[extropy-chat] Casimir Torque Project

Fri May 6 18:44:59 UTC 2005

```--- Hal Finney <hal at finney.org> wrote:
> There are no discontinuities in nature. All of your materials are
> of atoms which have a finite size. There are no infinitely sharp
> points
> where force drops instantaneously from 1 to 0.  (Note that I disagree
> that your design would produce any rotary force at all, but I am
> trying
> to point out some flaws in your own model.)

I didn't mean to suggest infinitely sharp points.  But if there is
counter torque concentrated in a space about the thickness of an atom
or so, then I should probably find consistent fractures or bends in the
material along that thickness where the counter torque tried to oppose
the forward torque, right?  Proving a new way to generate such
concentrations of force might also be useful.

> I don't understand where you get the claim that Casimir is a non-
> conservative force.  My understanding is exactly the opposite.  Can
> you
> provide a reference, or a derivation, which argues that Casimir force
> is non-conservative?

The Casimir effect *between parallel metal plates, as almost everyone
has investigated it* is conservative.  (Most people assume that the
Casimir force must always be conservative, because the one particular
formulation everyone's heard of is conservative.  That's analogous to
living on a plain and assuming plants can never be as tall as adult
human beings due to the physics of how a grass stalk supports itself,
without ever knowing about trees and wood.  By that analogy, I'd be
going around trying to find a tree, or to find proof that no such thing
existed.  The mere fact that no one had ever seen one before would not,
in itself, constitute proof, even if I would admit up front that there
was a good chance I might not find one either - but that alone wouldn't
be reason not to look.)

As I have already shown, it is possible that the Casimir effect may
become nonconservative in the particular geometry that I am
investigating - and of course there are no references on that.  If