Is space compressible?

[Puma]

I was asking some Big Bang related question on Reddit and someone replied

"The big bang is an explosion of space itself. A shock wave requires an explosion propagating into pre-existing material.

Not only was there no pre-existing material, there was no pre-existing space to hold it.

This all makes sense in general relativity, but is somewhat alien to our terrestrial existence where geometry is Euclidean and physics is Newtonian."

I was not aware that there is a formula connecting space density to mass and energy? I would like to read more about this if it exists and would like to know if there a readable book on models of space time?

Are variations in space density in your opinion just as viable as curved space? Eg would all phenomena be explicable with such an alternative model.

Thanks in advance

 

[A.T.]

re variations in space density in your opinion just as viable as curved space?

Curved space means that there is more or less space in a sphere of a given circumference than in flat space. Is that what you mean by "variations in space density".