Graphics and Archaeology: Interpreting the Past

Snowbird, Utah
20-23 May 2000

Presentation:

What Are We Looking At?

Presenters:

• Duncan Brown

Summary:

Duncan approached his presentation initially from a "consumer perspective of computer graphics" as an archaeologist. A major concern of his was the superficiality and the deceit of the archaeological data:

• photos of holes in the ground
• giving rise to site plans
• artistic impressions and renderings
• CGI representations [how do we make this leap from the evidence?]
  • how do we reach the estimation/inference of interiors like these that show color, reliefs, fountains, etc.?

"We're in danger of finding our own facts from information that is not complete." We need to rethink our way of looking at this material that we collect.

Duncan's own interest was in material culture, most specifically medieval ceramics. He projected an image of the painting "The Loss of Innocence". It was a still life showing a huge display of metal and ceramic "stuff". He characterized it as his beginning and his end - his job is to find fragments of such things and discover a context. Origins of the objects and types of interpretations to reconstruct the type of insights seen in the painting were of most interest to him.

Currently he is working with Alan Chalmers to discover answers to the question - were bright colors significant to the medieval consumer of ceramics in those days? To test his theories, he needs to view these colors in their original light. Electric light is not sufficient or correct. Recreations of the medieval environment were very important. Computer simulations offer a reasonable alternative to understanding light and its effects on pottery colours.

They chose a medieval merchant's house in South Hampton to use as their testbed. The challenge has been - how do we know the colours on the computer are accurate to what would be really seen? They have focused on 3 years study of perception experiences. Now they are engaged in modeling the flame lighting of the past - this includes understanding the medieval fuels (tallow, beeswax, unrefined beeswax, tallow spills, olive oil, etc.) for their spectral signatures. Further work will look at the variances caused by dust, smoke, daylight in the interior.

Accuracy is of high importance. The methodology is related to Alan's work on rock art as featured in the proceedings.

Conclusions / Issues:

• Is it an issue that they are looking at perception with a house, even when it was purchased in a place of manufacture outside of the home environment?
  • There is that issue, but there isn't, on the face of it, any more reason for brown-pot makers to need/want to make green-pots instead for their audience
• It was noted that in the pottery examples, there was glaze only on the top half of the items (jugs)
  • everyday functionality may have driven this, however, it might indicate also that light sources were higher
• "Archaeological deceit" was a concern - the appearance that we know more than we do from what remains
  • archaeologists have been beguiled in how images represent their data
  • it was an opinion that archaeologists might lack the theory of how to apply this technology and how to properly use the information generated by it
  • the perception is that inputs into a computer becomes data even if it isn't - later, the data becomes facts
  • we don't have a theoretical framework of how the use of [information] fragments become facts
• Duncan noted - I was taught two things:
  • there are no facts in archaeology
  • computers are high-speed morons
• The interpretation of reconstructions is not fact - it is conjecture
  • we should be able to tag (turn on/off what is conjecture versus found information) so that seeing pieces of the pot that are missing (or not) might help in the audience's interpretation of the information available
• Work in these areas is an opportunity to integrate other specialists' work
  • yes, we have to leverage some assumptions that when we work from this reconstruction of a medieval house, there were experts in furniture and such giving their inputs to this final environment