Experimental Black-Hole Evaporation?

Attention is called to the existence of a physical system which has all the properties of a black hole as far as the quantum thermal radiation is concerned but in which all of the basic physics is completely understood. This model of the behavior of a quantum field in a classical gravitational field is the motion of sound waves in a convergent fluid flow. This system is considered to form an excellent theoretical laboratory where many of the unknown effects that quantum gravity could exert on black-hole evaporation can be modeled. It is noted that the low-energy fluid equations which have led to quantum thermal sonic emission by a transonic background flow break down at high frequencies because of the atomic nature of the fluid. The phonons emitted are quantum fluctuations of the fluid flow and therefore affect their own propagation in exactly the same way that graviton emission affects the space-time on which the various relativistic fields propagate. It is shown that the very arguments which lead to black-hole evaporation also predict that a thermal spectrum of sound waves should be given out from the sonic horizon in transonic fluid flow.