Tom Nakashima wrote:
"Robert11" wrote in message
...
Hello:

Was reading a book on ballistics the other day, and the author was
describing conditions
where a rifle barrel would drop a small amount as a shell was fired.

He used an example that if one held a fly rod rod truly horiz., and gave
the handle a very quick
upward (I think he means backwards; toward ones head) pure rotation, the
tip momentarily goes Downward.

Have my rods away for the season, so can't try it.

Can't visualize this happening.

Does it ?

Yes

Why does it, if so ?

You might be able to see it more clearly with a full-flex rod as in the case
of bamboo.
While holding the rod in the horizontal position, the start of the arm
motion upward begins the stored energy in the rod and translates it
throughout the length. Since the fly rod has a continuous taper with the
thicker part at the butt and thinning as it progresses towards the tip, the
upswing motion caused the tip to bend momentarily and ever so slightly
downward before it begins to move and follow the rod stroke path.

That explains nothing.

Wolfgang
who suspects that the downward motion is an illusion......but wouldn't
be much surprised if it is in fact real. in either case, recent
developments in the roffian math club suggest rather strongly that a
comprehensible answer will forever remain but a dream.