# How to explain curvature of spacetime at the time of big bang [duplicate]

According to Einstein mass causes curvature of spacetime ,so he basically defined mass using space i.e (mass is something which causes curvature of spacetime).Now at the time of bigbang there was no space (i.e if big bang is rapid expansion of space then definitely there is no space to experience curvature because of the high energy and mass).How to explain this To put everything in simple statement...what'S outside what we call space? or what is absence of space?

## marked as duplicate by AccidentalFourierTransform, Qmechanic♦Jun 3 '18 at 15:13

The Big Bang singularity predicted by General Relativity is un-physical due to divergent physical quantities like density and curvature. Therefore the Big Bang theory starts at $t = 0$ with a hot and dense state of Planck scale and from this point on the universe expands according to GR.