eli5: When space-time “bends” due to gravity, what is it bending ‘inside’ of, or in respect to?

Question

eli5: When space-time “bends” due to gravity, what is it bending ‘inside’ of, or in respect to?

In: Physics

Answer 1

Reality.

space-time is a fancy word for Reality. Everything that has, does or can exist needs to exist somewhere/when. This where/when is space-time. When space-time “bends” it just means that the Reality’s becomes non Euclidian. e.g. Two straight parallel lines DO converge.