From: SFPhysics@aol.com
Date: Tue Sep 28 1999 - 16:33:11 PDT
From: SFPhysics@aol.com Message-ID: <d554e940.2522aa37@aol.com> Date: Tue, 28 Sep 1999 19:33:11 EDT Subject: Re: Pinhole Digest #250 - 09/28/99
> What I wondered about during the 9/8 storm was that the lightning was
> going neither up nor down, but sideways and looping! I have never
> witnessed this before! (Though being a native bay area person my
> experience is admittedly little) Some level of humidity? Concentration
> of salt particles? Gamma ray activity ? Magic?
> I just bought a photo at the Harvest Festival taken by a Santa Cruz
> local (Wood) over the boardwalk. The bolt twists and turns like some
> great sidewinder snake and finally ends in an upward fork! AHHH!
> Heidi Strahm Black
> East Side Union High School District
> blackh@exchange.esuhsd.org
>>
Hi Heidi:
The electrical discharge will always take the path of lease resistance from
greatest concentration of charge to greatest concentration of opposite
charge. If the air currents are circulating in spirals with the moisture and
electrical charges caught up in them then the discharge will simply follow
the pattern. Colder drier air is the better insulator if memory serves so
the discharge should follow the warmer wetter path.
Several neon artists have discovered neat ways to show electrical discharge.
The flat disc lightning tubes used in Star Trek for the Borg regeneration
chambers have a constantly changing lightning pattern using glass beads to
make the discharge take various paths. In line tubes with beads also make
multiple changing paths possible. Heat effecting density, ionization trails,
gas eddys, etc., all move the path around.
Do they still sell Geisler (sp?) tubes that have discharges in interesting
patterns?
Al Sefl
SFUSD teacher at large......
p.s. Has anyone ever built a "spherics" meter where the charges of the
clouds going over are recorded on a strip chart recorder. They do not
normally work well in the San Francisco Bay Area where the marine layer seems
to have some dampening effect.
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