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The mystery of the missing neutrinos · Daniel and Kelly’s Extraordinary Universe

0:08
Speaker 1: Hey, jorgey, have you seen a particle lying around here? Um?
0:12
Speaker 1: Why did you lose one? Yeah? I had this new trino,
0:15
Speaker 1: actually more than one, and what happened? You lost him? Yeah?
0:19
Speaker 1: It was here I turned around. You know exactly how
0:22
Speaker 1: many particles are you missing? Daniel? Let's see I want
0:26
Speaker 1: to it was about sex tillion. How do you lose
0:30
Speaker 1: a sextillion particles? Well, actually it was one sextillion particles
0:34
Speaker 1: per second. Daniel, you expect us to believe that you're
0:37
Speaker 1: not going to destroy the world with your physics experiments. Hi,
0:56
Speaker 1: I'm Jorge, I'm a cartoonists and the creator of PhD comments.
1:00
Speaker 1: Hi I'm Daniel. I'm a particle physicist, and I have
1:03
Speaker 1: not yet destroyed the world. And welcome to our new
1:07
Speaker 1: true physics crime podcast. Daniel and Jorge uncover mysteries of
1:13
Speaker 1: the universe and explain them, in which we hunt down
1:16
Speaker 1: those responsible for the missing particles. That's right, And it's
1:19
Speaker 1: always the last person you expect, or the last with
1:24
Speaker 1: the last force, the last fundamental force you expect. That's right.
1:28
Speaker 1: It was the butler in the library with the strong force.
1:34
Speaker 1: It was the butler with a particle collider using the
1:37
Speaker 1: strong force. But welcome to our podcast, in which we
1:39
Speaker 1: explore everything that's amazing about the universe, from space physics
1:43
Speaker 1: to particle physics and basically everything in between, including comics.
1:48
Speaker 1: That's right, Welcome to Daniel and Jorge Explain the Universe,
1:51
Speaker 1: a production of I Heart Radio that includes apparently even comics.
1:55
Speaker 1: I guess comics are part of the universe. Comics are
1:57
Speaker 1: made of particles, just like everything else, are they, though?
2:00
Speaker 1: Are they more like an idea or an art? Is
2:04
Speaker 1: art made out of particles? Art is just a concept
2:06
Speaker 1: in your brain. Your brain is made of particles. So yeah,
2:09
Speaker 1: basically it's math made out of particles. Okay, that's a
2:12
Speaker 1: deeper question, but our philosophy. Daniel and Jorge expound ignorantly
2:17
Speaker 1: on philosophy. Daniel Jorge get derailed in the first few
2:21
Speaker 1: minutes of every podcast. Jorge can't get to the topic
2:25
Speaker 1: of explaining the universe within ten minutes. Well, let's get
2:28
Speaker 1: into its. So today's podcast, we'll be talking about a
2:31
Speaker 1: big mystery in physics, apparently one of the biggest mysteries
2:34
Speaker 1: in particle physics. For a long time, you guys were
2:38
Speaker 1: wondering about this for a while. It seems. Yeah, we're
2:40
Speaker 1: always looking for mysteries and particle physics, and a lot
2:43
Speaker 1: of people in our field are focused on the heavy particles,
2:46
Speaker 1: the new, the big, the fat stuff, the Higgs boson
2:48
Speaker 1: the top cork, the kind of stuff you need a
2:51
Speaker 1: lot of energy to make in particle colliders. But there
2:53
Speaker 1: are also a lot of really interesting, fascinating puzzles about
2:57
Speaker 1: the tiniest, the lightest, the weird, these little particles out there. Right, Yeah,
3:02
Speaker 1: I'm not on a diet. I just need to decay
3:05
Speaker 1: some some heavy particles in my body, that's right. So
3:09
Speaker 1: this week we are cutting back on the rich diet
3:12
Speaker 1: of heavy particles we've been feeding you, and we will
3:14
Speaker 1: be sprinkling you some salad of light particles. So this
3:18
Speaker 1: was a mystery for a long time that you guys
3:20
Speaker 1: couldn't figure out, right, And it's a huge mystery. It's
3:22
Speaker 1: like sixtialing of these particles are missing every second. Yeah,
3:26
Speaker 1: I had to look that up. Sex tillion. That's ten
3:29
Speaker 1: to the twenty and so ten to the twenty. It's
3:33
Speaker 1: a big number. It's a hard number to even wrap
3:35
Speaker 1: your head around, but that's the number of neutrinos that
3:38
Speaker 1: hit the Earth every second, So then the podcast will
3:41
Speaker 1: be tackling the topic the mystery of the missing neutrinos.
3:54
Speaker 1: And this is a classic story in experimental physics when
3:57
Speaker 1: people thought they understood something basically how many neutrinos the
4:01
Speaker 1: Sun makes and how many we should see here on Earth,
4:03
Speaker 1: and then they went out to measure it and they
4:05
Speaker 1: didn't get the answer they expected, and so that was
4:07
Speaker 1: a big puzzle for a long time. Right, I mean,
4:10
Speaker 1: you guys basically deal with mysteries, right like when things
4:12
Speaker 1: go missing. That's when you guys get it excited. Well,
4:15
Speaker 1: I like to think that most of science is like
4:17
Speaker 1: a detective story. You know, you're trying to put the
4:20
Speaker 1: pieces together. You're looking for the evidence, you see if
4:22
Speaker 1: it fits. Sometimes you think maybe somebody's lied to you,
4:25
Speaker 1: and you have to try to understand did you miss here?
4:27
Speaker 1: Is the evidence wrong? You need to re measure. So
4:30
Speaker 1: a lot of science is sort of like trying to
4:32
Speaker 1: unravel a detective story. That's what's fun about it for me. Now,
4:36
Speaker 1: do you guys see yourselves more like you know, Humphrey
4:39
Speaker 1: Boger type of detectives or more like a Jim Carrey
4:43
Speaker 1: as Van Toura type of detectives more like the Woody
4:46
Speaker 1: Allen um, you know, not really understanding, worrying about imposter syndrome,
4:52
Speaker 1: you know, trying to pretend to think of yourself as
4:54
Speaker 1: Humphrey Bogard, but you dressed like as Jim Carrey. Would
4:58
Speaker 1: you look like Wooden? That kind of what I'm getting
5:01
Speaker 1: from you, and I get paid like none of them. No,
5:08
Speaker 1: but you're right, we are detectives of the universe. We
5:10
Speaker 1: are trying to understand the story of the universe. How
5:13
Speaker 1: this whole thing came together, how the holding fits together,
5:16
Speaker 1: doesn't make sense. And you know, remember that science is
5:20
Speaker 1: of the people, by the people, and for the people,
5:22
Speaker 1: and so the things we work on are the things
5:24
Speaker 1: that get us interested so that we can tell a story,
5:27
Speaker 1: so that we can try to find an interesting mystery
5:30
Speaker 1: to unravel, so that we can tell the story of
5:32
Speaker 1: the universe. And so sometimes things go missing in this universe, right,
5:36
Speaker 1: like you think that there's something or you you according
5:38
Speaker 1: to your math or your theories, you think that there
5:41
Speaker 1: should be something there or used to see a lot
5:44
Speaker 1: of something, but you don't. And so that's a that
5:46
Speaker 1: kind of throws everything into question. Yeah, and it's sort
5:49
Speaker 1: of good news and bad news. And we do this
5:51
Speaker 1: a lot in science. We say, well, we predict that
5:54
Speaker 1: if we make some measurement, you know, we know what
5:56
Speaker 1: we'll see. Like if you say, let's go count the
5:58
Speaker 1: number of red stars versus white stars. We think we
6:02
Speaker 1: know the answer, let's just go check. And usually it's
6:04
Speaker 1: a totally on You get the answer you expected, you
6:07
Speaker 1: move on. But sometimes you don't get the answer you expected,
6:10
Speaker 1: and that's either an amazing opportunity to learn something new
6:14
Speaker 1: about the universe or a huge headache. Yeah, and so
6:17
Speaker 1: the mystery that we're talking about here today is that
6:19
Speaker 1: you guys were expecting there to be a lot of
6:22
Speaker 1: neutrinos somewhere, but they're they're not there. You're missing, Yeah, exactly.
6:29
Speaker 1: We know the Sun makes a huge number of neutrinos
6:31
Speaker 1: and its fusion furnace, and a guy went out to
6:34
Speaker 1: measure these things and they're really hard to spot, and
6:37
Speaker 1: he saw a lot of neutrinos, but not nearly in
6:39
Speaker 1: the number he expected. There was an enormous number of
6:42
Speaker 1: neutrinos missing, and so that was a mystery for a
6:45
Speaker 1: long time. Yeah, Like you had some physics, it's a
6:47
Speaker 1: math about the Sun that it should be spewing out
6:50
Speaker 1: a ton of neutrinos, but we where are they? That
6:53
Speaker 1: was the mystery. That was the mystery, And so I
6:56
Speaker 1: was wondering, are people aware of this mystery? Do people
6:59
Speaker 1: know how this work? And you know here you see, Irvine,
7:01
Speaker 1: we have a special relationship with a neutrino. Do you
7:04
Speaker 1: know why? Um? I do, because I'm an avid listener
7:06
Speaker 1: of Daniel and Horry explain the universe for those of
7:09
Speaker 1: you who are, and maybe you should explain. Well, the
7:13
Speaker 1: guy who discovered the neutrino, Fred Ryness, was a professor
7:16
Speaker 1: at u C Irvine, and he won the Nobel Prize.
7:20
Speaker 1: And the building you work in, Daniel, is called after this. Yeah,
7:24
Speaker 1: it's called Ryness Hall. And I see a bust of
7:26
Speaker 1: the guy in the lobby, and you know, there's a
7:28
Speaker 1: huge picture of his experiment on the wall. And so
7:31
Speaker 1: I figured, well, most folks that you see Irvine must
7:34
Speaker 1: be aware. It's not like we're winning physics Nobel prizes
7:37
Speaker 1: every week around here, and so you got one. You
7:41
Speaker 1: should expect people to know, Yeah, exactly, And so I
7:45
Speaker 1: thought people should know about this. Probably everybody around here
7:48
Speaker 1: knows all about neutrinos. So I walked around campus to
7:50
Speaker 1: ask people if they knew what a neutrino was and
7:54
Speaker 1: if they knew about the mystery and then missing neutrinos. Yeah,
7:56
Speaker 1: so before you listen to these answers, think about it
7:58
Speaker 1: for a second. If someone asked you what a neutrino
8:01
Speaker 1: is and whether you knew that a lot of them
8:04
Speaker 1: are missing apparently, think about what you would answer. Here's
8:08
Speaker 1: what people had to say. Do you know what a
8:10
Speaker 1: neutrino is? No? No, I have not. You know they
8:13
Speaker 1: were discovered by a professor here at you see your vine. No,
8:16
Speaker 1: I didn't women about No, I've never heard of yeah neutrino. Yeah,
8:22
Speaker 1: I heard about it. I read about it. I mean
8:24
Speaker 1: I read something about that in a Physics Building US
8:27
Speaker 1: lecture hall um, But I can't remember. I know I
8:32
Speaker 1: read that someone discovered it from here as an anti
8:36
Speaker 1: neutrino or something like that. I have not. I've heard
8:40
Speaker 1: of it. Do what it is? I've I've heard of it.
8:42
Speaker 1: I don't know the specifics of what it is I have.
8:46
Speaker 1: Do you know whether neutrinos can turn into other kinds
8:48
Speaker 1: of neutrinos? No? I don't. All right, Daniel sounds like
8:52
Speaker 1: you need to do a lot more branding work there
8:54
Speaker 1: at the university. I gotta say I was a little disappointed.
8:57
Speaker 1: I mean, I love the fact that these dedans are
8:59
Speaker 1: willing to answer or a a question, that their game for it,
9:02
Speaker 1: total respect for that. But almost nobody had even heard
9:05
Speaker 1: of a neutrino. There was one guy who was like
9:07
Speaker 1: something in the physics building. Maybe I think I read
9:10
Speaker 1: about it somewhere. Sounds like, you know, he was waiting
9:12
Speaker 1: for the bathroom and killing time by reading a poster
9:15
Speaker 1: or something. Oh, that's what you should do. You should
9:17
Speaker 1: go around campus putting little like bumper stickers on the
9:21
Speaker 1: inside of bathroom stalls. That's where people do the most reading,
9:26
Speaker 1: probably if they look up from their phone, which is
9:29
Speaker 1: kind of gross if you think about it. But let's
9:32
Speaker 1: not think about that. Yes, so if you're listening to
9:33
Speaker 1: this podcast in a bathroom stall, you know, hey, think
9:36
Speaker 1: about neutrinos instead. But hey, actually you're listening to this
9:39
Speaker 1: podcast abound netrinos, so you're doing both at the same time.
9:41
Speaker 1: But yeah, maybe it would help if you change the
9:44
Speaker 1: name of your building to the neutrino something like that.
9:47
Speaker 1: You know, Yeah, perhaps perhaps Anyway, I apologize to fred
9:51
Speaker 1: Ryness and the fred Ryness family because all the students
9:53
Speaker 1: walk around campus have no idea about this incredible discovery
9:57
Speaker 1: made by physicist here on campus. That's okay, we are
10:01
Speaker 1: going to educate everybody today about the amazing particle that
10:04
Speaker 1: is the neutrino and the mystery of why they went missing.
10:07
Speaker 1: And don't feel too bad. I didn't. I don't think
10:09
Speaker 1: I knew what a neutrina was until you know, I
10:11
Speaker 1: started talking to you a couple of years ago. So
10:14
Speaker 1: it's not it's not an essential part of your diet,
10:17
Speaker 1: I guess. No. You can mostly get on with your
10:19
Speaker 1: life without knowing when antrino is, that's true. But you
10:22
Speaker 1: are sort of bombarded by them a lot. Yeah, they're
10:25
Speaker 1: everywhere around you. There are a hundred billion neutrinos passed
10:30
Speaker 1: through every square centimeter of the Earth per second. So
10:34
Speaker 1: you hold out to your fingernail, that's like the size
10:36
Speaker 1: of your thumbnail. It's a hundred billion per second. Wow,
10:40
Speaker 1: that's a lot of neutrinos in my thumb. It is
10:43
Speaker 1: a lot of neutrinos, and they're all pumped out from
10:46
Speaker 1: the fusion in the sun, like the sun when it
10:48
Speaker 1: does all that fusion. It combines all those elements to
10:51
Speaker 1: make heavier and heavier elements. It pumps out a lot
10:53
Speaker 1: of energy and a lot of that is in the
10:54
Speaker 1: term of photons, but also neutrinos because this is fusion reaction,
10:58
Speaker 1: so a lot of neutrinos are produced. Yeah, all right,
11:01
Speaker 1: so let's get down into the details of it. So
11:03
Speaker 1: let's talk about what a neutrino even is before and
11:07
Speaker 1: then we'll talk about where why people thought they were
11:10
Speaker 1: missing so many of them were missing. So, Daniel, what
11:13
Speaker 1: what is it? Neutrino? How would you describe what it is?
11:17
Speaker 1: It's a really weird little particle because it's an essential
11:20
Speaker 1: part of our sort of periodic table of particles, but
11:23
Speaker 1: it's not part of the atom. Like to make an atom,
11:26
Speaker 1: you need quirks to make protons and neutrons, and then
11:28
Speaker 1: you need an electron to go around it to balance it.
11:31
Speaker 1: Then there's this neutrino particle. What is it for? We
11:34
Speaker 1: don't really know why it exists. We found it, we
11:37
Speaker 1: see that it's there. It's sort of bounces things out
11:40
Speaker 1: a little bit, but it's not part of the atom,
11:42
Speaker 1: like you are not made of neutrinos. You aren't. There
11:44
Speaker 1: are no neutrinos in you. So it's something that can exist,
11:48
Speaker 1: right basically, and does exist a lot in the in
11:51
Speaker 1: the universe, but it doesn't really interact with anything that
11:55
Speaker 1: we're made out of, right, Like, it doesn't. You can't
11:59
Speaker 1: really feel them, that's right. Neutrinos are very snobby, and
12:03
Speaker 1: so you remember that there are several ways for particles
12:05
Speaker 1: to interact. They can interact via electromagnetism that's light, and
12:08
Speaker 1: they can interact via the strong force that's gluons that
12:11
Speaker 1: holds a nucleus together. And then there's this other force,
12:14
Speaker 1: the weak nuclear force, which is really really weak. That's
12:17
Speaker 1: the only force that neutrinos feel, right, And it's both
12:20
Speaker 1: really weak and only really works if you're really really
12:24
Speaker 1: close to it, right, Like if you're neutrina just happens
12:27
Speaker 1: to pass very very near the nuclear of your atoms,
12:32
Speaker 1: then it might react with you, right, yeah, And you
12:35
Speaker 1: can think of the weak nuclear force is sort of
12:36
Speaker 1: like another version of electromagnetism, but with a really heavy photon.
12:41
Speaker 1: Like the photon, the real one, the one that makes
12:44
Speaker 1: them light, has no mass. It flies across the universe,
12:47
Speaker 1: it can go forever right, you shine a flashlight from here,
12:50
Speaker 1: your photons can still be traveling billions and billions of
12:52
Speaker 1: miles away. But the weak nuclear forces like a version
12:55
Speaker 1: of that with a really heavy, slow photon. And and
12:59
Speaker 1: so it's really think I've ever heard of that term before, Daniel,
13:02
Speaker 1: A heavy photon. Yeah, it's like a heavy photon. And
13:04
Speaker 1: in fact, the weak forces you can have a heavy light. Yeah,
13:07
Speaker 1: I feel like that would be a great science fiction
13:10
Speaker 1: novel title heavy light. Somebody out there copyr at that.
13:14
Speaker 1: For us, it's like slow heavy light. And so it's weak,
13:17
Speaker 1: and it's very short range. And so, as you were saying,
13:19
Speaker 1: a neutrino can pass through an enormous amount of matter
13:21
Speaker 1: without interacting, Like if it passes through a light year
13:24
Speaker 1: of lead, that has a fifty percent chance of interacting.
13:27
Speaker 1: Like you you send a hundred neutrinos through light year
13:30
Speaker 1: of lead, you get about fifty of them coming out
13:32
Speaker 1: the other side not even noticing. Right, it doesn't feel
13:35
Speaker 1: the electromagnetic force, which is what you would sort of
13:39
Speaker 1: need to feel in order to like push my particles
13:42
Speaker 1: or even for me to feel really sort of feel
13:45
Speaker 1: them in the traditional sense of the word of feeling
13:48
Speaker 1: or touching something. That's right. If you shoot an electron
13:51
Speaker 1: at a light year of lead, it will bounce off
13:53
Speaker 1: the surface of it or get absorbed because they will
13:56
Speaker 1: interact with the other electrons, or it will interact with
13:58
Speaker 1: the atomic nucleus. And if you shoot a proton at
14:02
Speaker 1: a piece of lead, it will interact with the atomic
14:05
Speaker 1: nucleus via the strong force. But the neutrino doesn't feel
14:08
Speaker 1: the strong force, and it doesn't feel electromagnetism too, so
14:10
Speaker 1: they two strongest ways particles can interact. The neutrino doesn't
14:14
Speaker 1: feel at all. It's like a little ghost particle flying
14:16
Speaker 1: through the universe. And it's both a ghost and apparently
14:19
Speaker 1: um a multifaceted ghost. Yeah. It comes in three flavors,
14:24
Speaker 1: fruity ghosts and chocolate ghost and goes no, they're all
14:29
Speaker 1: diet flavors. Remember this thing has no mass, right, it's heavy.
14:34
Speaker 1: It's heavy. There's there's romaine, there's iceberg, and there's alfalfa
14:40
Speaker 1: flavored calorie wise, it's the lettuce of particles. Yes, it's
14:44
Speaker 1: the lettus of particles. Yeah, it's interesting because we have
14:47
Speaker 1: we talked on the program once about how there's different
14:50
Speaker 1: kinds of electrons. Is the electron, the one you know
14:52
Speaker 1: and love, that's part of you that makes up electricity,
14:55
Speaker 1: and then it has these cousins, the Muan and the tow.
14:57
Speaker 1: So together there's three particles. We call them leapt the electron, Mwan,
15:01
Speaker 1: and tow. The weird thing is the neutrinos also have
15:04
Speaker 1: three versions, the electron neutrino, the muon neutrino, and the
15:08
Speaker 1: town neutrino. So there's three kinds of neutrinos, just like
15:11
Speaker 1: these three kinds of electrons. Now, why are they tied
15:14
Speaker 1: to the electron and the meu on and the town.
15:15
Speaker 1: Couldn't just just call them, you know, romaine neutrino between
15:20
Speaker 1: you know, I was at the meeting and I totally
15:22
Speaker 1: suggested that and I was shot down. You know, They're like,
15:25
Speaker 1: you're just a lobbyist for big Salad, And hey, I
15:29
Speaker 1: am a lobby salad. I am a big pro salad person,
15:33
Speaker 1: all right, So but yeah, why are they sort of tied?
15:35
Speaker 1: Why do we associate them with electrons? And that's really
15:38
Speaker 1: fascinating because it turns out that each neutrino is a
15:41
Speaker 1: different kind. And if you take a neutrino, we call
15:43
Speaker 1: an electron neutrino and you interact with it using this
15:46
Speaker 1: slow photon, the w boson. Then they can turn into
15:49
Speaker 1: an electron, but a muon neutrino can only turn into
15:53
Speaker 1: a muon and a town neutrino can only turn into
15:55
Speaker 1: a towel. And so these two talk to each other.
15:58
Speaker 1: They're like paired, like the electro on and the electron
16:00
Speaker 1: neutrino come together somehow. Um, they're like part of a grouping.
16:05
Speaker 1: You know, we're always looking at particle physics for patterns
16:07
Speaker 1: and organizations, and it turns out that these two are related,
16:11
Speaker 1: and the muon and the muon neutrino related in the
16:13
Speaker 1: town the town neutrino related. There's something about the universe
16:16
Speaker 1: that that requires them to be connected, right, And you
16:19
Speaker 1: associated them with electrons because they can sort of turn
16:22
Speaker 1: into electrons or they sort of come from electrons or something.
16:26
Speaker 1: There's some something that ties them together as opposed to
16:29
Speaker 1: like tying them to like corks or something. Yeah, precisely,
16:32
Speaker 1: you can use a w boson to turn an electron
16:34
Speaker 1: neutrino into an electron, but you can't turn it into
16:37
Speaker 1: a muan neutrino. And and there's something really weird about this,
16:40
Speaker 1: Like the universe keeps count. For example, you can't turn
16:44
Speaker 1: a mu on into an electron. The universe like has
16:46
Speaker 1: account like the number of muans in the universe the
16:49
Speaker 1: number of electrons in the universe, And you can't just
16:51
Speaker 1: like take one from here and put it in the
16:52
Speaker 1: other column. The universe doesn't let you do that. You
16:55
Speaker 1: can't mix a match. You can't make some match like
16:57
Speaker 1: you might imagine, Hey, take a mu on and turn
16:59
Speaker 1: it in to an electron and a photon. Get rid
17:01
Speaker 1: of that extra mass. There's nothing physically wrong with that.
17:04
Speaker 1: We have no reason why that doesn't happen. We just
17:07
Speaker 1: don't see it, right. We just we've never seen that happen.
17:10
Speaker 1: And so for some reason, the universe likes to keep
17:13
Speaker 1: the same number of electrons and muans. They just can't
17:16
Speaker 1: turn into each other. And we thought for a long
17:19
Speaker 1: time that the same was true of neutrinos, that if
17:21
Speaker 1: you had an electron neutrino, it had to be an
17:23
Speaker 1: electron neutrino forever. You couldn't just turn it into a
17:25
Speaker 1: muon neutrino. We thought the same rule that applied to
17:28
Speaker 1: electrons also applied to neutrinos. Oh, I see, because electrons
17:34
Speaker 1: can't mix a match. You thought neutrinos couldn't mix a
17:36
Speaker 1: match between these three different kinds that it can take
17:41
Speaker 1: the form of yeah, And that's what we're doing all
17:43
Speaker 1: the time in physics. We're saying, here's a rule. How
17:45
Speaker 1: broadly does that rule apply? Right? This rule seems to
17:48
Speaker 1: apply to electrons, mules, and taels for reasons we don't understand, Like,
17:52
Speaker 1: we have no understanding for why you can't turn a
17:55
Speaker 1: mu on into an electrono photon. We just don't see it.
17:58
Speaker 1: It's just it's a descript and of what we haven't seen,
18:01
Speaker 1: not like a deep understanding of the universe. Maybe someday
18:04
Speaker 1: somebody will come up with an explanation like, oh, it
18:06
Speaker 1: makes perfect sense because these things are built out of
18:09
Speaker 1: different little you know, sub muans or something. I don't know.
18:13
Speaker 1: But so we see that happening for electronic MUAs and towels,
18:16
Speaker 1: and we thought maybe the same thing applied, right, all right,
18:21
Speaker 1: So that's in a trino. It's this kind of snobby
18:23
Speaker 1: particle that camp doesn't want to bother with us, apparently,
18:27
Speaker 1: doesn't doesn't really like us, apparently, And so I just said,
18:31
Speaker 1: it's kind of it's there in the universe, floating all
18:33
Speaker 1: around us, but it doesn't really interact with us. And um,
18:36
Speaker 1: I think if you want to learn more, we have
18:38
Speaker 1: an episode on the neutrino. Right, if you kind of
18:40
Speaker 1: scroll through, there are archives and you'll you'll find the
18:43
Speaker 1: neutrino episode just on the neutrino. Yeah, sometime late last
18:46
Speaker 1: year we put out a whole episode on the neutrino
18:48
Speaker 1: and how it's discovered and what it means and how
18:50
Speaker 1: it interacts and gory details about neutrinos. Right, all right,
18:55
Speaker 1: so let's get into how you guys lost a six
18:57
Speaker 1: stillion of them per second in this universe. It was
19:01
Speaker 1: before my time, so I don't know why you're putting
19:04
Speaker 1: the blame on me. That's sorry. We'll lay out the
19:06
Speaker 1: clues and the hints of the spoilers um of this mystery,
19:11
Speaker 1: but first let's take a quick break. Al Right, So
19:27
Speaker 1: we're surrounded by neutrinos and they're all around those but
19:29
Speaker 1: they don't they can't touch us. But at some point,
19:31
Speaker 1: you guys physicists, you guys lost a lot of them,
19:35
Speaker 1: like you didn't know where they were. I know, I
19:38
Speaker 1: had them in my hand and then I put my
19:40
Speaker 1: keys down and I turned around. You know, they were gone, Like,
19:43
Speaker 1: doesn't happen to you? And it's totally reasonable, right, did
19:46
Speaker 1: you guys try to put it pussing an ad in
19:47
Speaker 1: the back of like milk cartons or something. Yeah, we
19:50
Speaker 1: just drew a blank box. Have you seen these neutrinos?
19:53
Speaker 1: Have you seen this? Actually you can't see them. Have
19:56
Speaker 1: you detected any with some heavy water by any chance? Well,
20:01
Speaker 1: it's funny because you know, we are surrounded by neutrinos,
20:04
Speaker 1: but they're not just sitting around. It's not like we're
20:06
Speaker 1: swimming through them. We're not like in a pool of neutrinos.
20:09
Speaker 1: It's more like we're in a wind of neutrinos. Oh,
20:12
Speaker 1: I see, we're they're going through us. You know, they're
20:15
Speaker 1: not they're not even stopping relating, hanging out. Yeah. They're
20:18
Speaker 1: produced by the Sun and they shot out a great energies.
20:21
Speaker 1: Something like three percent of the energy of the Sun
20:24
Speaker 1: is pumped out just in terms of neutrinos. So that's
20:27
Speaker 1: a lot of energy. Right. The Sun is a big blob.
20:30
Speaker 1: It produces a lot of energy, and these are shot
20:33
Speaker 1: out from the Sun and you know, neutrinos are very
20:35
Speaker 1: light the way almost nothing, and so they're traveling at
20:38
Speaker 1: nearly the speed of light. Probably, like looking at the Sun,
20:41
Speaker 1: even three is enough to blind you, you know. Yeah,
20:44
Speaker 1: if neutrinos could interact with your eyeballs, that they would
20:47
Speaker 1: blind you. So don't So one more reason to not
20:50
Speaker 1: be like President Trump and look at the Sun, especially
20:54
Speaker 1: on an eclipse. Okay, so you guys calculated that the
20:58
Speaker 1: Sun should be making a lot in neutrinos a hundred
21:01
Speaker 1: billion per square centimeter per second on Earth. But um,
21:07
Speaker 1: but we didn't see that. Like that's how much your
21:09
Speaker 1: model of the sun predicted should be pumping out of
21:11
Speaker 1: the Sun. How many neutrinos should be pumping out of
21:14
Speaker 1: the Sun. But you're saying that the mystery was that
21:16
Speaker 1: we didn't see any neutrinos like that here on Earth. Yeah,
21:20
Speaker 1: and this started from like do we understand the sun?
21:23
Speaker 1: Like we think we understand what's going on. There's all
21:25
Speaker 1: these different elements in there. They're fusing. The fusion process
21:28
Speaker 1: produces this and that and heat and neutrinos. So if
21:31
Speaker 1: we understand the Sun, we should be able to check
21:34
Speaker 1: those calculations. We should be able to run a calculation
21:36
Speaker 1: that says how many neutrinos does the Sun produced per
21:39
Speaker 1: second and then go out and measure it. And this
21:42
Speaker 1: is not because people were interested in like the deep
21:44
Speaker 1: particle physics of neutrinos. People thought, oh, yeah, we understand atrinos.
21:47
Speaker 1: They just want to understand the Sun. And so they
21:50
Speaker 1: predicted how many neutrinos the Sun should produce those hundred
21:54
Speaker 1: billion per square centimeter per second, and then like looking
21:57
Speaker 1: at the chemistry of it, right, like you know that
21:59
Speaker 1: it's fusing hydrogen, and so you know what comes out
22:04
Speaker 1: of that fusion should have these percentages of stuff coming out. Yeah,
22:08
Speaker 1: and there's different mixtures and each element produces neutrinos and
22:12
Speaker 1: different energies and all this stuff. And so put that
22:15
Speaker 1: all together, it's called the standard Solar model. That's a
22:18
Speaker 1: model for like what's cooking in the Sun and what's
22:20
Speaker 1: what it's pumping out. A guy named John Bacall calculated
22:24
Speaker 1: that he had his model of the Sun and he
22:25
Speaker 1: predicted a hundred billion per square centimeter per second, and
22:29
Speaker 1: then his colleague Ray Davis said, well, I'm gonna go check,
22:32
Speaker 1: and so he built an experiment to go see neutrinos
22:35
Speaker 1: and try to measure these things and calculate how many
22:38
Speaker 1: neutrinos were actually flying into the earth. And he found
22:41
Speaker 1: what a bloody knife for He has this crazy experiment
22:46
Speaker 1: which involved a hundred thousand gallons of dry cleaning fluid.
22:53
Speaker 1: And you know, when you're physicists, you have to sort
22:55
Speaker 1: of make do, Like there's the experiment you wish you
22:58
Speaker 1: could do, and then there's the experiment you can afford
23:00
Speaker 1: to do. And usually what you can afford to do
23:03
Speaker 1: relies on what's commercially available cheap. And you know, Americans
23:07
Speaker 1: use a lot of dry cleaning fluid, so it's not
23:09
Speaker 1: that expensive to buy a lot. Is not that expensive
23:12
Speaker 1: to buy a big volume of dry cleaning fluid which
23:15
Speaker 1: contains a lot of chlorine. Oh, the chlorine was important, yes,
23:19
Speaker 1: because when an electron neutrino hits a chlorine atom, it
23:22
Speaker 1: turns it into argon. This is like alchemy, right. There's
23:25
Speaker 1: a neutron inside the chlorine nucleus, and when the neutrino
23:29
Speaker 1: hits it, it turns it into a proton and an electron,
23:32
Speaker 1: and the proton stays behind the chlorine turns into argon.
23:36
Speaker 1: So if you have a huge vat of this dry
23:39
Speaker 1: cleaning fluid. Then very occasionally one chlorine atom will get
23:43
Speaker 1: turned into argon. Wait, so a hundred thousand gallons of
23:46
Speaker 1: dry cleaning fluid was not his first choice. He had
23:51
Speaker 1: in mind something even crazier. Oh man, it's super toxic.
23:55
Speaker 1: You want to imagine working with that stuff. You probably
23:58
Speaker 1: killed off a bunch of grad students and that experiment,
24:03
Speaker 1: but they, you know, the body's worth resolved. Yeah, and
24:08
Speaker 1: the living ones never had children. So, um, what do
24:13
Speaker 1: you mean dry cleaning fluid? Is it like chloral chlorophy
24:16
Speaker 1: phil what if? What if? Yes, it's chlorophyll exactly. It's
24:22
Speaker 1: a pyro chloro floro carbon. No, No, I'm not sure
24:26
Speaker 1: exactly what it was, but it's some hydrocarbon that has
24:29
Speaker 1: a lot of chlorine in it and it's used typically
24:32
Speaker 1: in commercial applications for dry cleaning. Um. But he just
24:35
Speaker 1: had this enormous vat of it, a hundred thousand. And
24:37
Speaker 1: remember that neutrinos. There's a lot of them, but each
24:40
Speaker 1: one is a very small chance of interacting. So the
24:42
Speaker 1: bigger your volume, the more likelihood you are to get
24:46
Speaker 1: one of these chlorine atoms to turn into argon. So
24:49
Speaker 1: he was just looking at a handful of things a
24:51
Speaker 1: year of these events. Yeah, it's not like, you know,
24:54
Speaker 1: you turn this thing on and you got chlorine popping
24:57
Speaker 1: into argon every two seconds. You know, It's more like
24:59
Speaker 1: once a month maybe if you're lucky. It's kind of
25:01
Speaker 1: like a laying out a giant net, right, That's what
25:04
Speaker 1: these giant vad was, right, which just like like a
25:07
Speaker 1: catcher's mid for neutrinos, because neutrinos don't really interact with
25:11
Speaker 1: the walls or the you know, the ground of the earth,
25:16
Speaker 1: of the clouds of the atmosphere, but they do interact
25:18
Speaker 1: kind of with chlorine atoms in a way that you
25:21
Speaker 1: can observe. Yeah, they interact with all that other stuff too,
25:24
Speaker 1: but just really rarely and chlorine atoms. You can get
25:26
Speaker 1: a really pure sample that has almost no argon in it,
25:29
Speaker 1: and the only way to turn chlorine into ar gon
25:32
Speaker 1: basically is to hit it with a new trino. So
25:34
Speaker 1: any are gone in there you can mostly assume came
25:37
Speaker 1: from neutrinos. So that's why he chose that substance, and
25:41
Speaker 1: then he could bubble it out every once in a
25:43
Speaker 1: while and see if he found ar gone in there.
25:45
Speaker 1: And how do you think he's sourced that hundred thousand
25:47
Speaker 1: gallons of dry I think he had a front. He
25:49
Speaker 1: just called the local local fashion cleaners and worlds like, hey,
25:55
Speaker 1: can you do this tomorrow? No, he probably just drove
25:57
Speaker 1: around to the dumpster behind the local dry cleaners and
26:00
Speaker 1: just used theirs, you know, all right, So that's how
26:02
Speaker 1: you that's how you measured. He measured. He put out
26:04
Speaker 1: a giant vat of it try to catch them, and
26:06
Speaker 1: he didn't see enough. He didn't catch enough to kind
26:09
Speaker 1: of justify the model of the sun that we had. Yeah,
26:12
Speaker 1: John McCall's calculation predicted a hundred billion per square centimeters
26:15
Speaker 1: per second, and he did his calculation and integrated it
26:18
Speaker 1: all and he got about a third of that value.
26:21
Speaker 1: So he was so two thirds of the neutrinos were missing,
26:24
Speaker 1: like an enormous number, sixty six billion per square centimeter
26:27
Speaker 1: per second. We're just gone, just missing, just not there,
26:32
Speaker 1: just not there. And so he went back to his
26:34
Speaker 1: friend and said, did you check your calculations? Are you
26:37
Speaker 1: sure the sun is pumping all those numbers out? Were
26:41
Speaker 1: they friends? Were they? Yeah? They were friends? There they
26:43
Speaker 1: were you know, this is a scientific collaboration. And they
26:46
Speaker 1: both ended up with Nobel prizes, so everybody's happy. But
26:49
Speaker 1: they he went back to checked his numbers, and you know,
26:51
Speaker 1: with the sun, there are things you can observe the
26:54
Speaker 1: solar model predicts also light and other things, and so
26:57
Speaker 1: there's a lot of ways to check that his model
26:58
Speaker 1: of the sun was right. And he went back and
27:00
Speaker 1: he double checked everything, and he's like, you know, I'm
27:02
Speaker 1: pretty sure my model of the Sun is correct. And
27:05
Speaker 1: we had a pretty solid understanding of solar physics and
27:07
Speaker 1: astrophysics at the time. So the question was then, see then,
27:11
Speaker 1: like did you did you take did you make a
27:14
Speaker 1: mistake in your um how many grad students did you
27:18
Speaker 1: dissolve in the drug cleaning fluid did you use did
27:22
Speaker 1: you use dry cleaning fluid or brand new dry cleaning fluid?
27:26
Speaker 1: You know, well, that's why it's sometimes an amazing opportunity,
27:30
Speaker 1: but also sometimes the headache, like sometimes the explanation is prosaic,
27:33
Speaker 1: you know, like oops, you jiggled the cable and it
27:36
Speaker 1: wasn't connected correctly and that's the source of every problem.
27:39
Speaker 1: Or remember that new Trino experiment that thought they discovered
27:41
Speaker 1: new trina is going faster than light. And then the
27:43
Speaker 1: answer was wiring. Yeah, they didn't jiggle the cable correctly.
27:47
Speaker 1: So often the mistake is just that there's simple as
27:50
Speaker 1: a calculation or some other small bug. But sometimes it's
27:54
Speaker 1: a big clue that that gives you insight into how
27:56
Speaker 1: the universe works. And what do you think that moment was? Like?
28:00
Speaker 1: You know, like if you expect to see you know,
28:02
Speaker 1: if you expect your three kids to go home one day,
28:04
Speaker 1: when only one of them comes home, you know, that's
28:06
Speaker 1: a big well, it depends on which kid. I guess,
28:14
Speaker 1: not your favorite one. Um no, I think it must
28:18
Speaker 1: have been exciting. I think probably the first of his frustraants.
28:20
Speaker 1: Ah man, something's wrong, you know. But we are detectives
28:24
Speaker 1: in me and we like to unravel this stuff. We
28:26
Speaker 1: like to think about ways to double check your answers,
28:29
Speaker 1: and let's check this, and let's check that, and let's
28:30
Speaker 1: check this other thing and everything. Everybody double checked it.
28:33
Speaker 1: And then other people did experiments, you know, not just
28:36
Speaker 1: this one guy with his vada experiment with his Vada fluid.
28:39
Speaker 1: Other people did experiments with other substances, and everybody agreed.
28:43
Speaker 1: We were seeing about one third of the neutrinos that
28:45
Speaker 1: we expected to see. So somewhere between the Sun that
28:49
Speaker 1: you know, spewing out all of these neutrinos and your
28:53
Speaker 1: vat of dry cleaning fluid, two thirds of those neutrinos
28:57
Speaker 1: go missing, disappear exactly, have no alibi, all right. So
29:02
Speaker 1: that so that was a big mystery in physics, and
29:04
Speaker 1: it was it was a big deal, right, because it's
29:06
Speaker 1: sort of you know, there's a lot in in this theory,
29:09
Speaker 1: in this prediction, right, there's your understanding of the sun,
29:12
Speaker 1: there's your understanding of particles, there's your understanding of how
29:15
Speaker 1: particles interact with other particles, and so like, if this
29:18
Speaker 1: is not jiving, then that's that's kind of a big deal. Yeah,
29:21
Speaker 1: And it was an outstanding mystery for decades. It was like,
29:24
Speaker 1: here's something we don't understand. Maybe somedays somebody will figure
29:27
Speaker 1: it out, um, and so decades really for decades. Yeah,
29:31
Speaker 1: Davis started his experiments in the sixties, and so this
29:34
Speaker 1: is something which was an outstanding problem in physics for
29:37
Speaker 1: a while. And you know, we have those problems today,
29:39
Speaker 1: like a list of things we don't understand, like what
29:41
Speaker 1: is dark matter. Eventually that will be a history problem,
29:44
Speaker 1: all right, we'll know the answer and we'll look back,
29:46
Speaker 1: but at the time it's just a question mark. And
29:49
Speaker 1: so this was an open question for a long time.
29:51
Speaker 1: I feel like it's one of those primetime specials, you know,
29:55
Speaker 1: years later, the mystery still bothers him. I wish sometimes
29:59
Speaker 1: we could just like fast forward, do a musical montage,
30:01
Speaker 1: like like a musical montage my way to the answer
30:04
Speaker 1: what is dark matter? She has some physicist hitting the
30:07
Speaker 1: boxing um what we called the boxing ball, putting on
30:11
Speaker 1: a lab coat, standing at the chalkboard, looking confused, having
30:15
Speaker 1: a moment of inspiration running Philadelphia Courthouse guests exactly, low,
30:24
Speaker 1: please provide the sound music for that musical montage. But yeah,
30:30
Speaker 1: and then finally the mystery was solved. Right, finally, you
30:33
Speaker 1: guys figured it out. They found the missing nutrinas we
30:36
Speaker 1: did find the missing neutrinos. All right, let's get into
30:39
Speaker 1: how they found these missing neutrinos. But first let's take
30:42
Speaker 1: another quick break. All right, Daniels, how did they find
30:56
Speaker 1: the missing six dillion neutrinos per second that were somehow
31:01
Speaker 1: misplaced by physicists. Well, they had this idea. They thought, well,
31:04
Speaker 1: maybe then trinos aren't missing, maybe they're just hiding, and
31:08
Speaker 1: maybe they're hiding because they turned into other types of neutrinos.
31:13
Speaker 1: And we talked earlier about how there's three kinds of
31:15
Speaker 1: neutrinos electrons, muans, and towels, and they thought, well, what
31:18
Speaker 1: if some of these are turning into muan neutrinos or
31:22
Speaker 1: some of these are turning into town neutrinos. Oh my god,
31:24
Speaker 1: they faked their death. That is such a standard opera
31:29
Speaker 1: plot points. Should have been the first thing we thought of, Right,
31:31
Speaker 1: did you look for neutrino with a weird mustache on it,
31:34
Speaker 1: check to see if they had they had any large
31:36
Speaker 1: outstanding debts or something. Yeah, Well, we thought, remember, well,
31:40
Speaker 1: we're sure that electrons and muans can't turn into each other.
31:43
Speaker 1: We know that doesn't happen. We don't know why, but
31:45
Speaker 1: we've never seen it happen. Dedicated experiments looking for that
31:48
Speaker 1: haven't seen it. But people thought, you know, we could
31:51
Speaker 1: explain this mystery if if electron neutrinos were turning into
31:55
Speaker 1: muans and tows wouldn't another kind of neutrino interact with chlorine? Also, like,
32:01
Speaker 1: how does that explain? No, it wouldn't. So a muan
32:04
Speaker 1: neutrino that comes and hits the chlorine, doesn't turn it
32:07
Speaker 1: into argon. What does it do something different or it
32:10
Speaker 1: just doesn't interact with the chlorine. It doesn't interact with
32:13
Speaker 1: the chlorine in a way that turns into argons. You
32:14
Speaker 1: can't measure muan neutrinos or town neutrinos um by looking
32:18
Speaker 1: at chlorine. And so what people did was they built
32:21
Speaker 1: another experiment, one that was sensitive to muans and one
32:24
Speaker 1: that was sensitive to town neutrinos. So there's an experiment
32:28
Speaker 1: called the Snow experiment. It was at Submarine Neutrino Observatory
32:32
Speaker 1: and it could detect separately the rates of electron muan
32:36
Speaker 1: and town neutrinos. And then they found them. And then
32:38
Speaker 1: they found them, They're like, uh, there they are. We
32:41
Speaker 1: saw them, these neutrinos. So you use your credit card.
32:44
Speaker 1: You're still alive. Precisely, they were able to spot them
32:47
Speaker 1: into those neutrinos are they're They're just a different flavor.
32:51
Speaker 1: So there's a bunch of neutrinos coming from the Sun.
32:53
Speaker 1: Some of them turned into different kinds of neutrinos, and
32:57
Speaker 1: then they go through us and the Earth. And you're
33:00
Speaker 1: saying that they were only missing because we weren't looking
33:04
Speaker 1: for the right kind of neutrino precisely. And it's important
33:07
Speaker 1: to understand the Sun only makes electron neutrinos. There's three
33:10
Speaker 1: different kinds where the Sun just makes electron it's like
33:13
Speaker 1: a pure source of electron neutrinos because you have electrons
33:16
Speaker 1: and fusion, right, the electrons with the lightest ones, and
33:19
Speaker 1: so electrons are the thing that's in the atom, and
33:22
Speaker 1: so electron neutrinos or what's made in the sun. So
33:25
Speaker 1: the Sun produces all these electron neutrinos. But then there's
33:28
Speaker 1: three kinds, and so by the time they get here,
33:30
Speaker 1: they sort of sloshed around and some of them become
33:32
Speaker 1: muns and some of them become town neutrinos. Right, And
33:35
Speaker 1: they do this randomly or is it like a their
33:38
Speaker 1: decay from like an energy high energy state to a
33:41
Speaker 1: lower energy state or is it just kind of random?
33:43
Speaker 1: Like do they I want to? I feel like more
33:45
Speaker 1: like a towel. Is that how you get dressed every day?
33:48
Speaker 1: So sort of randomly quantum mechanical wardrobe to I feel
33:52
Speaker 1: like the working cartoon is tomorrow. I don't know if
33:55
Speaker 1: you just invented quantum fashion. Jorge, Yeah, um, though it's
34:00
Speaker 1: not entirely random, there's some random element to it, but
34:03
Speaker 1: it's actually really fascinating and reveals something really deep about neutrinos.
34:08
Speaker 1: You see, the weak force the thing that can interact
34:11
Speaker 1: with neutrinos. It sees neutrinos differently than the Higgs boson does.
34:16
Speaker 1: So those w bosons and the Higgs bosons are sort
34:18
Speaker 1: of disagreeing about how to talk to the neutrinos. Wait,
34:22
Speaker 1: what what do you mean? Yeah, well, so the weak
34:25
Speaker 1: force says, okay, there's three kinds of neutrinos. There's electron neutrinos, mionutrinos,
34:29
Speaker 1: and town neutrinos. And like I said earlier, the difference
34:32
Speaker 1: between those is that the weak force can turn an
34:34
Speaker 1: electron neutrino into an electron or a muon neutrino into
34:38
Speaker 1: a muon. That's how the weak force sees neutrinos. But
34:41
Speaker 1: the Higgs boson comes along and it says, no, no, no,
34:44
Speaker 1: there's three neutrinos. There's numbers one, two, and three, the
34:47
Speaker 1: lightest one, the medium one, and the heaviest one. And
34:50
Speaker 1: you're like, okay, that's cool, which one is which? But
34:53
Speaker 1: it turns out they don't overlap. It's not like neutrino
34:56
Speaker 1: number one is the electron neutrino, and two number two
35:00
Speaker 1: who is the muon neutrino the Higgs boson. What it
35:03
Speaker 1: says electron number one, it means a weird mixture of electron,
35:07
Speaker 1: muon and taw, and the Higgs boson neutrino number two
35:10
Speaker 1: is a different mixture of electron, muon and tao. So
35:13
Speaker 1: it's like these things look at it totally differently. They
35:15
Speaker 1: see a different mixture. Are they still different things or
35:18
Speaker 1: does it depend on who's interacting with them. It depends
35:20
Speaker 1: on who's interacting with it. So if you're just flying
35:23
Speaker 1: through space, what you need is to have a certain mass,
35:26
Speaker 1: Like for a particle to fly through space, you need
35:27
Speaker 1: to be a thing. You need to have a fixed mass.
35:31
Speaker 1: Your mass can be zero or whatever, like for a photon,
35:33
Speaker 1: but for any particle to propagate through space, it needs
35:37
Speaker 1: to have its mass specified. Remember that's how you get
35:40
Speaker 1: masses by moving through the Higgs field. So the Sun
35:43
Speaker 1: makes you using the weak interaction. You're an electron neutrino,
35:46
Speaker 1: you're flying through space, you have mass because of the
35:50
Speaker 1: Higgs boson, and then you're either electron one, two or three, right,
35:54
Speaker 1: But the electron neutrino is a weird mixture of one, two,
35:57
Speaker 1: and three. So as it's flying through ace, these things
36:01
Speaker 1: fly through space differently. The electron one, electron two, electron
36:04
Speaker 1: three parts of the electron neutrino fly through space differently,
36:08
Speaker 1: So by the time they get to Earth, you have
36:10
Speaker 1: a different mixture of electron one, two, and three. And
36:12
Speaker 1: maybe you're amuan neutrino or maybe your town neutrino. Wow,
36:16
Speaker 1: that makes no sense, Daniel. So I start off as
36:21
Speaker 1: one kind of netrino and you're saying that on the way,
36:24
Speaker 1: the universe just kind of like looks at me differently.
36:27
Speaker 1: And by the time I get to my destination and
36:29
Speaker 1: two different things. Say your family goes on a trip together,
36:32
Speaker 1: and one of you is thirsty and one of you
36:34
Speaker 1: is hungry, and one of you is totally satisfied. Now
36:36
Speaker 1: along the way, maybe you get some food and drink.
36:39
Speaker 1: So by the time you get your location, the different
36:42
Speaker 1: people in your family are feeling different than when they
36:44
Speaker 1: left because the trip has been a different experience for
36:47
Speaker 1: each of you. So by the time you get there,
36:50
Speaker 1: it's kind of like you're a different family. But that's
36:53
Speaker 1: because like time has passed and maybe I got thirstier
36:56
Speaker 1: or hungrier, or I drank some water on the way.
36:58
Speaker 1: Is there something actually happened on the way for these
37:00
Speaker 1: neutrinos or is it just kind of like a the
37:03
Speaker 1: universe sort of corrects itself, and the different parts of
37:07
Speaker 1: the electron neutrino fly through space differently because they have
37:10
Speaker 1: different masses. The electron neutrino doesn't actually have like a
37:13
Speaker 1: mass like you can say with the mass of the
37:15
Speaker 1: electron is but the electron neutrino doesn't have a mass.
37:18
Speaker 1: It's a weird mixture of three neutrinos that do have masses.
37:22
Speaker 1: So there's a different categorization, like a different set of
37:26
Speaker 1: names based on the Higgs. Yes, there's different ways to
37:29
Speaker 1: categorize neutrinos, and the Higgs boson categorizes them one way
37:32
Speaker 1: and the weak force categorizes them differently. They don't agree.
37:37
Speaker 1: And the Higgs force decides how you get mass, and
37:39
Speaker 1: so it says you get this mass, you get that mass,
37:42
Speaker 1: you get this other mass, and the weak force decides
37:45
Speaker 1: what particle you turn into, like you turn into electron,
37:47
Speaker 1: you turn into new and you turn into a tow
37:49
Speaker 1: and because they don't agree, you get these really weird behaviors.
37:53
Speaker 1: But then what comes out the other what arise here
37:55
Speaker 1: on Earth is actually two different Is it still the
37:59
Speaker 1: same electron neutrino or is it now something that's been
38:03
Speaker 1: changed because of the what happens when you go through
38:06
Speaker 1: the actual universe, it's something that's been changed. And so
38:10
Speaker 1: electron neutrina starts out with some mixture of of neutrino one, two,
38:14
Speaker 1: and three, and then those fly through space differently because
38:17
Speaker 1: they have different masses, and by the time it gets here,
38:20
Speaker 1: it's a different mixture, and that different mixture can be
38:22
Speaker 1: more likely to be a muan neutrino. So then when
38:24
Speaker 1: it gets to Earth it can be like, oh you
38:26
Speaker 1: know what, now I'm the meu and neutrino. But when
38:28
Speaker 1: it interacts with like argone than it does care whether
38:31
Speaker 1: it's precisely then it does care. And so when they
38:35
Speaker 1: it cares at the beginning at the end. But the
38:37
Speaker 1: suwhere in the middle of the universe is like no, no, no, no, no,
38:39
Speaker 1: I don't I don't like what you're starting out with.
38:42
Speaker 1: I'm gonna change up your identity. Yeah, it's like it
38:44
Speaker 1: spins all the knobs in flight, and then when you
38:47
Speaker 1: get here you're like, huh, you're totally different. You know.
38:50
Speaker 1: It's like if everybody got an airplane and then in
38:54
Speaker 1: flight you like swapped heads and legs of all the passengers, right,
38:58
Speaker 1: and then when you got the other to the flight,
39:00
Speaker 1: you'd be like, wow, I don't recognize anybody. That is
39:05
Speaker 1: both disturbing and also confusing. It's is it more like
39:09
Speaker 1: kind of like you know, like um, like shooting light
39:12
Speaker 1: through a prism or something like somehow going through the
39:14
Speaker 1: medium separates out the nature of it. Yeah, it's it's
39:18
Speaker 1: a lot like that. Um. And for those people who
39:21
Speaker 1: are like really good with linear algebra, it's essentially what
39:24
Speaker 1: you're doing is you're rotating the basis set. You have
39:26
Speaker 1: a different eigenvectors that describe the sort of space of particles,
39:31
Speaker 1: and the Higgs boson uses one set of eigenvectors and
39:33
Speaker 1: the weak forces a different set, and they don't agree,
39:35
Speaker 1: so you can rotate from one to the other. And
39:37
Speaker 1: why is there such a discrepancy between what the universe
39:41
Speaker 1: sees or things and what the math and the physics
39:44
Speaker 1: and the collisions all predict. We don't know. We don't
39:47
Speaker 1: know why the weak force and the Higgs boson see
39:49
Speaker 1: these things differently. It's fascinating. We just don't know why
39:52
Speaker 1: they don't agree. They're very different forces, right, and so
39:55
Speaker 1: they I guess they have the right to make whatever
39:57
Speaker 1: choice they like, But we don't know. We don't know.
40:00
Speaker 1: I um they're rotated in this way, like why neutrinos one, two,
40:04
Speaker 1: and three are not aligned with the electron, muon and
40:07
Speaker 1: town neutrinos because it's not the case for the other particles,
40:10
Speaker 1: like the EMU and tao. The weak force interacts with
40:13
Speaker 1: them the same way the Higgs boson does. Like the
40:14
Speaker 1: electron has a specific mass, the muon has a specific mass,
40:18
Speaker 1: and so does the too. So it's a weird twist
40:21
Speaker 1: that only happens for neutrinos. It's like in the Murder Mystery,
40:24
Speaker 1: it's like, no, actually turned out nobody killed Mr Green.
40:27
Speaker 1: Actually he turned into Mrs Mrs Plum. Turns out Mr
40:31
Speaker 1: Green has two identical twins or a member of identical triplets,
40:35
Speaker 1: and they all speak weird accents, and due to some
40:38
Speaker 1: magical or unexplainable quantum phenomenon of the universe that's what happened. Yeah,
40:43
Speaker 1: and it's not something we understand, and we actually don't
40:46
Speaker 1: even understand how the neutrinos talked to the Higgs boson,
40:49
Speaker 1: Like most particles get their mass from the Higgs boson,
40:52
Speaker 1: but we don't actually know the neutrinos do, because that
40:56
Speaker 1: to get your mass from the Higgs boson, you have
40:57
Speaker 1: to have a particle and an antiparticle, like the electron
41:00
Speaker 1: and the anti electron. But we don't know if neutrinos
41:03
Speaker 1: have antiparticles or if they are their own antiparticles the
41:07
Speaker 1: way a photon is. So there's a lot of mysteries
41:10
Speaker 1: about neutrinos. I feel like we started out with such
41:12
Speaker 1: an um simple mystery where are they? And we've turned
41:15
Speaker 1: out like turning into a fundamental mystery of the universe
41:19
Speaker 1: that we don't know precisely. And that's what's amazing about
41:21
Speaker 1: these experimental checks. You know, they go out there like, yeah,
41:24
Speaker 1: we think we understand this, let's just go double check.
41:26
Speaker 1: Huh didn't work. I wonder what that means? Dot dot
41:29
Speaker 1: dot crack open deep mystery of the universe. Right, that's
41:32
Speaker 1: the possibility every time you're about to do a boring
41:34
Speaker 1: experiment is that it could be the thread that unravels
41:37
Speaker 1: your entire understanding of something fundamental about the universe. And
41:41
Speaker 1: you wouldn't maybe think that was the case, just because
41:43
Speaker 1: these particles are so inconsequential to our everyday lives, right,
41:48
Speaker 1: so non interactive with everything else. But it turns out
41:51
Speaker 1: then maybe cracking them open what tell us a lot
41:56
Speaker 1: about the universe. Yeah, they are. There are a lot
41:58
Speaker 1: of them, and they ignore, but they have a lot
42:01
Speaker 1: of tiny little clues and when you add them all up,
42:03
Speaker 1: they tell you something really fascinating about how the universe works.
42:06
Speaker 1: And there's a lot of mysteries there. We still don't
42:08
Speaker 1: know the answer to um. There might be CP violation
42:11
Speaker 1: in neutrinos, to all sorts of weird stuff. But they're
42:14
Speaker 1: really challenging to measure because they mostly ignore you, and
42:17
Speaker 1: so you have to build really big detectors and wait
42:19
Speaker 1: a long time just to do anything basically with neutrinos.
42:22
Speaker 1: Is this going to drive out the price of my
42:24
Speaker 1: drug cleaning? Daniel? Is what I is? How I wouldn't know.
42:28
Speaker 1: Let's bring this back to me, right. I have seen
42:33
Speaker 1: sort of a lot of like a lot of particle physics.
42:36
Speaker 1: I know in your field is sort of turning towards
42:39
Speaker 1: neutrinos because it is sort of like a place where
42:41
Speaker 1: there are still a lot of big open questions. Yeah,
42:44
Speaker 1: the entire United States high energy community is turning towards neutrinos,
42:48
Speaker 1: focusing their energy on these questions because we think that
42:50
Speaker 1: there are a lot of mysteries there that might be open.
42:53
Speaker 1: In fact, there probably are still questions we don't even
42:56
Speaker 1: know how to ask about neutrinos. It's like the beginning
42:59
Speaker 1: of a field uh neutrino physics. So there's a bright future.
43:02
Speaker 1: There's a lot of people working on it, a lot
43:04
Speaker 1: of really fascinating questions, and I think in ten years
43:06
Speaker 1: will know a lot more about the way the whole
43:08
Speaker 1: universe works, just from these tiny, little ghostly particles. All Right,
43:12
Speaker 1: so we we figured out the mystery, Daniel, we will
43:16
Speaker 1: take credit. What fraction the Nobel Prize did we get
43:18
Speaker 1: I don't remember, as John Renes with the weak fours
43:22
Speaker 1: in the in the Mysterious Force, in the Underground lab
43:29
Speaker 1: the Unknown, Deep Mystery of the Universe. It was Ray
43:31
Speaker 1: Davis with a hundred thousand gallons of dry cleaning underground.
43:35
Speaker 1: So the next time you look out into the universe
43:37
Speaker 1: or see will not see this time, but be out
43:40
Speaker 1: on a sunny day and look the sunlight all around you.
43:42
Speaker 1: Maybe think about all the mysterious little neutrinos that are
43:45
Speaker 1: going through you and everything else, and what secrets of
43:48
Speaker 1: the universe they are hiding. We hope you enjoyed that.
43:51
Speaker 1: Thanks for joining us, See you next time. Before you
44:01
Speaker 1: still have a question after listening to all these explanations,
44:04
Speaker 1: please drop us the line. We'd love to hear from you.
44:07
Speaker 1: You can find us on Facebook, Twitter, and Instagram at
44:10
Speaker 1: Daniel and Jorge That's one Word, or email us at
44:13
Speaker 1: Feedback at Daniel and Jorge dot com. Thanks for listening
44:17
Speaker 1: and remember that Daniel and Jorge Explain the Universe is
44:20
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