I recently read an article summarising, in a superficial way, some speculations about what might happen at the singularity of a black hole. It prompted the following, rather wild and completely uninformed, alternative, alcohol-fueled, speculation on the walk back from the pub last night. I haven't looked at the relevant equations so don't know if it has any mileage? Probably not!
What if, just as Newtonian mechanics is a decent approximation to relativity for everyday life, the central tenet of relativity, the constancy of light speed, is only a decent approximation for the everything we can observe, even astronomically? Could it be that the speed of light is actually an extremely weak function of the gravitational field or its gradient such that it is constant to the accuracy that we can observe in all ordinary gravitational fields but varies in the extreme fields at a black hole singularity such that it tends to zero there. Nothing could then get to the singularity although it could approach infinitesimally close. If E= mc2 still applies, the energy content of the matter approaching the singularity would tend to zero. If energy were to be conserved it must be converted into something else. Could this be dark energy? What if dark energy can transform into dark matter and dark matter and/or energy can travel faster than light. It could then escape the black hole into the wider universe.