The Question
(Submitted April 20, 1998)
Can you explain to me what quantum gravity is, and if so how does it
relate to black holes?
The Answer
Current theories of gravity are based on the geometric curvature of space.
Current theories of other fundamental forces in the universe are 'quantum
field theories', where particles pass other particles back and forth among
themselves to interact.
We know that geometric gravity theories conflict with quantum field
theories, and that this conflict means that we don't know what happens
under extreme conditions.
A quantum theory of gravity would involve particles passing 'gravitons'
back and forth among themselves. This quantum theory would probably be a
more accurate description of gravity, and might be accurate enough to
describe the extreme conditions found at the center of a black hole.
David Palmer
for Ask an Astrophysicist
