# Definition of "spacetime" [spacetime]

- (noun) The four-dimensional continuum of the three spatial dimensions plus time.

- (noun) An n-dimensional continuum consisting of dimensions of both space & time. Normally spacetime is considered as having 4 dimensions (x, y, z, t), but higher-dimensional spacetimes are often encountered in theoretical physics, e.g. the 5-dimensional spacetime of Kaluza-Klein theory or the 11 dimensions of spacetime in M-theory.

- (noun) A specific region of the universe with mathematically different properties than the surrounding spacetime. Synonymous with "metric" within the context of general relativity.

## Use "spacetime" in a sentence

- "My objection to punching a hole in spacetime is the same as my earlier objections."
- "Compared to that, the tiny risk to humanity, the planet and solar system, the galaxy and all other things that currently exist in spacetime is more than worth it."
- "Given that all biological processes apparently reduce to subatomic particles of matter interacting with each other and with waves of radiation in spacetime, is it fair to say that biology is essentially physics?"