Answerer

Maybe we can use the renormalization 'tactics' again on gravity.

lpetrich

I wonder what, exactly, is meant by black holes not really existing?

Is it that quantum gravity has no true black-hole solutions?

Even if the solutions resemble classical-gravity black holes at much more than Planck sizes?

Jesse

I think he just meant that he doubted that singularities exist.

I wonder though, are there any physicists who also doubt that the region of spacetime inside the event horizon exists? I know an observer should only take a finite amount of time to cross the event horizon by his own clock, but it seems like there are still some worrying physical infinities involved, like the fact that if the observer looks at the outside universe while he's falling in an infinite amount of outside-universe-time will be compressed into the moments before he crosses the event horizon. Couldn't you use this to do infinite computations and solve the halting problem, for example? Just have a satellite orbiting the black hole which performs step after step of a given computation, and then if it halts it beams a signal detailing the step on which it halted at the observer, which from the observer's point of view will catch up to him at some point before he hits the singularity, so he's guaranteed to either get a signal and know when the computation halts or to not get a signal and know the computation never halts. But maybe even if the signal travels at light speed there will always be a finite amount of satellite-time after which it is impossible to send a signal to the observer which reaches him before he hits the singularity, that could be a way out of the problem. But if not, and if it really would be possible to see the outcomes of infinite computations by travelling through the event horizon, that might be a reason to be question whether the region inside exists at all (and if quantum gravity indicates that black holes always evaporate, perhaps any infalling matter would always see the hole shrink and vanish before it could reach the horizon).

Answerer

This begs the question of where Big Bang start from? Singularity? Or a very, very small quantized spacetime?

Unbeliever

As an object approaches the event horizon of a black hole, time slows down for it relative to more distant objects, and would appear to completely stop at the event horizon. So when the original star collapsed, as its surface reached the event horizon it would appear, from a distant perspective, to never cross it, which would keep it from ever becoming a singularity as far as we could tell. Is this a fair assessment of the situation?