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Lightning

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eggshaped
136794.  Sat Jan 20, 2007 11:42 am Reply with quote

You're in an open field when a storm cloud is above. There is about to be a lightning strike, how can you significantly increase your chances of safety?

Alternatively, what should you not do if you wish to be safe?

 
smiley_face
136796.  Sat Jan 20, 2007 11:46 am Reply with quote

DON'T lie down.

I think the best thing to do is crouch and cover your head with your hands and assume the "I'm in an aircraft that's about to crash. I know what, I'll put my hands over my head - That'll save me!" position.

 
Ameena
136797.  Sat Jan 20, 2007 11:48 am Reply with quote

Apart from not being there in the first place, or magically finding a metal cage and quickly hopping inside it? Well, I've heard that squatting down on the balls of your feet is meant to work. I dunno why lying down flat wouldn't - I mean, you're lower that way, and lightning is supposed to strike the highest point around, isn't it? Or maybe if you just wore rubber or something...
I wonder how much of that I will be klaxoned for... ;)

 
eggshaped
136800.  Sat Jan 20, 2007 11:51 am Reply with quote

I'm not klaxoning here, because I don't really know the answer 100% myself.

The fact about wearing rubber seems like nonsense, seeing as the lightning has just travelled 50,000(?) ft through a poor conductor (air) I doubt that a small layer of rubber will make much difference.

Carrying a portable faraday cage sounds like a good idea though.

 
eggshaped
136802.  Sat Jan 20, 2007 11:53 am Reply with quote

Why do you think that adopting the certain-aircrash-death posture will make any difference? I know that's what they suggest, but it seems pretty futile to me.

 
grizzly
136805.  Sat Jan 20, 2007 11:58 am Reply with quote

Convention is to bend down making yourself as low as possible and to brace your knees with your arms, the intention being that if lightning were to strike you then in this position there is less chance of your heart stopping.

Also, you'll want to avoid wearing any metal jewellery since the current will heat it to melting point and give you serious burns (wired bras can be a serious problem for women involved in lightning strikes).

You'll significantly improve your chances of not being struck if your skin is dry. When people are struck in storms it is more likely that the current will travel across your skin to the ground (of course water is a good insulator but your sweat has plenty of salt in it, making it a very good conductor), boiling the water as it goes scolding you.

You don't want to go and stand under a tree. The current boils the sap causing the bark to explode off the tree sending splinters of wood everywhere.

Lightning also has some interesting long term effects on its victims. Although it causes very little physical damage to nerves (when viewed on scans) lightning seems to effect the way the brain works (we discussed this somewhere else in more detail).

 
grizzly
136807.  Sat Jan 20, 2007 12:02 pm Reply with quote

eggshaped wrote:
Why do you think that adopting the certain-aircrash-death posture will make any difference? I know that's what they suggest, but it seems pretty futile to me.


The position is similar but different, you brace your knees instead of your head, as stated in my post above.

Lieing down on the ground is not a good idea. Assuming that it has been raining the current can travel 10 to 15 feet from where it strikes through the water on the ground. I've heard of this causing multiple deaths at sporting events when entire teams or groups of spectators are hit.

 
smiley_face
136808.  Sat Jan 20, 2007 12:02 pm Reply with quote

grizzly wrote:
You'll significantly improve your chances of not being struck if your skin is dry. When people are struck in storms it is more likely that the current will travel across your skin to the ground (of course water is a good insulator but your sweat has plenty of salt in it, making it a very good conductor), boiling the water as it goes scolding you.


Yup. That rain-repelling cream is fantastic!

The underwired bras thing reminds me of a story of a woman who died because of it...

Found it. It's in the Darwin Awards.

 
eggshaped
136810.  Sat Jan 20, 2007 12:03 pm Reply with quote

Sites seem to say that this is a good position:



The idea is that if the lightning strikes close by, the ground current will go up one foot, then pass to the other foot and back to earth.

Would this really help? I mean assuming that electricity wishes to be grounded, if it has forced itself up to your ankles, is it really going to leave the rest of your body untouched because you've set up a convenient little circuit with your feet?

 
Sand
136812.  Sat Jan 20, 2007 12:05 pm Reply with quote

Quote:
1. PLAN in advance your evacuation and safety measures. When you first see lightning or hear thunder, activate your emergency plan. Now is the time to go to a building or a vehicle. Lightning often precedes rain, so don't wait for the rain to begin before suspending activities.

2. IF OUTDOORS...Avoid water. Avoid the high ground. Avoid open spaces. Avoid all metal objects including electric wires, fences, machinery, motors, power tools, etc. Unsafe places include underneath canopies, small picnic or rain shelters, or near trees. Where possible, find shelter in a substantial building or in a fully enclosed metal vehicle such as a car, truck or a van with the windows completely shut. If lightning is striking nearby when you are outside, you should:

A. Crouch down. Put feet together. Place hands over ears to minimize hearing damage from thunder.

B. Avoid proximity (minimum of 15 ft.) to other people.


That was from this site but some of that stuff is stating the obvious and reminds me a little of the what to do if you suspect a bomb training I once recieved. One of the tips for that is do not pick it up, do not put it in a bucket of water and do not carry it to your local police station. Um, if it's a bomb I'll be right infront of Shaggy and Scooby Doo, not watching the clock get to 1 second before snipping the red wire, no the blue wire!

I have also heard that placing your left hand on the floor while crouching could minimise damage from an actual strike too. This supposedly because you are offering the electricity a path of least resistance to the Earth (where it is in fact going, via you) that avoids your heart. It does seem to make sense but how much good it would do you with that much electricty running through you is anyone's guess. It would also mean you cannot protect your ears fully, as the quote suggests.

 
grizzly
136814.  Sat Jan 20, 2007 12:05 pm Reply with quote

BTW lightning can travel a long distance from a storm, it isn't known precisely why or how yet. I've seen documentaries citing instances where people have been struck on bright blue days when the nearest storm was 5 to 10 miles away.

If you can hear the thunder you're close enough to a storm to be hit by lightning.

 
smiley_face
136815.  Sat Jan 20, 2007 12:06 pm Reply with quote

eggshaped wrote:
Would this really help? I mean assuming that electricity wishes to be grounded, if it has forced itself up to your ankles, is it really going to leave the rest of your body untouched because you've set up a convenient little circuit with your feet?


Electricity will, on the whole, take the shortest possible route, and avoiding your body is certainly shorter than going up into the torso and back out.

Thinking about it (in a very much logical blagging sense) as a parallel, different resistances result in different currents, so while the electricity passes through all of the body, the current is lower in the torso so wouldn't cause the heart to go into fibrillation.

Maybe...

 
smiley_face
136817.  Sat Jan 20, 2007 12:09 pm Reply with quote

Here's a slightly less dubious source for the Hyde Park story...

http://query.nytimes.com/gst/fullpage.html?res=9D02E7DE1038F93BA15753C1A96F958260

 
eggshaped
136818.  Sat Jan 20, 2007 12:10 pm Reply with quote

Also any site which has this theory also says that "lightning usually hits the tallest thing around".

I always thought that lightning just hits where it's going to hit and it's pretty unlikely that something as tall as a human (even if they're carrying a brolly) will make any difference.

I read somewhere* that an umbrella will only make a difference if the bolt was going to hit within 3 feet of the person involved, and that if you're within 3 feet of a strike you're in trouble anyway as most deaths are caused by ground-currents.



*that great QI source

 
eggshaped
136820.  Sat Jan 20, 2007 12:13 pm Reply with quote

Quote:

Electricity will, on the whole, take the shortest possible route, and avoiding your body is certainly shorter than going up into the torso and back out.

Thinking about it (in a very much logical blagging sense) as a parallel, different resistances result in different currents, so while the electricity passes through all of the body, the current is lower in the torso so wouldn't cause the heart to go into fibrillation.


Yes, I would think that's the theory, but surely the path of least resistance is not to go through one's body at all, irrespective of how one is stood.

 

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