Archimedes Palimpsest

A “palimpsest” is a manuscript written on parchment or paper that was reused from an older manuscript. In the case of parchment, the old writing is scraped off the parchment, and the new document written on top of it. This was done because parchment was so expensive.

Over 1,000 years ago, probably in Constantinople, someone transcribed some of Aristotle’s original Greek manuscripts onto parchment. A couple centuries later (about 800 years ago), some monks scraped those parchments clean (along with parchments from four other manuscripts) and reused them to make a book of prayers — a palimpsest.

In modern times, a collector noticed that traces of writing were still visible “under” the prayer book’s writing. Some of this was recognized as the work of Archimedes — in some cases, the only remaining copy in Greek of those works. Many pages were recovered by scholars working with ultraviolet lighting and other techniques, but many other pages stubbornly resisted every attempt to recover them. This was very frustrating for the scholars, and over the years they have tried many techniques.

Most recently — and very successfully — they tried an exotic new X-ray technique that required the use of the Stanford Linear Accelerator (a huge piece of equipment used for particle physics research) to generate the required radiation. It works by detecting the iron atoms left by the original ink, even when very few atoms remain. The photo above right is an example of the result, which is ongoing as I write.

Here’s a decent newspaper article about the effort, and here’s the project web site.