St. Elmo's Fire

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Offline hamza

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St. Elmo's Fire
« on: 17/10/2007 14:37:20 »
Do things within a St. Elmo's fire burn down or do they remain unharmed..

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Offline eric l

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St. Elmo's Fire
« Reply #1 on: 17/10/2007 15:30:25 »
St. Elmo's fire can start a fire, just like lightning can.  But in general it will be much less harmful than lightning.
"Wonder is no wonder" (Simon Stevin 1548-1620)

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lyner

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St. Elmo's Fire
« Reply #2 on: 18/10/2007 10:39:02 »
There is a lot less energy  in St E's fire than a lightning strike - based on  totalcharge and PD.
St E occurs when the local field strength  (around a sharp object) is enough to ionise the air around it and a small current flows. This glows and forms what is, effectively, a  region around the point which is a conductor with a large radius - smoothing out the sharp point  - reducing the field strength and slowly discharging the  object.
This, in turn, prevents the build up of a big charge and, thus, prevents a big lightning  strike. So-called lightning conductors work this way.