John VanSickle wrote:

> The cross product of two 3d vectors certainly does yield another vector.
> If it didn't, half of my code wouldn't work!

I said "pseudovector".  A velocity vector, for example, is a real
thing.  If I have a right-hand or left-hand coordinate system
doesn't matter.  But if I take the cross product of two sides
of a cube side in a fashion which yields a normal pointing
outside the box in a LHS, when I switch to a RHS the same
cross product will yield a normal pointing inside the box.
Since it is non-physical for a quantity to depend on the
coordinate system used, the term "pseudovector" is used.

The same thing happens with angular momentum, which is a 
pseudovector (it's defined as a cross-product).  It is
fundamentally different from linear momentum.

In Physics, this is important when considering conserved
quantities like parity.

Dan

-- 
http://www.flash.net/~djconnel/

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