0:00:03 > 0:00:05There are some great questions
0:00:05 > 0:00:11that have intrigued and haunted us since the dawn of humanity.
0:00:13 > 0:00:15What is out there?
0:00:19 > 0:00:20How did we get here?
0:00:25 > 0:00:27What is the world made of?
0:00:30 > 0:00:36The story of our search to answer those questions is the story of science.
0:00:36 > 0:00:39Of all human endeavours,
0:00:39 > 0:00:43science has had the greatest impact on our lives -
0:00:43 > 0:00:46on how we see the world, on how we see ourselves.
0:00:47 > 0:00:52Its ideas, its achievements, its results are all around us.
0:00:52 > 0:00:57So how did we arrive at a modern world?
0:00:58 > 0:01:02Well, that is more surprising and more human than you might think.
0:01:07 > 0:01:11The history of science is often told as a series of eureka moments,
0:01:11 > 0:01:14the ultimate triumph of the rational mind.
0:01:14 > 0:01:17But the truth is that power and passion,
0:01:17 > 0:01:23rivalry and sheer blind chance have played equally significant parts.
0:01:25 > 0:01:30In this series I'll be offering a different view of how science happens.
0:01:30 > 0:01:36It's been shaped as much by what's outside the laboratory as inside.
0:01:36 > 0:01:37Oh!
0:01:39 > 0:01:42This is the story of how history made science
0:01:42 > 0:01:44and science made history,
0:01:44 > 0:01:47and how the ideas that were generated changed our world.
0:01:47 > 0:01:51It is a tale of power...
0:01:52 > 0:01:54..proof...
0:01:55 > 0:01:56..and passion.
0:02:06 > 0:02:09This time, an ancient human ambition -
0:02:09 > 0:02:11the search for limitless power.
0:02:26 > 0:02:31We are the most power-hungry generation that has ever lived.
0:02:31 > 0:02:34Energy is the heartbeat of our civilisation.
0:02:38 > 0:02:42The pursuit of power has created and destroyed fortunes.
0:02:42 > 0:02:45It has raised and toppled nations.
0:02:45 > 0:02:48And it has utterly transformed how we live our lives.
0:02:53 > 0:02:58But this relentless search for more power has an importance
0:02:58 > 0:03:03that is far greater than discovering what it can do for us.
0:03:03 > 0:03:08When people ask themselves "What is power?" as opposed to simply, "Where can I get more of it?"
0:03:08 > 0:03:13well, that led to some of the greatest insights in the whole history of science.
0:03:26 > 0:03:29The 17th century was a pivotal edge,
0:03:29 > 0:03:34when the balance between man and nature began to change forever.
0:03:37 > 0:03:40There was no electricity.
0:03:40 > 0:03:42There were no cars, no trains.
0:03:42 > 0:03:48The most common power sources had to be fed and watered.
0:03:48 > 0:03:51Horsepower meant just that.
0:03:58 > 0:04:03But a remote beach in Holland would provide a glimpse of what was to come.
0:04:21 > 0:04:26If you had been walking along a beach in north-west Holland 400 years ago
0:04:26 > 0:04:31you might have seen a much larger version of one of these zip past.
0:04:35 > 0:04:37It was called the wind chariot.
0:04:39 > 0:04:43Designed to carry heavily armoured soldiers along the coast line...
0:04:45 > 0:04:49..it amazed and terrified in equal measure.
0:04:50 > 0:04:55Here was the power of the wind being harnessed to produce motion on land.
0:04:56 > 0:05:00- It must have been an extraordinary sight.- Oh, yes.
0:05:00 > 0:05:05The people were afraid of it and they called it a devil's rig.
0:05:05 > 0:05:08The devil's rig. Very dramatic, yeah.
0:05:08 > 0:05:11- How fast? - It could outpace a horse running.
0:05:11 > 0:05:16Outpace a horse? So that must have made it one of the fastest things in the world at the time.
0:05:16 > 0:05:19Probably one of the fastest things.
0:05:19 > 0:05:22- Using wind power. - Just wind power.- Very impressive.
0:05:26 > 0:05:33The wind chariot was designed by an engineer and mathematician called Simon Stevin,
0:05:33 > 0:05:37a remarkable man who would literally change the face of Holland
0:05:37 > 0:05:40and help turn it into a great trading empire.
0:05:43 > 0:05:47Because Stevin's ambitions for wind power went far beyond chariots.
0:05:49 > 0:05:53He wanted to transform his country using mathematics.
0:05:59 > 0:06:01Mathematics was changing.
0:06:01 > 0:06:04For hundreds of years, in the universities,
0:06:04 > 0:06:09geometry and arithmetic had been important theoretical pursuits.
0:06:09 > 0:06:16Practical applications, like building bridges and firing canons, were limited.
0:06:16 > 0:06:19But now, men like Simon Stevin would use maths theory
0:06:19 > 0:06:22to create something much bigger...
0:06:22 > 0:06:25A new, mathematically grounded science.
0:06:25 > 0:06:31And that would help them solve a whole range of complex problems.
0:06:40 > 0:06:45Now, Stevin was clearly a mathematician who didn't mind getting his hands dirty.
0:06:45 > 0:06:51He saw the value of applying mathematical knowledge to the solution of practical problems.
0:06:52 > 0:06:56The problem Stevin turned his mathematics to
0:06:56 > 0:07:00was a crucial one in low-lying Holland -
0:07:00 > 0:07:02How to keep the country dry.
0:07:04 > 0:07:07For over a century, Holland's windmills had been scooping water
0:07:07 > 0:07:13from drainage ditches, tipping it into canals to carry it away.
0:07:13 > 0:07:19But Stevin was convinced that mathematics could make windmills much more efficient.
0:07:22 > 0:07:26We're at the top of the windmill now and this is the gearing system.
0:07:26 > 0:07:28This was the heart of what Stevin did.
0:07:28 > 0:07:33Mathematically it's interesting because what he's done is, there is no whole number relationship.
0:07:33 > 0:07:38It's not like two to one, three to one between this and this. There's no regular relationship.
0:07:38 > 0:07:42Also you can probably see these things are angled.
0:07:42 > 0:07:46It is not a simple vertical plane meeting a horizontal plane.
0:07:46 > 0:07:48It's going at an angle.
0:07:48 > 0:07:51And that is quite difficult to deal with mathematically as well.
0:07:51 > 0:07:55It looks crude, but it is fantastically refined.
0:07:55 > 0:07:59It's very impressive. I'm looking forward to seeing it run.
0:08:15 > 0:08:20Magnificent isn't it? It's like being inside an enormous clock.
0:08:22 > 0:08:25Standing here, you get the impression of
0:08:25 > 0:08:30immense, inexorable power which is sort of just driving round and round.
0:08:30 > 0:08:35And the thing which surprises me is it is so quiet.
0:08:35 > 0:08:41And that is a tribute to Stevin's mathematics because he obviously got it right. The interactions all work.
0:08:41 > 0:08:43There's very little clanking.
0:08:43 > 0:08:49If all that power was being wasted in sound and heat, this whole place would be vibrating.
0:08:49 > 0:08:52But actually it's very smooth.
0:08:55 > 0:08:58This new, mathematically designed windmill
0:08:58 > 0:09:02was three times more efficient than the ones it replaced.
0:09:05 > 0:09:07It's almost poetic.
0:09:07 > 0:09:12I mean, this is a mathematical model realised in a physical reality.
0:09:16 > 0:09:20Stevin designed new paddle wheel shapes, sluices,
0:09:20 > 0:09:25even a chain of windmills that could be used to drain not just fields, but a lake.
0:09:29 > 0:09:32What's more, he patented his many inventions
0:09:32 > 0:09:34to ensure his work would be well rewarded.
0:09:34 > 0:09:37Mathematics made Stevin rich.
0:09:37 > 0:09:42And it wasn't long before it started to change the whole country.
0:09:46 > 0:09:51Simon Stevin had shown what really well designed windmills were capable of.
0:09:51 > 0:09:56And people now began to ask themselves, "If they could drain lakes, what else could they do?"
0:10:01 > 0:10:05Holland was already an emerging European force.
0:10:05 > 0:10:10Now the power of windmills helped turn it into an industrial power house.
0:10:26 > 0:10:32Seeds and nuts were ground to extract their valuable oil.
0:10:37 > 0:10:39Paper mills became mechanised.
0:10:42 > 0:10:49Wood could be cut 30 times faster and with greater precision than by hand...
0:10:54 > 0:10:59..helping to turn this small country into the biggest ship builders in western Europe.
0:11:05 > 0:11:10To the sound of mathematically designed mills whirring in the wind
0:11:10 > 0:11:14Holland became an even more dynamic trading nation...
0:11:17 > 0:11:20..and Amsterdam one of the richest
0:11:20 > 0:11:24and most cosmopolitan cities on earth.
0:11:26 > 0:11:29Here, you could buy almost anything -
0:11:29 > 0:11:31diamonds, furs, exotic spices.
0:11:31 > 0:11:35Amsterdam was enjoying a golden age.
0:11:35 > 0:11:40The city produced the first central bank, the first stock exchange
0:11:40 > 0:11:42and the first economic crash.
0:11:48 > 0:11:52The growth of Holland changed the power map of Europe.
0:11:53 > 0:11:57It had been helped by advances in windmill design
0:11:57 > 0:12:01and new mathematically based science.
0:12:01 > 0:12:05And a belief amongst men like Simon Stevin
0:12:05 > 0:12:07that science should be useful.
0:12:09 > 0:12:13It was obvious what power could do.
0:12:13 > 0:12:19But what was still missing was any scientific understanding of what power actually is.
0:12:26 > 0:12:32That would only begin to emerge far later, on the other side of the Channel.
0:12:39 > 0:12:45The English country house of the 18th century was a place of intrigue,
0:12:45 > 0:12:48romance and gossip.
0:12:52 > 0:12:55But, between visits from dashing cavalry officers,
0:12:55 > 0:12:57these bastions of high society
0:12:57 > 0:13:01also hosted the occasional visiting experimenter.
0:13:03 > 0:13:06The home of an unlikely alliance
0:13:06 > 0:13:11that marked the birth of a world changing new source of power.
0:13:15 > 0:13:20Science had become popular entertainment for the drawing room.
0:13:22 > 0:13:27Most of these contraptions had been developed to explore the wonders of the age,
0:13:27 > 0:13:30like static charge and magnetism.
0:13:33 > 0:13:34Oh!
0:13:35 > 0:13:37Now that really is impressive.
0:13:41 > 0:13:43Now, this was a real crowd pleaser.
0:13:43 > 0:13:48The vacuum trick. What you do is you take an alarm...
0:13:48 > 0:13:51set it to go off...
0:13:51 > 0:13:54then put it in here...
0:13:54 > 0:13:57and pump out the air.
0:13:59 > 0:14:01Right.
0:14:01 > 0:14:04The alarm clock goes off...
0:14:05 > 0:14:07..and you hear...absolutely nothing.
0:14:09 > 0:14:14No-one fully understood the science behind these demonstrations.
0:14:15 > 0:14:21But the ability to dazzle and intrigue helped bring new ideas
0:14:21 > 0:14:24to a new and attentive audience.
0:14:25 > 0:14:28Matthew Boulton was an entrepreneur
0:14:28 > 0:14:30who belonged to the Lunar Society,
0:14:30 > 0:14:34so called because they met on the night of the full moon.
0:14:34 > 0:14:37They were industrialists,
0:14:37 > 0:14:40experimenters and natural philosophers
0:14:40 > 0:14:44who all shared a love of practical knowledge.
0:14:48 > 0:14:53A leading lunar man was Scottish engineer, James Watt.
0:14:54 > 0:14:59For some years Watt had been working with prototype steam engines.
0:14:59 > 0:15:06And this prompted Matthew Boulton to invite him to take part in a joint business venture.
0:15:07 > 0:15:11He had heard that Watt was trying to develop a new type of steam engine.
0:15:11 > 0:15:15As he later wrote to Watt, the reason for backing were twofold -
0:15:15 > 0:15:21love of you and love of a money-getting ingenious project.
0:15:21 > 0:15:23Now, the plan was clear.
0:15:23 > 0:15:26Boulton had the capital, Watt had the idea.
0:15:26 > 0:15:28Together they would get seriously rich.
0:15:28 > 0:15:30This was capitalism in action.
0:15:39 > 0:15:42The steam engine had enormous global impact.
0:15:42 > 0:15:50And yet the surprising thing is, there was hardly any scientific theory behind it.
0:15:50 > 0:15:51That would come later.
0:15:56 > 0:15:59This is a Boulton and Watt steam engine.
0:15:59 > 0:16:03And this the familiar bit - man, coal, furnace.
0:16:03 > 0:16:07But what you might not expect is it is stationary and it is vast.
0:16:07 > 0:16:10This single machine occupies the whole building.
0:16:24 > 0:16:31So vast that this engine, originally built to keep the nearby canal topped up with water,
0:16:31 > 0:16:33boasts its very own driver.
0:16:38 > 0:16:42- Hello.- Hello.- Nice to see you. - You're the driver? - Yes, I'm the driver of this engine.
0:16:44 > 0:16:48I am amazed. This is still working, isn't it? Actually doing the job.
0:16:48 > 0:16:53This, at this moment, is actually maintaining the canal. The electric pumps British Waterways
0:16:53 > 0:16:56normally use are switched off and we're actually doing that job.
0:16:56 > 0:17:00- Can I have a go at driving?- You certainly can. Step round this lever.
0:17:00 > 0:17:02Always wanted to drive a steam engine.
0:17:02 > 0:17:05This wasn't quite what I'd imagined it. Right OK.
0:17:05 > 0:17:10- So..- Turn that lever to the left, about a quarter of a turn.
0:17:10 > 0:17:13There's a sort of narrow window between...
0:17:13 > 0:17:15There is. There are indeed.
0:17:15 > 0:17:20What drove the engine was not so much the power of the steam directly,
0:17:20 > 0:17:26rather an industrial version of that country house trick - the vacuum.
0:17:27 > 0:17:32The steam is injected, then cooled, creating a vacuum.
0:17:32 > 0:17:36It's this which drags the piston head down
0:17:36 > 0:17:39providing the engine with its lifting power.
0:17:39 > 0:17:40Close it another quarter of a turn.
0:17:47 > 0:17:50- What's happened?- Well, you actually closed it too far.
0:17:53 > 0:17:55This is not good.
0:17:55 > 0:18:02I was thinking it was really quite simple and then within 30 seconds of taking charge of this machine
0:18:02 > 0:18:04I managed to stop it, which is quite bad.
0:18:04 > 0:18:06That's looking good.
0:18:11 > 0:18:14James Watt didn't invent the steam engine
0:18:14 > 0:18:17or even the idea of using a vacuum.
0:18:17 > 0:18:21Engines had been powered this way for decades.
0:18:21 > 0:18:24Watt's fame, and that of his machine,
0:18:24 > 0:18:29rests instead on one small modification
0:18:29 > 0:18:33located here, right at the bottom of the engine.
0:18:33 > 0:18:36It may not look like much, but down there
0:18:36 > 0:18:40is James Watt's unique contribution to the story of power.
0:18:40 > 0:18:43It's called a separate condenser.
0:18:43 > 0:18:49It's where the steam was cooled to create the all-important vacuum
0:18:49 > 0:18:56well away from the hot cylinders, a small but ingenious technical innovation with enormous benefits.
0:18:58 > 0:19:02The Boulton and Watt steam engines were far more efficient than their rivals.
0:19:02 > 0:19:05They used a quarter of the amount of coal.
0:19:08 > 0:19:11The potential savings were enormous.
0:19:11 > 0:19:15Something any business man could understand. Over to you.
0:19:15 > 0:19:18Thank you.
0:19:21 > 0:19:25Why some ideas change the world while others languish,
0:19:25 > 0:19:32unloved and unnoticed, is seldom down to their intrinsic merit.
0:19:37 > 0:19:43The success of Boulton and Watt's engine was not just due to new technology,
0:19:43 > 0:19:48but also a clever piece of financial engineering.
0:19:50 > 0:19:54The machines were complicated and needed someone to install them
0:19:54 > 0:19:58and that someone was more often than not James Watt himself.
0:19:58 > 0:20:02In his letters he complains bitterly about all the travelling he had to do.
0:20:04 > 0:20:05Walk on.
0:20:05 > 0:20:07Gee up, boys. Go on. Go on.
0:20:10 > 0:20:13And you can sort of see why, can't you?
0:20:13 > 0:20:15Lots of jolting. Now this is bearable...
0:20:15 > 0:20:17Short trip, middle of summer.
0:20:17 > 0:20:19But imagine there it's cold, it's winter,
0:20:19 > 0:20:24it is absolutely lashing down - completely different experience.
0:20:27 > 0:20:31But the discomfort of 18th-century travel was a price worth paying
0:20:31 > 0:20:36because once his engines had been installed, the money began to flood in.
0:20:38 > 0:20:43This three-page document was the key to Boulton and Watt's wealth.
0:20:43 > 0:20:47It's a patent. It covers Watt's adaptations to the steam engine.
0:20:47 > 0:20:53Now, you had to go on paying royalties year after year, long after the machine was installed.
0:20:53 > 0:20:59Any savings you made from the machine, a proportion went straight back to them.
0:20:59 > 0:21:06I think it's very telling how scientific discovery is rarely far away from the smell of money,
0:21:06 > 0:21:10and that's especially true of the search for power.
0:21:20 > 0:21:23But, for all the riches on offer, there was still no real
0:21:23 > 0:21:28scientific framework to explain what power actually is.
0:21:28 > 0:21:34Science would have to wait till steam power became a force throughout the land.
0:21:34 > 0:21:37HORSE NEIGHS
0:21:45 > 0:21:49The big demand for steam engines was in the West Country,
0:21:49 > 0:21:52pumping flood water from mines.
0:21:52 > 0:21:57Their owners soon became reliant on Boulton and Watt's more efficient machines.
0:21:57 > 0:22:02Some mine owners, fed up with royalties, stopped paying.
0:22:02 > 0:22:06Boulton and Watt got tough and responded with legal writs.
0:22:07 > 0:22:11It's said that a delivery man who came to one of these mines
0:22:11 > 0:22:18was seized by the ankles, hung over the mine shaft and asked if he still wanted to deliver that writ.
0:22:18 > 0:22:22The man behind that particular story was Richard Trevithick.
0:22:23 > 0:22:29To get round of Watt's patent Trevithick began to build his own engines.
0:22:35 > 0:22:40This was his greatest achievement, the Puffing Devil,
0:22:40 > 0:22:42all eight horsepower of it.
0:22:49 > 0:22:52And unlike Boulton and Watt's engine, it moved.
0:22:59 > 0:23:06Trevithick's genius was he built high pressure steam engines where the steam drives the piston.
0:23:06 > 0:23:10So he didn't need vacuums or condensers.
0:23:10 > 0:23:18Instead of being the size of houses, his steam engines were small, powerful, mobile.
0:23:18 > 0:23:23And as an added bonus they produced that wonderful "whoo-hoo" noise.
0:23:23 > 0:23:27That's the sound of high-pressure steam escaping.
0:23:31 > 0:23:34ENGINE WHISTLES
0:23:44 > 0:23:49I'd read that people thought they were incredibly dangerous, and not unreasonably,
0:23:49 > 0:23:51that they would blow up, the high-pressure system.
0:23:51 > 0:23:55You're quite right. They didn't have the knowledge of metallurgy
0:23:55 > 0:23:58we do today, and they did get boiler explosions.
0:23:58 > 0:24:01There's no risk of this one blowing up, I take it?
0:24:01 > 0:24:03Not at all.
0:24:03 > 0:24:10This new steam engine clearly pointed to a better way of moving goods and people around.
0:24:10 > 0:24:15Yet Trevithick has not gone down in history as the father of the modern railway.
0:24:18 > 0:24:22I gather that he actually did, on one occasion, manage to get
0:24:22 > 0:24:27his steam car, if you like, on a track, on a railway. Why didn't it work?
0:24:27 > 0:24:32The engine weighed five tonnes or so, so the rails broke under the weight of the engine.
0:24:32 > 0:24:37- So the problem wasn't the train at all. It was the rail it was running on.- Absolutely.
0:24:37 > 0:24:38Yes, the engine worked a dream.
0:24:38 > 0:24:42- Right. That is incredibly ironic isn't it?- Yeah.
0:24:46 > 0:24:51The history of science is full of moments like this.
0:24:51 > 0:24:56Great ideas have to come at the right place and the right time.
0:24:56 > 0:25:00Sadly for Trevithick, the place and time were wrong.
0:25:03 > 0:25:05So why didn't he die rich and famous?
0:25:05 > 0:25:12Well, it's partly because he didn't have his own Matthew Boulton to get his inventions out there
0:25:12 > 0:25:14and to make sure he was raking in the cash.
0:25:14 > 0:25:18But it's also because his ideas were well ahead of their time.
0:25:18 > 0:25:25In the early 1800s, if you wanted to get from A to B, you were better off buying a horse.
0:25:28 > 0:25:33Steam engines would eventually bring unprecedented change
0:25:33 > 0:25:37borne out of a combination of different forces.
0:25:37 > 0:25:41The Lunar Society, where men of science and business
0:25:41 > 0:25:44could meet and exchange ideas.
0:25:44 > 0:25:48Technical innovations, like high-pressure steam.
0:25:48 > 0:25:52The promise of money and the protection of patents.
0:26:04 > 0:26:08From all this emerged a previously unimaginable source of power...
0:26:18 > 0:26:20..the mechanical equivalent of countless horses
0:26:20 > 0:26:25to work the factories and mills of the 19th-century landscape.
0:26:34 > 0:26:37The steam engines, their profits, their owners,
0:26:37 > 0:26:41these were the forces shaping Victorian Britain.
0:26:48 > 0:26:53But the effects of all this power were felt far beyond the world of heavy industry.
0:26:53 > 0:26:58The new aristocracy of factory owners and businessmen knew
0:26:58 > 0:27:02just how they wanted to use their new-found influence.
0:27:02 > 0:27:07Some used their wealth to campaign for social change,
0:27:07 > 0:27:10like the abolition of slavery or the education of women.
0:27:10 > 0:27:17The search for power had given political power to a new group of people, the middle classes.
0:27:19 > 0:27:22The quest for power had produced so much...
0:27:22 > 0:27:27but with no more scientific understanding than had existed a century before.
0:27:27 > 0:27:32Only now, belatedly, came the theorists.
0:27:41 > 0:27:46The Victorians were utterly entranced by the power of steam.
0:27:46 > 0:27:52But the science behind it posed some of the greatest questions of the age.
0:27:52 > 0:27:57It demanded a new theory, a new way of looking at nature.
0:27:57 > 0:28:01Fortunately help was at hand.
0:28:04 > 0:28:08This is Mrs Beeton's Book Of Household Management,
0:28:08 > 0:28:12a Victorian classic which contains pretty well everything you need to know
0:28:12 > 0:28:15about how to run a household efficiently and well,
0:28:15 > 0:28:18including how to sack your servants.
0:28:18 > 0:28:24"Frugality and economy are virtues, without which no household can prosper."
0:28:26 > 0:28:32Mrs Beeton, like so many in Victorian society, was obsessed with efficiency.
0:28:32 > 0:28:37Waste was not just uneconomical, it was also un-Christian.
0:28:39 > 0:28:42In the kitchen, if you had old bones, you made soup.
0:28:42 > 0:28:45If you had old bread, you made a pudding.
0:28:45 > 0:28:49And this obsession was shared by the scientific community.
0:28:49 > 0:28:55In fact, it led to the development of a whole new concept, that of energy.
0:28:59 > 0:29:06As steam engines took off, people became interested in comparing which engines were most efficient.
0:29:08 > 0:29:14A new theory of energy would now help them make precisely that sort of judgment.
0:29:18 > 0:29:21No-one really knew what energy is.
0:29:21 > 0:29:27Some people thought of it as a fluid which flows from one place to another.
0:29:27 > 0:29:32But what was becoming increasingly clear is it could be transferred.
0:29:34 > 0:29:38The steam engine, like a kettle, could be explained scientifically.
0:29:38 > 0:29:44As it burns, chemical energy from the coal is turned into heat.
0:29:44 > 0:29:48This energy heats the kettle and the water inside....
0:29:48 > 0:29:52Which turns into steam, which can then be used to perform work.
0:29:55 > 0:30:00It sounds really simple, but this was a turning point in science.
0:30:00 > 0:30:05For the first time, such diverse things as heating coals,
0:30:05 > 0:30:09warming water, production of steam, even the spinning of windmills
0:30:09 > 0:30:13could all be united by a single concept - that of energy.
0:30:14 > 0:30:21It led to the formulation of a new law of physics, one that is absolutely fundamental.
0:30:21 > 0:30:24It's called the first law of thermodynamics.
0:30:27 > 0:30:32The first law of thermodynamics is a mathematical description of energy,
0:30:32 > 0:30:35known as conservation of energy.
0:30:35 > 0:30:41It states that energy cannot be created or destroyed.
0:30:41 > 0:30:46So you can never get more out than is contained in the fuel you put in.
0:30:50 > 0:30:54And it applies to every source of power there is -
0:30:54 > 0:30:58from kettles, to steam engines,
0:30:58 > 0:31:00to windmills.
0:31:02 > 0:31:04Everything.
0:31:09 > 0:31:15Thermodynamics was one of the crowning glories of 19th-century science,
0:31:15 > 0:31:18inspired in part by the need to explain
0:31:18 > 0:31:21that wonder of the age, the steam engine.
0:31:23 > 0:31:27And by an obsession with thrift and efficiency.
0:31:27 > 0:31:31But thermodynamics was only one component
0:31:31 > 0:31:37of what was to be a far more comprehensive theory of energy and power.
0:31:58 > 0:32:06In June 1772, a small sailing expedition set off for the coast of France
0:32:06 > 0:32:10on a voyage that would help point science towards the modern age.
0:32:16 > 0:32:22Its leader was John Walsh, recently retired from the British East India Company.
0:32:22 > 0:32:27Walsh was fascinated by the electricity found in nature.
0:32:32 > 0:32:36He went looking for it, not in the skies, but under water...
0:32:39 > 0:32:40..in a fish....
0:32:46 > 0:32:48..the torpedo fish...
0:32:49 > 0:32:54..which uses electric shocks to catch its prey.
0:33:02 > 0:33:07Walsh wanted to find out whether the power emitted by this strange fish
0:33:07 > 0:33:11was the same as that given off by lightning...
0:33:12 > 0:33:14..or a spark generator.
0:33:17 > 0:33:21Having done numerous experiments on himself and his crew,
0:33:21 > 0:33:25Walsh now headed back to London to try and find out
0:33:25 > 0:33:29just how the torpedo fish produced electric shocks.
0:33:34 > 0:33:39Some of the fish Walsh brought back are still preserved
0:33:39 > 0:33:41at the Hunterian Museum in London.
0:33:41 > 0:33:48They were dissected by the renowned surgeon John Hunter to reveal some very peculiar organs.
0:33:51 > 0:33:57Well, you see these two patches of white tissue, one top, one bottom either side of the fish?
0:33:57 > 0:34:01These are things which Hunter hadn't seen before in other fish,
0:34:01 > 0:34:03other rays that he'd dissected.
0:34:03 > 0:34:07Right. This one looks very different.
0:34:07 > 0:34:10It's a much more detailed dissection,
0:34:10 > 0:34:12but also Hunter's worked a bit of magic on it
0:34:12 > 0:34:17by injecting it with a red dye to show where the blood vessels are.
0:34:17 > 0:34:23The electric charge seemed to come from these tiny cells,
0:34:23 > 0:34:28now known as electrocytes, found within the electric organs.
0:34:28 > 0:34:33It is extraordinary because you begin to see where the charge would have come from.
0:34:33 > 0:34:37You can actually see each of the cells. It is beautiful, isn't it?
0:34:37 > 0:34:39- A work of art.- A work of art in its own right, isn't it?
0:34:42 > 0:34:46Walsh was convinced that the electricity from the torpedo fish
0:34:46 > 0:34:50was not only the same as the electricity in lightning,
0:34:50 > 0:34:54but that it must be possible to produce it using a machine.
0:34:56 > 0:34:59But plenty of people did not agree with Walsh.
0:34:59 > 0:35:05It seemed almost sacrilegious to claim that electricity from a machine made by man
0:35:05 > 0:35:10was exactly the same as electricity from a fish which had been created by God.
0:35:15 > 0:35:20And yet, proof that this was the case was not far away.
0:35:30 > 0:35:37In the archives of the Royal Society in London sits a letter that dates back to 1800.
0:35:39 > 0:35:43Written by an Italian scientist, Alessandro Volta,
0:35:43 > 0:35:49essentially it contains instructions on how to build your very own torpedo fish.
0:35:59 > 0:36:03This is a copy of the letter that Volta sent to the Royal Society.
0:36:03 > 0:36:07It's in French, got a useful diagram over in the corner.
0:36:07 > 0:36:10I've also got a box here of bits and pieces.
0:36:10 > 0:36:16Right, first of all I need some zinc and some copper.
0:36:17 > 0:36:22Also I need some bits of cardboard or tissue
0:36:22 > 0:36:26capable of soaking up a briny solution.
0:36:30 > 0:36:33It is very hard to believe
0:36:33 > 0:36:35this is actually going to do anything.
0:36:35 > 0:36:37We shall see.
0:36:43 > 0:36:47A piece of copper on the top and I've got a lead on it.
0:36:48 > 0:36:52Now, if you look at it closely, it really does resemble
0:36:52 > 0:36:56the working bits, if you like, of a torpedo fish.
0:36:57 > 0:37:02And he suggested to call it an artificial electric organ.
0:37:04 > 0:37:07The "voltaic pile", as it became known,
0:37:07 > 0:37:10could generate a significant electric current.
0:37:13 > 0:37:17Volta couldn't measure it, but he could demonstrate
0:37:17 > 0:37:21that it delivered a shock, just like the torpedo fish.
0:37:21 > 0:37:22Ohh!
0:37:22 > 0:37:24Oh! Ooh!
0:37:24 > 0:37:28What's interesting is that Volta, when he writes to the Royal Society,
0:37:28 > 0:37:30effectively gives away all his secrets,
0:37:30 > 0:37:35which is a bit of a shame for him because this turned out to be
0:37:35 > 0:37:39one of the greatest technological discoveries of all time.
0:37:39 > 0:37:42It is of course the battery.
0:37:48 > 0:37:52What is really surprising, looking at it from a modern perspective,
0:37:52 > 0:37:56is that for a long time people had no idea what to do with the battery.
0:37:56 > 0:37:58It had not obvious practical application.
0:37:58 > 0:38:00There was nothing to plug it into.
0:38:00 > 0:38:04It would be a generation before somebody managed to find
0:38:04 > 0:38:07a really significant practical use.
0:38:07 > 0:38:12An ingenious response to a rather urgent problem.
0:38:18 > 0:38:21On the 18th June 1815,
0:38:21 > 0:38:26the armies of the Duke of Wellington and the Emperor Napoleon met at Waterloo.
0:38:30 > 0:38:34It was a battle on whose outcome rested the fate of Europe.
0:38:37 > 0:38:41By the end of the day, the battle was over. The French had lost.
0:38:41 > 0:38:46Wellington was keen to get this good news to London as quickly as possible.
0:38:46 > 0:38:50Major Henry Percy was ordered to carry the message.
0:38:51 > 0:38:56He mounted his battle-weary horse and rode off across Belgium until he got to the coast.
0:38:56 > 0:38:59When he arrived, he had to wait for the correct wind and tide
0:38:59 > 0:39:02before finally he could set sail for England.
0:39:04 > 0:39:07In all, it took him four days to reach London,
0:39:07 > 0:39:10four days during which I'm sure the people in the war office
0:39:10 > 0:39:13were biting their fingernails with anxiety
0:39:13 > 0:39:16because many expected the French to win.
0:39:16 > 0:39:20Now, if you could have got a secret message from Waterloo to London
0:39:20 > 0:39:27faster than Major Percy, you could have made a fortune, betting on an improbable English victory.
0:39:30 > 0:39:34There was clearly a need for faster communication.
0:39:36 > 0:39:41Volta's Pile was about to get plugged into something useful.
0:39:42 > 0:39:49And this time it was science that led the way, thanks to a man called Hans Christian Oersted.
0:39:52 > 0:39:57The story goes he was about to give a lecture and he was preparing his equipment.
0:39:57 > 0:40:01Amongst it, he had a voltaic pile and some wire.
0:40:01 > 0:40:05When he connected up the wire, something utterly unexpected happened.
0:40:09 > 0:40:12The needle of a nearby compass twitched
0:40:12 > 0:40:15and every time he connected the wire
0:40:15 > 0:40:18or disconnected,
0:40:18 > 0:40:20it moved again.
0:40:22 > 0:40:26People had known for centuries that compass needles were deflected by magnets.
0:40:29 > 0:40:33Somehow the electric current in the wire was also acting like a magnet,
0:40:33 > 0:40:39deflecting the needle, which left Oersted completely baffled.
0:40:41 > 0:40:44Now, he obviously realised this was important
0:40:44 > 0:40:48because he did further research and published his findings.
0:40:48 > 0:40:51But I think it's extremely unlikely he ever appreciated
0:40:51 > 0:40:56just what a massive impact his discovery would make on the world.
0:40:59 > 0:41:06Within a few years, that twitching compass needle had grown into the electric telegraph.
0:41:10 > 0:41:17The power of electricity could now be used to get messages from A to B almost instantaneously.
0:41:17 > 0:41:22Telegraph tables were soon running right across the globe.
0:41:26 > 0:41:32And when the telegraph came together with that other great invention the steam engine,
0:41:32 > 0:41:34the combination was unstoppable.
0:41:40 > 0:41:43Steam power did the heavy work -
0:41:43 > 0:41:47draining mines, spinning cotton,
0:41:47 > 0:41:49powering a new railway network.
0:41:49 > 0:41:54And with the telegraph that ran alongside those same railways,
0:41:54 > 0:41:59the battery brought control - political and financial.
0:42:02 > 0:42:06Together, they helped build the empires of 19th-century Europe.
0:42:12 > 0:42:18The stage was now set for the next step in the scientific understanding of power.
0:42:31 > 0:42:35The tiny, twitching needle of the telegraph had shown
0:42:35 > 0:42:38how electricity from a battery could be truly useful.
0:42:40 > 0:42:44But what's happening here is also something which is much more profound.
0:42:44 > 0:42:47It is the coming together of two great forces
0:42:47 > 0:42:51that previously were regarded as utterly separate.
0:42:51 > 0:42:57And covering the link between two things as disparate as an electric current and a magnetic compass
0:42:57 > 0:43:01was one of the greatest achievements of science,
0:43:01 > 0:43:05a major step towards a unified concept of energy.
0:43:08 > 0:43:10Electricity was the crowd pleaser.
0:43:10 > 0:43:14Flashes, sparks, electric shocks.
0:43:14 > 0:43:19Magnetism was altogether more sedate, something of interest mainly to navigators.
0:43:19 > 0:43:24But when the two came together, they created the science of electromagnetism
0:43:24 > 0:43:26that would dominate the 19th century.
0:43:28 > 0:43:34Electromagnetism not only explained the relationship between electricity and magnetism,
0:43:34 > 0:43:38it would go on to explain the very nature of light...
0:43:39 > 0:43:41..of radio waves...
0:43:41 > 0:43:44of x-rays.
0:43:44 > 0:43:49And it helped persuade 19th-century physicists
0:43:49 > 0:43:53that they had now discovered all the fundamental laws of nature.
0:43:56 > 0:44:02As it turned out, this cosy assumption was somewhat wide of the mark.
0:44:09 > 0:44:13At the turn of the 20th century, the discovery of a new element
0:44:13 > 0:44:17was splashed across front pages all over the world.
0:44:29 > 0:44:35One reason for all the excitement was the way radium behaved.
0:44:35 > 0:44:39It spontaneously glowed in the dark...
0:44:40 > 0:44:44..and created ghostly patterns on photographic plates.
0:44:46 > 0:44:49It seemed to be creating energy out of nowhere.
0:45:00 > 0:45:05Radium's mysterious properties caught the public imagination,
0:45:05 > 0:45:10helping to sell a new range of consumer products...
0:45:13 > 0:45:17..which was unfortunate, since radium is radioactive.
0:45:17 > 0:45:20- ..Yes.- Thank you.- Have a look.
0:45:20 > 0:45:22OK. So what am I looking at?
0:45:22 > 0:45:26Well, you're looking at a variety of radioactive consumer products,
0:45:26 > 0:45:27mostly from the 1920s,
0:45:27 > 0:45:31- produced in the United States. - So this one here, for example,
0:45:31 > 0:45:35- you actually put...- Water in it. - You put water in it?
0:45:35 > 0:45:40That is the most famous of the radioactive quack cures, at least in the United States.
0:45:40 > 0:45:43Over half a million of these were sold.
0:45:43 > 0:45:46This is a similar device, except, rather than put the water in it,
0:45:46 > 0:45:49you would put this in the water.
0:45:49 > 0:45:52This is not radioactive now, I take it? Or mildly?
0:45:52 > 0:45:56Yes, it is radioactive, but it's mild.
0:46:00 > 0:46:03It is quite spooky, I must admit.
0:46:03 > 0:46:06I can hear it still active all these years later.
0:46:08 > 0:46:10So great was the hype
0:46:10 > 0:46:14that small amounts were put into toothpaste,
0:46:14 > 0:46:16heat pads, toys.
0:46:18 > 0:46:23Just the name radium was enough to sell a product.
0:46:23 > 0:46:25Radium, er...condoms!
0:46:28 > 0:46:32Oh, it's an empty box. I was looking forward to seeing a radium condom.
0:46:39 > 0:46:44The scientists responsible for first isolating radium were Marie Curie
0:46:44 > 0:46:46and her husband, Pierre.
0:46:49 > 0:46:54It didn't take them long to recognise its extraordinary potential.
0:46:56 > 0:46:59One of the things that stood out in Marie's mind
0:46:59 > 0:47:01and piqued her curiosity and interest
0:47:01 > 0:47:05was the tremendous amount of energy being released by the radium.
0:47:05 > 0:47:12- So they saw radium as a potentially unlimited source of energy, did they?- Yes. Absolutely.
0:47:14 > 0:47:20Just one gram contained enough energy to turn a tonne of freezing water into steam...
0:47:20 > 0:47:24while one tonne of radium could do the work
0:47:24 > 0:47:28of one-and-a-half million tonnes of coal.
0:47:31 > 0:47:35The problem facing the scientists is that all this seemed to go
0:47:35 > 0:47:38completely against the established laws of physics.
0:47:42 > 0:47:45Radioactivity presented a serious problem for scientists.
0:47:45 > 0:47:49They knew that energy cannot be created or destroyed.
0:47:49 > 0:47:51That is the first law of thermodynamics.
0:47:51 > 0:47:57But they also knew that these radioactive substances were pouring out huge amounts of energy.
0:47:57 > 0:47:59So where was it coming from?
0:48:07 > 0:48:11Across the world scientists had been studying radioactivity intensely.
0:48:15 > 0:48:18People noticed something peculiar -
0:48:18 > 0:48:22that as radioactive substances emit energy, they transform.
0:48:22 > 0:48:24They turn into something else.
0:48:24 > 0:48:27Radium, for example, becomes lead.
0:48:27 > 0:48:30And as they transform, they become lighter.
0:48:30 > 0:48:35In other words, as they emit energy, they also lose mass.
0:48:42 > 0:48:49The link between energy and mass was eventually explained by Albert Einstein's famous equation.
0:48:50 > 0:48:56Energy equals mass times the square of the speed of light.
0:48:59 > 0:49:04The energy from the radium wasn't coming from some magical source,
0:49:04 > 0:49:06but from the mass itself.
0:49:12 > 0:49:18People had previously realised that you could describe heat and movement in terms of energy.
0:49:18 > 0:49:22Now it seemed you could also describe mass in the same way.
0:49:22 > 0:49:25Energy which hadn't even existed as a concept
0:49:25 > 0:49:29was now being used to explain the very nature of matter itself.
0:49:32 > 0:49:37In fact there wasn't much that could not be explained in terms of energy.
0:49:38 > 0:49:41Not just steam engines...
0:49:41 > 0:49:43and windmills,
0:49:43 > 0:49:45but living things.
0:49:45 > 0:49:51Stars, even galaxies were all governed by the laws of energy.
0:49:55 > 0:49:58In its quest to understand what power is,
0:49:58 > 0:50:04science had uncovered secrets which lay at the very heart of the universe.
0:50:11 > 0:50:16The theory encapsulated in E equals MC squared would eventually lead
0:50:16 > 0:50:21to the release of nuclear energy and the atomic bomb.
0:50:21 > 0:50:26But the consequences of that belong to a different story.
0:50:27 > 0:50:33Instead, to complete the story of power, I want to go back to the 19th century.
0:50:38 > 0:50:40CLOCK TICKS
0:50:40 > 0:50:46Back then theories of energy might have been lighting up men's minds,
0:50:46 > 0:50:49but they weren't lighting up homes.
0:50:49 > 0:50:52Not yet, at any rate.
0:50:53 > 0:50:57Most people's domestic lives were largely unaffected
0:50:57 > 0:51:01by developments in thermodynamics or electromagnetism.
0:51:01 > 0:51:05Outside there were telegraphs and steam trains,
0:51:05 > 0:51:09but at home, gas lamps, candles and open fires.
0:51:13 > 0:51:18What changed our personal relationship with power was the discovery
0:51:18 > 0:51:23that the link between electricity and magnetism worked both ways.
0:51:23 > 0:51:29Oersted had shown that an electric current could act just like a magnet.
0:51:31 > 0:51:37British scientist Michael Faraday was the first to demonstrate the opposite,
0:51:37 > 0:51:41that moving a magnet could produce an electric current.
0:51:43 > 0:51:48He used the idea that switching on an electric current could make a magnetised piece of metal move
0:51:48 > 0:51:51to build the world's first electric motor.
0:51:51 > 0:51:54But he also demonstrated the reverse is true.
0:51:54 > 0:51:58Take a magnet, push it through some copper wire
0:51:58 > 0:52:01and you produce electricity.
0:52:03 > 0:52:04Beautiful, isn't it?
0:52:06 > 0:52:08It's called electromagnetic induction
0:52:08 > 0:52:12and it was the key to the electric age.
0:52:18 > 0:52:22If one could keep the magnet moving fast enough,
0:52:22 > 0:52:27one could produce an electric current that was continuous.
0:52:27 > 0:52:30What was needed was something to keep the magnet moving.
0:52:38 > 0:52:41Something like this.
0:52:43 > 0:52:47Niagara Falls, one of the most powerful waterfalls in the world.
0:52:52 > 0:52:57This is about as close as I can get to the Falls and it really is magnificent.
0:53:03 > 0:53:08There's about a 150 million litres of water coming over the Falls every single minute.
0:53:08 > 0:53:11And you can really feel the power.
0:53:22 > 0:53:26The challenge lay in finding a way of converting this mass of energy
0:53:26 > 0:53:30into an altogether more useful form - electricity.
0:53:31 > 0:53:38Until very recently, I couldn't have stood here because there would have been millions of litres of water
0:53:38 > 0:53:41just pouring down here, sweeping everything away.
0:53:41 > 0:53:45Up that way, about a kilometre or so,
0:53:45 > 0:53:47is the power station.
0:53:56 > 0:53:59The project began deep under ground.
0:53:59 > 0:54:03Tunnels were dug into solid rock by hand
0:54:03 > 0:54:07to divert some of the water to an electrical generator.
0:54:07 > 0:54:11Those taking part sensed the dawn of a new age.
0:54:17 > 0:54:24When it was first built, it was described as a feat to rival the pyramids, the temples of the Greeks,
0:54:24 > 0:54:29the great cathedrals of Europe, a monument to the scientific age.
0:54:33 > 0:54:36And personally I think they were right.
0:54:36 > 0:54:41Because these giant turbines really are the ultimate expression
0:54:41 > 0:54:45both of what power is and what power does.
0:54:46 > 0:54:51Huge magnets turned by the power of falling water,
0:54:51 > 0:54:56creating enough electricity to power three quarters of a million light bulbs.
0:54:57 > 0:55:00But for electricity to become a true commodity,
0:55:00 > 0:55:03something that could be bought and sold,
0:55:03 > 0:55:07there was one final barrier to overcome -
0:55:07 > 0:55:13how to get electricity from here in Niagara to the places you'd actually want to sell it.
0:55:13 > 0:55:16Cities like Buffalo, 24 miles away,
0:55:16 > 0:55:20or power-hungry New York, 400 miles away.
0:55:23 > 0:55:28The problem was the power loss as the current travelled along the cable.
0:55:30 > 0:55:35If you happened to live near a generating plant like this, then you were fine.
0:55:35 > 0:55:39But the further away you moved, the less power you got.
0:55:39 > 0:55:41After just a mile,
0:55:41 > 0:55:44you would begin to notice the difference.
0:55:44 > 0:55:49After two miles, hardly any current would be getting through at all.
0:55:52 > 0:55:56But here at Niagara, this problem was overcome.
0:55:56 > 0:56:01Its generators produced what's known as alternating current -
0:56:01 > 0:56:04high voltage, low power loss...
0:56:05 > 0:56:10..which meant that electricity could finally travel.
0:56:12 > 0:56:17When, in 1896, this new form of current was switched on,
0:56:17 > 0:56:22it took less than a second to reach Buffalo, over 20 miles away.
0:56:25 > 0:56:30In that instant was born the electric age.
0:56:40 > 0:56:46The discovery of what power can do for us has transformed our lives
0:56:46 > 0:56:51and set us on a relentless search for new sources of energy.
0:56:53 > 0:56:56From deep within the earth to inside the smallest atom,
0:56:56 > 0:57:04to the sun itself, a hunger for more power knows few bounds.
0:57:04 > 0:57:10Small wonder that our planet alone in the solar system glows in the dark.
0:57:26 > 0:57:28But the quest to find out what power is
0:57:28 > 0:57:32has had an equally profound effect.
0:57:33 > 0:57:35Using the language of mathematics,
0:57:35 > 0:57:39we have shown energy to be a basic property of the universe.
0:57:42 > 0:57:47And it's the coming together of the practical and theoretical approaches to power
0:57:47 > 0:57:49which underpins the modern world.
0:57:51 > 0:57:56For a long time, the search for power was led by practical men.
0:57:56 > 0:57:58And then the theorists caught up.
0:57:58 > 0:58:03And to the plaintive cry, "Can we have limitless power?"
0:58:03 > 0:58:05replied a resounding "No."
0:58:05 > 0:58:10But that search also led to the uncovering of the fundamental laws of nature
0:58:10 > 0:58:14which now tell us how everything in the universe operates.
0:58:25 > 0:58:29Next time, the great puzzle of existence...
0:58:30 > 0:58:33What is the secret of life.
0:58:48 > 0:58:51Subtitles by Red Bee Media Ltd
0:58:51 > 0:58:54E-mail subtitling@bbc.co.uk