“Ever since Charles Babbage’s conceptual, unrealised Analytical Engine in the 1830s, computer science has been trying very hard to race ahead of its time. Particularly over the last 75 years, there have been many astounding developments – the first electronic programmable computer, the first integrated circuit computer, the first microprocessor. But the next anticipated step may be the most revolutionary of all. Quantum computing is the technology that many scientists, entrepreneurs and big businesses expect to provide a, well, quantum leap into the future. If you’ve never heard of it there’s a helpful video doing the social media rounds that’s got a couple of million hits on YouTube. It features the Canadian prime minister, Justin Trudeau, detailing exactly what quantum computing means. Trudeau was on a recent visit to the Perimeter Institute for Theoretical Physics in Waterloo, Ontario, one of the world’s leading centres for the study of the field. During a press conference there, a reporter asked him, half-jokingly, to explain quantum computing.”