WEBVTT - Do protons live forever? 0:00:08.440 --> 0:00:12.639 Hey, Daniel, I'm worried about how long I'm going to live? Man, 0:00:12.840 --> 0:00:15.880 aren't we all these days? I know, but I mean 0:00:15.920 --> 0:00:18.200 like down to the particle level, Like, are my who 0:00:18.600 --> 0:00:21.959 electrons going to be around forever? Well, we actually have 0:00:22.040 --> 0:00:25.720 good news there. We do think that electrons can live forever. 0:00:25.880 --> 0:00:29.400 All right, that's cool. What about my protons? I got 0:00:29.440 --> 0:00:33.440 some tough news there. Didn't last very long. Currently we 0:00:33.479 --> 0:00:37.720 think protons live for only a trillion trillion trillion years. 0:00:37.920 --> 0:00:41.200 I don't. Well, that's good. I guess even my protons 0:00:41.240 --> 0:01:00.639 are procrastinators. They are professional protonic procrastinators. I am more 0:01:00.680 --> 0:01:04.440 handmade cartoonists and the creator of PhD comics. Hi. I'm Daniel. 0:01:04.520 --> 0:01:07.640 I'm a particle physicist, but I might one day decay 0:01:07.680 --> 0:01:11.480 into something else, into a lighter Daniel or a lower 0:01:11.560 --> 0:01:13.959 energy state. Unfortunately, I seem to be violating the laws 0:01:13.959 --> 0:01:18.520 of physics and decaying into a heavier Daniel as to 0:01:18.600 --> 0:01:21.240 all humans. Unfortunately that seems to be the direction. But 0:01:21.280 --> 0:01:24.080 welcome to our podcast Daniel and Jorge Explain the Universe, 0:01:24.120 --> 0:01:26.520 a production of I Heart Radio in which we take 0:01:26.560 --> 0:01:29.440 the universe and crack it in half and pour all 0:01:29.480 --> 0:01:32.760 those little explain eons into your brain. We take you 0:01:32.800 --> 0:01:35.600 on a tour of all the amazing, the massive, the enormous, 0:01:35.680 --> 0:01:39.640 the crazy and all the tiny, mysterious, weird quantum stuff 0:01:39.680 --> 0:01:42.360 of the universe and explain it all to you. That's right, 0:01:42.360 --> 0:01:45.280 so it lives in your head, possibly forever. Hopefully you 0:01:45.319 --> 0:01:47.720 won't forget us. Will always be there in your brain, 0:01:47.760 --> 0:01:50.160 because we all know that once you've understood something in physics, 0:01:50.400 --> 0:01:53.160 you know it forever. I have never forgotten a single 0:01:53.200 --> 0:01:57.960 thing that matter where Really it's hard to unlearn. Huh No, 0:01:58.080 --> 0:02:00.400 that's exactly the opposite of true. I'm the kind of 0:02:00.440 --> 0:02:04.000 person that can learn something fairly quickly and then forget 0:02:04.040 --> 0:02:07.840 it fairly quickly. I guess, um, does the information decay 0:02:07.880 --> 0:02:10.480 in your brain or it dissipates or I think it 0:02:10.560 --> 0:02:12.560 just gets replaced by all the stuff on Twitter that 0:02:12.600 --> 0:02:15.119 I scroll through and shoves it back out the other 0:02:15.160 --> 0:02:17.040 side of my brain, pushes it out the other ear. 0:02:17.240 --> 0:02:20.119 That's right. Information understanding decay. Yeah. We like to talk 0:02:20.120 --> 0:02:24.160 about science and the cosmos and the universe and everything 0:02:24.200 --> 0:02:27.200 in between, and including all the things that are out 0:02:27.200 --> 0:02:29.440 there and all the things that are not yet out there, 0:02:29.480 --> 0:02:31.400 and all the things that will not be out there 0:02:31.440 --> 0:02:34.440 in the future. That's right because everything that you wonder 0:02:34.520 --> 0:02:37.560 about the universe are the same things that scientists wonder 0:02:37.600 --> 0:02:40.079 about the universe. Where did it come from, how did 0:02:40.080 --> 0:02:42.720 it get here? How long will it last? And how 0:02:42.760 --> 0:02:45.959 long will you last? Yeah, so big question is how 0:02:45.960 --> 0:02:50.760 long do particles stay around? Do they live forever? Or 0:02:50.800 --> 0:02:52.840 at some point are they not around? That's right because 0:02:52.840 --> 0:02:55.880 particles are these weird, fleeting quantum objects, and I don't 0:02:56.160 --> 0:02:59.240 always obey the same rules that you and I obey 0:02:59.360 --> 0:03:01.480 that we're from earlier with that makes sense to us, 0:03:01.520 --> 0:03:04.520 and yet we are made out of them. Everything in 0:03:04.520 --> 0:03:07.160 the universe is made out of particles. So it's essential 0:03:07.520 --> 0:03:10.519 that we understand how they work and the rules under 0:03:10.520 --> 0:03:13.840 which they operate, because they might very well determine our future, 0:03:13.960 --> 0:03:16.520 even if you have to wait a trillion trillion trillion 0:03:16.600 --> 0:03:18.800 years to find out. Yeah, because we know that. You know, 0:03:18.840 --> 0:03:22.160 as humans, we don't live forever, at least not yet. 0:03:22.720 --> 0:03:24.680 I don't know. I've never died so far. How about you. 0:03:26.200 --> 0:03:30.959 I think, probabilistically speaking, you are unlikely to be around 0:03:31.280 --> 0:03:34.720 for a few years. Yeah, But it's mostly because the 0:03:34.840 --> 0:03:37.840 arrangement of our particles and our atoms at some point 0:03:37.920 --> 0:03:40.600 doesn't work and it dissipates in our particles go back 0:03:40.600 --> 0:03:43.480 into the soil and back into dust. And so I 0:03:43.520 --> 0:03:46.520 think an interesting question is, like how long do your 0:03:46.600 --> 0:03:49.560 particles last? That's right? Like the particles that you're made 0:03:49.600 --> 0:03:52.080 out of right now, are they gonna be there at 0:03:52.080 --> 0:03:54.280 the end of the universe? That's right? Even if that 0:03:54.440 --> 0:03:58.160 arrangement that makes you isn't around anymore. With that little 0:03:58.200 --> 0:04:00.280 bit of your fingernail and that tip of your knows 0:04:00.360 --> 0:04:03.240 will it be around inside some starr and get fused 0:04:03.280 --> 0:04:06.120 into a piece of gold someday and get blown out 0:04:06.160 --> 0:04:09.760 in a supernova and have trillions and trillions more cycles, 0:04:09.880 --> 0:04:11.800 or will it only last a few more years and 0:04:11.880 --> 0:04:15.360 decay into something totally unrecognizable? Right? Because I guess particles 0:04:15.640 --> 0:04:18.160 come from nothing, right, Like you know, at some point 0:04:18.160 --> 0:04:20.560 there weren't any particles and then they suddenly sort of 0:04:20.640 --> 0:04:23.960 popped down, And we know that particles pop into existence 0:04:24.000 --> 0:04:26.160 all the time in the vacuum, and so, but the 0:04:26.279 --> 0:04:28.880 question is, once you form a particle, does it stay 0:04:28.880 --> 0:04:31.960 around forever as a particle or do things happen to 0:04:32.000 --> 0:04:34.760 it to make it disappear? Yeah, particles certainly were formed 0:04:34.760 --> 0:04:37.640 in the very early universe. We had this hot, dense state, 0:04:37.720 --> 0:04:40.240 all this energy stored in the fields, and then as 0:04:40.279 --> 0:04:43.320 the universe cooled, that energy sort of isolated into these 0:04:43.320 --> 0:04:46.839 discrete packets that we now call particles. And we'd like 0:04:46.920 --> 0:04:49.400 to play this mental game as particle physicists say, you 0:04:49.480 --> 0:04:52.040 had just one particle in the universe, what would it do? 0:04:52.320 --> 0:04:55.920 Would it sit there forever or would it eventually spontaneously 0:04:55.960 --> 0:04:58.919 break into lighter particles? And so that's the game we 0:04:58.920 --> 0:05:01.799 play with electrons, and we think a single universe filled 0:05:01.800 --> 0:05:04.960 with just one electron would stay that way forever. But 0:05:05.040 --> 0:05:08.200 the open question is is that also true for proton 0:05:08.360 --> 0:05:10.120 So to be on the podcast will be asking the 0:05:10.200 --> 0:05:19.039 question do protons live forever? And if so, how do 0:05:19.120 --> 0:05:22.440 they plan for their retirements? Right? Do they have professional 0:05:23.200 --> 0:05:28.440 protonic um retirement accountant? I hope they've been proactive in 0:05:28.520 --> 0:05:32.760 saving Yeah, I hope that there is paraded. If you 0:05:32.800 --> 0:05:36.600 live forever, you would have like an infinite number of grandchildren, 0:05:36.640 --> 0:05:39.400 which I suppose could support you in your old old age. 0:05:39.600 --> 0:05:42.600 There you think they still like you after an infinite 0:05:42.640 --> 0:05:46.640 number of years, Great great great great great Grandpa die 0:05:46.720 --> 0:05:48.760 already and give us all your stuff. Now you have 0:05:48.800 --> 0:05:52.200 to go great trade for infinity. Nobody wants to call you. 0:05:52.320 --> 0:05:54.720 I ran at a time there. Yeah, alright, So electrons 0:05:54.800 --> 0:05:57.240 live forever, we know that. That's like fact number one. 0:05:58.240 --> 0:06:00.760 They never what does that mean? They never decayed or 0:06:00.880 --> 0:06:04.960 they never like spontaneously disappear. It's an important distinction. Like 0:06:05.279 --> 0:06:08.520 an electron, you can destroy it. You throw an electron 0:06:08.560 --> 0:06:12.159 against a positron, you can turn that energy into something else. 0:06:12.240 --> 0:06:14.880 You can turn it into a photon. Right, that kind 0:06:14.920 --> 0:06:18.120 of stuff happens. But so you can kill an electron, yes, 0:06:18.160 --> 0:06:20.280 but they just don't die on the that's right. And 0:06:20.320 --> 0:06:22.720 you know in some superhero movies that is the definition 0:06:22.720 --> 0:06:26.160 of immortal, like elves or in fantasy novels are often 0:06:26.200 --> 0:06:29.680 immortal but can be killed in battle, which always confused me. 0:06:30.080 --> 0:06:33.320 But electrons are sort of like elves. They will sit 0:06:33.360 --> 0:06:36.000 around forever. Like you put an electron in its own universe, 0:06:36.200 --> 0:06:38.720 it will just sit there forever, you know, learning how 0:06:38.760 --> 0:06:41.880 to sing valid essentially, but never turning into anything else, 0:06:42.960 --> 0:06:46.200 or not even spontaneously like you know, some particles just 0:06:46.240 --> 0:06:49.360 they're sitting around, they can split into other particles, right, 0:06:49.400 --> 0:06:52.920 that's right. Almost every particle decays. It's only the ones 0:06:52.960 --> 0:06:55.640 that are the lightest ones that can turn into anything 0:06:55.640 --> 0:06:57.719 else that are sort of stuck. Those are the ones 0:06:57.760 --> 0:06:59.960 that we call stable. So an electron is a stay 0:07:00.000 --> 0:07:03.440 able particle. A single electron universe will stay a single 0:07:03.480 --> 0:07:07.640 electron universe basically forever. Like it can't break down into 0:07:07.680 --> 0:07:11.960 something else spontaneously, or it probably won't know if it could, 0:07:12.160 --> 0:07:15.000 it will eventually. So this is a statement about like, 0:07:15.240 --> 0:07:18.960 not a statement about probability, but about possibility. If an 0:07:18.960 --> 0:07:21.520 electron is really alone in the universe, if there's not 0:07:21.520 --> 0:07:24.800 not even any like weird quantum positrons popping out of 0:07:24.800 --> 0:07:27.200 the vacuum to annihilate it, it will sit there forever, 0:07:27.320 --> 0:07:30.080 has zero chance of decaying into anything else, because what 0:07:30.240 --> 0:07:33.520 could it decay into. There is no particle lighter than 0:07:33.560 --> 0:07:36.760 the electron that the electron can turn into that follows 0:07:36.800 --> 0:07:39.480 all the rules, and we'll dig into all of that. Okay, 0:07:39.520 --> 0:07:44.360 So electrons are like elves, probably l ron or electron. 0:07:45.680 --> 0:07:49.120 What would be his elf name or her name? Elvin, 0:07:49.200 --> 0:07:53.480 elvin name Sorrylfish elfish or Elvin. Oh man, I'm way 0:07:53.520 --> 0:07:55.640 on my depth here. So we're made out of electrons 0:07:55.680 --> 0:07:59.480 and also protons. Under the question is do protons live forever? 0:07:59.520 --> 0:08:01.800 That's right, and this is one of the deepest open 0:08:01.920 --> 0:08:05.320 questions in modern physics. Does a proton sitting in the 0:08:05.400 --> 0:08:09.200 universe by itself eventually turn into something else? Or will 0:08:09.240 --> 0:08:11.920 it last forever? So that's an awesome question, and so 0:08:12.000 --> 0:08:14.080 as usual, Daniel went out there and ask people on 0:08:14.120 --> 0:08:18.240 the internet if they thought protons lived forever. So, as usual, 0:08:18.320 --> 0:08:20.440 before you hear these answers, think about it for a second. 0:08:20.480 --> 0:08:24.040 Do you think protons live forever? Here's what people had 0:08:24.040 --> 0:08:27.480 to say. I don't really understand what living forever means 0:08:27.480 --> 0:08:32.080 for protons, but I do understand that they are converted 0:08:32.120 --> 0:08:36.160 into different forms. Seeing a bita plas t K where 0:08:36.200 --> 0:08:40.280 the proton gets converted into a neutron and a positroon 0:08:40.400 --> 0:08:44.680 is released. I believe protons, if kind of like left alone, 0:08:44.800 --> 0:08:48.240 just by themselves, they probably could live till the end 0:08:48.280 --> 0:08:51.800 of the eternity, till the end of the universe, unless 0:08:51.840 --> 0:08:57.440 some external effects can either destroy them or change them 0:08:58.000 --> 0:09:01.360 like maybe you know fusion or fish, and protons can 0:09:01.440 --> 0:09:05.080 change from one to another, but they are still protos. 0:09:05.320 --> 0:09:08.600 I do not believe they live forever. I know electrons 0:09:08.760 --> 0:09:12.079 live forever because you guys covered that in a previous podcast. 0:09:12.679 --> 0:09:16.240 But I believe protons can be broken down obviously, you 0:09:16.320 --> 0:09:19.840 guys do it as certain by smashing them and creating 0:09:19.840 --> 0:09:24.280 new particles. Intitively, I would say that, um, we know 0:09:24.360 --> 0:09:28.160 that like prodom is made up of two upquarks and 0:09:28.240 --> 0:09:31.760 one dunk parks. I think so that I would think 0:09:31.800 --> 0:09:34.880 that a prodom may not live forever in a form 0:09:34.960 --> 0:09:37.800 of a proto. I have no idea about this. I 0:09:37.840 --> 0:09:40.959 would say that they probably do not live forever, because 0:09:40.960 --> 0:09:43.880 it doesn't make sense that they would not decay at 0:09:43.880 --> 0:09:46.560 some point. I would have to assume that protons don't 0:09:46.600 --> 0:09:49.760 live forever, because before the Big Bang, we think the 0:09:49.840 --> 0:09:54.720 universe was a big, hot, dense ball of energy, and 0:09:54.760 --> 0:09:56.960 so I would have to guess that the universe could 0:09:56.960 --> 0:09:59.920 return to such a state. I guess that decaying all 0:10:00.000 --> 0:10:03.440 of time, and if the next holiday destination is Geneva, 0:10:03.480 --> 0:10:05.800 then they really have a short time left. I don't 0:10:05.920 --> 0:10:08.360 think so, alright. I feel like it's a lot of 0:10:08.360 --> 0:10:11.880 confidence here in these answers. People are like no, and 0:10:11.880 --> 0:10:14.800 some people are like yes, and some people are like 0:10:15.000 --> 0:10:17.800 depends on what you mean living forever exactly. Got some 0:10:17.920 --> 0:10:21.080 legalistic answers also, but it's fair because it's a bit 0:10:21.120 --> 0:10:25.200 of a vague question, Like it's possible obviously to destroy 0:10:25.200 --> 0:10:28.599 a proton. We do it every twenty five nanoseconds the 0:10:28.679 --> 0:10:31.840 large change on collider by smashing them together. But really 0:10:31.880 --> 0:10:34.560 the deep physics question is if you leave a proton alone, 0:10:35.000 --> 0:10:38.080 will it decay into something else? Can you turn it 0:10:38.120 --> 0:10:41.200 into something else? And that has deep implications for our 0:10:41.280 --> 0:10:43.760 understanding of the very beginning of the universe, why our 0:10:43.840 --> 0:10:46.160 universe is made out of matter, and also for like 0:10:46.200 --> 0:10:48.800 our understanding of the fundamental theory of everything, how it 0:10:48.880 --> 0:10:52.280 all links together. It turns out proton decay is really 0:10:52.320 --> 0:10:55.400 little lynch pin for a lot of big questions. Wow, 0:10:55.679 --> 0:10:58.480 that's a lot of stuff to hang on one simple question. 0:10:59.120 --> 0:11:02.199 It's amazing, And it turns out proton decays really really 0:11:02.240 --> 0:11:05.120 frustrating for particle theorist. Right, So it seems like we 0:11:05.120 --> 0:11:08.400 can kill protons, but the question is do they spontaneously 0:11:09.160 --> 0:11:12.000 die at some point or breakdown or did you have 0:11:12.080 --> 0:11:15.199 a proton does it sit around forever? So maybe, Daniel, 0:11:15.240 --> 0:11:17.480 let's step through it one thing at a time. First, 0:11:17.480 --> 0:11:20.760 of all, let's talk about particles dying in the first place, 0:11:20.880 --> 0:11:23.640 or I guess you use the term decay. That's right. 0:11:23.679 --> 0:11:26.360 We prefer the term decay. Or you have transformed into 0:11:26.400 --> 0:11:29.720 something else, something lighter and more femoral. We don't like 0:11:29.760 --> 0:11:32.319 to talk about them dying. We call it passing, not dying. 0:11:33.000 --> 0:11:35.800 You're graduating to the next phase of your particle existence, 0:11:36.000 --> 0:11:39.800 you're leveling up. But yes, in general, particles do like 0:11:39.880 --> 0:11:42.480 to decay, and that's just a function of time moving 0:11:42.520 --> 0:11:45.520 forward and entropy. You know, the same way that you 0:11:45.920 --> 0:11:48.600 can't have a bunch of gas particles in the corner 0:11:48.600 --> 0:11:50.520 of a box and have them to stay there. They 0:11:50.600 --> 0:11:53.319 like to spread out because energy likes to diffuse. That 0:11:53.480 --> 0:11:57.000 increases entropy and disorder in the universe. You can't have 0:11:57.040 --> 0:12:00.720 that much energy isolated in a quantum field, so that 0:12:00.840 --> 0:12:03.160 a particle is in a really heavy state. They like 0:12:03.280 --> 0:12:05.760 to decay down to the lowest state. They like to 0:12:05.840 --> 0:12:08.840 spread that energy out. They give off a photon or 0:12:08.880 --> 0:12:12.800 they eject another particle. They turned into multiple particles, and 0:12:12.840 --> 0:12:15.200 they just essentially stepped down the ladder as far as 0:12:15.240 --> 0:12:19.240 they and again we're not talking about like particles disassembling 0:12:19.440 --> 0:12:21.240 you know, like if if I build a lego in 0:12:21.280 --> 0:12:23.160 my house, you know, with my kids, it's not gonna 0:12:23.240 --> 0:12:27.400 last very long. It's kind of eventually get dissembled. We're 0:12:27.440 --> 0:12:31.880 talking really about like quantum transformation, like a particle literally 0:12:31.880 --> 0:12:34.920 like transforms into other things. Yeah, let's take an example 0:12:35.000 --> 0:12:37.680 of the muan. The muan is a heavy version of 0:12:37.679 --> 0:12:41.480 the electron, and the muan turns into an electron and 0:12:41.520 --> 0:12:44.600 then a couple of neutrinos to satisfy some conservation laws. 0:12:45.000 --> 0:12:47.160 But the muan doesn't last very long at all, last 0:12:47.200 --> 0:12:50.440 for micro seconds and it just turns into the electron. 0:12:50.520 --> 0:12:53.520 And as you said, it's not like the muan is 0:12:53.559 --> 0:12:56.360 just the electron with a couple of neutrinos bound together, 0:12:56.440 --> 0:12:59.080 and then it breaks apart and those little internal pieces 0:12:59.120 --> 0:13:02.160 fly out. This really is like alchemy. Like the muon 0:13:02.720 --> 0:13:05.840 is an excited state of the muan field and then 0:13:05.880 --> 0:13:09.320 it transforms into an excited state of the electron field 0:13:09.360 --> 0:13:13.040 and to neutrino fields. And so that's our current understanding 0:13:13.040 --> 0:13:16.160 of how this muon decay happens. You have isolated heavy 0:13:16.280 --> 0:13:19.640 particle turns into three lighter particles. Right, it's not a 0:13:19.720 --> 0:13:23.480 rearrangement and it just it doesn't spontaneously like it's just 0:13:23.520 --> 0:13:25.760 sitting there. A muon is just sitting there and then 0:13:25.800 --> 0:13:29.880 suddenly pop, it just turns into an electron and two neutrinus. Yeah, 0:13:29.880 --> 0:13:32.920 it's one of the real quantum randomness is in our universe, 0:13:33.200 --> 0:13:36.800 Like it has a probability at any moment to decay. 0:13:36.920 --> 0:13:40.480 When an individual muan actually decays is determined by some 0:13:40.640 --> 0:13:43.600 random quantum toss of the dice. If you have like 0:13:43.880 --> 0:13:47.120 a thousand muons in a bottle, then half of them 0:13:47.160 --> 0:13:49.640 will decay after a certain time, then another half after 0:13:49.679 --> 0:13:53.880 another certain time, etcetera. On average, but each individual one 0:13:53.960 --> 0:13:56.079 is determined by a random toss of the dice. It's 0:13:56.120 --> 0:13:59.240 just like radioactive decay of a nucleus, which is exactly 0:13:59.280 --> 0:14:01.120 the same kind of process. I see. It's not that 0:14:01.160 --> 0:14:03.520 it's delicate and like you know, you're stacking blocks and 0:14:03.559 --> 0:14:06.760 then suddenly when passed by or you push a little 0:14:06.760 --> 0:14:10.000 bit and it topples over it. It's literally like you know, 0:14:10.120 --> 0:14:14.960 in its fabric of its existence, to just spontaneously turn 0:14:15.000 --> 0:14:16.760 into something else. Yeah. The picture I have in my 0:14:16.800 --> 0:14:19.440 head is that it's like you know, flipping a coin 0:14:19.640 --> 0:14:22.680 or rolling a die, every microsecond, and if it gets 0:14:22.720 --> 0:14:25.760 the right answer, boom, it decays, and if it doesn't, 0:14:25.800 --> 0:14:28.120 it sticks around it a new one for a while. Um. 0:14:28.440 --> 0:14:31.120 And so it's just like keeps rolling that die or 0:14:31.120 --> 0:14:33.280 picking a random number until it gets the right one 0:14:33.320 --> 0:14:35.320 and then it decides. All right, now it's time for 0:14:35.360 --> 0:14:38.080 me to become an electron and a couple of neutrinos. Right, 0:14:38.280 --> 0:14:40.960 but you're telling me that it needs to have like 0:14:41.080 --> 0:14:43.840 a path for the decay, like it has to have, 0:14:44.600 --> 0:14:47.680 you know, kind of a solution for its decay. Yeah, 0:14:47.720 --> 0:14:50.280 you can't just turn into anything, right. A muan can't 0:14:50.320 --> 0:14:52.760 just like say, hey, I'm going to become a photon. Cool, 0:14:52.840 --> 0:14:56.760 that sounds like fun. The universe has rules, and these 0:14:56.840 --> 0:15:00.520 rules determine what particles can decay into other particles. The 0:15:00.560 --> 0:15:03.240 important thing to understand about these rules is that mostly 0:15:03.520 --> 0:15:05.720 we have no idea where they come from. They're just 0:15:05.760 --> 0:15:09.240 like our description. It's like you watch a bunch of particles, 0:15:09.240 --> 0:15:12.280 you see what happens. You try to notice patterns, and 0:15:12.320 --> 0:15:15.400 you codify those patterns into rules. That doesn't mean you 0:15:15.520 --> 0:15:17.960 know why that rule exists. So when we say, like, 0:15:18.400 --> 0:15:21.680 you know, charge is conserved, doesn't mean we know why 0:15:21.760 --> 0:15:24.440 it's conserved. It just means that we've never seen this 0:15:24.560 --> 0:15:27.360 rule broken, so we think it's a fundamental rule of 0:15:27.400 --> 0:15:30.560 the universe. And so that's one of them. Right. Why 0:15:30.640 --> 0:15:33.600 can't a muan just turn into a photon. Well, muan 0:15:33.720 --> 0:15:36.720 has electric charge and a photon doesn't, so to do 0:15:36.760 --> 0:15:39.440 that would break that rule of conserving electric charge. Right, 0:15:39.480 --> 0:15:41.560 it has to be a decay that makes sense to 0:15:41.600 --> 0:15:44.520 the universe. Okay, it's not like a total magic like 0:15:44.680 --> 0:15:46.720 an el can just turn into a dwarf, that's right. 0:15:47.000 --> 0:15:48.960 You have to like fill out a big application and 0:15:48.960 --> 0:15:51.400 submitted to the universe's lawyers and they have to check 0:15:51.440 --> 0:15:53.680 all the boxes and they say, all right approved. It's 0:15:53.720 --> 0:15:58.000 more like getting a bank loan than magically transforming, all right. 0:15:58.040 --> 0:16:00.600 And if there's nothing for you to decay to, like 0:16:00.720 --> 0:16:03.160 in according to the laws of the universe, then you 0:16:03.240 --> 0:16:05.600 can't decay. You're like stuck, that's right. And that's the 0:16:05.680 --> 0:16:08.920 situation with the electron. There's nothing lighter than the electron, 0:16:09.000 --> 0:16:11.320 like the muon can decay to electron because the muon 0:16:11.440 --> 0:16:14.240 is heavier than the electron. It can go down, but 0:16:14.320 --> 0:16:17.600 to go up. It's not spontaneous decay. The electron can't 0:16:17.600 --> 0:16:20.520 decay up into the muan. There's nothing for it to 0:16:20.520 --> 0:16:23.720 go down to. It's the lightest thing on its ladder. Now, 0:16:23.760 --> 0:16:27.680 there are other lower mass particles, like a photon for example, 0:16:27.720 --> 0:16:30.520 but again an electron can't get to be a photon 0:16:30.840 --> 0:16:35.240 because that would violate the conservation of electric charge. Okay, 0:16:35.320 --> 0:16:37.920 so then there are rules. And if there's no step 0:16:38.040 --> 0:16:40.320 down for you to go down to, then you're stuck. 0:16:40.400 --> 0:16:43.120 That's right. And you know, there's another particle that's very 0:16:43.160 --> 0:16:46.000 similar to the proton. It's the neutron. And the neutron 0:16:46.160 --> 0:16:48.560 is almost the same as a proton. It's a slightly 0:16:48.640 --> 0:16:51.920 different arrangement of quarks. Like the proton is made out 0:16:51.920 --> 0:16:56.120 of these smaller particles called quarks, and the proton is 0:16:56.160 --> 0:16:59.680 two ups and and down. The neutron is two downs 0:16:59.720 --> 0:17:02.880 and an up. Now, the neutron is slightly heavier than 0:17:02.920 --> 0:17:05.760 the proton, a tiny bit more mass, so the neutron 0:17:05.840 --> 0:17:09.160 can turn into a proton, no problem. And it also 0:17:09.200 --> 0:17:12.960 shoots off an electron to conserve electric charge. So that happens. 0:17:13.040 --> 0:17:15.399 And if you have like a neutron sitting around and 0:17:15.520 --> 0:17:18.760 on average, after about nine hundred seconds, it will turn 0:17:18.800 --> 0:17:21.840 into a proton. But because the proton is lighter than 0:17:21.840 --> 0:17:24.879 the neutron, there's nowhere for the proton to go. Because 0:17:24.880 --> 0:17:27.359 there's this weird rule we have observed that says you 0:17:27.480 --> 0:17:31.240 have to keep constant the number of cork triplets, like 0:17:31.280 --> 0:17:34.800 the number of particles made out of three quarks cannot change, 0:17:34.840 --> 0:17:36.760 all right, And there's kind of a rule that says 0:17:36.760 --> 0:17:40.159 that when you decayed down into something, you need like 0:17:40.200 --> 0:17:42.040 a force to help you do it. That's right. All 0:17:42.160 --> 0:17:46.000 these decays happen through some force, right, Like when the 0:17:46.080 --> 0:17:49.440 muon decays into the electron, he uses the weak force. 0:17:49.600 --> 0:17:51.720 What does that mean, Like like the weak force has 0:17:51.720 --> 0:17:54.119 to be involved or you actually need to like inject 0:17:54.240 --> 0:17:56.000 some weak force into it. It means that the weak 0:17:56.040 --> 0:17:59.480 force is involved. What actually happens when it decays is 0:17:59.480 --> 0:18:03.000 that the mu and turns into immuon neutrino and a 0:18:03.200 --> 0:18:06.399 w boson, and that w boson then turns into an 0:18:06.400 --> 0:18:10.720 electron and a second neutrino, so it like mediates the decay. 0:18:10.840 --> 0:18:14.200 It's like every time you feel a force the wall 0:18:14.320 --> 0:18:17.240 is pushing back on you for example, Really that's happening 0:18:17.240 --> 0:18:21.960 by the exchange of energy from photons, and so all interactions. 0:18:21.960 --> 0:18:24.280 Every time particles talk to each other, it happens through 0:18:24.359 --> 0:18:26.760 one of the forces. Okay, so then when you decay, 0:18:27.160 --> 0:18:29.840 you need this force to kind of like pass the 0:18:29.960 --> 0:18:34.240 energy around between the resulting bits. Yeah, exactly. And so 0:18:34.320 --> 0:18:37.040 you know, another example is a particle called the pion. 0:18:37.600 --> 0:18:40.320 Pion is two corks, a cork and an anti cork, 0:18:40.720 --> 0:18:43.879 and this thing can turn into two photons, and that 0:18:44.000 --> 0:18:47.480 happens via electromagnetism. Essentially, the cork and the anti cork 0:18:47.520 --> 0:18:49.960 and decide to annihilate each other and turn into these 0:18:50.000 --> 0:18:52.919 two photons. And so that there's something for it to 0:18:53.040 --> 0:18:56.000 turn into doesn't break any of the rules, and there's 0:18:56.000 --> 0:18:57.600 a force to make it happen. All right, So we 0:18:57.640 --> 0:19:00.879 know that particles can decay if there's thing, you know, 0:19:01.040 --> 0:19:03.760 less energetic that they can decay into, and if you 0:19:03.840 --> 0:19:06.399 follow the rules of the universe. So now the question 0:19:06.480 --> 0:19:08.919 is do protons de case So mostly you and I 0:19:08.920 --> 0:19:12.600 are now to protons and electrons and neutrons, and so 0:19:12.680 --> 0:19:15.560 the question is due protons decay? So let's get into that. 0:19:15.840 --> 0:19:30.720 But first let's take a quick break, all right, Dianiel, 0:19:30.920 --> 0:19:34.120 we're talking about whether protons live Forever, and I feel 0:19:34.119 --> 0:19:37.719 like that's like an eighties song or something. Do Protons 0:19:37.760 --> 0:19:41.760 Live Forever? Sounds like a heavy metal you know, hair band, 0:19:42.119 --> 0:19:45.560 sounds like a love The protons of my love will 0:19:45.600 --> 0:19:49.480 be here to the end of the universe. That's probably 0:19:49.480 --> 0:19:53.280 in the next bill. There you go, Yeah, you have 0:19:53.280 --> 0:19:55.840 a rock band in your garage with other physicists. No, 0:19:56.119 --> 0:19:58.600 definitely not, And if I did, I would not admit 0:19:58.680 --> 0:20:01.919 it here on the podcast. How I see you do 0:20:02.000 --> 0:20:05.640 it under an alias another particle name. That's right exactly. 0:20:06.040 --> 0:20:07.960 The rock and electrons, all right, So we're all made 0:20:07.960 --> 0:20:11.080 out of electrons, protons and neutrons, and so the question 0:20:11.119 --> 0:20:14.600 is do protons a because we know electrons cannot decay 0:20:14.680 --> 0:20:18.879 spontaneously into someone else, but do protons decay? And so 0:20:18.920 --> 0:20:21.680 the protons are different than electrons because protons are made 0:20:21.720 --> 0:20:24.760 out of other particles. Right, Protons are made out of quarks. 0:20:25.080 --> 0:20:27.280 So you take a proton, you look inside it, deep 0:20:27.320 --> 0:20:31.359 inside it, and you find three particles. You find two 0:20:31.480 --> 0:20:35.080 up corks and a down cork, and that means that 0:20:35.160 --> 0:20:36.919 like it's made out of these three particles. It's just 0:20:36.960 --> 0:20:40.119 an arrangement of those particles, right, But we have this 0:20:40.240 --> 0:20:42.639 rule in the universe that we don't understand. And this 0:20:42.760 --> 0:20:46.480 rule says that there's a fixed number of these cork triplets. 0:20:46.720 --> 0:20:49.080 We call this a barrion. It's just three quirks together, 0:20:49.320 --> 0:20:51.000 and you can make three qurks together and loss of 0:20:51.040 --> 0:20:54.080 different arrangements. And for some reason, every time you have 0:20:54.119 --> 0:20:57.679 an interaction, the number of baryons doesn't change. What do 0:20:57.680 --> 0:21:00.879 you mean, like interactions, but corks always have and three. No, 0:21:01.040 --> 0:21:03.680 but if you do have a triplet of quarks involved, 0:21:03.760 --> 0:21:06.600 then you'll have the same number of triplets when you're done. So, 0:21:06.680 --> 0:21:10.080 for example, a neutron decays to a proton. He started 0:21:10.119 --> 0:21:13.000 with one triplet the neutron, which is an up down down, 0:21:13.440 --> 0:21:15.920 and you ended up with one triplet the proton up 0:21:16.000 --> 0:21:19.440 up down. Like, you can't go from one barrion to 0:21:19.600 --> 0:21:22.600 zero baryons, or from ten burrions to eight burrions. You 0:21:22.640 --> 0:21:24.679 have to have the same number of burrions when you 0:21:24.720 --> 0:21:27.119 start and when you finish, which is not something we 0:21:27.200 --> 0:21:29.960 understand at all. So it's not related to threes, like 0:21:29.960 --> 0:21:31.520 if I start with two, I have to end up 0:21:31.520 --> 0:21:34.399 with two as well. No, there's no conservation on cork pairs. 0:21:34.760 --> 0:21:37.679 Cork triplets have this special property. If you have a 0:21:37.720 --> 0:21:40.000 qurk triplet, you have to end up with a cork triplet. 0:21:40.359 --> 0:21:42.960