Black
Hole Facts and Theories
http://archive.ncsa.uiuc.edu/Cyberia/NumRel/GravWaves.html
Black holes emit x-ray radiation and get smaller and smaller
until they disappear, or "evaporate".
Most black holes are formed from the death of large stars (larger
than the sun) that run out of fuel and cannot sustain its nuclear reaction.
The star loses the force pushing itself outward and is overcome by the force
of its own gravity pulling inward. Eventually, the star has so much gravity
and is so compacted that it "eats itself" until there is nothing left
but a hole in the "fabric" of space-time, created by the gravity left
over from the star.
The gravity around the "hole" of a black hole is so strong that NOTHING
can make its way back out after a critical distance.
http://archive.ncsa.uiuc.edu/Cyberia/NumRel/BlackHoleAnat.html
This shows the ripples in space-time from immense gravity emanating from the singularity.
The critical distance at which nothing can escape is called
the Event Horizon.
Even light cannot travel back out of a black hole after crossing the Event Horizon.
Even before crossing the event horizon, though possible to travel
away from the black hole, it is not easy. Even light has a hard time getting
out, so light being emitted from something almost at the Event Horizon but not
yet inside the threshold takes a much longer time to escape and be seen by someone
then it would in normal space going at 186,000 miles per second.
Animated "gif" at: http://spaceplace.jpl.nasa.gov/svlbi_do1.htm
A smoother, QuickTime ".move" version here (1.4 Mb):
http://starchild.gsfc.nasa.gov/Videos/general/blackhole.mov
Any object would be, after being bombarded with radiation, distorted,
and crushed at the atomic level or lower and therefore would not survive.
Although once you cross the event horizon you cannot escape
the black hole, it is not the main part of the black hole, the destination of
the doomed object, or the point at which and object is completely gone, only
an invisible circle around the black hole that represents the point of no return,
where the gravity is too strong to avoid the "hole". The event
horizon can be thought of as an exponentially increasing slope of the hole.
The real core of the black hole, the main part, is called the Singularity.
The event horizon is just the space around it.
http://archive.ncsa.uiuc.edu/Cyberia/NumRel/GenRelativity.html
The Singularity is the true point of destruction, the actual
hole part of the black hole, although any object, especially a person, would
be long dead before they reached the Singularity.
Some black holes are spinning and have several event horizons
called the "Ergosphere", "Outer Event Horizon", and "Inner
Event Horizon".
http://physics.syr.edu/courses/PHY312.98Spring/projects/jebornak/html/rotating.html