4 ms·

Some predictions suggest particle-sized black holes are a possible outcome of very energetic collisions. If they didn't evaporate, they'd be relatively common

Some predictions suggest particle-sized black holes are a possible outcome of very energetic collisions. If they didn't evaporate, they'd be relatively common because the universe is quite an energetic place. This suggests either that particle-sized black holes don't exist, or that they evaporate very quickly. This is a good thing. Because some predictions imply they could be created at the energies CERN generates. And if they didn't evaporate they'd end up in or around the earth, with very unfortunate consequences. None of this solves the information paradox. But if microscopic black holes turned out to be a thing, it would make it slightly - not much, but a little - easier to consider that it might be possible to experiment on them directly.

mr_toad 5y ago
> with very unfortunate consequences Less than you might suppose. A micro black hole that the LHD could generate is a tiny tiny hole, and you can only cram a tiny amount of matter down it at once. An extreme lower bound on the time such a black hole might take to grow large enough to destroy the Earth is on the order of 10,000 years. More likely it would take longer than the lifetime of the Earth. https://s3.cern.ch/inspire-prod-files-8/836037ce600a972222901517045a5412 https://s3.cern.ch/inspire-prod-files-8/836037ce600a97222290...
- lliamander 5y ago
  But can we safely dispose of the micro black hole (say, by launching it into space) and how long do we have before it becomes too big to deal with?
  - PaulHoule 5y ago
    It would make a good science fiction story. Somebody drops a black hole into the Earth which interacts very weakly with the Earth other than gravitationally so it is falling back and forth through the Earth every 90 minutes or so with the Earth rotating around it so it shows up at different spots. As the hole takes on mass the height it reaches will diminish and rotationally it will catch up with the Earth, but it takes a while. People rush to move a https://en.wikipedia.org/wiki/Very_large_floating_structure https://en.wikipedia.org/wiki/Very_large_floating_structure into place to catch it.

mr_toad 5y ago

> with very unfortunate consequences Less than you might suppose. A micro black hole that the LHD could generate is a tiny tiny hole, and you can only cram a tiny amount of matter down it at once. An extreme lower bound on the time such a black hole might take to grow large enough to destroy the Earth is on the order of 10,000 years. More likely it would take longer than the lifetime of the Earth. https://s3.cern.ch/inspire-prod-files-8/836037ce600a972222901517045a5412 https://s3.cern.ch/inspire-prod-files-8/836037ce600a97222290...

lliamander 5y ago
But can we safely dispose of the micro black hole (say, by launching it into space) and how long do we have before it becomes too big to deal with?
- PaulHoule 5y ago
  It would make a good science fiction story. Somebody drops a black hole into the Earth which interacts very weakly with the Earth other than gravitationally so it is falling back and forth through the Earth every 90 minutes or so with the Earth rotating around it so it shows up at different spots. As the hole takes on mass the height it reaches will diminish and rotationally it will catch up with the Earth, but it takes a while. People rush to move a https://en.wikipedia.org/wiki/Very_large_floating_structure https://en.wikipedia.org/wiki/Very_large_floating_structure into place to catch it.