“According to Einstein’s Theory of General Relativity, nothing can escape from the gravity of a black hole once it has passed a point of no return, known as the event horizon,” explained Niayesh Afshordi, a physics and astronomy professor at Waterloo in 2020 about echoes in gravitational wave signals that hint that the event horizon of a black hole may be more complicated than scientists currently think based on research reporting the first tentative detection of these echoes, caused by a microscopic quantum “fuzz” that surrounds newly formed black holes.
Hawking Radiation
“This was scientists’ understanding for a long time until Stephen Hawking used quantum mechanics to predict that quantum particles will slowly leak out of black holes, which we now call Hawking radiation,” wrote Afshordi, referring to Hawking’s 1974 conjecture that if one takes quantum theory into account, it seems that “black” holes should glow slightly with “Hawking radiation”, consisting of photons, neutrinos, and a myriad of massive particles.