Re: CERN Atom Smasher May End the World

Tim Little wrote:
> I don't think we'd detect them.  If they don't decay then they
> probably only interact gravitationally - and their mass would still be
> tiny.  Who would notice if a flood of such microholes passing through
> ate even a few billion atomic m***** worth of material per second,
> throughout the volume of the Earth?

I love Google Calculator. I put "1 billion atomic mass units per second 
in earth m***** per 5 billion years" in and got 4.38565013 * 10^-26. So 
yeah, even though that's a dramatic underestimate (an AMU is about the 
mass of a proton, much smaller than the average Earth atom) it'd still 
take a while before we noticed Earth shrinking. :)

> Maybe a neutrino detector would,
> but I expect they'd throw out such a signal as spurious.

Hm. Feeding more numbers into Google, I calculate that if black holes 
eat one billion atoms per second spread evenly throughout Earth's 
volume, a 1000-cubic-meter detector like the Sudbury Neutrino Detector 
would have 0.03 atoms eaten per year. So that would be rather rare, and 
the fact that the water in a neutrino detector is much less dense than 
the rest of Earth would make it even rarer.

On the other hand, I bet there'd be cosmological evidence if micro black 
holes were stable and common.

I don't know enough about the theory to make an educated guess about 
numbers, but wouldn't the cores of large stars be large and dense enough 
to slow down micro black holes moving at a significant speed? Stick a 
micro black hole in the hot, dense interior of a star and pretty soon I 
bet you could force-feed it up to macro size. We'd see stars 
unexpectedly collapse in on themselves for no apparent reason. Neutron 
stars would probably be even more susceptible, I expect we wouldn't see 
any of those last for long.

Micro holes feeding on cold interstellar or intergalactic gas might 
produce a signal we'd detect, no idea how strong that would be.