Daniel and Kelly’s Extraordinary Universe - Are neutrinos hiding the dark matter?

Episode Date: October 19, 2021

Daniel and Jorge talk about how dark matter might be hiding under the "neutrino floor" Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

This is an IHeart podcast. Why are TSA rules so confusing? You got a hood of you. I'll take it off. I'm Manny. I'm Noah. This is Devin. And we're best friends and journalists with a new podcast called No Such Thing, where we get to the bottom of questions like that.

Why are you screaming? I can't expect what to do. Now, if the rule was the same, go off on me. I deserve it. You know, lock him up. Listen to No Such Thing on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. No such thing.

I'm Dr. Joy Hardin-Bradford, host of the Therapy for Black Girls podcast. I know how overwhelming it can feel if flying makes you anxious. In session 418 of the Therapy for Black Girls podcast, Dr. Angela Neal-Barnett and I discuss flight anxiety. What is not a norm is to allow it to prevent you from doing the things that you want to do. The things that you were meant to do. to listen to Therapy for Black Girls on the iHeart Radio app, Apple Podcasts, or wherever you get your podcast.

Your entire identity has been fabricated. Your beloved brother goes missing without a trace. You discover the depths of your mother's illness. I'm Danny Shapiro, and these are just a few of the powerful stories I'll be mining on our upcoming 12th season of family secrets. We continue to be moved and inspired by our guests and their courageously told stories. Listen to Family Secrets Season 12 on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. I'm Dr. Scott Barry Kaufman, host of the Psychology Podcast.

Here's a clip from an upcoming conversation about how to be a better you. When you think about emotion regulation, you're not going to choose an adaptive strategy, which is more effortful to use, unless you think there's a good outcome. Avoidance is easier. Ignoring is easier. Denials is easier. Complex problem solving takes effort. Listen to the psychology podcast on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Hey, it's Horhe and Daniel here, and we want to tell you about our new book. It's called Frequently Asked Questions About the Universe. Because you have questions about the universe, and so we decided to write a book all about them. We talk about your questions, we give some answers, we make a bunch of silly jokes.

As usual, and we tackle all kinds of questions, including what happens if I fall into a black hole, or is there another version of? of you out there. That's right. Like usual, we tackle the deepest, darkest, biggest, craziest questions about this incredible cosmos. If you want to support the podcast, please get the book and get a copy, not just for yourself, but, you know, for your nieces and nephews, cousins, friends, parents, dogs, hamsters. And for the aliens. So get your copy of frequently asked questions about the universe. It's available for pre-order now. Coming out November 2nd, you can find more details at the book's website, UniverseFaQ.com. Thanks for your support. And if you have a hamster that can read, please let us know. We'd love to have them on the podcast. Hey, Daniel. What kind of floors do you have in your office? Actually, I'm glad you asked because I'm kind of proud of them.

I put wood floors into my office last year. What? Like you did it yourself in your university office? Yeah, I did. It just snuck in. did it on a weekend. Do you ask permission to do it? I figure better to ask forgiveness than permission. Oh, man. Well, I guess you better not mention it on a podcast or anything. I would never be so short-sighted. And let me guess, did the floors you put in? Are they made out of

particle boards since you're a particle physicist? No, but they are particularly snazy. Are they made out of fluorine? Florinos. Or are they fluorescent? They are scintillating. I think reached the floor of the pun space there. Glad to know there's a bottom. Hi, I'm Horham, a cartoonist and the creator of PhD comics. Hi, I'm Daniel. I'm a particle physicist and a professor at UC Irvine, and technically I'm an experimentalist, but I don't actually like to build things.

But you are an amateur carpenter, would you say, or a florist? I'm definitely an amateur. Nobody is paying me to put in their floors. Welcome to our podcast, Daniel and Jorge Explain the Universe, a production of IHeard Radio. In which we dig through the floor of your understanding and into all of the mysteries of the universe. We try to understand everything that's out there above our heads and below our feet and all around us. From the crazy mysteries inside black holes to the swirling insanity that is our galaxy, to the tiniest particles that are flying through our bodies.

That's why we try to break through the ceilings and the floors of our brains and our human understanding of how the universe works because there is a lot more than what is immediately around us beyond our floors and ceilings. Do you think it's possible to hear an idea which would break your mind, which would like literally make you go insane? You mean like it makes you insane and then you hear it or you hear it right before you go insane? Yeah, it makes you go insane. Like if I reveal to you the true nature of the universe and it blew your eyes,

mind in such a way that you just couldn't function afterwards. Oh, boy. Well, let's hope it doesn't happen today because we got to record this podcast. Live on the air, we blow Jorge's mind. It could be like a weapon of mass destruction almost, like an earworm that disables your brain somehow. I think I read a book like that. It was called Lexicon, actually. There was a word that if you heard it or if you saw it written, it would blow your mind. Was it particle wood floors? I don't know what it was because if I had read it, then it would have blown my mind. So I didn't finish the book. It was like a warning. The book doesn't tell you what the word is? It can't, man. It can't. Oh, boy. But anyways, we do try to talk about everything in the universe that's interesting and that

might be hiding out there for humans to discover and to blow our minds with once we sort of figure out how everything works because it is a pretty mysterious and interesting universe. That's right. And we want to know how it works. And more specifically, we want to know what's in it. What's it made out of? We look at this universe with wonder and admiration, but we also look at it with curiosity. We wonder what makes it up and what makes it tick. And as a particle physicist, I'm always trying to break it down into the smallest pieces

to understand like what are the Lego bricks of the universe and how do they work? Yeah, and do they hurt when you step on them as well? But it is an interesting question, this question of what is the universe made out of? And it turns out that it's made out of things we have no idea about. It turns out most of the universe is made out of mysterious things and mysterious energies. So there's still a lot of work left for particle physicists.

Yay, the mystery is not solved. You can never retire, Daniel. I don't know why you're celebrating. Well, on one hand, it's disappointing and frustrating to not know the answer to this great mystery the universe. On the other hand, it's exciting. It's an opportunity because it means that we have crazy discoveries ahead of us. I think that one day humans will know what the universe is made out of.

They will hold that knowledge in their little brains. I hope it doesn't blow their minds and melt their brains out of their noses. Yeah. So when you think about what the universe is made out of, it turns out that physicists have figured out that most of the stuff in the universe, like the stuff that the matter in the universe, is apparently not the regular kind of stuff that we are used to, like the atoms and all the corks and electrons that you and I are made out of

and that cats and bananas are made out of. It turns out most of the stuff in the universe is something completely different. and mysterious. That's right. And we make this mistake all the time in science and in physics, that we see one kind of thing around us or one kind of behavior around us. And we assume that that's it, that everything follows these rules, that the whole universe obeys these principles that we see around us.

And then we discover, oops, it turns out this is unusual. It doesn't hold generally. And there are lots of circumstances where the rules are totally different from relativity to quantum mechanics. And here's another scenario. where we have spent hundreds or thousands of years studying the nature of matter only to learn that the kind of stuff we've been studying that makes up me and you and hamsters and ice cream and lava is only 5% of the stuff in the universe and that most of the universe is something totally different. Yeah, well, most of the universe, it turns out, is something called dark energy, but about 27% of the rest of the things in the universe, the energy and matter, is something that business is called dark matter, right, Daniel? That's right. It's a kind of matter that we know is out there. We know it's matter. We know it's some kind of stuff. It feels gravity. It causes gravity. It's shaped the structure of the universe. We know it's there. But we don't know what it is. We don't know what is made out of. We don't know how it's made or what rules it follows.

Yeah. It's kind of like a giant cosmic elephant in the room, right? That's invisible at the same time. Like the whole universe knows it's there. It feels its presence. It's being affected by it. It's definitely there, but nobody can see it. So it's like having a giant elephant, invisible elephant in the room. Yeah, and it's a reminder of a really important point that the universe that you see and the universe that we know is just one slice of the universe. That there's a lot going on around us that is invisible to us. That doesn't mean it isn't there. And in fact, what we see is a little tiny fraction of what's out there in the universe.

So it's not just dark matter that's out there. There's lots of particles out there in the universe that are invisible or almost invisible to us. For example, neutrinos are these tiny little particles that are flying everywhere produced from the sun, but you don't see them, even though there are billions flying through your fingers. So the universe is mostly dark and invisible to us. Yeah, it seems to be hiding from us. But do you think it's hiding, Daniel? What doesn't it want us to see?

Why are you so suspicious, man? Maybe it's just like gently walking us down the garden path to reveal its beautiful secrets. I see. It's just leading us down the path to hopefully it's not going to blow our minds and kill us at the end. I trust the universe. All right. So dark matter is something that is big and mysterious. It's a big part of the universe.

But we actually don't know what it is. The name dark matter is just kind of a placeholder, right? Like dark just means it's invisible and matter just means, you know, we feel it's gravity. But we don't actually know what it is, even though we are sort of actively wondering what it is and we're trying to find ways to study it. Yeah, it's a bit of a fine point. Some people say dark matter exists. Other people say we haven't discovered dark matter yet. How can both of those things be possible?

Well, we know that dark matter exists, but we don't really understand what it's made out of or what it is. So what we're looking to do is understand like, is dark matter made of a new kind of particle? And if so, what? Or is dark matter made out of something else entirely? So we know it exists, but we haven't been able to isolate it.

Yeah, we've been looking for a while now. I mean, dark matter was discovered kind of in the 90s, right? And people have been thinking about it, looking for it, devising experiments, and without success. We haven't sort of seen anything that can tell us more concretely like, hey, that was made by a little bit of dark matter. We actually have clues about the existence of dark matter dating all the way back to the 1930s. And then in the 1970s, it really became mainstream when Vera Rubin saw how galaxies were rotating.

And since then, this bared a very exciting and active program to try to understand what dark matter is made out of. But yeah, we haven't seen it yet. Yeah. And part of the problem is it's invisible, right? It's invisible and you can't see it or touch it. And so it's really hard to study something that, you know, you can't see or touch. That's right. So far, the only way we know how to interact with dark matter is through gravity.

And gravity is the weakest force in the universe, which makes it a very, very bad way to discover particles because particles have almost no mass. So they have very, very weak gravity. Yeah, gravity is really weak. But also, I think one of the things that might be preventing us from seeing and stunning dark matter better, is this concept that we're going to talk about today that has to do with neutrinos, which are also kind of elusive and invisible particles. That's right.

So we're looking for something elusive and almost invisible, and it might be hiding behind something else also elusive and also almost invisible. So today on the program, we'll be tackling the question. Are neutrinos hiding dark matter? Oh, man. This is such a mistrustful episode, Daniel. Exactly. So much suspicion. Like who's hiding what?

Who's keeping the truth from us? Man. Let's just have like a universe truth telling commission where everybody comes to the table and says what they got and what they know and everybody can just share all the information. Maybe a better title would have been, our neutrinos walking us down the poorest path of knowledge and enlightenment. Maybe neutrinos just have a grand plan. And this is just part of the plan, you know.

Keep us in darkness for a while and then boom, reveal the truth. So it blows our minds without. actually melting our brains. Wow, these neutrinos, man. All right, and this has to do with this concept called the neutrino floor that physicists talk about. And that might be the thing that is hiding or kind of preventing us from seeing or experimenting with dark matter.

Yeah, exactly. We have these experiments to look for dark matter, and they are worried that dark matter might be hiding for them by hiding under the neutrino floor. In the what, the universe basement? or the what's under the neutrino floor? I guess that's the question we'll be tackling today. All right.

Well, we were, as usual, wondering how many people out there had heard of the neutrino floor or had any guesses as to what it could be. So Daniel went out there and asked people on the internet this question. That's right. We are still in pandemic mode. So if you'd like to participate and you're out there on the internet, please don't hesitate to write to me to questions at danielandhorpe.com. I know you want to hear your voice in the podcast.

You desperately want to participate. You just haven't yet. So send us that email. It's easy. It's fun. Yeah, so think about it for a second. If I say the words neutrino floor, what does it make you think of? Here's what people had to say.

I know what a neutrino is and I know what a floor is, but putting those two things together, neutrino and floor and assuming there's only one of them, makes it feel like we're talking about some kind of minimum, a global minimum in something to do with neutrino. So, I don't know, like the lowest energy that a neutrino could possibly have. Or in the distribution of neutrinos energy, which we observe, what is the smallest one? Or like, what is the lightest neutrino that can possibly exist? Well, we know what that is. The neutrino floor.

I don't know, so probably the neutrino floors. Is it a floor made of neutrinos? Could be. The floor is the bottom of something, right? Yes. And what would be the bottom of? Something like the bottom of what they're composing. And, ah, okay. What are they composing? Particles? Yes, it's a kind of particle. But the neutrino floor means probably something like the bottom of something to do with neutrinos.

Let's say the smallest possible neutrino or the lowest energy neutrino or something like that. I think the neutrino floor is the baseline saturation of neutrinos throughout the universe and perturbations in the that floor would indicate something weird going on if you detect extra neutrinos, maybe? Is this the absolute lowest state of energy that a neutrino can be in? Is there like something weird about neutrinos where they have to have some energy and they just approach a floor where they don't get any less energy? I don't know. Neutrino floor, I'm guessing, is the lowest amount of neutrinos.

that could exist in the universe. So that would be the theoretical lower limit of how many would have to exist in order for the universe to be stable. The first thing that comes to mind is neutrinos are small and perhaps the floor is defining a smallest particle that we can know of.

So maybe the neutrino floor is the smallest particle that we know of at the moment. Maybe that's basically a maybe a base, like a base plate of neutrinos where we can basically detect some measurements according to whatever neutrinos hit that area. Neutrinos I have learned in the podcast are pretty much everywhere and many, many of them. So I guess if you don't have another source of neutrinos, the neutrino floor would be the sort of normal or median neutrino density that you would find. All right. A lot of great answers. I feel like any of these could be the real answer. These are great speculative answers. None of them are right, but they are great examples of people brainstorming and using their

physics knowledge and coming up with totally reasonable ideas for what this crazy concept could be. Well, these all seem plausible. And I think everyone's sort of latching onto the word floor as kind of like the bottom of something or like the minimum of something or like the point at which you can't go below. Exactly. And that's reasonable. And that's why floor is in there. But as you'll hear us talk about today, that's not exactly what we're talking about. We're not talking about the lowest energy state of neutrinos or literal floors made out of neutrinos. Huh. Can you have a neutrino house? Is that possible? Well, it wouldn't give you much privacy, and it wouldn't shield you from the weather,

but you would still have to pay taxes on it. So I don't think it's a great idea. Oh, boy, but it's neutral taxes, though, right? It's weak taxes. You have to pay it in dark matter dollars, maybe. Maybe you could pay in weak dollars. As the U.S. dollar might be these days. All right, well, the general topic, though, is dark matter and why we can't measure it as well as we should be able to. And so let's maybe recap for folks, what is dark matter?

Dark matter and how we know it's there. Yeah, so very briefly, dark matter is most of the stuff in the universe. We know that out there deep in space and also around us here, there is some kind of matter which has gravity and so it affects the way things move and the way the universe has been shaped and evolved, but we don't know exactly where it is and what it is. But we are sure that it's there and that it's here. It was discovered initially because we were looking at how galaxies rotate.

When galaxy spin, you might wonder, like, why don't the stars fly off into intergalactic space like ping pong balls would on a merry-go-round? And the answer is gravity. Gravity holds them into the galaxy. But you can ask, is there enough gravity to hold the galaxy together? Because we can measure how fast the galaxy is spinning and we can count up how many stars there are to estimate how much gravity there is. So you can do this kind of cross-check. This is a great kind of thing to do in science. It's just like double-check that things make sense. And 99% of the time, they do and you move on and it's really boring.

But sometimes they reveal like a cosmic mystery, a clue that there's something missing in our understanding. And that's what happened here because the galaxies are spinning way too fast. There's not nearly enough gravity to hold them together if you just count the mass of the stars that we can see. So people thought, well, there must be some other kind of stuff out there in the galaxy. And people had other ideas too, like maybe we just don't understand gravity or it's something wrong with our theory of gravity. But pretty soon we had other evidence of dark matter that convinced us it was real and it was matter. For example, we understand that dark matter has shaped the whole evolution of the universe. Since it's most of the matter of the universe, it's most of the gravity, which changes how

the stuff in the universe flows. You know that there are galaxies and filaments of galaxies and super clusters and this, all this structure in the universe, that's controlled by dark matter. If dark matter hadn't been around, we wouldn't have had that structure, we wouldn't have galaxies and stars today. So we have lots of evidence for dark matter in the universe, but we don't yet know exactly what it's made out of. Yeah, we definitely know it's there

like we've mentioned before. It's like having an elephant in the room. It's like you can feel its presence in the universe. And like you were saying, like we know it's there because it explains the rotation of galaxies. And also like, I think we've covered this in another episode that it's sort of the only way to explain

how the universe is the way it is now. Like, if you took out dark matter from the beginning of the universe, like, we wouldn't end up with the same universe. Yeah, you wouldn't at all. The universe wouldn't have galaxies and stars form as early as they did in our universe. So we're pretty sure that that gravity is there. We just don't know what it is that's generating that gravity. All right. So we know the elephant is there in the room.

We can smell the, you know, elephant dung. And we know we can feel its attraction or repulsion. But what do we actually know about dark matter? Like, do we know anything about it? except other than its effects in terms of its matter and gravity? We do know some things because we've been looking for it, and we know, for example, that it doesn't feel some of the forces, like electromagnetism, the force that makes things reflect light

or makes things glow, doesn't feel that force at all. It has no electric charge. If it did, it would reflect light or it would glow because it has some temperature. But it doesn't, so it doesn't feel electromagnetism. We know that it doesn't feel the weak force. We've also looked for it using the weak force, and that's actually what we'll talk about.

today experiments that tried to look for it using the weak force and it also doesn't feel a strong force similarly if it felt the strong force it would have crazy interactions with our matter that we could see but it does feel gravity which means that it has mass right it changes the shape of space means it has mass it has some energy to it but we also know a little bit more about how much energy it has we actually know something about the temperature of dark matter you might think like well how could you measure the temperature of dark matter you can't like take a thermometer and it in there because it can't interact with the dark matter. What we do is we look at how dark matter is clumped and spread through the universe. If dark matter was hot, if its particles were moving

really, really fast, it would spread out a lot. And that would change the shape of the universe, how things were distributed like the galaxies and where they are. And if dark matter was cold, if it was slow moving, it would tend to clump a little bit more. And that would give you a different shape for the universe. And what we see is that dark matter is pretty cold. It's not like some fast-moving little particle that spreads out a lot. Tends to be cold and clumpy. Yeah, dark matter is pretty cool, for sure. But we also sort of know kind of where it is, right?

Or the kind of the distribution of it or the shape of it throughout the universe. Like we know it's sort of like a giant cloud or some people call it a halo around our galaxy. And when you look out into the universe, you can see that there's sort of ripples and clumps of it here and there. Like it's not evenly distributed throughout the universe. It seems to clump to things and there's clumps of it out there in space. That's right. And describing it as a halo is accurate, but it suggests sort of that dark matter follows the normal matter, that dark matter is there where normal matter is.

When actually it's the opposite, normal matter follows the dark matter because dark matter is much more gravity. The reason there is a galaxy right here is because there was a big clump of dark matter. And so all the normal matter fell into that gravitational well and was then squeezed together into a galaxy. So yes, not everywhere through space, it's in these big clumps. And we can tell where the really big clumps are because they have enough gravity. But we can't tell, for example, is there a blob of it right here in the room with me?

Because it's really hard to measure the gravity of smaller objects. So we can tell where the dark matter is with like really fine resolution, smaller than like, you know, a chunk of the galaxy. We can't even tell like down to the solar system where the dark matter is. Right. But the big mystery of dark matter is that we sort of don't know what it is, right? Like we know it's there. We know there's something or some, something. I don't know if the thing is even the right word,

but there's something there that's pulling us gravitationally, but it could be like a particle or could be something non-particle. It could be like, I don't know, some kind of like new kind of stuff, right? Absolutely, it could. And we need to keep an open mind because all of our ideas about what matter is come from studying the kind of matter we are made out of. But we know that dark matter is different.

It has to be different. It's not made out of atoms. and so it might follow very different rules and whole different concepts. So on one hand, we could try to extrapolate from what we know and say, everything out here is made of particle. So maybe dark matter is also. But maybe dark matter is made of lots of different kind of particles. Or, as you say, even something weirder, something that's not a particle.

And we did a whole fun podcast episode about what an unparticle might be. That's weird, new kind of matter that people are playing with conceptually. But it also could be something that nobody has thought of at all, something totally new and weird that blows our minds. Right. It could be an unparticle or maybe it's a fun particle. Who knows? Or it's an unidea.

Waiting to join the party. All right, that's what dark matter is. It's something that's there. We know it's there, but we don't know what it is. And because it's invisible, it doesn't interact with the electromagnetic force. And so how do you study something like that? How do you look for something that's invisible and doesn't want to be touched? So let's get into that.

But first, let's take a quick break. The U.S. Open is here, and on my podcast, Good Game with Sarah Spain, I'm breaking down the players from rising stars to legends chasing history, the predictions, well, we see a first time winner, and the pressure. Billy Jean King says pressure is a privilege, you know. Plus, the stories and events off the court, and of course the honey deuses, the signature cocktail of the U.S. Open. The U.S. Open has gotten to be a very fancy, wonderfully experiential sporting event. I mean, listen, the whole aim is to be accessible and inclusive for all tennis fans, whether you play tennis or not. Tennis is full of compelling stories of late.

Have you heard about Icon Venus Williams' recent wildcard bids or the young Canadian, Victoria Mboko, making a name for herself? How about Naomi Osaka getting back to form? To hear this and more, listen to Good Game with Sarah Spain, an Iheart women's sports production in partnership with deep blue sports and entertainment on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Presented by Capital One, founding partner of I Heart Women's Sports. Imagine that you're on an airplane, and all of a sudden you hear this.

Attention passengers. The pilot is having an emergency, and we need someone, anyone, to land this plane. Think you could do it? It turns out that nearly 50% of men think that they could land the plane with the help of air traffic control. And they're saying, like, okay, pull this, do this, pull that, turn this. It's just... I can do my eyes close. I'm Mani.

I'm Noah. This is Devin. And on our new show, No Such Thing, we get to the bottom of questions like these. Join us as we talk to the leading expert on overconfidence. Those who lack expertise lack the expertise they need to recognize that they lack expertise. And then, as we try the whole thing out for real. Wait, what? Oh, that's the run right.

I'm looking at this thing. See? Listen to No Such Thing on the IHeart Radio app, Apple Podcasts, or wherever you use. get your podcasts. Hola, it's HoneyGerman. And my podcast, Grasasas 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 talk 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 code, 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. 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. All right, we're talking about the neutrino floor, and how somehow that floor is preventing us from or hiding maybe dark matter and our understanding of what it's made out of. We talked about what dark matter is. And now, Daniel, how are people, I guess, trying to study dark matter? I mean, it's invisible and you can't touch it with your finger or any kind of instrument, really, because it only feels certain forces.

How do you look for something that elusive? It's overwhelming, you know, to say, I want to look for something. I don't really know what it is, if it's even a particle, if it's something I haven't imagined yet. I don't know how to interact with it. In general, that's an unsolvable problem. We just don't know in science how to tackle such a big problem. So what we do is we break it into pieces and we say, well, let's assume that we're lucky. Let's assume that dark matter is something that we do know how to discover and that we're lucky

and it can talk to us. So we make a bunch of totally unjustified assumptions and hope that they're correct. So for example, we assume that dark matter is made of particles because that's basically all we know how to do. And we assume that dark matter is made of one kind of particle because that's just simpler. And as we said earlier, there's no justification for assuming that dark matter is made of particles other than everything so far has been made of particles. And there's no justification for assuming it's one kind of particle because, you know, our matter is made of lots of different kinds of particles. But it's just sort of like the simplest place to start.

I see. Because, you know, most of the stuff we are familiar with and that we have at our disposal and that we know about is made out of particles, right? And not just sort of like any particles, but sort of like a certain range of sizes of particles, right? Yeah, exactly. And we think that dark matter is heavy. We do have some evidence there because we know that it's cold. If dark matter was really, really low mass, then it would have enough energy to be zipping around at higher speed. So we have some evidence that dark matter, if it is a particle, it's probably on the heavier side. But we don't know if that particle feels any forces other than gravity. Like we know it feels gravity, but if it only feels gravity, it would make it very, very difficult to ever discover a particle of dark matter.

because even if it's heavy, it might weigh, you know, like as much as a gold nucleus. But how much gravity does a gold nucleus have? Almost zero. It's very difficult to measure the gravity of a single particle. So in order to discover dark matter, we also make another almost totally unjustified assumption, which is that there's some new force out there that dark matter feels and we also feel and we can use that to discover dark matter. What?

Okay, I got stuck a little bit a while ago because you said that it has to be heavy because it's cold. Couldn't it also be a small or light particle and also be cold? It can be. It's possible. We think it's more likely because it's cold that it's heavy that would make it easier for it to be slow moving, right? Well, we know something about its velocity. And if it's light, then it would have to be even low energy to be cold. So yeah, it's possible to have cold light particles, but they're less likely, we think.

All right. And so then you said we have to assume it interacts through a new kind of force that we have no idea about, and I guess maybe explain why that is, is it, couldn't it also be interacting through the weak or strong forces, maybe in a different way than you thought, but it could also be interacting through those forces? Yeah, and we've looked for it interacting through those forces and we haven't seen it. You know, if dark matter interacted with the strong force, then everything that feels a strong force would interact with dark matter. And it should be pretty easy to find because the strong force is very strong. Like any blob of matter that's out there,

every rock, for example, should be hit by dark matter. be interacting with dark matter. But we don't see that. You know, we don't see those things. We study particles really carefully. And the strong force, again, is very, very strong. So if dark matter was interacting with matter using the strong force, we would see weird unexplained effects. We would discover dark matter years and years ago. Same thing for the weak force. We have looked for dark matter interacting with our particles using the weak force. And we haven't seen it. And we know these forces really, really well, like very precise measurements of these forces in colliders and other experiments.

So any deviations from our theories of these forces would be hints of dark matter. And we've looked for that and we just haven't seen it. I see. There's no evidence that it feels a weak or strong force so far. That's right. And we've studied those in the wazoo, out the wazoo, and around the wazoo. I don't want to know where the wazoo of an elephant is. So then is that where we're at now?

Like we've given up on the weak force and the strong force for dark matter? We've given up on those. And so we said, well, what if there's another force? right? What if there's another force that dark matter can use to interact with our matter? And if there is, then we can use that to discover it. The argument for that existing is mostly, boy, I hope it exists because that would make it possible to discover dark matter. There are some other hand-wavy arguments to suggest that maybe it's reasonable, but mostly it's the first one. It's just out of desperation. It's the only way we would be able to see it, so let's hope it's true. Yeah,

exactly. Let's start there. And, you know, if we don't find it, then we need to re-examine these assumptions and go back and think, well, what if there's another way? Let's be more clever about it. But it also makes sense in science to try the simplest thing first. Hey, maybe we'll get lucky and dark matter will be some heavy kind of particle that has a new force that interacts with our detectors. And we can discover it that way. It'd be silly not to try the simplest thing first.

Right. But I guess it doesn't sound that simple, right? Like making up a whole new, we're assuming a whole new force in the universe that nobody has ever seen or felt before. It seems a bit of a stretch because like if someone. such a force exists, then our matter can interact through it, wouldn't we have noticed by now? Yes. And so it has to be a weak force, not weak with a capital W like the weak force, but it has to be like a feeble force. So you're right. Exactly. If there is this other force and our particles can feel it, then we should see it in experiments.

We have other experiments also that are looking for these kinds of forces. And so we hope it's out there. But if it's true, it would have to be very, very feeble. And that's why these experiments are very difficult. Is that the official name? Have you guys christened it yet? The feeble force? No, we haven't christened it. The fantastic feeble force. And it's very confusing, of course, because it's particle physics naming. This particle we're talking about is called the Wimp, weakly interacting massive particle, but weekly interacting there does not mean interacting through the weak force. It means interacting through some new, not very powerful force. So they should have called it like the fimp, the feebly interacting massive particle. Yeah, because you don't want to call it the powerful

interacting massive particle that would be inappropriate for any podcast. That's right. Or the limp or something, right? The lightly interacting massive particle. There you go. All right.

So if Dark Matter is interactive through this new imaginary force we're hoping to see, how would we see it? It's not imaginary. It's hypothetical. There's a difference, right? Between hypothetical and imaginary.

It's all about spin. I mean, you say it's like making it very complicated. On the other hand, it's sort of ambitious, right? Like this way, if we discover dark matter, we get two discoveries for the price of one. We find a new particle and boom, new force at the same time. It's like Nobel Prize with the side of another Nobel Prize. I see. It's like, how are we going to find the big invisible elephant in the room? Well, I'm glad you asked. We're going to use invisible camels. Yes, exactly. Exactly. And in this case, you need the invisible canyels to show you where the invisible elephant is.

And so you assume both exist. And then when you discover them, boom, two discoveries. Boom, you got a zoo. Two animals for the price of one. That's right. So we're looking for the zimp, the zoo interacting massive particle. All right. So then what are these experiments?

What do they look like? How do you look for a force you don't even know it exists? So there's actually three different ways that we look for the wimp. They're called make it, shake it, or break it. But today we're going to talk about just one of them because it's the one that's related to neutrinos and the neutrino floor, and that's the shake-it. And this is a strategy of looking for dark matter by basically making a really big chunk of stuff

and putting in a really quiet place so you don't expect anything to happen and then looking to see if dark matter ever bumps into part of your really big chunk of stuff. This is one of those like xenon detectors, right? So it's a huge tank of liquid and actually gaseous xenon that's deep, deep underground. And xenon, because xenon is one of the noble elements.

So if you have a big tank of xenon, it basically does nothing. It doesn't like give off flashes of light or interact. And so if something does cause the xenon to do something, it means something has penetrated. Something is like kicked the xenon or giving it a little boost or something. You take your big, vast tank of xenon, and you bury it deep, deep underground so that particles from space don't hit it. And then you put basically cameras,

little photo multiplier tubes to watch it and ask like, did any of my xenon atoms get bumped? Right, but doesn't xenon sort of move or does things by itself? Like, how do you know what I mean? Like if you put something in a room, how do you know it's something moved it or if it moved by itself? Yeah, so it's cryogenic. So it's very, very cold liquid xenon.

And they do a lot of work to try to isolate other sources of noise. This is the kind of detector where they're hoping to see one dark matter particle come through over like several years, right? So in order to claim discovery, when you see like one example, you need to make sure there are no other ways for this kind of thing to happen, no other things that might look like your invisible camel. And so they do a lot of work to shield this thing from particles from the outside, from radiation, from the rock, and also to cool this thing down. So there's no internal noise. Right. And I think the idea is not that there's only one particle of dark matter there per year.

It's more like it's full of dark matter particles, but only like once in a blue moon do they sort of interact. with the xenon particles. Exactly. We think that the Earth is moving through a dark matter wind. Like we think that dark matter is this big halo that surrounds the galaxy

or the galaxy is embedded in the halo of dark matter. So we think that dark matter is probably everywhere. And so we have dark matter in our room with us right now. Probably a good bit of it. And so there's this wind of dark matter.

But as you say, we don't have a high probability to interact with that dark matter. Most of the time when dark matter pass it through normal matter, nothing happens. So you need to do a lot of that. You need to shoot dark matter through your detector a lot of times. And that's why you wait a long time and you have a really big detector. And you're exactly right. We expect like thousands and millions and billions of dark matter particles to pass through. But this is a very weak interaction. It's very feeble. And so only occasionally

will the dark matter particle bump into xenon in a way that we can see. Right. Because I think when you say like weak or feeble, you don't necessarily mean like it hits it and it doesn't create and effect, it's more like the probability of this interaction is very low because it is after all presumably a quantum interaction. It is a quantum interaction and we talk about it in terms of cross sections because we like to use like a classical physical analogy. Imagine that you're shooting two particles at each other or two balls at each other. The chances that those balls will hit each other depends on their cross-sectional areas. If you shoot two like basketballs at each other, it's much easier for them to hit than if you should.

shoot two ping pong balls at each other. And so we think that dark matter has a very low cross-section with the xenon nucleus, which means basically it sees the xenon nucleus as a tiny, tiny little dot and most of the time just flies right by. Whereas other particles, you know, like quarks, have a very large cross-section with the xenon nucleus. If you shot a cork through a tank of xenon, it would interact with basically everything. Right.

So that's the basic experiment. You're saying you take a block of really cold xenon. You put it under a lot of insulation so nothing else can reach it. And then you just wait, as we're moving through the universe, we're moving through a cloud or a haze of dark matter. And hopefully, eventually, maybe one day this dark matter will interact with your xenon in some way that you can detect. And then you'll be like, hey, there is the dark matter. That's right. And we look for these little flashes of light that indicate that dark matter might have come through and kicked one of these xenon atoms,

which caused it to either like lose an electron or to give off a little scintillation flash of light. So that's the signal that we're looking for. All right. Well, sounds simple enough, but there is apparently a sort of a hiccup in this schematic, in this idea, and it has to do with the neutrino floor. So let's get into that or under that. But first, let's take a quick break. The U.S. Open is here.

And on my podcast, Good Game with Sarah Spain, I'm breaking down the players from rising stars to legends chasing history. The predictions will we see a first-time winner? and the pressure. Billy Jean King says pressure is a privilege, you know. Plus, the stories and events off the court, and of course the honey deuses, the signature cocktail of the U.S. Open. The U.S. Open has gotten to be a very fancy,

wonderfully experiential sporting event. I mean, listen, the whole aim is to be accessible and inclusive for all tennis fans, whether you play tennis or not. Tennis is full of compelling stories of late. Have you heard about Icon Venus Williams' recent wildcard bids? or the young Canadian, Victoria Mboko, making a name for herself. How about Naomi Osaka getting back to form? To hear this and more, listen to Good Game with Sarah Spain,

an Iheart women's sports production in partnership with deep blue sports and entertainment on the IHeart radio app, Apple Podcasts, or wherever you get your podcasts. Presented by Capital One, founding partner of IHeart Women's Sports. Imagine that you're on an airplane and all of a sudden you hear this. Attention passengers. The pilot is having an emergency. and we need someone, anyone, to land this plane. Think you could do it?

It turns out that nearly 50% of men think that they could land the plane with the help of air traffic control. And they're saying like, okay, pull this, until this. Pull that, turn this. It's just, like, do my eyes close. I'm Manny. I'm Noah. This is Devon.

And on our new show, no such thing. We get to the bottom of questions like these. Join us as we talk to the leading expert on overconfidence. Those who lack expertise, lack the expertise they need to recognize that they lack expertise. And then, as we try the whole thing out for real, wait, what?

Oh, that's the run right. I'm looking at this thing. Listen to no such thing on the Iheart radio app, Apple Podcasts, or wherever you get your podcasts. 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. Hola, it's Honey German, and my podcast, Grazie's 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. Yeah? But the whole pretending and code, 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 Podcast, or wherever you get your podcast. All right, we're trying to find dark matter, Daniel, and it's invisible and it doesn't want us to see it or touch it or bump into it.

But it might have a weakness, which is a totally new kind of force. Yeah, exactly. And so we are hoping that it will reveal itself in this very quiet tank of liquid xenon deep underground. There's actually several of them. There's one underground in Canada. there's one underground in China and there's one underground in Italy these are all competing tanks of liquid xenon.

Interesting. It's interesting to think there are three places in the world where there's a block of xenon just waiting for something to happen and trying to ignore everything else that's going on in the universe basically, right? Yeah, yeah. It's not exactly a block.

It's liquid xenon mostly. There's a gashes phase on the top. But yes, this tank of xenon. And it must be interesting to be sitting there and babysitting it, you know, because it could be that one day when you're on shift, that's the day you see the signal that dark matter makes itself obvious. Most days, nothing happens or most days you hope nothing happens. You just sit there and the end result of sitting there for eight hours is, yeah, we saw nothing

today. So it's very strange like gambling with the universe, wondering if today is going to be the day you see something. It's like you're staring down dark matter. It's like who's going to blink first? It's like you're staking out dark matter. You're sitting outside of dark matter's house and it's never left to buy groceries, and you've been there for years, and you're wondering if it's ever going to come out. You're waiting for it to peek out of its blind, and you're like, I knew somebody was home. All right, so we're waiting for a dark matter to bump into a xenon atom in one of these tanks around the world, but there's sort of a confusing factor here.

There's something that might prevent us for ever maybe finding any of these dark matter bumps. Exactly, or at least that complication. And you brought up one of them earlier, which is, aren't there other ways for Xenon to get bumped or xenon to bump into itself. And, you know, this is an indirect experiment. It's not like we capture the dark matter and we can like see it and look at it and study it and parade it around the world in a dark matter zoo, right?

All we see is that the xenon atom got bumped. We don't ever directly see what bumped it, right? And so there are other things that might be able to bump xenon. And we try to shield the detector from that by having a deep underground under many layers of rock. So, for example, muons and other compounds. Cosmic ray particles from space don't bump it. But there is one kind of cosmic ray, a particle from space, which can get through all of that rock and can bump xenon and can mimic this dark matter signal.

Yeah, because dark matter is not the only elusive and invisible particle or stuff in the universe. There are also neutrinos, which we know are invisible and don't interact with the electromagnetic force. That's right. And they can penetrate through the entire earth without thinking twice. And so it's no big deal for them that we shield these tanks. of xenon with layers and layers and layers of rock, they just fly right through. And most of the time, they also fly right through that tank of xenon without interacting or causing anybody any trouble, right?

But neutrinos do feel the weak force and the nucleus of the atom also feels the weak force. And so sometimes, very rarely, a neutrino will bump into xenon and it would look a lot like what would happen if dark matter bumped into xenon. It would bump the xenon through the weak force or through maybe this new hypothetical, i.e. imaginary force that you guys are hypothesizing. It might bump it through the imaginary camel force, I don't know, but it would definitely bump it through the weak force. Neutrinos feel the weak force, and so do the components of a xenon atom. And so we definitely expect these neutrinos to bump xenon at some rate.

And you can't tell the difference between a neutrino bump and a potential dark matter bump. We can't for an individual bump. We can't look at an individual bump and say, oh, this one was a neutrino, this one was a dark matter. But we do have some handles for telling like, Is it more likely to have been dark matter or is it more likely to have been a neutrino based on what time of year it was? Oh, interesting. It's seasonal. Because, you know, the earth goes around the sun, which changes, for example, how much dark matter we are flowing through. Our velocity through the dark matter halo of the galaxy changes during the year, right? And so dark matter's natural flux, which comes from the motion of the actual the sun, the whole solar system through the Milky Way, peaks in June. And then it reaches. its lowest point in December, but neutrinos have a different pattern because neutrinos are produced by the sun. And so they have a different pattern. Oh, that's interesting. But I guess I'm confused

because I thought we didn't know that much about where dark matter was. How do we know that dark matter is even seasonal if we can't really see or touch it? We're assuming that dark matter is distributed through the galaxy fairly evenly. And we know something about its rotation because we know something about its like distribution and that requires it to be rotating at some rate. And so We know something about where the dark matter is. We can't resolve it down to like, here's a piece of dark matter or even there's a clumpier piece of space that has more dark matter in it. But we just assume that dark matter is like evenly distributed through the galaxy. And you're also assuming that it's spinning.

I hadn't heard that one before. You're assuming that the dark matter and the galaxy is spinning with the galaxy? It has to be because if it wasn't spinning, it would just fall towards the center. And the reason that the dark matter is in a halo is because it's spinning. If it wasn't spinning, it would just fall into the black hole of the center of the galaxy. Oh, I see. So when you say it's seasonal, I guess what you mean is like, you know, as this earth goes around the sun, sometimes we're kind of swimming upstream of the dark matter

currents and sometimes we're swimming downstream of the dark matter wind or current. Exactly. And just like on a boat, if you're moving with the wind, you don't feel it. And if you're moving upwind, you do feel it. Or maybe more like on a bicycle, the wind is at your back. You don't really feel the wind. And when you're going uphill and the wind is down your face, you feel it more strongly. And so you have a higher flux of wind.

And so if more dark matter particles are passing through our detectors, we expect to see more of them. I remember we had this podcast episode about the Dama experiment. This is another dark matter experiment that actually claimed to have discovered dark matter and saw a seasonal variation just like you would expect. Turns out there are other reasons not to believe that experiment, but that's the kind of thing we see. If we ever do see a lot of interactions, then we would expect them if they are dark matter to come in this pattern where there's more in one part of the year. and fewer in another part of the year.

I see. But generally speaking, that's what the neutrino floor is. It's like, you know, we're trying to look for dark matter and we're trying to find it when it bumps into xenon tanks, but the neutrinos could also be there bumping into xenon. And so that's when you say like the neutrino floor, it's more like you're saying sort of like there's a base level of noise that we expect from neutrinos.

Yeah. And if dark matter interacted with xenon more than this neutrino floor, right, at a higher rate than this neutrino floor, it wouldn't be a big deal. The rate would be above the floor. We could tee dark matter interaction with xenon. It'd be all great. We collect our Nobel Prize.

If the dark matter rate is low, is small. The probability for dark matter to hit xenon is small enough, then it's going to be below the neutrino floor, meaning that we expect to get more interactions from the neutrino interacting with xenon than we do from dark matter. And that's going to make it very difficult to disentangle this dark matter signal from the neutrino floor that looks just like it.

Right. it's like a base level of noise or like, you know, it's like there's a little bit of fog on the floor and you're trying to find your keys that you dropped or like if you're trying to find your keys, it's hard on a foggy floor. But if you're trying to find a basketball, maybe that would stick out more. Yeah, or if your keys are floating or something. All right. So then that's the neutrino floor. It's sort of like fuzzing up our view of dark matter through this hypothetical new force. But you're saying the seasonality of these two things maybe will let us kind of break through that fog. It's going to be tricky, right? Because in order. to make these arguments, you need to see more than one interaction. Like if you just see one and it comes in June, you might say, well, dark matter is most likely to come in June. So I guess this is more likely dark matter than neutrinos, which tend to peak in January when the Earth is closest to the sun. But it's not a great argument. When you need to do is see like a hundred of these things and show that they tend to cluster in June, that there are more in June than there are in January in December.

Because otherwise, you could just be seeing like a rare neutrino interaction in June. So it means that we need to see a lot more of them to really be confident. I see. But the problem is that the experiment is really feeble. And so you don't get hundreds of them or you would at least have to wait hundreds of years maybe to get a hundred of them. Yeah. And so far we haven't seen any. So we've been running these tanks.

And the plan is to make them bigger and bigger and bigger. So they got the technology to work on a smaller tank and then they scaled it up and up and up. And right now they're running these tanks with many tons of liquid xenon underground. And you're right, the idea is to either run them for years or decades or make them bigger. So we're impatient to see dark matter and so we're making them bigger and bigger and bigger. And right now we're at the point where we should start to see the neutrino floor very, very soon. We were all hoping to discover dark matter before we hit the floor, but we didn't see anything. And so now we're like right at the neutrino floor and we might spot it just before we get there,

but we might also have to dig into the neutrino floor. I guess what do you mean like hitting the floor? It means that you have enough xenon out there that if there was dark matter, you would have seen it by now. And we know how neutrinos interact. So we know when we should expect to see neutrinos interacting with our xenon. And neutrinos don't interact very often. And so far our tanks have been smaller.

But now we have these much bigger tanks. And so we expect to see neutrinos interacting with them pretty soon. Meaning like we're out there. We're running these detectors. we're gathering the data, we're analyzing it. You know, a year or two, these experiments will come out with the results, and they will be sensitive to neutrinos. Like, they should have seen neutrinos.

Interesting. All right. Well, then I guess what are the possible outcomes here? It could be that you build these giant tanks and then you find nothing except neutrinos. What would that mean about dark matter? What would that mean about dark matter? That would be disappointing. It would mean either that dark matter does exist and is a wimp and does interact with

xenon just at a lower level than we're capable of seeing, right? Just like even more feeble than the interactions with neutrinos. So that's one possibility. Another possibility is dark matter is real and it's a particle, but it doesn't have this invisible camel force that we made up to give us a window to interact with it, that the only thing it feels is gravity. And that would mean it would be very, very difficult to ever discover the particle nature of dark matter because particles don't feel a lot of gravity.

But I mean, we definitely know it's there. it would just maybe confirm that we could maybe never see it or really experiment with it, at least from using these ideas. Using these ideas. And so we'll have to be more clever. And people are working on other ideas. They're working on other ways to detect dark matter that would be more sensitive. One of my favorites is an idea for directional dark matter that can see dark matter only if it's moving in one direction and not in the other.

And that helps like remove the neutrino background because neutrinos tend to be moving from the sun. So if you can tell the direction that something bumped your xenon or xenon equivalent, you can help understand if it's neutrino or something else. We have an idea for the direction. We think the dark matter wind is going. So that's one way forward. And then there are other crazier ideas like maybe dark matter is not a wimp. Maybe it's an axiom and go check out our fun podcast episode about how to discover axions.

Or maybe it's made of primordial black holes or maybe it's made of weird, crazy elephants. We just don't know. So we've got to be more creative. But this is the first thing to try is this heavy particle that has a new weak kind of interaction. And so it makes sense to try it. But if we don't see it, it just means we need to sort of broaden our ideas a little bit. It could be an invisible rhino, not an elephant. This whole time, you've been holding onto this idea this whole time.

You just now drop it on us. That's right. But it seems, I guess, kind of crazy that you would build all these, I mean, I'm guessing billions of dollars in experiments based on an idea that is so hypothetical. Do you know what I mean? But I guess you have to do it because you have to check off that box. Yeah, well, there are people in the theoretical physics community who say it's ridiculous and it's a huge waste of money. These experiments don't cost billions of dollars.

They do cost tens of millions of dollars. And I think the idea is strong enough that it's worth checking. Other people do think that it's a very narrow idea. It has a lot of assumptions that are not justified and it's a lot of money to spend on those kinds of experiments. So there's some very vocal people out there who think that the whole thing is a waste of time. I am very curious. My judgment is, do I want to go to this seminar and see the results?

Every time these experiments, Xenon, Lux, and Panda X put out new results, I'm desperately curious to see what they say. So I'm willing to spend my taxpayer dollars on funding these experiments. You're willing to bet on the camels. I want to know if the camels are out there. Yes or no. It'll be a whole new particle zoo for the universe to lead us to. And maybe we can recover some of the expenses by charging admission.

There you go. you can pick up those dark matter dollars from the floor. See, yeah, I'm learning to monetize, monetize, monetize, man. Become a Patreon of our invisible camels, please. There you go. Has physicists ever tried using Patreon to fund their research? I don't know. And I don't think anybody's ever kick-started a particle physics experiment either.

Zero out of $40 million pledged. Well, it's not too late. All right. Well, that gives us an answer here. Are neutrinos hiding dark matter? Potentially, it kind of sounds like maybe the answer is, Yes, I mean, we're getting pretty close to the floor, and it sounds like if dark matter is there, we'll never see it because of these neutrinos. Neutrinos are definitely clouding the issue and can make it harder to find dark matter.

But I'm still holding out hope. We're not at the floor yet, and it could be that one of these detectors reveals results that are above the floor that are at a rate the neutrinos couldn't reproduce and is a much more convincing sign of dark matter. But we'll find out in a year or so. All right. Stay tuned. In the meantime, thanks for joining us. We hope you enjoyed that. See you next time. Thanks for listening, and remember that Daniel and Jorge Explain the Universe

is a production of IHeart Radio. For more podcasts from IHeart Radio, visit the IHeart Radio app, Apple Podcasts, or wherever you listen to your favorite shows. Why are TSA rules so confusing? You got a hood of you. I'm gonna take it all! I'm Manny. I'm Noah. This is Devin. And we're best friends and journalists with a new podcast called No Such Thing,

where we get to the bottom of questions like that. Why are you screaming? I can't expect what to do. Now, if the rule was the same, go off on me. I deserve it. You know, lock him up. Listen to No Such Thing on the IHeart Radio app, Apple Podcasts, or wherever you get your podcast. No such thing.

I'm Dr. Joy Hardin-Bradford, host of the Therapy for Black Girls podcast. I know how overwhelming it can feel if flying makes you anxious. In session 418 of the Therapy for Black Girls podcast, Dr. Angela Neal-Barnett and I discuss flight anxiety. What is not a norm is to allow it to prevent you from doing the things that you want to do, the things that you were meant to do. Listen to Therapy for Black Girls on the IHeart Radio app, Apple Podcasts, or wherever you get your podcast. Hi, it's Honey German, and I'm back with season two of my podcast.

Grazias, come again. We got you when it comes to the latest in music and entertainment with interviews 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'll talk about all that's viral and trending, with a little bit of cheesement and a whole lot of laughs. And of course, the great vivas you've come to expect. Listen to the new season of Dresses Come Again on the IHeart Radio app,

Apple Podcast, or wherever you get your podcast. This is an IHeart podcast.