Does anyone know what the official theory is for how lightning rods work? I've heard some different claims and I don't know which is correct.
Some people say that lightning rods help prevent lightning strikes by dissipating the voltage difference between the sky and the ground. Storm clouds mostly carry positive charges while the ground carries a negative charge.
The rods are pointed on the end specifically so that they act as electron emitters, though the emission is nowhere near rapid enough to generate a visible corona. The rods carry the negative potential up from the earth, spray it into the air, and help ionize the air and dissipate the charge-difference in the air that could lead to a lightning strike near the building.
And other people say that none of this happens. The rods are simply there to provide an easy route for the strike to follow, rather than along a path that leads right through the frame of the house, for example.
There is no dissipation or ion-streaming effect, and the rods don't need to be pointed at all... a cut-off flat or rounded stub is equally as effective.
Rods also don't do anything to reduce the frequency of strikes, and buildings with lightning rods are struck no more or less than structures without them.
So which of these is it? Is there any charge dissipation occurring, or is it only just an easy path to ground?
[This message has been edited by Scalar (edited 09-28-2005).]
