In Science X Exists In A Superposition of the Known and Unknown. It Is Not A Corporate Property.
John Singer Sargent's painting of Madame X makes an artistic statement with X sometimes marking where treasure can be found on a map and in science X can be many treasures, defined and undefined. It is not a corporate property!
Elon Musk has achieved many business milestones but his antics around Twitter and its rebranding as “X” is putting off previous supporters or those who were just neutral. In any event X is a letter that has many uses in STEAMy fields, notwithstanding its over use in the steamy swamp of the less salubrious triple X areas of the internet. Find out more from Techstuff and This Week In Science (c 45 sec in) here.