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lunar archery (was: Physics Question)



To get optimal performance in an airless environment,
the bow and arrows would need to be adapted in various
ways. An unmodified bow and arrow would have problems.

For starters, the arrow leaves a typical bow quite
cockeyed. It depends on aerodynamics to straighten
itself out.

Also, the feathers are typically set at an angle,
which leads (again via aerodynamics) to some spin
stabilization.

Diana, goddess of the moon and of archery, would
start by removing the feathers from her arrows,
because they are useless, and because they cause
nasty perturbations when they hit the rest during
launch.

She would then find some way non-aerodynamic way
to spin-stabilize the arrow, perhaps by attaching
something like the a whorl of a drop-spindle and
spinning it up before launch. The design of the
bearings would be interesting.

Without some sort of stabilization, the arrow would
tumble. Smallish amounts of tumbling wouldn't
significantly affect the energetics, but would
greatly detract from the penetrating effect of the
shot.

However, simple spin stabilization doesn't do the
whole job, especially on long-distance shots, where
the parabolic trajectory differs noticeably from a
straight line.

Solution: Use a two-shaft arrow. One shaft carries
the arrowhead and is spin-stabilized at an orientation
suitable for striking the target. The other shaft
crosses at the other shaft's center of mass, crossing
at an angle, and is used for launching.