By coincidence I received this interesting phys-l note just after I was
rereading a section of the book "Surely you are Joking, Mr Feynman" (by
Feynman, of course). In section 4 (page 173... in my copy) Feynman at Cornell was
having a hard time coming up with a good physics idea when he sees a
spinning plate in the cafeteria and decides to have some fun doing some
irrelevant calculations on the plate. This physics, done only for fun, cured his
dry spell.
Alex. F. Burr
In a message dated 5/22/2013 6:30:27 P.M. Mountain Daylight Time,
jsd@av8n.com writes:
Sometimes physics is hard work ... but sometimes it's nice to do some
physics just for fun. Here are a handful of stories...
Recently there was some discussion of dropping metal squares and
comparing them to cardboard squares. That motivated me to do some
informal experiments:
-- I dropped a square in the broadside "pancake" orientation
-- I dropped a square in some other orientations.
-- I dropped a circular disk in various orientations.
-- I experimented with spin-stabilized disks, like Frisbees.
-- I dropped some rectangles in various orientations.
-- I dropped some airplane-shaped cutouts in various orientations.
-- I dropped a long thin slat in the /tumbling/ mode.
-- I experimented with adding pennies to the cardboard, to shift
the center of mass, thereby changing the stability.
-- I wondered about the definition of "stability". Most of these
things are unstable by any definition ... yet under suitable
conditions they can be sufficiently "close" to stable that the
instability doesn't matter. This is an important concept.
I don't really have the vocabulary to think about or talk about it.
-- et cetera....