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I was struck by lightning, but not hurt. Explanation???

Posted on 2010-09-03
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Last Modified: 2012-08-13
Here's the story.  A friend and I were sitting in the back of a truck shooting a gun.  It was raining lightly, but not lightning, yet. I was holding an umbrella and sitting in an aluminum chair.  Leaning up against the truck was an all steel rake; so I was grounded.  We heard two pretty close together strikes quite a ways off.  I told my friend we should go in and he said ok.  About 5 seconds later a bolt hit very close.  I felt a definite shock go through my hand, that was holding the umbrella, and down through my elbow that was on the arm of the aluminum chair.  The shock hurt, but not too bad. No burns or anything like that.  I have been shocked by a 100,000 volt stun gun before. I would say this was about 2 or 3 times that.  My mother came out of the house and told me the TV was out.  Well...turns out the bolt hit the satellite dish and completely fried it, the wires, the TV and the receiver.  The wires and where the wires enter the house were burnt very badly.  This was obviously where the bolt hit.
I had heard of "finger bolts" or off shoots of the main bolt before.  I just assumed for years that this is what hit me.  Well...after a little research, I discovered that people that get by the main bolt can die.  People that get by the finger bolt just get their shoes blown off, skin burned very back and usually have neurological side effects and can go into temporary cardiac arrest.  Needless to say, my experience was nowhere near this extreme.  Like I said, it felt like a really bad stun gun shock and then I had a little numbness in my arm and a little tingling. That was it.  My question is; I know I didn't get hit by the main bolt,  I'm pretty sure I didn't get hit by a "finger bolt", so what shocked me?

Thanks
-Paul
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Question by:paulfarmer
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by:d-glitch
d-glitch earned 100 total points
ID: 33599005
A quick refresher on lightning from the government:

     http://www.newton.dep.anl.gov/askasci/wea00/wea00054.htm

A bird sitting on a high voltage transmission line doesn't feel a thing.
The line and the bird are both at the same high voltage.
There is no voltage difference to cause a current to flow.

The earth is normally considered to be at ground/zero potential.
But the earth is very large.
When lightning strikes a point on the ground, the potential of that point jumps by millions of volts.
The voltage of the surrounding area jumps as well.  The further away, the smaller the voltage difference.

You may have been sitting far enough away to get a voltage jump of 100 kV.
This is in the range of typical static electric shocks.  
Noticable, even painful, but so short in duration to not cause a problem.
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by:Infinity08
Infinity08 earned 150 total points
ID: 33599025
If the umbrella was in you hand, your elbow of the same arm was on the chair, the chair was on the car, and the pole was leaning against the car, then that was probably the path of least resistance. So, the electricity only passed through your underarm.

In other words, this would (usually) not be life threatening (the electricity didn't pass through any vital organs).

Not getting any burns from a lightning strike is not uncommon. The electric current often "flashes" around the surface of the body in a fraction of a second, which isn't enough to cause burns in most cases. Contact points with metal might be more problematic.

However, the lack of visible physical damage does not mean that no damage was done. Many lightning strike survivors (but not all) have a range of issues after being struck by lightning. Forgetfulness, sleep disorders, depression, and even seizures are among the observed symptoms.

That said, since it seems the current didn't pass through any vital organs in your case, I'd say you're reasonably safe. Likely the nerves in your arm have been impacted (which would explain the numbness you felt), but if you have no complaints, there was probably no lasting damage.


Caveat : I have no medical training, so take what I said with that in mind. If you are unsure, talk to a real doctor :)
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by:Paul Sauvé
ID: 33599630
A friend and I were sitting in the back of a truck shooting a gun.
Could it be that what protected you was that you were in the truck and the (rubber) tires insulated from the brunt of the strike?
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by:paulfarmer
ID: 33600193
Possible they helped, but as I said; Leaning up against the truck was an all steel rake; so I was grounded.
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LVL 17
ID: 33601053
I don't think three inches of rubber tyre is going to slow down a lightning bolt that has just jumped several miles from heaven to earth. That's why they say to unplug your television during a thunderstorm, not just switch it off, as if your arial is struck, the bolt won't care a jot about the little gap between the two switch contacts, it will just leap across and melt all the wires in your house.
I'd go with d-glitch's suggestion of 'The further away, the smaller the voltage difference.' You were far enough away from the main point of the strike not to be fried, but close enough to feel a fairly big shock.

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by:aleghart
ID: 33605335
>Leaning up against the truck was an all steel rake; so I was grounded.

You weren't, but the truck had a better grounding potential than when it was insulated with rubber tires.

You may have been picking up induced energy, which would be present in a larger area around the actual strike point.  The umbrella would have a large area of metal exposed, inducting current looking for ground.  The path to ground may have been through your arm to the truck body, rake, to earth.

It didn't have to be a hit from a bolt.

There are induced currents underneath high power lines.  Dance around with an umbrella and tin-foil hat and I'm sure you'd pass some current to earth through your bare feet.

As for rubber tires not offering insulation....big difference from a TV or radio.  A strike to an antenna might energize the device, which would have a tiny gap between electrical contacts and the chassis, which you might be touching.   An improperly grounded antenna might just pass the current to your house electrical...and if your TV or radio is not grounded, then that means _you_.
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patrickab earned 250 total points
ID: 33613463
Around all large flows of electrical current is a charged field. You will have been shocked by that field rather than the main bolt of lightening.

Many years ago, when in water up to my chest and holding onto a sailing dinghy's metal stay I was 'struck' by lightening - luckily not the main bolt. It made my arm go rigid and painful for a few days - but it all wore off and I've never had any subsequent problems. Had it been the main bolt I'm sure that would have been it for me.
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by:NovaDenizen
ID: 33628086
My guess is that the rake was a better path to ground than you were, so the lightning (or a finger bolt) went through the ladder instead.
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