Quoting Marc LeBrun <mlb@fxpt.com>:
Hold one end of a long string of beads and get it twirling around a vertical axis with a vigorous stirring motion (like in some cowboy lasso tricks, but without the noose loop). [...] Can you give an expression describing the "onion curve" the ? string forms at a given speed?
This system can no doubt be modelled to different degrees of approximation, but I seem to recall that the first approximation is a Bessel function, the number of whose nodes increase with the velocity of rotation, or perhaps with the kind of jiggling given to start it all off. There are probably references in places like American Journal of Physics. - hvm ------------------------------------------------- www.correo.unam.mx UNAMonos Comunicándonos