Black holes are real

More than anything else, Hawking’s name is associated with black holes – another kind of singularity, formed when a huge star undergoes complete collapse under its own gravity. These mathematical curiosities arose from Einstein’s theory of general relativity, and they had been debated for decades when Hawking turned his attention to them in the early 1970s.

His stroke of genius was to combine Einstein’s equations with those of quantum mechanics, turning what had previously been a theoretical abstraction into something that looked like it might actually exist in the universe. The final proof that Hawking was correct came in 2019, when the Event Horizon Telescope obtained a direct image of the supermassive black hole lurking in the centre of giant galaxy Messier 87.