Brian Cox Lecture - GCSE Science brought down to Earth

well, good morning everyone, good morning everyone, welcome today to today's star

lecture

with Professor Brian Cox. My name is Julius Gherman. I oversee all the University's work with young people, schools and colleges, and we do a lot of work like this with people like you. to encourage you to think about the University and it is my team today that has worked with your professors to bring you here today and we hope that you really enjoy the inspiration of today's event and Professor Cox will be introduced in a moment and I would like to make some very, very quick housework before we start, since you all know it and your teachers have specially chosen you to come today.

You are one of the five hundred lucky people. that they will come here today, but also because so many people were interested in coming today, this event was sold out if you want, their teachers responded within a few hours, that's why they are here, so everyone should thank their teachers so later, but There are many more schoolchildren around the country and indeed around the world who will be watching this on a live webcast now because there are some housekeeping things that I wanted to go over, it means that they have to be very well behaved and Please try not to do it. speak and throughout the conference because it will be broadcast around the world.

May I also ask you now, can you check if your mobile phones are on silent? It's very important that you've checked it, so do it and in terms of photography. you can take pictures during the conference if you want, but you can't take flash pictures please, so again, if you understand how cameras might work, it's very important that you don't use flash photography, we're not expecting a fire alarm, so if you hear a fire alarm it's real you need to treat it as real and listen to the student ambassadors and staff members who will direct you to the nearest exit now before Brian starts you will be introduced by the vice president and the Vice-Chancellor of University Professor Rod Coombs Now, how can I describe the role of the Vice-Chancellor and Vice-Chancellor? um it's quite difficult, I was thinking in a language that you will understand that he is one of the bosses, one of the people in charge of this university, so he is a bit like all his directors, but while his directors are in charge of institutions with maybe one or two thousand students and Professor Coombs oversees this institution that has about 40,000 students, so he is a very important person and now he is going to introduce Professor Brian Cox will join hands for Professor Rod.

Well, good morning Julian and thank you for that introduction. I have never been praised so much in an introduction before, but before continuing I just want to thank Julian and his team for all the work they have done. Done and all the purple people you see around here worked very hard to organize this, so I think we should give Julian and his team a round of applause for all the work they have done. Well, I'm not going to sleep much. Since I know it's Brian you want to hear from me, not me, but I just want to say a few words to introduce Brian and put things in context and obviously you've seen him on TV, you've seen the shows he's done. and who have been so successful in raising the profile of

science

among young people and people of all ages and all generations the wonders of the universe the wonders of the solar system stargazing live from Jodrell Bank, in fact, where I will go tonight to host another group of International Visitors to Jodrell Bank, which of course is also part of the University of Manchester and before its television career, you may not remember the students here, but I'm sure the teachers do they will remember.

Brian was in a pop group called Deary. I remember them. Actually, he was also in a pop group when he was that age, but he wasn't as famous as Brian, so we won't say more about that. I'm sure you know this too, but what I want to emphasize is. that Brian is a working university professor and a working university researcher here at this university and at CERN in Geneva, where the Large Hadron Collider is, which is where Brian does a lot of his research, so he finds time to combine being like me and my colleagues, a university professor who teaches students who do research and all the other fantastic work he does to popularize

science

and get people's attention, so don't think of Brian as just someone who is in television, he was saying. for me now that he's going to be giving some

lecture

s over the next few weeks to our freshmen on quantum mechanics and I know because I also got a degree in physics, that's pretty difficult stuff and it's not easy to teach quantum mechanics to college freshmen.

So, you know, he's doing a solid job every day, in addition to doing these glamorous things with you. So why do Brian and others like Brian spend so much time trying to get young people like you excited about science? Well, actually, you just have to dig a little deeper into what science does for us to see what the answer is when I was not much older than you, when I was in sixth grade at school in 1969, I was about to take my A level exams and it was when we first put a man on the moon when the loud alarm went off on the moon and we all looked at those things and we looked at the technology and we thought what fantastic technology, what fantastic science, isn't it amazing that Can we do this thing so well? thing you just put on silent on your phone.

I love my iPhone. By the way, these things have more computing power than that spaceship that went to the moon in 1969. How can that be? How can it be that iPhone? It has more computing power than the spaceship that went to the moon, well, the answer is because from then until now many people who started out doing science at school like you have worked at university, have carried out research and have worked with companies. . and develop new science and develop ways of applying new bits of physics, new bits of chemistry, new bits of mathematics, with the result that we have advanced between 1969 and now to the point where more of these things will be sold in the next year. in the world there will be more mobile phones sold than computers and in some parts of the world computers and in some parts of the world people will never bother to buy a computer because they will just use one of these to surf the Internet, this is how science changes .

In our world, it creates a continuous flow of progress and of course challenges and sometimes difficult things to overcome, but without it, where would we be if we had no soul? And it's that kind of commitment to the role that science plays. in the world that means that Brian and people like him take the time to make sure that there are more people engaged, excited and that they don't have to ask Ziya to do more science and produce more progress for everyone, so I think What Brian is doing is very important. I think he is also, of course, extremely attractive, entertaining and engaging, and that's perfect, because science should not be thought of as boring or dry.

There is nothing more exciting than an experiment that goes well. and that goes well, yeah, it really excites you, so what I want you to do is enjoy Brian's lecture, but when you're on the bus back and when you talk to your parents about what you want to do, think. about science think about the fact that you can be a part of all that kind of activity and think about that when you think about what you're going to do next year or the year after in school, whether you go to college whether you go to college. university, what are you going to study, etc., that's the end of my sermon and now let's move on to the main attraction, so without further ado, could you welcome Professor Brian Cox?

I'm going to say what Oldham schools my boys are, that's my hometown son, you're not welcome, everyone is particularly welcome, like my friends from Oldham, it's great to see you and yes, I want to talk about Schuyler, a little goal, I want talk about the universe, but particularly the two big pillars of our understanding of the universe that we have built over the last century and that we are absolutely still building now, two of those pillars that I hope will contribute to building in the future and the two pillars two things that you may not learn in school but that you will surely learn in college.

One pillar is called relativity, which is Einstein's great contribution to science, and the other is something called quantum mechanics, which is a fascinating theory. It seems very strange, you may have heard of things like Schrodinger's cat. Things will be in two places at once, but of course quantum mechanics is our theory of everything that happens in the universe except gravity, and today the place where we explore that in detail is a Large Hadron Collider in the CERN in Geneva, the place where I work when I'm not playing with TV, so I want to give you an idea of ​​what we're doing now at the Large Hadron Collider and what we hope to discover in the coming years. one or two years of absolutely current cutting-edge research, but the first thing I plan to say about ambition because I said that we want to understand the universe and our two great theories about it is to observe the magnitude of the problem and that is One of the things that I believe What first captured my imagination when I started getting into science when I was five six seven years old was sheer ambition because this is a picture of the universe, it's actually depicting the night sky if any of you are interested in astronomy, that thing Up there is the Orion constellation that can always be seen in the winter sky, but I want to focus.

I want you to focus on a piece of heaven that is somewhere around here. I'm going to zoom. Now I see this piece of sky that you would cover if you took a fivepence piece and held it about 25 meters away, so imagine taking a fivepence piece and placing it 25 meters away on a little piece of sky a few years ago . The Hubble Space Telescope that's orbiting the Earth looked at that little piece of sky, the five-penny piece of sky, and took a picture, opened the shutter of its camera for thousands and thousands and thousands of seconds and just gathered the lights of that piece of sky was chosen deliberately because it is a boring and uninteresting piece of sky, in reality for the surface of the

earth

you would see practically nothing in it, but this is the photo that Hubble took and you see that it is anything reserved empty, it is called the Hubble Deep Field image is one of the most important and fascinating images in the recent history of astronomy and it is not empty, it has a lot of structure, many points of light, there are actually more than 10,000 points of light or spots in that image and virtually every one of them, more than 10,000, are actually galaxies, distant galaxies, so they are not stars, they are galaxies.

Now those galaxies, on average, have a hundred billion stars like our Sun, at least a hundred billion stars. in each of those ten thousand spots the most distant object in that image and I'm going to talk a little bit about how we know these things in a moment but the most distant object is thirteen point two billion light years away was Actually, Discovered in this image just a few months ago, light now travels at 300,000 kilometers per second (186,000 miles per second) and at that speed it takes more than 13 billion years to travel from the most distant object in that image to Earth to the Hubble Space Telescope.

When you think that the Earth is just under five billion years old, it means that most of the light from most of the galaxies in that image began its journey to Earth before it existed on Earth and if some of the most distant galaxies there were halfway back when the solar system was just a cloud of gas and dust that had not yet coalesced into the Sun and the planets and moons of the solar system, so imagine what that looks like, that's a moment, remember five pens, peas, piece of sky 25 meters away, imagine what that looks like when you spread it over the sky hiya, well, this is a beautiful map of the observable universe, each point on that map is a galaxy with 100 billion stars like our Sun, at least there you see it.

The structure there is not randomly distributed, it is very interesting. I'm going to show right at the end of the talk that we think we're starting to understand where that structure came from, just to get an idea of ​​the scale of that little line. Up there you may not even be able to see it back, but that's the billion light-year line, so it takes light a billion years to travel from one end of that line to the other. This is the observable universe and I am going to show you there is a ridiculous number that I have to show you it is better to show it than to say this is the number of stars that we believe are in the opposite, we know it by observation or in the observable universe right now thirty thousand billion million million stars like our Sun some larger some smaller 350 billion large galaxies sevena billion smaller dwarf galaxies that's the observable part of the universe we have pretty strong evidence now the universe is significantly larger than that but we can see this blob around us blob from which light has had a chance to travel during the history of the universe so the universe is big is what I wanted to tell you and I don't know if you know a comedian called Woody Allen who once said that the universe is probably infinite, which is bad, it gives you one of those people who don't remember where they put things, but underneath there it's huge, so how can you or Donna get started?

Yes, I will go there, we are, so how is it possible? Start thinking about explaining you know how we know it in the first place, how we know it's so big, how we discovered that on this planet we're on now and how we could start making theoretical guesses, I guess if you like where it came from how started how fast light travels all those facts that I've told you or all those numbers that I've given that our best estimate of how the universe works is of course science and I wanted to show you a little video on what is the best definition of science or scientific method that I have heard comes from a very famous physicist named Richard Fineman, who won a Nobel Prize for constructing one of the first quantum theories. of electricity and magnetism is called quantum electrodynamics this dates back to the 1940s and 1950s it is our best theory today about how light interacts with matter what Feynman was I also recommend that you read his books he was a brilliant teacher, a brilliant lecturer and also a Nobel Prize winning Physicist and he gave this lecture I think it was in the 1960s and it is just a one minute definition of the law of the scientific method in general we look for a new law by the following process first we guess it then we force it, that is really true, then we calculate the consequences of the assumption to see what happens if this is correct, if this law that we assumed is correct, we see what it would imply and then we compare the result of the calculation with nature or we say, compared to experiment or experience, compare it. directly with the observation to see if it works if it does not agree with the experiment it is wrong in that simple statement it is the key to science it does not make it different how beautiful your conjecture is it does not even leave a doubt intelligent are you the one who made the assumption or what's your name if you don't agree with the experiment, oh that's it, so I think it's a really beautiful description of what science is, it's really very simple, it's the application of common sense in many ways, what is being seen. the universe looking at nature guessing how it works seeing what the consequences of that assumption are is testing you against nature and as Fineman said the great power of science, no matter who you are, there is no authority in science if your guest is not in accordance with nature, then it is wrong and that's it, it's easy to say, but how can we compare ideas about the origin and evolution of the universe with nature?

If you think about it, there is only one way to look at the wider universe from The Earth is certainly the universe beyond our solar system and that is to collect the light from distant stars and planets and there is an immense amount of information contained within that light. This is our son. We are so tremendous. I think the cell video is nice. It's not a computer graphic, it's a real movie of the Sun taken by an orbiting spacecraft that just watches the Sun every day and you see that it's a dynamic, violent place that could fit a million Earths inside that ball. bright plasma.

On a million billion planets Earth burns 600 million tons of hydrogen fuel every second to turn it into helium, so it's a gigantic and powerful object many years ago now dating back to Newton and even before we looked at the world. light from the Sun and after Newton we found a way to analyze it by dividing it into the colors that compose it, so that with a prism you essentially create a rainbow from the light of the Sun, just as nature makes a rainbow from some lights using water drops and this is a current image of that rainbow.

Of course, there are many different colors of the rainbow, from blue to red, but when you look at sunlight in a laboratory and you are very careful and pass it through a very precise prism, then you see that it is not just a variety of colors has dark lines all these black lines intersect in the rainbow what are those lines are the signatures the fingerprints if you want of the chemical elements themselves look what happens is that you will know that an element is a nucleus with electrons spinning at around it and each element has a different nucleus and a different arrangement of electrons, what happens with starlight is that the light shines through elements in the atmosphere of the stars to elements like hydrogen, oxygen and helium, and Because those elements have different electron structures around their nucleus they absorb different colors of light, very specific colors that correspond to moving in the electrons in very specific ways, for example, these two lines here are very famous, they are called lines of sodium.

Sodium absorbs light in the yellow part of the spectrum, if you heat sodium, it emits lights in the yellow part of the spectrum, because of the way its electrons are arranged around the atom, what you are seeing here is that the signature, the traces fingerprints of the elements in the Sun, it is interesting because you can immediately read what the sun is made of because you can do an experiment on Earth, see what colors the elements absorb or emit and you can look at the light of the stars, you can see from what stars are made of, but also and this is the point to look at the broader universe, something very interesting happens when you look at this spectrum, these black lines in the rainbows of the most distant stars and galaxies, so here's a galaxy distant galaxy, you can look at the light from that galaxy, what you find, of course, is that the spectrum is the same the black lines are all the same because the chemical elements are the same throughout the universe except that in all distant galaxies the lines They're displaced They're moving They're not in exactly the same place Now there's an explanation for that Of course, it could be that the elements are somehow different in different parts of the universe, but it's interesting, isn't it?

They are all displaced in the same way and there actually turns out to be a pattern for this change, so what is the explanation? The explanation for the change is very simple: the universe is expanding, so if you look at very distant galaxies, you will find that all the distant galaxies are moving away from us, think about what that does to light, what happens to it. In the light, the light begins. its journey from distant galaxies light is a wave just imagine a wave on its journey through space space is stretching because the universe is expanding is light traveling from distant galaxies towards us what does that do well stretches light so the wavelength of the light is stretched, the wavelength is colored, red light has a longer wavelength than blue light, so since the light, let's say, comes from a star, it is hydrogen , say, emits a line up here and travels through the universe to us. you actually get what's in blue, so let's say that as an element down here that emits light in blue, it travels through the universe, it stretches, it stretches, it stretches, it moves toward the red part of the spectrum because it stretches. and this is how you see the whole.

The fingerprint of atoms moved from the blue part of the spectrum to the red as light expands into space, that's what we observed, so it's a very direct measurement that tells us the universe is expanding. , that's one piece of the puzzle, just qualitatively. you can say that tells us that our universe is stretching, space itself is stretching, how do you quantify that? Although well, this is in many ways even more fascinating. You see that there are certain types of objects, certain types of phenomena that occur in the universe and that we know the brightness very precisely now imagine how useful it is if you know how bright a light is and you place it somewhere very far away and then you look and see how bright it seems to you then you will be able to calculate how far away it is it is very simple obviously it gets dimmer and dimmer the further away it is from you now this is an image of one of the types of cut out objects whose brightness we know very precisely and it is actually this one here, those are the beautiful images, this is the galaxy, so this is an island, as I said, with 100,000 million, maybe 200,000 million stars like our Sun, there are maybe a billion of stars in the center of this galaxy shining brightly.

It looks like a star that must be closer to us than that galaxy because it's so bright it's not really bright it's actually something called a supernova explosion this is a star in the galaxy it's on the edge of the galaxy it's the same distance away that the billion suns in the center and the hundred billion stars in the disk at the same distance but it's going to be as bright as a billion suns, how could there be one star shining as bright as a billion? Well, it's something called a supernova explosion, it's the death of a massive star, but it's actually very interesting and what we think is called a type 1a supernova, it's something called a white dwarf, so that's the final fate of Silla, It's a star that has burned up all its fuel and is just sitting there in space, gradually fading away, but it's a white dwarf that had a companion star orbiting around it.

Now the white dwarf, the dying star, sucks matter out of the star. companion star until it becomes too massive to sustain itself and then it collapses and explodes and we know that process very well, it was a process that was actually predicted from quantum mechanics from our theory of atoms and molecules back in the 1930s, so it's a very specific process and we can calculate precisely how bright the explosions should be because we understand the mechanism perfectly, so we know how bright they are. It looks bright because we took a photo of it so we can calculate how far away it is and this is the second piece of evidence you need so we have two things now that we have so you look up in the sky and you see things are moving quickly away from us. because you can measure the change in light and we know exactly how far away those things are because we can look for things like these supernova explosions and distant galaxies.

Now these are rare. We average about one supernova per century per galaxy, which is very rare, but there are a lot of galaxies and this is a beautiful image, I think again, from the Hubble Space Telescope, which is an image of galaxies at the bottom as they are normally seen and at the top like They were looked at on a particular day or a particular week when we were looking at them when there was a supernova explosion, so see here, there is the galaxy as it usually looks, there is a supernova explosion, galaxy, supernova , galaxy, supernova, supernova in hundreds of galaxies that have been measured and we have made a map of the universe we have the distant galaxies we know how far away they are we know how fast they recede in what happens well, I just want to, I just want to talk to you about a supernova specific, but let's say what about the fascinating one?

Like I said, they happen very rarely. A supernova in our galaxy occurred on average once every 100 years. The most famous occurred in 1054 AD. This is an image of it today, it's called the Crab Nebula. You can see it with a small telescope in the sky: a beautiful expanding cloud of gas, so this is a star that died and exploded in 1054 and exploded, how do we know that? Because it was observed by Chinese astronomers and I think it is particularly interesting and it is a place that is not a pleasure. In one of my television programs I visit this place called Chaco Canyon, which is in the southwest of the United States, very close to the border with Mexico, there was a civilization here a thousand years ago, but they built structures like these huge castles and houses in the desert. the ruins that you tend to think of I used to think in a cliché way that Native Americans on the plains know how to ride horses and you have an impression of what they are like in western movies, cowboy and Indian movies, actually, a lot of these civilizations.

They are extremely sophisticated and they built these giant structures they are still there in the desert this is in the Chaco Canyon of New Mexico and these people this is a photo of me of course but the fascinating thing is not me but this here because these people saw that explosion in 1054 we firmly believe and this is a painting of the explosion the supernova now this was six thousand light years away which is a star very far from us this is a drawing of the crescent moon this is a drawing of a new star that appeared shining as brightly as the moon and this handprint is believed to point towards a place in the sky and with computer simulationsIn modern times you can turn the sky back to see what it would have looked like on that July 4, 1054 when the supernova occurred and you discover that, in fact, that supernova would have occurred next to the moon exactly at that place, at that point in the world. sky, it would have exploded as brightly as the moon and the moon was in That form that is presented is a beautiful piece of detective work that tells us that these people a thousand years ago observed a new star shining brightly in the sky for two weeks of the Krabbe supernova explosion, so when you put all that together, what do you get?

We have a lot of distant galaxies, we know how far away they are, we know how fast they are moving away, we found something called Hubble's law and it's basically very simple, it says that the further away a galaxy is, the faster it is moving away from us. Now how should we interpret that? I mean, you could naively say: Well, does that mean we're somehow at the center of the universe and everything is flying? Well, not really, if you think a little more, if you think about, for example, baking bread. You take a piece of dough and put it. raisins and put it in the oven, then the bread expands so that all the raisins move away from the other raisins.

If you sit on a raisin, what you would see is Hubble's law, exactly Hubble's law, you see those close to you moving away more slowly, those further away moving away faster because all the bread is stretching, all of space is stretching at a constant rate, so you get this fascinating law which is exactly what we observed and I wanted to give you the number because it is a very interesting number. I gave a lecture. None of you know The Hitchhiker's Guide to the Galaxy. They don't even know that Douglas Adams does, you do it brilliantly, very well.

If you don't know, you should read it. It is a wonderful, fun, and hilarious book. In the Hitchhiker's Guide to the Galaxy there is a very famous number that is the answer to the love of the universe and everything and it is the number 42, it has been famous for years. Everyone who knows Douglas Adams knows the number. Actually, it turns out remarkably The Hubble constant can be written like this: 42 miles per second for three million light years. What does that mean? It means that for every 3 million light years you move away from Earth, things are fine if you move three million light years away from Earth.

If you go three million light years away, then on average things will move away at 42 miles per second, that's pretty slow, in fact, there you go, six million light years away things will move away at 84 miles per second. second, and so on, every 3 million light years. Here, add another 42 miles per second to the recession speed of things, now there's something else that's actually an exercise you can do if you like to do a little math and Max, I think it's fun eventually, not always, but eventually, and what you look at here. You see? This is the distance in miles.

I've written in miles so I can have 42 there, but you can turn it 2 kilometers quite easily, so that's a distance of 3 million light years. You could write it in miles. or kilometers is also an easy thing to do, just type on your calculator, you can do kilometers, kilometers canceled, so the Hubble constant is actually the two double constants of the unit, a 1 in seconds, because these go a distance disappears with the distance that you have 1 over seconds, which implies that maybe you could flip it correctly, you could say well, what if that's 1 over seconds and I flip it to 1 over the Hubble constant?

I get a time, what is that time? Well that time turns out to be the age of the universe so you can do it really just convert light years to miles or convert miles to kilometers and light years to kilometers cancel them out turn it around and you get a number and the number is fine with most precise modeling that we have today, you will find that you get something that is on the order of 14 billion years if you do that, a very simple sum to do actually this is the most accurate. I think it's remarkable the more precise determination of the age of the universe we have right now is 13.73 or so, not 1.2 billion years, that's a remarkable measurement, isn't it?

That's the age of our universe measured simply by looking at the light from distant galaxies, so I encourage you to give it a try. in that, you can do it, an investigation, you can do noble and constant work to calculate the age of the universe, so that's part of my talk, that's how the things that I said at the beginning, how we know it, we know that the universe . It was very hot and very dense 13.7 3 billion years ago because we have analyzed the light from distant galaxies, we know that it has been expanding and cooling since then, what could we say about the processes that built the stars, the planets and the galaxies?

I haven't said anything about it, we just measure how fast it expands. There is something else that is very interesting and it actually goes back to research that was done just 100 meters from this room, across the road at the bend in In the last century, almost exactly 100 years ago, a man named Ernest Rutherford who in a little laboratory that's still there across the road, if you have time you can go and see it after the lecture, discovered what the atomic nucleus was. the first person to see that Timms built from a nucleus a small, dense nucleus with electrons running around on the outside simply by doing experiments on the workbench, that was the beginning of a journey that we have followed since what is now called physics of particles and What we discovered is that as you go back in time, you start here 13.7, three billion years after the Big Bang and you go back in time towards the Big Bang, which happens well, the universe shrinks , the universe becomes hotter and hotter and hotter and follows suit. from Rutherford we find that it gets progressively simpler and simpler in surprising ways and we don't really know a deep reason for this other than what we've seen experimentally remarkably when you go back to the first second or the first thousandth of a second. or the first millionth of a second after the Big Bang, you discover that the universe was extremely simple, so our picture is that the universe has been expanding and cooling since it began and becoming more complicated, so things like you and I , the stars and the planets. and galaxies, these complicated structures that we see in the universe are, in a sense, properties of a cold old universe, in a sense, they have crystallized, but if you go back in time, the universe, that structure melts as the universe heats up and you find a very simple universe, in fact a universe that we can understand to a large extent, so the problem, the scientific problem in the spirit of Richard Fineman, is to do the following: we want to guess how this structure arose and then we want to do experiments, but one of the experiments here what we really want to do is build a time machine and go back to the first billionth of a second after the Big Bang or before and observe what's happening in the universe, we can't do that. unfortunately, but what we can do is recreate those conditions in a laboratory, the conditions are very hot, very dense, a very energetic space and this is the laboratory in which we do it, it is called the Large Hadron Collider at CERN in Geneva , has 27 kilometers in circumference and is the largest. science experiment ever attempted the largest science experiment ever built and this is in two countries most of this at the bottom of the picture is France the top is Switzerland that is the Geneva airport runway if you had ever been to Geneva you would have landed on that runway there, so that's an airport, the experiment we built dwarfs an airport, its job is to take the nuclei of hydrogen, the simplest element, the individual protons that make up the atomic nucleus of hydrogen and accelerate them to the 99.999999% of the speed of light, an immense number.

That means, in more visible terms, that they travel these 27 kilometers sounding 11,000 times per second and we do it with two beams of protons, one that we send in one direction and the other in the other, and we collide them with each other in those collisions and by the way we can collide up to 600 million protons every second at the Large Hadron Collider, in each of those collisions we reproduce the conditions that were present less than a billionth of a second after the universe began and we take photographs of those collisions and I wanted to show you part of one of the large cameras we built to take these photographs.

This is the Atlas detector, parts of which were built here in Manchester and at the time it was being built so you can see the kind of inside. This thing is 40 meters long and 20 meters high, but it's actually essentially a digital camera. The collisions happen somewhere in the middle of this structure that is now filled with instruments that take pictures of the collisions and we watch, we just watch and watch. what we are looking for why we build this immense machine well from today from now on then this is what we know about the universe so we know today that the universe is built only with these things these are the fundamental components of the universe From now on, the Large Hadron Collider starts taking data and some of it may look familiar, this one may look familiar, this is the electron, so the first subatomic particle to be discovered is the first fundamental particle that wants to be discovered, which turns around the atomic nucleus. to make atoms, these two things are maybe a little familiar, they are called up and down quarks, the proton is made of two up quarks and the down quark and the neutron is made of two in and up downs, so those two things in atomic core blocks and that's what you need to build you and me and the

earth

and the stars and the planets and everything we can see in the sky.

Every galaxy we can see we think is made of just those, the up and down quarks, the electron and this thing. called a neutrino completes the set of these four and is a kind of unusual particle in a sense that you may not have heard of neutrinos, they are actually intimately involved in the way the Sun shines and, indeed, in the suns in the Sun's process goes through converting hydrogen into helium, produces copious amounts of these things called neutrinos, so many that you actually have to lift your thumbnail, which is about a square centimeter, there are something like 60 billion of them. neutrinos per second passing through your Miniature of the Sun and of F through every square centimeter of this room you don't feel them because they interact so weakly with normal matter, but they are there and they allow the stars to shine, so they are important and that It is all you need. to make a universe as far as we can say just those four particles for some reason that we don't understand at all, nature saw fit to make two carbon copies of those, as they were now carbon copies that you probably don't know anymore because you don't do that, you scan things but you have two precise copies of those four particles, these are identified khals, except they are heavier, so this thing is called a muon, it is the same as an electron in every way, except it is heavier, this is a towel just like the electron the muon in all but the heaviest sense, we have no idea why nature decided to do that, they don't seem to be of any use, but we have discovered them so that we have reasonably good evidence that they do not exist.

So that is one of the great mysteries of physics. Actually, why did nature choose that pattern? You just need to sit down. It seems like you need four to build everything nature has. 12 We don't know why that is one of the mysteries, but we have the other mystery. By the way, I don't know anything about that, so we don't really know how to look, we're just waiting for something to come up, someone smart to come up with some kind of theory, but there's something much more specific that we're looking for. for which I can prove with an equivalent equation and I apologize for putting an equation and some of you may not like equations, although this one is worth looking at because it is incredibly simple in many ways, this equation that I am going to present now describes everything we know about the universe except gravity, so everything from the way atomic nuclei work, the way atoms, molecules come together, the way light interacts with atoms and molecules , radioactive decay, the way stars shine on a fundamental level, everything we know about the universe.

At the beginning of the 21st century is in this equation, it may not seem simple to you, it does not seem simple to many very often and if you think about it, it is quite amazing that you can write a piece of mathematics that describes every phenomenon that we know in the world. universe plus gravity in such a simple and beautiful way, but there is a problem with it and I'm tempted to say can anyone see what it is? But that would be unfair, wouldn't it? And the problem is actually Not a problem, the related prediction is foundin these last two lines.

The first two lines contain symbols that represent all the particles here, so all those things combined in these symbols are the forces of nature, electromagnetism, all those forces, the nuclear forces that glue the nucleus together. Altogether everything is described in the first two lines, the bottom two lines contain this symbol which is a Greek letter Phi and which actually represents a particle that is not here correctly, in other words there is a particle here that is predicted by our best theory of the three. of the four forces of nature that has not yet been discovered and may not even exist, but is predicted to exist in the spirit of Richard Fineman, we have to go look for it and this is one of the key things that the LHC does.

Well, this is called the Higgs field, so this is called the Higgs particle, which you may have heard of, it's a particle that was predicted to exist for our theory to work, so you actually sit down and do math. , it does not work. You find a way to fix the math so that it describes the things you can see, and the only simplest way we can find to do it is to introduce this new thing. What does it do well? It gives mass to everything in the universe, so if you look at your hand, it's made of subatomic particles and they have mass, they have substance, obviously, what we discovered fifty years ago is that if you write on the masses, you say that the electrons got tangled, we weighed it in 1897. actually, let's put it in our equations it turns out that everything fails it doesn't work correctly at all you can't make predictions it's wrong you can't do it so what a scientist named Peter Higgs discovered is that you can introduce the mass in a very interesting way, a clever way that really solves all these difficulties.

I think the equations work and it's really simple. In fact, it's simply this: the universe says that Peter Higgs is full of a field called the Higgs field, so you can imagine. This room is full of something called the Higgs field. Inside your body there is a Higgs field out to the galaxies. most distant parts of the universe like a Higgs field everything has to pass through it so that all the particles in you and now pass through and talk to the The way the Higgs field works is that if you think of a particle without mass as light, as light as a stream of particles flying around the universe, they do not talk to the Higgs field, that means they do not gain mass, they remain massless, they pass through the universe without obstacles, but electrons and quarks and everything that makes up your body, those things have to talk to the Higgs field, they interact with it, they get pulled back in some way, so they gain mass and can't traverse the universe at the speed of light that mechanism which is quite simple it's almost like pulling something through a vat of molasses it's actually our best theory for how mass appears in the universe if that's true and it sounds a little complicated but if it's true then we have to find these things the Higgs particles and the Large Hadron Collider, if it's not true and it may not be true because it's just a theory, then we know that we will see the origin, the process, I suppose, that causes mass to enter the universe, which is interested in himself.

Because we say you have substance because of this mechanism, but I think the key to remember is that this is our theory of three of the four forces of nature, so everything that happens in the universe besides gravity on one level fundamental. It is represented by this theory and we need to know that mechanism in order to make more progress, and that is what makes the LHC exciting and the director of CERN said in the press a couple of weeks ago and I think most physicists are I agree with him that the LHC continues to work as well as it is now, so we should have an answer to that question within two years.

I would say that by the time you have finished your A levels and are thinking about going to study physics at University, then you may be arriving at university and learning how mass enters the universe due to the discoveries at the Large Hadron Collider, so it's an exciting time to be there. I just want to mention one thing that's fun before we move on to the last part of the talk and occasionally one of the things that CERN is famous for is ridiculous stories that it could destroy Switzerland or something, even destroy the planet. You read about it in all kinds of press articles, it's complete nonsense and it was quite surprising to most scientists because where did it come from?

I don't know who invented somo, who Dan Brown is or something, I don't know, but what's interesting is in the spirit of Richard Feynman again and the science. It's not about opinions, it's not about arguments from authority, you have to do experiments, so you could say well, what experiment could you do to determine if colliding particles of these energies could destroy countries, machines or even planets? Our universe is what you could do. Well, it's interesting that nature has been doing this experiment throughout the history of the planet. This is the only graph I want to show you, but it's a graph of particles called cosmic rays hitting the earth.

Now cosmic rays are constantly hitting the earth. There are subatomic particles. like protons at the LHC and bombard the Earth with energies far superior to anything we can generate at the Large Hadron Collider. In fact, in this graph, all of these collisions here are measured cosmic rays hitting the atmosphere. Everyone has greater energies. that the LHC and this is actually a graph called a logarithmic graph, so each bit increases by a factor of 10, so those that are there have an energy, well, these have an energy 100 times those, these, a hundred times, these, 100 times the, like this.

These particles up here bombard the Earth with energies many millions of times greater than the energies with which we collide the particles with the LHC. Many more of them have hit the Earth in Earth's history and will someday hit the LHC, and of course the Earth is still here. so this is a beautiful demonstration of your interest in science itself because we don't know where some of those very high energy particles in space come from, we don't know the mechanism that accelerates them to these immense energies, but we do know because We measure them and they bombard the Earth all the time, of course we know that the Earth is still here, so there is a beautiful experiment that tells us that particle physics is a sure thing now in the last few minutes that I mentioned at the beginning.

There are two pillars of our understanding of the universe and one of them, quantum mechanics, is what I have talked about, is the theory of subatomic particles, the theory of everything, and I kept saying all the time, apart from gravity, theory of gravity. our best theory is Einstein's theory of general relativity, written in 1915, and I wanted to talk just a couple of minutes about relativity because it's a beautiful piece of science and it's very important right now because a beautiful experiment was done two years ago. . Results were announced weeks ago that confirmed for the first time with very, very, very high precision, so the most precise confirmation we've ever had that Einstein wasn't wrong, right?

It's just that his theory of gravity passed the test of the most accurate experiment I've ever been able to do, and I just wanted to show you a little bit about the results of that experiment that was reported just two weeks ago, since there was actually an experiment thought of back in the day. 1960s, so some of these scientists have been working their entire lives. races 50 years and get these results, but relativity first is a very beautiful and easy way to describe what it is here. Albert Einstein Einstein was a genius because he often thought very simply in images about how the world works and what fascinated him in the past. early 20th century and about 1905 was the result of a Scottish physicist named James Quark Clark Maxwell, who predicted, although he didn't really know it at the time, he predicted that light travels at the same speed no matter how you look at it.

It's a little strange to predict that essentially what I'm saying is that if I fly to that place right now at the speed of light or let's say at 75% of the speed of light I fly towards that light, the light will reach me. the face at the speed of light not twice the speed of light or 1.75 times the speed of light but the speed of light is something very strange to predict but it emerged from 19th century theoretical physics from experiments on electricity and magnetism Einstein was the first person to take that genuinely seriously and say what it entails, well, what if I say that nature works like this, so no matter how I move in relation to you, we all agree that The speed of light?

Well, he came up with a beautiful thing called Thought Experiment to figure that out and I can tell you that in about a minute and it's the house of relativity, he thought of this thing called a light clock, so imagine that I have a very strange type of clock that It consists of only two seated mirrors. there like this and my pendulum is light bouncing between the mirrors so we can imagine one tick two ticks one second two seconds three seconds it works like a very precise clock but remember that we have agreed that we all agree on what the speed of light is No It doesn't matter how anyone moves, so what happens if I literally put this watch on this stage and just walk across the stage?

Do you see? You see the clock ticking, but because I'm moving, you see something that looks more like that. because I started there and walked over here, so the light from your perspective bounced off that in a triangle, what does that imply? If it's really true that we both agree on the speed of light, we both think it's the same, then you see my watch running slower than I do, because light had to travel farther to make a tick than when it was stationary. , so that is a prediction, it is very strange, the prediction says that moving clocks run slow, time slows down when you move from your perspective watching me move through the scenario that turns out to be correct turns out to be true and in fact the factor by which slows down is given by this little equation here you can solve using Pythagoras and the reason I show the equation is because maybe you can see, you know that the square of the hypotenuse is equal to the sum of the squares of the other two sides, you know maybe you can see that the squares and the square roots and things here when you solve it, that's the answer you get, it's fascinating because that equation is built into the satellite navigation system, so when you get on to your car, set up the sat nav and off you go, the sat nav system basically works by measuring time.

Differences between clocks on satellites and clocks on Earth: Satellites move relative to the ground and are at a high altitude, so gravity is a little weaker. It turns out that that means time passes at a different rate. How well did Einstein predict 100 years ago? would shift 36,000 nanoseconds per day (a nanosecond is a billionth of a second, since I sound like 36,000 nanoseconds, but light travels 30 centimeters in a nanosecond, which means the satellite navigation system would shift 36,000 30-centimeter lots in His position measurement is about 10 kilometers, so the satellite navigation position would change 10 kilometers per day if what Einstein discovered in 1905 when thinking about a light clock with two mirrors was not taken into account. beautiful piece of physics and found its application a century later in satellite navigation.

What does that have to do with gravity in these measurements? Well, Einstein went from thinking about moving clocks to thinking about what happens with time and the? space in the presence of heavy objects like planets and stars, and discovered how their theoretical prediction was that motion not only bends space and time, but heavy things like planets and stars also bend space and time. and he made predictions about what that means: it actually means that when you travel through space near a planet you feel like you feel a force because you move through space and time bent and curved that force is gravity it's a wonderfully theory elegant in fact I even wrote it that's Einstein's theory of general relativity the whole theory of gravity the best theory of gravity we have in one line, actually, oh, this here just tells you how the mass of a planet or a star and this right here tells you how space and time curve, that's it, that's it and then where the image is as things move.

Through this curved space they bend because they are passing through a curved space and that is what we feel as the force of gravity. About two weeks ago a fascinating little experiment was completed, a thing called gravity probe B, it was a spacecraft orbiting the Earth. and simply measured the curvature of space and time andIt was done in a very simple way using small spinning tops called gyroscopes they simply carried them around the earth. Einstein's prediction was that as they revolved around the earth, the gyroscopes would move a little and move. a little bit because space and time are curved, so they wouldn't point in the same direction every time they went through that motion, that little change was the amount that, if you look at the planet Pluto, it's like the planet now, it's so small, you have been demoted if you look at Pluto from the surface of the earth and look at the disk, the angle, the angular distance from top to bottom, so measure the angle by looking from Pluto's north pole to the south pole. of Pluto then that's the amount of change in these little gyroscopes Einstein predicted in 1915 it was measured two weeks ago and the prediction was in exact agreement with the measurement as far as we could see, so Einstein's theory has been proven so Absolutely beautiful and precise. in recent weeks and completely agreed with his 1915 predictions, a beautiful piece of physics, so in closing, those are the two pillars of our understanding of the universe that we have at the moment, we have Einstein's theory, a theory very strange that space and time is folded by stars and planets and movement slows down the clocks work their technology is used in the satellite navigation system and we have quantum mechanics that describes everything else, but we are testing again at the Large Hadron Collider, so we've developed this picture of the universe expanding and cooling over 13.7 billion years emerging structure that eventually became things like stars and planets and, indeed, people, Is there any way we can go back beyond that?

Yes, experimentally I said that we could go back to about a billionth of a second after the universe began with a Large Hadron Collider, well, it's an end, I just want to show you one image, the last image I want to show you, which one is this one? actually you saw, you may have seen in this in this in these The images that I've been showing is this image here, it's an image of the early universe that was taken by a satellite called W map. It's actually a picture of the universe as it was about 300,000 years after the Big Bang and that's the point at which the universe had expanded and cooled enough to become transparent to light, so before that time , about 300 thousand years ago, the universe was in some ways like a giant star, it was very hot, very dense light could not travel through it, but at that point the universe had expanded and cooled enough for atoms could form and light could travel through it that light has been traveling around the universe for approximately 13.7 billion years and we can capture it and measure it and this is an image of that light, so this is the image of the oldest light you can see in the universe captured by a satellite called the W map and it's actually an image of the different temperature variations in that light, so essentially what you see and What was known for many decades is that when you looked You saw the night sky glow with a particular temperature that was, I suppose, the echo of the Big Bang, in a sense, the universe was once very hot and it has still been cooling.

I have a temperature to this day, but it is very cold, but what was discovered a few years ago was that if you look very closely, you will see that not everything is the same temperature, so there are red parts and yellow parts and parts green. and blue bits, these are all different temperatures, very small variations in temperature, very difficult to measure, but what we believe are the seeds of galaxies have been measured, so we believe that the beginnings of galaxy formation that led to the formation of stars the planets and we are encoded in that light the small dense the bits that have a slightly higher temperature we actually and well actually those anyway a different temperature has actually seeded the galaxies but there is something very interesting in this which is what I want to finish I think the point is that we also have theories that tell us how those small fluctuations formed and their theories about how the universe behaved a million million million million millionths of a second after they started the so-called quantum fluctuations in the early universe, so now we have theories that can take this data and we can think about events that may have occurred a million million million million millionths of a second after the Big Bang, extrapolate them forward and some of Those theories fit this.

The data is very good, so I think the most notable thing to me about science at the turn of the 21st century is that not only have we been able to use it for technological purposes, as they say, we can build iPhones, we can build satellite navigation. system we have medical science that has transformed our lives our life expectancy now is not twenty or thirty years but 80 years in 90 years are notable achievements but in reality we have also been able to tell the story of the origin and evolution of the universe to Until certain point, yes, we are very, very sure that we know what happened about a millionth of a second after the Big Bang onwards.

We have a very powerful image of that, there are things we don't know, but we have a pretty solid story. about whether that would have happened, but we also have indications that we understand what might have happened a million million million millionths of a second after the universe began and I think that in closing is a tremendous achievement. I showed this image at the beginning. I like it a lot, it is a photograph taken by Apollo 17 in 1972 on its way to the moon, it was a photograph that was taken and it is one of the few photographs that was taken with Antarctica very visible only because of where the moon was when Apollo 17 was on its On the trip to the moon, the Earth was tilted and the really beautiful thing I think is an image of Africa, so this is the continent of Africa dominating the image.

One of the few images of Earth where Africa is dominant and I think it's notable because if you think about it, this is the Rift Valley, so this is the cradle of humanity, this is where humans came from, recently our species began, it began its journey towards homo sapiens, the earlier versions of our species were where the oldest footprints were found here. in Tanzania they are only a little over three million years old, so in just three million years we have gone from the first hominid footprints, the first vertical footprints that our ancestors left in the sands of Tanzania, to the moon and beyond and to be able to tell a story of the origin and evolution of the universe, how we have done it so well is through the scientific method, so it is something beautiful and powerful, it tells powerful stories, not only is it useful, I think it is good, it is there, it is part of being human to wonder about the origins, evolutions and our destiny, so with that I will say thank you.

I hope many of you want to continue that journey. By the way, there are a lot of unanswered questions that we have yet to answer. I'm sure some of you will play an important role. part in answering those questions, but for now thank you very much. I have them. In fact, I have. I have a list of some questions here, so I wasn't there. What we proposed to do is ask their names on this list I think they were randomly selected or something so maybe you could ask the question if you can remember it the last time I did this and most people couldn't remember what question they had fact, but I hope You will be able to remember it, so the first was by Jacob Woodland of Ripley's Academy and Thomas Church of England.

So, Jacob, if you remember your question, which is a very good question, how can the universe expand if there is nothing outside of it? they expand forever, that's all, so it's a brilliant question house or two and both brilliant questions, the first is the answer, the first part of what they're expanding to is that our current theory of space and time is that space and time itself are the thing that is stretching, so if you think you're not actually stretching, think about the Big Bang that happened in a box and then it expands like it happened in the middle of this room and It expands because it is the same space that was created in the Big Bang.

Bang and it's space that's expanding, so I know it's very hard to imagine, but that's the best theory we currently have for what happened, so it's not that everything is expanding into something, but that the box itself is what is being stretched, so there is nothing outside of it. in that sense, the second question about whether it will expand forever, we think not, and it is due to measurements like the measurement of the Hubble constant, so these are measurements of how fast things are moving away from each other and it turns out that this is one of the great mysteries that I could have referred to at the end of the talk but someone in this room can solve it we don't know how to solve it at this moment it turns out that everything is accelerating in its expansion as literally as you can see how much more distant galaxies are not, you would expect that because gravity is an attractive force, everything went flying in the Big Bang and then everything was trying to attract itself towards everything else and therefore if it is slowing down, and that's where everyone thought.

I really thought, "Well, the universe must start with a Big Bang and it must be slowing down, but actually it turns out that it is now accelerating, which implies that it will exist forever and continue to expand forever, but the mechanism that causes the acceleration It's not understood at all, we call it dark energy, so it has a name. It turns out that something like 70% of the energy in the universe is absorbed in this accelerated expansion, but we don't know what it is at all, it's a big question and such. Maybe you can answer it in a few years, I hope it's true and without all that stuff about Eve Simpson replacing Thomas Church, we know it's another Eve from the same school, it was just announced that antimatter has been held back for a short time.

Will this help CERN scientists understand if there is a connection between antimatter and dark matter? That's what they may have seen in India. That's a good question again. Thanks in this week's articles, CERN managed to capture it. antimatter atoms hydrogen now antimatter, I should say, it's produced all the time in these cosmic ray collisions I mentioned, we've been using it for years in particle physics experiments, but we've never been able to build atoms, so get an antiproton. and put an antielectron in orbit around the proton and for any period of time, so the big advance is that we have worked hard to do it and that's interesting because once you have hydrogen atoms, the hydrogen atom is the best understood, probably the best. system understood in the universe we understand how hard atoms work with extremely high precision because they are very, very simple, so by building antihydrogen atoms we can observe in detail the way the differences behave, if there are differences between matter and antimatter. and that's a huge question because we don't know if they behave exactly the same or if there are small differences.

We think there may be small differences because we need to explain why there really isn't much antimatter in the universe today. When it was probably done right, it must have been made in equal amounts from the Big Bang, so that's a big question: could it be dark matter? So dark matter, I mentioned dark energy, the other big question, which is a little bit more, maybe a little bit easier. to see what we might get an answer is that another 25 26 percent of the universe is made up of something called dark matter and they are not the particles that I showed in that image, so actually what I said here is everything in the universe I had. be very careful saying everything we can see in the universe and there are a lot of things we can't see and we don't know what they are and they are something like 96% of the universe so that's kind of a bit embarrassing in a complete theory of the universe.

Part of it we believe is in the form of dark matter. We don't think we're very safe. There is actually no antimatter because you would see it colliding with matter and releasing a lot of it. of energy and light and we don't see that, so we think it could be something else, it must be something else and we think there are certain types of particles that we think we could find at the Large Hadron Collider that are very strong candidates for that. So it's not dark matter, but it's interesting because we want to see if there are differences in behavior between antimatter and matter.

So what about Alex from the University of Sports ous Alex Engram? I can't really read the other videos, Alex, well how many planets do you have? Think carefully, yes, we found out how many planets there are. That's a very fascinating question now because until about 10 years ago we hadn't discovered any planets orbiting distant stars other than those in the solar system, so we just couldn't. See them, but until the day oftoday we have discovered over 500 planets and we have missions up there that are looking, they are finding 500 might be out of date, they are discovering 10 20 30 50 a week, just that everywhere.

We looked at there being planets around distant stars, so now I think we have very good evidence that probably solar systems, well, almost certainly, solar systems are very common, so there are probably many, if not most, if not all, of the stars you see in the sky. They have planetary systems and in fact a few months ago a result was announced where we had found a planet which of course could be the big ones are the easiest to see so you tend to find planets that look like a little to Jupiter and Saturn, the great gas giants. but actually recently we found an Earth-like planet, which is a rocky planet a little larger than Earth, but it's in the area around the star where there could be liquid water on the surface, so it's a planet that It probably has about the same composition as Earth. about the same temperature as Earth so it's potentially the planet that could support oceans and water and life and we're starting to see them everywhere in the sky now so I suspect all of those were thirty billion billion stars and the observable universe probably a good fraction of them have a lot of planets orbiting around them, so it's an exciting time.

I have four questions left. I have time for a couple more, yeah, sure, and what about a lawsuit? Will is a teacher question in fact how? You say virtual Carl High School vite on the right? You won't be able to read there anytime soon, so it's a bit surprising since the teachers we ranked tend to find that physics is the area of ​​science that students struggle to engage with right away, so I was. just wondering what it was that got to you when it inspired you to pursue physics as a career rather than what the other sciences are, yeah, I mean, I wonder what inspires you because I know all of you and those of you here, presumably here because at least I find physical science interesting and what really inspired me was astronomy and it was particularly when I was growing up when I was 12 years old.

I think there was actually a series on the BBC by astronomer Carl Sagan called cosmos that, and first of all, I'd like to know about. Let's just say the book and the DVDs, we can get them now, are absolutely magnificent, although this is essentially thirty years old, it is one of the best, if not the best, science series I have ever seen. There were thirteen and you can get them on DVD, you can buy the book. Sagan was a powerful communicator and I think what captured my imagination the most was that he presented Science. I hope to try to present it not as something quite dry that you know you have an Angela. man, you sit there and when you do some calculations and there you go and then you go and do something more interesting.

The sciences that I have tried to say is the exploration of the universe, it is the process of exploration in our universe, so all those wonderful things. that we're talking about planets around other stars, you know, we're getting to the point where we're looking for habitable planets around other stars. We can do it because of telescope technology, because we can build telescopes, go into space technology and the history of our origins and evolution, all that science stuff, so I think for me understanding that was the key, it's not about sums and maps, it's about doing math because that's the language of science, but actually it's about a broader vision, it's about exploring the universe and then Carl Sagan to this day is the best person that I've heard in terms of expression, I think for cosmos, I would say that "I'll borrow it.

I'll have your teachers buy it for you. Just a couple more questions. What about them? A Benissa, a Darby High School Berry beer and what would you like to have discovered in the next 10 years. What would I like to know discover discover in the next 10 years I think I'm referring to one of the things I didn't mention, so obviously the Higgs particle all of this is in the menu, we talked about dark matter and dark energy, it will be wonderful that one of the most important questions in theoretical physics is why gravity is such a weak force.

I didn't really mention that, but there are four forces of nature, three of them, electromagnetism and the strong and weak nuclear forces, so they are the forces that bind particles together to form atoms and molecules and those forces are about the same. force, more or less, but gravity is a million million million million times weaker than the other three forces, which you can imagine if you think about this laser pointer I have here. I can lift it off the ground even though the Earth is trying to knock it down, so I can resist and you can resist the force of a planet, so the gravitational pull of the Earth is small compared to the courses that Stickles puts together right there. we can just lift that up so we don't have an explanation for that, obviously it's genuinely fundamental that it could be like that, but it seems strange that three of the four forces are more or less the same, we can describe them in the same framework, but gravity is, like I mentioned, their best working theory is a theory from 1915 and it works with incredible precision, so there's probably something very interesting about gravity and I'd love to see an answer to that, but it's more of a question because I think it's We ran out of time and it's another one unless someone has a random question.

Oh, does anyone have a random date? Yes, yes, you had your first hand, your random question. I did not say that. Anyway, yeah, it's a very good question and because I think what science does is look at the universe and the things you can explain, you explain them and the things you can't explain, like Fineman said at the beginning, you try to come up with a experiment to look at the theory to try to progress so to me that's what science is right now and we don't have an answer to a question like a simple question why the universe started out right why wait there's no answer No we have an answer to that right now, so I'm personally NOT one of those people who sees a huge conflict between and, to put it in your words, religion and science, there is a conflict, conflicts arise if you say things like and I think that The Earth is 6,000 years old, so we have, I was going to say, strong, extremely strong evidence.

We know how old the Earth is very precisely from the measurements we can make on it for approximately four and a half billion years and when we know that we know all the universes quite precisely, but I don't think that in any way prevents any kind of faith or religious belief about how jitan is perfectly, so I think there is some structure that allows all these wonderful things to happen and I think anyone who says that conflict is really misunderstanding both is my correct point of view. I think it's probably Prince moment. Thank you very much again.

A real pleasure. Thank you. I'm sure you really enjoyed it. I won't do it. I'm trying to summarize, but what we were following and what people were saying on Twitter actually about this conference because people have been talking about it all over the world and like I said, you're very lucky to see it yourself and we had some technical issues. , so I apologize to the people who watched the live broadcast. There were some problems to start with and first they said Professor Cox, he's in slow motion haha, he sounds like Darth Vader and a really good Barry White impression, but I fixed it.

Fortunately, I'm just one of the other things someone said, what an extraordinary lecture, no notes, where were the Brian Coxes of this world when I was in school and someone else tweeted? I have never seen such a quiet audience. Cox rocks, um and they. and to finish with Brian Cox as a legend, if only my physics teacher was that sexy, so I'm on that note. Can we all join our hands in a game of Professor Brian Cox?