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Does dark matter have an anti-particle? · Daniel and Kelly’s Extraordinary Universe

• 0:00
  Speaker 1: Hey, everyone, a quick note to let you know that
• 0:02
  Speaker 1: our preschool science TV show on PBS Kids called Eleanor
• 0:06
  Speaker 1: Wonders Why just launched its second season. It's a show
• 0:10
  Speaker 1: about curiosity and exploration and learning to use science to
• 0:14
  Speaker 1: find your own answers to questions or Hey and I
• 0:17
  Speaker 1: created the show a few years ago, and the second
• 0:19
  Speaker 1: season has just premiered. We're so excited to share this
• 0:23
  Speaker 1: new batch of stories and adventures. Check it out on
• 0:25
  Speaker 1: PBS Kids. Eleanor Wonders Why.
• 0:37
  Speaker 2: Hey, Daniel, have you run out of ideas to explain
• 0:40
  Speaker 2: dark matter yet?
• 0:41
  Speaker 1: You know, we're not even close.
• 0:43
  Speaker 2: None of them have worked out, you know.
• 0:44
  Speaker 1: Also not even close to working out?
• 0:47
  Speaker 2: Are you close to having any ideas?
• 0:49
  Speaker 3: Oh?
• 0:49
  Speaker 1: We have so many ideas.
• 0:52
  Speaker 2: Are they all going in the right direction? Though?
• 0:54
  Speaker 1: We'll never know until one of them works out.
• 0:56
  Speaker 2: Being what you need is like an idea that's an
• 0:58
  Speaker 2: anti idea going in the opposite direction.
• 1:03
  Speaker 1: Or maybe an anti idea will collide with all of
• 1:05
  Speaker 1: our ideas and make pure podcast energy.
• 1:08
  Speaker 2: Maybe we'll finally blow up.
• 1:10
  Speaker 1: We'll annihilate our lack of understanding.
• 1:13
  Speaker 2: No, no, we don't want to annihilate our careers. We
• 1:16
  Speaker 2: just want to blow up.
• 1:17
  Speaker 1: I wouldn't mind annihilating some ignorance.
• 1:35
  Speaker 3: Hi.
• 1:35
  Speaker 2: I'm orgem a cartoonist and the author of Oliver's Great
• 1:38
  Speaker 2: Big Universe.
• 1:39
  Speaker 1: Hi. I'm Daniel. I'm a particle physicist, and I'm always
• 1:42
  Speaker 1: wondering what crazy new idea is going to revolutionize physics.
• 1:46
  Speaker 2: You're wondering which idea or you're trying to come up
• 1:49
  Speaker 2: with an idea to revolutionize physics. Wouldn't be more productive
• 1:52
  Speaker 2: to do the latter.
• 1:54
  Speaker 1: I'm trying to do all of them. Man, I'm trying
• 1:56
  Speaker 1: to come up with ideas. I'm looking forward to the ideas,
• 1:59
  Speaker 1: and I also sometimes just enjoy fantasizing about some time
• 2:02
  Speaker 1: in the deep future when those ideas have already been
• 2:05
  Speaker 1: found and proven right, and humanity is just like marinating
• 2:08
  Speaker 1: in the understanding.
• 2:09
  Speaker 3: Man.
• 2:10
  Speaker 2: M you seem to have like three brains here working
• 2:13
  Speaker 2: at the same time, past, present, in future. I mean
• 2:17
  Speaker 2: that's part of the problem.
• 2:18
  Speaker 1: Daniel, hmm, maybe I need a better cooling system.
• 2:21
  Speaker 2: I'm inn overheat, yeah or do Yeah, I'll just focus
• 2:24
  Speaker 2: focus on the present and what ideas are there. But anyways,
• 2:28
  Speaker 2: welcome to our podcast. Daniel and Jorge explain the Universe
• 2:31
  Speaker 2: a production of iHeart Radio in which.
• 2:33
  Speaker 1: We focus on the past, the present, and the future
• 2:35
  Speaker 1: of our understanding of the universe. We trace you through
• 2:39
  Speaker 1: the history of human thought to show you why we
• 2:41
  Speaker 1: think what we think in the present, and we try
• 2:44
  Speaker 1: to sketch out for you the future of human understanding,
• 2:47
  Speaker 1: the ideas that are being considered, the crazy ideas that
• 2:50
  Speaker 1: are just over the horizon, and try to even anticipate
• 2:53
  Speaker 1: what's past the edge of human imagination.
• 2:55
  Speaker 2: That's right, because science is the ultimate idea generator. Coming
• 2:59
  Speaker 2: up with the explaining for how the universe works, what's
• 3:02
  Speaker 2: going on in it, what are things made out of,
• 3:05
  Speaker 2: and maybe what ideas themselves are made out.
• 3:07
  Speaker 1: Of the universe is sort of like a big cosmic
• 3:10
  Speaker 1: mystery novel. We are gathering clues and trying to crack
• 3:14
  Speaker 1: the case. We don't actually know if there's an answer.
• 3:16
  Speaker 1: There's no guarantee that the universe does actually make sense
• 3:20
  Speaker 1: and that it can be understood by us. But along
• 3:23
  Speaker 1: the way it's going to take some creativity, some inventiveness,
• 3:26
  Speaker 1: some openness to crazy new ideas that might rock our world.
• 3:31
  Speaker 2: I guess the mystery novel is better than science fiction
• 3:34
  Speaker 2: for the universe genre.
• 3:37
  Speaker 1: I guess so. Science fiction to me is just like
• 3:39
  Speaker 1: mystery novels about.
• 3:40
  Speaker 2: Science the size of get murdered or what do you mean?
• 3:45
  Speaker 1: Nobody needs to get murdered. But it's always a mystery.
• 3:48
  Speaker 1: Like when you're reading a science fiction novel, you're wondering, like,
• 3:51
  Speaker 1: how does this universe work? What are the laws of
• 3:53
  Speaker 1: that universe? Truly the same process we do in actual
• 3:56
  Speaker 1: science for the real universe we're actually living in, trying
• 4:00
  Speaker 1: to crack the case and figure out what are the rules?
• 4:02
  Speaker 1: How does this little universe work?
• 4:04
  Speaker 2: I see, it's not a who done it? It's more
• 4:05
  Speaker 2: of a what done it?
• 4:07
  Speaker 1: What's it doing?
• 4:08
  Speaker 4: Yeah?
• 4:08
  Speaker 2: Exactly why done it? Or is that more philosophy?
• 4:12
  Speaker 1: Yeah? Maybe maybe more like how's it doing it?
• 4:15
  Speaker 2: How's it going? This is the strain a little far
• 4:20
  Speaker 2: from the mystery genre here. Yeah, it is a big mystery.
• 4:23
  Speaker 2: There are huge mysteries out there in the universe. How
• 4:26
  Speaker 2: long will it be around? And what are the things
• 4:29
  Speaker 2: in it made out of? We still don't really know.
• 4:32
  Speaker 1: There are so many questions that we don't have answers to,
• 4:34
  Speaker 1: and so many ideas that we are considering. When you
• 4:37
  Speaker 1: look back at the history of human physics and think
• 4:40
  Speaker 1: about the progression of our understanding. It can seem like
• 4:43
  Speaker 1: maybe it was linear, like we understood this and then that,
• 4:46
  Speaker 1: and then this other idea came along. But the truth
• 4:48
  Speaker 1: is that it's a multi branching tree of explorations, people
• 4:52
  Speaker 1: going down dead ends all the time, and when you
• 4:54
  Speaker 1: fast forward to the current forefront of human understanding and ignorance,
• 4:59
  Speaker 1: you see that happen in real time. You see lots
• 5:01
  Speaker 1: of different ideas being explored to explain the current mysteries
• 5:05
  Speaker 1: of the universe.
• 5:06
  Speaker 2: Yeah, because science and exploration is a human process, and
• 5:09
  Speaker 2: so like any human process, it's we're bound to make mistakes,
• 5:12
  Speaker 2: we're bound to go down the wrong path, We're bound
• 5:15
  Speaker 2: to be totally convinced that one idea is totally true,
• 5:17
  Speaker 2: but then later we find out that, uh, maybe it's.
• 5:20
  Speaker 1: Not exactly And it all seems so painfully obvious in hindsight, Like, man,
• 5:25
  Speaker 1: if I was around back then, I totally would have
• 5:28
  Speaker 1: figured that out and written that seminal paper. But it's
• 5:30
  Speaker 1: so much harder when you're actually standing at the forefront
• 5:33
  Speaker 1: of human understanding and one of the biggest mysteries that
• 5:36
  Speaker 1: we're trying to crack today is what is the universe
• 5:39
  Speaker 1: made out of? What is all the stuff that's out there?
• 5:42
  Speaker 1: We know that most of the universe is not made
• 5:44
  Speaker 1: out of the kinds of particles that we are made
• 5:46
  Speaker 1: out of, atoms, made of quarks and electrons, but something else,
• 5:50
  Speaker 1: something much more mysterious, something we have not yet cracked.
• 5:54
  Speaker 2: Yeah, we've talked about in the podcast a lot. There's
• 5:56
  Speaker 2: a whopping ninety five percent of the universe that we
• 5:59
  Speaker 2: have no idea what it is, what it's made out of,
• 6:01
  Speaker 2: where did it come from, how does it work. That's
• 6:04
  Speaker 2: a pretty big percentage of the universe.
• 6:06
  Speaker 1: Yeah, we don't know what kind of books it likes
• 6:07
  Speaker 1: to read, whether it read science fiction or mystery or
• 6:10
  Speaker 1: just romance novels. I mean, we basically know nothing about
• 6:13
  Speaker 1: this stuff.
• 6:13
  Speaker 2: That's right. We don't know if it killed anyone, whether
• 6:16
  Speaker 2: it's there was just circumstantial evidence.
• 6:19
  Speaker 1: Was it in the library with a candlestick or not.
• 6:21
  Speaker 1: Nobody knows.
• 6:22
  Speaker 2: Yeah, No, I think it was in the particle collider
• 6:25
  Speaker 2: with the proton accelerator.
• 6:29
  Speaker 1: Yeah. Maybe. And a big chunk of that ninety five
• 6:32
  Speaker 1: percent is something we know is a kind of matter,
• 6:35
  Speaker 1: it's stuff, it's something that's out there, but we can't
• 6:38
  Speaker 1: see it or touch it. And so this mystery of
• 6:41
  Speaker 1: dark matter is something that really preoccupies particle physicists in
• 6:44
  Speaker 1: particular because we want to understand what is that dark
• 6:47
  Speaker 1: matter made out of.
• 6:49
  Speaker 2: It's been one of the biggest mysteries in the last
• 6:51
  Speaker 2: thirty forty years where we looked dot into the cosmos
• 6:54
  Speaker 2: and found that there are things holding galaxies together that
• 6:58
  Speaker 2: are kind of invisible intangible.
• 7:01
  Speaker 1: Absolutely, it dates back even more than thirty or forty years.
• 7:04
  Speaker 1: We've been confused about it since the nineteen thirties. It's
• 7:07
  Speaker 1: a long history of confusion about dark matter and many
• 7:10
  Speaker 1: many ideas about what it might be.
• 7:12
  Speaker 2: Yeah, and as you said, particle physicists are interested in it,
• 7:15
  Speaker 2: but we don't even know if if it is a particle,
• 7:17
  Speaker 2: right Daniel.
• 7:18
  Speaker 1: We indeed have no idea what it is, whether or
• 7:21
  Speaker 1: not it's a particle, and if it's a particle, whether
• 7:23
  Speaker 1: it's a new, weird kind of particle we have never
• 7:26
  Speaker 1: seen before.
• 7:26
  Speaker 2: So today on the podcast, we'll be tackling the question
• 7:34
  Speaker 2: could dark matter be its own anti particle? Wait, wouldn't
• 7:38
  Speaker 2: an anti dark matter particle be called a light matter particle?
• 7:42
  Speaker 1: A lot of people get confused about these two topics,
• 7:44
  Speaker 1: or I get a lot of emails where people try
• 7:46
  Speaker 1: to connect these two ideas. Dark matter antimatter. Are the
• 7:50
  Speaker 1: two things the same, it's the missing anti matter action
• 7:53
  Speaker 1: explanation for dark matter. These things are very confusing to
• 7:56
  Speaker 1: hold in your head at the same time. So I
• 7:57
  Speaker 1: thought it'd be fun to do an episode to explore
• 8:00
  Speaker 1: or the connections between dark matter and antimatter, because there
• 8:02
  Speaker 1: really are some interesting, cutting edge ideas about dark matter
• 8:05
  Speaker 1: and anti matter.
• 8:07
  Speaker 2: You want to bring this topic into the anti dark
• 8:10
  Speaker 2: that's right.
• 8:11
  Speaker 1: I want to illuminate dark matter, not anti illuminated.
• 8:14
  Speaker 2: You want to pro explain it, not anti confused people,
• 8:16
  Speaker 2: or you do want to anti confuse people.
• 8:18
  Speaker 1: I guess I'm confused about whether I want to do
• 8:20
  Speaker 1: that or not.
• 8:21
  Speaker 2: Yeah, well this is an interesting question, and so as usual,
• 8:25
  Speaker 2: we were wondering how many people out there had thought
• 8:26
  Speaker 2: about the possibility that dark matter could be its own
• 8:29
  Speaker 2: anti particle.
• 8:31
  Speaker 1: Thanks very much for everybody who plays for this segment
• 8:33
  Speaker 1: of the podcast. If you'd like to hear your voice
• 8:35
  Speaker 1: on the future episode, we would welcome you to participate.
• 8:38
  Speaker 1: Please just write to me to questions at Danielanjorge dot
• 8:41
  Speaker 1: com and I'll add you to the list.
• 8:43
  Speaker 2: So think about it for a second. Do you think
• 8:46
  Speaker 2: dark matter could be its own anti particle or do
• 8:49
  Speaker 2: you Anti not think that the dark matter could not
• 8:52
  Speaker 2: be its How I think you just did Anti failed
• 9:00
  Speaker 2: to do that.
• 9:00
  Speaker 1: Yeah, I'm going to give that a dark anti chuckle.
• 9:03
  Speaker 2: There you go. Here's what people had to say.
• 9:05
  Speaker 5: Well, I would say that dark meta could be pretty
• 9:10
  Speaker 5: much anything, because we have no idea what it really is.
• 9:13
  Speaker 1: But if it would be its.
• 9:14
  Speaker 5: Own antiparticle, wouldn't it annihilate itself on a large scale?
• 9:18
  Speaker 5: If it's anything like meta and anti meta no idea.
• 9:22
  Speaker 4: Well, then there would need to be a partner particle
• 9:25
  Speaker 4: in the dark matter particle antiparticle, and the dark matter
• 9:30
  Speaker 4: particle would annihilate when they met dark matter. Antiparticle's gone wild.
• 9:36
  Speaker 2: Well, I don't really see why dark matter couldn't be
• 9:39
  Speaker 2: its own antiparticle.
• 9:39
  Speaker 3: I think I remember you saying that photons are their
• 9:41
  Speaker 3: own anti particle.
• 9:43
  Speaker 1: But I really have no idea.
• 9:44
  Speaker 3: I think that dark meta can't be its own anti
• 9:48
  Speaker 3: particle because if it was, it would annihilate and produce photons,
• 9:54
  Speaker 3: which we would observe and I don't think we've observed.
• 9:57
  Speaker 1: That it's documenta to go? Is this school already? I
• 10:01
  Speaker 1: don't know. To be honest, I don't understand the question really.
• 10:04
  Speaker 1: So if it's a particle, how can it beat its
• 10:06
  Speaker 1: own antiparticle?
• 10:07
  Speaker 2: All right, a lot of interesting, thoughtful answers. A lot
• 10:10
  Speaker 2: of people seem to be a little bit confused about
• 10:13
  Speaker 2: what do you even mean and whether dark matter is
• 10:16
  Speaker 2: even a particle? Like do we know that for sure
• 10:18
  Speaker 2: or not?
• 10:19
  Speaker 1: Yeah? Yeah, all good questions, really great comments here.
• 10:22
  Speaker 2: Yeah, it might help if you maybe explain the other
• 10:25
  Speaker 2: question to them a little more.
• 10:27
  Speaker 1: No, that's all the fun, man.
• 10:30
  Speaker 2: You enjoy airing their confusion.
• 10:32
  Speaker 1: I enjoyed trying to get a sense for what the
• 10:34
  Speaker 1: average podcast listener will think when you see the topic
• 10:36
  Speaker 1: of the episode.
• 10:37
  Speaker 2: Well, pretty awesome answers here, And so let's dig into it, Daniel,
• 10:40
  Speaker 2: what do you know about what dark matter is made
• 10:42
  Speaker 2: out of?
• 10:42
  Speaker 3: It?
• 10:43
  Speaker 1: Yeah? So, as you said earlier, we do know something
• 10:45
  Speaker 1: about dark matter. We have a sort of precision ignorance,
• 10:48
  Speaker 1: and that we know very well how much of this
• 10:51
  Speaker 1: stuff there is. We look out into the Cosmo, so
• 10:54
  Speaker 1: we see evidence for it everywhere. All that evidence is gravitational,
• 10:59
  Speaker 1: but it tugs on stuff and changes the whole structure
• 11:02
  Speaker 1: of the universe. As you say, it's the reason that
• 11:04
  Speaker 1: galaxies can spin so fast and still hold themselves together.
• 11:08
  Speaker 1: There isn't enough gravity from all the luminous matter, the
• 11:11
  Speaker 1: stars and the gas and the dust to hold galaxies
• 11:14
  Speaker 1: together as they spin so fast, and yet they don't
• 11:17
  Speaker 1: like throw their stars into intergalactic space. Very often. We
• 11:20
  Speaker 1: see evidence of dark matter in the very early universe
• 11:23
  Speaker 1: from the light in the cosmic microwave background, which shows
• 11:26
  Speaker 1: us ripples in that early universe plasma. Those ripples are
• 11:30
  Speaker 1: affected by the density of dark matter as everything was
• 11:33
  Speaker 1: sloshing around. So there's evidence for dark matter everywhere in
• 11:36
  Speaker 1: the universe. We know that it's there, we know that
• 11:39
  Speaker 1: it's stuff. It has gravity, but we don't know what
• 11:42
  Speaker 1: it's made out of.
• 11:44
  Speaker 2: Is that technically what makes it matter? The fact that
• 11:46
  Speaker 2: it has gravity, or the fact that it has mass
• 11:49
  Speaker 2: that then maybe has gravity to it, or can something
• 11:52
  Speaker 2: have gravity without mass.
• 11:53
  Speaker 1: Something could have gravity without mass because remember gravity is
• 11:57
  Speaker 1: actually connected to energy more deeply than it is to mass.
• 12:00
  Speaker 1: Mass is just a kind of energy. So for example,
• 12:03
  Speaker 1: you get enough photons into one spot in space. They
• 12:06
  Speaker 1: will curve space and create effectively gravity. In principle, you
• 12:10
  Speaker 1: can even make a black hole just out of photons,
• 12:13
  Speaker 1: so you don't need mass in order to curve space
• 12:15
  Speaker 1: and have gravity. One reason that we're convinced that dark
• 12:18
  Speaker 1: matter is matter is because of how it behaves as
• 12:21
  Speaker 1: the universe expands. Think about normal matter, atoms, protons, et cetera.
• 12:26
  Speaker 1: As the universe expands space gets bigger, that stuff gets
• 12:30
  Speaker 1: more dilute, It gets less dense because you've got the
• 12:33
  Speaker 1: same number of protons and now you've got more space,
• 12:36
  Speaker 1: so the density of that stuff is decreasing. Dark matter
• 12:39
  Speaker 1: acts exactly the same way as the universe expands. The
• 12:43
  Speaker 1: density of dark matter changes exactly the same way the
• 12:46
  Speaker 1: density of protons and electrons does, and that's different for
• 12:50
  Speaker 1: other kinds of stuff like photons radiation. The density of
• 12:54
  Speaker 1: photonic energy changes differently than for protons because photons also
• 12:59
  Speaker 1: gets their wavelengths stretched as the universe expands, and dark
• 13:02
  Speaker 1: energy is something totally different. Its density doesn't decrease as
• 13:05
  Speaker 1: the universe expands, but dark matter behaves exactly the same
• 13:08
  Speaker 1: way other kinds of matter do, and so we're pretty
• 13:11
  Speaker 1: convinced that dark matter is actually a kind of matter.
• 13:14
  Speaker 2: I guess what is it about dark matter that makes
• 13:16
  Speaker 2: it dilute like regular atoms. Is it's inertia, or it's
• 13:22
  Speaker 2: mass or what.
• 13:24
  Speaker 1: We don't know, right. If it's a particle, then that
• 13:26
  Speaker 1: makes perfect sense because you can increase space, but you're
• 13:29
  Speaker 1: not changing the number of particles, and so it will
• 13:31
  Speaker 1: dilute in exactly that same way. If it's something else
• 13:35
  Speaker 1: other than a particle, then you not me. But this
• 13:37
  Speaker 1: is something we notice, and it's a really big clue
• 13:40
  Speaker 1: that tells us that dark matter really is matter. Obviously,
• 13:43
  Speaker 1: it has energy, and it seems to contribute also gravitationally
• 13:47
  Speaker 1: to those tenser equations, the same way other kinds of
• 13:49
  Speaker 1: matter does. But more importantly, I think it dilutes in
• 13:53
  Speaker 1: the same way it matter does. Why that is we
• 13:55
  Speaker 1: don't know, But it feels like a big clue that
• 13:57
  Speaker 1: it's a kind of matter.
• 14:00
  Speaker 2: And if it's a kind of matter, does it have
• 14:02
  Speaker 2: to be a particle? Oring have matter without particles?
• 14:05
  Speaker 1: We've never seen matter without particles. That doesn't mean you can't, right,
• 14:09
  Speaker 1: We've only ever studied a tiny fraction of all the
• 14:12
  Speaker 1: energy in the universe. The kind of stuff that makes
• 14:14
  Speaker 1: up atoms and gas and dust and ice cream and
• 14:16
  Speaker 1: kittens is five percent of the universe. And our quantum
• 14:20
  Speaker 1: field theory, with these fundamental fields that ripple to make
• 14:23
  Speaker 1: particles and all that stuff, that explains that very very well.
• 14:27
  Speaker 1: But it's a little bit of a reach to say
• 14:29
  Speaker 1: that everything else in the universe has to follow the
• 14:31
  Speaker 1: same rules. Maybe it does, and it certainly would be
• 14:34
  Speaker 1: nice and neat and a confirmation of quantum field theory
• 14:37
  Speaker 1: if dark matter was described by quantum fields and the
• 14:40
  Speaker 1: ripples in those fields were particles. But we don't know, right.
• 14:43
  Speaker 1: Dark matter is a big chunk of the universe, and
• 14:46
  Speaker 1: it's not something we understand, so there's no guarantee that
• 14:49
  Speaker 1: it's made of particles.
• 14:50
  Speaker 2: But the leading theory of it is that it is
• 14:53
  Speaker 2: sort of quantum some kind of quantum particle, or is
• 14:56
  Speaker 2: it not even that established, or may it's the only
• 14:58
  Speaker 2: thing you got.
• 15:01
  Speaker 1: I think it says something interesting about the way science
• 15:03
  Speaker 1: is done. Right. We don't know that dark matter is particles,
• 15:06
  Speaker 1: and yet most of the theories of dark matter are
• 15:09
  Speaker 1: that it's a particle. Why is that? Mostly because that's
• 15:11
  Speaker 1: the only thing we've got, right, it's so much easier
• 15:14
  Speaker 1: to talk concretely about various kinds of new particles because
• 15:18
  Speaker 1: we know how to do that. We had that toolkit already.
• 15:20
  Speaker 1: It's much harder to be creative and be like, huh,
• 15:22
  Speaker 1: what if dark matter or something else. We talked once
• 15:25
  Speaker 1: on the podcast about whether dark matter was a kind
• 15:27
  Speaker 1: of unparticle, something which looked the same no matter how
• 15:30
  Speaker 1: much you zoomed in, you never like revealed its discrete
• 15:33
  Speaker 1: quantum nature. But those theories are much more speculative and
• 15:36
  Speaker 1: much harder to deal with, just because we've never seen
• 15:38
  Speaker 1: that kind of matter, so you just really out there
• 15:41
  Speaker 1: into the wilderness Intellectually. That doesn't mean that dark matter
• 15:45
  Speaker 1: has to be a particle. But the reason that most
• 15:47
  Speaker 1: of the theories of dark matter are particles is because
• 15:49
  Speaker 1: we're all particle physicists trying to figure this out.
• 15:54
  Speaker 2: Particle physicists trying to get grant to study dark matter. Perhaps.
• 15:57
  Speaker 1: Yeah, I mean, if you invite a carpenter over to
• 15:59
  Speaker 1: fix a hole in your house, else, what's he going
• 16:00
  Speaker 1: to do? Suggest some carpentry, Right, So that's what we're doing.
• 16:03
  Speaker 1: We're patching up our lack of understanding the universe using
• 16:05
  Speaker 1: the only tools we have.
• 16:07
  Speaker 2: Well, I guess if it is a quantum particle, what
• 16:09
  Speaker 2: do we know about it? We know that it would
• 16:11
  Speaker 2: have mass and maybe inertia, but maybe it wouldn't feel
• 16:15
  Speaker 2: the electromagnetic force or the strong force or the weak force.
• 16:18
  Speaker 2: But it does feel gravity.
• 16:20
  Speaker 1: That's right. We know that it feels gravity because everything
• 16:23
  Speaker 1: feels gravity. Everything that has energy feels gravity. We're confident
• 16:26
  Speaker 1: doesn't feel the strong force or the weak force or
• 16:29
  Speaker 1: the electromagnetic force. There's a couple of asterisks though, that
• 16:33
  Speaker 1: are really important. One is there could be more forces.
• 16:36
  Speaker 1: There could be some new dark electromagnetism, and there could
• 16:39
  Speaker 1: be like dark photons, so there could be all sorts
• 16:42
  Speaker 1: of forces that only dark matter feels. Right, It doesn't
• 16:45
  Speaker 1: mean that dark matter doesn't feel any force. It just
• 16:48
  Speaker 1: might not feel our kinds of force. And also, the
• 16:52
  Speaker 1: second really important caveat is that dark matter could contain multitudes. Right,
• 16:56
  Speaker 1: our kind of matter is many kinds of particles. We
• 16:59
  Speaker 1: got six core we've got six leptons, we've got all
• 17:01
  Speaker 1: sorts of bosons. Why do we imagine dark matter is
• 17:04
  Speaker 1: one particle? Well, that's just like the simplest first idea.
• 17:07
  Speaker 1: Dark matter could be very complex. It could be lots
• 17:10
  Speaker 1: of different particles with different masses and different kinds of interactions,
• 17:14
  Speaker 1: just like our kind of matter. So when we speak
• 17:16
  Speaker 1: about dark matter, we shouldn't be like monolithic and say
• 17:19
  Speaker 1: it does feel this, it doesn't feel that. There could
• 17:21
  Speaker 1: be lots of different kinds that do and don't feel,
• 17:23
  Speaker 1: various different kinds of forces.
• 17:25
  Speaker 2: It could be a day not an it.
• 17:27
  Speaker 1: Yeah, exactly what are dark matters pronouns? I don't know.
• 17:32
  Speaker 2: Well, I mean like you're saying, there might be different
• 17:34
  Speaker 2: kinds of dark matters.
• 17:35
  Speaker 1: Yeah, exactly. You can imagine a whole different set of
• 17:37
  Speaker 1: state of dark matter. And maybe most of it doesn't
• 17:40
  Speaker 1: feel electromagnetism in the weak force and gravity, but maybe
• 17:44
  Speaker 1: some tiny fraction of it does. Right, maybe some tiny
• 17:46
  Speaker 1: fraction of it isn't actually that dark.
• 17:49
  Speaker 2: Or maybe I wonder there could be an infinite number
• 17:51
  Speaker 2: of kinds of dark matters.
• 17:52
  Speaker 1: Oh man, that blows my mind. Could there be an
• 17:54
  Speaker 1: infinite number of kinds of particles?
• 17:56
  Speaker 3: Yeah?
• 17:56
  Speaker 1: I suppose, so there's no limit to the number of states.
• 17:59
  Speaker 1: You could have the number kinds of quantum fields. Yeah, sure,
• 18:02
  Speaker 1: let's have an infinite dark matter. Awesome, there's a new.
• 18:04
  Speaker 2: Theory right there, the infinite dark man, the infinite dark Yeah,
• 18:08
  Speaker 2: theory of.
• 18:09
  Speaker 1: Cham Cham's infinitely dark universe.
• 18:12
  Speaker 2: Right right, Like, maybe we feel some forces in common
• 18:15
  Speaker 2: with dark matter, but maybe there's other kinds of matter
• 18:18
  Speaker 2: out there that we have no relation to, but maybe
• 18:20
  Speaker 2: dark matter does.
• 18:22
  Speaker 1: Yeah, absolutely, there could be. I think also, you should
• 18:24
  Speaker 1: come up with a color palette, like a color called
• 18:27
  Speaker 1: infinitely dark. You know, there's all these shades of black
• 18:30
  Speaker 1: people invent hmmm, infinitely dark. Yeah, that'd be a good
• 18:33
  Speaker 1: coat of paint right there.
• 18:35
  Speaker 2: All right, we'll copyright it and we'll make no money
• 18:38
  Speaker 2: from it.
• 18:39
  Speaker 1: It's your idea, man, don't give me any credit.
• 18:42
  Speaker 2: I'll take it, all right. Well, there's the as you said,
• 18:46
  Speaker 2: there's this idea that maybe dark matter is something weird,
• 18:50
  Speaker 2: and there's other kinds of weird stuff out there in
• 18:52
  Speaker 2: the universe, and sometimes people are maybe quick to wonder
• 18:57
  Speaker 2: if those two things are connected. And one weird thing
• 19:00
  Speaker 2: in the universe is antimatter. And so let's talk about
• 19:04
  Speaker 2: whether dark matter is related to antimatter or whether it's
• 19:07
  Speaker 2: anti not related to antimatter, one of those two. But first,
• 19:12
  Speaker 2: let's take a quick break all right, we're talking about
• 19:27
  Speaker 2: dark matter, and we're posing the question whether dark matter
• 19:30
  Speaker 2: is maybe related to antimatter, like is dark matter made
• 19:34
  Speaker 2: out of antimatter? Or I guess specifically, is dark matter
• 19:38
  Speaker 2: its own antimatter?
• 19:40
  Speaker 1: So first, let's just think about antimatter as a completely
• 19:42
  Speaker 1: separate direction, Like we're talking about matter versus dark matter,
• 19:46
  Speaker 1: a completely separate question is matter versus antimatter?
• 19:49
  Speaker 2: I like you're using versus It feels like there's there's
• 19:52
  Speaker 2: gonna be a fight, like shark versus tornadoes, shark versus Godzilla?
• 19:58
  Speaker 2: You know, can cong versus Godzilla?
• 20:00
  Speaker 4: Yeah?
• 20:00
  Speaker 2: There you go.
• 20:01
  Speaker 1: Consider first a completely separate kind of question. Like if
• 20:03
  Speaker 1: you're trying to get to know somebody, you might ask,
• 20:06
  Speaker 1: you know, do they like mystery novels versus science fiction novels?
• 20:09
  Speaker 1: That's one dimension. You might also ask, like do they
• 20:12
  Speaker 1: like Mexican food or Italian food?
• 20:13
  Speaker 4: Matter?
• 20:14
  Speaker 1: And that's a separate kind of question.
• 20:15
  Speaker 2: No, it's the same thing. People who like science fiction
• 20:18
  Speaker 2: always like Mexican food.
• 20:21
  Speaker 1: Wow, there are plenty of pizza love and science fection
• 20:26
  Speaker 1: readers out there. I promise you that's not.
• 20:29
  Speaker 2: I don't believe it.
• 20:30
  Speaker 1: So back to antimatter. This is like a subset of
• 20:33
  Speaker 1: a kind of matter. Antimatter is a totally normal thing
• 20:36
  Speaker 1: in our universe. We have particles like electrons and protons,
• 20:40
  Speaker 1: and what we've noticed is that we also have other
• 20:43
  Speaker 1: kinds of particles like the positron and the anti proton.
• 20:47
  Speaker 1: These are very very similar to the particles we know
• 20:49
  Speaker 1: and love, They just have the opposite charges. And so
• 20:52
  Speaker 1: it turns out that like the quantum field that gives
• 20:55
  Speaker 1: you an electron can also do something else. It can
• 20:57
  Speaker 1: wiggle in another way that gives you a part with
• 21:00
  Speaker 1: the opposite electric charge, the positron, and the same is
• 21:04
  Speaker 1: true for the quarks. The quark fields can also wiggle
• 21:06
  Speaker 1: in a way to give you anti quark particles. And
• 21:09
  Speaker 1: so what we notice is that the fields that give
• 21:11
  Speaker 1: us matter have this capacity to also generate antimatter.
• 21:15
  Speaker 2: Well, this is a part that it's always confused me.
• 21:17
  Speaker 2: I know that antimatter is matter with the charges flip,
• 21:19
  Speaker 2: but sometimes some particles have multiple charges like right, Like
• 21:22
  Speaker 2: quarks can field multiple forces like the electromagnetic force and
• 21:26
  Speaker 2: also the strong force. So does that mean that an
• 21:29
  Speaker 2: antiquark has all of its sigence flip or some of
• 21:32
  Speaker 2: its science flip are the different flavors of sign flippage.
• 21:35
  Speaker 1: Well, what you call matter in what you call antimatter
• 21:37
  Speaker 1: is a little bit arbitrary. Like we could have called
• 21:40
  Speaker 1: the electron matter and the positron antimatter, or we could
• 21:43
  Speaker 1: have called the positron matter in the electron antimatter, and
• 21:46
  Speaker 1: that arbitrary from field to field. Also, like we could
• 21:49
  Speaker 1: keep calling the electron matter and call the anti quarks matter. Also,
• 21:53
  Speaker 1: it's a little bit arbitrary. Really, what we're trying to
• 21:55
  Speaker 1: get at is that there's a symmetry in these fields.
• 21:57
  Speaker 1: These fields can do two different kinds of things, and
• 22:00
  Speaker 1: so specifically, like anti quarks have the flipped electric charge,
• 22:04
  Speaker 1: but they can also have a flipped color charge and
• 22:06
  Speaker 1: a flipped weak charge. So if you have, for example,
• 22:09
  Speaker 1: a red quark, it's anti cork has the opposite electric charge.
• 22:13
  Speaker 1: It also has an anti red color for the strong force,
• 22:16
  Speaker 1: and what about the weak force. Yeah, so the weak
• 22:18
  Speaker 1: force actually is two different charges, which makes it very complicated,
• 22:22
  Speaker 1: and those are also flipped. And that's one way to
• 22:24
  Speaker 1: understand what happens when matter and antimatter meat. A lot
• 22:28
  Speaker 1: of these properties that the quarks and the electrons have
• 22:30
  Speaker 1: These are conserved quantities like charge and color and whatever.
• 22:34
  Speaker 1: And when matter and antimatter meat, they balance each other
• 22:36
  Speaker 1: out in terms of those quantities. So you can take
• 22:39
  Speaker 1: a particle that has electric charge and then another one
• 22:41
  Speaker 1: that has the opposite electric charge. You can put them
• 22:44
  Speaker 1: together to make a photon which is neutral, which has
• 22:46
  Speaker 1: no electric charge. You can only do that because the
• 22:49
  Speaker 1: accounting works out. They balance each other out to get
• 22:52
  Speaker 1: you to zero.
• 22:53
  Speaker 2: But I guess what do you what do you call
• 22:54
  Speaker 2: a quark that has the opposite electric charge, the opposite
• 22:58
  Speaker 2: weak force charge, but the same strong force charge. Is
• 23:01
  Speaker 2: it still anti?
• 23:02
  Speaker 1: It's a little bit arbitrary, But that particle would have
• 23:05
  Speaker 1: an anti particle with all of those charges flipped.
• 23:08
  Speaker 2: Oh, I see, So you use anti when all the
• 23:10
  Speaker 2: charges are flipped. But if something you only hell only
• 23:13
  Speaker 2: has one thing flipped, you just call that like another particle.
• 23:16
  Speaker 1: It's more than We talk about this in terms of pairs, right,
• 23:18
  Speaker 1: this is a particle anti particle pair. But again, which
• 23:21
  Speaker 1: one you call anti, which one you call not anti
• 23:23
  Speaker 1: is totally arbitrary, so you can make up whatever rules
• 23:25
  Speaker 1: you want. Really, the thing is that the fields can
• 23:27
  Speaker 1: generate two different kinds of particles with opposite characteristics. M.
• 23:33
  Speaker 2: Daniel. I'm starting to suspect here that maybe you just
• 23:35
  Speaker 2: call this thing wrong.
• 23:39
  Speaker 1: I'm not anti against that.
• 23:41
  Speaker 2: Yeah, I mean I think you're saying that antimatters really
• 23:44
  Speaker 2: just matter.
• 23:44
  Speaker 1: Yes, antimatter is just another kind of matter, yes.
• 23:47
  Speaker 2: Yeah, And the anti is just like if you pick
• 23:49
  Speaker 2: one kind of matter and you flip all its signs
• 23:52
  Speaker 2: and you call that it's anti matter, but not necessarily right.
• 23:55
  Speaker 1: Yeah. In the same way, there are relationships between other
• 23:58
  Speaker 1: bits of things we call matter, like the electron and
• 24:00
  Speaker 1: the muon in the towel. These are all very very
• 24:02
  Speaker 1: similar particles. They just have different masses. There's some relationship
• 24:06
  Speaker 1: between them. We see lots of different kinds of these relationships,
• 24:09
  Speaker 1: these patterns in our particle physics, and there's lots of
• 24:12
  Speaker 1: different dimensions there. There's like the symmetries of the leptons.
• 24:15
  Speaker 1: This is symmetries of matter and antimatter. This is the
• 24:18
  Speaker 1: symmetry between the quarks and the leptons. There's all these
• 24:20
  Speaker 1: reflections and patterns we see in the particles, most of
• 24:23
  Speaker 1: which we don't understand, and the names for them are
• 24:26
  Speaker 1: terrible because they date back to when we understood even
• 24:28
  Speaker 1: less well.
• 24:29
  Speaker 2: I think I figured it out. I think what you're
• 24:30
  Speaker 2: saying is that it makes sense to call something an
• 24:32
  Speaker 2: anti electron or an anti quark or an antiproton, but
• 24:36
  Speaker 2: it doesn't really make sense to use the term antimatter.
• 24:39
  Speaker 2: Like that term doesn't really apply to anything specific.
• 24:43
  Speaker 1: It does not really apply to anything specific. Really, what
• 24:45
  Speaker 1: it does is tell you what kind of things we
• 24:47
  Speaker 1: tend to not have in the universe, Like matter really
• 24:50
  Speaker 1: is like about the stuff that we see in the universe.
• 24:52
  Speaker 1: We see lots of protons, we see lots of electrons,
• 24:54
  Speaker 1: so we call those matter. It turns out there are
• 24:57
  Speaker 1: other states which tend to not appear very often in universe.
• 25:00
  Speaker 1: They do sometimes, but not very often, and so that's
• 25:03
  Speaker 1: why they get called antimatter.
• 25:05
  Speaker 2: So really there should be like matter, and then there
• 25:08
  Speaker 2: should be anti the most common matter.
• 25:12
  Speaker 1: Really, matter contains multitudes, right, there's lots of different things
• 25:15
  Speaker 1: that matter can do, right, and only a few of
• 25:18
  Speaker 1: those states exist. In the same way with muons. Muons
• 25:20
  Speaker 1: don't exist very often in the universe. They're created sometimes
• 25:23
  Speaker 1: in collisions and then decay away. We don't call them
• 25:26
  Speaker 1: anti matter because they're not around very often.
• 25:29
  Speaker 2: No, but do you know what I mean? Like, I
• 25:30
  Speaker 2: think what you're saying is what you call antimatter. Typically
• 25:33
  Speaker 2: you really what you mean is anti common matter? Yeah, sure,
• 25:36
  Speaker 2: Like the term antimatter doesn't really exist.
• 25:39
  Speaker 1: Yeah, but then how do you deal with particles that
• 25:41
  Speaker 1: are never around anyway? Like we have top quarks, those
• 25:44
  Speaker 1: things never exist except on their specialized conditions, and we
• 25:46
  Speaker 1: have anti top quarks. Neither of those things really exist
• 25:49
  Speaker 1: very often, So the whole thing's a mess. I totally agree.
• 25:51
  Speaker 2: Yeah, Like you can have anti top quarks, but it
• 25:54
  Speaker 2: doesn't make sense to call it anti matter.
• 25:57
  Speaker 1: Yeah, exactly. Neither top quarks or anti toop quarks are
• 26:01
  Speaker 1: ever around in the universe and any significant density. And
• 26:05
  Speaker 1: it is arbitrary which one you call anti in which
• 26:07
  Speaker 1: one you call not anti. The takeaway is that all
• 26:10
  Speaker 1: these particles can do this really interesting thing where they
• 26:13
  Speaker 1: can create two different states. Electrons really are cousins of positrons.
• 26:18
  Speaker 1: The electron field can do this thing. It can wiggle
• 26:20
  Speaker 1: in an electron way and in a positron way. So
• 26:23
  Speaker 1: then we think about dark matter, where like, hmm, what
• 26:26
  Speaker 1: about dark matter? Can dark matter do that? Also?
• 26:29
  Speaker 2: Well, the question is it can dark matter, have it's
• 26:32
  Speaker 2: an anti version of it? Or could dark matter be
• 26:35
  Speaker 2: an anti version of some other particles?
• 26:38
  Speaker 3: Oh?
• 26:39
  Speaker 1: I see, The question is does dark matter have its
• 26:41
  Speaker 1: own anti dark matter? Right like, if dark matter is
• 26:44
  Speaker 1: a particle, do the fields that generate those particles? Can
• 26:47
  Speaker 1: they also make another kind of particle, which we call
• 26:50
  Speaker 1: anti dark matter, And again totally arbitrary, which one you
• 26:53
  Speaker 1: call it dark matter, which one you call it anti
• 26:55
  Speaker 1: dark matter? Doesn't make any difference. The question is it
• 26:58
  Speaker 1: doing both things or is it some new weird kind
• 27:01
  Speaker 1: of particle where it can't do that it is its
• 27:04
  Speaker 1: own anti matter, where like, instead of a field that
• 27:07
  Speaker 1: can generate pairs like positrons and electrons, it's some weird
• 27:10
  Speaker 1: field that generates only one singular kind of particle. We're
• 27:14
  Speaker 1: not considering the question whether anti hour matter is dark matter.
• 27:18
  Speaker 1: Is dark matter made of positrons and anti quarks. That's
• 27:21
  Speaker 1: not possible because we know it doesn't feel electromagnetism and
• 27:23
  Speaker 1: all that stuff, and antimatter does.
• 27:26
  Speaker 2: Right. Well, that's kind of the question I was wondering about. Somehow,
• 27:29
  Speaker 2: maybe our understanding of our fields and charges it's not
• 27:33
  Speaker 2: quite complete, And so if you flip certain things in
• 27:36
  Speaker 2: our kind of matter, maybe you get dark matter. I
• 27:38
  Speaker 2: don't know.
• 27:38
  Speaker 1: All the matter particles that we know about except for
• 27:40
  Speaker 1: neutrinos have charges. Right, So electrons and muons and towels
• 27:44
  Speaker 1: and quarks and all that stuff have charges. And so
• 27:47
  Speaker 1: if you flip them and you make anti matter, then
• 27:49
  Speaker 1: they still have charges. It's just the opposite charges, and
• 27:52
  Speaker 1: so that means they really can't be the dark matter.
• 27:55
  Speaker 1: There is a question about neutrinos. Neutrinos we don't understand
• 27:58
  Speaker 1: very well. Possible, then trino's actually a potential example of
• 28:02
  Speaker 1: a particle that might be its own anti particle, And
• 28:06
  Speaker 1: it's one reason why people wonder about dark matter. Is
• 28:09
  Speaker 1: dark matter like the electron where it has a particle
• 28:12
  Speaker 1: and an antiparticle pair, or is dark matter like the
• 28:15
  Speaker 1: way people might think the neutrino is where it is
• 28:18
  Speaker 1: its own anti particle.
• 28:19
  Speaker 2: Right right. But here's where I win the Nobel price, Daniel.
• 28:22
  Speaker 2: What if the electromagnetic force that we know about, we
• 28:25
  Speaker 2: think it only has plus or minus two charges, But
• 28:27
  Speaker 2: what if it has a third charge?
• 28:29
  Speaker 1: Well, there is a third charge. Zero neutrinos have zero
• 28:31
  Speaker 1: electric charge, right right?
• 28:33
  Speaker 2: Well, okay, what if there's a fourth charge, and somehow
• 28:37
  Speaker 2: if you take like an electron and you flip it
• 28:39
  Speaker 2: to this fourth charge, then we can no longer interact
• 28:43
  Speaker 2: with it. And so it would sort of behave like
• 28:45
  Speaker 2: dark matter, wouldn't it?
• 28:46
  Speaker 1: Love the creativity, totally willing to explore this with you,
• 28:49
  Speaker 1: But it feels like electric charges are either zero or
• 28:52
  Speaker 1: positive or negative, and if it's not zero, then it's
• 28:56
  Speaker 1: got to be positive or negative, and then it's going
• 28:58
  Speaker 1: to feel electricity, in which case it's not dark matter.
• 29:01
  Speaker 1: So I don't know how to escape that.
• 29:02
  Speaker 2: Mathematics, Well, it's sort of like, aren't some particle don't
• 29:06
  Speaker 2: some particles have three charges?
• 29:07
  Speaker 1: So the strong force has three charges for example, red, green,
• 29:10
  Speaker 1: and blue, instead of just plus and minus. Oh, I see,
• 29:12
  Speaker 1: So you want to expand electromagnetism to say it's not
• 29:15
  Speaker 1: just on a single number line, it's on some more
• 29:18
  Speaker 1: complex structure.
• 29:19
  Speaker 2: Yes, that is my Nobel Price proposition.
• 29:22
  Speaker 1: I guess I would say, why does it have to
• 29:23
  Speaker 1: be electromagnetism, Why not just have these particles have no
• 29:27
  Speaker 1: electric charge? Why change electromagnetism.
• 29:30
  Speaker 2: Well, we're trying to figure out if it could maybe
• 29:32
  Speaker 2: explain dark matter. Right, if it does have some other
• 29:34
  Speaker 2: dimension of electromagnetism. Maybe it could be dark matter.
• 29:38
  Speaker 1: It's possible that electromagnetism is different from what we think
• 29:40
  Speaker 1: it is. Although electromagnetism like the best tested theory out there,
• 29:45
  Speaker 1: like to nine decimal places we understand electromagnetism, So that'd
• 29:49
  Speaker 1: be a pretty tricky needle to thread.
• 29:51
  Speaker 2: That's why I would be awarded the Nobel price.
• 29:53
  Speaker 1: Yea, or at least five or six? Absolutely five, yeah,
• 29:57
  Speaker 1: I mean swing for the fences, man, if you're going
• 29:59
  Speaker 1: for it, absolutely yeah.
• 30:00
  Speaker 2: I'll take all of them for the next one hundred years, all.
• 30:03
  Speaker 1: Right, Yeah, we'll send them all to your infinitely black
• 30:06
  Speaker 1: painted mansion. But I think it's more likely that dark
• 30:09
  Speaker 1: matter just has zero electric charge. I mean, we have
• 30:11
  Speaker 1: examples of particles with no electric charge, like neutrinos. That's
• 30:14
  Speaker 1: not exotic or weird. So why can't dark matter just
• 30:18
  Speaker 1: have no electric charge?
• 30:19
  Speaker 2: Okay, it sounds like you're not entertaining the notion that
• 30:22
  Speaker 2: maybe dark matter is some sort of anti version of
• 30:25
  Speaker 2: our regular matter. And the question you actually want to
• 30:28
  Speaker 2: ask today is is this sort of property of dark matter? Right? Like,
• 30:33
  Speaker 2: does dark matter behave like the other kinds of particles
• 30:37
  Speaker 2: where it has an anti version of itself.
• 30:40
  Speaker 1: Or is it some weird thing named after mysterious Italian
• 30:43
  Speaker 1: physicist et Torre Mayerana, where it is its own anti
• 30:47
  Speaker 1: particle somehow.
• 30:49
  Speaker 2: Now I guess why is this question more interesting than mine?
• 30:54
  Speaker 1: I think all questions are interesting. Of course, if the
• 30:57
  Speaker 1: dark matter is somehow a reflection of our kind of matter,
• 31:01
  Speaker 1: it would have to be a reflection in some new
• 31:03
  Speaker 1: way we haven't even imagined. In that sense, it wouldn't
• 31:06
  Speaker 1: be like antimatter. It'd be like yet another reflection, the
• 31:10
  Speaker 1: way we see patterns between electrons and muons and towels,
• 31:12
  Speaker 1: and we see patterns between quarks and leptons. Say, for example,
• 31:15
  Speaker 1: we discover dark matter, and we discover that every particle
• 31:18
  Speaker 1: has a weird dark version of itself. There's a dark
• 31:21
  Speaker 1: upcork and a dark top cork, and a dark electron,
• 31:23
  Speaker 1: and that, like our kind of matter, is like weirdly
• 31:26
  Speaker 1: reflected into dark matter. Then you can make a connection
• 31:29
  Speaker 1: between matter and dark matter and say, oh, there's some
• 31:31
  Speaker 1: reflection here. It'd be a different relationship than the one
• 31:34
  Speaker 1: described by matter and antimatter, but there would be some
• 31:37
  Speaker 1: sort of symmetry there. I think maybe that's what you're
• 31:40
  Speaker 1: going for. That would be possible, and that would be awesome,
• 31:43
  Speaker 1: And if we discover dark matter and see that structure,
• 31:45
  Speaker 1: I'll make sure that you get credit for it.
• 31:47
  Speaker 2: Awesome, thank you. But it sounds like you want to
• 31:50
  Speaker 2: explore this question of whether dark matter it can be
• 31:52
  Speaker 2: its own antimatter. And I didn't mean to minimize it.
• 31:55
  Speaker 2: I just I was just wondering, why is this question interesting?
• 31:58
  Speaker 2: Why does it matter if something is its own antimatter.
• 32:01
  Speaker 1: I think it's interesting because it's one of the few
• 32:03
  Speaker 1: tools we have right. We've been thinking about particle dark
• 32:05
  Speaker 1: matter for a long time, and for a long time
• 32:07
  Speaker 1: people have been assuming that, well, if dark matter is
• 32:10
  Speaker 1: a particle, it's probably like the other ones, in which
• 32:12
  Speaker 1: case there's some anti version of it, like people call
• 32:14
  Speaker 1: the dark matter particle KAI. So maybe there's a Kai
• 32:17
  Speaker 1: and an anti Kai, and the two things like both
• 32:20
  Speaker 1: exist in our universe. That's sort of like the standard approach.
• 32:23
  Speaker 1: Most dark matter theories have a particle and an anti
• 32:26
  Speaker 1: particle for the dark matter, but we haven't found any
• 32:29
  Speaker 1: of those things yet. We've been looking for this particle
• 32:31
  Speaker 1: for a long long time and haven't seen it. So
• 32:33
  Speaker 1: people are trying to be creative and people thinking, well,
• 32:35
  Speaker 1: maybe it's a little different from what we imagined. Maybe
• 32:39
  Speaker 1: it operates in a different way, and this field is
• 32:40
  Speaker 1: a little bit different, And it's important also for how
• 32:43
  Speaker 1: you look for it because it changes how that particle
• 32:46
  Speaker 1: gets mass. If the particle is its own anti particle,
• 32:49
  Speaker 1: then it doesn't get its mass from the Higgs field
• 32:51
  Speaker 1: the way our particles do. Has to get its mass
• 32:53
  Speaker 1: in some other way, and that means you can't use
• 32:56
  Speaker 1: the Higgs field to discover dark matter.
• 32:58
  Speaker 2: Wait, wait, wait, let's maybe take a step. So I
• 33:00
  Speaker 2: think the scenario trying to paint for people is that
• 33:03
  Speaker 2: dark matter is out there, it's a particle, and it's
• 33:06
  Speaker 2: subject to some certain forces, definitely not the electromagnetic force,
• 33:11
  Speaker 2: perhaps definitely gravity, maybe some other kinds of forces out there.
• 33:15
  Speaker 2: And the question is, could that dark matter have its
• 33:18
  Speaker 2: signs flipped to where it becomes antimatter but then it's
• 33:22
  Speaker 2: its own antimatter as opposed to having dark antimatter just
• 33:27
  Speaker 2: exist out there in the world.
• 33:28
  Speaker 1: Yeah, exactly right.
• 33:29
  Speaker 2: You're asking a very specific question, which is could it
• 33:32
  Speaker 2: be its own antimatter, not just like does it have antimatter?
• 33:35
  Speaker 2: Anti dark matter, but whether it's its own anti matter particle.
• 33:39
  Speaker 1: Yeah, saying something is its own anti particle, it's kind
• 33:42
  Speaker 1: of weird. It's kind of just like saying there is
• 33:44
  Speaker 1: no anti version of it. There's just one example. Another,
• 33:47
  Speaker 1: maybe a clearer way to say it is like, does
• 33:49
  Speaker 1: this field, the dark matter field that makes dark matter
• 33:52
  Speaker 1: particles make two kinds that are paired in this way
• 33:54
  Speaker 1: we've been talking about, like electrons and positrons, quarks and
• 33:57
  Speaker 1: anti quarks, or does it just make one that just
• 34:00
  Speaker 1: make a single solitary particle. And we do have some
• 34:03
  Speaker 1: examples of particles that are their own anti particle or
• 34:06
  Speaker 1: don't have antiparticles. However, you want to say it, like
• 34:09
  Speaker 1: the photon, right, what's the anti particle of the photon?
• 34:13
  Speaker 1: There isn't one. The photon already has zero in all
• 34:15
  Speaker 1: those charges. You flip them, you still get zero. The
• 34:17
  Speaker 1: electromagnetic field can make a photon, doesn't make an anti photon.
• 34:21
  Speaker 3: Mmm.
• 34:22
  Speaker 2: So in the same way, are you saying that the
• 34:25
  Speaker 2: question is whether dark matter has any charge at all
• 34:28
  Speaker 2: in any of the force fields. Really, that's kind of
• 34:30
  Speaker 2: what you're asking, right.
• 34:32
  Speaker 1: That's a clever idea. But if dark matter is its
• 34:34
  Speaker 1: own antiparticle. It's possible for it to still have some charge.
• 34:38
  Speaker 1: It would just mean that there is no anti version
• 34:40
  Speaker 1: of it.
• 34:41
  Speaker 2: H What do you mean, like if it had a
• 34:42
  Speaker 2: charge in some kind of force field, couldn't just flip
• 34:45
  Speaker 2: it and wouldn't that be its anti matter version?
• 34:48
  Speaker 1: But that flipped version might not exist, right, Like take
• 34:50
  Speaker 1: neutrinos for example, trus very concrete example, because we don't
• 34:54
  Speaker 1: actually know if anti neutrinos even exist in the universe.
• 34:58
  Speaker 1: We've seen particles we call them neutrinos. We talk about
• 35:01
  Speaker 1: it as if there are neutrinos and anti neutrinos, but
• 35:03
  Speaker 1: we're not even actually sure if anti neutrinos are a thing.
• 35:07
  Speaker 1: It could be that all the neutrinos we've ever seen
• 35:09
  Speaker 1: are just neutrinos, right, And so you might ask, well,
• 35:12
  Speaker 1: but neutrinos have no charge, but they do have weak charges, right,
• 35:15
  Speaker 1: They interact with the weak force. So there are those
• 35:18
  Speaker 1: weird hypercharges and isospin and all those weird weak quantum numbers.
• 35:22
  Speaker 1: But it could just be that there aren't the anti
• 35:24
  Speaker 1: versions of them. Like you say, just flip the charge.
• 35:26
  Speaker 1: But it's not like you can take a particle and
• 35:28
  Speaker 1: just like flip a switch on it to make the
• 35:30
  Speaker 1: anti version of it, the field has to be capable
• 35:33
  Speaker 1: of generating that. Maybe the fields just don't right. I mean,
• 35:36
  Speaker 1: there's a different quantum mechanical math that describes fields that
• 35:39
  Speaker 1: make one kind of particle and fields that make pairs
• 35:42
  Speaker 1: of particles. And it's possible we've worked out all the
• 35:44
  Speaker 1: mathematics to have particles that don't have antiparticles or are
• 35:48
  Speaker 1: their own antiparticles, whichever way you want to say it.
• 35:51
  Speaker 2: Wait, so the neutrino doesn't have an anti neutrino, or
• 35:54
  Speaker 2: we've never seen an anti neutrino, or it technically could
• 35:57
  Speaker 2: have one, but if we've never seen.
• 35:58
  Speaker 1: One, we've seen lots of neutrino. We don't know whether
• 36:01
  Speaker 1: there are anti neutrinos.
• 36:02
  Speaker 2: But theoretically there could be, right, Like, all do you
• 36:04
  Speaker 2: have to do is flip the sign.
• 36:07
  Speaker 1: There are versions of the theory of the universe in
• 36:09
  Speaker 1: which neutrinos have anti neutrinos, and that makes neutrinos a
• 36:13
  Speaker 1: specific kind of particle. They're called direct particles that can
• 36:16
  Speaker 1: generate both the particle and the anti particle. But it
• 36:19
  Speaker 1: could also be and it's totally consistent with everything we've
• 36:22
  Speaker 1: seen in the universe so far and all experiments that
• 36:24
  Speaker 1: neutrinos are their own anti particle or have no anti particle.
• 36:28
  Speaker 1: There's another kind of mathematics for particles invented by Mayorana
• 36:32
  Speaker 1: that explains everything we've seen in the universe without anti neutrinos.
• 36:36
  Speaker 2: But what do you take that math and just flip
• 36:38
  Speaker 2: the sign on the of the trino? What do you get?
• 36:41
  Speaker 2: Does it just explode? Does it just break down the
• 36:43
  Speaker 2: theory or what I'm trying to figure out? What what
• 36:46
  Speaker 2: you mean?
• 36:47
  Speaker 1: Take the math and flip the sign that you have
• 36:49
  Speaker 1: another field, right, So instead of having one field that's
• 36:52
  Speaker 1: generating the two particles, you can imagine there's another field
• 36:55
  Speaker 1: out there that generates like a complementary particle. So instead
• 36:59
  Speaker 1: of a field generating a pair of particles, now you
• 37:02
  Speaker 1: are inventing two different fields, one for a neutrino and
• 37:05
  Speaker 1: one for another particle, which is the neutrino with all
• 37:07
  Speaker 1: of its charges flipped, which you'd be tempted to call
• 37:10
  Speaker 1: an anti neutrino, but it's not generated from the same field,
• 37:13
  Speaker 1: so it doesn't really have that particle anti particle relationship.
• 37:16
  Speaker 2: As opposed to like an anti electron is not a
• 37:19
  Speaker 2: different field or is it the same field?
• 37:21
  Speaker 1: No, an anti electron and an electron are generated from
• 37:24
  Speaker 1: a single quantum field. It's two things that a single
• 37:27
  Speaker 1: field can do. Single field can ripple an electron like way,
• 37:30
  Speaker 1: and it can ripple in an anti electron like way.
• 37:33
  Speaker 1: There's no separate anti electron quantum field. So why can't
• 37:36
  Speaker 1: the neutrina do that. It's possible that it does, right,
• 37:39
  Speaker 1: we just don't know. Is a neutrino direct like, in
• 37:42
  Speaker 1: which case there is a neutrino and an anti neutrino
• 37:44
  Speaker 1: generated by one field, Or is a neutrino mayerana, in
• 37:48
  Speaker 1: which case it can only generate one particle. We just
• 37:51
  Speaker 1: don't know which is which. And the same question applies
• 37:53
  Speaker 1: for dark matter. Is dark matter it's own antiparticle? Is
• 37:56
  Speaker 1: it like that way the neutrino might be, or is
• 37:59
  Speaker 1: it the way electrons and quarks are.
• 38:01
  Speaker 2: I guess I'm losing a little bit of tra here
• 38:04
  Speaker 2: because it seems like the question of whether dark matter
• 38:07
  Speaker 2: can have an anti version. I think what you're saying
• 38:09
  Speaker 2: is that it could have its own and anti version,
• 38:12
  Speaker 2: or we could just ignore it. That it can have
• 38:15
  Speaker 2: an its own anti version.
• 38:16
  Speaker 1: It's a question about like, what is the nature of
• 38:19
  Speaker 1: the particle dark matter? Is it like electrons and positrons?
• 38:23
  Speaker 1: Are there particles out there that are paired and dark
• 38:26
  Speaker 1: you know, the kai and the anti kai? Or is
• 38:29
  Speaker 1: dark matter a different kind of particle, not like electrons
• 38:32
  Speaker 1: and positrons, made in a different kind of way.
• 38:34
  Speaker 2: Whose field doesn't work both ways? Is what you're saying. Yeah, exactly,
• 38:38
  Speaker 2: that's the difference. Like some particles fields work both ways
• 38:42
  Speaker 2: and can generate matter and anti matter versions of them,
• 38:46
  Speaker 2: but some for some reason don't. And you're saying it
• 38:49
  Speaker 2: sounds like the reason is like we just don't include
• 38:52
  Speaker 2: it in the math.
• 38:53
  Speaker 1: There's a way to write the mathematics where that doesn't happen.
• 38:56
  Speaker 1: You can write it in a way that doesn't. You
• 38:57
  Speaker 1: can write it in a way that doesn't for the Chino.
• 39:00
  Speaker 1: The jury is still out about which is the correct
• 39:02
  Speaker 1: mathematics for dark matter?
• 39:04
  Speaker 2: Also, but for like the photon, what we know that
• 39:07
  Speaker 2: it can't or what?
• 39:08
  Speaker 1: So the photon is different. It's neither direct nor myrona
• 39:11
  Speaker 1: because it's not a matter particle. Photon is radiation, right,
• 39:14
  Speaker 1: it's a wiggle in the electromagnetic field. So it's not
• 39:18
  Speaker 1: a fermion at all. It's a boson. It's a totally
• 39:20
  Speaker 1: different kind of particle. That's why the photon and the
• 39:23
  Speaker 1: z boson these don't have anti particles. They're different kind
• 39:27
  Speaker 1: of ripple in a different kind of field.
• 39:28
  Speaker 2: It sort of feels like we're asking, is dark matter
• 39:31
  Speaker 2: an apple or an orange? But we've never seen an
• 39:33
  Speaker 2: apple or an orange? If we don't even know if
• 39:34
  Speaker 2: apples or oranges exist.
• 39:38
  Speaker 1: I mean, if you want to make the frend analogy, no,
• 39:40
  Speaker 1: if you want to make the fruit analogy, that's awesome.
• 39:42
  Speaker 1: It's like saying, everything we've ever seen is an apple,
• 39:45
  Speaker 1: except maybe neutrinos are oranges. Is dark matter an apple
• 39:49
  Speaker 1: or an orange? Well, we've never seen an orange, but
• 39:50
  Speaker 1: we've also never seen dark matter, so who knows? That's
• 39:54
  Speaker 1: the fruit analogy?
• 39:55
  Speaker 3: Well?
• 39:55
  Speaker 2: Right, that isn't that what I said? Like, we're saying,
• 39:57
  Speaker 2: but we have seen apples, is dark matter and apple
• 40:00
  Speaker 2: on orange? We don't know if oranges even exist.
• 40:02
  Speaker 1: Yes, that's right, but we do know apples exist, yes,
• 40:05
  Speaker 1: so we have this mathematics for oranges. We're like, oh, that's.
• 40:07
  Speaker 2: Interesting, suggest that maybe oranges exist, but we don't know
• 40:11
  Speaker 2: for sure, and we don't know for sure. Any seems
• 40:13
  Speaker 2: to be an arbitrary choice.
• 40:15
  Speaker 1: Well, the universe is kind of arbitr of the universe picks.
• 40:17
  Speaker 1: We have two options. We don't know which it is.
• 40:20
  Speaker 1: We're close to figuring out if the neutrino is an
• 40:23
  Speaker 1: apple or an orange. We don't know, but we have
• 40:26
  Speaker 1: these two competing kinds of mathematics, and we want to
• 40:28
  Speaker 1: be creative about dark matter because we're worried, frankly, that
• 40:31
  Speaker 1: we've been too close minded, that we're too focused on
• 40:33
  Speaker 1: the kinds of matter we're familiar with, So trying to
• 40:36
  Speaker 1: break out of that box a little bit and consider
• 40:38
  Speaker 1: other kinds of fruits.
• 40:39
  Speaker 2: So, then the question we're really asking here today is
• 40:42
  Speaker 2: is dark matter an orange or an apple? Right?
• 40:46
  Speaker 1: Sure?
• 40:47
  Speaker 2: I want to dig into what it would mean for
• 40:49
  Speaker 2: dark matter to be either of those fruits and what
• 40:52
  Speaker 2: that means about what it's made out of. Possibly, So
• 40:54
  Speaker 2: let's dig into that for first. Let's take a quick break,
• 41:09
  Speaker 2: all right, So then the question we're really asking here
• 41:11
  Speaker 2: today is is dark matter an apple or an orange?
• 41:14
  Speaker 2: Apple means that it can have its an antimatter version
• 41:18
  Speaker 2: of it, and orange means it cannot.
• 41:20
  Speaker 1: I love first of all, that the vocabulary for particle
• 41:23
  Speaker 1: physics is so bad that we have to borrow it
• 41:25
  Speaker 1: from fruits. Now, yeah, that makes it clearer somehow.
• 41:30
  Speaker 2: Yeah, it does to me. I mean, you know, when
• 41:34
  Speaker 2: you use jargon, it just kind of last mind.
• 41:37
  Speaker 1: Apples and oranges are also jark, and it's just different.
• 41:41
  Speaker 2: But I know apples and I know orangines. That of
• 41:43
  Speaker 2: our listeners know apples and oranges. We're really asking if
• 41:48
  Speaker 2: dark matter is is an apple or an orange? And
• 41:51
  Speaker 2: so what would it mean for it to be an apple?
• 41:53
  Speaker 2: What would it mean for dark matter to have antimatter
• 41:56
  Speaker 2: versions of itself as opposed to it being an orange,
• 41:59
  Speaker 2: which wouldn't mean it cannot have an anti version of
• 42:02
  Speaker 2: it if.
• 42:03
  Speaker 1: It's an apple. If there's an antimatter and a matter
• 42:05
  Speaker 1: version of dark matter, that means something important. It means
• 42:09
  Speaker 1: that it interacts with the Higgs boson and it gets
• 42:12
  Speaker 1: its mass from the Higgs field. In order to get
• 42:16
  Speaker 1: your mass from the Higgs field, you have to be
• 42:18
  Speaker 1: a particle anti particle pair. That's absolutely essential. The Higgs
• 42:21
  Speaker 1: field will not interact with you if you don't have
• 42:23
  Speaker 1: a matter and an antimatter version of yourself.
• 42:26
  Speaker 2: How do you know, though, how has the Higgs boson.
• 42:30
  Speaker 1: It's part of the way the Higgs mechanism works. You know,
• 42:32
  Speaker 1: as an electron is flying through space, it interacts with
• 42:35
  Speaker 1: the Higgs field and it makes momentarily positrons. Like the
• 42:38
  Speaker 1: mathematics of the interaction between particles and the Higgs field
• 42:42
  Speaker 1: just doesn't work without the antimatter as well.
• 42:44
  Speaker 2: Wait, it doesn't work as well, but it does work,
• 42:47
  Speaker 2: or it doesn't work at all.
• 42:48
  Speaker 1: No, sorry, it just does not work if you don't
• 42:50
  Speaker 1: have matter and antimatter.
• 42:52
  Speaker 2: In addition, or at least the possibility of having an
• 42:55
  Speaker 2: anti version of yourself.
• 42:57
  Speaker 1: Right, Yeah, those fields have to be able to do
• 42:58
  Speaker 1: both things. Has to be an apple field in order
• 43:01
  Speaker 1: to interact with the Higgs field.
• 43:02
  Speaker 2: And if it cannot, then you don't feel mass. You
• 43:05
  Speaker 2: don't have mass.
• 43:06
  Speaker 1: Or what if it cannot, then you do not feel
• 43:08
  Speaker 1: the Higgs field, which has two important consequences. One, it
• 43:12
  Speaker 1: means if you can't use the Higgs boson to discover it.
• 43:15
  Speaker 1: If dark matter has a matter and antimatter version, then
• 43:18
  Speaker 1: that means that it interacts with the Higgs field. That
• 43:20
  Speaker 1: means if we make a bunch of Higgs bosons. Sometimes
• 43:22
  Speaker 1: those Higgs bosons will turn into a dark matter, an
• 43:26
  Speaker 1: anti dark matter pair. We could like make a bunch
• 43:28
  Speaker 1: of Higgs bosons and a large hadron collider and some
• 43:30
  Speaker 1: of them could turn into dark matter. That would be
• 43:33
  Speaker 1: very exciting. The other thing is if you don't interact
• 43:36
  Speaker 1: with Higgs field, that it means you don't get your mass
• 43:37
  Speaker 1: from the Higgs field. Means you can't make this kind
• 43:40
  Speaker 1: of matter from Higgs bosons. It means you have to
• 43:42
  Speaker 1: get your mass from some other mechanism.
• 43:44
  Speaker 3: Right.
• 43:44
  Speaker 1: Remember, the Higgs field is one way to get mass,
• 43:47
  Speaker 1: but not the only way that things get mass. It's
• 43:49
  Speaker 1: just one example. If there are particles out there that
• 43:52
  Speaker 1: are oranges that are their own antimatter, then if they
• 43:55
  Speaker 1: have mass, they don't get it from the Higgs field.
• 43:58
  Speaker 1: And that might be the case for neutrinos. That might
• 44:00
  Speaker 1: even explain why neutrinos are so crazy low mass, much
• 44:05
  Speaker 1: lower mass than everything else in the.
• 44:07
  Speaker 2: Universe, because they don't interact with the Higgs field. They
• 44:09
  Speaker 2: get their mass from something else.
• 44:11
  Speaker 1: That's the idea, right, That's one reason why people are
• 44:14
  Speaker 1: suspicious that maybe neutrinos don't have anti particles. Because neutrino
• 44:18
  Speaker 1: mass is super tiny. It's like a billion times lower
• 44:22
  Speaker 1: than the masses of electrons and quarks and these other particles.
• 44:25
  Speaker 1: It's very very small. It suggests that maybe they're getting
• 44:29
  Speaker 1: their mass in another way.
• 44:31
  Speaker 2: So then the question, the repercussions of this question then
• 44:34
  Speaker 2: is whether or not dark matter interacts with the Higgs
• 44:37
  Speaker 2: field or that's one of the repercussions.
• 44:39
  Speaker 1: Yeah, that's one of the repercussions. And that's an important
• 44:41
  Speaker 1: one because it means if dark matter gets mass. I remember,
• 44:45
  Speaker 1: the mass of dark matter is the thing that like
• 44:47
  Speaker 1: shapes the universe and bends space times so that we
• 44:49
  Speaker 1: get galaxies Like this is an important consequential thing. Where
• 44:53
  Speaker 1: does the mass of dark matter come from? If not
• 44:56
  Speaker 1: the Higgs field, But it also has consequences for how
• 44:59
  Speaker 1: we see it. There matter interacts with the Higgs field,
• 45:01
  Speaker 1: it means we can make it in colliders. It means
• 45:03
  Speaker 1: fundamentally it also has to feel the weak force in
• 45:06
  Speaker 1: some way. Some part of dark matter at least has to,
• 45:09
  Speaker 1: which means that we could maybe interact with it, and
• 45:11
  Speaker 1: our detectors and all these millions of dollars we spent
• 45:14
  Speaker 1: building quiet tanks underground looking for dark matter might see
• 45:17
  Speaker 1: a signal. But if dark matter is not, if it's
• 45:20
  Speaker 1: an orange and it doesn't get its mass from the
• 45:22
  Speaker 1: Higgs boson, then something else is making most of the
• 45:25
  Speaker 1: mass in the universe, and it means it's much less
• 45:28
  Speaker 1: likely we can use our particle physics experiments to discover
• 45:31
  Speaker 1: dark matter.
• 45:32
  Speaker 2: Well, that's a pretty big bed on apples. Well, it
• 45:36
  Speaker 2: sounds like you're saying like, if it can interact with
• 45:38
  Speaker 2: the Higgs, then we can maybe see it in our colliders,
• 45:40
  Speaker 2: because in our colliders we can make higgs, and so
• 45:43
  Speaker 2: you could use those higgs to make dark matter. But
• 45:45
  Speaker 2: we haven't so far, right, we have not so far.
• 45:48
  Speaker 2: Isn't that evidence towards saying maybe dark matter is it orange?
• 45:52
  Speaker 1: Yeah? Exactly. Well, it rules out some versions of the apple.
• 45:55
  Speaker 1: There's always ways to escape these bounds. Maybe it's a
• 45:57
  Speaker 1: different kind of apple, or maybe it's a really low
• 46:00
  Speaker 1: mass apple or something. But yeah, we have never seen
• 46:03
  Speaker 1: the Higgs boson turned into dark matter so far. That's
• 46:06
  Speaker 1: one reason to motivate this kind of creativity, to think
• 46:08
  Speaker 1: outside of the apple box and imagine, you know, maybe
• 46:11
  Speaker 1: dark matter is actually a banana. Who knows.
• 46:14
  Speaker 2: It sounds like you're getting on top of your apple
• 46:15
  Speaker 2: box here potizing about fruit fruit collisions.
• 46:21
  Speaker 1: Maybe dark matter is just a smoothie after all.
• 46:25
  Speaker 2: Yeah, there you go.
• 46:26
  Speaker 1: It's a quant mechanical smoothie superposition of all the possible fruits.
• 46:29
  Speaker 2: Right right, And this episode's brought to you by Jump
• 46:31
  Speaker 2: a Juice.
• 46:34
  Speaker 1: And Sherman Williams. Infinitely dark.
• 46:38
  Speaker 2: I feel like we just spent an hour trying to
• 46:40
  Speaker 2: ask a question of whether a dark matter interacts with
• 46:42
  Speaker 2: the Higgs field or not. Yeah, we have just started
• 46:45
  Speaker 2: with that question.
• 46:46
  Speaker 1: Yeah, let's go back in time.
• 46:47
  Speaker 2: Let's pull another fruit from the either and let's use
• 46:51
  Speaker 2: that to go back in time. No, but do you
• 46:53
  Speaker 2: know what I mean? Like, does it all just come
• 46:54
  Speaker 2: down to that one question, does dark matter interact with
• 46:58
  Speaker 2: the Higgs field or not? And the second question, and
• 47:00
  Speaker 2: I guess would be how will we find out?
• 47:01
  Speaker 1: I don't think that's the only question. I think more fundamentally,
• 47:04
  Speaker 1: we're just curious about the nature of dark matter. That's
• 47:06
  Speaker 1: a consequence of it. But we're wondering how many different
• 47:09
  Speaker 1: kinds of matter can there be in the universe. Is
• 47:11
  Speaker 1: dark matter an example of a new kind of matter?
• 47:14
  Speaker 1: Or is it a weird version of the neutrino? Is
• 47:16
  Speaker 1: it actually neutrinos. Fundamentally, we just want to know, like
• 47:19
  Speaker 1: what kinds of stuff can the universe do? Because the
• 47:22
  Speaker 1: more kinds of ways we can see the universe wiggle,
• 47:24
  Speaker 1: the more clues we might get about simplifying that, about
• 47:27
  Speaker 1: drilling down to the next layer of reality and understanding
• 47:30
  Speaker 1: why we have all these weird reflections. Why are there
• 47:32
  Speaker 1: electrons and muons and towels and matter and antimatter and
• 47:35
  Speaker 1: quarks and leptons. Aren't they all just like putting together
• 47:38
  Speaker 1: tiny little squiggly bits of the deeper theory. The more
• 47:41
  Speaker 1: we gain and understanding the kinds of ways quantum fields
• 47:43
  Speaker 1: can wiggle, the closer we are to figuring out what's
• 47:46
  Speaker 1: underneath it all. So I think there's a deeper mystery
• 47:49
  Speaker 1: there just about the nature of dark matter, not just
• 47:52
  Speaker 1: whether it interacts with the Higgs field. That's an important
• 47:54
  Speaker 1: consequence and effects whether we can see it.
• 47:56
  Speaker 2: We just want to know if dark matter is an
• 47:58
  Speaker 2: apple or a north or even if oranges exist. Apparently
• 48:02
  Speaker 2: we don't.
• 48:02
  Speaker 1: We don't, but we do have experiments coming online pretty
• 48:05
  Speaker 1: soon to try to figure out if neutrinos are their
• 48:07
  Speaker 1: own particle or not. We have a whole episode about this,
• 48:10
  Speaker 1: and also about the fantastically mysterious life of Ettore Mayorana,
• 48:14
  Speaker 1: who disappeared strangely on a sea voyage and nobody ever
• 48:17
  Speaker 1: heard from him again. So check out the episode about
• 48:19
  Speaker 1: whether neutrinos are Mayorana particles. That might give us a
• 48:22
  Speaker 1: clue about whether the universe allows matter particles to be
• 48:25
  Speaker 1: their own anti particles, or whether oranges exist.
• 48:29
  Speaker 2: Do we have an episode coming up about colliding apple
• 48:33
  Speaker 2: or what have you? Collide them with an orange?
• 48:35
  Speaker 1: We didn't before, but now we do.
• 48:37
  Speaker 2: Just make apple pie, all right? Well, another interesting exploration
• 48:41
  Speaker 2: into the ideas that particle physicists are considering about what
• 48:46
  Speaker 2: the nature of matter out there is, including dark matter,
• 48:49
  Speaker 2: maybe the biggest kind of matter there is in the universe.
• 48:53
  Speaker 1: Some day in the future, somebody will listen to this
• 48:54
  Speaker 1: podcast and think, Man, those folks had no idea. The
• 48:58
  Speaker 1: answer was right in front of them all along.
• 49:00
  Speaker 2: It was a banana the whole time. Plot twist from
• 49:06
  Speaker 2: the first episode, we've been saying it's a banana.
• 49:09
  Speaker 1: We've been definitely laying the pipe for that plot twist.
• 49:11
  Speaker 2: Yeah, yeah, We've been peeling away at the plot twist
• 49:16
  Speaker 2: for a long time. All right, Well, we hope you
• 49:19
  Speaker 2: enjoyed that. Thanks for joining us, See you next time.
• 49:27
  Speaker 1: For more science and curiosity, come find us on social media,
• 49:30
  Speaker 1: where we answer questions and post videos. We're on Twitter, Discord, Instant,
• 49:35
  Speaker 1: and now TikTok. Thanks for listening, and remember that Daniel
• 49:39
  Speaker 1: and Jorge Explain the Universe is a production of iHeartRadio.
• 49:43
  Speaker 1: For more podcasts from iHeartRadio, visit the iHeartRadio app, Apple Podcasts,
• 49:48
  Speaker 1: or wherever you listen to your favorite shows.