Tree Talk: Thunder and fireworks

It's hard to imagine the 4th of July without fireworks! The first official celebration occurred on July 4, 1777 – one year after the adoption of the U.S. Declaration of Independence – with a display of fireworks and firing of cannons and guns. The fireworks tradition has continued ever since, with the addition of family get-togethers, picnics and parades.

Like many inventions, fireworks were created by accident. Around 800 AD, a Chinese alchemist mixed sulfur, charcoal and saltpeter in an attempt to find, of course, the secret to eternal life. Instead, the mixture accidentally caught on fire and gunpowder was born. History had its first fireworks when the powder was packed into bamboo or paper tubes to create giant firecrackers. For many years, all fireworks were simply orange-colored until Italian inventors added metals to the mixture, creating the first colorful explosions in the 1830's. The impressive annual celebrations we enjoy are years of danger, invention and beauty wrapped into a simple package. Nearly all fireworks come from China, and Americans incinerate about $1 billion each year on fire-cracking fun.

Mother Nature offers fireworks of her own in the form of dramatic summer thunderstorms. If you hear thunder, lightning is close enough to strike you. Lightning occurs when strong negative charges in low clouds and strong positive charges on the ground meet in the air. In a fraction of a second, lightning heats the air around it to temperatures up to 54,000 degrees F, five times hotter than the surface of the sun! The heated air expands explosively, creating a shockwave as the surrounding air is rapidly compressed. The air contracts rapidly as it cools, creating the sounds of thunder. We see the lightning before we hear the thunder because light travels much faster than sound waves. According to the National Weather Service, you are not safe anywhere outdoors during a storm. Height, pointy shape and isolation are the dominant factors controlling where a lightning bolt will strike – so a lone tree is definitely a likely target for a strike and is not a safe place to seek protection during a storm. Electricity seeks the path of least resistance, and the sap and moisture inside a tree make it a better conductor than the surrounding air. Yes, lightning can strike the same place repeatedly: The Empire State Building is hit an average of 23 times every year.

While sheltering indoors during a storm, stay away from windows and doors to avoid potential damage from flying debris on the outside. Cellular phones are safe to use, but corded telephones are not. Avoid showering, bathing, washing dishes or doing laundry, since plumbing and bathroom fixtures can conduct electricity.

Stay safe during Mother Nature's lightshows so you can continue to enjoy life's celebrations. Happy Independence Day, America.