[extropy-chat] ultra-compact dwarfs found lurking

[Robert J. Bradbury]

Spike,

Re:
> So I worked out the orbit mechanics and convinced myself
> that such a system could be stable for eons.  spike

*But* when you are talking *millions* of stars you are
talking what I believe has been traditionally called a
"many body problem".  There is just enough chaos that
if you wait long enough "shit will happen".

This is the same idea behind Jupiter sticking its fingers
into the solar system just enough to be hurling comets
out of it or into the Sun.  And then you have gradual
influences on the asteroid belt.  We are just fortunate
that most of this happened long before we got here.
But I've never seen anything that indicates we've got
a good simulation capability for all of the Near Earth Objects
that have been discovered to know when the heck we are going
to get whacked next.  I do know there are lots of estimates
floating around.  But they are based mostly on statistics
and not actually knowing when something might get shifted
just enough to send humanity the way of the dinosaurs.
With "many body problems" the computational requirements
to predict precisely what will happen go up *very* fast
as you increase the number of bodies involved.

In a low density system one can hope that things will be
stable for a long time.  In a high density system that
may not be the case.

Go watch Armageddon -- and be very afraid.

Robert