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Particle Fever (2013)
- No, I don't know.
- A few people. I was... it was terrible. Tomorrow's will be better. I don't think I can say that. Say it in a public forum. I need... I need evidence. It's big, no? Ever since I entered physics, people have been talking about this machine. The Large Hadron Collider, the biggest machine ever built by human beings, is finally going to turn on. And after many, many years of waiting and theorizing about how matter got created and about what the deep fundamental theory of nature is... all those theories are finally going to be tested, and we're gonna know something. And we don't know what it's gonna be now, but we will know, and it's gonna change everything. And if the LHC sees new particles, we're on the right track. And if it doesn't, not only have we missed something, but we may not ever know how to proceed. We are at a fork in the road, and it's either going to be a golden era... Oh! Or it's going to be quite stark. And I've never heard of a moment like this in history, where an entire field is hinging on a single event. - Hi. - Hi. - I'm David. - I'm Fabiola. Fabiola, nice to meet you. So, look, I have suggested to be on this side because this big wheel is quite spectacular. Yeah, yeah. More than ever, this will require the collaboration between the theory and experimentalists, so it would be a very nice period where we work together and, uh... Well, it's fun to finally interact with experimentalists. I mean, I used to be just in my office, coming up with, you know, crazy ideas. It's a big thing. There is a general sense waiting for this machine to start, this massive machine that has taken so many years to build. We are all in great anticipation of what it might find. And every time there's even a rumor that a new particle is discovered... even before it turns on... the entire field goes into a fever pitch. The experiment was designed initially in the mid '80s and has taken this long to construct. There are 10,000 people of over 100 nationalities. That includes countries which are mortal enemies of each other, like India and Pakistan, and Georgia and Russia, and Iran and Israel. All have physicists working on this machine. These big blue things are 7-ton superconducting magnets, which have to be cooled with liquid helium to the coldest temperatures on Earth, colder than empty space. There are 100,000 computers connected all over the world to deal with the data. In fact, the worldwide web was invented at CERN so that physicists all over the planet could share the data. The United States was building a machine just like this, in fact, a bigger machine, in Texas, but they ran into a small technical difficulty. I doubt anyone believes that the most pressing issues facing the nation include an insufficient understanding of the origins of the universe. Unfortunately, the Superconducting Super Collider was canceled by Congress in 1993. And finally, he's saying, "Well, if we don't do it, the Europeans will do it." Let them do it! We'll steal their technology like they steal our technology. It got very political. It was very expensive, very complicated. It's hard for physicists to explain why we do these kinds of experiments. The purpose of the machine is not military application. It's not commercial application. It's to understand something about the basic laws of physics. There are two kinds of particle physicists: There are the experimentalists. They built the big machines, run the experiments, analyze the data, and try to discover things, like new particles; And then there are the theorists, like me. We construct the theories that try to explain everything we see in nature. Without us, the experimentalists are in the dark, but without them, we'll never know the truth. I mean, if you go, it won't be so terrible. When I was at Stanford, I had a mentor: Savas Dimopoulos. Savas only likes to work on the biggest puzzles. Now, just for fun, I wanted to tell you that the enabling technologies that... He has some of the most famous theories that will be tested at the LHC, but he doesn't know if any of them are true, so there's an intensity with which he approaches physics. If he works on a paper that could result in a Nobel Prize, he doesn't allow more than three people on the paper, because you can only share the Nobel Prize with three people. That's the level at which he's operating and the impact he's trying to have. Takes us beyond the confines of atomic physics. In particle physics, you have to have a threshold amount of intelligence, whatever that means. But the thing that differentiates scientists is purely an artistic ability to discern what is a good idea, what is a beautiful idea, what is worth spending time on, and, most importantly, what is a problem that is sufficiently interesting, yet sufficiently difficult that it hasn't yet been solved, but the time for solving it has come now? So people have been waiting for this experiment, the LHC, for a very long time. Nothing like it has ever happened. All the superlatives are justified. This is the case where the hype is... the hype is approximately accurate. To get, you know, 3,000 people to work on an experiment together, whose goal is to understand what's going on at distances a thousand times smaller than the proton... this is... this is a really extraordinary testament to what... to some of the highest ideals we can have as human beings. It's... Nima and I got our PhDs around the same time. He's a couple years ahead of me. And Nima is the star of our generation, and he's the guy we all followed and looked up to and tried to keep up with and tried to outpace if we could. Since the mid '70s, we've had an amazingly successful theory of nature that we call the Standard Model of particle physics. But sitting in the heart of the theory is a sickness, very, very glaring conceptual problems that infected this fantastic understanding. Why is the universe big? Why is gravity so much weaker than all the other forces? The kinds of answers that this theory gives to these questions seems so patently absurd that we think that we're missing something very, very big. And on top of all of that, there is one prediction of this theory... absolutely crucial for it to even make internal theoretical sense... and this is the famous Higgs particle. The Higgs, or something like it, must show up. If it doesn't show up, there's something truly, deeply wrong, very, very, deeply wrong with the way we think about physics. There are strong reasons to think that some of these questions will find answers at the LHC. There's been no shortage of ideas for what they might be, but this is really this generation of people's... my generation of people's... only shot. Ah, so the boss comes. I first came to CERN in 1987. I was a very young undergraduate student, and I remember the first time I entered the site. I was a bit scared by the corridors in the CERN main site, so I was almost lost in those corridors. For me, it has been a wonderful experience, because I had the chance of being involved right from the beginning and to see, really, an experiment from starting and... from zero, essentially. I've seen two inventors place out of the ten, and we probably have seen... I don't think I can describe right now the excitement about first beam. I mean, the entire control room is like a group of six-year-olds whose birthday is next week, you know, and there's going to be cake, and there's going to be presents, and all their friends are going to be there, and they just, you know... they just know it's going to be great. You know, they're kind of scattered, and I can't imagine, 'cause they're not that big, right? I've been a postdoc here for a year, so I'm a relative newcomer. But my timing is sort of perfect. I mean, to be on the ground floor when the data first comes... it's awesome. That means I have 5,000 emails. There's a huge difference between theorists and experimentalists. I mean, when I started college, I absolutely did not want to do physics. Physics meant to me everything that was boring: Textbooks, theories, proofs. But then I discovered the experimental side, and the experimental side is the hands-on aspect. It's about taking a theory, which is abstract, and making it real. How do you build an experiment to discover something that the theory predicts? And that aspect is what I love. Of course, when constructing the whole thing, we several times thought, "What if the whole thing just does not work?" I really believe now this will work, but the next thing is, will we ever find something? So maybe we will just find nothing new. It would be a catastrophe for physics. We would, somehow... none of the open questions which we have at the moment would've been answered. So the LHC is basically the most fundamental of experiments. It's like what any child would design as an experiment. You take two things, and you smash them together. And you get a lot of stuff that comes out of that collision, and you try to understand that stuff. Now, in this case, what we're smashing together is tiny protons, which are inside the center of every atom. And in order to get them going as fast as possible, we have to build this huge 17-mile ring, and we run those protons around the ring multiple times to build up speed, almost to the speed of light, and then we collide two beams going in opposite directions at four points, and at those four points are four different experiments: ATLAS, LHCb, CMS, and ALICE. Now, I work on the ATLAS experiment. And ATLAS is like a huge seven-story camera that takes a snapshot of every single collision, and that's billions of collisions. And the hope is that we'll see the very famous Higgs particle. But every time we've turned on the new accelerator at a higher energy, we've always been surprised. So the real hope is that we'll see the Higgs, but that there's also something amazingly new. You can liken it to when we put a man on the moon. It's that level of collaborative effort. I would say, even bigger than that. This is closer to something like human beings building the Pyramids. Why did they do it? Why are we doing it? We actually have two answers. One answer is what we tell people, and the other answer is the truth. I'll tell you both. And there's nothing incorrect about the first answer. It's just... it doesn't... it's not the thing that drives us. It's not how we think about it, but it's something you can say quickly, and the person you're talking to won't, you know, get diverted or pass out or pick up the SkyMall catalog if you happen to be next to them on an airplane. Answer number one: We are reproducing the physics, the conditions, just after the big bang. We're doing it in this collider, and we're reproducing that so we can see what it was like when the universe just started. This is what we tell people. Okay, answer two: We are trying to understand the basic laws of nature. It sounds slightly more mild, but this is really where we are and what we're trying to do. We study particles, because just after the big bang, all there was was particles, and they carried the information about how our universe started and how it got to be the way it is and its future. At the beginning of the 1900s, it became clear that all known matter, everything that we know about, is made of atoms, and that atoms are made of just three particles: The electron, the proton, and the neutron. In the '30s, other particles were discovered, and by the 1960s, there were hundreds of new particles, with a new particle discovered every week. And there was mass confusion, until a number of theorists realized that there was a simple mathematical structure that explained all of this, that most of these particles were made of the same three little bits we call quarks, and that there are only a handful of truly fundamental particles, which all fit together in a nice, neat pattern. And there was born the Standard Model. Eventually, all the particles in the theory were discovered, except one: The Higgs. And the Higgs is unlike any other particle. It's the linchpin of the Standard Model. Its theory was written down in the 1960s by Peter Higgs and a number of other theorists. We believe it is the crucial piece responsible for holding matter together. It is connected to a field which fills all of space and which gives particles, like the electron, mass and allowed them to get caught in atoms and thus is responsible for the creation of atoms, molecules, planets, and people. Without the Higgs, life as we know it wouldn't exist. But to prove that it's true, we have to smash particles together at high enough energy to disturb the field and create a Higgs particle. If the Higgs exists, the LHC is the machine that will discover it. Let's assume you're successful and everything comes out okay. - Sure. - What do we gain from it? What's the economic return? How do you justify all this? By the way, I am an economist. I don't hold it against you. The question by an economist was, "What is the financial gain of running an experiment like this and the discoveries that we will make in this experiment?" And it's a very, very simple answer. I have no idea. We have no idea. When radio waves were discovered, they weren't called radio waves, because there were no radios. They were discovered as some sort of radiation. Basic science for big breakthroughs needs to occur at a level where you're not asking, "What is the economic gain?" You're asking, "What do we not know, and where can we make progress?" So what is the LHC good for? Could be nothing other than just understanding everything. The first time I ever saw ATLAS was in 2005. I had come out just to see what ATLAS would look like because there was a possibility that I could be working on it as a postdoc. I can remember walking in and just being like... You know, just stunned. I mean, me, stunned, you know, just, you know, already kind of having an idea of the magnitude. People tell you, "Oh, it's five stories tall." And you go, "Oh, okay, five stories tall." And then you see. Five stories completely filled with microelectronics... All custom designed, all hand-soldered. You know, it's like as if it's a five-story Swiss watch. There was this issue about the BCIDs. We had our extended barrel out earlier, but it should be back in, and we should be... everything running normal. Okay, so one more announcement. We have to be extremely careful what we do to the system. I mean, we know that anybody who's even updating a number somewhere might stop our system for more than an hour quite easily. So please be absolutely sure that you yourself and everybody in your system is not touching the system, unless it's been agreed by the shift leader, yeah? Nothing should be touched, yeah? And that includes all things that you're absolutely dead certain they will not do anything wrong. Especially those things. It's being called the largest scientific experiment in history, and some say one that could cause Armageddon. It's the strangest experiment ever: Mankind's most ambitious attempt to understand how we all got here. Thousands of scientists from around the world spent 20 years designing an extraordinary machine. It cost 5 billion and will switching on very soon. This is a genesis machine, a window on creation. Five months of testing on... They're looking for something called the God Particle, but skeptics are saying nobody knows what will happen when they turn on the switch. A group of French scientists believe the collider might create a black hole that could swallow up the earth, and they filed suit to stop the project from going forward. Hello? No, absolutely not. Well, no, there is no scientific ground to what they say. It's not possible that the LHC is going to destroy the world. It's absolutely ridiculous. Okay, it is 9:15. We are 15 minutes away from beam. We've been sitting here, about 7:00, and absolutely nobody brought food. Again, 15 minutes to beam. - Ciao, ciao. - Stress levels are high. Ciao. But since I'm in a room full of Italians, the stress level's pretty cool here. But we have no coffee either. No coffee. Who didn't bring coffee? What we're going to see today is the launch of the first beam of protons around this enormous ring. Very shortly, Lyn Evans, the project director, is going to be addressing CERN staff, who are gathered at different points around this massive complex. It's just the first glimpse at the fact the machine can run. I mean, so what you need, really, is, you need two beams colliding together for quite a few... quite a long period of time before you calculate, get enough... sufficient statistics in which to actually be able to look for the new physics. But single beam, the first beam, isn't even that. You're not even getting any collisions. It's just one beam going around in a circle, not even at the high energies. Just one beam going around in the low energy circle, that sort of says, "Okay, we made it around the ring once for the first time." And it's a huge event. Right, after 19 years, you've been waiting for this first step. Let's get started, everybody. Now comes the day of reckoning. Five, four, three, two, one... Now. No beam. Yeah. So where are we with the injection kicker? Oh, well... they're out. Okay, never mind. Let's go. Five, four, three, two, one, zero. We get a beam on this pulse? I hope so. Yes! Well, last night I was, like, waking up constantly. Like, "Did we set that right? What about... did we disable... oh, my gosh!" Marzio. I have a plot for you. Okay, check this out. This is Z. This is timing, in nanoseconds, which we knew from the cosmic data. - That is very nice. - Yes. Upstairs, I think people were more excited about this. If you're in Google, that means... that's the world. This is the most important thing today. This is the first, and this tells us a lot of things. It tells us that the magnetic properties of the machine are good, that the aperture is clear. There's nothing is sticking into the beam pipe anywhere. So a very, very encouraging sign and remarkable progress. Did you guys see our beautiful plot? - What? - Okay, I want to show you this. Come on, show them the plot. You can take a picture of... here you go. Well, see if you can get it. I don't think there's anyone else I can show my plot to, so... It worked. It just worked. And there are so few times in life where it just works. And there are so even fewer times in life where it just works great. We rocked. I mean, Tile, first beam... We destroyed that shit. They got a beam circulating. They've had beams circulating for a full 30 seconds. So let me understand. This is one beam going one way? They have one beam going one way, and then they went to the other beam going the other way. Well, does it work? The second beam, did it go fully around? - Everything... - they both went around. I think they had the beam go around about a million times. Something like that. Yeah, their Twitter feed said 10 million. Now we'll become, you know, CERN Twitter junkies. I guess this is exciting. My logical self wants to be excited. My psychological self is very cautious. My parents are both Iranian and both physicists, and my father in particular had real political difficulties with the regime, and we had to go underground for a number of years, and we ended up escaping from Iran through the border of Turkey. But then, through a number of wonderful accidents, we ended up in Canada. I got interested in physics when I was 13 or 14 years old. It just offered the way to combine the two things I really loved: Mathematics and things in the natural world. You almost done? Yeah. - It's just saying "What if?" - It's, uh... yeah. You're preparing a broader audience for this. Okay, now I'm going to just do something fun. Just do something fun. What would be fun? No, don't write "hell." It's a public... All right, I'm sorry! - How about that? - There we go. Thinking about the LHC has been the center of my intellectual life for about 15, 16 years now. Depending on what happens with the LHC, you know, these are 15 years I could come to see as the best possible thing I could've been doing with this time, or it could just be that the entire 15 years might as well have not happened, had no impact, and then that's just 15 years that are gone. It's not the sort of thing where there's a consolation prize. You know, it's a fairly binary situation. I definitely won't feel, "Oh, well, "I gave it a good old college try. "It's all fine anyway. It's just trying that counts." I don't believe that. I don't believe it's just trying that counts. I believe getting it right is what counts. Okay, please take your seats. Now it's time for the entertainment part. So as with every great physics event, we're going to start with a big bang, the ATLAS big bang event, and that's going to follow with music all evening, people from ATLAS, who are going to be performing for you. So let's get started. Take 2,000 intelligent, ambitious, type "A" personalities. You make them work 16-hour days, high-pressure situation, lots of stress. You know, that's the recipe for disaster. Or at least it's a recipe for a reality television program. But all that physics, Higgs, extra dimensions, supersymmetry, microscopic black holes, macroscopic black holes, Z-primes, you name it, the physics that the theorists only dream of is ours to discover. Thank you. Oh, yeah Thanks to the Large Hadron Collider Thank you, ATLAS! I grew up in Turkey from Greek parents and a middle-class family, and then, in the '60s, we became refugees. We had to leave Turkey because of ethnic tensions between Greeks and Turks over the island of Cyprus, and there were a lot of political cross currents, left, right, and I was a young, impressionable 13-year-old hearing the pro-left and pro-right arguments, so one day I would be convinced that one side was right. The other day, I would be convinced the other side was right. And then I was getting confused. How could both of these things be true if they were contrary to each other? So I decided to focus on a field where the truth didn't depend on the eloquence of the speaker. The truth was absolute. Of course, when I started out, I thought that within maybe five years the theories that I was working on were going to be tested and I was going to know the experimental truth and move on to the next round of ideas after that. Little did I know that the experiments would take far longer, and here I am, 30 years after, still not knowing the truth. Peter? I can show you here a nice event. Did you see this from... - Ah, no. - Andreas showed me this. - I haven't seen it. - This is from yesterday night. This is now a real beam gas event. So you see the tracks also bent... - Bent by the field? - Very nice. Ah, no, I haven't seen... In some sense, I started form the wrong perspective and in the wrong way, because I'd been studying a lot of literature when I was at high school level. So literature, art, philosophy, history, and very little physics and mathematics. I'd also been studying music, piano, and so I was very much attracted by art. There are many similarities between music and physics. Classical music follows rules of harmony, which are really rules of physics and mathematics. But, also, I was fascinated by big questions. That is the possibility of addressing and answering big questions about nature, the universe, why, when, how, and when I finished high school, I thought that physics allow us to address this big question in a more practical way than, for instance, philosophy. That's why I decided to study physics. Yes, we lost these two there... I managed to go through, like, the four gallons of milk that I had in the fridge, but... We were just waiting for collisions, waiting for collisions. And finally, then this helium leak, which really, uh... it's really frustrating. We cannot even go there and investigate what happened. You have to warm up the magnets, and warming up the magnets needs to be done on a very slow pace and... in order not to break them... then you can investigate and cool them down again. The world's largest atom smasher, the Large Hadron Collider, is to be shut down for at least two months. CERN, the European Organization for Nuclear Research... Scientists at CERN are trying to put on a brave face. A faulty electrical connection between two magnets led to a ton of liquid helium being leaked into the 27-kilometer tunnel. The first high-speed particle collisions were due to take place later this month. The goal now is simply to get this vastly complex machine working. Fucking hell, look at that. This is just unbelievable. You've got magnets just sheared off their jacks. We've actually put in enough energy to melt it and to vaporize a whole tube of... And the stuff's all covered in a sort of black, metallic dust. Completely catastrophic, eh? Completely catastrophic. There's no more vacuum in the beam vacuum, so can as well open it up and see whether there's any dust, because if there's dust, it means we have to clean all the way until it's... I hope, in the worst case, we have not to take out more than 20 or so magnets. Both my family and my students detect a definite level of... let's say pessimism and disappointment. The built expectation that now we were going to know the truth, it fizzled and delayed, and it's just, uh... I thought I was stronger than this. It surprised me. I did say that I thought it was a mistake for CERN to have this gigantic celebration for things just when it just had a few protons wandering around in one direction around the ring, that it was just a bad idea to have so much hoopla before anything was actually happening. At the time when people were asking me if I was going to CERN to celebrate, I said, "I'm going to go to CERN "when there's a reason to celebrate, you know, "when things are colliding into each other, "when something is starting to happen, not for some crappy PR reason." And that backfired. That, I think... really, that really backfired, and I think that was a PR disaster. It was a PR disaster largely of CERN's own making. You don't go around, you know, having gigantic parties before anything has happened. So the magnets that have come out are being refurbished, and so they're sort of trundling through about six magnets a week now. So that's no longer the bottleneck. Now they're kind of getting to the state where they're ready to start redoing the interconnects in the tunnel, and they're already about a week or two behind on that. Given the complexity... The other thing is that they're drilling these bloody holes in the magnets. - Because they, like... - what I heard this last time, they were saying that all their tools are breaking and that sort of business. But it begs the question, of course, you know, what are the risks? I mean, you kind of basically, you're going... I don't know. We didn't actually think so much about the collateral effects of the helium. - Nobody has. - Yeah, nobody. - Yeah. - Nobody. Well, there's been a lot of investigations into the cause of the original problem, and the general agreement is that we run at half design energy. Experimentalists aren't going to be happy. Well... So, yeah... so the latest schedule is this: We just put out is D-Day, beams back on the 21st of September. Isn't that a bit optimistic? Isn't that a bit optimistic for, uh, this year? When you're dealing with something that is a long-term project... and the LHC is a long-term project. It's a 20-year project. You can't think about the end. Ever. If you start out a marathon thinking, "I can't wait to get to the finish line; "I'm gonna have my Gatorade at the finish line; I'm gonna have my greasy french fries at the finish line," or whatever motivates you... if you start thinking that at mile one and it's, like, ten minutes into the race, and you're thinking to yourself, "Wow, I'm only at mile one. I've got 25.2 miles to go." And if you're thinking that at the start, then you're done. Mentally, you are done. This is what doing discovery physics means. This is what doing discovery means. Why do people have curiosity? Why do we care about how distant parts of the universe, things that happened billion years ago, like the big bang, why do we find them that interesting? It doesn't affect what we do day-to-day. But nevertheless, once you have curiosity, you can't control it. It'll ask questions about the universe. It will ask questions about harmonic patterns that create art, music. - That's a sculpture? - That's a sculpture. Yeah, doesn't it look like a bunch of broken tiles? That's what it's supposed to look like. And it's, uh... and when I saw it, I thought it was just rubble left over from the construction. Right, yeah. You can, in principle, move it. So people go up and move pieces? - No, people don't. - But people could. Why would they have it so you can move it around if you weren't going to move it around? No, I think you're right. I think you're allowed to move it around. It's certainly a different experience of it. I agree. See, I thought that that belonged here. It's just... it's the perfect spot. It certainly changes everything. - It does. - Slate and granite. I guess that's the granite, and that's the slate. Hmm. It's interesting. There's something philosophically about this piece of art that bothers me. It's taking a lot of sort of random things and making some order out of it. Yes. It's trying to make order out of something where there isn't any, instead of taking things that don't seem ordered and figuring out that there is order. The way we try to reduce the complexity of the world is by looking for patterns, what we call symmetries. We take all the particles we know today, and we attempt to fit them into some kind of underlying structure. Are they the remnants of some more beautiful and complete picture of the laws of nature? It's like, you go to Egypt, and you see ruins. If you look at it the right way, I could draw a pyramid and see that these chunks of stone are actually the remains of something very clean and very symmetric, very beautiful. We know that the Standard Model is incomplete. We know that there's other stuff out there, that there are other particles that we haven't seen yet. Dark matter is a speculated particle which we think actually dominates the universe, and yet we've never seen it directly, and it's not part of the Standard Model. That's one of those rocks. We think, possibly, that that and many other particles are still out there and are all part of a much bigger symmetry, a much bigger theory that includes the Standard Model, but much more. The most popular theory is called supersymmetry, or SUSY for short. Supersymmetry was a theory that sort of started to develop in the late '70s. Savas was one of the first authors of the first theories of supersymmetry. It is the unfathomable depths of... Supersymmetry is our best guess of what else is out there, the bigger theory that incorporates our current theories, the Standard Model. But for it to be true, we have to discover those other particles. If I could choose a dream of any theory that the LHC could find, actually, I would love for them to see supersymmetry. Supersymmetry says, for every type of particle, say the electron, there's a heavy superpartner. So you have the... and they have really stupid names, unfortunately, called the selectron. You just add an S to the name. The squark. Uh, the sup, the sdown. Supersymmetry, or SUSY, is extremely important for the theoretical community because it solves many mathematical problems with the Standard model. Now, experimentally, it would be the experimentalists' dream. You know, tons of particles that are just coming out, and you just don't even know what to do with... you know, can't even write the data fast enough in order to discover them. So that'd be my dream. It used to be that in the control room life, it was kind of a luxury. You know, you could kind of... you could, you know, kind of style your hair for the day because you didn't have to wear a hard helmet all day. You could wear nice shoes, you know, because you were in the control room environment. Now, it's all back to, you know, bring the dirtiest clothes that you own to work because you're gonna be crawling around in, like, you know, hard helmets, steel-toed boots. Not the most attractive shoes, but, you know, I kind of like them. We're pulling out the electronics. We're fixing things that we didn't actually have time to get to during the last shutdown. The goal of this is that it would be in even better shape for next beam. Okay, so that is, I think, all that I have to say. Hope the theorists aren't driving you crazy. Don't listen to them, by the way, because theorists, they can sometimes... Just telling you. You got to come back to the experimental world so that you can touch bases with reality. All right, I'll talk to you soon. One of the most basic facts about the universe is that it's big. So you might wonder, "Why is the universe big?" There's actually a single number, called the cosmological constant, that plays a crucial role in determining what the universe looks like. In fact, around ten years ago, astronomers discovered a really remarkable fact: The universe is getting bigger and bigger at a faster and faster rate. But this rate is a million, billion, billion, billion, billion, billion, billion times slower than what we'd actually predict. When you're off by a factor of a million, billion, billion, billion, billion, billion, billion, there's something very wrong with your understanding of basic physics. Even worse, this one number, the cosmological constant, needs to have this extremely precise value. And if the value is different even by a tiny bit, we would radically change what the world looks like around us. If you saw a situation where, if the parameter has a very dangerous value and you change it a little bit, the world would change radically, and we'd be dead. We couldn't possibly live. You would wonder where that came from. You know, how is that possible? So just on the face of it, you would look at the situation and say, "Wow, someone really cared to put this parameter "at just the right value so that we get to be here "and that it's a pleasant universe and really cares a lot." This is the sort of thing that really keeps you up at night. It really makes you wonder, "Maybe we've got something "about the whole picture, the big picture, totally, totally, totally wrong." Before I went to elementary school, my mother started telling me biblical stories. She told me that if we are good, we'll go to paradise, and we will stay there forever. And when she said "forever," I started panicking. I kept asking, "Forever?" "Forever?" You mean, it never ends? Like, you wake up, and you know that then, you go back to sleep, and this never ends, never ends, never ends. I started crying. She told me, "What's wrong with you? "This is paradise. "It will be a lot of fun. You'll be very happy there." But this idea of eternity, something infinite, scared me. There is a scientific alternative to believing there's someone out there who loves us, twiddling the dials very finely for things to work out. And this alternative, said briefly, is that everything we see in our observed universe is actually a very small part of a much, much vaster multiverse. You might literally imagine that, from some bird's eye point of view, if you went to enormous distances, you would see that our universe is actually a little pocket inside a vastly bigger space. In this picture, these mysterious numbers, like the cosmological constant, are actually basically random. And out there in the multiverse, next to us somewhere, is another region where these numbers take on some other random value, and then another region where they take on some other random value still. Only in a tiny sliver, a minuscule part of this gigantic multiverse, for completely accidental reasons, do these numbers take on the very, very special values which allows structures to grow, stars to form, galaxies to form. Ultimately, things like us to form. This is the really opposite extreme interpretation of the presence of fine-tuning as intelligent designers would want to give. If you believe that someone out there cares and twiddles the parameters so that you can exist, that puts our existence at the very core of reality. If you believe that our entire universe is a tiny, little, minuscule spec in a gigantic multiverse which is mostly lethal, that's a polar opposite philosophy for what the universe looks like. In fact, it's an idea that many physicists loathe, because certain questions then become things that we will not hope to be able to understand. Nima is now an advocate for this idea that the laws of physics are different in different parts of this multiverse, that what we measure in experiments are not deep mysteries of nature, but they're just random accidents in our universe, that maybe even the Higgs itself is a random accident that has occurred in our universe and let's life exist, but has no explanation. In a sense, it's the end of physics. On the one hand, we have the direction that we've been on for the last 400 years, towards increasing beauty, simplicity, symmetry, and a path that has time and time again paid off with deeper and deeper insights about the way the world works. On the other hand, we have the idea of the multiverse, which would move us to a real picture not of symmetry and beauty and order, but fundamentally of chaos on enormous distances. This is the really very, very big-scale question which the LHC is going to push us in one way or the other. What happens, for example, if... Oh, blimey. Yeah, there's a lot of... Hi, Katja. You all right? Oh, you're not recording this, huh? Yes, we're all on the... Yeah, don't worry about all the other crap. We've got the beams going around again. The magnet repairs are holding up well, and our next challenge is to take these beams up to high energy and collide them. Okay. We're very, very aware of the damage we can do. Here we go. That's what worries me stiff at the moment. The original proposal for ATLAS was in 1989. And you're kind of riding this idea. You've got this dream of physics. This dream of physics is what pulled everyone along for those 19 years. And so here, now, today, finally, with high-energy collisions, we can start to look for that dream of new physics. Uh, blue. The control room, yes. The control room. This is the control room. The pressure of it being an event, of course, is there. And, of course, anything can go wrong, and it has. Last weekend was a complete disaster. We were discussing the possibility that we do collisions during the night rather than the plan, 9:00 in the morning. Of course, this has caused major, sort of knock-ons for, one, the experiments, and two, for the media service. Good morning, everybody. I propose we start. I will take you briefly over the whole summary of the weekend, just to get you up to date what happened. During the night, we tried to set up again for high intensities, for 450 GeV collisions, but then we were cut short because we encountered a vacuum. What everybody wants, from a physics point of view and from being sure, is doing it secretly before and showing it to the media during the day. And I think this was also the wish of Fabiola. It's the wish of everybody, because this is, of course, then you're much more certain. But this does not work nowadays. Media wants to see this little risk. I understand. So that means we have to adapt to that. Let's see. This... this is not it. It doesn't seem like... You got to hit the reload. I'm reloading it. Yeah, I wonder if we should stop. Everyone is reloading it. Maybe we should stop. There you go. - Hey! - All right. Okay, now. And, indeed, welcome to CERN, the European Organization for Nuclear Research, in Geneva. Welcome to the CERN control center. And here on the screen we can see the four different experiments: ATLAS, CMS, LHCb, and ALICE. And the program for today is to first send one beam in one direction, a second beam in the opposite direction. They will circulate in parallel for a while, and when everything is ready and under control, the separation is going to be removed, and the beams are going to be made to collide in the four points around the LHC machine. I just think to myself, if you imagine, like, Thomas Edison, like, inventing the lightbulb... if he had tried to invent the lightbulb with, like, a hundred camera crews in his workshop, and they would've been like, "Oh, my God, "you can't even turn it on? "Come on! Turn it on now! "Come... ugh, we're still waiting? Come on. Ah, come on. What's wrong with this guy?" So the violet... there's always one vertical, horizontal beam. One beam. Shh! Please. So a few minutes. Okay, thank you. Thank you, bye. Wow. Everybody hear? Few minutes away. So we should watch that one, our trigger rate, this one, the separation bumps, and the event displays. Okay, these are the three screens to watch. If you have three eyes, one there, one here, and one over there. So, okay, both beams are at 3.5 TeV, and we've just collapsed the separation bumps and brought the beams into collision inside the four experiments. - Starting. - They're starting. They're starting. - Oh. - Ooh. Okay, they're starting. Two beams, one in blue, one in red, each circulating in opposite directions. They have to get closer and closer. When the numbers on the four readers say zero, it means that the beams are finally aligned. This is the historical moment we were all expecting. It can be anytime now. Wow! Wow! Fantastic! Beautiful. - Wow. - We are ready. First things first. I just have to say: "data." It's... it's unbelievable how fantastic data is. You have this invariant mass. This is for the Z to mu-mu channel. And you have this mass peak of the Z, in order to estimate your backgrounds. It's like the world at ATLAS and LHC and CMS and all those places has suddenly changed. I mean, it's like, all of a sudden, there's data. And after so many years of not having data and new data, new physics, there's just so much possibility, and even though you're rediscovering the Standard Model, that is more exciting. But the most exciting thing about the data is not the first collision. Because the first collision, okay, great. First collision, everyone loves the first. But the most exciting thing about the data is the, you know, 1 millionth collision or the 2 millionth collision or the fact that collisions just keep coming and coming and coming and coming, and the more and more collisions we have, the more and more chance we have to look at the interesting physics, because it just means more and more and more data for us. The running is pretty good. But right now, it's running amazingly. Yeah, right now, but the day of reckoning is in several months. We heard rumors on that. Well, we should be hearing rumors now. We really should be hearing rumors now. I'm a little worried, actually. Yeah. - Well, we're hearing murmurs. - What, what's... Murmurs. We're hearing murmurs. There either... there isn't much there, or they're doing a very good job keeping a poker face. Or they're still at the point where half of... where they're still trying to figure out what's a murmur and what's a rumor, internally. And I think that's probably actually true. Right. The problem is that, also, I take completely innocent remarks and vastly over-interpret them. Obviously, we're going to learn about the first discovery on Twitter and Facebook. That's so sad, but I think it's true. It is. You mean, I shouldn't check the arXiv first thing in the morning... I need to check my Facebook? - The arXiv is the last thing. - The arXiv is the last... First, like, check Nima's Twitter feed. Then check the arXiv. If Nima has a Twitter feed, then there's something has been discovered. It is August 7, 2011, and, this is a significant time for the LHC. The first big set of data was presented at the end of July. The data has little extra bits in it which could be interpreted as a Higgs. Even though the LHC is running at half power, it actually has gotten data much, much faster than anybody expected. And that allowed them to be sensitive to the Higgs boson. It's fucking cool right now. There was huge excitement because the Higgs' results of the two main detectors, CMS and ATLAS, were first shown, together, in the same meeting. For me, as Run Coordinator, I discussed every little problem where we lost here a little bit of data and there a little bit of data, so somehow I really feel attached to this data set. So somehow it makes me proud if the Higgs is found or not with this data set. The three, two, ones, so the effect... The mass of the Higgs, namely the weight of the Higgs, can actually tell us or give us a hint about what comes next. If the mass is on the lighter side, then that's consistent with some of the standard things we've been looking for. Supersymmetry generally favors that the Higgs is as light as possible. About 115 times the mass of the proton. It's 115 GeV: Giga electron volts. If, on the other hand, the Higgs is 140 GeV, 140 times the mass of the proton, it's a terrible mass, because 140 GeV is associated with theories that rely on the multiverse. ATLAS has a little bump here, a small excess visible near 140. And now, holy crap. It's 140! It's starting to look like nature has made its choice. What do we learn if the LHC does discover a Higgs at 140 and nothing else? Chaos. Okay? The problem with the multiverse is that it says the Higgs might be the last particle we ever see. - So what we should do... - I think the Higgs mass issue... If we don't see any new particles besides the Higgs, we don't get any explanation for dark matter. We don't know how the Higgs itself got a mass. We never get access to the deeper theory. All that information could be in the other universes. We may be at the end of the road. That's it. I guess, um... Well, if it's right at that number, then it would be so fucking astounding. Where the F is SUSY, right? I mean, there's nothing. I mean, where's all the other stuff? Where are the other particles? What happened to dark matter? I mean... I've heard of many theories saying that new particles might be at even higher energies, so... Right. Who knows? I mean, it always comes differently. Who knows if there are other interesting things. You know, somehow it always comes differently than you expect. I know that the theorists are all up in arms, because, you know, it could be a heavy Higgs, but, you know, I've always said, like, the worst-case scenario, I think, would be Higgs and Higgs only. - Who knows? - I know. I know. Come on, it's just a little excess. If this doesn't show up by the end of next year, then we can change subject, I think. If you don't see any supersymmetric signal... Well, but if it's 140, that would be serious. Yeah, yeah. Yeah. Don't tell me. This is my nightmare. It's only 30 for me. At the moment, it's scary. - At the moment, it's scary. - It's scary. Yes, then we have to wait another couple of years for the next round. No, another two years, I'm saying... But still, it doesn't matter. You'll be working harder. No, but independent of that, I think you'll know the truth. Yes, yes, no. And that's the important thing. No, you're right. Yes, of course. Coffee is a very serious business in the life of a theorist. It's not like physics research, where you can wait for 30 years before you know if you are right. Within a few minutes, it pays off. If you succeed, it's great. If you fail, you get to try another one in another minute. In particle physics, you construct a theory 20 years ago, and it may take that long before you know if you're on the right track. Jumping from failure to failure with undiminished enthusiasm is the big secret to success. Well, the hint that the Higgs was 140 GeV has disappeared. All of the new data that just came in didn't make the peak bigger. It sort of filled in the gaps. And now the peak doesn't look very good. In fact, the belief is that it's gone away and that the Higgs can't be 140 GeV. In order for us to believe that we've discovered it, that peak needs to be big and basically keep growing as the data comes in. It's a statistical thing. We call it the Greek letter "sigma." If you reach a height of 5 sigma, that's when you know that you've seen something. And the probability that that just happens by accident is 1 in 31/2 million. But the Higgs, it's not at 140, which is a bit of a relief, because there's still hope it might be down around 115. We like 115, because if the Higgs is that light, the theory says there has to be new particles, like supersymmetry, otherwise the universe is unstable. It wouldn't have survived this long. This is one of the one of the few truly perfect academic institutions in the world. I mean, there's no excuse... no excuse at all... not to think and work and get things done. That's its only problem. There's no excuse at all not to think and work and get things done. You can't blame it on anything if it doesn't work. Okay, supersymmetry versus multiverse. Oh, boy. All right. That's, uh... If we're going to start doing that, this is going to be interesting. We have been anticipating that whatever happens is going to throw the field in one direction or another. Oh, shit! Now that we're really on the doorstep of actually knowing the actual number, I really care intensely about what that number is. Well, faster than we thought, there's news that there's going to be another announcement about the Higgs. I've heard tons of rumors, and I've heard they're things on blogs, and there's already stuff in the newspaper. 18 hours or so until the announcement, so I'm really looking forward to what they're going to say, and I want to be there. Actually, I'm thinking of going early in the morning, or I'll send my young colleagues, who have more stamina to sit and occupy a chair for me. It is July 3rd... the night of July 3, 2012, and I am driving to Princeton, to the Institute, to hang out with Nima and a big crowd, who are all staying up until 3:00 in the morning because they're going to present the Higgs data at CERN at 9:00 in the morning Geneva time. Certainly the biggest thing that's happened... the discovery of new fundamental particles... in my lifetime. And the Higgs is a particle like no other, like nothing we've ever seen before, and it is weird, and we do not understand it, but... but, uh... and I missed my exit. Cinq, six, sept, huit, neuf. You need quite some skills to sit on it. - It's possible. - Okay. You know, there's one ball missing. Oh, it's, uh... exactly. No, there's one ball missing, so it's... you always think you fall down. Okay. Look at some of these people, like, totally asleep. Yeah, no, those are the sleeping bags. My volume is up. I don't know why I'm not getting sound. There isn't like, a thing on here with sound, is there? Who reads lips here? Can anyone see if they get sound? Try streaming it in their offices or something? Many apologies, guys. I don't know what's going on. - Ah, Peter Higgs. - Ah, there he is. - Here he is. - Very good. Someone with an iPad. Not as well seated as my summer student. - No! - Right. Peter Higgs doesn't even get a good seat. Good morning, everybody here in Geneva. Today is a special day: We hear two presentations from the two experiments. ATLAS and CMS. We are starting in a non-alphabetical order, and I ask Joe Incandela from CMS to take the floor. Okay. Okay. So I will give the status of the CMS Higgs search. I want to really dedicate this to the CMS collaboration. This is a picture we took last week. We had a party. This is only 400 or 500 people. Remember, there are 4,000 people in the experiment. This is not the real CMS detector. That's down underground. This is the spare that we keep upstairs. So one page for the theorists. That's all they deserve. No, I'm kidding. The Standard Model is here... is shown here. This is what we know. And we have now... But one of the big stories of this year was, as you know... those of you in the field... is pile-up. We had to deal with very intense beams like never before seen in the field with many, many interactions, and this slide shows... the colors correspond to tracks from different particles. And it was in these kind of events that we're looking for one of the rarest particles ever made, and that's what we call the Higgs. And so this is where things stood last week. As you know, if you look at the radiative corrections... So if you know the W and top mass very well, you can actually predict a long band. Yeah, yeah, so we're there at four. One at the Tevatron. They really had a tour de force measurement. Ah, sorry, yeah, here it is. And we end up with four event classes... Ah, there it is! Okay, so, to wrap up, in summary: We conclude by saying that we have observed a new boson with a mass of 125.3 plus or minus 0.6 GeV at 4.9 standard deviations. Thank you. 125.3. Okay, so now... Wow, 125? Do you know ATLAS's result? This isn't... You heard about this? Okay. I think I can only say congratulations to everybody. I will say a few words more later. Now we go immediately to ATLAS. Fabiola Gianotti, please. Thank you. Good morning. ATLAS is very pleased to present here today updated results on Standard Model Higgs searches based on up to 10.7 inverse femtobarn of data recorded in 2011 and 2012, and it's a big honor and a big emotion for me to represent this fantastic collaboration at this occasion. So let's go to the results for this channel. You can see here the results for the 2011 to 2012 and the combination of the two. The gamma jet and jet-jet background with one or both jet... requirement that the energy in a cone around the photon is below... a structure which reproduces very well the LHC bunch rate with three bunch, small gaps... so then, of course, we collect... Yeah. A few GeV and a few hundred GeV at the level... is fit in the nine different categories with an exponential function to model the background, so, no theoretical prediction, no Monte Carlo. The background is determined from the side bands of the possible signal. From this spectrum, the background fit, you get this plot here. Now the grand combination. Here it goes. So this distribution is extremely clean, except one big spike here... in this region here. Excess with a local significance of 5.0 sigma at a mass of 126.5 GeV. Good. As a layman, I would now say, "I think we have it." - Come, Lyn, come here. - Come here! Okay. - There's Peter. - Peter is there. - Yeah. Get Peter. - Peter's there. Peter! Well, I would like to add my congratulations to everybody involved in this tremendous achievement. For me, it's really an incredible thing that it has happened in my lifetime. Not only in your lifetime, Peter. That's a great day, huh? That's a great day. And I think all of us, and all of the people outside watching it in the different meeting rooms, everybody who was involved and is involved in the project can be proud of this day. Okay, enjoy it. We found the Higgs! Scientists this morning announced they are almost certain they have discovered what's being called the "God Particle." It is not every day that you see a whole bunch of scientists standing up with champagne bottles and cheering. Now, the God Particle, we physicists wince when we hear those words... It's the last piece of the puzzle physicists have been looking for for decades. - Thank you all. - Thank you for your attention. Thanks to everybody on the panel. If I could just ask you all to remain seated just for a few minutes. Clear passage here, please. Can we have a clear passage? - Thank you. - Thank you. Congratulations. Thank you. Thank you. I did feel a sense of pride when the Higgs was announced, but I felt a sense of pride for humanity, that, you know, we little people on a little planet with tiny brains can go so deep and understand what happens. Now we're talking about subnuclear distances a thousand times smaller than an atomic nucleus. Nevertheless, we can get things right, and just the power of the human mind. It's astonishing that there are any laws of nature at all, that they're describable by mathematics, that mathematics is a tool that humans can understand, that the laws of nature can be written on a page. It's the greatest of all mysteries. There is a strong sense that we are hearing nature talk to us. Turns out, the Higgs mass is about as interesting as it could be. It's sort of in no man's land. It doesn't prefer symmetries, and it doesn't prefer multiverse, but it's right in the middle. The data is puzzling enough that it hasn't excluded any of the theories I was involved with, but it hasn't confirmed them either. But until we look at detailed properties of the Higgs, and until we have the high-energy version of the LHC in a couple of years, we will not be able to make a stronger statement. The most important, first lesson of the discovery of the Higgs is that physics works. The Higgs, on the one hand, completes the most successful scientific theory we've ever had, on the other hand, opens the door to some very major paradoxes that we now must address. We're at a fork in the road, and the LHC is steadfastly refusing to push us in one direction or the other: The multiverse on the one side, and some beautiful symmetry on the other side. It's cranking up the suspense as much as it possibly can. Before the LHC started, we would always say, "New physics is just around the corner." And now we're kind of like, "New physics is still out there." And, for one, I'm not discouraged by this, by any means, because we know that new physics has to be out there. The next step is, the LHC goes into a shutdown, stays off for two years for improvements and upgrades, and when it returns, it's going to be twice the energy. And for sure, my vote's for supersymmetry. Jesus. That was exciting. If this is true, the Higgs is about 125 GeV, and that means... um, yeah, actually almost all of my models are ruled out, which... all the supersymmetry models, which is pretty cool. I mean, supersymmetry could still be true, but it would have to be a very strange version of the theory. And if it's the multiverse... well, other universes would be amazing, of course, but it could also mean no other new particles discovered, and then a Higgs with a mass of 125 is right at a critical point for the fate of our universe. Without any other new particles, that Higgs is unstable. It's temporary. And since the Higgs holds everything together, if the Higgs goes, everything goes. It's amazing that the Higgs, the center of the Standard Model, the thing we've all been looking for, could actually also be the thing that destroys everything. The creator and the destroyer. But we could discover new particles, and then none of that would be true. And anyway, we have something to do. There is a very nice sentence in the Divine Comedy by Dante who says, "Nati non fummo a viver come bruti, ma per seguir virtute e canoscenza," which means, "We were not born "to live as animals, but to pursue knowledge and virtue." So science and knowledge are very important, like art is very important. It's a need of mankind. I just saw, two weeks ago, Werner Herzog talking about and then screening his new movie. But it was about these incredible caves that they discovered a few years ago in France. Stunningly beautiful. Gorgeously drawn horses, bison, rhinoceros, lions, because, 40,000 years ago, this is what was going on there. - In exploration... - and science is exploration... there needs to be the set of people who have no rules, and they are going into the frontier and come back with the strange animals and the interesting rocks and the amazing pictures, and to show us what's out there, discover something. Why do humans do science? Why do they do art? The things that are least important for our survival are the very things that make us human. |
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