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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.
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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
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.
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