The great texts of the ancient world

don't survive to us in their original form.

They survive because Medieval scribes copied them

and copied them and copied them.

And so it is which Archimedes,

the great Greek mathematician.

Everything we know about Archimedes as a mathematician

we know about because of just three books,

and they're called A, B and C.

And A was lost by an Italian humanist in 1564.

And B was last heard of in the Pope's Library

about a hundred miles north of Rome in [unclear] in 1311.

Now Codex C was only discovered in 1906,

and it landed on my desk in Baltimore

on the 19th of January, 1999.

And this is Codex C here.

Now Codex C is actually buried in this book.

It's buried treasure.

Because this book is actually a prayer book.

It was finished by a guy called Johannes Myrones

on the 14th of April, 2029.

And to make his prayer book he used parchment.

But he didn't use new parchment,

he used parchment recycled from earlier manuscripts,

and there were seven of them.

And Archimedes Codex C was just one of those seven.

He took apart the Archimedes manuscript and the other seven manuscripts.

He erased all of their texts,

and then he cut the sheets down in the middle,

he shuffled them up,

and he rotated them 90 degrees,

and he wrote prayers on top of these books.

And essentially these seven manuscripts

disappeared for 700 years, and we have a prayer book.

The prayer book was discovered by this guy,

Johan Ludvig Heiberg, in 1906.

And with just a magnifying glass,

he transcribed as much of the text as he could.

And the thing is that he found two texts in this manuscript

that were unique texts.

They weren't an A and B at all;

they were completely new texts by Archimedes,

and they were called "The Method" and "The Stomachion."

And it became a world famous manuscript.

Now it should be clear by now

that this book is in bad condition.

It got in worse condition in the 20th century

after Heiberg saw it.

Forgeries were painted over it,

and it suffered very badly from mold.

This book is the definition of a write-off.

It's the sort of book

that you thought would be in an institution.

But it's not in an institution,

it was bought by a private owner in 1998.

Why did he buy this book?

Because he wanted to make that which was fragile safe.

He wanted to make that which was unique ubiquitous.

He wanted to make that which was expensive free.

And he wanted to do this as a matter of principle.

Because not many people are really going to read Archimedes in ancient Greek,

but they should have the chance to do it.

So he gathered around himself the friends of Archimedes,

and he promised to pay for all the work.

And it was an expensive job,

but actually it wouldn't be as much as you think

because these people, they didn't come for money,

they came for Archimedes.

And they came from all sorts of different backgrounds.

They came in from particle physics,

they came from classical philology,

they came from book conservation,

they came from ancient mathematics,

they came from data management,

they came from scientific imaging and program management.

And they got together to work on this manuscript.

The first problem was a conservation problem.

And this is the sort of thing that we had to deal with.

There was glue on the spine of the book.

And if you look at this photograph carefully,

the bottom half of this rather brown.

And that glue is hide glue.

Now if you're a conservator,

you can take off this glue reasonably easily.

The top half is Elmer's wood glue.

It's polyvinyl acetate emulsion.

It doesn't dissolve in water once it's dry.

And it's much tougher than the parchment that it was written on.

And so before we could start imagining Archimedes,

we had to take this book apart.

So it took four years to take it off.

And this is a rare action shot, ladies and gentlemen.

(Laughter)

Another thing is that we had to get rid of all the wax,

because this was used in the liturgical services

of the Greek Orthodox Church

and they'd used candle wax.

And the candle wax was dirty,

and we couldn't image through the wax.

So very carefully we had to mechanically scrape off all the wax.

It's hard to tell you exactly

how bad the condition of this book is,

but it came out in little bits very often.

And normally in a book, you wouldn't worry about the little bits,

but these little bits might contain unique Archimedes text.

So tiny fragments

we actually managed to put back in the right place.

Then, having done that, we started to image the manuscript.

And we imaged the manuscript

in 14 different wave-bands of light.

Because if you look at something in different wave-bands of light,

you see different things.

And here is an image of a page

imaged in 14 different wave-bands of light.

But none of them worked.

So what we did was we processed the images together,

and we put two images into one blank screen.

And here are two different images of the Archimedes manuscript.

And the image on the left

is the normal red image.

And the image on the right is an ultraviolet image.

And in the image on the right

you might be able to see some of the Archimedes writing.

If you merge them together into one digital canvas,

the parchment is brightened in both images

and it comes out bright.

The prayer book is dark in both images

and it comes our dark.

The Archimedes text is dark in one image and bright in another.

And it'll come out dark but red,

and then you can start to read it rather clearly.

And that's what it looks like.

Now that's a before and after image,

but you don't read the image on the screen like that.

You zoom in and you zoom in

and you zoom in and you zoom in,

and you can just read it now.

(Applause)

If you process the same two images in a different way,

you can actually get rid of the prayer book text.

And this is terribly important.

Because the diagrams in the manuscript

are the unique source for the diagrams

that Archimedes drew in the sand in the fourth century B.C.

And there we are, I can give them to you.

With this kind of imaging --

this kind of infrared, ultraviolet, invisible light imaging --

we were never going to image through the gold ground forgeries.

How were we going to to that?

Well we took the manuscript,

and we decided to image it in X-ray florescence imaging.

So an X-ray comes in on the diagram on the left

and it knocks out an electron from the inner shell of an atom.

And that electron disappears.

And as it disappears an electron form a shell farther out

jumps in and takes its place.

And when it takes its place,

it sheds electromagnetic radiation.

It sheds an X-ray.

And this X-ray is specific in its wavelength

to the atom that it hits.

And what we wanted to get

was the iron.

Because the ink was written in iron.

And if we can map

where this X-ray that comes out, where it comes from,

we can map all the iron on the page,

and theoretically we can read the image.

The thing is that you need a very powerful light source to do this.

So we too it to the Stanford Synchrotron Radiation Laboratory

in California,

which is a particle accelerator.

Electrons go around one way,

positrons go around the other.

They meet in the middle,

and they create subatomic particles

like the [unclear] quark and the [unclear] electron.