Online archaeology and anthropology exhibits

January 13, 2008 8:06 PM

The Penn Museum of Archaeology and Anthropology has a nice collection of online exhibits, including ones on Roman glassmaking, the ancient history of wine, and a history of body modification. (Other exhibits have appeared on Mefi previously.)
posted by Upton O'Good (3 comments total)

Fantastic. I was at the Met with some friends the other night and we were wondering how the Romans got that incredible iridescent sheen on their glassware. Turns out the answer is: by being dead a long, long time.

"The main constituents of glass are silica, lime, and soda. If the glass is surrounded by moisture, the soda and lime will be dissolved out, turning the glass surface into a water-rich gel. When the soil dries out for a season, this gel turns into a paper-thin film of silica that wraps loosely over the vessel’s shape. [...] As the outer shell breaks away, it exposes the flimsier individual silica films beneath and disrupts their integrity: the coatings become patchy and variable in thickness. To the human eye, the patches scatter light in such a way as to produce a brilliant peacock feather look that we call iridescence."

I'll have to start neglecting to dry my glassware. Thanks for the post.
posted by phooky at 8:31 PM on January 13, 2008

I'll be checking this out later. Thanks Upton.
posted by Abiezer at 12:25 AM on January 14, 2008

Also previously on MeFi.
posted by The Michael The at 6:05 AM on January 14, 2008