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Author Topic: Lightning on water....how far is safe ?  (Read 4087 times)

Offline neilep

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Lightning on water....how far is safe ?
« on: 03/01/2006 16:26:00 »
So there I am in the bath, playing with my submarine when one of the ceiling bulbs goes pfffzzzzttt..pop!!

This got me thinking three things !

First thing I thought was, if I was in your average bog standard submarine a few metres below the surface when lightning strikes directly above ...would I be ok ?

Second thing I thought was, if I was out in the sea swimming away quite happily, how far would I need to be away from the lightning strike to be safe ?

Third thing I thought was, I need to change the light bulb !

Men are the same as women.... just inside out !!
« Last Edit: 03/01/2006 16:27:29 by neilep »


 

Offline DoctorBeaver

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Re: Lightning on water....how far is safe ?
« Reply #1 on: 03/01/2006 17:08:15 »
The 4th thing you thought was "Oh bugger, I forgot the water"

:D
 

Offline neilep

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Re: Lightning on water....how far is safe ?
« Reply #2 on: 03/01/2006 19:13:11 »
You voyeur you !!!

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another_someone

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Re: Lightning on water....how far is safe ?
« Reply #3 on: 03/01/2006 19:48:23 »
As far as I am aware, metal skinned aircraft can survive direct lightning hits, I would have thought a metal skinned submarine would too.  Ofcourse, if your submarine is made of plastic, it might be a very different matter.
 

Offline neilep

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Re: Lightning on water....how far is safe ?
« Reply #4 on: 03/01/2006 20:08:01 »
Thanks George...setting aside the submarine....is it possible to address the swimming part of the query.

I know nothing about how much electricity is in your average thunderbolt  (more than a triple A battery I would have thought....hang on !!)  Ok..I found these two quotes..."a typical lightning bolt may transfer 1020 electrons in a fraction of a second, developing a peak current of up to 10 kiloamperes.

 a typical lightning bolt bridges a potential difference (voltage) of several hundred million volts.."
.

I imagine one would have to be quite far...a few tens of yards perhaps ! maybe a lot lot more depending on depth of water.....and what about depth ?...would the electricity penetrate deep ?



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another_someone

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Re: Lightning on water....how far is safe ?
« Reply #5 on: 03/01/2006 22:07:56 »
http://whale.wheelock.edu/archives/ask98/0066.html
quote:

Subject: Fish, Does Lightning Strike Them?
Dagmar Fertl (Dagmar_Fertl@mms.gov)
Wed, 4 Feb 1998 15:04:45 -0500

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     Hi Jamie, wow, what a question.  I asked a meteorologist friend at
     work about this one.  This is what we came up with.
     
     Fish can be killed by lightning.  Water conducts electricity really
     well (that's why they tell you to not play a radio or use a hairdryer
     in the bathtub or near water).  My friend told me that when she was a
     little kid, that sometimes kids would go to a nearby creek and catch
     fish and throw them into the swimming pool during a storm, and they
     certainly did die when lightning hit the water.  
     
     We agree with you in one respect that it has something to do with how
     lightning travels in the water.  As you probably know well, lightning
     is attracted to metal and anything that is tall.  A swimming pool is
     reinforced with metal rods under the concrete, so that's probably why
     those fish in the swimming pool died during a lightning strike.  
     That's also why you're not allowed to swim in a pool during a
     thunderstorm.
     
     We know that fish in creeks are in very shallow water and should be
     zapped by lightning pretty well if it was to hit the water.  We think
     that those fish probably don't get hit much since there are usually
     trees or something that would attract the lightning.
     
     A fish in the open ocean faces a different situation.  Salt water
     conducts electricity really well (has to do with the minerals and ions
     in the water).  We guess that when lightning hits the ocean's surface,
     the charge dissipates very quickly at the water's surface and probably
     isn't a big threat to the fish.  Also, anything floating on the ocean
     or standing in it (like a drilling platform or ship) would attract the
     lightning.  For that same reason, when I go out to sea to do whale
     research, as soon as we see lightning, we're told that we have to go
     into the inside of the ship because the ship would probably be easily
     hit by lightning (as well as any people standing up high on the flying
     bridge).
     
     Thanks for your really great question.  I learned a lot myself.  I
     know this doesn't really answer your question, but I hope it helps.
     
     Dagmar


______________________________ Reply Separator _________________________________
Subject: Does Lightning Strike Fish?
Author:  RGNAB@aol.com at ~smtp
Date:    2/4/98 1:03 PM


Help!  My name is Jamie, and I'm desperately trying to find information for my
fifth grade science project.  I'm not having any luck using the encyclopedia's
or books in our library.  My question is:  Why aren't fish killed by lighting?
I know that game wardens use electrodes to stun the fish during catches to
chart growth.  I think that the fish must sense the weather change and go
deep.  I also thought that maybe the way lighting travels in the water might
have something to do with it.  I live on a 32 acre lake in Tennessee, and we
never see any fish belly up after a storm.  Help!  Why is this?

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Re: Lightning on water....how far is safe ?
« Reply #5 on: 03/01/2006 22:07:56 »

 

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