All language subtitles for Into The Atom_EN

In the late 1800s,
tubes like this

were a staple
of the popular science lecture.

When electricity was applied
to the metal at this end...

it would give off a glow
that thrilled crowds

still mystified by electricity.

In 1897, physicist J.J. Thomson

of England's
Cambridge University

set out to find out
what these mysterious rays were.

When Thomson moved a magnet

near a tube
modified to reveal the rays,

he saw that it bent
the path of that beam.

Electricity, he realized,

must be made up of negatively
charged particles---

what soon came to be called
electrons.

But electrons weren't just
the unit of electricity.

Thomson found that even
when he used different metals

to generate the rays,

the resulting electrons
were always the same.

His bold conclusion was that

the electron must be
a tiny piece of every atom,

thousands of times smaller
than the atom itself.

These things were
much, much smaller

than anyone had ever thought
a physical thing could be.

But over time,
people began to agree

that this was a piece

of every atom in the universe--

that all of matter had these
little parts inside them.

Now the race was on to identify
the rest of the atom's pieces

and understand
how they fit together.

This challenge drew many
of the best minds in science,

including a 22-year-old
physicist

from one of England's
leading scientific families.

"My dear Mother,

Two letters from you,
so here a second from me."

- Henry Gwyn Jeffreys Moseley--
- Harry to his friends--

was born with science
in his blood.

Both his grandfathers had been
members of the Royal Society,

and his father was a famous
naturalist and Oxford professor.

But he died when Harry
was just three,

leaving him to be raised
by his mother, Amabel.

"Firstly, the garden.

"Please occupy yourself

"in taking many hundreds
of rose cuttings.

Put them quite close together
and ram the earth round them."

Harry and his mother
grew very close.

Together, they laid out a garden
alongside their country cottage.

And throughout his life,

his letters home were filled
with instructions.

"Such penstemons as the mole
killed must be replaced.

The quamashes would like
to be planted..."

As any good gardener, he knew
what he wanted planted where,

and he told people what to do.

He got to be very good
at telling people what to do.

I hope the burrowing progresses
and that it is being done

with reference
to our pretty ground plan.

Moseley earned a degree
in physics

at Trinity College Oxford,
and then elected

to pursue graduate studies
200 miles to the north,

in smoggy Manchester,
whose industrialists

had generously endowed
the local university.

The laboratory
that Moseley came to

in 1910 was, at that time,

one of the most advanced
physical institutes

in the world.

But for Moseley,
the real attraction

was that it was run by the
brightest star in physics:

an irrepressible New Zealander
named Ernest Rutherford.

Rutherford had leapt
into the study of radioactivity

as soon as Marie and Pierre
Curie announced their findings.

And he had already won
the Nobel Prize

for his discovery
that radioactive atoms

give off different kinds of rays
and particles as they decay.

So by 1910,

he was undoubtedly among
the great physical scientists,

thinking hard about the nature
of radioactivity,

about how to understand atoms
and their parts.

Moseley was soon assigned
a research project

on radioactivity,

and Rutherford kept close tabs
on his progress.

Good morning, Moseley.

So how's it all going?

He would daily make a round and
visit all of the young workers

where they were carrying out
their experiments.

The tube is giving off alpha
and gamma rays.

They're producing
secondary electrons

"Papa," as they called him...

Have you tried
shielding?

...would pour out advice,

often seeing right to the heart
of the matter.

That should do it,
that should help.

He was constantly at the elbows
and shoulders

of his young students,
coaxing them on, offering advice

on the nitty-gritty
of experimental technique.

He seemed to have the magic
hands to get things to work.

* Carry onward,
Christian soldiers... *

It was a very happy atmosphere
in his laboratory

because it was like
a band of brothers, almost.

Rutherford's band of brothers

was one of the finest groups
of young scientists

ever assembled in one place.

Among them were Hans Geiger,

who would invent
the radiation detector

known as the Geiger counter;

Charles G. Darwin, grandson
of the great biologist;

and James Chadwick,
a future Nobel Prize winner.

He had a very active group

of young researchers
who were wondering

about ultimate questions of,
"What is the nature of matter?"

with new discoveries
practically every week.

One of the most exciting
discoveries

came just a few months
after Moseley's arrival,

as Rutherford's team
continued to probe

the structure of the atom.

They knew that J.J. Thomson's

tiny, negatively charged
electron

was one piece of the puzzle.

But that left two big
unanswered questions.

Since atoms are
generally neutral,

that meant that the atom itself

had to somehow have
a positive charge

to balance
the negative charge out.

But where in the atom
were the positive charges needed

to offset
those negative electrons?

And a related question,
since people knew by this point

that electrons
were so much less massive

where was the mass distributed?

Rutherford and his students

had been trying to answer
these questions

with the help of the positively
charged alpha particles

that poured out of radium
during radioactive decay.

They aimed a beam
of alpha particles

at an ultra-thin sheet
of gold foil.

Most of the time,

these alpha particles
would sail right through.

But every now and then,

some of these projectiles
would actually bounce

practically right back
in their faces.

And that was really,
really unexpected.

It was the most incredible thing
that has ever happened to me.

It was almost as if
you had fired a 15-inch shell

at a piece of tissue paper
and it came back and hit you.

In late 1910, Rutherford
came into the lab one day

and announced he knew what this
surprising result meant.

It meant that the atom
must be mostly empty space

but have some incredibly dense,
hard center.

If the atom's positive charge
and most of its mass

were concentrated
in a tiny central core,

it would let most particles
sail through

but repel any positive charge
that came near the center.

Then you can give the incoming
alpha particle a real kick

and sometimes turn it
all the way around.

So with that, we had this really
quite brand new vision

of the structure of the atom.

Almost all of its mass
was concentrated

very, very tightly
in a minute, little space,

in what we would now call
the nucleus.

And then separated
by mostly nothing,

you have these negatively
charged electrons

sort of whizzing around,

but at a great, great distance
on the scale of the atom.

One of the most remarkable
things about the atom

is that it is mostly made
of nothing!

I think the feeling
in those hallways,

the laboratories of Manchester
was one of great excitement.

They could sense that Rutherford
and his team

had literally cracked open
a new view of matter.

But while all this
was going on around him,

Moseley was consigned
to plugging away

on radioactivity
research projects.

I'm repeating someone else's
experiment to please Rutherford,

so the work is not very
exciting.

I'm hoping to be through with it
soon.

From his correspondence,

I think he found it actually
slightly mundane

just to be following on
behind other people

and not really making his own
distinctive marks.

So in the spring of 1912,

when a piece of his
radioactivity equipment broke,

Moseley seized the opportunity

to strike out
in a new direction.

"My dear Mother,

"I'm sorry that I didn't answer
your letter sooner,

"but I was very busy.

"Last Thursday, we got
the result we were searching for

using the X-rays."

Moseley had turned his attention

to some exciting news
out of Germany.

X-rays, the same rays
that had so captivated the world

15 years earlier,

had been found to have
properties like those of light.

Ever since Newton,
it had been known that a prism

could split light into
a series of distinct colors,

each with its own wavelength
or frequency.

What the German scientists
had discovered was that X-rays

could be split up, or
diffracted, in the same way:

with the help of a crystal.

Only the resulting image
was not a rainbow,

but a symmetrical pattern of
spots on a photographic plate.

Power on.

15 volts and steady.

Intrigued, Moseley asked
Charles G. Darwin

to join him in investigating
this curious X-ray pattern.

220 degrees,
ten minutes...

Darwin was actually
a mathematician,

and that's really why Moseley

got hold of his services,
because he knew that this

was going to imply some
complex mathematics.

Moseley and Darwin concluded

that the atoms
inside the crystal

were neatly arrayed in rows
that reflected the X-rays

to create the pattern of spots.

Excited by this discovery,

Moseley and Darwin
asked Rutherford for permission

to devote all their time
to this new project.

I don't really think
that we are equipped.

We don't really have
the supervision

for this sort of thing.

Rutherford, who knew nothing
about X-rays,

was not very enthusiastic
about this new departure,

so he at first opposed it.

Are absolutely you sure this is
something you want to do?

We were fired by our interest
in this unexplored field,

and we had no idea
where it would lead.

At the time,
X-rays were still mysterious.

We simply wanted to know
what they really were.

Finally, we persuaded him
to let us try.

Okay, well,
on the condition

that if you run into trouble
of any kind, you do...

I think it was essentially
their enthusiasm for the subject

which convinced Rutherford that,
yeah, this was worth a shot.

And keep me informed
all along the way.

Certainly, sir.

For six months,

the two young researchers
holed up in the laboratory.

220 degrees,
20 minutes.

15 volts and steady.

"I wish I were with you
to see all the fresh spring,

"but here, it's all work.

"I'm like a gnome
after a long winter of darkness,

longing for some light."

Working with Moseley

is one of the most strenuous
things I've ever done.

He is without exception the
hardest worker I've ever known.

I'd arrive at the laboratory
in the morning

and meet Moseley
just as he was leaving.

He'd been at it
all through the night--

15 straight hours.

Indeed, one of Moseley's skills
was knowing where in Manchester

you could get a meal
at 3:00 in the morning.

"We've sent a letter off
to Nature

"describing what we have found
so far.

"But we must keep on
with the work.

Many others are
on the same track."

Moseley was not alone in
realizing this was exciting.

There was some pretty steep
competition,

like William Bragg and his son
William Lawrence Bragg,

who were already working hard
and fast on similar techniques.

Aware of this competition

and anxious to return to
Rutherford's work on the atom...

I thought I'd come by
to bid you farewell.

Darwin decided
to leave the partnership

in the summer of 1913.

I suppose this makes sense.

You were always
a better theoretician

than you were a lab tinkerer.

Will you go on alone?

Certainly.

I think this might lead
to something.

Rather than abandoning
the work...

I wish all the best.

...Moseley changed his approach,

leaving basic research on X-rays
to others.

Moseley says, "Well, okay.

"I'm not quite sure
what these things are,

but I know perfectly well
how to use them."

Having done the basic work
with Darwin,

he decided to use the method
as a tool

to investigate the nature
of the elements.

And that is when

his brilliant discoveries began.

Moseley set out to learn
if each element

had a unique X-ray spectrum--

a bar code like the ones
that had been discovered

a half century earlier
using light.

To find out, he placed
a sample of an element

inside an X-ray tube.

When a beam of electrons
struck the sample,

the element gave off X-rays.

Moseley could then determine
the element's X-ray spectrum.

The whole subject of X-rays
is opening up wonderfully.

When we fire electrons
at a target made of platinum,

we get a sharp line spectrum
of five wavelengths.

Tomorrow, I will search for the
X-ray spectra of other elements.

I believe they will prove much
more important and fundamental

than the ordinary light spectra.

While the light spectra
had been invaluable

in identifying new elements,

they hadn't solved
certain puzzles

about the ordering of the
elements in the periodic table.

The elements were arranged
in columns

with similar chemical
properties,

but they also tended to fall

in order of increasing
atomic weight--

the amount a single atom
of an element weighed.

But it's not perfect.

Every now and then,
there seemed to be anomalies,

little reversals
where chemical properties

seemed to suggest
one kind of ordering

but their weights suggested
the opposite order.

For example, there was cobalt
and nickel.

Chemically speaking, cobalt,
should occur before nickel,

and yet its weight is higher.

And nobody knew why these
inversions were happening.

To find out if X-rays
could solve this riddle,

Moseley set out to test
ten neighboring elements

in the periodic table,

including that troublesome pair,
cobalt and nickel.

But Moseley quickly realized
he had a problem.

For each element he tested,

he had to use the lab's vacuum
pump to empty the tube of air.

Vacuum pumps were jealously
guarded devices.

Lots of people in the lab needed
a vacuum to do their research,

and you had to join the queue.

But Moseley realized that
if he could put

lots of these little elements
at once in the same tube,

then he could really
make progress.

So he designed a long X-ray tube
and built a tiny railroad car

to carry his samples along
inside it.

He tied a little piece
of silk fishing line to them

and then tied that line
to a little bobbin.

By turning the bobbin,

Moseley could bring his samples,
one after the other,

into the line of fire.

And so he could do
all of these elements

in one go, if you like,
with the same vacuum tube.

As each metal was struck
by the electron beam,

it gave off X-rays.

When diffracted by a crystal,

they created a series of lines
on a strip of film.

I've worked out a simple way

of finding the wavelengths
of my different elements.

Once he got it up and running,

he said, "It's so easy,
it's almost a sin

to snatch the bread
from those hungry Germans."

In five minutes, I can get
a strong, sharp photograph

of the x-ray spectrum.

Moseley found,
just as he had hoped,

that each element had a unique
X-ray spectrum.

In just four days,
I've got the spectrum

of chromium, manganese, iron,
cobalt, nickel and copper.

There is here a whole new branch
of spectroscopy.

But not even Moseley
expected what he found

when he compared the spectra of
all ten elements in his series.

The result of these measurements
was absolutely extraordinary.

He decided to simply take
his photographic film

and to arrange the film
according to its frequency.

Each piece of film represented

a different element
in his series.

The frequencies
of the X-rays that came out

had an amazingly simple
relationship.

As he laid them out,
one after the other,

Moseley found that
their dominant X-ray lines

rose in frequency,
step by step.

And that produces
this beautiful staircase.

He had no idea when he started
to measure these frequencies

that the result, now known as
Moseley's staircase,

would come about.

That was a great surprise.

I think he must have been
astonished.

And I think the scientific world
was astonished

that it was that simple.

It would be years
before scientists understood

the reason
for this striking pattern.

But Moseley knew at once he had
made a fundamental discovery.

He thought, "Now I have
a means for the first time

"to really tell
which element is which

and to put them
in a proper order."

Moseley's X-ray lines
showed that cobalt and nickel

were just where they should be,

even though their atomic weights
were out of order.

The conclusion was inescapable:

the X-ray spectra
of the elements

didn't depend
on their atomic weights

but on something even simpler.

There was a remarkably
simple relationship

between the wavelength

or the frequency of that X-ray
that came out

and something they came to call

the atomic number
of the element.

Up to now, "atomic number"
had simply referred

to the number of an element's
box in the periodic table.

All the way back to Mendeleev,
it's where in the row you are.

It's counting one by one.

But Moseley's results
showed atomic number

was much more than
a convenient label.

What we have here is proof

that there's a fundamental
quantity in the atom

which increases by regular steps

as we pass from one element
to the next.

This fundamental quantity
can only be the charge

on the central positive nucleus.

Moseley had discovered
that the nucleus

was not one big positive blob,

but a collection
of positively charged particles

that increased in number
with each heavier element.

Building on Moseley's work,
Rutherford would soon discover

this next piece of the atom,
the proton,

and show that each element
in the periodic table

is defined by the number
of protons in its nucleus:

its atomic number.

Our experiments show that
the atomic number

always increases by a single
unit from element to element.

For hydrogen,
the atomic number is one;

for helium, two;
for lithium, three, and so on.

Moseley's discovery
put the periodic table

in a whole new light.

For the most part,

elements were arranged
in increasing atomic weight.

But that's not the real reason
for that tremendous order

that we find
among all the elements.

It really is marching along
atomic number,

the amount of positive
electric charge on that nucleus,

none of which was known
in Mendeleev's own day.

Weights didn't matter.

Something fundamental
that was deeper in the atom

was what mattered.

Moseley's proof that
the properties of an element

are determined
by its atomic number,

not its atomic weight,
ranks in importance

with the discovery
of the periodic law itself.

In some respects,
it's even more fundamental.

Moseley and atomic number,

that's really the crucial moment

where we find out
what an element really is.

Armed with his X-ray machine,

Moseley could quickly
sort through

the dozens of supposed
new elements

chemists had claimed
to have found,

separating the real
from the imagined.

He could distinguish
between types of matter

with a brand new technique--

not dependent
on their chemical properties,

but by measuring the atomic
number based on these X-rays.

Moseley's X-rays allowed him

not only to rule out elements
that didn't exist,

but also to predict
what new elements

would eventually be found.

In 1914, Moseley measured
the X-ray spectra

of 30 additional elements beyond
the first ten.

They, too, fell into line
according to atomic number,

clearly revealing

where elements were missing

and where no new ones could fit.

"For the first time,"
one scientist marveled...

40, 41...

"It was possible to call the
roll of the chemical elements--

"to determine
how many there were

and how many remained
to be discovered."

The idea
that somebody could know

how many elements God created,
that was terrific.

After Moseley's work,

it was clear that there were
seven and only seven elements

remaining to be discovered.

But since we can now predict the
X-ray spectra of these elements,

they should not be difficult
to find.

In 1914, Moseley's
continuing work on the elements

was interrupted
when his country called.

"My dearest Mother,

"I am now a second lieutenant
in the Royal Engineers.

England had been drawn into war
by events in Europe.

Like many others
of his generation,

Moseley felt a duty to serve.

I was very lucky
to get into the army so quickly

because RE commissions
are much in demand.

He had a bit of a difficulty
actually getting into the army

because he wasn't an engineer

and the Royal Engineers
wanted engineers.

He badgered the recruiting
officers to allow him in.

By the summer of 1915,
Moseley was stationed in Turkey.

It gets hotter here by the day,

and only cool nights and sea
bathing keep life tolerable.

I had mixed feelings
about the enlistment

of so many young men
of science--

pride over their ready response
to the country's call,

apprehension about irreparable
losses to science.

On August 3, 1915,
he wrote from Gallipoli.

"My insides returned to duty

"and let me once more enjoy the
good things which are sent us,

foremost among them
your Tiptree jam."

One week later, as they
attempted to take a ridge,

Moseley's brigade was
overwhelmed by Turkish troops.

The 27-year-old
communications offer

was shot in the head and killed.

The news of Moseley's death was
a terrible shock at Manchester

because by that time, it was
already clear that Moseley

was one of the most brilliant

young physicists
of his generation.

In the scientific community,

there was a big sense
of outrage,

particularly from Rutherford,

because he did feel Moseley
was someone special.

The services he could have
performed for his country!

Instead, they exposed him

to the chances
of a Turkish bullet.

Tributes poured
in from around the world,

none more moving

than that of American physicist
Robert Millikan,

who had met Moseley during
a visit to Rutherford's lab.

"He threw open the windows

"through which we can glimpse
the sub-atomic world

"with a clarity
never dreamt of before.

"27 years old.

"If the European war
had done nothing worse

"than snuff out
this one young life,

that alone would make it one of
most hideous crimes in history."

In the decades
after Harry Moseley's death,

chemists found all the missing
elements he had left room for.

By 1945, every space was filled,

from the lightest element,
hydrogen,

to the heaviest, uranium.

The periodic table was complete.

Except it wasn't.

By this time, the next
generation of element hunters

had already begun
a whole new chapter.

They had figured out
how to create new elements--

elements that didn't exist
anywhere on earth.

The central character
in these events

was a young American chemist
named Glenn Seaborg.

He set out with a simple desire

to make one of these
new elements.

But he would end up
changing the world forever,

unleashing a force of
unimaginable destructive power.

The story begins
in late January 1939,

when a young physicist
in Berkeley, California,

learned of a startling discovery
in an unusual way.

One of my father's colleagues,
Luis Alvarez,

was sitting in a barber shop
getting his hair cut

when he read about this
in the paper.

Buried on an inside page
of the San Francisco Chronicle

was a story from Washington:

German chemists
had split the uranium atom

by bombarding it
with neutrons.

I stopped the barber mid-snip

and ran all the way
to the radiation laboratory

to spread the word.

The first person I saw was my
graduate student, Phil Abelson.

I was at the control console
operating the cyclotron.

About 9:30 a.m.,

I heard the sound
of running footsteps outside.

Phil, the Germans
have split the uranium atom!

Hahn and Strassman have done it.

Uranium split in two!

Joey!

When he told me
what he had read,

I was stunned.

Word spread quickly across the
University of California campus.

One of the first to hear
the news was Glenn Seaborg,

then a 26-year-old chemistry
instructor.

And he was just stunned,
and he spent hours

walking the streets of Berkeley
thinking about it.

I was exhilarated
at the discovery,

but at the same time,
I felt stupid

for having overlooked
this possibility.

I'd missed the chance
for an astounding discovery.

Many others had missed it too.

In fact, the splitting
of the atom-- nuclear fission--

was so unexpected
that it forced scientists

to rethink what they knew
about the atom.

To understand why,

we need to step back
a few years to 1932,

when another
of Rutherford's boys,

James Chadwick, discovered
the final piece of the atom:

the neutron.

The neutron has almost
the same mass as the proton,

and they both occupy
the nucleus.

But the neutron
is electrically neutral--

hence its name.

Right away, scientists realized
this made the neutron

the perfect projectile
for firing at the atom.

Unlike those positive
alpha particles

that Rutherford and his students
had been using,

it would not be repelled
as it approached the nucleus.

It could go right in.

You didn't have to fight
the electrical repulsion

to get this object
to go inside the nucleus

and probe the structure there.

One of the first
to use the neutron in this way

was an Italian physicist
named Enrico Fermi.

In 1934, Fermi began firing
neutrons at uranium atoms,

creating a shower of fragments
he would then analyze.

He found that a neutron

sometimes chipped off a piece
of the uranium nucleus,

lowering its atomic number

and turning it
into a different element,

a few spots lower
in the periodic table.

But some of Fermi's fragments

didn't match any of the elements
just below uranium.

What could they be?

Fermi concluded that sometimes,

an incoming neutron is absorbed
by the uranium nucleus

and then spontaneously changes.

The neutron
becomes a shape shifter

and changes itself
into a proton!

But when you change the number
of protons in the atom,

you change the chemistry,

you have changed the identity
of the atom.

They eventually concluded...

They published a paper
saying they had found

"transuranic elements"--

elements that were even heavier
than uranium.

They figured they had pushed

beyond the end
of the periodic table.

For this remarkable achievement,

Fermi won the Nobel Prize
in December 1938.

But even as he was shaking
the hand of the King of Sweden,

German scientists
were making the discovery

that would prove Fermi wrong.

Like almost everyone else
at the time,

Fermi had underestimated
the neutron.

It was very much smaller

than the nucleus
it was being fired at.

It had no electric charge.

It couldn't shove things around
by electric repulsion.

So Fermi's team
hadn't checked to see

if the neutron had broken
the uranium nucleus in half,

into much lighter elements.

They figured there's no way
this tiny little wimpy thing

could bust apart something
as huge, as massive,

as an entire uranium nucleus.

Breaking a nucleus in two
with a neutron

would be like breaking
a boulder in half

by tossing a pebble at it.

We all knew it was impossible
for uranium atoms

to break apart in that way.

But when the Germans repeated
Fermi's experiments,

they found that's exactly
what happened.

They did not find things that
looked heavier than uranium.

They found well-known elements
that were about half as heavy--

much, much lower
on the periodic table.

The uranium nucleus
had been split in two

in a way that no one
had imagined possible

or even worth looking for.

The tremendous energy released
when the atom split

had profound implications
for a world at the brink of war.

Across the world,

physicists came to remarkably
similar conclusions right away.

Could the energy trapped
in that nucleus

be used to make an explosive
unthinkably more powerful

than conventional
chemical explosives?

A lot of people were thinking
about the possibility

of the atomic bomb.

But my father,
he was mostly thinking

about the scientific
implications.

For Seaborg,
the discovery of fission

presented an unexpected
opportunity:

a second chance
to be the first

to discover elements
beyond uranium.

Fermi had said he had discovered
all these transuranium elements.

Those findings
just went out the window.

So if there were transuranium
elements to be found,

well, they were still there
to be discovered.

And Berkeley was the perfect
place to do it.

Under the leadership
of Ernest Lawrence,

Cal's Radiation Laboratory
had led the world

in the development
of the cyclotron,

a device for flinging
subatomic particles

at ever-greater speeds.

What Lawrence did was figure out
you could take a proton

or some particle
that you are accelerating

and put it in a circular path

using magnetic fields
to make it go in a circle.

By rapidly switching
the electrical charge

of the two "D"s

Lawrence kept the proton chasing
the ever-moving negative plate,

boosting its speed on each pass.

You hit it once.

When it comes around again,
you hit it again,

you hit it again,
you hit it again.

And then suddenly,

you've got this really energetic
tiny particle.

that you can then aim
at your target

and use it to study
what's going on.

Just weeks after the news
of fission broke,

a young Berkeley physicist
named Ed McMillan

set out to study
this new phenomenon.

He would repeat
the Germans' experiment

by bombarding uranium atoms
with neutrons

from the cyclotron.

To prepare his target,

he applied a thin layer
of uranium oxide

to a piece of filter paper.

His goal was to split
the uranium atoms

and track how far
the resulting fragments flew.

Ed started by capturing
the fission products

in a stack of thin foils.

But eventually,

he found that cigarette papers
worked just as well.

He stacked the cigarette papers

behind the uranium-coated
filter paper.

When this target was struck with
neutrons from the cyclotron,

atomic fragments would scatter
in all directions.

Some would burrow into the stack
of cigarette papers,

penetrating
to different distances.

McMillan then checked the papers
one at a time

to see how far the radioactive
fragments had traveled.

As expected,

he found different levels of
radioactivity on each paper.

The surprise came when he
measured the target itself.

It was much more radioactive
than expected,

suggesting that one product of
the reaction hadn't moved at all

but remained
on the filter paper.

This lack of mobility

implied that it might not be
a fission product at all.

As the possibilities raced
through McMillan's mind,

he quickly arrived
at an explanation:

this fragment had stayed put

because it was much heavier
than the others.

Instead of splitting
into smaller pieces,

a uranium atom had absorbed
an incoming neutron,

and then that neutron
had spontaneously changed

into a proton, in just the way
Fermi had proposed.

What McMillan was seeing

was what Fermi thought
he was seeing.

If so, this would be
a brand new form of matter--

the real element 93.

But to prove it, he would need
to show that its chemistry

was unlike any other element,
a precaution Fermi hadn't taken.

For help on this, McMillan
turned to an old friend,

Phil Abelson, who was back
in Berkeley on a short vacation.

Phil Abelson was really taken

by this activity
McMillan had found,

and he decided he was going
to follow up on it.

It was certainly
a very productive vacation,

because it didn't
take him long--

really a few days--
to rule out

that it was any of the other
elements, 92 and down.

We had discovered element 93.

They named it neptunium
because it was beyond uranium,

just as the planet Neptune
is beyond Uranus.

With this discovery,

the search for elements
had entered a whole new realm.

Up to now,
it had been a matter

of finding elements
that already existed in nature.

But from this point on,

element hunters would be
creating new elements.

There was no telling how far
the periodic table might extend.

McMillan immediately set out
to create element 94.

While Ed was doing
this research,

he lived at the Faculty Club,
just down the hall from me.

I kept track of his progress
at breakfast, in the hallway,

even in the shower.

My father was fascinated
by McMillan's search for 94,

and he knew that McMillan
was closing in on it.

And then suddenly,
McMillan disappeared.

Like many other
American scientists,

McMillan had been called to help
the country prepare for war.

He had moved

to the Massachusetts Institute
of Technology

to join the team
developing radar.

So my father wrote to him

and asked him if he could
continue with this project,

looking for 94
as a collaborator.

And Ed McMillan
very graciously said,

"Yes, I would be delighted
if you would do so."

If Ed had left for MIT
just a few months later,

he certainly would have been
the one to find element 94.

As it was, I was in the right
place at the right time.

It would be the discovery
that changed everything for me.

As a chemist,
Seaborg was thrilled

at the chance to create
a new element.

But he conducted his research

with one eye on the changes
that were sweeping the world.

In the past year,
Germany had invaded Poland.

France and Great Britain
had declared war.

Italy had sided with Germany.

Fighting now raged across much
of Europe and North Africa.

Albert Einstein,
alarmed at these events

and aware of Germany's
head start in nuclear research,

had written
to President Roosevelt,

urging him to launch
an American effort

to create an atomic bomb powered
by the fission of uranium.

By now, it was clear

there are two very different
kinds of uranium.

Only one of them
was easy to split.

The one that would do that
most readily

was a very unusual
kind of uranium

that had fewer neutrons
in the nucleus,

this very fissionable,
potentially explosive

kind of U-235.

But that's only about
one percent of all the uranium.

The much more common element
is the uranium 238,

but it doesn't fission.

But Seaborg realized

he might be able
to turn this inactive uranium

into a new element
that was capable of splitting.

We knew early on

that element 94
could be a big prize.

If we could transform U-238
into a fissionable material,

we would increase 100-fold

the amount of material
usable for a bomb.

With this goal in mind,

Seaborg picked up
where McMillan had left off.

He knew from McMillan's work

that uranium bombarded
with neutrons

sometimes changed
into neptunium.

But neptunium itself
was radioactive,

spontaneously changing form.

Could it be shape-shifting
into element 94?

To find out, Seaborg and
graduate student Arthur Wahl

used the Berkeley cyclotron
to create a sample of neptunium

in the same way McMillan had.

Now, Arthur, what we want here
is the sample...

Okay

directly in line.

You see?

They would then watch for signs
that neutrons inside it

were changing into protons,
forming element 94.

Sure enough,
a special radiation detector

showed that's exactly
what was happening.

But to be sure they had
a new element,

they'd need to create enough
of it to test its chemistry.

For that, they'd have to wait
for neptunium to break down,

atom by atom, into what
they hoped was element 94.

After a month, Seaborg and Wahl
had enough material to test.

Mindful of Fermi's mistake,
they painstakingly checked

to make sure the product
of their experiment

was not an element that had
already been discovered.

And it took them weeks

to actually separate it
from every other known element,

but they were eventually
successful in doing that.

The last possibility
was finally eliminated

late one night in February 1941.

There was then no doubt
they had discovered element 94:

plutonium.

We felt like shouting our
discovery from the rooftops.

Under normal circumstances,
we would have rushed

to publish our claim to the
discovery of a new element.

But they realized that if this
was a fissionable element,

it was of military importance,
and there was a war going on.

And so they actually had
to keep it secret.

Maybe for the first time ever

in this history of this race
to find and create new elements,

Seaborg was not able
to just tell anyone he knew

about this very exciting
new discovery.

What had changed was
the condition of the world.

By now, German planes

were regularly bombing
English cities,

Japan had entered the war,

and there were reports
that Adolf Hitler

had launched an effort
to create an atomic bomb.

In response to Einstein's plea,
President Roosevelt

had authorized
a modest research program

into the possibility of a weapon

fueled by the fission
of uranium-235.

And Seaborg realized,
here is a type of material

he'd made from scratch
in the laboratory

that might be
an even more efficient fuel

for that kind of weapon.

But was it?

Discovering plutonium
was just the first step.

Seaborg would need to create
much more of it

to find out if this new element
was capable of fission.

Joining Seaborg to answer
this critical question

was Emilio Segrè,
a Jewish physicist

who had fled Italy
amidst rising anti-Semitism.

I hope he's paying attention
to Mussolini.

They placed a two-and-a-half-
pound sample of uranium

next to the cyclotron
and bombarded it with neutrons.

During the early work
on the discovery of plutonium,

they were working
with very small amounts,

so they were not concerned
about radioactivity.

But to test
for the fissile nature,

they had to use
much larger quantities,

and that meant that they had to
worry about radiation exposure.

They were not really set up
to do that kind of work,

but they had to just improvise.

And so they would have goggles,

they would have
lead-lined gloves,

and they ended up using buckets
on poles.

On looking back on it,
my father said,

"Gee, you know,
it really seemed primitive,"

although they managed to do it.

Seaborg and Segrè
separated element 93

from the rest
of the reaction products,

spun it to further purify
the sample,

and then did it all over again.

We called it a night
at 10:00 p.m.,

but we were back
first thing in the morning

to repeat the process--

six cycles
over the next three days.

It was tedious work,
but the hours flew by

because we knew we were
on the verge of a discovery.

The work was finally completed
in March 1941.

The result of all these
separations

was a very small amount
of plutonium

that they put on a small dish.

And they actually covered it
with Duco Cement

so that it wouldn't go anywhere.

They labeled it Sample A.

Then came the moment of truth:

was this new element fissile?

Was it a potential source
of immense power?

We placed Sample A in the path
of the cyclotron's neutrons...

Okay, Joe.

...and had our answer
almost immediately.

The counter registered the
unmistakable kicks of fission.

They knew immediately
what the implications were.

There was a large portion
of uranium

that could not be used
in a bomb.

What plutonium offered
was a chance

to turn all of that uranium 238
into a fissionable material.

Seaborg figured out how to take

this uranium 238

and turn it into a new element,
plutonium,

which readily fissions.

And that meant there could be
much more material

made for bombs,
or for use in nuclear power.

Seaborg's discovery
soon came to the attention

of the leaders
of the nascent American effort

to create an atomic bomb,

including physicist
Arthur Compton

and Harvard president
James Bryant Conant,

who met in late 1941
to discuss Seaborg's findings.

That lunch where they discussed
the possibility

of creating a bomb
was on December 6, 1941.

Just right
on the ten yard line...

The next day, my father was
home at the Faculty Club,

listening to a football game
on the radio,

when the announcer broke in.

We interrupt this program

to bring you
a special news bulletin.

The Japanese have attacked
Pearl Harbor, Hawaii, by air,

President Roosevelt
has just announced.

The attack also...

Our team had already
been working hard

in anticipation of war.

In an instant "the day
that shall live in infamy"

made work on anything else
seem irrelevant.

The American people,
in their righteous might,

will win through
to absolute victory!

With America now in the war,

the atom bomb effort
took on a new urgency.

The leaders of the effort

asked Seaborg to report
to the University of Chicago,

where he would spend
the next four years

working on the Manhattan
Project.

Newly married
and just 30 years old,

he was put in charge
of a team responsible

for separating plutonium
from other fission products.

The responsibility
for creating the plutonium

fell to Enrico Fermi,

who had fled fascist Italy
after winning the Nobel Prize.

In an abandoned squash court

under the university
football stands,

Fermi's team built
a nuclear reactor

out of wood, graphite
and uranium.

In a historic experiment
in December 1942,

"Chicago Pile 1" went critical,

spitting out energy and neutrons
at an ever-rising rate.

Their first-ever nuclear reactor
was actually creating

a self-sustaining
nuclear reaction.

Certain nuclei
would split in two.

That would release some neutrons
as well as energy.

Those neutrons then collide
with other atoms.

And then you get a cascade,
which we call a chain reaction.

Fermi's chain reaction

not only showed
an atomic bomb was possible,

but also provided
a more efficient way

to turn uranium-238
into plutonium.

From Fermi's experiment
emerged two distinct strategies

for making an atomic bomb.

One would seek to concentrate
the tiny amount

of natural uranium
that could be split.

The other would focus
on making plutonium.

Our challenge was to find a way

to separate relatively small
amounts of plutonium

from tons of material
so intensely radioactive

that no one could come near it.

As the magnitude
of the challenge became clear,

Seaborg would recruit
more than a hundred chemists

to join him in the effort.

"No matter what you do with
the rest of your life," I said,

"nothing will be as important
as your work on this project.

It will change the world."

In 1943, banking on the process
Seaborg's team had developed,

the U.S. government
began building

a huge separation plant
in Hanford, Washington.

Here, in buildings as long
as three football fields,

plutonium would be made
by remote control.

When my father got out there,

he was just awestruck,
and he couldn't believe

that this element
that he had discovered

would result in these
huge plants being built.

From Hanford

came the pounds of plutonium
that were needed for a bomb.

On July 16, 1945,

at a desert site near
Alamogordo, New Mexico,

scientists
from nearby Los Alamos

conducted the first test
of an atomic bomb

with a weapon made
from plutonium.

A blinding flash of light
and a deafening explosion

signaled the beginning
of the nuclear age.

Just three weeks later,
an American bomber

dropped a uranium bomb
on the city of Hiroshima,

killing 100,000 Japanese.

Three days after that,

a plutonium bomb destroyed
the city of Nagasaki,

finally bringing the war
to an end.

Only then could Seaborg
reveal the discovery

that had made this bomb
possible.

For their discovery of the first
two elements beyond uranium,

Ed McMillan and Glenn Seaborg

won the Nobel Prize
in Chemistry.

But Seaborg wasn't content
to rest on his laurels.

Seaborg had the ambition
to create more new elements,

to go beyond element 94,
beyond plutonium.

So even before the war ended,
he and his Chicago team

had resumed the hunt
for new elements.

Thank you, Bob Murphy,
and good evening, everyone...

Late in 1945,

my father was on a radio program
called "Quiz Kids."

A most distinguished scientist,
Glenn T. Seaborg.

And one of the kids asked him,
as kids do,

"Have you found any
new elements lately?"

Well yes, Dick.

Recently, there have been
two new elements discovered--

elements with atomic number 95
and 96.

And that's how the world came to
know about americium and curium.

Back at Berkeley after the war,

Seaborg and his team
continued their quest,

bombarding heavy elements
with smaller ones

in hopes they would fuse to form
a brand new type of matter.

They created five new elements
in the next ten years,

including berkelium
and californium,

and rearranged the periodic
table in the process.

Since Seaborg and McMillan
first ventured beyond uranium,

more than 25 new entries
have been added to the table,

including elements named
for Lawrence, Mendeleev,

Fermi, Einstein, Curie,
Rutherford, and Seaborg himself.

Around the world today,

others continue to hunt
for new elements

using techniques like those
Seaborg pioneered.

So far, there are 118
known elements,

each with its own distinct
personality.

And yet all these elements,
and any new ones we might find,

are made up of just a few things
in combination--

not air, water, earth and fire,
as the ancient Greeks believed,

but protons, neutrons
and electrons.

Amazingly, all of matter--

planets and stars,
plants and animals, you and me--

it's all made of just
these three basic parts--

protons, neutrons
and electrons--

mixed in different ratios.

We know all of this because
of a long chain of people

who've struggled to answer
the simple question,

"What is the world made of?"

We're surrounded by matter.

It's everything that we see
and interact with.

And yet at the time
this quest began,

nobody understood
what it was made of.

Nobody understood anything
about it.

Just making one tiny step

in the understanding
of the natural world

sometimes takes generations.

There is no guide book
to tell us how to do this.

We have to figure it out.

Nature is wonderful and
mysterious, and it is hidden.

But if you apply
the tools of science,

you can make it reveal
its secrets.

It's taken centuries
just to identify the elements,

with each generation
of scientists

building on the work of those
who came before.

But this is just the first step.

Still to be answered
are myriad questions

about how these building blocks
fit together

to make the infinite variety
of substances in nature,

and how we can combine them
in novel ways

to make fantastic new materials
nature never imagined.

Answering those questions
will take the efforts

of many more
scientific detectives

like the ones we've met.

As much as we've learned
in the search for the elements,

we've only begun to solve
the mystery of matter.