Frank,
> But the failure to visualise these higher order derivative > is because I am thinking in terms of straight line motion. > If I think instead in terms of circular motion, or better > still, helical motions, then things become very much easier. Has it crossed your mind that 'jerk' and 'jounce'... well not so much 'jerk' but at least 'jounce' and above, may require (take place in) one of Savvy's higher-order time dimensions ? Jones

