Scientists at the Israel Institute of Technology have created a sound analogue of a black hole in laboratory conditions, confirming the existence of stable Hawking radiation. This is reported in an article published in the journal Nature Physics. The research is summarized in a press release on Phys.org.
“Black hole” consisted of 800 rubidium atoms and had a length of about 0.1 millimeters. The atoms moved faster than the speed of sound, so sound waves could not leave the object. Outside the “event horizon”, the gas flowed slowly, so the sound waves could move freely.
In an ordinary black hole, Hawking radiation appears when a pair of virtual particles appears at the event horizon, which turns into a particle-antiparticle pair. In this case, one particle falls over the horizon, and the other flies away. The researchers found that the analogue of a black hole produces a pair of sound waves, and also confirmed the correlation between them, repeating the experiment 97 thousand times over 124 days.
Earlier, physicists from Mexico and Israel first demonstrated the existence of Hawking radiation using ultrashort laser pulses and photonic crystal fiber. However, so far, the stability of the radiation has not been confirmed.