Science Questions

Where is the safest place in a wood or a forest to run in a thunderstorm? Paul Batrachat, Stevenage

Well, you might think that standing under a tree is a really good idea because then the tree will get hit by lightning rather than you because it’s a much better path than you are. The problem is that sap tends to heat up, turns to steam and then explodes, so you get bits of tree flying off and they can hit you and do more damage than possibly even by being hit by lightning itself.

Also the tree is behaving as a wonderful lightning conductor and this is raising the the electrical potential of the ground around the tree.  Animals like cows and sometimes horses are found dead in fields because the electricity flows over the ground.  It’s easier for the electricity to go up the cow’s front legs, along its body and down its back legs, killing it in the process, than it is to go across the ground.  At least some of the electricity does.  So you could still get taken down by electricity spreading away across the forest floor.

October 2007