Just What Are Thunder and Lightning Anyway?
You know, we’re at that time of year when every evening has the potential for severe weather. Have you ever wondered just what are thunder and lightning? Although the odds of being struck by lightning are approximately 1 in 600,000, it is hardly surprising that so many people rush for shelter when one of the 100 lightning bolts that occur every second on Earth strikes. With temperatures reaching almost 30,000°C (54,000°F) and speeds of 130,000 mph, not to mention up to one billion volts of electricity in every bolt, getting in the way of a lightning strike is not exactly recommended. Just what causes lightning, though, and just what are those threatening peals of thunder that usually go along with it?
Lightning storms happen when there is an imbalance between positive and negative charges. When there is a storm and lightning?d particles of rain, ice or snow collide, the energy balance becomes even more disturbed and the lower parts of the storm clouds become negatively charged. Meanwhile, the Earth itself and some of the things on it, such as trees and church steeples, become positively charged, and so Mother Nature uses lightning bolts, which pass between the two charges, to correct the imbalance.
As for the thunder that is typically heard a few seconds after a lightning strike, it is caused directly by the lightning – specifically, by the extreme heat that the lightning generates. When the air around the lightning bolt heats up, it expands very quickly and vibrates, and it is this vibration that we hear as thunder.