April 29, 2019

Lurking in the shadow, ringing across the Universe: the dark secrets of blackholes

On a bleak December evening in 1915, a German lieutenant scribbled away in his notebook as the World War I raged outside the trench on the Russian front. The barrack reverberated with the noise of war; exploding of shells, shouting of orders, whistles and the cries of wounded men. As he pored over Einstein’s paper, he was more and more incredulous. What his calculation proved was that if any mass is compressed to fit a certain radius, something very strange happens; no known force would stop it from collapsing and nothing would be able to escape that radius. He had found the first exact solutions to Einstein’s equations of general…