Audible free book & trial at: http://www.audible.com/computerphile Our thanks to them. P vs NP in The Simpsons and Futurama. Featuring author Simon Singh. http://simonsingh.net Simon on Numberphile: http://bit.ly/SimonSinghPlay Clarification: NP actually stands for non-deterministic (or nondeterministic) polynomial. Simon did us a favour by speaking off-the-cuff on this topic and it is our fault for not cleaning up things in the edit. However Simon's (excellent) book covers this in more detail (pages 157-159 in hard cover) and, in it, he opts for nondeterministic without the hyphen. http://www.facebook.com/computerphile https://twitter.com/computer_phile Film by Sean Riley and Brady Haran. See the full list of Brady's video projects at: http://bit.ly/bradychannels