Within relativity (both special and general), changes of reference frames can change both the notions of space and of time, with one depending on the other as well. As a consequence, it is necessary to treat both concepts in a unified manner. Hence the term spacetime.
Term introduced by Herman Minkowski to describe the ontological status of space and time in the theory of special-relativity and subsequently also in general-relativity and more modern theories.
Within relativity (both special and general), changes of reference frames can change both the notions of space and of time, with one depending on the other as well. As a consequence, it is necessary to treat both concepts in a unified manner. Hence the term spacetime.
The term has outgrown its original context and is now used in other theories.
