[Doctor Stochastic]

Not quite true. Were the expansion reversed, the universe would be compressed to a density beyond which current physical theories do not function.

[betty boop]

Not quite true. Were the expansion reversed, the universe would be compressed to a density beyond which current physical theories do not function.

Does this mean that the singularity itself is "dense?" If the physical theories do not function, how do we know this? By logical inference from an entirely hypothetical reversal of its expansion?