0:00:06 > 0:00:11Alchemy, the dream of turning base metals into gold,
0:00:11 > 0:00:15used to be an offence punishable with a long prison sentence.
0:00:19 > 0:00:21But here at one of the most advanced
0:00:21 > 0:00:23nuclear research facilities in the world
0:00:23 > 0:00:26they're attempting a new type of alchemy.
0:00:26 > 0:00:30They're trying to command the extreme forces of nature
0:00:30 > 0:00:35and make one element change into another brand new element.
0:00:38 > 0:00:42This is the latest chapter in the extraordinary story of
0:00:42 > 0:00:46scientists' battle to control the building blocks
0:00:46 > 0:00:48that make up our universe.
0:00:48 > 0:00:49The elements.
0:00:49 > 0:00:54I'm Jim Al-Khalili.
0:00:54 > 0:00:58As a nuclear physicist my life's work wouldn't have been possible
0:00:58 > 0:01:00without the pioneering chemists
0:01:00 > 0:01:03who first explored the mysteries of matter.
0:01:03 > 0:01:04It's beautiful.
0:01:04 > 0:01:10I've seen how they laboured to discover hidden elements and
0:01:10 > 0:01:16crack the secret code of the natural world to create the periodic table.
0:01:20 > 0:01:24Now the story turns to the scientists who unlocked
0:01:24 > 0:01:29the potential of the 92 elements which made up our planet.
0:01:31 > 0:01:34I'll discover how they endeavoured to combine them
0:01:34 > 0:01:36and create our modern world.
0:01:39 > 0:01:45Their mission to control nature is a tale of struggle and serendipity,
0:01:45 > 0:01:48of accident meeting design.
0:01:48 > 0:01:52And of the power of the elements harnessed
0:01:52 > 0:01:55to release unimaginable forces.
0:02:27 > 0:02:31Everything around me has been created as the result
0:02:31 > 0:02:35of chemical reactions unlocking the power of the elements
0:02:35 > 0:02:37and turning them into compounds.
0:02:39 > 0:02:45The element iron fortified with chromium, carbon and nickel
0:02:45 > 0:02:49makes the stainless steel cladding around this building.
0:02:49 > 0:02:53Its glass is a union of silicon and oxygen.
0:02:56 > 0:02:59Just 92 elements created our planet.
0:03:00 > 0:03:05Our quest to combine them spans centuries.
0:03:06 > 0:03:08People had been mixing, muddling
0:03:08 > 0:03:12and making compounds from prehistoric times.
0:03:12 > 0:03:16Inspired by the alchemists, early experimenters added
0:03:16 > 0:03:20all sorts of chemicals together just to see what happened.
0:03:20 > 0:03:23But it was more cooking than a real science,
0:03:23 > 0:03:26what you might call "bucket chemistry".
0:03:28 > 0:03:32Unsurprisingly some of the earliest breakthroughs
0:03:32 > 0:03:34were made entirely by chance.
0:03:36 > 0:03:39One discovery by a German chemist,
0:03:39 > 0:03:44Heinrich Diesbach, was a milestone in the paint industry.
0:03:47 > 0:03:50Science historian Professor Allan Chapman
0:03:50 > 0:03:55is going to show me how Diesbach stumbled across the ingredients
0:03:55 > 0:03:57of the first synthetic paint.
0:03:57 > 0:04:00- Hello, Allan.- Good to see you.
0:04:00 > 0:04:02- Wonderful engine isn't she? - Fantastic.
0:04:02 > 0:04:05The development of the paint that goes onto these engines
0:04:05 > 0:04:08which we call Brunswick Green was itself a mixture
0:04:08 > 0:04:12of two artificially developed paint compounds in the 18th
0:04:12 > 0:04:13and early 19th century.
0:04:13 > 0:04:15The first of these was Prussian Blue,
0:04:15 > 0:04:19developed in the 18th century, a deep beautiful, rich blue.
0:04:19 > 0:04:24And mix that with another chemical substance, chrome yellow,
0:04:24 > 0:04:26then you produce these wonderful colours
0:04:26 > 0:04:30which Isambard Kingdom Brunel and his successors painted on these gorgeous
0:04:30 > 0:04:32Great Western railway engines.
0:04:32 > 0:04:37Before the discovery of Prussian Blue, most pigments
0:04:37 > 0:04:39were derived from nature.
0:04:39 > 0:04:44The best blue pigments came from rare lapus lazuli.
0:04:46 > 0:04:51Allan Chapman is going to try to recreate Diesbach's discovery.
0:04:51 > 0:04:54He's starting with one unusual ingredient
0:04:54 > 0:04:58that ended up in the recipe by accident.
0:04:58 > 0:04:59First of all, take your blood.
0:04:59 > 0:05:01Take your blood.
0:05:01 > 0:05:04And pour it into the crucible.
0:05:04 > 0:05:09And then we take the potash, and the potash is the alkaline material
0:05:09 > 0:05:12which we now call potassium carbonate.
0:05:12 > 0:05:16Diesbach was trying to make red paint, not blue,
0:05:16 > 0:05:21but he had no idea his potash had been contaminated.
0:05:21 > 0:05:24And we think of course that it was the blood that formed the contaminant
0:05:24 > 0:05:26that changed the reaction of the colour
0:05:26 > 0:05:29and produced a blue rather than a red.
0:05:30 > 0:05:34Heating blood alters its proteins, enabling them to combine with
0:05:34 > 0:05:40the iron in blood cells and the potassium carbonate, or potash.
0:05:40 > 0:05:44What's happening in the reaction now is that the carbonate is reacting
0:05:44 > 0:05:45with the haemoglobin
0:05:45 > 0:05:49and other structures in the blood to produce this extraordinary, thick,
0:05:49 > 0:05:52what might best be simply called a gunge.
0:05:52 > 0:05:57After heating the gunge to an ash and then filtering and diluting it,
0:05:57 > 0:06:00Diesbach added green vitriol,
0:06:00 > 0:06:04what we now call iron sulphate, unaware he was about to create
0:06:04 > 0:06:12a complex iron compound, Ferric ferrocyanide, or Prussian Blue.
0:06:12 > 0:06:14Now, watch this carefully,
0:06:14 > 0:06:18it will effervesce and might effervesce violently. So watch this.
0:06:21 > 0:06:23Look at that!
0:06:27 > 0:06:31And notice the very nice green beginning to emerge.
0:06:31 > 0:06:36Now for the final solution, it says to add the spirit of salt.
0:06:36 > 0:06:40This acid should help draw out the Prussian Blue.
0:06:40 > 0:06:41And shut the cupboard down
0:06:41 > 0:06:45because it will throw off all sorts of toxic gases.
0:06:47 > 0:06:52- There we are.- Now, you're talking. - There's a real deep one!
0:06:55 > 0:06:58Almost caught the bottle. Look at that.
0:06:58 > 0:07:00Now that is Prussian blue, that's brilliant.
0:07:00 > 0:07:06That's lovely, isn't it? The very first ever synthetic pigment,
0:07:06 > 0:07:08and dry that out and pulverise it
0:07:08 > 0:07:12and mix it up as a powder and you have a paint.
0:07:12 > 0:07:17Diesbach's chance encounter with blood had given the world synthetic
0:07:17 > 0:07:21Prussian Blue paint from a compound of iron.
0:07:24 > 0:07:28Iron is the Earth's most abundant element.
0:07:30 > 0:07:35Our planet is essentially a vast sphere with an iron core.
0:07:36 > 0:07:40Though it's a silvery, lustrous metal,
0:07:40 > 0:07:43contact with damp air sees it quickly rust.
0:07:43 > 0:07:49The planet Mars is thought to be red due to iron oxide.
0:07:50 > 0:07:56Adding just 1.7% of carbon makes iron into the more durable steel,
0:07:56 > 0:07:59which helped launch the Industrial Revolution.
0:08:05 > 0:08:09Diesbach had glimpsed the potential of making compounds.
0:08:11 > 0:08:15But scientists' understanding of how elements combined
0:08:15 > 0:08:18and could be controlled was still hazy.
0:08:23 > 0:08:28In a bid to master the elements, one German chemist, Justus von Liebig,
0:08:28 > 0:08:32became obsessed with creating explosive combinations.
0:08:35 > 0:08:40His passion was sparked when, as a child in Darmstadt,
0:08:40 > 0:08:43he saw a peddler letting off fireworks.
0:08:43 > 0:08:46They were powered by silver fulminate,
0:08:46 > 0:08:49the same chemicals found in bangers.
0:08:56 > 0:09:00Liebig had found his vocation.
0:09:03 > 0:09:06But it was as much Liebig's personality
0:09:06 > 0:09:10as his love for explosives which powered his great breakthrough.
0:09:12 > 0:09:18It was said that he was arrogant, irascible, pugnacious and pigheaded.
0:09:18 > 0:09:21Not a man to cross you might think.
0:09:21 > 0:09:25So when German chemist Friedrich Wohler got an
0:09:25 > 0:09:32angry letter from Liebig in 1825, you can imagine his heart sinking.
0:09:32 > 0:09:36Liebig had read a paper written by Wohler
0:09:36 > 0:09:41about a compound he had made called silver cyanate. This is its formula.
0:09:42 > 0:09:46It's made in equal parts from the elements
0:09:46 > 0:09:49silver, carbon, nitrogen and oxygen.
0:09:49 > 0:09:52Wohler described it as harmless and stable.
0:09:52 > 0:09:58Liebig saw silver, carbon, nitrogen and oxygen and exploded
0:09:58 > 0:10:03because this was exactly what made up HIS silver fulminate.
0:10:03 > 0:10:07How could two substances that were apparently made of
0:10:07 > 0:10:11the same amounts of the same elements, behave so differently?
0:10:11 > 0:10:14True to character, Liebig decided
0:10:14 > 0:10:19there was only one answer, that Wohler was wrong.
0:10:19 > 0:10:22He dashed off a furious letter to Wohler
0:10:22 > 0:10:24slamming him as a hopeless analyst.
0:10:24 > 0:10:27Well, Wohler wasn't having any of that.
0:10:27 > 0:10:33He challenged Liebig to make Silver cyanate and test it for himself.
0:10:33 > 0:10:37Dr Andrea Sella has studied 19th century chemistry
0:10:37 > 0:10:42and is attempting to create Wohler's silver cyanate.
0:10:42 > 0:10:47The rules of chemistry really said that the only thing that counted was
0:10:47 > 0:10:51what in your material, what its composition was.
0:10:51 > 0:10:54And, so here we have this lovely white powder
0:10:54 > 0:10:57which we're now going to filter off
0:10:57 > 0:11:02and according to the then rules of chemistry,
0:11:02 > 0:11:07this should be absolutely identical to Liebig's material.
0:11:07 > 0:11:12And what would Liebig have expected to happen?
0:11:12 > 0:11:14Liebig expected something really quite nasty.
0:11:14 > 0:11:17I actually made a small amount of it earlier
0:11:17 > 0:11:20and we'll put it here on this little piece of aluminium foil.
0:11:20 > 0:11:23You take a match...
0:11:23 > 0:11:27If this was Liebig's material then something interesting should happen.
0:11:27 > 0:11:29Why don't you have a go? I'll step back.
0:11:29 > 0:11:31Thank you very much(!)
0:11:31 > 0:11:33Are you sure about this? Should I...
0:11:33 > 0:11:35Go for it.
0:11:36 > 0:11:38Be a chemist.
0:11:38 > 0:11:40HE LAUGHS
0:11:49 > 0:11:51- Nothing.- Nothing.
0:11:51 > 0:11:54Now this would have been totally shocking to Liebig
0:11:54 > 0:11:57because Liebig was expecting that something which
0:11:57 > 0:12:01had silver, carbon, nitrogen and oxygen in it would be explosive.
0:12:01 > 0:12:04And yet here was something with the same composition
0:12:04 > 0:12:06and yet it didn't go bang.
0:12:06 > 0:12:10- So, same ingredients, same elements in the same proportions.- Absolutely.
0:12:10 > 0:12:13But they had to be two different compounds.
0:12:13 > 0:12:15They were two totally different compounds.
0:12:17 > 0:12:22Liebig and Wohler had discovered a fundamental characteristic
0:12:22 > 0:12:23of the elements.
0:12:23 > 0:12:29One which would in time explain how just 92 elements
0:12:29 > 0:12:33could give rise to the extraordinary complexity of the modern world.
0:12:35 > 0:12:39They'd stumbled on what would later be called "isomers".
0:12:39 > 0:12:41What made their compounds different
0:12:41 > 0:12:44was the way that the elements were connected.
0:12:44 > 0:12:47If I take these building blocks I can use them to make...
0:12:51 > 0:12:52a space shuttle...
0:12:56 > 0:12:58..or a plane...
0:13:01 > 0:13:05..or a boat.
0:13:05 > 0:13:07It all depends how I fit the pieces together.
0:13:07 > 0:13:09The same is true with the elements.
0:13:09 > 0:13:13Like the explosive fulminate or the calm cyanate.
0:13:13 > 0:13:18It seems that the same elements combined together in different ways
0:13:18 > 0:13:22will give rise to different compounds with different properties.
0:13:22 > 0:13:28Chemists began to suspect that the key to designing new compounds
0:13:28 > 0:13:32was in understanding how the elements combined.
0:13:32 > 0:13:35And this was all down to atoms.
0:13:36 > 0:13:41Atoms are infinitesimally small particles of matter.
0:13:41 > 0:13:44The image of these silicon atoms
0:13:44 > 0:13:48is magnified more than 10 million times.
0:13:48 > 0:13:53These are gold atoms. At the start of the 19th century,
0:13:53 > 0:13:55science first began to consider
0:13:55 > 0:13:59that all elements may be composed of atoms.
0:13:59 > 0:14:02What scientists now realised was that the arrangement of
0:14:02 > 0:14:07the atoms, the way they were connected together, was crucial.
0:14:07 > 0:14:09And by studying the element carbon
0:14:09 > 0:14:13hey made one of chemistry's great breakthroughs.
0:14:13 > 0:14:20In 1796 Yorkshire chemist, Smithson Tennant, was investigating what
0:14:20 > 0:14:25diamonds were made of, when he decided to burn one.
0:14:25 > 0:14:30Now he used sunlight and a magnifying lens to heat the diamond.
0:14:30 > 0:14:35But I'm going to speed things up and use a glass blowing torch
0:14:35 > 0:14:36and I have some liquid oxygen.
0:14:36 > 0:14:40Now if I hold this then in the flame and heat it up...
0:14:44 > 0:14:49And there we have it whizzing around, that's beautiful.
0:14:56 > 0:15:00The bubbles coming off were collected by Smithson Tennant,
0:15:00 > 0:15:02they're pure carbon dioxide.
0:15:02 > 0:15:06Now, he knew that he'd started with just two ingredients -
0:15:06 > 0:15:08diamond and oxygen.
0:15:08 > 0:15:12And what he produced was a gas made up of just carbon and oxygen.
0:15:12 > 0:15:16So, he knew that diamond had to be carbon.
0:15:16 > 0:15:19Now that's almost disappeared.
0:15:19 > 0:15:23It's gone. That diamond doesn't exist any more,
0:15:23 > 0:15:27it's in the air that I'm breathing. It's turned into carbon dioxide.
0:15:27 > 0:15:32So, unfortunately diamonds aren't forever.
0:15:35 > 0:15:39Tennant's revelation left scientists with a conundrum.
0:15:39 > 0:15:41They knew carbon already,
0:15:41 > 0:15:46as graphite, one of the softest elements on the planet.
0:15:46 > 0:15:53So how could it be the same element as the hardest substance, diamond?
0:15:53 > 0:15:56What was carbon's secret?
0:15:57 > 0:16:01At the end of the 18th century, Tennant didn't yet know that
0:16:01 > 0:16:06elements were made of atoms, so he was unable to find the answer.
0:16:06 > 0:16:10It would be another half century before a young Scotsman
0:16:10 > 0:16:15called Archibald Scott Couper took up the challenge.
0:16:15 > 0:16:18Couper was a rising star in chemistry.
0:16:18 > 0:16:23In 1856 when he was 27, he went to Paris to work with one of
0:16:23 > 0:16:27the eminent chemists of the day, Charles-Adolphe Wurtz.
0:16:31 > 0:16:34Couper was fascinated by the way
0:16:34 > 0:16:38carbon atoms combined with other atoms.
0:16:38 > 0:16:43And he came up with the idea of bonds, links between the atoms
0:16:43 > 0:16:46to explain how the elements join with each other.
0:16:52 > 0:16:56This is Couper's paper, written in June 1858.
0:16:56 > 0:16:59The ideas in here would spark a revolution
0:16:59 > 0:17:02in the way we interpret chemistry.
0:17:02 > 0:17:06And this is Couper's picture of the way the atoms are connected.
0:17:06 > 0:17:11The C stands for Carbon and the H for hydrogen,
0:17:11 > 0:17:14and these lines are Couper's bonds
0:17:14 > 0:17:17that explain how he thought
0:17:17 > 0:17:20the atoms all joined together.
0:17:20 > 0:17:22And this is the real genius,
0:17:22 > 0:17:28somehow Couper realised that carbon doesn't just have one link,
0:17:28 > 0:17:30but four.
0:17:30 > 0:17:35Because of its four bonds, it can attach with different strengths
0:17:35 > 0:17:40to other carbon atoms, that's why it can exist in two extreme forms.
0:17:40 > 0:17:44In diamond, all four bonds are connected to other carbon atoms in
0:17:44 > 0:17:48three dimensions, that's why diamond is so hard.
0:17:48 > 0:17:52But in graphite, only three of the bonds are connected to other carbon
0:17:52 > 0:17:57atoms in a single plane, making the connections weaker,
0:17:57 > 0:18:00which is why graphite is a much softer material.
0:18:02 > 0:18:07Carbon's four bonds give it another extraordinary property.
0:18:07 > 0:18:10Imagine I am a carbon atom.
0:18:10 > 0:18:13I can use one hand to link to another atom and my other hand
0:18:13 > 0:18:18to link to a second, leaving my feet free to make more links.
0:18:21 > 0:18:26So, carbon's four bonds means it can combine
0:18:26 > 0:18:29with lots of other atoms.
0:18:30 > 0:18:34It can form rings and long chains,
0:18:34 > 0:18:38something that makes it rare amongst the elements.
0:18:43 > 0:18:48Carbon. It has us in its nurturing grasp from our birth to our death.
0:18:51 > 0:18:54It's found in everything from a whale's backbone
0:18:54 > 0:18:56to the smallest virus.
0:18:57 > 0:19:02Carbon is in DNA, cellulose, fat, sugar.
0:19:04 > 0:19:08Daily, each of us takes in 300g of it.
0:19:09 > 0:19:12Earth's carbon, like most other elements,
0:19:12 > 0:19:16was ejected from dying stars which means
0:19:16 > 0:19:19we're all made of stardust.
0:19:25 > 0:19:29Couper had solved a fundamental puzzle.
0:19:29 > 0:19:34He'd explained why carbon could be found in so many compounds,
0:19:34 > 0:19:37why it made up so much of the natural world.
0:19:37 > 0:19:42Now, he just had to publish his findings to claim the credit.
0:19:42 > 0:19:44But a German chemist,
0:19:44 > 0:19:49Friedrich Kekule had hit upon exactly the same idea.
0:19:49 > 0:19:55Kekule spent time studying in London, and it was apparently whilst
0:19:55 > 0:20:01on a London bus that he claimed he'd had a flash of inspiration.
0:20:01 > 0:20:05Most of us sit on the bus dreaming about Leeds United, what we're going
0:20:05 > 0:20:09to have for supper when we get home, or what's on the telly.
0:20:09 > 0:20:11But Kekule claimed he dreamt of
0:20:11 > 0:20:15whirling atoms embracing in a giddy dance.
0:20:15 > 0:20:17He saw them uniting into chains,
0:20:17 > 0:20:20pulling more atoms together.
0:20:20 > 0:20:23Suddenly the conductor shouted, "Clapham"
0:20:23 > 0:20:30and Kekule came to with new ideas of structure formed in his mind.
0:20:30 > 0:20:33Kekule raced to get his concept into print.
0:20:33 > 0:20:37Couper's boss had been slow to get his paper published,
0:20:37 > 0:20:40so Kekule took all the credit.
0:20:41 > 0:20:47And in science there's no prize for second place.
0:20:47 > 0:20:52Despite having been the first to unravel carbon's secrets,
0:20:52 > 0:20:54Couper got none of the glory.
0:20:54 > 0:20:58When he discovered that his boss, Adolphe Wurtz had somehow
0:20:58 > 0:21:00delayed in sending his paper,
0:21:00 > 0:21:05he flew into a rage at Wurtz, who promptly expelled him from the lab.
0:21:05 > 0:21:09From there, he disappeared completely from chemical history.
0:21:09 > 0:21:14No scientific papers, no letters to journals, no experiments, nothing.
0:21:20 > 0:21:23Couper missed out on his chance for recognition
0:21:23 > 0:21:26and soon after lost his mind.
0:21:26 > 0:21:30He would spend years in an asylum.
0:21:37 > 0:21:39But once carbon's secrets had been revealed,
0:21:39 > 0:21:43a world of opportunity beckoned for many others.
0:21:43 > 0:21:47There are more known compounds of carbon
0:21:47 > 0:21:49than of any other element,
0:21:49 > 0:21:53so understanding how it could combine gave us the means
0:21:53 > 0:21:56of creating compounds by design.
0:21:56 > 0:22:00Suddenly it seems everyone was manipulating the elements
0:22:00 > 0:22:02so it wasn't long before industry
0:22:02 > 0:22:05was cashing in on this new found certainty,
0:22:05 > 0:22:09and modern, industrial chemistry was born.
0:22:15 > 0:22:19Combining elements into new compounds would not only offer
0:22:19 > 0:22:23the prospect of building fortunes,
0:22:23 > 0:22:28science's mastery of carbon chemistry began to shape our lives.
0:22:28 > 0:22:32It's hard to imagine a world without plastics today.
0:22:32 > 0:22:37One, invented in 1907 had the catchy title of
0:22:37 > 0:22:43polyoxybenzylmethylenglycolanhydride better known as Bakelite.
0:22:46 > 0:22:50It soon appeared almost everywhere.
0:22:50 > 0:22:56The wonder material could be moulded into a myriad of different shapes.
0:22:56 > 0:22:59New discoveries came thick and fast.
0:23:00 > 0:23:05In the 1930s, American Chemist, Wallace Carothers
0:23:05 > 0:23:07tapped into a mass market.
0:23:07 > 0:23:11He converted carbon chemistry into cash
0:23:11 > 0:23:14when he invented what's in here.
0:23:14 > 0:23:19It looks a bit like a cocktail, at the bottom is a carbon chain,
0:23:19 > 0:23:24hexamethylenediamin. That's "hexa" for hexagon.
0:23:24 > 0:23:26Six carbon atoms.
0:23:26 > 0:23:30And floating above it is another carbon chain,
0:23:30 > 0:23:32decanedioyl dichloride.
0:23:32 > 0:23:35And on the boundary between the two chemicals
0:23:35 > 0:23:38they're reacting together to form bonds.
0:23:38 > 0:23:41So if I pull out this glass rod,
0:23:41 > 0:23:45I make a string which is more and more of the chemicals
0:23:45 > 0:23:48bonding together into very long chains.
0:23:51 > 0:23:55I'm going to make use of this device as a spinning wheel.
0:23:58 > 0:24:01With just a few elements, carbon,
0:24:01 > 0:24:07nitrogen, oxygen, and hydrogen, found in coal, water and air,
0:24:07 > 0:24:09Carothers had designed
0:24:09 > 0:24:11his very own unique fibre.
0:24:11 > 0:24:14It could be spun as fine as a spider's web,
0:24:14 > 0:24:17but had the strength of steel.
0:24:18 > 0:24:20It was called Nylon.
0:24:23 > 0:24:27When nylon stockings first went on sale in America,
0:24:27 > 0:24:31the entire stock of 5 million was sold in a day.
0:24:32 > 0:24:36Nylon began a revolution in synthetic chemistry,
0:24:36 > 0:24:39but Carothers didn't live to see its success.
0:24:39 > 0:24:41He suffered from depression
0:24:41 > 0:24:45and just three weeks after the basic patent for Nylon had been filed,
0:24:45 > 0:24:48at the age of 41, he committed suicide
0:24:48 > 0:24:53by slipping a carbon compound, potassium cyanide, into his drink.
0:24:59 > 0:25:05Nylon became a global phenomenon, progress appeared unstoppable.
0:25:05 > 0:25:08But inevitably, perhaps,
0:25:08 > 0:25:13our increasing control of the elements brought new dilemmas.
0:25:20 > 0:25:23The automobile was just 35 years old
0:25:23 > 0:25:28when Thomas Midgley Junior, an engineer with General Motors,
0:25:28 > 0:25:31found a chemical remedy to help its engine
0:25:31 > 0:25:33run smoothly and more efficiently.
0:25:33 > 0:25:36Cars at that time had terrible trouble
0:25:36 > 0:25:39with their engines knocking and misfiring.
0:25:39 > 0:25:43Midgely had tried to solve this by experimenting,
0:25:43 > 0:25:46it's said, with everything from butter
0:25:46 > 0:25:51and camphor to ethyl acetate and aluminium chloride.
0:25:53 > 0:25:56Success finally came with a lead compound,
0:25:56 > 0:26:00tetra-ethyl lead, known as TEL.
0:26:00 > 0:26:04It worked brilliantly, nothing else came close.
0:26:05 > 0:26:08By the 1970s, the US alone
0:26:08 > 0:26:14was adding around 200,000 tonnes of lead to its petrol every year.
0:26:17 > 0:26:21But research was emerging to suggest that it was causing harm,
0:26:21 > 0:26:23both to humans and the environment.
0:26:23 > 0:26:29In 1983 a Royal Commission questioned whether
0:26:29 > 0:26:32"any part of the Earth's surface
0:26:32 > 0:26:36"or any form of life remains uncontaminated".
0:26:37 > 0:26:41Midgley's compound began to be phased out.
0:26:41 > 0:26:46Today almost all of the world's petrol supplies are unleaded.
0:26:50 > 0:26:52Lead.
0:26:52 > 0:26:56The alchemists thought it was the oldest metal.
0:26:57 > 0:27:01The Romans were the first to use it on a large scale.
0:27:01 > 0:27:07It is so stable that Roman lead pipes still survive to this day.
0:27:07 > 0:27:13Our word "plumbing" comes from the Latin word for lead, plumbum.
0:27:15 > 0:27:19Lead is toxic to humans as it deactivates the enzymes
0:27:19 > 0:27:21that make haemoglobin in blood.
0:27:23 > 0:27:26Although no longer used in petrol,
0:27:26 > 0:27:32much of the lead produced each year still ends up in cars, in batteries.
0:27:34 > 0:27:39Lead may have forced scientists to face difficult questions,
0:27:39 > 0:27:41but it didn't stop them forging ahead
0:27:41 > 0:27:46in their bid to control and manipulate the natural world.
0:27:46 > 0:27:50And their work with one group of elements was to spark a
0:27:50 > 0:27:57revolutionary idea - the prospect of creating new, manmade elements.
0:27:59 > 0:28:03It was a concept that would shake the foundations of chemistry...
0:28:03 > 0:28:06- EXPLOSION - ..to its core.
0:28:06 > 0:28:10At its heart, were the radioactive elements.
0:28:13 > 0:28:20In 1896, French scientist Henri Becquerel
0:28:20 > 0:28:24was working with uranium crystals
0:28:24 > 0:28:27and found ultraviolet light made them glow.
0:28:27 > 0:28:29It looks eerie.
0:28:29 > 0:28:32He left uranium salts overnight
0:28:32 > 0:28:37on a photographic plate that had never been exposed to light.
0:28:37 > 0:28:40In the morning, he found a dark shadow on it
0:28:40 > 0:28:44and realised that the uranium salts must have been the source of energy.
0:28:44 > 0:28:48Bequerel had discovered radioactivity.
0:28:49 > 0:28:53Scientists began to investigate.
0:28:53 > 0:28:57One was a young Polish chemist, Marie Curie.
0:28:59 > 0:29:03Marie began collecting uranium ore, called pitchblende.
0:29:03 > 0:29:04CLICKING
0:29:04 > 0:29:07Testing it with an electrometer,
0:29:07 > 0:29:10- she found... - RAPID CLICKING
0:29:10 > 0:29:14..that it was four times more radioactive than pure uranium.
0:29:14 > 0:29:17She checked it 20 times. What could be going on?
0:29:17 > 0:29:20Then she had a brainwave, she decided there was
0:29:20 > 0:29:24something else in the pitchblende that was boosting its radioactivity.
0:29:24 > 0:29:27Something more radioactive than uranium.
0:29:27 > 0:29:30But what? Could it be a new element?
0:29:31 > 0:29:35Marie Curie didn't have a well-equipped lab,
0:29:35 > 0:29:36it was far more basic.
0:29:36 > 0:29:38A bit like this.
0:29:44 > 0:29:47One chemist called it a cross between a horse stable
0:29:47 > 0:29:49and a potato cellar.
0:29:49 > 0:29:53She had a tonne of pitchblende, some say 10 tonnes,
0:29:53 > 0:29:56delivered by horse and cart.
0:29:56 > 0:29:59And then with just basic equipment like this,
0:29:59 > 0:30:02she attempted to isolate her mystery elements.
0:30:07 > 0:30:12Her experiments had a myriad of complex stages, including
0:30:12 > 0:30:17potentially lethal processes using highly flammable hydrogen gas.
0:30:26 > 0:30:28But all her hard work was worth it.
0:30:28 > 0:30:31With just her primitive kit,
0:30:31 > 0:30:34Marie Curie discovered two radioactive elements.
0:30:34 > 0:30:38Polonium, named after her native Poland
0:30:38 > 0:30:42and another that would launch an entire industry, radium.
0:30:45 > 0:30:50Radium was once the key component in luminous paint.
0:30:50 > 0:30:52It's intensely radioactive.
0:30:55 > 0:30:58The world fell in love with radium,
0:30:58 > 0:31:02assuming its invisible energy must be good for you.
0:31:02 > 0:31:06The French slapped on Radium face powder.
0:31:06 > 0:31:09The Germans ate Radium chocolate.
0:31:10 > 0:31:14The Americans wore Radium branded condoms.
0:31:14 > 0:31:19But the magic faded when doctors realised
0:31:19 > 0:31:24that far from boosting health, it triggered cancers.
0:31:24 > 0:31:28Marie Curie didn't live to see the amazing journey
0:31:28 > 0:31:31the radioactive elements would take us on.
0:31:31 > 0:31:34Because whilst they're naturally occurring elements,
0:31:34 > 0:31:39they would take man one step closer to a seemingly impossible dream.
0:31:39 > 0:31:43To create entirely new elements.
0:31:47 > 0:31:52Ernest Rutherford was working with radioactivity to investigate
0:31:52 > 0:31:58the subatomic world, when he made an astonishing discovery.
0:31:58 > 0:32:00At the beginning of the 20th century,
0:32:00 > 0:32:03it was widely believed that atoms never change.
0:32:03 > 0:32:08That carbon atoms will always be carbon atoms, gold always gold.
0:32:08 > 0:32:10Well, Rutherford overturned this idea
0:32:10 > 0:32:14by taking a great leap forward in scientific thinking.
0:32:16 > 0:32:19I'm surrounded by some of the original equipment used by
0:32:19 > 0:32:24Rutherford and the early pioneers to unlock the secrets of the atom.
0:32:24 > 0:32:30Rutherford had concluded that the atom was mostly empty space,
0:32:30 > 0:32:36with tiny electrons buzzing around a central nucleus containing protons,
0:32:36 > 0:32:38positively charged particles.
0:32:38 > 0:32:42Protons are vital to an atom's identity.
0:32:42 > 0:32:46The number of protons gives an element its uniqueness.
0:32:46 > 0:32:50Carbon atoms have six protons in their nucleus.
0:32:50 > 0:32:53Seven means nitrogen.
0:32:53 > 0:32:57Rutherford came to the shattering conclusion
0:32:57 > 0:33:01that the number of protons in the nucleus of a radioactive element
0:33:01 > 0:33:03could change because it decayed.
0:33:07 > 0:33:11Rutherford realised some of the mysterious radioactivity
0:33:11 > 0:33:16was actually miniscule fragments of atoms containing protons,
0:33:16 > 0:33:19which were being fired out of the nucleus.
0:33:19 > 0:33:22He named them alpha particles.
0:33:24 > 0:33:27Much as life forms break up and decay,
0:33:27 > 0:33:32so some elements themselves break up, radioactive decay.
0:33:35 > 0:33:39As the tiny chips of the atom, the alpha particles, fly off,
0:33:39 > 0:33:42its nucleus shrinks.
0:33:43 > 0:33:48Rutherford realised that as the nucleus loses protons,
0:33:48 > 0:33:50the atom's identity changes.
0:33:50 > 0:33:54It turns from one element into another.
0:33:57 > 0:34:01We can glimpse radioactive decay in a cloud chamber.
0:34:04 > 0:34:09If you look carefully, you can see trails of vapour
0:34:09 > 0:34:12which are caused by alpha particles
0:34:12 > 0:34:14being spat out from the source.
0:34:14 > 0:34:16Now they are incredibly tiny,
0:34:16 > 0:34:19they're a hundred thousandth of the width of a single atom.
0:34:19 > 0:34:23They show radioactive decay.
0:34:25 > 0:34:30Rutherford was studying this when he suddenly realised
0:34:30 > 0:34:33that it could transform the atom of one element
0:34:33 > 0:34:34into the atom of another.
0:34:34 > 0:34:37So if that happened naturally,
0:34:37 > 0:34:41could it also be made to happen artificially?
0:34:41 > 0:34:45Could Rutherford deliberately create one element from another?
0:34:47 > 0:34:48Rutherford loved simplicity,
0:34:48 > 0:34:53and this simple piece of kit was his basic apparatus.
0:34:53 > 0:34:56He introduced a radioactive source at this end
0:34:56 > 0:35:01which blasted alpha particles toward the screen on the far end.
0:35:01 > 0:35:05When he filled the chamber with nitrogen,
0:35:05 > 0:35:08he saw flashes that weren't from the alpha particles.
0:35:10 > 0:35:14Rutherford suspected that a change was taking place.
0:35:14 > 0:35:18Now, the nucleus of nitrogen contains seven protons,
0:35:18 > 0:35:22whereas an oxygen nucleus has eight protons.
0:35:22 > 0:35:26Now, in Rutherford's experiment he was firing alpha particles,
0:35:26 > 0:35:28each one containing two protons,
0:35:28 > 0:35:31and these alphas were colliding with the nitrogen.
0:35:31 > 0:35:33This is where the alchemy takes place.
0:35:33 > 0:35:37Because the collision knocks out a single proton,
0:35:37 > 0:35:40these were what were causing the flashes on the screen.
0:35:40 > 0:35:45But what's left behind is now no longer nitrogen.
0:35:45 > 0:35:50The extra proton it's gained means that it has transmuted into oxygen.
0:35:52 > 0:35:56The small flashes on Rutherford's apparatus
0:35:56 > 0:35:59proved an explosive moment in science.
0:35:59 > 0:36:03Turning nitrogen into oxygen was as weird as stroking a cat
0:36:03 > 0:36:06and having it suddenly turn into a dog.
0:36:06 > 0:36:11A fire can reveal how different these two elements are.
0:36:13 > 0:36:15This is liquid nitrogen.
0:36:17 > 0:36:20See what happens when I pour it on the fire.
0:36:26 > 0:36:29The fire goes out.
0:36:29 > 0:36:32This is liquid oxygen.
0:36:40 > 0:36:42It burns much more brightly.
0:36:42 > 0:36:48Rutherford had turned one element into a completely different one.
0:36:51 > 0:36:53Scientists had previously believed
0:36:53 > 0:36:56elements were fixed and unchangeable.
0:36:56 > 0:37:00Now, Rutherford had proved that they could be transformed.
0:37:00 > 0:37:04This suggested another intriguing possibility.
0:37:06 > 0:37:11Rutherford's work, turning one known element into another,
0:37:11 > 0:37:14gave scientists hope that they could turn an element
0:37:14 > 0:37:16into a completely new one.
0:37:16 > 0:37:18For many years progress was very slow
0:37:18 > 0:37:21because they simply didn't know enough about the atom.
0:37:21 > 0:37:28Then in 1932, here in Cambridge, a crucial part of the atom was found.
0:37:28 > 0:37:31James Chadwick discovered neutrons.
0:37:34 > 0:37:39These are particles without an overall positive or negative charge,
0:37:39 > 0:37:44that along with positively charged protons, make up the nucleus,
0:37:44 > 0:37:46the heart of the atom.
0:37:48 > 0:37:53Italian scientist, Enrico Fermi, saw the potential of the neutron
0:37:53 > 0:37:57in the quest to make brand new elements.
0:37:57 > 0:38:00The team who worked with him thought he was infallible
0:38:00 > 0:38:03and nicknamed him "The Pope".
0:38:03 > 0:38:06Fermi's big idea was to create a new element,
0:38:06 > 0:38:09one beyond the end of the periodic table.
0:38:10 > 0:38:12Further up even than uranium,
0:38:12 > 0:38:16the heaviest naturally occurring element on Earth.
0:38:16 > 0:38:21If Rutherford could turn nitrogen into oxygen,
0:38:21 > 0:38:26Fermi wondered what would happen if uranium was made heavier still,
0:38:26 > 0:38:28by adding more protons to its nucleus.
0:38:29 > 0:38:34Could he go beyond nature and create a new element?
0:38:34 > 0:38:37Fermi experimented on uranium
0:38:37 > 0:38:40using Rutherford's technique of pounding the nucleus.
0:38:41 > 0:38:46Others had also tried using positively charged alpha particles,
0:38:46 > 0:38:50but so far no-one had succeeded in creating new elements.
0:38:51 > 0:38:54Then one day when Fermi was playing tennis,
0:38:54 > 0:38:58he realised where the other scientists were going wrong.
0:38:58 > 0:39:00He was hammering away at the tennis balls
0:39:00 > 0:39:03when he suddenly had a moment of true clarity.
0:39:05 > 0:39:09He knew that the nucleus of the atom is positively charged
0:39:09 > 0:39:11as are the alpha particles.
0:39:11 > 0:39:16So they tend to repel one another making it highly unlikely
0:39:16 > 0:39:19for the alphas to enter the nucleus. But then,
0:39:19 > 0:39:23it occurred to Fermi that if he used neutrons,
0:39:23 > 0:39:24particles with no charge,
0:39:24 > 0:39:27then the nucleus wouldn't repel them,
0:39:27 > 0:39:31making it much more likely that they would be able to penetrate it.
0:39:33 > 0:39:38So in 1934, Fermi began to experiment
0:39:38 > 0:39:43by shooting neutrons at the nucleus of uranium.
0:39:46 > 0:39:51Fermi was hoping that when the neutron entered the uranium nucleus,
0:39:51 > 0:39:53it would make the whole thing unstable.
0:39:53 > 0:39:57The nucleus likes to be balanced, so if it has too many neutrons,
0:39:57 > 0:40:00it will convert one of them into a proton,
0:40:00 > 0:40:02spitting out an electron.
0:40:02 > 0:40:07Fermi reasoned that this would increase the number of protons,
0:40:07 > 0:40:09giving him a brand new element.
0:40:11 > 0:40:15As he ran the experiment, Fermi found elements he didn't recognise.
0:40:15 > 0:40:17So what were they?
0:40:17 > 0:40:22He worked his way down the periodic table, checking for known elements.
0:40:22 > 0:40:27He tested for radon, actinium, polonium, all the way down to lead.
0:40:27 > 0:40:32The new elements were none of these.
0:40:32 > 0:40:37So in 1934 the man they called the Pope
0:40:37 > 0:40:40made a leap of faith.
0:40:40 > 0:40:43He proclaimed to the scientific world
0:40:43 > 0:40:48that he'd created elements heavier than uranium.
0:40:48 > 0:40:55Scientists were electrified and began to investigate Fermi's claim.
0:41:09 > 0:41:15In 1938, a team of German scientists led by chemist Otto Hahn
0:41:15 > 0:41:19decided to repeat Fermi's work.
0:41:19 > 0:41:20Only they quickly found
0:41:20 > 0:41:24that his claim to have created a new element was wrong.
0:41:27 > 0:41:30They identified one of his elements as barium
0:41:30 > 0:41:33which has 56 protons in its nucleus
0:41:33 > 0:41:37compared with the uranium he started with which has 92.
0:41:37 > 0:41:39Hahn was intrigued.
0:41:39 > 0:41:43It's as though uranium had been split in two.
0:41:53 > 0:41:57Hahn wrote of his confusion to a colleague, Lise Meitner,
0:41:57 > 0:41:59who was working in Sweden at the time.
0:41:59 > 0:42:03As an Austrian Jew, Meitner had recently fled Nazi Germany
0:42:03 > 0:42:06and was spending Christmas 1938
0:42:06 > 0:42:10at the seaside with her nephew, Otto Frisch.
0:42:10 > 0:42:13Meitner puzzled over the mystery
0:42:13 > 0:42:17and together with Frisch she considered the uranium nucleus.
0:42:17 > 0:42:21Because it's a relative giant it must be quite unstable.
0:42:21 > 0:42:26Then they started to think about water droplets,
0:42:26 > 0:42:29and Meitner imagined the uranium nucleus
0:42:29 > 0:42:31like a very wobbly, unstable drop
0:42:31 > 0:42:36ready to divide with the impact of a single neutron.
0:43:00 > 0:43:05She suddenly realised that the uranium's nucleus had split in two.
0:43:05 > 0:43:10Both Fermi and Hahn had witnessed what we now know as nuclear fission.
0:43:13 > 0:43:16Then Meitner worked through the calculations.
0:43:16 > 0:43:20She reckoned that the combined mass of the two fragments
0:43:20 > 0:43:25was slightly less than the mass of the original uranium nucleus
0:43:25 > 0:43:27by about a fifth of one proton.
0:43:27 > 0:43:31She wondered what had happened to this missing mass.
0:43:31 > 0:43:34Then it slowly dawned on her.
0:43:34 > 0:43:38Einstein's famous equation e=mc2.
0:43:38 > 0:43:43The missing mass had been converted into pure energy.
0:43:50 > 0:43:55Meitner's flash of insight heralded the creation of the nuclear age,
0:43:55 > 0:43:59where exciting possibilities for a new form of energy
0:43:59 > 0:44:02would be countered by its potential for weaponry.
0:44:09 > 0:44:14This site at Orford Ness used to be a military testing ground,
0:44:14 > 0:44:18one of the most secret places in Britain.
0:44:21 > 0:44:25Back in 1939, Lise Meitner's work on nuclear fission
0:44:25 > 0:44:29was published as war cast a long shadow across Europe.
0:44:29 > 0:44:33It shook not just the scientific community,
0:44:33 > 0:44:36governments who stood on the brink of conflict
0:44:36 > 0:44:39became aware of the extraordinary power
0:44:39 > 0:44:41that could now be wrought from an element.
0:44:41 > 0:44:46On both sides of the Atlantic, scientists were scrambled to
0:44:46 > 0:44:50investigate the potential of this new discovery.
0:44:50 > 0:44:53The result was the US led Manhattan project.
0:44:53 > 0:44:58Its aim was to produce the first atomic bomb.
0:44:58 > 0:45:01Using scientists from America,
0:45:01 > 0:45:06Canada and Europe, the 2 billion project's rapid progress
0:45:06 > 0:45:09was fuelled by fears that Nazi Germany
0:45:09 > 0:45:12was investigating nuclear weapons of its own.
0:45:16 > 0:45:20Both the Germans and the Allies knew that the uranium nucleus could be
0:45:20 > 0:45:25split by bombarding it with neutrons to release a huge amount of energy.
0:45:25 > 0:45:27But to be effective,
0:45:27 > 0:45:31that energy needed to be released almost instantly,
0:45:31 > 0:45:35a slow reaction would produce a uranium fire but no bomb.
0:45:35 > 0:45:40So both sides poured their efforts into perfecting
0:45:40 > 0:45:43the key to a rapid energy release on a grand scale.
0:45:44 > 0:45:46A chain reaction.
0:45:48 > 0:45:51Imagine this ping-pong ball is a neutron,
0:45:51 > 0:45:56flying towards an unstable uranium nucleus, a mousetrap.
0:45:56 > 0:45:58It sets off the mouse trap
0:45:58 > 0:46:03which in turn forces a new neutron into the air.
0:46:07 > 0:46:11Now in a chain reaction, this is what would happen.
0:46:11 > 0:46:14One neutron to set it off,
0:46:14 > 0:46:19but loads of mousetraps of uranium primed and ready.
0:46:26 > 0:46:29Now imagine each mousetrap of uranium releases a
0:46:29 > 0:46:33blast of energy, that same energy that Lise Meitner had calculated.
0:46:33 > 0:46:36The resulting blast would be enormous.
0:46:51 > 0:46:58In 1942, Italian physicist, Enrico Fermi, now living in America,
0:46:58 > 0:47:03became the first man to unleash uranium's chain reaction.
0:47:05 > 0:47:07Uranium.
0:47:09 > 0:47:11It harbours the power not only to win wars
0:47:14 > 0:47:16but to electrify millions of homes.
0:47:16 > 0:47:20Before its radioactive secrets were revealed,
0:47:20 > 0:47:23this element's glow under ultraviolet light
0:47:23 > 0:47:27made uranium glass a desirable asset.
0:47:27 > 0:47:33About seven weeks worth of your year's electricity
0:47:33 > 0:47:37comes from nuclear fission part fuelled by uranium.
0:47:37 > 0:47:39And it's used in tank shells
0:47:39 > 0:47:44as its great weight allows it to drive through armour.
0:47:47 > 0:47:54But processing uranium for bombs was both difficult and costly.
0:47:54 > 0:47:58America would need to come up with a suitable alternative
0:47:58 > 0:48:00to create its nuclear arsenal.
0:48:03 > 0:48:08In California, scientists were focussing on trying to create
0:48:08 > 0:48:10a new element heavier than uranium.
0:48:14 > 0:48:18The key to this was a machine called a cyclotron
0:48:18 > 0:48:23which gave rise to this giant machine, a synchrotron.
0:48:23 > 0:48:26Both machines operate on the same principle.
0:48:26 > 0:48:31They use huge magnets to steer charged atoms round and round,
0:48:31 > 0:48:33faster and faster.
0:48:33 > 0:48:37The magnets are so powerful that if one of them was switched on,
0:48:37 > 0:48:41it could rip a sledgehammer straight out of my hands.
0:48:41 > 0:48:44Now, the way to make a new element is to
0:48:44 > 0:48:49increase the numbers of protons in a nucleus of an existing element.
0:48:49 > 0:48:53And in a cyclotron, the way this was done,
0:48:53 > 0:48:55was that when the charged atoms
0:48:55 > 0:48:57reached a tenth of the speed of light,
0:48:57 > 0:49:02they were steered and smashed into a metal target,
0:49:02 > 0:49:04with the potential to create a new element.
0:49:07 > 0:49:12Finally, man's dream of creating a building block from
0:49:12 > 0:49:18beyond the end of the periodic table was about to be realised.
0:49:18 > 0:49:23American physicists, Edwin McMillan and Philip Abelson,
0:49:23 > 0:49:28blasted uranium with a beam of particles to create element 93.
0:49:35 > 0:49:37They named it Neptunium.
0:49:37 > 0:49:43The first element heavier than uranium to be created by man.
0:49:45 > 0:49:51Chemists were once limited to using the elements nature provided.
0:49:51 > 0:49:56Now science breached this frontier, creating synthetic elements.
0:49:56 > 0:50:01And, with this new power would come new dilemmas.
0:50:03 > 0:50:08In 1941, the next element to be forged by mankind
0:50:08 > 0:50:11would become infamous...
0:50:11 > 0:50:14it was called plutonium.
0:50:16 > 0:50:19Scientists quickly realised that
0:50:19 > 0:50:23plutonium was capable of undergoing nuclear fission
0:50:23 > 0:50:27in a way that could fuel an explosive chain reaction
0:50:27 > 0:50:30and it was soon being made into a bomb.
0:50:30 > 0:50:36The discovery of nuclear fission to the creation of the first atom bombs
0:50:36 > 0:50:39took less than 7 years.
0:50:39 > 0:50:41And on August 6th, 1945
0:50:41 > 0:50:47the full accuracy of Lise Meitner's scribbled calculations was revealed.
0:50:47 > 0:50:521,900 feet over the Japanese city of Hiroshima,
0:50:52 > 0:50:57one piece of Uranium 235 was fired into another,
0:50:57 > 0:51:00causing a rapid chain reaction.
0:51:00 > 0:51:05Just over half a gram of mass was converted into energy,
0:51:05 > 0:51:08that's one tenth of a 10p coin.
0:51:08 > 0:51:15But it exploded with a force equal to about 13,000 tonnes of TNT.
0:51:21 > 0:51:26Three days later, Nagasaki was hit by a plutonium bomb,
0:51:26 > 0:51:33bringing the death toll from the two bombs to an estimated 200,000.
0:51:46 > 0:51:48Plutonium.
0:51:48 > 0:51:51It was named after the planet Pluto
0:51:51 > 0:51:56and also shares its name with the Roman god of the underworld.
0:51:57 > 0:52:05Bombarding Uranium 238 with neutrons creates this powerful element.
0:52:05 > 0:52:10A gram of plutonium has same energy as a tonne of oil.
0:52:10 > 0:52:16Many of the Cold War's nuclear bombs contain plutonium.
0:52:16 > 0:52:21The first man made objects destined to leave our solar system,
0:52:21 > 0:52:23the two Voyager space probes,
0:52:23 > 0:52:25are powered by plutonium.
0:52:29 > 0:52:34The dream of turning lead into gold is what drove the early alchemists.
0:52:34 > 0:52:40And the dark race to create the atom bomb was a kind of modern alchemy.
0:52:40 > 0:52:45The war had revealed the frightening power of these unstable elements.
0:52:45 > 0:52:47But they had offered a tantalising glimpse
0:52:47 > 0:52:50into their infinite possibilities.
0:52:50 > 0:52:55The lure of scientific discovery, of creating entirely new elements
0:52:55 > 0:52:59at the extremes of the periodic table had proven irresistible.
0:52:59 > 0:53:05The thirst to create yet more elements drives the physicists
0:53:05 > 0:53:09at the GSI Helmholtz Centre for heavy ion research
0:53:09 > 0:53:11in Darmstadt, Germany.
0:53:13 > 0:53:17Their mission is to reach the limit of chemistry,
0:53:17 > 0:53:19to find the ultimate element
0:53:19 > 0:53:22which will stretch the laws of physics to their boundaries.
0:53:22 > 0:53:27So far, they have made six new elements.
0:53:27 > 0:53:33The latest confirmed is element 112, which they've named Copernicium,
0:53:33 > 0:53:36after the astronomer Copernicus.
0:53:38 > 0:53:41And this is where it all starts,
0:53:41 > 0:53:45in one of the world's most powerful nuclear accelerators.
0:53:47 > 0:53:52Scientists are using the high-tech equipment
0:53:52 > 0:53:54behind this 70 tonne lead door
0:53:54 > 0:53:58not only to make some of the heaviest elements ever created,
0:53:58 > 0:54:00but to study their properties,
0:54:00 > 0:54:04to try and understand their characteristics if you like.
0:54:04 > 0:54:06They're attempting to finish the work
0:54:06 > 0:54:09that chemists like Mendeleev started
0:54:09 > 0:54:14and to discover the secrets at the outposts of the periodic table.
0:54:14 > 0:54:17But they first have to create the new elements.
0:54:21 > 0:54:25This is the control centre for the giant accelerator,
0:54:25 > 0:54:30which is essentially a gun for firing one element into another.
0:54:30 > 0:54:32This small piece of zinc
0:54:32 > 0:54:35is identical to the sample used in the accelerator.
0:54:35 > 0:54:40Charged atoms of zinc are fired towards a lead target.
0:54:40 > 0:54:43Nearly 50 million volts of electricity
0:54:43 > 0:54:48accelerate these atoms towards the target so that when they collide,
0:54:48 > 0:54:52they are travelling at 67 million miles an hour.
0:54:52 > 0:54:56That's nearly 4,000 times faster than the space shuttle.
0:54:56 > 0:54:58The idea is that at this speed
0:54:58 > 0:55:02there's a chance the atoms might fuse together,
0:55:02 > 0:55:05creating an atom of a new element.
0:55:05 > 0:55:09In this case, element 112.
0:55:19 > 0:55:23But it's obviously not as simple as it sounds.
0:55:23 > 0:55:26Too much energy and the colliding atoms break up
0:55:26 > 0:55:30too little and the new element isn't created at all.
0:55:30 > 0:55:33In fact, even with the perfect energy
0:55:33 > 0:55:35the chances of union are remote.
0:55:35 > 0:55:38It's a bit like you winning the lottery
0:55:38 > 0:55:43with 3,000 balls to choose from rather than just 50.
0:55:48 > 0:55:49Beating these enormous odds,
0:55:49 > 0:55:54scientists have created new, single atoms,
0:55:54 > 0:55:58so unstable they only exist for seconds.
0:55:59 > 0:56:04But that's still long enough to determine some of their properties.
0:56:04 > 0:56:10In tests, element 112 has proven volatile and unstable
0:56:10 > 0:56:13and it reacts a little like mercury.
0:56:13 > 0:56:18It would be liquid at room temperature if enough were made.
0:56:18 > 0:56:23Because of that similarity its creators realised it should be
0:56:23 > 0:56:27positioned just beneath Mercury on the periodic table.
0:56:29 > 0:56:33Physicists here are becoming the new chemists.
0:56:33 > 0:56:38Soon they'll be attempting to create element 120.
0:56:38 > 0:56:44The discoveries made here at GSI may seem distant, even arcane
0:56:44 > 0:56:48but it's vital to push the periodic table to its limits.
0:56:48 > 0:56:52Without studying these man made, highly unstable elements
0:56:52 > 0:56:57we may never fully understand the story of our universe.
0:57:06 > 0:57:11My journey began with those alchemists whose daring experiments
0:57:11 > 0:57:14led to the discovery of many of the elements.
0:57:14 > 0:57:17They paved the way for the early chemists
0:57:17 > 0:57:20whose mission to find out what the world is made of led to
0:57:20 > 0:57:25them splitting matter and bringing order to the seemingly random chaos
0:57:25 > 0:57:31of the elements, culminating in the creation of the periodic table.
0:57:31 > 0:57:35Scientists were able to use these discoveries
0:57:35 > 0:57:40and the ordering of the elements to build the modern world.
0:57:40 > 0:57:45Finally, they could command nature's building blocks to their will.
0:57:46 > 0:57:50But our story is still far from finished.
0:57:50 > 0:57:52The fleeting glimpse we've had
0:57:52 > 0:57:55of the exotic outposts of the periodic table
0:57:55 > 0:58:00gives a hint to what the story of the elements may yet hold.
0:58:00 > 0:58:02Their possible reactions,
0:58:02 > 0:58:06their properties, their unimagined potential.
0:58:06 > 0:58:10And that is what scientists now have to work on,
0:58:10 > 0:58:15to reveal the secrets the elements have so far refused to surrender.
0:58:15 > 0:58:21What's so exciting is that no-one knows where that part of this
0:58:21 > 0:58:24astonishing story may yet take us.
0:58:34 > 0:58:38Subtitles by Red Bee Media Ltd
0:58:38 > 0:58:42E-mail subtitling@bbc.co.uk