0:00:00 > 0:00:04Engineering is all about problem solving.
0:00:04 > 0:00:08It's what chaps in hard hats do to improve our world,
0:00:08 > 0:00:13using science and spanners and really sharp pencils.
0:00:13 > 0:00:18So if you've ever wondered, "What did steam ever do for us?",
0:00:18 > 0:00:25"How high can we build?" and "When can I move to Mars?"
0:00:25 > 0:00:28then prepare to have your nuts tightened
0:00:28 > 0:00:32as we find out the things you need to know about engineering.
0:00:32 > 0:00:35Now logic dictates that we should start at the beginning. So...
0:00:40 > 0:00:43Who were the first engineers?
0:00:43 > 0:00:46We humans think we're pretty clever.
0:00:46 > 0:00:51We've built megacities housing more than 30 million people,
0:00:51 > 0:00:55skyscrapers stretching half a mile high,
0:00:55 > 0:00:59and space-age materials strong enough to stop a bullet.
0:00:59 > 0:01:03We are the planet's first and only engineers.
0:01:03 > 0:01:06Or are we?
0:01:06 > 0:01:10In fact, long before the Greeks or the Romans
0:01:10 > 0:01:14even thought of putting one brick on top of another,
0:01:14 > 0:01:18engineers were already hard at work all over the world.
0:01:22 > 0:01:25Take a massive structure like the Hoover Dam.
0:01:25 > 0:01:29Made from six and a half million tons of concrete,
0:01:29 > 0:01:35it's over 1,200 feet wide, and holds back nine trillion gallons of water,
0:01:35 > 0:01:41enough to flood the entire state of New York to a height of one foot.
0:01:41 > 0:01:46But Canada has a dam twice as long, big enough to see from space.
0:01:46 > 0:01:49And this one was built by...
0:01:49 > 0:01:51..beavers.
0:01:51 > 0:01:54Nature's been at it for a long time.
0:01:54 > 0:01:57Civilisation is what, 10,000 years old.
0:01:57 > 0:02:03Biology's been at it for 3.5, maybe 3.8 billion years.
0:02:03 > 0:02:06So it's had the head start on us, and it will do for some time.
0:02:06 > 0:02:13As for skyscrapers, African termites regularly build towers 30 feet high.
0:02:13 > 0:02:16That's more than half a mile at human scale.
0:02:16 > 0:02:19And they come with individual rooms and air conditioning.
0:02:21 > 0:02:23With human engineering and Mother Nature,
0:02:23 > 0:02:26there's like a completely different approach to the subject.
0:02:26 > 0:02:29We try and come up with a concept.
0:02:29 > 0:02:31We find a problem and we try and engineer a solution.
0:02:31 > 0:02:35Whereas nature, her designs were much more random.
0:02:35 > 0:02:37She took various paths, they failed,
0:02:37 > 0:02:40and only the successful paths go forward.
0:02:40 > 0:02:43And the wonderful thing about nature is you see all these amazing things
0:02:43 > 0:02:46that have been produced by natural things going on
0:02:46 > 0:02:48that have created amazing engineering.
0:02:48 > 0:02:52OK, what about those bullet-proof jackets then?
0:02:52 > 0:02:57It takes vats of acid, 700 degrees Celsius,
0:02:57 > 0:03:00and a load of toxic by-products to produce Kevlar,
0:03:00 > 0:03:03one of the toughest man-made materials.
0:03:03 > 0:03:08An incy wincy spider's bottom, at room temperature,
0:03:08 > 0:03:11produces silk that's five times stronger.
0:03:11 > 0:03:15The point is, no matter how ingenious we become,
0:03:15 > 0:03:20Mother Nature, the original engineer, almost always got there first.
0:03:20 > 0:03:22SNEEZING
0:03:23 > 0:03:28There is one engineering concept that we came up with all by ourselves.
0:03:28 > 0:03:31With the exception of certain bacterial flagella -
0:03:31 > 0:03:35that's microscopic bug-hairs to you and me -
0:03:35 > 0:03:37the natural world is completely devoid
0:03:37 > 0:03:40of something that we take for granted.
0:03:40 > 0:03:45The rotary bearing, otherwise known as the wheel.
0:03:45 > 0:03:47So, what first got us moving?
0:03:47 > 0:03:52In engineering terms, the wheel is child's play.
0:03:52 > 0:03:55Any toddler knows that the ones on the bus go round and round.
0:03:57 > 0:03:59But how does the wheel actually work?
0:04:01 > 0:04:04Looking at the engineering behind the wheel
0:04:04 > 0:04:06is more complicated than you might think.
0:04:06 > 0:04:10How the wheel works, good question. The more you think about it, the trickier it becomes.
0:04:10 > 0:04:12For a reasonably simple device and concept,
0:04:12 > 0:04:15the wheel's actually reasonably complicated to think about.
0:04:15 > 0:04:19You try and think about the maths of it, you've got to be aware that,
0:04:19 > 0:04:22you know, if you're drawing your... I'll need a piece of paper for this.
0:04:22 > 0:04:25A wheel itself isn't a machine itself without the axle,
0:04:25 > 0:04:28and all sorts of weirdness and then suddenly,
0:04:28 > 0:04:32something Fred Flintstone should have been able to cobble together looks kind of complicated.
0:04:32 > 0:04:37Without the wheel, moving heavy objects is a pain.
0:04:37 > 0:04:40Literally, because the resulting friction means lots of effort,
0:04:40 > 0:04:43but not a lot of result.
0:04:43 > 0:04:48You could try using a lever, such as a crowbar.
0:04:48 > 0:04:53This magnifies the force you apply, helping to overcome the friction.
0:04:53 > 0:04:58But it won't win you any favours with the hippo!
0:04:58 > 0:05:02Plonk him on a board, and add a few logs as rollers,
0:05:02 > 0:05:05and you get rid of the friction completely.
0:05:05 > 0:05:08Which is great, except for all that running back and forth
0:05:08 > 0:05:12to replace the rollers. To get round this,
0:05:12 > 0:05:15you attach them to the board.
0:05:15 > 0:05:18And before you know it, you have an axle and wheels.
0:05:18 > 0:05:22But instead of rolling, the axle rubs against its housing,
0:05:22 > 0:05:26so now you've brought back the friction.
0:05:26 > 0:05:31Luckily, though, the wheel's radius is much larger than the axle's.
0:05:31 > 0:05:35It's basically a kind of circular crowbar,
0:05:35 > 0:05:38continuously overcoming the friction.
0:05:38 > 0:05:43Now, remember those logs? They got rid of friction altogether.
0:05:43 > 0:05:48So let's put them back, only this time much smaller, around the axle.
0:05:48 > 0:05:50Now you've got rid of the friction again,
0:05:50 > 0:05:52and invented the modern bearing.
0:05:55 > 0:05:58Which is great news for hippopotamus delivery guys everywhere!
0:06:00 > 0:06:04Once we had the wheel, there was no stopping us, literally.
0:06:04 > 0:06:06Not until somebody came up with the brake.
0:06:06 > 0:06:09And, of course, somebody had to invent the road.
0:06:09 > 0:06:13And even that was no good once you got to something like a river valley.
0:06:13 > 0:06:15That gave the engineers another job to do.
0:06:15 > 0:06:18They had to come up with the bridge.
0:06:18 > 0:06:22So how do bridges work?
0:06:22 > 0:06:26To understand bridges, we need to think about bats.
0:06:26 > 0:06:31That's Beam, Arch, Truss and Suspension -
0:06:31 > 0:06:34the four basic types of bridge.
0:06:34 > 0:06:40A simple beam bridge is like a log across a river valley.
0:06:40 > 0:06:43As it tries to support both your weight and its own,
0:06:43 > 0:06:46the beam has to deal with two forces.
0:06:46 > 0:06:50Tension, which stretches the lower surface,
0:06:50 > 0:06:53and compression, which squashes the top.
0:06:53 > 0:06:58But bring along too many of your gang, and,
0:06:58 > 0:07:01suddenly, you need a truss.
0:07:01 > 0:07:05A truss provides reinforcement by adding a bit more bridge
0:07:05 > 0:07:10and harnessing the structural strength of the triangle.
0:07:10 > 0:07:16The Romans preferred a more elegant and much curvier solution. The arch.
0:07:16 > 0:07:21Actually, they probably nicked this idea from the Etruscans,
0:07:21 > 0:07:25who never bothered to patent it, so that's their tough luck.
0:07:27 > 0:07:31You can think of an arch as a beam bent into a semicircle.
0:07:31 > 0:07:36Now the weight produces only compression. There is no tension.
0:07:36 > 0:07:40Unless you happened to be an ancient Roman bridge builder.
0:07:40 > 0:07:45They had to stand under their creations while the scaffolding was removed,
0:07:45 > 0:07:48which might explain why so many of their arches are still with us.
0:07:50 > 0:07:54A well-built masonry arch has simply no desire to fall down.
0:07:54 > 0:07:56It's just not what it's going to do.
0:07:56 > 0:08:00It has to break in at least three places before it'll collapse.
0:08:00 > 0:08:03Which makes them very good for earthquake resistance
0:08:03 > 0:08:06and kind of just general longevity,
0:08:06 > 0:08:09which is why you see Roman and Saxon arches around now.
0:08:09 > 0:08:11They just don't break.
0:08:11 > 0:08:14Now, here's another way to build a bridge.
0:08:14 > 0:08:19Flip an arch on its head and you get the suspension bridge.
0:08:19 > 0:08:21This time it's all tension.
0:08:21 > 0:08:25The overhead cables are in a constant tug-of-war
0:08:25 > 0:08:27with the weight on the bridge.
0:08:27 > 0:08:31It's exactly the same principle as your granny's washing line!
0:08:34 > 0:08:39Speaking of washing, tackling this little lot would take forever
0:08:39 > 0:08:42if it weren't for the miracle of steam.
0:08:42 > 0:08:46But apart from allowing me to remove all the unsightly wrinkles
0:08:46 > 0:08:48from these unmentionables,
0:08:48 > 0:08:54have you ever asked yourself, what did steam ever do for us?
0:08:54 > 0:08:58Steam is great for making frothy coffees, stripping wallpaper
0:08:58 > 0:09:02and ironing socks. Preferably not all at the same time! SCREAMING
0:09:02 > 0:09:06But engineers love steam because it's good at transporting energy.
0:09:09 > 0:09:13When water is boiled, it absorbs heat, turning it into steam,
0:09:13 > 0:09:17which can be piped under pressure to where it's needed.
0:09:17 > 0:09:22Steam is a wonderful material because it can take heat energy
0:09:22 > 0:09:25and transfer it from one place to another.
0:09:25 > 0:09:27You start with heat and you can turn it into movement.
0:09:27 > 0:09:31And ultimately, from movement, you can then turn it into electricity.
0:09:31 > 0:09:34A further advantage of steam is that it's based around water,
0:09:34 > 0:09:38which is largely everywhere. It's non-corrosive.
0:09:38 > 0:09:41It's great, get some water, boil it up, create this vapour.
0:09:41 > 0:09:43And then you can drive stuff.
0:09:43 > 0:09:482,000 years ago, a Greek chap called Hero invented the aeolipile,
0:09:48 > 0:09:51a kind of steam-driven spinning ball.
0:09:51 > 0:09:55Unfortunately, he only ever used it as a party trick,
0:09:55 > 0:09:58and the idea sort of ran out of steam.
0:10:00 > 0:10:05The ancient Greeks also had rudimentary railways called rut-ways.
0:10:05 > 0:10:08So if our hero had thought to combine the two,
0:10:08 > 0:10:11we might have had space travel by the Middle Ages,
0:10:11 > 0:10:13and I'd have my hover-boots by now.
0:10:15 > 0:10:20It was 1,700 years before steam powered its next revolution.
0:10:20 > 0:10:22The industrial one.
0:10:22 > 0:10:25The first practical design was the Newcomen Engine,
0:10:25 > 0:10:28used to pump water out of mines.
0:10:28 > 0:10:32But Scottish engineer James Watt wasn't impressed.
0:10:32 > 0:10:34He realised that most of the steam's energy
0:10:34 > 0:10:36was used up reheating the cylinder
0:10:36 > 0:10:39after it was cooled during each cycle.
0:10:40 > 0:10:44His external condenser worked outside the engine,
0:10:44 > 0:10:49so the cylinder stayed hot, and more of the steam could be put to work.
0:10:49 > 0:10:53The early beam engines, they used to inject the steam into the piston,
0:10:53 > 0:10:55then cool it as quickly as they could
0:10:55 > 0:10:58and it would suck the piston down and turn things that way.
0:10:58 > 0:11:02The trouble was, the whole cylinder was cooled during the cycle.
0:11:02 > 0:11:07James Watt, the Scottish inventor, then took the idea forward
0:11:07 > 0:11:11and put an external condensing cylinder so that the cooling work
0:11:11 > 0:11:15was done externally, leaving all the main heat in the cylinder.
0:11:15 > 0:11:19And this dramatically increased the efficiency of the steam engine.
0:11:19 > 0:11:22He marketed this by boasting how many horses it would replace,
0:11:22 > 0:11:24which gave us the term "horsepower",
0:11:24 > 0:11:27and kick-started the Industrial Revolution.
0:11:31 > 0:11:35Today, power stations and nuclear submarines use steam turbines,
0:11:35 > 0:11:38which are much more efficient than pistons and valves
0:11:38 > 0:11:40and work on exactly the same principle
0:11:40 > 0:11:45as our Hero's 2,000-year-old toy.
0:11:48 > 0:11:51Impressive though the ships and locomotives of the steam age were,
0:11:51 > 0:11:55there was one form of transport that would have to wait
0:11:55 > 0:11:57for the internal combustion engine.
0:11:57 > 0:12:01No, not the car, because they had steam-powered versions of those too.
0:12:01 > 0:12:04I'm talking about the aeroplane.
0:12:04 > 0:12:06So my next question is:
0:12:10 > 0:12:17Fully loaded, the world's largest commercial aeroplane weighs 560 tons.
0:12:17 > 0:12:20That's almost 50 London double-decker buses,
0:12:20 > 0:12:25complete with passengers. And yet all that's keeps it aloft is thin air.
0:12:28 > 0:12:31So thin, in fact, that it's unbreathable.
0:12:31 > 0:12:34And the only thing between that and you
0:12:34 > 0:12:37is less than half an inch of plexiglass!
0:12:37 > 0:12:42Frankly, being at 30,000 feet is just plain terrifying!
0:12:44 > 0:12:47Outside of the aircraft fuselage at 30,000 feet
0:12:47 > 0:12:50is a pretty hostile place for a human body.
0:12:50 > 0:12:52You're hurtling through the air at 500 miles an hour,
0:12:52 > 0:12:56you're at temperatures of probably -60 degrees C.
0:12:56 > 0:12:58There's very little oxygen at that sort of altitude,
0:12:58 > 0:13:00so it's hard to breathe.
0:13:00 > 0:13:05In World War II, some of the bombers flew at that sort of altitude.
0:13:05 > 0:13:09So the crews would often get injured and/or die
0:13:09 > 0:13:15just because of the hostility of the environment of high altitude.
0:13:15 > 0:13:18It's not a place a person is supposed to be.
0:13:18 > 0:13:20Even inside the plane,
0:13:20 > 0:13:22the air pressure is kept much lower than at sea level,
0:13:22 > 0:13:26which is a real pain in the ear.
0:13:26 > 0:13:30It also means that water boils at just 90 degrees,
0:13:30 > 0:13:33which is why airline tea tastes so horrible!
0:13:33 > 0:13:36- Eurgh!- To pressurise the air,
0:13:36 > 0:13:42you have to pump air in using the jets on the plane.
0:13:42 > 0:13:44And that uses fuel and it costs money.
0:13:44 > 0:13:49So you don't take the full pressure of sea level pressure with you.
0:13:49 > 0:13:51But you do pressurise them a bit
0:13:51 > 0:13:55and they're pressurised to about an altitude of 9,000 feet.
0:13:55 > 0:13:59And so every time a plane goes up to altitude and comes back down,
0:13:59 > 0:14:02it gets stretched slightly and it shrinks slightly.
0:14:02 > 0:14:04And it's a little bit like bending a paper clip.
0:14:04 > 0:14:07You can only do this so many times before the thing starts to crack.
0:14:07 > 0:14:12Meanwhile, at 500mph, a plane's windscreen has to be especially tough
0:14:12 > 0:14:15to withstand the threat of bird strike,
0:14:15 > 0:14:20which every year causes roughly 1.2 billion worth of damage.
0:14:21 > 0:14:24To test their designs against the effects of bird strike,
0:14:24 > 0:14:28the aeroplane manufacturers fire poultry at them
0:14:28 > 0:14:34at speeds at up to 180mph from a giant chicken gun.
0:14:38 > 0:14:40And all the time,
0:14:40 > 0:14:44you are sitting beside up to 60,000 gallons of aviation fuel,
0:14:44 > 0:14:49which, weight for weight, has 15 times the energy of TNT.
0:14:51 > 0:14:53Given that commercial planes are struck by lightning
0:14:53 > 0:14:55roughly once a year,
0:14:55 > 0:14:58just be grateful that they're designed like huge Faraday cages
0:14:58 > 0:14:59to keep you safe.
0:15:01 > 0:15:03In fact, thanks to engineering,
0:15:03 > 0:15:06air travel is reckoned to be 20 times safer than driving.
0:15:06 > 0:15:08Aargh!
0:15:08 > 0:15:09Oops!
0:15:11 > 0:15:16I'm not afraid of flying, or at least, I wasn't,
0:15:16 > 0:15:19but I am really terrified of those glass elevator things.
0:15:19 > 0:15:23You know the ones that go up and down the side of a skyscraper?
0:15:23 > 0:15:25Which is why my next question is,
0:15:25 > 0:15:27how high can we build?
0:15:29 > 0:15:30When it comes to tall buildings,
0:15:30 > 0:15:34engineers have always played "who's got the biggest?"
0:15:36 > 0:15:39This "edifice complex" led the ancient Egyptians
0:15:39 > 0:15:41to build the Great Pyramid of Giza,
0:15:41 > 0:15:44which, at 481 feet,
0:15:44 > 0:15:48held the record for nearly 4,000 years.
0:15:48 > 0:15:53Although today, it's 30 feet shorter thanks to erosion, and theft.
0:15:55 > 0:15:58I'm pleased to report that it was an English building,
0:15:58 > 0:16:00Lincoln Cathedral, that stole the title
0:16:00 > 0:16:03of World's Tallest from the Egyptians,
0:16:03 > 0:16:07a record it held onto for another 250 years.
0:16:07 > 0:16:11Still not exactly what you'd call a skyscraper, though, is it?
0:16:11 > 0:16:14It wasn't until the invention of the steel frame
0:16:14 > 0:16:17that buildings really took off.
0:16:17 > 0:16:20This carries all the weight of the structure,
0:16:20 > 0:16:22but doesn't add much weight of its own.
0:16:22 > 0:16:27So the glass walls of a modern skyscraper are really
0:16:27 > 0:16:28just decorative curtains.
0:16:29 > 0:16:33One problem skyscrapers regularly face is wind.
0:16:35 > 0:16:37This can set up resonant oscillations,
0:16:37 > 0:16:39causing a building to sway violently.
0:16:41 > 0:16:46A single straight blow won't be enough to push the building down.
0:16:46 > 0:16:49But if by freak chance, the wind happens to be
0:16:49 > 0:16:52flicking to one side of the building and another,
0:16:52 > 0:16:55at just the right rate to wobble it,
0:16:55 > 0:16:57putting those pushes and pulls at the right times,
0:16:57 > 0:17:01eventually the wobble on the building will build up
0:17:01 > 0:17:05to such an extent that the whole thing will crash right down.
0:17:05 > 0:17:08But change the shape of the building every few storeys,
0:17:08 > 0:17:11and the wind gets confused.
0:17:11 > 0:17:13So the diners in that top-floor restaurant
0:17:13 > 0:17:15are less likely to lose their lunches.
0:17:17 > 0:17:19At just over half a mile high,
0:17:19 > 0:17:22the undisputed high-rise champion is Dubai's Burj Khalifa.
0:17:24 > 0:17:28But Saudi Arabia is already planning the Kingdom tower,
0:17:28 > 0:17:31the first to reach the one-kilometre mark.
0:17:31 > 0:17:37That's almost seven Pyramids of Giza stacked on top of each other!
0:17:37 > 0:17:40The very tallest towers require elevators that travel
0:17:40 > 0:17:42at 40 miles an hour.
0:17:42 > 0:17:46Keep going up at that speed and in 90 minutes you'd reach outer space!
0:17:48 > 0:17:51Not everything in the engineering world is part of
0:17:51 > 0:17:53this "mine's bigger than yours" game.
0:17:53 > 0:17:56Far from it. In fact, the next big thing on the horizon
0:17:56 > 0:18:02is positively, almost infinitesimally tiny.
0:18:02 > 0:18:07So, what's so big about being small?
0:18:07 > 0:18:09Please do not adjust your screen.
0:18:09 > 0:18:12Things are about to get very tiny indeed.
0:18:14 > 0:18:18Because nano-engineers measure things in nanometres,
0:18:18 > 0:18:20or millionths of a millimetre.
0:18:21 > 0:18:26If you were to scale a metre up to the size of the whole planet,
0:18:26 > 0:18:30then a nanometre would be the size of this marble.
0:18:30 > 0:18:34A nanometre is roughly what your beard would grow,
0:18:34 > 0:18:37the length your beard would change, in the time it takes
0:18:37 > 0:18:40to take a razor off the sink and towards your face.
0:18:40 > 0:18:45A human hair is about 100,000 nanometres across.
0:18:45 > 0:18:48Incredibly, that's 30 times bigger
0:18:48 > 0:18:53than the working steam engine built recently by German scientists.
0:18:53 > 0:18:56But 3,000 times smaller than that
0:18:56 > 0:18:59is the world's first nanocar!
0:18:59 > 0:19:02Made from a single molecule, its wheels would have to rotate
0:19:02 > 0:19:06three million times to cross the head of a pin.
0:19:06 > 0:19:09So it isn't going to break any speed limits.
0:19:10 > 0:19:13The spherical wheels are made from one of the building blocks
0:19:13 > 0:19:16of nanotechnology - the Bucky ball.
0:19:17 > 0:19:20This new form of carbon was only discovered in 1985,
0:19:20 > 0:19:24when it was created in the lab by accident.
0:19:24 > 0:19:29Buckminsterfullerene, to give it its proper name,
0:19:29 > 0:19:34can be stretched into a hollow fibre 100 times stronger than steel
0:19:34 > 0:19:36and six times lighter.
0:19:36 > 0:19:40Scientists predict that these materials may soon
0:19:40 > 0:19:42lead to all sorts of minor miracles,
0:19:42 > 0:19:47like self-replicating nano-machines that heal us from inside.
0:19:49 > 0:19:53But altering things at a molecular level is risky.
0:19:53 > 0:19:56If these man-made microbes were to multiply out of control,
0:19:56 > 0:19:59they could devour all life on earth,
0:19:59 > 0:20:03leaving behind nothing but a mass of grey goo.
0:20:04 > 0:20:07Whatever you think of nanobots,
0:20:07 > 0:20:11we all know that real robots are huge, awkward things
0:20:11 > 0:20:14that speak in a dreary monotone.
0:20:14 > 0:20:16A bit like politicians, really.
0:20:16 > 0:20:19Except that robots are supposed to be clever.
0:20:19 > 0:20:23So that leads me rather naturally to my next question.
0:20:27 > 0:20:33Today we've got smart phones, smart cars, and even smart bombs.
0:20:33 > 0:20:36But beside the world's top supercomputers,
0:20:36 > 0:20:40these are distinctly dumb.
0:20:40 > 0:20:41Here's a thought for you.
0:20:41 > 0:20:47If my computer was as smart as me, would I be allowed to turn it off?
0:20:47 > 0:20:49Or would that be murder?
0:20:51 > 0:20:55In 2009, IBM built an artificial brain
0:20:55 > 0:20:58with about nine trillion synaptic connections.
0:20:58 > 0:21:01It needed a million watts of electricity,
0:21:01 > 0:21:05and 6,500 tons of air conditioning gear,
0:21:05 > 0:21:09and compared to the computing power of a human brain,
0:21:09 > 0:21:14it measured an impressive 1% - about the same as a cat.
0:21:15 > 0:21:18Intelligence isn't just about calculation.
0:21:18 > 0:21:21It's about intuition, it's about knowing things.
0:21:21 > 0:21:23It's about being able to understand things.
0:21:23 > 0:21:25And I don't think computers are there yet.
0:21:25 > 0:21:30They used to have a test question for artificial intelligence
0:21:30 > 0:21:34that went along the lines of, "Time flies like an arrow,
0:21:34 > 0:21:36"and fruit flies like a banana."
0:21:37 > 0:21:40And no machine had any idea what you meant.
0:21:40 > 0:21:43Supercomputing speed is measured in
0:21:43 > 0:21:47quadrillions of calculations per second, called petaflops.
0:21:47 > 0:21:52And the undisputed top of the flops is a Japanese machine called K,
0:21:52 > 0:21:58which recently clocked up a cool 10.5 on the petaflop-ometer.
0:21:58 > 0:22:02That's about 100,000 times faster than the average PC.
0:22:04 > 0:22:08K runs the world's most advanced computer simulations,
0:22:08 > 0:22:12virtual versions of everything from tomorrow's weather
0:22:12 > 0:22:14to the entire universe.
0:22:14 > 0:22:17But to be classed as truly intelligent,
0:22:17 > 0:22:20a computer has to pass the Turing Test.
0:22:20 > 0:22:23Basically, this is just a cosy little chat
0:22:23 > 0:22:25using something like text messaging.
0:22:25 > 0:22:28If after five minutes you didn't realise
0:22:28 > 0:22:31you were talking to a machine, then it would pass
0:22:31 > 0:22:36and win itself the Loebner Prize - 100,000,
0:22:36 > 0:22:38plus a solid gold medal.
0:22:38 > 0:22:41But, after 32 years, it is yet to be won.
0:22:43 > 0:22:47Still, a little computing power goes a very long way.
0:22:47 > 0:22:49Quite literally, as it turns out.
0:22:49 > 0:22:56This small memory stick holds 100,000 times as much information
0:22:56 > 0:23:00as the computer that powered NASA's Apollo moon missions.
0:23:00 > 0:23:04Now that's what I call an engineering challenge.
0:23:04 > 0:23:09So, how on earth did we get to the moon?
0:23:09 > 0:23:13The total number of people to have set foot on the moon is 12.
0:23:13 > 0:23:18Unless, of course, you believe it all took place in an aircraft hangar.
0:23:20 > 0:23:24The half-million-mile round trip required a Saturn V rocket,
0:23:24 > 0:23:28which stood 60 feet taller than the Statue of Liberty,
0:23:28 > 0:23:32and had roughly six million components.
0:23:32 > 0:23:35So even NASA's 99.9% reliability target
0:23:35 > 0:23:39meant they could still expect 6,000 parts to fail.
0:23:42 > 0:23:48The Saturn V is still the largest, most powerful rocket ever built,
0:23:48 > 0:23:50and yet most of it had only one job -
0:23:50 > 0:23:55to overcome earth's gravity by accelerating the small spacecraft
0:23:55 > 0:23:58to 25,000 miles an hour -
0:23:58 > 0:24:03faster than any human has travelled before or since.
0:24:03 > 0:24:05What you're trying to do when you climb into a rocket
0:24:05 > 0:24:07to try and travel to the moon
0:24:07 > 0:24:11is escape from the gravitational bonds of the earth,
0:24:11 > 0:24:15and that needs you to travel at 25,000 miles an hour.
0:24:15 > 0:24:18That's seven miles a second.
0:24:18 > 0:24:21Once you've got into space, the challenges continue to happen.
0:24:21 > 0:24:24Because now you have to get from the earth orbit to a lunar orbit.
0:24:24 > 0:24:26So you're orbiting the moon,
0:24:26 > 0:24:28but then you need to land on the moon.
0:24:28 > 0:24:32Apollo 11's Eagle touched down on the moon,
0:24:32 > 0:24:34with just 20 seconds of descent fuel left.
0:24:34 > 0:24:37But Neil Armstrong landed so gently
0:24:37 > 0:24:40that the shock absorbers didn't even compress.
0:24:40 > 0:24:43So his "one small step" down to the surface
0:24:43 > 0:24:48was more of a three-and-a-half-foot giant leap.
0:24:48 > 0:24:51And Buzz Aldrin had to remember not to lock the door,
0:24:51 > 0:24:53because there was no handle on the outside.
0:24:55 > 0:24:59When it was time to go home, just two-and-a-half hours later,
0:24:59 > 0:25:03Aldrin accidentally broke the switch that started the ascent rocket.
0:25:03 > 0:25:06With no tools on board,
0:25:06 > 0:25:09they only managed to fix it by shoving in a ballpoint pen.
0:25:13 > 0:25:17The Apollo missions were so incredibly far ahead of their time,
0:25:17 > 0:25:20that the first man to walk on the moon
0:25:20 > 0:25:23could have met the first man to fly.
0:25:23 > 0:25:26When Orville Wright died in 1948,
0:25:26 > 0:25:30Neil Armstrong was already nearly 18 years old.
0:25:30 > 0:25:32But it's been 40 years
0:25:32 > 0:25:36since a man last dirtied his boots with moon dust.
0:25:36 > 0:25:37What I want to know is -
0:25:42 > 0:25:45Looking for a new place to live?
0:25:45 > 0:25:48Our solar system has dozens of vacant properties.
0:25:48 > 0:25:51But by far the most desirable is Mars.
0:25:53 > 0:25:57Right now, you can buy an acre of Martian real estate
0:25:57 > 0:26:01for less than the price of a decent haircut, whatever that is.
0:26:01 > 0:26:05But just how suitable a home is the Red Planet?
0:26:05 > 0:26:08For starters, it's not too far away.
0:26:08 > 0:26:11Sometimes as little as 36 million miles.
0:26:12 > 0:26:15So you'll be there in just six months.
0:26:15 > 0:26:18Going to the moon is like popping to the shops,
0:26:18 > 0:26:20compared with Mars which is more like a trip
0:26:20 > 0:26:22across the entire Atlantic.
0:26:22 > 0:26:24And for those two journeys, you would prepare quite differently.
0:26:24 > 0:26:26One you could do in your slippers, almost.
0:26:26 > 0:26:33Mars has days, seasons and weather, all similar to earth's.
0:26:33 > 0:26:37Admittedly, the atmosphere is a little thin and lacking in oxygen.
0:26:38 > 0:26:39And it can get a bit chilly,
0:26:39 > 0:26:44around minus 130 degrees Celsius at the poles.
0:26:44 > 0:26:47There's no oxygen, there's terrible sandstorms,
0:26:47 > 0:26:50it's very corrosive and it's very cold.
0:26:50 > 0:26:53So it's not a great holiday destination at the moment.
0:26:53 > 0:26:57But with some TLC and a little hard work,
0:26:57 > 0:27:01Mars could make an ideal second home.
0:27:01 > 0:27:03It's called terraforming, and the goal is
0:27:03 > 0:27:06to thicken the atmosphere and raise the temperature.
0:27:09 > 0:27:11It might sound like science fiction,
0:27:11 > 0:27:14but real-life engineers are working on it right now.
0:27:16 > 0:27:20One idea involves giant space mirrors,
0:27:20 > 0:27:23reflecting enough sunlight to melt the ice caps.
0:27:23 > 0:27:27This would release water and carbon dioxide
0:27:27 > 0:27:29to kick-start global warming.
0:27:30 > 0:27:33Another suggests building solar-powered factories
0:27:33 > 0:27:35to produce those greenhouse gasses.
0:27:36 > 0:27:40Or, how about redirecting a few passing asteroids
0:27:40 > 0:27:43and crashing them into the Martian surface?
0:27:43 > 0:27:46Each impact would release enough energy
0:27:46 > 0:27:49to raise the planet's temperature by three degrees.
0:27:49 > 0:27:52But according to some estimates,
0:27:52 > 0:27:57all this could take as much as 100,000 years.
0:27:57 > 0:27:59So instead of changing Mars,
0:27:59 > 0:28:02it might be quicker to change ourselves.
0:28:03 > 0:28:07Maybe things aren't so bad here on earth after all.
0:28:07 > 0:28:09I mean, I know we've got our problems,
0:28:09 > 0:28:12but at least we stand a fighting chance of sorting them out,
0:28:12 > 0:28:17thanks to the brilliance and ingenuity of our engineering.
0:28:23 > 0:28:25Has anybody got a screwdriver?
0:28:27 > 0:28:28Screwdriver?
0:28:39 > 0:28:42Subtitles by Red Bee Media Ltd