Quote from: mad aetherist on 06/02/2019 04:27:56

My limited understanding of GR is that Einstein said that light always goes straight but that the bent spacetime gives the illusion that the light's traject is bent.  Same for objects i think.

How would space be 'bent'? I don't understand

Gravitation is described as objects following straight paths through curved spacetime but this is a meaningless interpretation because the curvature of spacetime can only ever be measured (in principle) by the paths of the worldlines though it, so it's exactly the same as saying that objects follow curved paths through flat spacetime. It's not wrong to model it as straight paths through flat spacetime, it's just equivalent to curved paths through flat spacetime. Either way, mass curves worldlines towards it proportional to their distance.

A lot is made of general relativity not including a description of how mass is able to curve spacetime (curve worldlines) but nobody question how energy does the same thing. If it's not an issue for energy then it shouldn't be an issue for mass given we know there's an equivalence between the two.