What does the space- time fabric bend into when large mass or matter bends the space time curvature?
It is not really bending. That is just a happy image that is used to prop up our thought processes so that we can try to understand what the mathematics is telling us. It is rather like those pictures you see in quantum mechanics books that try to give you a picture of what is happening in the quantum world – a world of complex numbers that we cannot really picture. What is happening is that the equations describing the various “metrics” of space and time no longer look the way they do when there is no mass present. The solutions to those equations give the impression that space has become curved or that the time “axis” is no longer orthogonal to the spacial axes. Remember that in general relativity the metric tensor is related to the “mass energy tensor” so effectively one determines the other. Relativity itself really says nothing about “beyond the universe”. These colourful expressions have been “bolted onto” relativity in the hope of making further progress (which to date has not s
