Archives - Physics: Page 19
Author: amparo enriquez (Sat Mar 04, 2006 1:00 pm)
Title: physics
Stephen W. Hawking argued in the 1970’s that black holes are not truly black.
The holes emit a quantum glow of thermal radiation. But his analysis had a problem.
According to relativity theory, waves starting at a black hole horizon will be stretched by an infinite amount as they propagate away. Therefore Hawking’s radiation must emerge from an infinitely small region of space, where the unknown effects of quantum gravity take over.
Physicist have grappled with this problem by studying black hole analogues in fluid systems.
The fluid molecular structure cuts off the infinite stretching and replaces the microscopic mysteries of spacetime by known physics. The analogies lend credence to Hawking’s conclusion. They also suggest to some researchers that space time has a “molecular” structure, contrary to the assumptions of standard relativity theory.