An accelerating reference frame for electromagnetic waves in a rapidly growing plasma

In 1974, Hawking showed that black holes can evaporate by the emission of low temperature thermal radiation, now named Hawking radiation. Shortly thereafter, a closely related effect called Unruh radiation became apparent. The author discusses how, according to Unruh and Davies, observers of the electromagnetic field in an accelerating reference frame should see thermal radiation at a temperature T: KT = h/2π a/c where a is the acceleration relative to an inertial frame, c is the speed of light and h and K are Planck's and Boltzmann's constant respectively. In a frame accelerating at g = 980 cm/sec2, equivalent to the acceleration experienced at the earth's surface, this thermal radiation is at a temperature of only 4 x 10-20 degrees K. Therefore, physicists hoping to observe this radiation, have sought out systems being subjected to extreme acceleration