User blog:Vel!/Call for math facts

Any interesting math facts to plug into the IRC bot's database?

Criteria:


 * They can be about any mathematical topic, including discussions of metamathematics and computer science.
 * They have to be presentable in about 200 characters.
 * Advanced or obscure facts are preferred over elementary or well-known ones. ("Did you know that 10^100 is often called 'googol'" is unlikely to impress anyone.)