View Full Version : From every angle, what is the complete shape of a black hole?

2011-Aug-23, 10:20 AM
Is it shaped like a tornado, or a sphere, or is it flat like a disk? If there was a way to view a black hole, dimming the brightness around it to get a clear look, what would be its full shape if you could view all around the outside of it from every possible angle?

2011-Aug-23, 12:06 PM
Spherical. (Maybe slightly flattened if spinning?)

2011-Aug-23, 11:16 PM
Kerr black holes:

Jeff Root
2011-Aug-24, 12:51 AM
The tornado or funnel shape that you see in diagrams is just
a graph of the gravitational field strength or gravitational
potential in the region of a black hole. Such a diagram can be
made for the Earth or any other object. The only differences
are that the graph for a black hole goes much deeper and has
much steeper sides than the graph for less dense objects.

To envision the "shape" of a black hole, imagine taking a very
large mass -- like a large star -- and squeezing it down more
and more so that it gets more and more compact. Just keep
on squeezing it. At some point the surface gravity becomes
so intense that light can't escape from it anymore, and it will
be black, but the shape doesn't change. It is still spherical.

-- Jeff, in Minneapolis