Historians learn a great deal from historical texts -- and not only that which was written, but that which was unwritten. Join Robert and Christian as they explore the world of palimpsests, the erased books just under the surface of ancient tomes. Modern technology allows us to uncover more and more of their secrets, while the idea of the palimpsest itself serves as a powerful metaphor for media, the mind and maybe life itself.
Palimpsests: Reading History's Blank Pages
Image Caption: Bifolio, under ultraviolet light, of the 10th century palimpsest manuscript by Archimedes which shows a diagram that illustrates the sphere and the cylinder theorem as well as a large initial with a hand belonging to the 13th century prayer book text which was superimposed over the Archimedes manuscript by a Byzantine monk. The 10th century manuscript is the earliest surviving copy of Archimedes treatises, and contains the only known copy of his "Method of Mechanical Theorems" and the only copy in the original Greek of "On Floating Bodies." (© George Steinmetz/Corbis)
What is the oldest book in the world? (HowStuffWorks)
What was Archimedes' death ray? (HowStuffWorks)
The Age of Erasable Books (The Atlantic)
'Aurora Leigh' by Elizabeth Barrett Browning
'The palimpsest of the human brain' by Thomas De Quincey