Translator: Kelly Clarke Reviewer: Denise RQ
When I was a little kid I had two big heroes.
One was a TV hero, MacGyver.
Now, MacGyver was a physicist.
And he used his knowledge of physics and science
to get out of all sorts of troubles in his fight against evil and crime.
The other big hero was a cinema hero, Indiana Jones.
And of course, Indiana Jones was an archaeologist
traveling around the world
having amazing adventures in the search for famous lost artifacts.
But now, this placed me in face of a dilemma.
What to become when I grew up?
A physicist or an archaeologist?
And what did I do in the face of this dilemma?
I became a computer programmer.
(Laughter)
Computer programming is fantastic, it's great.
But the truth is that I was not completely happy.
And then I had a thought.
What if I used the methods from physics to address the questions from archeology?
This way I could combine them both.
I decided to try this out, and I went on to study both physics and archeology.
And what are the questions of archeology?
Well, if you think about Indiana Jones
you might think about trying to find the lost Ark of the Covenant,
or trying to find a golden idol in the jungles of Central America.
And to find these artifacts,
you might be thinking about going on an archaeological excavation.
So, this is an experience that I thought I needed.
And I went on a few excavations.
But one of the first ones in which I was involved
was located high up in the mountains of Crete.
It was a site called Karfi.
And Karfi was one of the last settlements of the so-called Minoan civilization.
Now, working at Karfi implied waking up before 5 am,
climbing a mountain, with equipment,
and performing all sorts of different tasks at this site.
Now, this included removing a lot of soil and heavy stones,
and this was often done under very high temperatures.
I can assure you that at the end of a working day,
you did not look like a very impressive Indiana Jones.
I am also extremely sorry to report,
but we were unable to locate the lost Ark of the Covenant
nor did we find any gold or silver treasure.
But what we did find was, in many respects,
far more interesting than any treasure,
because we found features and artifacts that told us
about the daily lives of the people living at Karfi,
how they managed to survive in this very difficult environment,
what kinds of technology they had access to,
how was their society organized,
and also, insights into their art, their religion, and their culture.
And these are some of the real questions of archeology.
And very important,
archaeologists want to know when, how, and why these things changed.
In the case of Karfi, it is a very touching story
and a story which illustrates
how the lessons of the past can still be useful today.
As I mentioned to you,
Karfi was one of the last settlements of the so-called Minoan civilization.
But the Minoan civilization is far better known
for the much bigger sites which are located near the coast.
And the most famous of these is the palace site of Knossos,
a place associated in Greek mythology
to the legend of King Minos and the Minotaur.
At about 1,200 BC, these big sites were attacked,
and much of the population fled inland.
So actually,
the people and their descendants living at Karfi were war refugees.
They went to live in this desolate place because at least there, they had safety.
Now, how can physics help archeology to build similar stories?
I can probably guess what many of you are thinking about,
and that is probably a time machine?
Well, for the moment, we still don't have access to a time machine,
but there are actually many different ways in which physics can help archeology.
And one of them is through something
that many of us love to do, but we all have to do: eating.
You see we are what we eat.
In the sense that the food that we eat
is not only determined by our personal choices,
but also by the environment in which we are placed,
the technology we have access to,
our social or economic status,
and also, by the culture to which we belong.
The consumption of some foods in some cultures is promoted,
whereas the consumption of those same foods in different cultures
is considered taboo.
But we are also what we eat in the physical sense.
The vast majority of the atoms that make up our bodies,
we get from the food that we eat.
And by counting the atoms in our bodies,
we can actually reconstruct our dietary histories.
But in order to be able to do that, I had to go into an environment
that could not be more different than what I found at Karfi.
I had to go and work in an applied physics lab.
There, I had access to clean rooms,
where I could treat, chemically and physically, archaeological samples.
And there also, I was surrounded by high tech instruments,
and it was in this context that I met a lady, a very special lady,
that would become extremely important in my life.
Her name is Olga, and she is a 5 ton-accelerator mass spectrometer.
(Laughter)
What Olga allows us to do is to determine how old archaeological samples are,
and she does this through a process known as radiocarbon dating
in which the radioactive isotopes of the element Carbon are counted.
At the lab, there were also other machines, smaller than Olga
but that worked on similar principles.
And what these machines count
are the proportions of non-radioactive isotopes.
And these are very useful
because we can actually identify different foods using this method.
For example, by counting
the proportions of the non-radioactive isotopes of the element Carbon,
it is often possible to distinguish
between the protein coming from marine foods
from the protein coming from terrestrial foods.
And now, I would like to tell you about one of my favourite examples
in which these methods from physics were applied to archaeological research.
And that was the study of prehistoric populations
living in coastal areas in southern Scandinavia.
It all started with archaeological field work,
and archaeologists finding human remains.
They took bone samples from these human remains,
and they were sent for radiocarbon dating.
This allowed archaeologists to place these human remains in a time line.
These same bones samples were also analyzed
for the non-radioactive isotopes of Carbon.
And what the results showed was that for a long time period
the main source of protein for these populations was marine foods.
This is time period known as the Mesolithic,
before the introduction of farming,
when people lives in small groups of hunters and gatherers.
They had a subsistence economy.
They would collect wild foods, and they would hunt wild animals.
In the case of these southern Scandinavians living near the coast,
they were fishing marine fish, collecting marine mussels,
and hunting mammals like seals or sea lions.
At about 4,000 BC, there was a sharp change,
and the main source of protein became terrestrial foods.
And what one witnesses here is the arrival of a new technology:
domesticated animals and plants.
The domestication of plants and animals was first achieved around 10,000 years ago
in the Middle East, during this so-called Neolithic Revolution.
Domesticated animals would spread, eventually reaching Europe.
But it was not only these domesticated animals and plants arriving,
other new technologies also arrived: new people,
new ways of people organizing themselves,
and a new culture, a Neolithic culture.
And this culture would give rise to some impressive developments,
some of them quite visible
like the big stone monuments of the Neolithic.
The most famous of them all, I am sure that you know it, Stonehenge.
And there is a special reason why I am mentioning Stonehenge.
Because archaeological excavations in the area of Stonehenge
found evidence for Mesolithic constructions and possibly, monuments.
And so perhaps, Stonehenge is part of a tradition
that dates back to the Mesolithic.
Now, archaeologists are not certain about this,
but it is certainly interesting to think about the interaction, the encounter
between these two very different Mesolithic and Neolithic cultures.
For me, this is one of the most fascinating things about archeology:
the study of the encounter of cultures
and of the developments that arose from this encounter,
developments that perhaps expanded the existing knowledge,
and perhaps allowed us to look into the future in a different way.
And this brings me to what I would like to be the main message of my talk
that when you are faced with a dilemma,
when you are faced with options or ideas that seem to be radically opposed,
it may be worthwhile to find the crossing point,
because from this crossing point, new and extraordinary things may emerge.
In my personal case,
I placed myself at the crossing point between physics and archeology.
And there I have been quite happy with the outcome.
Or to put it in other words,
I realized that I don't have to choose between MacGyver and Indiana Jones.
And until today, I remain a huge fan of both.
Thank you.
(Applause)