Phonons are able to avoid the attraction of the funnel.
For a long time in the world of astrophysics, it was believed that the force of attraction of black holes is absolute. That is nothing, not even light, can escape once caught in its event horizon. Then, in 1974, a little-known young but talented physicist named Stephen Hawking made a bold assumption that due to the nature of quantum physics, black holes should actually emit subtle amounts of electromagnetic radiation (later called Hawking radiation), and slowly shrink in size. Recently, the Israeli physicist Jeff Steinhauer said that proved that Hawking’s theory created by them in laboratory conditions, acoustic black hole.
Instead of water or light as the medium for the experiment, Steinhauer used sound waves. First, he cooled a cloud of rubidium atoms to absolute zero, which led them to the condition of the condensate Bose — Einstein. Then, Steinhauer have used lasers with their help, the cloud has created a kind of funnel, in the center of which the velocity of the atoms was higher than the speed of sound.
In his theory Hawking predicted that particles of light can escape the event horizon. But in the experiment of Stenhamra the role of these particles was given to the phonons (elementary quasi-particle sound). In the experiment, the scientist noted that the phonons are able to avoid the attraction of the funnel. On their observations, the researcher gave the pages of the scientific journal Nature Physics.
The scientist also noted that avoiding the gravity funnel, the particles are in a state of confusion with the particles located on the edges of the clouds. In other words, their physical properties are identical. This so-called state of quantum entanglement is one of the key features of Hawking radiation. According to the theory, this radiation is generated when particles and antiparticles are connected in pair to the boundary of the black hole (the process is very conventional for quantum mechanics). The event horizon thus, as the knife cuts the pair, which leads to the entrainment of a single particle inside the black hole while the other particle becomes the Hawking radiation that escapes the gravity of a black hole.
The results of observations of Steinhauer important not only because they actually confirm Hawking’s theory, but also because they can help us to better understand the phenomenon known as the information paradox. This is a known contradiction is a cornerstone in physics (according to which information cannot be lost completely), and our current theories about black holes (if they are slowly converging, as suggested by Hawking, the information is lost in this process). If we have more evidence that Hawking radiation really exists, the more money we will have to resolve the information paradox.
“The interests of the people to black holes and Hawking radiation in more associated with a desire to test new theories and laws in physics, rather than with a desire to learn more about the black holes […] confirmation of the existence of Hawking radiation is a step towards the possibility of finding out that these new laws are,” shares, Steinhauer in an interview with Business Insider.
Anyway, physicists do not believe that the experiment of Steinhauer in fact proves the existence of Hawking radiation. In the end, this is a simulation of a black hole. No matter how accurate it is, it is still a simulation.
“This experiment, if we consider all the facts, truly amazing,” says theorist and practitioner Silke, Weinfurtner.
“But he does not prove the existence of Hawking radiation from astrophysical black holes.
George Unruh, a physicist who first proposed the holding of such experimental observations, agrees with Winterterm:
“Serious open require serious evidence. In any case, I agree that it is a very beautiful experiment. Many thought that similar experiments were conducted for at least the last 10 years, but Steinhauer did it first”.
