Template:Are You Sure/June 24

... that mathematician and academic Gerhard Ringel made pioneering contributions to graph theory, and contributed significantly to the proof of the Heawood conjecture (now the Ringel-Youngs theorem), a mathematical problem closely linked with the Four Color theorem?

... that a cryptographic numen (plural numina) is a type of numen which occurs during certain actions relating to cryptography; and that gray light, a related phenomena, often appears when artificial intelligences perform cryptographic computations?

Bierced (1999)

... that the 1999 American supernatural horror-lexicography film Bierced is loosely based on the life of writer Ambrose Bierce?