Re: [Paddlewise] Anyone understand lightning?

From: Rafael Mier Maza <sildriel_at_ciateq.net.mx>
Date: Tue, 20 Aug 2002 17:20:44 -0500
Bob wrote:

What I don't understand are the specific mechanics of lightening in a
way that tells me when and why it's dangerous.  On a narrow stream that
sits low between high banks populated by large trees, is there risk of
being directly injured by lightening or only the risk of indirect injury
from a falling tree that's been hit on higher ground.  Am I better off
on the low, narrow water than on the higher bank?

Hi Bob,
My two cents. I understand that lightning will approach, develop or touch 
pointed objects, that are connected to ground, even if ground is not that 
good. A wet tree can make a good connection to ground.

The reason for picking pointed objects is that in sharp edges the electric 
field concentrates and is easier to brake the air in ionized particles that 
travel to the cloud or  back from the cloud, depending on their charge.

Points are so attractive to lightning that there is a rule of thumb that 
says that a lightning will not strike any object that is under a 45 degrees 
virtual shade.  A large building with a pointed lightning absorver will 
protect all small houses inside of the virtual 45 degree umbrella.

When I was a kid, all houses under the churches with big towers, (very 
popular in Mexico) were protected from lightning and we saw lightning hit 
the tower but never houses close by.

So I am sure that in a flat big lake a kayaker with wet paddle, specially 
with alluminum shaft is a better landing sharp point than the flat 
water.  On the other hand, paddling in a river with V shape mountains on 
the sides makes it very very unlikely that a lightning will hit a paddler 
in the water. Many trees will give the 45 degree shadow, as well as the 
mountain itself. Speaking from physics point of view the  cannon is inside 
a V of equal potential (ground) and there is no attraction to the lightning 
there. The closest ground point as viewed from the clouds is the tallest 
tree or cliff or church or whatever up there.

I wouldn't mind paddling in such a river but I have escaped from lakes 
quickly when thunderstorms approach.

I keep  worrying when thinking about sailboats with big alluminum masts.

Best Regards,

Rafael
el cayuco chief.
Mexico.

***************************************************************************
PaddleWise Paddling Mailing List - Any opinions or suggestions expressed
here are solely those of the writer(s). You must assume the entire
responsibility for reliance upon them. All postings copyright the author.
Submissions:     PaddleWise_at_PaddleWise.net
Subscriptions:   PaddleWise-request_at_PaddleWise.net
Website:         http://www.paddlewise.net/
***************************************************************************
Received on Tue Aug 20 2002 - 15:17:10 PDT

This archive was generated by hypermail 2.4.0 : Thu Aug 21 2025 - 16:30:58 PDT