Black holes have a fearsome reputation. They have imperilled a thousand stricken starship crews in the pages of science fiction, and the language used to describe them even in non-fiction often implies menace. In popular science, they ‘lurk’ at the centres of galaxies, waiting to ‘devour’ passing stars. I’m not sure this sort of imagery is justified, though it can be hard to avoid. A lot of the time black holes are passive, quiet beasts.

With the death of Stephen Hawking and the discussion it produced on black holes it was a little surprising that there was little or no mention of the man who created the subject, J. Robert Oppenheimer, who died in 1967 at the age of 62. He often said that the J stood for nothing, but I have a copy of his birth certificate on which his first name is given as ‘Julius’. In his day Oppenheimer was the most celebrated physicist in the United States. His portrait had been on the cover of Time magazine and he was on first-name terms with much of the Washington establishment, until he lost his security clearance in 1954. It was said by people who had known him before that the experience changed him profoundly and he appeared diminished. He did not appear diminished to me when when I arrived at the Institute for Advanced Study in Princeton in 1957 and was ushered into his office. The first thing he asked me was what was ‘new and firm’ in physics. I was spared trying to give an answer when his phone rang. It was from his wife. ‘It was Kitty,’ he said when he hung up. ‘She has been drinking again.’