“Using laser light, Steinhauer manipulated the fluid to flow faster than the speed of sound.Like a swimmer battling a strong current, sound waves travelling against the direction of the fluid become ‘trapped’.
Those that form astride this sonic event horizon become the equivalent of Hawking radiation.
To amplify these sound waves enough for his detectors to pick them up, Steinhauer established a second sonic event horizon inside the first, adjusting the fluid so that sound waves could not pass this second event horizon, and are bounced back.
As the soundwaves repeatedly strike the outer horizon, they create more pairs of soundwaves, amplifying the Hawking radiation to detectable levels.”It cannot be confirmed if the resulting radiation has the different frequencies that Hawking radiation is supposed to have, or if this is what would happen in supermassive black holes light-years away.“I find it a very exciting and interesting experiment,” William Unruh, a theoretical physicist from the University of British Columbia, told Science News.
Physicist Jeff Steinhauer from the Technion-Israel Institute of Technology in Haifa — via his laboratory-manufactured artificial black hole — may have caught a glimpse of radiation, which physicist Stephen Hawking theorized four decades ago.
Hawking, in the mid-1970s, theorized that black holes are not totally black, calculating that a tiny amount of radiation would be able to escape the pull of a black hole,” Nature explains.