My grandfather was a college physics professor who devoted his life to lightning research. I grew up in a household where electrical theory was a common dinner table conversation, but the most memorable teacher on the subject of lightning was Mother Nature herself.
I was 8 the summer we visited my grandparents in Lincoln, Nebraska. There was a huge thunderstorm brewing. We could hear thunder in the distance and my brother and I sat and counted the time between boom and flash. “One, two, three, four, five, six” FLASH! The sound of thunder travels a mile in 5 seconds, so this one was getting close. The rain came and then subsided. We thought the storm had passed over. I went to bed. An hour later, a crashing noise woke me in terror just in time to open my eyes and see blinding light right outside my upstairs window. Everyone was scurrying around the house, calling to each other to make sure we were all okay. Eventually the storm passed and we went outside, drawn by the fire trucks racing down the street. Lightning had split the elm tree outside my window in two. Fortunately, it hadn’t fallen on the house, but at the end of the street, a small grocer wasn’t so lucky. Lightning zipped into his store and on its way to ground cremated everything on the way. The next morning, the poor man stood outside his charred rubble selling “lightning-baked potatoes” for a nickel. We bought one as a souvenir.
Lightning, a gigantic spark of 100 million to 1 billion volts of static electricity is formed when rain clouds are negatively charged at the base and positively charged at the top. Ice in the clouds seems to be the stimulus for forming lightning as ice has a negative charge while water droplets maintain a positive charge. Sometimes large drops of water become negatively charged while small ones carry the positive charge. Lightning occurs when the negative charge at the base of the cloud discharges its energy toward the positive charge of earth below it and heaven help anything in the path.
Conductors substances through which electricity can pass quickly hurry the trip to earth. Water and metal are excellent conductors. Anything tall will be struck first as in the case of the tree next to my window. Humans, being mostly water, are excellent conductors. A tall human on a flat surface like a field is at risk. When lightning strikes the ground, its charge can spread out quite a distance if there is a conductor like water present. That’s why you don’t want to be swimming in a pool or lake or standing in water outside. You don’t even want to be in the bathtub or have your hands in a sink of water in case lightning electricity comes into the house via metal pipes.
Each second, there are 50 to 100 cloud to ground lightning strikes in the world. Most of them average 2-3 miles in length and carry a charge of 10000 amps at 100 million volts. Lightning is the number one cause of storm-related deaths. In the U.S., 200 people die a year from lightning and 750 are seriously injured.
The antidote to being an electrical conductor is to be insulated. Being inside a wooden structure is good. Your car is also a safe haven but not because it has rubber tires. Your safety depends upon the fact that the electrical current will travel along the outside of the metal body of the car and dissipate into the ground via the tires and rainwater. Just make sure you stay inside until the storm is past and that you stay there until you are sure there are no downed power lines on the ground.
Lightning is an awesome spectacle of Nature to behold. Just remember to do it from a safe place inside. Electricity will always seek ground and you don’t want to be the conductor to speed its quest.
