"Feeding, Caring for and Maintaining Your Black Hole" by Bozo de Niro
Bozo
Like many physicists, I am not too worried about black holes at LHC.
But what if we did have a small black hole somewhere on earth. What
would happen?
Most non-physicists I talk to have heard that black holes suck up all
matter, and once captured by a black hole, there is no way out. So
they seem pretty dangerous.
But this is not really so obvious. A black hole formed from nearby
matter will have the same mass as as the matter it was formed from. So
from a distance, it will also have the same gravitational attraction.
Remember F=M1*M2/r^2, there is no mention of how compact the
arrangement of the source is.
So if a black hole was formed in Geneva, no one would feel it at least
initially outside a very small radius around it.
A LHC black hole would not weigh much, something like 1 Tev/c^2. This
is not much more than a couple of lead atoms. And since gravitation is
a very weak force compared to electromagnetism, even atoms close by
will not be very impressed by its gravitational pull, unless they get
pretty close by.
Even if they come in reach, they would more likely go into orbit
rather than crash straight in.
So maybe mini black holes are completely harmless ... but
I still see three options:
1. It evaporates due to Hawking radiation.
2. It speeds off at greater than escape velocity, leaving the Earth
behind (consuming a small amount of matter in the process).
3. It falls into the Earth and oscillates back and forth through the
Earth, slowly growing in mass.
Which leaves an ethical existential question, how do you care for,
feed and maintain a black hole?
-BdN-
J. J. Lodder
> http://groups.google.com/group/sci.physics.research/browse_thread/thread/b49bf
2890b24e27f#
>
> Like many physicists, I am not too worried about black holes at LHC.
> But what if we did have a small black hole somewhere on earth. What
> would happen?
>
> Most non-physicists I talk to have heard that black holes suck up all
> matter, and once captured by a black hole, there is no way out. So
> they seem pretty dangerous.
Having a medium size black hole (say at 6000 K)
in distant earth orbit would be real nice.
We could regularly feed it mass
to compensate for Hawking radiation
and solve humanities energy problems forever.
We would have to keep it up though,
to prevent it from exploding.
Jan
gb6...@yahoo.com
[Moderator's note: Quoted text snipped. -P.H.]
> So maybe mini black holes are completely harmless ... but
> I still see three options:
>
> 1. It evaporates due to Hawking radiation.
>
> 2. It speeds off at greater than escape velocity, leaving the Earth
> behind (consuming a small amount of matter in the process).
>
> 3. It falls into the Earth and oscillates back and forth through the
> Earth, slowly growing in mass.
>
> Which leaves an ethical existential question, how do you care for,
> feed and maintain a black hole?
>
> -BdN-
Once it forms theoretically nothing can escape and it grows. It
may grow into a galaxy of its own. It may eat up galaxies alltogether,
all galaxies, then spit them out in a big bang. A black hole the size
of an atom is all it takes.
Phillip Helbig---remove CLOTHES to reply
nos...@de-ster.demon.nl (J. J. Lodder) writes:
> Having a medium size black hole (say at 6000 K)
> in distant earth orbit would be real nice.
> We could regularly feed it mass
> to compensate for Hawking radiation
> and solve humanities energy problems forever.
What would this provide that the Sun doesn't? (In both cases, mass is
converted into energy, of course.)
> We would have to keep it up though,
> to prevent it from exploding.
Not a problem with the Sun.