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View Full Version : Exploding black holes rain down on Earth


Monique
Dec5-03, 01:08 PM
http://www.newscientist.com/news/news.jsp?id=ns99994446

I am sorry if this was already dicussed earlier, but I thought it was pretty weird: black holes raining down on Earth :O

Soveraign
Dec5-03, 01:20 PM
Part of what's fascinating to me is the rate at which these black holes dissipate; that they are so small, and their massive gravity extended for so short a distance that it is virtually impossible for them to come into contact with another particle so that they actually grow.

But I do wonder, does the existing model actually give a non-zero probability that they will grow? Or is there some other contraint as to why they do not absorb another nearby particle (thus making this probability actually zero)?

NateTG
Dec5-03, 03:37 PM
Originally posted by Soveraign
Part of what's fascinating to me is the rate at which these black holes dissipate; that they are so small, and their massive gravity extended for so short a distance that it is virtually impossible for them to come into contact with another particle so that they actually grow.

But I do wonder, does the existing model actually give a non-zero probability that they will grow? Or is there some other contraint as to why they do not absorb another nearby particle (thus making this probability actually zero)?

As black holes get smaller, they radiate higher energy photons, and 'evaporate' more rapidly. That means that it's very unlikely for a small black hole to stay around for very long at all, and the mass of a stray molecule or two in the air will probably not tip the balance to make them large enough to start sucking in air.

AFAIK, the behavior of super-small black holes is extremely interesting to scientists because it is at a crux between Qantum Mechanics and Special relativity which both make different assumptions about the universe, and both make very good predicitions.

Soveraign
Dec5-03, 06:00 PM
I'm aware of the evaporation of black holes (at any size) and the fact they have such a short life time on that small scale that they are not expected to suck in nearby particles. What I'm curious about though is that probability actually zero or only nearly zero? Or, even if it isn't quite zero, the density of matter in the atmosphere just isn't enough no matter what the circumstance to cause the thing to grow (which I suspect is closer to the truth considering we are still around :) ).

If that is the case, then what, exactly, would be the critical density of matter to cause a super-small black hole, created possibly from some stray high energy particle, to successfully suck in nearby matter? Would such a condition exist inside known celestial bodies?

OR, are the mechanics at that level such that it is quite litterally impossible for a nearby particle to actually get close enough to be sucked in, thus the question of critical density being irrelavent?

I'm curious if anyone has attempted to work out some theoretical predictions? (something possibly testable by the LHC)

d00dz
Dec5-03, 11:10 PM
These black holes would be invisibly small, with a mass of only 10 micrograms or so. And they would be so unstable that they would explode in a burst of particles within around a billion-billion-billionth of a second.

Why wouldn't these be detected by radio observatories since they explode at such a rate?