I’ve always had a love-hate thing with deep space. On the one hand, I’m fascinated (note to terrible poets: I’m happy to consider a poem about space for our terrible poem breakdown series). On the other hand, I find myself overwhelmed by the feeling of insignificance when thinking about anything farther away than the moon.
Good news for me! It turns out that if a) I become an astronaut, and b) I fall into a black hole, I might not actually suffer what has always sounded to me like an extreme sort of mental torture:
[P]hysicists had long assumed [that] the astronaut would happily pass through the event horizon [of a black hole], unaware of his or her impending doom, before gradually being pulled inwards — stretched out along the way, like spaghetti — and eventually crushed at the ‘singularity’, the black hole’s hypothetical infinitely dense core.
“Happily”? Nothing can escape the event horizon! What would happen to the atoms in your body? What would happen to your soul? For years I’ve lain awake in bed, staring at the too-dark ceiling, shivering at the prospect.
Some more recent views of quantum mechanics predict a somewhat more routine demise:
But on analysing the situation in detail, Polchinski’s team came to the startling realization that the laws of quantum mechanics, which govern particles on small scales, change the situation completely. Quantum theory, they said, dictates that the event horizon must actually be transformed into a highly energetic region, or ‘firewall’, that would burn the astronaut to a crisp.
A little better. But here’s the problem: once you’re burned to a crisp, you still disappear into the event horizon. That’s it! You’re done! You don’t even get worms. You don’t even get to be space dust.
Luckily, Stephen Hawking has come up with a new theory!
In place of the event horizon, Hawking invokes an “apparent horizon”, a surface along which light rays attempting to rush away from the black hole’s core will be suspended. In general relativity, for an unchanging black hole, these two horizons are identical, because light trying to escape from inside a black hole can reach only as far as the event horizon and will be held there, as though stuck on a treadmill.
However, the two horizons can, in principle, be distinguished. If more matter gets swallowed by the black hole, its event horizon will swell and grow larger than the apparent horizon.
Why is this good for me? Because I would avoid the singularity.
If Hawking is correct, there could even be no singularity at the core of the black hole. Instead, matter would be only temporarily held behind the apparent horizon, which would gradually move inward owing to the pull of the black hole, but would never quite crunch down to the centre. Information about this matter would not destroyed, but would be highly scrambled so that, as it is released through Hawking radiation, it would be in a vastly different form, making it almost impossible to work out what the swallowed objects once were.
Almost impossible – but that’s not the same as impossible! My information can escape! All it takes is a little descrambling on the other end.
Given the choice between total oblivion and a small hope for survival in some form, who would choose the former? And why aren’t we all out celebrating this development!? I for one will be sleeping better tonight. Within my tangible body. Under the tangible covers. In my tangible bed.
Dreaming of permanence.