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What is a glueball? · Daniel and Kelly’s Extraordinary Universe

• 0:08
  Speaker 1: Hey, Daniel, what's it like to discover a new particle
• 0:11
  Speaker 1: of nature?
• 0:12
  Speaker 2: You know, it's a lot less dramatic than you might expect.
• 0:16
  Speaker 1: Oh really, there's no Eureka moment or some grand reveal.
• 0:19
  Speaker 2: It's usually a lot more gradual than like dropping a
• 0:23
  Speaker 2: velvet curtain or something. It's more like watching water drain
• 0:25
  Speaker 2: out of the tub to reveal the toys at the bottom.
• 0:28
  Speaker 1: You make it sound so exciting.
• 0:29
  Speaker 2: I'm not sure how Steven Spielberg is going to portray
• 0:32
  Speaker 2: that in a moment of my life. But you know,
• 0:34
  Speaker 2: it gets even worse. Sometimes we don't even agree about
• 0:38
  Speaker 2: whether or not we did discover something.
• 0:40
  Speaker 1: Sometimes it's like it is that a toy at the
• 0:42
  Speaker 1: bottom of the tub or is that something else? But
• 0:45
  Speaker 1: what do you mean? Like, sometimes you discover something and
• 0:47
  Speaker 1: some people are like, no, I don't think that's the thing.
• 0:49
  Speaker 2: Yeah, we can basically disagree about anything in particle.
• 0:52
  Speaker 1: Physics, even about whether you disagree or not.
• 0:54
  Speaker 2: That's the one thing we can agree on.
• 1:11
  Speaker 1: I am more handmade cartoonists and the creator of PhD comics.
• 1:14
  Speaker 2: Hi, I'm Daniel. I'm a particle physicist and a professor
• 1:17
  Speaker 2: at UC Irvine. And when I got into this field.
• 1:20
  Speaker 2: I really did think there were going to be more
• 1:22
  Speaker 2: discoveries to be had.
• 1:23
  Speaker 1: Well, isn't it kind of up to you to make
• 1:25
  Speaker 1: those discoveries? Why are you sound like you're complaining.
• 1:28
  Speaker 2: It's partially up to me, but it's also up to nature.
• 1:31
  Speaker 2: You know, when you go out and do research, you
• 1:33
  Speaker 2: never know what you're going to find, and you never
• 1:35
  Speaker 2: know what's out there for you too fine. It's like
• 1:38
  Speaker 2: the folks who were hoping to discover life on Mars.
• 1:40
  Speaker 2: They worked hard, they did their job, they built their rovers.
• 1:44
  Speaker 2: There just wasn't life on Mars for them, too fine.
• 1:47
  Speaker 2: And it's sort of the same way in particle physics.
• 1:49
  Speaker 2: It's been a little bit dry for us thirsty folks.
• 1:52
  Speaker 1: Mmmm. Are you going to ask for your money back
• 1:54
  Speaker 1: from nature or your career back?
• 1:56
  Speaker 2: I'm hoping the government doesn't ask for their ten billion
• 1:59
  Speaker 2: dollars back. We'll have to auction off bits of the LHC.
• 2:07
  Speaker 1: Yeah, yeah, there you go, offer it the souvenirs like
• 2:10
  Speaker 1: memorial you know, special keepsakes. You get a little bit
• 2:13
  Speaker 1: of this super conducting magnet.
• 2:15
  Speaker 2: The world's nerdiest Etsy shop bits of the LHC. There
• 2:18
  Speaker 2: are actually people who've done salvage on the super Conducting
• 2:21
  Speaker 2: super Collider in Texas. A lot of the equipment there
• 2:24
  Speaker 2: was just abandoned and people have grabbed some of it
• 2:26
  Speaker 2: and saved it as keepsakes.
• 2:28
  Speaker 1: A bit of people would buy a piece of the LC, right,
• 2:30
  Speaker 1: wouldn't they. It's the thing that discovered the Higgs boson.
• 2:34
  Speaker 1: That's kind of a big deal. Like you might actually find,
• 2:37
  Speaker 1: you know, the little sensor pad that actually caught the
• 2:39
  Speaker 1: first Higgs. Let's let's get in on that. Let's kill
• 2:43
  Speaker 1: it on the Daniel and Jorge online shop.
• 2:46
  Speaker 2: It can be like pieces of the true Cross. We
• 2:48
  Speaker 2: can sell more of them than actually existed.
• 2:51
  Speaker 1: Yeah, there you go. Amazingly. It's magical as well. It
• 2:55
  Speaker 1: multiplies the LHC. But what do you think you would
• 2:58
  Speaker 1: have done if you hadn't been a particle physics someone
• 3:00
  Speaker 1: who explores life on Mars.
• 3:03
  Speaker 2: Well, I actually did two degrees as an undergraduate physics
• 3:06
  Speaker 2: and computer science, and I also applied to grad school
• 3:09
  Speaker 2: and computer science. I was going to do artificial intelligence
• 3:12
  Speaker 2: and machine learning, so that was sort of my other life.
• 3:15
  Speaker 1: Wow, man, I'm sorry to say, but you totally missed
• 3:18
  Speaker 1: that boat. He would probably a billionaire, I guess, But
• 3:22
  Speaker 1: then we wouldn't have this podcast, or we would have
• 3:25
  Speaker 1: a super popular podcast about Ki.
• 3:27
  Speaker 2: Yeah, but then I'd be responsible for people's self driving
• 3:29
  Speaker 2: cars crashing, and I don't know if I could handle
• 3:31
  Speaker 2: that kind of responsibility.
• 3:33
  Speaker 1: Well, it's not your fault, it's the car's fault. That's
• 3:35
  Speaker 1: why you give them sentience to absolve yourself of any responsibility.
• 3:39
  Speaker 2: Right right, Just like we're not responsible for whether our
• 3:41
  Speaker 2: kids grew up to be serial killers or not.
• 3:43
  Speaker 1: Exactly right, Wait, what what's going on with your kid there?
• 3:48
  Speaker 1: Maybe it's your kids are already making a head.
• 3:52
  Speaker 2: I do wonder about those serial killers and whether their
• 3:55
  Speaker 2: parents feel responsible. Yeah.
• 3:56
  Speaker 1: I thought you're gonna say I do wonder about my son.
• 3:58
  Speaker 1: I was like, whoa, But anyways, Welcome to our podcast,
• 4:02
  Speaker 1: Daniel and Jorge Explain the Universe, a production of iHeartRadio.
• 4:06
  Speaker 2: We are not responsible for the incredible, crazy, bonkers, beautiful
• 4:10
  Speaker 2: universe out there, but we do feel responsible for helping
• 4:13
  Speaker 2: you to understand it. We dig in deep into what's
• 4:16
  Speaker 2: going on out there in the universe, and we try
• 4:18
  Speaker 2: to process it. We chop it up, and we serve
• 4:20
  Speaker 2: it all up to you, hoping to educate and entertain
• 4:24
  Speaker 2: you at the same time.
• 4:25
  Speaker 1: It's right, welcome to our two hundred and ninetieth course
• 4:29
  Speaker 1: meal here on the amazing food for thought that is
• 4:32
  Speaker 1: the universe, because it is pretty awesome. And to be honest,
• 4:35
  Speaker 1: I do feel a little bit responsible to that.
• 4:37
  Speaker 2: You know, you were reaching for a big number there,
• 4:39
  Speaker 2: but I think the number of episodes is more like
• 4:41
  Speaker 2: four hundred and eighty or something.
• 4:42
  Speaker 1: By now, oh my goodness, it's like the banquet that
• 4:45
  Speaker 1: never ends. Like maybe it's more like a buffet where
• 4:48
  Speaker 1: we take a bring on this food little by little.
• 4:50
  Speaker 2: That's right. Every course has to be super tiny for
• 4:52
  Speaker 2: you to be able to finish course number five hundred.
• 4:55
  Speaker 2: Eventually we'll get to dessert.
• 4:56
  Speaker 1: Now, do we reveal each course of this meal or
• 4:58
  Speaker 1: do we just let the work and let the food
• 5:01
  Speaker 1: say that good.
• 5:01
  Speaker 2: Bottom Every episode is letting the water drain and hoping
• 5:04
  Speaker 2: that there's some understanding to be revealed.
• 5:08
  Speaker 1: That is how we record it. We just sit down,
• 5:11
  Speaker 1: you start talking, and we hope that some knowledge comes
• 5:14
  Speaker 1: out of it.
• 5:15
  Speaker 2: We hope there's gold and not a floating turret in
• 5:17
  Speaker 2: that Baptob.
• 5:18
  Speaker 1: Oh Man, can you say that on our podcast? I
• 5:20
  Speaker 1: guess you just did.
• 5:21
  Speaker 2: Let's see if it guests passed the sensors.
• 5:23
  Speaker 1: Which are you?
• 5:24
  Speaker 2: Yes?
• 5:26
  Speaker 1: Crazy? Well, speaking of pushing things out, let's dive into
• 5:31
  Speaker 1: the topic of the episode here today. So it is,
• 5:34
  Speaker 1: as we said, an amazing and incredible universe full of
• 5:36
  Speaker 1: amazing and lots of little things, lots of little things
• 5:40
  Speaker 1: out there that keep the universe together.
• 5:42
  Speaker 2: And over the last fifty years or so, we have
• 5:44
  Speaker 2: pulled apart matter to reveal its basic constituents. We know
• 5:48
  Speaker 2: that you are made of molecules, which are made of atoms,
• 5:51
  Speaker 2: which are built out of electrons, protons and neutrons. We've
• 5:55
  Speaker 2: even pulled the protons and neutrons apart to discover that
• 5:57
  Speaker 2: they are made of quarks. We have found the quarks
• 6:00
  Speaker 2: out there and other versions of the electron. We have
• 6:02
  Speaker 2: this wonderful periodic table of the fundamental particles that we
• 6:06
  Speaker 2: describe using the standard model, which paints a very nice
• 6:09
  Speaker 2: picture of what's going on microscopically inside of me and
• 6:13
  Speaker 2: you and at the hearts of stars.
• 6:15
  Speaker 1: That's right. We've come a long way from thinking that
• 6:17
  Speaker 1: the universe and everything in it is made out of
• 6:19
  Speaker 1: four things like earth, wind and fire and water, to
• 6:23
  Speaker 1: basically chop up the entire matter of the universe into
• 6:26
  Speaker 1: smaller and smaller bits until we get to basically bits
• 6:30
  Speaker 1: that you can't chop up anymore.
• 6:31
  Speaker 2: And it's been a really fascinating ride, not just discovering
• 6:34
  Speaker 2: what matter is inside of us, which is mostly the upcork,
• 6:39
  Speaker 2: the down cork, and the electron because you can assemble
• 6:41
  Speaker 2: the upcork and the down cork into protons and neutrons
• 6:44
  Speaker 2: and put the electrons around them to make atoms, but
• 6:47
  Speaker 2: also to discover what else the universe can do. The
• 6:50
  Speaker 2: things that we are made out of are the stable bits,
• 6:53
  Speaker 2: the things that last forever and can get mixed together
• 6:56
  Speaker 2: to make more interesting chemistry. But there are also other
• 6:59
  Speaker 2: weird things that the universe can do, things that don't
• 7:01
  Speaker 2: last for very long, so they take special conditions to
• 7:04
  Speaker 2: reveal them.
• 7:05
  Speaker 1: Yeah, the universe has its own buffet of things that
• 7:08
  Speaker 1: it can make out there, and not just the things
• 7:10
  Speaker 1: that we can eat that make up who we are.
• 7:12
  Speaker 1: There's lots of other things out there in the universe,
• 7:14
  Speaker 1: and little by little we've put together a pretty complete
• 7:17
  Speaker 1: picture of what's out there or what can be out
• 7:19
  Speaker 1: there in the universe.
• 7:20
  Speaker 2: We have a whole fun series of podcast episodes about
• 7:23
  Speaker 2: the discoveries of these particles, how the top quark was discovered,
• 7:27
  Speaker 2: how the gluon was discovered, how the photon was discovered.
• 7:30
  Speaker 2: All these pieces of the Standard Model, and we put
• 7:32
  Speaker 2: them together into a picture and ask like, does it work?
• 7:35
  Speaker 2: Are there any missing bits? And that's how some of
• 7:38
  Speaker 2: those discoveries were made. We like assemble them together and
• 7:41
  Speaker 2: we notice patterns. We say, huh, there's a hole here.
• 7:43
  Speaker 2: I wonder if there's another particle missing. The way you
• 7:45
  Speaker 2: can look at the periodic table and say, where's element
• 7:48
  Speaker 2: thirty four? Why is there a thirty three and a
• 7:50
  Speaker 2: thirty five? There should be one in the middle. In
• 7:52
  Speaker 2: the same way, we filled in a lot of the
• 7:54
  Speaker 2: gaps in the Standard model just by looking for patterns
• 7:56
  Speaker 2: and hoping for simplicity and mathematical beauty and symmetry. And
• 8:01
  Speaker 2: this has been a very useful guiding principle in helping
• 8:04
  Speaker 2: us to discover things. That's how, for example, we knew
• 8:07
  Speaker 2: to look for the Higgs boson.
• 8:09
  Speaker 1: Yeah, we have a periodic table for the fundamental particles
• 8:12
  Speaker 1: of nature. It's called the Standard Model, and it does
• 8:15
  Speaker 1: kind of look like the periodic table right, it's a
• 8:17
  Speaker 1: grid and you got little spas for all the different
• 8:19
  Speaker 1: particles like quarks and electrons and neutrinos, and they're sort
• 8:24
  Speaker 1: of in order. Also, it sort of looks like a
• 8:26
  Speaker 1: periodic table. Yeah, because there are patterns there.
• 8:29
  Speaker 2: Like you can take the electron, the muon and the
• 8:31
  Speaker 2: tow and you notice that they're increasing in mass. The
• 8:34
  Speaker 2: muon is heavier than the electron, the tow is heavier
• 8:37
  Speaker 2: than the muon, And the same pattern exists in the upcork,
• 8:40
  Speaker 2: the charm cork, and the top cork. The charm in
• 8:42
  Speaker 2: the top is just like heavier versions of the upcark.
• 8:45
  Speaker 2: So we notice these patterns. We see these things in
• 8:47
  Speaker 2: the table, and so we arrange our table in that
• 8:49
  Speaker 2: way to bring out those patterns to like inspire us
• 8:52
  Speaker 2: to think about what could be explaining them. And so
• 8:55
  Speaker 2: there's sort of two directions to think about there. One
• 8:57
  Speaker 2: is like, well, what's inside these particles? Is there a
• 9:00
  Speaker 2: deeper layer of reality? And so that's definitely something we're exploring.
• 9:03
  Speaker 2: But sometimes we look in the other direction and we say, well,
• 9:06
  Speaker 2: what are the consequences of these particles? What can these
• 9:09
  Speaker 2: particles do? If this is real? If those particles are
• 9:11
  Speaker 2: actually out there, what do we expect to see in
• 9:13
  Speaker 2: our colliders? What can these things come together to make?
• 9:17
  Speaker 2: And that's another very fruitful way to test our understanding
• 9:20
  Speaker 2: of what's going on in the particle world.
• 9:22
  Speaker 1: Yeah, so we have a grit called the standard model,
• 9:24
  Speaker 1: and it's called the standard model because they think it's
• 9:27
  Speaker 1: standard and it's a model. But when did they come
• 9:30
  Speaker 1: up with this name? I wonder? And how did they
• 9:31
  Speaker 1: know it is going to be standard for the entire universe?
• 9:35
  Speaker 2: I knew you were going to have concerns about the names.
• 9:37
  Speaker 2: The standard model itself comes out of the seventies when
• 9:41
  Speaker 2: people realized that there were connections between the weak force
• 9:45
  Speaker 2: and electromagnetism and that explained a lot of what we
• 9:48
  Speaker 2: were seeing happening with the electron and the muons, and
• 9:51
  Speaker 2: so they put this together into a model of leptons,
• 9:54
  Speaker 2: which then became a standard model of leptons, and so
• 9:57
  Speaker 2: it was sort of adopted around then. And the standard
• 10:00
  Speaker 2: that sense, just sort of means like consensus. There are
• 10:02
  Speaker 2: lots of different views of what was happening in particles,
• 10:05
  Speaker 2: and this just sort of emerged as the most popular model,
• 10:08
  Speaker 2: the one that people thought was the most parsimonious and
• 10:11
  Speaker 2: explained what we were seeing, and it also predicted the
• 10:14
  Speaker 2: Higgs boson, and so when we saw the Higgs boson
• 10:17
  Speaker 2: in nature, people were like, Yep, that's it.
• 10:19
  Speaker 1: The standard model is the way to go interesting. It's
• 10:22
  Speaker 1: it's like the thing that all physicists can agree on, kind.
• 10:25
  Speaker 2: Of mostly that can happen. It can happen, although of
• 10:30
  Speaker 2: course there are lots of disagreements about what is the
• 10:32
  Speaker 2: standard model. Some people, for example, say that the standard
• 10:35
  Speaker 2: model requires neutrinos to have no mass, but we know
• 10:38
  Speaker 2: neutrinos do have mass, and some people say, no, no,
• 10:41
  Speaker 2: we can have massive neutrinos in this standard model. And
• 10:44
  Speaker 2: so there's a lot of disagreement about exactly what constitutes
• 10:47
  Speaker 2: the standard model. Probably was a bad idea to call
• 10:49
  Speaker 2: it standard in the first place.
• 10:52
  Speaker 1: Ye should have called it a model. But it's interesting because,
• 10:56
  Speaker 1: like what you said, is that it's not just a
• 10:58
  Speaker 1: sort of like a listing of all the fundamental particles,
• 11:01
  Speaker 1: kind of like the periodic table is. It's also kind
• 11:03
  Speaker 1: of about the rules that govern what happens between the
• 11:06
  Speaker 1: things in the table, and a lot of it is
• 11:09
  Speaker 1: also just the math of how all of these things
• 11:11
  Speaker 1: work just like the periodic table. It's not just the
• 11:13
  Speaker 1: listing of element. It's also like a model of how
• 11:15
  Speaker 1: the electron you know, orbits around the nucleus, and what
• 11:19
  Speaker 1: happens when two atoms get close together, how do they
• 11:22
  Speaker 1: share electrons and things like that. The Standard model also
• 11:24
  Speaker 1: there's a lot more to it than just the listening
• 11:26
  Speaker 1: to particles.
• 11:27
  Speaker 2: Yeah, exactly. We often focus on the matter particles like
• 11:31
  Speaker 2: the upcork, the down cork, and the electron, but also
• 11:33
  Speaker 2: in the standard model we have the force particles, the photon,
• 11:36
  Speaker 2: the W, the z, the gluon, and as you say,
• 11:39
  Speaker 2: these play a very important role in building things. Without
• 11:42
  Speaker 2: the forces, you couldn't put the up, the down, the
• 11:44
  Speaker 2: electron together to make ice cream or kittens or lava
• 11:48
  Speaker 2: or hamsters or anything. Right. Really, the forces are required.
• 11:51
  Speaker 2: And I often feel that way when somebody says, oh,
• 11:53
  Speaker 2: the atom is mostly empty space, because they imagine the
• 11:57
  Speaker 2: tiny little nucleus or the tiny electrons really are apart
• 12:00
  Speaker 2: from each other in mostly empty space. But the truth
• 12:02
  Speaker 2: is is not really empty. It's filled with fields, force
• 12:05
  Speaker 2: fields and virtual particles tying them together. It's a swarm
• 12:09
  Speaker 2: of oscillating energy and so you're right, we need to
• 12:11
  Speaker 2: think not just about the little bits of matter, but
• 12:13
  Speaker 2: also the forces that tie them together and how that
• 12:16
  Speaker 2: works and what those can do. And that's something we
• 12:19
  Speaker 2: are still exploring, still trying to figure out.
• 12:22
  Speaker 1: Yeah, I think that's something that maybe a lot of
• 12:23
  Speaker 1: people don't know. And I wonder if that's because, you know,
• 12:26
  Speaker 1: when they discovered the Higgs Boson, it was kind of
• 12:28
  Speaker 1: a big deal. At least that's what the headline said.
• 12:30
  Speaker 1: That it was a big deal because it completed this
• 12:33
  Speaker 1: standard model. The Higgs Boson sort of like was the
• 12:35
  Speaker 1: cherry on top where it put the last little lego
• 12:38
  Speaker 1: piece or jigsaw puzzle piece on the standard model and
• 12:41
  Speaker 1: then you guys were done, right, you could all retire
• 12:44
  Speaker 1: and become hey experts or something.
• 12:47
  Speaker 2: We've been napping in our offices ever since. Yes, confirmed,
• 12:50
  Speaker 2: Oh okay, that's good to know. Then I do want
• 12:52
  Speaker 2: my money back, Please wait for the check. Yeah, and
• 12:57
  Speaker 2: so it was sort of a big deal because they
• 12:59
  Speaker 2: said they'd the standard model. But you're telling me maybe
• 13:02
  Speaker 2: that it's not complete. Maybe it's something that people disagree about.
• 13:06
  Speaker 1: Still.
• 13:06
  Speaker 2: Yeah, well, it's not like the New York Times were
• 13:08
  Speaker 2: liars or anything. When they said it completed the standard model.
• 13:11
  Speaker 2: That's true from one perspective, from the perspective of like
• 13:15
  Speaker 2: looking at the periodic table of fundamental particles and saying,
• 13:18
  Speaker 2: do we have all the pieces necessary to make a
• 13:20
  Speaker 2: complete theory? You know, are there any obvious holes? And
• 13:23
  Speaker 2: so we had found the top core, we had found
• 13:25
  Speaker 2: the Towe leapt on, and the last like definitely predicted
• 13:28
  Speaker 2: missing fundamental piece, little jigsaw piece, as you say, was
• 13:32
  Speaker 2: the Higgs boson. It was definitely missing, and we definitely
• 13:35
  Speaker 2: needed to find it if the Standard Model was real,
• 13:37
  Speaker 2: if it was a description of nature. And now we
• 13:39
  Speaker 2: found it, and it clicks in, and we do have
• 13:42
  Speaker 2: what we consider a fairly complete theory. Of course, it
• 13:44
  Speaker 2: doesn't describe gravity or dark matter or all sorts of
• 13:47
  Speaker 2: other crazy stuff. And we just did an episode about
• 13:49
  Speaker 2: like the problems of the Standard Model. But you know,
• 13:52
  Speaker 2: from one perspective, it really did complete it. It was
• 13:54
  Speaker 2: like an obvious hole that needed to be filled. There
• 13:56
  Speaker 2: are no more open holes in that sense, like fundamental
• 13:59
  Speaker 2: particle that the Standard Model predicts that we haven't found yet.
• 14:02
  Speaker 2: From another perspective, there's lots of things left to study,
• 14:05
  Speaker 2: you know, like how these particles dance together to make
• 14:08
  Speaker 2: new things. That's not how these particles come together to
• 14:12
  Speaker 2: make more interesting, complicated things. That's not something we fully
• 14:15
  Speaker 2: yet understand. And there are lots of predictions there that
• 14:18
  Speaker 2: have not yet been verified.
• 14:19
  Speaker 1: Yeah, I feel like you're pulling off a nice marketing
• 14:21
  Speaker 1: trick here, where you're saying, like, what we did was awesome,
• 14:24
  Speaker 1: and where's all that money? And we finished it, but
• 14:27
  Speaker 1: there are still things less to do to keep giving
• 14:30
  Speaker 1: us money.
• 14:31
  Speaker 2: That is the summer of every science grant proposal ever, basically,
• 14:37
  Speaker 2: not just in particle physics.
• 14:39
  Speaker 1: I see, it's just a reflex for you know.
• 14:41
  Speaker 2: Well, you know that's the story. It's like, look, we
• 14:43
  Speaker 2: did awesome stuff with the money you gave us. We
• 14:45
  Speaker 2: will do more awesome stuff with the future money we
• 14:47
  Speaker 2: hope you keep giving us. That's the way it works.
• 14:50
  Speaker 1: Well, like you said, there's still more to discover, I guess,
• 14:53
  Speaker 1: or to check off about all of the things that
• 14:55
  Speaker 1: the standard model predicts. And so one of those predictions
• 14:58
  Speaker 1: is kind of an interesting sounding object.
• 15:02
  Speaker 2: It is a super fun prediction of the standard model,
• 15:05
  Speaker 2: and one people have been hunting for for a long
• 15:08
  Speaker 2: time and disagree about whether it's possible to find it,
• 15:12
  Speaker 2: or whether we already have.
• 15:14
  Speaker 1: It's a sticky subject. Well, to the end of the episode,
• 15:16
  Speaker 1: we'll be tackling the question what is a glue ball?
• 15:25
  Speaker 1: That sounds like something that happens when you're playing with glue.
• 15:29
  Speaker 2: It does sound like a very everyday object, but it's
• 15:31
  Speaker 2: also a very esoteric prediction by the standard model that's
• 15:36
  Speaker 2: been surprisingly difficult to verify.
• 15:39
  Speaker 1: Actually, it does kind of sound like something that might
• 15:41
  Speaker 1: be useful, like a ball made out of glue that
• 15:43
  Speaker 1: then you can use to stick things together.
• 15:46
  Speaker 2: It sounds like the thing you could keep next to
• 15:47
  Speaker 2: your rubber band ball. Yeah right, let's start selling those.
• 15:53
  Speaker 2: You can get those on our online store now, balls.
• 15:56
  Speaker 1: Of glue, oh man.
• 15:58
  Speaker 2: With little bits of the LEDC stuck inside.
• 16:01
  Speaker 1: Yeah, there you go. Or it's sticking together bits of
• 16:04
  Speaker 1: the lac.
• 16:05
  Speaker 2: Even better, How does the lac work it's held together
• 16:07
  Speaker 2: with spit in glue balls.
• 16:09
  Speaker 1: Well that might be actually true, right.
• 16:11
  Speaker 2: That might be actually trueious.
• 16:13
  Speaker 1: I mean, I'm sure a lot of physicists were drilling
• 16:16
  Speaker 1: when they were putting it together. That's where all this
• 16:18
  Speaker 1: bit comes from. Well, anyways, as usual, we were wondering
• 16:20
  Speaker 1: how many people out there had heard of a glue
• 16:22
  Speaker 1: ball or have any idea what it can be.
• 16:25
  Speaker 2: So thank you very much to everybody who answers these
• 16:27
  Speaker 2: random questions. It's super helpful to get a sense for
• 16:30
  Speaker 2: what people already know and what they think about these ideas.
• 16:34
  Speaker 1: So think about it for a second. What do you
• 16:36
  Speaker 1: think a glue ball can be? Here's what people had
• 16:40
  Speaker 1: to say.
• 16:40
  Speaker 3: There must be some silly ball made by kids to
• 16:43
  Speaker 3: play with during lunch of races. Yeah, I'm kidding. So
• 16:48
  Speaker 3: glue ball is a very relatively new concept. It is
• 16:51
  Speaker 3: basically combination of glue on particles without anyone and squawk.
• 16:56
  Speaker 1: A glue ball sounds like something to do with glue ons.
• 17:00
  Speaker 1: That's maybe like a ball of glue on, just a
• 17:02
  Speaker 1: bunch of them just interacting and stuff, just hanging out.
• 17:06
  Speaker 4: A glue ball. Yeah, I have no clue what that
• 17:09
  Speaker 4: could possibly be. The only thing that comes to mind
• 17:12
  Speaker 4: maybe is it might have something to do with glue ones.
• 17:15
  Speaker 4: But other than that, I can't even begin to guess.
• 17:18
  Speaker 1: Uh, probably something my cat pukes after she ates some clue.
• 17:23
  Speaker 1: I don't know. All right, sounds like we're not the
• 17:26
  Speaker 1: only ones who thought it's a kit's toy, or that
• 17:31
  Speaker 1: it involves spit somehow from cats.
• 17:34
  Speaker 2: I feel sorry for that guy's cat. I mean, who
• 17:36
  Speaker 2: lets their cat eat glue? Seriously?
• 17:38
  Speaker 1: I don't know. But are you responsible if your cat
• 17:40
  Speaker 1: eats glue? Or is that the cat's faut.
• 17:42
  Speaker 2: I don't know, But if your cat turns out to
• 17:43
  Speaker 2: be a serial killer, maybe you are responsible.
• 17:46
  Speaker 1: Well, at least the cat wouldn't get far, very far.
• 17:48
  Speaker 1: Just get stick to everything. The sticky glue ball, serial
• 17:54
  Speaker 1: killer sticky cat? Did you mean?
• 17:57
  Speaker 2: But I think a lot of these folks really got
• 17:59
  Speaker 2: the idea from the name, right, a ball of gluons.
• 18:03
  Speaker 2: Maybe this is actually a thing in particle physics that
• 18:06
  Speaker 2: has gasp an appropriate name.
• 18:09
  Speaker 1: Well, I don't know, it's if it is a ball
• 18:11
  Speaker 1: or not. I bet it's more like a teohedron or something.
• 18:14
  Speaker 2: I see you're gonna withhold judgment, all right, let's dig in.
• 18:16
  Speaker 1: Yeah, let's see what happens here. We'll step us through this, Daniel,
• 18:23
  Speaker 1: What is glue ball?
• 18:24
  Speaker 2: So a glue ball is a predicted particle that would
• 18:28
  Speaker 2: be made entirely of gluons, No quarks, no electrons, no
• 18:33
  Speaker 2: other matter particles at all, just gluons.
• 18:38
  Speaker 1: M Okay, So it's a theoretical or a predicted object
• 18:43
  Speaker 1: that can happen out in nature, and you would get
• 18:45
  Speaker 1: it by putting together gluons. Now what are gluons?
• 18:48
  Speaker 2: Right? So this is a predicted particle of the standard model.
• 18:50
  Speaker 2: It says gluons should be able to come together and
• 18:53
  Speaker 2: make this weird thing we call a glue ball. So
• 18:56
  Speaker 2: to understand that, you have to understand what is a gluon? Right. So,
• 18:59
  Speaker 2: as we said, each of the forces that are out there,
• 19:02
  Speaker 2: the fundamental forces that we know about, get mediated in
• 19:05
  Speaker 2: terms of fields, but you can also think about them
• 19:08
  Speaker 2: in terms of particles. Like what happens when two electrons
• 19:12
  Speaker 2: talk to each other, But they're doing it as they're
• 19:14
  Speaker 2: pushing on each other, and they push on each other
• 19:15
  Speaker 2: using their electric fields. But you can also think about
• 19:18
  Speaker 2: those fields as like a swarm of virtual photons. So
• 19:22
  Speaker 2: one way to think about how two electrons talk to
• 19:24
  Speaker 2: each other is that they bounce photons back and forth.
• 19:27
  Speaker 2: They're using photons to send messages to each other. So
• 19:30
  Speaker 2: every force that's out there you can think about in
• 19:32
  Speaker 2: terms of a field or the particle for that field.
• 19:36
  Speaker 2: So for electromagnetism, we have the photon, which is the
• 19:39
  Speaker 2: particle which carries the electromagnetic force. And then for the
• 19:43
  Speaker 2: strong force, we also have fields, and those fields are
• 19:47
  Speaker 2: gluon fields, and so the gluon is the particle that
• 19:51
  Speaker 2: carries the strong force. So, for example, how do you
• 19:55
  Speaker 2: make a proton. We make it out of upquarks and
• 19:57
  Speaker 2: down quarks. How do you tie the up quarks and
• 20:00
  Speaker 2: down quarks to gather into a proton? You use gluons.
• 20:04
  Speaker 2: So inside the proton is not just upquarks and down quarks.
• 20:07
  Speaker 2: There's a whole mess of gluons in they're holding it together.
• 20:10
  Speaker 1: Yeah, we talked a little bit about this in our
• 20:12
  Speaker 1: last podcast, about how photon are the particles that kind
• 20:16
  Speaker 1: of mediate, like you said, the electromagnetic force, like every
• 20:19
  Speaker 1: time an electron is repelled by another electron, or an
• 20:22
  Speaker 1: electron is attracted to another particle like a proton, there's
• 20:25
  Speaker 1: an exchange of photons. But we also kind of talked
• 20:27
  Speaker 1: about how these are not like real, real particles, like
• 20:31
  Speaker 1: they don't actually exchange these particles. It's more sort of
• 20:34
  Speaker 1: like in the sense of like quantum virtual particles.
• 20:36
  Speaker 2: Right, Yeah, that's exactly right. I find it more intuitive
• 20:39
  Speaker 2: to think about these things in terms of fields, like
• 20:42
  Speaker 2: the electron has a field and it's using that field
• 20:45
  Speaker 2: to push on another electron. But if you don't like
• 20:47
  Speaker 2: the idea of fields, you can also think about these
• 20:49
  Speaker 2: things in terms of virtual particles, and you just replace
• 20:52
  Speaker 2: the field with an infinite number of virtual particles that
• 20:56
  Speaker 2: are filling space. Mathematically, it's really the same thing. And
• 20:59
  Speaker 2: those are the virtual particles, which you're not like real particles.
• 21:02
  Speaker 2: But these fields are also capable of having real particles,
• 21:05
  Speaker 2: Like what is a real photon? A photon that leaves
• 21:07
  Speaker 2: the Sun and hits your eyeball. That's a ripple in
• 21:10
  Speaker 2: the electromagnetic field. And in the same way, a gluon,
• 21:14
  Speaker 2: like a real gluon, is a ripple in the gluon field.
• 21:18
  Speaker 2: So there can be virtual gluons exchanged between particles inside
• 21:21
  Speaker 2: a proton, for example, and they're also real gluons that
• 21:24
  Speaker 2: can like fly through space.
• 21:26
  Speaker 1: Okay, so there are real gluons and virtual gluons, and
• 21:30
  Speaker 1: so like you're saying, these are the particles that mediate
• 21:33
  Speaker 1: or that transmit the strong force, which is what keeps
• 21:37
  Speaker 1: quarts together to make protons and neutrons, And those are
• 21:40
  Speaker 1: the nuclei and all of the atoms in your body.
• 21:42
  Speaker 1: But maybe let's paint the picture of how these gluons
• 21:46
  Speaker 1: actually keep things together, and then let's talk about what
• 21:49
  Speaker 1: happens when you try to glue two gluons together. So
• 21:51
  Speaker 1: let's get into that, but first let's take a quick break.
• 22:07
  Speaker 1: All Right, we're talking about glue balls, which is not
• 22:09
  Speaker 1: a toy, but it is a pretty good name for
• 22:11
  Speaker 1: a toy.
• 22:12
  Speaker 2: Yeah, that's right. Gluons sound ridiculous, but they are a
• 22:16
  Speaker 2: real thing in particle physics, and we use them in
• 22:18
  Speaker 2: our calculations and exist in nature sticking your quarks together
• 22:23
  Speaker 2: to make you okay.
• 22:25
  Speaker 1: So we talked about how gluons are the particles that
• 22:28
  Speaker 1: transmit the strong force, and so you said they sort
• 22:30
  Speaker 1: of come up when, for example, a quark is attracted
• 22:34
  Speaker 1: to another quark. So maybe paint is a picture. I'm
• 22:36
  Speaker 1: a quark and I have another quark here next to me,
• 22:39
  Speaker 1: and I feel the strong force between us. What does
• 22:42
  Speaker 1: that mean? Does that mean I'm like throwing gluons at
• 22:44
  Speaker 1: each other, or does it mean that there are virtual
• 22:47
  Speaker 1: gluons popping up in the space between us, or what
• 22:49
  Speaker 1: does that mean?
• 22:50
  Speaker 2: Yeah, the way you should think about it is that
• 22:53
  Speaker 2: quarks have a field. That field is just like an
• 22:57
  Speaker 2: electric field from an electron. But electrons have a electric charges,
• 23:01
  Speaker 2: which is what makes the electric field, and quarks have
• 23:04
  Speaker 2: a different kind of charge. They have a charge for
• 23:07
  Speaker 2: the strong force, which is a different force from electromagnetism,
• 23:10
  Speaker 2: and that kind of charge we call a color charge
• 23:13
  Speaker 2: because it has three different varieties red, green, and blue.
• 23:17
  Speaker 2: So electromagnetism has like plus and minus charges, the color
• 23:21
  Speaker 2: charge is much different and very weird as three versions
• 23:24
  Speaker 2: of it. Quark can be like blue or green or red,
• 23:28
  Speaker 2: and so it can have a field, a color field,
• 23:32
  Speaker 2: and that color field pulls or pushes on other things
• 23:35
  Speaker 2: that have color charges to them. So, for example, that
• 23:39
  Speaker 2: quark inside your proton has a color field, and that
• 23:42
  Speaker 2: color field is applying a force to the other quarks
• 23:45
  Speaker 2: inside the proton. And now you can always think about
• 23:47
  Speaker 2: these fields in terms of virtual particles, and so the
• 23:50
  Speaker 2: virtual particle for this field is a glue on. So
• 23:53
  Speaker 2: one way to think about it is these quarks are
• 23:55
  Speaker 2: bound together because of their color field that's putting forces
• 23:58
  Speaker 2: on the other quarks, or that they're exchanging virtual gluons
• 24:02
  Speaker 2: constantly to tie themselves together into a proton.
• 24:06
  Speaker 1: And you sort of need this idea of particles that
• 24:09
  Speaker 1: transmit the force because these forces are not, as far
• 24:13
  Speaker 1: as we can see, instantaneous, like from a quark here
• 24:17
  Speaker 1: and you're a quark over there. I don't exert a
• 24:19
  Speaker 1: force and you kind of immediately or magically right like
• 24:22
  Speaker 1: there's something that has to somehow go from here to there.
• 24:25
  Speaker 2: No information can move instantaneously in the universe, and that's why.
• 24:29
  Speaker 2: For example, if you take an electron, it has a
• 24:32
  Speaker 2: static electric field, but then if you wiggle that electron,
• 24:36
  Speaker 2: the whole field doesn't move all at once. If that
• 24:39
  Speaker 2: field extends from here to your neighbor's house. But if
• 24:42
  Speaker 2: you wiggle the electron, your neighbor can't tell that you
• 24:45
  Speaker 2: wiggled it instantly. They have to wait for that wiggle
• 24:48
  Speaker 2: to move through the field to get to him. And
• 24:50
  Speaker 2: that's what we think of as a ripple in that field,
• 24:53
  Speaker 2: which you can interpret as a particle. In fact, that's
• 24:56
  Speaker 2: how you make photons. You take electrons and you wiggle them.
• 24:59
  Speaker 2: That's an he is and so you can interpret these
• 25:02
  Speaker 2: ripples in the field sometimes in terms of real particles
• 25:05
  Speaker 2: if they have certain properties special ripples or if there
• 25:07
  Speaker 2: are other kinds of ripples in the field, then we
• 25:09
  Speaker 2: just call them virtual particles.
• 25:12
  Speaker 1: Okay, so now let's paint the picture. I have a
• 25:14
  Speaker 1: quark right here in front of you, and it's a
• 25:16
  Speaker 1: red cork, and you right next to me have a
• 25:18
  Speaker 1: green cork, and so, which means that two quarks are
• 25:20
  Speaker 1: sort of attracting each other, right, I'm pulling on each
• 25:23
  Speaker 1: other to smush them together through the strong force. But
• 25:26
  Speaker 1: they're not moving yet. What's happening? Are there like virtual
• 25:29
  Speaker 1: gluons popping up in between the two? Is my quark
• 25:33
  Speaker 1: sending gluons to your quark? How would you describe it?
• 25:38
  Speaker 1: Or nothing's happening until one of them moves.
• 25:40
  Speaker 2: Remember that these are quantum particles, so you can't really
• 25:43
  Speaker 2: think of them as having like a specific location and velocity.
• 25:47
  Speaker 2: The same way you can't really think about the electron
• 25:49
  Speaker 2: as having a specific location and velocity as it moves
• 25:52
  Speaker 2: around the nucleus. Instead, you can think of it as
• 25:55
  Speaker 2: having like a probability distribution of various possible locations around
• 25:59
  Speaker 2: the nuclear Because it's trapped in a little well, the
• 26:02
  Speaker 2: nucleus creates an electromagnetic potential, which traps the electron inside
• 26:06
  Speaker 2: of it, and the electron is somewhere in that well,
• 26:08
  Speaker 2: but we don't know exactly where. So in the same way,
• 26:11
  Speaker 2: these quarks all create color potential, a strong force potential
• 26:16
  Speaker 2: which traps the other quarks with them inside this potential.
• 26:20
  Speaker 2: So where is any individual quark well, it's not determined
• 26:23
  Speaker 2: just as a probability distribution, but it's all balanced and solved,
• 26:26
  Speaker 2: and all the quarks have a happy wave function to
• 26:29
  Speaker 2: be on top of each other inside this little potential
• 26:32
  Speaker 2: well that they all create. So it's like a little
• 26:34
  Speaker 2: bound state of these quantum functions.
• 26:37
  Speaker 1: I guess it's sort of like you know, like you're saying,
• 26:40
  Speaker 1: the quark that I have here in my red QRK
• 26:42
  Speaker 1: isn't really like a billiard ball. It's more like a
• 26:45
  Speaker 1: fuzzy cloud here that I'm holding. And then your quark
• 26:49
  Speaker 1: is also not a billiard ball. It's another fuzzy cloud.
• 26:52
  Speaker 1: And so when I sort of bring them together, the
• 26:55
  Speaker 1: two clouds cand of merge or smoosh together into one,
• 26:59
  Speaker 1: sort of like a system made out of two particles.
• 27:02
  Speaker 1: That's kind of what you're saying, right, It's like it's
• 27:04
  Speaker 1: more like the two quantum functions or wave functions merge
• 27:08
  Speaker 1: together to make one that maybe has some sort of
• 27:10
  Speaker 1: potential to stay together.
• 27:11
  Speaker 2: Remember that quantum mechanics tells us that the universe is random,
• 27:15
  Speaker 2: but it's not totally random. It's still deterministic in some way.
• 27:19
  Speaker 2: Like old Newtonian classical physics told us that everything was
• 27:22
  Speaker 2: like a billiard ball, and if you bounce things the
• 27:24
  Speaker 2: same way twice, the same thing would happen. Everything was deterministic.
• 27:27
  Speaker 2: Quantum mechanics says, well, we're deterministic, but only about the probabilities.
• 27:31
  Speaker 2: Quantum mechanics says, I will predict exactly what the probability
• 27:35
  Speaker 2: of various outcomes is. I won't to tell you which
• 27:38
  Speaker 2: outcome is going to happen, but i'll tell you the
• 27:40
  Speaker 2: various probabilities. So here quantum mechanics applies to these little particles,
• 27:45
  Speaker 2: and it says, well, your red cork has a higher
• 27:46
  Speaker 2: chance of being over here and the smaller chance of
• 27:48
  Speaker 2: being over there, and they have to satisfy all the
• 27:50
  Speaker 2: mathematics of the equations. And so you can solve these
• 27:53
  Speaker 2: equations and figure out where the red cork is likely
• 27:55
  Speaker 2: to be, given that there's a blue cork nearby and
• 27:58
  Speaker 2: a green cork nearby side the proton. The really cool
• 28:01
  Speaker 2: thing about the strong force is these weird charges. Like
• 28:05
  Speaker 2: the atom is neutral because you have a positively charged
• 28:07
  Speaker 2: nucleus and a negatively charged electron. Plus one and minus
• 28:10
  Speaker 2: one makes zero. Right, Well, the proton has no color
• 28:14
  Speaker 2: charge because inside of it it has one of each
• 28:17
  Speaker 2: of the charges. It has a red, a green, and
• 28:20
  Speaker 2: a blue, and together those add up to make no
• 28:23
  Speaker 2: color or white as we call it, in the same
• 28:26
  Speaker 2: way that like having one of each of the electromagnetic
• 28:29
  Speaker 2: charges plus and minus add up to zero electromagnetic charge.
• 28:33
  Speaker 1: And so that's how the quarks add up. But then
• 28:35
  Speaker 1: where do the gluons come in?
• 28:37
  Speaker 2: So the gluons are super duper weird and much more
• 28:40
  Speaker 2: complicated than in electromagnetism. Electromagnetism you have two charges and
• 28:45
  Speaker 2: you just have the single photon which transmits it. The
• 28:47
  Speaker 2: photon itself is not charged, right, The photon is a
• 28:50
  Speaker 2: neutral object, which is going to be important because photons,
• 28:53
  Speaker 2: they don't like, bounce off of each other. They pass
• 28:55
  Speaker 2: right through each other for the most part. Check out
• 28:56
  Speaker 2: our whole podcast episode about lightsabers and photons bouncing off
• 29:00
  Speaker 2: each other. But gluons are different. Gluons are charged in color.
• 29:04
  Speaker 2: In fact, gluons have two colors. So for example, like
• 29:08
  Speaker 2: a quark has one color like red or blue or green,
• 29:11
  Speaker 2: a gluon has two colors simultaneously. It can be like
• 29:15
  Speaker 2: red and anti blue or blue and anti green.
• 29:19
  Speaker 1: Does that depend on sort of like what the two
• 29:22
  Speaker 1: quarks are that are interacting? Like if I have a
• 29:25
  Speaker 1: red cork and you have a green cork, is it
• 29:27
  Speaker 1: that they can only exchange red green or red anti
• 29:31
  Speaker 1: green bluons?
• 29:33
  Speaker 2: Yeah, it's just like that. If you have, for example,
• 29:35
  Speaker 2: a blue cork and a green cork, a blue cork
• 29:38
  Speaker 2: can emit a blue anti green gluon and then it
• 29:43
  Speaker 2: becomes green. Its blueness has gone into the gluon and
• 29:48
  Speaker 2: it becomes green because they also gave that gluon anti green.
• 29:51
  Speaker 2: Then the green cork absorbs the blue anti green gluon
• 29:56
  Speaker 2: and it becomes a blue cork. So like a blue
• 29:59
  Speaker 2: cork and a green cork, or can swap colors by
• 30:02
  Speaker 2: exchanging a gluon.
• 30:05
  Speaker 1: And so this swapping happens when they move relative to
• 30:09
  Speaker 1: each other. Is it always happening at all times? Like
• 30:11
  Speaker 1: with these virtual particles? What exactly is going on?
• 30:15
  Speaker 2: Well, like everything else quanta mechanical, nothing is definitive. So
• 30:18
  Speaker 2: you have your quarks inside the proton, and none of
• 30:21
  Speaker 2: them are like actually red, or actually green or actually blue.
• 30:24
  Speaker 2: They all have a probability to have one of those
• 30:27
  Speaker 2: colors simultaneously, And if you really needed to know, you
• 30:31
  Speaker 2: would like send a really high energy particle inside the
• 30:34
  Speaker 2: proton to break it up to figure out what the
• 30:36
  Speaker 2: color was, and then the universe would roll the die
• 30:38
  Speaker 2: and say, Okay, this one happened to be green at
• 30:40
  Speaker 2: that moment, or this one happened to be red at
• 30:42
  Speaker 2: that moment. But just right now, inside your proton, as
• 30:44
  Speaker 2: everything is jiggling, each of your quarks has a simultaneous
• 30:48
  Speaker 2: probability for each of these colors. But the fact that
• 30:51
  Speaker 2: the gluon has to have these colors itself makes it
• 30:54
  Speaker 2: really complicated. So two gluons can also interact with each
• 30:58
  Speaker 2: other the way two photons really cannot. Two gluons can
• 31:01
  Speaker 2: talk to each other directly.
• 31:03
  Speaker 1: Okay, and you're talking about the real gluons or the
• 31:05
  Speaker 1: virtual gluons.
• 31:06
  Speaker 2: Both all kinds of gluons. These fields all bounce off
• 31:10
  Speaker 2: each other and interact with each other and make more gluons.
• 31:12
  Speaker 2: Two gluons can come together to make two more gluons.
• 31:15
  Speaker 2: It gets really complicated really fast, because everybody's talking to
• 31:19
  Speaker 2: everybody else.
• 31:20
  Speaker 1: All right. So then gluons are particles, just like an
• 31:24
  Speaker 1: electron is or a photon is that they have their
• 31:26
  Speaker 1: own field in the universe. I'm trying to put the
• 31:29
  Speaker 1: picture here together. And what they do is they sort
• 31:32
  Speaker 1: of fly or exist between different quarks that have the
• 31:36
  Speaker 1: color charge, and that's sort of how the strong force
• 31:40
  Speaker 1: comes about. And they have different flavors, different colors. And
• 31:43
  Speaker 1: sometimes these gluons can interact with each other, and I
• 31:46
  Speaker 1: imagine they can also stick to each other, which is
• 31:49
  Speaker 1: maybe where a glue ball comes in exactly.
• 31:52
  Speaker 2: Because they can talk to each other, and they have
• 31:54
  Speaker 2: charges relative to each other, they feel forces relative to
• 31:57
  Speaker 2: each other. They can also get bound together. They can
• 32:00
  Speaker 2: form complicated stuff.
• 32:02
  Speaker 1: But wait, if two gluons can interact and push on
• 32:05
  Speaker 1: each other, what causes to push it? Is there a
• 32:08
  Speaker 1: force another force particle just for transmitting the strong force
• 32:12
  Speaker 1: or the glue force between gluons.
• 32:14
  Speaker 2: No, they can push on each other directly, the way
• 32:17
  Speaker 2: like a photon can push on an electron directly. That's
• 32:20
  Speaker 2: an immediate interaction. Those two fields couple and energy can
• 32:24
  Speaker 2: flow from one to the other. Gluons can talk to
• 32:26
  Speaker 2: each other directly without any other intermediate particle. Like quarks
• 32:30
  Speaker 2: can't talk to each other directly. They have to use
• 32:33
  Speaker 2: photons or gluons, whatever, But those photons can talk to
• 32:36
  Speaker 2: quarks or two electrons. Gluons can talk to each other directly,
• 32:40
  Speaker 2: like in the language of finement diagrams. You can have
• 32:42
  Speaker 2: a vertex that's just like gluon, gluon, gluon or four
• 32:46
  Speaker 2: gluons in fact, can make a vertex, so you don't
• 32:48
  Speaker 2: need an intermediate field. This is the field and it
• 32:51
  Speaker 2: can talk to itself.
• 32:53
  Speaker 1: And that's kind of weird, right because for example, the
• 32:55
  Speaker 1: photon is another particle that transmits forces, but it can
• 32:58
  Speaker 1: interact with itself.
• 33:00
  Speaker 2: That's right. It can't interact with itself, so you can't
• 33:02
  Speaker 2: have like a light ball. There is ball lightning out there,
• 33:05
  Speaker 2: I think people think, but it's not like photons bound
• 33:07
  Speaker 2: together in the same way. But gluons, because they can
• 33:10
  Speaker 2: do this, they can talk to each other, they can
• 33:12
  Speaker 2: feel forces relative to each other. They can create a
• 33:15
  Speaker 2: little potential well and trap each other inside, and they
• 33:19
  Speaker 2: can make. We think this particle called a glue ball,
• 33:23
  Speaker 2: which is a particle made just out of gluons, which
• 33:27
  Speaker 2: is really weird because it would have no matter particles inside,
• 33:31
  Speaker 2: no fermions at all, no electrons, no quarks, nothing that
• 33:35
  Speaker 2: we think of as making up matter. It would be
• 33:37
  Speaker 2: pure force.
• 33:39
  Speaker 1: Now do gluons only attract each other or do they
• 33:42
  Speaker 1: also repel each other? Or does it depend on what
• 33:45
  Speaker 1: color combination they are.
• 33:46
  Speaker 2: It depends on the color combination. It also depends on
• 33:49
  Speaker 2: the distance. The strong force is super duper weird, and
• 33:52
  Speaker 2: it's very attractive at some distances and repulsive at other distances.
• 33:56
  Speaker 2: And the strong force in general is very difficult to
• 33:58
  Speaker 2: understand and also to do calculations with one because it's
• 34:02
  Speaker 2: so strong. Like a lot of times when we're doing calculations,
• 34:06
  Speaker 2: the actual calculation we want to do is impossible. Say,
• 34:09
  Speaker 2: for example, I want to know how an electron is
• 34:12
  Speaker 2: going to move through the universe. To really know that,
• 34:14
  Speaker 2: I have to account for like all the electrons that
• 34:17
  Speaker 2: are out there, the electrons in other galaxies. Technically those
• 34:20
  Speaker 2: affect my electron, but because they're so far away, I
• 34:23
  Speaker 2: can ignore it. I'll mostly get the right answer that's
• 34:25
  Speaker 2: not true for the strong force. The strong force is
• 34:29
  Speaker 2: so strong, so powerful that a lot of these effects,
• 34:32
  Speaker 2: other quirks in other places and gluons that are created
• 34:36
  Speaker 2: by other gluons become very very difficult to calculate and
• 34:39
  Speaker 2: are not small effects. And so the approximations that help
• 34:43
  Speaker 2: us succeed in doing otherwise impossible calculations for other forces,
• 34:47
  Speaker 2: those tricks don't work for the strong force. So a
• 34:50
  Speaker 2: lot of basic stuff about the strong force we just
• 34:52
  Speaker 2: don't know how to calculate because gluons can do this
• 34:55
  Speaker 2: thing where they create other gluons, and because the force
• 34:59
  Speaker 2: itself is so so powerful.
• 35:00
  Speaker 1: Mmmm. Well, going back to my question, I guess is like,
• 35:03
  Speaker 1: what makes two gluons attract each other? Is it like
• 35:07
  Speaker 1: all the red ones attract anything with red or repel
• 35:09
  Speaker 1: anything that has read in it? You know, like you
• 35:12
  Speaker 1: have a red blue glue on, what does it get
• 35:15
  Speaker 1: attracted to a green blue?
• 35:20
  Speaker 2: Well, you can't have a red blue gluon. You can
• 35:23
  Speaker 2: have like a red anti blue or a blue anti red,
• 35:26
  Speaker 2: or like a red anti red gluon. But whether they're
• 35:29
  Speaker 2: attracted to each other or repel to each other depends
• 35:31
  Speaker 2: on a lot of complicated calculations. I mean, the attraction
• 35:35
  Speaker 2: comes from like having a potential. Now, are all forces
• 35:38
  Speaker 2: in the universe really come from potential differences? Forces are
• 35:41
  Speaker 2: due to changes in the potential. Things like to roll
• 35:44
  Speaker 2: down hill as a gravitational force because the gravitational potential
• 35:48
  Speaker 2: energy is lower at the bottom of the hill, or
• 35:50
  Speaker 2: electrons are pushed towards the nucleus because that's where the
• 35:53
  Speaker 2: bottom of the electromagnetic potential is. So to think about
• 35:56
  Speaker 2: things in terms of forces pulling or pushing, you have
• 35:59
  Speaker 2: to understand where the potential is at a minimum, and
• 36:02
  Speaker 2: that's really complicated. For the strong force, it's not always
• 36:04
  Speaker 2: that simple. Remember we even try to talk about it
• 36:06
  Speaker 2: once for the weak force, and it's not always obvious whether,
• 36:10
  Speaker 2: for examples, W bosons and Z bosons push or pull
• 36:13
  Speaker 2: on each other. They can do both or sometimes it
• 36:15
  Speaker 2: depends on the context. And that's even more complicated here
• 36:19
  Speaker 2: for the strong force. So in some arrangements, these gluons
• 36:22
  Speaker 2: can tug on each other, create a potential minimum and
• 36:25
  Speaker 2: get trapped in this well and become a bound state.
• 36:28
  Speaker 1: Okay, so I'm getting the sense that it's complicated. It's complicated,
• 36:31
  Speaker 1: but it can seem to happen throughout If you sort
• 36:34
  Speaker 1: of pierce through all of the mass, there are situations
• 36:37
  Speaker 1: where you can get a couple of two or maybe
• 36:41
  Speaker 1: more gluons kind of wanting to hang out with each other,
• 36:45
  Speaker 1: really close together. That's kind of the idea I'm getting.
• 36:48
  Speaker 2: Yeah, from the calculations, which are not perfect and are approximate,
• 36:51
  Speaker 2: and nobody is one hundred percent confident in them, we
• 36:54
  Speaker 2: see this prediction emerge that gluons should be able to
• 36:56
  Speaker 2: get bound to each other and create this persistent state
• 36:59
  Speaker 2: that lives for a while, not forever. It's not stable.
• 37:02
  Speaker 2: It's not like you can make a glue ball and
• 37:03
  Speaker 2: then come back a billion years later and still have
• 37:05
  Speaker 2: a glue ball. But very briefly, they'll hang out in
• 37:07
  Speaker 2: this little state, do their thing, and then explode into
• 37:10
  Speaker 2: a shower of other particles.
• 37:12
  Speaker 1: That's the prediction, and so when they come together, that's
• 37:16
  Speaker 1: what you would call a glue ball, Etceterronically, the gluons
• 37:19
  Speaker 1: don't stick around very long.
• 37:21
  Speaker 2: They're not as sticky as we'd like them to be.
• 37:24
  Speaker 1: Gluons are not sticky. You mean, glue balls don't stick together.
• 37:29
  Speaker 1: And you were saying this is a good name.
• 37:31
  Speaker 2: Maybe in super symmetry, we'll have super gluons and those
• 37:34
  Speaker 2: will make super glue balls that will really stick together.
• 37:37
  Speaker 1: There you go, all right, so then so gluons can't
• 37:41
  Speaker 1: stick to each other, and then you think this happens. Now,
• 37:44
  Speaker 1: does this happen with real gluons or virtual gluons, or
• 37:46
  Speaker 1: it can happen to both.
• 37:48
  Speaker 2: This happens from real gluons. So if you create enough
• 37:50
  Speaker 2: real gluons, they can come together to make a glue
• 37:53
  Speaker 2: ball in the same way that for example, if you
• 37:55
  Speaker 2: make quarks, you make a spray of quarks. Quarks do
• 37:58
  Speaker 2: not like to be a part Two quarks are very
• 38:01
  Speaker 2: far apart from each other. There's a huge potential energy there,
• 38:04
  Speaker 2: and that potential energy gets turned into other particles, and
• 38:07
  Speaker 2: those particles quickly find partners and form masons and baryons.
• 38:11
  Speaker 2: Those are combinations of pairs or triplets of quarks. So
• 38:14
  Speaker 2: for example, you have protons or pions or k masons
• 38:17
  Speaker 2: or all sorts of other stuff. You know, at the
• 38:19
  Speaker 2: Large Hadron Collider, when we smash two protons together, we
• 38:22
  Speaker 2: expose the quarks inside them. Briefly, we got these sprays
• 38:25
  Speaker 2: of quarks and gluons but they really don't like to
• 38:28
  Speaker 2: be by themselves, and so they very quickly create these
• 38:30
  Speaker 2: streams of other particles with them, and then they form
• 38:34
  Speaker 2: these states. And so what we actually see in our
• 38:36
  Speaker 2: detector are streams of like protons and chons and neutrons
• 38:40
  Speaker 2: and all sorts of other stuff. So quarks do this,
• 38:42
  Speaker 2: they find partners and form other states. And so we
• 38:45
  Speaker 2: think that maybe gluons can do this too, that like
• 38:47
  Speaker 2: two or three gluons can come together and make something
• 38:50
  Speaker 2: we call a glue.
• 38:51
  Speaker 1: Ball, because the math is telling you that they are
• 38:55
  Speaker 1: sort of compatible, that there is sort of a way
• 38:57
  Speaker 1: where you can put together two or three gluont where
• 38:59
  Speaker 1: they'll want to stick together exactly.
• 39:01
  Speaker 2: And they will be color neutral. They will be white.
• 39:04
  Speaker 2: You can match all their colors together to make a
• 39:06
  Speaker 2: color neutral object, which in principles should last for a
• 39:09
  Speaker 2: little while.
• 39:10
  Speaker 1: All right, Well, let's stick a little bit deeper into
• 39:12
  Speaker 1: what a glue ball is like and whether or not
• 39:15
  Speaker 1: we found it, and if we have, what does it
• 39:17
  Speaker 1: mean about our understanding of the universe. But first, let's
• 39:20
  Speaker 1: stick another quick break. All right, we're talking about a
• 39:36
  Speaker 1: very sticky subject glue balls, which is what happens when
• 39:40
  Speaker 1: you potentially get a couple of gluons together, they'll maybe
• 39:43
  Speaker 1: stick to each other and form basically a ball.
• 39:46
  Speaker 2: Of glue, a literal ball of fundamental glue.
• 39:50
  Speaker 1: It sounds like you're saying that if you take a
• 39:52
  Speaker 1: couple of gluons and they do stick together, then they
• 39:54
  Speaker 1: wouldn't be stick anymore because it would all sort of
• 39:56
  Speaker 1: cancel each other out in terms of their charge. Right,
• 39:59
  Speaker 1: So glue ball be sticky at all, It wouldn't right,
• 40:02
  Speaker 1: it would just be lethal.
• 40:03
  Speaker 2: That's a great point. They'd be sticky on the inside, right,
• 40:07
  Speaker 2: but all the stickiness would be reserved for the other gluons.
• 40:09
  Speaker 2: On the other hand, you know, that's also truer protons. Technically,
• 40:13
  Speaker 2: protons have no color charge, and yet if you bring
• 40:16
  Speaker 2: a bunch of protons together, they can get stuck together
• 40:18
  Speaker 2: from the residual color charge. If you're on one side
• 40:21
  Speaker 2: of the proton, you might be closer to one of
• 40:23
  Speaker 2: the quarks than the others, so the charges don't exactly balance,
• 40:26
  Speaker 2: and that's how the nucleus is together. So in principle,
• 40:29
  Speaker 2: it might be possible to like have a bunch of
• 40:32
  Speaker 2: glue balls and have them all stick together. But yeah,
• 40:34
  Speaker 2: they're stickiest on the inside, for sure.
• 40:37
  Speaker 1: You mean they might be sticky on the outside, but
• 40:40
  Speaker 1: from afar, a glue ball would not be very glue.
• 40:43
  Speaker 2: Yeah, a glue ball technically has no color charge and
• 40:45
  Speaker 2: no electric charge either.
• 40:47
  Speaker 1: All right, well, what else can you tell us about
• 40:49
  Speaker 1: these theoretical glue balls.
• 40:51
  Speaker 2: So it's predicted that if these gluons exist, that they
• 40:54
  Speaker 2: would not be very very heavy. You know, they would
• 40:56
  Speaker 2: only be like one to five giga electron volt in mass,
• 41:01
  Speaker 2: which is not that heavy. You know, a proton is
• 41:03
  Speaker 2: about one gigle electron bolts. So we're talking about something
• 41:06
  Speaker 2: that's like one to five times as massive as the proton,
• 41:09
  Speaker 2: and that sounds like something we should be able to
• 41:11
  Speaker 2: discover because our collider has found things that are much
• 41:14
  Speaker 2: much heavier. We're usually limited by the energy. You want
• 41:16
  Speaker 2: to make something really massive, you have to pour enough
• 41:19
  Speaker 2: energy into the collision to make that thing, because remember
• 41:22
  Speaker 2: energy and mass are sort of interchangeable. You want to
• 41:25
  Speaker 2: make a heavy Higgs boson, you have to have enough
• 41:27
  Speaker 2: energy of one hundred and twenty five protons in your collision.
• 41:31
  Speaker 2: But our collider is super powerful. It's thirteen thousand GeV
• 41:36
  Speaker 2: in the collision, so there's plenty of energy to make
• 41:38
  Speaker 2: heavy stuff. Glue balls are really pretty light in comparison,
• 41:41
  Speaker 2: They're not really very massive. There are only a few
• 41:43
  Speaker 2: proton masses worth.
• 41:45
  Speaker 1: Well, it's interesting that they have mass, right the gluons, Like,
• 41:48
  Speaker 1: does an individual gluon have mass by itself? It's a
• 41:51
  Speaker 1: force force transmitting particle, Does it have mass on its own?
• 41:55
  Speaker 2: It doesn't. Gluons themselves do not have mass, like photons
• 41:58
  Speaker 2: do not have mass, but a globe all would have mass,
• 42:01
  Speaker 2: the same way that, like a proton has mass, Most
• 42:04
  Speaker 2: of the mass of a proton doesn't come from the
• 42:07
  Speaker 2: quarks that make it up, Like a proton is one GeV,
• 42:10
  Speaker 2: but the quarks inside of it are like one percent
• 42:13
  Speaker 2: of that mass. Most of the mass of the proton
• 42:16
  Speaker 2: actually comes from the gluons inside the proton. Because remember
• 42:20
  Speaker 2: that mass is this weird thing. It's not just like
• 42:22
  Speaker 2: how much stuff is inside something. It's all of the
• 42:25
  Speaker 2: internal stored energy. So if you have a bunch of
• 42:28
  Speaker 2: energy stored in the bonds between your quarks, that counts
• 42:32
  Speaker 2: towards your mass. And that's true for other kinds of things,
• 42:35
  Speaker 2: like if you could get a bunch of photons and
• 42:38
  Speaker 2: store them inside something. Even if they're massless, they would
• 42:41
  Speaker 2: add to the mass of that object. In fact, you
• 42:44
  Speaker 2: take a rock and it absorbs a photon, that rock
• 42:47
  Speaker 2: gets more massive because it's now absorbed that photon's energy.
• 42:50
  Speaker 2: So mass is a weird thing. You can make it
• 42:52
  Speaker 2: out of massless stuff.
• 42:54
  Speaker 1: Well, we talked about before, and I know we talked
• 42:56
  Speaker 1: about this in our book. Frequently asked questions about the
• 42:58
  Speaker 1: universe that the mass doesn't really exist, Like mass is
• 43:03
  Speaker 1: just energy, and what you think of as gravity or
• 43:06
  Speaker 1: inertia is really just what happens when you kind of
• 43:10
  Speaker 1: concentrate energy in one little spot. And so that's kind
• 43:13
  Speaker 1: of what's happening here. Is like an individual gluon doesn't
• 43:16
  Speaker 1: have mass, but when you put it together with another gluon,
• 43:19
  Speaker 1: you're sort of trapping energy in one spot and then
• 43:22
  Speaker 1: suddenly you've got a little spot of energy, and so
• 43:25
  Speaker 1: that feels gravity and it feels inertia.
• 43:27
  Speaker 2: Yeah, that's what we call mass, right, that's inertial. Mass
• 43:30
  Speaker 2: is localized. Internally stored energy has this property that if
• 43:35
  Speaker 2: you push on it, it takes a force to accelerate it.
• 43:37
  Speaker 2: That's what we call inertial mass, and that's kind of
• 43:40
  Speaker 2: a weird and deep mystery of the universe. But yeah,
• 43:42
  Speaker 2: you can make it out of massless stuff, as you say,
• 43:45
  Speaker 2: as long as you concentrate some energy in there. And
• 43:47
  Speaker 2: glue balls definitely have energy inside them. These gluons have
• 43:51
  Speaker 2: energy even though they are massless.
• 43:53
  Speaker 1: All right, Well, it sounds like a glue ball is
• 43:55
  Speaker 1: not really sticky, and like you were saying, it's also unstable,
• 43:58
  Speaker 1: like it's not only not sticky, but it doesn't want
• 44:01
  Speaker 1: to stick to its over.
• 44:02
  Speaker 2: Yeah, like many of these particles, it's unstable. You know,
• 44:05
  Speaker 2: the proton is a very unusual particle because it is stable,
• 44:09
  Speaker 2: but every other combination of quarks, for example, is unstable.
• 44:13
  Speaker 2: Even the neutron will fall apart in about eleven minutes.
• 44:16
  Speaker 2: And these other particles, pions and chons, they're created, they
• 44:20
  Speaker 2: live sometimes very briefly before they spray out into other
• 44:24
  Speaker 2: lighter particles. And the glue ball is no different. It's
• 44:26
  Speaker 2: a combination of these strong color charged particles. But it
• 44:29
  Speaker 2: also decays into other stuff. And so for example, glue
• 44:33
  Speaker 2: ball can turn into two photons, or can turn into
• 44:37
  Speaker 2: like four quarks or a shower of gluons or all
• 44:40
  Speaker 2: sorts of other stuff.
• 44:41
  Speaker 1: You can get showered with blue bits.
• 44:44
  Speaker 2: Yeah, they can basically explode into little bits of glue.
• 44:46
  Speaker 1: Wow, doesn't sound very glue like at all. I'm slowly
• 44:52
  Speaker 1: ungluing your use of the name glue here. Oh man, Well,
• 44:56
  Speaker 1: I get The big question now is have we found
• 44:58
  Speaker 1: glue balls? Theoretical, we think they can exist and maybe
• 45:03
  Speaker 1: exist out there using our math, but have we found one?
• 45:06
  Speaker 1: Have you ever seen a googball?
• 45:07
  Speaker 2: The weird thing is that we're not sure. Sometimes it's
• 45:10
  Speaker 2: very obvious when you've discovered a particle because there's only
• 45:14
  Speaker 2: one thing that it can do and nothing else can
• 45:16
  Speaker 2: do that. So, for example, when we discovered the Higgs boson,
• 45:19
  Speaker 2: we didn't see the Higgs directly, but we saw pairs
• 45:23
  Speaker 2: of photons that it decayed into that were flying apart
• 45:26
  Speaker 2: from each other with a very specific characteristic energy. We
• 45:29
  Speaker 2: found lots and lots of examples of photons with those
• 45:32
  Speaker 2: kinds of energies, and we said, this can only really
• 45:34
  Speaker 2: come from the Higgs boson, and therefore we're pretty sure
• 45:37
  Speaker 2: we found the Higgs boson. And the key there is
• 45:40
  Speaker 2: that it was doing something unusual, something that made it
• 45:43
  Speaker 2: like stick out from the background. Now, glue balls are
• 45:46
  Speaker 2: much more complicated because number one, we're not exactly sure
• 45:50
  Speaker 2: what they can do, Like, we're not sure exactly how
• 45:53
  Speaker 2: much masks they have. Maybe they have one GV, maybe
• 45:55
  Speaker 2: they have five GV. Maybe we're wrong and they have
• 45:58
  Speaker 2: like fifty gvre. Because the calculations we talked about are
• 46:02
  Speaker 2: very complicated and make a lot of approximations that nobody
• 46:05
  Speaker 2: really believes are right, and we hope didn't mess up
• 46:08
  Speaker 2: the calculations. And also there's lots of other particles down there,
• 46:12
  Speaker 2: like the Higgs boson we found it where there are
• 46:14
  Speaker 2: very very few particles of that kind of mass, very
• 46:17
  Speaker 2: heavy particles, but there's lots and lots of very light particles.
• 46:20
  Speaker 2: If you look at like the list of particles, there's
• 46:22
  Speaker 2: like hundreds of particles around one GeV, all sorts of
• 46:26
  Speaker 2: crazy combinations of quarks. So it's hard to pick out
• 46:30
  Speaker 2: a new one and say, oh, this one is a
• 46:32
  Speaker 2: glue ball, especially because we're not exactly sure what a
• 46:35
  Speaker 2: glue ball would look like.
• 46:36
  Speaker 1: Hmmm, I see, the theory doesn't predict what it would look.
• 46:39
  Speaker 2: Like, so the theory is impossible to do perfectly. There's
• 46:41
  Speaker 2: lots of approximations people have made, and they make different predictions.
• 46:45
  Speaker 2: Some predict like one point four GeV, some predict five GeV,
• 46:49
  Speaker 2: and they also give different predictions for how these things
• 46:52
  Speaker 2: might appear. You know, these glue balls have different properties
• 46:55
  Speaker 2: from the other particles, like they're weird internal spin and
• 46:58
  Speaker 2: other quantum states. Those might make like characteristic signatures, you know,
• 47:03
  Speaker 2: like how they turn into other particles, and how those
• 47:05
  Speaker 2: particles look. There were angles between each other and the
• 47:08
  Speaker 2: relative spin states and this kind of stuff. But again,
• 47:11
  Speaker 2: different theoretical calculations make different predictions here, and it's also
• 47:15
  Speaker 2: sometimes hard to disentangle from what we're seeing out there. So,
• 47:18
  Speaker 2: for example, there is a particle that people have found
• 47:21
  Speaker 2: that has about one and a half GeV. It's called
• 47:24
  Speaker 2: the F zero, and there's a raging debate in the
• 47:27
  Speaker 2: literature about whether or not it is a glue ball.
• 47:31
  Speaker 2: Some people say this is totally consistent with the glue ball,
• 47:34
  Speaker 2: and other people say, no, Look, it can do this
• 47:35
  Speaker 2: and that, and gloe balls shouldn't be able to do that,
• 47:37
  Speaker 2: so we don't think it's a glue ball. Nobody can
• 47:39
  Speaker 2: really agree about whether the F zero is a glue
• 47:43
  Speaker 2: ball or not.
• 47:44
  Speaker 1: Whoa wait, wait, wait a minute. You've discovered a particle
• 47:46
  Speaker 1: out there. You gave it the name F zero, but
• 47:49
  Speaker 1: you don't know what it is. What do you mean
• 47:50
  Speaker 1: you don't know what it is? What do you mean
• 47:52
  Speaker 1: you've found something that you don't know what it is?
• 47:54
  Speaker 1: Wouldn't that be a big deal.
• 47:55
  Speaker 2: So we found this particle, we've seen it decay into
• 47:58
  Speaker 2: like two pions into four pions, right, and so we
• 48:02
  Speaker 2: know that it exists. We can see that it's there.
• 48:04
  Speaker 2: Like you find the pions, you add up their energies,
• 48:07
  Speaker 2: they're consistent with a particle of mass one and a
• 48:09
  Speaker 2: half GeV. That doesn't mean that we know what's inside
• 48:13
  Speaker 2: the F zero, Like, is the F zero made out
• 48:15
  Speaker 2: of two quarks? Can you explain what the F zero
• 48:17
  Speaker 2: is doing just using quarks or do you need this
• 48:19
  Speaker 2: special gluon state to explain it? People disagree about whether
• 48:23
  Speaker 2: what the F zero is doing can be explained using
• 48:26
  Speaker 2: only quarks or requires gluons to explain it.
• 48:29
  Speaker 1: I see, so you're not quite sure if you found
• 48:31
  Speaker 1: a particle, you found something that could be a particle.
• 48:35
  Speaker 2: We found something. The F zero is definitely something. It exists,
• 48:38
  Speaker 2: We're just not sure what's inside of it? Like, is
• 48:40
  Speaker 2: the F zero made out of quarks or is it
• 48:42
  Speaker 2: made out of gluons? Nobody's one hundred percent sure because
• 48:46
  Speaker 2: it's a mess down there, and it's hard to make
• 48:48
  Speaker 2: very precise measurements of what the F zero is doing.
• 48:50
  Speaker 2: We're sure it's there. Nobody's doubting that the F zero
• 48:53
  Speaker 2: is real. They just don't really know exactly what it's
• 48:56
  Speaker 2: doing and what it's made out of.
• 48:58
  Speaker 1: Well, are people looking for glon or is this something
• 49:01
  Speaker 1: you're just looking at from the debris of other experiments?
• 49:05
  Speaker 1: Is there like a glue ball experiment other and are
• 49:08
  Speaker 1: the scientists called glue ballers.
• 49:11
  Speaker 2: This is a really exciting frontier in particle physics, but
• 49:14
  Speaker 2: also very very difficult. You know, it's a place where
• 49:16
  Speaker 2: we don't have crisp predictions and it's really hard to
• 49:19
  Speaker 2: see what's happening because everything is a big, messy spray
• 49:22
  Speaker 2: of particles. It's not like very crisp and clear one
• 49:25
  Speaker 2: photon one electron bouncing off of each other like in
• 49:28
  Speaker 2: the early days. You got like a big mess of
• 49:31
  Speaker 2: stuff you have to sift through. But there are dedicated
• 49:33
  Speaker 2: experiments just to understanding the strong force and specifically to
• 49:38
  Speaker 2: understanding gluons. So at Jefferson Lab in the East Coast
• 49:41
  Speaker 2: the United States, it is an experiment called glue x.
• 49:44
  Speaker 2: I don't know if they pronounced it gluks or glue
• 49:46
  Speaker 2: x or glueeks. I'm not exactly sure, but it's an
• 49:49
  Speaker 2: experiment that's running right now to study specifically gluons. What
• 49:53
  Speaker 2: can they do? Can we find glue balls? Can we
• 49:56
  Speaker 2: see it doing other stuff maybe that we didn't expect?
• 49:59
  Speaker 1: Have they found it?
• 50:00
  Speaker 2: They have not yet found confirmation of glue balls. They're
• 50:03
  Speaker 2: trying to study this f zero, but they don't have
• 50:05
  Speaker 2: enough data yet to confirm whether or not that's real
• 50:08
  Speaker 2: and understand it's decay products. So far, they've been putting
• 50:11
  Speaker 2: out preliminary studies and understanding all sorts of other things.
• 50:14
  Speaker 2: This is a sort of general powerful detector that can
• 50:17
  Speaker 2: study lots of different things about the strong force, because
• 50:20
  Speaker 2: whether glue balls exists is one question, but there's so
• 50:23
  Speaker 2: many other questions about what's going on with the strong force,
• 50:26
  Speaker 2: and this is exploring a lot of them.
• 50:27
  Speaker 1: Would you say then that they're kind of stuck at
• 50:29
  Speaker 1: the moment.
• 50:30
  Speaker 2: I would say it's a sticky question.
• 50:32
  Speaker 1: Yeah, for sure, well, let's see if they do find
• 50:34
  Speaker 1: glue balls. And it's kind of an interesting idea because
• 50:37
  Speaker 1: I think, as you're saying, it's not just about finding
• 50:40
  Speaker 1: the glue ball themselves. It's about understanding how the strong
• 50:44
  Speaker 1: force works, right, Like, it's one of the fundamental forces
• 50:47
  Speaker 1: of nature. It's what keeps our nucleus in our atoms together.
• 50:51
  Speaker 1: But it sounds like we don't really sort of like
• 50:53
  Speaker 1: know everything about it or know exactly how it works,
• 50:56
  Speaker 1: and so finding or not finding a glue ball would
• 50:58
  Speaker 1: sort of tell you a little bit of about what's
• 51:00
  Speaker 1: going on at that level.
• 51:02
  Speaker 2: Yeah, that's exactly right. The same way that understanding the
• 51:05
  Speaker 2: structure of the atom has taught us a lot about electromagnetism.
• 51:08
  Speaker 2: You know, why electrons fill these shells, the hyper fine
• 51:11
  Speaker 2: splitting of electron energy levels has led to a really
• 51:14
  Speaker 2: deep understanding of magnetism and spin and electricity and all
• 51:18
  Speaker 2: this kind of stuff. You know, seeing these forces in action,
• 51:20
  Speaker 2: what kind of complex things they can do or reveals
• 51:23
  Speaker 2: their fundamental nature. So we're trying to do the same
• 51:26
  Speaker 2: thing for the strong force, like see the strong force
• 51:28
  Speaker 2: in action, see what it's capable of, what it can't do,
• 51:32
  Speaker 2: and that'll tell us if we understand what it's doing
• 51:34
  Speaker 2: or not. But in the end, it's much harder than
• 51:37
  Speaker 2: it is for electromagnetism because it's more complex. Instead of
• 51:40
  Speaker 2: one photon, we have eight gluons of all sorts of
• 51:42
  Speaker 2: different colors, sloshing around and banging into each other and
• 51:46
  Speaker 2: confusing each other. It's like having a conversation with eight
• 51:48
  Speaker 2: Toddlers at the same time.
• 51:50
  Speaker 1: Every PhUSE is a stream, but it sounds like it
• 51:53
  Speaker 1: is a prediction of the current standard model, like our
• 51:56
  Speaker 1: current model of the universe does predicted glue balls should exist,
• 52:00
  Speaker 1: and so if you find them, it would be another confirmation,
• 52:03
  Speaker 1: maybe the final confirmation about the standard model. But if
• 52:06
  Speaker 1: you don't find them, and you can conclusively say that
• 52:08
  Speaker 1: they do not exist, then maybe we need to rethink
• 52:11
  Speaker 1: our whole model of the universe.
• 52:12
  Speaker 2: Yeah, that's exactly right. It would be almost as big
• 52:15
  Speaker 2: a deal as discovering the Higgs boson if we did
• 52:19
  Speaker 2: find confirmation of a glue.
• 52:20
  Speaker 1: Ball or not a confirmation about blueball.
• 52:23
  Speaker 2: Yeah, if you could prove that glue balls don't exist,
• 52:26
  Speaker 2: that would also be fascinating.
• 52:27
  Speaker 1: I can just see the headline scientists fine glue balls
• 52:30
  Speaker 1: do not exist.
• 52:33
  Speaker 2: Scientists fail to find glue balls.
• 52:35
  Speaker 1: Again, Scientists get stuck with blue balls. All right, Well,
• 52:38
  Speaker 1: we hope you enjoyed that. Thanks for joining us, see
• 52:41
  Speaker 1: you next time.
• 52:50
  Speaker 2: Thanks for listening, and remember that Daniel and Jorge Explain
• 52:53
  Speaker 2: the Universe is a production of iHeartRadio. For more podcasts
• 52:57
  Speaker 2: from iHeartRadio, visit the iHeartRadio app, Apple Podcasts, or wherever
• 53:01
  Speaker 2: you listen to your favorite shows.