MICHAEL EMERSON: Previously on The Mystery of Matter...
He realizes that something
fundamentally different's happened.
This air is some kind of super air.
How could I explain this?
LAVOISIER: This subject is destined to bring about a revolution
in physics and chemistry.
ALAN ROCKE: The discovery of oxygen really served as a starting gun
for a worldwide race for new elements.
EMERSON: Davy had found a powerful new tool
for the discovery of elements: the battery.
HUMPHRY DAVY: Nothing promotes the advancement of knowledge so much
as a new instrument.
¶ ¶
Major funding
for The Mystery of Matter: Search for the Elements
was provided by...
The National Science Foundation,
where discoveries begin.
Additional funding provided by...
The Arthur Vining Davis Foundations,
dedicated to strengthening America's future
through education.
And by the following:
One of the oldest tricks in the chemist's tool box
is called the flame test.
More than a thousand years ago, Arab alchemists discovered
that every substance gave off a telltale color as it burned.
But as the number of elements grew,
this test became less and less useful,
because some elements gave off such similar colors
it was hard to tell them apart.
One day in 1859, a German chemist
named Robert Bunsen described this problem
to his good friend physicist Gustav Kirchhoff.
A few days later, Kirchhoff came to Bunsen's laboratory
with an instrument made from two telescopes,
a wooden box and a prism.
They used Bunsen's latest invention-- the Bunsen burner--
to heat their samples.
Light from the burning element passed down the barrel
of this telescope to the prism, which split the light
into a spectrum of colors.
What they saw when they looked
into the eyepiece was a revelation.
You see a whole collection of sharp bright lines
at very particular wavelengths.
And that map of lines is distinctive for every element.
DAVID KAISER: It's almost like each element has its own barcode.
It's a unique way of saying this is that element, not some other.
EMERSON: Like Humphry Davy's battery,
the "spectroscope" kicked off a whole new round
in the discovery of elements starting with cesium
and rubidium, discovered by Bunsen and Kirchhoff themselves,
quickly followed by thallium and indium,
discovered by other chemists who seized on their new tool.
Astronomers, too, embraced the new technology,
turning the spectroscope to the heavens.
In fact, there's one element that we found
by first looking at the sun.
We didn't even know it was here on earth.
It was helium.
KAISER: By the middle of the 19th century,
there had been an explosion in the numbers of new elements
that had been found.
And this was exciting, but it also led to a kind of muddle
that seemed to have no order, no reason behind it.
ROCKE: Chemistry looked like an unruly garden,
a jungle of bewildering details.
Human beings like to make things simple.
And part of the whole, scientific enterprise is
to bring order out of what appears to be chaos,
to bring simplicity out of complexity.
EMERSON: But the ever-rising number of elements, now up to 63,
promised chemists just the opposite of simplicity:
more and more variety, with no end in sight.
How many elements were there?
Was this going to continue forever?
EMERSON: The man who would finally bring order to the elements
was a young Russian chemistry professor
named Dmitri Mendeleev.
He didn't set out to be a savior.
He was simply trying to organize the textbook he was writing.
But as he grappled with this challenge over one weekend
in 1869, Mendeleev would make a discovery for the ages:
the periodic table of the elements.
Today it hangs in every chemistry classroom
in the world, one of the most familiar images
in all of science.
But behind the table is a fascinating untold story.
Who was this man and how did he do it?
Mendeleev had recently been named a professor
at the University of St. Petersburg,
the leading institution in Russia's capital.
But getting there had been a long, improbable journey
from humble beginnings.
Mendeleev was born in Tobolsk, Siberia,
which is basically smack in the middle of Russia
if you look at it on a map.
It's very much the boonies of imperial Russia.
EMERSON: His father, the headmaster of the local high school,
went blind during the year of Dmitri's birth,
leaving Mendeleev's mother to support and raise
about a dozen children.
Maria Mendeleeva sensed something special
in her youngest child.
So in 1849, she set out with her 15-year-old son
on a 1,500-mile trip by horse-drawn sleigh
in search of a school that would accept him.
Like most students from the provinces,
Dmitri was turned away in Moscow.
But in St. Petersburg, he landed a spot
in the teacher training school his father had attended.
Exhausted by the journey, Maria died a few months later.
She took me out of Siberia and sacrificed what remained
of her money... her life...
so that I could get an education.
From her I learned that it is through work not words
that we must seek divine and scientific truth.
EMERSON: Scientific truth was elusive for any young chemistry student
in the mid-1800s.
There were deep divisions in the field
over even the most basic concepts,
particularly the atomic weights of the elements.
Most chemists believed each element
had its own unique kind of atom,
and ever since the early 1800s, they'd been working
to determine how much an atom of each element weighed.
ROCKE: That's how one distinguished on element from another.
So it was crucial to understand
what were the correct atomic weights
for each of the elements.
EMERSON: Everyone agreed that hydrogen, the lightest element,
should be assigned a weight of one, and that heavier elements
should have proportionally higher weights.
But that's where the agreement ended.
GORDIN: Did carbon weigh six or did it weigh 12?
Did it weigh four?
That depended on who you talked to and when you talked to them.
By the late 1850s people were incredibly confused.
This was an unsupportable situation.
Something had to be done.
EMERSON: Hoping to sort out the mess, chemists organized
their first-ever international meeting held
in Karlsruhe, Germany, in 1860.
GORDIN: Mendeleev, being a young, enterprising student,
goes to this meeting, and he hears a very important speech
by an Italian chemist, Stanislao Cannizzaro.
EMERSON: Cannizzaro laid out a persuasive case
for a new, uniform system of atomic weights.
MENDELEEV: I still remember the powerful impression Cannizzaro made.
He seemed to advocate truth itself.
GORDIN: After Karlsruhe, something astonishing starts to happen.
Within a few years of the congress,
you start seeing lots of different attempts
to organize the elements that are all based
on these new, post-Karlsruhe weights.
EMERSON: A French geologist arranged the known elements
in a spiral along the outside of a cylinder--
like the stripes on a barber pole--
and found that elements with similar properties tended
to fall into columns.
An English chemist arranged the elements
by atomic weight in rows of seven
and found that their properties repeated
like musical notes one octave apart.
By the end of the 1860s, five different European scientists
had detected glimmers of a hidden order among the elements.
But no one could quite put the puzzle together.
That's where things stood when Mendeleev finally
landed a professorship at the University of St. Petersburg.
One of the duties of his new post was
to teach introductory chemistry.
He has to teach this class, hundreds of students,
and he has to give them a textbook.
There are no up-to-date Russian language
college-level textbooks available.
EMERSON: So Mendeleev set out to write his own:
Principles of Chemistry, in two volumes.
He completed the first volume in 1868
and on Friday, February 14, 1869,
he sent the first two chapters of volume two
off to his publisher.
MENDELEEV: Marina.
He was in a hurry to finish it because he was struggling
to make ends meet.
(Speaking Russian)
GORDIN: He hasn't yet gotten any royalties
from the textbook, because it hasn't been written yet.
He's got to keep his family fed and clothed.
He has at this point two children and a wife,
so he was always looking for more funds.
EMERSON: To make a little extra money, Mendeleev planned
to take a short break on Monday to do some consulting
for a cheese-makers cooperative.
But he had something on his mind.
His publisher was expecting the next chapter
of his textbook in two weeks, and he still hadn't settled
on a way to organize the rest of his book.
Mendeleev had spent most of the first volume
covering a few common elements like hydrogen
and oxygen in great detail.
GORDIN: You learn a huge amount of chemistry, but it's slow.
Volume one contains just eight elements
out of the 63 that were then known.
When it came to writing the second volume
of his textbook, Mendeleev realized
that he had better find an organizing principle
fairly quickly, because he had
to cover the remaining 55 elements.
MENDELEEV: Since I'd set out to write a book
called Principles of Chemistry,
I felt I had to establish a system
for classifying the elements.
A system based not on chance, or guesswork,
but on some sort of principle.
(speaking Russian)
EMERSON: The problem gnawed at him all weekend.
GORDIN: He's trying to come up with a way
of packing more elements in the same amount of space.
He couldn't ramble the way he did in volume one,
however useful that was.
EMERSON: Mendeleev had already hit on the idea
of focusing on whole families of elements
rather than treating one at a time.
Chemists had long known that certain elements resemble
each other in much the way family members do.
You can often tell people are related
because they have the same sort of face.
They have the same nose, they have the same color eyes.
There's something in common, and that's something very similar
in these chemical families.
They tend to react similarly to the same kinds of substances.
EMERSON: Mendeleev had ended volume one with two chapters
on a well-known family, the halogens:
chlorine, fluorine, bromine and iodine.
He began volume two in the same way,
with chapters on sodium, potassium and lithium,
a family called the alkali metals.
GORDIN: He realized that a family of elements is a good way
of organizing so you can do more with less space.
EMERSON: The problem was, there was no obvious family to turn to next.
For insight into what other elements
might be grouped together, Mendeleev looked more closely
at the two families he already had.
GORDIN: And in that process, he figures out
something rather extraordinary about the elements.
He looks to the atomic weights of sodium and lithium
and looks at the difference between them.
And then he does the same thing for fluorine to chlorine,
and notices that those two differences
are very close to each other.
EMERSON: Was this just a coincidence... or a clue?
Excited, Mendeleev wrote down the lightest elements
and their atomic weights.
After seven elements, he broke off and started a new row,
keeping elements with similar chemical properties
in the same column.
The numerical pattern continued to hold.
MENDELEEV: The eye is immediately struck by a pattern,
a regular change in the atomic weights of the elements
within the horizontal rows and the vertical columns.
GORDIN: He notices that there's a regularity in the differences.
That is, the changes that happen within a family
happen regularly across families.
And that's the fundamental insight
that gets him thinking about
how to organize all the other elements.
SCERRI: Mendeleev had begun the weekend trying to solve the problem
of what to do next in his textbook.
But having reached this a-ha moment,
he dropped everything else and he poured all his energy
into revealing an absolutely fundamental principle of nature.
When he was taken by an idea, he was really taken by it.
He starts putting together this system.
And he's trying to figure out the hard spots,
the things that don't quite make sense.
Maybe I can scratch out this element here
and put this element in its place.
Should I change the atomic weights?
Do I have to rethink their properties?
And the problems of it, the intellectual puzzle,
just grabs him.
EMERSON: The challenge Mendeleev faced was similar
to one of his favorite diversions,
the card game called Patience, in which the object is
to arrange playing cards by both suit and number.
That process of keeping several different variables in mind
is kind of analogous to how Mendeleev was thinking.
He started using both the regular increasing order
of atomic weights and the relationships
of chemical properties with each other to build two dimensions.
EMERSON: Mendeleev didn't just lay out the known elements
in order of rising atomic weight.
GORDIN: When it looks like the next element
doesn't have the properties it is supposed to have,
he scooches it over and leaves a blank spot.
And has the audacity, has the daring to suggest
that there might one day exist an element
that would fill that space.
EMERSON: The few scraps of paper left
from Mendeleev's struggle that weekend reveal
that he sometimes arranged the chemical families
in rows instead of columns.
Unhappy with this early attempt at a table,
he moved the alkali metals to a new position
in the next draft below, but kept them together.
SCERRI: Mendeleev is not moving elements individually.
But he is moving them as a block.
It's as if it's a composite piece of a jigsaw puzzle
that he's moving all together.
EMERSON: On Monday morning, a driver arrived to take Mendeleev
to the train station for his trip to the cheese cooperative.
He was well into his task but still struggling
to make all the pieces fit.
We know this because one of the surviving fragments is a letter,
delivered that morning, concerning arrangements
for his trip to the cheese cooperative.
SCERRI: And on the back of the letter, which still bears the stain
of a cup, Mendeleev has sketched a few symbols
and has carried out some very simple calculations.
He's looking at differences in atomic weights.
EMERSON: So he was still working on the problem,
even after wrestling with it all weekend.
The drafts of Mendeleev's table show plainly
the struggle he went through.
HOFFMANN: The bottom of the page he lists the elements to be classified.
As he fits them into the table on that page,
he crosses out the elements.
It's just what you and I would do.
We can see the effort in that page.
He's making mistakes.
He's correcting them.
It's full of crossings out.
There are things that don't quite fit.
This is a human being trying to understand this world.
EMERSON: Hour after hour, Mendeleev worked on the table,
missing one train after another.
Finally, he dismissed the coachman.
The cheese makers would have to wait.
(knocking on door)
(speaking Russian)
EMERSON: That afternoon, a visitor found him distraught,
unable to capture the order he knew was there,
just out of reach.
Later that day, Mendeleev came to a choice
that would crystallize his thinking.
The elements involved were iodine and tellurium.
GORDIN: Iodine's a little lighter than tellurium
so it should come first.
But Mendeleev looks at that and says,
"Well, if I put iodine first, it's in the wrong family.
It is actually a halogen, which is the next row down."
If he stuck to that weight rule, it would put an element outside
of the family it obviously belonged in.
GORDIN: So he decides tellurium, the heavier element,
should go first.
It always bothered him that iodine was lighter
than tellurium but came after.
That breaks the order of atomic weights,
but it preserves the family resemblances,
which are more important than just the increase
of atomic weights.
EMERSON: With that principle established,
Mendeleev hurried toward the end.
GORDIN: And the more he worked on it, the better it looked.
EMERSON: Finally, that evening, Mendeleev completed his table.
Before leaving the next day, he ordered 200 copies printed
and sent to leading European chemists.
By the time he left for the cheese factory,
Mendeleev knew that he was onto something extremely important.
I think he realized that day that he had cracked it.
EMERSON: With a few modifications, soon made by Mendeleev himself,
his 1869 draft is easily recognized
as the periodic table of the elements--
incomplete but unmistakable.
In his published table, Mendeleev left blanks
for some of the elements he thought were missing.
ROCKE: Not only did he leave a blank space,
but he suggested an approximate atomic weight
for that future element.
And the fact that Mendeleev on that first weekend
is already thinking this way, that's a sign
that he believed that there's something deeper going on here.
EMERSON: Mendeleev believed his table was more than a convenient way
to arrange the elements.
He was convinced he had discovered a law of nature:
that the properties of the elements are determined
by their atomic weights and vary in a regular,
periodic way, across the table.
PETSKO: It's periodic because the properties
of the elements repeat in a regular fashion.
When you wrap around from one row to the next
and come back to where you were, the elements that are
in the same column have similar properties.
He had an almost mystical feeling
that this was there in nature
and not so much a human invention as a discovery.
EMERSON: Given the remarkable regularity of his table,
Mendeleev couldn't believe nature
would have just left some spaces empty.
Laws of nature do not permit exceptions.
There must be an element which we have not yet discovered.
Go look for that element.
And he was bold enough not only to say an element is missing
but to predict.
The periodic law allows us not only to predict
what new elements will be found, but also to determine
in advance their chemical and physical properties.
EMERSON: In 1871, Mendeleev published an article making predictions
about three of the missing elements
based on the properties of their neighbors in the table.
Chemists really weren't used to making predictions of any kind,
let alone ones to this degree of specificity.
They are remarkably precise and quite daring
for Mendeleev to print them.
EMERSON: Four years later, a French chemist
found a new metal so soft it melted in his hand.
He called it gallium.
It seemed to be a good fit for the empty spot below aluminum,
but the density didn't match Mendeleev's prediction.
He wrote the Frenchman suggesting
that he check his data.
SCERRI: So you can just imagine this Frenchman
who actually has the element in his hands hearing
from this Siberian who has never seen the element,
daring to say to him that he's made a mistake.
But sure enough, when the French scientist rechecked
his measurements, Mendeleev was correct.
So not only had Mendeleev predicted the element,
but he knew the properties of the element better
than the discoverer of the element knew them.
Within 15 years all three of the detailed predictions
are discovered and that catapults Mendeleev
to chemical superstardom.
I never thought I would live to see my ideas verified.
I was wrong.
EMERSON: But in 1894, two British scientists made a discovery
that threatened to bring Mendeleev's
carefully crafted edifice crashing down.
They found a new gas they called argon
that didn't seem to fit into the table.
When Lord Rayleigh and William Ramsay discovered argon,
it looked like a problem, a very serious challenge
to the periodic table itself.
Mendeleev's first reaction to almost anything
that was contradictory to the system was to be
hostile to it and suspicious.
And Mendeleev therefore decides it's not an element.
There are lots of reasons to think that.
First, it doesn't react with anything.
PETSKO: Chemists couldn't get it to do anything.
It was inert.
It behaved like no other gas
that anybody had ever encountered.
GORDIN: And secondly, it has no place on the table,
so how can it exist?
Matters got worse when Ramsay announced
he'd also isolated helium 30 years
after it was first detected in the sun.
It was definitely an element,
and it too had no place in the table.
And then just three years after that,
William Ramsay's research group discovered three new rare gases,
krypton, xenon and neon.
GORDIN: They display the same kind of properties.
They are all inert gases.
And they display the same increase of atomic weights
as the other natural families do.
And that changed the situation dramatically.
What began as a single anomaly, a single puzzle,
now looked like a group of elements.
MENDELEEV: Now we can see that helium, neon, argon, krypton and xenon
are as closely united as any other group.
And so Mendeleev makes the single biggest revision
to the system he ever did.
He puts in a new column.
And that is the family of noble gases.
MENDELEEV: My periodic system is in no way injured
by these discoveries.
In fact, they confirm and strengthen it.
It turned out to be a vindication
of the periodic system.
And, if anything, made it even more profound a discovery.
EMERSON: Mendeleev's table had finally brought order
to chemistry's unruly garden.
ROCKE: After Mendeleev, one could see that each element had a place.
It was a grand design that worked.
Chemistry wasn't just one thing after another,
random substances we've dug up from the earth.
They are interlinked in a complicated and rich way.
MENDELEEV: We are at the dawn of a new era in chemical science,
approaching a new understanding of the still-mysterious nature
of the elements.
As the 19th century drew to a close,
the periodic table's ability to corral the elements contributed
to a growing sense that the work
of science was just about complete.
Most of nature's building blocks had been found,
measured and cataloged.
Chemists agreed these elements had been,
and always would be, the same-- forever fixed, unchanging.
All that remained was to fill in the few remaining blanks.
Or so it seemed.
In fact, this smug sense of satisfaction was about
to be shattered by something and someone completely unexpected.
She was the unlikeliest of revolutionaries,
a graduate student-- a woman-- from Poland
who had left her homeland to pursue her passion
for science in Paris.
Yet in four short years, her discoveries
would transform our understanding
of matter and make her one of the most famous women
in the world.
She worked on something that was relatively obscure
and turned it into a blockbuster.
New elements, new properties and a whole new way
to look at the world.
EMERSON: The world would know her as Marie Curie,
but she was born Maria Sklodowska,
into a family of Polish patriots,
at a time when Warsaw was under Russian rule.
Poland had been literally wiped off the map,
its residents forbidden to speak their own language
or teach their own history.
But Maria's family secretly defied the czar,
speaking Polish at home and reciting patriotic poetry
to preserve their Polish heritage.
QUINN: She used to go by an obelisk erected in honor
of the Russian people
and spit on the obelisk on the way to school.
So you can see Maria learned early
to be a fighter and resister.
EMERSON: The daughter of two teachers, Maria excelled
in science and math.
But in Russian-ruled Poland, women were not allowed
to attend university let alone become scientists.
Very, very few places in Europe or elsewhere had opportunities
for young women to study science.
So one of the few places she could was, in fact, in Paris.
EMERSON: But because her family was too poor to send her,
Maria would first have to work for six long years
as a governess to support her older sister's studies.
Only at age 24 did she finally get her chance.
QUINN: She waited her turn and she didn't give up.
And when the turn came she took it.
CURIE: I was lost in the great city.
But the feeling of living there alone,
taking care of myself without any help,
didn't depress me at all.
I had been waiting for this opportunity for a long time.
EMERSON: Paris in the 1890s was like no other place on earth--
a living showcase for the wonders
of science and technology.
The city boasted such modern marvels
as electric streetcars and telephone exchanges.
At the laboratories of Louis Pasteur,
scientists were conquering diseases
that had plagued humanity for centuries.
The Lumière brothers were thrilling crowds
with their new invention: pictures that actually moved.
And rising above it all was the brand new Eiffel Tower,
which would remain the world's tallest structure
for nearly half a century.
Here was Paris, the kind of intellectual, artistic,
technological capital of the universe.
This was where the modern age was born.
QUINN: She felt this precious sense of liberty.
She could say whatever she wanted,
go wherever she wanted.
And she took it all in and loved it.
Everything I saw and learned was a new delight to me.
I had only one regret.
The days were too short and went by too quickly.
EMERSON: Adopting the French form of her name, Marie,
she enrolled at Paris' pre-eminent university,
the Sorbonne, where she could study
under the leading lights of French science.
One of them was Gabriel Lippmann,
a future Nobel Prize winner.
QUINN: Another was Henri Poincare,
who was one of the leading mathematicians
of the 19th century.
One of her math instructors was a mountain climber.
Another was an aviator.
These were exciting people,
scientists who had exciting lives.
CURIE: It was like a new world open to me,
the world of science which I was at last permitted
to know in all liberty.
EMERSON: Marie graduated first in her class in physics and,
with Professor Lippmann's help, received a grant
to do research on magnetism.
A friend suggested she seek out a French physicist
who had studied the subject
and might have some lab space for her.
The meeting would change her life.
CURIE: Pierre Curie seemed to me very young,
though he was 35 at the time.
I think it was pretty much electric from the beginning.
With all my heart I thank you for your photograph.
I showed it to my brother Jacques-- was I wrong?
He finds you very fine but he also said,
"She has a very decisive look, maybe even stubborn."
EMERSON: Pierre Curie was a first-rate researcher,
but he had never bothered to complete his dissertation
and was content teaching at an industrial college.
He was diffident, modest, and shy.
He was very much an outsider.
He had been homeschooled by his politically radical father
along with his brother Jacques.
CURIE: In a family photograph you see him with his brother.
His head is resting on his hand.
It's a pose of dreaming, as if he is looking
at some inner vision.
EMERSON: Pierre was a man of ideas, not action.
But he was galvanized by this young woman
and pursued her as he had nothing else in his life.
PIERRE CURIE: It would be a beautiful thing
if we could spend our lives near each other,
true to our dreams, in science, where every discovery,
no matter how small, lives on.
EMERSON: Pierre's proposal posed a dilemma for Marie.
She had planned to get a first-rate scientific education
in Paris and then return to her beloved Poland
to teach and care for her aging father.
QUINN: Her mother had died of TB early on
and he was counting on Marie coming back.
EMERSON: Now this ardent young man was offering her an exciting life
as a working scientist.
It was a decision that would mean abandoning my family
and my country.
Marie had all those feelings of responsibility for her father,
for her family, and then for Poland on top of that.
EMERSON: In the end, their mutual devotion
to each other and to science overcame Marie's resistance.
QUINN: She wrote one of her friends: "Fate has brought us together,
and we simply can't bear to be apart."
EMERSON: The newlyweds left on a cycling honeymoon
after a simple ceremony in 1895.
By 1897, even with a toddler to care for,
Marie had set her sights on getting
what no other woman had ever received in France:
a doctorate in physics.
At the time, the world was abuzz with excitement
over a new discovery:
mysterious rays that had the power
to see through solid objects.
You could, by this process, look at the bones
inside of your living hand.
It's as if you had a magical set of glasses
that lets you see inside of living creatures.
And that sparks the public imagination.
EMERSON: Doctors instantly recognized X-rays
as an invaluable diagnostic tool.
KAISER: There was a great rush of excitement
from working scientists as well.
In that first year,
there were about 1,000 scientific articles published,
at a time when the entire physics community
in the world was only about a thousand members.
EMERSON: But with so many others doing research on X-rays,
Marie felt it would be hard to make an original contribution.
And so she picked something that she could work on
where there was less competition.
In fact, no competition.
EMERSON: Just a year earlier, a French physicist named Henri Becquerel
had discovered a different kind of ray given off
by the element uranium.
These "uranic rays" were powerful enough
to penetrate thick black paper and create an image
on a photographic plate.
But the images were not nearly as striking
as those created by X-rays, and they seemed
to have no practical value.
So after writing a few papers about this scientific curiosity,
Becquerel dropped the subject,
thinking it had been squeezed dry.
Marie just thought that this was a tremendous thing to work on,
particularly as a graduate student.
The subject was attractive to me because it was entirely new.
Little had been written about it.
There was another reason Becquerel's uranic rays appealed
to Marie.
She had spotted a clue that might reveal more about them.
As you can see, air is normally a poor conductor of electricity.
The current can't jump this gap, so the bulb doesn't light.
But Becquerel had noticed his uranic rays
had the mysterious power to charge the air around them,
allowing electricity to leak across.
The amount of electricity was incredibly small,
about a trillionth the amount needed
to light this little bulb.
No meter of the day could measure it.
But Marie had a secret weapon Becquerel didn't.
Right in Marie's own household was perhaps the world expert
in how to measure tiny little electrical effects.
The two of them, Pierre and Marie Curie,
designed this really quite ingenious instrument
to measure these very subtle electrical effects
from her samples.
EMERSON: They placed a layer of uranium on a metal plate,
then charged the plate with a battery.
As expected, electricity leaked across the gap
to the plate above.
To measure this tiny current,
the Curies would use this second device
to create a matching amount of electricity.
Inside was a special crystal
that could generate its own tiny charge thanks
to a phenomenon called piezoelectricity.
More than 20 years earlier,
Pierre and his brother Jacques had discovered
that certain crystals give out electricity
in response to pressure.
The amount of electricity generated when you squeeze
or stretch that crystal depends precisely
on how hard you press on that crystal.
And that means you have a way
to make a very, very sensitive measurement
of minute little electrical currents.
EMERSON: By placing a weight on the pan below,
Marie stretched the piezoelectric crystal
inside the device.
Then, by slowly relieving the tension--
unstretching the crystal--
she could generate a charge exactly offsetting the one
coming from her uranium sample.
She could tell the two charges were equal
when the spot of light from this third instrument was
at zero on the scale.
KAISER: Though it didn't look very pretty,
this sort of pulled together little contraption
was exquisitely accurate and could allow them
to make measurements like no one else in the world.
EMERSON: But using these instruments required extraordinary
concentration and dexterity.
Ever so gradually, Marie relieved the tension
on the crystal while carefully watching the spot of light
to keep the two charges in balance
and timing how long it took to lift the weight
entirely off the pan.
The faster she had to remove the weight,
the stronger the activity of her test sample.
And that's why, when you see pictures
of Marie Curie in this experiment,
she's sitting there with a stopwatch.
Termina.
Ma petite étudiante.
C'est très bien.
CURIE: I never dreamt that I was about to embark on a new science
that Pierre and I would follow for the rest of our days.
Day after day, working in a cramped, unheated storeroom,
Marie painstakingly carried out her measurements.
She compiled data on uranium,
then went to test the other known elements
to see if any of them could also electrify the air.
She was not expecting to make any sort
of earth-shattering discoveries.
QUINN: She thought she would do
some sort of diligent work
on a whole lot of elements, and she would measure their power.
KAISER: It's exactly what you'd expect
for a perfectly legitimate PhD dissertation.
EMERSON: And for a while, the results were predictably dull.
No other elements showed this strange property.
QUINN: Things were going along pretty routinely
until one day in February of 1898.
And that was the day that everything changed.
CURIE: Pierre?
EMERSON: In the course of a single week,
Marie made two startling discoveries.
She found that the element thorium
could also make air a better conductor.
KAISER: That was the first real solid indication
that this was not unique to uranium.
This might be a property of matter,
not a curiosity of one particular element.
It was necessary to find a new term
to define this new property of matter.
I proposed the word "radioactivity."
EMERSON: The next surprise came when Marie tested pitchblende--
the raw ore from which uranium is taken.
Something was very wrong.
(speaking French)
EMERSON: Pitchblende seemed be four times
as radioactive as uranium itself.
When I find a result like that,
as a scientist, my first reaction is,
"I made a mistake" or "The machine isn't working."
KAISER: She did what every good scientist should do,
which was doubt it, be extremely skeptical,
and check every last step of that chain.
EVE CURIE: So my mother made her measurements over again.
Ten times, 20 times, until she was forced
to accept the results.
EMERSON: In time, the Curies realized this was no mistake.
The readings from pitchblende were real.
RAMIREZ: A light bulb went off and they said,
"Well, maybe there is something else in there."
Very soon they began to suspect that there was another element
in pitchblende which was producing
this enormous radioactivity.
KAISER: There must be some new thing under the sun,
some new element that had never been seen before.
And it must be intensely radioactive,
since it was present in amounts so small
that no one had ever detected it.
EMERSON: Since neither Marie nor Pierre was a member
of the Academy of Sciences, they asked Marie's mentor,
Gabriel Lippmann, to deliver the paper announcing this discovery.
PETSKO: This was one of the most important papers
in the history of chemistry.
And yet it was almost universally ignored.
ROCKE: Who was this Marie Curie?
She was a graduate student.
She spoke French with a Polish accent.
She was married to a teacher in an industrial school.
And she was a woman.
RAMIREZ: These are strikes that are definitely against you.
And so her ideas just weren't embraced
because she was so different.
EMERSON: But Marie knew she was onto something important.
QUINN: She had lit upon, almost by accident,
an extremely exciting discovery.
And as soon as he figured that out,
Pierre abandoned his work on crystals and joined her.
EMERSON: To track down their mystery element,
Marie and Pierre subjected pitchblende
to a battery of chemical procedures.
RINGE: You break up your rock.
You try to dissolve it.
You treat it with all kinds of other chemicals.
EMERSON: The goal is to separate the ore into portions
with different chemical properties
all the while tracking the radioactive signal.
She then throws away everything that isn't radioactive.
It's getting more and more concentrated
as she goes through these steps.
EMERSON: The Curies soon discovered that two distinct parts
of the pitchblende with different chemical properties
were both radioactive.
That meant not one but two new elements
might be hidden in the ore.
By July 1898, they were able to announce the discovery
of one of those substances with certainty.
Marie, you will have to name it.
EVE CURIE: The former Mademoiselle Sklodowska thought
of her occupied native country
whose very name had been erased from the map of the world.
Could we call it polonium?
QUINN: Poland, remember, was still not a country.
This was one way of putting it on the map.
Et bien, voila.
Polonium it is.
EMERSON: Marie next turned her attention to the second mystery element.
KAISER: She finds the activity is through the roof.
It's nearly a thousand times more active
than even her uranium sample had been.
EMERSON: Marie's polonium sample had not been pure enough
to yield a unique spectral line.
Would this new, more powerful element pass the test?
KAISER: By 1900 spectroscopy was often seen as the gold standard
for identifying the materials you're working with.
And if Marie Curie wanted to make some claim
that she found in fact a whole new element,
she was going to have to meet the chemists on their own terms.
She'd need spectroscopic evidence.
Regarde ici.
Il ya une ligne...
EMERSON: Marie's sample showed the presence
of the well-known element barium.
But it also revealed a pattern
of spectral lines never seen before,
strong evidence that she and Pierre
had tracked down their mystery element.
RINGE: She could tell that she had an element
that hadn't been seen before
because the spectral lines she got were different.
QUINN: And in the notebook Pierre writes
in very bold ink the name they decided
to give the new element: radium.
ROCKE: But in the 19th century there had been scores
of claims of elements that later proved
not to be elements at all.
You needed to do more.
SACKS: To satisfy the chemical community,
a spectral line wasn't enough.
They had to see the real stuff which could be weighed,
which could be measured.
It was important, as you would with any other element,
to isolate this element, to weigh it
and to place it on the periodic table.
RINGE: So in order to be absolutely certain,
she had to have pure material
and that's what she set out to do.
It was my mother who had no fear of throwing herself
into that daunting task.
Without personnel, without money, without supplies.
EMERSON: To isolate even a speck of radium,
Marie would need to process huge quantities of pitchblende,
a job too big for her tiny laboratory.
The only space available for this work
was a drafty old shed once used as a dissecting room
for the school's medical students.
As Greer Garson and Walter Pidgeon showed
in the 1943 film Madame Curie, the Curies worked tirelessly
to separate the radium from tons of pitchblende residue
they had shipped from a mine in Bohemia.
CURIE: Sometimes I had to spend the whole day mixing a boiling mass
with a heavy iron rod nearly as big as I was.
I would be broken with fatigue by the end of the day.
And yet we spent the happiest days of our lives
in this miserable old shed.
An entirely new field was opening before us.
EMERSON: Marie soon realized that radium was a smaller part
of the pitchblende than she ever imagined--
less than a millionth of one percent.
Isolating it was going to be an enormous job.
QUINN: Marie's daughter said that,
had it been up to Pierre,
he might not have taken the next step.
The world has done without radium up to now.
What does it matter if it isn't isolated
for another hundred years?
I can't give it up.
There is a special passion which goes
with the discovery of elements,
and a line in the spectrum is not enough.
She was after an understanding of nature.
And there was very, very little that would stand in her way.
EMERSON: In 1902, after four years of arduous work,
Marie finally succeeded in isolating one-tenth
of a gram of radium chloride from ten tons
of pitchblende residue.
Four years to produce the kind of evidence
that chemical science demands.
All of this effort so that she could actually
convince the remaining chemists that this was a real,
honest-to-goodness element.
EMERSON: She measured radium's atomic weight at 225.9--
very close to the current value of 226.
And she placed it correctly in the periodic table.
EVE CURIE: Radium officially existed.
The incredulous chemists-- and there were still a few--
could now only bow before the facts,
before the superhuman obstinacy of a woman.
KAISER: Here she was still basically a graduate student
and the whole world was beginning to talk
about her discoveries.
In just these four years she's now discovered
two brand new elements.
Even more important, she's shown that this strange emanation,
this radioactivity, is a feature of matter,
not specific to one quirky little substance.
And she's also developed a quite impressive technique
for finding more.
This was the beginning of identifying elements
by their radioactive power.
EMERSON: The same technique would soon be used by others
to identify more new radioactive elements.
In 1903, Marie Sklodowska Curie
became the first female scientist
ever awarded a doctorate in France.
By then it was clear radioactivity
was a pivotal scientific discovery,
deserving of recognition.
KAISER: There's no doubt that Marie Curie
had done the lion's share of this work.
And yet, when the time came to recognize this work,
it very nearly went to other people.
A number of prominent French scientists
nominated Pierre Curie and Henri Becquerel
for the Nobel Prize in 1903.
And in this letter, they didn't mention Marie Curie at all.
EMERSON: One of the nominators was Gabriel Lippmann.
QUINN: It's quite remarkable since Gabriel Lippmann
was her teacher, her mentor.
He actually presented her very first paper to the Academy.
So he knew about her importance in this work
and how central she was to these discoveries.
And yet his cabal of Frenchmen just left her off the list.
And the idea that she could be an important scientist
just didn't occur to them.
She was totally invisible.
Pierre-- and we have to give him total credit for this--
turned around and said, "I did not conceive of this idea.
"I helped with the work, but it was someone else's idea
that made it possible, and that's Marie Curie."
QUINN: Pierre was adamant that Marie needed to be included.
He immediately wrote back and said,
"Wouldn't it be better, from an artistic point of view,
to award the prize to Marie Curie and to me?"
EMERSON: In the end, Marie did share in the Nobel
with Pierre and Henri Becquerel.
She would go on to win a second all her own.
But the real prize was the magical substance
for which she would always be known.
Some nights the Curies would stop by the laboratory
to admire the element Marie called "my child."
EVE CURIE: They arrived in the Rue Lhomond.
Pierre put the key in the lock.
The door squeaked and admitted them to their world.
SACKS: Eve Curie in her biography of her mother...
Don't light the lamps.
SACKS: ...describes the wonder of the Curies
as they went into their lab and saw these glowing vials.
MARIE CURIE: From all sides, we could see gleamings suspended in darkness,
like faint fairy lights.
Do you remember the day you said to me,
"I would like radium to be a beautiful color"?
EVE CURIE: Radium had something better than a beautiful color.
It was spontaneously luminous.
The fact that radium glowed in the dark seemed magical.
But it was also troubling, because it almost seemed
to violate some kind of fundamental physical law.
GATES: Scientists had known for some time that light is a form
of energy, so if you distill something
and it suddenly glows in the dark,
you have to ask the question:
Where does that energy come from?
It's not changing shape, it's not interacting
with the environment to get this energy.
But it is just glowing, infinitely,
and we had no idea why it did that.
It was Marie who had the flash of insight:
perhaps some types of matter were changing
from one kind to another, their atoms splitting apart
and releasing energy in the process.
This theory of the source of the energy is very seductive;
it explains radioactivity very well.
EMERSON: But it was an idea many chemists refused to accept.
MENDELEEV: Tell me, please, how much radium salt is there
in the entire earth?
A few grams!
On this shaky foundation they want
to overturn our understanding of the nature of matter.
EMERSON: Even the Curies were reluctant to accept it.
GATES: The Curies themselves,
they wanted to think of elements
as immutable, unchangeable parts of nature.
The idea that one could have transmutation
from one element to another was very disturbing,
even to her, at first.
EMERSON: But the Curies' discoveries inspired others
around the world to pursue this daring theory.
KAISER: The idea that finally got pieced together was
that the energy was, in fact, coming from the disintegration
of these atoms themselves.
Radioactivity was a sign that the atom itself was unstable.
It could break apart.
This discovery implied something even more profound.
Up to then, most scientists had believed
atoms were the smallest units of matter--
solid, unsplittable lumps.
But if radioactivity was atoms falling apart,
there must be even smaller pieces
inside still awaiting discovery.
Thanks to this Polish expatriate,
this graduate student, this young mother...
scientists hoping to solve the mystery
of matter now had a pressing new question to answer:
What's inside the atom?
Next time on The Mystery of Matter...
MOSELEY: There's a fundamental quantity in the atom
which increases by regular steps as we pass
from one element to the next.
WARK: I think he must have been astonished.
Phil, the Germans have split the uranium atom!
GATES: Seaborg figured out how to turn it
into a new element, plutonium.
SEABORG: No matter what you do with the rest of your life,
nothing will be as important as your work on this project.
It will change the world.
Major funding
for The Mystery of Matter: Search for the Elements
was provided by...
The National Science Foundation,
where discoveries begin.
Additional funding provided by...
The Arthur Vining Davis Foundations,
dedicated to strengthening America's future
through education.
And by the following:
for the elements and watch bonus
videos on the featured
scientists, visit pbs.org
/mysteryofmatter.
The Mystery of Matter:
Search for the Elements
is available on DVD. To order,
visit shopPBS.org or call
1-800-PLAY-PBS.
EMERSON: Joseph Priestley was the first to publish his discovery
She just said, "Hey, you don't like what I'm doing?
I'm just going to work harder and prove you wrong."
There's just so much about her and her stick-to-itiveness
from the beginning.
It's so moving and so wonderful.
WOMAN: Her courage throughout her life
is an enormous inspiration to everyone,
but especially to women.
WOMAN: She was certainly an inspiration to me.
I come from a generation when it was also not quite yet
fashionable to be a scientist.
And here was a woman who had achieved it.
To not only be a scientist but to be a wife, a mother,
a part of a community.
Those are very hard to do all at once.
She was able to do that.
And as women came along, they could look at that and say,
"Well, maybe I can do it too."
If you look a little different, if you're a different gender,
a different race, there are many barriers to overcome.
But you do what Marie did, which is you put your head down
and you work harder.
MAN: Curie's legacy is many fold.
She changed cherished truths
and notions about how the world seems to work,
what's the universe made out of.
She challenged an equally steadfast notion
of who should be contributing,
who could play the game of science.
She showed by example that there could be all kinds of people
doing really breathtakingly important science.
All kids of people could have a hand
in pursuing the mystery of matter.