Is Space Really Curved

Space is indeed curved — in four dimensions. Many people think the fourth dimension is simply time, and for some astronomical equations, it is. Einstein used time as a fourth dimension to describe a coordinate system called space-time.

Is space time curved or flat?

Spacetime is not flat. It can’t be: Einstein’s general theory of relativity says that matter and energy curve spacetime, and there are enough matter and energy lying around to provide for curvature. … To put it succintly: space can be flat even if spacetime isn’t.

Are there flat objects in space?

a non-planet is mass-dependent, and making a thin, rigid body fails on… [+] You can have a flat “thing” in space, but it wouldn’t be a planet if you did. … must clear the neighborhood around its orbit (so that there are no other comparably large bodies also in/near its orbit).