Re: physics "art"

[Gordon Smith <slipstk@OLEMISS.EDU>]

At 03:14 PM 9/1/99 -0400, you wrote:
> Here's a new thread, as the academic year opens:
>
> We're looking for a site with public domain "physics art."  Define it
> however you want - any suggestions?

It's not a domain, but on the topic of "physics art"...

What about Lichtenberg's Figures?

I came across this in Ganot's Physics:

"Lichtenberg's figures - This experiment well illustrates the opposite
electrical conditions of the two coatings of a Leyden jar.  Holding a jar
charged with positive electricity by the hand, a series of lines are drawn
with the knob on a cake of resin or vulcanite; then having placed the jar
on an insulator, it is held by the knob, and another series traced by means
of the outer coating.  If now a mixture of red-lead and flour of sulfur be
projected on the cake, the sulphur will attach itself to the positive
lines, and the red lead to the negative lines; the reason being that in
mixing the powders, the sulphur has become negatively charged and the red
lead positively.  The sulfur will arrange itself in tufts with numerous
diverging branches, while the red lead will take the form of small circular
spots, indicating a difference in the two electricities on the surface of
the resin.  These figures form, in short, a very sensitive electroscope for
investigating the distribution of electricity on an insulating surface."

There's a nice picture of a resin plate, touched by the positive Leyden
knob, and dusted with lycopodium powder which looks almost dandelion-ish...

Another one would be Nobili's rings.  Anybody heard of this one?

-G-
-----------------------------------------
Gordon Smith
National Center for Physical Acoustics
Coliseum Drive
University, MS 38655
slipstk@olemiss.edu