Re: corrupting the youth

["John S. Denker" <jsd@MONMOUTH.COM>]

> > Or if its a piece of opaque cardboard, you
> > can paint a dot on one side and say the normal vector must point that way.

I wrote:

> Yes, assuming the cardboard also has a sense of circulation
> marked on it, perhaps by considering it a bivector and
> ordering the edges (first this edge, then this other edge).

Which was OK in context, but perhaps some elaboration
would be helpful:

1) If all you want to know is which side of the cardboard
is which, all you have to do is paint a dot on one side.

2) If you want to designate a direction of circulation in
the plane of the cardboard, you can either
 2a) draw an arc-with-arrowhead on it, or
 2b) mark one side _and_ apply some pre-existing Right-Hand
    Rule or the equivalent.

Note that in case (2a) you can mark the direction of
circulation without specifying a preference for either
face.  You can put matching arcs on both faces, or you
can put tiny arrowheads on the _edge_ of the cardboard
(running around the edge, belt-wise).

3) If you don't have a pre-existing Right-Hand Rule and
you want to use the cardboard to _define_ what you mean
by right-handed, you must mark a direction of circulation
_and_ paint a dot on one side.  This creates a chiral
object.  (Situations (1) and (2a) neither require nor
create any notion of handedness.)