Quote Originally Posted by LegioXXXUlpiaVictrix
- Einstein's theory of relativity says certain waves move straight through space, but space is bent. You could also say (easier to understand I think) that space is straight, but those certain waves bend off.
It is easier to understand relativity without the effects of gravity (bent space).

That is why the easier version is refered to as special relativity... special because it refers to a flat spacetime (no gravity)... a restricted subset of the more general set of solutions.

While general relativity being the more difficult version to understand includes the effects of gravity. And by definition treats gravity as a geometric effect... in other words space is bent by gravity.