Watch this: Origins of the unknown thing, the letter “X”

Mathematics scholars have always used the letter  ‘x’ to denote an independent variable. In x-rays it was used to describe the unidentified radiation in x-rays, and for the entertainment fans out there its used in the  TV show The X Files. We ask ourselves how the letter become the symbol that commonly represents the unknown? Terry Moore’s TED talk takes us back to the origin of “the unknown thing,” explaining how its translation from Arabic to Latin was facilitated by Spanish phonetics and the Greek alphabet. Enjoy