Daniel and Kelly’s Extraordinary Universe - How long does a neutron live?

Episode Date: August 18, 2022

Daniel and Katie talk about how one of the basic building blocks of matter is surprisingly impermanent and mysterious. See omnystudio.com/listener for privacy information....

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Starting point is 00:02:22 I guess it depends on which particle you ask. All right, well, let's start with your protons. How are they feeling this morning? They're feeling pretty positive. And your electrons, any negativity there? Well, I would say they're all charged up. And what about those neutrons? We don't want to overlook them.
Starting point is 00:02:39 How are they doing? Eh, there come see, come saw. All right, well, let's see if this podcast can get them excited. Well, I'm excited, even if my neutrons are kind of just me. Hello, I'm Daniel. I'm a particle physicist and a professor at UC Irvine, and I contain multitudes of particles. And I am Katie Golden.
Starting point is 00:03:16 I host the podcast Creature Feature about animals. And my particles, I think I've got at least 10 of them. You know, really your podcast is a lot. also about particles since all animals are also made of particles. That's right. So who's the physicist now? We're all physicists. That's the point. Every podcast is really about particles. Even those true crime podcasts, even the Bigfoot podcast, even those paranormal ESP podcast that consistently outrank ours in the natural science category. But welcome to the podcast, Daniel and Jorge, explain the universe in which we treat the entire
Starting point is 00:03:57 universe as a crazy swarm of particles. Particles that are mysterious, particles that are weird, particles that follow very strange quantum rules, but particles that do follow rules in the end, rules that we think we can understand, that we can digest, that we can explain to you. On this podcast, we hope to wrap our minds around everything in the universe, break it down to its tiny little particles, and feed them to you one by one. My co-host and friend Jorge Cham can't be here today, but we are very lucky to have our regular co-host, Katie. Katie, thanks a lot for joining us. Of course. I am ready to learn about particles because, you know, they seem important given that I need them in me to make me me. To make you, you indeed. But you know, what is the eunis of you
Starting point is 00:04:47 diving right into the philosophical questions at the heart of particle physics? One thing we have learned recently about particles and the universe is that we all seem to be made up of the same kinds of particles i'm made of protons neutrons and electrons you're made of protons neutrons and electrons what's the difference are there katy particles and daniel particles no it turns out that the only difference between daniel and katy fundamentally or between an apple and a banana or between kittens and lava is how those particles are put together you take that same basic set of building blocks and you can make anything. You're blown my mind.
Starting point is 00:05:25 So if we sort of melted down Katie and Daniel into just the particles and then rearranged all the Katie particles into Daniel particle, like the Daniel blueprints, then that would just create a Daniel, even though those were originally my particles. That's exactly right. It seems like our universe follows the same principles as Legos, that the same basic building blocks can be used to make anything, right? If your little brother used your Legos to make a huge dinosaur and then you smashed it and used it to build a pirate boat, you could reuse those dinosaur Legos to make your pirate ship. Now here, of course, I have to quibble with the fundamental flaw of Lego toys.
Starting point is 00:06:05 The original Legos were just the basic building blocks. And I love that simplicity that I had no bias to them. You really could use them to make anything. These fancy new modern Legos, you know, they come with stuff printed on the sides or specific shapes, right? So they're sort of like predetermined what you have to build. I'm talking about the true original Legos. Yeah, I usually just built the tallest tower I could make out of my Legos and then usually put a bunch of guys on it. So it's like just this big tower of Babel.
Starting point is 00:06:36 I don't know what that says about me, but yeah, I agree. Although I do like that modern Legals do have different kinds of Legos. Like it started out, I think, with just the one Lego block unit. But now you have all sorts of. different types of Legos. You have like the sort of OG blocks, but you also have these long skinny ones. You have ones that can rotate. You have like connector Legos. But is that at all similar to how the universe works? Seems to be very similar to how the universe works. I'm made of protons and neutrons and electrons and so are you. And so is basically everything that you've
Starting point is 00:07:12 ever eaten, everything you've ever tripped over, everything you've ever thrown at your sibling. They're all made of the same ingredients. And if you look at the period, table, you can see that's true, right? Every element on the periodic table is just made of protons, neutrons, and electrons arranged in different numbers. You start with one proton and electron, you have hydrogen. You add in another proton, you get helium. Keep adding protons, you get different elements. You're just adding more of the same basic building blocks, but you make fundamentally different elements. But those different elements are not really fundamentally different. The only difference between carbon and neon or between lead and gold is the number of protons inside those nuclei.
Starting point is 00:07:52 So really, you can build anything with the same basic building blocks. It's so hard to wrap my head around that. So, you know, just like, it's just a seems that it's a numbers game. Because like usually with Legos, if you just have like five Legos, it doesn't suddenly turn into from like, you know, a sugar into like gold or something like that. But with On the atomic levels, when you change just the number of these tiny particles, it turns from, you know, something that if you eat, nothing would happen to you to something if you eat it, it would be bad and drive you crazy, like eating lead versus drinking air. I guess we don't really drink air, but you get the idea.
Starting point is 00:08:34 Yeah, absolutely. It might seem like a small difference. You just add in a proton, what's the big deal? But it completely changes its emergent behavior. All these characteristics that we're familiar with, the way metals are shiny and conduct electricity, the way some of these elements are float around and ignore the other ones that are not very active. All of those properties are determined by how many protons and how many electrons there are in each atom. And so like the fact that metals are metallic and conductive comes from the fact that their electron shells are not filled,
Starting point is 00:09:06 which is determined by the number of protons inside the nucleus. So it's not just an irrelevant detail, it's a totally determining fact, but it's fascinating. They're all made out of the same bits. The other fascinating thing to me is that we're all made out of roughly the same ratios of bits. Like any given atom has basically a one to one to one proton to neutron ratio. So lead has more protons than hydrogen, but it also has more neutrons and it also has more electrons. That means that not only are we all made out of the same three basic building blocks, but we're were made out of them in the same proportions.
Starting point is 00:09:41 It's not like Katie has more electrons and Daniel has more protons, right? We're the same building blocks in the same proportions just rearranged differently. So you mentioned that the number of protons sort of changes the element and the number of electrons. This kind of changes the characteristic of these elements. But you didn't mention neutrons too much being sort of the determinant of what these elements are. Why are neutrons different in terms of protons and electrons? Yeah, it's a good point. And neutrons are sadly often overlooked, which is why we are dedicating almost our entire podcast today to talking about these mysterious funny particles.
Starting point is 00:10:22 But you're right that neutrons don't really determine as much the identity of the atom. And that's because they are electrically neutral. Like if you add another proton to the atom, then in order to make it electrically neutral, you have to add another electron in orbit around it. And that really changes the chemical properties. It changes how this thing interacts, whether or not its electron orbitals are filled or whether it's got an opening. That very strongly affects the behavior of the atom. If you add another neutron, then you don't need to add another electron.
Starting point is 00:10:51 So you can add neutrons no big deal. You can't just add neutrons any time you like to any atom. It does make them heavier and it makes these other versions of the elements. These are called isotopes. So for example, you can have hydrogen, which is just a proton, but you can also have deuterium, which is a proton and a neutron. So you put those together inside the nucleus, you have an electron around it.
Starting point is 00:11:11 It's still called hydrogen, but it's like a heavy version of hydrogen. For example, if you put that together into H2O, but instead of the hydrogen, you have this heavy version of hydrogen with a neutron also in the nucleus, then you get what's called heavy water, which we sometimes use in nuclear experiments, right? So it does change a little bit,
Starting point is 00:11:28 sort of the flavor of the element to add neutrons or to take them away, but it doesn't change its fundamental identity, which is determined by the, charged objects, the proton and the electron. So that's really interesting to me. Why is the neutron involved at all in the atomic structure if it's just kind of this, it seems like this neutral fluff particle, just this like dead weight, but is that really true? No, the new John often overlooked, but it does play a vital role in keeping the nucleus together. We're going to dig into it
Starting point is 00:12:00 a bit more on the podcast, but very briefly, think about how the nucleus stays together, right? If you have the nucleus of an atom that has like 25 protons in it, those things are all positively charged. Why don't they just like bust apart? Why don't they repel each other? Because they all have the same positive charge. The answer is that the nucleus is held together by the strong force, which is much more powerful than electromagnetism. And neutrons, even though they are neutral electromagnically, they do involve the strong force. Turns out the nucleus is a bit of a delicate puzzle, keeping those protons from flying apart. You need the neutrons. It's a little bit of a spacer. And so it's easier to make stable nuclei if you include the neutrons. I see. So without the
Starting point is 00:12:44 neutrons, the protons would not be able to stand each other's presence. I know people like that and like in group dynamics that kind of keep the piece. So that's, that is really interesting. So I guess without neutrons, we wouldn't exist. We would not be held together. But it's odd to me though that that neutrons have, it seems like they're fundamentally different from like a proton or an election because they don't have this charge. So, you know, how did that even really happen? Yeah, well, these are deep questions about the universe. Like, why do we have neutrons anyway, right? It's just sort of how the universe coalesces. Remember, we go back to the very early part of the universe where everything is just energy and the universe then expands and cools. And as it cools,
Starting point is 00:13:28 it sort of like crystallizes into lower energy states and sort of like coming. And so, like, come together and form stable particles. And by looking around in the universe and seeing sort of what was made, we can tell sort of like what the options were. We don't know like why it's possible to build neutrons necessarily, but we see that a lot of them sort of emerged from the chaos of the early universe. And that's another really fascinating aspect of these particles is their age. Like protons, we think that protons probably live forever.
Starting point is 00:13:57 Like you make a proton, you can just hang out forever and stick around until the end time. Same with an electron. Electron is stable. You have an electron sitting in empty space. It will just stay an electron for a billion years, maybe a trillion years, a quadrillion years. And what that means is that the protons and electrons inside your body were probably made during the Big Bang. So you are made of ancient multitudes. I mean, you know, thank you for that. Thank you for calling me old. So neutrons weren't necessarily made during the Big Bang. Bing, you're saying? So neutrons were also made during the Big Bang, right? As the universe cooled, we got protons, we got electrons, we got neutrons. But there's a difference between
Starting point is 00:14:41 protons, electrons, electrons, that goes beyond just their electric charge. Neutrons don't seem to last forever the same way that protons and electrons do. In fact, they don't last very long at all. So that makes them fundamentally weird and different. And by studying the details of how long the neutron lives and what it turns into, we might get some clues to these questions. about like, why are there neutrons after all? What's going on inside the neutrons? Are they irrelevant little particles? Or are they the most important clue we have to the nature of the universe? So, yeah, now I'm really curious. Like, what does it mean for a neutron to be alive? And then how does it die? And how long does that process take? And so today on the podcast, we'll be
Starting point is 00:15:25 answering the question. How long does a neutron live? All right, Katie, and you've already called me out, I see, for using the word live in the title, because are neutrons alive after all? And, you know, as a particle physicist, I think about these particles as sort of having a lifetime. But you're right, neutrons are not alive, nor are they dead in any sort of biological sense. I mean, if you corner a biologist and try to get them to answer the question, What is life?
Starting point is 00:15:57 They're going to start sweating and giving you a really complex answer. So it's not a simple question. But no, I get it. So it's like a neutron does not always remain a neutron in the sense that it does not stay the same forever. And so that could be seen as it, you know, essentially decaying or dying, right? Exactly. When we talk about particle lifetimes, we're talking about how long the particle exists before
Starting point is 00:16:22 it turns into something else. So some particles in the universe are stable, like electrons and protons and the quarks that make up those protons. And photons, for example, you can create a photon with a flashlight, shoot it out into space, and it might fly for billions or trillions of years. Some of the photons received by your eyeballs, when you look up at night, have been crawling across the universe for billions of years. It's incredible how long they have survived. So some particles sort of live forever. And again, we're using live in a sort of anthropomorphic biological analogy to life. Really, we just mean exist.
Starting point is 00:16:59 But other particles don't. Other particles are not stable. And the neutron is one of those. That's really interesting. So, yeah, I didn't really think of neutrons as being an impermanent thing. When I think about the building blocks of life, I mean, I picture them as these like little permanent spheres that, you know, make everything and just stay the same. And, you know, that is just this kind of like solid foundation to everything.
Starting point is 00:17:25 But now you're shaking that all up. What if I told you that one of your Legos, a specific kind of Lego, if you didn't use it, it would just like evaporate or turn into other kinds of Legos. That sounds like an excuse a little brother would give when he's stealing all my Legos. All right, but this is not a family therapy podcast, at least not yet. So I was curious if other people had thought about the lifetime of the neutron, if people were aware that neutrons don't live forever and how long they thought it might live. So I went out there to our cadre of internet volunteers who are willing to answer hard physics questions without
Starting point is 00:17:58 any opportunity to prepare themselves. Thank you very much. And if you would like to join this hearty group, then please don't be shy. Write to me to questions at danielanhorpe.com. So think about it for a moment. Do you know how long a neutron lives? Here's what people had to say. I guess my guess would be that it would live indefinitely until some other force overpowers the forces that hold it together. The neutron lives like a free neutron. Shouldn't be that long, but I don't know. Probably not more than a few minutes.
Starting point is 00:18:38 I think that actually this is something that's really confused me as I've started to look into and tried to understand particle physics and quantum physics and everything. And I think that possibly it's just an instant. Yeah, neutrons just like a lot of particles just exist for an instant. On the other hand, it could be they could last for my entire lifetime. So, yeah, it could be a long time as well. Well, neutrons make up part of atomic nuclei. So they live for at least as long as the longest lived,
Starting point is 00:19:17 elements. So at least a few million years, but I think universe scales tend to be quite extreme. So I guess since they don't live for only fractions of a millisecond, I'm going to guess they live for billions of years. I don't know if a neutron lives forever. And I think the answer to that question is we don't know if neutrons live forever. I know that proton decay is still actively being studied and debated. And I don't think a neutron would be much different. And as of now, I believe we do not know how long they live or if they decay away. I know that protons decay into neutrons because they emit a positron. So one can wonder whether neutrons can also emit an electron and, in a sense, decay into protons.
Starting point is 00:20:06 But this process doesn't happen. So while a proton has a lifetime of, I don't know, off the order of a few seconds, A neutron, I know it's a number of years, and I think the amount of time is comparable to the age of the universe, something like that. I really like the answer, probably just an instant or maybe my entire lifetime, because even though that seems funny, like how could you compare an instant to an entire lifetime? How could you be so equivocal? On the universal scale, those are almost the same in a certain way, right? when you look at the entire lifetime of the universe and instant in one human lifetime are not that different. Exactly. And that's the incredible thing about all of these numbers in physics.
Starting point is 00:20:55 When you're talking about how long something lives, it could be some crazy, tiny, tiny number 10 to the minus 20 seconds, or could be cosmic, the scale of the lifetime of the universe, right? Which is like, you know, six tillions of seconds. And so it's hard to know, like on that huge scale, where to put these numbers. And so if you don't have any information, then you're right, his entire lifetime does feel sort of like an instant. And that's one of my favorite things about physics is that it may think about these cosmic sweeps of time and recognize the fact that something that might take our entire lifetime is basically meaningless on the time scale of the universe. Well, way to make me feel both old and small. So in terms of neutrons, like it is interesting.
Starting point is 00:21:39 Like if they live like a human lifetime that makes me feel a little less alone or if they live like an instant that almost makes me feel sorry for them, it's really hard not to anthropomorphize something once we're talking about how long it lasts, as if the neutron particularly cares. But I guess I want to know like what is a neutron? Should I feel sorry for it? Well, I'm not going to tell you how to feel about the particles, but I'm happy to tell you how they're put together and what they mean. And so in the case of a neutron, we've been talking about it as if it was a particle in itself. Like atoms, we said, are made out of protons and neutrons in the nucleus surrounded by electrons. And that's true, but we can also drill one step deeper to understand what is the neutron itself made out of.
Starting point is 00:22:26 Now, in the case of some fundamental particles like the electron, we don't know if they're actually fundamental or made out of even smaller little Lego building blocks. So far, the electron just looks like it's only made out of itself. But that might just be because we haven't zoomed in far enough. We don't have colliders capable of blowing up electrons and seeing what's inside them. In the case of protons and neutrons, we actually have been able to break them up and see what's inside. For about the last 50 years or so, we have had colliders capable of smashing these particles and showing us what they are made out of. And fascinatingly, the proton and the neutron are made out of the same two building blocks, up quarks and down quarks. So there's two funny little particles.
Starting point is 00:23:08 They have weird fractional electric charges, which allows them to get added up to make a neutron or a proton. So for example, a neutron is an up quark, which is charged two thirds, and then two down quarks, each of which are charged minus one third. So a neutron is an up, down, down. It's three of these corks put together and you get zero electric charge. So physicists, when you're asked, what's up quark? Do you just say, not much? What's upcork with you? Or do you have an actual answer to what's an upcork?
Starting point is 00:23:42 And I guess what's a down cork. I don't know. What's up is down. What's down is up sometimes in physics. You know, as I always say, I'm not going to be held responsible for the names of these particles. But, you know, there are some reasons why we call them upcorks and down corks. They are organized together by the weak force into this pair, this up and down pair that get linked together by the W boson, which we're going to talk about in just a minute. But actually in the nucleus, the up quarks and down quarks are not held together by the weak force.
Starting point is 00:24:08 They're held together by the strong force. So quarks have electric charges, but that's not what's holding them together. Like you think about the way molecules are held together. They're held together because of the electric charges. These electrons are like whizzing around and making these ionic bonds or covalent bonds. The electric charges are basically irrelevant once you get inside the proton and the neutron because there's a much more powerful force at play. And that's the strong nuclear force.
Starting point is 00:24:34 which totally overwhelms the electromagnetic force and is able to hold all of these particles together. And the strong nuclear force does that by using gluons. So your mental picture of a neutron shouldn't be like three little Lego pieces that clicked neatly together and that's it. Instead, it's more like three tiny little dots surrounded by a swarm of these gluons
Starting point is 00:24:54 that are holding it together. So it's more like a bag of gluons with three hard dots in it. So, oh my gosh. So gluons, it's just this sort of like swarm of these things that hold together the up quarks and down quarks. So the more we split things apart and try to think about the even smaller thing that holds the smaller things together, it gets really difficult for my brain not to start
Starting point is 00:25:20 hurting. But all right, so do we know like how many gluons are in neutron or is it just kind of this mass of stuff that we know holds together the up corks and down corks, but we can't necessarily quantify how many of these things there are. Yeah, that is a great question because probably you're wanting to put together a model of what's going on inside the neutron that has like a basic recipe and those things click together to make a neutron. The way like pieces of a jigsaw puzzle get clicked together to make a bigger picture, right? But that's not really the way we think about these gluons. Blueons in this case are force particles. They're not matter particles. What that means is
Starting point is 00:25:57 that they don't really exist in the same way that the matter particles do. They exist as a representation of the force between the matter particles. So you have the up quark and the two down quarks. They're sitting there and they're pulling on each other. The strong force is holding them together. How do you think about that force? Well, there's a few different ways of doing it. One is to think about them exchanging particles,
Starting point is 00:26:17 like zooming gluons back together. That's how they hold themselves together. And you can use that same strategy to think about how other particles talk to each other. Like what happens when two electrons push against each other because they have the same electric charge. How does that actually work? microscopically, well, you can think of them as shooting photons towards each other, because photons are the force particle for the electromagnetic force.
Starting point is 00:26:40 So inside the neutron, these quarks are holding onto each other by shooting gluons at each other. That's one way of thinking about how the forces are working inside the neutron. There's another way of thinking about it, which doesn't use this sort of like virtual particles, these gluons sipping back and forth. You just think about fields. Like if you're more comfortable thinking about an electron being surrounded by its electric field and the way that it pushes on other electrons is that its electric field pushes on it, then you can think about the interior of the neutron that same way, as having three quarks, each surrounded by a field from the strong force, and those fields are tugging on each other. Those are gluonic fields. You can
Starting point is 00:27:17 think about them as either like a huge tower or virtual gluons, which appear and disappear very quickly, or you can think about them in terms of fields. They're two equivalent mental pictures for the same fundamental process that's going on. But you can't really like count the number of gluons because they're not particles that exist in the same way as the quarks. So, okay, in my recipe that I'm writing for home-baked neutrons, I'm just going to put down a pinch of gluons. There you go. Exactly. So you said that these are strong, strong forces holding this neutron together. But we were just talking about how maybe these neutrons break apart. So how would they break apart if you have these really strong forces holding them together? Great question. And it reveals something about the way I think a lot of people think about particles and their decay. What happens when a particle decays? Is it breaking apart? Are you taking its pieces and they're reassembling them to build something else, right? Well, what's happening when a neutron decays is not actually that it's breaking apart at all. It's that one piece of its internal structure. One of those quarks changes its nature. So remember that a neutron is up, down, down, right? Two down corks and an up quark. Well, what? happens if one of those down corks changes its flavor and becomes an upcork, then you have two
Starting point is 00:28:37 upcorks and a down instead of two down corks and an up. Now remember that upcorks are charge plus two thirds and a down cork is charge minus one third. So now you have plus two third, plus two third, minus one third gives you a charge of plus one. That's a proton. So what happens when a neutron decays is that one of its down corks converts into an upcork and the neutron becomes a proton. So it doesn't break apart. It flips from being a neutron to being a proton. That's amazing.
Starting point is 00:29:07 So it's less of a death of a particle and more of a transformation of a particle. Do we have any idea of why a down quark would become a up quark? Yeah, like, you know, why does a down quark decide? It wants to be an up quirk one day. You know, like, why isn't it just happy being an upcork? It's a great question, and it's a really deep question. is like, why does any particle decay?
Starting point is 00:29:31 You know, why do muons just hang out and be muons? Why do they decay to electrons and a couple of neutrinos? Why does anything decay? And the reason is that the universe is constantly getting colder and spreading out. Entropy and statistical mechanics tells us that the universe doesn't like to have energy localized in a little spot. It likes for it to spread out. Sort of fascinating and quantum mechanical.
Starting point is 00:29:53 The universe likes to occupy multiple quantum states instead of like being focused on a single quantum state. What that means essentially is that any particle will always decay into a lower mass particle. If it's possible for you to take a step down the mass ladder to break up into smaller particles with less mass, then you always will. The universe is constant pressure. It's the same as if you have like a hot object sitting on a surface, it's going to spread its energy out to the neighboring stuff. The same way you have a very high mass particle. It wants to break up into lower mass particles. And it turns out that the neutron is heavier than the proton just by a little bit. And so the neutron can do this.
Starting point is 00:30:35 It can take a step down into a lower energy configuration. So the neutron is a higher energy state, which means it has a little bit more mass and it decays down into a proton. It does this by flipping one of the down quarks into an upcork. So with my freshly baked neutron, it's kind of like a hot souffle. And then if I leave that out, it's going to cool down and and collapse into a proton. I got it. Oh, speaking of souffle, I did leave one out, so we're going to need to take a quick break
Starting point is 00:31:03 while I go check on that. I'm sure it's fine. And then we hopefully will come back and I'll still have my neutron souffle intact and we'll continue talking about how long do these neutrons live? How do I resuscitate my neutron suflay? So we'll be right back.
Starting point is 00:31:25 December 29th, 1975, LaGuardia Airport. The holiday rush, parents hauling luggage, kids gripping their new Christmas toys. Then, at 6.33 p.m., everything changed. There's been a bombing at the TWA terminal. Apparently, the explosion actually impelled metal, glass. The injured were being loaded into ambulances, just a chaotic. chaotic scene. In its wake, a new kind of enemy emerged, and it was here to stay.
Starting point is 00:32:01 Terrorism. Law and Order Criminal Justice System is back. In season two, we're turning our focus to a threat that hides in plain sight. That's harder to predict and even harder to stop. Listen to the new season of Law and Order Criminal Justice System 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 exploring human potential.
Starting point is 00:32:36 I was going to schools to try to teach kids these skills, and I get eye rolling from teachers or I get students who would be like, it's easier to punch someone in the face. When you think about emotion regulation, like you're not going to choose an adaptive strategy, which is more effortful to use unless you think there's a good outcome. as a result of it if it's going to be beneficial to you because it's easy to say like like go you go blank yourself right it's easy it's easy to just drink the extra beer it's easy to ignore to suppress seeing a colleague who's bothering you and just like walk the other way avoidance is easier ignoring is easier denial is easier drinking is easier yelling screaming is easy
Starting point is 00:33:15 complex problem solving meditating you know takes effort listen to the psychology podcast on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts. Hello, Puzzlers. Let's start with a quick puzzle. The answer is Ken Jennings' appearance on The Puzzler with A.J. Jacobs. The question is, what is the most entertaining listening experience in podcast land? Jeopardy Truthers, who say that you were given all the answers, believe in... I guess they would be Kenspiracy theory. That's right. Are there Jeopardy Truthers? Are there people who say that
Starting point is 00:33:57 it was rigged? Yeah, ever since I was first on, people are like, they gave you the answers, right? And then there's the other ones which are like. They gave you the answers, and you still blew it. Don't miss Jeopardy legend Ken Jennings on our special game show week of the Puzzler podcast. The Puzzler
Starting point is 00:34:15 is the best place to get your daily word puzzle fix. Listen on the IHeart radio app, Apple Podcast or wherever you get your podcasts. I'm Simone Boyce, host of the Brightside podcast, and on this week's episode, I'm talking to Olympian, World Cup champion, and podcast host, Ashlyn Harris.
Starting point is 00:34:39 My worth is not wrapped up in how many things I've won, because what I came to realize is I valued winning so much that once it was over, I got the blues, and I was like, this is it. For me, it's the pursuit of greatness. It's the journey. It's the people. It's the failures. It's the heartache.
Starting point is 00:35:01 Listen to The Bright Side on the IHeartRadio app, Apple Podcasts, or wherever you get your podcasts. Okay, so bad news is that my souffle did collapse. The good news is, I guess it's now a proton, so all isn't lost. That's always the backup plan for your neutron souffle. Turns out, charge it up to a proton suflay. Like, you know, a souffle that collapses is still going to taste pretty good. So a neutron that decays into a proton is still a particle. It'll still build things like delicious soufflays.
Starting point is 00:35:46 Exactly. And so we were talking about how neutrons decay and how they turn into proteins. And people might be wondering, like, what's going on with the electric charges? Like, can you just turn a down quark, which is charge minus a third into an upcork, which is charge plus two thirds? Like, charge doesn't just come for fruit. You can't just, like, create charge. How do you just convert a neutron into a plus one charged proton, right?
Starting point is 00:36:12 The answer is that the universe does do the accounting quite carefully. And when a downcork converts into an upcork, it also emits a W particle. Okay, now you're just making up particles. What's a W particle? So a W particle is the force particle for the weak nuclear force. We got all these different forces. We have electromagnetism. We have the strong force. We have the weak force. Each one we think of as carried by a particle. So photons carry the electromagnetic force. Glouons carry the strong force. W particles carry the weak nuclear force. The weak nuclear force is like the weirdest, strangest, most amazing force there is.
Starting point is 00:36:52 It's not very powerful, but it can do all sorts of really strange stuff. And we have a couple of podcast episodes dedicated just to understanding the weak force and parity violation and all that crazy stuff. But in this case, the weak force is here to help balance the books. When a downcork becomes an upcork that sort of costs one electric charge, you've gone from a neutron to a proton. So to balance the books, you also need to create something with negative charge. And the amazing thing about these W particles is that they do have charge.
Starting point is 00:37:21 So the W can have a positive or a negative charge. In this case, you emit a W minus, which balances the charges. So you've gone from a neutron to a proton and a W minus. So the proton is plus one. The W minus is minus is minus. That all adds up to zero. The W minus itself doesn't live for very long, and it turns into an electron and an antineutrino. Okay.
Starting point is 00:37:43 So an electron does have a negative charge. So it still retains that negative charge. What is an anti-neutrino? Yeah, an anti-neutrino is one of these little ghostly particles. So you and I are made of protons and neutrons and electrons, which are made of up-corks and down-corks. But there's this other particle, this neutrino, which exists in the universe and can be made. And the sun is pumping out like bigillions of them every second.
Starting point is 00:38:08 But they're very strange little particles because they don't appear normally inside matter. Like, I am not made out of neutrinos. and you are not made out of neutrinos in any way, but it's something that the universe can exist. It's like a Lego building block that's never used in making anything bigger or larger. It's just sort of like floating around in the universe. Yeah, I remember those Lego blocks.
Starting point is 00:38:28 They're usually like these like weirdly shaped, clear little ones. And they would just kind of not be used in anything, get quickly lost or eaten. Exactly. And neutrinos are strange because they're very, very low mass. They're almost massless, but not entirely. And they also hardly interact. They don't have any electric charge.
Starting point is 00:38:47 They don't have the strong force. So they basically just fly through everything. So a neutrino, when it's produced, can fly through like a star without blinking an eye. To a neutrino, the whole universe is transparent. And so that just sort of like flies out. And so to summarize then when a neutron decays, it turns into a proton, an electron, and then an anti-neutrino. And so that's what happens when a neutron decays.
Starting point is 00:39:09 That's spooky. So a neutron does kind of create a ghost when it decays. scientifically speaking exactly and we should also be clear about what we mean about neutron decay because people might be wondering like does that mean that the neutrons that are in my body right now
Starting point is 00:39:26 are going to like break up like they don't last for long like am I dying because my neutrons are decaying yeah I want to know if I will spontaneously turn into a pile of protons electrons and ghost particles in my best interest to know and that's one of the really fascinating mysteries about neutron decay is that neutrons do decay but only sort of like when they're on their own floating out in the universe when a neutron is inside a nucleus when it's hanging out with other protons when it and its proton brethren have built something larger then it can last forever you know you have a stable nucleus like iron right iron can live forever we think if you have an iron atom sitting alone in the universe it's made of protons and neutrons and electrons it can sit there we think forever we think it's stable If it's not perturbed, it will just hang out until the end of time.
Starting point is 00:40:16 That includes the neutrons inside the iron, right? They're there, they're neutrons. They will hang out forever. Their down quarks are not going to flip into upcorks, turning them into protons. This is like the ultimate Ziploc bag technique. So keeping neutrons fresh forever. I love that technology for my strawberries. They're so good, but they go bad so fast.
Starting point is 00:40:40 Exactly. So the neutrons in your body are in. atoms and so they are likely to last as long as those atoms last but if you take a neutron out of the atom and you have it by itself hanging out in free space now we can talk about the lifetime of that neutron what does it do when it's left alone well a neutron sitting there in empty space last till the end of time or will it decay so if you put like a proton and then a neutron an electron you have them just hanging out in free space and you just wait the proton will last forever we think the electron will last forever we
Starting point is 00:41:10 think, but the neutron will not. The neutron by itself will decay. One of those down quarks will flip, that's the actual sound it makes, and it'll turn into a proton, electron, and an antineutrino. So when we talk about the neutron lifetime, we're talking about the isolated neutron, not a neutron that's inside the nucleus. So when it's inside the nucleus, what is that Ziploc effect that is keeping it from decaying? Yeah, it's a great question. And there's a lot of mysteries there because we don't really understand very well how the strong force works. We talked about it briefly a little earlier, but when protons and neutrons are locked together inside a nucleus,
Starting point is 00:41:46 it's not like you just have these particles and they're stuck together like Legos. They're also talking to each other because remember a proton and a neutron, they're not just linked together quarks. They're little bags of gluons. When you get a proton or neutron close enough together, then their gluons talk to each other. Those bags leak a little bit. they're not totally separate from each other and really they sort of like weave themselves into a
Starting point is 00:42:10 larger mosaic you might wonder inside a heavy hydrogen atom where you have not just a proton but a proton and a neutron what's making the proton and neutron stick to each other right the proton is positively charged the neutron is negatively charged why do they stick together at all why don't they just float apart the answer is their gluons you get them that close together then the gluons inside each other's bags talk to each other and they click together into sort of a larger object, which is not really any more just an isolated proton, not really any more isolated neutron, but this combined object that has these linkages together. So is that why when you keep adding neutrons to an atom that it becomes maybe less stable
Starting point is 00:42:53 because you start to weaken those gluon forces? Yeah, you can make it less stable or more stable, right? The way that you organize the protons and the neutrons inside the nucleus totally determined whether something is stable or not. We have a fun podcast episode about the islands of stability and how heavy you can make something and keep it stable. We don't know the answer to that because the strong force is very difficult to do calculations with.
Starting point is 00:43:17 Like we can't sit down with pencil and paper and solve the quantum mechanics of the nucleus the way we can with the hydrogen atom. Folks who have done physics in college have done like the Schrodinger equation for the hydrogen atom. When we know those equations, we can solve them. We can find the states of the electron. We don't know how to do those calculations for the strong force because it's much more powerful and much more sensitive to tiny details.
Starting point is 00:43:40 So we don't actually know like the answer to those. We can't do it with pencil and paper. We have massive computers trying to do those calculations, but it's really challenging. So mostly it's experimental. We try to like build heavier stuff and see if we can keep it together. People shoot like neutrons at atoms and see like, ooh, can I get one to stick in there and make something which lasts longer? So it's a whole area of research, how to weave protons and neutrons. neutrons together into stable objects.
Starting point is 00:44:06 We think that they organize themselves in terms of these shells, this nuclear shell model that tells you how to build protons and neutrons together into a stable nucleus, sort of analogous to the way electrons organize themselves in shells on the outside of the atom. It's really fascinating. So I am feeling more and more like a physicist based on my childhood because I would try to just build the biggest thing out of Legos and then kind of hold it up and see if it could sustain itself or if it would fall apart. and it sounds like that's what you guys are doing
Starting point is 00:44:35 just with more expensive equipment. But yeah, so that is interesting. You are saying that maybe they arrange themselves into shells. When you're talking about shells, I'm assuming this is not like a mollusk shell or something. So what is a shell in terms of particle physics? Yes, when we talk about shells, we think of like spheres and other arrangements. We think that the protons and neutrons inside the nucleus
Starting point is 00:45:00 have somehow found stable ways to organize themselves. into these little mosaics. Instead of thinking about them really as protons and neutrons anymore, you really should think about them as components of this fabric, this nuclear fabric, which likes to weave itself together. The incredible thing is that it's stable. Like in many configurations, even for very, very heavy elements, these things are quite stable.
Starting point is 00:45:22 Again, we don't really understand it. And so there's two different communities of physicists here, the ones that like to make really big blobs of protons and neutrons and understand like how are they working together. And then there's the folks who just want to like dig inside one neutron and say, well, let's just study the neutron by itself. Let's zoom inside the neutron and see if we can understand what makes that quirk flip from one to the other. How often does that happen? How long does it take and what does that mean about the neutron? So you've got like the nuclear physicist who's studying like
Starting point is 00:45:51 huge blobs of neutrons and protons inside the nucleus. And they have us particle physicists looking to break it apart and see what's inside. That's really interesting. So now that we have isolated the neutron. We've broken apart that atom. It's outside. It's vulnerable. Now what happens? So now we can see how long it takes to pop into a proton and electron and a neutrino. And so this is a really interesting question. Just like, how long does it take? Remember, protons will live for trillions of years. There's two amazing things about the neutron lifetime. How long a neutron will survive on its own. First is that it's very short. It's like 15 minutes. A neutron does not last very long. The person who said it's basically instantaneous on a cosmic time scale,
Starting point is 00:46:36 that's right. You know, neutrons last like 15 minutes. It's nothing, you know, cosmically. You make a neutron, you leave it there, you go to get a coffee and you come back, it's gone, you know? That's kind of sad to me. I don't know why. Again, I'm like attributing emotions to these things in the universe that, as far as I know, don't feel emotions, but it seems very disconcerting that something as fundamental as a neutron lasts about as long as it takes for my soup to cool down. Yeah. So if you want to build something out of neutrons and you make yourself a big pile of neutrons, you better get to work. No time for a coffee break before you get started. Like you're going to use them or lose them. The other fascinating thing about the neutron lifetime is we don't actually know what it is.
Starting point is 00:47:22 We've tried to measure it. And we have two very different ways of measuring the neutron lifetime, like two very different experimental setups. And they get different. results. Like one group put a bunch of them in a bottle and wait to see how many they have like 10 minutes later and they get an answer of like 14 minutes and 39 seconds. And other folks use a beam of neutrons and count how many protons come out and they get a different answer. They get 14 minutes and 48 seconds. So there's like a 9 second difference. So we don't even actually know. Well, I see what the problem is. Probably one group is using one Mississippi's and the other group is using one potato two potato.
Starting point is 00:48:03 You have solved this mystery. It has befuddled physicists for decades, and today you have figured it out, Katie. Wow, thank you so much. Your contributions to particle physics. So you're welcome, everyone, for me solving this physics problem. When we get back, I'm sure Daniel will make some kind of argument that, no, it's not as simple as one Mississippi or one potato. But, you know, I'll let them have a short break to work that one out because I think my
Starting point is 00:48:30 argument is pretty airtight. December 29th, 1975, LaGuardia Airport. The holiday rush, parents hauling luggage, kids gripping their new Christmas toys. Then, at 6.33 p.m., everything changed. There's been a bombing at the TWA terminal. Apparently, the explosion actually impelled metal glass.
Starting point is 00:49:04 The injured were being loaded into ambulances, just a chaotic, chaotic scene. In its wake, a new kind of enemy emerged, and it was here to stay. Terrorism. Law and order, criminal justice system is back. In season two, we're turning our focus to a threat that hides in plain sight. That's harder to predict and even harder to stop. Listen to the new season of Law and Order Criminal Justice System on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. I'm Dr. Scott Barry Kaufman, host of the psychology podcast.
Starting point is 00:49:46 Here's a clip from an upcoming conversation about exploring human potential. I was going to schools to try to teach kids these skills, and I get eye rolling from teachers or I get students who would be like, It's easier to punch someone in the face. When you think about emotion regulation, like you're not going to choose an adaptive strategy which is more effortful to use unless you think there's a good outcome as a result of it if it's going to be beneficial to you.
Starting point is 00:50:11 Because it's easy to say like, go you, go blank yourself, right? It's easy. It's easy to just drink the extra beer. It's easy to ignore, to suppress, seeing a colleague who's bothering you and just like walk the other way. Avoidance is easier.
Starting point is 00:50:23 Ignoring is easier. Denials is easier. drinking is easier, yelling, screaming is easy. Complex problem solving, meditating, you know, takes effort. Listen to the psychology podcast on the IHeartRadio app, Apple Podcasts, or wherever you get your podcasts. If a baby is giggling in the back seat, they're probably happy. If a baby is crying in the back seat, they're probably hungry. But if a baby is sleeping in the back seat, will you remember they're even there?
Starting point is 00:50:54 When you're distracted, stressed, or not usually the one who drives them, the chances of forgetting them in the back seat are much higher. It can happen to anyone. Parked cars get hot fast and can be deadly. So get in the habit of checking the back seat when you leave. A message from NHTSA and the Ad Council. Have you ever wished for a change but weren't sure how to make it? Maybe you felt stuck in a job, a place, or even a relationship.
Starting point is 00:51:19 I'm Emily Tish Sussman, and on she pivots, I dive into the inspiring pivots of women who have taken big, leaps in their lives and careers. I'm Gretchen Whitmer, Jody Sweeten, Monica Penn, Elaine Welteroff. I'm Jessica Voss. And that's when I was like, I got to go. I don't know how, but that kicked off the pivot of how to make the transition. Learn how to get comfortable pivoting because your life is going to be full of them. Every episode gets real about the why behind these changes and gives you the inspiration and maybe the push to make your next pivot. Listen to these women and more on she pivots now on the IHeartRadio app, Apple Podcasts, or wherever you get your podcasts.
Starting point is 00:51:56 Okay, and so we're back and we've got this two teams of, I would assume, very smart, very professional scientists, but they're coming to slightly different answers on how long it takes for a neutron to decay. One group 14 minutes 39 seconds. The other group 14 minutes and 48 seconds. So what the heck is going wrong? Is one group just wrong? We don't know. It's really fascinating to have watched this series of experiments over a couple of decades. You know, whenever you do something in physics, you try to do it a couple of ways because it's easy to make mistakes. You're doing something hard. You're making assumptions. You're doing the best you can. But it's very easy for mistakes to creep in. And so it's great practice to have two different groups of people doing it two different ways, making different mistakes.
Starting point is 00:52:54 In the end, we're supposed to be measuring the same thing about the universe. The neutrons should just have a certain lifetime and we should be able to measure it and get the same answer. And if we don't, that means that one of our assumptions is wrong where somebody's making a mistake or there's something deeper going on, right? Something is happening in one of these experiments that we don't understand, which could be like a clue as to how the universe works. So originally these two groups made these measurements, and they didn't get the same answer, but nobody was worried because their error bars were pretty large. You know, the difference was like eight or nine seconds, but the uncertainty was like 30 seconds. So people thought, oh, we'll just keep working and maybe the numbers will creep together as they get more precise. The opposite has happened.
Starting point is 00:53:33 Both groups have been working hard to reduce those uncertainties, you know, figure out the sources of error and potential bias in their experiments, shaving them off, calibrating them, cross-checking them. And as the uncertainties have decreased and now those uncertainties are like less than a second or two, the size of the difference between the two experiments has stayed the same. In fact, it's even crept up a little bit from like eight to almost 10 seconds. Hmm. Okay. So we have team bottle, I'm going to say, and then team beam. So what are these teams doing?
Starting point is 00:54:04 Because they have very different methods going on here, which that may somewhat explain why they're getting different results. So first let's go over like team bottle. What is team bottle doing? Just, you know, shaking up some neutrons in a bottle, seeing what happens to them. That's basically it. Yeah, they have a neutron source. This is actually at Los Alamos, New Mexico, where I grew up. I obviously wasn't involved in this experiment.
Starting point is 00:54:26 It's a huge facility there. As far as you know, anyways, go on. I may have been unwittingly roped into this experiment. No, they have a bunch of neutrons there, and basically they put them in a bottle. They get them ultra cold, so they're not moving very fast. And neutrons are a bit hard to store because. they don't have electric charge. So you can't like use magnetic fields or electric fields to control them. You have to use gravity. You get them cold so they slow down and let them just like fall into this
Starting point is 00:54:52 container. They call it the bathtub. And basically they just collect a bunch of neutrons. They very carefully count how many neutrons they start with. And then they measure the number of neutrons in their bottle. And then they come back 10 minutes later and measure it again. And they come back 10 minutes later and they measure it again. And that's the essence of the experiment. It's like if you think something doesn't last very long, put a bunch of them in a bottle, count how many you have. come back later and count them again. So it's a very simple experiment in that way. So you've got this ice cold bottle of delicious neutrons.
Starting point is 00:55:21 Man, that makes me thirsty. And so they would measure these and they would find that they are sort of disappearing at a certain rate. And that is how they got at 14 minutes and 39 seconds. Exactly. An important thing to understand is that the neutron lifetime doesn't mean that every neutron has a clock in it and it expires exactly after 14 minutes and 39 seconds. It's an exponential decay. Every neutron has a probability to decay at any moment.
Starting point is 00:55:47 And if some fraction of your neutrons will decay and a shorter time and a fraction of the neutrons will last longer, just like radioactive decay, it's the same fundamental process. In fact, it is that process, protons turning into neutrons, which drives also radioactive decay. So you don't like watch one neutron, just ask how long did it live? You have a whole population of neutrons and you count how many you have over time and you fit that to a function in exponential decay. and you measure sort of the parameter, the slope of that function. So it's a bit more than just watching one neutron decay.
Starting point is 00:56:17 That's why you have a population of them. So they have these in a little bathtub, and then every once in a while they try to count all of them. They push them against this counter, which is covered in boron and zinc, and that makes the neutrons give off a little flash of light, and they count how many flashes of light they saw, and that tells them how many neutrons they have left.
Starting point is 00:56:34 I see. So these two experiments would be like two groups of alien scientists measuring the average lifespan of a human. Like, sure, our lifespans are going to differ, but they're not going to differ by, like, hundreds of years. They're going to differ by a matter of a few years. And so you should, in theory, even if these two alien scientist groups
Starting point is 00:56:55 have different methods of measuring our lifespan, they should, in theory, be able to both come up with the same average lifespan. But in this case, they're not. So then what is Team Beam doing? The Team Beam is taking the opposite approach, Whereas Team Bottle is saying, let's count how many neutrons we still have left. Team Beam is asking how many neutrons disappear.
Starting point is 00:57:15 So they have a beam of neutrons that they create and they count how many protons are created within these beams because remember, a neutron decays and it decays into a proton. So to count how many neutrons have disappeared, they count how many protons are created. And so instead of counting how many neutrons they still have, like the bottle guys are doing, they're counting how many neutrons have left the room. So in the analogy you were talking about with human lifetime, instead of counting how many humans do we still have left, they're counting graves. I see. I mean, it makes me wonder, and again, this is probably, you know, me strolling in without having done the rigorous testing that Team Beam has done.
Starting point is 00:57:55 But like, could there be like some infiltration of protons, like protons coming from some other source that is messing with their results? Absolutely. That's the kind of thing that they've been thinking about for like the last 20 years. years. So you're right, it's something to be worried about. But they're very careful. They shield their experiments that magnetic fields to prevent anything from creeping in and they filter these protons out using magnetic fields and are very careful to only count the protons that they think come from their beam. So each experiment has like a long list of ways that they can get it wrong. And over the last 10 years, they've been like going down that list and thinking, how can we check this? How do we really
Starting point is 00:58:32 know this is true? Can we do this another way just to verify, just like as a sanity check? maybe there's something going wrong here. And they've gone down that list. And nobody's found any basic mistakes. And as a result, they've been able to shave down their uncertainty because now they have like multiple ways of doing every step of their experiment to convince themselves that their number is correct. So we still have team bottle and team beam doing very careful work.
Starting point is 00:58:56 Nobody has an idea for what might be different where the mistake could be, but they're still getting different answers. Well, so bringing it back to the aliens observing Earth analogy, I mean, I wonder if maybe there could, like, these teams could be doing everything perfectly and executing the experiments perfectly, still getting the different results, but not because they made an error, but because there's something else going on. So, for instance, maybe if the team Alien 1 is just counting the number of humans left after a certain amount of time and getting the lifespan average from that,
Starting point is 00:59:31 they may not be taking into account like new births or something. And then for Team Alien just measuring the graves, you know, what if you have a grave that has like more than one person in it? So could there be something going on where these, you know, let's not blame the groups of scientists or the intern or the janitor, nobody's doing anything wrong. But they are actually correct. But just because their method of measurement is different,
Starting point is 01:00:00 there is some mysterious mechanism going on that is creating that difference. Yes, absolutely. That is sort of the hope, right? The boring answer is like, oh, it turns out the cable wasn't plugged in, right? Or this temperature was set to the wrong number. And like, you know, from a experimental point of view, that would be satisfying to figure it out. But more exciting would be if it reveals that one of the assumptions that are made that suggest these two experiments should be getting the same answer are fundamentally wrong.
Starting point is 01:00:26 So people have been very creative about this. and there is one cool idea floating out there that maybe when the neutron decays, it doesn't always decay into a proton. Maybe sometimes it decays into something else, like dark matter. Some tiny fraction of time the neutron turns into dark matter. And that would explain this difference because remember that the beam folks, they won't see it if the neutron decays into something else. They only count the number of times the neutron decays into a proton
Starting point is 01:00:54 because they assume it always decays into a proton. Now, the bottle folks, they will see that neutron disappear because they're counting the neutrons themselves. So if the neutrons sometimes decay into something which is not a proton, then these two groups will get different numbers. So there's this fun idea out there about how maybe neutrons will sometimes decay into dark matter instead of into protons. That is really cool. I love that when in science, like if you get an unexpected result or something that seems like a mistake, it could actually lead you to an even bigger, even more interesting. discovery. And there's so many times in the history of science when you do that. When people do experiments, they think just like wrapping up everything, tying up the loose ends, we're pretty sure
Starting point is 01:01:35 we understand what we're going to see. And then there's a discrepancy and it's persistent and it won't go away. And sometimes you tug on that thread and it unravels like everything we thought we knew about the universe. You know, the whole discovery of quantum mechanics was from people like, hmm, that's weird. You don't really understand what's going on with the photoelectric effect. So these little discrepancies are very important. They're very powerful ways to test. your assumptions and to maybe get a clue that there's something new going on in the universe. We don't know and the dark matter idea is just sort of like a category of possibilities. The specific theory that was bounced around for a few years about the neutrons decay into
Starting point is 01:02:11 dark matter doesn't look like it works. They made this very specific prediction that it would decay into a new state and then that state would decay into dark matter and along the way it would make a tiny little flash of very specific light. And so the bottle folks looked for this flash of light but they didn't see it. But that doesn't mean that it's wrong. There might be some other explanation in the same vein. The neutrons could be turning into something else.
Starting point is 01:02:32 We don't expect a new kind of dark matter or even something else weirder. So are they looking into new experiments that they could potentially do to sort of find out what's going on here? Exactly. They're trying to develop like a third way to measure the neutron lifetime because that'll give us a handle. It's like a vote, right? We develop a third totally independent way with different assumptions than either the first two. It'll tell us which of those first two is correct. and which one is not actually measuring the neutron lifetime the way we thought it was.
Starting point is 01:02:59 So a third way to measure this is actually in space because one way to make neutrons is to smash protons against the Earth's atmosphere, which happens all the time out there in space because space is filled with high energy cosmic rays protons from the center of the galaxy or from other solar systems, smashing into Earth's atmosphere, creating these showers of particles, including neutrons. Now, most of these neutrons then like rain down on the Earth's surface, and as they do, because they're by themselves, they're not inside atomic nuclei, they turn into protons. So if you can count like the number of neutrons created at the edge of the atmosphere,
Starting point is 01:03:35 with a number of protons you then see raining down, you can get a sense for how many of those neutrons have converted from neutrons into protons, and that's a way to measure the neutron lifetime. It's a bit tricky and it's more complicated, which is why it wasn't like the first option or the second option, but now we need a third option and we need to figure this out. And so people are even talking about like building probes, that can orbit Venus, because Venus might have the perfect atmosphere to do this kind of experiment, because it's got so much CO2 in it.
Starting point is 01:04:03 So it's using a whole planet as a test tube. Exactly. Particle physicists are not content to just do experiments in one tiny little lab. We want to use the whole universe as our experiment. I see. You're just trying to use your research budget for travel. I get it. Exactly.
Starting point is 01:04:22 What's this first class ticket to Venus, Daniel? Now, can you explain this charge? But this is something that's really important, you know, not just because we want to understand what's inside the neutron and how does it work and is the neutron turning into something else. The neutron lifetime is a really important component of our universe. You know, in the early universe, neutrons were made as we talked about. But if they didn't last for long enough, they couldn't get slurped up into atomic nuclei. So the length of the neutron lifetime sort of determines how many isotopes are made, how much helium is made.
Starting point is 01:04:55 And so it's important to get this number right. You know, it determines like the hydrogen to helium ratio that's made during the Big Bang. It also determines like how long stars will live because the more helium you get, the smaller and heavier the stars are that are made, which don't burn as long. So this is like a fundamental ingredient to the early universe calculations. It's something we really need to understand. So even a discrepancy of a few seconds is very important to determine what is causing that and what the answer is to this, right?
Starting point is 01:05:25 And it goes to really deep questions in particle physics about the strong force. You know, this is something that we can't sit down and predict very confidently. It takes massive calculations to try to get a sense for how quarks talk to each other because the forces are so strong and so difficult to calculate with. It's something physicists called non-perturbitive, which means that we can't make many of our typical assumptions and simplifications when we do these calculations. So this is a great laboratory to force the universe to teach us something about how the
Starting point is 01:05:53 strong force actually works to force it to like tell us here's how this happens here's the result of this calculation so it's a really powerful way to try to get some insight how these little particles are talking to each other and in the end i got neutrons and you got neutrons so this should be important to all of us yeah it is interesting it's such a humble particle that you think of this it's like neutral doesn't seem to have such a big role to play but really it's so important to not only to keep us together apparently like i don't want to fall apart and a bunch of protons and W-minuses, and then which turns into ghost particles and electrons. I want to stay me for as long as possible, but also just it seems like it's really important
Starting point is 01:06:33 to understand them to understand the universe. Yeah, and it's an enduring mystery. We're going to stay tuned to figure out what's going on with these neutrons, how long they live, and whether Team Bottle or Team Beam got it right. This is exciting. I want to print shirts, Team Bottle, team beam, and see where the dye lay. Thank you, everybody, for joining us on this journey, the journey inside our atoms and your atoms and the universe's atoms where tiny little clocks determine the fate of neutrons and the fate of stars. And thanks very much, Katie, for joining us on this very particular podcast. Thanks for having me. And good luck with your neutron souffle. Tune in next time, everybody.
Starting point is 01:07:19 Thanks for listening and remember that Daniel and Jorge Explain the Universe is a production of iHeartRadio. For more podcasts from iHeartRadio, visit the iHeartRadio app, Apple Podcasts, or wherever you listen to your favorite shows. Rupino to the show, and we had a blast. Take a listen. Sue and I were, like, riding the lime bikes the other day, and we're like, whee! People ride bikes because it's fun.
Starting point is 01:08:05 We got more incredible guests like Megan in store, plus news of the day and more. So make sure you listen to Good Game with Sarah Spain on the Iheart Radio app, Apple Podcasts, or wherever you get your podcasts. Brought to you by Novartis, founding partner of IHeart Women's Sports Network. If a baby is giggling in the backseat, they're probably. probably happy. If a baby is crying in the back seat, they're probably hungry. But if a baby is sleeping in the back seat, will you remember they're even there? When you're distracted, stressed, or not usually the one who drives them, the chances of forgetting them in the back seat are
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