Re: mist maker / electrostatic motor

[Leigh Palmer <palmer@SFU.CA>]

> On Wed, 17 May 2000, Leigh Palmer wrote:
>
> > I think heating of the air drives the whirligig. I've never given
> > the "conventional" explanation.
>
> Then it would behave as a ramjet?  Or would the geometry of the hot region
> somehow cause air to be ejected from the tip of the needle?

Expansion of the air near the tip may push everything in its vicinity
away, including the tip. The effect is independent of polarity; that
is the reason for my conjecture. What has a ramjet to do with it?

A van de Graaff Generator is self-excited. If it is symmetrical
(top and bottom takeoff brushes identical) it should be possible to
produce either polarity of charge on the dome. I've tried initially
biasing our vdG with a battery, but I always get the same final
polarization direction. Should I try a Wimshurst to bias it?

I figure if anybody would know, Bill will, and everyone else will
want to hear his answer.

Leigh