Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Slim Pickings on 21/11/2011 03:01:02

Title: How does the energy from a lightining strike dissipate?
Post by: Slim Pickings on 21/11/2011 03:01:02

Slim Pickings asked the Naked Scientists:
   
Hi there, I am interested in what happens to the energy of a lightning strike after it hits the ground/water/building.  Obviously the material being struck will influence where the energy goes or how it is used. How would the energy dissipate?  Dependent on the surface material, does it continue straight downwards into the planet? 

And if you were touching a radiator (or another earth) and there was a strike just outside the house would you get zapped?  How far away would you have to be to be safe from a shock travelling "sideways" through the earth?

What do you think?

Title: How does the energy from a lightining strike dissipate?
Post by: syhprum on 21/11/2011 17:04:03

The current from the lightning strike tends to flow out radially it a thin moistened layer of soil producing quite a large voltage gradient over a considerable area.
This often kills large numbers of cattle by stopping their hearts, whole football teams have been affected.

Title: How does the energy from a lightining strike dissipate?
Post by: Geezer on 21/11/2011 19:11:10

Quote from: Slim Pickings on 21/11/2011 03:01:02

How would the energy dissipate? 

It dissipates as sound, light and heat. I would think it mainly dissipates as heat.

Depending on conditions, it can generate some pretty high temperatures, quite enough to melt sand to produce fulgurites http://www.minresco.com/fulgurites/fulgurites.htm