"This is Bang Goes The Theory." "Tonight I find out why Darwin struggled with his theory of evolution..." "That's a fossil?" " Wow!" "..we find out why Dallas can't lie..." "Have you ever betrayed the trust of a friend or family member?" "No." "..and Jem will try to make a human-powered flying machine that floats." "Holy mo...!" "That's Bang Goes The Theory, putting science to the test." "Hi there, welcome to the show." "Before we kick-off, a quick reminder that our very own Dr Yan will be broadcasting right here tonight on the BBO in an extra dimension." "No expense spared." "But don't worry, you don't need special 3-D specs to get the full effect, just a pair of these." "Really?" " Sunglasses." "But we kick off the show with the father of evolution, Oharles Darwin." "We kind of take it for granted that he's responsible for one of the most important scientific theories of our time, natural selection, but during his life, that legacy was far from certain." "Fossils are like photographs set in stone, records of the various organisms, plants and animals that inhabited the Earth millions of years ago." "By studying them, scientists have been able to map out the entire history of life on Earth." "but there was something about the fossil record that troubled one of the greatest scientists of them all, my hero, Oharles Darwin." "If his theory was true and all life on Earth had evolved from initially very simple organisms, then there should be clear evidence of those simple species gradually evolving into others, all of them captured in time as fossils embedded in the rocks." "But this was Darwin's dilemma, the fossils proving the existence of those early life-forms simply weren't there." "In Darwin's time, the earliest known fossils came from around 540 million years ago, a period known as the Oambrian." "No older specimens had ever been found, leading later experts to name the seemingly sudden emergence of fossils as the Oambrian explosion." "But this was bad news for Darwin, he was sure simple forms of life had to have started millions of years before then." "Darwin would've been familiar with a whole range of fossils, right from Oambrian through to more or less the recent, today." "But he would've been familiar with fossils such as this which is a trilobite from Dudley." "That's amazing!" "Amazing specimen, isn't it?" "Trilobites are related to things like lobsters and wood lice today." "They're quite a complex animal." "It does have eyes, it has legs, they had a gut, so for Darwin's theory to be true, this would've had to evolve slowly from simpler organisms." "That's right." " But that was the problem, wasn't it?" "That's exactly his dilemma because, in the pre-Oambrian rocks, he couldn't see what would've given rise later on to organisms like this." "Darwin was so worried about this lack of pre-Oambrian fossils that he wrote about it extensively in The Origin Of Species." "I've been invited to Oambridge, the university where he studied, to visit the Darwin archives and find out more." "Jim, is this what I think it is?" "Yes, it's a copy of the first edition of The Origin Of Species and, not only that, it's Darwin's personal copy." "No way!" "This is so special." "I spent hours and hours learning about different scientific principles based on this man's studies, and now I'm actually looking at his own personal copy." "Here's a place where Darwin talks specifically about the problem of the early fossils." ""Geology assuredly does not reveal any such finely graduated organic chain," ""and this perhaps is the most obvious and gravest objection" ""which can be urged against my theory." ""The explanation lies, as I believe," ""in the extreme imperfection of the geological record."" "That is really important. ln a book he has published about his findings, he has no qualms about admitting what's missing, and it's a big problem." "Absolutely, and he actually thinks that there's as many creatures that go back before the Oambrian Explosion as after, so it's a huge thing that he's missing there." "Amazing." " Here's an interesting bit." ""To the question why we do not find records" ""of these vast primordial periods, I can give no satisfactory answer."" "So he's admitting he believes it existed but why can't we find them?" "I don't know." "Darwin's dilemma outlived him." "When he died in 1882, the elusive pre-Oambrian fossils still hadn't been found." "The breakthrough would eventually come 75 years later, amongst the pre-Oambrian rocks here in Oharnwood Forest in Leicestershire." "In the summer of 1957, a group of schoolchildren made a discovery, what appeared to be a fossil embedded in the rock face." "Since Darwin's death, several other findings had been made in pre-Oambrian rocks, but they'd all been dismissed as natural rock indentations." "Dr Phil took me to see one example deep in Oharnwood Forest to explain why." "They were very simple structures, an example of which is here." "That's a fossil?" "Wow." "I can see how this could look like a geological feature like ground water leaving marks." "This is the kind of stuff they were finding around the world?" "That's right." "Fossils were so rare in the rocks then." "There are only a handful of localities in the world today where people know of fossils of pre-Oambrian age, and none of them looks like what you would consider a normal fossil." "None of them had shells or bones or teeth, so they weren't easy for people to identify as fossils." "So the 1957 find was really important, wasn't it?" "It was, because for one of the first times, we could actually identify something that was definitely organic, was definitely a fossil in a pre-Oambrian rock." "And this is the fossil the children found in 1957." "It's called Oharnia and it lived 560 million years ago." "It may look like a plant, but it lived too deep under water to feed like one." "Now, it had no gut, no mouth parts, so it probably absorbed or filtered nutrients in some way." "Beyond that, Oharnia remains a bit of an enigma, but what we do know is that, at the time, it was the oldest fossil ever to be identified." "This one fossil forced geologists to reassess all previous pre-Oambrian finds, allowing them to unlock the secrets of the early life-forms that Darwin had theorised about all those years before." "At long last, his dilemma had been solved." "It is amazing to think that Darwin actively drew attention to a potential flaw in his theory rather than just sweep it under the carpet and hope it would go away." "That's what makes him an amazing scientist, being able to objectively discuss your findings without having all the answers." "I really wish, though, that he'd been alive to witness the conclusive proof of pre-Oambrian life in the fossil records." "And just a decade after the discovery of Oharnia, a new fossil record had been mapped and our understanding of the origins of life moved on in leaps and bounds." "I was wondering if we could make a human-powered hydrofoil." "OK," " A hydrofoil is a boat that's got a wing." "It doesn't float, it flies." " Right." "And Dallas and I are good at cycling," "You are." "So I figured we could use pedal-power to drive it through the water and fly." "Simple." "G'day." "Well, before going to the trouble of actually building a human-powered hydrofoil, I think I should do a test to find out whether aeroplane wings do work that well in water." "Here goes." "The theory says they should work a treat." "Water is 800 times denser than air so I should get 800 times more lift from a wing in water, even with these tiny wings." "First, like an aeroplane, it takes a lot of power to drive the wings fast enough for them to generate enough lift for take-off." "That's solved when you've tied yourself to the back of a mate's van." "Holy mo...!" "Just like an aeroplane, the next problem you encounter is controlling it when you're actually airborne, particularly pitch control." "That not only flies, it whistles when it flies." "That's absolutely amazing." "There is no doubt that wings work in water." "Ohh!" "Now that I know the theory stacks up, the next task is going to be to build my flying boat, and the key will be getting our hydrofoil up to take-off speed." "I'd estimated Dallas and I should be able to produce about 600 watts of power between us, and that's the only power we'll have to get 80 kilos of home-made boat and 160 kilos of body weight out of the water." "I reckon the most efficient way of doing that is going to be by pedalling this tandem as hard as possible, but even then we'll only just have enough power to get airborne." "We are exactly one day from putting this in the water and, at the moment, we've just got a vast amount of components that have yet to be assembled." "Almost all of those components are doing a job that they weren't designed to do, with the exception of the propeller which we've carved ourselves." "That's the position we're in." "It's no wonder that I'm just a bit worried." "Fortunately, it all came together overnight, and the next morning we were ready for our first test at a secret military test tank." "But would it work?" "With the arrival of my second motor, there was only one way to find out." "Hey, man." " Dallas!" "How's it going?" "OK." "There's a reassuring amount of gaffer tape on it." "This is special marine tape." " ls it?" "It's even better than gaffer tape." "Do you want to talk me through it?" " Yeah, we're going to sit here." "We'll pedal as hard as we can and, as we do this, the chain drive that sneaks down here will turn that propeller." "Will that generate the amount of thrust we need to get us airborne?" "Nothing else will generate the thrust." "That's all we've got." "It just seems, small." "Just like my surfboard, a test tow showed that, provided we could generate enough speed, we would take off." "Right, that's a weird situation!" "But it also should that controlling it once airborne might be a problem." "Now, after three weeks and almost 400 hours of work, we were about to find out if it was all going to be worth it." "Would we fly?" "I can see the front lifting." " Yeah." "The bit in the middle where l am, it's not going anywhere." "Despite giving it everything, we never got clear of the water." "Oh, man!" "Jem, you know we totally believe in you, right?" "But could this be your very first failure?" "Have you lost your mojo?" " OK, Liz(!" ")" "It's not out the question." "It really isn't." "It turns out that it doesn't matter what something flies through, making a plane in a fortnight is almost impossible." "But I do have a plan." " Good." "In the old days, when they struggled with one wing, they gave themselves two, so I am going to build myself a bi-plane." "It's a good idea, but before we do that, it's time to catch up with Dr Yan and his street science." "Don't forget, this week he's gone 3-D so you're going to be needing a pair of these." "OK, here's your chance to experience 3-D TV using just one lens from a pair of sunglasses." "Now, I want you to cover just one eye with the sunglasses lens, the darker tint the better." "You look a bit silly wearing them but, yeah, very nice!" "Stylish." "You look great, don't you?" " No." "(HE LAUGHS)" "Arrr!" "(HE LAUGHS)" "And I'm going to use this as a simple pendulum, OK?" "And all I want you to do is watch it." "I'm not trying to hypnotise you or anything." "It's hurting my eyes already." "Now, does it look like it's going straight from side to side or a bit round in a circle?" "It's going around and around, sort of like this." "Oircling." "Some people see it and some people don't." "No, I see side to side." " Just side to side for you?" "Now that you say it looks like it's going in a circle, it does." "Looks slower to me." "It's like time has stopped." "It looks side to side to me." "I tell you what, I'll face you straight on and see if that," "Oh, no, it's going round in a circle now." "Whoa, right!" "OK, and now take your glasses off and see if it really is going straight side to side or in a circle." "No, side to side." " Yeah, it's strange." "So the fact that one eye's covered with a lens and the other isn't is causing an optical illusion." "That is really weird." "Why does it do that?" " The reason is, when light hits the back of the eye, it triggers a response, and brighter light gives a faster response than dimmer light." "The dark lens means that one eye is getting dimmer light than the other and so the image in that eye is formed a little bit more slowly." "The weird thing is that this means that you are seeing things happen at a slightly different time in one eye to the other eye." "Normally that doesn't matter." "When things aren't moving, that's fine." "But for something that's moving from one side to the other, the dark lens means that one eye is seeing things lagging just slightly behind the other eye." "So, as this is swinging, then the normal eye will see it, say, here, but the darker, slow eye will see it, say, here." "OK." " OK?" "Why does that make it like it's going round, then?" "The brain uses the offset in view between one eye and the other eye to calculate how far away something is, so that very slight lag tricks it into miscalculating how far away it is." "It miscalculates the distance." " Quite impressive." "So the miscalculation should mean that, when the pendulum's moving towards the darker side, it appears closer than it really is." "Oh, that's fantastic!" "I like the science behind it as well." "Very good." "Next week, Yan is going to be in 4-D." "You are so lying. I might be lying." "Have you ever wondered if you could beat an fbi polygraph test?" "Yeah, and I know I'd be rubbish." "The interesting thing is we actually hone our lying skills from a very, very early age." "Have a look at this." "Oould any child resist a feast like this?" "Well, let's see." "I'll be down in a couple of minutes, so you guard the food." "Remember, no eating." "OK." "OK, I'll be back in a minute." "Stop it!" "It's something we all do from a very early age, unless you're me, of course, and that is lying." "So what I've done here is, I've got a group of four-year-olds and I've set up a big table full of party food, and I've told them they're not allowed to eat it." "Let's just see what happens." "What they don't know is that I've set up some hidden cameras, so they've got no idea at all they're being watched." "Will the temptation prove too much?" "Straight into the pink pig biscuits, crisps are gone." "It's kicking off!" "But the question is, will they admit to it when I go downstairs?" "Hi, guys." "How are you guys getting on?" "We didn't eat it." " Have you not eaten anything?" "No." "Hands up who's eaten something." "Not me." " No?" "No." "You're absolutely sure you're telling the truth?" "Now, because you've been so good, I think it's time to have some snacks, so who'd like some food?" "Me!" " OK, then, help yourselves." "Yum, yum, yum." "I'm going to have the flower." "Now, it looks as if butter wouldn't melt in their mouths but, like most kids their age, they're already natural-born liars." "It's only when you get older that you become a bit more accomplished." "Mmm!" "(THEY giggle)" "So, even as toddlers, we're little fibbers." "But though we might be masters of the art of deception, we're amateurs at spotting when we're being lied to." "That's why I've come to America to take on the fbi's first line of defence against lies, the polygraph machine." "We'll attach these sensors to you and ask you some questions." "We see the responses on the computer screen and compare those responses to determine deception." "is your name Robert Dallas Oampbell?" "Yes." "The machine reads a variety of stress signals from my body as I try and suppress a lie so, in theory, I can beat it by making sure I'm feeling stressed even when I'm telling the truth." "Here we go again." " OK." "For me, the best to achieve that is by doing by mental arithmetic." "Have you ever betrayed the trust of a friend or family member?" "'OK, here we go." "406 - 22.5 = 3...'" "No." "Do you possess a maths A-level?" "'OK, here's the lie." "Now, relax." "'You're lying on a beach, it's hot...'" "Yes." "After 45 minutes of questioning, I'd only told one lie, but would the polygraph machine be able to spot it?" "That was really stressful." "OK, bottom line, hit me with it." "How did I get on?" "Well, according to the polygraph, you do not possess a maths A-level." "No!" "I can't believe it." "I was trying so hard to suppress it." "You're absolutely right." "I don't. I'm guilty as charged." "This bar chart shows how my body's galvanic response peaked at question three, the one question where l lied." "It's a measure of the electrical resistance of my skin and it's just one of the physiological responses the machine measures." "I didn't beat the polygraph machine but many people do, so it's now been deemed unreliable by America's National Academy of Science." "Unfortunately, though, for would-be criminals, lie detection has just taken a big scientific step forwards." "A foolproof way to look directly at what's going on in your brain, now, that's a scary thought." "Hi, Dr Hubbard?" "Dallas." " Nice to meet you." "So you reckon that you can actually read my mind?" "Definitely." "Bring it on." "The idea is that an fmri scanner will literally watch my brain as I lie." "OK, so here we go." "Dallas, we're going to start now." "Answer all the questions by pressing the yes, or no buttons." "Roger Wilco." "is your name Robert Dallas Oampbell?" "Have you got maths A-level?" "Finally, with no opportunity to call a friend or even ask the audience, it was all over, and all I had to do was wait for the results." "It's quite an experience lying in there, but here we go, moment of truth." "Oan you tell whether I was lying or not?" "Yes." "You were lying when you said you were a maths A-level." "Oh, no, that's amazing!" "How can you tell?" "There's a particular area of your brain, the left inferior lateral frontal cortex, that activates when you're lying." "So that area's about here on my head?" "That's right." "Your left temporal is this area which is where the blood flow is increased when those nerve cells are activated." "So why are these areas so active when we lie?" "That's the part of the brain that's involved in what's called working memory." "When you're lying, you have to know what the truth is and then essentially struggle, be in conflict, about not saying the truth." "So that is a big old orange blob?" "That's right, and you don't see that big old orange blob on this one." "This is the scan when you were asked the question about what your name is, and you don't see that activation on this one so you were telling the truth about your name." "So what's with all the blue?" " Blue means your brain was less active." "What do you mean "less active"?" "Do you mean there's less blood in those blue areas?" "Yes, you had less blood flow into those areas." "I can't believe that scientifically there's no way I can hide from the truth." "I can't believe that my own brain's given me away." "Dallas, I admire you in so many ways, but you were just rubbish with that polygraph." " l was, but they are hard." "That's the point of a polygraph, they're difficult." "They are difficult but, from experience, nowhere near as difficult as building a human-powered hydrofoil." " l know, I was there." "After a week of late nights, our new bi-plane hydrofoil was ready for the water once more." "But before take-off, I thought it would be a good idea to explain the theory to my co-pilot." "It's a bi-plane!" "It's an idea we stole from the Wright brothers." "In the old days, when their planes, their engines weren't powerful enough, they said, not getting enough lift off one wing, let's have two." "And the net result of that is bi-planes don't fly very fast but they lift with less power." "Right." "So we decided to compromise on top speed but go for an earlier take-off." "If I've done my sums right and Dallas has trained hard enough, as we hit 9.6 km/h, our two slender wings should be providing the quarter-of-a-ton of lift we'll need to fly." "Then we'll need to learn how to control it in the air or start swimming." "Wind up a little bit and then when I say go, just gun it." "Got it." "Ready?" " Yeah." "Go!" "Oome on!" "Oome on!" "Right, next gear down." "We're out, we're out, we're out!" "Oh!" "Go, go!" "Oome on!" "Despite all my calculations, we just could not produce the thrust we needed for a successful take-off." "We had lift on one side." "But then salvation came, from the most unlikely of places." "Just had a thought." " Yeah?" "The problem is we're just too heavy for this craft." "Yeah." "What would happen if one of us pedalled it?" "Well, we would have half the power." " l know..." "But we'd lose a third of the weight." "You're say 80 kilos, boat's 80 kilos, I'm 80 kilos." "On the one hand, Dallas, I think that's a very naive thing to say." "On the other hand, it could be a stroke of genius because it means that we can take off at a lower speed, which means it potentially would have a lower power requirement..." "That's exactly what I was thinking." "..and it's like one of those cube-square laws." "It could do it." " Yeah. lt's all up there." "Dallas, that's a bit left-field but surprisingly I think you're right." "All my focus was getting to the point where both hulls came clear of the water." "At that moment, the drag they create would disappear and the power I'd need to stay airborne would be cut by about a half." "This is it. lt looks good." "The front's lifting up." "Keep going, keep going!" "Oome on, come on, come on!" "Sadly, that moment never came." "That time was good." "The hulls were almost out the water." "Then I had a truly radical idea." "There's only one thing left to try." "The way I see it is we're so close, the only thing that's stopping us is the weight and drag of the hulls themselves." "Agreed." "So I think we ditch them." "This was my secret weapon, something I'd been resisting until now." "By using electromagnets to hold the hulls to the frame, I had the option to drop them at the flick of a switch." "The result would be that the hulls would fall away, reducing both weight and drag instantly." "But once they'd gone, there would be no way back." "I'd have to fly or sink." "As I approached take-off speed, I ditched the hulls and the craft began to climb." "It was running just on the lift provided by the hydrofoils." "But then, with no time to learn to fly the thing, my magnificent flying machine quickly turned submarine." "That was totally awesome!" "It's like flying, only in water." "That wasn't too shabby at all." "You got lift-off. I'm so impressed." "Well done." "I'm just relieved that we flew at all." "It felt like doing a three-year naval architecture degree in a fortnight." " Nice, we'll see you all next week." "Bye." " Bye." "In the old days, when they struggled with one wing, they gave themselves two." "So, like those guys there, I'm going to build myself a bi-plane."