Latest / Daniel and Kelly’s Extraordinary Universe / Do protons live forever?

Transcript

Do protons live forever? · Daniel and Kelly’s Extraordinary Universe

0:08
Speaker 1: Hey, Daniel, I'm worried about how long I'm going to live? Man,
0:12
Speaker 1: aren't we all these days? I know, but I mean
0:15
Speaker 1: like down to the particle level, Like, are my who
0:18
Speaker 1: electrons going to be around forever? Well, we actually have
0:22
Speaker 1: good news there. We do think that electrons can live forever.
0:25
Speaker 1: All right, that's cool. What about my protons? I got
0:29
Speaker 1: some tough news there. Didn't last very long. Currently we
0:33
Speaker 1: think protons live for only a trillion trillion trillion years.
0:37
Speaker 1: I don't. Well, that's good. I guess even my protons
0:41
Speaker 1: are procrastinators. They are professional protonic procrastinators. I am more
1:00
Speaker 1: handmade cartoonists and the creator of PhD comics. Hi. I'm Daniel.
1:04
Speaker 1: I'm a particle physicist, but I might one day decay
1:07
Speaker 1: into something else, into a lighter Daniel or a lower
1:11
Speaker 1: energy state. Unfortunately, I seem to be violating the laws
1:13
Speaker 1: of physics and decaying into a heavier Daniel as to
1:18
Speaker 1: all humans. Unfortunately that seems to be the direction. But
1:21
Speaker 1: welcome to our podcast Daniel and Jorge Explain the Universe,
1:24
Speaker 1: a production of I Heart Radio in which we take
1:26
Speaker 1: the universe and crack it in half and pour all
1:29
Speaker 1: those little explain eons into your brain. We take you
1:32
Speaker 1: on a tour of all the amazing, the massive, the enormous,
1:35
Speaker 1: the crazy and all the tiny, mysterious, weird quantum stuff
1:39
Speaker 1: of the universe and explain it all to you. That's right,
1:42
Speaker 1: so it lives in your head, possibly forever. Hopefully you
1:45
Speaker 1: won't forget us. Will always be there in your brain,
1:47
Speaker 1: because we all know that once you've understood something in physics,
1:50
Speaker 1: you know it forever. I have never forgotten a single
1:53
Speaker 1: thing that matter where Really it's hard to unlearn. Huh No,
1:58
Speaker 1: that's exactly the opposite of true. I'm the kind of
2:00
Speaker 1: person that can learn something fairly quickly and then forget
2:04
Speaker 1: it fairly quickly. I guess, um, does the information decay
2:07
Speaker 1: in your brain or it dissipates or I think it
2:10
Speaker 1: just gets replaced by all the stuff on Twitter that
2:12
Speaker 1: I scroll through and shoves it back out the other
2:15
Speaker 1: side of my brain, pushes it out the other ear.
2:17
Speaker 1: That's right. Information understanding decay. Yeah. We like to talk
2:20
Speaker 1: about science and the cosmos and the universe and everything
2:24
Speaker 1: in between, and including all the things that are out
2:27
Speaker 1: there and all the things that are not yet out there,
2:29
Speaker 1: and all the things that will not be out there
2:31
Speaker 1: in the future. That's right because everything that you wonder
2:34
Speaker 1: about the universe are the same things that scientists wonder
2:37
Speaker 1: about the universe. Where did it come from, how did
2:40
Speaker 1: it get here? How long will it last? And how
2:42
Speaker 1: long will you last? Yeah, so big question is how
2:45
Speaker 1: long do particles stay around? Do they live forever? Or
2:50
Speaker 1: at some point are they not around? That's right because
2:52
Speaker 1: particles are these weird, fleeting quantum objects, and I don't
2:56
Speaker 1: always obey the same rules that you and I obey
2:59
Speaker 1: that we're from earlier with that makes sense to us,
3:01
Speaker 1: and yet we are made out of them. Everything in
3:04
Speaker 1: the universe is made out of particles. So it's essential
3:07
Speaker 1: that we understand how they work and the rules under
3:10
Speaker 1: which they operate, because they might very well determine our future,
3:13
Speaker 1: even if you have to wait a trillion trillion trillion
3:16
Speaker 1: years to find out. Yeah, because we know that. You know,
3:18
Speaker 1: as humans, we don't live forever, at least not yet.
3:22
Speaker 1: I don't know. I've never died so far. How about you.
3:26
Speaker 1: I think, probabilistically speaking, you are unlikely to be around
3:31
Speaker 1: for a few years. Yeah, But it's mostly because the
3:34
Speaker 1: arrangement of our particles and our atoms at some point
3:37
Speaker 1: doesn't work and it dissipates in our particles go back
3:40
Speaker 1: into the soil and back into dust. And so I
3:43
Speaker 1: think an interesting question is, like how long do your
3:46
Speaker 1: particles last? That's right? Like the particles that you're made
3:49
Speaker 1: out of right now, are they gonna be there at
3:52
Speaker 1: the end of the universe? That's right? Even if that
3:54
Speaker 1: arrangement that makes you isn't around anymore. With that little
3:58
Speaker 1: bit of your fingernail and that tip of your knows
4:00
Speaker 1: will it be around inside some starr and get fused
4:03
Speaker 1: into a piece of gold someday and get blown out
4:06
Speaker 1: in a supernova and have trillions and trillions more cycles,
4:09
Speaker 1: or will it only last a few more years and
4:11
Speaker 1: decay into something totally unrecognizable? Right? Because I guess particles
4:15
Speaker 1: come from nothing, right, Like you know, at some point
4:18
Speaker 1: there weren't any particles and then they suddenly sort of
4:20
Speaker 1: popped down, And we know that particles pop into existence
4:24
Speaker 1: all the time in the vacuum, and so, but the
4:26
Speaker 1: question is, once you form a particle, does it stay
4:28
Speaker 1: around forever as a particle or do things happen to
4:32
Speaker 1: it to make it disappear? Yeah, particles certainly were formed
4:34
Speaker 1: in the very early universe. We had this hot, dense state,
4:37
Speaker 1: all this energy stored in the fields, and then as
4:40
Speaker 1: the universe cooled, that energy sort of isolated into these
4:43
Speaker 1: discrete packets that we now call particles. And we'd like
4:46
Speaker 1: to play this mental game as particle physicists say, you
4:49
Speaker 1: had just one particle in the universe, what would it do?
4:52
Speaker 1: Would it sit there forever or would it eventually spontaneously
4:55
Speaker 1: break into lighter particles? And so that's the game we
4:58
Speaker 1: play with electrons, and we think a single universe filled
5:01
Speaker 1: with just one electron would stay that way forever. But
5:05
Speaker 1: the open question is is that also true for proton
5:08
Speaker 1: So to be on the podcast will be asking the
5:10
Speaker 1: question do protons live forever? And if so, how do
5:19
Speaker 1: they plan for their retirements? Right? Do they have professional
5:23
Speaker 1: protonic um retirement accountant? I hope they've been proactive in
5:28
Speaker 1: saving Yeah, I hope that there is paraded. If you
5:32
Speaker 1: live forever, you would have like an infinite number of grandchildren,
5:36
Speaker 1: which I suppose could support you in your old old age.
5:39
Speaker 1: There you think they still like you after an infinite
5:42
Speaker 1: number of years, Great great great great great Grandpa die
5:46
Speaker 1: already and give us all your stuff. Now you have
5:48
Speaker 1: to go great trade for infinity. Nobody wants to call you.
5:52
Speaker 1: I ran at a time there. Yeah, alright, So electrons
5:54
Speaker 1: live forever, we know that. That's like fact number one.
5:58
Speaker 1: They never what does that mean? They never decayed or
6:00
Speaker 1: they never like spontaneously disappear. It's an important distinction. Like
6:05
Speaker 1: an electron, you can destroy it. You throw an electron
6:08
Speaker 1: against a positron, you can turn that energy into something else.
6:12
Speaker 1: You can turn it into a photon. Right, that kind
6:14
Speaker 1: of stuff happens. But so you can kill an electron, yes,
6:18
Speaker 1: but they just don't die on the that's right. And
6:20
Speaker 1: you know in some superhero movies that is the definition
6:22
Speaker 1: of immortal, like elves or in fantasy novels are often
6:26
Speaker 1: immortal but can be killed in battle, which always confused me.
6:30
Speaker 1: But electrons are sort of like elves. They will sit
6:33
Speaker 1: around forever. Like you put an electron in its own universe,
6:36
Speaker 1: it will just sit there forever, you know, learning how
6:38
Speaker 1: to sing valid essentially, but never turning into anything else,
6:42
Speaker 1: or not even spontaneously like you know, some particles just
6:46
Speaker 1: they're sitting around, they can split into other particles, right,
6:49
Speaker 1: that's right. Almost every particle decays. It's only the ones
6:52
Speaker 1: that are the lightest ones that can turn into anything
6:55
Speaker 1: else that are sort of stuck. Those are the ones
6:57
Speaker 1: that we call stable. So an electron is a stay
7:00
Speaker 1: able particle. A single electron universe will stay a single
7:03
Speaker 1: electron universe basically forever. Like it can't break down into
7:07
Speaker 1: something else spontaneously, or it probably won't know if it could,
7:12
Speaker 1: it will eventually. So this is a statement about like,
7:15
Speaker 1: not a statement about probability, but about possibility. If an
7:18
Speaker 1: electron is really alone in the universe, if there's not
7:21
Speaker 1: not even any like weird quantum positrons popping out of
7:24
Speaker 1: the vacuum to annihilate it, it will sit there forever,
7:27
Speaker 1: has zero chance of decaying into anything else, because what
7:30
Speaker 1: could it decay into. There is no particle lighter than
7:33
Speaker 1: the electron that the electron can turn into that follows
7:36
Speaker 1: all the rules, and we'll dig into all of that. Okay,
7:39
Speaker 1: So electrons are like elves, probably l ron or electron.
7:45
Speaker 1: What would be his elf name or her name? Elvin,
7:49
Speaker 1: elvin name Sorrylfish elfish or Elvin. Oh man, I'm way
7:53
Speaker 1: on my depth here. So we're made out of electrons
7:55
Speaker 1: and also protons. Under the question is do protons live forever?
7:59
Speaker 1: That's right, and this is one of the deepest open
8:01
Speaker 1: questions in modern physics. Does a proton sitting in the
8:05
Speaker 1: universe by itself eventually turn into something else? Or will
8:09
Speaker 1: it last forever? So that's an awesome question, and so
8:12
Speaker 1: as usual, Daniel went out there and ask people on
8:14
Speaker 1: the internet if they thought protons lived forever. So, as usual,
8:18
Speaker 1: before you hear these answers, think about it for a second.
8:20
Speaker 1: Do you think protons live forever? Here's what people had
8:24
Speaker 1: to say. I don't really understand what living forever means
8:27
Speaker 1: for protons, but I do understand that they are converted
8:32
Speaker 1: into different forms. Seeing a bita plas t K where
8:36
Speaker 1: the proton gets converted into a neutron and a positroon
8:40
Speaker 1: is released. I believe protons, if kind of like left alone,
8:44
Speaker 1: just by themselves, they probably could live till the end
8:48
Speaker 1: of the eternity, till the end of the universe, unless
8:51
Speaker 1: some external effects can either destroy them or change them
8:58
Speaker 1: like maybe you know fusion or fish, and protons can
9:01
Speaker 1: change from one to another, but they are still protos.
9:05
Speaker 1: I do not believe they live forever. I know electrons
9:08
Speaker 1: live forever because you guys covered that in a previous podcast.
9:12
Speaker 1: But I believe protons can be broken down obviously, you
9:16
Speaker 1: guys do it as certain by smashing them and creating
9:19
Speaker 1: new particles. Intitively, I would say that, um, we know
9:24
Speaker 1: that like prodom is made up of two upquarks and
9:28
Speaker 1: one dunk parks. I think so that I would think
9:31
Speaker 1: that a prodom may not live forever in a form
9:34
Speaker 1: of a proto. I have no idea about this. I
9:37
Speaker 1: would say that they probably do not live forever, because
9:40
Speaker 1: it doesn't make sense that they would not decay at
9:43
Speaker 1: some point. I would have to assume that protons don't
9:46
Speaker 1: live forever, because before the Big Bang, we think the
9:49
Speaker 1: universe was a big, hot, dense ball of energy, and
9:54
Speaker 1: so I would have to guess that the universe could
9:56
Speaker 1: return to such a state. I guess that decaying all
10:00
Speaker 1: of time, and if the next holiday destination is Geneva,
10:03
Speaker 1: then they really have a short time left. I don't
10:05
Speaker 1: think so, alright. I feel like it's a lot of
10:08
Speaker 1: confidence here in these answers. People are like no, and
10:11
Speaker 1: some people are like yes, and some people are like
10:15
Speaker 1: depends on what you mean living forever exactly. Got some
10:17
Speaker 1: legalistic answers also, but it's fair because it's a bit
10:21
Speaker 1: of a vague question, Like it's possible obviously to destroy
10:25
Speaker 1: a proton. We do it every twenty five nanoseconds the
10:28
Speaker 1: large change on collider by smashing them together. But really
10:31
Speaker 1: the deep physics question is if you leave a proton alone,
10:35
Speaker 1: will it decay into something else? Can you turn it
10:38
Speaker 1: into something else? And that has deep implications for our
10:41
Speaker 1: understanding of the very beginning of the universe, why our
10:43
Speaker 1: universe is made out of matter, and also for like
10:46
Speaker 1: our understanding of the fundamental theory of everything, how it
10:48
Speaker 1: all links together. It turns out proton decay is really
10:52
Speaker 1: little lynch pin for a lot of big questions. Wow,
10:55
Speaker 1: that's a lot of stuff to hang on one simple question.
10:59
Speaker 1: It's amazing, And it turns out proton decays really really
11:02
Speaker 1: frustrating for particle theorist. Right, So it seems like we
11:05
Speaker 1: can kill protons, but the question is do they spontaneously
11:09
Speaker 1: die at some point or breakdown or did you have
11:12
Speaker 1: a proton does it sit around forever? So maybe, Daniel,
11:15
Speaker 1: let's step through it one thing at a time. First,
11:17
Speaker 1: of all, let's talk about particles dying in the first place,
11:20
Speaker 1: or I guess you use the term decay. That's right.
11:23
Speaker 1: We prefer the term decay. Or you have transformed into
11:26
Speaker 1: something else, something lighter and more femoral. We don't like
11:29
Speaker 1: to talk about them dying. We call it passing, not dying.
11:33
Speaker 1: You're graduating to the next phase of your particle existence,
11:36
Speaker 1: you're leveling up. But yes, in general, particles do like
11:39
Speaker 1: to decay, and that's just a function of time moving
11:42
Speaker 1: forward and entropy. You know, the same way that you
11:45
Speaker 1: can't have a bunch of gas particles in the corner
11:48
Speaker 1: of a box and have them to stay there. They
11:50
Speaker 1: like to spread out because energy likes to diffuse. That
11:53
Speaker 1: increases entropy and disorder in the universe. You can't have
11:57
Speaker 1: that much energy isolated in a quantum field, so that
12:00
Speaker 1: a particle is in a really heavy state. They like
12:03
Speaker 1: to decay down to the lowest state. They like to
12:05
Speaker 1: spread that energy out. They give off a photon or
12:08
Speaker 1: they eject another particle. They turned into multiple particles, and
12:12
Speaker 1: they just essentially stepped down the ladder as far as
12:15
Speaker 1: they and again we're not talking about like particles disassembling
12:19
Speaker 1: you know, like if if I build a lego in
12:21
Speaker 1: my house, you know, with my kids, it's not gonna
12:23
Speaker 1: last very long. It's kind of eventually get dissembled. We're
12:27
Speaker 1: talking really about like quantum transformation, like a particle literally
12:31
Speaker 1: like transforms into other things. Yeah, let's take an example
12:35
Speaker 1: of the muan. The muan is a heavy version of
12:37
Speaker 1: the electron, and the muan turns into an electron and
12:41
Speaker 1: then a couple of neutrinos to satisfy some conservation laws.
12:45
Speaker 1: But the muan doesn't last very long at all, last
12:47
Speaker 1: for micro seconds and it just turns into the electron.
12:50
Speaker 1: And as you said, it's not like the muan is
12:53
Speaker 1: just the electron with a couple of neutrinos bound together,
12:56
Speaker 1: and then it breaks apart and those little internal pieces
12:59
Speaker 1: fly out. This really is like alchemy. Like the muon
13:02
Speaker 1: is an excited state of the muan field and then
13:05
Speaker 1: it transforms into an excited state of the electron field
13:09
Speaker 1: and to neutrino fields. And so that's our current understanding
13:13
Speaker 1: of how this muon decay happens. You have isolated heavy
13:16
Speaker 1: particle turns into three lighter particles. Right, it's not a
13:19
Speaker 1: rearrangement and it just it doesn't spontaneously like it's just
13:23
Speaker 1: sitting there. A muon is just sitting there and then
13:25
Speaker 1: suddenly pop, it just turns into an electron and two neutrinus. Yeah,
13:29
Speaker 1: it's one of the real quantum randomness is in our universe,
13:33
Speaker 1: Like it has a probability at any moment to decay.
13:36
Speaker 1: When an individual muan actually decays is determined by some
13:40
Speaker 1: random quantum toss of the dice. If you have like
13:43
Speaker 1: a thousand muons in a bottle, then half of them
13:47
Speaker 1: will decay after a certain time, then another half after
13:49
Speaker 1: another certain time, etcetera. On average, but each individual one
13:53
Speaker 1: is determined by a random toss of the dice. It's
13:56
Speaker 1: just like radioactive decay of a nucleus, which is exactly
13:59
Speaker 1: the same kind of process. I see. It's not that
14:01
Speaker 1: it's delicate and like you know, you're stacking blocks and
14:03
Speaker 1: then suddenly when passed by or you push a little
14:06
Speaker 1: bit and it topples over it. It's literally like you know,
14:10
Speaker 1: in its fabric of its existence, to just spontaneously turn
14:15
Speaker 1: into something else. Yeah. The picture I have in my
14:16
Speaker 1: head is that it's like you know, flipping a coin
14:19
Speaker 1: or rolling a die, every microsecond, and if it gets
14:22
Speaker 1: the right answer, boom, it decays, and if it doesn't,
14:25
Speaker 1: it sticks around it a new one for a while. Um.
14:28
Speaker 1: And so it's just like keeps rolling that die or
14:31
Speaker 1: picking a random number until it gets the right one
14:33
Speaker 1: and then it decides. All right, now it's time for
14:35
Speaker 1: me to become an electron and a couple of neutrinos. Right,
14:38
Speaker 1: but you're telling me that it needs to have like
14:41
Speaker 1: a path for the decay, like it has to have,
14:44
Speaker 1: you know, kind of a solution for its decay. Yeah,
14:47
Speaker 1: you can't just turn into anything, right. A muan can't
14:50
Speaker 1: just like say, hey, I'm going to become a photon. Cool,
14:52
Speaker 1: that sounds like fun. The universe has rules, and these
14:56
Speaker 1: rules determine what particles can decay into other particles. The
15:00
Speaker 1: important thing to understand about these rules is that mostly
15:03
Speaker 1: we have no idea where they come from. They're just
15:05
Speaker 1: like our description. It's like you watch a bunch of particles,
15:09
Speaker 1: you see what happens. You try to notice patterns, and
15:12
Speaker 1: you codify those patterns into rules. That doesn't mean you
15:15
Speaker 1: know why that rule exists. So when we say, like,
15:18
Speaker 1: you know, charge is conserved, doesn't mean we know why
15:21
Speaker 1: it's conserved. It just means that we've never seen this
15:24
Speaker 1: rule broken, so we think it's a fundamental rule of
15:27
Speaker 1: the universe. And so that's one of them. Right. Why
15:30
Speaker 1: can't a muan just turn into a photon. Well, muan
15:33
Speaker 1: has electric charge and a photon doesn't, so to do
15:36
Speaker 1: that would break that rule of conserving electric charge. Right,
15:39
Speaker 1: it has to be a decay that makes sense to
15:41
Speaker 1: the universe. Okay, it's not like a total magic like
15:44
Speaker 1: an el can just turn into a dwarf, that's right.
15:47
Speaker 1: You have to like fill out a big application and
15:48
Speaker 1: submitted to the universe's lawyers and they have to check
15:51
Speaker 1: all the boxes and they say, all right approved. It's
15:53
Speaker 1: more like getting a bank loan than magically transforming, all right.
15:58
Speaker 1: And if there's nothing for you to decay to, like
16:00
Speaker 1: in according to the laws of the universe, then you
16:03
Speaker 1: can't decay. You're like stuck, that's right. And that's the
16:05
Speaker 1: situation with the electron. There's nothing lighter than the electron,
16:09
Speaker 1: like the muon can decay to electron because the muon
16:11
Speaker 1: is heavier than the electron. It can go down, but
16:14
Speaker 1: to go up. It's not spontaneous decay. The electron can't
16:17
Speaker 1: decay up into the muan. There's nothing for it to
16:20
Speaker 1: go down to. It's the lightest thing on its ladder. Now,
16:23
Speaker 1: there are other lower mass particles, like a photon for example,
16:27
Speaker 1: but again an electron can't get to be a photon
16:30
Speaker 1: because that would violate the conservation of electric charge. Okay,
16:35
Speaker 1: so then there are rules. And if there's no step
16:38
Speaker 1: down for you to go down to, then you're stuck.
16:40
Speaker 1: That's right. And you know, there's another particle that's very
16:43
Speaker 1: similar to the proton. It's the neutron. And the neutron
16:46
Speaker 1: is almost the same as a proton. It's a slightly
16:48
Speaker 1: different arrangement of quarks. Like the proton is made out
16:51
Speaker 1: of these smaller particles called quarks, and the proton is
16:56
Speaker 1: two ups and and down. The neutron is two downs
16:59
Speaker 1: and an up. Now, the neutron is slightly heavier than
17:02
Speaker 1: the proton, a tiny bit more mass, so the neutron
17:05
Speaker 1: can turn into a proton, no problem. And it also
17:09
Speaker 1: shoots off an electron to conserve electric charge. So that happens.
17:13
Speaker 1: And if you have like a neutron sitting around and
17:15
Speaker 1: on average, after about nine hundred seconds, it will turn
17:18
Speaker 1: into a proton. But because the proton is lighter than
17:21
Speaker 1: the neutron, there's nowhere for the proton to go. Because
17:24
Speaker 1: there's this weird rule we have observed that says you
17:27
Speaker 1: have to keep constant the number of cork triplets, like
17:31
Speaker 1: the number of particles made out of three quarks cannot change,
17:34
Speaker 1: all right, And there's kind of a rule that says
17:36
Speaker 1: that when you decayed down into something, you need like
17:40
Speaker 1: a force to help you do it. That's right. All
17:42
Speaker 1: these decays happen through some force, right, Like when the
17:46
Speaker 1: muon decays into the electron, he uses the weak force.
17:49
Speaker 1: What does that mean, Like like the weak force has
17:51
Speaker 1: to be involved or you actually need to like inject
17:54
Speaker 1: some weak force into it. It means that the weak
17:56
Speaker 1: force is involved. What actually happens when it decays is
17:59
Speaker 1: that the mu and turns into immuon neutrino and a
18:03
Speaker 1: w boson, and that w boson then turns into an
18:06
Speaker 1: electron and a second neutrino, so it like mediates the decay.
18:10
Speaker 1: It's like every time you feel a force the wall
18:14
Speaker 1: is pushing back on you for example, Really that's happening
18:17
Speaker 1: by the exchange of energy from photons, and so all interactions.
18:21
Speaker 1: Every time particles talk to each other, it happens through
18:24
Speaker 1: one of the forces. Okay, so then when you decay,
18:27
Speaker 1: you need this force to kind of like pass the
18:29
Speaker 1: energy around between the resulting bits. Yeah, exactly. And so
18:34
Speaker 1: you know, another example is a particle called the pion.
18:37
Speaker 1: Pion is two corks, a cork and an anti cork,
18:40
Speaker 1: and this thing can turn into two photons, and that
18:44
Speaker 1: happens via electromagnetism. Essentially, the cork and the anti cork
18:47
Speaker 1: and decide to annihilate each other and turn into these
18:50
Speaker 1: two photons. And so that there's something for it to
18:53
Speaker 1: turn into doesn't break any of the rules, and there's
18:56
Speaker 1: a force to make it happen. All right, So we
18:57
Speaker 1: know that particles can decay if there's thing, you know,
19:01
Speaker 1: less energetic that they can decay into, and if you
19:03
Speaker 1: follow the rules of the universe. So now the question
19:06
Speaker 1: is do protons de case So mostly you and I
19:08
Speaker 1: are now to protons and electrons and neutrons, and so
19:12
Speaker 1: the question is due protons decay? So let's get into that.
19:15
Speaker 1: But first let's take a quick break, all right, Dianiel,
19:30
Speaker 1: we're talking about whether protons live Forever, and I feel
19:34
Speaker 1: like that's like an eighties song or something. Do Protons
19:37
Speaker 1: Live Forever? Sounds like a heavy metal you know, hair band,
19:42
Speaker 1: sounds like a love The protons of my love will
19:45
Speaker 1: be here to the end of the universe. That's probably
19:49
Speaker 1: in the next bill. There you go, Yeah, you have
19:53
Speaker 1: a rock band in your garage with other physicists. No,
19:56
Speaker 1: definitely not, And if I did, I would not admit
19:58
Speaker 1: it here on the podcast. How I see you do
20:02
Speaker 1: it under an alias another particle name. That's right exactly.
20:06
Speaker 1: The rock and electrons, all right, So we're all made
20:07
Speaker 1: out of electrons, protons and neutrons, and so the question
20:11
Speaker 1: is do protons a because we know electrons cannot decay
20:14
Speaker 1: spontaneously into someone else, but do protons decay? And so
20:18
Speaker 1: the protons are different than electrons because protons are made
20:21
Speaker 1: out of other particles. Right, Protons are made out of quarks.
20:25
Speaker 1: So you take a proton, you look inside it, deep
20:27
Speaker 1: inside it, and you find three particles. You find two
20:31
Speaker 1: up corks and a down cork, and that means that
20:35
Speaker 1: like it's made out of these three particles. It's just
20:36
Speaker 1: an arrangement of those particles, right, But we have this
20:40
Speaker 1: rule in the universe that we don't understand. And this
20:42
Speaker 1: rule says that there's a fixed number of these cork triplets.
20:46
Speaker 1: We call this a barrion. It's just three quirks together,
20:49
Speaker 1: and you can make three qurks together and loss of
20:51
Speaker 1: different arrangements. And for some reason, every time you have
20:54
Speaker 1: an interaction, the number of baryons doesn't change. What do
20:57
Speaker 1: you mean, like interactions, but corks always have and three. No,
21:01
Speaker 1: but if you do have a triplet of quarks involved,
21:03
Speaker 1: then you'll have the same number of triplets when you're done. So,
21:06
Speaker 1: for example, a neutron decays to a proton. He started
21:10
Speaker 1: with one triplet the neutron, which is an up down down,
21:13
Speaker 1: and you ended up with one triplet the proton up
21:16
Speaker 1: up down. Like, you can't go from one barrion to
21:19
Speaker 1: zero baryons, or from ten burrions to eight burrions. You
21:22
Speaker 1: have to have the same number of burrions when you
21:24
Speaker 1: start and when you finish, which is not something we
21:27
Speaker 1: understand at all. So it's not related to threes, like
21:29
Speaker 1: if I start with two, I have to end up
21:31
Speaker 1: with two as well. No, there's no conservation on cork pairs.
21:34
Speaker 1: Cork triplets have this special property. If you have a
21:37
Speaker 1: qurk triplet, you have to end up with a cork triplet.
21:40
Speaker 1: And so, for example, when we smash protons together at
21:42
Speaker 1: the large change on collider, two protons come in. We
21:45
Speaker 1: destroy those two protons. We always make at least two
21:48
Speaker 1: baryons that come out. Okay, So then neutrons, which were
21:53
Speaker 1: also made out of those don't live forever. You're saying,
21:56
Speaker 1: like a neutron, if you just leave it alone in
21:58
Speaker 1: the universe, it's gonna not be a neutron for law.
22:00
Speaker 1: That's right. It only lasts about eight hundred and eighty
22:03
Speaker 1: seconds on its own. Now, the neutrons in your body
22:05
Speaker 1: are much more stable because the environment in your body
22:08
Speaker 1: keeps them sort of stuck together. But if you had
22:11
Speaker 1: a neutron by itself in the universe, after about eight
22:14
Speaker 1: hundred eighty seconds, it would turn into a proton and
22:17
Speaker 1: an electron. And you notice that keeps the number of
22:20
Speaker 1: baryons a number of cork triplets constant, because the neutron
22:23
Speaker 1: is one and the proton is one. Oh, I see,
22:26
Speaker 1: so alright, So a neutron by itself candycy, but it
22:29
Speaker 1: turns into a proton basically turns into a proton plus
22:32
Speaker 1: an electron to carry off the other half of the
22:34
Speaker 1: electric charge. To follow that one rule. And so what
22:36
Speaker 1: happens there for the neutron, like the quarks inside just
22:39
Speaker 1: kind of flipped and then it becomes something else. Yeah,
22:41
Speaker 1: one of the down corks becomes an up cork, and
22:44
Speaker 1: it gives off a w boson, which is where you
22:46
Speaker 1: get the electron and actually a little neutrino, which is
22:49
Speaker 1: how neutrinos were discovered. But these arrangements of quarks, like
22:53
Speaker 1: one arrangement of quarks and up down, down, it gives
22:56
Speaker 1: you a neutron, a different set of quarks up up,
23:00
Speaker 1: down that gives you a proton. The proton is the
23:03
Speaker 1: lowest mass arrangement of quarks, Like, there's no way to
23:06
Speaker 1: make an arrangement of quarks that has a lower mass
23:09
Speaker 1: in the protons. So it's sort of like the lightest
23:11
Speaker 1: thing on the ladder of bury on. But for quark triplet, Yes,
23:15
Speaker 1: for quark, you can make something out of two quarks.
23:17
Speaker 1: You can make something out of two quarks, like a
23:18
Speaker 1: pion has lower mass. But the cork triplet ladder, for
23:21
Speaker 1: some reason, it's on its own. It's like a special
23:23
Speaker 1: thing in the universe. And if you're on that ladder,
23:26
Speaker 1: you have to stay on that ladder, and the proton
23:29
Speaker 1: is the bottom rung of that ladder. There's no lighter
23:32
Speaker 1: arrangement of three quarks than the proton. So that's why
23:35
Speaker 1: the proton seems to be stuck unless you can somehow
23:38
Speaker 1: jump off this ladder. I see, it's like once he
23:42
Speaker 1: has three quarks, instead of stuck having three quarts, exactly,
23:45
Speaker 1: you can do something, make a different arrangement of three quarks.
23:48
Speaker 1: You can move up or down the ladder by injecting energy.
23:50
Speaker 1: You're waiting for it to decay. But you have to
23:53
Speaker 1: have something on the ladder. Once you have something on
23:55
Speaker 1: the ladder. But couldn't I like, you know, split up
23:58
Speaker 1: that triplet. Can't three quarts make up a proton just
24:01
Speaker 1: like you know, when they decide to go their separate ways,
24:03
Speaker 1: then you destroy the proton. Basically, you can do that
24:06
Speaker 1: if you create a larger system, right, so you like
24:09
Speaker 1: involve it in some other bonds and some other configurations,
24:13
Speaker 1: then you can destroy a proton, for example. But a
24:16
Speaker 1: proton on its own will never decay. We think it
24:19
Speaker 1: might be stable. We've never seen a proton jump off
24:22
Speaker 1: the ladder, and every interaction we've ever seen keeps the
24:26
Speaker 1: same number of these barrier I see. But I mean,
24:29
Speaker 1: like can quarks exists on their own, you can't have
24:31
Speaker 1: quirks on their own. They have such a strong interaction
24:34
Speaker 1: with other corks, and the strength of that interaction gets
24:37
Speaker 1: stronger and stronger as quirks get further and further apart,
24:40
Speaker 1: which creates so much energy around them that they create
24:43
Speaker 1: particles out of the vacuum to make these pairs and triplets.
24:47
Speaker 1: So you never see corks by themselves. They're always in
24:49
Speaker 1: these pairs or triplets or maybe in weird exotic larger
24:53
Speaker 1: combinations tetra corks and hexa corks. But there's a special
24:56
Speaker 1: relationship that the universe has with these triplets of quirks
24:59
Speaker 1: that we don't understand. We've never seen a proton decay,
25:03
Speaker 1: and so we think there might be some special rule
25:07
Speaker 1: that protects these cork triblets. On the other hand, we
25:10
Speaker 1: have very good reason to think that protons might decay
25:15
Speaker 1: or that they should, So it's not for certain. It's
25:18
Speaker 1: definitely not for certain. No, it's something we don't understand
25:21
Speaker 1: it's a core mystery at the heart of physics. All right,
25:23
Speaker 1: So you've never seen a proton spontaneously decay, and what
25:27
Speaker 1: does that mean? Like, have we actually like put a
25:29
Speaker 1: proton on their microscope and left it there for a
25:31
Speaker 1: couple of hours or days or years. Yeah? Actually we
25:34
Speaker 1: put like ten to the thirty four protons under a
25:37
Speaker 1: microscope and we waited a few years to see if
25:40
Speaker 1: any of them decay. What do you mean, like you
25:42
Speaker 1: actually put them in a little container and left them
25:44
Speaker 1: there a really big container. Right. One way to do this,
25:47
Speaker 1: one way to ask, like does a proton decay? Can
25:50
Speaker 1: we measure it? Is to take a single proton and wait.
25:53
Speaker 1: But if you think that a proton might take like
25:55
Speaker 1: a trillion trillion trillion years to decay, then your experiment's
25:59
Speaker 1: going to take the trillion trillion trillion years. Instead, what
26:02
Speaker 1: you can do is say, well, I'm gonna take a
26:04
Speaker 1: trillion trillion trillion protons, which is not that hard to
26:07
Speaker 1: make because every piece of matter has a lot of
26:10
Speaker 1: protons and see if any of them decay. Because if
26:14
Speaker 1: none of them decay within a year or two years,
26:16
Speaker 1: then I can make a statistical argument about how long
26:19
Speaker 1: they live. Oh, I see, So that's what you have
26:22
Speaker 1: in the in the large hattern collider, not in the
26:24
Speaker 1: large hedge and collider. That's not where we study proton decay.
26:26
Speaker 1: But in big underground experiments like super Commo Conda and
26:30
Speaker 1: the upcoming do and experiment are perfect for looking for
26:33
Speaker 1: proton decays. All right, So you don't think that they
26:36
Speaker 1: can decay, but do you think they might? What makes
26:38
Speaker 1: you think they might decay? Well, the universe sort of
26:40
Speaker 1: doesn't make sense if protons can't decay. Like, if protons
26:44
Speaker 1: could decay, the whole universe would make a lot more sense,
26:47
Speaker 1: which makes us want them to decay, even though we've
26:49
Speaker 1: never seen them. And the reason it is that, well,
26:52
Speaker 1: you know, we have more baryons in the universe than
26:55
Speaker 1: anti barions. Well, we talked about earlier how you have
26:59
Speaker 1: to have the same umber of barrions in the universe.
27:01
Speaker 1: That's the opposite for anti berrions. Like you can actually
27:05
Speaker 1: create a burrion and anti berion together because it keeps
27:09
Speaker 1: the number of burrions the same because anti berrions count
27:12
Speaker 1: for minus one. And again, a barion is a triplet
27:15
Speaker 1: of court that's right. Yeah, And so we think that
27:17
Speaker 1: the universe started off with no particles, as you said,
27:20
Speaker 1: and then particles were made, which must have made the
27:23
Speaker 1: same number of burions and anti burions, but somehow we
27:26
Speaker 1: ended up with a lot more protons than anti protons. Like,
27:30
Speaker 1: we think there are almost no antiberians out there, so
27:33
Speaker 1: there must be something out there which lets us either
27:37
Speaker 1: create burions on their own or destroy anti berions preferentially.
27:41
Speaker 1: There's something out there to explain why we have so
27:44
Speaker 1: much more matter than anti matter. Something allows us to
27:48
Speaker 1: make these buryons. Right, But isn't it just sort of
27:50
Speaker 1: like electrons to like, you know, you can create and
27:52
Speaker 1: destroy electrons. What makes us think that then electrons can't
27:56
Speaker 1: decay but protons might be able to so, right, the
28:00
Speaker 1: same argument goes for electrons that we think, you know,
28:03
Speaker 1: why do we have more electrons in the universe than positrons? Right?
28:07
Speaker 1: This is this whole question of antimatter. But there are
28:09
Speaker 1: other reasons that we think that protons might decay, and
28:12
Speaker 1: that comes from like looking at the patterns of the forces.
28:15
Speaker 1: We have the electromagnetism, which is a force. We have
28:18
Speaker 1: the weak force, we have the strong force, and we
28:21
Speaker 1: have gravity. And people like to try to put these together,
28:24
Speaker 1: they say, well, it's weird to have like four different
28:27
Speaker 1: forces or five different forces. Can we fit these together
28:30
Speaker 1: into a larger pattern that has just one overarching you know,
28:35
Speaker 1: ring to rule them all, so to force. And every
28:38
Speaker 1: time the theorists do this, every time they put those
28:40
Speaker 1: pieces together, it always ends up predicting a new little
28:43
Speaker 1: force that we haven't seen very much anymore, that hasn't
28:46
Speaker 1: been around since the beginning the universe, that can decay protons,
28:49
Speaker 1: that turns protons into a pion and a pository. What So,
28:55
Speaker 1: when you try to, you know, kind of squish all
28:57
Speaker 1: the forces together like you think they're radically Like if
29:00
Speaker 1: I try to come up with a like a super
29:02
Speaker 1: megaporce that includes all the other forces, you're saying, I
29:06
Speaker 1: have to come up with a new fifth force. Yeah, well,
29:09
Speaker 1: it's sort of like it's a part of this megaporce
29:11
Speaker 1: that doesn't happen very much anymore. So put all these
29:14
Speaker 1: forces together into one megaphorce. And that megaphorce because it
29:19
Speaker 1: was around in the early universe, before the universe cooled
29:21
Speaker 1: and the forces broke into these different forces that we
29:24
Speaker 1: know today, it would have treated all the particles equally
29:27
Speaker 1: like quarks and electrons and all those stuff. And so
29:31
Speaker 1: this force should be able to turn quirks into leptons
29:34
Speaker 1: for example, and back and forth. And currently our forces
29:37
Speaker 1: can't do that, Like, none of the forces that we
29:39
Speaker 1: have today are capable of turning quirks into leptons. They
29:43
Speaker 1: aren't capable of doing that. But this leftover force, there
29:47
Speaker 1: might be a particle which exists in the universe but
29:50
Speaker 1: requires so much energy to create that we hardly ever
29:53
Speaker 1: see it, which means it's very unlikely for it to
29:56
Speaker 1: do anything. But it might vary occasionally every true brillion
30:00
Speaker 1: trillion trillion years be responsible for the decay of a proton.
30:04
Speaker 1: I see, maybe protons have this secret weakness, that this
30:07
Speaker 1: is hidden force that hasn't been around since the beginning
30:10
Speaker 1: of time. Yeah, and maybe that's the key, right, because
30:13
Speaker 1: every time they put one of these theories together, it
30:15
Speaker 1: always predicts that protons will decay. It's just like a
30:19
Speaker 1: natural consequence of making this megaphorce. It has this symmetry
30:22
Speaker 1: where it treats the quarks and the leftons in the
30:25
Speaker 1: same way. It always predicts this new X particle. The
30:29
Speaker 1: X particle would take like the two up corks inside
30:32
Speaker 1: the proton and turn them into like a positron and
30:35
Speaker 1: a down cork, and that gives you a proton turning
30:39
Speaker 1: into a pion and a positron. And so it's just inescapable.
30:43
Speaker 1: And every time the theorists make one of these theories,
30:46
Speaker 1: they're like, darn it, my theory predicts proton decay. It's
30:50
Speaker 1: very frustrating for them that I can't escape this prediction.
30:53
Speaker 1: I say, all right, well, let's get into how we
30:56
Speaker 1: might be looking experimentally for evidence that the proton case
31:00
Speaker 1: and when we can expect an answer. But first let's
31:03
Speaker 1: take another quick break. All right, Daniel, do protons and
31:18
Speaker 1: love live forever? It's the question, But I guess we're
31:22
Speaker 1: only tackling the proton partire today. Yeah, don't come to
31:24
Speaker 1: a particle physicist for questions about love unless it's about
31:27
Speaker 1: love of particles. A right. So, um, there are reasons
31:31
Speaker 1: to think maybe the proton does decay. One is that,
31:34
Speaker 1: you know, it might explain antimatter, and the other one
31:37
Speaker 1: is that the theory set of point to maybe a
31:40
Speaker 1: possible kind of new force which would allow protons to decay.
31:44
Speaker 1: Second of the idea, Yeah, and remember this is all theoretical.
31:47
Speaker 1: This is like, we look at the way the universe
31:49
Speaker 1: is arranged, and we think it would make more sense
31:51
Speaker 1: if we added this one other piece, but that piece
31:55
Speaker 1: would mean that protons should decay. So then we go
31:57
Speaker 1: when we look for it, we said, well, maybe they do,
32:00
Speaker 1: we just haven't noticed. Maybe it takes a long long time,
32:03
Speaker 1: and so we just need to be really patient. Okay,
32:04
Speaker 1: So it is that theoretically we don't think that the
32:08
Speaker 1: proton can decay, but if it does, it kind of
32:13
Speaker 1: means the existence of a new force. Is that kind
32:15
Speaker 1: of the significance of this decay. Yeah, so we have
32:18
Speaker 1: to invent this rule. This number of barriyons is fixed rule,
32:21
Speaker 1: which we don't really like because it doesn't really make
32:23
Speaker 1: any sense and it violates our understanding of matter and
32:26
Speaker 1: antimatter asymmetry, and it keeps us from having this new
32:29
Speaker 1: mega force, etcetera. So we'd love to get rid of
32:32
Speaker 1: that and replace it with this new force and allow
32:35
Speaker 1: protons to decay. But for that to be true, we
32:37
Speaker 1: have to actually see one decay, and we have to
32:39
Speaker 1: prove that they can, because nobody's ever seen. So if
32:43
Speaker 1: you see one decay, then it's like you have to
32:45
Speaker 1: break the laws of physics. Kind yes, if you see
32:47
Speaker 1: one decay, that's guaranteed Nobel Prize because you get to
32:50
Speaker 1: rewrite the laws of physics in a way that makes
32:52
Speaker 1: much more sense to everybody, that like fits together with
32:55
Speaker 1: some real symmetry and beauty. And so everybody's sort of
32:59
Speaker 1: hoping that protons will decay. I mean not your protons,
33:02
Speaker 1: not my protons, but some proton somewhere we hope will
33:05
Speaker 1: eventually decay. Did they already print that Nobel Prize? Like
33:08
Speaker 1: Nobel Prize for the decay of the proton. It's just
33:10
Speaker 1: sitting on the shelf waiting for people to claim it.
33:13
Speaker 1: You know. It's one of those experiments out there that
33:15
Speaker 1: if you make it work, if you see this thing,
33:16
Speaker 1: it's basically a guaranteed Nobel Prize. There are a few
33:19
Speaker 1: things like that, you know, find the Higgs boson, see
33:22
Speaker 1: gravitational waves, find a magnetic monopole. These things that people
33:26
Speaker 1: have been looking for forever. They think should exist, but
33:29
Speaker 1: nobody's ever seen one. If you found and it would
33:32
Speaker 1: really you know, fill in a missing box in our
33:35
Speaker 1: understanding of the universe. So yeah, go look for one.
33:37
Speaker 1: Exposed the proton get a prize. That's right, This is
33:40
Speaker 1: particle is ten most wanted list, right, So then there
33:43
Speaker 1: are a couple of experiments out there that are actually
33:45
Speaker 1: trying to win this Nobel prize. They're trying to see
33:48
Speaker 1: if protons decay and and so what's involved here, Daniel?
33:51
Speaker 1: Are they just put a bunch in a box and
33:53
Speaker 1: then stare at them or or do you shake it?
33:55
Speaker 1: Do you shake the box? What do you have to do?
33:58
Speaker 1: He's trying not to shake the box. And in fact,
34:00
Speaker 1: you know, you can play a sort of simple calculation
34:03
Speaker 1: with any blob of protons like you. You know, you,
34:06
Speaker 1: for example, have like ten to the twenty eight protons,
34:09
Speaker 1: something like a trillion quadrillion protons in your body, so
34:14
Speaker 1: you know already that protons lived for more than, you know,
34:18
Speaker 1: a hundred years, because people don't tend to die of
34:20
Speaker 1: proton decay, you know, like people just like suddenly disintegrate,
34:23
Speaker 1: like Thanos snapping his thumbs. But also, I mean you
34:26
Speaker 1: said that the protons in my body are kind of
34:28
Speaker 1: bound together with other protons and neutrons, and that helps
34:31
Speaker 1: him live longer. Yeah, but unfortunately that's the only kind
34:34
Speaker 1: of proton we can really study like, we can't take
34:37
Speaker 1: pure individual free protons and study them on their own.
34:40
Speaker 1: All we can do is study protons that exist in matter,
34:43
Speaker 1: which are in bound states. And so that's a big
34:45
Speaker 1: asterisk on all of the results that we're going to
34:48
Speaker 1: talk about today that none of them actually involves studying
34:51
Speaker 1: free protons. Okay, So then stepping through, what are these
34:54
Speaker 1: experiments and what are they doing? Well, the most powerful
34:57
Speaker 1: result right now, the one that tells us the most
34:59
Speaker 1: about proton decay, comes from this experiment in Japan. It's
35:02
Speaker 1: super Commoo Conda, and they basically have a thirteen story
35:07
Speaker 1: stack of water and it's just a huge container filled
35:10
Speaker 1: with water, and it's surrounded by cameras essentially, and it's
35:14
Speaker 1: totally dark and it's underground. And this is an experiment
35:17
Speaker 1: that's mostly designed to look for neutrinos coming from the
35:20
Speaker 1: Sun or coming from deep space or from supernovas, but
35:24
Speaker 1: it's also good for looking for proton decay because if
35:27
Speaker 1: proton decays in this tank, they think they will see it. Oh,
35:31
Speaker 1: I see so, but it's filled with water. I guess
35:34
Speaker 1: water has hydrogen oxygen, and those all have protons and
35:38
Speaker 1: they have something like ten to the thirty two protons
35:41
Speaker 1: basically sitting in the tank, and so if none of
35:44
Speaker 1: them decay in a year, then you know that the
35:47
Speaker 1: half life of the proton is more than ten to
35:50
Speaker 1: the thirty two years. But these are not isolated protons.
35:53
Speaker 1: They're in these bound states within the atoms. That doesn't
35:56
Speaker 1: that protect them, it does protect them potentially. And so
35:59
Speaker 1: as we were saying early here, like this is a
36:00
Speaker 1: big asterisk in all of these results. We would love
36:04
Speaker 1: to have ten to the thirty two free protons in
36:07
Speaker 1: the container that we could study and then we could
36:09
Speaker 1: directly understand this question. But we don't all the protons
36:13
Speaker 1: we have our inbound states, and we don't have ionized
36:16
Speaker 1: hydrogen gas in large enough containers that we build cameras around,
36:20
Speaker 1: and so we just have to sort of like make
36:22
Speaker 1: the measurement on bound protons and assume that it also
36:25
Speaker 1: works for free protons. But it's a big assumption, but
36:27
Speaker 1: it's also all we can do currently. All right, So,
36:31
Speaker 1: staring at water, what expery went you make? Particle physics
36:35
Speaker 1: sounds so exciting. I mean, look for variations and the
36:42
Speaker 1: loss of physics in violations of symmetry of matter and
36:46
Speaker 1: antimatter otherwise known as staring at water. If it happened,
36:49
Speaker 1: it would be kind of dramatic because you would have
36:51
Speaker 1: this special signature because you would get a pion on
36:55
Speaker 1: one side, which turns into two photons. You get these
36:58
Speaker 1: two little splashes in your camera, and on the other
37:01
Speaker 1: side you would get a positron, which makes a little splash.
37:04
Speaker 1: So they've simulated exactly what this would look like in
37:06
Speaker 1: their cameras and it's very weird and unusual and different
37:09
Speaker 1: from anything they've ever seen before. And so they've been
37:12
Speaker 1: running this thing for years and years and years and
37:14
Speaker 1: they've never seen a single one, and so that means
37:17
Speaker 1: that they can pretty confidently say that the lifetime of
37:20
Speaker 1: the proton is more than ten to the thirty four years,
37:25
Speaker 1: which is a huge number because remember the universe, the
37:29
Speaker 1: entire universe is only thirteen billion years old, so like,
37:34
Speaker 1: this is many orders of magnitude longer than the history
37:37
Speaker 1: of the universal But again, these are in bound states,
37:41
Speaker 1: or do you calibrate for that as well? These are
37:43
Speaker 1: in bound states. No, we can't really calibrate for that.
37:45
Speaker 1: We don't really know how to extrapolate from bound state
37:49
Speaker 1: protons to unbound protons to free protons. We just sort
37:53
Speaker 1: of like assume it's going to be something similar. Okay,
37:56
Speaker 1: So then that's one experiment. The super Cameo super co
38:00
Speaker 1: Neo Conda Conda all right, sounds like superhero or something.
38:05
Speaker 1: Is an awesome experiment in Japan, and then we're building
38:08
Speaker 1: one here in the United States that we talked about
38:10
Speaker 1: on a recent episode called Dune Deep Underground Neutrino Experiment.
38:15
Speaker 1: And these neutrino experiments essentially for free, you get a
38:19
Speaker 1: proton decay experiment because the same thing they can be
38:22
Speaker 1: used to look for neutrinos in Dune's case from a
38:24
Speaker 1: neutrino beam or from the Sun or from supernovas, can
38:28
Speaker 1: also look for decays of protons. And this is kind
38:32
Speaker 1: of a similar idea to write, like you have a
38:33
Speaker 1: big vat of stuff and you wait for it to change. Yeah, exactly.
38:37
Speaker 1: And in the case of Dune is not water, it's
38:39
Speaker 1: liquid argone. They're pioneering a new technology to take this
38:43
Speaker 1: noble gas argone and they cool it down until it's
38:46
Speaker 1: a liquid, but it has the same property that it's
38:48
Speaker 1: very quiet. So mostly if you have a huge several
38:52
Speaker 1: ton container of liquid argone underground and you put cameras
38:56
Speaker 1: on it, it'll stay dark. But if you see an
38:58
Speaker 1: interaction like a new trino or or a proton decaying,
39:01
Speaker 1: you should be able to spot that, because it's like
39:04
Speaker 1: taking a picture of a single tiny flash of light
39:07
Speaker 1: in a very dark room. Since it's camera can pick
39:09
Speaker 1: that up. Cool, and so far they haven't seen it.
39:12
Speaker 1: But again, this one is also you're looking at argons,
39:15
Speaker 1: so you're looking at protons in a bound state inside
39:18
Speaker 1: of the nucleus of the argon at them. That's right,
39:20
Speaker 1: But hey, that's all we can do. Dune hasn't turned
39:22
Speaker 1: on yet. They're still building it. It's gonna be turning
39:24
Speaker 1: on in a few years. But because it's a much
39:27
Speaker 1: larger volume, they have many more tons. It will provide
39:30
Speaker 1: even more stringent limits on the lifetime of the proton.
39:34
Speaker 1: Or maybe they'll get lucky, maybe they'll see one decay.
39:37
Speaker 1: But I guess, why can't you just like isolate a
39:40
Speaker 1: proton and look at it. Is that hard? I mean,
39:41
Speaker 1: you guys do it at the large hattern collider. Yeah,
39:43
Speaker 1: you can isolate a proton and you can look at it,
39:46
Speaker 1: But a single proton will not tell you much about
39:48
Speaker 1: the lifetime of the proton unless you wait a very
39:50
Speaker 1: very long time. So you either need a lot of
39:53
Speaker 1: protons or a lot of time, and a lot of
39:57
Speaker 1: protons are very hard to keep isolated. I mean, could
40:00
Speaker 1: have a gas of protons. We do that the hydrunk glider,
40:03
Speaker 1: but you know we have like tend of the twelve
40:05
Speaker 1: protons tend to thirteen protons. You need to keep these
40:08
Speaker 1: things isolated. You need to watch them and then you
40:11
Speaker 1: need to instrument it, right, You need to be watching
40:13
Speaker 1: for them to decay. And so that's much easier to
40:16
Speaker 1: do when you have a neutral substance, something which is quiet,
40:19
Speaker 1: which doesn't otherwise make lots of flashes of light. Oh,
40:22
Speaker 1: I see, it's like you can isolate a whole bunch
40:24
Speaker 1: of protons, but then you actually have to notice if
40:26
Speaker 1: like one of them the kids. Yeah, because a bunch
40:29
Speaker 1: of protons together, it's called the plasma, and a plasma
40:31
Speaker 1: is not a quiet thing to instrument, right, That's like
40:34
Speaker 1: where we try to do fusion and stuff like that.
40:36
Speaker 1: So it's a pretty trick the experiment to do for
40:38
Speaker 1: actual free protons, which is why we only ever do
40:41
Speaker 1: it for protons in a bound state. But you're right
40:44
Speaker 1: that doesn't actually tell us about free proton. All right,
40:47
Speaker 1: So there are people looking for this decay of the proton.
40:50
Speaker 1: Then there's people staring at water and argon waiting for
40:53
Speaker 1: one of these protons to suddenly die. That's right, staring
40:57
Speaker 1: at water waiting for a Nobel prize to about out
41:01
Speaker 1: of a little tiny proton. Hey, if I told you
41:04
Speaker 1: stare at this tank, a Nobel prize might appear. You know,
41:06
Speaker 1: you might devote a couple of years to that. Yeah,
41:08
Speaker 1: shorter than a PhD. A couple of trillion years, why not?
41:13
Speaker 1: Or you might not see anything. Unfortunately, that's usually the
41:17
Speaker 1: case in particle physics. You're looking for something crazy. You're
41:20
Speaker 1: hoping you might see something spectacular, but you see nothing.
41:23
Speaker 1: But the good news is that most of our experiments
41:26
Speaker 1: are still interesting even if you don't see anything, because
41:29
Speaker 1: you can still say something. You can say, we didn't
41:31
Speaker 1: see the proton decay. Therefore we know it doesn't decay
41:35
Speaker 1: on average in less than tend of the thirty four
41:38
Speaker 1: tend of the thirty five years. So you still get
41:40
Speaker 1: to say something interesting about physics. Alright. So it sounds
41:43
Speaker 1: like you're pretty confident then that we can say that
41:46
Speaker 1: the proton does not decay or won't die, or we'll
41:49
Speaker 1: live for at least ten to the thirty four years,
41:53
Speaker 1: which is pretty much forever, right, it's almost forever. I mean,
41:56
Speaker 1: it's a lot longer than our universe has been around
41:59
Speaker 1: so far. But it's also still a real problem for
42:02
Speaker 1: theoretical physicists when they try to construct their grain unified theories,
42:07
Speaker 1: their theories of everything, when they want to understand what
42:09
Speaker 1: happened to the very beginning of the universe, they have
42:12
Speaker 1: to do it in a way that keeps the proton
42:15
Speaker 1: from decaying, and that's theoretically very tricky. It's like, you know,
42:19
Speaker 1: they have to pass through the eye of a needle
42:21
Speaker 1: to keep the proton from decaying in their theory. And
42:23
Speaker 1: so everybody would be very happy to see a proton decay, oh,
42:27
Speaker 1: I see, because it would make the equations easier to solve.
42:30
Speaker 1: It would mean that all the theories which predict proton
42:32
Speaker 1: decay might actually be correct. And those equations are beautiful
42:36
Speaker 1: and they make a lot of sense, and they answer
42:38
Speaker 1: a lot of other questions about like matter and antimatter
42:41
Speaker 1: and the forces being unified. But those equations can't be
42:45
Speaker 1: right if the proton doesn't decay. If the proton doesn't decay,
42:48
Speaker 1: those equations are just wrong, even though they're beautiful and
42:51
Speaker 1: they're simple and they're attractive. So then we need to
42:53
Speaker 1: find some other way to solve those problems. And theoretically
42:57
Speaker 1: that's just much harder without proton decay. So it's not
43:00
Speaker 1: just a whole bunch of physicists looking staring at water.
43:03
Speaker 1: You're staring at water waiting for the proton to die, hoping, hoping.
43:07
Speaker 1: You're hoping for the proteon to die here. That's right,
43:10
Speaker 1: that's the big twist. You thought we would be rooting
43:12
Speaker 1: for the proteon to lift forever, but instead we're anti protons.
43:19
Speaker 1: You're like, just die already. We're cheering on its demise
43:22
Speaker 1: to retire and win my noble pride. That's right. Somebody
43:25
Speaker 1: in a very future universe will finally see a proton
43:28
Speaker 1: decay in a trillion trillion trillion years. I hope they're
43:31
Speaker 1: still giving out Nobel prizes. Then I hope our protons
43:33
Speaker 1: are still around. All right. Well, we hope you enjoyed
43:37
Speaker 1: that and got a little bit of a sense of
43:39
Speaker 1: how long things live in the universe. Apparently, some things do,
43:42
Speaker 1: some things don't, and it's amazing the cosmic importance of
43:45
Speaker 1: one little proton, a single proton in a vat of
43:48
Speaker 1: water in Japan, decaying could crack open the answer to
43:52
Speaker 1: these deep mysteries about the beginning of our universe, the
43:55
Speaker 1: balance between matter and antimatter, how everything fits together. It's
43:59
Speaker 1: incredibly import And then it just really highlights the connection
44:02
Speaker 1: between particle physics and cosmology and astrophysics, and really, particle
44:06
Speaker 1: physics is basically the whole universe. That's what I'm saying.
44:09
Speaker 1: She's saying, give us more money. We're studying everything that's right.
44:12
Speaker 1: That's what everything I say translates to effectively. All right, Well,
44:16
Speaker 1: I hope that give you some stuff to think about.
44:18
Speaker 1: The protons in your body and the electrons might live forever,
44:21
Speaker 1: but particle physicists are hoping they don't see you next time.
44:32
Speaker 1: Thanks for listening, and remember that. Daniel and Jorge Explain
44:35
Speaker 1: the Universe is a production of I Heart Radio. Or
44:38
Speaker 1: more podcast from my Heart Radio, visit the I Heart
44:41
Speaker 1: Radio app, Apple Podcasts, or wherever you listen to your
44:45
Speaker 1: favorite shows. Yea