General relativity is a theory of gravity – the best theory of gravity we have. It was the insight of a German physicist in 1915. Fifty years later, that theory was ready and able to explain the bizarre properties of such newly discovered exotic objects as black holes, pulsars and quasars
ALBERT Einstein used to tell that the unique flash of insight that set him on the path to general relativity came when he realised that a man falling from a roof – or a person trapped inside a freely falling lift – does not feel the force of gravity. People…
