Re: Lightning Beads

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: William Beaty <billb@xxxxxxxxxx>



That effect in the video is easily reproduced, and was part of the
Electricity show at the Museum of Science in Boston at one time (and might
even still be there?)

The museum had a large Jacob's Ladder for museum shows made from a
backwards pole pig, with a big electric heater in series with the line
voltage as ballast.  When the arc rose up along the v-shaped electrodes,
it grew to about 30 inches IIRC. And then something interesting occurred:
when the arc wafted off the ends of the rods and the current path broke,
the arc did not wink out.  Instead it dissipated as segments which then
shrunk, appearing as "flames" for a moment.

I interpret this to be hot, incandescent air, perhaps with a bit of metal
ions from the rods.  I suspect that when the wattage in a Jacob's Ladder
arc is high enough, the glowing arc is so hot that it does go dark
instantly when the current stops, but instead remains incandescent and
rises fluttering upwards just like the glowing flames in any fire.

The lightning in that video looks much the same.

Also note that the lightning in the video is probably classed as "hot
lightning," the rarer type which lasts for a significant part of of a
second and which carbonizes wood and can starts fires.  The more common
type of lightning only lasts for milliseconds and might destroy a tree via
a steam explosion from peak wattage, but where the total energy is far too
low to make flames.

This might be important, because I bet high-energy "hot lightning" is
required in order to create that flames/beads effect.


One atmospheric physicist told me that the record for a well-verified
lightning strike duration is around 10 seconds.  A tech in Seattle told me
he saw one as a child down south which lasted several seconds and which
melted the aluminum flag pole at his grade school.



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William J. Beaty                            SCIENCE HOBBYIST website
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