0:00:03 > 0:00:07There are some great questions that have intrigued
0:00:07 > 0:00:11and haunted us since the dawn of humanity.
0:00:13 > 0:00:15What is out there?
0:00:18 > 0:00:20How did we get here?
0:00:24 > 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.
0:00:38 > 0:00:41Of all human endeavours, science has had the greatest impact
0:00:41 > 0:00:45on our lives - on 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.
0:00:53 > 0:00:57So how did we arrive at the modern world?
0:00:57 > 0:01:02Well, that is more surprising and more human than you might think.
0:01:07 > 0:01:09The history of science is often told
0:01:09 > 0:01:11as a series of eureka moments,
0:01:11 > 0:01:15the ultimate triumph of the rational mind.
0:01:15 > 0:01:17But the truth is that power and passion,
0:01:17 > 0:01:22rivalry 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.
0:01:32 > 0:01:35It's been shaped as much by what's outside the laboratory as inside.
0:01:35 > 0:01:37Whoa! Whoa!
0:01:39 > 0:01:41This is the story of how history made science
0:01:41 > 0:01:47and science made history. And how the ideas that were generated changed our world.
0:01:49 > 0:01:56It is a tale of power, proof and passion.
0:02:06 > 0:02:09This time, delving deep to find order and beauty.
0:02:09 > 0:02:12What is the world made of?
0:02:22 > 0:02:23Appearances deceive.
0:02:27 > 0:02:32Beneath the surface, our world is stranger than we can possibly imagine.
0:02:33 > 0:02:37Standing here, it certainly feels as if I am standing on a solid surface.
0:02:37 > 0:02:41But this is an illusion, however convincing.
0:02:41 > 0:02:44Nothing is really solid.
0:02:44 > 0:02:49And you and I? Well, we consist almost entirely of empty space.
0:02:49 > 0:02:54If you took the entire population of the world, all six billion of us,
0:02:54 > 0:03:00and removed that empty space, then we could be squeezed into a cube smaller than that.
0:03:04 > 0:03:07And it gets stranger.
0:03:09 > 0:03:12Mobile phones and other electronic devices which we rely on.
0:03:12 > 0:03:19Well, they rely on particles that, by any normal definition, simply don't exist.
0:03:20 > 0:03:26These insights all come from our attempts to find out what the world is made of.
0:03:30 > 0:03:34Over the millennia, our understanding has moved ever deeper,
0:03:34 > 0:03:38revealing new layers that make up the material world.
0:03:43 > 0:03:48It may seem like an academic, esoteric quest.
0:03:48 > 0:03:50It's anything but.
0:03:50 > 0:03:56Every time we've gone down a layer and achieved a deeper understanding of matter,
0:03:56 > 0:04:02that knowledge has spawned new technologies and huge amounts of wealth and power.
0:04:08 > 0:04:13The first people who systematically tried to unlock the secrets
0:04:13 > 0:04:17of what the world is made of, and to alter it, were the alchemists.
0:04:31 > 0:04:34They flourished in the late Middle Ages,
0:04:34 > 0:04:39working in secret, protecting their knowledge with codes and ciphers.
0:04:42 > 0:04:46It's easy to dismiss the alchemists as deluded mystics,
0:04:46 > 0:04:49forever trying to turn lead into gold.
0:04:50 > 0:04:52Or, perhaps, conmen,
0:04:52 > 0:04:56who used simple chemistry to impress the gullible.
0:05:00 > 0:05:03But the roots of a scientific investigation
0:05:03 > 0:05:07of what the world is made of, lie in their secret laboratories.
0:05:10 > 0:05:14The alchemists' beliefs about matter were largely based on ideas
0:05:14 > 0:05:17that had come down from the ancient Greeks, who believed that,
0:05:17 > 0:05:22well, pretty well everything around you was made up of earth, fire, air and water.
0:05:27 > 0:05:31Theirs was a system of beguiling simplicity.
0:05:31 > 0:05:37Everything in the world was a combination of just four idealised elements...
0:05:38 > 0:05:40Earth. Water.
0:05:40 > 0:05:42Air. Fire.
0:05:44 > 0:05:51Now, they were completely wrong in that, but the central principle, that you can explain a complex world
0:05:51 > 0:05:55by just simple building blocks or elements, that was important.
0:05:59 > 0:06:05But what really interests me about the alchemists is their practical abilities.
0:06:05 > 0:06:08I want to try and repeat a bizarre experiment,
0:06:08 > 0:06:14performed by one of the last of the alchemists, a German called Hennig Brand.
0:06:17 > 0:06:21Brand believed he was on the brink of discovering the philosopher's stone,
0:06:21 > 0:06:25a substance that reputedly turned base metals into gold.
0:06:26 > 0:06:29He thought he could find it in human urine.
0:06:37 > 0:06:40- How long have you had this? - Well, we've not had it...
0:06:40 > 0:06:42Whoa! Jeez, yeah, no, I got a good waft of that one!
0:06:43 > 0:06:45- But it gets worse.- Gets worse!
0:06:45 > 0:06:49I suspect Hennig Brand was not tremendously popular with the girls.
0:06:51 > 0:06:54Having boiled down our starting material, we will then,
0:06:54 > 0:06:56sort of, reduce it to a solid.
0:06:56 > 0:07:01Finally, we'll distil it and see if we can get something interesting.
0:07:04 > 0:07:08Let me try and bring you into the mindset of the alchemists.
0:07:08 > 0:07:14They believed that everything on Earth was in some way alive - and that included metals.
0:07:14 > 0:07:17Metals would grow in the earth like seeds and,
0:07:17 > 0:07:22like the human body decomposing, they would also decompose. They would rust.
0:07:23 > 0:07:25But metals could also be improved.
0:07:25 > 0:07:28They could be made better. They could be purified.
0:07:28 > 0:07:33And if that happened, they became gold, the purest metal of all.
0:07:36 > 0:07:40It was the legendary philosopher's stone
0:07:40 > 0:07:44that the alchemists believed could bring about this transformation.
0:07:48 > 0:07:51Here it is. Here it is. We've been...
0:07:51 > 0:07:53It looks absolutely putrid, I have to say.
0:07:53 > 0:07:57Well, I can tell you that, even as a chemist, and I've smelled
0:07:57 > 0:08:01- a lot of stuff, this is seriously, seriously unpleasant.- OK.
0:08:01 > 0:08:04So we've boiled down about half a litre of urine
0:08:04 > 0:08:07to this and you can see that it's starting to get a bit pasty.
0:08:07 > 0:08:09There's all sort of white solids.
0:08:09 > 0:08:12Oh, God! Oh, God that is bad!
0:08:12 > 0:08:14That is really bad! Oh.
0:08:14 > 0:08:20But what he would have had to do was to transfer it into this retort.
0:08:20 > 0:08:22So we're going to pour it in through the top.
0:08:22 > 0:08:25I'm just going to run it down this glass rod.
0:08:25 > 0:08:28And the next thing presumably is extreme heat?
0:08:28 > 0:08:32And now, the trial by fire, if you will.
0:08:37 > 0:08:40It involved great technical skill.
0:08:40 > 0:08:45Controlling temperature, making the furnace and glass retorts.
0:08:47 > 0:08:53But his strong constitution and persistence produced strange results.
0:08:59 > 0:09:02So what had he extracted from the urine?
0:09:04 > 0:09:08I can show you and, if you look, we've actually got it stored
0:09:08 > 0:09:11under water, much as Brand probably would have stored it.
0:09:11 > 0:09:15I think what we should do is see what happens when it burns.
0:09:16 > 0:09:18Oh! Whoo! Whoo! Whoo!
0:09:18 > 0:09:22- You can see the plumes of white smoke.- Good Lord! Am I OK to touch?
0:09:22 > 0:09:24You can, in fact, lift it, yes.
0:09:24 > 0:09:30- Good Lord.- It's beautiful and I think terrifying at the same time.
0:09:30 > 0:09:32It is phantasmagorical, isn't it?
0:09:32 > 0:09:35I mean it really is unearthly.
0:09:35 > 0:09:37It's magic of the highest order.
0:09:43 > 0:09:47Brand, of course, never found the philosopher's stone.
0:09:50 > 0:09:54His discovery was named "Giver of Light", or phosphorous.
0:09:57 > 0:09:59It became rather important.
0:10:02 > 0:10:05It was later used to make the match.
0:10:08 > 0:10:13It's tempting to think of the alchemists as a bunch of mystics who made a few lucky discoveries,
0:10:13 > 0:10:17but if you look at the equipment behind there, it tells a very different story.
0:10:17 > 0:10:20You have scales, oven, retort -
0:10:20 > 0:10:24equipment you would find in any modern chemistry lab.
0:10:24 > 0:10:27I have absolutely no doubt that the quest to understand what the world
0:10:27 > 0:10:34was made of was hugely helped by the work done down the years by the alchemists.
0:10:36 > 0:10:39But by Brand's time, the alchemists were on the wane.
0:10:39 > 0:10:46And the ancient idea of a world made up of just four forms of matter was about to be demolished.
0:10:52 > 0:10:57As Europe moved out of the Middle Ages, new forces started to shape science.
0:10:59 > 0:11:02Powerful, absolute monarchies ruled the continent.
0:11:04 > 0:11:09They were hungry for weapons as they battled for supremacy.
0:11:11 > 0:11:16That led to a strategic interest in more and better metals.
0:11:27 > 0:11:32The hunger for metals was insatiable and the dirty business
0:11:32 > 0:11:38of getting metal ores out from deep underground became ever more important.
0:11:40 > 0:11:45Mines were one of the places where challenges to the age-old beliefs started to emerge.
0:11:54 > 0:11:58Air had long been considered a single indivisible substance,
0:11:58 > 0:12:01a basic building block of the world.
0:12:01 > 0:12:06But as Europe industrialised, it became increasingly obvious that this was far from the truth.
0:12:06 > 0:12:09People realised, from personal experience,
0:12:09 > 0:12:14that there were lots of different airs, with very different properties.
0:12:18 > 0:12:25There was bad air, which killed men down mines and mysteriously extinguished candles.
0:12:27 > 0:12:32There was fire damp, which ignited below ground without warning.
0:12:34 > 0:12:40And the wonderfully-titled Phlogisticated Air, produced by combustion.
0:12:47 > 0:12:49All of this raised questions.
0:12:49 > 0:12:50What were these airs?
0:12:50 > 0:12:52How many were there?
0:12:52 > 0:12:57Across Europe, experimenters went looking for answers.
0:13:05 > 0:13:10In Yorkshire, the challenge was taken up by the natural philosopher Joseph Priestley...
0:13:12 > 0:13:15..a man who set out to probe the hidden mysteries of nature.
0:13:20 > 0:13:22Joseph Priestley was a precocious youth.
0:13:22 > 0:13:25By the age of four, he could recite perfectly
0:13:25 > 0:13:30all 107 questions and answers in the Westminster Shorter Catechism.
0:13:30 > 0:13:34He joined the church, but he also became a brilliant experimenter.
0:13:34 > 0:13:39He was looking for God, not just in the Bible, but in the natural world.
0:13:41 > 0:13:45Priestley was among the foremost air experimenters of the day.
0:13:47 > 0:13:54And it was these new airs or gases that would help create a new vision of what the world is made of.
0:13:56 > 0:14:00Priestley set out to study airs by heating different substances...
0:14:03 > 0:14:07..including an old alchemist favourite, red calx.
0:14:12 > 0:14:17I love the way the colour changes, as it's going from a sort of orange to a very rich red.
0:14:18 > 0:14:25Priestley heated it to a high temperature and the orange powder transformed into a shiny metal.
0:14:25 > 0:14:27Mercury.
0:14:27 > 0:14:34And with a new piece of equipment, the pneumatic trough, he collected a new air.
0:14:37 > 0:14:38OK, and here it is.
0:14:39 > 0:14:43A precious container full of mystery gas. Now, to test it.
0:14:43 > 0:14:45Turn it upside down
0:14:45 > 0:14:48- and then quickly remove the lid.- OK.
0:14:48 > 0:14:50Ready? Lid.
0:14:50 > 0:14:53- Ah!- And it reinflames... - Gorgeous. Right.- ..quite nicely.
0:14:53 > 0:14:55Goes out again and then it burns.
0:15:01 > 0:15:05He described what he'd collected as "good air".
0:15:07 > 0:15:10And he was enchanted by its fiery properties.
0:15:16 > 0:15:21It turned out to be the most important of the new airs yet discovered.
0:15:23 > 0:15:28In 1774, Priestley went on a fateful trip to Paris.
0:15:28 > 0:15:33Now, he could never ordinarily have afforded such a thing, but on this occasion he went as the guest of a
0:15:33 > 0:15:39British aristocrat and he took with him knowledge of his new discovery.
0:15:46 > 0:15:50When he arrived in Paris, Priestley was invited to dine
0:15:50 > 0:15:54with the golden couple of French experimental science,
0:15:54 > 0:15:57Antoine and Marie-Anne Lavoisier.
0:16:01 > 0:16:05They had created the best-equipped private laboratory in Europe,
0:16:05 > 0:16:08dedicated to measurement and precision.
0:16:10 > 0:16:16He had a vaulting ambition to define a new science - of chemistry.
0:16:17 > 0:16:23His contribution to how we live now is arguably as great as that of Newton or Darwin.
0:16:23 > 0:16:27When he was a young man, Lavoisier said, "I am avid for glory".
0:16:27 > 0:16:31And he achieved that, though at huge personal cost.
0:16:38 > 0:16:45They couldn't have been less alike, the Paris sophisticate and the working-class Yorkshire man.
0:16:54 > 0:16:58I imagine that Priestley was rather overwhelmed by the occasion,
0:17:00 > 0:17:08by the magnificent setting, the fine wines, by Antoine Lavoisier and by his brilliant guests.
0:17:08 > 0:17:13As he later wrote to his wife, "most of the philosophical people of the city were present".
0:17:15 > 0:17:20And, as evening developed, the conversation turned to the subject of airs.
0:17:22 > 0:17:30Priestley soon told them about his recent discovery, an air with fiery properties,
0:17:30 > 0:17:34and then he also told them exactly how to make it.
0:17:36 > 0:17:40Across the table, Lavoisier listened intently.
0:17:40 > 0:17:44As Priestley later noted, "everyone round that table expressed great surprise".
0:17:47 > 0:17:53Armed with Priestley's knowledge, Lavoisier set off to repeat the experiment.
0:17:55 > 0:17:58And was soon boasting of HIS discovery,
0:17:58 > 0:18:00the same air, but with a new name.
0:18:03 > 0:18:05Lavoisier called it "oxygen".
0:18:06 > 0:18:08It is the gas of life.
0:18:12 > 0:18:19But what Lavoisier did next is, I think, a defining moment in the story of science.
0:18:22 > 0:18:25He decided to run the Priestley experiment in reverse,
0:18:25 > 0:18:31the gas and the shiny metal recombined to form red calx.
0:18:33 > 0:18:35Now, the really significant bit...
0:18:35 > 0:18:40He found it weighed exactly the same as before.
0:18:43 > 0:18:48This was to become a fundamental principle of modern chemistry.
0:18:52 > 0:18:54This was momentous.
0:18:54 > 0:18:57Lavoisier had discovered that everything balances.
0:18:57 > 0:19:01You can take a substance, split it down into simple elements
0:19:01 > 0:19:05then recombine those elements and you get back to where you started.
0:19:05 > 0:19:11For me, this marks the beginning of a modern understanding of matter, of how the world is really made.
0:19:15 > 0:19:18The science of chemistry now emerged.
0:19:20 > 0:19:21Out of connections.
0:19:22 > 0:19:26Between the practical skills of the alchemists.
0:19:27 > 0:19:31The discovery of new gases.
0:19:32 > 0:19:35And a dedication to precise measurement.
0:19:37 > 0:19:43The new chemistry would help create a new vision of what the world is made of.
0:19:53 > 0:19:58Meanwhile, outside the laboratories of the rich, science was developing
0:19:58 > 0:20:03a taste for the spectacular, powered by the new interest in airs.
0:20:06 > 0:20:09We're about to re-enact a very important moment in the history of science.
0:20:09 > 0:20:12There should be flames, shouts, screams and,
0:20:12 > 0:20:16obviously, this is why we're all wearing funny costumes.
0:20:19 > 0:20:25In the small French town of Annonay, descendents of a famous family of papermakers, the Montgolfiers,
0:20:25 > 0:20:33recreate the time when an ancient dream of taking to the skies became a reality.
0:20:37 > 0:20:40It's incredibly hot and smoky under there.
0:20:40 > 0:20:46The Montgolfier brothers, when they originally did this experiment, they had no idea about the theory.
0:20:46 > 0:20:51They were practical men who wanted to make money and they thought what was happening to straw,
0:20:51 > 0:20:56producing something called Montgolfier Gas, which contains levity, which is what lifts it up.
0:20:56 > 0:21:02And now we're cooking! Whoa! This is... This is seriously hot.
0:21:12 > 0:21:14That was a sight.
0:21:14 > 0:21:19It was great fun. We know about flight, but imagine you had never seen anything fly like that before.
0:21:19 > 0:21:20It would blow your mind.
0:21:26 > 0:21:32The first balloon, made entirely out of paper, soared a mile into the heavens.
0:21:45 > 0:21:49The race was now on to carry a man into the skies.
0:21:54 > 0:21:59And in November 1783, two brave volunteers took to the air.
0:21:59 > 0:22:04The first humans to look down at the surface of their own planet.
0:22:08 > 0:22:13But very soon, the hot air balloon had a rival,
0:22:13 > 0:22:16backed by the scientific establishment of France.
0:22:19 > 0:22:22Just ten days later, another balloon rose.
0:22:22 > 0:22:27This was driven by a newly-discovered gas, called inflammable air.
0:22:29 > 0:22:36It was 13 times lighter than normal air and considerably less dangerous than using a blazing pile of straw.
0:22:37 > 0:22:39It had huge lifting power.
0:22:44 > 0:22:47This was science as public event.
0:22:48 > 0:22:51Half the city of Paris turned out to watch.
0:22:53 > 0:22:58400,000 people, all staring upwards in amazement.
0:23:00 > 0:23:04But its success laid down a challenge to the chemist.
0:23:05 > 0:23:12How could they make enough of this new gas to fill the skies with floating aeronauts?
0:23:13 > 0:23:18It was a challenge picked up by the champion of the new chemistry...
0:23:20 > 0:23:24..Antoine Lavoisier.
0:23:24 > 0:23:31Ever the experimenter, his solution was daring, to find a way to break apart a fundamental substance...
0:23:31 > 0:23:33Water.
0:23:38 > 0:23:40- Hi, there.- Hi.
0:23:40 > 0:23:42- Nice to see you again. - Good to see you, Michael.
0:23:42 > 0:23:44I love this. I'm very impressed
0:23:44 > 0:23:49because I've got a drawing here of what Lavoisier's original apparatus looked like
0:23:49 > 0:23:52and I think that's pretty damned close.
0:23:54 > 0:23:59This apparatus was constructed to test Lavoisier's idea
0:23:59 > 0:24:04that water could be split into two very different gases,
0:24:04 > 0:24:08oxygen and the new inflammable air.
0:24:08 > 0:24:13- So what we have is a system to essentially make rust in a great hurry.- OK.
0:24:13 > 0:24:16So we have iron in the centre and then we have water
0:24:16 > 0:24:20which is trickling down, and by raising the temperature,
0:24:20 > 0:24:23what we do is, we essentially speed up the reaction.
0:24:23 > 0:24:26Right, so the oxygen in the water is going to bind to the iron?
0:24:26 > 0:24:31Absolutely. The iron is essentially the oxygen getter in this system.
0:24:33 > 0:24:36If I let a bit of water in at this end,
0:24:36 > 0:24:39that's going to get very hot and you can see
0:24:39 > 0:24:44with trained steam and that's why we have a bit of pressure behind it.
0:24:44 > 0:24:50- But it's now going to drain through and in the centre it should be reacting with the iron.- Right.
0:24:50 > 0:24:53- We may be able to see bubbles down the far end.- Hurray!
0:24:53 > 0:24:56- We've got bubbles. - Congratulations. Well done!
0:24:56 > 0:24:57I'm very impressed.
0:24:57 > 0:24:59And those bubbles cannot be steam.
0:24:59 > 0:25:04- Right.- Because the steam would be condensed here in the copper coil
0:25:04 > 0:25:07and so that must be some, let's call it non-condensable gas.
0:25:07 > 0:25:11But is it inflammable air?
0:25:13 > 0:25:15We're getting anxious now, aren't we?
0:25:15 > 0:25:17Well, we're ready.
0:25:17 > 0:25:20We're going to put the splint in there.
0:25:20 > 0:25:24And it was definitely hydrogen and it worked.
0:25:24 > 0:25:26- It was in fact that pop sound... - Yeah.
0:25:26 > 0:25:29..that you do get when hydrogen ignites. There's no question.
0:25:29 > 0:25:33That was inflammable air as it was called in the 18th century.
0:25:37 > 0:25:40Lavoisier's success encouraged Napoleon
0:25:40 > 0:25:45to create a military balloon corps powered by hydrogen gas.
0:25:51 > 0:25:56These two gases that make up water, hydrogen and oxygen,
0:25:56 > 0:25:59were part of Lavoisier's bold new vision
0:25:59 > 0:26:01of what the world is made of...
0:26:06 > 0:26:10Elements. 33 in all.
0:26:10 > 0:26:14His list included the newly discovered gases,
0:26:14 > 0:26:17but he didn't get it entirely right.
0:26:17 > 0:26:21He also included heat and light.
0:26:21 > 0:26:26It was a tentative new list of the building blocks of matter.
0:26:39 > 0:26:46Lavoisier's work coincided, tragically for him, with the upheaval of the French Revolution.
0:26:46 > 0:26:52He made money from collecting taxes. He was a hated tax farmer.
0:26:52 > 0:26:55Lavoisier must have realised that he was vulnerable.
0:26:55 > 0:26:59A member of the revolutionary government had denounced former tax farmers like him
0:26:59 > 0:27:03as leeches on the people, but he chose not to flee.
0:27:08 > 0:27:12Here in La Place de la Concorde,
0:27:12 > 0:27:14Lavoisier was put to death.
0:27:14 > 0:27:18This was more than an individual tragedy.
0:27:19 > 0:27:22As one of Lavoisier's colleagues put it,
0:27:22 > 0:27:29it took just an instant to sever his head and over 100 years would not suffice to produce another like it.
0:27:37 > 0:27:42We have now gone down a layer in our understanding of what the world is made of...
0:27:44 > 0:27:46To a world of elements.
0:27:48 > 0:27:54Each of them considered an unbreakable building block of matter
0:27:54 > 0:27:58and this new understanding would begin to release great power.
0:28:07 > 0:28:12Our journey now moves to the sublime landscape of the Lake District.
0:28:13 > 0:28:19At the end of the 18th Century this was home to William Wordsworth, one of the great poets of the day.
0:28:28 > 0:28:32Wordsworth was a leading member of a movement called Romanticism.
0:28:32 > 0:28:37They prized feelings and intuition over cold hard logic.
0:28:37 > 0:28:42Romantic science sounds like a contradiction in terms
0:28:42 > 0:28:48but, as we'll discover, the romantic poets had a surprisingly profound effect on the story of science.
0:28:51 > 0:28:54That might sound unlikely,
0:28:54 > 0:28:59but the link can be found here in Wordsworth's Dove Cottage.
0:29:04 > 0:29:10So this is, of course, William Wordsworth and over here we've got another of the romantic poets.
0:29:10 > 0:29:15This is Samuel Taylor Coleridge, Rime Of The Ancient Mariner and Kubla Khan.
0:29:15 > 0:29:19But the man I've really come to see is him,
0:29:19 > 0:29:22Humphry Davy, one of Britain's greatest chemists.
0:29:22 > 0:29:24So what's he doing here?
0:29:29 > 0:29:35Well, Humphry Davy and the romantic poets shared an interest in poetry,
0:29:35 > 0:29:42in the power of nature and in a certain mood-altering substance.
0:29:42 > 0:29:44LAUGHTER
0:29:46 > 0:29:52They called it laughing gas and Davy generously shared it with his romantic friends.
0:29:57 > 0:30:00But the connections went much deeper.
0:30:07 > 0:30:08Isn't it gorgeous?
0:30:08 > 0:30:10You can see why Davy loved this place
0:30:10 > 0:30:13and he shared with the romantic poets a belief that if only you
0:30:13 > 0:30:19could understand the laws of nature and live in harmony with them, then the world would be a better place.
0:30:21 > 0:30:23Poets and men of science stood in awe
0:30:23 > 0:30:28of the hidden powers contained within nature.
0:30:29 > 0:30:32They just had different ways of showing it.
0:30:36 > 0:30:42And in 1801, Davy's social connections landed him a post at the Royal Institution in London.
0:30:42 > 0:30:47Here he was able to carry out research and give public lectures.
0:30:49 > 0:30:54His youthful glamour and taste for the spectacular made him an immediate success.
0:30:56 > 0:30:57- Hi, there.- You might need that.
0:30:57 > 0:30:59- Ready to perform, then?- Yeah.
0:30:59 > 0:31:02Show time! As I'm sure Humphry Davy once said.
0:31:02 > 0:31:09'Dr Peter Wothers is helping to recreate the extravaganza that Davy brought here 200 years ago.'
0:31:14 > 0:31:18- Carefully add a drop. - OK. Can we...- Just... Yeah.
0:31:23 > 0:31:26APPLAUSE
0:31:27 > 0:31:30See what happens to your sheep.
0:31:32 > 0:31:36There would have been an enthusiastic crowd drawn to these wonderful exhibitions.
0:31:36 > 0:31:41Somewhere over there, some ardent young women drawn by his charisma.
0:31:45 > 0:31:52Over there you'd probably have seen Samuel Coleridge who was drawn, he said, to collect new metaphors.
0:31:52 > 0:31:54AUDIENCE GASPS
0:31:54 > 0:32:00And sprinkled throughout the crowd, a new breed of entrepreneur and factory owner who had come here
0:32:00 > 0:32:03to collect valuable chemical information.
0:32:11 > 0:32:14Humphry Davy had an instinctive understanding
0:32:14 > 0:32:22of how spectacle and showmanship could be used to establish science as a powerful force in society,
0:32:22 > 0:32:27controlled by a new breed of experts, men like him.
0:32:31 > 0:32:36He thrilled his audience with his mastery of one of the wonders of the age...
0:32:36 > 0:32:37electricity.
0:32:41 > 0:32:42Is this going to be dangerous?
0:32:42 > 0:32:46Potentially, yes. It's very unpleasant material.
0:32:46 > 0:32:47OK. I'll button up well, then!
0:32:47 > 0:32:52Davy heated an unassuming white powder called potash
0:32:52 > 0:32:56to a molten state and then passed electricity through it.
0:32:56 > 0:33:00And did Davy have any idea what he was going to get when he did this experiment?
0:33:00 > 0:33:05- I don't think he did, no. - He just did it for a laugh.
0:33:05 > 0:33:07Electricity broke the potash apart
0:33:09 > 0:33:14..to reveal one of its building blocks.
0:33:14 > 0:33:17A new element with a lilac glow.
0:33:17 > 0:33:21He called it potassium.
0:33:21 > 0:33:26The smoke you can see is actually potassium that's been formed
0:33:26 > 0:33:31but is instantly reacting with the air.
0:33:33 > 0:33:36This element was so volatile, so reactive,
0:33:36 > 0:33:40that it disappeared almost as soon as it was isolated.
0:33:45 > 0:33:47I'll just fish a chunk out.
0:33:47 > 0:33:49- So this is potassium.- How funny.
0:33:49 > 0:33:53- I've never seen potassium. It looks like a metal, doesn't it? - It looks like a metal,
0:33:53 > 0:33:55but if we cut this it's a very soft metal.
0:33:55 > 0:33:57You can see what potassium really looks like.
0:33:57 > 0:33:59- This is pure potassium metal.- Right.
0:33:59 > 0:34:01And you can see that this is already reacting
0:34:01 > 0:34:03with the oxygen from the air.
0:34:03 > 0:34:07So it's really impressive that Davy was able to do this 200 years ago.
0:34:07 > 0:34:11It was quite a remarkable achievement to isolate this reactive metal.
0:34:12 > 0:34:16Davy had a real knack for finding new elements.
0:34:16 > 0:34:19Eight of them in less than two years.
0:34:19 > 0:34:21Oh, God!
0:34:22 > 0:34:25- There we are. - I was not expecting that.
0:34:26 > 0:34:32But the significance of Davy's work lay in far more than new elements.
0:34:32 > 0:34:37It extended to science itself and to popular culture.
0:34:42 > 0:34:48There was the young author, Mary Shelley, who was inspired and disturbed by Davy's work.
0:34:48 > 0:34:56It influenced her when she wrote Frankenstein, a novel which created a powerful and enduring image
0:34:56 > 0:35:01of the mad experimenter who is dabbling in forces way beyond his control.
0:35:01 > 0:35:05And then there was Davy's friend, the poet Samuel Taylor Coleridge.
0:35:05 > 0:35:08Now he actually helped coin the name "scientist"
0:35:08 > 0:35:11to describe what people like Davy did.
0:35:11 > 0:35:14Alternatives included "science man",
0:35:14 > 0:35:16but it was "scientist" that stuck.
0:35:18 > 0:35:21But others in the audience had a more practical reaction.
0:35:21 > 0:35:24Was chemistry useful? Was there money in it?
0:35:30 > 0:35:34Chemistry was about to become a power in the world,
0:35:34 > 0:35:40but the journey it took to get there was wonderfully unpredictable.
0:35:43 > 0:35:49It starts in the tropics with a deadly problem that threatened the empires of the 19th century.
0:35:52 > 0:35:58In Jamaica, once a British colony, I'm hoping to see how they tried to deal with it.
0:35:59 > 0:36:03It's quite early morning. It's already unbelievably hot.
0:36:03 > 0:36:05- Yeah, man. - We have a while to go, don't we?
0:36:05 > 0:36:07How high are we? Do you know?
0:36:07 > 0:36:12Oh, when you reach by Cinchona, you are 5,002 feet above sea level.
0:36:12 > 0:36:15Right. Do you get mosquito up here?
0:36:15 > 0:36:18- Is it too high?- Oh, just a few.
0:36:22 > 0:36:27On the upper slopes of the blue mountains grows a truly remarkable tree.
0:36:28 > 0:36:31I like it here. It's nice.
0:36:31 > 0:36:33It's just great to get off.
0:36:35 > 0:36:42There are lots of unpleasant creatures in the tropics but the deadliest by far is the mosquito.
0:36:42 > 0:36:46It has killed more people than anything else in history.
0:36:46 > 0:36:50Now, it carries yellow fever, Dengue fever, but also malaria.
0:36:50 > 0:36:56And in the 19th century, malaria was a huge problem for empire builders like the British.
0:36:56 > 0:36:58Right. Is it this way?
0:36:58 > 0:37:00- How big is it?- About this high.
0:37:00 > 0:37:03- OK. And how old is it?- This way.
0:37:03 > 0:37:08The best defence against this disease was the bark of the Cinchona tree.
0:37:08 > 0:37:11- You know the tree? You ever seen it before?- It's that one there.
0:37:11 > 0:37:15- Yes. This one here.- Right, this is it.- It's starts blooming there.
0:37:15 > 0:37:19Yeah, this is probably the most amazing tree in history.
0:37:19 > 0:37:22- It has relieved more human suffering than anything else.- Yeah.
0:37:22 > 0:37:25- Right, and it's the bark we want, isn't it?- Yeah.
0:37:25 > 0:37:29- I'm told it's fairly horrible. Have you tried it before? - Yeah, man. Real bitter.
0:37:29 > 0:37:34I've seen somebody, when I was doing medicine, I saw somebody die of malaria
0:37:34 > 0:37:36so I have huge, huge appreciation for this.
0:37:36 > 0:37:39Right, am I going to enjoy it?
0:37:39 > 0:37:43Oh, God! Oh, God!
0:37:43 > 0:37:45Oh, you were right!
0:37:47 > 0:37:50That is really, really bitter. Just dries up your mouth, doesn't it?
0:37:50 > 0:37:54On the grounds that something which is horrible is doing you good
0:37:54 > 0:37:57then this must be extraordinarily good stuff.
0:37:59 > 0:38:04Cinchona plantations were established all over the tropics.
0:38:04 > 0:38:10But every year the empires of Europe needed hundreds of tons of the bark to combat malaria.
0:38:11 > 0:38:16So governments looked to chemists to come up with a synthetic alternative.
0:38:19 > 0:38:23In 1820, a couple of French chemists managed to isolate
0:38:23 > 0:38:28the active ingredient in the bark and they called it quinine.
0:38:28 > 0:38:33What people desperately wanted to do next was obviously produce an artificial version of quinine.
0:38:33 > 0:38:40The problem was nobody had done anything as complex as that before.
0:38:42 > 0:38:49The attempts to do so would open the world to chemistry on an industrial scale.
0:38:55 > 0:39:02The challenge to make artificial quinine was taken up in a makeshift lab in London's East End...
0:39:02 > 0:39:06in an attic room by young William Perkin.
0:39:10 > 0:39:16And I like to think he found his inspiration round the corner, in his local music hall.
0:39:17 > 0:39:20MUSIC: "Boiled Beef And Carrots"
0:39:23 > 0:39:25Isn't it magnificent?
0:39:25 > 0:39:30Now the theatre and in fact all of London would have been lit by gas lights.
0:39:30 > 0:39:32And the gas was produced from coal.
0:39:32 > 0:39:38Now, one of the rather nasty side products of that process was a black viscous substance called coal tar.
0:39:38 > 0:39:44A certain Charles Mackintosh used this stuff and produced waterproof Macs.
0:39:44 > 0:39:49But Perkin was about to make a discovery which was far, far more lucrative than that.
0:39:51 > 0:39:56The chemicals he used to try and create quinine are highly toxic.
0:39:56 > 0:40:00So I'm going to use substitutes to show what the process looked like.
0:40:00 > 0:40:03Now from coal tar, other chemists had produced
0:40:03 > 0:40:09a substance called aniline which contains similar amounts of carbon, hydrogen and nitrogen as quinine.
0:40:09 > 0:40:12So this seemed like a pretty good place to start.
0:40:12 > 0:40:16He mixed up his aniline with sulphuric acid
0:40:16 > 0:40:19and also a substance called potassium dichromate
0:40:19 > 0:40:21which is a sort of chemical mixer.
0:40:21 > 0:40:25And then he left it all to sort of brew for a while.
0:40:25 > 0:40:28What he found was black, gunky, really quite revolting.
0:40:28 > 0:40:32I'm surprised he didn't chuck it away, but he didn't.
0:40:32 > 0:40:37In his laboratory, at the top of his parents' house, he distilled, he mixed.
0:40:37 > 0:40:41He eventually produced a very interesting little powder.
0:40:42 > 0:40:45He had not discovered artificial quinine.
0:40:48 > 0:40:55He had instead discovered something which had never been seen before and which he really wasn't expecting.
0:40:55 > 0:40:57He had discovered the colour mauve!
0:40:59 > 0:41:06He had created the first great synthetic dye and made the world a far more colourful place.
0:41:11 > 0:41:17Perkin never did make quinine but he did create a fashion sensation.
0:41:17 > 0:41:21The rich and famous loved his synthetic mauve.
0:41:24 > 0:41:25This is really beautiful.
0:41:25 > 0:41:29It's an antique Victorian dress.
0:41:29 > 0:41:33Now, Perkin's mauve was more than simply a fashion statement.
0:41:33 > 0:41:35The aniline dyes, which were used to colour this dress,
0:41:35 > 0:41:40were the first to be produced on a truly industrial scale.
0:41:40 > 0:41:47So strange as it may sound, this dress marks a significant moment in human history, when the synthetic
0:41:47 > 0:41:51took over from the natural on a truly massive scale.
0:41:57 > 0:42:03By the 1870s, Perkin's factory was making hundreds of tons of dye a year.
0:42:03 > 0:42:09Adding Perkin's green and Britannia violet to his growing catalogue of vivid colours.
0:42:12 > 0:42:18Perkin is rightly celebrated as the father of industrial chemistry
0:42:18 > 0:42:24but the lead soon passed to Germany where industrial chemists worked out how to make ammonia,
0:42:25 > 0:42:29which led to artificial fertilisers
0:42:29 > 0:42:33which today sustain the global population.
0:42:40 > 0:42:44But the journey that began in the tropics with the search for quinine
0:42:44 > 0:42:49also led here...to the killing fields of the Great War.
0:42:54 > 0:42:57Uniforms were coloured khaki with artificial dyes.
0:43:05 > 0:43:09Explosives were produced by the same process used to make fertilisers.
0:43:13 > 0:43:18It brought us the horrors of poison gas, chlorine.
0:43:18 > 0:43:22A gas used in the dye industry that Perkin had pioneered.
0:43:22 > 0:43:28The First World War has been described as the "Chemist's War".
0:43:35 > 0:43:39Industrial chemistry became a force in world history,
0:43:39 > 0:43:43the result of connections between the discovery of elements,
0:43:45 > 0:43:47the growth of European empires
0:43:49 > 0:43:51and the colour mauve.
0:43:53 > 0:43:58But the search for what the world is made of was far from over.
0:44:02 > 0:44:05In universities across the world, researchers had been trying
0:44:05 > 0:44:10to make sense of what elements might themselves be made of.
0:44:14 > 0:44:22The main theory was that every element is made of tiny indivisible chunks of matter called atoms.
0:44:26 > 0:44:33Atoms of different elements join together to make up everything you see or touch.
0:44:37 > 0:44:42There was just one rather tricky problem with the idea of the atom -
0:44:42 > 0:44:44proof.
0:44:48 > 0:44:51Seeing is believing. Nobody had actually seen an atom.
0:44:51 > 0:44:56They're far too small. Lots of physicists were sceptical about their existence.
0:44:56 > 0:45:00Ernst Mach, who leant his name to the speed of sound, said,
0:45:00 > 0:45:02"They are just things of thought."
0:45:02 > 0:45:08The first physical evidence for the existence of atoms would come from a gloriously unexpected source.
0:45:12 > 0:45:14From the world of the supernatural.
0:45:16 > 0:45:21To the modern mind, William Crookes is a puzzling sort of scientist.
0:45:21 > 0:45:29His interests range from discovering new elements to investigating the world of spirits and ghosts.
0:45:34 > 0:45:38Crookes' interest in spiritualism was probably triggered by the death
0:45:38 > 0:45:41of his younger brother at a tragically young age.
0:45:44 > 0:45:51At the same time, there were photographs claiming to show ectoplasm, spirits, apparitions.
0:45:55 > 0:45:59Crookes set about a scientific investigation of these claims.
0:46:05 > 0:46:11Crookes invited some of the leading mediums of the day to come to his house and be tested
0:46:11 > 0:46:13and they passed the test with flying colours.
0:46:13 > 0:46:17He claimed to have seen acts of levitation,
0:46:17 > 0:46:20an accordion playing by itself
0:46:20 > 0:46:26and strange phantom figures, some of which he photographed.
0:46:28 > 0:46:31Was Crookes being naive?
0:46:31 > 0:46:36Well, it was only decades since the telegraph had been invented.
0:46:36 > 0:46:40If you could communicate across the world then why not with the dead?
0:46:49 > 0:46:52The thing is, even in his own laboratory, Crookes was coming
0:46:52 > 0:46:58across stuff which was very hard to explain, stuff which was really, if you like, out of this world.
0:46:58 > 0:47:02This thing here is called a Crookes tube
0:47:02 > 0:47:05and it's simply a glass tube out of which the air has been sucked,
0:47:05 > 0:47:08a couple of electrodes and a fluorescent screen.
0:47:10 > 0:47:14He passed a high voltage across the electrodes...
0:47:14 > 0:47:17and the result was really quite striking.
0:47:18 > 0:47:21Isn't that gorgeous?
0:47:21 > 0:47:22Looks like a sort of green ray.
0:47:26 > 0:47:28Was this a spiritual emanation?
0:47:28 > 0:47:32Crookes was a careful experimenter.
0:47:32 > 0:47:36He found the glow could be bent with a magnet,
0:47:36 > 0:47:39suggesting the glow was in some way electrical.
0:47:39 > 0:47:41What he did next was very ingenious.
0:47:41 > 0:47:42Right.
0:47:44 > 0:47:50Crookes made a new tube with another addition, a tiny metal paddle wheel.
0:47:52 > 0:47:55Let's see what happens when we turn it on.
0:47:56 > 0:47:59Ha! Spectacular.
0:48:03 > 0:48:07This suggested the strange glow was made up of moving particles,
0:48:07 > 0:48:10something with a mass to push a wheel.
0:48:13 > 0:48:15Now Crookes was thrilled.
0:48:15 > 0:48:18As far as he was concerned, this proved beyond all reasonable doubt
0:48:18 > 0:48:23that what was happening was a stream of particles were making it spin.
0:48:23 > 0:48:27He called this force, this stream, "radiant matter",
0:48:27 > 0:48:30and he thought it was a sort of fourth state of being.
0:48:34 > 0:48:36For all his skills as an experimenter,
0:48:36 > 0:48:40Crookes didn't have a convincing theory of what was happening.
0:48:44 > 0:48:50But his curiosity would trigger a whole sequence of experiments that would in turn transform physics,
0:48:50 > 0:48:58chemistry and also create a whole new way of looking at this deeply strange world that we all live in.
0:49:04 > 0:49:10Atomic theory really started to come into focus here in Cambridge University
0:49:12 > 0:49:15in the rather unassuming Cavendish Laboratory
0:49:17 > 0:49:23with the work of the physicist, Joseph John Thomson, known as JJ.
0:49:27 > 0:49:33He realised that what was causing the tube to glow and the paddle wheel to spin, were a stream of
0:49:33 > 0:49:38tiny charged particles, particles far, far smaller than even atoms.
0:49:41 > 0:49:46He built more accurate and delicate versions of Crookes' tubes.
0:49:48 > 0:49:55Thomson calculated the particles causing the wheel to move were 1,000 times smaller than an atom.
0:49:55 > 0:49:57It caused a sensation.
0:49:59 > 0:50:05They were named electrons, the first sub-atomic particles to be discovered.
0:50:07 > 0:50:14It was an achievement that gained JJ Thomson the Nobel Prize for physics in 1906.
0:50:16 > 0:50:23A new layer of our understanding of what the world is made of opened up in the early 20th century.
0:50:23 > 0:50:26The world was made of atoms
0:50:26 > 0:50:30and they were made up of three fundamental particles,
0:50:32 > 0:50:35protons and neutrons packed into a nucleus,
0:50:35 > 0:50:39surrounded by electrons moving in orbits.
0:50:46 > 0:50:52A suitably grand location to give you a sense of the world of the atom is St Paul's in London.
0:50:55 > 0:51:02It's a place where you can start to picture the scale and proportions inside the atom.
0:51:04 > 0:51:07If you can imagine St Paul's Cathedral as an atom,
0:51:07 > 0:51:10then the nucleus, which is at the heart of the atom,
0:51:10 > 0:51:17and where almost all the mass resides, would be smaller than a single grain of sand.
0:51:26 > 0:51:29The rest is effectively a void.
0:51:32 > 0:51:33It is remarkable.
0:51:33 > 0:51:41Everything you think of as solid matter, the building, me, you, the floor I'm standing on,
0:51:41 > 0:51:46almost all of it is empty space.
0:51:50 > 0:51:55That's why, if you took out the empty space, the entire population
0:51:55 > 0:52:00of the world could fit inside the size of a single sugar cube.
0:52:03 > 0:52:11And scientists soon realised that inside the atom the traditional laws of physics simply don't apply.
0:52:13 > 0:52:19In the early days of atomic theory, they thought of the atom as being like a sort of mini solar system.
0:52:19 > 0:52:26You've got the nucleus, the sun at the centre and round it spun the electrons like mini planets.
0:52:26 > 0:52:31Soon, however, they realised that electrons are nothing like planets.
0:52:31 > 0:52:34The electron is an unbelievably weird beast.
0:52:34 > 0:52:36And you simply cannot pin it down.
0:52:39 > 0:52:42An electron is never just in one place.
0:52:42 > 0:52:47It flits around as if it were in many places at the same time.
0:52:48 > 0:52:51By the altar, up there in the dome,
0:52:51 > 0:52:53just behind me,
0:52:54 > 0:52:56all at the same time.
0:52:59 > 0:53:05A new theory was required to explain this strange sub-atomic world.
0:53:05 > 0:53:12The behaviour of electrons could only be described, not as certainties, but as probabilities.
0:53:13 > 0:53:18Not where electrons are, but where they are likely to be.
0:53:18 > 0:53:21The new theory was known as quantum.
0:53:25 > 0:53:27Niels Bohr, the father of quantum physics,
0:53:27 > 0:53:32once said that if you're not profoundly shocked when you hear about it
0:53:32 > 0:53:34then you haven't understood it.
0:53:34 > 0:53:38Even Albert Einstein initially rejected quantum theory, saying,
0:53:38 > 0:53:41"God does not play dice with the universe."
0:53:44 > 0:53:51But quantum theory is nonetheless the foundation of our modern technological society.
0:53:57 > 0:54:041945, and the wartime generation celebrated victory and the possibility of peace and plenty.
0:54:06 > 0:54:10They dreamt of how technology could make their lives better.
0:54:11 > 0:54:16And behind many of these dreams was the science of the electron.
0:54:18 > 0:54:24There was a brand-new world and what made it possible were these.
0:54:24 > 0:54:26Valves.
0:54:26 > 0:54:28Now it is rather gorgeous, isn't it?
0:54:28 > 0:54:33It's a distant cousin of the Crookes tube and its job was essentially
0:54:33 > 0:54:36to control the flow of electrons, to amplify or to switch things.
0:54:39 > 0:54:43The valve was the workhorse of the electrical industry.
0:54:44 > 0:54:48It was used to amplify electrical signals in radios
0:54:48 > 0:54:53and telephone exchanges, and to switch binary signals in early computers.
0:54:53 > 0:54:57They were manufactured by the million.
0:54:59 > 0:55:05The trouble is, big, chunky, uses a lot of power, gets really hot and is incredibly...
0:55:05 > 0:55:08- SMASHES - ..breakable!
0:55:12 > 0:55:16The strange world of quantum theory was to provide a replacement.
0:55:20 > 0:55:24It was in a telephone company that quantum theory came of age.
0:55:28 > 0:55:32Bell Labs wanted a better, cheaper way of connecting Americans.
0:55:33 > 0:55:37To do that, they needed to replace the valve.
0:55:40 > 0:55:44Their research team was led by William Shockley,
0:55:44 > 0:55:48a slick, clever and rather unlikeable individual.
0:55:50 > 0:55:54And this is what Shockley's team came up with.
0:55:54 > 0:55:59It is a curious looking beast but this is a model of the world's first transistor.
0:55:59 > 0:56:05'You can only make a transistor if you understand how electrons behave.
0:56:05 > 0:56:07'You need quantum theory.'
0:56:07 > 0:56:11But essentially it was doing what a valve does, control the flow of electrons,
0:56:11 > 0:56:15but it did so using the laws of quantum mechanics.
0:56:15 > 0:56:19Now, I would put the transistor right up there with the ten greatest
0:56:19 > 0:56:23inventions of all time, because it utterly transformed the world.
0:56:23 > 0:56:28Big, clunky valve radios soon gave way
0:56:28 > 0:56:36to small portable transistor radios, and these in turn were replaced by the micro-processer.
0:56:36 > 0:56:43It is astonishing when you think that in just 60 years we have gone from this,
0:56:43 > 0:56:50a single transistor, to this, a micro-processor that contains over two billion transistors.
0:56:58 > 0:57:02For me, the micro-processor is the ultimate expression
0:57:02 > 0:57:07of the power that has been unleashed by trying to understand what the world is made of.
0:57:13 > 0:57:18Delving ever deeper into matter has undoubtedly changed our society.
0:57:18 > 0:57:23The buildings we live in, the way we travel, how we communicate.
0:57:23 > 0:57:30In short, our modern way of life is largely a product of the attempts to find out what we're all made of.
0:57:31 > 0:57:34Our attempts are far from over.
0:57:34 > 0:57:38There will be new layers to discover, ever more strange.
0:57:38 > 0:57:45Perhaps what now seems unbelievable is simply what we do not yet understand.
0:58:06 > 0:58:10Next time, the most personal question we have asked.
0:58:10 > 0:58:12How did we get here?