Classical physics contend that the gravity of a black hole is so strong that nothing, not even a ray of light can escape a black hole. In 1970’s Stephen Hawking made the prediction that black holes are not completely black, and they evaporate over a period, emitting tiny amounts of radiation in the process. Israeli scientists Prof Jeff Steinhauer have reported that the strongest evidence of Hawking’s prediction being right was obtained, and the details have been published in a new paper in Nature Physics published on 15 August 2016.
Black holes to radiate particles:
While physics dictates that gravity of a black hole is enormously making it impossible for anything, even light to escape it. However based on quantum mechanics, quantum effects afford black holes to radiate particles in a process which is spread over a vast realm of time and ultimately cause it to evaporate. This process now known as Hawking Radiation was described by the famous physicist in 1974.
However, the amount radiated is so minuscule to make the phenomenon hardly discernable. Now Prof Steinhauer, from the Technion – Israel Institute of Technology in Haifa has created an acoustic black hole and has seen particles slipping out of the black hole just as predicted by the famous physicist.
However, how does this happen?
There is nothing like a vacuum in space and matter-antimatter are always coming in and out of existence because both annihilate each other. If one of these twin particles is pulled into the event horizon of a black hole before the pair annihilates, the other particle will slip off as Hawking Radiation.
Steinhauer built an analog black hole using icy atoms at almost absolute zero. His setup used sound waves instead of light and phonons instead of photons. When the pair of phonons was created near the analog black hole, one particle fell in, and the other escaped much like the matter –antimatter pair.