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: https://www.youtube.com/watch?v=sn5QpZornj0 Reverse Polish and Stacks: Coming Soon http://www.facebook.com/computerphile https://twitter.com/computer_phile This video by Sean Riley and Brady Haran. Computer Science at the University of Nottingham: http://bit.ly/nottscomputer Computerphile is a sister project to Brady Haran's Numberphile. See the full list of Brady's video projects at: http://bit.ly/bradychannels