0:00:02 > 0:00:03This is absolute genius.
0:00:03 > 0:00:08So sit down, buckle up and get ready for take-off!
0:00:08 > 0:00:11Each show, we'll introduce you to a different genius,
0:00:11 > 0:00:14an amazing person who had a genius idea which shaped the world.
0:00:16 > 0:00:18And they will inspire us to
0:00:18 > 0:00:22come up with our own genius idea at the end of each show.
0:00:22 > 0:00:24But, will it be any good?
0:00:24 > 0:00:28Will it be any good? It will be Absolute Genius!
0:00:28 > 0:00:32And on today's show, a GENIUS engineer...
0:00:32 > 0:00:34Who solved a STINKER of a problem!
0:00:36 > 0:00:39Prepare to be blown away by his brilliance!
0:01:13 > 0:01:16Today we're going to introduce you to an amazing man who came up with
0:01:16 > 0:01:19a genius solution...
0:01:19 > 0:01:21TOILET FLUSHES
0:01:21 > 0:01:24..to a very whiffy problem. I'd leave that for a minute, if I were you.
0:01:24 > 0:01:28Thanks to him, whatever was in there has now gone
0:01:28 > 0:01:30and we don't have to worry about where it is.
0:01:30 > 0:01:33Just leave it to today's genius,
0:01:33 > 0:01:36who invented London's first giant sewer system.
0:01:36 > 0:01:41Ladies and gentlemen, we give you, Sir Joseph Bazalgette.
0:01:41 > 0:01:46Huh? Do you mind, I'm rather busy!
0:01:46 > 0:01:48Inspired by his genius idea, we will be coming up with our own
0:01:48 > 0:01:50later on using the power of poo.
0:01:50 > 0:01:53Yes, but now let's find out more about the man himself
0:01:53 > 0:01:57and the humming problem that he solved.
0:01:57 > 0:01:58PFFT! PFFT!
0:01:58 > 0:02:00Joseph!
0:02:00 > 0:02:03PFFT!
0:02:05 > 0:02:10Have you ever wondered what happens when you flush the loo?
0:02:10 > 0:02:12All the waste that goes down your toilet ends up
0:02:12 > 0:02:16underground in the sewer, where it's safely carried away.
0:02:16 > 0:02:20But more than 150 years ago in London,
0:02:20 > 0:02:23there was nowhere for raw sewage to go.
0:02:23 > 0:02:26So it was dumped straight in the River Thames.
0:02:27 > 0:02:32And in the hot summer of 1858 the smell became unbearable.
0:02:32 > 0:02:34It was called The Great Stink.
0:02:40 > 0:02:44To demonstrate, we've enlisted the help of the closest thing
0:02:44 > 0:02:46we can find to a poo machine.
0:02:46 > 0:02:49It's Hepworth the cow and a few of her friends.
0:02:50 > 0:02:52It's still warm.
0:02:52 > 0:02:55'We're recreating the River Thames in Victorian London.'
0:02:55 > 0:02:57Pat. Cow pat.
0:02:57 > 0:02:58Thank you, Hepworth!
0:02:58 > 0:03:00'So if you get queasy, look away now.'
0:03:00 > 0:03:02In there with some water.
0:03:02 > 0:03:03A bit of decorum, boys!
0:03:06 > 0:03:09This represents the poo produced by two and a half million Londoners.
0:03:09 > 0:03:12Look, that's sprayed on my trousers!
0:03:14 > 0:03:16Let's recreate the moment,
0:03:16 > 0:03:19to see what the river would have looked like back in the day.
0:03:19 > 0:03:22- See if it flows.- There you go.
0:03:22 > 0:03:25Oh, someone had a bad night there, somewhere in East London.
0:03:25 > 0:03:27Urghh!
0:03:27 > 0:03:30MUSIC: "Jerusalem"
0:03:34 > 0:03:38MUSIC: "EastEnders" theme
0:03:38 > 0:03:41Would you want to live there? Look at it!
0:03:41 > 0:03:43It wouldn't have been nice, would it?
0:03:43 > 0:03:45Right, what are we going to do about my trousers?
0:03:45 > 0:03:47Take them off, come on, I'll towel them dry.
0:03:51 > 0:03:56So that was the great stinky summer of 1858.
0:03:57 > 0:03:59- Stick your hooter in there. - Smell that!
0:03:59 > 0:04:02Imagine if London still hummed like that!
0:04:02 > 0:04:03Would it put off the tourists?
0:04:03 > 0:04:06We've recreated the smell to find out.
0:04:08 > 0:04:11What do you think that smells of?
0:04:11 > 0:04:13- I don't know, it smells bad. - Bad, yes!
0:04:13 > 0:04:17- Would you have come to this city if it smelled like that?- No.
0:04:17 > 0:04:18- No, right.- Neither would I.
0:04:18 > 0:04:24You know why? Because that is the smell of human poo!
0:04:24 > 0:04:26Poo!
0:04:26 > 0:04:28It is, exactly!
0:04:29 > 0:04:30But it was no laughing matter.
0:04:32 > 0:04:36People were getting sick and dying.
0:04:36 > 0:04:38At first they blamed the smell.
0:04:38 > 0:04:41But disease was actually being spread by harmful bacteria,
0:04:41 > 0:04:44leaking from the river into people's drinking water.
0:04:49 > 0:04:52To find out more about the bacteria in poo,
0:04:52 > 0:04:55we've come to the University of Reading...
0:04:55 > 0:04:58to meet Genius Helper - Dr Gemma Walton.
0:05:02 > 0:05:03Phew, it's a bit whiffy in here!
0:05:03 > 0:05:05There are lots of brown jars with bubbles in them!
0:05:05 > 0:05:08Hello, Gemma, don't know if I should be shake your hand...
0:05:08 > 0:05:10- You can at the moment.- OK!
0:05:10 > 0:05:13Gemma is a gut microbiologist.
0:05:13 > 0:05:16She's recreated part of the digestive system,
0:05:16 > 0:05:20to study the good and BAD bacteria inside us.
0:05:20 > 0:05:24And yes, before you ask, that brown stuff IS what you think it is.
0:05:24 > 0:05:29So, can you tell from your own poo how healthy you are?
0:05:29 > 0:05:32In terms of how healthy you are you'd have to look more specifically
0:05:32 > 0:05:37at the bacteria there, but one thing that doctors do actually use...
0:05:37 > 0:05:38What's that?
0:05:38 > 0:05:41..is a Bristol Stools Chart.
0:05:41 > 0:05:47Now, this is a list of types of poo in terms of consistency...
0:05:47 > 0:05:50Here's your menu for today, sir, would you like type six,
0:05:50 > 0:05:54which is your fluffy pieces with ragged edges, a mushy stool, sir?
0:05:54 > 0:05:57Like a sausage but with cracks on its surface. Ouch!
0:05:59 > 0:06:01Oh, dear.
0:06:01 > 0:06:03Settle down, boys!
0:06:03 > 0:06:07How much bacteria is there in our poo?
0:06:07 > 0:06:11So, a stool sample can be anywhere, typically, from 30 - 60% bacteria,
0:06:11 > 0:06:15so there's lots and lots of bacteria in a stool sample.
0:06:15 > 0:06:20'We want to examine our own stool to see the bacteria inside.
0:06:20 > 0:06:23'Well, not ours, someone lent us one.'
0:06:23 > 0:06:25I think we should give a name to our donator.
0:06:25 > 0:06:27Do you, what would you like to call it?
0:06:27 > 0:06:34- Erm, Steve.- Steve, all right. I'll just pick up Steve's sample.
0:06:34 > 0:06:38Steve...Steve's not been very well!
0:06:38 > 0:06:40So just take a small amount.
0:06:40 > 0:06:44Some bacteria in poo is harmful, so we're wearing protective gear.
0:06:44 > 0:06:47Examining your own stools at home is NOT recommended!
0:06:50 > 0:06:53'First, we're heating our poo sample, to kill the bacteria...'
0:06:53 > 0:06:56Get it, how's Steve smelling?
0:06:58 > 0:07:01Do you want to pop a few drops all over?
0:07:01 > 0:07:03'..then, we're staining it with special dye.'
0:07:03 > 0:07:05Wash that off.
0:07:05 > 0:07:07Once it's dry we can look at it under a microscope
0:07:07 > 0:07:09- and see the bacteria.- Ooh!
0:07:10 > 0:07:14Right, let's see how much bacteria Steve's sample has on it.
0:07:18 > 0:07:22- All these little shapes that you see here are bacteria.- Ah, OK.
0:07:22 > 0:07:25Human waste contains billions of bacteria.
0:07:25 > 0:07:27That's why we wash our hands after going to the loo.
0:07:27 > 0:07:30But in Victorian times, people were washing in -
0:07:30 > 0:07:35and drinking - dirty water contaminated by sewage.
0:07:35 > 0:07:39If you had a case of diarrhoea, you've got a good sewage system,
0:07:39 > 0:07:43and hand-washing facilities so you can keep it pretty well contained.
0:07:43 > 0:07:45However, if you were in a situation
0:07:45 > 0:07:48where sewage was getting into the water system,
0:07:48 > 0:07:51and people with diarrhoea etc weren't being able to
0:07:51 > 0:07:54contain it, you get bacteria that cause diarrhoea
0:07:54 > 0:07:57going into your drinking water, which can undoubtedly cause further
0:07:57 > 0:08:01cases of it and also, if the only thing you've got to rehydrate
0:08:01 > 0:08:04yourself with is water that is contaminated with bacteria
0:08:04 > 0:08:08that cause diarrhoea, you're in a bit of a tricky situation.
0:08:09 > 0:08:13People had been putting up with the stench and disease for long enough.
0:08:13 > 0:08:16The Great Stink was the final straw.
0:08:16 > 0:08:18London needed the help of a genius.
0:08:21 > 0:08:23Enter Joseph Bazalgette -
0:08:23 > 0:08:27London's Chief Engineer, with a background in building railways.
0:08:29 > 0:08:33Parliament gave him the job of solving London's sewage nightmare.
0:08:33 > 0:08:37And what he came up with was a GENIUS piece of engineering.
0:08:41 > 0:08:45Bazalgette's genius idea was to build a system of big sewage pipes
0:08:45 > 0:08:48to catch London's waste BEFORE it flowed into the river
0:08:48 > 0:08:50and London's drinking water.
0:08:51 > 0:08:55The sewage was then carried eastwards and pumped out to sea.
0:08:55 > 0:08:58No more stink. Genius!
0:09:00 > 0:09:03Inspired by Bazalgette's genius idea,
0:09:03 > 0:09:05we'll be coming up with our own later on.
0:09:05 > 0:09:08But right now we're here at London's glittering Leicester Square,
0:09:08 > 0:09:11but we're not going to a premiere, oh, no...
0:09:11 > 0:09:13No, we're going underground into the sewer.
0:09:15 > 0:09:18Not many people get to go inside Bazalgette's sewers.
0:09:18 > 0:09:20So this is a real treat.
0:09:20 > 0:09:22And to guide us...
0:09:23 > 0:09:25..it's Genius Helper, Rob Smith -
0:09:25 > 0:09:27a flusher for Thames Water.
0:09:27 > 0:09:30His job is to keep London's sewers flowing.
0:09:33 > 0:09:37It's amazing to think this huge network of tunnels is right
0:09:37 > 0:09:39underneath Leicester Square.
0:09:42 > 0:09:46OK, I can't even describe the smell in here.
0:09:47 > 0:09:50It's a little bit soft underfoot, isn't it?
0:09:50 > 0:09:53- It's really soft there...- Blurgh!
0:09:57 > 0:09:58This vapour in the air,
0:09:58 > 0:10:01this very fine mist in the air, what is that?
0:10:01 > 0:10:06A mixture of good, old English rainwater,
0:10:06 > 0:10:10and a bit of sewage, but not too much.
0:10:11 > 0:10:16Bazalgette's genius sewer system took over ten years to finish.
0:10:16 > 0:10:21It used 318 million bricks and involved 82 miles of new
0:10:21 > 0:10:26underground sewers, linking to more than 1,000 miles of street sewers.
0:10:26 > 0:10:31It was the biggest sewer system the world had ever seen.
0:10:32 > 0:10:36London finally had somewhere to dump its smelly waste.
0:10:36 > 0:10:40And disease spread through sewage started to disappear.
0:10:41 > 0:10:46Anything that goes down the toilet or plughole ends up here.
0:10:46 > 0:10:47From loo paper to cooking fat.
0:10:47 > 0:10:52It's the job of Rob and his team to clear any nasty blockages...
0:10:52 > 0:10:54by hand!
0:10:54 > 0:10:56We're supposed to be helping,
0:10:56 > 0:10:58but the tunnels are flooded with rainwater.
0:10:58 > 0:11:01Rob thinks it's too dangerous to go any further.
0:11:02 > 0:11:06Right, the task was going to be that you were going to digging out
0:11:06 > 0:11:09and removing fat but actually it's being done by natural means
0:11:09 > 0:11:13because the rainfall we've had has flushed the fat away.
0:11:13 > 0:11:17It has left a couple of bits and pieces on the rails down there,
0:11:17 > 0:11:18so who's the mountaineer?
0:11:18 > 0:11:22Well, neither of us, but he looks like he's just about to throw up,
0:11:22 > 0:11:24- so it'll have to be me.- Right.
0:11:24 > 0:11:28Now, I'm not saying he's faking it, but seconds after I volunteered,
0:11:28 > 0:11:29look at him!
0:11:29 > 0:11:31Is that what he's getting rid of?
0:11:31 > 0:11:35- Yeah!- Oh, my... Urghh!
0:11:35 > 0:11:37This is the BAFTA moment where he falls in.
0:11:37 > 0:11:38Hold onto the rail!
0:11:38 > 0:11:42Hold onto the rail, stand sideways, face the wall. That's it.
0:11:42 > 0:11:45- What is it?- That's a pair of pants!
0:11:45 > 0:11:46Pants?!
0:11:46 > 0:11:50The elastic from the top of someone's pants!
0:11:50 > 0:11:53Oh, mate, it looks disgusting!
0:11:53 > 0:11:54Aaaagh!
0:11:56 > 0:11:57Oh, my life!
0:12:00 > 0:12:02He's retching! Come on!
0:12:05 > 0:12:07He wants to have a go!
0:12:07 > 0:12:09I know, I can see, he's really keen!
0:12:10 > 0:12:13Other one through, and so on and so forth.
0:12:13 > 0:12:15Think crab-like, yeah?
0:12:15 > 0:12:17'It's disgusting.
0:12:17 > 0:12:20'But flushers have to do this kind of nasty work every day.
0:12:20 > 0:12:23'Without them, Bazalgette's sewers would clog up.'
0:12:23 > 0:12:25- Straight down?- Yes, straight down.
0:12:25 > 0:12:27Is this Bazalgette's exact design?
0:12:27 > 0:12:28Yeah.
0:12:28 > 0:12:30Why did he make it so big?
0:12:30 > 0:12:35It's what you call forward-planning. Well, he was a genius.
0:12:35 > 0:12:36He was a genius?
0:12:36 > 0:12:39He was a genius, he looked ahead.
0:12:39 > 0:12:44He didn't build for tomorrow, he built for 150 years time.
0:12:44 > 0:12:46That's a clever guy, yeah.
0:12:46 > 0:12:49Right, shall we get out of here?
0:12:49 > 0:12:53- Yes, please.- Go for a shower.
0:12:53 > 0:12:57Yeah, and then the water will end up here.
0:12:57 > 0:13:00Bazalgette predicted the population would grow,
0:13:00 > 0:13:04so he designed his sewer tunnels big enough to cope.
0:13:04 > 0:13:09Good job, because there are three times as many people in London now.
0:13:16 > 0:13:20And breathe! Phew!
0:13:20 > 0:13:22Oh, London air has never smelt so good!
0:13:22 > 0:13:25I tell you what, I've got an absolutely new-found respect
0:13:25 > 0:13:27for the guys that work here, doing that.
0:13:27 > 0:13:29It's an amazing job and they work really hard.
0:13:29 > 0:13:32- Cheers, then, Rob. Thanks very much. - Pleasure.
0:13:32 > 0:13:35Glad you liked my tunnels, boys, now go and get washed.
0:13:35 > 0:13:38But there was a time when we didn't have any sewers at all,
0:13:38 > 0:13:42and people had to store their muck at home!
0:13:42 > 0:13:44Imagine that!
0:13:44 > 0:13:48Yes! It's time for the NOT so genius idea.
0:13:48 > 0:13:49In medieval times,
0:13:49 > 0:13:53toilet waste dropped straight into chambers called cesspits.
0:13:53 > 0:13:57But you had to be careful, even if you were an expert.
0:13:57 > 0:13:59In 1326, Richard, a muckraker -
0:13:59 > 0:14:04the person who went around clearing up other people's filth -
0:14:04 > 0:14:06fell through his own rotten floorboards
0:14:06 > 0:14:10into the cesspit below and drowned in his own poo!
0:14:10 > 0:14:14URGHH! A not so genius way to go to the loo.
0:14:18 > 0:14:20We've been inside Bazalgette's genius sewer
0:14:20 > 0:14:24and discovered things that once went down a toilet.
0:14:24 > 0:14:26That's the elastic from the top of someone's pants!
0:14:26 > 0:14:29But where does it all go?
0:14:30 > 0:14:34Meet Genius Helper, Nick Mills, from Reading sewage works.
0:14:39 > 0:14:40What does this machine do?
0:14:40 > 0:14:43This removes anything that floats in the sewage
0:14:43 > 0:14:44that comes into the works.
0:14:44 > 0:14:46- Wet wipes...- pants!
0:14:46 > 0:14:47Can we have a look?
0:14:47 > 0:14:50You can have a look, don't get too close.
0:14:50 > 0:14:54So, in essence, it's just a big sieve, really, yeah?
0:14:54 > 0:14:55Absolutely right, yeah.
0:14:55 > 0:14:59Urghh, the smell is absolutely... What's that?
0:15:01 > 0:15:02And where does the water go next?
0:15:02 > 0:15:05That goes onto the next stage of the process
0:15:05 > 0:15:07which I'm going to take you to now.
0:15:09 > 0:15:11Oh, what is this place?
0:15:11 > 0:15:15Here we settle out the solids in the waste water,
0:15:15 > 0:15:18and the clean water weirs over the top and goes on.
0:15:20 > 0:15:22This is the worst smell we've had so far, why's it so bad in here?
0:15:22 > 0:15:26We're starting to concentrate the solids, we call it sludge,
0:15:26 > 0:15:29and that has quite a strong odour.
0:15:29 > 0:15:32It's been called many things along this journey -
0:15:32 > 0:15:34stools, sludge...
0:15:36 > 0:15:38Look at it!
0:15:42 > 0:15:46Once the solids have been filtered out, the water's treated
0:15:46 > 0:15:49so it's clean enough to go back into the river.
0:15:49 > 0:15:52All that harmful bacteria has gone.
0:15:52 > 0:15:55But what happens to the sludge left behind?
0:15:55 > 0:15:57MUSIC: Theme from "2001 A Space Odyssey"
0:16:04 > 0:16:06What's inside these big, fat space eggs?
0:16:06 > 0:16:08Inside these digesters is sludge.
0:16:08 > 0:16:12OK, so what happens to the sludge inside here?
0:16:12 > 0:16:15So the sludge spends about 15 days in here with different bacteria
0:16:15 > 0:16:17that eat away at the sludge and
0:16:17 > 0:16:19produce a biogas that's full of methane.
0:16:19 > 0:16:22We use that in engines to generate electricity and heat.
0:16:22 > 0:16:25- Right, a reusable energy - poo's got power!- Poo power!
0:16:25 > 0:16:26Absolutely, certainly has.
0:16:26 > 0:16:30So, the poo from Bazalgette's sewers is a useful source of energy.
0:16:30 > 0:16:33Better out than in! Pffft!
0:16:33 > 0:16:37We're going to make our own methane, turning poo into energy.
0:16:37 > 0:16:41From sludge like this, you get methane.
0:16:41 > 0:16:44So while we make some gas, here are some facts about cack.
0:16:46 > 0:16:49The Genius Top Five.
0:16:49 > 0:16:52At five, the world's most expensive coffee drink
0:16:52 > 0:16:56is made from coffee beans eaten and pooed out by civet cats.
0:16:56 > 0:16:58The digestive process improves the taste!
0:16:58 > 0:17:00I think I'll stick to tea.
0:17:00 > 0:17:04At four, your body finds it hard to digest sweetcorn kernels
0:17:04 > 0:17:06that's why they sometimes turn up in the loo.
0:17:08 > 0:17:11At three, Cheryl Cole's cack smells of strawberries.
0:17:11 > 0:17:14No, it doesn't, even Cheryl has to go to the bog,
0:17:14 > 0:17:18and everyone's poo contains honking bacteria.
0:17:18 > 0:17:21At two, humans are naturally programmed to hate the smell of poo,
0:17:21 > 0:17:25so we don't touch it and end up sick from the bacteria inside.
0:17:28 > 0:17:31And at one, penguin poo can be seen from space!
0:17:31 > 0:17:33Their droppings show up as dark stains
0:17:33 > 0:17:36on satellite images from Antarctica.
0:17:36 > 0:17:38The dirty flappy flappers!
0:17:38 > 0:17:42So, then, Nick, this is a condensed version of what we saw outside,
0:17:42 > 0:17:44the big, fat, space eggs, right?
0:17:44 > 0:17:47That's right, so you can see the sludge and we are going to get you
0:17:47 > 0:17:49to feed them, because they are hungry at the moment,
0:17:49 > 0:17:52and they are going to produce more biogas, the bacteria that is,
0:17:52 > 0:17:56and they'll go down this tube, and bubble up through into these
0:17:56 > 0:17:57where we can collect it.
0:17:57 > 0:18:00Has anyone in 60 years of television fed poo before?
0:18:00 > 0:18:03- What do you feed it with?- With the sludge you've just seen on site.
0:18:03 > 0:18:05- Feed poo with poo?- Absolutely.
0:18:05 > 0:18:08So how do we know when methane has been produced?
0:18:08 > 0:18:10It will bubble up into this column here and displace the water
0:18:10 > 0:18:12so we can measure how much we've produced.
0:18:12 > 0:18:14So it looks like when you let one go in the bath?
0:18:14 > 0:18:17Yeah, we've just got this cylinder on top. Choose your colour.
0:18:17 > 0:18:20- Yellow!- You like yellow, don't you?
0:18:20 > 0:18:25I'll have blue, then. So we don't forget, here's a...
0:18:25 > 0:18:28- So, I'll leave you guys to feed the digesters.- All right, sounds good.
0:18:28 > 0:18:31- Get the shovels.- Give it a stir.
0:18:33 > 0:18:35Urghh, it stinks!
0:18:35 > 0:18:37I'm going in.
0:18:37 > 0:18:40The bacteria in the digestors will eat the sludge we're feeding them.
0:18:40 > 0:18:43Have you ever thought this is where yours could end up?
0:18:43 > 0:18:46In an experiment like this.
0:18:46 > 0:18:48In the process, they'll naturally release gases,
0:18:48 > 0:18:50full of methane energy.
0:18:50 > 0:18:53It's called anaerobic digestion.
0:18:53 > 0:18:57It works best when it's in a warm environment, about 40 C.
0:18:57 > 0:19:00The sludge and the bacteria are loving the heat.
0:19:00 > 0:19:02Can I borrow your poo poker?
0:19:02 > 0:19:03Yes, please.
0:19:04 > 0:19:08Right, the bung is in the bunghole, switch on the mixers,
0:19:08 > 0:19:09and let it ferment.
0:19:09 > 0:19:12Right, we've got 30 minutes, time starts now.
0:19:16 > 0:19:17Now all we can do is wait.
0:19:18 > 0:19:20And wait.
0:19:20 > 0:19:23Don't mess about with it.
0:19:23 > 0:19:2515 minutes left!
0:19:25 > 0:19:28Each time gas is released, it bubbles up into the glass columns...
0:19:28 > 0:19:29Ten minutes left.
0:19:29 > 0:19:31..pushing the liquid down.
0:19:31 > 0:19:34Five minutes left!
0:19:34 > 0:19:36The less liquid, the more gas!
0:19:38 > 0:19:40Three, two, one...
0:19:40 > 0:19:42BEEP
0:19:42 > 0:19:44- I've won.- Mine's definitely lower.
0:19:44 > 0:19:46- No, I've won.- No, a little bit less.
0:19:46 > 0:19:49Nick, come here, expert opinion - who's won?
0:19:49 > 0:19:51Right, let's have a look.
0:19:51 > 0:19:54I can see from this that Dick has produced more gas.
0:19:54 > 0:19:56Come on! You see, I put in more sludge!
0:19:56 > 0:19:58- You always do produce more gas. - True.
0:19:58 > 0:20:01We saw the gas bubbling up through the water, up into the tube,
0:20:01 > 0:20:02it's still there, but what is it?
0:20:02 > 0:20:05The biogas is mostly made up of methane - 65%.
0:20:05 > 0:20:07OK, and what's the deal with methane?
0:20:07 > 0:20:11Methane is an explosive gas and it's also full of energy, obviously.
0:20:11 > 0:20:13Did you say, "explosive"?
0:20:18 > 0:20:20This methane gas being explosive sounds good, doesn't it?
0:20:20 > 0:20:24It does sound good, but I want to see the energy, I want to see it.
0:20:24 > 0:20:27- If only Fran, our genius scientist was here to tell us more.- Yeah.
0:20:27 > 0:20:29- BOTH:- Hooray!
0:20:29 > 0:20:31Our genius scientist, Fran,
0:20:31 > 0:20:35can explain things in ways even WE can understand.
0:20:35 > 0:20:36She loves a good experiment,
0:20:36 > 0:20:40and always pops up when you need her most.
0:20:40 > 0:20:44So I thought, let's see the energy in methane.
0:20:44 > 0:20:46So, I've got a balloon of methane here,
0:20:46 > 0:20:50and some soapy water, so let's bubble methane through the
0:20:50 > 0:20:53soapy water and we'll get bubbles that are full of methane.
0:20:53 > 0:20:56- Farty bubbles!- Exactly.
0:20:56 > 0:20:59What I'm doing to do is set fire to these bubbles, so we see the energy
0:20:59 > 0:21:02and why don't we set fire to them...
0:21:02 > 0:21:05- in your hand, Dick?- Good idea.
0:21:05 > 0:21:08Course you did, Fran!
0:21:08 > 0:21:11Fran's an expert - this is not something to be messed with at home.
0:21:11 > 0:21:13If we get a nice, big handful of those...
0:21:13 > 0:21:14Why's it always me?
0:21:14 > 0:21:16- And let's just set fire to them!- No!
0:21:16 > 0:21:17So three, two, one...
0:21:19 > 0:21:20Aaaagh!
0:21:22 > 0:21:23Were you OK, then?
0:21:23 > 0:21:26Well, it was quite warm. Look at my arm hair!
0:21:26 > 0:21:30Look what you've done to my arm hair! It took me 36 years to grow that!
0:21:33 > 0:21:35So you could see the energy being released from methane
0:21:35 > 0:21:38with the flame and you could feel the heat a little bit.
0:21:38 > 0:21:42That was good, but what we want is an explosion...
0:21:42 > 0:21:43we've heard it's explosive.
0:21:43 > 0:21:47Ah, well, to make methane explosive, you've got to add oxygen.
0:21:47 > 0:21:49Right, have you got any oxygen?
0:21:49 > 0:21:52- Just so happens I have.- Oh, good.
0:21:52 > 0:21:55Over here I've got a balloon, a very small balloon of oxygen
0:21:55 > 0:21:58- and another balloon of methane. - Good friend.
0:21:58 > 0:22:02So, I'm going to bubble these through the soapy water again...
0:22:02 > 0:22:03Is it going to go bang in there?
0:22:03 > 0:22:06Well, why don't we just do the same as before,
0:22:06 > 0:22:08you scoop them up and we set fire to them in your hand.
0:22:08 > 0:22:10- It's a nice idea.- Why not?
0:22:14 > 0:22:19That's it. Three, two, one...
0:22:19 > 0:22:20Aaaaagh!
0:22:20 > 0:22:23# Boom! Shake, shake, shake the room!
0:22:23 > 0:22:25# Tick, tick, tick, tick, boom! #
0:22:25 > 0:22:27It was brilliant, but we want to see the power of poo
0:22:27 > 0:22:29on an even bigger scale. Massive.
0:22:29 > 0:22:31Ah, I can imagine you do.
0:22:31 > 0:22:36If I was to do that, I think I'd need to go to a big, open field.
0:22:37 > 0:22:40I love big, open fields.
0:22:45 > 0:22:49We've been on a whiffy adventure, examining the stinky stuff
0:22:49 > 0:22:52running through Bazalgette's genius sewer...
0:22:52 > 0:22:55That's the elastic from the top of someone's pants!
0:22:55 > 0:22:57..and we've met genius helpers who've made
0:22:57 > 0:22:59power from the poo in his sewers.
0:22:59 > 0:23:00Methane power!
0:23:02 > 0:23:06We're ready to reveal our own genius idea.
0:23:07 > 0:23:12Our Genius idea - demonstrate the power of poo on a big scale!
0:23:12 > 0:23:14Our challenge -
0:23:14 > 0:23:17to build the average household out of cardboard boxes,
0:23:17 > 0:23:22calculate the methane they'd produce from five days of poo,
0:23:22 > 0:23:25then ignite it and let rip!
0:23:25 > 0:23:27I hope you're ready. I hope you're ready.
0:23:27 > 0:23:30Cos this is going to be explosive.
0:23:30 > 0:23:32But first we need to work out how much methane is
0:23:32 > 0:23:34produced by a typical family.
0:23:35 > 0:23:38Watch and learn, children, Dick and Dom's maths lesson.
0:23:38 > 0:23:41The average person's poo from one day
0:23:41 > 0:23:43will give us 13.5 litres of methane.
0:23:44 > 0:23:46Times that by that first. Yes?
0:23:46 > 0:23:48Clever boy, clever boy.
0:23:48 > 0:23:51Times that by 5 days AND 2.4 -
0:23:51 > 0:23:54the number of people in the average household.
0:23:54 > 0:23:55What's he talking about?
0:23:55 > 0:23:56- Hang on a minute!- No!
0:23:56 > 0:23:58- Shhh.- Times five is...
0:23:58 > 0:24:00I refuse to do... I know.
0:24:00 > 0:24:03It's there, look. See? There's the answer.
0:24:03 > 0:24:05And that's a lot of gas!
0:24:05 > 0:24:10So it's 162 litres of methane.
0:24:10 > 0:24:13Yep. That's right. It says it there.
0:24:14 > 0:24:16Time to call in our Genius Helper..
0:24:18 > 0:24:22It's Mark Turner, special effects whiz and explosives expert.
0:24:22 > 0:24:25The last time we saw this man, he locked Dick in a cage,
0:24:25 > 0:24:27next to almost a million volts of electricity.
0:24:29 > 0:24:32So what can we do with 162 litres of methane?
0:24:32 > 0:24:35- I reckon ten boxes will sort you out.- All right.
0:24:35 > 0:24:38What I'd like you to do is make them up, take the bottoms down,
0:24:38 > 0:24:41I'll go and prep the balloons for these boxes - I'll see you in a bit.
0:24:43 > 0:24:47- So we just need to put the boxes together.- What is that?
0:24:47 > 0:24:50There you go, one, sealed.
0:24:51 > 0:24:54Yes, that's me - 2.4 Dick and Doms.
0:25:02 > 0:25:04We've got a mummy and daddy.
0:25:04 > 0:25:06I think we need a .4, don't we?
0:25:06 > 0:25:08That could be Mark.
0:25:14 > 0:25:18Look at that, it's brilliant! Look at the family, everyone.
0:25:18 > 0:25:22And there you have it, the average family household of 2.4 -
0:25:22 > 0:25:24Daddy Dick, Mummy Dom, and little baby Mark.
0:25:24 > 0:25:29- Shall we go and produce some methane?- Yes!- Come on.
0:25:29 > 0:25:34Or in fact, to save time, let's use some Mark produced earlier.
0:25:34 > 0:25:36162 litres of it.
0:25:36 > 0:25:38How many do you put in per box?
0:25:38 > 0:25:39- One per box.- Oh, only one.
0:25:39 > 0:25:42- Little Mark!- Oh, it's me!
0:25:42 > 0:25:43Right, let's get them into position.
0:25:43 > 0:25:46- Mark, would you like to take yourself?- I will.
0:25:50 > 0:25:53Finally we're ready for the Genius idea.
0:25:53 > 0:25:58In this very quiet field we're about to make a VERY big bang,
0:25:58 > 0:26:01using the power of poo!
0:26:01 > 0:26:02PFFT!
0:26:02 > 0:26:04PFFFFT!
0:26:04 > 0:26:07And we're all set, the typical British household is there,
0:26:07 > 0:26:09ready and waiting.
0:26:09 > 0:26:12And you, Bazalgette, you've got front row seats to watch our
0:26:12 > 0:26:14Genius idea - methane explosion.
0:26:14 > 0:26:17And all of this is to celebrate what a genius you are
0:26:17 > 0:26:19for inventing the London sewer system.
0:26:19 > 0:26:22Yes, thank you, Bazalgette, for helping us to collect the poo
0:26:22 > 0:26:26which creates the methane which will help all of this family go bang.
0:26:26 > 0:26:29Actually, you might need these in your ears.
0:26:29 > 0:26:31And your mouth open. Good lad.
0:26:31 > 0:26:33Right, Mark, we're ready.
0:26:33 > 0:26:35Standing by.
0:26:35 > 0:26:37Three... Two...
0:26:37 > 0:26:38One...
0:26:44 > 0:26:48It went right through me! Look what it did to Bazalgette!
0:26:48 > 0:26:51Oooh, my back!
0:26:56 > 0:26:59Mark's head's intact - we blew his head off.
0:26:59 > 0:27:01Mark's torso!
0:27:01 > 0:27:04Looks like me and you are in 1,000 pieces, mate!
0:27:04 > 0:27:08The methane, with the oxygen, literally blew it to bits.
0:27:08 > 0:27:13We've seen the genius of Sir Joseph Bazalgette for ourselves,
0:27:13 > 0:27:16and been inspired by his sewage.
0:27:16 > 0:27:20And we've transformed human waste into energy.
0:27:23 > 0:27:24Explosive methane energy!
0:27:24 > 0:27:27Who'd have thought poo could be so powerful?!
0:27:29 > 0:27:32So there you are. That's what the gas from YOUR poo can do.
0:27:32 > 0:27:36Yeah, you think your dad or grandpa can do a ripper.
0:27:36 > 0:27:37THAT was a ripper!
0:27:37 > 0:27:40It certainly was. Bazalgette, you are an absolute genius.
0:27:40 > 0:27:41Thank you, boys.
0:27:46 > 0:27:47Aaaagh!
0:27:53 > 0:27:54BOGEYS!!
0:28:00 > 0:28:02It went right through me!
0:28:02 > 0:28:04- Don't wobble it! - I'm not doing anything!
0:28:04 > 0:28:06Just stand still, then!
0:28:08 > 0:28:11Subtitles by Red Bee Media Ltd