Black holes have an escape velocity higher than the speed of light. Since nothing can travel faster than that, nothing can escape. This is the simplest mechanical reason of a black hole. But when you add thermodynamics and quantum mechanisms into the combination, things get chaotic. Considering all of this, physicist Stephen Hawking suggest the hypothesis in 1974 that black holes are in fact not black; instead, they release radiation, they lose energy, and with the passage of time they shrink. Though, the amount of radiation is too small to be detected in cosmological black holes, so how can we check this idea?
Professor Jeff Steinhauer from the Israel Institute of Technology has not only discovered a method to test it but in a new paper, printed in Nature Physics, has shown the strongest evidence however that this black hole emission, now well-known as Hawking radiation, is very real. Steinhauer built an acoustic black hole, a setup that has a definite frequency much bigger than the energy of the sound “particles” (the phonons), which can only travel at the speed of sounds.
Professor Steinhauer told IFLScience,"If there is a photon inside the black hole, it cannot go against the movement because the movement it is faster than the speed of sound. It is like a person trying to swim against the waves. If the waves or currents are faster than they can swim, they go backward instead of going forward."
This might appear basic, but it’s a properly accurate model of the actual thing. And more essentially, this acoustic black hole was detected emitting the long searched Hawking radiation. Hawking’s idea was essential because quantum mechanics and relativity do not work well together. Black holes involve both theories, so there is a nonstop and wide investigation of their properties by resembling some of the equations we have.
Steinhauer added, "The point of learning black holes is to learn about the original laws of physics, not just about black holes themselves."
The idea of Hawking radiation comes from one of these calculations. Every bit of space-time has energy and occasionally that energy can abruptly turn into a particle-antiparticle pair before interacting and turning again into energy. If this particle creation occurred on the event horizon of a black hole, one particle could be caught by the object’s gravity and fall in, whereas the other escapes.
The escaped particle would be connected to its mate lost in the black hole, by a property known as entanglement. The Hawking radiation from Steinhauer’s black hole showed this entanglement, giving the strongest new evidence that Hawking radiation is very real.