Re: [RC] [RC] That Time of Year.....again! - Truman Prevatt
If a lightning rod is working correctly it dumps charge - reducing the
potential difference between sky/ground - rather than drawing the
strike. So if there is a strike it is not near as bad and the rod
provides a quick path to ground. By reducing the local potential
difference, hopefully the strike will happen somewhere else since
lightning takes the path of least resistance. If there is, however, a
strike the rod gives the charge a low resistance path to ground,
hopefully keeping it from doing much damage. However, the hay barn we
lost (twice) had lightning rods on it. There was a lot of research in
the 70's into things called directed energy weapons. There were two
types, electron beam and proton beam. The biggest electron beam weapon
I am familiar with being tested is no more than a small lightning bolt.
The threshold voltage between cloud bottom and the earth sufficient to
initially ionize the air - and provide a path for the strike - is on
the order of 25,000 volts/square inch. The entire charge from a large
cloud can take a very narrow path to the ground in about 2/1000's of a
second. A direct hit by lightning - independent of grounding, rods, or
any other type of prevention will smoke a structure like a barn.
The second time our barn was smoked was pretty spectacular. We were
near in working on a calf. The thunder heads were building and we knew
we needed to get done and get out of there. When the strike hit - we
felt a small charge ourselves although we were about 1/4 of a mile
away. I looked up and barn is literally exploding. Metal from the roof
was found up to 300 feet away. There was a fence that ran about 75
yards on one side - it was vaporized. That is there was a 100 foot
stretch of fence that was gone. It didn't melt - it was turned into
vapor. I suspect that the strike came sideways through the fence and
directly hit the barn in the side - thus causing it to literally
explode.
In my area we lose a horse or two a year to lightning (but there are a
lot of horses around). Some are in barns some are in the open. The
safest place to be is in a metal object sitting on rubber tires - your
car.
When lightning takes a direct hit it packs an awesome punch.
Truman
-- We imitate our masters only because we are not yet masters
ourselves,
and only
We
imitate our masters
only because we are not yet masters ourselves, and only
because
in doing so we
learn the truth about what cannot be imitated.
