Abstract

Professor Mark Warner gives a talk about the questions raised by so-called “charmed chains”: https://www.youtube.com/watch?v=_dQJBBklpQQ – see the abstract below for more details.

For this talk, admission is free to everyone. As always, wine and cheese will be served after the talk.

(Abstract:) Even after 350 years, classical mechanics shocks both physicists and laymen. In weeks, several million viewed Mould’s discovery that a siphoned chain rises liked a charmed snake. Physics explanations abounded, all apparently wrong! Equally disturbing are chains falling with an acceleration greater than g.

Bernoulli, Leibnitz and Huygens first described a hanging chain, the catenary, while Hooke used it inverted as an ideal arch. Moving chains have worried Cambridge Mathematicians and Physicists since the 1850s: the Astronomer Royal, George Airy, published on them, stimulated by the first telecommunications revolution; the 1854 Maths Tripos had questions on them. But such chains should not rise like a snake, nor fall faster than g! We pursue this deficiency in classical dynamics with theory, demonstrations and films: can pasta be thus charmed, what about fishing weights on a line?