- #26

JesseM

Science Advisor

- 8,496

- 12

GR requires a universe where there is always a fixed relationship between the distribution of energy (including energy due to mass) and the curvature of spacetime at every point. It doesn't really tell you what "creates" what, it just gives you the mathematical relationship. But because this relationship is supposed to hold at every single point, you can't have a situation where there's first some curvature without the corresponding mass/energy distribution, and only later does it collect that mass/energy.So my current question about GR is: Does GR require a universe where mass creates gravity in order for it to work? What happens to GR when it's applied on a universe where gravity creates mass.. Or should I say "matter" instead of mass?