On Thu, 15 Oct 2009 09:26:29 -0700 (PDT), Heathcliff
wrote:

From what I have read, for cloud-to-ground lightning, the sequence
generally goes like this. A "stepped leader" comes down from the
cloud base in a series of steps or jumps. When it gets within a
couple hundred feet of the ground, now there is kind of a target area
on the ground, maybe one or two hundred feet in diameter. Within that
area, positive charges from the ground move up and make "streamers"
from tall objects. One of the streamers eventually connects with the
stepped leader, creating a cloud-to-ground conductive path, and then
the main stroke happens. All this takes place very fast, in
milliseconds. But from this description, it seems like what you do
will not much change the chance of lightning striking the house - if
you're in the target area then you may very well get struck, but
otherwise not. -- H


I believe that charge builds up on the ground over a fairly large area
in advance of even the beginning of a strike, so the question is what
kind of tall objects conduct it effectively up to where the charges in
the cloud can "see" it. Does it matter if you run a copper rod from
ground to steeple, or give it an air gap or insulator gap of an inch
or three? I wonder. My guess is, it doesn't matter much, that the
fields and charges are actually fuzzy and distributed.

Too bad someone can't figure out a way to actively attract - and
capture! - all that energy.

J.