 Yn ymwhysh Chevhurd Hallan yng ngyflaeth. A yw'r lei'r le 이걸 yw ein ddael gan Yng Ngwylltyn Fyloedd Fyloedd. Rwy'n ei hwn o'r rei ei hynny a oedd y ddweud â'r Fyloedd Fyloedd Fyloedd, i gyd ymddynt yng ngyflaeth yw'r usud ar y ddweud Fyloedd. Mae'r oled 5 o ddweud ar gyfroedd o'n mynd i ddweud a'r gwenafdd o'r ddweud. Yna'r ddweud am ymddysig a ddweud i'r ddweud hefyd. ddysgu cymryd, mae'n gwych yn ymwneud yn deimlo'r hanes, a rydw i maen nhw'n ddweud eich hun o'i fath o'r hollegau. Rydw i'n mynd i'n ddweud mewn gwirionedd. Felly, rydw i'n ddegi'n gwybod yn ddegi'n mynd i'n ddegi'n ddegi. ar gyfer gwlad am gweithio ar gyfer y byddwyr i ddigonnog a'r ysgol Ysgrifennig, gwweld ar ymddi'r lle hwn i am ymddangos am ymgyrch â'r af countryside ac ymddi'r lle bod yna gallai ei gweld hynny yw'n ei wath ar gael i ddechrau hynny, ond byddenni weithio'r gweithio yn meddwl. Rydyn ni'n meddwl bod rwy'n meddwl yn ei weld fathcrydd ar eich bod arnymnol yng Ngheitwyr. Yn y gallwch chi'r pallig yn gweithio'r diwylliannol yr ymquadriegol, Felly, mae'n cael ei wneud yn fwy, ac mae'n dweud yn cael eu fawr yn ei gweithio. Fawr iawn i'r FFWD. Mae'n ddadfod David James, a'n ddweud i'r ddwy'n gweithio'r llyfr o'r unig i ddim ymgyrchu o'r Llyfrgellwynau Jynghraen, o'r Shreffordd, Helm University. A oedd ydym Leone Foster a Sean Clarkson, sy'n chwilio'n gweld ymgyrch, yma yw'r eistedd o'i ymyd? Yn ystafell, mae'n gweld i'r Llywodraeth 2012, yn y cyffredin o fwy o'r wneud, mae'n bod yn fwy o bwld o'r cyffredin, mae'n fwrdd ymweld yn fwy o'r ffantastig gael. Ond yma'r ffantaf, mae'n rhaid i'n rhoi bod yma yw'r cyffredin, sy'n fwy o'r cyffredin. Mae'n rhaid i'n rhaid i'n fwy o'r ffantafol. Mae'n wneud i ddweud bod hi'n cyngorlo cyngor i'r colli awdurdod. Roeddwn i ddim yn ymhygoel i chi yw, a gweld i'r hynny'n gwneud hynny i'r cyngorlo cyngorlo cyngorlo. Mynd i'n gweithio yma o'r llwyddiad yma yn y llwyddiad. Mynd i'n gweithio cyngorlo cyngorlo cyngorlo cyngorlo, rydym wedi bod yn cymryd o'r phwnghysg ar y fan hyn yn y cwm. ond we use that knowledge to try to create new products, to create ideas, to work with athletes to make them be better at what they're trying to do. So sort of things we do, we look at things like forces are very important to us, you know, understanding what the fundamental forces are, where they're acting, how big they are. That's a really good starting point. We also spend a lot of time looking at materials. The world of sport has gone through this sort of a revolution in terms of the materials that get used. Felly, ychydig, mae'r rachysgau tynnu'r rachysgau tynnu arweithio yn y roi 1970 ac yn ym 1980, yn ymweithio'r rachysgau tynnu. Mae'n treffaeth gwaith, ond mae'r rhaid yn ymwneud yn ei wneud, oherwydd hwnnw'ch chi'n gweithio John McEnroe swyddfa ar y TV oedd eich cwbl pan yw'r cymryd i'n mynd i'r cyffredin yn Wymbledyn. Ond mae eich bwysig yw'r rachysgau tynnu arweithio. Yn rhaid i'r gweithio'r rachysgau tynnu. Not just that, obviously we've got the European Football Championships happening at the moment as well. Football in the 1960's was played with leather footballs that used to absorb moisture off the grass and rain. We used to double en masse during the game. And, of course, now today we play with balls that are quite different, you know, thermally bonded synthetic balls that were all together quite different really. And that has implications for how the game is played. So materials are really important to us. I guess another area of things we look at Os y gallwn ar gyfer frein iawn, ac mae'n gweithio, a hynny mae'n gofio'r bod yn y bwysig ac mae'n gofio'n gofio'r cyfrifthau ar gael. Rwy'n credu y ffrin iawn i'r rhaglen, mae'n gofio'n gwneud. Ond yn dweud, mae'n gweithio'n gweithio, mae'n gweithio'n gweithio'n gweithio eich swymau o'r gweithio'n gweithio ar yr iawn, o'r gweithio a'r cychlyst o'r gweithio ar yr ael. Mae'r gwyllt o ffrin iawn i'r sport, yn frywyd golygiadau isi gyda, ac rwy'n rai fydd rwy'n cael eu gwahod o… sydd gweinydd o'r cyd-gylcheddau neu'r cyfnodau, maen nhw'n gweithio i fy enwau o'r gair, ac mae gweithio gyda'n rhai fydd rydyn ni, oherwydd, oherwydd o'ch chi fod ni'n golygu fydd o'r fyfyd, mae'n mynd i gyda'r mynd i gweithio'r gweithio. Felly mae'n gweithio i'r newid ynhell o'r fyrniad. Felly mae'n gweithio i fynd i gynt11. I gogyntgedwch an ни failure a yr hynny Kiardwch yn rotate'r dweud.. ..ynd i fe bydd yn gwbl fwych ar hyn cyhoedd fan fy modd. Rydych ti'r tym Llyw Gyd Casgrothau Po, yn gwimbod yn ei tardu iddo yn gallu wneud hynny. Ei hwn yn agon ôl, mae rydy patientsau ym bwrdd yboxing afael sy'n hollaw i adeiladau sydd.. ..wy modd yn ddelch yn gwybod yn Flyniad y Pas yw. Mae'n olygu gydig o'r dyn nhw yng Nghymru. Mae'n olygu'n gydig i'r ddyfyn nhw'n dyn nhw'n fwy o'r dweud o'r dwylo'r Llyfrgell Pwysigol. A'r dyn nhw'n ddwylo'n ddim yn ddwylo'r dyn nhw'n ddwylo'r dynnigol ar y gydigol sy'n ddwylo'r ddylch. Yn ystod y gwybod dyn nhw yw'r dweud yng Nghymbrun. I'm sure we're going to start off with a bit of a scientific hypothesis. And that is that top sprinters equal great long jumpers. As a question, do these two disciplines go together? Very nice. There's quite a lot of anecdotal evidence to suggest that this might be the case. For instance, Jesse Owens in 1936 was one of the all-time great athletes who won the 100 meter sprint and he won the long jump. Fin Mynd Cffbd that's just just one example so I don't know maybe it's true Maybe it's not I've got some other examples as well. I've got other fantastic athletes. Carl Louis, again an amazing sprinter won gold medals in the 100 meters and also won gold medals at the long Jump so athletes seem to be able to move between these disciplines quite easily. And also, of courseamary and Jones slightly more recently winner of the 100 meter sprint and and the long Jump as well. ond we can't just use these anecdotal bits of evidence, we have to really delve deeper into the data before we can start to maybe draw any conclusions. So what we've got here is we've got a massive data set and I'll try and talk you through it. Essentially what we've got here, so first of all we've got these are years, these are dates on the bottom so we're going from 1918 up to 2010, 2014. And each data point represents the average of the top 25 performances in that year, so it's a huge data set this. So we've gone through all the record books and figured out who are the top 25 competitors in any year. This is a global data set, who are the top 25 and we figured out their average, we've plotted it on a graph. And we've got two data sets here, it's a tiny bit complicated. We've got the 100 metre sprint in time here. So in 1922, if we go up here we can see that the average 100 metre time for female sprinters was just more than 13 seconds. We've got another data set as well, we've got the long jump. So on the long jump in the same year 1922 the average distance jump was just about 4.9 metres or something like that. So that's the data set we've got and you can see there's been big changes. So obviously in the 100 metre sprint times have come down really rapidly, they've kind of leveled off. Equally in the long jump distances have gone up and then leveled off. What I find amazing is they seem to be quite symmetrical in terms of the shape and the profile, they've got very similar features. So for instance here and here you see this dip in performance and that coincides with the Second World War. So I think it's really fascinating. During the Second World War obviously it's such a global impact on our world that people just couldn't participate in sport. They had far too many other things to be worried about so sport and performance dropped. You see another interesting trend here is that really both in the 100 metres and especially in the long jump after 1989-1990 performance is level off or they go down until that date and then it goes level. What's quite interesting here is 1989 was the year that widespread drugs testing was introduced and that's when we see a very significant change in how our athletes are performing. Now I'm going to just manipulate this data slightly and what I've done here is I've actually represented the 100 metres, not in time, not the performances in time but in actual speed. So average speed and that means that we can just compare these two data sets a bit easier. So you see they're very similar. We can actually correlate these two data sets now, plot them against each other and we get this really nice correlation, very, very strong correlation indeed. So they all line up on a line and we've actually got the female data there and the red dots and then the blue dots are the males and it's all in a nice flat straight line continuum there. So we've got a very, very strong relationship. That's a highly significant relationship that means something really interesting is going on here. So we're pretty sure that there's a very strong link between running fast and being a good long jumper. It's pretty confident about that. So I guess the question, we kind of now want to ask ourselves as well, this guy, Usain Bolt, he's the fastest sprinter in the world. So how far could he jump? He doesn't do the long jump but just theoretically ask ourselves the question, how far could he jump? And to do that we're going to have to delve into the physics of this event. So what are the physics of this event? Well, essentially the long jump is really a case of sprinting down a track, you've got 40 metres run up, you hit the board and then you've got to jump as far as you possibly can. Once you're in the air, your movement through the air, we act like a projectile. You might have heard of projectile motion in your school lessons. Well, as a long jumper, once you take off, your movement through the air is that of a projectile. We've got some good physics that can explain projectile motion. So this will help us to understand this question or push forward on this question as to how far could Usain Bolt jump. So what is projectile motion? Well, essentially projectile motion, we've got some equations that can explain really the path of an object as it flies through the air. Given an initial set of conditions, say it's launch angle and it's launch speed, where would it go? What would the range be? And it all depends because it really depends on the angle that you take off at. So if you take off at a very steep angle, you're not going to get particularly far because you're essentially using a lot of your speed just to go high and you're going to come down. If you take off too shallow, again, you're not going to have enough height to get the range. And of course what we find, and I'm sure many of you will kind of know this if not theoretically, but maybe by experience or just intuitively, you'll know that the optimum angle to get the maximum possible range is 45 degrees. So literally halfway between being horizontal and vertical. That's the optimum. We've got some sort of nice bit of physics, nice bit of maths to explain that. Essentially the distance that we're travelling, that's the thing we're interested in. So d is the distance, okay, v squared, it's velocity times velocity times itself. That's the launch velocity. That's how fast we're sort of launching it at. G here, that's the gravity. That's the acceleration due to gravity. So when you kind of know this, if you hold something in there and you drop it, it accelerates downwards due to the earth's gravity. And it accelerates at 9.81 meters per second per second. So that's the acceleration due to gravity. We've also got the launch angle. So there are key things. And really the two things that we can change as a long jumper are our launch velocity and our launch angle. If we take off at 45 degrees, we get the maximum range. And of course the range we get is also dependent on how fast we run. Really dependent on how fast we run because that's a squared relationship. So you times it by itself so that becomes really dominant. Now things are a bit more complicated in the long jump. And they often are. We start off with these sort of nice simple ideas and quickly find out that they're a bit more complicated. And one of the complicating factors in the long jump, when you're doing the long jump, is actually a difference between your take-off height and your landing height. And that's because you take off and you've got what we call your centre of mass somewhere in the middle of your body. And you take off and that might be maybe a metre high or something like that on your take-off. When you land, because you sort of bend over when you land, your landing height is different to your take-off height in terms of where your centre of mass of your body is. Now this changes that optimum angle and so it actually reduces the optimum angle down from 45 degrees. Because another problem as well and that's that, if you're a long jumper, you're running down the track as fast as you can, you put your foot down, it's pretty much physically impossible for you to take off at 45 degrees. You've got such amount of horizontal speed, it would take a monumental effort to jump upwards to get a 45 degree angle. It's just not possible. We haven't got the power in our legs to be able to do that. So what tends to happen is that athletes tend to take off with a launch angle of about 33 degrees. If you measure loads of athletes, that seems to be the optimum angle that they take off at. And there's another thing that happens as well and it's that when you do this take-off, you put your foot down and you sort of jump upwards, you actually lose speed doing that. So you might be running along at your maximum speed, you hit the board, but then you lose speed in that take-off moment, maybe sort of 10-20% of your running speed. So all that you have to sort of consider how all these things now play into it. I think we can deal with this though and we can actually start to still answer this question. What half hour would you say in bolt jump? You need to know how fast he can run first, that's one of the first things we need to know. And we've got some good data here. This is when Usain Bolt got his world record in 2009 at the World Athletics Championships in Berlin. Some scientists tracked his movement down the 100 meters. And effectively we've now got this nice bit of data where we knew where he was at different stages in that race and we've got a nice plot. Now of course what happens in the 100 meters, you don't run at a constant speed all the way along because you start off stationary, then you accelerate to a high speed and then maybe you sort of coast in at that speed. So your speed's changing throughout the race. And of course, I guess a lot of us would probably know as well, that to figure out the speed that someone's moving at, we're actually talking about the gradient of this distance versus time graph. And the athletes are going at their fastest when that graph is at its steepest. And actually, if you see, the graph is at its steepest around here, around the 40 meter mark, about four and a half seconds. So what we can do is we can calculate the gradient of that graph and that's the speed, the maximum speed that Usain Bolt can run at. So essentially what we do is we divide the distance travelled by time. So speed is distance divided by time. We kind of know that because we talk about miles per hour distance divided by time, don't we? Figure it out. And his maximum running speed in this event anyway when he got his world record was 12.1 meters per second. Just imagine, it's what it says, he's covering 12.1 meters in one second. And if you imagine that this whole room, I'd imagine, from that far end to that far end is probably about 10 meters, he's covering that distance in our seconds, giving the idea of the amazing speed that he's travelling at. So we know the speed. We're pretty sure that's his maximum running speed. So how far could he jump? Well, we've got his max sprinting speed. Handily, he actually can reach that speed because he accelerates from zero up to that speed and he can do that in 40 meters, which is quite handy because that's the length of the run-up for the long jump. So he could hit the board at 12.1 meters per second. If we assume, say, he loses 15% of his speed, some athletes would lose less than this, but this is a sort of a conservative estimate, say he loses 15% of that speed at take-off. So he takes off at 10.3 meters per second. Assume he takes off at 33 degrees, so this is the sort of very well-known take-off angle. We can assume he's got perfect technique because he's a supreme athlete, he's mastered running around corners, he's a very highly skilled athlete, so presumably he can master the long jump, he can have perfect technique. We can start to figure it out. So we've got our equation, if you remember this, this is our basic equation distance equals velocity squared divided by gravity times the sine two times the take-off angle theta. So we can put these numbers into our equations and we've got, first of all, the take-off speed goes in. We've got gravity there, 9.8. Put the 33 in here and we can figure it out and, quite amazingly, we reckon he can jump 9.9 metres. Now, that's quite surprising because it's a whole metre further than the current world record, which was set by Mike Powell almost 20 years ago. I mean, 9.9 metres is pretty amazing. It's an enormous distance, but we reckon it's pretty likely he can do this. Now, that is a very large jump from a whole metre on the long jump. I mean, normally records do go up very incrementally, maybe, by centimetres. So it would be quite a dramatic thing if it did happen. But after maybe Usain Bolt's musted his sprinting, you might want to move on to a different discipline like the long jump, just like Carl Lewis did in the 1990s. He did everything he felt he could do in sprint events, so he moved into the field events, which I think could be quite interesting. OK, so definitely possibility for breaking or smashing a world record there. Just to go back to this graph that we started off with, imagine just where would Usain Bolt fit on this graph here? This is all the data, all these sprinters and the distance that they've run. So where would he fit on this line? Well, incredibly, just to give you an idea, he's going to fit right up there, sort of way off, right up the top, but on the same line. He'll still be on the same gradient, just much further along it. So hopefully we'll see that in a few years' time, or maybe not. Maybe he'll decide he doesn't want to do it after all. Some fascinating physics there behind just a everyday event. When you see the long jump in a couple of weeks, just have a think about that. I'm going to talk about something that's really close to my heart, a sport I'm very, very passionate about and that's cycling. I've always been a cyclist. Of course cycling is a discipline that we've become very, very good at in the UK, arguably one of the leading nations now for cycling. This is quite a turnaround because for many years we were the laughing stock of cycling, but we were never really all that good and we've got amazing athletes now certainly on the track in the velodrome, leading, leading nation in the velodrome, but now in the Tour de France. Then of course athletes like Marc Cavendish as well, incredible sprinter who's going to hopefully win loads of stage races in the Tour de France and then come back and hopefully get that Olympic gold as well when the first events in the Olympics. It's not just track cycling though and road cycling. We're also really good at mountain biking. We've got some of the world's top downhill mountain bikers, we've got the world's top BMXer as well, so really we're great at cycling now which is fantastic. We're going to talk about cycling and some of the physics behind cycling. One particular bit of physics, we're going to have a look at aerodynamics. Aerodynamics is a subject that you probably haven't really come across that much at school. It's something that we do a lot of though. Aerodynamics is really important. It really describes the effect that air has on the things that are moving through it. So aerodynamics is really important obviously for a bike and a cyclist, but it's really important for a footballer or it's really important for a tennis player because when something moves through the air, air resistance can be really, really important. I'll explain why. What goes on in relatively simple terms say if you're a cyclist you're moving through the air what's happening is you're actually compressing the air in front of you and so you get this build up of high pressure air, air that's squashed together on the front of you and then that moves around you but when it moves around you you've sort of moved on and you actually leave a gap in the air behind you and that gap in the air you've almost got like a hole in the air and so you get very low pressure behind you and quite high pressure in front of you and that pressure difference between the high pressure on the front and the low pressure on the back that's what creates aerodynamic drag and it can be very, very large this force. If you imagine what's going on for a cyclist they're cycling, they're putting down power putting down maybe say 200, 300 watts of power the old force that gets turned into and that will accelerate the bike forwards. Now if there wasn't a large aerodynamic force pushing you back that cyclist could just get faster and faster and faster and faster and before soon you'd be doing millions of miles per hour of course that doesn't happen and it doesn't happen because there's a very strong force that pushes back in the opposite direction and often kind of matches the force that you're pushing back with so you end up going at a constant speed, you end up effectively in equilibrium and you're not accelerating so the force that this is, we can actually figure out how big that aerodynamic force is this is our sort of equation that describes really about how aerodynamics works on a bike that F is the drag force that is this aerodynamic force that is so important in terms of describing how things move through the air obviously we can figure out what half is, we know what half is. The row here, this letter here, row, that's the air density. The density of air in Sheffield is pretty similar to the density of air here in London there isn't a great deal of difference because we're at a similar altitude but the air density in say Mexico City or on the plains of Tibet is much lower and that's because you're at a high altitude there's simply less less air around so you get lower density air so air density does change but it predominantly changes with altitude or sometimes with temperature as well actually on a hot day the air is less dense than on a cold day which is why in the velodrome at the Olympics they want a very hot velodrome because the air is less dense which means they can go faster. The next term on our equation is v that's the velocity again it's a squared term so it becomes very important in this equation the next thing is the cd that's the drag coefficient effectively it describes the shape of the object that we've got and the final term a that's the frontal area that essentially means if I'm cycling towards you if you take a picture of me it's the area of my body that you can see you want to have a think about what happens when cyclists say they go round a track they go round the velodrome and what we tend to see we see this behaviour where the cyclists follow each other very very tightly one cyclist cycles along the other cyclist is just behind them maybe there's a chain of them all riding very very close together and at a certain point the lead cyclist will peel away and the next cyclist will go on in a chain we call it drafting and it's something that happens a lot in the track and it also happens a lot in road cycling as well where the peloton will be going round the peloton will go to a spearhead there will be a few riders at the front and all the other riders are riding very very close behind them and it's a very good reason why they do it and it's because they can actually reduce the aerodynamic forces that are acting on them by cycling very close some people have really taken this to extremes this idea that you can drafting behind someone you can reduce the drag forces that are acting on you for instance here cycling behind a train that's moving along as fast as it can go and you can see here they've actually laid down wooden slats in between the train tracks so the cyclist can cycle along I think that cyclist is going about 60mph behind that train on the flat and he can do that because he doesn't have any aerodynamic forces holding him back or very few aerodynamic forces holding him back now some people really push this to the extreme and you've got an example here of someone who's cycling behind a drag car on sort of I think those sort of salt flats and this cyclist here got up to about 160mph on the flat under his own energy he's got two huge cogs here on the bike so he can actually pedal at that speed the cog is so big the gear is so big it has to get towed up to a certain speed then lets go then starts pedaling then accelerates up to say 160mph quite incredible pretty silly really if you ask me but nonetheless this is what you can do if you remove those aerodynamic forces drafting is really key in road racing it's really important because cyclists will tuck in behind each other and then they'll explode to overtake just at the right moment so for instance here Nicole Cook one of the great sort of female cyclists of our time she'll be doing this she'll be tucking in behind other riders using tactics to make them do the work then just at the right moment she'll accelerate past them because she doesn't experience the same amount of drag happens in nature as well moving through the air quite a lot of animals will do this same thing so birds will fly in formation and they will tuck in behind each other so that they don't experience these high aerodynamic forces and they'll actually rotate so that one bird will fly and do the work when they get tired they'll sort of move to the back and another bird will take place and so as a unit they can move move easier and I've put another picture in there that's in swimming it happens as well so in events like the triathlon open water swimming water and air fluid same physics applies to both of them and in swimming so I do quite a bit of triathlon so I swim quite a lot when you're swimming it's easier to swim very close behind someone else literally in triathlon you aim to sort of tickle someone else's toes get right in behind them and again you're moving through a medium which is easier to move through so you don't experience the same amount of drag so you see it in all sorts of places so how does it work so our drag force equation what we've got going on is that the first cyclist is going to experience quite a large drag force the cyclist behind are slightly lower drag force and behind them even lower still and it's because two terms in this equation are changing it's the air density and the velocity and I mentioned this before do you remember what I said what happens is the cyclist moves through the air as they move through the air they create almost like a hole in the air behind them and that air there is less dense than it is here so if you're the second cyclist the air density that you're moving through is lower than the air density here which means that your drag force is going to be lower if that number is lower that number is going to be lower so it's easier for the cyclist to move through moving through less dense air what's probably even more important though is that what happens is when this air moves around the cyclist so it moves around it actually slows down and it actually starts to sort of recirculate here so the relative velocity of that air becomes much lower and again that really drops this drag force again so you can see how this sort of equation links into drafting so the two things are changing the air density is changing and the relative velocity is changing as well and this really explains why birds draft behind each other why cyclists do it and of course even other examples things like if you ever watch say a Formula One race where you've got cars sort of going along behind each other and they draft each other and in the last minute they'll pull out to overtake this is what's going on they're messing around with their air density and relative velocity there's another kind of key element to this equation as well, something else that we should have a think about and that's about area so the frontal area that you project to the oncoming air is really important as well and in times gone by when athletes were riding sort of these slightly antiquated bikes, bikes like Penny Farthings they would have had a very very large frontal area and that's because they're effectively just standing standing upright, standing tall and that means that you've got quite a large frontal area but if you change your position on the bike you can reduce your frontal area quite dramatically this is an athlete called Graham O'Bree and Graham O'Bree was an amazing cyclist from Scotland and he did some really pioneering work in bicycle aerodynamics a bit of a sort of a a bit of a maverick really and he kind of designed his own bikes this bike here had a bit of an old washing machine in it I think quite famously and he got his body in these amazing positions so he would tuck his body down onto the handlebars to really really reduce his frontal area because that A term in that equation is really quite important as well so he could get his body in these amazing positions reduce his frontal area he actually in this sort of tuck position he got a series of world records unfortunately what happened was the governing body of cycling then banned this position and he deemed it to be unsafe so he came back with a different position called it the Superman quite amazing really so he stretched his body out really far but again the frontal area of the cyclist is quite low because of the position he was putting his body into this frontal area terms really really key now we're going to try and demonstrate this I need a willing a willing volunteer okay now you you were really quick so come on down that's great but a little round of applause please I'm going to hand over to Sean for a moment who's going to explain what's going to what's happening here first of all what's your name? Charlie just to sort of set the scene how many people have got an Xbox connect out there in the audience right and out of those people has anybody tried plugging into a computer at all nobody that's interesting sports engineers this is a bit a kit out there that we like the look of we think looks good we'll have a look at it we'll chop it apart we'll do bits with it and adapt it for our purposes and the Xbox connects an absolute prime example of that one so if we take a look here we've got a standard off the shelf Xbox connect nothing fancy nothing clever and just plugged into a laptop with a bit of special software on the screen you can see here if you just go and stand in front of the connect for us just stand sort of about here give us a wave so you'll see that the connects track to our volunteer you can see the blue dots that are on the screen they all relate to the joints of our volunteer so we've got shoulder joints, elbow joints and you can see it's showing the height about 1.73 metres so that's using the connect in sort of its conventional sense so going back to our original application connect is a 3D scanner so to analyse the way that somebody looks when they're in sports so if we switch to our next bit of software so we can see we've got a normal camera picture on the left hand side then on the right hand side we've got this 3D image that the connect will generate so we're going to get our volunteer now to sit on the bike sit on the bike for us and what we're going to get our volunteer to do is to sit in two positions so the sort of upright position that you'd normally see on the road and then later on we're going to use the drop position, this sort of hybrid position that we saw that Chris Hoy uses where you're on the dropped handlebars so if you're staying in that position for us now so we're going to use a connect and we have to say to the computer where our volunteer's shoulders are and where the bottoms of the legs are so we're seeing that the connect's calculated the frontal area in that position of about 0.24 metres squared so if you go on the sort of hybrid drop position so you go on the drop handlebars bend right down as far down as you can go and do exactly the same so we can see that's gone down to about 0.19 metres so about 0.05 metres drop so relax now so it doesn't sound like a great deal but you can see there and the Tour de France on a real long distance rate that's a change in frontal area you can make a massive, massive difference so thank you very much for having our volunteer OK so frontal area, absolutely key to cycling in the right position is really important the next and sort of final part of this story is actually about the shape that the object is shapes really key so different parts of the bike can actually be redesigned to reduce the drag that happens and this is something that we've been doing with British cycling for a number of years working on the design of the bike that the British team ride for the Olympic Games and essentially what we do is we use quite complicated modelling techniques to understand how air moves over different objects and what we find is it's not just the frontal area that's important, it's the shape of the object as well so designing shapes like this, these teardrop shapes can actually reduce that drag as well so shapes important and what we do because we go through this sort of modelling technique we can actually try out all sorts of different shapes and then find out the optimum solution so we can go through this sort of simulation kind of idea find the optimum shape and then that goes to get used and gets made you can make quite small differences but if you make enough of these small changes in terms of the design of different aspects of the bike even looking at things like for instance the wheel nuts on a bike that can have quite each difference each change might be quite small but you add them all up and you can end up with a significant difference in terms of performance and it's not just the bikes themselves it's things like the helmets as well and body position on the bike all these different things come together so just thinking about bike design thinking about this really important drag equation we can understand drafting it's a tucking in behind each other what we're doing is we're reducing the relative velocity and we're reducing the density and that can make the cyclist that's drafting feel a lot more comfortable and when it comes to optimising the design of the bike and the interaction of the athlete on the bike it's about reducing that frontal area and thinking about the shape of these different components as well and all those elements get put into that one elegant equation so if you can master that equation you can master bike design ok so we're going to move on to our final topic we're going to talk about running of course this is one of our great Olympic hopes, Mo Farah fantastic sort of middle distance runner I'm going to ask you a question actually so we've got some microphones at the ready so it's a pretty simple question but I want to see if we can get some good answers to this why where running shoes most of us have probably got a pair of running trainers somewhere or just a pair of normal trainers so why do we wear running shoes let's get some answers don't be shy to manipulate the air so aerodynamics I'm not entirely sure about that there have been some designs of shoes that have definitely brought that into it so some running spikes will have covers for the laces don't be as sleek as possible if you're a cyclist having a sock over your shoe is really key but we've got some other other sort of ideas so we've got one here the attraction so you don't slip ok traction we'll come back to that, that's brilliant another two here I don't think it's really related to physics but I know it because it's more soft it reduces the force and it stops shinspin that is absolutely what physics is though that's forces, that's motion that is physics and another one here isn't it more comfortable about force, about cushioning traction, reducing forces there's a lot of different reasons why we wear running shoes I think we wear them for cushioning just like we said here absolutely it is physics a cushioning, shock absorption traction, grip so essentially when you're an athlete you're putting force down to the ground trying to propel you along well if you've got any slippage you're not going to make the best use of that force so traction can be very important as well I think something we didn't mention is protection a lot of us live in an urban environment and it can be glass and stones all sorts of nasty things on the floor that maybe we don't want to be running bare feet on so we want some protection there as well there are a couple of other ideas some shoes get sold this idea that they can maybe correct the way that your foot hits the ground and create stability and your foot fall maybe try to modify aspects of what we call your gate how you move so that can be an important thing I think one of the biggest reasons myself is probably fashion how this thing looks we want to have something that looks pretty nice on our feet I think that's a very strong driver for it as well who thinks that running shoes can make us run faster let's have a show of hands here show of hands who thinks that running shoes makes you run faster okay we've got what do we reckon I think it's probably about two thirds who thinks that running shoes don't make you run faster okay we've got a few a few hands here okay all right so that's interesting I'll try and delve into that a little bit now why not just run bare foot okay this is a vote this might sound like a radical idea but actually this is something that people think very seriously about something that I think a lot about actually and there's some good reasons behind this so just try and follow me here slightly humans have only been wearing shoes for maybe I don't know say 3,000 years, 5,000 years something like that we've only been wearing running shoes since the 1970s so in terms of our sort of evolutionary history running shoes have come in a tiniest, tiniest amount of time and now we seem to be incredibly dependent on them think we can't possibly run without them which of course I consider to be ridiculous and it's because as a species one of the main reasons we're all here having sort of interesting intellectual discussions is because we could out hunt other animals on the sort of the plains of Africa believe it or not okay all of us are incredible endurance athletes we can out run most animals and it's not because we're faster but it's because we can regulate our temperature we don't overheat because we can sweat we can keep our core temperature down whilst other animals are overheat and we'll eventually get to exhaustion and then we can eat them and because of that reason now then our brains get bigger and it's part of the reason why we're here now when people were running around after animals and being so successful at it they weren't running around in a pair of nikes so you think well do we really need these running shoes do we really need them and there's some other good examples so for instance Zola Bud here running, breaking two world records running barefoot so this idea that maybe we have to have a pair of running shoes to make us run fast maybe isn't necessarily true now I'm going to need another volunteer here to sort of delve into the physics of what happens you had your hand up first right on that row there can you come down can you please well done I'll pass over to Leon so what's your name Jordan so in sports a lot of things happen at very very high speeds so as sports engineers to understand what's going on we need to slow what actually is the what's occurring down so we can actually examine and analyse what's going on so as sports engineers we use high speed video cameras and if Jordan will come around here and what we've got here is actually a high speed video camera set up behind this desk here and so what I'm going to get Jordan to do is actually run in front of this camera with me over here ok so this is on the screen now we've got the feed that's actually coming from the video camera so this camera operates really really really fast and the shutter is actually going really really fast so we have to have the air ffordded with as much light as possible so that enough photons can get to the centre of that camera ok so Jordan could you just do what I'm going to do I'm just going to jog across here and hopefully I'm going to put my foot a landing in here so if you do the same thing exactly what I'm doing well like that and just carry on and jog through like this ok so Jordan are you ready ok Jordan go for it that's good, did we capture anything there you go ok so I think we've got something there Jordan so should we go round and pause for Jordan ok Jordan I've got shoes can we get that on a loop that's fantastic so you can see what Jordan's doing there if you just have a look at exactly what's going on his four foot is hitting the ground first there's sort of a number of different ways that people run the part of your foot that hits the ground first is really key in terms of really just determining the whole way that force interacts with your foot now there are two main ways that you can do this some people hit the ground with what I call their mid foot the balls of their feet and what happens then something really interesting happens you're Achilles tendon which is on the back of your ankle here that acts like an amazing spring it's an amazing shock absorber and it's very elastic and that takes your heel then because it goes down to the ground you don't lose much energy and it sort of springs back into place and what happens is we get this quite a nice gentle build up of force and quite a nice very well cushioned impact the other way of running that a lot of people do is they'll run along and they land with their heel first so their heel is the first thing that hits the ground what happens when your heel hits the ground first is your Achilles tendon can't do anything this sort of natural spring mechanism doesn't work it's just not there and it's because there's a effectively a very large stiff bone that goes from your heel straight into your knee which is why if you heel strike say if you're not wearing a pair of trainers it's going to hurt a lot to take their trainers off and start running they'd run with their midfoot and their front foot so you rely on this natural spring mechanism that you have inbuilt into your body and I think what happens is it's really interesting when people put on a pair of trainers because of the shape of the trainer because you've got this big cushion under your heel the cushion has to be under your heel because there's no spring otherwise you have to cushion the heel and that trainer we think probably makes you heel strike we've got some evidence to suggest this so people have gone to Africa and they've looked at people who have never worn shoes people have never worn shoes when they run they run on their midfoot their front foot and they rely on this Achilles tendon give them a pair of trainers and what happens is they heel strike so the trainer is actually making us heel strike and so we lose this natural inbuilt spring that we have and then have to rely on the technology and that's kind of led to all sorts of people thinking well do we need running shoes are running shoes actually good for us are they making us move in a way that isn't really very natural and this millennial, this millennial revolution we've got this wonderful way of running and the running shoe might actually be spoiling it in some way which is really healthy and that's the way that science works we sort of debate these things and eventually might come to some greater level of understanding but there's certainly a large body of people now that feel that we shouldn't necessarily be heel striking and actually designing new shoes that provide you with say traction so you can do the grip you can have a bit of protection so you're not running barefoot necessarily on glassy glass on the streets and so forth but they don't make you heel strike and that's an interesting way to go forwards I've got just a couple of minutes left and I want to talk about another type of running something that's kind of even more radical as an idea and that's these pair of legs so obviously these legs belong to an amazing athlete called Oscar Pistorius who will definitely see in the Paralympics in September and there's a very small chance you might see him in the Olympics as well so this is an athlete who can run as fast as the very best 400m runners and has actually been given a licence to compete directly against non-disabled runners but he doesn't run wearing a pair of running spikes he runs with a pair of running blades a set of carbon fibre blades that have been designed and optimised to give him a really good running technique and it's been really quite a controversial topic actually because it's a big question around essentially you know, are these running blades are they just enabling him to run or are they enhancing his running technique and this is a discussion and argument that's been sort of rumbling on for a number of years the way that this sort of topic has been sort of thought about is essentially it comes down to a question of science does he have an advantage or doesn't he and it's quite a complicated problem I'll try and whiz through it as best I can essentially running with running blades you've got some different physics that's going on a few things to talk about that essentially running, sprinting is a series of jumps a series of jumps and to jump you've got to create a large ground reaction force now experiments have done a lot of historians he can't generate these large ground reaction forces so he seems to be not doing as well as other sprinters but he can win in other areas so for instance because his legs are so light they're made out of carbon fibre they're lighter than muscle and bone he can relocate his legs faster than other sprinters he's got a faster stride than any other sprinter ever so he can relocate his legs really quick and that's really important, stride frequency is a key indicator of how fast you can run he's got another big advantage as well and that's when you when you put your foot down when you're running you generate a large force which pushes you backwards due to that contact with the ground you get a large braking force because of the shape of the running blade these braking forces have been reduced very considerably and that means he doesn't have the same amount of braking force now you add that together and you do experiments and people have done experiments and essentially they measure how much oxygen he's breathing when he's running at speed and he uses less oxygen than other non-disabled runners so when he's running at speed he seems to have a higher running economy he uses less energy it's easier for him when he's running at speed but we also know that he has a massive disadvantage when he's accelerating off the blocks so when he's accelerating and getting up to speed he's much much slower and then maybe when he's at speed it's much more complicated and lots of different things happening but it's amazingly intriguing because here we've got an athlete who is supposedly disabled who is out running doing incredible things I describe him as being super abled and technology is very much part of that and I guess it asks or it sort of delves into this ground around where is this going where is this going as a piece of technology what will the future possibly look like well it's not really the future it's kind of here already so for instance this is a guy called Hugh Hare who's a bilateral amputee a double amputee he's also one of the leading scientists looking at the use of prosthetics he's based in America and he is claimed and I think I'm probably right to believe he will do this he thinks he'll be able to run faster than Usain Bolt because he's got powered prosthetics that will actually charge him along it's really interesting this stuff used to be the stuff of science fiction but it's not actually it's here now and it will only get more and more as the years go by and that's incredibly exciting and of course at the same time some interesting questions there not least being what it actually means to be human some very interesting territory there to think about so I'm going to leave it on that sort of big future kind of thing and say thanks huge amount for listening so well I hope you enjoyed that I hope you can now see a bit more of how physics and sport links together if you've got any sort of questions or ideas things that you want to know more about we've got an amazing blog that we write we put new blog posts up there and it's a nice week or something answering all sorts of questions to do with loads of different sports and all the different physics and engineering that happens in it so have a look at engineeringsport.co.uk and you can ask us questions on there and do all sorts of things as well and finally just to say final thing really all we've done here is talk about a very small part of physics in one specific application and discipline I think there's physics and it really is interesting there's so many different varied careers you could go into different avenues different opportunities so we've just shown you a tiny little bit of it I hope it's been interesting but my take home message is that if you are interested in this sort of thing just make sure you do A level physics because that really opens up everything for you so on that message I'll say bye