Lightning

[danial stocks]

I think lightning is essentially DC./ As someone pointed out before it 
starts as staitic electricity ie there is a charge of one type on the cloud 
and the opposite type on the earth.. when this gets beyond the ionization 
point of the air, it sparks over.. the 'crackle' before a strike [also can 
be noticed by all your hair standing up - if this happens lie down fast! as 
you are about to get hit!!!] is corona discharge - small ionization  which 
drops the puts some ions in the air, making a much easier path before a 
major strike - the vtg across an ionized gas is of a much lower value than 
the voltage required to cause a breakdown - flouro tubes starter systems 
work by this method also..  at this point there is a massive charge dumpage 
from clouds - earth [& vice versa] - most ofter there are leader strikes 
going up, then main strike coming down.. while the effect of the strike may 
cause much ringing, oscillation etc in nearby conductors, the bolt itself is 
basically current flow in one direction - ie the electrons dont go down to 
earth, then back up etc.. so basically DC..
interesting to see what happens when a bolt hits a radio antenna.. all the 
coils in the antenna matching room [made out of 1" dia copper pipe] look 
like someone has come and belted them all in with a sledgehammer!
Cheers,
Dan
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