of an energy intense process, right, Yeah, if you wanted to rebuild the sun and reverse engineer the sun, that's tricky, and people are doing that right, that's called fusion. But there are other ways to make neutrinos. We do them at particle colliders of course, and so for me National Accelerator Lab, which used to be the host of the largest energy collider in the world, the Tevatron, before it got outpaced by the large Hadron collider, but has a place in my heart because it's where I did my pH d thesis. It's not been converted mostly into a neutrino facility. They build the most intense neutrino beams in the world. And you might wonder like, well, how do you make neutrinos? Well, like everything else, we start with the building blocks we have. So in this case protons, we shoot them up to really really high energies and we just smash them into rock. Basically, seems like you're answered to everything. Particle physicists just just like, how do we detect these particles? How do we make particles? We just smash them? Hey, you know, when all you have is a hammer, everything is a nail. And so we try to solve every problem with a particle accelerator. And so we smash protons into a carbon target more specifically, and that creates a huge spray. So protons are these bound little objects of quarks which have the strong interaction and they smash into carbon, which is also chock full of protons and neutrons. And there's protons and neutrons smash into each other and break open those strong forced bonds and then reform as all sorts of other weird exotic particles made out of those corks, things like pions and chaons. These are just rearrangements of the corks that were once inside the protons and neutrons into other higher energy configurations. So pions, for example, are like an upcork and an anti upcork. Kons are also two corks, but they sometimes contain a strange cork. And the cool thing about kaons and pions and all this other stuff that's produced is that they are not stable. They decay because they're like higher energy, higher mass, and when they decay they often produce neutrinos. Yeah, and so you didn't have any neutrinos to start with, but you smashed stuff together in outcome neutrinos. It's part of this amazing like alchemy that is particle physics. Right. You don't need to have the basic ingredients of it. You just need to have energy, create the right interactions, and then sometimes the thing you want to fly out. So like if I'm trying to give the talk to a teenage neutrino, I would say, like when a particle decays, uh, and they love each other very much. When a particle has had a long, rich life about you know, tending the minus six seconds and it's ready to move on, then yes, it decays and other stuff, including sometimes a neutrino. And so most of the stuff that comes out is this big explosion of stuff we don't want, right It's pions and cans and protons and all sorts of crap that we're not interested in. And so what we do is we try to filter it out. We use magnets to bend any charge particles out of the way that separates the charged and the neutral stuff. We can just send all the charge particles into the rock, for example, to absorb it. It's like Looney Tunes like whiley Coyote like drawing a fake road on a on a cliff or something, and although Roadrunner always runs through it, which that Looney Tunes logic of like road Runner can like go pass right through that fake painting of a road, whereas while E Coyote smashes into it. That seems like, exactly what these physicists are doing. Yeah, exactly. The road runner passes right through everything. Yeah, and the next age is exactly that is to send the neutral part of the beam also into rock, and they pass it through two hundred and forty of rock, so that everything else that's neutral that didn't get filtered out by the magnets does get absorbed by the rock because everything else has long interactions or even though it's neutral, like a neutron, its components might have electromagnetic interactions, right, and so everything else eventually gets absorbed by the rock except for the neutrinos. So you create this spray which is mostly not neutrinos, and you filter everything else out and then you get a neutrino beam. So this is just an extremely expensive and huge calendar. But instead of the method of action being the little gaps and the calendar, it's like the types of forces that these particles would interact with, and neutrinos just are like I don't know, I don't care. Yeah, you're shielding it from everything else except from the neutrinos, and then only the neutrinos fly out. And so you started out with a beam of protons in one direction, you end up with a beam of neutrinos. So have we gotten to the point where we can shoot out a beam of neutrinos and then have like a technological receptor organ that then these neutrinos hit and then we detect them. Yeah, so we know how to build new no detectors, various technologies for that supercomioconda in Japan, for example, here at Fermulab, they have the Minerva detector, which uses scintillating strips to detect charged particles. And the hope is that a neutrino will bounce into an electron and produce a muon and so this is something that happens very very rarely, but if you have an intense enough beam of neutrinos, it will happen. And so the ideas you can produce neutrinos and then you can also detect them. So it seems like you know the basic components of communication, because it seems a little bit like a catch twenty two where it's like you the way you filter out all particles except neutrinos is that you're relying on the fact that neutrinos really don't interact with much but when you have the receptor for the neutrinos, you're hoping that there's that very small chance that they do actually have that weak force interaction. And so is it a difference in the matter that we're using in the receptor, like is there something different about that fluid, or is it that it's just relying basically on statistics that if you shoot enough of these neutrinos outwards, there are enough of them that are going to make it through this basically neutrino gun, and then there's enough chance that at least some of them are going to hit into the receptor. Yeah, you're exactly right, it's the second one. It's statistics. So we think that neutrinos are also interacting in the rock. They're passing through hundreds of meters of rock, and some of them are interacting. So imagine like a really bright beam of neutrinos it's passing through the rock and a very tiny fraction that are interacting in the rock. By the time you get to our detector that we hope it also interacts. Inside the detector, we can see those. The key is that nothing else is going to survive. So you have this intense beam of neutrinos, which mostly ignores the rock, but as a few interactions, and then we capture a few of those interactions in our detector, but nothing else can get there. So we're pretty sure when we see something in our detector that it's only because of the neutrinos. So have we ever sent a message with neutrinos? So we I've done it. And it's astonishingly inefficient because you know, we can't see most of the neutrinos. Like, if you send twenty two trillion protons into this beam, then on average you see point eight neutrinos with the detector, right, So twenty two trillion protons make less than one neutrino on average that we see. Isn't that always the start of a new technology? Is just it's astonishingly inefficient. Yeah, So they actually did this test. They were like, well, that's interesting. I wonder if we could use this to send information. The ideas they can like turn the beam on and turn the beam off. Turn the beam on, turn the beam off, and can you detect that with the detector. Can you tell that somebody upstream is changing the beam And if so, then that's the basis for communication. It's just like two kids with flashlights across the street. Right from there, you can build up something more complicated, but the fundamental basics is can you flip a switch when you're creating the beam and detect that switch being flipped when you're looking at the beam downstream? But you sing that we've done that, right, They have done this exactly. The Minerva detector did this experiment a few years ago and they sent a message. They wrote the word neutrino in askey code. So it takes two bits zeros and one to send this piece of information, and it took them six minutes to send these bits through two hundred and fifty meters of Earth over a one kilometer distance, and so they've done it. Like you can look up the data and you can see that the new Trino detector registered a lot more neutrinos when the beam was on than when it wasn't on, And so they can use that to define a threshold like oh, this is a one, this is a zero, and they were able to do it successfully. You know, the rate is like zero point one bits per second, which is not good enough to stream the office, you know on your mobile platform, like certain certain Internet providers, which I won't mentioned, so I don't get Sue exactly. But you know, as you say, it's the first step. It's a demonstration of the proof of principle. The rest is up to the engineers. And it's cool. It's done with neutrinos. It's like, ah, but why is it not done faster? I mean, come on, give him a break. It's fast, like every individual neutrino is traveling almost at the speed of light. The problem is you can't rely on one neutrino to carry your message because it takes twenty two trillion before you're likely to even see one of them. Like you're doing a statistical, longitudinal study over many years for humans. It's like, you know, I can imagine some alien scientists thinking like using like statistics and human behavior is not super fast because we have to wait for these long statistical models over many years. Except in this case, like the neutrinos are much faster, but still like takes six minutes to get that statistical significance of enough of these neutrinos hitting our big technological eyeball. Yeah, and the limit there is the technological eyeball. If we could build that to be more sensitive or larger either one, than we could see neutrinos more reliably. We can take as many neutrinos to carry the same bit, the zero or the one, then we could have a higher throughput. Right now, it's pretty limited. I mean, for example, if you wanted to send all the information on the Internet using this neutrino link, you would take about fifteen billion years to download, which is still longer than the age of the universe. Right, and people are still making up stuff on the Internet, so you're just going to fall behind again, unnamed Internet provider, Am I right? All? Am I right? Fifteen billion years just to send an email. Maybe you should switch from new tremail back to normal photon mailk. Maybe this is why all my job applications have sent to space have not resulted in any interviews. But I think what this shows us is that the universe is more complex than what we can just see with our eyeballs or our earballs or our fingerballs. That there's a lot more going on out there. The universe is sending us all kinds of information that biologically we cannot see, but we are capable using is of discovering that it exists. And maybe also of manipulating it, of using it to talk to each other or maybe to the aliens. Wow, I mean it kind of. It's also like with our initial question about like why didn't we evolve to be able to detect neutrinos, It seems like a lot of it is we're just too small. So if there's like a giant alien species out there whose eyes are so big or their sensory organ is so big that they do have a statistical significance of receiving these neutrinos, maybe there's giant aliens who can like detect or consume neutrinos, or maybe they're not that big, but their eyeballs are imagine like humans with eyeballs the size of swimming pools. That would be a cool science fiction novel. Somebody out there right that for us? Please? All right, and thanks very much Katie for joining us on today's exploration and discovery of the crazy world of neutrinos. Thanks for having me, for putting that mental image in my head. I appreciate it. Alrighty go give your new Trinish now our arrest. Thanks for joining us, Thanks for listening, and remember that Daniel and Jorge Explain the Universe is a production of I heart Radio. For more podcast from my heart Radio, visit the i heart Radio app, Apple Podcasts, or wherever you listen to your favorite shows. H