All language subtitles for The Modern Alchemist 3of3 The Philosophers Stone_Subtitles01.ENG

Gold. This is what alchemists
dreams were made of.

The medieval thinkers spent
their lives trying to find a way

to turn cheap metals,
such as this lead, into gold.

Success would bring them fame
and infinite fortune,

but is such magic even possible?

Join us in the search
for the philosopher's stone.

APPLAUSE

The alchemists were obsessed with
the idea of producing

a philosopher's stone.

A magical rock or powder that could
turn metals into gold.

There are even stories of espionage,
kidnap and even murder

in a bid to steal
the secret of the stone.

But what about the gold I just made?

Well, I'm afraid we cheated.

I'm not an alchemist.
My name is Dr Peter Wothers

and I'm a chemist
from the University of Cambridge.

I did start with lead.

It was a specially prepared
form of lead that reacts

with the oxygen from the air
to give this beautiful lead oxide.

This yellowy orange compound here.

So we did cheat here.

And my philosopher's stone, well,

it was just a hot coal which
started this reaction.

Some alchemists used this reaction
to try to convince people

that they could make gold.
But is such a feat even possible?

In the last of this year's Royal
Institution Christmas lectures,

I hope to find out.

In the previous lectures,

we've looked at the elements in the
air, and water, and now we are

going to look at the elements in the
earth and how we can extract them.

How we can use them and whether
we can turn one into another.

To help me, I have a giant periodic
table made up

of members from the audience
here at the Royal Institution.

Let's just look at the elements
we have already talked about.

We have lead, can you stand up,
please, lead? Thank you.

We were looking at you

and you were reacting with
the oxygen from the air.

Can you stand up please, oxygen? OK.

This is how we normally
find our metals in the earth.

We don't find them lying around,

they are normally combined with
the oxygen from the air.

Or maybe sulphur, or occasionally
other metals. Thank you very much.

If we put our periodic
tables down now, please.

But occasionally, we can find
metals just lying around.

The classic case is gold.
Where are you, gold?

You are so special because sometimes
you can be found just lying around.

In fact, here's a piece of you here.
This is a gold nugget.

Thank you, periodic table, at ease.

This is pure gold. And it can be
found like this in nature.

In fact,
this is how it is normally found.

Now the remarkable thing about gold
is that it doesn't change over time.

So you could leave it for tens,
hundreds, even thousands

of years and it'll still
have this beautiful appearance.

I've got a very old
piece of gold to show you now.

Would you please welcome, from the
Museum of London, Meriel Jeater.

APPLAUSE

I gather that this is a piece of
local gold, is that right?

Exactly, yes. It was found in London,
in Cannon Street in 1976.

It's actually a Roman gold and
emerald necklace. That's beautiful.

This is pure gold wire running
through these emeralds?

That's right, yes. And you say this
is from the early Roman times?

This is how old? Nearly 2,000 years
old, yes. 2,000 years old.

Has this been heavily restored?

It's been given a bit of a clean
to get the mud off.

Just the mud off and the gold itself
was looking just like this? Exactly.

That's why it's so wonderful
for archaeologists. Exactly.

For me as a chemist, I think it's
incredible that you can find

gold in this state
and it doesn't tarnish over time.

It doesn't combine with oxygen or
water or anything.

This is how you find it.

You can see that clearly it was
highly prized

and I think maybe you should take
it back to the museum.

Thank you very much. Pleasure.
Big round of applause, please.

APPLAUSE

This has lasted so well
because it was so highly prized,

so valued there but also
because it didn't change over time.

But, of course, we have a saying
about the value of gold.

Sometimes people are told,
"You're worth your weight in gold."

Have you ever been told you're
worth your weight in gold? Yeah.

Oh, you have! Oh, good.
Who told you that?

I can't remember. Probably a parent.

Maybe we should ask gold. Where's
gold sitting? Are you gold, yes?

Have you been told that you're
worth your weight in gold before?

I think my parents...
They've told you this, have they?

I think we should see just how much
gold that would be.

Would you like to come down to
the front, please?

APPLAUSE

Would you like to face
the front here.

Would you like to tell
everyone your name? Emma.

Take a seat on here.

If you just carefully sit down on
there. That's beautiful, lovely job.

OK, right, are you sitting
comfortably?

Yep. Then we'll begin.
This is where I get very excited.

This is all real gold. And it's
pretty good stuff, actually.

Have you ever held a big
block of gold before?

No. No. Well, have a feel of this.

That is pretty exciting, isn't it?
Would you like to feel this as well?

I'm afraid I can't let
everybody have...

I know, it's amazing, isn't it?

This is actually about the same as
six large bottles of fizzy pop.

I'm just going to put this on here.

OK, I think you need more than that.
Let's keep going.

Let's put this one on. It really is
pretty good stuff, this.

This is 24ct pure gold.

And this one here.

More. More still.

Not quite. No.
OK, let's try this one.

I think it's almost level
but not quite.

I think we need just
a little bit more.

Has anyone else in the audience
got any gold?

LAUGHTER

I found some on the way in.

Oh, you've got some?

Isn't that Nobel prize-winning
chemist Prof Sir Harry Kroto?

I think it is.

APPLAUSE

So what exactly...I think
I might know what this is.

Is this really your Nobel Prize?
Yes, they give them away.

This is solid gold, isn't it?
It's solid gold. And I want it back.

Well, of course, Harry.
I trust you. Oh, thank you.

Right, anyway,
maybe this is just what we need.

Let's just try that on there.

Oh, I think that's pretty well
balanced now.

I think that's quite amazing.

I think that is 43kg of gold and
one Nobel Prize.

Thank you very much.
Big round of applause.

Stay where you are for a moment.

APPLAUSE

Thank you, Prof Kroto, for saving
the day. This is quite amazing.

43kg, but it doesn't actually
look too much there, does it, Emma?

What do you think?

As you say, it's very dense

and this is why it doesn't actually
take up much space.

If you were made of gold,
you would weigh 800kg,

which is about as much
as a small car.

Which is quite a lot really, isn't
it? So that's pretty impressive.

How much do you think this is worth?
How much do you think? Have a guess.

Um...quite a lot.

I think you're right there.
Quite a lot, yes.

Anyone have any other ideas?
Shout it out. Yes?

One million? One million, actually,
you're not far off.

It is even more than that.

This is about £1.5 million
worth of gold just sitting here.

Which is pretty impressive,
isn't it? All right, now.

If you just stay where
you are sitting, please.

I need to unload this first of all.
I'll just take that and...

LAUGHTER

Just going to put these over here.

A few little bits left.

There we are. That's fantastic.
OK, thank you very much, Emma.

Big round of applause.

APPLAUSE

Gold really is an incredibly
dense substance.

But actually,
it's not the densest element.

Could we just have cards
up for a second, please?

That honour goes to osmium. You are
the densest thing in the universe.

Well, at least on Earth.
Did you know that?

I don't mean that in a bad way.
This is just you as an element.

Osmium is incredibly dense indeed.

Can we just keep the cards
up for the people in the same row

as osmium and gold.
Everyone else down.

Caesium stay up, barium stay up.
All the way over to mercury.

Why is it, then, that these
elements are so incredibly dense?

The most dense element is osmium,
closely followed by iridium.

Well, atoms after osmium,
iridium, gold,

all these other
ones are getting heavier.

So the atoms themselves are heavier

and yet these ones are the most
tightly packed.

So it's not just to do with how
heavy the atoms are.

We also need to look at the bonding
that we have between them.

And this is what
we can see in the graph here.

This shows how much energy
we need to put in to separate

a certain number of atoms
of these elements.

And we see that we've got
a peak around tungsten.

This is why we use tungsten
in light bulb filaments,

because it's very difficult
to pull them apart.

And we have very high temperatures.

But as we go beyond tungsten,
the bonding isn't quite so strong

but the atoms are getting heavier.

And so it's bit of a balance
between the strength of the bonds,

how tightly they are packed,
and how heavy the atoms are.

This is why we reach a maximum for
osmium and iridium.

Gold, platinum and so on are still
very dense afterwards,

but the maximum is there for
osmium and iridium.

So osmium is even more expensive
than gold, in fact.

And if someone was really going to
pay you a compliment

they would say, "You are worth
your weight in osmium."

Actually, these metals are not
the only precious things

we can extract from the earth.

There are even non-metals that we
can sometimes find as well.

Hello. Hello, Prof Kroto.

I'm assuming you would
like your Nobel Prize, would you?

I'd swap it for those bigger ones.
Yes, so would I, I think.

Well, there we go.
Thank you very much.

Perhaps you could tell us
what you won the Nobel Prize for.

It's for discovering
an alternative to these.

This is graphite and this is diamond.
These structures.

These are actually the only ones
that I knew about

when I was at school.

In the text books, there were just
two types of carbon.

Two different forms called
allotropes.

One has this arrangement.
This one is the graphite.

This is the sort of thing you
find in your pencils.

It's pretty soft and well, carbon,
it's just an arrangement of carbon.

Diamond looks very different
though, doesn't it?

I don't suppose...you've very
kindly lent us your gold,

I don't suppose you have a spare
diamond on you, do you?

I don't myself
but my wife actually has one.

A-ha! You don't want to take that as
well, do you? Well, just borrow it.

I hope I get it back. Thank you,
Mrs Kroto. Of course, yes.

You can trust me.

This is a beautiful ring here. Is it
an engagement ring or something?

It's really quite lovely.

The diamond comes out quite easily,
doesn't it? Yes.

LAUGHTER

We can see it more clearly now.
Look at that. It's beautiful.

What a beautiful diamond. It is
a real diamond though, is it?

It as real as you can get.
It's quite stunning.

Of course, we want to show that this
graphite is made up of carbon.

There is one way we can do this.

We can burn our carbon in oxygen
and we'll get, what would we get?

Carbon dioxide. See?
He's pretty good. Carbon dioxide.

And then if we bubble that through
lime water? Calcium carbonate.

Calcium carbonate. That's the test
for carbon dioxide, of course.

And it would be white.
I didn't ask you that one.

You are getting carried away now.
Let's just see this over here.

We have some apparatus.

This is where we are going to
burn some graphite

and show that it is made of carbon.

What's bubbling through
here is just oxygen.

This won't react
with our lime water at all.

We are going to see
if we can light the graphite

and get it burning inside the
oxygen. There we are. Thank you.

That's great.
So now we have a hydrogen flame.

This won't produce anything.
It's only going to produce water.

You can see the water just
beginning to condense.

Beautiful.
I'm going to turn the flame off.

Look at that. What do you think?
It's brilliant.

It is literally brilliant, yes.

This is the carbon combining with
oxygen that's flowing through here.

Hopefully, we are going to see this
changing colour, giving us

a milky colour. Showing that there
is carbon dioxide present.

I think we should test diamond as
well, don't you? What do you think?

ALL: Yes!

Yes? Does Mrs Kroto mind?

OK. In the name of science.
That's very kind of you.

Harry seems a little nervous.
Are you sure this is a real diamond?

I think it's a real diamond, yes.
Let's give it a go then.

We will just put it on there.
And again, we'll put this on here.

Right, so we have our flame.
Here we go. The moment of truth.

Now can we get our diamond to
burn in the oxygen?

WATER BUBBLES

Ah, look at that!

I hope you can afford to
pay for this.

The good news is, Harry, it is
a real diamond.

LAUGHTER

OK.

I think this is absolutely stunning.

That diamond there, it is
burning in oxygen.

It's combining with
the oxygen of the air.

Have you ever seen a diamond burning
like that before? No, I haven't.

It is quite stunning to see.
That's right.

There are no flames
coming from this.

So this is just the heat of the
reaction as the carbon combines

with the oxygen that's present,
flowing through here,

forming carbon dioxide. That is
absolutely stunning.

Just look at that.
It's glowing all by itself.

It's absolutely brilliant.
I think that's amazing.

And look,
our lime water is going milky.

It's the most expensive
lime water I've ever seen.

I think you are probably
right there.

It really is the most expensive
lime water you've ever seen.

Well, we are waiting for your
diamond just to... Disappear.

To disappear, yes.

Maybe you could tell us
about your Nobel Prize again.

I think it has something to do with
this. I think it does, yes.

Would you like to come round to
the front, actually.

We'll compare it to these ones.

This one was the graphite.
This is the diamond.

And this is the third form,
the well-characterised form.

It consists of 60 carbon
atoms in the shape of a soccer ball.

And it was such a fantastic surprise
when we discovered it.

One of the clues to its structure was
Mr Fuller's geodesic domes.

In Montreal, we had visited that.
And I remembered it.

It was in a book of mine

and when we were trying to work out
how a sheet of graphite like this,

or a graphing sheet, might close up,

what we discovered was, it could
close up if it had 12 pentagons.

You cannot close a sheet of
hexagons up. It won't close up.

But if you have 12 pentagons,
it will.

And you are all familiar with
that in the case of the normal

soccer ball with 12 black pentagons
and 20 hexagons.

And that's the magic that Mr Fuller
knew, and other people as well.

And I called it Buckminsterfullerene

because there are double
bonds as there are in benzene.

So the "ene" ending was just
a beautiful sort of ending

to a great name.

So since my time at school,
the textbooks have to be rewritten

with a new form of carbon
discovered by this chap here.

And colleagues in the States. And
your co-workers in the States.

We should have another
look at your diamond here.

It seems to have decreased in size.

I think we should come clean.

Don't worry, we didn't destroy
Mrs Kroto's engagement ring.

That really would be quite harsh.
This is a pretty low-grade diamond.

It still looks pretty good
to the naked eye

but the experts say it's not
very valuable at all.

But it is a real diamond.

And it is combining with oxygen

and I think that's a pretty stunning
reaction. Thank you, Prof Kroto.

It's a real privilege to have a
Nobel Prize winner here,

helping out with an experiment.
Thank you very much.

APPLAUSE

So is it possible that we could take
this worthless carbon dioxide

and get our diamond back from that?

I mean, that really would be
the alchemist's dream.

Recovering something
precious from something worthless.

We've got a demonstration here that
shows that this may be possible.

I'll just turn this round.

Now this tank is filled with
carbon dioxide gas.

We've put some solid carbon
dioxide in the bottom,

which is slowly evaporating,
turning into the gas.

We can't see the gas because,
of course, it's colourless.

But it is there.
How can we test for this?

Does anyone know another
use for carbon dioxide? Yes?

To put out flames.
To put out flames, yes, exactly.

I wonder if we have a flame, please.
Is there a flame anywhere?

Ah, yes. Here is a flame
that certainly needs putting out.

If I just lower
this into the tank...

There we are.
You can see that it goes out.

This is because, of course, the tank
is filled with carbon dioxide.

And carbon dioxide doesn't
support combustion.

Right, now then. We have also placed
in this tank some magnesium metal.

I'm just going to fish this out.

This is a little
nest of magnesium metal.

I'm going to
light the magnesium here

and it burns with a brilliant white
flame. There we are.

Now I'm going to lower
this into the carbon dioxide.

It seems to be burning even
more vigorously now.

The flame is still burning.

But what about this? This
one...well, this one still goes out.

Our petrol is extinguished
in the carbon dioxide,

but the magnesium
is reacting with it.

The magnesium is stealing the oxygen
away from the carbon dioxide

and, well, we'll have a look at what
we've got at the bottom

but let me take this out.
You can see magnesium oxide

covered over what was
the magnesium here,

but look in the centre.
What we've now got is black carbon.

The magnesium removes the oxygen
leaving behind the carbon

from the carbon dioxide.

We can get our carbon
back from carbon dioxide

but, well, it's not a diamond yet.

Is it possible to turn
that carbon into a diamond?

Well, actually, this is what happens
deep within the earth,

and this is a diamond in a rock

just as it would have
come out of the earth.

This is really quite
beautiful indeed.

Deep within the earth,
the carbon is heated up

and compressed with huge
temperatures, huge pressures,

and the carbon we saw there,
the black carbon,

is converted into diamond.

Recently, chemists have learnt
how to copy this process,

how to turn graphite or other
forms of carbon into diamond.

I'd like a volunteer to help me
out with this one, please.

Would you like to come down
to the front, please?

APPLAUSE

If you'd like to come down to
the front. Your name is...?

Lewis. Lewis, OK.
Now, this is a diamond.

Would you like to just hold this?

What do you think,
are you impressed? Yeah.

Looks like a piece of glass, doesn't
it? It actually really is a diamond.

This is a synthetically grown
diamond and this has been prepared

not from the high temperature, high
pressure system that we also use,

this is a technique
called chemical vapour deposition

where the diamond is gradually
built up a layer at a time.

I'd like you to take this,
not keep it, but bring it over here

and just place it on top.

This is some ice here.
Hold it like this.

Just put that on top of there
and push through this ice.

How does that feel? Cold. It feels
very cold and what's happening?

Water's coming off.

This is ice, solid ice,
and it seems to be going...

You've chopped all the way through
this quite cleanly there.

As you say, it's got very cold.

Do you know why it's got colder?
No idea.

It's used your energy
to heat up this block of ice,

so yes, you're getting cold
because it's taking the energy

from your fingers here.
Let's try this again.

If I just put this on here,
it slices through like butter.

It's really quite amazing.
It feels very strange.

I'm not sawing. It's not cutting
because it's hard,

it's cutting because it's
a very good conductor of heat.

Quite remarkable, so cleanly
through this block of ice.

Feels very strange. Thank you very
much, thank you for that.

APPLAUSE

That remarkable
property of diamond

was because it's an incredible
conductor of heat.

To demonstrate this
and explain why this is so,

I'd like some other volunteers,
please.

I'd like six people so if we could
have all of you, six of you,

if you could come down
to the front, please?

In a row, facing the audience.
Sit next to each other.

I'd like all of you to face that
direction, please,

turn around and face that way.

Just close up a little bit,
a little bit friendlier.

Come this way, please. Lovely job.
Close up there

and put your hands on the shoulders
of the person in front.

Face that way. That's good.

Now, at the moment, these are
all pretty weak bonds here.

Watch what happens when I give
a bit of energy this way.

Don't do anything,
just behave normally.

Lucy, can you feel anything?

It was very difficult to get
this energy through there

and this is because
of all these weak bonds.

What I'd like you to do is just
spread yourselves out a little more

and hold arms
with very rigid arms.

Rigid, straight arms. That's it.

Now I'm just going to do
the same thing again.

Give you a jolt that end and now you
can see you're certainly moving.

Thank you very much indeed,
thank you for all your help.

APPLAUSE

This is why our diamond is such
a good conductor of thermal energy.

It's because the bonds are so strong
holding these carbon atoms together,

they're so rigid, that this energy
is very easily transmitted through.

Diamond is the best conductor of
heat of any substance known,

until very recently when scientists
discovered a new form of carbon,

another form, called graphene,
which is a single sheet of graphite.

That is an even better conductor of
heat. They're the best ones known.

We've seen then that we can
convert charcoal,

we convert graphite into diamond
under very high pressures

or using the other technique
of chemical vapour deposition.

Surely if the alchemists had focused
on that, they would have changed

their attention away from trying
to turn base metals into gold.

But of course, they were focused
on metals because metals

were incredibly important
and still are very important.

It's only gold that has
this unique property

that we can find it lying around.
Most metals we find in their ores.

Ores like this here.

This is the natural mineral -
does anybody know what it is?

It is an iron ore.

Does anyone know what
the name of the iron ore would be?

Very good, you're doing well.
Hematite it is.

This is the mineral hematite.

This is now our source for iron

but it's locked up with the iron
combined with oxygen.

Somehow we have to learn how
to extract the metal out of this.

After all,
it doesn't just fall from the skies.

But remarkably, sometimes it does
just fall from the skies

and this is what we have here.

This is actually very heavy as well.

This is a lump of iron that did fall
from the skies about 5,000 years ago

and it landed in Australia.
Look at this.

What I wanted to show you here
was the comparison

between these two pieces.

We can see that this is developing
this reddish-brown colour,

the same as the hematite.

This contains iron.
It is a slice of iron

but it is gradually combining
with oxygen

to form this mineral hematite.

We can show that it is a meteorite

if we were to take a slice
through this.

If we took a slice through this,

what we would see
is something like this.

This is a slice through a meteorite
and it's really quite beautiful.

This has been cut
and we can see the side here.

This is the outer surface
of the meteorite

and here it's been cut with this
incredible pattern here.

This pattern
has been etched with acid.

It etches away certain types
of the minerals that are in here.

The forms of the iron, it etches
away certain of them

and it reveals this beautiful
crystal structure

and this proves
that it's a meteorite,

because it's impossible to get
this pattern here on Earth.

That's because we need to cool
down molten iron

with a little bit of nickel in.

We'd need to cool it down
over such a slow rate,

just one degree
over thousands of years,

if we wanted to see
these crystals develop.

This really is
quite stunning indeed.

Over time, the metal of this
beautiful meteorite

will turn into this ore here.

We can't wait thousands of years
to see that

but we can speed this process up

and we can show how iron combines
with the oxygen to form iron oxide.

I'd like a volunteer
for this one, please.

I'd like someone from this side,
who shall we have?

Would you like to come down
to the front, please?

APPLAUSE

Would you like to tell us
your name, please? Rose.

Rose, OK, we have some iron
over here. This is just iron wool.

Would you like to feel this?

It's just the sort of thing
you would use to clean your pots

and pans if you're
helping out at home.

Now, I'll put on my goggles

and we're going to combine this
with some oxygen.

We want to see how much this weighs
by itself. This weighs 15.9 grams.

Now, the question is,
what will happen

when this combines
with the oxygen from the air?

How do you think
its mass will change?

Will it go up, go down,
stay the same?

What do you think, when it burns?

It will go up? It will go up,
and why's that?

Because it will become more dense.
It will become more dense.

Let's have a look and see,
shall we?

I'm just going to apply
a light here.

This beautiful reaction is the
iron combining with the oxygen

and look what's happened
to the mass.

It's gone down. It's getting lower.

-0.16, so whoever said it
goes down, you're quite right.

But look now what's happening.
It's going up again.

It's is getting heavier so whoever
said it goes up, you're quite right.

Everyone's right, that's good.
Why did it go down?

It went down initially because
this iron wool was treated with oil,

just to try and stop it combining
with the oxygen from the air.

Once this reaction has
started, it is combining with oxygen

and that's why it's getting heavier.
You were quite right.

It is getting heavier because
the iron is forming iron oxide.

Thank you very much indeed.

APPLAUSE

Iron is pretty reactive stuff.

It reacts with oxygen
and this is how

we would normally find our metal,
combined with oxygen.

What about if you couldn't extract
the iron from this?

What about before we knew
how to do this?

The only iron that we would have had
would have been iron

from a natural source
such as this meteorite.

This sort of iron was used
to make tools and so on.

I think we have an example of a tool
using some natural iron here.

Would you please welcome
Dr Caroline Smith

from the Natural History Museum.

APPLAUSE

This is really beautiful.
What exactly is this?

This is an Inuit knife
and it's made of walrus tusk,

so walrus ivory, but in the end
you can hopefully see

it actually has an iron blade.

When this was discovered, the Inuits
hadn't yet learnt

how to make iron,
how to extract it from the ore.

That's right. They had to have
a source of metallic iron.

At the time, it was thought
that the iron in this knife

was actually from a meteorite called
the Cape York meteorite,

a very large meteorite
which was found in Greenland.

This knife actually
came from Greenland,

but we're not actually sure
that's right, now,

we think it might be
from somewhere else.

I gather that you've performed
an analysis on this

and more research suggests
that you are beginning to question

whether this is a meteorite,
but it has to be naturally occurring

because they didn't have the
technology.

Exactly. They didn't have
the technology to extract iron

from things like hematite
so they had to have a source

of native iron, metallic iron.

We think now that maybe
this is actually from a place

called Disko Island,

which is an island off the west coast
of Greenland,

and it's one of the very
few locations on earth

where you get metallic iron
existing in metallic form.

You very kindly brought
a couple of samples for us.

These are from Disko Island.

They look quite different but this
one clearly looks very metallic.

You can see this here,
it's got quite a shine to it.

It's quite a heavy specimen.
It is very heavy.

This looks like a piece of iron but
this is naturally occurring iron?

This is naturally occurring iron
found at the surface of the Earth.

In fact, tons of this iron
has been found.

But why hasn't this one
corroded into the hematite?

What we think happened is that
about 55 million years ago,

lava was erupted in this place,
in Disko Island,

and as the lava was coming up,

it went through sedimentary rocks
that have got a lot of carbon in,

and the lava picked the carbon up

and you've got a chemical reaction
happening where the iron,

which was bonded with oxygen
just like here in the hematite,

actually became metallic iron.
It reduced the iron from the lava.

We can see this is also
a sample of iron, so this is iron.

This is a sample of lava
from Disko Island

so there is some metal in there
but not as big as that.

This one is a very grey colour
and that's due to the graphite

and carbon in here?

You can see a bit
of a smudge on the paper.

There's a black smear there.

That's just from the carbon that's
present in here, the graphite?

That's right. Actually, we've got
a clip of a blast furnace to show.

This is how iron is now manufactured

and this is using carbon to steal
away the oxygen from the iron ore,

from the hematite.

This is how we're producing iron but
what you're saying now is that...

Nature beat us to it
about 55 million years ago.

Exactly. That is quite amazing.

Thank you very much for bringing
these samples on.

Now, I really wanted to produce
some molten iron for you

here in the lecture theatre,
but clearly we couldn't bring in

a blast furnace, so we had to think
of another way to do this.

We can learn
from what we did earlier,

when we used the magnesium metal
to steal the oxygen away

from the carbon dioxide.

We can do the same thing now
with our iron oxide.

We can use a more reactive metal

and we are going to use
the metal, aluminium.

You may be wondering why there's
a safe under here.

This is because we have a bit
of an embarrassing story here.

We accidentally locked Andy's
Christmas bonus in the safe.

We tried getting into the safe
and it's pretty hard.

It's made of pretty solid stuff.
We can't really get into this

but the energy generated
as the oxygen is taken away

by the aluminium to form iron
should be enough to get in here.

Can we have a little look in here?

Get the camera right in to show
what's inside this vessel.

This is made of a very tough form
of carbon. This is made of graphite,

and you may be able to see
the orangey colour.

That's our iron oxide.
It's mixed with aluminium powder.

The thing you see sticking out there
is a little bit of magnesium

I'm going to use to start
this reaction.

Hopefully, we should generate
some iron

and see if we can get through
into the safe.

Sounds like a good idea, doesn't it?
If it's the only way to do it.

I think we will need
a safety screen around this, though.

I'm going to need a glove as well.
Thank you very much.

Feeling confident? Yeah, I can't see
what could go wrong.

What could possibly go wrong?
Exactly.

Let's give it a go. You'll see
a bright white light first of all.

That's just the magnesium
we saw earlier.

The magnesium combining
with the oxygen from the air.

OK. We should know when it starts.
I think it's started now!

This is our little blast furnace
here. Look at that, fantastic.

We've got some molten metal there.
Can we lose the safety screen?

That would be good if we can
possibly take this off. Lovely job.

Right off the top very carefully.
I'm just going to see...

I'll give you that,
see if we can pick up this.

What have we got here?
Yes, that's wonderful.

It releases such an enormous amount
of energy

as the aluminium combines with
the oxygen from the iron oxide.

Good news, Andy.
Good news and bad news.

The good news is there's a hole
in the top of the safe.

The bad news is there's a lot
of smoke coming from outside.

I think I've just found
the key as well!

Now he finds the key! At least
we got into the safe, well done.

Thank you very much for that.

APPLAUSE

We formed there during
that reaction aluminium oxide

as the aluminium
took the oxygen away.

This is how we find
aluminium in nature.

We find it as aluminium oxide
and here's a sample here.

What do you think of that?

It is light and this is because
it's a very light metal, aluminium.

How can we get
our aluminium out of this rock?

This, for a long time,
was a great problem.

It was only solved when chemists
realised they could use

an even more reactive metal
and this was the metal over here,

the metal potassium.

When this was first discovered,
it was a bit of a curiosity.

There was this amazing
substance, aluminium,

and it did have very
remarkable properties.

I'll need another volunteer
from the audience.

We'll have someone this side.

In the green, would you like
to come down, please?

APPLAUSE

Your name is? Ailish.
Ailish, OK, great.

Obviously you've seen a lot
of aluminium before, haven't you?

It's very cheap now because now
we have worked out

how to extract it from the ores,
but initially,

it was incredibly difficult and that
made it incredibly expensive.

In fact, so valuable
and so strange that this chap,

this is Napoleon III,

he had a whole cutlery set
made from aluminium.

I think we have some
aluminium utensils here

so you have a look at these.
What do you think?

Very light. They are very light,
aren't they?

This was the remarkable thing.

With Napoleon's cutlery set,
he had his cutlery,

and it was so valuable
that if he had a huge feast,

he would give his most honoured
guests the aluminium cutlery

and all the rest
had to make do with gold.

OK, it seems strange to us now

because we do know
how to extract aluminium

and it is incredibly abundant
and we can find loads of it around

but it was very difficult
to get it out.

Can I just say,
it does feel very light indeed.

That is one
of the remarkable properties.

It isn't actually
the lightest metal that's known.

Do you know what the lightest metal
is? Lithium.

Oh, yes, you're quite right. It is
lithium. Give us a wave, lithium!

Lithium is in fact a metal
and it is incredibly light.

We have made the world's first
lithium spoon,

which is very exciting. Here it is.

This is our special RI spoon.

Isn't that beautiful?
Would you like to feel this?

It's really light.
It really is. It's amazingly light.

It feels almost like plastic
but it is solid metal.

It is quite remarkable,
don't you think?

This is my dinner, I think.

Some soup. Of course,
cutlery sinks in it,

but would you just drop it in
and step back?

Look at that? First of all,

it is incredibly light
and it's floating on the surface,

but it's also reacting.

I'm going to fish that out.
It's very reactive indeed.

I don't think lithium spoons are
going to catch on at all, do you?

This is because it's just
too reactive. Too explosive.

Exactly, thank you very much indeed.

APPLAUSE

A bit of coughing there
just from the reaction

as the lithium combines
with the oxygen.

It's reacting with the water vapour.

COUGHING

Yes, yes. Thank you. The lithium
there, it floats on the surface.

It is incredibly light but
it's incredibly reactive as well.

That may be the world's
first lithium spoon

but I think it's safe to say it's
also going to be the world's last.

It does show how reactive lithium is
and maybe be can use this element

to prepare new elements,
and we can indeed.

We have a reaction here to generate
a new element from silicon dioxide.

Does anyone know
where we find silicon dioxide?

Any ideas, right at the back?

In sand, you're quite right.

We find silicon dioxide, it is sand.

We've got some lithium in here
and some sand.

We've mixed the two together, little
lithium pelts and some sand,

and I'm going to heat this up
at the moment and see what happens.

This is lithium with silicon dioxide

and the silicon dioxide
is a mineral, it's just sand.

Quartz is the same stuff,
silicon dioxide,

so sand is smashed up
pieces of quartz.

I'm hoping that we should see
a reaction take place

and there we are.

This is a very violent
reaction again

and this is as the lithium
is stealing the oxygen away

from the silicon dioxide
that makes up the sand.

Anyone have a guess at what we're
going to make? Silicon, very good.

We take the oxygen away
from the silicon dioxide

and we end up with silicon.

Remarkably, this is a single crystal

of a very purified silicon.

It's very valuable and very precious

and I need to put on some
special gloves for this.

It's hard, it's very solid.

It's sort of like a metal
and it's incredibly heavy.

Actually, I can hardly
lift this thing up,

but it's grown in this
very special way here.

This is one crystal of silicon

but it has a seam running
all the way along the top here.

This just proves that it is
in fact one crystal.

Why do people grow these?

They grow them
from the molten silicon.

They would keep purifying it,
heating it

and allowing it to cool into
this rather strange-looking shape.

They do this because they're
trying to make these,

and this is a silicon wafer.

It's just a sheet of silicon,
just a slice from this,

and these are used to make
silicon chips.

This is the same slice of silicon

and then they're etching in
and adding other reagents to this,

gradually building up
the silicon chips that we have

in our mobile phones
and in our computers.

A fantastic use for this element,
silicon.

The element we extract from sand.

Chemists are always finding new uses
for the elements.

Even though this has been known
for well over 100 years,

it is only relatively recently
that we have found out

how to use this element
to make silicon chips.

So far in the lecture,

we swapped elements around
to make different useful materials.

We've stolen oxygen
from iron oxide to make iron,

and we've stolen it from sand.

We've even rearranged
the structures of carbon

to turn graphite into diamond.

What we still haven't done
is turn one element into another.

That's what the alchemists were
trying to do,

to turn lead into gold.
Is this possible?

Can we turn one element
into another?

Yes, this is
the process of radioactivity,

and this occurs deep in the Earth
and indeed all around us.

Can we have our periodic table up,
please?

Those of you,
you elements who are radioactive,

I'd like you to stand up, please.

All the radioactive elements.
That's all of this front row here.

Yes, you're all radioactive.

Bismuth, we're not sure about you,
you're unknown,

but actually you're so radioactive,

you're no longer
who you thought you were.

You'd better sit down again.
What does that mean?

Why do you have to sit down again?

It's because
during radioactive decay,

an element changes
into another element.

If we have cards down for a moment,
please?

Remember,
what makes an element unique

is the heart of the atom itself.

That's the number of protons
that it has within it.

This represents
what's inside an atom.

This is its nucleus, and we have to
count the number of the red spheres,

these represent the protons,

to work out what element this is.

In fact, this is the element
uranium.

The thing about uranium is - oops -
it's unstable,

and bits drop off.

The nucleus here just gets so large

that it's very difficult for all
these things to stay together

and, yes, bits do drop off
and when they drop off,

it's changed into different element.

It's the number of the red protons
that define an element,

so if we lose two,

it's no longer what we thought
it was to start off with.

Can we find uranium in our periodic
table. Where's uranium?

Would you like to stand up?

Uranium, you are radioactive,
and bits do drop off.

Quite slowly, don't worry,
we won't notice.

But actually when it does happen,
when it does fall off,

you change into a different element

and you move a couple
of spaces along.

You become thorium, so maybe you
should move over to thorium.

Better put your card down because
you're not "U" any more. Get it?

You're no longer you,
you're actually thorium.

You'd better go over there,
you are on thorium's space now.

Actually, both thorium
and uranium have also decayed,

and if you decay now, you're going
to become the element radon.

You're also radioactive, I'm afraid,
so if you decay,

you lose a couple of protons
in an alpha particle.

You're not radon any more,
you've become polonium.

Can we see this in action?

We can, using this apparatus here.

This is known as a cloud chamber.

The tank that we see here contains
an atmosphere of alcohol vapour

and it's got a lot of vapour
in there

and it's actually trying
to form little droplets.

There's a temperature gradient.

There's a little heating wire
at the top and it's cooled down

from underneath,
so it's gradually freezing.

It wants to form droplets
but actually it's much easier

if there's something there
to help it.

Any charged particles
can cause this.

All the tracks that you can see now,

all these little wispy white trails,

are actually particles of radiation.

This is natural radiation
just in the air around us.

We don't tend to think of
radioactivity as being very natural,

but of course,
we're all weakly radioactive

because of some of
the radioactive elements in us.

Here, we can see radiation in action
here just in the air around us.

I'm going to introduce into this
a sample of a radioactive element

called americium.

Look at that.
You can see the tracks forming here.

Each little track that we see is the
result of a charged particle

being emitted
from the element americium

and the particles emitted
are alpha particles.

The alpha particle is two protons,
two neutrons,

and actually that is the heart
of an atom of helium.

What we're actually seeing here
is the birth of helium atoms,

which I think is quite remarkable.
I'll just put this away.

It is possible then
to change one atom into another.

Nature seems to do this, but can we?

Actually, it is possible,

and one of the first people to
generate lots of different atoms

was this chap here, Glenn Seaborg.

In fact, he even has an element
named after him.

Where's seaborgium? There we are,

right in the middle
of the periodic table.

In 1980, Seaborg did
an amazing experiment.

He took bismuth
and he turned it into gold.

This is what the alchemists
had been dreaming of.

He changed one element into gold.

What he did was take bismuth -

can we have our periodic table
up for a second, please?

He took the element bismuth and
he fired atoms of carbon and neon

at this and it knocked out
a number of protons

until we ended up with gold.

Unfortunately, he only ended up
with the few thousand atoms

and this is not enough
to get him rich.

It was a very expensive experiment,
took a lot of money to get this

and all he made was a few atoms,
but it is possible to do it.

Radioactivity is a natural process
but it can also be brought about

by firing one atom at another,

and changing it and creating new,
heavier elements

or even to make gold.

Do we even want to make gold?

Are there other things
that fascinated the alchemists

which modern scientists
have taken one step further?

This is another
naturally occurring rock

that has really quite
remarkable properties.

This one amazed
the early alchemists.

I'll show you why.

Over here, our audience members
have some paper clips.

Have you got some paper clips?

I'd like you to put your paper clips
onto here, just onto the rock.

They should stick by themselves.

It's not a surprise to us because
we've all seen magnets before,

but just imagine if you were the
first person to ever see a magnet.

I have a book here from the 1530s

that describes this magnetic rock,
this lodestone.

They really did find it
quite remarkable.

This here shows this magnetic rock.

There's a ship sailing past
a mountain that's supposedly made

of this lodestone,
this magnetic ore.

You can see here, these are
the nails from the ship.

They've supposedly been sucked
out of the ship, so this is

a sort of warning that there's this
incredibly strange magical material

with these amazing properties
which would suck the nails

out of your ship
and you'd be shipwrecked.

There's a warning for you.
OK, thank you.

Nowadays, scientists have learned
how to make even stronger magnets

from the elements, and if we just
have our periodic table up again,

some of the strongest magnets
now made use the element neodymium.

Give us a wave, up there, very good.

The strongest magnets in the world
are made with neodymium.

This element was discovered
in the 1880s,

but it was over 100 years later
that scientists learnt how to use

this element
to create these magnets.

Thank you very much, periodic table.

I have a couple
of these magnets here

and they really
are very strong indeed.

These are little neodymium magnets.

Here we are, just try to pull
these apart?

I can't. Are they stuck together?

No, they're not stuck together.
Try again.

Give them to your neighbour,
see if he can get them?

Can you pull those apart? No.

I promise you
they're not stuck together.

I could probably slide them or
something if I push. Look at that.

They're very strong magnets indeed.

Even though the element neodymium
has been known for over 100 years,

these magnets have only
recently been developed.

Now, these really are quite strong

and I think to show just how strong
these are, I need another volunteer.

I think we should have
one from this side.

Would you like to come down
to the front, please?

APPLAUSE

OK, very good. Are you feeling
strong? You are, that's good.

Tell us your name, please.
Marie. Marie.

We're just going
to bring down this rig here.

We're going to suspend you
from the ceiling

using this little magnet here.
That's the only magnet.

This is a block of iron.
It's not magnetic.

I can show that with a paper clip,

just holding the paper clip,
it stays on it

but it's not attracted to it.

This is our magnet.

I'm not going to put the paper clip
on this, I'd never get it off again.

If you'd like
to come over here, please.

I just need to very carefully
put this in the middle. Perfect.

Just clip this on as well.

OK, so you're feeling strong?

If you just hold on to here.
That's it.

Can you just raise up the
winch then, please?

Hold on strong, hold on tightly and
we'll just see if we can lift you

off the ground so you need
to hold on very tightly.

Might need to move forward
a little bit.

Keep holding on
and just watch the feet.

There we are, look at that!

You are now suspended
from the ceiling. That's fantastic!

APPLAUSE

It really is pretty strong
magnets there.

We can actually hang from them.

It's just using the power
of these new magnets

but these are incredibly useful
and they find uses for instance

in turbines, but are also used
in electric cars and so on as well.

These new materials -
very, very useful.

We can create even more amazing
materials using the elements.

Can we just have our periodic table
up for a moment?

We were using magnets
there to suspend

and these were
the neodymium magnets,

but this, we're going to use
some superconductors

and the superconductors
are made from the elements yttrium,

just here. Give us a wave, yttrium.

And from barium, so give us
a wave, barium. Very good.

And copper.
OK, there's copper,

and oxygen at the top there.

Put you four elements together
and we get these amazing materials -

high-temperature superconductors.

This is called a Mobius strip.
It's a rather strange looking thing.

How many sides has this got? Two.
Well, you'd think so.

Actually, if you start here
and you keep on going round,

you actually come back underneath.

If you keep going round, you come
back where you started from.

It actually has one side,
this mathematical shape,

which is very unusual.

I can show you this using
our little superconductor.

This Mobius strip is covered
with these neodymium magnets,

these very strong magnets.
We've got a superconductor here

and this is the superconductor

that's made from the barium, the
yttrium, the copper and the oxygen.

This is the ceramic there.
This is this disc in the centre.

We are cooling it
with liquid nitrogen

in this little holding tray
on the top.

It levitates quite nicely.

There we are, it's come back
to where it was.

Now it's actually hanging
underneath this strip,

but it needs to be cooled down

so we are cooling it
with liquid nitrogen.

That's in order to enable
these superconductors to work.

They only work at these
very low temperatures,

so eventually it's going to warm up
and it will fall off the track

so you need to catch it
when it does fall.

You're meant to catch it!

Just pass it to me straight away,
thank you. That's lovely.

Thank you very much.
Thank you for all your help there.

APPLAUSE

Really quite remarkable properties
then of this ceramic

made out of the elements barium,
yttrium, copper and oxygen.

We've come a long way
since the days of the alchemists

when the whole world could be made
from air, water, earth and fire.

I hope you've enjoyed our quest
to discover

what's really making up
the world around us.

If you remember one thing
from these lectures,

it's that the work of the chemist
is not complete.

New combinations are being
discovered all the time

and nobody knows what exciting
properties they may have.

I'd like everyone to pick up
your cards one last time

and have a look at your card.

Just remember what element you've
got, and I want you to go home

and research about your element

and think what uses
can we put this element to,

and what new possibilities
could there be? Who knows?

You may be able to solve some
of the challenges of the future

and maybe even make something
more valuable than gold.

Thank you and goodnight.

APPLAUSE

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