For decades, scientists have continued to be mystified by the elusive properties of blackholes. Whether small, medium or supermassive, hypotheses about black holes often run into obstacles since their sheer distance from Earth and their distinctive properties make it impossible for humans or human-made objects to approach one closely. Scientists have therefore started creating artificial black holes inside labs to study their properties. And one such experiment, carried out by scientists at the Technion- Israel Institute of Technology, has proved that Stephen Hawking had been right about black holes all along.
What did Stephen Hawking say?
Astrophysicists, particle physicists and other sundry researchers had for long believed that a black hole was a star that collapsed onto itself. It has been theorised that a collapse of the star created such a region in space-time where gravity is so high that even light cannot escape. Once particles of light cross the point of no return – or event horizon – they disappear into the darkness. Black holes are thus believed to be star-eaters.
In 1974, however, Nobel prize-winning physicist Stephen Hawking theorised that black holes are indeed not as dark as imagined but instead emitted a soft light that was constant and had no other source. Hawking theorised that at the event horizon, the black hole itself kept emitting a constant stream of photons, known as virtual particles, thus creating a soft yet steady stream of light, much like a star. These particles are created as s result of transient quantum fluctuations, which means they exist but keep popping in and out of existence.
This phenomenon was dubbed the Hawking Radiation. Though the latter was convinced of this characteristic feature of a black hole, proving the same had been impossible as it involved studying an actual black hole in space. Until now.
An analogue black hole
To study the phenomenon more closely, physicists in Israel managed to create a lab-grown, analogue black hole using some thousand atoms. This faux black hole exhibited all properties of a black hole in the state in which it is believed to exist in space.
“A black hole is supposed to radiate like a black body, which is essentially a warm object that emits constant infrared radiation…Hawking suggested that black holes are just like regular stars, which radiate a certain type of radiation all the time, constantly. That’s what we wanted to confirm in our study, and we did,” study co-author Jeff Steinhauer Phys.org.