From i to u: Searching for the quantum master bit

by Matthew Chalmers

IF YOU'VE ever tried counting yourself to sleep, it's unlikely you did it using the square roots of sheep. The square root of a sheep is not something that seems to make much sense. You could, in theory, perform all sorts of arithmetical operations with them: add them, subtract them, multiply them. But it is hard to see why you would want to. All the odder, then, that this is exactly what physicists do to make sense of reality. Except not with sheep. Their basic numerical building block is a similarly nonsensical concept: the square root of minus 1. [Read more] ...