Re: toroidal perpetual motion machine

[John Denker <jsd@MONMOUTH.COM>]

At 06:14 PM 6/29/00 -0400, Hans G. Ammitzboll wrote:
> In your tug-o-war example,
> you seem to pit the inside meniscus against the outside meniscus.

Agreed.  That was the point of the analogy.

> Fine, there are unbalanced forces,

Agreed, the meniscus produces a force that is unbalanced (i.e. not balanced
by any force yet mentioned).

> but now add the inside rubber against the outside rubber

You speak of the outside rubber pulling up.  It needs to pull up exactly
enough to balance the meniscus.  Is that a coincidence, or is there some
law of physics that you're invoking?  And what happens if we float the tube
in alcohol or something else with a different size and density of
meniscus?  And why does not outside rubber pulling down from below just
cancel the effect of outside rubber pulling up from above?

To simplify your analysis, imagine an inner-tube with just enough density
to float exactly half-submerged.  All forces so far identified are
symmetric, except for the meniscus that climbs above the plane of symmetry.