Feynman: How the train stays on the track FUN TO IMAGINE 7

Now! High quality version at https://www.youtube.com/watch?v=P1ww1IXRfTA Physicist Richard Feynman explains... From the BBC TV series 'Fun to Imagine' (1983). You can now watch higher quality versions of some of these episodes at www.bbc.co.uk/archive/feynman/