A new mazda motion of the dynamic rotational dynamics, a few basic things, they can act together and fascinating ways that build complexes and good for the third frontier in physics, the game we dont talk about and not this is middle frontier here, this complexity. Its generally not the republican. Its all quite messy, but its real and this is where we live. And thats why its important. I think they should get a lot more attention because this is what is running the world. Sustained physical flaws. This is an example of some of the things around in everyday life, differently our Current Research topics. Here are some pictures. I dont know if this thing is called. It is a new drizzle honey from if youre into that type of thing. I have a friend when i was a phd student at cambridge. Spent her entire phd studying basically the drizzling process of honey. Start started atop the not so bright and the dems at the bottom in a puddle appeared but what happens in between is genuinely complicated and they assured complicated and they assured us it was very in portland. The point is the mathematics of that comment the frontier of physics research. These are bubbles in underwater, this is what a study. This is where there is no computer model that can predict the average is in various ways. We can get useful information out. Its no computer model that can simulate the behavior. This is the reason i have a job because i cant do that. And yet this process happens every time you pour out water into the class. This is what is going on. We understand the basic physical laws exactly the details of light it can be the shape. This one is quite nice. The thing to look at it and it will be if you take them in grand materials sugar or flour or Something Like that. Couples, whatever and you pour it out. It will form a coat. It gets to a certain angle and it would just get bigger and bigger and bigger. That angle, as steep as it can be depends on what materials are made, how went they are and all these Little Things. Theres no simple way to predict the angle of repose. If you let them look at them through the microscope, it is actually very difficult to predict the process. It depends how much they interlock and take together. And yet thats the sort of thing you see in your kitchen and its relevant to real world problems. So all this is worth looking at. The first being install of these everyday things are not just toys. Its just perception and what you get the kids to play with on a sunday afternoon. Im about to tell you that its not right. This is the reason why appeared on the back to show a video here. One of these exits of these eggs is raw and one of them is spoiled. Youre going to tell me which one is which. Thats interesting, isnt it . Which one is raw . This one, yeah. Isnt that funny . Has anyone in the room use that . Who put boiled eggs back in the fridge . Apparently some people do. Its okay come you could admit to it. So heres the thing. You saw and recognized it when you saw it. This one is raw and when you stop, he very briefly put your finger on the top to stop it did if the egg is liquid on the inside dummies out the shell because nothing stops it. It gets pushed around by the liquid again. The principle with all a what it means that once something is spinning can they keep spinning and must he do to stop it here unless you do something to stop it in the point in the same direction. So thats all very useful. People go home and play with eggs. But this demonstrates the principle, which is much more important, which is this thing here is a picture of the orchard deep field. The Hubble Space Telescope has been in spacebar than 25 years. To take this particular picture, that if you took a drinking straw i think about that big and made it 2. 5 meters long, which is almost the width of the screen and he peered at the sky [inaudible] for my american publishers sent me back to thing in bed [inaudible] nobody mentions the power of the sun as rare. So anyway, the point is you have the two and a half long straw. You can see through the end of it is that. A huge amount. They are 11 and a half days, which is all very nice. Now hubble has been increased, not touching anything for 25 years. How was something just floating, how to set point at something so precisely . How does it know where to point . Thats the problem. The answer is on the inside of a something which is almost it back with the same as spinning makes except its not actual eggs. Its not spinning things because of the loss when they are spinning, they stay spinning the same direction and theres nothing to stop them. How both can affect every move around. So the same principle that tell apart the raw egg and boiled egg also lets the Hubble Space Telescope orient itself in space. It is the same physics in what is seen as a trivial thing in the kitchen and one of making these images make everybody extremely happy. The nice thing is once you get in the habit of looking is that you spot them in places and thats rewarding. So i want to take that eighth video to attack i dont normally do, but a Corporate Group of people during the day, trying to impress their bosses. So i did my bit and i was running out for bid on time. So i got to the end and should the egg video and some of us clapping. I said i want to tell you how it works. Come and asked ask me afterwards and i cleared off the stage. I had these middleaged men tugging at my sleeve saying is that this . Ive explain yes, yes. It does not go away when youre not a child anymore. Some of the nicest thing about these patterns is the peels can take a long time, but you carry it with you until it time. So the reason the picture is here is that i lived in the states for five years and the last two years within rhode island. We dont really have bloopers. Theres nothing wrong with us. We just dont have blueberries. We do now, but we didnt when i corrupt. So its addictively excited about the concept of blueberries. Ive always been lots of jam and preserves and it would be great when i left rhode island to take home light through bright blue blueberries. You should all know, by the way, when you go for picking in england, you have a soccer because you either have to bend down and really hurt yourself, hurt your back picking strawberries or you could scratch to pieces. They make it so easy in this country. Blueberry picking in this country is that we see. Anyway, i collected gallants because here in america. Im not prejudiced or anything. So i went back to make gm and you put the sugar and step in the paint and you start oiling it up. I waited and im sure plenty of you have made blueberry jam and you know what happens. What happens is what happens if you let the boiling have been. What you put in start slow, what comes out is bright fuchsia paint, which is weird. And its not blue. So i took it home, told everyone it was like berry jam. Its wrong. Says six meant later when i is back in the u. K. , i had a friend who direct it history documentaries and he was making a documentary about why swimming in the 16th and 17th centuries. They are quite decent women who wear the midwives, this would have picked up the pieces doing all sorts of useful jobs. They wrote things down. There is systematic. Theyre these things that kept coming up. Theyre obviously not testing for witchcraft, which is what they thought they were doing. Maybe theres something going on. So there were a few things he showed me. One of them is that thing that said if you boil the water in the morning, which is here in and it goes to all the colors of the rainbow, id think i was bewitched if i tried it, at seven i think think i bewitched if that were. And one of those things was if you take verbena, one of the colorful flowers you get in this manner. This neck of the woods as well. And you put it on someones skin that changes color. Then they are bewitched. I would add a bit to think about this. It turns out the bright purple and red and the pigment that makes them, the bright vivid colors is a chemical and they are really interesting. They are, not for things. Red cabbage has lost in it. Not all, but a lot of the bright touchable pigment are a mess. This thing is they act as ph indicators. If you get some red cabbage, boil it, the water is interesting because it would now be bright red. You can go around the kitchen putting it on things yet highly entertaining. It changes color. If you put it on something else, it goes blue. But alkaline is yellow and green. If you put it on acid things, it goes red. And it sort of depends on the pain youve boil it in. Theres a huge range of colors. And so, your sweat can change ph depending on what youve been doing, what youve been needing for your genetics. So as i put verbena, which just means oil and water on my skin, nor really they didnt change color. Then they change color. Iraq and what those witches, wise women were testing for is the ph indicator and they were testing the ph of people spy, which is quite interesting. And then i remember the blueberry six months before hand. If any of you to make jim know, when you make blueberry jam, what goes in the pan is blueberries and water and sugar and lemon juice. The recent blueberry jam is bright pink as it is basically the entire name is zach inept at that newspaper for the lemon juice. So i didnt stand a chance of having blueberry jam. But it was almost worth it for that little thing. Thats useful. So you build up these patches through life, through experience is as long as you know what youre looking for. And then they have the more serious consequences. This video here, the thing to watch is how fast it happened it but you are about to see his pants come in and shapes the classes from side to side. So it flushes. But if you look at the rate of sloshing, you will see that the bigger the class happens relatively slowly and a little vodka shot glass there happens really quickly. You can imagine something further off if you put water, it goes release only. But theres a lesson here. The lesson is invasive and cylindrical vessel like that, the bigger the radius, the larger the circle at the top, the solar liquid will slosh and it a few let it go to equilibrium. It does depend mostly on the range. A little bit on the depth in shape. So that is interesting. That is something called the natural frequency. Any system that can isolate, it will have one particular rate at which his swing to get back to being still. And this is the reason is bill mike t. Every day in my department at University College london. At the end of a long corridor, i am british, therefore i drink lots of tea. Im at work im always in a hurry. So i go to the tea room and make tea and then i base that during the corridor. Every morning i spill my tea. The reason i spill my tea is that by walking rate, when you bought, affect affiliate there is a bit of regular chasing of the mug in this case and it just so happens that youve given it a little bit of a push. And if you give something a little bit of a push at the same frequency as that natural sloshing frequency in this case, will make it really, really big. Its like pushing a child on the swing. If you push it at the right rate they will get higher and higher. They just dont go anywhere. But if you had except the rate base, it just so happens that my step rate matches the sloshing rate of my tea mug and therefore every morning i get enormous sloshing going on. I could slow down. I could get a very small cup and start drinking espresso because then it wouldnt matter. I buy coffee for all sorts of things, but none of them drinking it. The other thing i could do is start drinking hot shot at with milk on top because it goes down the oscillation and kind of keeps it in, which is why youve got a with lots of head on it. It dampens down the oscillation. Pubs everywhere should be very grateful for those physics. So that makes this though my teeth. If you push it to the exact rate, you push up really high. But then its got more serious consequences. There is an earthquake in mexico city. Mexico city was very bad and afterwards, your army corps of engineers looked to see what lessons could be learned from what they found in terms of building and they found something really interesting. And they were basically fine. Buildings about 20 stories high and there were lots of them, the ones in the middle fell over, which is weird. So then they had to look at the actual earthquake itself and might have in the ground. Its pretty unusual. Theres lots of sediment they are. Its a very specific hard base of sediment on top. The consequence, an earthquake come in the shape of an earthquake is normally quite complicated to the consequence of geology in this case was the foundations of mexico city basically shook the frequency. So the geology amplified one particular rate. Tall buildings tend to sway. And each had a natural swaying rate. The taller the building, the slower the rate. It happened in this case that the natural frequency of the buildings between 20 stories high is almost exactly the rate of that particular earthquake. So there are the ones where the shaking became through and they fell over. So youve got a very important Civil Engineering con the client which you can see in the cup of tea. Want to know about things, you can also do something about them. In this case, not in mexico, but this building here, which was for a while the tallest building in the world. This is quite close. If you dont like swaying buildings, this is not the building to go in. Everybody else is not a tall building. Extremely clever. I would love to go. In the middle of this building, a third of the way down from the top. Inside they put something fascinating. That these are stories from this that they put a gigantic pendulum five stories high hanging down the middle of the building and then they spraypainted gold. Why wouldnt you. But its weighed independently of the building. The reason they put it there and its fantastically clever. Youve got the pendulum hanging in the middle. When the Building Space that way, the pendulum is left behind and if the Building Space back, so the building and the pendulum sort of swaying against each other, which reduces the overall swaying of the building to about a third of what it wouldve been otherwise. It takes about 30 seconds for a ticket from one side to the other. You can see this video of the people watching it during an earthquake. It have to be pretty interested to be staying in and watching. Theres a video on youtube. But it harder. So once you have these, you can manipulate those around you. These are big problems, not just trivial little toys. And this is the professional scientists and engineers. Really those subjects are about what you can create using these patterns. I like the finding things out, but the game i really enjoy the most is the locked into the lab. I dont know how to do it and ive got lots of little toys to play with. What am i going to do . It doesnt always lead where you expect. The reason this picture is here, this is a natural diamond. They dont often, i cant. To walk around at this timberlake, which surrounds most of them. They are very often founded. The reason this picture is here is because of a friend of mine in my life and as a phd student called jazz. His job was to study diamonds being hit very hard. So they came here is to breaker rock. The larger breakout but should you want a break time ends. But how diamonds breakup of the impact lately. The way you do that is to have a thing called in our case a tube about how wide, five meters long. And its easier to move some thing so you put your diamonds down dissent with highspeed photography and offense of clever diagnostics like this. And massive reservoir of pressurized sphere and then you put this slug of plastic and rock in this case here. So when you release the helium, it pushes the team down here. Now it could accelerate the project files to two kilometers per second. The newest one is straight to cambridge. Causing lots of holes and lots of old buildings. That being here, which was invented in the chamber, there was a huge battle for the change. And so, the projectile hit the diamond. You have a big sword of flame to set the rags on fire. It was sway, being on the stab and they would be no holes in it. But you needed all of this year to absorb the momentum and you needed to rank better in order to stop and contain everything. You needed something in there. I just had a problem the problem was you could take all these pictures, that he wanted to get the bits of diamondback are the problem is he never did because he disappeared into the ranks. And so he spent a while trying to work out what he could do. Which physical tools could be used and get his fifth of diamondback to see whether they broke up further down the line. Ill never forget the day walked in i love having come from the local supermarket that these two big banks full of strawberry jello. And he put these down. So he spent two days working out what ratio had to go with the jello to make the right thing. He cleaned out the gas chamber and put strawberry jelly. The idea was to strawberry jelly you could set it audio mind so you set this all up, put the diamond down there, evacuated the thing, lots of helium over here. They shut everything down in price button. The project comes down to kilometers per second. It goes straight into diamond. A whole lot disappears. Now, but no one had told him was that when you put it under pressure, jello liquefies. So the strawberry jelly and only liquefies and resolidifies and he never got his diamondback and he did spend the next three days during that. But i have enormous respect for this. I love him for a bit for having done it. If it had succeeded, that wouldve been a revolution of diamond catching technology. Sometimes it goes wrong. Sometimes you do your best to use tools ended as the work. You learn something. Thats where the real fun with the tools comes from because then you could work out ways to do something with them. And sometimes it works and sometimes it doesnt. You dont need to laugh in all of this sort of thing is the equipment to that Critical Thinking drive what youre doing, to learn something from Critical Thinking. This guy here one a prize in 2009. Some of you may know the prices may chew last and then makes you think. If you dont know what they are, look them up. Anyway, when he was six or seven years old, his grandmother caught him cracking his knuckles. I do this with High School Kids and the 2000 children start cracking their knuckles. So you know the Little Popcorn noise. And he said to do that because if you do that, when you get old, you look at arthritis. But he wouldnt take her word for it. So for the next 60 years, this awkward click the knuckle on his right hands, but not on his left. At the end of 60 years, he didnt have arthritis in either hand and read a scientific paper on it. So its not necessarily the recommended way for doing science. But you have to give them credit for not taking someones word for it. Testing it and having dedication to follow through. If they had been around you would have had arthritis. But he learned something and theres a lot of Little Things in life, not necessarily serious or important. You can either go for yourself. The problems you can have some basic knowledge and tested out and you can test your hypothesis whether its right or wrong. Can anyone tell me what time it is . I cant see it. Ive not been on for too long. All of this stuff is about every day complexity. The first thing is understanding the basic rules of the world. The reason this picture is here is my grandfather, my mothers father is one who trained during the Second World War and after the war he went to work at emi. There was loads of paper tape with code written on it. And then Something Like that, loads of laptops couldnt really tell you what theyre up to. And the problem is that when youre dealing with this kind of thing, especially with things like touch screens, its very easy to get taken away from the basics of the physical world. And yet we still live in it. We still have bodies that are the same size, chairs that are still about the same size, and this is about the right size for a piece of toast. But the problem is this is technology, it takes it lets you be a little bit lazy, for a start, because there are a lot of things you dont have to worry about anymore, and you cant fix it anyway. Any sufficiently advanced technologies are indistinguishable from magic. And an ipad, whats it called . Surface, have passed that boundary by a long way. So, but in contrast to that, the internet makes possible more access to information than ever before. The problem now is not that the information isnt accessible, its that you dont understand it when you get there, because its complicated. But that makes it really important. The way to deal with all this complication, i think, the way to start is to understand the framework, because it still has to obey conservation of energy, it still has to obey these basic rules. It doesnt seem to make it very clever to have it happen efficiently. The fundamental rules of physics are not broken however magic the device seems. So i think this is really important because, you know, theres lots of confusing things in the world, and theres too much information, right . But the framework, when it comes to the physical world, the framework doesnt change, doesnt apply to economics. But we have a fundamental set of physical laws in fizz you cans that are physics that are at the root of everything, and the same things apply to, you know, the big important things like energy plies and, you know supplies, and medical testing and all that kind of thing. So i think its really important that we dont trivialize these toys because thats our way in in a complicated, confusing world. Noticing these Little Things about the world that teaches the basic physical laws that provide the framework for everything that happens around us, thats an important thing. And be everyone can try it. The time i knew when i might have, i might have done something useful with the book, so i gave it to im a [inaudible] player. Probably most of you have never be heard of that sport. I like it. My club in wimbledon, in london, you know, lots of people there. They know me as an athlete, they dont know much about my science, so theyre very good for constructive feedback. And i sent one of the draft chapters to one of my friends, and i got a text message back a few weeks later, and it said so he was working overseas in switzerland x the text message said im sitting at breakfast in a posh hotel in switzerland, and i really want to push toast off the table because i dont believe what you wrote. [laughter] and thats the good thing. He he doesnt have to believe me. He can just annoy the waitress, right . But hes free to push toast off the table and watch it happen for himself. And if he doesnt agree with me, he can push toast off the table in front of me, and well both look at the evidence. Its right there, and you can play with it, and it just takes a bit of habit and a bit of confidence because physicists are not very good about, you know, sharing, i think, the idea that this isnt just about knowing things, its about your perception of the world, your perception of things changes. And you walk around carrying that. And its very useful, and no one tells you that. So ive told you now, so you all know. So well skip that bit. The other thing that isnt going away is the complexity, having dealt with the fact that maybe we can do something about those foundations. The other thing we have to deal with once we understand the framework is being comfortable with ambiguity and being comfortable with the difference between not knowing everything and knowing nothing. Horizon is a very longrunning series of bbc science shows, and we made one in 2004, this is thats me in one of britains Weather Forecasters, john hammond, and we made this horizon so we had a few unusual winters of weather in 201314, and we made this show about why that happened. And if the bbc had ever understood how complicated the answers to the question was, they wouldnt have let us make the choice, so we didnt tell them. [laughter] its all these things,wets comply catted weathers complicated. And you get this a lot here because your weather map includes a much larger area than ours. I dontyouve got el nino, the t stream, the north atlantic oscillation, all these different things, all these patterns overlaid on each other. And so we understand a lot about the weather. We dont understand everything. We cant weather scientists cant piece together why these winters werent particularly bad, but its not as simple as a causes b causes c. Hard to predict in advance, but afterwards you can kind of trace back. The importance thing is theres a huge difference between not knowing anything and having, having that sort of knowledge. Cant say in two sentences, but theres a huge amount of understanding. And i think this is a sort of, theres a point coming up where this is what science is like now. The interesting bits are not that complicated in the middle. And the problem with the complicated bit is foundations are still the same. You can explain the dynamics and various other subtle patterns. You use the same rules to explain it, but it takes, you know, a long essay and not two sentences, and you have to put a little bit more work in putting all the pieces together. So in order to trust the Weather Forecast, fundamentally you have to trust the system that the Weather Forecast is based on x the system is science. The system is weve got some evidence, were doing the test the hypothesis against it, revise our opinions and get more ed and work our way through it. So because its complicated, you have to trust where it comes from in order to trust the overall thing. So being comfortabling with uncertainty and understanding what it means to have understanding of a complex system, i think thats a very important thing. Because this there is never goio be an answer thats just one thing. And i think each of us has three life support systems, a body, our planet and our civilization, and each of them is keeping us a alive in its own way, and theyre independent systems. For example, one of reasons that Climate Change is an issue is that its two of these life support systems butting up against each other. Weve got our planetary system which kicks along, and we rely on it, and then weve got our infrastructures of civilization which keeps us alive in terms of food and water and growing stuff and all that kind of thing. And we have to negotiate that boundary. But each of i mean, its interesting, its funny, you can lay weeings, and it satisfies curiosity and all this kind of stuff. But if youre more pragmatic than that, this is the reason for doing it. If youre not interested in anything else, youre probably still interested in keeping yourself alive, and the rules that keep these life support systems going are the patterns of physics that you can see in your kitchen. So its probably quite important to understand them. And these all end up being quite complicated systems. But the fundamental layers of understanding are built from the same things. And so thats my, you know, if youre not convinced by physics just being interesting, hopefully, youre convinced by that as a reason. So, you know, this is a kind of classlike environment, theres going to be homework [laughter] so things you can try at home to get you started on playing with toys. So lemonade in britain, i need to change that for u. S. Audiences. We are very uncities candidated with lemonade sophisticated with lemonade. What that should say is soda. In britain we call stuff lemonade that has never been near a lemon. But you are better than that [laughter] sometimes. Sprite doesnt count. Anyway, bottle of fizzy stuff, take the label off so you can see, stick some raisins in the top, watch what happens. Its very interesting. Also very good at parties, if youre with boring people. Its got two effects, it makes the boring people go away and makes the interesting people come to you, so you win both ways. [laughter] spill some coffee and let it, leave it alone. Take a picture of the spill and then come look at it later and take a picture of whats happened to it afterwards when its dried. Theres a really important difference that youve all seen that is worth looking at. And get a teaspoon, if you cant be involved with the mess, get a teaspoon and get a ceramic cough cough coffee mug and listen. And push some toast off the table. If you want to extend that one, see if you can find a way to knock it off in a way that it doesnt always fall butter side down. Its messy, right . There is a physical solution. It is quite messy. But its worth trying. So im going to stop talking, and we have time for questions. Thank you. [applause] if you do have a question, we ask that you come and ask it at the microphone and keep your question in the form of a question. Thank you. Teal free to ask about feel free to ask about anything. I mean, anything in reason. Theres a race going on here. Whos going to get this first. Go on. Oh, god, hes got notes. How do you develop the practice of say that again . How do you racks practice it . Practice. Well, my publisher would say read the book, but by, you start by it starts with looking for things that are the questions that kids would and then looking at why. Thats, in the modern world, thats the easiest way to do. Its really hard to resee the things youve stopped yourself seeing. So, but once you spot one, hold onto it, right . Youll have those thoughts that drift through your mind that say, oh, isnt that odd . And be it starts with at that point not dismissing it, right . File it away. Youll see something, right . And even if its con trails in the sky or the way that ripples travel across a pond, therell be some little thing, oh, thats a bid odd to. Hold on to that, thats the first bit. Better than looking it up. But it starts with catching the thoughts. Adults are always suppressing things, right . Thats what part of the process of growing up and being an adult is, theres too much complication in the world, so your brain just, you know, you learn to suppress anger and frustration, and, you know, youre always putting the lid on yourself. When it comes to science, take the lid off and just hold onto what came out. So thats the place to start. Yes. Im not sure the british practice of making tea, but i was wondering if theres a tea bagging involved on your walk back to your office, and if that would be analog to that pendulum in the building. So, ah. So the way the tea bag has got two effects it could have, actually. The first thing is if you make tea properly, you take the bag out before you put the milk in. I wish someone teach starbucks that. Anyway half laugh if in an industrial setting the process, one of the common ways of preventing it is to put battles in the container which is to put in things that stick out and are obstacles to the sloshing movement, so inside underwater. So a tea bag would definitely do that. [inaudible] yeah. So if you can face the washing up so you want the shelves thats what an industrial engineer would do who didnt have to do the washing up. The other thing you can do is have a cup, a mug that comes around a little bit, hold the sloshing in. And then what else would a tea bag do, what sort of thing . You would get a bit swaying, but the swaying, theres an interesting thing now with upper shah, let me think about that for a bit, was the tea bag isnt free to sway in the same way as the ppped lumbar is, so its range of motion would be very limited. It might depend on whether you had a tea bag or a flat one. I think the major effect would be abouting as a battle and just getting in the way of fluid trying to move past it. Because in order for that sloshing to happen, the fluid underneath has to move as well. But the fluid all the way down is actually shifting a little wit, so if you stop that process. So we can all do the experiment now, go home, its time to have some tea. And the other thing the tea could do just a little bit is reduce the if it was sitting on the bottom. So lots of experiments to do. I dont know the answer, but you can all go and try. Thats the west i can do with that. Yes. Hi this. Hi there. Your friend in this case blasting diamond parts and then trying to analyze. That im sure it happens both ways, but when youre a physicist and youre looking for a job, i hoon, do you typically find more often youve got the one crazy idea and youre just going to make a job of it and get someone to pay you for it, or do you find it more often after you decided that you like this bit of physics that now im just going to search for jobs in this arena . People dont always pay us to play with toys. That is the sad thing. So, yeah, exactly. Boo. What normally happens is that its driven by an application. So it depends on theres pure physics researching and applied physics research, and ideally you always dealing with a little bit of both. The applied one is when this is a problem and you find ways to solve it. When youre an academic if physicist, you can do all the experiments you like as long as you can find a way to afor them. So pay for them. So this is always a bit of a balance. I mean, theres so many answers to that question, but normally you create an opportunity to do Something Interesting and assume its going to take you to the next interesting thing. Its not like you go after a single goal. You turn jobs into what you want them to be but youre interested in what youre good at, you know, what interests you will be something youre good at, so its not like you get to pick. Theres no [inaudible] just curious for your input. Thank you. Just for the record, any all questioners so far have been very homogeneous in terms of their gender. No, they havent, thatses not quite true. Theyve been quite homogeneous, but lets have a mix of people coming to the microphones. Right, go on. Youre still allowed. Im okay then . [laughter] yeah. Okay. Ive got to you have to at least get me started with the toast thing. I think whats going on is the butter has a greater mass its nothing to do with the butter. Oh, really . You can try it without butter on. Okay. So i havent got a clue. [laughter] but you see, you could have, you could have. All it would have taken, right, is for you not to do the thinking, but to actually go and get two pieces of toast and put butt or on one and not on the other one and watch im constantly trying to teach my students especially the young ones not to think they can think through a problem and get to the answer. Youve got to check along the way against reality. So before you go out about thinking about up some enormous hypothesis what you do is you try it with butterwithout, and see if there is a difference. Part of the discipline of science is not thinking too many steps ahead. Youve dot to prioritize the first problem youve got to prioritize the first problem and they they check, and then you find out where the first problem is worth worrying a about. Sorry to shoot you down, but its not about the butter. Yes. Your genderrer question, all the men in physics and then you. How do do you get more women involved in physics . Because really it could be very exciting. That is a question thats got an hour and a half answer which i will spare you, but there are the first be thing everyone can do if youre interested in this is read a book called delusions of gender, and its about the socialization of brains and how fundamentally above everything else, humans are social creatures, and we behave, we are programmed almost to behave in the way that we think people expect us to behave. And so the gender, having a gendered society created problems that are very hard to escape because your brain is constantly even though youre not aware of it, what am i expected to do. So the first thing is Everybody Needs to realize that book which is reference to the hilt with very solid academic references. The biggest thing is changing the environment. So science has traditionally been seen as something which is, its about right and wrong, its almost an aggressive our way or the highway type thing. And its not traditionally seen as being about conversations. And the manner in which a lot of fizz bicses departments and engineering departments still operate is very old school and aggressive male. And changing that culture is the biggest something thing that will change the number of women in physics. And that involves the men accepting that making, modernizing the workplace is better for everybody. Its not doing things for the women. Its modernizing manager which makes it were the for everybody there. Im very proud to work this a t. At ucl where the people who go home, you know, at 4 00 to collect their kids are the men, not the women. So i think really this is lots of types of diversity. We to not have a diverse scientific work force, and its a huge problem but making it better but the idea has to be pushed forward by everyone because its better, not because its giving something to somebody else or sort of creating friction. Its better for everyone. Its an attitude thing. Theres always these things about the leaky pipeline and, you know, stereotypes and why women stop doing it. There was a report that was published in britain three or four years ago that suggested evidence at the moment, the reason women dont leave, reason women leave physics is because theyve got Better Things to do. They can do the technical stuff and the social skills. So they go off and get paid huge amounts of money in industry. Is so theres lots of different ways of looking at it, but that attitude change that its a modernization process and its not optional and a culture change has to be taken very seriously. Thats a hard because people assume, everyone thinks their thing is normal, right . And theres a lot more listening needed about different ways of the way you can run science. So, yeah, its a hard problem. Our last two questions. Last two questions then. So i know that Quantum Mechanics, things very small follow one set of laws and things that are very large follow another set of laws, can you talk about the stuff in between and what laws they follow . So there is yeah. The interesting thing about scaling laws in physics is that all of the forces are present all of the time. But theres always a sort of hierarchy of priority. So, for example, where i am standing on stage gravity is the force which is making most difference to my body immediately, you know . There are electrostatic forces, surface tension and all kinds of things, but gravity dominates because of this size. So all of the forces are always there. Finish so sheer force is from viscosity, for example. I can move my hand around, but the viscosity area is basically negligible, so it doesnt make any different, but if you were to make my hand really, really small, the viscosity of the air suddenly started to matter more. So as you make things smaller and faster, exactly the same laws are there, but different ones are at top of the hierarchy. Thats why i a tall or the if youve got a towel or if you got some absorbent material, the liquid will only go so far. But if youve got something that was quite big with a play frame with great big holes, youd put it in a butted being, and nothing putting, and nothing would go anywhere. The ones that dont matter are so insignificant most of the time that we can completely discount them to a good approximation. So its an interesting problem because you shift, and it become interesting when you do things like working out what life would be like on a different planet. Theyve got different values, so the hierarchy could be different even for something my size. So it leads to all this interesting sort of speculation about how your [inaudible] in different environments. If you want alien life, dont bother going to mars. Just go to the bottom of the ocean. Last question. One comment to the gender thing is giving women the opportunity to rise to the challenge. So challenging women to come up and ask questions is the first thing that actually gets up here to do it. One comment on that. My question with was very similar to hers, so im going to switch it up a little bit. Do you think that we have all the tools necessary to create a universal theory of everything, and is that possible . Oh, philosophy. Lets finish on philosophy. So universal theory of everything has, there are different interpretations of what that means. In it broader sense, its a set of consistent theories that explain everything we see experimentally. Theory of everything, the grand unified theory is this thing where Quantum Mechanics and general relativity have to mesh, but they dont play nicely with each other. Black holes are, you know, one thing. And they might be quite far apart, those two theories dont have to talk to each other until you get inside a black hole or back at the beginning of the universe. We though that Quantum Mechanics and general relativity cannot both be perfectly right because they have to talk to each other at some point, and at the moment they cant do it. So theres that kind of grand unified theory whether some modification needs to be found, but no ones quite found where the matching process is. When out comes to the the bigger question of how you, whether a theory of everything is possible, i think that history is littered with scientists who thought that it was just about the tidying up now. Weve basically found everything, its just about science is full of surprises. I think that, the thing that the reason im hesitating is for it to be science, it has to be testable. For you to have a theory, it has to be testable, and a lot of theories about the universe and the multiverse ask things like that, its very difficult to test them. So it may be possible to have theories that explain everything we see, but there could be two of them that both explain everything we see, and we cannot distinguish between them because we cant create an experiment because we cant go outside our own universe, for example. Finish so it is likely that something will not be testable. But it doesnt mean that we cant get the right place. And i cant think of thinking worse than science as a friend of mine once said very, very well, science knows it doesnt know everything because otherwise it would stop. And it would be, its such fun to do, and its such a fun journey to go on, but it would be a terrible thing if it was to stop because it wouldnt be fun. So maybe i hope we dont have find a theory of everything, because then well keep having fun, and maybe thats a good place to finish. [applause] [inaudible conversations] be. [applause] and live now to the National Association for be business economics hosting their annual policy conference here this washington. Todays speakers include White House National trade Council DirectorPeter Navarro and former Budget Office director douglas elmendorf. This event just getting underway. To deliver this keynote address is indeed a great honor, and today the broad topic i want to talk about is whether trade deficits matter