# Is a planets orbit really a straight line through curved spacetime? [duplicate]

My understanding is that general relativity concludes that gravity isn't real because it does not exist in all frames of reference. Also that mass and energy warp spacetime into a curved geometry. Does that then mean that objects in orbit are actually traveling in straight lines in curved spacetime?

Your first line is incorrect, gravity is real, just jump up and you will confirm that. Frames of reference are used to find how gravity affects our measurements of spacetime.

• @Wjdavis5: this is a semantic nicety. Because motion is explained by the geometry some like to claim that gravity isn't a force. This is a bit silly because the mass times the norm of the four-acceleration is non-zero in loads of situations, and to me $ma$ certainly seems equal to $F$. Jun 9 '15 at 16:34