Re: The Olympics

[David Bowman <David_Bowman@GEORGETOWNCOLLEGE.EDU>]

Regarding Joel's question:

> How significant is the "bi" part of your comment?

It's not significant at all.

> Wouldn't the components
> be individually conserved, even if it were a regular vector;  As in, Linear
> Momentum components in the absence of the corresponding component of net
> Force?

Yes.

The only reason I included (parenthetically) the (bi) prefix was as a
defensive measure to head off a potential nit pick from anyone claiming
(properly) that angular momentum is not a really a true vector, but is
really a more subtle geometric object which could legitimately be called
a covariant anti-symmetric 2nd rank tensor, a 2-form, a pseudovector (in
3-D), or a bivector.

No matter what you call it *each* of its components have a time
derivative that is the corresponding component of the net applied
torque (which is the same kind of geometric object as the angular
momentum is).  So when the net torque completely vanishes all the
angular momentum components are separately conserved.

David Bowman
David_Bowman@georgetowncollege.edu