Subtitles section Play video Print subtitles MELISSA FRANKLIN: Hi. You know, they don't usually let me up here. [CHUCKLING] But when they do, there's people sending paper airplanes at me during the Ig Nobel Prize ceremony, which takes place every year, and I'm sure some of you will attend. Hi. I can't see you, but I know you're young. [CHUCKLING] You have some glasses, and those are sort of diffraction grating glasses. You don't have to-- I just want to say, if you get bored with what I'm saying, just start looking up there, because it's really just very, very relaxing. [CHUCKLING] But later, we're going to actually use them for a demo. But to begin with, I just want to tell you, I'm very interested in the vacuum, in measuring the universe with nothing in it. So I guess I should get the clicker. So this stuff-- the apple, all that virus, I'm not interested in that at all. It's stuff. I get that out of my universe. Now, here's an atom. The atom has a nucleus, and it has electrons. And the nucleus is made up of protons and neutrons, which have quarks inside, which I'm sure you know. And I'm interested in the quarks. I really like quarks. But I'd like to have the universe without any atoms in it. Here is my world. So if you think about me, my name is Melissa. You would look at the quarks. All the quarks that exist in the universe that make up all the matter, and all the leptons-- electrons, et cetera, the neutrinos-- and all the forces that hold all those particles together to make matter, and black holes, and stuff. [CHUCKLING] Here's what you would find. And unfortunately, I'm really old, but-- I was not a part of finding the charm quark, the c quark. And I was not a part of finding the bottom quark, but almost. But after 25 years of trying, I was on the team that found the last quark. You can't find one. It's over. [CHUCKLING] There's only six. So I was on that team. And then I was also on the team recently that discovered the Higgs. And I wanted to tell you what I'm interested in, and why we were looking for the Higgs, and what it meant to me. So here is what's called the standard model. Those are all the particles and the forces. And if you're a theorist, and you have soft skin and stuff-- I'm an experimentalist-- you would write this equation down, and you would say, this is the standard model, and this describes the universe. But people like me don't really-- it doesn't fit inside my head. I like reading it aloud. When you go home, you could try reading equations aloud. It's fun with friends. It's very fun. There must be a game. It's not a drinking game. It's more of a just good fun game. So here's the thing. For each of these terms in this equation-- the way experimentalists like to think about it is a diagram. And this is a Feynman diagram. There's a guy called Feynman, and this is his diagram. And a diagram takes one of the terms in that equation and says, let's see what it looks like if we're human. And so here, for instance, time is going along to the right. And what it's showing is matter and antimatter electrons come together, annihilate into light, which then turns into antimatter and matter muons. These are just heavier particles. And we say, oh. Ha. I can write this down. Can I measure it? So that's sort of my life. I can write down every possible diagram like this and try and measure it. Now, for the people interested in archeology, you might want to understand Feynman diagrams, because 1,000 years from now, after everything happens, probably, you'll find diagrams like this, just sort of like hieroglyphs. And you'll probably understand them. Could be sooner than 1,000 years. It could be-- OK. But I'm just saying. I'm just saying. People who are interested in linguistics or stuff like that, just look at that, and don't just not think about it. OK, here is me. When you're in science, you have a lot of thoughts about yourself, who you are. Here's the top quark on my shoe. That's me. But as an experimentalist, I can make me a line drawing, and it has just as much information. So this is the real me on the left, and before children, and the right me. [CHUCKLING] The me that-- it's the spiritual. For those interested in religious studies, this is the spiritual me. So I want to describe the vacuum. I want to describe the world with nothing in it. I take everything out. Is there something there? I'll give you a hint. Yes. But it's kind of an interesting idea. And if you're a literature person, you will see that Samuel Beckett thought about this a lot. Samuel Beckett starts with two people and nothing else-- Waiting for Godot. And then he goes to Murphy, which is just a guy strapped to a chair sitting alone. And then The Unnameable, which is nobody, really. So in literature, we discuss this idea of the vacuum. And the Samuel Beckett, if you haven't read him, then you can start tomorrow. And so if I want to understand the vacuum-- so there's nothing there-- what do I do? So I want to tell you one thing. And if this is the only thing that you remember, it's this. The ground state doesn't talk to us. So what do I mean? The lowest energy state of anything doesn't say anything to us. It doesn't reveal what it is. And I want to do a demo with my friend Daniel Davis to show that. So do we understand the ground state? The lowest energy state is just there, like a lump sitting on a chair. And you can't tell anything about that lump. So to begin with, put on your glasses, and pull down the house lights, and rock and roll. So what we're going to show-- so these glasses are diffraction grating glasses, and they will act like a prism and separate all the colors that are coming out. So right now, what you should see from an incandescent light is a spectrum of the rainbow. Do you guys see it? Look a little to the right or to the left. AUDIENCE: Yes. MELISSA FRANKLIN: Yeah? OK. Now, next to it, we have something which is just hydrogen gas. Hydrogen gas, normally, you can't see anything. Now what do you see? Do you see two lines, or three? AUDIENCE: Three. MELISSA FRANKLIN: OK. So what we're doing is we're exciting the atom because we're putting an electrical current through it. So I'm just saying, I don't want to just look at hydrogen. I want to put electrical current through it. And then I can see its nature. I can see about its structure by looking at those lines. And then if I look at the next one down, I'm going to put an electric current through helium. Isn't it beautiful? Do you see the lines? Is anyone thinking, I don't know what you're talking about? [CHUCKLING] No? So helium is a different atom. So you can see the structure of helium by the light it gives off. And the final one is neon. AUDIENCE: Whoa. MELISSA FRANKLIN: [CHUCKLES] I love this. I love demos. Daniel also loves demos. OK. Thank you. OK. So you're saying, what does that got to do with anything? Not really anything. Doesn't really have anything. [APPLAUSE] OK. It doesn't have anything to do with anything, but here's the thing. I want to understand the vacuum, but I'm going to have to excite it, OK? If I want to understand the structure of the vacuum, I'm going to have to excite it. So there was this guy called-- this is a theorist guy, those are the cute ones-- called Peter Higgs. And he solved this theoretical problem. And in order to solve the problem, he had to introduce something called the Higgs field. So let me just say, this is how we understand the Higgs field. Remember the Lagrangian? Remember that equation? If to that equation of the standard model you add what I'm going to call a Higgs field, and I'll tell you what it is, and you put it through a machine, what you will come out is a Higgs boson, which is a particle. And then all the particles in the universe will have mass, and everybody will be happy. But the problem is, this is what a theorist would draw, but I'm the person who has to build that machine. So that machine takes the Higgs field and puts an electric current through it. So what's a field? Is this too boring? Are we boring? No, we're not boring. OK. So this is a wind map of America. And at every point there, it shows the strength of the wind by how white it is, and the direction. So at every point in the world, you can imagine a field tells you the strength and the direction. So if it's a gravitational field, it should tell you how fast you should fall, and in what direction. So imagine that I have-- so let's go back one step. So this is the wind field. If I want to excite the wind field somehow, I would get something like a tornado. So an excitation of the wind field would be an amazing amount of energy in wind, like a tornado. So what I want to do is I want to take the Higgs field, which I can't see. And the Higgs field has no direction. And it has no size, so you cannot feel it in any way. I want to take that, and I want to make a tornado. And then I want to-- that's my whole life. [CHUCKLING] Actually, it doesn't seem as important as the last speaker. So when-- [CHUCKLING] I was thinking, I shouldn't even come up here, really, because-- but then I thought, OK. OK, Melissa, it's going to be fine. And I knew that my friend Daniel was here. OK. So here's what we want to do. In order to make an excitation of this field-- and I don't even know if it's there-- I just need a whole bunch of energy in a very short amount of time. And so what I do is I take a lot of protons, and I collide them together at very high energies, and I'm putting a huge amount of energy into a tiny little space in a tiny little time. And I use my theory that I learned from going to college-- I did go to college. [CHUCKLING] I didn't get a physics degree, though. I just want you to know that. Although it might say that my CV. [LAUGHTER] What I want to do is I want to take that Feynmann dagger, and I run it right down the diagram that can actually make a Higgs boson by making all this energy in a really small place. And I say, oh, yeah, I can draw this, because the theorists say I can. And then I just have the LHC-- the Large Hadron Collider-- and I just push the button, and this happens. Protons collide. And so what's really happening-- I'm walking around a lot. So what's really happening is that about 100 billion protons hit 100 billion protons every 25 nanoseconds. So nano is small. [CHUCKLING] Yeah, it's really small. Every 25 nanoseconds. So 25 nanoseconds is like the amount of time it takes light to go 25 feet. I do that. Protons are going to collide. The quarks inside the protons are going to collide. I can make my Higgs boson one time out of every 10 to the something or other. 10 to the 10 trillion. 10 trillion. I sound like that guy in the bad, bad movie. Anyway-- [LAUGHTER] If I can do this, and I can do it like for two years, I can probably get enough Higgs bosons that I can say, I excited the field and I actually got a boson out. There must be a field there, right? And so all I have to do is build a 27-kilometer accelerator in Switzerland. And then hire maybe-- I don't know-- 20,000 people. And then I have to build a detector to see what comes out of these proton collisions. And this is the detector. And you'd think those people are really small, but they're French. [CHUCKLING] So you have to-- obviously, French people are the same size. But-- [CHUCKLING] --the point is, when you're working on this detector, you actually sometimes get a little-- you should go to the bathroom first. Anyway, it's very, very tall. It's very tall, so when you're working up at the top, it's a little scary. Anyhow, we built this detector very fast. Sorry. I know that-- and this comes out. All of a sudden, protons, quarks collide. Whole bunch of stuff comes out, and our whole lives for the next five years is just figuring out what happened. What happened? OK. So we waited two years of taking data every 25 nanoseconds. And we weren't allowed to look at the data. And the reason is, if you're going to be studying psychology, then you know that [INAUDIBLE] said that humans are very bad at statistics naturally. So don't trust yourself. So what we do is we blind ourselves. We don't actually-- we don't look at anything. We don't look at the data for two years. And then all of a sudden, one day, we make a plot. And we make a plot of the mass of the Higgs boson, or what we think it might be, and the number of events, and we see something-- the red thing there-- that wouldn't be there if there wasn't the Higgs boson. And we go, wow. This is not exciting. [CHUCKLING] OK. But you're saying, wow, that's not exciting. OK. Let's just talk about this. My team is 3,000 people. It's not my team. I'm not the boss. Otherwise, I wouldn't-- yeah. [LAUGHTER] Yeah. I'd probably-- yeah. My team is 3,000. There's another experiment that's 3000. You gotta check each other. That's about the whole Harvard undergraduate class. Imagine that everybody in the whole class-- like not just 1, 2, 3, 4, all of you-- were all working on the same project. That would be weird. It's a lot of people, so I don't even know who I am, unfortunately. And this is how I feel afterwards. [CHUCKLING] Now I know everywhere in the universe-- everywhere in the universe-- there's a Higgs field that I can't touch. But I know it's there intellectually, so I kind of feel weird as I'm walking. And a lot of my colleagues feel weird also. So I just wanted to tell you two more things. Should I stop? Because I think-- no? It's OK? AUDIENCE: Keep going. MELISSA FRANKLIN: So you're thinking, that's a weird thing to do, Melissa. It's a weird thing to want to do. It's very specific. But I kind of wanted to tell you what the whole project was of physics. So it turns out that Harvard has a thing called the Harvard Lampoon. Has anyone ever heard of it? It's the humor magazine, and various other things. And there was a guy many, many years ago. A guy called O'Donnell. And he decided that he wanted to write down the laws of cartoon physics. I thought that was kind of interesting. He didn't make them up. He just wrote them down. He turned out to end up writing for David Letterman and Saturday Night Live and stuff. But what's interesting to me about his laws of cartoon physics are, what is the overarching idea of physics? If we put all the things we know together, what do we find as an overarching idea? So what is the overarching idea here? Well, the first law is gravity doesn't work until you look down. So I'm going to show you three laws, and then we're going to come up with the answer. As speed increases, objects can be in more than one place at the same time. And an anvil always falls more slowly than any person. You guys have watched TV. [CHUCKLING] A lot of Harvard students haven't, but just pretend you have. So what is the idea here? Why are these funny? And Walt Disney says this. [VIDEO PLAYBACK] [END PLAYBACK] Oh. Walt Disney. [VIDEO PLAYBACK] - Impossible cartoon actions will seem plausible if the viewer feels the action he's watching has some factual basis. For example, the idea that only the cow's tail could ring a bell hanging on her neck may seem far-fetched, but it has some basis in fact. There is an anatomical connection between the bell here and the tail here. That is the spinal column. And so it seems entirely plausible that pulling her tail would ring the bell. [BELL RINGING] [END PLAYBACK] MELISSA FRANKLIN: All right. OK. So this is really interesting. So what Walt Disney says is, it has to be plausible but impossible. And that's what makes it funny. So I was trying to think of physics. Real physics. What do real physics, and particularly particle physics do? And so we're more interested in the possible, I'd have to say, in science. But what we do is incredibly implausible. What I just talked about was me describing to you spacetime, and how we measure what it looks like. But "particle physics is the unbelievable in pursuit of the unimaginable. To pinpoint the smallest fragments of the universe, you have to build the biggest machine in the world. To recreate the first millionths of a second of creation, you have to focus energy on an awesome scale." So we're looking for the implausible possible. And for instance, this summer, five undergraduates are coming to CERN-- which is the place where the Large Hadron Collider is-- to help us figure out the next puzzle. Thanks.
B1 chuckling melissa higgs field field boson franklin Melissa Franklin - Visitas Thinks Big 2019 - Harvard University 2 0 林宜悉 posted on 2020/04/07 More Share Save Report Video vocabulary