A little bit of magic - bootstrapping, allows the separation of code and machine, allowing one single piece of code to run on many different machines. Professor Tom Rodden introduces the idea. EXTRA BITS - Complexity: Reverse Polish and Stacks: Coming Soon This video by Sean Riley and Brady Haran. Computer Science at the University of Nottingham: Computerphile is a sister project to Brady Haran's Numberphile. See the full list of Brady's video projects at: