BLACK HOLES HOW DO WE KNOW THEY’RE REAL?
Of all the far-out concepts in astronomy, black holes may be the weirdest. A region of space where matter is so tightly packed that nothing – not even light itself – can escape, these dark behemoths present a pretty terrifying prospect. With all the normal rules of physics breaking down inside them, it’s tempting to dismiss black holes as the stuff of science fiction. Yet there’s plenty of evidence – both direct and indirect – that they really do exist in the universe.
EINSTEIN’S ‘ROBUST PREDICTION’
As a theoretical possibility, black holes were predicted in 1916 by Karl Schwarzschild, who found them to be an inevitable consequence of Einstein’s theory of general relativity. In other words, if Einstein’s
