And what about numbers, like the square root of − 1, which seem impossible or absurd? A negative number times a negative number, after all, by mathematical convention is positive; so how can any number multiplied by itself give you a negative number? No ordinary number, of course, can; those so defined are called “imaginary,” and assigned the label i; . Such numbers, it turns out, can be manipulated like any other and find wide use in such fields as aerodynamics and electronics.
