Upside down pendulum

This is David Acheson talking about the inverted pendulum and other things: https://www.youtube.com/watch?v=BJ7_fFABc9s And here's his book: US: http://www.amazon.com/1089-All-That-Journey-Mathematics/dp/0199590028 UK: http://www.amazon.co.uk/1089-All-That-Journey-Mathematics/dp/0199590028/ And here he is discussing mathematical curiosities: http://plus.maths.org/content/1089-and-all Visit my blog here: http://stevemould.com Follow me on twitter here: http://twitter.com/moulds Buy nerdy maths things here: http://mathsgear.co.uk