Those of us at all aware of crank theories of the pyramids know that there is a stumbling block for those devotees who believe that the Great Pyramid was built by a mysterious ancient civilisation, earthly or extraterrestrial: this stumbling block is the cartouche of Khufu/Cheops painted in one of the relieving chambers, at a location that was not accessible before 1837. Hence the theory, first proposed by the writer Zecharia Sitchin and subsequently taken up by the world of unorthodox (...)