how many people killed by lightening every year out of however many million people and thousand thunder storms?
Of course, you're right that the chances of being hit by lightning are very small - but that shouldn't lead to complacency. We've already seen in this thread one guy who's actually been hit by lightning (not directly, but through a fence). We've also heard from people who have seen cows and football players being hit. The thing is, although the chances of being
directly hit are small, the chances of being injured or even killed
indirectly are high enough that you should take it very seriously.
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)
This is great! I don't think I've ever heard anyone illustrating the principles of electricity with grazing cows before! A fine show!
