100 Greatest Discoveries (2004) s01e03 Episode Script
Chemistry
For us, life unfolds on human scales Miles Feet Inches But beneath the surface of things is another round, a billions times smaller than we are.
A dimension that hold the secrets in understanding our world What makes steal strong Why ice cream is delicious What makes life possible Secrets that help us create what we imagine The human creativity of chemistry there is just nothing more beautiful than it This is the realm of chemistry And these are the greatest discoveries Ancient great philosophers believed that there were just four elements Earth, air, fire and water And the air was the underlying element.
A single substance responsible for the makeup of everything in the world Centuries later, Leonardo Da Vinci was among the first to suggests that instead of being an element, air might consists of two different gases It remained a mystery until our first great discovery.
England, the later part of eighteenth century clergy man and sometimes scientist Joseph Priestley conducted a serious of experiments searching for new airs What today we called gases To find out more about what Priestley was up to, I paved a visit to Arnold Thackray.
President and historian in the Chemical Heritage Foundation in Philadelphia Pennsylvania Priestley wrote and wrote and wrote on every subject that you have thought of.
He wrote about history.
He wrote about religion.
He wrote about politics Science He wrote about science endlessly.
And Priestley was among who knew everything.
He would tell you the principle of it,the history of it, the theory of it and he was quiet literally the man who knew everything.
But along with everything else, Priestley did his famous experiment right That's exactly correct.
And there are two things that go into that experiment.
The one is mercury, this strange substance simultaneously a liquid and metal.
And that's just crazy, I mean, whoever heard a liquid metal.
And so it was really puzzling what is this thing and people were fascinated by it, and so they want to explore it And cause another thing went into it, was the technology to deal with gases.
And here in Priestley's experiments and observations on different kinds of it We have the technology of collecting gases over liquids In tubes, you can see through.
Exactly, so you can see the gas, you can see what's happening to the gas And now, you really are in business What Priestley dose is takes a burning glass to get around heat lens He focuses it on this orange powder, the mercuric cawks He heats it, changes it in to this metal mercury and a gas comes off But Priestley doesn't really realize what it is that he has found The answer was emerged in 1774, after Priestley paved a visit to Paris And shared the story of his discovery with another scientist Antoine Lavoisier Paris was a marvelous place for Priestley to visit because Antoine Lavoisier is in Paris talk of the town Doing the work that will end up as his" elementary text on chemistry" And Lavoisier who is also marking about with the gases He has aware of what Priestley has done He's fascinated by the report on the new air, decides to repeat the experiment He has lots of apparatus, better apparatus.
He is a meticulous lab experimenter And among all the things, he weighs the things Lavoisier by weighing says something being emitted.
He called the thing emitted, oxygen.
He rewrites the whole script of chemistry And he creates a list of elements that we still use today Oxygen, hydrogen, sulfur You can correctly say that Priestley discovered oxygen But Lavoisier invented it.
So, with Priestley's experimental work on gases, with the discovery of oxygen, And with Lavoisier I 's articulation of the system of language We have the whole conceptual skim which 19th century's academic works is built 20th century's industrial innovation.
We have pharmaceuticals, we have biotechnology, we have cell phones We have plastics That's exactly right And all these things begin with the discovery of oxygen.
That's where it starts That's a lot to breed in.
In the early 19th century, a British god teacher named John Dalton was hard at work, pursuing the fascination with chemistry Which would lead to our next great discovery.
Dalton's experiments showed that the known elements such as the oxygen, hydrogen and carbon, combined in definite inconstant proportions From his calculations, he hypothesized that the elements must be made up of smaller invisible pieces of matter.
With relatively distinct weights.
He called these pieces of matter atoms So, what did Dalton discover Dalton's great discovery was what he called the relative weights of ultimate particles.
Ultimate particles.
That's what he called it.
It's a lovely phrase.
Later on, when he went public, it becomes atomic weights And we know it as atomic weights, but it was ultimate particles So, he used the word atoms.
He used the word atoms And the idea of atoms calls goes, back to Democritus.
The problem is, is the idea, is it in use.
And Dalton was the man who made the idea useful.
That was his great contribution Form his work, Dalton developed what came to be known as his atomic theory A revolutionary new system that defined the relationship between the atoms and the elements.
And this is enormously simple system and Dalton thinks very simply, very visually.
Here are the elements.
Here are the weights of the elements.
Here are the complex molecules.
And it's a wonderfully effective system It connects the thing that chemists can do weighting and balancing with the thing that you can't see The ultimate world of atoms.
That's genius.
How important was Dalton's discovery His atoms theory helped generations of scientists further unravel the mysteries of the atomic and molecular world.
Including our next great discovery.
In the early 18th hundreds, French chemist Joseph Gay-Lussac Was conducting a series of experiments, designing to study the Dalton's atomic theory, when he observed something odd When he combined equal volumes of different gases and measured their reactions The gases often produces twice the volumes than he expected.
How was this possible The answer was provided in 1811 by Amedeo Avogadro, a physics professor at the University of Turin in Italy.
While he studying the results of Gay-Lussac's research, Avogadro had an insight At the time, it was believed that the gases remained of single atoms.
Avogadro realized that this assumption was wrong The gases were remained of multiple atoms.
What came to be known as molecules.
The realization that the atoms could be rearrange to form molecules was the breakthrough that enable scientists to move out the chemistry dark ages.
And began systematically creating new compounds.
Our next great discovery occurred in the 19th century.
When many chemists believed that organic substances from organisms or living things Were somehow different from inorganic substance, from nonliving things.
But that was about to change.
In 1828, Frederick Waller was working in his lab, when something caught his eye.
Waller had placed two inorganic chemical in a beaker, potassium cyanate and ammonia sulfate Now, when you looked at the beaker, it contained a gram of small, white, niddle shaped crystals what made this remarkable was that Waller thought he had seen exactly the same crystals once before But there were important difference.
Those crystals had been organic.
He had crystallized them or studied the chemistry of various substances found in urea.
To make sure he wasn't mistaken, Waller analyzed the new crystals.
There was no mistake.
These crystals were the same as those he had isolated before He had made urea, which was something that come out of living thing he had made out of inorganic substance.
Later he said in a personal letter in a paper he wrote about that I had made urea without kidney.
And he knew what he had done Meet Roald Hoffmann, winner of the 1981 Nobel Prize in chemistry For developing a theory to explain organic chemical reactions So why is this discovery of artificially making urea, why is that a great discovery.
You know, in a constant of time when you need a discovery that sometimes a single one to cross a border, to break down the wall This is what this discovery was.
It's not that it was so important of itself.
But at the time that came the simple making of urea out of two inorganic chemicals When it came, it caught people's attention.
The whole story of the discovery is about the underlying basis that building blocks of all matter organic and inorganic.
Being the same, atoms.
If these LEGO Bricks had existed in the early part of 19th century, chemists could use them to help illustrated something they were seeing in their experiments A phenomena that led to our next great discovery.
The atoms of particular elements such as Sodium and chlorine seem to combine with each other according to fix ratios.
It was this combining power atoms that inspired German chemist August Kekule To develop a system for visualizing the chemical structure of various molecules.
Kekule represented the atoms by their symbols.
Then added marks to indicate how they bodied with each other.
Like links and chains.
It was a simple yet elegant formula.
Chemists now had devised for clearly illustrating the chemical structures of the molecules they were studying.
There was just one problem; benzene was the only chemical that was not fit Kekule's formula Benzene 's chain of carbon and hydrogen atoms required more combing power than the formula would allow.
And all these organic chemistry professors were puzzling about it, offering different explanations.
And one of them, August Kekulei sitting by the fire one of the evening, falls to sleep And starts to dream about a snake.
And if you think about the snake what kekule dreams off is a snake catches its own tail And if you think about this, May be, the thing is a ring.
And that gives you an answer to the puzzle.
The 6 carbon atoms of the Benzene molecules linked in a chain.
Like the snake it formed a ring.
Each of the hydrogen atom attached with alternating single and double bond Within a short time, kekule's insight was confirmed.
And its effect was revolutionary.
Chemists knew that all organic substances contained one or more carbon atoms in their molecules with kekule's discovery, they now had the underlying formula to how carbon combined with other molecules To form a world of chemical compounds.
The modern era of organic chemistry was born Now,with this thing being simple.
like it say the snake bite to its tail Why is this considered a great discovery Here is a recipe for new drugs, new medicine, new understanding To go back at time in Dalton's day, couple of hundreds compounds, soon as couple of thousands, soon as ten thousands, it 's astonishing, soon as hundreds thousands Last year, fifteen million new compounds were registered.
All built on this simple template.
This is the work of genius.
In 1869, a Russian chemistry professor named Dmitry Mendeleyev was writing a text book for his students When he began to wonder how he could be best explain them the 63 elements that were known at the time Help formulating thoughts, he constructed a card for each element On each card, he wrote the name of the element, its atomic way, its typical properties and its similarities to other elements He then laid the card like a game of solitary And began to arrange them over and over, searching for patterns Then came the moment of discovery.
Before him is something extraordinary The elements fell into 7 vertical groupings Each periodical grouping had members that resemble one and other, both chemically and physically.
Mendelevium had discovered the periodical table of the elements a map showing how all the elements related to one and another.
A map so precise that Mendelevium believed he could also use it to predict the existence and properties of three elements known yet to discovered.
One would like be boron on he said.
One like aluminum and one like silicon.
Eventually, the elements were discovered.
And Mendelevium was proved right.
It was actually a little bit of controversy because German chemist named.
Lothar Meyer had come up with roughly the same idea.
But Meyer didn't quiet have as much courage, so that's actually interesting thing Here this German come up with the same idea of periodicity of which there were hints already before But he doesn't like the predictions like Mendeleev does.
So, here we see the power of our risky prediction In having people accept a theory.
There is nothing more powerful than making a prediction that is not obvious And have it come true.
Yes have it come true.
The periodical table is our icon.
I mean that's what we associate with chemistry You going to any chemistry room you'll see it Why is the periodical table of elements significant It forever changed the way that everyone would learn and understand the elements.
The periodical table of elements is to chemistry as notes of music are to Beethoven's sonata.
And in honor of Mendeleev, his name is now literally attached to the periodical table The element 101 was named after him.
It's called mendelevium It's not only the chemists who like the periodical table.
I hear you carry one around.
I do carry one.
Yes sure.
Show me.
You 'll never know And I seem to use it a lot.
Let's see.
This is small So I am going to give you a test.
What's under nitrogen in periodical table Nitrogen is seven.
Yes.
I have to think of a second.
It's sulfur No, you are wrong so I carry it often.
So, it's phosphorus.
Oh.
Phosphorus.
Phosphorus is 15.
Yeah.
You have to add 8 that point.
Yes, that's why I carry it.
I can't remember.
So it's seven plus eight, fifteen phosphorus.
it's ok.
There is a pattern there.
I get it now.
At the turn of the nineteenth century, electricity was all the rage People were busy making batteries and connecting them just about anything to see the reactions.
Electricity was like a new kind of fire.
One of the great battery junkies of the day was Humphrey David, a self-taught English chemist In 1807, David was performing a battery experiment in his lab.
He melted some potash aluminum found in the ground that also forms in the ash's wood.
Chemists had speculated that potash was a compound of several elements, but are not able to prove it.
David wanted to see if electricity might provide the answer He reared some wire from one of his biggest batteries to the molten potash Pure potass began to emerge David had discovered the power of electricity to react to chemicals and transform them.
Eventually, electrical chemistry led to the rise of aluminum industry The production of semiconductors.
Solar panels.
LED displaces.
Even rechargeable Li-ion Batteries In the eighteen fifties, Robert Bunsen and his research collaborator Gustav Kirchhoff conducted a serious of experiments.
To determined why substances emitted specific colors When placed in a flame The color they determined indicates what elements are present in the substance.
For example, if sodium is place in a flame, they observed sheaves of yellow Copper, sheaves of green Strontium, sheaves of red Oh it's a good one.
While watching the experiments, Kirchhoff was reminded that how a prism spreads light into a rainbow of colors So, using a prism and a piece of small telescope.
Bunsen and Kirchhoff built the first spectroscope.
And analyticale device they hope would help them to see the spectra coming from heated substances.
And it worked.
As an element was put into a flame of a Bunsen burn, the light from the heated substances passed through the prism of the spectroscope.
Where they spread into a ribbon-like spectrum of colors, riddled with dark lights.
The combinations of bright colors and dark lines were like bar codes Indicating what atoms were present.
When burned, each element produced a completely unique spectrum.
Using their spectroscope, Bunsen and Kirchhoff were able to discover two new elements Cesium and rubidium.
One day, Bunsen and Kirchhoff decided to test their invention with the sunlight It produced the spectrum that featured two lines that were identical to those in the spectrum produced by sodium Bunsen and Kirchhoff had discovered the presence of sodium in the sun ninety three million miles away Suddenly, scientists had the tool to help them study the chemistry of the heavens.
Lifted off.
We have lifted off.
Today, the legacy of this great discovery lives on the exploration of the space.
A formal spectrum has been used to study the atmosphere of the planets, to search for signs of water, signs of life.
Our next great discovery is the story of Joseph Thomson and the electron.
So, everything that we can see is made of chemicals That's right.
What's the future They are all bounded as electronic actions.
To find out about it, I paved a visit to Harvard University.
Dudley Herschbach is a professor here and the winner of the 1986's Nobel Prize in chemistry.
For his research in the dynamic chemical elementary processes.
So, Thomson didn't discover the electrons.
Well, it's said that way, but he didn't discovering it said " Here it got, I've got this things.
Here it is.
" He did experiment it a lot and did measure the ratio of the charge, the electric charge, the mass.
And later he got a rough measurement of the charge, and therefore showed the mass was very very small.
It was about one to thousand to the mass that light is known as atoms, hydrogen atom.
So, it showed that he could expect a very small piece of an atom All, I was command a shock, Punch attended.
Yes.
The electrical piece from atoms was a very small part of the atom.
At the time of his discovery, Thomson was the professor of England University of Cambridge.
He was using a device called the Crookes tube in his experiment.
I happened to have here a little apparatus that's akin to the one that J.
J Thomson used in 1897 It's called a Cathode Ray Tube Just evacuated its little glass cylinder, with some electros And we can hook this up.
So, the key points of this experiment is very simply.
The replica of the first CRT.
Yeah.
It's the first cathode ray tubes is the accentor of the television tubes as a matter of fact.
You do the last one, and we should get the stream the cathode rays or electrons.
Going there and showing of banning in this phosphor cold piece of cupboard there.
Here I give you a magnetic field and you use to deflect the electrons.
When Thomson exposed the cathode ray to a magnet The stream would bend, since magnets could only affected matter.
This one of stream of rays were composed of kind of electrically charged substance, called radiated matter.
After many hours of observing and measuring, Thomson realized he'd found the first sub-atomic particles.
The ray was a stream of electrons.
It was a revolutionary discovery.
Some years later, student of Thomson Ernest Rutherford was able to show that the positive charge of the atoms Which is there to balance the negative charge of the electrons which was scooting around, was localized in a tiny tiny nucleus.
Hundred thousand of times smaller than the size atoms.
So, almost all the mass was of course in that nucleus as well Well, because electrons are so light, And that's still the model we have today.
That's the basic model for atoms and is the key on understanding the everything involving this Like chemistry.
Yes like chemistry particular.
That's right.
Scientists were just beginning to discover the anatomy of the atom Now, they wonder to understand its behavior Specifically the mechanism that enabled the atoms of certain elements to combine with the atoms of the other elements to form new substance.
In the early nineteenth hundreds, American chemist Gilbert Lewis developed a model of the atoms that provided an answer That's he who explained the electrons in atoms The chemistry about electrons, not about nucleus That the electrons in atoms went in shells around the nucleus In Lewis's model of the atoms, each shell allowed only maxima number of electrons Lewis theorized that two chemical elements might combine to form a compound, When they give up or accept electrons from their outer shells.
For example, on their own, sodium and chlorine are hazardous But when a single sodium atom gives up the electron from its outer shell and the single chlorine outer shell accepts it This exchange allows the two to combine And form the compound sodium chloride, table salt Gilbert Lewis's theory was an extraordinary breakthrough.
It enables scientists to begin making chemical compounds Millions of them, compounds that shift the face of modern life Our next great discovery stared in the 1890 With the discovery of unknown radiation called x-rays It caused sensation and scientists immediately began looking for other substances that made it strange, perhaps valuable forms of radiation.
Over the next several decades, a number of scientists investigated the phenomena And together ended up shedding the light on one of the greatest scientific snooping episodes of modern science.
French physicist Henri Becquerel made the first significant breakthrough.
In 1896, he conducted a series of experiments to see a various of minerals emitted radiation One of the mineral he happened to tests was uranium Becquerel's technique was to place different objects on top of an unexposed photographic plate, still wrapped in black paper Which sprinkled uranium onto another piece of black paper, then enclosed the object between the uranium and the photographic plate.
Later Becquerel were developed the plate and without fail a ghostly photographic outline of the object would appear.
From these experiments Becquerel was able to prove conclusively.
That he had found a source for the mysterious radioactive rays that everyone was looking for.
That source was uranium.
From Becquerel, the investigation of radio activity was taken up by Marie Curie.
Curie and her husband Pierre undertook the job of isolating whatever elements were responsible for the radio activity in uranium ore For two years, the curies boiled, sifted, filtered and processed several tons of uranium ore.
Finally, they succeeded in isolating two new elements containing the uranium which they called polonium and radium.
Marie curie concluded that radium was a million times more radioactive than uranium.
More importantly, she determined that the mysterious form of energy which enabled radioactivity to penetrate other materials Was not a result of chemical process, but seemed to be atomic in nature Unfortunately, her discovery came at a great cost.
The danger of being exposed to radioactivity was still unknown at the time.
In 1934, Marie curie died of leucocythemia Believed to be caused by radiation poisoning Even the notebook that she use to record observations, are still considered too radioactive to handle.
It was the atomic nature of radioactivity that eventually attracted the interest of physicist Earnest Rutherford, Whom we already mad the discovery of the electron Rutherford found that radioactive material go through a natural process of decay.
As the move soothe the process, the radioactivity spontaneously emits unstable and highly charged particles, with the power to penetrate matter Rutherford called them alpha and beta particles and gamma rays Since those discoveries, we've learned a lot about radioactivity, the dangers as well as the benefits.
Radioactivity has given us medical imaging A treatment for tumors A method for calculating the age of the earth And the power source for our space craft to explore the solar system Even some smoke detectors contain a small amount of radioactive material called americium Which helps create steady electrical current.
A smoke particles disrupt that current and the triggers alarm Centuries ago, alchemist set their sights high.
They thought infinite welfare and immortality through miraculous transformation of matter.
They came up with useful tools and glassware, But not majels chemists on the other hands, set their sights a bit lower.
And ended up changing the look and feel of the material world As did our next great discovery.
In the eighteen sixties, John Hyatt, a printer and amateur chemist in orbital in New York Made news when he discovered a way to explore the long stringing molecules of cellulose found naturally in plants and created the first plastic Fifty years later, Belgian born chemist Leo Baekeland took the next step in the discovery process One of the greatest pioneer was Leo Baekeland, who made a polymer called Bakelite.
The usual thing transfavorring the prepared man He was make the same things.
But he knew how to explore them.
He saw the interesting properties of this.
From two chemicals derived from coal, Baeckland discovered the wourld's first fully-sympathetic plastic And the landscape of the twenties century's was forever changed What exactly is a plastic.
Plastics are polymers.
So what are polymers.
Polymers are long chain molecules, not individual molecules that plumed up into any solitary or some sort They are really molecules that can stand out very far.
Chains of carbon atoms sometimes with some other elements So, what are the advantages.
Well, it's mutable.
You can pour it in some liquid form into some modes, Stranks that's not bad.
You can made bullet-proof vest from plastics and we've certainly seen that in terms of fibers they can mimic or even surpass the properties of natural fibers No fisherman in the world is going to go back to having nets out of cotton.
You can bet.
those nets are goanna be of nylon So, would you say the discovery of plastics is a great discovery.
We have science making polymers, making nylon, making rayon which has natural starting point But is modified into a polymer, making Plexiglas or polyethylene.
Those are the structure of our material of civilization I think polymers are, in that sense, a example of human creativity of chemistry.
That's there is nothing more beautiful than them The single gram of black powder costs five hundred dollar.
About 30 times of the price of gold Remarkably, it is a special kind of soot.
Made of molecules called carbon nanotubes Each nanotubes is about one billion of a meter in diameter Thinner than a strand of DNA.
Yet full of the world's promise that lots of people excited.
Including the scientists who helped discover them.
Richard Smalley is a professor of chemistry of Rice University in Huston Taxas.
In 1985, he and fellow chemists Robert Cole and Harold Crotone were studying chemical conditions in outer space.
Using sophisticated laser and spectroscopic equipment.
They were searching for evidence that might help reveal chemical nature of interstellar matter Instead, they found something else.
For which they shared the 1996's Nobel Prize for chemistry.
What exactly did you discover Well, in 1985, over a period of week, we discovered that there was one special cluster of carbon atoms That had precisely 60 atoms.
That was magic, it was specially stable compared with any other cluster.
And we wondered why.
Smalley, Crotone and Cole named the new molecules Buckyballs After Buckminster Fuller, the architect designed the geodesic dome What they really discovered was a whole new cluster of large all-carbon molecules.
Which came to be called fullerenes Molecules are not just when some atoms start together by good bonds There's another proper molecules and that's when you put the last atom, it's kind of clicks.
It's done.
It's stable.
And if you offer another atom, it says no, I am happy the way I am.
And that's what C60 was.
We were offering other carbon atom in the apparatus we built, and it said, no I am gonna stay with the 60.
So, here's the molecule, and this was a molecule my mind are same to explain the results, which has the most symmetry of any molecules ever discovered The big thing is about an nanometer in diameter, a ten extra emmi, an nanometer a billion to a meter.
In 1991, the significance of fullerenes gave even more momentum when Sumio lijima, a scientist at NEC cooperation, discovered yet another category of cage like wonders But these fullerenes were slightly different.
They were made of hollow molecules of pure carbon that form a seamless hollow tube called carbon nanotubes Or in honor of Smalley's discovery, buckytubes.
There's buckyballs right Yes.
And then there is buckytubes.
Yes, I've got, this is get off a big now, a tube of the diameter of ball is this big This is, this is a fullerene same sort of structure.
And here's the pentagon.
Here's the hexagon.
There are six pentagon here, six pentagon here, twelve total and between all this hexagon So, this thing is sort of bucky capsule But you can imagine the thing very long and in fact the things are made millions of times longer than their diameter now.
And these objects have incredible properties Like what Well, for one thing, if you hold, say, these plastics objects, which I could easy break it apart But if you hold buckytube in your hand, you had the poly.
You could find the stiffest object in the universe.
Stiffer than steel.
Stiffer than steel.
Stiffer than diamond.
Stiffer than diamond But you are a big guy compel it; you'll find you could strike out quite big before breaks And we expect we'll find that it's a hundred time stronger than steel in tension.
The strongest fiber which you could ever make up anything ever.
I was mean like a million years later, when you ask me now the strongest thing same thing.
Something has to be the strongest of all the possible objects.
This is it.
It's just carbons So, you could take coal, sewage, old rubber tires and convert them into buckytubes Think we can do with this.
So we can rewire the world We can make electrical cables that conducted electricity better than copper and one six its weight.
So, when you think about this, does it seem too to be true.
Does it seem magical.
It does.
How about the chance that you can discover something like this.
But, that's one of the fascinating things about those current statues of our understanding chemistry and physics.
In fact, we can calculate the behavior of things very well in The big mystery was buckyballs and its tubes is not that they were be great if you could make them It was finding out you could actually make them Carbon nanotubes is one of the reason that the word Nano Technology become so well-known.
Some are describing they are modern day's industrial revolution.
Nano Technology refers to building things from scratch, like this nano-motor It's the ability to assemble the atomic and molecular building blocks of nature To create a new generation of product applications that's stronger and more precise.
Is this the next round of chemistry Is this the next thing in chemistry I am glad to see you use the word chemistry about this because that's really what this is.
We can't afford to pick every atom up our fingers and put them.
We have to have atoms self-assemble.
And they have confronted some source of cheap atoms.
So, we can make this efficiently.
We have name for that.
we called it chemistry.
of course these days, we called it Nano Technology The same thing.
We are after to make a structure of particular exact form And do it hundreds of trillions of time a second, low cost with no environmental impact To give us an object that would allow us to do something had logically we could do another ones do.
Making objects with, if were really good, the ultimate level of finesse with nature always built the molecules of living cells.
We now do this everywhere.
So it keeps you coming to work.
Yes, there is certain romance about it.
It takes only two centuries to go from a time when atoms were mere hypothesize to the break would be able to snap atoms and molecules together and build new technology with fantastic possibilities.
The great discoveries that we just seen helped make it happen.
Exploring the beneath of the surface thing, inside the realm of chemistry, and changing the world
A dimension that hold the secrets in understanding our world What makes steal strong Why ice cream is delicious What makes life possible Secrets that help us create what we imagine The human creativity of chemistry there is just nothing more beautiful than it This is the realm of chemistry And these are the greatest discoveries Ancient great philosophers believed that there were just four elements Earth, air, fire and water And the air was the underlying element.
A single substance responsible for the makeup of everything in the world Centuries later, Leonardo Da Vinci was among the first to suggests that instead of being an element, air might consists of two different gases It remained a mystery until our first great discovery.
England, the later part of eighteenth century clergy man and sometimes scientist Joseph Priestley conducted a serious of experiments searching for new airs What today we called gases To find out more about what Priestley was up to, I paved a visit to Arnold Thackray.
President and historian in the Chemical Heritage Foundation in Philadelphia Pennsylvania Priestley wrote and wrote and wrote on every subject that you have thought of.
He wrote about history.
He wrote about religion.
He wrote about politics Science He wrote about science endlessly.
And Priestley was among who knew everything.
He would tell you the principle of it,the history of it, the theory of it and he was quiet literally the man who knew everything.
But along with everything else, Priestley did his famous experiment right That's exactly correct.
And there are two things that go into that experiment.
The one is mercury, this strange substance simultaneously a liquid and metal.
And that's just crazy, I mean, whoever heard a liquid metal.
And so it was really puzzling what is this thing and people were fascinated by it, and so they want to explore it And cause another thing went into it, was the technology to deal with gases.
And here in Priestley's experiments and observations on different kinds of it We have the technology of collecting gases over liquids In tubes, you can see through.
Exactly, so you can see the gas, you can see what's happening to the gas And now, you really are in business What Priestley dose is takes a burning glass to get around heat lens He focuses it on this orange powder, the mercuric cawks He heats it, changes it in to this metal mercury and a gas comes off But Priestley doesn't really realize what it is that he has found The answer was emerged in 1774, after Priestley paved a visit to Paris And shared the story of his discovery with another scientist Antoine Lavoisier Paris was a marvelous place for Priestley to visit because Antoine Lavoisier is in Paris talk of the town Doing the work that will end up as his" elementary text on chemistry" And Lavoisier who is also marking about with the gases He has aware of what Priestley has done He's fascinated by the report on the new air, decides to repeat the experiment He has lots of apparatus, better apparatus.
He is a meticulous lab experimenter And among all the things, he weighs the things Lavoisier by weighing says something being emitted.
He called the thing emitted, oxygen.
He rewrites the whole script of chemistry And he creates a list of elements that we still use today Oxygen, hydrogen, sulfur You can correctly say that Priestley discovered oxygen But Lavoisier invented it.
So, with Priestley's experimental work on gases, with the discovery of oxygen, And with Lavoisier I 's articulation of the system of language We have the whole conceptual skim which 19th century's academic works is built 20th century's industrial innovation.
We have pharmaceuticals, we have biotechnology, we have cell phones We have plastics That's exactly right And all these things begin with the discovery of oxygen.
That's where it starts That's a lot to breed in.
In the early 19th century, a British god teacher named John Dalton was hard at work, pursuing the fascination with chemistry Which would lead to our next great discovery.
Dalton's experiments showed that the known elements such as the oxygen, hydrogen and carbon, combined in definite inconstant proportions From his calculations, he hypothesized that the elements must be made up of smaller invisible pieces of matter.
With relatively distinct weights.
He called these pieces of matter atoms So, what did Dalton discover Dalton's great discovery was what he called the relative weights of ultimate particles.
Ultimate particles.
That's what he called it.
It's a lovely phrase.
Later on, when he went public, it becomes atomic weights And we know it as atomic weights, but it was ultimate particles So, he used the word atoms.
He used the word atoms And the idea of atoms calls goes, back to Democritus.
The problem is, is the idea, is it in use.
And Dalton was the man who made the idea useful.
That was his great contribution Form his work, Dalton developed what came to be known as his atomic theory A revolutionary new system that defined the relationship between the atoms and the elements.
And this is enormously simple system and Dalton thinks very simply, very visually.
Here are the elements.
Here are the weights of the elements.
Here are the complex molecules.
And it's a wonderfully effective system It connects the thing that chemists can do weighting and balancing with the thing that you can't see The ultimate world of atoms.
That's genius.
How important was Dalton's discovery His atoms theory helped generations of scientists further unravel the mysteries of the atomic and molecular world.
Including our next great discovery.
In the early 18th hundreds, French chemist Joseph Gay-Lussac Was conducting a series of experiments, designing to study the Dalton's atomic theory, when he observed something odd When he combined equal volumes of different gases and measured their reactions The gases often produces twice the volumes than he expected.
How was this possible The answer was provided in 1811 by Amedeo Avogadro, a physics professor at the University of Turin in Italy.
While he studying the results of Gay-Lussac's research, Avogadro had an insight At the time, it was believed that the gases remained of single atoms.
Avogadro realized that this assumption was wrong The gases were remained of multiple atoms.
What came to be known as molecules.
The realization that the atoms could be rearrange to form molecules was the breakthrough that enable scientists to move out the chemistry dark ages.
And began systematically creating new compounds.
Our next great discovery occurred in the 19th century.
When many chemists believed that organic substances from organisms or living things Were somehow different from inorganic substance, from nonliving things.
But that was about to change.
In 1828, Frederick Waller was working in his lab, when something caught his eye.
Waller had placed two inorganic chemical in a beaker, potassium cyanate and ammonia sulfate Now, when you looked at the beaker, it contained a gram of small, white, niddle shaped crystals what made this remarkable was that Waller thought he had seen exactly the same crystals once before But there were important difference.
Those crystals had been organic.
He had crystallized them or studied the chemistry of various substances found in urea.
To make sure he wasn't mistaken, Waller analyzed the new crystals.
There was no mistake.
These crystals were the same as those he had isolated before He had made urea, which was something that come out of living thing he had made out of inorganic substance.
Later he said in a personal letter in a paper he wrote about that I had made urea without kidney.
And he knew what he had done Meet Roald Hoffmann, winner of the 1981 Nobel Prize in chemistry For developing a theory to explain organic chemical reactions So why is this discovery of artificially making urea, why is that a great discovery.
You know, in a constant of time when you need a discovery that sometimes a single one to cross a border, to break down the wall This is what this discovery was.
It's not that it was so important of itself.
But at the time that came the simple making of urea out of two inorganic chemicals When it came, it caught people's attention.
The whole story of the discovery is about the underlying basis that building blocks of all matter organic and inorganic.
Being the same, atoms.
If these LEGO Bricks had existed in the early part of 19th century, chemists could use them to help illustrated something they were seeing in their experiments A phenomena that led to our next great discovery.
The atoms of particular elements such as Sodium and chlorine seem to combine with each other according to fix ratios.
It was this combining power atoms that inspired German chemist August Kekule To develop a system for visualizing the chemical structure of various molecules.
Kekule represented the atoms by their symbols.
Then added marks to indicate how they bodied with each other.
Like links and chains.
It was a simple yet elegant formula.
Chemists now had devised for clearly illustrating the chemical structures of the molecules they were studying.
There was just one problem; benzene was the only chemical that was not fit Kekule's formula Benzene 's chain of carbon and hydrogen atoms required more combing power than the formula would allow.
And all these organic chemistry professors were puzzling about it, offering different explanations.
And one of them, August Kekulei sitting by the fire one of the evening, falls to sleep And starts to dream about a snake.
And if you think about the snake what kekule dreams off is a snake catches its own tail And if you think about this, May be, the thing is a ring.
And that gives you an answer to the puzzle.
The 6 carbon atoms of the Benzene molecules linked in a chain.
Like the snake it formed a ring.
Each of the hydrogen atom attached with alternating single and double bond Within a short time, kekule's insight was confirmed.
And its effect was revolutionary.
Chemists knew that all organic substances contained one or more carbon atoms in their molecules with kekule's discovery, they now had the underlying formula to how carbon combined with other molecules To form a world of chemical compounds.
The modern era of organic chemistry was born Now,with this thing being simple.
like it say the snake bite to its tail Why is this considered a great discovery Here is a recipe for new drugs, new medicine, new understanding To go back at time in Dalton's day, couple of hundreds compounds, soon as couple of thousands, soon as ten thousands, it 's astonishing, soon as hundreds thousands Last year, fifteen million new compounds were registered.
All built on this simple template.
This is the work of genius.
In 1869, a Russian chemistry professor named Dmitry Mendeleyev was writing a text book for his students When he began to wonder how he could be best explain them the 63 elements that were known at the time Help formulating thoughts, he constructed a card for each element On each card, he wrote the name of the element, its atomic way, its typical properties and its similarities to other elements He then laid the card like a game of solitary And began to arrange them over and over, searching for patterns Then came the moment of discovery.
Before him is something extraordinary The elements fell into 7 vertical groupings Each periodical grouping had members that resemble one and other, both chemically and physically.
Mendelevium had discovered the periodical table of the elements a map showing how all the elements related to one and another.
A map so precise that Mendelevium believed he could also use it to predict the existence and properties of three elements known yet to discovered.
One would like be boron on he said.
One like aluminum and one like silicon.
Eventually, the elements were discovered.
And Mendelevium was proved right.
It was actually a little bit of controversy because German chemist named.
Lothar Meyer had come up with roughly the same idea.
But Meyer didn't quiet have as much courage, so that's actually interesting thing Here this German come up with the same idea of periodicity of which there were hints already before But he doesn't like the predictions like Mendeleev does.
So, here we see the power of our risky prediction In having people accept a theory.
There is nothing more powerful than making a prediction that is not obvious And have it come true.
Yes have it come true.
The periodical table is our icon.
I mean that's what we associate with chemistry You going to any chemistry room you'll see it Why is the periodical table of elements significant It forever changed the way that everyone would learn and understand the elements.
The periodical table of elements is to chemistry as notes of music are to Beethoven's sonata.
And in honor of Mendeleev, his name is now literally attached to the periodical table The element 101 was named after him.
It's called mendelevium It's not only the chemists who like the periodical table.
I hear you carry one around.
I do carry one.
Yes sure.
Show me.
You 'll never know And I seem to use it a lot.
Let's see.
This is small So I am going to give you a test.
What's under nitrogen in periodical table Nitrogen is seven.
Yes.
I have to think of a second.
It's sulfur No, you are wrong so I carry it often.
So, it's phosphorus.
Oh.
Phosphorus.
Phosphorus is 15.
Yeah.
You have to add 8 that point.
Yes, that's why I carry it.
I can't remember.
So it's seven plus eight, fifteen phosphorus.
it's ok.
There is a pattern there.
I get it now.
At the turn of the nineteenth century, electricity was all the rage People were busy making batteries and connecting them just about anything to see the reactions.
Electricity was like a new kind of fire.
One of the great battery junkies of the day was Humphrey David, a self-taught English chemist In 1807, David was performing a battery experiment in his lab.
He melted some potash aluminum found in the ground that also forms in the ash's wood.
Chemists had speculated that potash was a compound of several elements, but are not able to prove it.
David wanted to see if electricity might provide the answer He reared some wire from one of his biggest batteries to the molten potash Pure potass began to emerge David had discovered the power of electricity to react to chemicals and transform them.
Eventually, electrical chemistry led to the rise of aluminum industry The production of semiconductors.
Solar panels.
LED displaces.
Even rechargeable Li-ion Batteries In the eighteen fifties, Robert Bunsen and his research collaborator Gustav Kirchhoff conducted a serious of experiments.
To determined why substances emitted specific colors When placed in a flame The color they determined indicates what elements are present in the substance.
For example, if sodium is place in a flame, they observed sheaves of yellow Copper, sheaves of green Strontium, sheaves of red Oh it's a good one.
While watching the experiments, Kirchhoff was reminded that how a prism spreads light into a rainbow of colors So, using a prism and a piece of small telescope.
Bunsen and Kirchhoff built the first spectroscope.
And analyticale device they hope would help them to see the spectra coming from heated substances.
And it worked.
As an element was put into a flame of a Bunsen burn, the light from the heated substances passed through the prism of the spectroscope.
Where they spread into a ribbon-like spectrum of colors, riddled with dark lights.
The combinations of bright colors and dark lines were like bar codes Indicating what atoms were present.
When burned, each element produced a completely unique spectrum.
Using their spectroscope, Bunsen and Kirchhoff were able to discover two new elements Cesium and rubidium.
One day, Bunsen and Kirchhoff decided to test their invention with the sunlight It produced the spectrum that featured two lines that were identical to those in the spectrum produced by sodium Bunsen and Kirchhoff had discovered the presence of sodium in the sun ninety three million miles away Suddenly, scientists had the tool to help them study the chemistry of the heavens.
Lifted off.
We have lifted off.
Today, the legacy of this great discovery lives on the exploration of the space.
A formal spectrum has been used to study the atmosphere of the planets, to search for signs of water, signs of life.
Our next great discovery is the story of Joseph Thomson and the electron.
So, everything that we can see is made of chemicals That's right.
What's the future They are all bounded as electronic actions.
To find out about it, I paved a visit to Harvard University.
Dudley Herschbach is a professor here and the winner of the 1986's Nobel Prize in chemistry.
For his research in the dynamic chemical elementary processes.
So, Thomson didn't discover the electrons.
Well, it's said that way, but he didn't discovering it said " Here it got, I've got this things.
Here it is.
" He did experiment it a lot and did measure the ratio of the charge, the electric charge, the mass.
And later he got a rough measurement of the charge, and therefore showed the mass was very very small.
It was about one to thousand to the mass that light is known as atoms, hydrogen atom.
So, it showed that he could expect a very small piece of an atom All, I was command a shock, Punch attended.
Yes.
The electrical piece from atoms was a very small part of the atom.
At the time of his discovery, Thomson was the professor of England University of Cambridge.
He was using a device called the Crookes tube in his experiment.
I happened to have here a little apparatus that's akin to the one that J.
J Thomson used in 1897 It's called a Cathode Ray Tube Just evacuated its little glass cylinder, with some electros And we can hook this up.
So, the key points of this experiment is very simply.
The replica of the first CRT.
Yeah.
It's the first cathode ray tubes is the accentor of the television tubes as a matter of fact.
You do the last one, and we should get the stream the cathode rays or electrons.
Going there and showing of banning in this phosphor cold piece of cupboard there.
Here I give you a magnetic field and you use to deflect the electrons.
When Thomson exposed the cathode ray to a magnet The stream would bend, since magnets could only affected matter.
This one of stream of rays were composed of kind of electrically charged substance, called radiated matter.
After many hours of observing and measuring, Thomson realized he'd found the first sub-atomic particles.
The ray was a stream of electrons.
It was a revolutionary discovery.
Some years later, student of Thomson Ernest Rutherford was able to show that the positive charge of the atoms Which is there to balance the negative charge of the electrons which was scooting around, was localized in a tiny tiny nucleus.
Hundred thousand of times smaller than the size atoms.
So, almost all the mass was of course in that nucleus as well Well, because electrons are so light, And that's still the model we have today.
That's the basic model for atoms and is the key on understanding the everything involving this Like chemistry.
Yes like chemistry particular.
That's right.
Scientists were just beginning to discover the anatomy of the atom Now, they wonder to understand its behavior Specifically the mechanism that enabled the atoms of certain elements to combine with the atoms of the other elements to form new substance.
In the early nineteenth hundreds, American chemist Gilbert Lewis developed a model of the atoms that provided an answer That's he who explained the electrons in atoms The chemistry about electrons, not about nucleus That the electrons in atoms went in shells around the nucleus In Lewis's model of the atoms, each shell allowed only maxima number of electrons Lewis theorized that two chemical elements might combine to form a compound, When they give up or accept electrons from their outer shells.
For example, on their own, sodium and chlorine are hazardous But when a single sodium atom gives up the electron from its outer shell and the single chlorine outer shell accepts it This exchange allows the two to combine And form the compound sodium chloride, table salt Gilbert Lewis's theory was an extraordinary breakthrough.
It enables scientists to begin making chemical compounds Millions of them, compounds that shift the face of modern life Our next great discovery stared in the 1890 With the discovery of unknown radiation called x-rays It caused sensation and scientists immediately began looking for other substances that made it strange, perhaps valuable forms of radiation.
Over the next several decades, a number of scientists investigated the phenomena And together ended up shedding the light on one of the greatest scientific snooping episodes of modern science.
French physicist Henri Becquerel made the first significant breakthrough.
In 1896, he conducted a series of experiments to see a various of minerals emitted radiation One of the mineral he happened to tests was uranium Becquerel's technique was to place different objects on top of an unexposed photographic plate, still wrapped in black paper Which sprinkled uranium onto another piece of black paper, then enclosed the object between the uranium and the photographic plate.
Later Becquerel were developed the plate and without fail a ghostly photographic outline of the object would appear.
From these experiments Becquerel was able to prove conclusively.
That he had found a source for the mysterious radioactive rays that everyone was looking for.
That source was uranium.
From Becquerel, the investigation of radio activity was taken up by Marie Curie.
Curie and her husband Pierre undertook the job of isolating whatever elements were responsible for the radio activity in uranium ore For two years, the curies boiled, sifted, filtered and processed several tons of uranium ore.
Finally, they succeeded in isolating two new elements containing the uranium which they called polonium and radium.
Marie curie concluded that radium was a million times more radioactive than uranium.
More importantly, she determined that the mysterious form of energy which enabled radioactivity to penetrate other materials Was not a result of chemical process, but seemed to be atomic in nature Unfortunately, her discovery came at a great cost.
The danger of being exposed to radioactivity was still unknown at the time.
In 1934, Marie curie died of leucocythemia Believed to be caused by radiation poisoning Even the notebook that she use to record observations, are still considered too radioactive to handle.
It was the atomic nature of radioactivity that eventually attracted the interest of physicist Earnest Rutherford, Whom we already mad the discovery of the electron Rutherford found that radioactive material go through a natural process of decay.
As the move soothe the process, the radioactivity spontaneously emits unstable and highly charged particles, with the power to penetrate matter Rutherford called them alpha and beta particles and gamma rays Since those discoveries, we've learned a lot about radioactivity, the dangers as well as the benefits.
Radioactivity has given us medical imaging A treatment for tumors A method for calculating the age of the earth And the power source for our space craft to explore the solar system Even some smoke detectors contain a small amount of radioactive material called americium Which helps create steady electrical current.
A smoke particles disrupt that current and the triggers alarm Centuries ago, alchemist set their sights high.
They thought infinite welfare and immortality through miraculous transformation of matter.
They came up with useful tools and glassware, But not majels chemists on the other hands, set their sights a bit lower.
And ended up changing the look and feel of the material world As did our next great discovery.
In the eighteen sixties, John Hyatt, a printer and amateur chemist in orbital in New York Made news when he discovered a way to explore the long stringing molecules of cellulose found naturally in plants and created the first plastic Fifty years later, Belgian born chemist Leo Baekeland took the next step in the discovery process One of the greatest pioneer was Leo Baekeland, who made a polymer called Bakelite.
The usual thing transfavorring the prepared man He was make the same things.
But he knew how to explore them.
He saw the interesting properties of this.
From two chemicals derived from coal, Baeckland discovered the wourld's first fully-sympathetic plastic And the landscape of the twenties century's was forever changed What exactly is a plastic.
Plastics are polymers.
So what are polymers.
Polymers are long chain molecules, not individual molecules that plumed up into any solitary or some sort They are really molecules that can stand out very far.
Chains of carbon atoms sometimes with some other elements So, what are the advantages.
Well, it's mutable.
You can pour it in some liquid form into some modes, Stranks that's not bad.
You can made bullet-proof vest from plastics and we've certainly seen that in terms of fibers they can mimic or even surpass the properties of natural fibers No fisherman in the world is going to go back to having nets out of cotton.
You can bet.
those nets are goanna be of nylon So, would you say the discovery of plastics is a great discovery.
We have science making polymers, making nylon, making rayon which has natural starting point But is modified into a polymer, making Plexiglas or polyethylene.
Those are the structure of our material of civilization I think polymers are, in that sense, a example of human creativity of chemistry.
That's there is nothing more beautiful than them The single gram of black powder costs five hundred dollar.
About 30 times of the price of gold Remarkably, it is a special kind of soot.
Made of molecules called carbon nanotubes Each nanotubes is about one billion of a meter in diameter Thinner than a strand of DNA.
Yet full of the world's promise that lots of people excited.
Including the scientists who helped discover them.
Richard Smalley is a professor of chemistry of Rice University in Huston Taxas.
In 1985, he and fellow chemists Robert Cole and Harold Crotone were studying chemical conditions in outer space.
Using sophisticated laser and spectroscopic equipment.
They were searching for evidence that might help reveal chemical nature of interstellar matter Instead, they found something else.
For which they shared the 1996's Nobel Prize for chemistry.
What exactly did you discover Well, in 1985, over a period of week, we discovered that there was one special cluster of carbon atoms That had precisely 60 atoms.
That was magic, it was specially stable compared with any other cluster.
And we wondered why.
Smalley, Crotone and Cole named the new molecules Buckyballs After Buckminster Fuller, the architect designed the geodesic dome What they really discovered was a whole new cluster of large all-carbon molecules.
Which came to be called fullerenes Molecules are not just when some atoms start together by good bonds There's another proper molecules and that's when you put the last atom, it's kind of clicks.
It's done.
It's stable.
And if you offer another atom, it says no, I am happy the way I am.
And that's what C60 was.
We were offering other carbon atom in the apparatus we built, and it said, no I am gonna stay with the 60.
So, here's the molecule, and this was a molecule my mind are same to explain the results, which has the most symmetry of any molecules ever discovered The big thing is about an nanometer in diameter, a ten extra emmi, an nanometer a billion to a meter.
In 1991, the significance of fullerenes gave even more momentum when Sumio lijima, a scientist at NEC cooperation, discovered yet another category of cage like wonders But these fullerenes were slightly different.
They were made of hollow molecules of pure carbon that form a seamless hollow tube called carbon nanotubes Or in honor of Smalley's discovery, buckytubes.
There's buckyballs right Yes.
And then there is buckytubes.
Yes, I've got, this is get off a big now, a tube of the diameter of ball is this big This is, this is a fullerene same sort of structure.
And here's the pentagon.
Here's the hexagon.
There are six pentagon here, six pentagon here, twelve total and between all this hexagon So, this thing is sort of bucky capsule But you can imagine the thing very long and in fact the things are made millions of times longer than their diameter now.
And these objects have incredible properties Like what Well, for one thing, if you hold, say, these plastics objects, which I could easy break it apart But if you hold buckytube in your hand, you had the poly.
You could find the stiffest object in the universe.
Stiffer than steel.
Stiffer than steel.
Stiffer than diamond.
Stiffer than diamond But you are a big guy compel it; you'll find you could strike out quite big before breaks And we expect we'll find that it's a hundred time stronger than steel in tension.
The strongest fiber which you could ever make up anything ever.
I was mean like a million years later, when you ask me now the strongest thing same thing.
Something has to be the strongest of all the possible objects.
This is it.
It's just carbons So, you could take coal, sewage, old rubber tires and convert them into buckytubes Think we can do with this.
So we can rewire the world We can make electrical cables that conducted electricity better than copper and one six its weight.
So, when you think about this, does it seem too to be true.
Does it seem magical.
It does.
How about the chance that you can discover something like this.
But, that's one of the fascinating things about those current statues of our understanding chemistry and physics.
In fact, we can calculate the behavior of things very well in The big mystery was buckyballs and its tubes is not that they were be great if you could make them It was finding out you could actually make them Carbon nanotubes is one of the reason that the word Nano Technology become so well-known.
Some are describing they are modern day's industrial revolution.
Nano Technology refers to building things from scratch, like this nano-motor It's the ability to assemble the atomic and molecular building blocks of nature To create a new generation of product applications that's stronger and more precise.
Is this the next round of chemistry Is this the next thing in chemistry I am glad to see you use the word chemistry about this because that's really what this is.
We can't afford to pick every atom up our fingers and put them.
We have to have atoms self-assemble.
And they have confronted some source of cheap atoms.
So, we can make this efficiently.
We have name for that.
we called it chemistry.
of course these days, we called it Nano Technology The same thing.
We are after to make a structure of particular exact form And do it hundreds of trillions of time a second, low cost with no environmental impact To give us an object that would allow us to do something had logically we could do another ones do.
Making objects with, if were really good, the ultimate level of finesse with nature always built the molecules of living cells.
We now do this everywhere.
So it keeps you coming to work.
Yes, there is certain romance about it.
It takes only two centuries to go from a time when atoms were mere hypothesize to the break would be able to snap atoms and molecules together and build new technology with fantastic possibilities.
The great discoveries that we just seen helped make it happen.
Exploring the beneath of the surface thing, inside the realm of chemistry, and changing the world