The word proximity means "nearness," and it is often qualified by the word close. "It was hard not to see him cheating, when our desks are in such close proximity to one another."
Proximity derives from the Latin proximus "nearest," which also gives us approximate, "close to the actual." It's interesting that the word proximity doesn't have an opposite (except the rather clunky remoteness): I suppose humans are interested in talking about how close two close things are, but when it comes to things that are remote, the distance doesn't matter so much.
