( intro music )
( applause )
Tonight,
I want to share with you
something that
scientists and academics
fear even more
than loss of life or limb.
And that is
loss of reputation.
So, how do you fail
without really trying?
I want to share with you
my collaboration
with this incredible team
out of Southampton University
on an absolutely
amazing archaeological site
that challenged me
in ways I never expected
to be challenged
and really showed me
the possibilities
and potential
for using new technologies
when you think
you're at the end of your rope.
Many of you have actually
flown over this site, Portus,
without even realizing it.
If you've ever been to Rome
and flown into the
Fiumicino airport,
you have flown
over the site of Portus.
Portus was the port of Rome
during the height
of the Roman Empire.
The site of Portus is a very
complicated landscape today.
You have Rome Fiumicino airport
to the north,
you have lots of houses,
you have lots of fields
as you can see in this image.
It's a mixed urban-rural
landscape
and the archaeological team
at Portus has been working there
for over 30 years
led by Professor Simon Keay,
one of the great
Roman landscape archaeologists
in the world.
So we decided to work together.
Do you see the hexagonal basin?
That was actually one of the
central parts of the site
of Portus.
You can see a beautiful
3D reconstruction here.
This is the main basin
into which ships would sail.
They would dock, leave their
goods at the warehouses,
they would be organized
and then sent further on
to the northeast, to Rome
and elsewhere within Italy.
So, I got ahold of some
great high-resolution
satellite imagery,
I looked at a lot of
previous publications
from Professor Keay and his team
and got down to work
with processing.
That's what I do.
And we started finding
some really amazing things,
which I want to share with you.
We started finding buildings.
We started looking at things
that may not be otherwise
visible.
By using the infrared part
of the light spectrum,
we are able to tease out
old roads.
We were able to
tease out buildings,
different areas of shading that,
potentially, could be
other warehouses
or other structures
and things
really started appearing.
I started getting so excited.
So, these were sent on
to Professor Keay and his team.
Except there was a problem.
They knew about all of them.
( audience laughter )
Now, my ego shrunk down
to atom-size,
and I talked to
Professor Keay on the phone.
And I said, "I don't understand.
What have I missed?"
He goes, "We just haven't
published any of those yet.
We saw them all
with aerial photography."
And I thought,
"Well, there goes technology.
They already knew about them.
What was I to do?"
Well, around that time
I started looking through
this high-resolution
satellite imagery company
called Digital Globe.
I started looking through
their satellite database.
And I noticed this
brand new satellite image
that hadn't been
in the database before.
And, so, we got a hold of this
brand new satellite imagery.
Now, Portus is
this amazing site,
so not only do you have
all of these warehouses
and buildings and roads
that they'd so carefully
mapped out for so long,
but there is this big mystery.
Simon Keay and his team
had spent over 30 years
looking for an amphitheater.
A site of this size
filled with so many people,
who were living and
processing all the goods from,
uh, from all over
the Roman Empire.
There had been incredible wealth
at a site like Portus.
And for the wealthy inhabitants
of Portus,
many of whom
likely lived in Ostia,
they would have needed
a place to go be entertained.
Think of it like a combination
of an ancient movie theater
and sports complex,
much like what you saw
in Gladiator ,
although on a slightly
smaller scale.
Where was the
missing amphitheater of Portus?
Now, Simon and his team
had told me,
"Well, it's probably somewhere
in the southern part
of the site.
I really don't know
where it is,
it may not even exist."
So, we got hold of this
brand new satellite data
and started processing it.
Some interesting things
started appearing.
To the east of the Tiber,
this is a before
and this is an after image,
you can see in that arrow,
it's pointing to a small band
about seven to eight meters
wide.
And we sent out a team
to do subsurface survey
and what they found was a canal.
One of the long-standing
questions
that they had
at the site of Portus was
"How in the heck do you
transport all these goods?"
Just along the Tiber itself,
you would have had logjams.
And what we are able
to suggest,
now that we've found this
new feature which is the canal,
or a smaller river
that would have
probably led up to Rome,
is that they would have
had these smaller channels
to divert traffic.
So, it would have been
a way for them
to have better organization
of transportation.
So, as I was processing
the data,
something came up.
So this is a before image.
This is an after.
You see an interesting
oval feature
with linear features running
from east to west.
Now I admit when I first
got a hold of the data,
and when I first started
processing it,
and when I first saw
this feature
I thought that has
got to be modern,
or at least
100 or 200 years old.
It's probably some old ditch
or drainage feature.
Something to do with
local agriculture.
The idea that it could be
this missing amphitheater
was the absolute last thing
on my mind.
I had been so humbled
by the utter lack
of discovery
from our previous work,
I thought best to
just not even say anything.
I'll send...
I'll send the Portus team
an image
and just let them tell me that,
once again,
I absolutely do not know
what I am talking about.
Well, when Professor Keay
saw this image
I was told, and quote,
"He fell out of his chair".
When I talked to him
on the phone,
he said, "I can't believe
what you might have found.
This is extraordinary.
This could help us
to rewrite the history
of how we understand
the landscape around Portus."
Previously in this area,
they had found a number of
mortuary features.
So, again,
a before and an after.
This feature, this ovoid feature
is 40 by 40 meters in size,
with an eastern and
a western gate.
With a clear east-west road
and you can see,
just to the north,
there is a series of
outbuildings.
Typically around an amphitheater
you're going to have rooms
or places where people dress
or practice or prepare
for whatever activities
are going to take place
in the amphitheater.
Whether they are fighting,
whether they're staging a play,
whatever is going on there.
They knew about none of this.
And what's even more
extraordinary
is that the Portus team had done
sub-surface survey already
and found nothing.
One of our favorite
sayings in archaeology is,
"Absence of evidence
is not evidence of absence".
They hadn't used
the right tools.
Now flipping that around,
the satellites
didn't find a lot of things
that they had found
on the ground using other tools.
So what this taught me
was this amazing lesson.
We have to be strategic
about when and where
we use certain technologies
and we have to understand
the landscapes in which we work.
Just because nothing has ever
been found in a particular place
doesn't mean
that the right angle,
or the right picture,
or the right new
sensing technology
won't be able to find it.
And this particular discovery
is allowing us...
It's not just finding something,
which, of course,
is cool and why I am--
One of the reasons
I am an archaeologist.
But it actually allows us
to ask better questions
about the site.
Why was this there?
Why was this particular feature
placed so prominently
in a landscape
that had so many
mortuary features?
What does that say
about the relationships
between the living and the dead
and honoring their memories?
Were there festivals held there?
Were there activities done
at this particular place
that honored the memory of
the deceased and so on.
We also found road extensions,
we found old river courses
along the Tiber.
We found numerous
other features
that we simply hadn't found
because we looked differently.
You've got to, sometimes,
when you're absolutely unsure
of what to do,
it was only through that...
that just... out of just being
completely down
and being in a gutter
that I was able to look up
and think
a little bit more clearly.
And that is what I would
challenge all of you to do
the next time that you think
you are at the end of your rope.
Sometimes you don't need to
look down,
sometimes look up.
And I just want to thank
National Geographic
for having me here.
The National Science
Foundation for--
for generously
funding my research.
You can follow me
at indyfromspace.
Thank you very much.
( applause )
( outro music )
