What can we learn by smashing muons together?

Daniel and Kelly talk about why particle physicists are excited about a muon collider. See omnystudio.com/listener https://omnystudio.com/listener for privacy information.

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Speaker 00

  This is an iHeart Podcast. Guaranteed Human. OnDeck is built to back small businesses like yours. Whether you're buying equipment, expanding your team, or bridging cash flow gaps, OnDeck's loans up to $400,000 make it happen fast. Rated A+ by the Better Business Bureau and earning thousands of five-star TrustPilot reviews, OnDeck delivers funding you can count on. Apply in minutes at ondeck.com. Depending on certain loan attributes, your business loan may be issued by OnDeck or Celtic Bank. OnDeck does not lend in North Dakota. All loans and amounts subject to lender approval.

• 0:33Speaker 01

  If you're a custodial supervisor at a local high school, you know that cleanliness is key and that the best place to get cleaning supplies is from Grainger. Grainger helps you stay fully stocked on the products you trust, from paper towels and disinfectants to floor scrubbers. Plus, you can rely on Grainger for easy reordering, so you never run out of what you need. Call 1-800-GRAINGER, click Grainger.com, or just stop by. Grainger, for the ones who get it done.

• 1:10Daniel Whiteson?

  People have wanted to know the answer to the question, "What is the universe made of?", since we've been asking questions about anything. It seems a reasonable thing to want to know the answer to. What am I made of? What are you made of? What are kittens made of? Lava or stars? Around us, we see an incredible complexity. We want to know if there's a simple explanation for this glorious universe. Does it have some kind of basic bits, a small number of which interact in complex ways so that from their to-ing and fro-ing emerges all of the complexity of chemistry and biology? We've made some good progress on that question, and we now know that you and I and kittens

• 1:54Daniel Whiteson?

  are made of three kinds of particles: up quarks, down quarks, and electrons. And in basically the same proportion, what makes you you and what makes lava lava is not the bits they're made of, but how they're put together. You are your arrangement of particles. And we figured most of that out by doing something pretty simple. Take this stuff around us, usually electrons or protons, and smash it together to study what comes out. And we found all sorts of exotic matter: muons, other quarks, Higgs bosons, stuff that isn't part of the atom. But what if we flipped the script and smashed some of that exotic matter together? What could come out? What might we learn? How could we even do that?

• 2:39Daniel Whiteson?

  We're going to dive into all that today on the episode. Welcome to Daniel and Kelly's extraordinarily smashy universe.

• 3:01Kelly Weinersmith?

  Hello, I'm Kelly Wiener-Smith. I study parasites and space. And while Daniel gets away with smashing particles into each other all day long, I feel like I would get in trouble if I smashed fish into each other all day long. So I feel like maybe there's a double standard here.

• 3:18Daniel Whiteson?

  Kelly, I don't think fish need you to smash. I think they do it all by themselves out there in the ocean.

• 3:22Kelly Weinersmith?

  I mean, they're not super smart, but they're not that dumb, Daniel.

• 3:27Daniel Whiteson?

  Hi, I'm Daniel. I'm a particle physicist and I love smashing particles, but I'll smash just about anything together.

• 3:33Kelly Weinersmith?

  Oh, and you know, I hope this goes without saying, but I don't actually want to smash fish together. I like, I like fish a lot.

• 3:40Kelly Weinersmith?

  So Daniel, today I want to know, what is the most surprising thing about working at CERN?

• 3:47Daniel Whiteson?

  I think one of the most surprising things about working at CERN is the natural beauty of the environment there. You are in this valley surrounded by incredible mountains. You have like the Alps on one side, you have the Jura on the other side, you have the Seine on another side. So it's already gorgeous. And then the valley is mostly filled with vineyards and sunflower fields. So summers I was there, I was biking to work through vineyards and then fields of like millions and millions of sunflowers. It's just really astonishingly incredible setting. And so I love sending students there because of course their minds are blown by the science, but also by the beautiful nature.

• 4:24Kelly Weinersmith?

  And then you go inside and it's physicists wearing socks and sandals and they kind of stink and the juxtaposition is just absolutely overwhelming and surprising. Is that, is that where this was going?

• 4:36Daniel Whiteson?

  No, it's just.

• 4:38Kelly Weinersmith?

  No, Kelly, no.

• 4:39Daniel Whiteson?

  Yes, exactly. No, it's a wonderful surprise. It's a bonus when you go to CERN. You're there for the science. Plus, also, it's in one of the most beautiful places in the world. So yay.

• 4:49Kelly Weinersmith?

  Yay, that does sound amazing. And I love physicists. And my husband wears socks and sandals, so I have learned to live with that.

• 4:57Daniel Whiteson?

  Well, I have a pop quiz question for you, Kelly.

• 4:59Kelly Weinersmith?

  Uh oh, okay.

• 5:00Daniel Whiteson?

  What is your best off-the-cuff pronunciation of the particle we're talking about today?

• 5:05Kelly Weinersmith?

  Uh oh. Uh, muon. Isn't that right? Muon?

• 5:09Daniel Whiteson?

  That's 100% right.

• 5:11Kelly Weinersmith?

  What? Everybody is shocked. Everybody, I could have maybe meow on. I could try to make some cat jokes. But no, I got this one right. You've probably said this particle many times on the show and.

• 5:21Daniel Whiteson?

  I guess so, yeah.

• 5:22Kelly Weinersmith?

  Yeah.

• 5:22Daniel Whiteson?

  Because the most common mispronunciation is muon, like what a cow might say. But it's muon, like the Greek letter mu.

• 5:31Kelly Weinersmith?

  All right, well, so here is getting into my head. When I hear a wrong pronunciation, I start getting really fixated on it because I don't want to say that. And so I will probably say muon at some point in the show now because my brain sabotages me at every corner. So on today's show, we're talking about smashing muons together.

• 5:53Daniel Whiteson?

  Absolutely, we are. We want to understand the nature of the universe and we will do just about anything to get there. From building $10 billion particle colliders in incredible natural settings to inviting aliens to come and tell us the secrets of the universe. We are just desperate to know here on the show. But you might be wondering, why would anybody smash muons together? Don't we have enough other stuff to smash together? So that's today's topic. Before we dive in, I went out there and asked our listeners what they thought we could learn from smashing muons together. Here's what folks had to say.

• 6:29Speaker 04

  And then we could learn what other subatomic particles muons decay into. And that could help us better understand the fundamental building blocks of matter in the universe.

• 6:38Daniel Whiteson?

  Fractions of.

• 6:41Speaker 05

  Particles. Just the importance of spending mutual activity time together and. Oh, wait, you've been smashing them into each other. Well, I'd say that's probably tetrachorax, then. We could unlock much larger energies. We could learn what's inside of them.

• 6:57Speaker 06

  Create a kind of a, some sort of exotic state of matter.

• 7:02Speaker 07

  Are muons something that cows emit? If there were two back to back and they emitted muons and they collided, what a smell. Oh, my.

• 7:14Speaker 08

  We could learn about dark energy.

• 7:17Speaker 09

  Uh, release some massive type of energy. This could be used for possible applications for nuclear fusion, maybe. It could be the best way to make chocolate.

• 7:27Speaker 10

  Why, we could learn the secrets of the universe. And whoa, ha, ha, ha. But seriously, I think it would be interesting to delve into a heavy electron, essentially, and maybe find out if there's something below that, if it's made of something.

• 7:43Speaker 11

  The constituents and why they decay into neutrinos and antineutrinos.

• 7:48Speaker 06

  So smashing muons is a new band that's taking over from smashing pumpkins. So first of all, you spelled moons wrong. And by smashing moons together, you would learn how to become a very bad ass supervillain. So it seems like because muons have greater mass than electrons but the same charge, it should be easier for us to see evidence of gravitational attraction between them.

• 8:15Speaker 12

  We could learn what happens if you smash muons together.

• 8:18Speaker 05

  See what makes up these particles and maybe get a better idea of how the universe is made up.

• 8:24Kelly Weinersmith?

  Amazing answers, and if you would like to be an extraordinary who shares their thoughts with us, go ahead and write us at [email protected] and we'll put you on our question list.

• 8:35Daniel Whiteson?

  That's right, and these are some hilarious answers. I'd love to see the band Smashing Muons perform live.

• 8:42Kelly Weinersmith?

  I like the one that said you spelled moons wrong.

• 8:45Daniel Whiteson?

  Exactly.

• 8:47Daniel Whiteson?

  I would love to build a moon collider. Wow, that would be amazing. We would learn so much.

• 8:52Kelly Weinersmith?

  Yeah, no, Daniel's always willing to risk humanity for, for the sake of learning something about physics. I am not on board.

• 8:59Daniel Whiteson?

  I think the answer about gravity was super interesting because they're right that muons have more mass and it's tempting to think, ooh, does that mean that we could use them to study gravity? But remember, gravity is crazy weak, like 10 to the 30 times weaker than other forces. So even though muons have more mass, you're not going to see their gravitational attraction.

• 9:20Kelly Weinersmith?

  Boo. You all just haven't figured out a way to really address that question, have you?

• 9:27Daniel Whiteson?

  No, I have figured it out. I just haven't gotten the funds for it yet to keep writing proposals for my black hole collider and to keep coming back saying no.

• 9:34Kelly Weinersmith?

  Wow. Good luck. Good luck. I don't think anybody should give you like a species annihilating tool because you might use it, but all right.

• 9:41Daniel Whiteson?

  I will 100% use it. Yes.

• 9:44Kelly Weinersmith?

  Okay. Nobody fun, Daniel. All right.

• 9:48Kelly Weinersmith?

  Let's, let's start by talking a little bit about like how we go about smashing particles together in a controlled way. So like, why do we build particle smashing colliders and how do we build them?

• 10:00Daniel Whiteson?

  Yeah, well, why do we build them? Because they're there.

• 10:03Kelly Weinersmith?

  Come on. Do you know that he died summoning Everest?

• 10:07Daniel Whiteson?

  Oh, boy.

• 10:08Kelly Weinersmith?

  Yeah.

• 10:09Daniel Whiteson?

  Right. Well, I'm willing to die to learn the secrets of the universe. Yes, I will press the big red button on that crazy collider. No, we are not just here to end humanity. We are here to learn the secrets of the universe. And there's a lot of unanswered questions about particle physics that we think building particle smashers can help us answer. So for example, we know that the world around us is made out of protons and neutrons and electrons. Inside those protons and electrons are quarks. So we have the up quark, the down quark, and the electron make up everything we know and love and what you had for lunch today and what you're going to have for lunch tomorrow and the next day and basically forever. But we also know that those three particles can't explain everything

• 10:50Daniel Whiteson?

  that's out there in the universe. But there are other exotic states of matter out there like the Electron has its heavy cousin, the muon, and an even heavier cousin, the tau. The quarks have heavy cousins as well, charm and strange and top and bottom. And then there's three neutrinos. So we have this periodic table of the fundamental particles has these 12 particles and only three of which are needed to make up the matter that we know and love and have for lunch every day. And so we have lots of questions about that table, like, why are there so many particles? Why is there such a big range of masses? What's the relationship between the electron and the quarks? Their electric charges balance very, very nicely to make hydrogen, but nobody really understands why.

• 11:34Daniel Whiteson?

  So there's a lot of unanswered questions about particle physics we'd love to answer. And a particle collider is a great way to do that.

• 11:41Kelly Weinersmith?

  All right, so muons are like electrons right after the like Thanksgiving, Christmas season. What is it that makes muons heavier than electrons?

• 11:53Daniel Whiteson?

  Yeah, great question. So muons are not electrons that got heavier. Electrons and muons are very, very similar, so we categorize them in the same way. Sort of the way you might like group carbon and silicon together. They have a lot of similar properties. They're in the same part of periodic table, but they're not the same. A muon is like an electron in that it has the same electric charge, right? They're both charged minus one and it doesn't feel the strong force. So it's very similar there and it's the same weak force charges. So that's all very similar, but it has more mass. And you ask, why does it have more mass? Well, the Higgs boson gives it more mass. So masses of these particles come from their interactions with the Higgs boson. So the muon interacts with the Higgs more than the electron does and gets more mass.

• 12:37Daniel Whiteson?

  That's kind of an answer to the question because you say, well, why do you have more mass? Because you interact more with the Higgs, but it sort of kicks the question down the road to like, okay, why does the muon interact with the Higgs more? We don't know. That's just a number we've measured in the universe and we don't have any explanation for it. So why is the muon heavier? We don't know. Why is the tau even heavier? We don't know. Why is the top super duper crazy heavy compared to all these particles? We don't know. So these are questions we don't have answers to. We're just like looking at the Pattern of the masses and going, hmm, there's probably something going on here. And in a hundred years, people will look back and be like, it was so obvious, you idiots. Come on, I would have won a Nobel Prize if I was a physicist in 2025. But, you know, science is not linear.

• 13:20Daniel Whiteson?

  It's not just like some path in your video game. When you're standing at the forefront of human ignorance, it's not obvious to know what is the right way forward.

• 13:28Kelly Weinersmith?

  Hmm. So in a previous episode, I remember you telling us that we don't know if electrons are fundamental or not because you all have like tried to break it apart a bunch of different ways and none of them have worked. Do we think they will break apart if you smash them together?

• 13:41Daniel Whiteson?

  We certainly hope so. We don't know. You're right, we have not seen inside the electron. And we don't know if smashing muons together will reveal their inner bits. It's one reason we might want to do that. And it's a deeper question, like what's inside any of these particles, quarks and electrons? We suspect that the answer we have today, these quarks and electrons and other kinds of leptons, is not the final answer, that these things are like the periodic table, that all their properties are emergent phenomena from the rearrangements of like smaller bits that do their thing in different ways. And that's why this looks like an electron. And if you rearrange them or if they are in a different energy state, it looks like a muon. One example of that is string theory. String theory says all of these are just strings vibrating in different ways. It's really just one fundamental thing.

• 14:26Daniel Whiteson?

  And when you zoom out and you see that string behaving in different ways, it looks like different particles. But of course, there's no evidence for string theory or anything inside these particles. But that's an example of what we'd like to know. The point I want to make is that there are burning questions about the nature of matter and energy and space and time. And we hope to answer these. So not just what's inside these particles, but like, why is our universe made of these particles? And not the antimatter version of these particles? The muon has an antimuon, the quarks have anti-quarks. Why are we all made of matter? And most of the universe seems to be made out of matter. Or even more broadly, like most of the universe is not actually made out of matter. It's made out of dark matter and we have no idea what that is.

• 15:08Daniel Whiteson?

  And so these are the unsolved questions in particle physics we'd love to get answers to. And if we could just download them from aliens, that would be great. But colliders are a great way to get answers to these kinds of questions.

• 15:20Kelly Weinersmith?

  Okay, so then let's dig into how colliders work.

• 15:22Daniel Whiteson?

  So you might be wondering like, how does a collider give you an answer to these questions? You smash particles together, how does that tell you about the nature of the universe? Right? Well, the cool thing about colliders is that they can create new particles or reveal what's inside the particles that we already know. So for example, when you smash these particles together at really high energy, you're giving the universe sort of a big budget. You're saying, here's a bunch of energy all in one place. Make whatever you can make. And you know, the time in the universe that we live now is when the universe is very dilute. It's very old and cold. There's not a lot of energy around. It's all very spread out. Back in the early days of the universe, you know, the first few seconds or the first few hundred thousands of years, there was a lot of energy density.

• 16:06Daniel Whiteson?

  And so the universe could do basically everything that it was capable of because there was always enough energy around. It could make top quarks, it can make Higgs bosons, it can make anything that was on its menu. These days, it can only make really low energy stuff like electrons and protons. So what you're doing when you smash particles together is you sort of recreate the early moments of the universe when there was enough energy to do everything, you know, before all of the budget had been spent. And so you smash the particles together and then the universe rolls a quantum die and says, hmm, what can I make with my energy budget? I'm going to pick from the list. And so if you smash those particles together often enough, you'll see everything on the list. That's really amazing that you can like explore what's possible in the universe, what's on

• 16:50Daniel Whiteson?

  the sort of nature's menu of ideas of what the universe is capable of doing. Even if you don't know that it exists in advance and you have no idea how to put it together, you just smash these particles together like a bunch of idiots and eventually the secrets of the universe just like pop out.

• 17:06Kelly Weinersmith?

  All right, well, so I'm, I'm old and cold and low energy, but probably it wouldn't be good to put me in a particle collider, I'm guessing.

• 17:13Daniel Whiteson?

  Have you tried it? I mean, geez, don't be so close minded, Kelly.

• 17:17Kelly Weinersmith?

  I mean, aren't there, so, so my daughter had a tour of CERN and I'm pretty sure that there were like signs everywhere being like, don't get in the collider.

• 17:25Daniel Whiteson?

  And we had a whole episode about that poor Russian guy who leaned into the beam. And it's not a good idea.

• 17:30Kelly Weinersmith?

  Yeah.

• 17:31Daniel Whiteson?

  I mean, I'm saying, don't get collided with a beam of particles, but with a beam of Kelly's, hmm, who knows?

• 17:36Kelly Weinersmith?

  Could be fun, could be fun. Okay, so then how do you actually break open a particle?

• 17:41Daniel Whiteson?

  Yeah, exactly. So one way to discover a new particle is you like smash the particles together and they turn into a blob of energy and boop, some like a Higgs boson pops out or something new or dark matter or whatever, and you flesh out your table. It gives you more context. Another way to make a discovery is to crack open one of the things you already know and say, oh, look, inside the proton, there are three little bits we call quarks, right? And so the way to do that is to exceed the energy of the bonds holding the particle together. So proton is not just like three quarks near each other. It's three quarks tied very tightly together with gluons. It's like really intensely bound together, but those bonds have some finite energy. If your beams, you like shoot an electron at that proton and the electron has more

• 18:25Daniel Whiteson?

  energy than the bonds holding the quarks together than those gluons have, then you're going to break that proton apart and you're going to see those quarks fly out. It's sort of like if you bounce a ball against the wall very gently, what happens? Well, it just bounces back off, right? You haven't put enough energy in to separate the bonds in the wall. But if you build a super fast gun and shoot your ball at the wall, it's going to crack the wall open, right? You're going to see what's inside the wall or behind it. It's the same thing with particles. If you shoot them together with less energy than they have in their bonds, then they're going to act as if they're fundamental because the bonds are going to hold them together. You're not going to see what's inside. But if you can crank the energy up so it's greater than those bonds, then you can shatter those particles and see what's inside.

• 19:10Daniel Whiteson?

  And that's how we saw what was inside the proton. We actually shot an electron at the proton and we saw it bounce off the little dots inside the proton.

• 19:19Kelly Weinersmith?

  So when we shot an electron at the proton and gave it enough energy where we could see it like bouncing off the quarks, did we have a theoretical expectation for when we should be able to find the quarks? And do we have something similar for electrons and muons?

• 19:38Daniel Whiteson?

  Great question. So the context there was exciting because we already had an idea for what was inside the proton. We had all these particles that nobody could explain. It was called the particles zoo. Basically, every time you turned on a collider, you discovered some new particle. There were so many of them. It was a wonderful time to be an experimentalist. But then the theorists sort of organized them and categorized them and said, oh, you know, this would make a lot of sense if all of these were made out of three different bits. They only knew about three different quarks back then. And that would explain all of these particles. And some people were like, yeah, that's cool, but it's just like mathematical chicanery. It's not real. And other people were like, no, no, no, they're real. They're really in there. So they sort of knew to look for them and what they were looking for and roughly the scale of the energy you would need. Today,

• 20:23Daniel Whiteson?

  we do not know what might be inside the electron or the muon or the quarks. If they are strings that you'd need like a solar system sized collider to see them, or maybe even bigger. But there are other theories about what might be inside them, all various different kinds of theories. And so it could be that it's like just around the corner that we're about to crack open the electron, or it could be that like, yeah, we need a solar system sized collider. So we don't have a good guess about when we might see these things.

• 20:50Kelly Weinersmith?

  Interesting. Okay. So it sounds like you all take the same particles and you smash them together over and over and over again. And so it feels like probably you just need to do that for like five minutes and then you analyze your data. But you all have been at it for a really long time. And so why do you keep doing it?

• 21:10Daniel Whiteson?

  That would be amazing. And you know, there are some examples of that, like when they turn on LIGO to see gravitational waves, they expected it to take years to see black hole collisions. And they saw one like the next day. And they were like, what are we fooling ourselves? This is a joke. And we didn't know when we turned on the collider, what we would see, because this is uncharted territory. Nobody had ever collided particles at this energy before. And we could have had like crazy pink elephants jump out, right? But the amazing thing about these colliders is how the universe determines what comes out of each collision. Like, it really is random, because we try our best to create exactly the same collision over and over and over again. And if you have in your minds like

• 21:52Daniel Whiteson?

  balls, like ping pong balls colliding, you know that if you do that over and over again, at exactly the same initial conditions, you'll get exactly the same outputs. You can predict exactly where they're going to go, at what angle and what energy. You can't do that with quantum particles, because quantum mechanics is deterministic in a different way than classical mechanics is. It only determines the probability of various things happening, not the actual events. So every time you collide particles, you draw from a probability distribution and say, well, what are we doing today? All right, we're doing it again. How about this time? And so you get different outcomes every time you collide the particles, which on one hand, might seem frustrating, like hmm, you don't have as much of a handle, you can't predict exactly what's going to happen. But on the other hand, this is exactly what allows you

• 22:34Daniel Whiteson?

  to explore the universe, because you don't have to know what's in that probability distribution. And the thing about that distribution is some things are super duper likely, like two protons come in, two protons come out. That's like 99% of collisions. But very rarely, like once in a trillion collisions, you get a Higgs boson. And we don't know if the tails of those distribution have super duper rare things, like maybe every quadrillion collisions, you get something bizarre and crazy, nobody's ever seen before. So one of the projects right now is to run the collider really fast, like lots of collisions, really long, to look for really, really rare stuff, stuff the universe only occasionally makes if you ask like a zillion times.

• 23:15Kelly Weinersmith?

  So how do you know when to stop then? Like, because at some point, if you haven't gotten a new result in like a decade, and the funders are like, really, we're going to keep paying for this? Like, how do you, like, do you have some way of saying, like, okay, we've done it enough, it's time to move on to something else?

• 23:31Daniel Whiteson?

  You have put your finger on the button right there, Kelly. Yeah, it's diminishing returns. Like, the longer you run your collider, the more you can set statistical limits on what can't be there. Like, if there was something big there that comes up pretty often, we would have seen it already. So we can say that that doesn't exist. But there could always be something weird and more rare than you could have seen that you might be able to capture if you just run longer and longer. But it is diminishing returns. And eventually, the mood shifts and people say, "Well, maybe we should build a bigger collider, higher energy, rather than to keep running the same one longer and longer." Or, maybe people decide, "This isn't worth the money. We're going to go off and do a different kind of science instead."

• 24:11Kelly Weinersmith?

  All right, well, let's take a break. And when we get back, we'll talk a bit more about how we get these particles moving so fast and how these colliders work.

• 24:28Speaker 13

  Cash flow crunch? OnDeck's small business line of credit gives your business immediate access to funds, up to $200,000, right when you need it. Cover seasonal dips, manage payroll, restock inventory, or tackle unexpected expenses without missing a beat. With flexible draws, transparent pricing, and control over repayment, get funded quickly and confidently. Apply today at ondeck.com. Funds could be available as soon as tomorrow. Depending on certain loan attributes, your business loan may be issued by OnDeck or Celtic Bank. OnDeck does not lend in North Dakota. All loans and amounts subject to lender approval.

• 24:59Speaker 14

  I'm Malcolm Gladwell, host of Smart Talks with IBM. I spoke with Dr. Laura Jayhai of Cleveland Clinic about how advanced computing is helping shorten the path from medical discovery to treatment.

• 25:11Speaker 15

  The moment that there is a compound that someone in a lab thinks it would be effective to treat a certain disease, it takes about 10 to 13 years, from that moment to when that drug is on a shelf for a patient. A big part of that gap could be computationally solved. Better simulation of compounds, designing drug trials that are more efficient, that would finish faster. That was the motivation to bring computational tools and technology closer to biomedical researchers.

• 25:46Speaker 14

  Learn more about how Cleveland Clinic and IBM are using AI and quantum computing to revolutionize biomedical research at ibm.com/smarttalks.

• 25:58Speaker 16

  Hey, it's Covino and Rich Davis from Covino and Rich. Buy smart, drive for less and trade for more. That's Toyota affordability and it starts with a great deal on an off-road ready Tacoma or half-ton Tundra, two of Toyota's most capable and longest-lasting trucks. Combining power for work, tech for adventures and style in between. Built on reputation for quality and reliability. Toyota trucks are known for holding their value, which can mean big savings when it's time for your next Toyota. So get a great deal today and great value tomorrow. Shop toyota.com for more. Toyota, let's go places.

• 26:43Kelly Weinersmith?

  All right, we are back and we're talking about how colliders work. We've talked about smashing particles together. I've managed to pronounce muon right almost the entire show. I'm proud of me. You're proud of me. So Daniel, tell us more about how these colliders work.

• 26:59Daniel Whiteson?

  So colliders have a few jobs. To get them up to high speed, what they have to do is push and bend, right? So most of the colliders we're talking about today are circular colliders, which gives you opportunities to like push the particles again and again and again. It's like when your kid is on a swing, right? You don't just give them one big push and then they're swinging. You start off slowly and you give them lots of gentle taps and then eventually they're swinging like crazy. It's the same story with colliders. You have particles that have an electric charge. They're moving in a circle and you have alternating pushes and bends. So you have a little linear accelerator that pushes the particles a little bit faster and then a magnet which bends them back in a circle and then a little pusher and then a bender and then a pusher and then a bender.

• 27:42Daniel Whiteson?

  So the pushers are RF cavities of chambers filled with electromagnetic waves that the particles basically surf and gather some of that energy and come out faster. It's like a fancy version of just having an electric field that accelerates the particle. It's an oscillating electric field that moves with the particle so it can continue to push it the whole way. And you can have like bunches of particles in there. So it's a fancy version of that. And then you bend them so that they keep going in a circle.

• 28:07Kelly Weinersmith?

  First of all, the RF cavities sound awesome. I don't think I had heard of that before. But so if you are trying to work with protons, neutrons, electrons, like they've got all these different charges and you're using magnets to try to make them bend. Does that mean that you're gonna like lose something like neutrons around the corner? Cause they don't respond to the magnets and they smash into the wall? Like, what's the limitation of the magnets?

• 28:29Daniel Whiteson?

  You can't build a circular particle collider of neutrons because you can't accelerate them and you can't bend them.

• 28:34Kelly Weinersmith?

  Okay.

• 28:34Daniel Whiteson?

  So you can only really work with charged particles. You can make a neutron beam if you have something else which decays into neutrons, but you can't like direct it or shape it. It's frustrating to work with neutrons because they're neutral. But we can do it for electrons or we could do it for protons. But you need a different kind of accelerator for protons or for electrons because they're very different masses. Electrons, very, very low mass. Protons, relatively high mass. And so you need an accelerator tuned specifically to the particle. You can't put electrons and protons in the same accelerator.

• 29:07Kelly Weinersmith?

  Got it. Okay.

• 29:08Daniel Whiteson?

  And at the Large Hadron Collider, we use fancy technology to make these magnets as strong as possible. Cause you either need a really big ring, so your bending is gentle, or you need a strong ring with powerful bending and then you need powerful magnets to do that bending. And so the most powerful magnets we use are superconducting magnets. And they use like 96 tons of superfluided helium, which cools it all down to like 2 Kelvin for a very strong magnetic field. It's like seven Tesla. And this is very cool, but it also means, haha, very cool. But it also means that anytime you want to fix it, you have to warm up the magnets. You do it gradually. It takes like weeks and weeks. And then when you repair it and then you gotta cool it down again, it takes weeks and weeks and weeks.

• 29:50Daniel Whiteson?

  So it's awesome to have them be super cool, but it would be really awesome to have room temperature superconducting magnets.

• 29:57Kelly Weinersmith?

  So was that like space constraint? It wasn't possible to build a big enough one where they could slowly be bent and you had to do it a little bit more of a harder bend?

• 30:06Daniel Whiteson?

  Yeah, CERN is already 33 kilometers around. Like, that's a big tunnel.

• 30:10Kelly Weinersmith?

  Yeah.

• 30:10Daniel Whiteson?

  And so, yeah, you could build a bigger one, but then the tunnel becomes crazy expensive. So nobody wants to build a new tunnel. These days, a lot of the conversations about colliders are like, what can we fit inside existing tunnels? Or also, how can we make tunnels cheaper? Right? So lots of people working in different directions. And in most colliders, you actually have two accelerators in the same tunnel. So for example, the Tevatron, we had a proton accelerator going one way and the antiprotons going the other way.

• 30:41Kelly Weinersmith?

  Because you wanted them to run into each other?

• 30:43Daniel Whiteson?

  Yeah, you want them to run into each other. And the Large Hadron Collider, we have protons going one way and protons going the other way at the same time because you want colliding beams. And so the Large Hadron Collider is actually two accelerators in the same tunnel. It's crazy.

• 30:57Kelly Weinersmith?

  So if you send a proton and an antiproton in opposite directions to smash into each other, is that a big explosion? She says hopefully.

• 31:05Daniel Whiteson?

  Yeah, in fact, that's what the Tevatron Collider was. And the SPS before, the Super Proton Signatron that discovered the WZ bosons, they collided protons and antiprotons. And there's a lot of different choices to make here about what particles to use and what particles to collide. There's some pros and cons here. So electrons are really nice to use because electrons appear to be fundamental, right? They don't have stuff inside of them. So you can like accelerate the electron up to a certain energy and you know all that energy is going to go into the collision with the antielectron, right? It's very clean in that way. Also because the electrons don't feel the strong force and so the interaction is limited. You don't get like crazy gluons everywhere.

• 31:48Daniel Whiteson?

  And so collisions with electrons in them are very clean, they're easy to understand. You can control the energy, there's not a lot of messy stuff in there. But because electrons have kind of a low mass, when they go around the corner, they have to radiate a lot of energy. And so electrons moving in an accelerator will radiate a lot of photons, which means that it's hard to get them up to really high energy. So electron colliders are good for precision measurements. You want to like study something you already know is there, create it lots of times in a really clean environment so you can study it in gory detail and measure its properties. Good to use electrons for your collisions. But if you want to explore a new energy range, you want to get to the highest energy you can, then you use protons.

• 32:34Kelly Weinersmith?

  So my brain today is kind of stuck on that conversation we had about whether or not electrons are fundamental. Does the fact that they work so well for these purposes suggest they really are fundamental? And why are we even still looking for a way to break apart the electron? Or it's just for the speeds we're talking about, assuming their fundamental works because we know they're fundamental when you're working with these particular kinds of energies? So even if we're wrong about it being fundamental, we can still go forward with this experiment.

• 33:02Daniel Whiteson?

  Yeah, it's the second one, exactly. We don't know if they're fundamental. They appear to be fundamental at our energy level, and so we can take advantage of that. The fact that they don't crack open, that they're very simple, that the whole electron is interacting with a whole positron. In contrast, protons are much messier because they're not fundamental and we can crack them open. So what happens when you collide two protons? You don't really collide two protons. At those energies, the protons aren't even bound together. The energy, the bonds, is almost zero compared to the energy of the protons. So you're colliding a bag of quarks with another bag of quarks. So the quarks interact with each other, or all the gluons inside the bag interact with each other. And so you can sometimes get like a bunch of different interactions all at the same

• 33:47Daniel Whiteson?

  time. It's kind of a mess. And because they feel the strong force, every time they interact, there are gluons everywhere. It's just like sprays of gluons all over the place. And so the fact that protons are not fundamental is one reason why they're so messy to collide. So you might think, well, why does anybody ever collide protons? Well, protons have a lot more mass than the electron, so when they go around the corner, they don't radiate as much energy, fewer photons. And so you can get protons up to higher mass than you can get electrons. So if you want to explore a new energy range, create stuff that hasn't existed before, protons are the way to go because they cover a big energy range. Like you accelerate protons up to 7,000 gig electron volts, for example. The quarks inside them are interacting at a lower energy because those quarks have

• 34:32Daniel Whiteson?

  a fraction of that proton's energy. So you get interactions at many, many different energies. Whereas with the electrons, you collide them at a certain energy. You know every collision has exactly the same energy because you're putting all that energy into the electron and it goes into the collision. Protons, you have these bags and you know what interacts with what? You can't control that. How much energy they have, you can't control that. It's a big mess, but it's a very, very high energy. And so if there is something new in there, you're probably going to see it.

• 34:59Kelly Weinersmith?

  Okay, so protons and neutrons are made up of up and down quarks, and gluons are the charges that hold those quarks together?

• 35:07Daniel Whiteson?

  Gluons are the particles that carry the strong force, and they are also charged under the strong force. So they're very, very messy. Gluons are to the quarks the way like photons are to electrons.

• 35:19Kelly Weinersmith?

  All right, so protons, high energy, messy. Electrons, low energy, clean.

• 35:24Daniel Whiteson?

  Exactly.

• 35:25Kelly Weinersmith?

  How have, for the, for the particle accelerators that we've made so far, how have we sort of split out our interest in protons and electrons?

• 35:33Daniel Whiteson?

  Yeah, so we've sort of been going back and forth. Some discoveries had been made at electron positron machines, like the discovery of the Jap-si particle was at an E plus E minus machine at SLAC. That's actually a rare example of a discovery at an E plus E minus machine, because they had to know exactly what energy to tune that machine to make that particle, because all the energy goes into the electrons. And if you remember, there's a whole controversy about like how they knew how to tune it. And they discovered exactly how to tune it like one day before their competitors were about to just announce the discovery of the Jap-si. And so there's a big scandal there. Go check out that episode.

• 36:10Kelly Weinersmith?

  So when you say E plus E minus, is that an electron and an anti-electron? Okay, got it.

• 36:16Daniel Whiteson?

  Yeah, exactly. So you smash electrons and anti-electrons together. They annihilate it into like a photon or something, which turns into, in this case, a charm and anti-charm. And that's what the Jap-si particle is.

• 36:27Kelly Weinersmith?

  All right, awesome.

• 36:28Daniel Whiteson?

  So that was at SLAC, and then CERN built the Super Proton Signatron, which collides protons with anti-protons, like antimatter again. We're not just talking about like scooping stuff up from around the earth and smashing it together. You have to make antiparticles, just like they did at SLAC when they used positrons.

• 36:46Kelly Weinersmith?

  That sounds like a lot of work.

• 36:47Daniel Whiteson?

  It is a lot of work, and they use the same strategy for the next accelerator, which is the Tevatron. This is the one outside Chicago where I got my PhD. This collides protons and anti-protons, and it discovered the top quark.

• 36:59Kelly Weinersmith?

  Way to go, Tevatron people. Did you discover the top quark, Daniel, in particular?

• 37:03Daniel Whiteson?

  I did not discover the top quark. That was in 1995, and I was in college. I do remember my particle physics professor announcing the discovery in class one day, and I got kind of chills. I was like, ooh, this feels like a momentous occasion. And it was, because in particle physics, you don't discover stuff very often anymore. It's like every 10 to 20 years. And so like, that was a moment, for sure.

• 37:25Kelly Weinersmith?

  Very cool. And did that make you want to go to grad school?

• 37:28Daniel Whiteson?

  It did. It made me like, ooh, maybe the next one's around the corner. I want to get involved.

• 37:32Kelly Weinersmith?

  Yeah, very cool. Little did you know.

• 37:35Daniel Whiteson?

  Yeah, exactly. And after the Tevatron, they built the Large Electron-Positron Collider at CERN. This one didn't discover any new particles. It was an E plus E minus machine, but it was really good for measuring the W and the Z in the top really, really precisely. And because of those measurements, we were very confident that the Higgs existed. Like, because of the properties of those particles, we could sort of triangulate what the Higgs might be doing, because the Higgs is involved in all those particles. So even though we hadn't seen the Higgs directly, we could sort of like intuit or deduce what the Higgs had to be like from measuring these things really, really precisely. And so it set the stage for the Higgs discovery.

• 38:15Kelly Weinersmith?

  Okay. And then what about the LHC?

• 38:18Daniel Whiteson?

  Yeah. So the Large Hadron Collider, which we're still running, this is protons and protons, so not protons and antiprotons. They made a different choice here. And one reason they did is that they wanted to go for really high rate. It's easier to make high rate collisions of protons and protons, because protons are everywhere. Antiprotons hard, because you got to make them. It's like manufacture antimatter, which requires like starting from a beam of matter and smashing it into this stuff and filtering out the rare antiprotons and then storing them. It's really complicated to make antimatter and smash it together. So they were like, let's just do the easy thing, proton-proton, because protons are everywhere and they're simple and they're stable. And then we can do it really, really high intensity for a long, long time in order to look for really, really

• 39:03Daniel Whiteson?

  rare things. And they discovered the Higgs boson.

• 39:06Kelly Weinersmith?

  Woo!

• 39:06Daniel Whiteson?

  Yeah. And you might be wondering, like, how does a proton interact with another proton? Don't you need matter, antimatter? Well, remember, the whole proton's not interacting with the other proton. You have like a bag of quarks and you have gluons. And so actually, what happens most of the time at the Large Hadron Collider is gluon-gluon collisions. So it's really kind of a gluon collider, which is crazy.

• 39:25Kelly Weinersmith?

  That is crazy. And then there was a particle collider that was partly built in Texas before we gave up on funding it, right? What kind of particle collider was that going to be?

• 39:35Daniel Whiteson?

  Yeah, so the superconducting supercollider, which never happened, unfortunately, that was going to be very similar to Large Hadron Collider. It's going to be proton-proton in the same way. And so it almost certainly would have discovered the Higgs boson. Also, it was going to be like three times more energy than the Large Hadron Collider. So it would have revolutionized particle physics. Like, they would have built it and discovered stuff which today is still out of our reach. Like, 30 years ago, they would have known the answers to questions we still don't know the answer to. Such a shame.

• 40:05Kelly Weinersmith?

  Does the tunnel still exist?

• 40:06Daniel Whiteson?

  The tunnel still exists and is mostly filled with water.

• 40:09Kelly Weinersmith?

  Ah, well, let's, let's start that project again. All right. Well, Daniel, while you and I go look for funding to start that project again, we'll take a break. And when we come back, we'll talk about why we should be smashing muons into each other.

• 40:30Speaker 00

  OnDeck is built to back small businesses like yours. Whether you're buying equipment, expanding your team, or bridging cash flow gaps, OnDeck's loans up to $400,000 make it happen fast. Rated A+ by the Better Business Bureau and earning thousands of five-star TrustPilot reviews, OnDeck delivers funding you can count on. Apply in minutes at ondeck.com. Depending on certain loan attributes, your business loan may be issued by OnDeck or Celtic Bank. OnDeck does not lend in North Dakota. All loans and amounts subject to lender approval.

• 40:59Speaker 14

  Hello, hello. I'm Malcolm Gladwell, host of Smart Talks with IBM. Imagine your business depends on a system you didn't build and don't fully control. For years, it works perfectly. It's fast, reliable, affordable. So over time, more and more of your operations rely on it. Then one day, the terms change. What once felt flexible now feels difficult to leave. Moving to another provider or bringing those capabilities back under your own control could take years, cost millions, and disrupt the business in the process. That's the challenge of digital sovereignty. Businesses today rely on all sorts of third-party

• 41:40Speaker 14

  systems: cloud platforms, data pipelines, AI models, software tools. Most days, these systems operate quietly in the background. But when something changes, like costs go up or rules shift, organizations are forced to confront how much control and flexibility they actually have. So to understand the challenge up close, I traveled to Paris to speak with IBM's Ana Paula Assis and acts as CIO, Giovanni Doniello, two people who think about these questions every day.

• 42:15Speaker 14

  Hear the full conversation at ibm.com/smarttalks or wherever you get your podcasts.

• 42:24Speaker 17

  This is Stugatz from Stugatz and Company Live. Buy smart, drive for less, and trade for more. That's Toyota affordability. And it all starts with a great deal on an all-wheel-drive Camry, Corolla Cross, or a Corolla Sedan with the latest features Entec, or test drive a spacious Grand Highlander or adventure-ready RAV4. And with so many hybrid models available, you can enjoy longer trips without all the stops. While Toyota's legendary resale value means you can get more at trade-in. Get a great deal today and a great value tomorrow. Shop toyota.com for deals and details. Toyota, let's go places.

• 43:13Kelly Weinersmith?

  All right, Daniel and I still have not figured out a way to get funding to resurrect that particle collider in Texas. I thought Texans like to go big, but apparently they don't like to go that big. And now we're talking about muons.

• 43:26Daniel Whiteson?

  So muons are attractive to use for a collider because they might be the best of both worlds. Remember, muons are like more massive electrons. And the only negative thing we had to say about electrons was they were so low in mass that when the way they're around corners, they lost a lot of their energy. So it's hard to get electrons up to high energy. All right, we'll just swap in muons for electrons. Now they have more mass, they can get to higher energies, right? So now they are like very high energy and they're cleaner than protons. Protons are these messy bags of quarks with the strong interaction. So this is like taking something which is massive, like the proton, but clean like the electron.

• 44:03Kelly Weinersmith?

  And would we need muons and antimuons? Or could we just smash muons into each other?

• 44:09Daniel Whiteson?

  You could just smash muons into each other, but you'd learn more if you smashed muons and antimuons into each other. Absolutely. And to make the same kind of discoveries at a muon collider, you don't even need to get the muons up to the same energies as the protons. Remember, protons are bags of three quarks. So you accelerate the protons to like 10 trillion electron volts. Each quark only has like 3 trillion electron volts. And that's what goes into your collision. To make those same discoveries at a muon collider, you only need to bring your muons up to like 3.3 trillion electron volts, not all the way to 10. So it's easier to make these discoveries at a muon collider because it's fundamental, because, or at least we can't tell if it's not fundamental. And so there are real advantages there.

• 44:53Daniel Whiteson?

  The kind of physics you can do at a muon collider is very powerful at lower energies and yet clean like an electron collider.

• 44:59Kelly Weinersmith?

  And so what do we think we would discover that would be different if we used a muon collider than if we had, you know, the pre-existing electron colliders?

• 45:09Daniel Whiteson?

  Yeah, so muon colliders can get to higher energies. Like, we think if you built a muon collider at just 10 trillion electron volts, it could discover the same kind of things that a proton collider at 100 trillion electron volts could discover. So it's like 10 times more efficient in that sense per discovery. Because at 100 ter electron volts, protons are insane bags of gluons. And most of the energy is just in the gluons. And every collision is very inefficient. You're not really getting any fraction of that 100 trillion electron volts. Whereas muons at 10 trillion electron volts, you can really precisely tune those interactions and you can find all sorts of crazy stuff. Plus, there's the added bonus. Remember, we said that muons have more mass. Why? Because they interact with the Higgs more.

• 45:53Daniel Whiteson?

  That means that if you collide muons together, you're going to get more Higgses because muons interact with the Higgses. And when the universe is like making its draw from its random probability distribution, what are we making today? If you start from muons, then the Higgses are a bigger part of that probability distribution than if you start from electrons. Because electrons hardly interact with the Higgs boson because they have such low mass. So in that sense, a muon collider is like a Higgs factory. It'll make tons and tons of Higgs bosons for us to study and learn about.

• 46:23Kelly Weinersmith?

  So the LHC is where we discovered Higgs. What would we learn if we saw more Higgs?

• 46:31Daniel Whiteson?

  Great question. So we found the Higgs, but we don't really know, is this the Higgs that Peter Higgs predicted? Or is it like a weird version of the Higgs? And so the next thing is to like, study in detail, measure its mass, measure its properties. Remember how we measured the top and the W and the Z at the Large Electron Positron Collider? And that set the stage for the discovery of the Higgs, because all those particles' properties really only made sense if the Higgs was there. So what we want to do is study the Higgs in gory detail and see like, well, is it decaying as a dark matter? Is it interacting with something else? Are there two Higgs bosons? These kind of things can be revealed if we study the Higgs in great detail. So far, we haven't seen any hints of that, but you never know what's around the corner.

• 47:15Kelly Weinersmith?

  Are there theoretical predictions that, I guess you've already, you're already not sure you've seen the only version of the Higgs. So there's probably a lot of questions you all have.

• 47:24Daniel Whiteson?

  There are. And there's lots of predictions about models with two Higgs bosons or three Higgs bosons, all sorts of crazy stuff that we're excited to look for. And a muon collider would be a great way to do that. It'd be very powerful in its physics reach.

• 47:38Kelly Weinersmith?

  Cool. Okay, so we've tried to figure out if electrons are fundamental by smashing them together and nothing has come apart. Is there any reason to think that muons being essentially heavy electrons would be more likely to break apart if there was something break apart a bowl about electrons and muons?

• 47:57Daniel Whiteson?

  No, not necessarily. So if they are fundamental, then there's no reason to imagine muons would be easier to break apart than electrons. But the advantage is it's easier to get muons up to higher energies. If there is some threshold above which you can see inside electrons and muons, it's much easier to get muons over that threshold than electrons. So in that sense, we're more likely to discover that muons are made of something else, little bits and bobs, than we are of electrons.

• 48:24Kelly Weinersmith?

  All right. Well, this sounds like a slam dunk. Why wouldn't we do this?

• 48:29Daniel Whiteson?

  Well, one of the real challenges is that muons are not stable. Like you have a pile of electrons, they're going to stay a pile of electrons. The protons that are inside you have been protons since the big bang. Like, these are really stable things. Muons last for 2.2 microseconds. So you can't just like say, hey, I've got a big pile of muons in a drawer. Do you need any, right? You open the drawer, they're gone. 2.2 microseconds, that's, you know, 10 to the minus six seconds. So it's not a lot of time, which means that number one, there aren't muons around. You can't just go like, go dig up muons. Like you want electrons and protons, you just start with hydrogen, which is everywhere. And you separate it and you have protons and electrons. Easy.

• 49:13Daniel Whiteson?

  If you want muons, you have to make them in collisions of other stuff and filter them out. And then they disappear after a millionth of a second. So there's a lot of challenges here. So making them, accelerating and cooling them and colliding them all within microseconds is not an easy thing to do.

• 49:31Kelly Weinersmith?

  And what about antimuons, which you'd probably want for these collisions? Is that harder still?

• 49:36Daniel Whiteson?

  Actually, it turns out those are just as hard. So there's a bonus. Yeah. So where do you get muons? Like, there actually are natural sources of muons because protons are hitting the upper atmosphere all the time. And when protons hit the atmosphere, they create showers of particles, some of which decay into muons. So, you know, muons are passing through you all the time, but not at the rate we need for the Large Hadron Collider. And so what they plan to do there is they're going to make their own muons. They start with protons, which are easy to get. They accelerate those up to reasonable energies, not crazy LHC level energies, and just like smash them into some block of stuff like, you know, carbon or whatever. And out the back comes a bunch of different particles, kaons, pions, whatever. And a lot of these will decay into muons.

• 50:22Daniel Whiteson?

  And so then you use a magnet to filter out the ones that you want because a magnet will bend a charged particle. So you get like muons going one way, antimuons going the other way. And other stuff goes at a different angle because it has a different mass. So now you have your muons and the clock starts ticking. You have a millionth of a second to accelerate these things and smash them together. But fortunately, physics comes to the rescue because if you get them going at really high speed, you can take advantage of special relativity. Remember that moving clocks run slow. So if you have a muon sitting on your table, it lasts for 2.2 millionths of a second. But a muon going at almost the speed of light can last for minutes and minutes.

• 51:00Kelly Weinersmith?

  Wow.

• 51:00Daniel Whiteson?

  Because its clock is running slowly. That's the only reason why muons make it all the way down from the atmosphere to the surface of the earth. They're created in the upper atmosphere and two microseconds is not enough time for them to get here. But their clocks are slowed down because they're relativistic. And so there's enough time for them to get here. In the same way, if we get our muons up to high speed, then we actually have longer to play with them.

• 51:23Kelly Weinersmith?

  Okay, that's awesome. All right, so we've got a chance of making this work. Did I hear you say at the LHC, are they starting to do this at the LHC? Or did I mishear you?

• 51:31Daniel Whiteson?

  I'm not sure what I said. We're not doing this yet. This is like very experimental technology. There's a lot of stuff that has to happen here. You have to make the muons and then you need to do something called muon cooling. Because the muons that are made come out at a spread of energies and directions. And you need a bunch of muons all organized. Like you want a marching band of muons where everything has the same energy in the same direction. You don't want like a mosh pit of muons. And so they do something called muon cooling, which is basically getting them all in line. It means like reducing the phase space that these muons are in, in sort of velocity and location. And to do this, they pass them through a bunch of filters, which tend to reduce the energy of the muons more for the higher energy ones. And so bring them sort of together, coalesce them.

• 52:16Daniel Whiteson?

  This is something still experimental. We're not like experts in muon cooling, but the way we're experts in dealing with protons, for example, because nobody's done this before. So it's sort of like a technology that's being developed. And then you have to accelerate these particles really fast. Protons, you got lots of time. It's like pushing your kid on the swing. You can push very gently all afternoon until they get up there. But with muons, the clock is ticking. So you have to accelerate them like really quickly. Requires different kinds of technologies. So what they actually want to do is separate the rings into an accelerating ring and a separate colliding ring. So you have an accelerating ring where you do like these crazy rapidly changing magnetic fields to accelerate your muons really, really rapidly.

• 52:56Daniel Whiteson?

  And then you move them into a ring where you can collide them together and observe those collisions to see what comes out.

• 53:02Kelly Weinersmith?

  So when you say that they Last 2.2 microseconds, but they last longer because of time dilation. When they disappear, what do they become? So like you said, they're not stable. Do they decay into like electrons that then mess up your experiments and they need to be pulled out? Like, what happens to them?

• 53:20Daniel Whiteson?

  Yeah, that's exactly right. They decay into electrons and then to neutrinos, but neutrinos mostly invisible. But that's actually a problem because now you have like sprays of high-energy electrons filling your detectors, which is bad. And so you have to work on shielding to block all those electrons from your detectors. You want to just see what happens when muons are colliding. You don't want to be buried under like massive sprays of electrons from all of your decaying muons. And so it's complicated. There's a lot of technology here that has not been fully developed. We think we know how to tackle these problems, but some of this is sort of in the like, we have an idea, we think it's going to work, let's try it. There's always surprises around the corner. So the timeline here is like, maybe we're going to get the funding together if we can

• 54:04Daniel Whiteson?

  convince everybody to build a demonstrator, like a mini version in the 2030s. And if that works, then we can ramp it up and start building a massive one, which we hope will turn on in like 2050.

• 54:16Kelly Weinersmith?

  Wow.

• 54:16Daniel Whiteson?

  Yeah.

• 54:17Kelly Weinersmith?

  And so is there like a consortium of scientists then writing up this grant?

• 54:21Daniel Whiteson?

  There is a community of folks, the muon collider community. They're very engaged, they're very active, they're very energetic. I think they have a good case, but there are other people who think, no, let's build another proton-proton machine. Or other people who think, no, we should build a linear accelerator with electrons and positrons, so we don't have to worry about any magnets.

• 54:40Kelly Weinersmith?

  Oh.

• 54:41Daniel Whiteson?

  So the field right now is a little bit split into different camps about what the best thing to do is. It's all very congenial, people disagreeing in good faith, but there's not a whole lot of clear consensus about what the next step is. And it's sort of an unusual moment in particle physics. Usually, we have one collider running and another one we're building, which is why we had this sort of zigzag we talked about before, like the Tevatron and then LEP and then the Large Hadron Collider. But right now, we're operating one and we're not building another collider. China has said, maybe they'll build one, but they don't really know. CERN has said they could build a 100 TeV machine, but we don't know if the money is there. Other people are pushing for this muon collider, and so we don't really know what the future holds for particle physics.

• 55:23Kelly Weinersmith?

  And what is the cost of a project like this? Like if Musk decided he really wanted a particle to be named the Muskon and he decided he was going to build one of each of these particle colliders, like, could he afford to do that? Or are we even exceeding Musk's vast wealth?

• 55:39Daniel Whiteson?

  No, Musk could afford to do that. I mean, I don't know what his liquid assets are, but you know, these are things that cost tens of billions, maybe up to $100 billion. So definitely Musk, who is likely to be the first trillionaire, could afford to build one of these things and insist that it be named after him. In fact, you know, since his name starts with M U, you could imagine some clever play on words there.

• 56:02Kelly Weinersmith?

  Yeah, absolutely. And that would have been a much better-

• 56:04Daniel Whiteson?

  The Muskon Collider.

• 56:05Kelly Weinersmith?

  There you go. That's right. That's right. That would have been a much better purchase than X, I think. But anyway, this is why I am not in the tech industry, nor am I an entrepreneur. I don't know what good investments are.

• 56:16Daniel Whiteson?

  Nor are you a business advisor to billionaires.

• 56:18Kelly Weinersmith?

  That is exactly true. Yeah, I have made lots of suggestions for how he could spend his money in my book and on shows, and he doesn't seem to be listening. But that's okay. All right. Well, this was fascinating. I hope that physicists find ways to have more of all of the different fun colliders that they want to be working with.

• 56:35Daniel Whiteson?

  Yeah, me too. These are really fun toys. The most exciting thing are the potential surprises. You know, these colliders really are ways to explore the universe without going anywhere. If you're excited about like landing a probe on a new planet, because you never know what you're going to find, that is exciting. And it's the same kind of excitement when you turn on a new collider at a new energy. Nobody has collided particles of this energy before. You have no idea what on nature's menu will be revealed. And that is really exciting. So I hope we get to build these things because the only obstacle between us and understanding is money. We are in the candy store of universal knowledge and we have the money in our pocket. And we're just deciding, hey, should we buy those sweets or not?

• 57:18Kelly Weinersmith?

  Or should we cure cancer and give it to the biologist? Uh, who's a better investment? You decide.

• 57:24Daniel Whiteson?

  No, no, it's a false choice. They're all good investments. All of these investments pay for themselves. And so it's not a zero sum game. We should do all of it. Let's cure cancer and build a Mion Collider.

• 57:34Kelly Weinersmith?

  Amen. You're right. Why am I dividing us, Daniel, when we could be brought together instead?

• 57:40Daniel Whiteson?

  All right. Believe in the universe, invest in humanity. Let's go explore it. Thanks, everyone.

• 57:44Kelly Weinersmith?

  Until next time.

• 57:52Kelly Weinersmith?

  Daniel and Kelly's Extraordinary Universe is produced by iHeartRadio. We would love to hear from you.

• 57:58Daniel Whiteson?

  We really would. We want to know what questions you have about this extraordinary universe.

• 58:04Kelly Weinersmith?

  We want to know your thoughts on recent shows, suggestions for future shows. If you contact us, we will get back to you.

• 58:10Daniel Whiteson?

  We really mean it. We answer every message. Email us at [email protected].

• 58:17Kelly Weinersmith?

  Or you can find us on social media. We have accounts on X, Instagram, Blue Sky. And on all of those platforms, you can find us at D and K Universe.

• 58:26Daniel Whiteson?

  Don't be shy. Write to us.

• 58:30Speaker 18

  With ChatGPT, you can do more than get answers. You can get things done. Whether you're leading a big project, planning an elaborate trip, or trying to balance work and life, ChatGPT can help. Give it a goal, plus things like files, notes, or project plans, develop a trip itinerary with daily updates, or create a prioritized schedule. So you can spend less energy sorting out the details and more on bringing your biggest ideas to life. Get started at chatgpt.com.

• 58:58Speaker 19

  This is Jason Timp from Hoops Tonight with Jason Timp. Buy smart, drive for less, and trade for more. That's Toyota affordability. And it starts with a great deal on an off-road-ready Tacoma or half-ton Tundra, two of Toyota's longest-lasting trucks, combining power for work, tech for adventures, and style in between. Built on a reputation for quality and reliability, Toyota trucks are known for holding their value, which can mean big savings when it's time for your next Toyota. So get a great deal today and great value tomorrow. Shop toyota.com for more. Toyota, let's go places.

• 59:29Speaker 13

  Cash flow crunch? OnDeck's small business line of credit gives your business immediate access to funds up to $200,000 right when you need it. Cover seasonal dips, manage payroll, restock inventory, or tackle unexpected expenses without missing a beat. With flexible draws, transparent pricing, and control over repayment, get funded quickly and confidently. Apply today at ondeck.com. Funds could be available as soon as tomorrow. Depending on certain loan attributes, your business loan may be issued by OnDeck or Celtic Bank. OnDeck does not lend in North Dakota. All loans and amounts subject to lender approval. This is an iHeart Podcast. Guaranteed Human.