The program of the original cyberneticians (c. 1950's) was to model
everything from population biology to global politics with differential
equations. I think they found that diffy Q's weren't expressive enough to
capture that complexities of real systems. In any case they have been largely
replaced by neo-cyberneticians (like us) and their computational models.
-- David McFadzean dbm@merak.com Memetic Engineer http://www.merak.com/~dbm/ Merak Projects Ltd.