Lightning may have played a role in creating life on earth. Nobel Prize winning chemist Harold Urey concluded that earth’s early atmosphere consisted of hydrogen, methane, ammonia, and water vapor. One of his students, Stanley Miller, introduced an electric spark, or lightning, into Urey’s chemical brew. Seven days passed when Miller found newly formed amino acids, the very building blocks of protein.

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While early civilizations tried to understand lightning, it became part of early religions and superstitions. The ancient Greeks believed lightning was a weapon used only by Zeus. Scandinavian’s believed Thor used lightning to chase away his enemies. Navajo Indians believe lightning has healing power. Even Santa Claus has reindeer named Blitzen and Donner, German for lightning and thunder.

In the 1700s, science was in its infancy and Benjamin Franklin was America’s foremost inventor and entrepreneur. His successes include bifocals, the Franklin stove, and Poor Richard’s Almanac which sold 10,000 copies a year in the Colonies. Franklin also dabbled in America’s great social experiments, the Revolutionary War and the Declaration of Independence. Then in 1752, Franklin started messing around with kites, keys, and lightning. His experiments proved lightning was electricity. He followed with the invention of the lightning rod. What Franklin didn’t know was lightning strikes the earth about 100 times per second, or about nine million times a day. Each bolt can light a 100 watt bulb for three months.

Today, we know lightning is a giant spark, static electricity on a planetary scale.

Lightning is the result of a process deep inside a cloud requiring the presence of graupel (hail) and ice crystals (snow).

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When graupel collides with an ice crystal, positive charges called protons are transferred to the ice crystal leaving the graupel negatively charged with electrons and the ice crystal positively charged with protons.

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Ice crystals are then carried by updrafts to the top of the cloud making it positively charged while the heavier graupel stays in the middle or falls to the bottom of the cloud making that portion negatively charged.

Since opposites attract, the negative charges at the bottom of the cloud cause a region of positive charges to grow on the ground. As the thunderstorm moves, this region follows like a shadow. Air is a pretty good insulator, but as the charges build in the cloud and on the ground, the electric potential also builds and eventually overcomes the air’s insulating effects.

Step 1

When this occurs, negative charges rush toward the ground in a series of steps, called the stepped leader. It is very faint and difficult to see. The electric field can easily exceed one million volts per foot.

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Step 2
Each step lasts only about fifty-millionths of a second and travels only a couple hundred feet. As the stepped leader approaches the ground, positive charges rush upward to meet it.

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Step 3
Upon contact, there is an exchange of electric charge, electrons race down to the ground...and protons race up to the cloud as the return stroke or lightning. The return stroke follows the path created by the stepped leader.

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That’s right, lightning travels up, not down and that’s the surprise twist!

Lightning kills about 100 Americans every year. Putting it another way, that’s one victim for every 86,000 flashes, one death for every 345,000 flashes, one injury for every 114,000 flashes. Your odds of becoming a lightning statistic are 1 in 600,000.

The problem is, as positive charges shadow the thunderstorm, they collect in tall objects like telephone poles, trees, and people if they are the tallest objects around. Suppose you’re a farmer in the middle of a field or a golfer in the middle of a fairway.

In both cases, you are the tallest object and protons like to gather near the top of the tallest object. Lightning is lazy, traveling the shortest distance from cloud to ground.

If you are the tallest object, you are likely to become a statistic. That’s the deadly truth.

On March 2nd 1995, lightning struck a group of ten children and their baseball coach in Broward County, Florida.

A seven year-old girl was directly struck and seriously injured. The police reported clear skies at the time of the lightning strike, but radar indicated a line of thunderstorms in the distant northwest. You’ve heard the saying, like a bolt out of the blue. Well they really do happen.

They’re called positive giants, a bolt of lightning that strikes from up to twenty miles away, like a bolt out of the blue. Positive giants come out of the top of the storm, from the anvil-shaped cloud, and can be much more destructive than regular lightning.

Skies can be clear and you don’t have to see lightning or hear thunder to fall victim. In fact, you’re more likely to be indirectly struck by lightning, by touching something conductive like a telephone. Most victims survive, but the electrical and heating effects of lightning can cause a wide range of physical and mental problems.

Remember, about 100 people die in the United States each year due to a direct lightning strike, but more than 900 will suffer nonfatal injuries. Shenandoah National Park Ranger Roy Sullivan was struck seven times and lived to tell the tale, and Edwin Robinson regained his eyesight and hair began to grow on his bald head after being struck by lightning. Some people have all the luck?

At any moment, there are 2,000 thunderstorms occurring around the world producing 100 bolts of lightning. That’s 8.6 million lightning strikes worldwide every day. Each one carrying up to 200,000 amps and one billion volts of electricity.

Lightning occurs all over the globe, but it is concentrated where the atmosphere is warm, moist, and unstable. Those criteria are easily met in Central America, Africa, the southeastern United States, and Indonesia which is the lightning capital of the world with over three-hundred thunderstorm days per year. Central Florida is the lightning capital of the United States. The corridor from Tampa to Titusville is known as “Lightning Alley”.

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Lightning strikes the United States about thirty million times a year and has a temperature is 50,000 degrees, or ten times hotter than the surface of the sun. Something striking the ground that often, at that temperature is bound to leave a calling card, and it does. When lightning strikes the sandy soils of Florida it often leaves behind glassy tubes called fulgurites. These solidified lightning bolts remain behind, buried in the ground, after lightning melts sand which cools into glass. Researchers at the University of Florida have recently found a fulgurite measuring seventeen feet.

There are five types of lightning. They are forked lightning, sheet lightning, ribbon lightning, bead lightning, and ball lightning. You may have noticed your favorite, heat lightning, was missing from the list. That’s because it doesn’t exist. What many people call heat lightning is just lightning from a distant thunderstorm. In this case, it is flashing sheet lightning which illuminates the night sky. Now you’re weather wise.

By the way, thunderstorms also produce optical phenomena at very high altitudes called red sprites and blue jets. Sprites are huge but weak flashes directly above thunderstorms which occur at the same time as powerful positively charged cloud-to-groung lightning. Jets streak out the top of thunderstorms into the stratosphere directly above the electrically active core.

And don’t forget about St. Elmo’s Fire. Not the movie, the spooky green glow which appears near the top of sailing masts. Named for the patron saint of sailors, it occurs when misty air ionizes producing a negative charge. Positive charges from the boat climb up the mast, the two meet, and the air glows. Neat huh?