The Why of X
One of the best teachers I’ve ever had, Eugene Wallingford, regularly writes in a thoughtful notebook called Knowing and Doing. He’s a computer scientist, as was I in a previous life. He approaches the study and the craft as a scientist - a position that most people in the field do not actively take. Perhaps that’s why he resonated with me so strongly.
Regardless, I liked the question his daughter posed so much I’m going to shamelessly steal it. She wondered why we commonly use the letter x as a variable to represent the unknown. From algebra to science fiction - it is a powerful and oft-used letter. It is really quite elegant and mysterious.
He happened upon the answer in an article called The Shakespeare of Iran. The gist: it was first used by the Perisan mathematician Omar Khayyam who called it shiy (meaning thing or something in Arabic). That was transliterated to Spanish during the Middle Ages as xay and then abbreviated to x. The other possibility is that it is based on the word xenos, which is Greek for the unknown and then abbreviated to x.
Either way, it is used in the pursuit to explore the unknown. Mathematics gives definition to the fuzzy. Algebra reveals a balance that was previously undisclosed. Geometry concisely explains a shape’s form. Proofs are poems. They have a distinct rhythm and beauty. I’m secretly envious of people who study them.
