Hod Lipson, a mechanical engineer who directs the Creative Machines Lab at Columbia University, has shaped most of his career around what some people in his industry have called the c-word.

On a sunny morning last October, the Israeli-born roboticist sits behind a table in his lab and explains himself. “This topic was taboo,” he says, a grin exposing a slight gap between his front teeth. “We were almost forbidden from talking about it – ‘Don’t talk about the c-word; you won’t get tenure’ – so in the beginning I had to disguise it, like it was something else.”