By Penelope Drastik, University of Wollongong What is the square root of -1? Most people would say that it doesn’t exist. Since the product of two positive numbers is positive, and the product of [...]
By Alastair Dyer Loosely speaking, we can think of covering a sphere by taking the surface of an n-torus (the surface of the shape given by gluing n doughnuts together) which is made out of [...]
