The one thing we all ‘know’ about black holes is that nothing escapes their ineluctable grasp.

That is mostly true – but since the 1970s, physicists have predicted that black holes could slowly lose energy in the form of thermal radiation.

This is Hawking radiation, and while it has been recreated in laboratory analogs, the mechanism whereby it siphons energy from a black hole, known as backreaction, has remained elusive.