LHC@home

Even if these tiny black holes -were- stable, the chances of them actually touching anything are infinitesimal. Consider this example: what would happen if the sun was suddenly changed into a black hole of the same mass? Would we get sucked in? No, because its mass is the same, our orbit would remain unchanged. In fact, because a black hole doesn\\\\\\\'t emit anything (aside from the theoretical hawking radiation that we really need quantum gravity to prove), and because in the case of the sun the horizon would only be about 3 kilometers across, planets could survive in a much tighter orbit than they can with our sun.

The same is true of particles - even if you did make a black hole out of two particles, chances are nothing would ever get close enough to fuse with it after that.

Personally I find the cosmic rays argument the most convincing: cosmic rays constantly bombard our atmosphere, some of them at far higher energies than the LHC is capable of producing. If black holes really could be produced in these collisions and they really -were- dangerous, we probably wouldn\\\\\\\'t be here right now.

All of this is really very elementary - took the astronomer I got it from all of half an hour to explain in an introductory astronomy class, and that\\\'s being generous. I really don\\\'t understand why people have so much trouble with it.