What to do in a thunderstorm?!!

[blockend]

To add to my theory that lightning doesn't always strike the tallest object, here's a picture of the shuttle rocket getting a miss while the launch pad takes a hit.

http://en.wikipedia.org/wiki/File:Sts8storm.jpg

 

[Red Light]

My dad once saw a lightning strike on a field of cows being herded by a farmer. The cows keeled over dead all around the farmer, but he was unhurt.

That's because cows have legs that are far apart while the farmers are close together.

 

[ColinJ]

That's because cows have legs that are far apart while the farmers are close together.

Yep. The current flows up one end/side of a cow and out the other, via the heart, which is stopped by the shock. The farmer not only has his/her feet close together (so less potential difference between them to drive current through him/her) but is also probably wearing rubber wellies. They wouldn't help much if the farmer got a strike on the head, but in terms of current bypassing the ground and taking an easier route through said farmer, they certainly would.

 

[Jimmy Doug]

I'm not at all convinced about the highest object theory. The house I grew up in was struck (it put the chimney through my bedroom ceiling) and that was surrounded by tall mill chimneys and higher houses on a ridge. Another house I lived had an electrical junction box in the garden hit and we were surrounded by hills and tall trees.

Lightning doesn't always hit the tallest object. Lightning can hit anywere, but the probability it hits an object increases the higher it is in relation to other surrounding objects. That's the theory anyway. Personally, I'd prefer not to put it to the test! If I see big anvils in the sky and I'm up a mountain or in the middle of a field, I try to get the hell out of there!

 

[Jimmy Doug]

Here's a brave man:

[media]

]View: http://www.youtube.com/watch?v=SSV1ocCEOdY[/media]

 

[sunnyjim]

Not convinced:

Not sure Brumjim's explanation was intended to convince anyone but his wife.... But.. just collect all that electricty generated in the frame by cycling through the earths magnetic field, then use it to power a motor to drive the bike to make it go faster and generate more power and...


<jumps on bike & cycles off to patent office>

 

[ColinJ]

"A bolt of lightning is a current that can generate up to 300,000 Amps."

Er, no ... it is a current of up to 300,000 Amps!

That looked fun though.

In the 1970s, I was shown round some of the electrical engineering labs at the then Lanchester Polytechnic (now Coventry University). They had some pretty scary equipment in the bowels of the building!

In one of the labs, I watched an experiment being done on the kind of porcelain insulator stack used to hang high voltage cables from pylons. The experiment consisted of applying several hundred thousand volts across the stack and then spraying it with salty water until 'something' happened.

I wasn't quite prepared for what the 'something' was! (I was a naive 18 year old at the time ... )

I watched the kV meter reading creeping up and could hear disturbing hums, crackles and hisses being emitted from the insulators, Then they started to emit an eerie glow. The whole gubbins was housed in a big wire mesh cage and I knew that we were safe but I wasn't quite prepared for the emotional impact of standing 10 feet away from what was effectively a mini lightning bolt suddenly flashing over!

I leapt about 3 feet in the air and gibbered like a very gibbery thing while the lab technicians almost wet themselves with laughter. Apparently, everyone reacts the same way the first time they witness it!

It certainly gave me more respect for lightning and I do my best to steer clear of it!

 

[Jimmy Doug]

Wow! That sounds mental! That place would be a great venue for any school trip! I bet they don't do it anymore, though: health and safety regulations and all that stuff.

 

[ClichéGuevara]

I just know I'm gong to look stupid now, but isn't the reason the farmer was okay in the cowfield, the same as why you're safe in a car and presumably why you'd be safe on a bike? Rubber insulators like wellies and tyres?

 

[Jimmy Doug]

Well, it's true I forgot to add that in my spare time I'm a super-hero!
The thing is, if you're in a place where you know you're vulnerable and you can't find adequate shelter, then you adopt this position. It's a last resort, of course. As I said, I've never actually had to do this, I guess I've been lucky so far.
This reminds me of another clue - apparently if you start hearing a humming noise then it's a bad. I think in that situation, then you really would need to be a superhero to avoid getting hit!

 

[Tynan]

how many people killed by lightening every year out of however many million people and thousand thunder storms?

more like to slide in the wet road and wreck while worrying about lightning

anyone ever see that spooky documentary where they were filming with a camera that could image electrical charge

a charge rises from the ground to meet the bolt coming down, with the charge from the ground rising a good thirty plus feet

 

[Lien Sdrawde]

I believe (with a fairly dubious amount of certainty) that your heart will only stop if it is in a certain phase of its beating pattern - AV to SV node and all that kind of thing.

I believe also that people who are struck often have a metallic taste sensation before it happens - so if you remember what it was like the first time you tried to bite the roof of one of your 'hot wheels' cars.... you know its either (a) time to pen a very very quick will, or (b) hit the deck sharpish.

On a side note for the younger generation, and girlies, if you missed out on 'hot wheels' and the desire to chew one, you could experiment experiencing this sensation by chewing a zinc tablet (available from any supermarket / chemist) - however, be warned that if you try this you will hate me till the moment you die, or, if you cant taste anything metallic you can be certain you are a severe alcoholic. Dont say I didnt warn you about chewing the zinc tablet - I would rather have taken my chances with the lightening.

 

[Red Light]

I just know I'm gong to look stupid now, but isn't the reason the farmer was okay in the cowfield, the same as why you're safe in a car and presumably why you'd be safe on a bike? Rubber insulators like wellies and tyres?

That's part of the answer but the principle one is the current flows away from the point of the lightning strike through the ground. The ground is a resistance and as you will remember from Ohm's Law at school, current flowing through a resistor generates a voltage. The greater the distance betwen two points the bigger the resistance between them and the bigger the voltage. Now on a cow the legs are far apart at the four corners and there is a heart between the front and the back legs. The lightining strike creates a big voltage between those legs causing current to flow up the back legs, through the heart and down the front legs (or vice versa) This stops the cows heart. The farmer on the other hand has two legs close together with usually just one of his brains in between them. So the voltage is much smaller and the current doesn't flow through his heart in going up one leg and down the other. But a former work colleague was playing in a football match when the pitch was struck and both teams ended up unconscious on the ground so there is an element of luck (plus footballers seem to be much more dependent on the brain between their legs)

 

[ColinJ]

I just know I'm gong to look stupid now, but isn't the reason the farmer was okay in the cowfield, the same as why you're safe in a car and presumably why you'd be safe on a bike? Rubber insulators like wellies and tyres?

So you reckon that something that is powerful enough to ionise up to 30 km of air to blast a current through it is going to have 'second thoughts' when it comes against a few mm of rubber?

I've already posted elsewhere about a lad who was truck by lightning near to where my sister lives in Coventry. Hang on - report.

One of his shoes had completely disintegrated.

Being inside metal cars is safe because they act like Faraday cages, just like the chain mail suit worn by Richard Hammond in that video clip, and like the metal cage in the electrical lab I described above.

You are 100% not safe riding your bike in a thunderstorm unless you are wearing a chain-mail suit at the time or are riding inside a big metal box! Even then, you'd probably crash when your tyres were vapourised ...

 

[Bman]

Hang on.

Isnt the lightning (electricity) just looking for the easiest way to ground (negative)?
Why would it travel up one leg and down the other?
Surely the route it has to travel up one leg and down the other is longer and has more resistance than the route it would take through the ground, between the feet?