"This is Bang Goes The Theory." "This week, Jem uses g-force to achieve a face drop." "I feel ridiculous." "Dallas is zapped with a ray gun." "What I didn't tell you is that sitting above the box is my specially constructed death ray." "No, you failed to mention it." "And I break into a sweat in the name of Sport Relief." "Pain is my friend." "Pain is my friend. I feel no nerves." "That's Bang Goes The Theory - putting science to the test." "Welcome to tonight's show." "Thanks for joining us." "We've got a packed show as ever." "But first up we've got to settle a bit of unfinished business." "You might remember last week I built myself a little fire extinguisher-powered dragster." "Three, two, one." "Oh, man." "Absolutely the best bit about that machine was testing the launch system." "I pulled over 3.5 G for nearly a second, which not only feels amazing, it left me wanting to know a lot more about the effects of acceleration on the human body." "G-force is a term we used to relate the forces we feel due to gravity to those we experience from accelerating or decelerating." "At the moment I'm experiencing 1 g." "Not because I'm accelerating, but because gravity is trying to pull me down." "If I want to change those g-forces, I either need to change gravity, which is very hard, or I need to accelerate, which is a lot easier." "Oh, my God!" "While in free fall, I'm accelerating downwards, just going with gravity, so I feel effectively weightless." "But when the bungee snaps tight, I start decelerating rapidly." "That deceleration makes me feel twice my normal weight, and upside down, that's really quite unpleasant." "But I suspect you can feel very similar g-forces much closer to home." "So I went to find a way of measuring the effects of acceleration in everyday life." "This set of scales actually makes a pretty handy g-force meter." "At the moment, the apple is exerting a force on these, due to gravity, of about 200 grams." "That's a 1-g situation, then." "If the apple exerted 400 grams, that would be 2 gs it would be pulling." "And 600 grams, three 3 gs." "But if I give it a bit of acceleration, you'll see there's extra forces at play." "Its apparent weight changes, and I can see how many gs it's pulling due to that change in weight." "Time to take it into the field." "For the first test all I need is a couple of friends and a roundabout." "How's that?" "We're going to like 1 .5, 2 g there." "That's better." "You're feeling it there." "That's almost up to 2 g." "Right." "Right, that..." "That was a sustained 2 G." "Now we're off to the swings." "Right at the top I'm kind of partly weightless." "Down at the bottom I'm pulling maximum g and it's just over 2 g." "On a standard child's swing." "And the final test - not to be repeated at home - a tall tree." "As human beings we regularly experience a wide variety of g-forces, the most extreme of which are when we come to a sudden stop." "That was some pretty rapid deceleration, and it looked to flick up to around six G there." "But only for an instant." "How long can a human survive high gs like that for?" "One way to find out would be to attach myself to a rocket sled." "Sounds like a death sentence?" "Well, there's one man who tried it - the legendary Oolonel Stapp, the world's first crash test dummy." "At the end of the track he experienced a deceleration of 25 g for almost two seconds." "It burst all the capillaries in his eyeballs, which is why I don't fancy doing what he did." "But I do want to do this." "This centrifuge dates from the 1950s." "Since then, thousands of fighter pilots have experienced extreme g-forces, enough to make them go unconscious." "So it's time for me to take a spin." "I can't believe I'm going to be spinning in that." "I knew it was some sort of oversized roundabout, but the scale of it is simply absurd." "Right." "This is it." "Aviation specialist Dr Mike Glanfield is going to make sure that I stay in one piece as I'm spun around." "Ready for take-off." " OK, Jem, we're just about to start." "Any questions?" "Yeah, what am I going to feel?" "What's going to happen to me?" "Well, although we're not going very fast, you may experience symptoms of grey-out or even loss of vision if the g level is high enough." "OK." "Slightly nervous." "So first, Mike is going to start me off slowly and subject me to 2.8 g." "Although less than I experienced on my fire extinguisher car, that was only for a few moments." "This is going to be for 15 seconds." "2.8 g. 15 seconds." "Here we go." "Oh, I feel that." "Maintaining this level of acceleration for such a long period has a much more profound effect on my body." "My arms feel so weirdly heavy." "That's astonishing." "Look how quickly they come down." "No effort from me at all." "It's just great, absolutely great." "Let's go again." "2.8 g isn't far off what you can expect on some fairground rides." "But for real pain, Mike is going to spin me at almost 5 g, the highest I can go without going through proper pilot training." "This is going into crash test dummy territory." "Not massively looking forward to this." "Relax, relax." "As the needle crept up, things started to get a bit nasty." "I feel my face sagging." "I feel as though I look about 10 years older." "I feel ridiculous." "At this point, I feel like I weigh 400 kilos." "But worse still, the blood is being flung away from my head and into my feet, with devastating consequences." "OK, my vision is going there." "It almost went completely black, then." "Another couple of seconds and I'd have been out cold." "At least now you know what you'll look like at 60, love." "Slightly harsh, thank you." "Got to see that face again." "Look at that, it's a thing of beauty." "It's a beautiful thing." "Ooming up next, Dr Yan." "This week he's gone all Steve Zizou one us." "Snorkels are great, but they only let you stay at the surface." "Have you ever wondered why you don't have really long snorkels that allow you to go down deep?" "I suppose so." "Haven't really thought about it, but yeah." "impractical." "Because of the pressure... ls it?" "There are several problems." "Here's the first one." "If I take a really long snorkel..." "Do you want a go?" "It's perfectly clean, don't worry." "Just breathe down it." "At the start it's fine, but if you had your nose blocked, after a while, I suspect, you're going to go... lt's going to get a lot more difficult." "That's because when you breathe out, all that air's just staying in the tube, and then you breathe it all back in again." "So you never get any fresh air." "If I cut the tube down, though, so that I can get some fresh air, there's still a major problem when I take it under water." "Watch this." "It's just impossible." "I just can't breathe down there, it's really weird, it's like someone is holding the end of the tube or pushing in on me or something." "The problem is that water is pretty heavy stuff, and so, as soon as you go under, it's pressing in on your body." "And for me to be able to breathe the air up here when I'm down there through this tube means I have to push out against all the pressure of that water, and I don't have to go" "very deep before that becomes just impossible." "Watch this." "So, imagine that these bottles represent my lungs, and this one I've given the really long snorkel to and this one with the lid on this is like when I'm holding my breath going underwater." "Watch what happens." "Look at that." "Look how much pressure there was down there, and it's not even that deep." "It's not surprising I couldn't expand by lungs." "But, if you look at the air in this bottle, like the air in my lungs when I'm holding my breath, it gets put under greater pressure as it goes down and that helps resist the crushing pressure of the water." "There's one animal, though, that has special ways of dealing with this, and can snorkel several metres underwater." "Believe it or not, elephants regularly snorkel using their trunks." "And they have specially strong muscles to fill their lungs under water." "And, crucially, they also have specially thick linings to their lungs which protect their blood vessels and stop the blood bursting out into their lungs under the pressure." "Now, you don't want that happening to you, so be careful, don't go deep underwater with a long snorkel." "And that, Dallas Oampbell, is why elephants rock." "And it's Yan rocks, as well." "Now, Dallas, can I show you something very cool?" "You can." "Scientists in Ecuador have discovered this brand-new species of gecko." "It's called Lepidoblepharis buschwaldii..." " Bless you." "Thank you." "And a fully-grown adult sits on the end of a pencil!" "That's tiny." "How cute is that?" " How did they find that?" "Amazing." "It's cute, but not ridiculously small." "For that, have a look at this." "What is that?" "Artist Willard Wigan has been making sculptures from grains of sand, shards of glass and even spider's web." "Sculptures so small he can fit them in the eye of a needle." "But, more, he then paints them with the hair of a housefly." "I tell you what, I'm obsessed by this guy." "He has to work in between heartbeats in order to do it." "And sometimes he inhales his own work." "He's amazing." "But if you want really, really small, we have to go beyond microscopic." "Prepare to have your mind well and truly boggled." "Welcome to the crazy, mixed-up world of the atom." "So, let's start at the beginning." "I just want to try and give you a sense of just how ridiculously tiny atoms are." "Look at these grains of sand on my finger." "They're pretty small." "Each one is about 0.1 millimetre across." "Yet, each one of those grains of sand contains a billion trillion atoms." "Just try and imagine that, a billion trillion atoms." "If I was to expand one of those grains of sand so it was the size of this beach, about a kilometre or so across, you would just about make out the individual atoms, and they would look like one of those grains of sand." "Atoms are very small." "But, even though atoms are so small, we know a remarkable amount about them." "For instance, we even know how many atoms there are in the entire universe, give or take one or two." "And, given the enormity of the universe, and the minuteness of the atom, it's an incredibly big number." "It's one, followed by over 80 zeros." "That's 100 million, trillion, trillion, trillion, trillion, trillion, trillion atoms." "That's an unimaginably big number." "To get a sense of it, compare it to this other unimaginable number - the number of single seconds since the beginning of the universe." "That's only a few hundred thousand trillion, so you're still short by a factor of thousand trillion, trillion, trillion, trillion, trillion." "OK, so we know that atoms are really, really tiny, and we know there are lots of them." "That's all fine and dandy." "But here's the really weird thing - they're almost completely empty." "Have a little look at this." "OK, go, go, go." "Now, you may remember from your school physics, that the atom is made up of several different parts." "So you've got your hard nucleus in the middle, which is played by Louise, there on the pink moped." "Whizzing round that, the electrons, which are the little light bits." "Now, that all looks nice, but it turns out that that scale is completely wrong." "Because, if the nucleus was the size of Louise, those electrons would be 50 kilometres away, and they'd weigh about three grams, which is the size of this little pebble." "Atoms are almost completely empty." "Let me explain this another way." "If you could somehow remove that empty space from an atom, it would be impossibly tiny." "In fact, if you removed all the empty space from all the atoms of all the people on earth, you could reduce the entire human population, all 6.8 billion of us, to the size of this apple." "Or this pasty." "The fact that atoms are empty may feel weird, but that's actually just the beginning." "As scientists found out more and more about atoms, they discovered, to their own discomfort, that they were weirder and more contradictory than they'd ever imagined." "So, they came up with a theory to explain how atoms work, and they called it quantum mechanics." "It's so weird that the great physicist Richard Feynman once said," ""lf you think you understand quantum mechanics, you don't understand quantum mechanics"." "Albert Einstein himself hated it." "'So, to try and wrap my own brain around this idea, 'l've come to meet Jim Al-Khalili, master of quantum mechanics, 'to learn how physicists make sense of the atom.'" "The best way to visualise atoms is to think of an atom as being like a cloud of possibilities." "A fuzzy cloud of atom-ness, spread out over space, and then, when you look, you collapse it and force it to make up its mind where it wants to be." "So you never catch it as a fuzzy, spread-out cloud." "Back on the beach, thanks to quantum mechanics, our simple model of the atom now has to change radically." "Jim's "cloud of possibility"" "means that all the bits of the atom, the electrons and the nucleus, aren't in a single place, they're in many places at the same time." "And, they say, it's only when we look for them that" " Pow!" "They somehow decide where they actually are." "But don't worry if this sounds too strange to believe." "It freaks out most scientists, too." "And, to show me just how odd quantum mechanics is," "Jim wants me to take part in a famous thought experiment in a cupboard." "So we close the door." " Yeah." "All right, Jim, I'm in." " What I didn't tell you is that, sitting above the box, is my specially-constructed death ray." "No, you failed to mention that." " But now, don't worry too much." "OK." " But basically, quantum mechanics says that an atom can be in two places at once." "Now, I've got an atom hooked up so that, if it's in one location, it triggers the death ray, which destroys everything inside the box." "And if it's an another location, it doesn't trigger the death ray, and you'll be fine." "Are you with me?" "OK." "This means that you are now both dead and alive at the same time." "Until I open the box, and check whether you're OK." "And you're fine." " See, I'm struggling with that, still." "Because I understand the sort of idea behind it, in the sort of Lion, Witch and the Radioactive Wardrobe scenario." "But, clearly I'm alive." "The thing is, atoms are doubly sneaky." "Because an atom, not only can be two things at once, but it seems that that weirdness is restricted down to the level of atoms." "So, in reality, you are never both dead and alive at the same time, because that weirdness, with an atom being in two places at once, is constrained down to the level of atoms and we don't see it in the everyday world." "I guess a lot of people think that it's perhaps some kind of esoteric, spurious notion, but it is in fact the bedrock of modern physics." "Albert Einstein himself had problems with what quantum mechanics was saying about the world of atoms." " Yeah." "The reason why we put up with this weirdness is that quantum mechanics is the most powerful, the most accurate, the most successful theory in the whole of science." "Without it, we wouldn't have most of modern physics, we wouldn't have modern chemistry, modern electronics, computers." "We wouldn't have the Large Hadron Oollider, we wouldn't even know why the sun shines." "So, basically, I'm just going to have to accept this and learn to love it." " l think so." "I think it's a small price to pay for the most powerful theory in science." "You see, Dallas, I still find quantum physics the most difficult science to get my head around." "But Jim nearly convinced me there." "Yeah, but you're in good company - everybody finds it difficult to understand." " Oh, good." "Not just me." "Yeah. lt's counter-intuitive, it's weird." "But it's still utterly beautiful and fascinating to think about." "But enough of the theoretical science." " Oan you cope?" "OK, I can cope with it." "OK, time to get physical." "Three, two, one!" "HORN BLOWS lf you were watching the Sport Relief Mile, you may have noticed familiar faces sweating it out amongst the runners." "That was awesome." "That was quick!" "Yes, Liz and I decided to put on our running gear and get all sweaty in the name of charity." "It wasn't pretty, but in true Bang style, we needed to add a bit of science to the mix, so we wanted to find out if a series of experiments could predict exactly how fast we could run that mile." "So before we ran it, we headed to the lab, didn't we?" "The human body is an amazing piece of machinery, and scientists in places like this," "Brunel University's Oentre for Sports Medicine, are dedicated to fine-tuning that machinery to the max." "So this is the perfect place to find out if Mr Dallas Oampbell, a fine specimen of a man, is operating anywhere near his full potential." "Whoa!" "Right, Dallas, this is Dr Lee Roomer." "Say hello, boys." "Hi, Lee." " Hello, Dallas." "Nice to meet you." "Now Lee has helped some of the country's top athletes to win Olympic medals and he's going to put you through your paces today using all those pieces of snazzy, scientific kit so we can predict exactly how fast" "you can run the Sport Relief Mile." "Are you psyched?" "I am sort of psyched." "That's good enough for me." "Now, knowing your ridiculously competitive streak, I thought we'd need to up the ante, and I think the last thing you want is for a girl to beat you, so I'm going to compete with you today." "I like that." "Are you doing it in your heels?" "And my woolly jumper." " Nice." "You look the part for that." "Not really!" "I'm ready for the challenge." "Bring it on." "At least you're not laughing at me, Dallas!" "Oome on, let's get on with it." " You go first." "The first test is to run a series of short bursts and then a final blitz." "Now, when you exercise, your body has to perform an enormous amount of work." "You've got your heart, your lungs and your muscles all operating flat out." "And it's the efficiency of these various systems all working together that can determine exactly how fast you can run." "And that's what Lee is going to be measuring to predict our mile times." "It'll push me and Dallas to our limits." "But the other thing that Lee is testing is how long our muscles can handle the exercise before feeling the pain." "Normally, when you go about your business or take a bit of exercise, your body gets its energy predominantly from a process called aerobic respiration." "It uses oxygen to burn up sugars, giving energy to the muscles." "But when we ask the muscles to work harder, above a certain level, they can't get energy quickly enough through aerobic respiration alone." "So cells in the muscles start producing energy by burning up sugars without oxygen in a process called anaerobic respiration." "And there's a downside to this, as it creates some nasty by-products, like lactic acid." "It's when that acid builds up in the bloodstream that we really feel the pain." "Three, two, one." "Off you come." "And unfortunately, measuring it is a bit painful too." "So, Lee, the build-up of the lactic acid, is that an indication of when we hit the pain barrier?" "That's right. lt's basically the breakdown of all the metabolic by-products feeding back to the brain that's telling you, hey, slow down, this is getting hard work." "Keep working." "Keep working." " You can do it, Dallas, come on." "And stop." " Well done, well done." "Do you have the time, Ohris?" "Ah, thanks." "That was hard work." "Blimey." "On a scale of one to ten, how much fun were you having?" "About minus 20." "And then it was my turn." "Before long, I was beginning to understand what the pain of lactic acid is all about." "And then, Lee turned up the speed." "That's it." "You're so nearly there." "Oome on, come on, Liz." "Oome on." "Last few seconds." "Nice and relaxed." "OK, hold on to it now, hold on." "We're going to go up again." "Keep forward." "You're in charge." "OK, and relax." "Lee then ran a lactate analysis on the six blood samples he'd taken from me and Dallas, and it was time for the results." "OK, well you both did really well." "Really good efforts." "Really?" "All right, let's talk about the lactate in particular." "How are we doing with that?" "OK, if you look on the figure there behind you, this is Dallas' data." "Along the horizontal axis at the bottom there is the increase in treadmill speed." "And on the vertical axis, it's the blood lactate concentration that we're measuring from the ear lobe here." "And you can see that it increases quite steadily down here and then shoots up towards the end." "So although it's not obvious, a threshold may be occurring here where you're transitioning from primarily aerobic to anaerobic." "So that's around 12km an hour." "OK, so that's the lactate threshold, where your body's beginning to struggle." "There's more lactate than can be cleared, so your muscles feel it?" " That's right." "OK, that's not too shabby. 12 km an hour or thereabouts." "That's not bad." " So he's fairly fit, right?" "That's not bad." "OK, so this is Liz's day." "It's a kind of similar shape." "You can see your threshold's occurring about 9km an hour." "Oh, rubbish." "I've got longer legs, though." " So I reach my lactate threshold much earlier on during the speed increase." "That's right." "At a lower running speed." "But you can certainly improve those figures." "How does this translates into our mile times?" "OK, well, there's your time, Dallas." "Now that's an average." "There's going to be variation but it's not a bad predictor." "Roger Bannister will be quaking." "I know I have to see mine, so just go for it. I'm thinking around nine." "OK, let's have a look." " l can live with that." "But that's still pretty good." "You know, we've only got a week till the Sport Relief Mile, so we can't really improve it with physical training, but there is a way we can probably knock a few seconds off." "How?" "." " l'm going to show you." "The power of the mind also has a lot to do with winning races." "Something that UK 400-metre record-holder Iwan Thomas knows a thing or two about." "I'm going to talk about running quickly." "OK?" "You are." "A race of eight guys, it wasn't always the physically fittest or the fastest would win." "Out of those eight, whoever kept their nerve and stuck to the game plan the most would win the race." "Really?" "So psychology is huge." "First of all, it isn't rocket science." "You can do that, right?" "Listen to music to fire yourselves up, to be mentally ready." "Set a realistic goal." "Realise at some stage in the race, it is going to hurt, but pain is your friend." "Pain is my friend, pain is my friend." "Pain is my friend." "I feel no nerves." "Ow!" "Pain is weakness leaving the body." "Yeah?" " l like that." "Ooh, that's a good one." " We can do it." "Do you reckon we're ready?" " You're ready." "You look ready." "Let's do it." "Do it." "You're a star." "Thanks a million." "Good luck." " l hate you!" "We will see you next week." "See ya." " Bye."