Sean Carroll - The Particle at the End of the Universe

Good night all. I'm Alec John, The Guardian journalist. I'm going to talk just for a couple of minutes just to introduce you to Sean. I saw him, not me and I won, telling you a little about Sean Carroll. They obviously know enough. about him to be here and hopefully read his book or you're going to read his book after you buy it outside, but Sean is a theoretical physicist at Caltech, this is the institution of Fineman and many other Nobel Prize-winning scientists. . He is also a dark energy specialist in general relativity, among many other things, until recently he is also a very prominent blogger on cosmic variance.

This is a very famous group blog. He now has his own blog and is a big voice in the worlds. of science communication, he has also appeared on many television shows in the U.S. TV shows I hope one day they show us here, even through the wormhole, with Morgan Freeman. I want to know if he knows more than Freeman later, if he gets the stories about it later, and most importantly, he's been on The Colbert too. Report which, as we all know, is a very important current affairs news program in the United States. He is also a scientific advisor to many Hollywood blockbusters.

If in the end he has questions about science and the Avengers, he is the man who did all that. happens, so you can ask him all your questions, including what's in Avengers 2. Sean is also, of course, an accomplished author. In January 2010 he wrote a book about the arrow of time, it was called From Eternity to Here and his last book is about the Large Hadron. Collider, the search for the Higgs boson and the people who made it possible, might even tell us what they actually found at the Large Hadron Collider last year in July, this Higgs-like thing, what is it, so please , welcome Sean to speak. about his book the

particle

at the end of the

universe

how the Higgs boson takes us to the edge of a new world thank you Alec thank you all for coming here tonight thank you to the Royal Institution for inviting me to speak it is such a historic place and very much like Michael Faraday sitting in the audience when Humphrey Davy was giving talks in the past, you can also tweet what is happening in real time with the hashtag our i

particle

and I really want to say how wonderful it is to not only be right Here where all these events happen , but also in London, the spirit of the city and the country is a little different than in my home country, the United States, which is like England's little cousin and one of the ways this manifests itself is when I'm on the Twitter machine and I see things like London for lovers, suggesting that the particle is the end of the

universe

, that's the fascinating date for the science lover, so I hope some of you have made it.

I probably know why I'm here and why you're here on the 4th of July this year. I was lucky enough to be in Geneva, Switzerland, at CERN, the giant particle physics laboratory and home of the Large Hadron Collider, the largest machine ever built by humans, and what was happening on July 4 were two presentations very exciting PowerPoint presentations, exciting enough that there were a lot of 20-something physicists camping out overnight to get good seats in the conference room, so, I mean, none of you were there, I was here at 5:00 a.m. . m. and you weren't there camping out to get good seats, but they were there and they didn't want to miss these PowerPoint presentations.

It was like a rock concert with many more Macintoshes open in their laps and then among the actual audience for the PowerPoint presentation were physicists in their 80s who collapsed with an emotional reaction to what they were told and what they were told, for Of course, we discover a new particle of nature, something we believe is what we've been looking for. for many decades the Higgs boson, but you know, there are particles, even discovering particles for a long time, why was this particular event so important to so many people? So the question of the talk that I am going to try to answer: What is the problem?

Why do we care so much? Why did people line up in advance to camp overnight in not-so-comfortable conditions just to get third-row seats for a couple of early-morning PowerPoint presentations in Geneva, Switzerland? Well, physicists knew this was It was no surprise that we have been searching for this particle for a long time. We had signs that we were getting closer. Part of the result of these hints was that I wrote a book about the whole thing that you can buy directly. there in the lobby, so it didn't surprise us, and yet we've done a very, very poor job of explaining why this discovery is so important, it's not that we haven't tried, physicists have tried to find smart tags. and things to impress a more general audience that this is a big problem, some of those labels, frankly, are not a good idea and we're sorry we invented those labels, we've left them behind but we still have them.

I didn't really make it and I had a theory as to why we can't explain the Higgs boson very well. The theory is that we used the wrong starting point. The kind of starting point we use to discuss particle physics. This guy, does anyone know? you know who this is a portrait of well you don't know believe me this is supposedly a portrait of democritus Democritus, an ancient Greek philosopher from 2,500 years ago, essentially Democritus was the first theoretical particle physicist, he was the guy who really pushed a idea. That was also promoted by his predecessor but his predecessor did not write anything and published or perish in the academic world so Democritus was the first to commit to printing the idea that the world is made of atoms as he called them what today we would call elementary particles because our 19th century ancestors went ahead and called things atoms even though they weren't really elementary, but that the idea of ​​democracy is really so amazing that we should take a step back and really appreciate what he was saying, You know, if you look around you, there is air.

There is wood, there are desks, uh, there is metal, there are other human beings, these substances seem very different, right, they have different properties, they look different, they react differently and yet Democritus says that they are not fundamentally different, just They are different provisions of the same underlying. things called atoms and that idea took a long time to get right, it turns out to be correct and what we are now intellectually descended from the ideas of Democritus is what we now call particle physics, of course, because he lived 2,500 years ago, there is no surviving image. Of what Democritus actually looked like, all that remains is one surviving nickname: he had the Laughing Philosopher, so because that was his nickname, it was a very popular subject for portraits in the Renaissance because the portrait painter could simply paint a self-portrait. of himself. laughing and then label him Democritus so this is Rembrandt's self-portrait label Democritus we have no idea what Democritus is like but we give him credit for launching the train we currently know particle physics the problem is that particle physics as an idea is not the right one way to think about the Higgs boson and that's the obstacle we all face, so instead of going back to Democritus, I like to talk about the Higgs boson by referring to these guys, a younger generation of important thinkers, these They are americans.

I'm not familiar with the phenomenon, as we might say, this is Insane Clown Posse, these two young gentlemen, this is Violent J and that is Shaggy 2, these are not the names their mothers gave them, but they are artists and this is a stuff. In the United States, these guys paint their faces and they have followers called Juggalos who have big events and they're rappers, they're musicians, so a couple of years ago they surprised the world because you know most of their songs involve more activities. alright, violence, you know, their parties, that's what they do, so a couple of years ago they shot the world with a reflective tune about the miracles of the world around them.

The melody was called miracles and if you read it, they say: Yo. I see miracles around me stop and look around me it's all amazing water fire air and earth strange magnets how they work damn wasn't the word but you can Google it, you can look it up now the kids received some disapproval from the scientific community by saying magnets, how they work, we know how magnets work, much of this was demonstrated right here, what I'm arguing for many, many years ago, so we have a working scientific understanding of the esoteric phenomenon known as a magnet, but anyway I want Give them some credit because even though we understand it, even though we have equations that we can attach to this idea, it's still amazing.

Think of a magnet. A magnet is something that can be attached to a piece of metal. on a refrigerator or something, you can stick a lot of things to a lot of other things, you can stick pieces of tape or gum or whatever, but when you take a piece of tape to the refrigerator, the tape has to touch the refrigerator in order to stick it. the gum has to touch the refrigerator to stick to it a small insect or a gecko that climbs the wall needs to touch the thing to stick to it a magnet if you hold it close to a piece of metal you can feel it pull before the magnet touches it goes through empty space and exerts a force and that the refrigerator exerts a force back according to Sir Isaac Newton that putting the two things together they don't need to touch how is that possible?

How does the magnet know there is one? a refrigerator nearby that you should be attracted to, so the answer, well, I'll tell you the answer, but first I'll tell you that it's not just these modern-day philosophers who are baffled by this, there's an older natural philosopher who was baffled by We have already given this a name. Sir Isaac Newton was very puzzled by this phenomenon known as action at a distance. Newton was interested in gravity, not magnetism, but it is the same as the earth exerting a force on the moon or satellites. that orbit around it.

The Earth does not touch each other, the Earth appears to push itself through empty space to exert this on things in its surroundings. Newton said that you can understand gravity throughout the universe in terms of an inverse square law, the force of Gravity gets weaker and weaker as you get further away as the distance between the two objects is squared, but he was very worried, in fact he said that this action at a distance phenomenon was meaningless even though it was Part of his theory for Newton is action at a distance. The distance aspect of his extremely successful theory of gravitation was very similar to what contemporary physicists think of quantum mechanics, an incredibly successful phenomenology, a set of rules that fit the data: wonderful precision and, without However, deep in our bones we think that it doesn't make sense, we can't.

It makes a lot of sense and Newton's problem with action at a distance was actually solved by another philosopher/scientist Pierre Simone Laplace Laplace came up with a new theory of gravity. It turns out that it wasn't actually a new theory of gravity. It was the same theory. like Newton's, no one talks about Laplace's theory of gravity, it's a way of rewriting Newtonian gravity, but it's a way that eliminates action at a distance, well, Laplace says that instead of just thinking about, you know random forces between objects very, very far away. Let's imagine that there is a field that fills the universe and what that means mathematically, simply that at each point in space there is a number, the number, the value of the field, just like the temperature of the air in this room, and at each point there is a value, the temperature at that point in the air but this is not a phenomenology of matter this is a fundamental characteristic of reality the gravitational potential field and the way it works is that near the earth here is the earth and this curve is the value of the gravitational potential the gravitational potential field is pushed down by the earth, then it just gently goes up and the gravitational force that an object feels is just the slope of that line the amount of wealth the speed at which the potential field The gravitational potential changes, so there is nothing acting instantaneously and spookily at a distance.

There is a smooth change from the position of the Earth to the position of the Moon. The gravitational potential is very low here on Earth and goes up as you move towards the Moon. Moon and that change continues forever. the earth is affecting something that extends throughout the universe the gravitational potential field there is nothing that acts instantaneously over a very large distance and this idea of ​​a field turns out to be quite useful it was not just Laplace in fact in the minds of the Physicists the person whose name is most closely associated with the concept of a field is Michael Faraday, who gave the lectures right here, in this very place, he said that the way to think about electricity is in terms of theelectric field and that's what we do these days, we talk about both. particles and about fields in a certain sense a particle in a field are opposite of each other true, a particle is something that is in one location here is the particle is nowhere else a field is the opposite of that a field is everywhere at each point in space there is a value of the field, so if you look at the image here on the left, these are traces of particles through a cloud chamber, there are individual lines, a particle moves through the chamber and It leaves a small trail behind that curves because they are moving.

In a magnetic field in the image on the right there is a magnet. You cannot see the field lines directly, but they are traced by the small iron filings that are in the vicinity of the magnet so that you can visualize the fact that around this magnet there is an invisible field that fills the space, so the Particles and fields are the two things that physicists talk about when we talk about the ingredients that make up reality. If you have In a little physical education, you may have come across the question: does light, for example, a particle or a wave, a wave is a kind of vibration in a field, so what is more important is the particle aspect of reality or is the field aspect of reality are fields that is the answer is not a mystery you always have they say that question they never tell you the answer I what decades of my life so what is the answer to this this is the answer are fields any questions about that so I I'm going to go into a little more detail, but not too much, but this is the crucial slide.

Well, there is no more information. There is no further information on this slide. The reason the Higgs boson is a concept is difficult to understand. It's because you need to stop thinking about the world in terms of particles, you need to start thinking in terms of fields and you say well, but things like this table are made of atoms and atoms have electrons and so on and electrons are particles, right? TRUE? There are particles in the world, no, there are not, that is the secret that we physicists have never told you but here I am, I am going to tell you right now the reason why you are allowed to think in particles is because of quantum mechanics, the world is made of fields, but quantum mechanics says that when you look at the world you don't see it directly, what really exists according to quantum mechanics is immensely richer than the things we can actually observe, so the reason you think there are particles is because in reality all these fields fill empty space at every point in space, there are dozens of tiny vibrating fields in front of you, but quantum mechanics says that when you look at the fields close enough, they resolve into individual particles , as in the image of the This is from David Deutsch and Oxford physicists, one of the founders of the theory of quantum computing, and says: "Imagine you are a frog, it doesn't care if you are a frog or not, "But it turns out that frogs have slightly better vision than humans." and what that means is that the frogs can see individual particles of photons of light, they all see the light from the light bulbs here from the screen, etc., light is two things, of course, light is a wave in the electromagnetic field , so there is a field that is filled.

At each point in space here there is a small electric field, a small magnetic field there vibrating and that is the light that reaches you. Quantum mechanics says to look at that light very carefully and it turns into individual particles called photons. Photons are the particles you see. When you look at a wave in the electromagnetic field, if you think about a light bulb or a flashlight and someone moves it away from you on a dark night, it gets dimmer and dimmer as it goes out in the distance and to you it just fades away. but if you were, if your vision were better, if you were as good as a frog at seeing things, it would stop getting darker and start flickering, so there's a point below which the glow never goes away, it just gets more intermittent and you What's happening is you.

We are making a transition from seeing many photons at once to seeing individual photons hitting your eye. The reason light resolves into photons is because quantum mechanics says that when you look at it, that's what you see. The relationship between particles and fields is that the fields are what the world is made of the particles are what you see so the atoms in this table the electrons the quarks the protons all of these are vibrations in the fields there is a field of quarks that is vibrating you look at it you see quarks there is an electron field that is vibrating this neutrino field that is vibrating is a gravitational field that is vibrating and so on, that is quantum field theory, it is very Hart, the central organizing concept of physics modern and no one tells you until you buy my book.

Let's put this in a little context, imagine where we were a few decades ago, in the 1930s, when particle physics was born, which you now know should be called field physics, but we'll stick with the old way of talking about it. in 1935 it could have been accepted if physicists were getting a little ahead of themselves because they had these three particles, they had this vision of what the universe was, there were atoms that made up this table, the air, you and me, and they knew what the structure of the atom there seemed to be a nucleus in the middle that had protons and neutrons, large heavy particles stuck together, there were electrons orbiting on the outside and the electrons were attracted towards the nucleus by the electromagnetic force.

There was also the nuclear force within the atomic nucleus that held the proton and neutron together and there is a gravity that holds the entire shabang together. Gravity says that every particle attracts every other particle and you look at this image around 1935 and you say that it is an image that seems to fit reality quite well. With these ingredients you can make everyone you've ever met meet the people you like the least, so they're all protons, neutrons, and electrons arranged in different combinations. However, science didn't stop, we kept doing things, we discovered more particles and it overcomplicated the picture, but to begin with, we looked inside the protons and neutrons and discovered that there were things called quarks, the up quark and the down quark combined different ways to give protons and neutrons, so as far as that goes, there was no increase in the number of particles, but instead of protons and neutrons, we say up quark, down quark, there was an increase in the number of forces that we passed from the straw from a nuclear force that supported the proton Neutron. together two different nuclear forces the strong nuclear force that holds the quarks together the weak nuclear force then you can go through your daily life and never realize that the weak nuclear force is weak, that's why they called it that, but nevertheless it is important if When you walk outside in Los Angeles, we have this thing where you walk outside, you look up at the sky, there is a bright point that shines with light called the Sun and sometimes it also appears in England, but the force is the way that that bright spot called The Sun is emitting energy essentially due to the weak nuclear force, when two protons come together, one of those protons can become a neutron, generating another particle called a neutrino and then they come together and release some energy atomic and we have nuclear energy. fusion, so that's the new picture now for reasons we still don't understand these four particles of matter, the neutrino, the down quark, the up quark and the electron for the particles that make up matter, turn out to be a single family of particles and there is another family and another. family there are three generations if you want no one knows why that is true it is the same pattern repeated three times that little bit is a mystery otherwise we have this image and if you want to make it a little simpler I made a flowchart for you and you can check the flowchart, you want to know what particle you are, here are the little questions you should ask yourself to have the three generations, here is the up quark, the down quark, the electron and the neutrino, but then there are other generations of matter particles on top . bosons and then, way up in the corner, there is this lonely little thing called the Higgs boson, so why in the world, with all the success of this image of particle physics, do we need another particle, another field that permeates the universe called the Higgs boson?

It dates back to the 1950s and 1960s, when particle physicists were trying to understand those nuclear forces. Well, if you think about it, it's the nuclear forces that you don't notice in your everyday life. Electromagnetism. Every time you open your eyes, you notice electromagnetism. Light is an electromagnetic phenomenon heat is an electromagnetic phenomenon remote controls laser pointers electromagnetism to gravity you certainly notice that it is quite easy, you do not notice nuclear forces and the reason is that gravity and electromagnetism extend over very large ranges to the that can go in principle infinitely far are not, they are important not only in this room but in cosmology in the structure of the universe itself, while the strong and weak nuclear force only extends a very, very short distance and that did not have It makes sense from the point of view of In the 1950s we understood the electromagnetism of gravity, but if we followed our noses and said well, maybe the strong force and the weak force are like gravity and electromagnetism, we kept coming up with a prediction which was obviously incorrect, the prediction was so large that the strong force the weak force should also have an infinite range, it was not a coincidence, it was a prediction of the model and one way of saying it is that the particles that carry the forces, the photon for electromagnetism, the graviton for gravity, they have no mass, they move at the speed of light.

They have no weight in themselves, they can simply travel throughout the universe carrying the forces they are associated with and mathematics kept predicting that the particles carrying the strong nuclear force and the weak nuclear force should also have no mass and therefore , they should give rise to far-reaching phenomenon, but they didn't, so this was an enigma, these annoying people, they discovered it and many Nobel Prizes have been awarded along the way, it turns out that just to make life difficult for the students of graduate in physics, nature has decided to do it. I use completely different methods to give a short range to the strong nuclear force and the weak nuclear force the strong nuclear force think about if I go back to the previous slide think about that flashlight that they are taking away from you like the force of gravity or the force of electromagnetism is an inverse square law the brightness of a flashlight is also an inverse square law the brightness decreases in distance squared as the flashlight gets further and further away from you, so in some ways what we want is the brightness we have I want a strong nuclear force flashlight or a weak nuclear force flashlight to be very bright if you are very close to it and then dim very, very quickly as you get further away, not gradually like electromagnetism or gravity, because of the way it works in the Two cases are really different in the strong nuclear force, the particles that carry the force are called gluons and they have no mass, but it says that if someone has shaken that flashlight that is being carried away from you, all the gluons bounce in. the proton or the neutron and they can't escape, they're confined, we say, they're actually massless particles, but there's a barrier that they go through and they can't go through, so if you look inside the proton, the strong nuclear force looks really bright and then , as soon as you go outside, you barely notice it You may have noticed this phenomenon here in England, sometimes at night the air is full of something that prevents you from seeing fog or smog.

We have in Los Angeles, it's an advanced form of fog and what happens is the light is absorbed. it's headed towards you so you see a flashlight up close and you have no problem seeing anything but if you move it further away suddenly you don't see it and the reason is because the light just dims because it keeps hitting this field of things that fill space smog or whatever in weak interactions that's how the universe works there is something, a field, a substance in empty space that absorbs the lines of force associated with weak interactions, which means that the interactions weak ones can only stretch a little before you no longer notice it and with that note what turns out to be predicted is that the W and Z bosons that carry the weak nuclear force are massive, they are very, very heavy, that is a prediction of the theory From this dimming theory, one could assume that this was not the idea of ​​a single solitary genius like Einstein, it took a lot of sociable geniuses to put this idea together, so here is my attempt to give some credit to Phil Anderson as a physicist. the condensed matter. who first suggested this idea that there is some kind of obscured field that causes force-carrying particles to gain mass Francois Claire Robert Brout Peter Higgs Tom Kimble Gerald Guralnik and Richard Hagen took Anderson's idea and made it respectable, made it compatible with thespecial relativity knocked down explicit theories and equations that we could solve and search for.

These guys tell the crystal how Abdul Salam and Stephen Weinberg realized that the usefulness of this idea is not in the strong nuclear force but in the weak nuclear force and showed how it actually gave masks to all particles, not just the W and Z bosons, and their order was the one that showed that everything was mathematically respectable, that the equations made sense, and once it appeared, he was a graduate student at the By the way, the way he showed that all of this It made sense, the train was launched, he and his thesis advisor won the Nobel Prize several years later, so what is this idea?

I've already said it, but let me say it again because it's the deepest thing that makes the Higgs boson so special, so difficult to understand and so valuable to professional physicists, even in empty space, the Higgs field is not zero, so I already told you that the world is made of fields, there is an electron field, a neutrino field. an electromagnetic field, a gravity field and if you move away from everything else in the universe, if you protect yourself, if you are looking at a small region of space that is as empty as possible, the fields are there, but they are just sitting at zero, they are not doing anything, they are in their lowest energy state, they are gradually vibrating a little bit due to the miracle of quantum mechanics .

Quantum mechanics says that fields cannot be silenced to a state of perfect silence. There's always a little bit of bubbling and boiling because of the Heisenberg uncertainty principle, but on average they're close to zero, they're there at zero, so if you were to plot this, here are all the fields in the universe, in empty space. some value that the field has here is where you are in space, so the electrons quarks gluons are simply vibrating due to quantum mechanics in the vicinity of zero near zero the Higgs field is different the Higgs field has the property that When you're out there in empty space and you ask what the field is doing in this little empty region of the universe it's not at zero it's shifted to some constant value it would take a lot of energy to move the Higgs field back to zero we say that the field Higgs has a non-zero expected value even in empty space, so the Higgs is there too, silently vibrating a little bit due to quantum mechanics, when it vibrates a lot, we call it a Higgs boson particle, a particle is a substantial vibration in the wave, but even when there are no particles around the Higgs field still exists, it is everywhere you go, you personally move through the Higgs field as you travel during the day and that is vitally important to how Your personal physics works because all the particles that make you up interact.

With this Higgs field, the weak nuclear force is attenuated due to the Higgs field, but also the other particles that compose them become heavier due to the Higgs field, so if the Higgs field did not exist, it turns out that this It's a long story that most of us just don't want to talk about it, so we talk faster and faster, which is exactly what I'm going to do. If you try to make our sensible theory, the weak interactions that you predict, are not just weak interactions. mediated by a massless particle but the electron is massless the up quark is massless all quarks all leptons exactly massless if weak interactions make sense if you don't have the Higgs field we know that's not right we know that the electron has a mass without the Higgs, the electron would be traveling at the speed of light, why would you personally care about that?

Because if the electron moved at the speed of light, it would not settle into the atoms. Well, if there were no full eggs filling empty space there would be no atoms, there would be electrons and quarks etc., but the electrons would be spinning around as photons at the speed of light everywhere in the universe, they would not settle, they would make an atom , there would be no atomic physics, therefore, there would be no chemistry, there would be no possibility for two atoms to come together therefore there would be no I know you don't like chemistry but it is important for you because without chemistry there is no biology with biology without biology no There is life, there are no lectures at the Royal Institution and so on.

Without the Higgs field, life as we know it would be completely impossible; Essentially, no one knows a way to get some interesting complex structure in the universe if it weren't for the Higgs field, but you put a Higgs field there, in empty space, now that the electron is moving through this thick molasses like the Higgs field and therefore picks up a mass, instead of moving at the speed of light, now the electron continues talking to the Higgs field. around it and it gains some weight because of that it has a mass it takes effort for the electron to move now it can settle down we can have atoms we can have chemistry we can have life you're getting an idea of ​​why this This notion of the Higgs field Filling empty space is so important to physicists, important enough that we build giant machines to go find it, so to summarize where we are, the reason the Higgs field is interesting is because it is based on a field which is non-zero, an empty space, a purely theoretical construct from 1964 intended to address the question of why weak interactions are so short range and since 1964 we have been looking for that thing and the Large Hadron Collider at CERN is the version most recent of our attempts to search for the Higgs boson, the particle that is obtained when you activate a vibration in the Higgs field, this is a graphic illustration of what the Large Hadron Collider looks like, this is the lake at CERN airport, sorry, Geneva airport, Lake Geneva, about one in every 16 passengers that lands at Geneva airport is associated with CERN in some way it's a big deal it's also underground you can't see it you know you notice that below are these buildings people live right above the Large Hadron Collider zooming below them many numbers can be attached to show how impressive 27 kilometers around nine billion dollars are for 10,000 people to participate in the construction and operation of the thing.

What it does is take protons, heavy particles made of quarks, and accelerate them to 99.999999. % the speed of light, then it crushes them and we look at what comes out right, this is what particle physics is, you know, grown children getting 9 billion dollars, what are they going to do? They're going to destroy things together, look what. comes out from inside the tube through which the protons move is empty is as empty as they can be is emptier than the atmosphere on the surface of the Moon because you don't want your protons to collide with things in the way and Also, the protons you don't want them to go in a straight line because then you can't make them hit each other, so the reason 27 kilometers is because the array of protons, hundreds of trillions of protons at any given time, are moving.

About the total energy of those protons is comparable to that of a freight train moving at maximum speed, so if you want to have magnets that bend the protons around the ring, you need giant superconducting magnets that are colder than space empty and colder than the universe itself. 1.8 Kelvin is a big deal, it took a long time to do it. A lot of the credit goes to these guys, Carlo Rubbia, who was director general of CERN, the European particle physics laboratory, and he really insisted that CERN plan to build the Large Hadron Collider despite the United States.

The United States was planning to build a competing machine, the United States eventually lost its nerve and therefore Rubia was right to do so and Lyn Evans, a Welsh physicist who was tasked with guiding the LHC from planning to completion , is the person most responsible for the LHC as we currently know it, let me pause for an additional little talk in parentheses that you didn't come here for, but I want to give it to you anyway because when I give these kinds of talks I love not just talking about physics. and machines, but also people, because science is a human effort, right, we make things, it is human beings that make science happen, it is not just a fall from the sky, so I like to show you photos of these people, but they will have noticed all these photos.

I'm showing you that people are all guys and you might get the wrong impression, you might get the impression that only guys who do physics are good at physics, so I need a little parenthesis, that's not what I mean. wanna. Point out the point and since I'm a scientist, I'll show you graphs. These are data. These are studies carried out by sociologists. What they did was create a CV, a curriculum vitae for job applicants and they gave them to professional scientists. and this is not, you know, in the 1950s, this is 2012, they gave them to the scientists and said who they would hire.

They did this for different people, sometimes the person's name was John, sometimes the applicants name was Jennifer on the left, you see what they were like. ranked if they were named John and on the right you see how they are ranked if they were named Jennifer by competency, increased ability, mentorship, and the salary they would be paid if we hired them the exact same resume, just different genders for the applicants. and by the way, you see that women were constantly biased even if their achievements were exactly the same as those of male applicants and, by the way, the bias was absolutely the same for male professors and female professors, they all discriminated against women that they tried.

To try to get a break in science, this is a problem and we have to do something about it. The good news is that we are doing something about it. This graph is the percentage in the US of women in PhDs in physics degree programs and it is increasing like a huge success and wouldn't you know it, if you look at the percentage of women in physics PhD programs from 1965 until now, has gone from 2% to 16%, this is not because the intelligence of women has increased by a factor of eight, this is because women and some men have complained about it and we are sure that gradually we are doing better in a hundred years, when you return to RI, because by that time we will all be immortal and uploaded to the singularity and you will hear about new results in physics, there will be as many women as men who will have contributed to them, so that's the end of my little mini talk in the middle, now let's build a hadron. collider building something like the Large Hadron Collider is not something you are trained for because it only happens once in the history of the universe, you realize that there is a fairly large part of one of the experiments that is part of the CMS Experiment Many One of the size limitations of the components these experiments used came from the fact that they knew that at some point they would have to be driven across a small French town road on the way from where they were built to the experimental site. site, so this is as big as it could be to get through there and no bigger than that, then you dig a tunnel, you dig it down to where you can lower the pieces down to have thousands of these magnets which are the strongest magnets. that the largest scale magnetic fields ever built to supercool, to make superconducting magnets, you would turn them down, there's very little tolerance, it's a few centimeters on both sides, sometimes you do this with thousands of magnets, while you're building this, you know they had to build a new tunnel because in one of these there are two experiments, Atlas and CMS, which do general-purpose physics at the LHC, they toss in the air.

They didn't toss a coin, but let's say they tossed a coin and one of them came to be near the campus. main one at CERN, the other is at the other end of the ring. CMS had to be at the other end of the ring so they need to build a new tube to lower the CMS into the ground and they only went down a couple of meters when suddenly the ancient Roman ruins, I mean it's in the middle of the border between France and Switzerland, there have been civilizations for a long time, so the physicists are expelled, the archaeologists are brought in for six months while you look carefully and they found, you know, coins in this small establishment from here from London, as well as from Rome and from other places and also the streets of the town obsessed with where the CMS actually exists now our parallel with the streets of the ancient Roman town that were there, so these streets never disappeared, they were just you know that it improved and developed along Over the years, eventually the archaeologists do their job, they clean up, you keep building, you put it all together, you turn it on, and it explodes.

Ten days after the LHC was turned on in 2008, there was an explosion of six tons of liquid. Helium was splashed on the floor. If anyone had been there, they would have gotten pretty hurt. Safety procedures were implemented. Nobody was hurt at all,but the LHC was closed for more than a year. This was an accident, of course, it wasn't planned, but. It was an accident that would have kept happening if they just tried to push the thing, so instead they turned everything off, went in, fixed everything, tightened the screws, checked the cables, and as a result, when they turned it back on in 2009, the machine it really worked. alright, that extra year really focused everyone's attention and since 2009 the Large Hadron Collider has been running like a huge success.

Like I said, there are two Atlas experiments over here that look like an alien spaceship. CMS are both very large, neither is. a bit smaller than Atlas, neither of them would fit inside this room if you want to have a bit of a sense of scale. I went around the people here, so that's a person, that's a person, this is a particle physics experiment, this is a beam where the protons go. come and collide with each other these are giant magnets that help you detect the particles like I said the world is changing here the heads of these two experiments Fabiola Gianotti is the head of Atlas currently the head is known as the spokesperson for particle physics jargon Joe y Candela from UC Santa Barbara is the spokesperson for the CMS collaboration but each collaboration is more than 3000 physicists when CMS for Atlas writes a scientific article there are 3000 authors this is the tradition in particle physics everyone who works on the experiment is an author of each article written has not read the articles they were authors of, but they are on the author list.

It is in every way overwhelming for CERN LHC particle physics as a whole. It is a truly impressive monument to humanity. Beings trying to figure out things trying to figure out how the universe works put together this incredibly complex machine, it could simply not have worked at all and it worked surprisingly well, some of its aspects are by no means gigantic. My favorite part of the Large Hadron Collider is the proton source, so a proton is just the nucleus of a hydrogen atom, so literally this fire extinguisher is the size of things this big, it's full. of hydrogen is the source of protons for the Large Hadron Collider, they open the little tap, the protons come out, they discharge the protons with electricity, they separate the electrons, they begin to accelerate the protons and it is ready to overcome the band of hundreds of trillions of protons around. the LHC but there are more than 100 trillion protons in a helium canister this helium canister is enough to charge the LHC with protons for about 10 billion years protons are not a scarce resource when building a particle physics laboratory so you take these protons, you accelerate them to the 99th point, etcetera, to the speed of light, you smash them and this is what you get, usually it makes a mess, a lot of particles come out and the particles don't have little labels that say I'm a muon, the particles come out with different velocities, different susceptibility to collision with other types of particles, different electromagnetic fields, etc., so an enormous amount of effort is put into analyzing the particles and you see that almost every collision you They give absolutely boring results because we understand physics so well that the known physics is almost every collision in the world.

If you took the data produced at the LHC and wrote it all to disk, you would fill the world's largest database in a matter of a couple of seconds. You can't do that, not even CERN can write data to disk so well, so they discard about 999,999 out of every million events and keep the data for about one event in a million, so you have to be very careful when trying this. to look at the good data, look at the data very, very quickly, look at the event, say if this is potentially interesting, okay, I'll keep it, this one is very interesting, you see the little blue lines, these little blue lines are electrons, these long ones. blue lines are muons. that's a difficult thing to do in a proton-proton collision, it's not impossible, but it's difficult, so keep this, put it on your web page, try to analyze it, what you're looking for is the Higgs boson and there are two problems when you are looking for.

For the Higgs boson, one problem is that because quantum mechanics doesn't predict exactly what the Higgs boson decays into, it predicts the distribution of things it can decay into, we could decay into the lower parts, W bosons. , gluons, etc., so it has many different channels. as we say, look for things that could be produced by first making a Higgs boson in this collision and then the Higgs boson decays very quickly, you never see the Higgs boson directly, the Higgs boson decays in about a second Zepto, no You need to know what that is, it's a very small period of time, you can see things that happened on time scales as small as a millionth of a second.

The second Zepto is much smaller than that, so you never see the Higgs boson, you only see what the Higgs boson converts. and when the Higgs boson becomes something else, the other problem is that there are other ways to produce that, so if the Higgs boson decays into two muons and two electrons, there are other ways that it could have been created two muons and two electrons, so it's a matter of statistics, which is why sometimes people say that looking for the Higgs boson at the LHC is like looking for a needle in a haystack. It's a cliché analogy and it's not accurate either.

Searching for the Higgs boson at the LHC is like searching for hay in a haystack. it's like looking for a little more hay of exactly a certain length than all the rest of the hay you have because if you create two W bosons through Higgs decay, you could have done it many other ways, but maybe there are a few more than you. It was expected because the Higgs boson also decayed, so the kind of thing after many hours of genius level manpower goes into this. This is what you are left with if you look at the book that I mentioned, that I wrote a book, there are these two.

The plots are in the book. These are the only pictures in the book where my editor at the beginning said no, we don't need to have that science thing that looks too complicated and scary and I said we paid nine billion dollars for these plots. they in the book concei said well nine billion dollars the price of the LHC these are the exciting results of the LHC as you see this is the number of certain types of events the particular events that we are looking for is when the protons collide and two photons come out, it's actually not that easy that only two photons come out and no other junk comes out when you do it, so this is a rare event that you see, that even though you have hundreds of millions of collisions per second at the LHC, you only get thousands or hundreds of such events and then count the total amount of energy in those photons and this is in strange particle physics units, so we don't measure the energy in kilowatt hours or something because then ordinary people could understand what what we're talking about, then we measure them in billions of electron volts and, for you, 100 billion electron volts, one hundred ten, etc. here's the number of events like this that we produced in the Atlas experiment here's the number we produced in the CMS experiment and you wouldn't notice it except for the fact that the useful particle puts a curve through it but there's a bulge right there and Right there, that lump is what we call the Higgs boson.

There is a new particle. Why is there a lump there? because everything else is random nonsense that arises because you have collided protons, the hit occurs because there is a new way to produce those photons: first you create a Higgs boson with a mass equivalent to 126 billion electron volts and then the Higgs boson . breaks down, so you're looking for new particles by bump searching, looking for a little more events of a certain type than you would predict if that particle wasn't there, you're looking for hay in a haystack, a little more hay from a very specific length now even Although these lumps don't seem that big, there are two experiments that are very, very important, so one experiment can't just fool us and they have thoroughly analyzed this data with very sophisticated mathematical machinery, there is no doubt that this lump is real there is one of the only way we can think of to make it is a new particle with precisely that mass a particle that has all the properties of the Higgs boson we are still not one hundred percent sure that it is the Higgs boson that was predicted by Peter Higgs and his contemporaries in 1964, but it walks and squawks like the Higgs boson does, it is certainly a very Higgs-like boson, so someone is going to win the Nobel Prize, we don't know who really isn't.

I don't even know for sure if anyone will win it, what I do know for sure is that this kind of discovery is better than the Nobel Prize. You know that some discoveries increase in importance by having a Nobel Prize associated with them, sometimes the Nobel Prize is elevated in importance by attaching itself to certain discoveries, there is no doubt in the world that the discovery of this new particle is worthy of recognition on a scientific level, like the Nobel Prize, the problem is that there is a tradition among Nobel prizes in science that organizations cannot give it to them, they can only give it to people and they cannot give it to more than three people for a single thing, so how many Do you remember how many people there are in the experiment? three thousand people in two different experiments, how many people came up with the idea of ​​the Higgs boson, well, you know, six, seven, eight, it depends on how you count, never three or less, so no one knows what will happen, how many people built the LHC, many thousands, plus there are at least three Nobel Prizes that deserve to be awarded, one for predicting the Higgs boson, one for finding it and one for building the Large Hadron Collider in the first place, I have no idea of what will actually be done, no one pays me to answer that question, so I won't, but it's also not the At the end of the road, we have been very excited to discover the Higgs boson.

I mean, this is literally the idea that the Higgs boson came here to Earth before me. I've never been alive in a time where we didn't know about the idea of ​​the Higgs arc, that's how long we've been looking for it, that's why Peter Higgs got a little confused at the seminars at CERN when it was discovered that They had really found it. I mean, here's a young, you know, graduate student. level and everyone doing this at the time was very young and baffled by this problem, wiring these short-range nuclear forces, they came up with this idea and wrote it down and everyone ignored them and then, over 40 years later, someone says oh yeah, here it is, we paid nine billion dollars and we found out it's science at its best, but we're not done yet.

The Large Hadron Collider wasn't built just to find the Higgs boson, it was built to find new particles, it just shut down. At the moment, it's fine, it's been in shutdown mode for two years. Well, they tighten the screws one more time and they will raise it to a much higher energy so that the LHC can be turned on again in 2015. We will be watching. in a regime of physical reality in which we have never appeared before, so we hope to discover new things. This is an example of what we hope to discover. Double the particles.

If you're wondering, maybe we just don't do it. We don't have enough elementary particles. There is an idea called supersymmetry which says that for every type of particle we know of there is a friend called a super partner. We didn't go through this because I'm just giving a one-hour lecture. a series of 12 1 hour lectures, but there are matter particles in the universe called fermions and there are forced transport particles called bosons and in the real world the fermions we know have no obvious relationship to the bosons we know, but supersymmetry says that for every boson there is a Fermi partner and vice versa, so because in the standard model of particle physics there is no relationship, the idea is that there are new super partners and, you know, keep your spirits up while the we search, we make up clever names if you have a Fermi in its companion ik boson gets an S at the beginning, so there are squarks for quarks, so there are spots of squarks and so on, the bosons, which are fermionic particles, get a Ino in the end, so there is a glue a sticky no W and Z we nose and z nose and so on and we are looking for these super partners if they exist and if they are within our reach the LHC will be able to find them, they may not exist, it turns out that The idea of ​​supersymmetry is not just a cool idea, it has all kinds of beneficial consequences.

Helps explain dark matter in the universe. Helps explain the mass of the Higgs boson. It is an integral part of superstring theory, which is our most promising theory. of quantum gravity many people want supersymmetry to exist, the universe doesn't care what we want, you may have noticed, so we may or may not find it, but it is one of the things we are looking for as an added benefit, a of thingsthat what supersymmetry predicts is that one Higgs boson is not enough, if supersymmetry is correct the world has five different Higgs bosons, so even if the particle we have found is a Higgs boson, it may turn out that be only 20% of the Higgs bosons that we will find. in the next few years, so we are very optimistic that new and interesting things will happen, of course, this is just an idea, this is not data, here is data, here is data, whatever you want to say, we know that the standard model of particle physics it is not.

The end of the story of the universe we know that because the standard model of particle physics constitutes what we call ordinary matter, it explains you and me and the table in the air and the Sun and the moon and the stars, it does not explain the universe because we can map the gravitational field of things in the universe and we see images like this. This is a map constructed by observing the bending of light through galaxies scattered throughout the universe. We can basically weigh the universe and we find that there is a lot more stuff than we can explain, so in the standard model of particle physics, we call them dark matter, they're not quarks, they're not electrons, they're not neutrinos or bosons.

Higgs, is something absolutely new, so we cannot end particle physics. there is a new particle called a dark matter particle or maybe twenty new particles called dark matter from many different particles that we don't know about yet, we are looking underground for dark matter particles to collide with things we are also trying to create dark matter or other particles associated with dark matter at the LHC, so it is absolutely clear, not just some kind of wishful thinking, that there must be new physics out there, the LHC is on target to try to look for it, we will have to see if in the meantime nature is kind or a little malicious to us if you don't focus your telescope on the rest of the universe if you stay in this room and think about your life as long as you are not a professional physicist or astronomer, if you think about physics, the laws of physics that They underlie the phenomena that you experience every day, the table, the chair, the shining sun, you and me, the rabbits, the bunnies, the trees, the grass, the insects, etc., all of these are made of particles described By the standard model of particle physics there are no new particles you need to describe bunnies.

I can guarantee it because if quantum field theory existed it says we could make them at the LHC, we would have made them a long time ago. Since quantum field theory is within the regime of a bunny, we know the particles that make up the bunny, the protons, the neutrons, the electrons, the quarks inside them and the four forces that hold them together and the Higgs field that fills empty space was the last piece of that puzzle, so on the last slide I try to emphasize that physics, particle physics, seeks because the fundamental laws of nature are not even close to being finished, we know that we have a long way to go, but as far as the fundamental physics underlying us, particle physics is done, we're done.

On July 4, 2012 I was going to put the final piece of the puzzle of the stuff we are made of, you and I together we have been searching for this for 2,500 years since Democritus and we were finally able to do it, we are not done yet, there are worlds beyond our daily experience, but this moment in history has not arrived. It will be forgotten in a thousand years. We will remember the day we found the Higgs boson. That is why it is so important. Thank you.