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Re: lightning dangers

A question that I like to ask my classes is, "Why are there so few (no)
lightening rods on houses any more?"

My answer, which I say I am unsure of, is that in the 50's through 70's,
all houses had lightening rods on them -- call TV arials. During this
time, the lightening rod manufacturers went broke, or made TV arials.
Now with TV-Cable and/or sattelite dishes, the need for lightening rods
has returned, but no one has stepped in to produce them. ???

But, there is probably a better explanation. ???

Oren Quist, SDSU

----------
From: William Beaty
Sent: Thursday, April 29, 1999 11:58 AM
To: PHYS-L
Subject: Re: lightning dangers


On Wed, 28 Apr 1999, Rick Tarara wrote:

But the question remains..has anyone actually seen a verified report of
someone killed by lightning while inside? I certainly haven't. The
note
from Dan suggests there are, but does anyone in the group have actual
knowledge of such instances?

I know of one particular museum department director who suffered a
painful, dangerous, embarassing lightning-strike phenomenon. He was
sitting on the toilet when lightning apparently struck his house or
something nearby. When I heard about this originally, I was mystified
because there was no complete circuit apparent when he received that
painful "zap" in the expected part of his anatomy. But in later years I
realized that Electrostatics doesn't require complete circuits. When
everything is acting like capacitors, we can have Displacement Currents
connecting various conductors together during discharge events.

Can displacement currents kill people? I have no idea. The above toilet
incident suggests that there is a danger. However, the size of the human
would determine the amount of displacement current being intercepted from
surrounding space. If I should stand next to a lightning strike while
holding a pair of long metal rods outwards (to form a dipole antenna), I
certainly will be "intercepting" a much larger displacement current than
if I had no rods. Perhaps the bathtub and the showerhead act as two
connections to very long metal antennae. But in that case, we would see
a
long spark leap from the showerhead to the person standing in the
bathtub.
If this is the source of the danger, then perhaps the remedy is, during
thunderstorms, to take showers while standing at the far end of the tub,
away from the shower head? :)

Questions: is it dangerous to take A BATH during a thunderstorm? What if
you touch the faucet? What if your bathtub is fiberglass?


((((((((((((((((((((( ( ( ( ( (O) ) ) ) )
)))))))))))))))))))))
William J. Beaty SCIENCE HOBBYIST
website
billb@eskimo.com http://www.amasci.com
EE/programmer/sci-exhibits science projects, tesla, weird
science
Seattle, WA 206-781-3320 freenrg-L taoshum-L vortex-L
webhead-L
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