Ron Parker wrote:
> Whoops, lathe and sor too.  What about TTFs that are created from the
> lower left corner?

... and superelipsoids, of course, which raises the question of why
superellipsoids are symmetric in x and y while almost everything else
is symmetric in x and z.

It's clear the only consistency in POV is there is no consistency.
It's like UNIX and basically every other piece-meal project.... the
inconsistency just adds to its attractive character.

> what's the cross-product of two 4-d vectors?

Good question!  I expect it would take 3 vectors to yield a cross
product :

y_i = a_j b_k c_l e_ijkl

(a, b, c are 4-vectors, e is a matrix)

where e_ijkl = 0 for and two elements of {i,j,k,l} equal,
+1, or -1 in other cases.

But cross products of 3-d vectors don't yield vectors, but pseudovectors,
as the result depends on handedness.  Either this or my physics background
is too faded for such details.

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

Post a reply to this message