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Why are neutrinos so light? · Daniel and Kelly’s Extraordinary Universe

• 0:08
  Speaker 1: Hey, Daniel, do you think antiparticles feel bad? What do
• 0:12
  Speaker 1: they have to feel bad about? I think anti particles
• 0:15
  Speaker 1: are super cool. Yeah, but you know, who wants to
• 0:17
  Speaker 1: be labeled anti anything? Nobody wants to be the bummer
• 0:20
  Speaker 1: in the room, you know. I guess that's true. If
• 0:22
  Speaker 1: you're a cartoonist, does that make me an anti cartoonist?
• 0:25
  Speaker 1: That doesn't sound very cool. What do you have against cartoons?
• 0:29
  Speaker 1: Does that make me the anti physicist? I don't know.
• 0:32
  Speaker 1: I guess it's like with twins, right, there's always one
• 0:34
  Speaker 1: evil twin. I think that's only true and soap operas.
• 0:38
  Speaker 1: Maybe I'm watching too many telenovelas. But you know, in
• 0:41
  Speaker 1: particle physics there is one particle like the photon, which
• 0:45
  Speaker 1: is its own anti particle. Really, it's its own evil twin.
• 0:50
  Speaker 1: That's right from the mouth of an anti physicist. Hi
• 1:08
  Speaker 1: am more handmade cartoonists and the creator of PhD comics. Hi,
• 1:12
  Speaker 1: I'm Daniel. I'm a particle physicist, and I'm not sure
• 1:14
  Speaker 1: yet whether I'm a physicist or an evil physicist. And
• 1:18
  Speaker 1: my physicist or my appro physicist. I guess it depends
• 1:22
  Speaker 1: on who destroys the world first. Well, I am definitely
• 1:24
  Speaker 1: anti destroying the world, Daniel, I know that for sure.
• 1:29
  Speaker 1: I am pro learning about the universe while not destroying it. Okay,
• 1:33
  Speaker 1: even a while prefix although you know, somebody gave me
• 1:36
  Speaker 1: the option, like, what if you could learn all the
• 1:39
  Speaker 1: secrets of the universe, but in doing so destroy it.
• 1:42
  Speaker 1: That would be a difficult choice. That would be a
• 1:44
  Speaker 1: difficult choice. Oh my god, somebody take this man's finger
• 1:49
  Speaker 1: off the button and away from any responsibility. Please. I
• 1:53
  Speaker 1: second that, I second man. But welcome to our podcast,
• 1:56
  Speaker 1: Daniel and Rhead hopefully don't destroy the universe, a production
• 2:00
  Speaker 1: of I Heart Radio in which we avoid destroying the
• 2:04
  Speaker 1: universe instead take it apart gently, piece by piece, and
• 2:08
  Speaker 1: put it back together in a way that makes sense
• 2:11
  Speaker 1: to you. And we like to talk about the galaxies
• 2:14
  Speaker 1: out there, the stars and the planets and all of
• 2:16
  Speaker 1: the incredible nebula out there in the cost. But we
• 2:19
  Speaker 1: also like to talk about the small things, the little
• 2:21
  Speaker 1: things in life and in the universe, the things that
• 2:24
  Speaker 1: we are all made out of, like the particles, that's right,
• 2:26
  Speaker 1: and the things that everybody is puzzling about. We think
• 2:29
  Speaker 1: that everybody wants to know how the universe works. And
• 2:32
  Speaker 1: you deserve an explanation that's not just the very basics,
• 2:35
  Speaker 1: the dumb down version, but an answer that takes you
• 2:38
  Speaker 1: all the way to the forefront of knowledge, that helps
• 2:41
  Speaker 1: you understand what science doesn't know right now. Yeah, because
• 2:45
  Speaker 1: scientists have this standard model of matter in the universe,
• 2:49
  Speaker 1: is sort of collection of particles and force particles that
• 2:54
  Speaker 1: they call the Standard Model of physics. Yeah, what do
• 2:57
  Speaker 1: you think about that name? The standard Model? You give
• 2:59
  Speaker 1: that an A rating. It's pretty standard, I guess for
• 3:04
  Speaker 1: physicists to claim something is standard, Yeah, I guess so.
• 3:08
  Speaker 1: And next I'm gonna tell you it's not actually great,
• 3:11
  Speaker 1: it's non standard. Now we have the standard model and
• 3:14
  Speaker 1: it has particles in it that make up stuff. Those
• 3:17
  Speaker 1: are matter particles like electrons and corks and that kind
• 3:21
  Speaker 1: of stuff. And we have particles that represent forces like
• 3:24
  Speaker 1: photons represent electromagnetism, and W and Z particles represent the
• 3:30
  Speaker 1: weak force, and the gluons represent the strong force. And
• 3:33
  Speaker 1: then in two thousand and twelve, we found the missing particle,
• 3:37
  Speaker 1: the Higgs boson. And you'll hear a lot of people
• 3:40
  Speaker 1: describe the Standard model as finally complete, like the Higgs
• 3:43
  Speaker 1: boson is the cap on the top of the period
• 3:46
  Speaker 1: and so, and do you haven't found anything new since?
• 3:48
  Speaker 1: Even though you've been like colliding particles but higher and
• 3:51
  Speaker 1: higher energy, you haven't found anything you used since? Do
• 3:55
  Speaker 1: you sound like sort of demanding, like, hey, what do
• 3:57
  Speaker 1: you discovered for me lately? You know? But yeah, where
• 4:01
  Speaker 1: my tax dollars are going to your salaries? That's true,
• 4:04
  Speaker 1: But remember that searching for new discoveries and particle physics
• 4:07
  Speaker 1: is like exploring. We're like wandering around the surface of Mars,
• 4:11
  Speaker 1: turning over rocks, hoping to find little green men or
• 4:14
  Speaker 1: weird new kinds of life. And it's true that since
• 4:17
  Speaker 1: two thousand twelve we have not found any new particles
• 4:20
  Speaker 1: at the large Hage Junklelider. And that gives some people
• 4:23
  Speaker 1: the feeling like, well, maybe the Standard Model is all
• 4:25
  Speaker 1: wrapped up. Maybe that's all there is. Maybe we can
• 4:28
  Speaker 1: just tighten the bow and move on. But there are
• 4:32
  Speaker 1: lots of really weird little problems with the Standard Model,
• 4:35
  Speaker 1: lots of interesting discoveries we've made along the way. Yeah,
• 4:38
  Speaker 1: it seems like a lot of big physics projects in
• 4:40
  Speaker 1: the US and internationally have sort of turned inwards to
• 4:44
  Speaker 1: look at one particular particle in the standard model, which
• 4:47
  Speaker 1: is the new trino. That's right. Often described as the
• 4:51
  Speaker 1: weirdest little particle, but not because they're rare. Really, yeah,
• 4:55
  Speaker 1: you call it the weirdest little particle. Yes, in a
• 4:57
  Speaker 1: in a totally positive way, in a in a very
• 5:00
  Speaker 1: loving we love you literal neutrinos. No, seriously, so weird
• 5:05
  Speaker 1: we like you anyways. Is that kind of what you're saying. Yes,
• 5:08
  Speaker 1: Physicists love the weird, the strange, the unexplained. That's where
• 5:12
  Speaker 1: the clues are, right, that's where the hints are to
• 5:14
  Speaker 1: tell you how to unravel the secrets of the universe.
• 5:17
  Speaker 1: If you look at everything and it just sort of
• 5:18
  Speaker 1: like makes sense instantly, well, that's boring. We want to puzzle,
• 5:21
  Speaker 1: We want something strange and weird, and so neutrinos are fascinating,
• 5:25
  Speaker 1: but again not because they're rare. They're everywhere. There's a
• 5:28
  Speaker 1: hundred billion neutrinos passing through my fingernail every second. But
• 5:32
  Speaker 1: there's so much that we still don't understand about them,
• 5:35
  Speaker 1: really basic questions that just don't have answers to. Yeah,
• 5:38
  Speaker 1: we are awash in neutrinos. There's no lack of neutrinos
• 5:41
  Speaker 1: in the world around you. But there is one question
• 5:44
  Speaker 1: about them that still puzzles physicists, and that's the topic
• 5:48
  Speaker 1: of today's episode. So to be on the podcast will
• 5:50
  Speaker 1: be tackling the question wire neutrinos so light? Why are
• 6:00
  Speaker 1: they light? Not light? Just why is there mass so little?
• 6:05
  Speaker 1: That's right, it's not like they've been on a diet.
• 6:07
  Speaker 1: It's not about why neutrinos are bright or not bright.
• 6:10
  Speaker 1: It's about why they don't have a lot of masks. No,
• 6:12
  Speaker 1: it's not that their low calorie like coke light. They
• 6:17
  Speaker 1: are actually low calorie. You could eat like a cubic
• 6:20
  Speaker 1: light year of neutrinos and gained no weight. It just
• 6:25
  Speaker 1: goes right through you. That's right. There's zero points on
• 6:28
  Speaker 1: the Weight Watchers diet. So go have your cheat day,
• 6:31
  Speaker 1: eat as many neutrinos as you want. Maybe I should
• 6:33
  Speaker 1: invent like a neutrino based snack. It sounds like toastinos,
• 6:38
  Speaker 1: but it would be a little neutral snack food, right,
• 6:41
  Speaker 1: no trino. Yeah, there you go, you know, speaking about
• 6:46
  Speaker 1: snack foods and quantum physics. We did get a hilarious
• 6:49
  Speaker 1: email from a listener today who suggested a really fascinating
• 6:52
  Speaker 1: snack food based physics experiment all snack foods these days
• 6:57
  Speaker 1: like a physic script experiment, like how ful rest? And
• 7:00
  Speaker 1: can we make a snack or flame and hot glowing
• 7:04
  Speaker 1: particles point the late entropy of my snack as much
• 7:07
  Speaker 1: as Bob. Yeah, And it's not about flame and hot
• 7:09
  Speaker 1: neutrinos though, that's the snack food I want to develop now.
• 7:12
  Speaker 1: This listener writes in and he says, I make a
• 7:15
  Speaker 1: sandwich and I shoot it into deep space. Then I
• 7:18
  Speaker 1: make a second sandwich, and instantaneously the first sandwich is
• 7:22
  Speaker 1: converted from new sandwich to old sandwich. And so he's
• 7:26
  Speaker 1: suggesting this is a version of sort of quantum sandwich
• 7:30
  Speaker 1: entanglement because the original sandwich is out there in deep
• 7:34
  Speaker 1: space and suddenly becomes the old sandwich he's made the
• 7:37
  Speaker 1: new more. Oh man, this is funny that this is
• 7:41
  Speaker 1: funny to you, Like this is even a job. How
• 7:48
  Speaker 1: there's just some words that are funny. And I think
• 7:50
  Speaker 1: sandwich is one of the weasels, as if this was
• 7:52
  Speaker 1: a weasel sandwich, that would be even funny. I see,
• 7:56
  Speaker 1: I see, I see. It's it's there's kind of a
• 7:58
  Speaker 1: joke about how name naming things is kind of like
• 8:02
  Speaker 1: transmitting information at the speed of light faster than this exactly, exactly,
• 8:07
  Speaker 1: the universe recognizes that that's no longer the latest sandwich. Instantaneously,
• 8:11
  Speaker 1: its status has change. It's a sandwich teleportation. Anyway, back
• 8:16
  Speaker 1: to the topic of neutrinos, back to the topic of
• 8:19
  Speaker 1: today's podcast. Yeah, why are neutrinos are lights? So I
• 8:21
  Speaker 1: guess um. First of all, neutrinos are light. Neutrinos are
• 8:25
  Speaker 1: very low mass. We identify particles essentially by their mass.
• 8:29
  Speaker 1: We look at the particles when we say how much
• 8:30
  Speaker 1: mass does it have, and there's a huge spectrum of values,
• 8:34
  Speaker 1: but neutrinos are the very, very bottom end of it.
• 8:37
  Speaker 1: We measured these things in terms of electron volts, and
• 8:41
  Speaker 1: a typical value, like for an electron is half a
• 8:44
  Speaker 1: million electron volts or a muan is a hundred million
• 8:48
  Speaker 1: electron volts. How much is a neutrino? Neutrino is less
• 8:52
  Speaker 1: than one electrono what it's like, Wow, it's like a
• 8:57
  Speaker 1: percentage of a percentage. Yeah, it's like one million. And
• 9:00
  Speaker 1: they even go higher like corks are billions of electron vaults,
• 9:04
  Speaker 1: almost two hundred billion electron vaults, and you know this
• 9:08
  Speaker 1: is weird. There's a huge spectrum here from a very
• 9:11
  Speaker 1: very very heavy to very very light, and even between
• 9:14
  Speaker 1: the leftons and the corks, the electrons and the top
• 9:16
  Speaker 1: corks example, there's a big range. But neutrinos are all
• 9:19
  Speaker 1: on their own at the very very bottom of this scale.
• 9:22
  Speaker 1: And that looks weird. That puzzles us. Really, it's the
• 9:25
  Speaker 1: only light particle, or I guess, the only low mass particle. Yeah,
• 9:29
  Speaker 1: because there are you have particles that have no mass,
• 9:31
  Speaker 1: that's right. We have photons that have no mass, but
• 9:34
  Speaker 1: neutrinos are the only fermion that have this small amount
• 9:38
  Speaker 1: of mass. Neutrinos are matter particles, right, and we didn't
• 9:41
  Speaker 1: know for a long time whether they had any mass,
• 9:43
  Speaker 1: but we recently discovered that they do have mass, but
• 9:45
  Speaker 1: it's a very very small amount. So zero makes sense
• 9:49
  Speaker 1: to us. A number similar to the other masses makes
• 9:52
  Speaker 1: sense to us. But a really weird, super tiny mass.
• 9:55
  Speaker 1: That's a clue. That's like there's something going on here
• 9:58
  Speaker 1: that you could figure out. Yeah, all right, so that's
• 10:01
  Speaker 1: a mystery. Why are neutrinos so much lighter or have
• 10:05
  Speaker 1: so much less mass than all the other particles. And so,
• 10:08
  Speaker 1: as usual, Daniel went out there into the wild of
• 10:11
  Speaker 1: the Internet, the pandemic Internet, to figure out how many
• 10:15
  Speaker 1: people o there knew about this mystery and why they
• 10:18
  Speaker 1: think that maybe neutrinos have such little mass. That's right,
• 10:21
  Speaker 1: So thanks to everybody who volunteered for the person on
• 10:24
  Speaker 1: the Internet interviews and listen to these fun answers and
• 10:28
  Speaker 1: think to yourself, do you know why neutrinos are so light?
• 10:32
  Speaker 1: Here's what people had to say. I'm not sure why
• 10:34
  Speaker 1: neutrinos are so as light as they are, as they're
• 10:39
  Speaker 1: like not zero like photons. Neutrinos get their mass, I
• 10:45
  Speaker 1: would assume by interacting with the Higgs field, like I
• 10:48
  Speaker 1: think everything else is supposed to. So why they are
• 10:53
  Speaker 1: so light would be because they interact very weakly with
• 10:59
  Speaker 1: the Higgs field. Do they do these interact sum so
• 11:03
  Speaker 1: they have some mass? Now? Why they interact so weekly
• 11:08
  Speaker 1: with the Higgs field is another question. I honestly don't know.
• 11:12
  Speaker 1: Neutrinos are light because they interact weekly with the Higgs
• 11:17
  Speaker 1: field because of how little they interact with the Higgs field. Man,
• 11:21
  Speaker 1: I don't know the billions of them flowing through space
• 11:25
  Speaker 1: all the time, and hardly any of them interact with
• 11:29
  Speaker 1: us big detectors on the ground filled with bleach or
• 11:32
  Speaker 1: something like that. I remember might imagine they get their
• 11:35
  Speaker 1: mass by the Higgs field. So I think that neutrinos
• 11:40
  Speaker 1: are made of dark matter and they are paired in
• 11:44
  Speaker 1: such a way that they almost cancel out in each other.
• 11:49
  Speaker 1: That means they don't show gravitation attraction. Maybe something to
• 11:54
  Speaker 1: do with inertia. All right, some pretty knowledgeable answers here.
• 11:58
  Speaker 1: There's a lot of references to the Higgs field. Like, wow, yeah,
• 12:02
  Speaker 1: some listeners to this podcast have learned something about the
• 12:05
  Speaker 1: Higgs field. That's awesome. Yeah. So a lot of people
• 12:07
  Speaker 1: say it's because it doesn't interact as much with the
• 12:10
  Speaker 1: Higgs field, right, And that's a totally solid answer, because
• 12:13
  Speaker 1: most particles out there, that's how they get their mass,
• 12:17
  Speaker 1: like the top cork, the electron, the bottom cork, the muan,
• 12:20
  Speaker 1: all those particles get their mass by interacting with the
• 12:23
  Speaker 1: Higgs field. It's almost like a synonym, right, It's almost
• 12:26
  Speaker 1: like the same thing, like how much mass you have
• 12:28
  Speaker 1: is how much you interact with the Higgs field. Yeah. Precisely,
• 12:30
  Speaker 1: before we discover the Higgs boson and understood this mechanism,
• 12:34
  Speaker 1: we didn't really understand like where mass came from, Like
• 12:36
  Speaker 1: it was just a description. When you try to push something,
• 12:39
  Speaker 1: this happens that it tends to take a force in
• 12:42
  Speaker 1: order to accelerate it. That's really what MASSI is in
• 12:44
  Speaker 1: inertial mass when we're talking about and then we discovered
• 12:48
  Speaker 1: this mechanism, this weird feel that if it existed, would
• 12:51
  Speaker 1: have exactly that property as you push on particles. It
• 12:54
  Speaker 1: would mean that when you pushed on a particle, it
• 12:56
  Speaker 1: would take a force to give it acceleration because of
• 12:59
  Speaker 1: the way this field interacts with those particles. So that
• 13:01
  Speaker 1: by itself is pretty super cool to take this like
• 13:05
  Speaker 1: very intuitive macroscopic experience of stuff having inertia and explain
• 13:09
  Speaker 1: it in terms of this weird microscopic particle interaction. You know.
• 13:13
  Speaker 1: I love when you can make that connection between the big,
• 13:16
  Speaker 1: the every day and the tiny, the microscopic. But hey,
• 13:18
  Speaker 1: maybe that's why I'm a particle physicist and even an
• 13:21
  Speaker 1: evil one. Alright, So maybe Daniel steps three, or let's
• 13:24
  Speaker 1: talk about mass and particles and and and just in general,
• 13:27
  Speaker 1: like how do particles get mass? And before we can
• 13:30
  Speaker 1: even talk about why one in particular has such little mass. Yeah,
• 13:33
  Speaker 1: and and remember first of all that most of your mass,
• 13:36
  Speaker 1: the stuff that makes you up, doesn't come from the
• 13:39
  Speaker 1: Higgs field. What makes up mass is not just the
• 13:43
  Speaker 1: sum of all the mass of all the particles inside you,
• 13:46
  Speaker 1: but also the energy that holds them together, because the
• 13:50
  Speaker 1: inertial mass comes not just from those particles, but from
• 13:53
  Speaker 1: any energy that's stored within the interesting because he equals
• 13:57
  Speaker 1: mc square. Like if you have energy stored, it's like
• 14:00
  Speaker 1: having mass stored. Yeah, mass essentially is a representation, it's
• 14:04
  Speaker 1: a feature of having energy. Any energy that's stored has inertia.
• 14:08
  Speaker 1: It takes some force to get it up to speed.
• 14:12
  Speaker 1: And that's not something we totally understand. And we could
• 14:14
  Speaker 1: do a whole other podcast about, you know, the mysteries
• 14:16
  Speaker 1: of mass and how it works and whether it's connected
• 14:19
  Speaker 1: to this whole other concept of gravitational mass, which is
• 14:23
  Speaker 1: the force of gravity between objects. But the thing to
• 14:25
  Speaker 1: understand is that the mass is this mysterious thing, and
• 14:28
  Speaker 1: most of it is stored in the energy of your bonds,
• 14:31
  Speaker 1: but about one percent of it is stored actually in
• 14:34
  Speaker 1: the mass of those part of So wait, um of
• 14:39
  Speaker 1: my mass, like how much I weigh and how much
• 14:41
  Speaker 1: I'm attracted by gravity to this planet is from the
• 14:45
  Speaker 1: energy inside of me, not from the actual particles. Yes,
• 14:48
  Speaker 1: but you just refer to gravitational mass, right, which is
• 14:51
  Speaker 1: a separate concept from inertial mass. Gravitational mass is how
• 14:55
  Speaker 1: much you're attracted by the gravitational force of the Earth.
• 14:59
  Speaker 1: Inertial mass is how much force does it take to
• 15:02
  Speaker 1: give you an acceleration. It's the M and F equals M. Right.
• 15:06
  Speaker 1: But they're the same, right, It turns out there the same.
• 15:08
  Speaker 1: I mean, they're different physical concepts, right, one is inertia
• 15:11
  Speaker 1: on the other's gravity. Turns out the number turns out
• 15:14
  Speaker 1: to be the same, which is a whole fascinating topic
• 15:17
  Speaker 1: we can dig into another time. But today we're mostly
• 15:20
  Speaker 1: talking about inertial mass. Okay, well yeah, yeah, how hard
• 15:23
  Speaker 1: I am just set a move and most of it
• 15:25
  Speaker 1: comes from the energy I have. It's stored inside of me,
• 15:28
  Speaker 1: that's right. If I'm feeling low energy, I should weigh less. Yeah,
• 15:32
  Speaker 1: And as you absorb energy from the Sun, for example,
• 15:35
  Speaker 1: you do weigh more. Like you go out in new
• 15:36
  Speaker 1: sun tan, you actually gain a tiny little bit of weight.
• 15:39
  Speaker 1: That no, that is true. Yeah, no, it's not measurable,
• 15:42
  Speaker 1: but every time you absorb a photon, you're getting more energy.
• 15:45
  Speaker 1: Even though photons have no mass, you absorb a photon,
• 15:48
  Speaker 1: you go up in mass. One more reason to wear
• 15:51
  Speaker 1: a hat when you're out in the sun. That's right,
• 15:54
  Speaker 1: Daniel Whiteson's stay in the dark diet. You should market that.
• 15:58
  Speaker 1: Eating blame and hot newtree, know, snap chips and staying
• 16:01
  Speaker 1: in the dark. That's the particle physics anti diet. And
• 16:04
  Speaker 1: I'm sure'll be anti profitable as well. I just gave
• 16:08
  Speaker 1: it away for free anyway. So all right, So that's
• 16:12
  Speaker 1: kind of wild to think about just that, you know,
• 16:14
  Speaker 1: like we're like batteries almost, Like most of what makes
• 16:17
  Speaker 1: us us is the energy we have stored inside of us. Yeah,
• 16:20
  Speaker 1: and we talked about that a lot of times, that
• 16:22
  Speaker 1: most of what makes you you is not the actual
• 16:25
  Speaker 1: nature of the particles that are used to build you,
• 16:27
  Speaker 1: but how they're put together. And that includes the energy
• 16:30
  Speaker 1: of those bonds. Right, You're like a bunch of lego
• 16:33
  Speaker 1: pieces bound together really tightly, and it's all about how
• 16:37
  Speaker 1: those lego pieces gripped together. That's what gives you most
• 16:40
  Speaker 1: of your mass. But the lego pieces themselves, those electrons
• 16:43
  Speaker 1: and quirks that make you up. They also have their
• 16:46
  Speaker 1: own mass, and that's kind of what we're talking about
• 16:48
  Speaker 1: here today, which is like, what's the intrinsic mass by
• 16:52
  Speaker 1: itself of the neutrina, that's right. And for electrons, for example,
• 16:56
  Speaker 1: they get their mass by interacting with the Higgs field.
• 16:59
  Speaker 1: And what that means microscopically is an electron can be
• 17:02
  Speaker 1: flying along and you can emit a Higgs boson and
• 17:05
  Speaker 1: then you can reabsorb that Higgs boson. And that's what
• 17:08
  Speaker 1: interacting with the Higgs field means. It can create virtual
• 17:11
  Speaker 1: Higgs boson. Alright, we talked about virtual particles last time. Yeah,
• 17:16
  Speaker 1: this is not like a real Higgs boson that you
• 17:18
  Speaker 1: could ever see. Only the electron creates it and can
• 17:21
  Speaker 1: reabsorb it. But the key thing is that in order
• 17:24
  Speaker 1: for an electron to be able to emit a Higgs boson,
• 17:27
  Speaker 1: it has to have an antiparticle. The electron can't do
• 17:30
  Speaker 1: that if the positron doesn't also exist. All right, let's
• 17:33
  Speaker 1: dive deep into these particle physics phenomenons and and processes.
• 17:39
  Speaker 1: But first let's take a quick break. All right, So, Daniel,
• 17:55
  Speaker 1: we're talking about the neatrino and why it has such
• 17:57
  Speaker 1: little mass. And we know that most particle get their
• 18:00
  Speaker 1: mass from the Higgs field, and you're telling me that
• 18:04
  Speaker 1: this massive that comes from creating virtual Higgs particles and antiparticles.
• 18:10
  Speaker 1: So every time my particles feel mass, you're saying they're
• 18:12
  Speaker 1: creating anti Higgs and Higgs boson. It's more about the
• 18:15
  Speaker 1: electron itself has to have an antiparticle. Will dig into
• 18:19
  Speaker 1: the details in a moment, but the short version of
• 18:21
  Speaker 1: the story is that any particle that gets its mass
• 18:24
  Speaker 1: from the Higgs boson also has to have an antiparticle.
• 18:29
  Speaker 1: The kind of interaction that it does with the Higgs
• 18:31
  Speaker 1: field means that to be consistent, it also has to
• 18:34
  Speaker 1: be possible for a Higgs to decay into the particle
• 18:37
  Speaker 1: and it's antiparticle. So if you don't have an antiparticle,
• 18:41
  Speaker 1: this interaction can't happen and you just can't get your
• 18:44
  Speaker 1: mass from the Higgs boson. The Higgs boson doesn't have
• 18:47
  Speaker 1: an anti Higgs boson, but in order for the electron
• 18:50
  Speaker 1: to be able to admit a Higgs boson and then
• 18:53
  Speaker 1: later reabsorb it, it has to have an antiparticle. There
• 18:56
  Speaker 1: has to be a positron why every particle that gets
• 18:59
  Speaker 1: mass from Higgs boson has to have an antiparticle, and
• 19:03
  Speaker 1: the reason why is fascinating. The way we think about
• 19:05
  Speaker 1: these particle interactions is three lines intersect. So for this
• 19:09
  Speaker 1: interaction where an electron emits a Higgs boson, you have
• 19:13
  Speaker 1: one initial particle, the electron, that's one line, and two
• 19:17
  Speaker 1: outgoing particles, the electron and the Higgs boson. Those the
• 19:20
  Speaker 1: other two lines. So maybe make a little diagram in
• 19:24
  Speaker 1: your mind of an electron line splitting into an electron
• 19:27
  Speaker 1: and Higgs boson. That's like a mini Fine Min diagram.
• 19:31
  Speaker 1: Now to be consistent with special relativity. For this interaction
• 19:36
  Speaker 1: to exist, then others also have to exist. If you
• 19:39
  Speaker 1: move an incoming particle from this diagram to the outgoing side,
• 19:42
  Speaker 1: it becomes an anti particle. So this little interaction means
• 19:46
  Speaker 1: you should also have another one where the Higgs comes
• 19:49
  Speaker 1: in and outgoes an electron and a positron. But that
• 19:52
  Speaker 1: interaction can only happen if there is a positron on
• 19:56
  Speaker 1: Nature's menu. Feel like maybe an audio podcast is maybe
• 20:02
  Speaker 1: not the best place to use sychematic to explain something,
• 20:06
  Speaker 1: so maybe let's break it down. I think what you're saying,
• 20:08
  Speaker 1: is that, you know, if we want an electron to
• 20:11
  Speaker 1: be able to split into an electron plus a Higgs boson,
• 20:14
  Speaker 1: which is kind of what happens when you try to
• 20:16
  Speaker 1: move an electron, then that process needs to be kind
• 20:20
  Speaker 1: of like reversible, or you have to be able to
• 20:23
  Speaker 1: get that process from any sort of order. Is that
• 20:26
  Speaker 1: kind of what you mean? Yeah, that's exactly what I mean.
• 20:28
  Speaker 1: And some of those reversals turn electrons into anti electrons,
• 20:32
  Speaker 1: and so anti electron have to be a possibility in
• 20:36
  Speaker 1: order for this interaction to work. It has to be
• 20:39
  Speaker 1: like a thing that can exist. Yeah, if the electron
• 20:42
  Speaker 1: didn't have an anti particle, then it couldn't emit a
• 20:45
  Speaker 1: Higgs boson. What because, um, I see, if it didn't
• 20:50
  Speaker 1: have if there wasn't an anti version of the electron,
• 20:53
  Speaker 1: that means that the whole process has to be canceled.
• 20:55
  Speaker 1: You can't have that process. Yes, yes, exactly, because this
• 20:58
  Speaker 1: process also require is this other process a Higgs boson
• 21:02
  Speaker 1: turning into the particle and its antiparticle. But if the
• 21:05
  Speaker 1: antiparticle doesn't exist, this process can't happen in any shape
• 21:08
  Speaker 1: or form. Like everything has to balance out cosmically, kind of.
• 21:12
  Speaker 1: That's right, because this process an electron emitting a Higgs
• 21:15
  Speaker 1: boson and then continue along its path. Somebody else from
• 21:18
  Speaker 1: another perspective could see it differently. They could see it
• 21:20
  Speaker 1: as a Higgs boson creating a particle and antiparticle because
• 21:24
  Speaker 1: of special relativity. Remember, everybody can see the same thing
• 21:27
  Speaker 1: from a different perspective, and so that process has to
• 21:30
  Speaker 1: also be possible, and that actually happens in the universe, right, Like,
• 21:33
  Speaker 1: sometimes the Higgs boson will hit a what an anti
• 21:37
  Speaker 1: electron and become an electron. Yes, sometimes we create Higgs bosons,
• 21:40
  Speaker 1: for example the Large Hadron Collider real ones, not virtual ones,
• 21:43
  Speaker 1: and they turn into a particle antiparticle pair like an
• 21:46
  Speaker 1: electron and a positron bottom cork and anti bottom cork.
• 21:50
  Speaker 1: This totally happens. It's how we discovered the Higgs boson. Okay,
• 21:54
  Speaker 1: So it's almost like a prerequisite for having mass is
• 21:57
  Speaker 1: that there needs to be an anti version of you
• 22:00
  Speaker 1: to have math exactly right. In order to get mass
• 22:03
  Speaker 1: from the Higgs boson, you have to have a partner.
• 22:06
  Speaker 1: You can't dance without a partner, right, you want to
• 22:08
  Speaker 1: dance with the Higgs, you have to have an anti particle, right,
• 22:11
  Speaker 1: and it doesn't have to actually exist, It just has
• 22:13
  Speaker 1: to be possible. Yeah, it has to be sort of
• 22:15
  Speaker 1: on Nature's list on the menu of things that could exist,
• 22:18
  Speaker 1: all right, Yeah, yeah, I guess um. For me to exist,
• 22:22
  Speaker 1: there has to be for me to have maths, there
• 22:24
  Speaker 1: has to be the possibility of an anti Jorge out there,
• 22:27
  Speaker 1: even if one doesn't exist, that's right. And so if
• 22:30
  Speaker 1: you can get rid of the anti Jorges, that means
• 22:32
  Speaker 1: that you're not going to get any mass from the
• 22:33
  Speaker 1: Higgs boson. There's a whole other particle physics diet for you.
• 22:37
  Speaker 1: There you go, the anti anti a twin diet. All right.
• 22:41
  Speaker 1: So then but then neutrinos. That's that's kind of where
• 22:44
  Speaker 1: the mystery of neutrinos come in, because neutrinos don't have
• 22:48
  Speaker 1: an anti version necessarily, right, Well, that's the question. We
• 22:52
  Speaker 1: don't know either. Neutrinos are just like the other particles
• 22:56
  Speaker 1: electrons and top quarks and whatever, and they haven't particles
• 23:00
  Speaker 1: and they get their mass from the Higgs boson, or
• 23:04
  Speaker 1: they're not. There's some other weird kind of particle that
• 23:08
  Speaker 1: doesn't have an antiparticle that that is its own antiparticle.
• 23:13
  Speaker 1: So those are the sort of the two possibilities, and
• 23:15
  Speaker 1: we don't know currently which it is. What are the
• 23:18
  Speaker 1: possibilities that natrinos don't have an anti version until they're
• 23:22
  Speaker 1: just weird and they somehow violate this you know, sort
• 23:25
  Speaker 1: of karmic requirement of the universe, or like the natrino,
• 23:29
  Speaker 1: it's so zen with itself that it satisfies its own
• 23:33
  Speaker 1: anti requirement. But yeah, the two possibilities are one that
• 23:36
  Speaker 1: it's a normal particle like the electron, it has an
• 23:39
  Speaker 1: anti particle and it gets its mass from the Higgs.
• 23:42
  Speaker 1: But in that case we don't understand, like why does
• 23:45
  Speaker 1: it get so little mass. The other possibility is that
• 23:48
  Speaker 1: it doesn't have an antiparticle, so it can't dance with
• 23:51
  Speaker 1: the Higgs, so it can't get its mass from the Higgs,
• 23:54
  Speaker 1: and it gets its mass in a totally different way. Oh,
• 23:57
  Speaker 1: I see, those are the two possibilities. Either it has
• 24:01
  Speaker 1: an antiparticle and it gets its mass from the Higgs,
• 24:04
  Speaker 1: or it doesn't. It's its own antiparticle and that makes
• 24:07
  Speaker 1: it this other weird kind of particle called the mayorona
• 24:10
  Speaker 1: for me, all right, well, um, it sounds like two
• 24:14
  Speaker 1: appealing options to a not physicist, but what have we measured,
• 24:17
  Speaker 1: We've met, Have we measured or or found an anti neutrino?
• 24:20
  Speaker 1: We haven't, right, We have not ever established whether anti
• 24:23
  Speaker 1: neutrinos themselves exist. We've seen neutrinos, but remember that's always
• 24:27
  Speaker 1: very indirect like neutrinos hardly ever interact. This is one
• 24:31
  Speaker 1: of the things that makes them so weird is that
• 24:33
  Speaker 1: they mostly ignore the rest of the universe. You have
• 24:36
  Speaker 1: a hundred billion neutrinos flying through your fingertip right now,
• 24:40
  Speaker 1: and you don't notice because they don't interact with you.
• 24:42
  Speaker 1: And so it's very difficult to feel neutrinos. And the
• 24:46
  Speaker 1: reason is that they only interact via one of the
• 24:48
  Speaker 1: forces that we know, and the weakest one, the weak
• 24:51
  Speaker 1: nuclear force. And so we have been able to see neutrinos,
• 24:56
  Speaker 1: and the last twenty or thirty years we've discovered that
• 24:59
  Speaker 1: they do have mass. But you can't like get a
• 25:02
  Speaker 1: pile of neutrinos and measure them. You can't say, here's
• 25:05
  Speaker 1: a spoonful of neutrinos and put them on a scale.
• 25:08
  Speaker 1: They're very, very light and very difficult to interact with.
• 25:10
  Speaker 1: So we have these very subtle experiments that can't actually
• 25:14
  Speaker 1: measure the masses themselves. They just measure the difference in
• 25:17
  Speaker 1: masses between the kinds of neutrinos, like electron neutrinos and
• 25:21
  Speaker 1: muon neutrinos and town neutrients. Oh, right, because we found
• 25:25
  Speaker 1: different types of neutrinos, right, we know there are three
• 25:28
  Speaker 1: types of neutrinos, and we've seen them change back and
• 25:30
  Speaker 1: forth from one to the other. We did a whole
• 25:32
  Speaker 1: fascinating podcast episode about how neutrinos change flavor from electron
• 25:37
  Speaker 1: to muan to flame and hot no to town neutrinos.
• 25:40
  Speaker 1: And so what we do know is this is sort
• 25:42
  Speaker 1: of the differences between the masses, and those are very
• 25:45
  Speaker 1: very small numbers, and so we we only know that
• 25:48
  Speaker 1: their differences. We don't know they're like absolute masses, that's right.
• 25:51
  Speaker 1: We only know their differences. We don't know their absolute values.
• 25:54
  Speaker 1: We've tried to measure their values and we know that
• 25:56
  Speaker 1: they're less than some number, but we don't know what
• 25:59
  Speaker 1: the mass is actually are. But we have measured the
• 26:02
  Speaker 1: differences between them, so we know, like the difference between
• 26:05
  Speaker 1: one and two and two and three. That doesn't even
• 26:07
  Speaker 1: tell us like the order, like which one is heavier
• 26:09
  Speaker 1: and which one is lighter. We can only measure these
• 26:12
  Speaker 1: two differences. We know, like, whatever they are, they're really
• 26:15
  Speaker 1: small compared to other particles. That's right, They're really small,
• 26:18
  Speaker 1: and they're not zero. And so, for example, if they
• 26:21
  Speaker 1: do have antiparticles and they do get their mass from
• 26:24
  Speaker 1: the Higgs boson, then it's a question of like why
• 26:27
  Speaker 1: such a small number. Every particle to get this mass
• 26:30
  Speaker 1: from the Higgs boson gets a different amount of mass
• 26:33
  Speaker 1: because it interacts with the Higgs boson more or less,
• 26:36
  Speaker 1: Like the top core interacts a lot with the Higgs boson,
• 26:40
  Speaker 1: the electron not nearly as much. So there's just like
• 26:43
  Speaker 1: a parameter, like a number, like a dial on the
• 26:46
  Speaker 1: universe that says how much you interact with the Higgs boson.
• 26:49
  Speaker 1: And we want to know, like why are these numbers
• 26:51
  Speaker 1: all different? Why are the values from neutrinos so small.
• 26:55
  Speaker 1: It's not an explanation to say, oh, neutrinos get their
• 26:59
  Speaker 1: mass because they hardly interact with their Higgs, Like why
• 27:02
  Speaker 1: why neutrinos different or weird or special? It's a totally
• 27:05
  Speaker 1: unanswered question. But it could be that there's no answer, right,
• 27:08
  Speaker 1: Like it could be that maybe the like the masses
• 27:10
  Speaker 1: a netrino, it's just a like a basic constant in
• 27:13
  Speaker 1: the universe that it just is because it is. But
• 27:15
  Speaker 1: that's not an answer. I don't know. I find that
• 27:17
  Speaker 1: totally unsatisfactory to say that the universe has like nineteen
• 27:21
  Speaker 1: different numbers and they just are what they are, Like,
• 27:23
  Speaker 1: why are they that and not something else? Was there
• 27:26
  Speaker 1: a moment in the beginning of the universe when these
• 27:28
  Speaker 1: were randomly chosen? Could they actually be any value? I
• 27:32
  Speaker 1: feel like sometime in the future of physics will discover
• 27:35
  Speaker 1: a reason why these numbers are what they are. We
• 27:38
  Speaker 1: just don't know it yet, you know, There's must be
• 27:40
  Speaker 1: some pattern, some simplification, some way that we can explain this.
• 27:45
  Speaker 1: So it's very unsatisfied to say, well, neutrinos get their
• 27:48
  Speaker 1: mass from the Higgs, and they just don't interact with
• 27:50
  Speaker 1: it very much for some reason we don't know. Right,
• 27:52
  Speaker 1: that's weird and unexplained, and that's just option A. Option
• 27:55
  Speaker 1: B is that it's a totally different kind of particle
• 27:59
  Speaker 1: that maybe it doesn't even get its mass from the Higgs.
• 28:02
  Speaker 1: That's right, And early on in the days of particle physicists,
• 28:04
  Speaker 1: there were two competing ideas for how particles could exist,
• 28:08
  Speaker 1: one from Paul Dirac, a Familish English physicist who predicted antiparticles,
• 28:13
  Speaker 1: and another from E. Tore Marana, an Italian physicist who
• 28:17
  Speaker 1: predicted that particles could be their own anti partner. All right,
• 28:21
  Speaker 1: let's get into what neutrinos could be and how that
• 28:25
  Speaker 1: would explain why they have such little mass. But first
• 28:28
  Speaker 1: let's take a quick break. All right, Daniel, neutrinos are
• 28:43
  Speaker 1: We know they're weird because they have such little mass,
• 28:46
  Speaker 1: but we don't know if it's because that's just how
• 28:47
  Speaker 1: they interact with the Higgs boson, or whether they get
• 28:51
  Speaker 1: their mass from a totally different way. Is that is
• 28:54
  Speaker 1: that any impossible? Can you get mass from not the
• 28:56
  Speaker 1: Higgs field? Yeah? There are other ways to get mass,
• 28:59
  Speaker 1: and one was predicted by Mayorana, and he came up
• 29:03
  Speaker 1: with a whole different way to like think about particles. Remember,
• 29:07
  Speaker 1: most of the particles that we think about today were
• 29:09
  Speaker 1: envisioned by Paul Diract. He was trying to put together
• 29:13
  Speaker 1: a theory of quantum mechanics that worked well with relativity,
• 29:16
  Speaker 1: and he came up with an equation called, of course,
• 29:18
  Speaker 1: the direct equation that described how particles moved through space.
• 29:23
  Speaker 1: And it's when he put that equation down on paper
• 29:25
  Speaker 1: and he looked at it, he noticed he said, wait
• 29:27
  Speaker 1: a second. This equation suggests not just that particles can
• 29:31
  Speaker 1: move through space, but that they should each have a partner.
• 29:33
  Speaker 1: There's like a symmetry in that equation that says, if
• 29:36
  Speaker 1: there's a particle, there should be an anti version of
• 29:38
  Speaker 1: version with the opposite charge. That's where the whole idea
• 29:42
  Speaker 1: of antiparticles came from from this guy, Paul Dirac. And
• 29:45
  Speaker 1: then of course we discovered electrons do have antiparticles, and
• 29:49
  Speaker 1: protons have anti particles and all that. Dirac was right.
• 29:53
  Speaker 1: I wonder if he had come up with a second equation,
• 29:56
  Speaker 1: what he would have called it? The rise of Skywalker.
• 29:58
  Speaker 1: Probably the rise of Diract. My second equation Diract strikes back,
• 30:07
  Speaker 1: all right. So that's one way that particles can be
• 30:10
  Speaker 1: they can have anti versions of itself. But then then
• 30:13
  Speaker 1: Majorona came up with another way. Yeah, he came up
• 30:16
  Speaker 1: with a different equation. He wrote his mathematics differently, and
• 30:18
  Speaker 1: he thought about the way you could have quantum mechanics
• 30:21
  Speaker 1: and relativity, and he put the math together in a
• 30:24
  Speaker 1: different way, and he came up with a way to
• 30:26
  Speaker 1: describe particles moving through space that didn't imply antiparticles, and
• 30:31
  Speaker 1: it totally works mathematically, Like, there's no reason we know
• 30:36
  Speaker 1: of why particles should be like diract particles instead of
• 30:39
  Speaker 1: like Myrna particles. Wow, but but it still predicts the antiparticles.
• 30:43
  Speaker 1: My irons particles don't have antiparticles. Well, yeah, they work
• 30:47
  Speaker 1: without antiparticles. So his equation is different. It doesn't have
• 30:51
  Speaker 1: this symmetry. It doesn't require there to be the opposite particle,
• 30:54
  Speaker 1: but it's still right and true. Well, it works mathematically,
• 30:58
  Speaker 1: but we've never seen one in the universe. So before
• 31:01
  Speaker 1: we discovered the positron, nobody knew whether every particle was
• 31:05
  Speaker 1: like the ones described by directs equation or by the
• 31:08
  Speaker 1: ones described by myronas equations. And then we discovered, oh,
• 31:12
  Speaker 1: all the particles, we know they do have an antiparticle,
• 31:15
  Speaker 1: so we'll put them on Diract town. And so far,
• 31:17
  Speaker 1: my irona has won zero of these battles, Like every
• 31:20
  Speaker 1: single particle we've discovered so far has been a direct type,
• 31:24
  Speaker 1: but it's possible that some of them could be Myrona particles.
• 31:28
  Speaker 1: We don't know. We have no reason to understand why
• 31:31
  Speaker 1: the universe likes direct particles and not Myrona particles. I mean,
• 31:34
  Speaker 1: Myrona was a cool dude, all right. So then the
• 31:36
  Speaker 1: idea is that maybe neutrinos are maybe one of these
• 31:39
  Speaker 1: Mayorana particles that don't have anti versions of itself. Yes, exactly,
• 31:44
  Speaker 1: neutrinos could be their own antiparticles. They could be Myrona particles,
• 31:48
  Speaker 1: so there's not like a separate particle that's the anti
• 31:52
  Speaker 1: electron neutrino. And if that's the case, if they are
• 31:55
  Speaker 1: Myrona particles, this special, weird kind of particle nobody's ever
• 31:59
  Speaker 1: seen before, then there's a very nice explanation for why
• 32:02
  Speaker 1: they would be so light, why they would have such
• 32:04
  Speaker 1: a small matting, because I guess Mayorana's equation kind of
• 32:09
  Speaker 1: allows for some particles who have very little mass. Yeah,
• 32:13
  Speaker 1: if you take his equations and you say, well, what
• 32:16
  Speaker 1: if there aren't three neutrinos, there are six, and three
• 32:19
  Speaker 1: of them are super duper heavy, like cosmically heavy, like
• 32:23
  Speaker 1: you know, each one weighs as much as like a
• 32:25
  Speaker 1: planet or something crazy. Then if you do that, then
• 32:30
  Speaker 1: because of the way the equations work out, you get
• 32:32
  Speaker 1: three really low mass neutrinos that pop out of the
• 32:35
  Speaker 1: equation to wait, so he posts that neutrinos don't have
• 32:39
  Speaker 1: maybe an anti version, they just have a heavy version. Yeah,
• 32:42
  Speaker 1: there's instead of there being three, there's like six, and
• 32:45
  Speaker 1: three of them are super duper cosmically heavy. And that
• 32:48
  Speaker 1: it's called the seesaw mechanism because those guys like steal
• 32:52
  Speaker 1: all the mass essentially in these neutrino fields and leave
• 32:55
  Speaker 1: only a tiny little bit left over to the neutrinos
• 32:59
  Speaker 1: that we know and of, And so this imbalance comes
• 33:02
  Speaker 1: from the way the matrices are diagonalized, etcetera, etcetera. Falls
• 33:05
  Speaker 1: out of the math. But essentially it's a very natural,
• 33:08
  Speaker 1: simple way to solve his equations and to get a
• 33:11
  Speaker 1: set of very heavy and very light nutreatments. So it'd
• 33:15
  Speaker 1: be sort of elegant. Instead of like flipping the charges,
• 33:18
  Speaker 1: you kind of almost flipped the mass kind of. Yeah. Yeah,
• 33:21
  Speaker 1: that's a good way to think about it. And unlike
• 33:23
  Speaker 1: with the Higgs boson, you don't have to just like
• 33:25
  Speaker 1: put a number in by hand. It's like it comes
• 33:27
  Speaker 1: out of the math naturally. If you have six of
• 33:30
  Speaker 1: these particles and half of them are heavy, then the
• 33:33
  Speaker 1: other one has just come out naturally to be very
• 33:35
  Speaker 1: very light, and that's what we look for. We look
• 33:37
  Speaker 1: for sort of natural explanations where you don't have to say,
• 33:41
  Speaker 1: this is just a number and I don't know what
• 33:42
  Speaker 1: it is. I'm just gonna stick it in there and
• 33:44
  Speaker 1: see that it works without any explanation. We look for
• 33:47
  Speaker 1: ways that it's a natural consequence of the math, the
• 33:50
  Speaker 1: way that anti particles are a natural consequence of directs math.
• 33:54
  Speaker 1: That tells us directs math is probably right about most
• 33:57
  Speaker 1: of the universe. Maybe my Irona's math is right about neutrinos,
• 34:01
  Speaker 1: you know, maybe finally he can get one on his
• 34:03
  Speaker 1: tally card. But I feel like Mayorana's equation would require
• 34:07
  Speaker 1: there to be like these crazy particles like a neutrino
• 34:10
  Speaker 1: with the massive a planet that that doesn't sound like
• 34:13
  Speaker 1: something we found, And it's not something we found absolutely,
• 34:16
  Speaker 1: And it's the less Daniel. What if it's dark matter?
• 34:19
  Speaker 1: What if the whole Earth is just one big neutrino.
• 34:23
  Speaker 1: But it's a classic trick in particle physics. To explain
• 34:26
  Speaker 1: something we see, you add a bunch of crazy stuff
• 34:29
  Speaker 1: that happens with particles that are really heavy because we
• 34:32
  Speaker 1: can't see those particles. We can't create them in our colliders.
• 34:35
  Speaker 1: We don't have enough energy. They're too rare, they would
• 34:38
  Speaker 1: they haven't been around since the Big Bang, And so
• 34:40
  Speaker 1: it's sort of like sweeping stuff under the rug, you know,
• 34:42
  Speaker 1: you push up all your problems into the really heavy
• 34:44
  Speaker 1: particles which nobody ever sees and are never created, and
• 34:47
  Speaker 1: so sort of can't be found. Kind of thing can't
• 34:50
  Speaker 1: be found exactly right, because to like create a planet
• 34:54
  Speaker 1: sized neutrino would require a crazy particle collector, yeah, particle
• 34:58
  Speaker 1: collider the size of a galaxy probably to create that
• 35:02
  Speaker 1: much energy, or like require conditions like the Big Bang, right,
• 35:05
  Speaker 1: because right now today it would be very unlikely for
• 35:08
  Speaker 1: us to see something like that if it existed or
• 35:11
  Speaker 1: could exist. Yeah, essentially impossible. Nothing is technically impossible when
• 35:14
  Speaker 1: you're talking about quantum mechanics, but essentially, but there are
• 35:19
  Speaker 1: ways for us to figure out if neutrinos are their
• 35:22
  Speaker 1: own antiparticles or not. All right, that would settle the
• 35:27
  Speaker 1: question of what kind of particle in New trinas are.
• 35:28
  Speaker 1: That would settle a question because if neutrinos have their
• 35:31
  Speaker 1: own antiparticles, then their direct particles and he basically runs
• 35:35
  Speaker 1: the board and wins everything. But if they do not
• 35:38
  Speaker 1: have their own antiparticles, if they are their own antiparticles
• 35:42
  Speaker 1: like the photon is, then my irona wins one. Now,
• 35:45
  Speaker 1: you know, if people get confused, we're only talking about
• 35:47
  Speaker 1: matter particles here. There are there are some particles like
• 35:50
  Speaker 1: the Higgs and the photon, which are their own antiparticles,
• 35:54
  Speaker 1: but they're not matter particles, so they're not governed by
• 35:56
  Speaker 1: this direct versus myron and distinction. Feel like, now they're
• 35:59
  Speaker 1: they're steaks. Daniel Well, I really like the math of
• 36:04
  Speaker 1: the Myrona particles, and so I'm sort of rooting for him.
• 36:07
  Speaker 1: I also like the underdog, you know, it's like, let's
• 36:10
  Speaker 1: give him one. Guys, come on, throw my bone. That's right,
• 36:13
  Speaker 1: Let's give him what. Also, let's give them the weirdest, best,
• 36:16
  Speaker 1: awesome one. Neutrinos are fascinating, so if you have to
• 36:18
  Speaker 1: pick one to win, it would be neutrinos. All right,
• 36:21
  Speaker 1: So you're saying, even if neutrinos are their own antiparticles,
• 36:24
  Speaker 1: that would still put them in the dirac column. Know,
• 36:26
  Speaker 1: if neutrinos have an antiparticle, that would put them in
• 36:28
  Speaker 1: the direct column right right, the opposite of what just
• 36:31
  Speaker 1: I just said. Yeah, if the anti of what you
• 36:33
  Speaker 1: just said, if neutrinos are their own antiparticles, then they're
• 36:37
  Speaker 1: in the myrona carloge and we have a possibility to
• 36:40
  Speaker 1: maybe even see this, to discover to tell the difference
• 36:43
  Speaker 1: between those two hypothesis, to figure out if neutrinos are
• 36:46
  Speaker 1: their own antiparticles or if they have antiparticles. Al Right,
• 36:51
  Speaker 1: it sounds like we have um overtime penalty goal here,
• 36:54
  Speaker 1: so maybe real quickly describe what this experiment is. Well,
• 36:58
  Speaker 1: it involves beta decay. Beta decay is the process where
• 37:02
  Speaker 1: you take a neutron and it turns into a proton
• 37:05
  Speaker 1: and it happens all the time. It's radioactive decay. And
• 37:07
  Speaker 1: what you get is a neutron turns into a proton
• 37:10
  Speaker 1: plus an electron and a neutrino. And this is actually
• 37:14
  Speaker 1: how neutrinos were first discovered, because we saw that neutrons
• 37:18
  Speaker 1: turned into protons and electrons. But there's some missing information
• 37:21
  Speaker 1: because we can't see the neutrino itself, and so people thought, oh, well,
• 37:25
  Speaker 1: there must be some little neutral particle carrying off some energy.
• 37:29
  Speaker 1: That's the origin of the name neutrino. Like little remaining
• 37:32
  Speaker 1: like a little remainder. Now, sometimes there's some nuclei they
• 37:36
  Speaker 1: can't do this, But what they can do is they
• 37:38
  Speaker 1: can do double beta decay. They can take two neutrons
• 37:42
  Speaker 1: simultaneously turn them into two protons, which should give you
• 37:46
  Speaker 1: also two electrons and two neutrinos. So what people are
• 37:51
  Speaker 1: looking for is neutrino lists double beta decay, the idea
• 37:56
  Speaker 1: that these two neutrinos that are produced one from each
• 38:00
  Speaker 1: to the neutrons might combine and annihilate each other. If
• 38:03
  Speaker 1: they are their own antiparticle, then they can do that.
• 38:06
  Speaker 1: They can just like slurp into each other, disappear, disappear. Yes,
• 38:10
  Speaker 1: but it sounds like maybe the idea is that there's
• 38:12
  Speaker 1: an experiment in which two neutrinos are created at the
• 38:15
  Speaker 1: same time, and if we suddenly see these two neutrinas disappear,
• 38:20
  Speaker 1: then that means that they are their own antiparticles and
• 38:23
  Speaker 1: they did sort of cancelate till they're out. Yeah, exactly.
• 38:26
  Speaker 1: So if neutrinos are myrona particles, then double beata to
• 38:30
  Speaker 1: cake can happen without any neutrinos flying out to be
• 38:33
  Speaker 1: like neutrino lists, double beta decay, and you might ask like, well,
• 38:36
  Speaker 1: how is it possible to even tell, Like you can't
• 38:39
  Speaker 1: see neutrinos directly, so how can you tell, like if
• 38:42
  Speaker 1: there weren't two neutrinos there, if there were, or there weren't. Yeah, well,
• 38:47
  Speaker 1: if there's a neutrino there, it carries off some of
• 38:49
  Speaker 1: the energy. Like that's how neutrinos were discovered. Remember, you
• 38:52
  Speaker 1: add up the energy of everything else and it doesn't
• 38:55
  Speaker 1: add up, like all the energy that came out doesn't
• 38:58
  Speaker 1: equals to the energy that went in. That's the evidence
• 39:01
  Speaker 1: for the existence of a neutrino. So if you see
• 39:03
  Speaker 1: this happen and there's no missing energy, no energy is lost,
• 39:08
  Speaker 1: then that tells you that there probably was no neutrinos created,
• 39:11
  Speaker 1: and neutrinos annihilated themselves. That you have neutrino lists double beat.
• 39:17
  Speaker 1: It sounds kind of impossible, right, Or what if the
• 39:21
  Speaker 1: ntrinos were created, they took some of the energy, but
• 39:23
  Speaker 1: then they canceled each other afterwards. Yeah, well it could
• 39:27
  Speaker 1: be that they like just go off in opposite directions
• 39:29
  Speaker 1: and so they do cancel each other. It's a very
• 39:32
  Speaker 1: hard experiment to do. So far, nobody's ever seen neutrino
• 39:36
  Speaker 1: list double beta decay. Nobody's ever seen this happen. But
• 39:39
  Speaker 1: it's difficult, right to have evidence for this not happening.
• 39:43
  Speaker 1: You have to create the situation where you think it
• 39:45
  Speaker 1: could happen, and then prove that you would see it
• 39:47
  Speaker 1: if it did happen, and then not see it. So
• 39:50
  Speaker 1: it's a very subtle experiment. It's hard, but I totally
• 39:55
  Speaker 1: lost a few steps back there. But it's like you
• 39:58
  Speaker 1: have to see something that's not the air, or you
• 40:01
  Speaker 1: have to you have to you have to not see
• 40:03
  Speaker 1: note that is there but not there at this time.
• 40:07
  Speaker 1: It's a very subtle experiment and total props to the
• 40:10
  Speaker 1: folks looking for a neutrinnutilists double bated a gay. It's
• 40:13
  Speaker 1: a fascinating question in particle physics, but it connects to
• 40:16
  Speaker 1: as much bigger, deeper question of like how do particles
• 40:19
  Speaker 1: get mass? And do particles have their own antiparticles? And
• 40:22
  Speaker 1: you know, why are there antiparticles anyway, which is a
• 40:26
  Speaker 1: question I've never really wrapped my mind or interesting. It's
• 40:29
  Speaker 1: it's like a little detailed question that's subtle, but it
• 40:33
  Speaker 1: might sort of upend the whole basis for the standard
• 40:37
  Speaker 1: model and our whole sort of understanding of what particles
• 40:40
  Speaker 1: are and what's possible exactly. And so the discovery of
• 40:43
  Speaker 1: the Higgs boson it's not the crowning achievement of the
• 40:46
  Speaker 1: standard model. That doesn't put the last piece in the
• 40:48
  Speaker 1: place and answer all of our questions. We don't step
• 40:51
  Speaker 1: back and go, oh, yes, beautiful, we're done. We've done it. No,
• 40:54
  Speaker 1: We're like, there are so many weird little bits that
• 40:57
  Speaker 1: don't make any sense, hanging ugly things off the back
• 41:00
  Speaker 1: of it, that we want to try to understand and
• 41:02
  Speaker 1: smooth over and figure out, because hey, we like the
• 41:05
  Speaker 1: weird stuff, not the shiny and cool stuff. All right, Well,
• 41:08
  Speaker 1: it sounds like there's still big questions out there about
• 41:11
  Speaker 1: our understanding of particles in the universe, And um, I
• 41:15
  Speaker 1: think it's time for people to the side. You know,
• 41:18
  Speaker 1: are you pro Dirac or anti new Urana? And it
• 41:22
  Speaker 1: is that the same thing? And what would happen if
• 41:26
  Speaker 1: Dirac and Myrna went to a conference together within an
• 41:28
  Speaker 1: highlate each other with the same energy and the opposite direction.
• 41:33
  Speaker 1: Would we even be having this conversation? That's right? Well,
• 41:37
  Speaker 1: I'm on team Irona because I hope that the universe
• 41:40
  Speaker 1: is weird, and then we find new stuff. If it
• 41:43
  Speaker 1: turns out that neutrinos have antiparticles and get their mass
• 41:46
  Speaker 1: from the Higgs, just like all the other particles, and
• 41:49
  Speaker 1: that's much less exciting than discovering a whole new kind
• 41:52
  Speaker 1: of particle that does something weird. So you're pro weird
• 41:56
  Speaker 1: or anti standard, that's right. I'm rooting for the model
• 42:00
  Speaker 1: of physics, not the standard model. All right, Well, we
• 42:03
  Speaker 1: hope you enjoyed that, and I think a little bit
• 42:05
  Speaker 1: differently the next time you look up into the sky
• 42:07
  Speaker 1: and um realize that you're based in these weird, mysterious
• 42:11
  Speaker 1: neutrinos that are maybe something totally different than the rest
• 42:15
  Speaker 1: of the universe, and maybe they hold a clue to
• 42:17
  Speaker 1: something even deeper about the nature of matter and reality
• 42:22
  Speaker 1: and the whole universe. Thanks for joining us. Let's see
• 42:24
  Speaker 1: you next time. Thanks for listening, and remember that Daniel
• 42:35
  Speaker 1: and Jorge explained. The Universe is a production of I
• 42:37
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• 42:41
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• 42:44
  Speaker 1: listen to your favorite shows.