One of the most famous buildings in Pompeii is the House of the Faun, an upper-class house which featured elegant mosaics that were the pride of the owner. >> One of the grandest atrium houses in Pompeii is the so-called House of the Faun. And the major work of art that came from it, discovered in the 1850s, was the Alexander mosaic, a large detailed mosaic that shows in polychrome technique. The battle between Alexander, who rides his horse and carries his long Macedonian sarissa or lance in his right hand, and Darius III of Persia. Alexander has just run through with his sarissa, a member of the close entourage of Darius and his chariot driver wheels that chariot around and drives the king out of danger. [MUSIC] The question that we're asking is how did the ancients see the mosaic in its location in the House of the Faun? And there are three aspects to this question. The two most important ones are first, how did the room in which it is located present itself? Because it's located in a large rectangular room, called an exedra, this is a large important room. The room is flanked by pilasters on the both sides and it is screened by two Corinthian columns in the center. Then the second important question is how did one see the mosaic in terms of the lighting situation? Because the mosaic has such detail in it. That one can reasonably assume that it was intended to be seen, and so, we have asked those two questions. And the third interesting question is how was the mosaic approached? Because It was located on the far side of a peristyle in the House of the Faun. And so you had a choice of going up the left branch, or going up the right branch of the portico. So which was preferred, or didn't it matter? What we have discovered is it is very difficult to reconstruct in one's mind's eye, the viewing and lighting conditions that may have existed. So we have used a 3D model, and the 3D model has been critical in our research. Ethan built the model, and the result of the model was that we now know that it would have been nearly impossible to see the Alexander exedra because the columns of the peristyle intervened. This is the first problem. Important Roman space are usually visible. They announce themselves, they present themselves so that they will call attention to their importance. Ethan was able to introduce into the 3D model a sophisticated lighting package that allowed us to set the time for 100 BC, the traditional date of the mosaic. And use the summer solstice and the winter solstice so that we could test the lighting quality. When the sun was at its highest in June or lowest in December, and the results were extraordinary. At the summer solstice, the sun was so high that it did not penetrate the Alexander exedra at all. But light only filtered from the garden through the portico and into the space with the mosaic was. The mosaic, consequently, was extremely dark. Then we thought the solution will be the winter solstice when the sun's low. And indeed, the sun streamed into the Alexander Mosaic. The problem was that four columns of the the peristyle and the two Corinthian columns of the Alexander exedra cast six long dark shadows across the mosaic. And the resulting intense light dark chiaroscuro effect was so intense that the mosaic was essentially illegible. This brings us to the third question, the preferred approach to the Alexander exedra. And what we find is the same condition in one of the columns in the left, or west peristyle, that was removed and the same footing modification took place. And that indicates that the architect and mosiacist wanted the viewer passing along the west portico to have an unobscured view to the Alexander exedra, which contain the mosaic. And so just at the critical point where one would see it at the best oblique angle to the right, the column's gone. This research exercise, and we hope these discoveries, reveal the importance of 3D computer modeling in archaeological research, and I underscore research. Models are wonderful for presentation, but we want to use them at a level that goes beyond presentation of information but rather at a research level to ask questions. So the model created for us, the two problems that seemed inconsistent with the way in which the mosaic should have been seen by its patron and his friends. And so it allowed us to address the ruins with new insights, with new questions. It allowed us to view these modifications to the columns in a way that we had never before, and no one else had ever before, comprehended. And if we're right, then this shows not only the importance of the mosaic to the ancient Pompeians, but also the importance of Advanced technology in current archaeological research.