Could artificial intelligence become sentient?

IT IS ONE of the oldest tropes in science fiction. On June 11th the Washington Post reported that an engineer at Google, Blake Lemoine, had been suspended from his job for arguing that the firm's "LaMDA" artificial-intelligence (AI) model may have become sentient. The newspaper quotes Mr Lemoine as saying: "If I didn't know exactly what it was, which is this computer program we built recently, I'd think it was a seven-year-old, eight-year-old kid that happens to know physics." And if not, might another machine do so one day? Arguing about intelligence is tricky because, despite decades of research, no one really understands how the main example--biological brains built by natural selection--work in detail.