On Feb 19, 12:13 pm, (Eugene Griessel) wrote:

I was watching the BBC program "Space" with Sam Neill this morning.
One of my least favourite programs because it seems to have been made
to excite and tittilate the ignorant rather than inform the knowledge
seeker. IMHO it's a curate's egg with lots of cruddy gee-whizz
graphics interspersed with brief bits of genuine science.

Pure special effects Disneyfied science

In episode 3 we are regaled with the breathless tale of "monsters"
that could consume the earth - black holes. Including a scenario of
what would happen to the solar system should one of these take it into
its head to devour us.

ISTR the one in the original "Space" series was about the size of a
pea and behaved exactly like the "bad boy" demented cosmic vacuum
cleaner of science fiction stories by going from planet to planet
gobbling them up and finally off to eat the sun. The reality would be
much different. Short of a direct hit on the Earth we would barely
notice an asteroid mass BH passing through the solar system. And a
solar mass BH (or solar mass anything) would be all too noticable as
it perturbs first the comets and then the planets from their orbits
and would be most disruptive.

Having recently discussed black hole/earth encounters, I was wondering
if anyone would care to comment on this particular depiction - and
how close it would be to what scientific thought holds for such an
encounter. Personally I think it sucks - but that is a complete
tailbone feeling, having nothing to do with either scientific thought
or logical analysis.

A rough analysis was done in a thread on sci.physics.relativity when
"Space" first came out.

http://groups.google.com/group/sci.p...a7b39c4d0845e1

Is the start of the thread. Beware of the usual cranks and nutters
posting into it.

The only thing that proved impossible to get a decent handle on was
whether or not an asteroid mass BH with Rs ~ 2um and a mass convertion
explosive yield of about 100MT/s would experience sufficient drag in
the minute or so it took to go through the Earth to lose most of it
velocity and be captured. Eventually for a large enough and/or dense
enough target it must be possible for a BH to be gravitationally
captured, but that proved too hard to analyse.

It was clear that a neutron star would stop a BH pretty easily, but
ordinary matter looked on the face of it too weak.

Regards,
Martin Brown