Albert Einstein predicted in his theory of general relativity that, at the end of black holes, there would be light, something that until now had not been able to prove. Now, a century later, research scientist at the Kavli Institute for Particle Astrophysics and Cosmology at Stanford and SLAC National Accelerator Laboratory, Dan Wilkins, has observed the first detection of light behind a black hole, demonstrating that the general theory of the Einstein’s relativity works .
Material falling into a supermassive black hole powers the brightest continuous sources of light in the universe and in doing so forms a corona around the black hole. ## This light can then be analyzed to map and characterize a black hole.
The researchers were studying X-rays gushing out of a supermassive black hole at the center of the spiral galaxy, Zwicky 1, 800 million light-years away when they discovered the unexpected phenomenon. Along with the expected X-ray flashes from the front of the black hole, the scientists also detected a series of "light echoes" from an origin that they could not initially locate .
The researchers soon realized that the echoes were coming from behind the supermassive black hole, which, true to Einstein’s theory of general relativity, was warping spacetime, allowing light to travel around the black hole .
According to Roger Blandford, study co-author , Luke Blossom Professor in the College of Humanities and Sciences, Stanford Professor of Physics, and SLAC Professor of Particle Physics and Astrophysics:
Fifty years ago, when astrophysicists started speculating about how the magnetic field might behave near a black hole, they had no idea that we might one day have the techniques to observe this directly and see Einstein’s general theory of relativity in action. .
This is the first time in history that light bending around a black hole has been visible. Until now, it has simply been theoretically possible. The main theory of what a corona is begins with the gas sliding into the black hole where it is superheated to millions of degrees. At that temperature, the electrons separate from the atoms, creating a magnetized plasma .
Any light that goes into that black hole doesn’t come out, so we shouldn’t be able to see anything behind the black hole. The reason we can see that is because that black hole is warping space, bending light, and twisting magnetic fields around itself. Caught in the powerful spin of the black hole, the magnetic field arches so high above the black hole , and turns so much on itself, that it eventually breaks completely.
Astronomers originally did not intend to confirm Einstein’s theory, formulated more than 100 years ago in 1915. Instead, they hoped to use the European Space Agency’s XMM-Newton space telescopes and NASA’s NuSTAR to observe the light emitted by the cloud of hot particles that form just outside the black hole’s point of no return or event horizon.