Sonic black hole

A black hole is an analogue of William Unruh 1981 imported model, which is intended to reflect the processes in a black hole in the form of an analogue. In particular, as the exploration of a phenomenon should be possible, which is not directly observable due to its properties (namely, " black ").

Simple Example

For illustration may serve the following, highly simplified (and therefore not entirely accurate ) Example: In a tub fish are exposed to, who can swim at a maximum speed of x km / h. Now the plug is pulled so that the outflow a vortex is created, which can run off with a top speed of y km / h the water. The discharge rate decreases with distance from the outlet. If y is now higher than x, fish that come too close to the drain, the suction can not escape because they swim slower than the vortex moves, and be rinsed away. The limit at which the outflow velocity is equal corresponds to the maximum swimming speed of the fish, would be analogous to the event horizon of a black hole. Fish that exceed this limit, have no chance to escape.

Acoustic black hole analogue

Unruh has designed an acoustic analogue of the black hole. In fluids, there will be different flow rates, which are spatially separated either faster or slower than the speed of sound. The limit would in turn according to the event horizon. Noise generated in the field of higher speed would not audible in the other. Balance referred to his model as a sonic black hole. A uniform concept has so far not enforced in Germany, occasionally is of dumb holes, and their counterparts, spoke pigeon holes.

In June 2009, scientists at the Technion in Haifa a much more complex analogue in a Bose -Einstein condensate instead of creating in water. The aim was to prove the so-called Hawking radiation, which does not at first succeed.

Optical black hole analogue

The German physicist Ulf Leonhardt 2008 presented a model of an optical black -hole analogue. Using optical fibers, he carried out experiments in which also analogues for Hawking radiation were observed.