if an astronaut falls into a black hole, will he turn into quantum fuzz?

Falling into a black hole is a confusing and complicated business, rife with paradoxes and weird quantum effects to reconcile. About a month ago, we looked at black holes’ interactions with the outside world when something falls into them, and today, we’re going to look into the other side of the fall. Conventional wisdom holds that inside a black hole gravity is exponentially increasing until time, space, and energy as we know it completely break down as the singularity. Notice I’m not talking about matter at all because at such tremendous gravitational forces and with searing temperatures in the trillions of degrees, matter simply can’t exist anymore. Movies imagine that singularity as some sort of mysterious portal where anything can happen, while in reality, we’re clueless about what it looks like or even if it really exists. We don’t even know if anything makes it down to the singularity in the first place. But what we do know is that somewhere, whatever is swallowed by the black hole should persist in some weird quantum state because we don’t see any evidence for black holes violating the first law of thermodynamics. Enter the fuzzball.

Quantum fuzzballs aren’t really objects or boundary layers as we know them. Instead, they’re a tangle of quarks and gluons made up of the matter that gave rise to the black hole and what it’s been eating over its lifetime. They don’t have singularities, just loops of raw energy trapped by the immense gravitational forces exerted on them. On the one hand, thinking of a black hole as just a hyper-dense fuzzball eliminates the anomalies and paradoxes inherent in descriptions of singularities, but on the other, simply making a problem go away with equations doesn’t mean it was solved. And that’s the real problem with quantum fuzzballs. They appear as exotic math in general relativity being extended deep into a realm where its predictive powers begin to fail, so while it’s entirely possible that we identified in what direction we need to explore and what we’d expect were we to look into a black hole, it’s equally likely that the classic idea of their anatomy still holds. Unless we drop something into one of those gravitational zombies nearby, we won’t know if the current toy models of what lies inside of it are right. All we have is conjecture.