"This is Bang Goes The Theory." "This week, I look into the science of smell..." "Oh, that's unbelievable!" "That definitely smells of rotten eggs." "..Dallas goes looking for aliens..." "Every year, over 50,000 tonnes of extraterrestrial matter rains down from space to the earth." "Now, that's a lot of stuff." "..and Jem drives to Manchester in a coffee-powered car." "I'm not going to be drinking it, I'm going to be using that to convert it into flammable gas." "That's Bang Goes The Theory, putting science to the test." "First up tonight, our sense of smell." "It's one of our bodies' most important and basic functions, but do we know exactly how it works?" "I'm going to find out." "This nose belongs to Jess." "Jess is a two-year-old springer spaniel who's rumoured to be one of the best sniffers in the business." "How good is she really, though?" "She's brilliant." "She never fails to find." "OK, we're going to put that to the test today, because in this flask I've got a chemical called cis-3-hexenal." "It might sound a little bit sinister, but actually, when you smell it..." "What does that smell of, Mandy?" "Oh, like fresh grass." " Exactly!" "This is a chemical you can make in the lab that smells exactly like fresh-cut grass." "In fact, if a perfume or a cleaning product smells of the great outdoors, it's likely to have this in it." "So here's the test." "In my pocket I've got two handkerchiefs soaked in this chemical." "One I'm going to keep for myself in my back pocket, and the other I'm going to give to Mandy to introduce to Jess to see if Jess can search me out." "Jess should be able to do this because of her incredible nose, inside of which are about 220 million smell receptors that connect to the brain." "Humans only have five million receptors, but they work in much the same way as Jess's." "But the question is, what's going on in that fabulous nose of hers?" "How can a chemical like this trigger the smell of fresh-cut grass?" "It all comes down to the molecules, the atoms bonded together that the liquid is made up of." "Amazingly, almost all the molecules we can smell, like our cis-3-hexenal, contain just a handful of elements." "These five, in fact." "We've got carbon, hydrogen, oxygen, nitrogen, and that yellow one at the end there is sulphur." "Now, these elements can combine into any number of complex molecules, giving you an incredible amount of different smells, everything from your morning coffee to your favourite perfume." "Each time Jess breathes in air, she's also picking up a few individual molecules of cis-3-hexenal that are coming off the hankie in my back pocket." "And this is what one of these molecules looks like." "We've got six carbon atoms down the centre, the black ones, surrounded by lots of hydrogen atoms, the white bits, and this red one here is the one oxygen atom." "As Jess sucks air into her nose, individual cis-3-hexenal molecules hit a smell receptor." "She smells that grass smell and knows she's on track to find me." "But why is it that every time one of the molecules hits the back of Jess's nose, it's translated into the smell of fresh-cut grass and not some other smell?" "Well, currently, the most widely held theory is that it's all got to do with shape." "The idea is that the molecule has to be the right shape for a smell receptor, a bit like a key fitting into a lock." "So imagine this lock is the receptor and this part of the key is the right bit of the molecule that will slot in, triggering a signal to the brain that says fresh-cut grass every time." "Better hide." "Right." "And wait." "Now, according to the molecular-shape theory, what's happening in Jess's nose is that the cis-3-hexenal molecules are slotting into the correct receptors, which in turn send a signal to the brain specific to that shape and therefore that particular smell." "So hopefully, Jess is following that trail of molecules all the way to this room." "That's Jess." "That's Jess scratching on the door." "What have you got?" "I can't believe how quick that was." "Good girl!" "That is amazing!" "I love the smell of tennis balls in the morning." "That's very deep!" "Now, it is 25 years since a very special DeLorean DMO-12 went back to the future." "I think it's an anniversary worth celebrating." "Unfortunately, I can't quite crack time travel, but a car that's powered by junk, that's a different story." "Back in 1989 I saw Back To The Future Two." "There, the mad professor had somehow managed to get his car to run on rubbish." "Fantastic plan, but surely something that could never ever happen?" "Until now, maybe." "20 years later, time travel is still out of the question, but running a car on rubbish might just happen." "Here's the basics." "Normal car, squirt a bit of petrol into a cylinder, then a spark makes an explosion." "Woah!" "A spark makes a fairly big explosion, the explosion is powerful enough to drive the piston up, that starts turning the engine, that starts turning the wheels, and the car goes forwards." "But it doesn't have to be petrol." "This is the thing." "Anything that makes a clean explosion in there can drive a car." "Have a look at this." "If you take wood shavings like these, put them in a confined space, and then get it very hot..." "Squeeze that end into there..." "That's up to temperature." "Now, this is a process called gasification." "The gas coming off there should be flammable." "What's happening is that when heated in this way, the wood breaks down to produce carbon monoxide and hydrogen." "If I feed that gas into my cylinder..." "There it goes, you can see it going in." "Drop the piston..." "Get ready with the spark." "Three, two, one... lt works, it totally works!" "So, in theory, wood gas will drive a piston." "But can we scale it up enough to drive a car?" "Gasification is not a new idea." "During World War Two, due to petrol shortages, thousands of cars ran on the gas from smouldering wood." "Nowadays the environment is the worry." "Ohopping down trees might not be the answer." "So, I've been on the hunt for a substance that's like wood, but is actually a complete waste product." "After numerous burn tests, I think I've found a perfect substitute." "Yes, coffee." "I'm going to drive my car on used coffee grounds, stuff that's usually just dumped in the bin." "How is that possible?" "Well, it turns out that used coffee grounds actually give as good, if not better, gas than wood." "But, to burn efficiently in a gasifier, like a giant version of my kettle, they need to be very dry." "And ideally, made into these... pellets." "A massive handful of these pellets should get me about two miles." "So that's about 66 EPM, espressos per mile!" "Or, the dregs of 41 espressos per kilometre." "If the fuel choice wasn't challenging enough, this is what I'm making the gasifier with, a pile of scrap metal." "This is what it's powering, a beautiful 1988 Volkswagen Scirocco, which looks like the Back To The Future car, if you squint." "Time to cut, shut, weld and grind, persuading our second-hand steel into its new role as a mobile gas production plant." "We need a system both small enough to mount on the car, and safe enough for other road users, because we're playing with explosive and poisonous gases." "A lot of blood, sweat and deafened ears have gone into this, our coffee-powered car." "We've still got the same 1980s boy-racer special, but we've added a bit." "All that scrap steel we had is now a system that converts waste into useful fuel." "This is the key to the operation, this old propane bottle." "Normally, when you burn wood-like substances, you get a mixture of carbon dioxide and steam given off." "But this reduces those gases to the highly flammable carbon monoxide and hydrogen." "When it leaves, it's in a fairly dirty, wet state and we need to clean it up before we feed it into the engine." "First, we send it into here." "There, the gas is flung round so fast that all the soot particles get whizzed off to the edge and drop out." "A bit like a high temperature cyclone vacuum cleaner." "Then it goes there, into that radiator, where the gas is cooled down and we condense out some of the water vapour." "It'll then come out of the radiator into the fine filter, where we remove even more of the smoke and tars." "Then, it's down this pipe on the way to the engine." "I've not got the engine running, so I've got a fan sucking the smoke through." "If this lights, I think we're in business." "Look at that!" "It's like an Olympic torch!" "It's this mix of carbon monoxide and hydrogen that's going to power me 210 miles from London to Manchester." "That was such a good build!" "I love that, seriously." "Awesome." "I absolutely loved making that car, but at the moment it's only ever driven round the car park and I've got to take it from London to Manchester." "Easy!" "I've no idea what's going to happen." "There's loads of coffee shops en route to refuel." "You'll be grand. I can't wait to see how that pans out." "First up, it's more street science from our very own Dr Yan." "who's decided to make lots of people happy and dish out free glasses of wine." "You might have noticed that when you have a cold and you can't smell anything, you can't taste very much either." "Do you mind holding your nose?" "I just want you to tell me what do you think it is." "It looks like gunk." "It's fine. lt's perfectly innocuous stuff, honestly." "Rhubarb." "Apple." "I wouldn't know." "It's actually celery." " l was near, apples are green!" "Our sense of taste and smell are intimately linked." "But that's not the end of the story." "I've got two bottles of wine here, one red, one white." "They're just ordinary wine from the supermarket." "If I put a blindfold on people, will they even be able to tell which is red and which is white?" "Do you prefer red or white?" " White, please." "I like both." "I'm going to give you two glasses, and it could be that they're both white, or both red, or one white and one red." "You've just got to tell me what colour you think each glass is." "OK, then." " But you've got to do it blindfold." "Take your blindfold." " lt looks like a sexy garter!" "Let's go for it." " Here's two glasses." "Feel free to taste them, tell me what you think." "I'm driving." "Oan we have more than a sip?" "Absolutely, feel free to have as much as you like." "It turns out that we use our eyes to sense flavour." "What something looks like can be just as important as its taste or smell." "All that information is brought together to come up with an overall sensation." "It's done in a bit of the brain just behind the eyes here, called the orbitofrontal cortex." "Oan you tell me what do you think?" " l think that's a white wine." "I think that's red and that's white." "That's white and that's red." " That one is the white one." "How about the other one?" " They're both red." "Very good." "I still think that's the red and that's the white." "I'll take this off." "There you go." " They're both...!" "Both red!" " How interesting." "That one tasted white." " lt's weird, isn't it?" "Try it again now you know what flavour it is." "It tastes darker now." "It does, actually!" "Red." "Why is that?" " What happens is that over time, we build up an association between what something looks like and its taste." "So the sight of something becomes integral to its flavour." "Which a lot of people do with food as well." "If the food doesn't look very nice, they'll think it tastes horrible." "Suppose this was white wine with red dye in it?" "That sort of experiment has been done, even on expert wine tasters." "Because they're so used to tasting wine, their association between its colour and its taste has become particularly strong." "So, if you give them white wine but you put red colouring in it, they can get quite misled." "What marvellous things they do in the name of science!" "Brilliant." "There's a lot of interest about the possibilities of there being life elsewhere in the universe." "Research into that sort of stuff is helping us understand how life might have started here on Earth." "My quest to get to the bottom of all this starts with an experiment that took place in Ohicago in 1952." "This is a reconstruction of it." "It's the classic Stanley Miller-Harold Urey experiment." "Essentially what it is is a closed system, designed to replicate the conditions on Earth several billion years ago." "Up here we've got our atmosphere filled with gases like hydrogen, methane and ammonia, very different to the atmosphere we've got now." "Down here, bubbling away, you've got a primitive ocean-creating water vapour." "The whole lot mixes here." "What they did was, they actually put a spark through the whole lot, using these two electrodes, to simulate lightning." "And then they went away for a week to see what happened." "So they came back after a week and had a little look inside." "What they found was this rather unpleasant brown, sticky, smelly stuff." "When they analysed it, they found it was full of chemicals called amino acids." "Not life itself, but certainly part of the building blocks that can make life possible." "This gunk, made from simple gases and a spark of electricity, was full of complex chemicals which OOULD go on to make life." "Indeed, for all its flaws, the Miller-Urey experiment suggested we might be getting close to learning how we all began." "That led others to speculate about another controversial idea." "If the basic chemicals you need for life could be created here on Earth, then could they have been created elsewhere in the universe?" "That wasn't quite as mad as it may seem." "We're fairly sure there are planets not too different from Earth elsewhere in the universe." "Oould the building blocks of life have been carried from one of them?" "Or could it even have been formed in the depths of space itself?" "Every year, over 50,000 tonnes of extraterrestrial matter rains down from space to the Earth." "That's a lot of stuff." "In fact, it's about twice the mass of your average aircraft carrier." "Most of it is in the form of dust, but every once in a while, something a little bit more substantial lands." "For instance, in 1969 a meteorite fell to the earth in southern Australia, the Murchison meteorite." "That weighed over 100 kg." "That's more than I weigh." "Now, if you're hoping to find the building blocks of life in space, looking at meteorites like Murchison might be a good place to start." "So, a handful of scientists here at Imperial Oollege in London have recently been analysing meteorites like Murchison, with startling results." "This is an actual fragment of meteorite that fell from space to earth." "It's over 4.5 billion years old, untouched by human hand." "This is Zita Martins from Imperial Oollege." "You're an astrobiologist, so it's your job to analyse these and find out what kind of molecules are present." "Oan we do that now?" "." " Of course." "This is a mass spectrometer, a fantastic bit of kit that can analyse the chemicals within our meteorites with incredible accuracy." "OK, so here are our results." "So if I just scroll down." "What are we actually seeing here?" "We are seeing a molecule called uracil, which is a molecule present in our genetic material." "Yes." "So this is really exciting results." "It's a hugely significant find." "Uracil is one of life's basic building blocks, and this one seemed to come from outer space, making it controversial stuff." "So controversial that many scientists argue that the results might be inaccurate, because the meteorite could have been contaminated by life on Earth." "But for the first time, Zita's results proved categorically that those chemicals were of extraterrestrial origin." "Normally, uracil is mainly built from the element carbon-12, but the uracil in the Murchison meteorite contained a very high ratio of carbon-13, incredibly rare on Earth, but common in space." "So when we look to our results, we know that we have a much bigger ratio of carbon-13 over 12, and therefore this molecule - the uracil - can only be formed in outer space." "And it's not contamination." "So there's absolutely no way that that could be synthesised on Earth?" " No way." "No." "This is such an important thing, how did it make you feel when you discovered it?" "Well, it was very, very exciting news and discovery and we were the first ones really proving that components of our genetic material were present already in our early solar system, so that's really big news and exciting and everything." "That's pretty..." "That's pretty amazing." "I guess the kind of million-dollar question..." "Life here on Earth, did we sort of come from space?" "Well..." " Or is that too far?" "Well, you can't say that." "We're not saying that meteorites brought life itself, we're just saying they brought the building blocks of life." "So, are we aliens?" "Well, these are the facts." "Thanks to Zita and her team, incredibly, we now know the most basic building blocks of life exist in space, and over the years have definitely come to Earth from space." "And for me, that's almost as exciting." "So if the building blocks for all life on Earth came from outer space, did those same building blocks lead to life on other planets?" "I need to know more." "I intend to find out." "Good. I'm going to make it my mission." "I need to build one of those life-making rigs, they are simply awesome!" "They look good." "They do." "Anyway, now it's time to go back, back to the future and my junk-fuelled car." "London to Manchester, 200 miles in a 1980s vehicle converted to run on coffee." "Ambitious is an understatement." "♪ Woke up early this morning... ♪ lt's half-past four in the morning, time to wake up and smell the coffee." "But I'm not going to be drinking it, I'm going to be using that to convert it into flammable gas that hopefully will get this car" "210 miles from BBO Television Oentre to Manchester." "It's London in the middle of the night, it's spookily quiet and I quite like it that way, because this thing is not exactly straightforward to drive..." "Aw!" "..because what you're doing is, when you're driving, you're also running a gas plant at the same time." "I'd set off early because I wanted to make sure I'd be at the Science Festival in Manchester by 3pm." "Dallas and Liz were already there, having sensibly chosen the train." "It was a relief to get onto the motorway, where l wouldn't have to constantly fight to match the varying power demands of the engine to the production rate of my gas plant." "This is 65 miles an hour now, this is as good as it gets." "Well, hopefully, it might even get better." "But 30 miles up the road, we had to pull over." "Our prototype coffee-powered car had got the jitters." "Fortunately, it was just out of fuel and back on the road, it looked like with enough coffee, anything was possible." "But there was one thing I had no control over." "'There are still long delays on the M1 northbound up towards junction 15, 'where that closure is in place for recovery of that lorry and car." "'Delays are now reportedly an hour and a half.'" "This is kind of the last thing I need." "The M1 was looking brilliant, moving along nicely, then we've hit this - this heavy traffic." "In a coffee-powered car, that's not what you want at all, because there's no air flowing up through the radiator now so things are going to get overheated." "I'm going to go burning through fuel that I don't want to burn through." "And I don't even know when this traffic's going to finish." "Dallas Oampbell." "Dallas." "Hey, Jem, how's it going?" "It's been really amazingly good..." " Yeah." "..until about a couple of miles back, and now the motorway is completely snarled up and it's just rubbish." "You should get here soon because the hotel's amazing and great." "That's the kind of motivation I need!" "Oh, I've got to go, there's room service here." "After finally escaping the traffic, the team and I had to service the coffee-conversion kit in the boot." "We'd have to do this every 60 miles." "Each service would eat up precious time, but if we didn't do it, we'd never get to Manchester." "At every stop, we'd have to drain off water, replace the filter, fill up with new coffee and deal with the red-hot coals." "It's an act of slight desperation, but in order to make sure this thing works properly, you have to clean the ash out periodically." "Otherwise, it sort of chokes it and you can't get the gas that you're producing through and into the engine." "I just hoped our "carpuccino" would become an "expresso", because I still had another 130 miles to go." "He should be here in two hours if everything's going well, right?" "I think he should be here now." "The car was back on form, but it wasn't our day." "Another traffic incident had closed the M6, so we had to take the A-roads." "Unfortunately, so did everyone else." "It's always a relief when the police go past and don't do anything." "It's still on answering machine." "'The person you're calling is unable to take your call.'" "We've made it from London so far and we're just going up to Manchester." " Good luck!" "Thank you..." "Oh, no!" "It was nice to make new friends, but it was proving almost impossible to match the gas production rate to the car's speed." "Manchester on time was now a distant memory." "'Traffic is still struggling on the A50 as you head east through Stoke." "'A lorry's broken down, there's an oil spillage on the carriageway as well causing us a problem." "'Lanes still blocked off.'" "When it's free, this thing runs like an absolute dream." "It's just in traffic like this, it overheats, it's not nice." "But if there's another hill like that in stop-start traffic like this, I fear we could burn something else." "And sure enough!" "Now with the fire extinguished, victory was in our sight." "♪ Halleluiah... ♪" "This is Manchester." "This is where we were aiming for..." "And this is a coffee-powered car!" "Oh, there he is, there he is!" " That's him!" "Dallas, Liz!" "Oh, my God!" "Oh!" "My God!" "That is incredible!" " You're a hero, what are you?" "There's no way this had any right to make it." "Look at the state of you!" "And there's probably one cup of coffee left in this thing." "Oh, my God." "Are you all right?" "Yeah, it's been incredible!" "We've got to go." "This is the end of the show." "So proud of him though." "We will see you soon." "Take care." "Bye bye." " Bye....oh guys."