[ music ]
>> Going to talk about secrets
in the ancient goat skin.
Archimedes oldest writings
under x-ray vision.
Uva is a senior staff scientist
at the Stanford synchrotron
radiation laboratory
in Palo Alto.
And I would say he's
sort of living
out the scientist's dream.
The scientist's dream you
thought was to get a Nobel Prize
or something like that but
maybe the scientist's dream is
to really hit on something or
do an experiment or do a theory
that really captures everyone's
imagination such that everyone
around the world wants
to hear about your work.
I think that's really
the scientist's dream
and I think Uva is
living that out right now.
I first heard about the
Archimedes palimpsest
in a PBS Nova presentation
about two years ago.
I then invited a person who
was featured on that show;
Chris Rory's from Drexel
University and an expert
on Archimedes and his works
to give a lecture here
in this colloquium series.
And he spoke last year
on a subject called
if Archimedes had a
computer why ships,
icebergs and buildings topple.
Maybe some of you
remember that talk.
Jan Hall in Boulder, are one
of our Nobel Laureates heard
that talk and subsequently
told me
that he had heard Uva Bergman
give a talk about the palimpsest
and the use of x-ray
measurements
to interpret the writings
and he said it was the best
talk he had ever heard.
And if I had the opportunity I
should invite Uva to give a talk
in this colloquium series.
And so that's how Uva
comes to us today.
His undergraduate, Uva's
undergraduate education was
in Germany at the
university of Carls Rua
[ assumed spelling ]
and also the university
of Hamburg.
He did his PhD work
in the United States
at the state university
of New York
at Stonybrook doing experiments
at the Brookhaven storage ring.
He did, subsequently
he did post doc work
at the European synchrotron
radiation facility in Grenoble
and also at the Lawrence
Berkeley lab.
Before coming to Stanford he
also had positions at Berkeley
and at the University
of California at Davis.
His research interests are
basically the development
and application of synchrotron
based hard x-ray measurements,
hard x-rays being
maybe in the five
to fifteen kilovolt
energy range.
The methods that he uses
and develops are emission
and absorption spectroscopy,
x-ray fluorescence imaging,
which by the way is the method
that will be highlighted today
in his talk, as well
as various types
of x-ray scattering experiments,
both resonant and non resonant.
The methods he uses have
been demonstrated and applied
to a variety of targets
or systems,
for example metaloproteins
[ assumed spelling ]
and biocatalysis
[ assumed spelling ]
, so he's got a foot in
the biotechnology area.
3-D transition metal compounds,
water and aqueous materials
which is a recent interest
of his, hydrocarbons
and fossil fuels and he's also
been involved in measurements
that we can hear about today on
ancient manuscripts, fossils,
and even brain sections.
So you can see he spans a
lot of applications and has
that diversity of experiments
that he's contributed to.
In any case, Uva has caught
the tiger by the tail.
He's been invited all over
the world to give this talk
and I'm delighted that
he is able to visit us
from sunny California today.
Would you join me in
welcoming Uva Bergman.
[ applause ]
[ silence ]
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>> I don't see my screen up.
[ silence ]
>> Those of you who
came in late,
we've got three big
glasses here.
[ inaudible ]
[ silence ]
>> Thank you very much for
this kind announcement.
I hope that, that was
not an exaggeration.
The, yeah so please
help yourself to the,
I hope they're enough.
If not, maybe you can
share some of them.
It's a great pleasure for
me to be talking at Myst
[ assumed spelling ]
. Myst is one of those labs
which when I was a child
I already heard about it.
It's a very famous place and
it's, and I think about it
as that's where you define
really what one second is
and what one meter is, etcetera.
And it's a really true
pleasure to be here.
The, I should say one thing,
the 3-D glasses are not needed
until the very end and
I will let you know
when they are needed.
So don't put them on quite yet.
I wouldn't have thought, I mean,
about four years ago I
would've never thought to get
into this project but I have
to say it has been a lot of fun
and I really have enjoyed doing
it even though it's a little bit
out of my normal
type of research.
This was the headlines
on July sixteen 1907 just
about 100 years ago.
In then called Constantinople
now Istanbul,
the Danish scholar Johan
Ludvig Heiberg discovered
that in an ancient thirteenth
century prayer book there were
drawings and writings from
the Greek genius Archimedes.
But let's start our
story earlier than that.
What you see here could
remind you if you live
in California it might remind
you of the Sierra foothills
on a sunny day, but in
fact it's the location
where on September
eleventh, 490 BC the fate
of western civilization was
hanging on a very thin thread.
A huge Persian army had landed
on the shore of Marathon,
led by King Darius
and was trying
to invade the Greek islands.
The Greeks after several
discussions sent Miltiades
with an army of 10,000 Athenians
and a 1,000 platoons
to the fight.
They were heavily outnumbered,
probably three to one at least.
About a mile away from the
battlefield the Greeks formed
their usual phalanx meaning
it looks like a turtle,
they all put their shields
up and slowly start to march.
When they reached about 200
yards just outside the reach
of the Persian archers,
they changed their tactics
into something which
hadn't happened
in ancient warfare until then.
Rather than slowly
walking into the hail
of the arrows they
rushed down the hill,
some of them later said
that they thought the
Greeks had lost their minds.
But what they really did
with this ingenious attack,
they completely surprised the
Persians, got into an in fight
and being much heavier armed
than the Persians they had
at that point the advantage.
The battle of Marathon
took a very short time.
At the end it is reported
that 6,400 Persian soldiers
were killed as compared to less
than 200 Greek fighters.
It was a complete defeat.
One of the Greek fighters with
the name of Pheidippides was,
and that is a legend, was
said to have run to Athens
to report victory after which
he supposedly dropped dead.
The distance, some in this room
might regret that Athens is
so far away from Marathon.
It was the first
victory of a new form
of a government namely
a democratic government.
It was also the first victory
of the oxidant over the orient.
It was not the only battle,
there were many battles before
and after, but this
is considered as one
of the most important ones.
And it marked the beginning of
the, of western civilization
and the age of classics.
There were the great
Greek philosophers,
the first one, Socrates.
Famous for saying, all I
know is I know nothing.
He was born just 20 years
after the battle of Marathon.
His student, Plato.
Besides writing very
important books like Republica,
he also had a saying
called ignorance the root
and the stem of every evil.
I think this holds today as much
as it did over 2000 years ago.
And he had a student, Aristotle,
who was by some considered
the first scientist.
He was very methodical
about how he did his work.
He also came up with this
extremely famous saying the
whole is more than
the sum of its parts.
He also happened to be the
teacher of a 13-year-old boy
with the name of Alexander,
later known as Alexander
the Great.
And then of course there were
the Greek mathematicians;
Euclid of Alexandria.
He is the one after whom we name
our three dimensional space.
A concept which has held 2200
years and has was thought
to be correctly describing
our universe
until Albert Einstein changed
everything by suggesting
that there is a four dimensional
space-time continuum.
And then there was
Archimedes of Syracuse.
Without any question,
the most influential
of the mathematicians,
and you can say that all
of modern science has
been based on concepts
which were developed
by Archimedes.
He was born, and he died
tragically at the age of 74,
75 years and the city state
of Syracuse in Sicily,
which was a Greek city state.
He was sent to Alexandria
to learn the teaching
to read the readings of
Aristotle and also of Euclid,
and he was not only a
mathematician he was an
engineer, he was an inventor,
and some would say
he was a physicist.
For example he invented
the pulley,
a tool which is used today, as
has been for thousands of years.
We name after him the Archimedes
crew, which is a pump system
to pump water from a lower
level to an upper level
and the same concept
is of course used all
around the world even today.
Those type of old Archimedes
crews are still used
in Third World countries and
I think even some of the pumps
in the car might
be similar to that.
During the siege of Syracuse
by the Romans, Archimedes came
up with a defense mechanism
depicted here of a combination
of hooks and levers
and it was used
to shake the Roman battleships
sometimes from underneath
and it was reported that they
were scared by this and in fact,
Syracuse was held much
longer with that help,
but eventually it did
fall to the Romans.
Probably most famous,
and I should say
that this is purely a legend.
We don't know how much truth is
to it is the eureka
moment of Archimedes.
King Heroes had a wreath and
he wanted to know he had given
that to the goldsmith to make
him a wreath out of pure gold,
and he wasn't sure whether the
goldsmith hadn't betrayed him
so we wanted to find out how can
we check whether this is really
pure gold, and you can
see that a wreath is
such a complex object that
is basically impossible
to calculate the volume even
though you can easily measure
its weight.
And he went to Archimedes
to for help
and supposedly Archimedes
taking a bath found the solution
and was so excited about it
that he reportedly ran naked
through the streets of Syracuse.
What Archimedes of
course had figured out is
that you can measure very easily
the volume of any object just
by dipping it into a liquid
and then measuring the
displacement of the liquid.
One way you could have done this
experiment then is you take the
wreath and put an equal amount
in weight of gold on a balance
and dip them both in water.
If they don't stay in
balance, it means the density
of the one object has
to be lower or higher.
And that's reportedly
what happened
so you can imagine King Heroes
was not very pleased about that.
Archimedes, and that
is very important.
He invented the law
of the lever,
very well known by our children.
If you have two objects A and B.
with mass A and B placing them
at a distance A and,
small A and small B,
A times A equals B times
B. How did he do that?
I'll show you a very short and
very beautiful, elegant way.
Suppose you have two objects
of equal weight you put them
at the same distance
they will balance.
There is no surprise,
and you can replace 2 x 4
or you can put the
4 in the center.
This will always
balance each other.
Now let's say we put 16
on there and we take 4
of them and replace them.
We put a larger one in
the center, where those 4
where the balance is happy.
Then you take the 16 and
then you replace them
so you can put them, so
you count 6 and you go
in the middle here
and put the 12 here.
So you know that this,
nothing fancy yet,
this will always be in balance.
Now all you have to do is go
back to the old and count.
Where was the center this
was six away six units away
and then where was this one?
This was 2 units away.
Now we have 4 times 6 equals
2 times 12 that's the law
of the lever.
It sounds very straightforward,
but it wasn't at the time
and even today, if you give this
problem to a group they tested
that of high school students say
can you show it very quickly.
It's not that easy just to ad
hoc show that this works out.
An extremely important law which
Archimedes has used through all,
throughout many, many of
his proofs in his works.
And I get back to that later.
It also led to this
legendary drawing and saying,
give me where to stand
and I will move the earth,
which of course Archimedes
would've never said but it shows
that the Greeks thought
the earth was round
and it shows also that the law
of the lever of course having
if you make one arm extremely
long you can move extremely
heavy objects.
He, Archimedes was the first
to calculate the value of Pi.
Some of them, some people say
that this was the was the
mathematical equivalent
of inventing the wheel.
And I'll show you how he did it.
This is of course the
ratio between the diameter
and the circumference
of a circle.
And he acted, like I would
say like a physicist.
He said, I can calculate the
triangle knowing the well-known
arithmetic or the well-known
geometry laws, and I could take
that as my first approximation
it's a bad approximation,
but it's my start.
So the circle has to be
larger than the triangle.
So let's do a better job now,
split each of those lines
in half and then
put in a hexagon.
Now you calculate the
hexagon and say oh.
This is a better approximation
so the circle has to be larger
than the hexagon and then
Archimedes continued.
He went to dodecahedron.
He went until 96.
Calculated that number, and
then he has a lower limit
for the circle.
But he wasn't happy with that,
he said, I want to trap it also
from the outside so he
started from the outside.
You can start with hexagon,
and then go downwards.
You also go to 96, he didn't
use the decimal system
but if you would use his
numbers and present them
in the decimal system
this is what came
out 3 point 1409 3 point1428.
The more precise
number is 3 point 1415.
And as you can see the lower
limit actually is a little
closer to Pi than
the upper limit.
And if you look at
the two examples here
with the hexagon
it's not a surprise.
The underestimation is a little
bit less wrong if you want
than the overestimation when
you shoot out on the outside.
A remarkable achievement
by Archimedes
and 3 point 14 actually is
the number, which is often use
in the construction business,
and it's a very good
number already.
Now we don't have
any original writings
of Archimedes that
have survived.
Archimedes wrote
on papyrus scrolls,
and his texts were written
in one basically all the writing
was without a break one line
after the other on these
long papyrus scrolls.
And here is a famous drawing
where you see him how he
how he could've looked
like when he was
doing his writings.
Subsequently, scribes copied the
work on other papyrus scrolls
until about the fourth century
when a revolution occurred
in similar to something
which we see today
with MP3 data files
replacing vinyls and CDs.
They were starting to use
instead of scrolls, parchment,
which is based on animal
skin, and I have a piece
of parchment here,
which I will hand out.
This is a from the
nineteenth century.
It's a little, it's
an English parchment.
This one is a sheepskin
and in fact,
we did our first test
we did on this type
of parchment it is
still produced.
The parchment had
two advantages first
of all it's very indestructive
it is based on an animal skin,
and it can endure very well and
second of all, you can bind it
in these books, and then
you can increase the density
of storage with the books.
What they used to write
it is an iron-based ink
and not every parchment
was written with this ink,
but most of them in
particular between I think
between the seventh or
fourth and twelfth century.
Even today, this
will for example,
which is from the
nineteenth century is written
with an iron-based ink.
The ink the iron gall
ink etches itself
into the parchment
it is very resistant
and stays there for a long time.
Three works of Archimedes
are known to the world.
Codex A which was last
seen around the year 1560.
Codex B., which was last heard
of in the year 1311 and Codex C,
which is the subject of my talk,
which was first discovered
in 1907 by Heiberg.
All of them were written,
probably around the 10th
century on parchment.
The reason why Codex C survived
is because it was recycled.
It was taken apart and
then reused in the form
of a palimpsest,
palimpsest meaning
that you scrape off the
original and you overwrite it
and then it survived as a prayer
book, not as Codex C. And that,
that tragic incidence,
if you want was probably
or most likely the rescue
of Codex C. Otherwise we
wouldn't have heard of it.
This is how you make
a palimpsest,
you take the original
book, take out the leaf try
to take some lemon juice,
some material scrape off
the ink as well as you can.
In the case of the Archimedes
palimpsest you cut the large
leafs in two rotate
them by 90 degrees
and then overwrite them
with your new text.
What you see here is that
the old text of course,
because was on the larger
page and written two columns
like this goes all
the way through.
So whenever you bind
your new book,
that old text will be very
close to the etchings.
It will go through
what you bind together.
And that's a problem
and several lines
of Archimedes writings were
lost because of this fact.
Anyway, so you bind
the smaller book
and then you have
your prayer book.
The ink of the top writing could
be the same material same ink
or could be another type of ink.
In the case of the Archimedes
palimpsest unfortunately,
it's the same kind of ink
so both the text underneath,
the tenth century copy, and
the prayer book text is written
with an iron-based ink.
What Heiberg had
discovered in 1907,
and that's why it made
headlines around the world was
that in this prayer book he
found the only surviving Greek
version of Archimedes
probably most famous work
On Floating Bodies.
All we know or all we knew about
On Floating Bodies was based
on the Latin translation from
one of the other Codices.
He also discovered two new
treatises, Ostomachion,
an ancient game,
which Archimedes was obsessed
with, very fascinating.
You can look it up.
It has I think twenty
triangles which you can put
in a square form and
there are forty more
than fourteen thousand
combinations
and Archimedes figured
out actually how many
combinations there are.
And probably most
importantly The Method
of Mechanical Theorems.
A treaties by Archimedes
which was incredibly advanced.
Some argued that this was
an ancient form of calculus.
Now Heiberg was not allowed
to remove the prayer
book from the Metochiam
[ assumed spelling ]
in Constantinople.
So what he did is
he photographed it
and then went back to Denmark
and transcribed it based
on his photographs.
And between 1910 and 1915
he published the complete
transcription, which did have a
lot of holes because of the fact
that he used of course
a probably dark room
where he made his copy and
also to some extent that he had
when he was reading the
text the mathematics
and he had used assumptions
which were holding
in the early twentieth century,
and he was also not
a mathematician.
So we have the Heiberg photos,
but they are, they
were incomplete.
Now let me tell you a little bit
very briefly about the Method
of Mechanical Theorems.
Archimedes wrote
that as a letter
to his friend the famous
Eratosthenes and you
at Myst might really appreciate
him because he was the first
to measure the size
of the earth.
And this was done,
about 200 years BC.
He knew that in Aswan which lies
exactly on the Tropic of Cancer
under summer solstice the sun
is perpendicular to the horizon.
Or basically there is no
shadow, and he also knew
that on the same
day at the same time
in his home town Alexandria
there was a 7 point 2 degree
angle of shadow.
What he had to do is
figure out the distance
between those two places,
and he knew that roughly
from the caravan travelings
to be about 5000 stadia.
One stadium being
180 meters roughly.
Now you have the
answer, 7 point 2
to the green distance equals 360
to the circumference
of the earth.
Eratosthenes' value corresponds
to about 39,700 kilometers.
Now the error here is
mostly based on the fact
that we don't know exactly
what one stadium is maybe there
wasn't even an exact
definition of one stadium.
It's a remarkable achievement
and to me it's even
more remarkable
that the great Columbus
when he landed on the shore
of what is now called America
thought he was completely
convinced in fact that
he had landed in India,
which is about three
times further away.
He did not know the
size of the earth.
Or at least if he knew it
he pretended not to know.
I read that he never knew it.
This is the letter of
Archimedes to Eratosthenes.
Greetings since I know you are
a diligent and excellent teacher
of philosophy and
greatly interested
in any mathematical
investigation
that may come your way.
I thought it might be
appropriate to write down
and set forth for you a
certain special method.
These are the first words
on the treaties The Method
of Mechanical Theorems.
And then he goes on, I presume
that we'll be some among
the present as well
as future generations
who by means
of the methods here
explained, will be able
to find other theorems which
have not yet fallen our share.
Let me give you an example
of the method applied
to calculate the
volume of a paraboloid.
So this is a parabola and if you
spin it you get a paraboloid.
Archimedes, and this is one
of the more simple examples
you can use, used his method
to calculate the
volume of a parabola.
What he did was very beautiful,
he said, while we know
if we have certain
distances for example,
we know the distance BD,
we know the distance OS,
we know the distance
MS, AS, and AD, we can,
because in general you can
just say X equals Y squared.
They are from very general
and simple relations.
So for example BD squared
divided by OS squared,
equals AD, I'm sorry,
so BD squared
by OS squared equals
AD divided by AS.
So that's very simple.
That's just, you don't put in
anything other than knowing
that this is a parabola.
And then you change these
equations to make it in a,
in this form, and you insert
the number Pi on both sides
and what you can then say
is if you have a circle
or let's say a shape, like a
little circle of this area,
Pi MS squared times the distance
AS is here, will be the same
as if you take an OS squared
times the distance AD.
And now you're back, you can
go back to the law of the lever
because you can do
now something.
You can say let me take an MS
squared circle or let's say
and MS squared disc and
an OS, Pi OS squared disc,
the one I put an AS, the
other one I put at AD.
So D and A are just the
same so I put it at this,
and they would balance
each other.
Very straight forward.
Nothing, you have not
put nothing in yet.
And now I do the same
thing again and again.
I take a smaller one and that
will balance the large discloser
in just by using that equation.
Or I take a larger one, it will
balance the other disc here
and I fill up my whole
cylinder with discs and here I,
in an imaginary way, I put
all the shape, all those discs
at the same location H.
Now in practice I cannot do
that very well but what I can
do is I can place them then
like this.
So I keep the center of
mass, I stable them all up,
and then I put the other, I
fill the other disc this way.
Now you have kept the balance.
We have used nothing else but
the formula for the parabola
and you have the solution
because the center of mass
of this is very simple,
it's just half the distance
so the volume of the
parabola is half the volume
of the cylinder which
encircles it.
This is using Archimedes method
of mechanical theorems
to solve this.
And it can be used for
many geometrical objects.
What is significant about the
method, and this is just coming
to light in the last years,
actually since the
palimpsest had resurfaced.
It's a geometrical discovery
with a physical thought
experiment.
Very opposite then
what we do often today.
Today often we do
physical experiments
with geometrical
thought experiments.
It also was a breakthrough
comparable
to modern integral calculus.
Because he used infinitely
many little discs to fill
up his parabola effects.
And some have argued that both
findings are essential features
of modern science and that the
method was 2,000 years ahead
of its time.
There's a lot of
speculation what would've been
if in the Renaissance
Galileo or DaVinci
or even Newton later
would've had that information.
I would've known about
Archimedes method,
would science be at a
different state today.
I think we will never know
the answer, but it's a lot
of speculation about that.
They didn't know it because
at the time Codex C was
in the prayer book
in the holy land
in the sons of our monastery.
Now after Heiberg had taken the
photos it had disappeared and,
that was right after
World War I,
and it was thought
to have been lost.
And then it resurfaced in
the 90's, 1998 it was sold
at Christie's for an incredible
amount of 2 million dollars
to a private owner who
reportedly pledged not
to limit extension agen
[ assumed spelling ]
manuscript.
This was incredibly
important and none of the work
which has gone on since
and which I'm showing today
would've been possible
without this pledge.
So we are very grateful
to the owner for that.
He was contacted by the
Walters Art Museum not too far
from here, go there for a visit,
it has a remarkable
collection of ancient documents.
It's in Baltimore downtown and
he agreed to lend the manuscript
for an integrated effort of
imaging and conservation.
And this effort is
still ongoing.
Now this was some
of the problems.
Here you see a photograph
of the first two pages
of the Archimedes palimpsest
in horrible condition,
much worse than when
Heiberg had seen it.
But even Heiberg hadn't
seen those pages very well.
They seem to be even a little
bit burned here on the edges
and whatever little
reading you can make
out is not the Archimedes
text, it's the text above,
it's the prayer book text.
There was not a problem.
Four of the leafs had these
medieval miniatures on them.
And at one point they
were thought to be maybe,
maybe they are part of
the original prayer book
but it was found
very quickly actually
that there were forgeries
which were put on after,
we know now they were put
on after 1939 actually.
And we have no idea whether
we think that the person
or the group did not of course
know that they didn't just deal
with the prayer book
which they wanted
to make appear more valuable.
We think they, that's what
we think they thought.
They had no idea what
they had in their hands.
St. Luke, the four evangelists,
underneath On Floating Bodies.
St. Mark, underneath On Floating
Bodies, Equilibrium of Planes.
Double bi-folio an original full
leaf, so we call those bi-folios
because in the original 10th
century that was one leaf,
and then only in the
palimpsest it was put together
as two leafs.
So it's 64, 57, either
or it's recto-inversal
[ assumed spelling ]
, St. Matthew, St.
John, underneath Method
of Mechanical Theorems.
Incredibly important
text underneath here.
And as you can see here,
the pages were deliberately
mutilated.
This is not decay, this
is someone putting,
cutting things out
with scissors.
It's way too straight
to be just decay.
The person wanted to make
these things purely very off.
Now we have seen it, x-ray
vision is one possibility
to look under these forgeries
or to look under these texts.
And of course as you know
the true superman is Wilhelm
Conrad Remkin
[ assumed spelling ]
who in 1895 took the first x-ray
image and you can see the size
of the jewelry at the time.
It has x-ray, this type of
x-ray imaging has revolutionized
science, there's no
question about it.
Independent of the other
fields of x-ray research
which has been going on since,
there's no one in this room
who hadn't had multiple
x-ray images taken.
You could also say
what is, if we,
and that's of course the
most obvious thought,
let's just take an
Archimedes page and put it
into an x-ray machine
and then see what we get.
And I can tell you not that we
tried it with an x-ray machine,
but we tried it, we tried
to get a transmission image
like a normal x-ray image is.
It's a transmission in which you
measure how much the different
density of sorts you
will not see anything,
you will see sometimes
something,
if the ink is still very
concentrated but for dilute ink
for thinning with a normal
transmission x-ray you will not
see anything.
The contrast is too small to
see it in a conventional x-ray.
Now I don't have to tell you
about x-rays, they're part
of the electromagnetic
spectrum and the only difference
to radio waves and microwaves
and infrared and ultraviolet is
that they're in the very high
frequency range typically you
can say, typically starting
at ten to the minus 8
and then almost to infinity
through short waves.
There were two very
important experiments
in terms of x-ray imaging.
Or actually one in x-ray
imaging and one other one.
This was a science paper
by Horvitz and Howell
in 1972 x-ray, a scanning x-ray
microscope using synchrotron
radiation and what they showed,
they imaged a two micron whisker
of silicon and they
report in their image,
they say the result
indicates the importance
of detecting fluorescence
remission rather
than transmission.
The signal is much better if
you do it, not in transmission,
but if you do it in
fluorescence remission.
Another important paper and
I'm glad to say that one
of the authors is actually
the late Mel Klein,
used to be a friend and
collaborator of mine,
is that the fluorescence
detection also helps you
when you do spectroscopy
on very dilute systems
such as metal proteins.
Okay?
And this was a, this is now one
of the absolute landmark papers
where they used it to show
fluorescence detection for X of,
that the signal is so
much better when you do it
in fluorescence rather
than in transmission.
Now I'll show you very
briefly the basic idea
of an x-ray fluorescence.
If you have completely
simplified the inner workings
of an atom with the
nucleus and the electrons,
the electrons are bound to the
nucleus depending on what number
of proteins you have
in the nucleus,
the larger the stronger
the electrons are bound
and every element in the
periodic table because of
that has its unique x-ray
fluorescence fingerprint.
You come in with an x-ray,
you knock out let's
say an inner electron,
it's filled from an
outer electron instantly
and then emits a fluorescence
x-ray, a secondary x-ray.
And the energy difference
between those two
orbits defines the energy
of that remitted
fluorescence x-ray.
And therefore every element
has its unique fingerprint
or spectroscopic fingerprint
of x-ray emission lines.
So if you want to now look at
iron in the ink in that case,
what you do is you
tune your detector
to just measure the spectrum
of the iron fluorescence
or the narrow range of energies
from the iron's fluorescence
and you do the imaging.
You cannot, of course, no
longer take the whole image
with a plate behind.
You have to use a
small beam and scan
because the fluorescence
loses the information
where the x-ray came from.
This shows you now a
spectrum of the acume
[ assumed spelling ]
taken from the Archimedes
palimpsest
and you can see some
of the lines.
This is the iron line,
the key alpha line
and this is the iron k beta
line, there's a little bit
of manganese, lots of
calcium, that is mostly
from the parchment, but
there's also some calcium
in parts of the ink.
And what you then do for the
imaging, you say okay I'm going,
in fact you can set several
windows on your detector.
We set up to about 5 windows.
You say I'll set a window on
iron, I set a window on calcium,
and then maybe one on manganese,
maybe something on copper,
and you set those windows
and you record those elemental
spectra as you go along.
And the experiment conceptually,
very straight forward,
you take a small x-ray
beam detector, you scan,
each time you hit this element
it'll give you a signal,
and you just rafter
through the whole thing.
In order to get an
image from one page
of the Archimedes palimpsest,
you need about 15
million measurements.
And that requires not only
a very powerful x-ray beam,
but also it requires a system
which can measure very fast.
Otherwise, there's no chance
that you can get such an image
in a reasonable amount of time.
This is a place of course
where you get powerful x-rays,
the Stanford line
accelerator center
in particular the Stanford
synchrotron radiation lab
which is in this conglomerate
of old, pretty old buildings,
but updated with a
new rings, be a three,
a powerful machine
today and it's one
of the many synchrotrons.
I'll just show you some which
are operating around the world.
They are about 70 around the
world of all various sizes.
This is the largest in Japan.
Super-photon Ring 8.
it's so large that they
didn't find a flat area,
so they built it around
actually a little mountain.
They advanced photon
source in Illinois
across the San Francisco Bay
at Lawrence Berkeley lab the,
a smaller ring, the
advanced light source,
the European synchrotron
radiation facility.
Berlin, I'm just
showing some of them.
Typically the new rings are
all in the three GEV range.
These are the most powerful,
these are the largest ones.
These ones are S powerful
but they are more
optimized on softer x-rays.
So the large rings are more
optimized on hard axis,
the smaller ones
more on soft axis.
The new generation
of x-ray synchrotrons
which are just now
starting up like soleil
[ assumed spelling ]
diamond and also the planned
NSLS2, there will be all
like sphere operating
about three GEV energy.
The concept is straight forward.
You have x-rays in
the vacuum ring
and then you have bending
magnets which give out,
send out a fan of x-rays
and you have underlaters
[ assumed spelling ]
and wigglers which send out
a very narrow cone of x-rays.
Very powerful.
In fact, the brightness which
means the intensity focused
into a small area,
culminated into a small area
in a small spectral range per
second is not just a million,
it's brighter than
a billion suns.
You can see here
ten to the tenth,
now the new ones are
going to up to above ten
to the twenty actually.
This is the brightest
of those things.
They are polarized
and they're tunable,
and they're short pulses.
We take for this work
we take advantage
of those three properties,
we don't take advantage
of the short pulses which is
done in some other experiments.
This is a quick inside look
of the new sphere three ring
and then the lab
is on the outside.
You can imagine when I joined
this project, I wrote a proposal
to the team saying that I
want to use the synchrotron
to image the Archimedes
palimpsest
and when the owner heard
that I'm using a beam
which is a billion
times brighter
than the sun he was
very pleased about that.
And so of course he wouldn't
just sned us the book we had
to start to do some
tests and the parchment
which I just handed around was
exactly part of these tests.
This was our very first
image we ever took at SSRL.
This is the writing
of the word ore.
I have the little snippet in
my bag, it's the same kind of,
it's the same handwriting
as what you have seen.
And it was done with a
forty micron pixel size.
Forty microns is
about six hundred dpi,
six hundred dots per inch, and
you can see very quickly that,
and this one's just
a very fast end,
you can see that in principle
that the method works.
And after, coming
up with numbers
and we did some radiation
damage tests on some parchment
where we exposed the parchment
to different doses of x-rays
and then established
a safe dose.
After that, after I
also convinced the team
that I can get a
fifty percent humidity
and temperature stability
inside the hutch
which was a pain in the neck.
Finally the team decided to
come and bring one page first
and then they came with
more pages for testing.
And here you see
Abigail Quanches
[ assumed spelling ]
the senior conservator
at the Walters Art Museum
and she was the only one allowed
to handle the palimpsest.
She's just putting in one of
the forgery leafs into our beam
and I'll show you a little bit.
The closest, this was
an early picture now,
things look a little bit better.
They were still, when we
used lead tape and sea clams
but the important thing is
probably just two things.
At the end of this
pipe there's our slit
which was a fifty micron pin
hole so that defines the size
of the beam and the beam
was pretty much collimated.
We also look with a detector
at a ninety degree angle
and the ninety degrees
are very helpful
because it reduces
the scattering.
It uses the polarization
of the x-rays similar
to your polarizing
sunglasses when you look
from the glare scattered
from a water puddle.
And it suppresses
the scattering.
We are not interested
in the scattering,
we are interested
in the fluorescence.
The fluorescence has no, is not
affected by the polarization.
It goes into, for Pi but the
scattering at ninety degrees,
it's basically the x-ray
bruster angle, the bruster angle
for x-rays is basically
ninety degrees
and so you can reduce the
scattering dramatically
if you look at ninety degrees.
All fluorescence measurements
and synchrotrons are done
at a ninety degree angle
with the polarization
of the synchrotron
in the storage.
Now let me start to
show you results.
This is the bottom
part of page one
of the Archimedes palimpsest.
It is the page where the
monk who had used the pages
from the original writings
and reassembled them
into his prayer book, where
he had dedicated his work,
it is called in the
scholarly community,
they call it a color form.
He writes down the date, the
name and sometimes the church
to which the work is dedicated.
We were able, our colleagues
with multispectral imaging,
which is an optical method
which has been very successfully
applied at this project,
they were able to
come up with a date
that no one knew the
name of the scribe.
This is now the x-ray image,
this is the iron x-ray which of
that same part and this, these
are all writings by the scribe,
the monk, and this, in this
fancy, this is ancient Greek
by the way, but these
fancy characters
that is his dedication.
And when you read it, it says
this was written by the hand
of prespitor Johannes Meronas on
the fourteenth day of the month
of April, a Saturday of the
year six thousand seven hundred
thirty seven which corresponds
in our calendar to 1229.
It was the day before Easter,
he had just finished his work,
and it took, it took
six hundred sixty six,
I think seven hundred
seventy seven years
if I'm not mistaking, yeah,
seven hundred seventy seven
years before his name was
finally revealed
with the x-ray image.
But of course as interesting
and as important this might be
or is actually to those who
look for other palimpsests,
to find out his name and then
maybe find other works by him
to look for other palimpsests,
we are really most people
are really interested
in the Archimedes writings
and now I show you the full,
the full view of this page, and
this is the full x-ray image.
You can see all the,
in this view,
all the Archimedes
writings are horizontal
and the prayer book
writings are vertical, so I,
this is now a flipped, this was
the section I just showed you.
So this is now a
flipped version.
So the Archimedes
writings are horizontal.
We also found another
interesting thing,
there was a hand as you can
see, it's basically like this.
This was Johannes
Meronas, he was doing,
he had done a little
drawing on that first page
and no one knew about
this drawing.
But more significantly this
contains the final proposition,
not the complete, but part
of the final proposition,
the most complex of any
propositions of Archimedes work
On Floating Bodies in
the original Greek.
And when we got this image,
my colleagues, we had a team
of at least eight
people all the time
and they were working very fast.
The images come in and there
was a data processing going
on very quickly, they were
transformed into these kind
of images from the let's say
the ASCI file of the numbers
of currents and sent
out to the scholars
and at half an hour
past midnight
after we had just sent it
out a little bit earlier,
we already got the first
reply from Ray Vernitz
[ assumed spelling ]
he's a Stanford professor
who's one
of the eminences on Archimedes.
He wrote this email back to us.
Column one, one-f, one-v,
that is the first page.
[inaudible].
I attached the transition of
lines two through 11 for you.
With very hard work, I squeezed
the three and half lines
through the collar, but
now I found it easy to read
and effectively [inaudible]
noting a couple of errors, too,
in my old [inaudible]
based reading.
The, what [inaudible]
had seen was
that we found a different
arrangement of some
of the diagrams and some
quite significant differences
to the Latin translations
of what was known until then
of this final proposition.
This is un-floating bodies.
And this is the first time
in modern times anybody has read
this text in the original Greek.
I told you that the pages where
originally one page and then cut
and bound together in the book.
Some of the pages were
actually ripped out
and all we had left is some
of the ripped out pages,
one or two is missing, but
what we had was these stubs,
which are like when you
rip out a page of the book
and the stub stays in.
And we had also the
pages, but we didn't know
which stub belongs
to which page,
because you cannot see
anything on the stub.
This is the normal
visual appearance
of this, of such a stub.
This is the multi-spectrum
pseudo-color image
from our colleagues
from Rochester Institute
of Technology and
while you get this one,
but you don't really see much.
And this is the extra image.
You can read it straight away
and we had about 15 or so
of the stubs and it
literally took only seconds.
This is an ancient
omega, by the way,
it looks like the infinite sign.
It looks literally, it took
very few time for the scholars
to then reassign the stubs
to the corresponding pages
and then finish the
transcription
of those pages with these stubs.
There was another surprise.
This is a, one volume 159 or 58,
ah, this is now in the middle
of this portfolio,
so it's the part
where the book was
bound together
and there was a little drawing.
It was the method on
it, very important.
There was a little drawing here.
This is already a
pseudo-color image.
The visual image,
you see nothing.
It's turned out very nicely,
but there are some debates
about some of the labels here.
You might see a [inaudible]
that wasn't new here.
[inaudible] wasn't new here.
And in the [inaudible]
image, that wasn't a surprise
as we brought out
the full image of it.
No one had seen that before.
Why in the [inaudible] image,
because we always thought
that there was more
actually iron in the ink,
but in this particular case,
we think what had happened is,
now here is the photograph
of this area.
We think what had happened
is when the image was strong,
when it was basically the
[inaudible] pushed it in
and then later when
the ink was removed,
the chalk of the pattern
collected in this grooves
and formed a thin
layer of calcium,
more amount of calcium then
in the rest of the pattern.
That's what we think.
We don't know it
precisely, but we were happy.
The irony in which you don't see
this, but in the calcium image,
you could see the full diagram
and we also settle a
longstanding dispute
about one of the letters.
That was done with the
[inaudible], by the way,
between rather the label
that [inaudible] said it would
only make sense if it's new
and it turned out to be new,
so [inaudible] was
very happy about that.
Now let's go to, this is one
of the important forgery pages,
which has the method
underneath here.
You get the normal view and
this is the x-ray image.
We ended up doing those
forgeries actually
from the back side.
The parchment doesn't
absorb much of the x-rays,
but the metals in the
ink of the forgery,
they [inaudible] quite a lot.
So in basically all cases,
what we did is we shone
through the backside and then
we get [inaudible] both sides,
which you see here also.
And then you'll flip the image
and then you can read the text,
which is really on the side
of where the forgery is.
And here, I can give
you a different example.
So these writings here
are on the backside
and then a little
bit fainter writings,
those ones on the
side of the forgery.
That's why I show this
image already in reverse.
And so I zoom in here.
This would be [inaudible]
writing on the backside,
not on the forgery side.
This would be Archmedus'
[assumed spelling] writing
on the forgery side.
And the extra images
were quite, I would say,
I would not say sensational,
but they were very, very helpful
and impressive to
bring out of this text.
Not everywhere, as
you can see here.
Unfortunately in this area
where there is so much iron
in the painting, in the forgery
painting, that the signal,
you can see a little
bit of text here,
but in some area right here,
it is basically with this kind
of image [inaudible],
it is basically not
possible to read everything.
In some cases, calcium helps
in these errors as well.
But what was shocking to me was
that after having sent all this
beautiful image to regular nets,
but he said, well, what really,
what really struck me
is this area down here.
[ laughter ]
And now I'll blow it up for you.
This is now this area
which I just pointed at.
The parchment ends here.
This is the end of
the parchment.
Everything you see below wasn't
parchment and added later to it.
So there's no information here.
The real information is here
and here now comes
[inaudible] scholar
and he reminds me very much
of the way on how we do work.
He says, okay, this one,
you can see it here.
This one has to be a copper.
And then, of course,
in all fairness,
he knows the rest of the line.
So he can already exclude a lot
of words that don't make sense.
This one is an alpha.
And now comes the real one.
You can see this thing here.
It's an iota.
In fact, it's an accent graph
and the only Greek letter
which has such an
accent is an iota.
So the work is Kappa Alpha Iota
and it means the word and a-n-d.
The line has to continue here.
[inaudible] had thought that
this was the end of the line.
[inaudible] had now basically
with this one [inaudible]
established
that there were two
lines of text missing.
The whole transcription
of [inaudible] was based
on one line of missing text
and that changes everything.
Let me again just
give you his comment.
The Khi [assumed spelling]
at the end is very safe,
because the Alpha's
almost entirely gone
and the Iota's almost
entirely gone.
The [inaudible] punitive
iota is clearly visible.
There are very few
alternatives to the reading Khi,
which in context, is
also quite likely.
The finding is significant
for the debate of arguments
on the concept of infinity,
which he discussed very
early in the method.
In the [inaudible]
transcript, and I cannot go
into much more detail
because it's a delicate issue
and I just don't know more
about it of what I tell you now.
[inaudible], he [inaudible]
a logic saying if it is true
for any line or if it's
true for any number,
it is therefore true for all.
Whereas based on the x-ray
image, [inaudible] he thinks
that ARchemedus [inaudible]
differently, but he argued
in the sense of that
not for any,
but for however many
lines are taken,
if I can take however
many lines I want,
I can therefore take an
infinite number of them
and it's a different
way of defining
or conceptualizing infinity.
This is an ongoing debate
and I think we will have
to wait a little bit
before this really settled.
Now let me show you
some stereo images.
My colleague, Bob Moore, he
suggested to use stereo image.
Before I put on the glasses,
I'll just show you
the way how we did it.
It's very straight forward.
All you have to do, say this
is the 45 degree angle and then
if you take the point where
the beam hits the parchment
and you rotate it, you
rotate your [inaudible]
by seven degrees and then
take the image again.
Seven degrees is a
good number, because,
here I'll give you mind.
Seven degrees is a good
number, because seven degrees is
about the end of your eyes
when you read a normal newspaper
unless you have [inaudible].
So that's about seven degrees.
And so you have to put them on
the [inaudible] of the left eye.
It should be straight forward.
So the left goes to the red
eye and now let me invite it
to the inner [inaudible],
parchment.
This is, you can probably make
out that this text looks to be
like floating above
and some of the text,
the horizontal text below.
I'll zoom in a little bit more.
I hope it comes out clearly.
You can get a feeling of
the depth of this parchment
by looking at it
with the stereo view.
I don't know whether it's
good to turn down the lights
for this one a little bit, yeah.
I'm just giving the sign to the.
[ silence ]
So you are having basically now,
you can also see how
wavy the parchment is.
It's not flat and this kind
of a stereo view image gives
you a hint of the waviness.
I'm zooming in a
little bit more,
so now you can see it again.
The vertical letters are
really floating there
from the front side of the
parchment and then some
of the [inaudible] writings
are well below the parchment.
And all the rest you see is
some residue [inaudible],
which was distributed in the
parchment during the process
of trying to erase the text
or maybe some [inaudible]
which was just left
from the [inaudible].
So these are the stereo
view images I have left
and keep the glasses.
I have one more a
little bit later.
And I would like to use that
image also to end my talk.
We didn't, we ended up not
using this technique for many
of the slides, because the
scholars [inaudible] quite happy
with a normal view.
They didn't really need
the stereo view in order
to do the reading better,
but it could have been doing.
And in some cases, maybe it
will be done in the future.
It takes because you have
to do the two [inaudible],
it just takes twice
as much time.
And it's very easy actually to
produce those images afterwards.
So let me just conclude
with an outlook.
We, the project is pretty much
finished from our point of view,
from the x-ray imaging
point of view,
but there's one small part,
which the scholars still want
to revisit and it's
part of the [inaudible],
which is that ancient
game and [inaudible]
in particular has insisted
that the calibration
should come one more time
to assess and to image that.
The reason why we
haven't done it yet,
is it's an incredibly damaged
page, which is hard to,
you don't even want to
pick it up in your hands.
So we have to come up with
a very safe, because we have
to put the page, we
don't image horizontally,
we image vertically, because
otherwise, we would have
to deflect the x-ray
beam which is rather hot,
to do efficiently, so we have
to hold it in a safe way.
I don't think it's
a big problem,
but they have been a little
bit reluctant to that.
They promised they'd come,
not next year, but in 2009.
Let's hope they do it.
And of course, there will be
a full translation available.
This work is ongoing.
There will be larger
publications with small parts.
For the x-ray part, I'm working
on a longer paper right now,
a review of modern science
to describe a little bit more
the x-ray forensics technique
and [inaudible] in this last
publication, which is, I think,
the [inaudible] Society
publication, there will be,
everyone will be brought in,
the conservators, the scholars,
and the scholars of course have
the main say [inaudible] as well
as the imaging experts.
The [inaudible] will
be on display as well.
We do not think it will ever be
re-put back into the book form,
so the pages will probably stay
separate as they are right now.
There are 174 pages and
an exhibition is planned.
Last thing I heard,
it will most likely be
at the Field Museum in Chicago.
I don't know where there's a
chance that it might happen
at the Smithsonian or something,
but I think that's what I heard.
That's what the plan to do
and I don't know the date.
It might be next year.
In may be sometime later.
A new book just came
out by [inaudible]
called the [inaudible].
If you like scientific
detective story,
I think it's a great book.
It is written in a very, I
think, in a very good way
and very entertaining way.
My colleague and I have
been playing with the idea
of an institute for
imaging of human heritage
at Stanford University and
we are basically at the point
of a white paper, which we
have submitted to the dean
of research and have
them have a look at it.
It will still might
take sometime.
But that could be
a large interest
in using not only x-rays,
but also techniques,
other advanced techniques to
look at some of the thousands
of old parchment documents
including many [inaudible].
The work has also, and
I'm very happy about it,
has inspired other
research and Bill mentioned
at the beginning brain imaging.
We have started to
look at Parkinson's
and Alzheimer's disease,
slices of brain,
large slices of full size.
X-ray's [inaudible] imaging
has been around for a long,
long time, but no one has really
applied it to large objects,
because of the fact that
you need to do it very fast.
Three milliseconds for
exposure time or one millisecond
for exposure time,
measuring on the fly.
So that is the new thing and
that came out of the necessity
of imaging these full pages.
The resolution is
not that critical.
We don't need like the
world's best resolution,
but we need to do
it fast, otherwise,
we cannot look at large objects.
And also fossils.
I will show you now if you
put on the glasses again.
This was a fossil image taken
of 122 million year
old transitional fossil
between a dinosaur and a
bird called the [inaudible].
And it's not largely effected,
but the [inaudible] comes
out just a little bit, because
it doesn't cause my depth.
X-ray image shows
you the feathers.
You can see the feather
on the side of this bird
and you can see the
bone structure.
We are creating those
fossils with looking
at different elements
at the same time
and then use the
different colors
for the different elements
to bring back the fossil.
Now, the interesting part of
this particular [inaudible].
This was found in the Gobe
Desert in China is that this,
we think that this is the heart.
And I'm going to zoom
in now a little bit.
You still have your glasses on.
This is now like the chest
section of, like, the fossil
and the heart would be,
I hope you all can see,
the heart would be
in this area here.
Why is the heart so important?
It is because dinosaurs
were not warm-blooded.
They were actually
cold-blooded, whereas we know
that birds flight
requires so much energy
that it's very likely that
the birds, the early birds
and even those dinosaur
related birds,
probably must have
been warm blooded.
And in March of next year,
we will get the [inaudible],
which is a very famous fossil
and we will get the best
specimen of that to assist
and to try and take
an image of that.
So this is just another research
and let me now thank
my collaborators.
It was, it's a great group of
people from different places
and I want to mention
everyone by name.
[inaudible] Martin
George has been wonderful
and then we know he's
the project director
at the [inaudible] Museum.
He's a very good friend and
great person to work with.
And we particularly
thank, of course,
the owner for being very
generous in lending us this book
and also supporting some
of the costs for the team,
not so much for us,
but for the team.
And of course the Department
of Energy [inaudible]
and I will end by just showing
you a couple of impressions
of what was going
on in [inaudible].
Thank you very much.
[ applause ]
>> Thank you.
That's a fascinating story.
I hope you all enjoyed the
special effects of the 3D.
And please leave these up
here on the stage as you leave
and I hope the parchment
comes back, too.
We have time certainly
for questions
and if you would
use the microphones,
we would appreciate it.
I had one question myself.
When we looked at these images,
was the monk also
using iron ink?
>> Yes.
>> So we are looking
at a superposition
that are always the
monks' writings.
Were they in the same language?
>> In the same language,
but as I pointed out,
they were at a 90 degree angle.
That was very important.
There were some [inaudible],
but also which comes out maybe
in the, maybe just let me
go back quickly to the,
and I will come back to it.
In this image, you can
see that with the x-rays,
because they are not
like an optical probe.
If you look at here, now
this is the monk text here
and then this is the
[inaudible] text underneath.
>> Yeah.
>> You can see that
at the intersections,
the iron signal adds up.
And so that means even
though there is text above,
it does help you to know whether
there is anything below or not.
So here it has nothing
below and here, it's clearly
from this [inaudible]
letter, it is below.
So yes, it is a mess, because
you have actually four objects.
You have the front
side, the back side,
and you have two inks, but
it is possible or has been,
in most cases, it has been
possible to still read it,
even though it's
both with iron ink.
>> Okay.
Another question was, was
the incident like white light
or was it somehow [inaudible].
>> The incident light was
chosen such that it was,
we used eight KV, which
is just above the iron.
So it was not quite resonate.
We want to keep the
elastic from getting away,
but it was specialized
on our end.
And then at one point,
we were looking
for some heavier elements and
we used higher energies, right?
And at one point, we only wanted
to look at the low energies,
so we went below the [inaudible]
and looked at some of the sulfur
and the light elements,
but that was very hard
because the cross section
is so small for that.
>> Okay.
Question.
>> I have a quick one.
When was the [inaudible]?
>> Yeah, this particular text
is, as I mentioned that shortly,
this particular text was
believed to be transcribed
around the year 950, okay?
And of course, the obvious
question is how close is it
to the original writing.
And the scholars believe from
using different methods and,
of course, we don't have
any original writings,
but you can use different
methods,
which you can sometimes use in
DNA, when you do some dating
of how changes in the
DNA occur and with text,
you [inaudible] it is believed
that is a very close
comparison to the original.
Probably about the fifth copy or
the fifth generation of copies.
And it was different in the
sense that it was not written
in one word as [inaudible] did.
It was written in pieces.
We also know that the
scribe, that the scribe
that we don't know who it is,
but who translated or who copied
that was not a mathematician.
He knew nothing about
mathematics,
because he did some very,
you know, simple errors
which a mathematician
would have not done.
Now that was a good thing,
because there's nothing worse
than getting a guy who thinks
he can edit the writing
of a genius, because you cannot
edit the writing of a genius.
[ laughter ]
>> I have a technical question.
Is it possible at all to
somehow get a depth dependent
on the imaging?
>> As a team at [inaudible],
we are trying that.
I don't think it
will be realistic,
just because of the
time scale involved.
You need so much more time
to do it, because, see,
if this pattern would be
perfectly flat, you could say,
okay, at this height, we have
it and we just go to this height
and all we see is the
text and in reality,
the parchment will
be seen as wavy.
And you will have to
realize that almost
for every little step, you would
have to realign your focal beam
and they're trying it.
I don't think, I don't think
it will be very helpful.
I also, to be honest,
I also don't think
that part is really
the biggest problem.
The biggest problem where the
x-ray for our reference failed
and obviously I didn't show
much of those examples today.
It's the fact that there
are really some parts
where there is no ink left.
Okay, and there are also
some parts in other writings
in this book where they used
a slightly different date,
so that was actually
our biggest problem.
Once you see the ink in most
places, you will be able
to somehow disentangle it.
>> Question here on the right.
And can you turn up the
volume on the aisle mics?
Thank you.
>> Have you considered the
use of laboratory based,
non-[inaudible] x-ray sources
for this commercial
x-ray fluorescent use
and that sort of thing?
>> Yes.
In fact, my colleague, Gene
Hall, who is not far away
from here, he has used,
he's here from Rutgers.
He has done the very first tests
with a commercial x-ray tube
like a [inaudible] machine.
It works.
You can see the text,
but it doesn't work,
because it takes way too long.
It look about eight hours to get
one letter with low resolution.
So you do need, you do need
the incredible brightness
and intensity of a synchrotron.
You do need to do
it extremely fast,
50 million measurements
for one page.
It's eight hours if you do
it with three milliseconds.
It's eight months if you do
it with a laboratory source.
And that's just not valid.
Plus, it's not polarized, so you
will always get more background.
Plus, it's a [inaudible]
spectrum,
in addition to the [inaudible],
so we will always get background
also from [inaudible] x-rays.
So the quality of image,
no matter how you do it,
even if you did not use the full
intensity, which you can get
at [inaudible], you can get 100
times stronger than what we use.
We just use as much as we can
to not saturate the detectors
and reimage it as fast
as we could, but the fact
that you can tune the
x-rays at your will
and you can do it very quickly
and that they're polarized is
just such a tremendous advantage
that is worth the trouble
to travel to [inaudible].
>> Yeah.
Question here on the left.
Yes?
>> You mentioned that you
never would have imagined being
involved in a project like this.
Will you talk a little bit about
how you did come to be involved?
>> Well, very good question.
Thanks.
It was a complete coincidence,
as you call these things.
I was at a conference in
Germany on photosynthesis.
And there was a short
conference.
We spent all the time and a lot
of my ongoing work is to look
at very dilute systems
like in that case spinach,
and spinach has, of
course we all know, iron in
but it also has the
magnesium in it,
which does actually
the splitting of water,
one of the most important
chemical processes
on Earth actually.
Splitting of water
and [inaudible] oxygen,
which is important.
And before was flying
back to the U.S.,
I stopped at my parents house in
the Black Forest and my mother,
she had put like a staple of
things on my desk basically,
which mothers always do.
So they give you all these
things, which you should read.
Just read those.
Look through them.
And there, I found a
magazine, a journal magazine,
called [inaudible],
which had an article
about the upcoming
[inaudible] in there.
And I read this article
and I found in fascinating,
because it is a fascinating
[inaudible]
and it was a fascinating
article.
And I think it was, when all of
a sudden I read in this article,
the iron dull ink, and the
iron dull ink was being used.
That's when I said, wait.
That's when I said instruct me.
I think if they wouldn't
have used the word iron,
I might have, it just
might have slipped through.
That kind of said we should be
able to do it, because you look
at manganese and leafs and
iron and leafs and that has
to be more difficult than
looking at the residues of iron
in an old page, right?
And then the rest was just to
use the same detection method,
namely x-ray [inaudible], but
not doing a [inaudible] with it,
but doing imaging with it
and actually imaging has been
around for a long time.
So in the morning, I went down
to my mom and said to her, look,
I think we can do that.
That should be easy
for us to help
to look through those tests.
And she said, of
course, sure, sure, sure.
[ laughter ]
>> You didn't say Eureka.
[ laughter ]
>> No, I didn't.
Are there any questions
from Boulder?
We don't have a picture of
you, so if you have a question,
just speak up and
interrupt as we go along.
Yes?
Another question?
>> Well, I wanted to ask,
[inaudible], do you just call
up the museum and say?
>> Oh, yes, so I send
an email and I flew back
and then the thing
sits on your desk
and you have other
things on your plan.
I have all the dates still.
I send an email to Abigail Quant
[assumed spelling] and I got
within the day, I got a
response from [inaudible]
and I said, you know what?
I think I have an
idea how to do it.
And he said, well, send us
a short proposal, because,
he said, we get hundreds of
ideas basically, literally,
and send us a short proposal.
Kind of one page.
And then after he read
that, he said, well,
why don't you come in April.
I sent it in November
2003 and in April 2004,
he said why don't you come.
We have a workshop,
because we are at a stage,
so the timing was
really perfect.
We had a statement where
all of the other methods
that we're using,
particular those optical
and ultraviolet methods,
are coming to kind
of their limitations.
And we are looking
for new methods.
Why don't you come and give a
short half an hour presentation
and then we will decide,
with other people,
we will decide whether we
can use one of those needs.
And it was at that conference,
at that workshop where I was
on April 5th of all days,
2004, where I also met
with my colleagues who had
suggested independently
to use a laboratory x-ray to.
I suggested to use the
[inaudible] and that's
when everything started and it
took us about another six months
to do all the tests,
besides all my other work.
And then a year later basically,
a little less than a year later,
they came with the first page.
So it was, I have to say, it
was incredibly un-bureaucratic.
It was very, it was wonderful,
because no one said
no, you can't do that.
You shouldn't do it.
We just did things on the side.
We didn't bother anybody.
We just started doing
things on the side.
>> Another question from the
conservative point of view.
Now, these days for ancient
documents, like the Declaration
of Independence,
people are so sensitive
about the humidity
conditions, you know,
whether you've got
filtered light coming
and not just bright lights
or fluorescent lights.
They're really almost
paranoid about the things.
It comes as a real surprise
to me that they would go
into this huge facility
with an intense display
of x-ray being a billion times,
how did you ever convince them?
Besides the parchment test.
That could be a trick.
How did you convince them
that it would be safe?
>> Let me, first of all,
the thing that really
cost me the most headache
in this whole project
was actually the humidity
and the temperature.
We could have bought an
air conditioning system
which was way too expensive,
but I would have had
to get funding for it.
And so we came up, I had
a student at the time.
We came up with a
really, we went to Sears
and bought a 100
dollar humidifier,
but when you really
measured the humidity,
it's like a calculator.
It goes from 44 percent to 56
percent and then it shuts off,
and then it drops down to 44.
So we came up with building
a tent where we let it leak
out of the tent, so
we got it to 50 plus
or minus two percent
hovering there.
So that was the humidity.
Temperature was easy because the
simple one is air conditioning.
So that made, that was fine.
The x-ray, when you
talk to anyone
about x-ray fluorescent
imaging, right,
in particular commercial people,
they always say it's a
non invasive process.
And it's not destructive.
It's not true.
I mean, we all know
that it's destructive
and that's why we don't get
a chest x-ray every day.
But you can, you can measure the
damage of x-rays to anything.
And doing the work
on the spinach,
we are extremely sensitive
to radiation damage.
Because we can see it very
much and it destroys our data.
So I had already some background
with being careful with samples.
In that case, it was
for different reasons.
So what we did is we said before
I even said to them, I said,
let's do some tests
and we did some tests
with some newer parchment
and then not only did
we visually inspect it,
but we send it to a lab into
Ottawa, where they measure.
They took it apart and look at
the fibers and they could do,
they could establish
what is called the
characteristic temperature.
So in other words, they
compared the fibers,
because the fibers
start to shrink
when you put x-rays on them.
They start to dry out.
And they compare I to what
happens to the parchment
when you put it in a
certain temperature.
And so they've established
that if you take a certain dose
of x-rays, there is no effect.
And then when you go 10 times
higher, you start to see
as if it starts to warm up and
that's, that was the result
that we then sent to the
[inaudible] and the rest is,
of course, they had to
have some confidence
that I don't just lie to them.
But what we really did do with
the imaging, we used a dose
which was about 100
times less than the safe,
10 to 100 times less
than the safe image.
So I'm not worried
that in 100 years,
all of a sudden these x-ray
papers will fall apart.
I don't think we did
any damage to them.
>> Henry Butler, you've
got the last question.
>> Henry Butler: Okay.
I was intrigued by your comment
about the well-known effect
of spinach on water,
which I don't know.
[ laughter ]
>> Yeah.
>> Henry Butler: Could
you explain it please?
>> Well, yeah, maybe I didn't
express myself clearly.
The reason why we study
spinach is, I mean,
the most important
catalytic reaction
on Earth arguably is
the splitting of water
to oxygen done by plants
and [inaudible] bacteria.
This process started about 3.8
billion years ago at a time
where the atmosphere
had no oxygen.
It was literally all
reducing methane and CO2.
And it slowly enriched
the atmosphere with oxygen
and then only three billion
years later, at the beginning
of the [inaudible] explosion,
the level of oxygen
was high enough
to sustain more complex life
forms such as trees and animals,
etcetera and everything
started from there.
It is that reaction to water
molecules in an O2 molecule
out in the [inaudible] CO2
as well as carbohydrates out.
It is that reaction
which is done
by a little magnesia
cluster made
out of four manganese
atoms and a calcium atom.
It's a little catalyst.
It happens in every leaf.
It happens inside of a mature.
And spinach because it is pretty
soft, is one of the materials
where you can concentrate this
manganese cluster in high from.
And my colleagues
from Berkeley and I,
we use x-ray splichostomy
[assumed spelling] to try
to find out how does
this process work.
It's one of the few, it's one of
the many big unsolved mysteries.
How exactly is the water brought
in and the oxygen spit out?
So we have, I mean, there are
literally dozens of groups
who apply different techniques
to look at this process
and that's the technique,
x-ray fluorescents,
[inaudible] is a technique
which I have on records
for 10 years now to
look at this process.
And it is the manganese.
So we don't look at the iron,
we look at the manganese,
but there is about three times
more iron in spinach as well.
If you know that according to
Popeye, there's tons of iron
in spinach, which
is actually wrong.
That was wrong of the
[inaudible] errors,
which was never created,
so we all grew
up eating spinach,
which is fine.
It's not bad, but
it doesn't have
as much iron as a lot of greens.
[ Laughter ]
>> Thank you.
Thanks for giving us an
excellent talk today.
[ clapping ]
[ silence ]
 
