## Stephen Hawking once sent his PhD student away with a very hard problem – finding exact rotating black hole solutions of Einstein’s equations with a cosmological constant – and was stunned when he came back a few days later with the solution

I was a student of Stephen Hawking’s – here’s what he taught me Like many students of my generation, Stephen Hawking had already had enormous influence on me long before we ever met. When I was hesitating about my A-level choices, it was his book A Brief History of Time that convinced me to continue …