We’re all familiar with the image of Benjamin Franklin flying a kite with a key tied to string as he tried to catch a lightning strike. Franklin was trying to confirm that lightning was electricity. He did prove that and he was lucky. It’s estimated that 24,000 people are killed each year by lightning, according to Outside Magazine. Today we know that the energy from a single bolt of lightning can power a 100-watt bulb for up to 90 days.

## The Bolt Formation

As a cumulonimbus cloud—a storm cloud—forms into an anvil shape, electrical charges develop. At the top of the cloud, positive charges gather; at the bottom, negative. This imbalance causes lightning and thunder. If the ground below is filled with positive charges, lightning will strike. According to the book Weather, lightning can heat the air around it to more than 54,000 degrees–and that explosive expansion of air causes the thunder we hear.

You can use the fact that light travels faster than sound to estimate your distance from a lightning strike. Count the seconds between seeing the bolt and hearing its thunder. Then divide that number by five. The answer will tell you the approximate distance in miles.

## Where and When

While thunderstorms can happen anywhere on Earth, they are most common in areas with warm, steamy weather. Therefore, the tropics see far more lightning than the north and south poles. In fact, Kampala, Uganda, has more thunderstorms and more lightning than any other place on the planet, according to the book Inside Lightning by Melissa Sweet: Thunderstorms light up the sky there 240 days a year.

In the United States, we’re used to having thunderstorms when the humidity rises. Here, Florida is the lightning hot spot. Scientists have even named the area from Orlando and Tampa south to Fort Myers and Lake Okeechobee the “lightning belt,” Sweet says.

And don’t believe that old adage about how lightning never strikes the same place twice. The Empire State Building is thought to be struck an average of 25 times each year, according to the New York City Office of Emergency Management. All told, the earth is hit by lightning about one hundred times every second.

## Types of lightning

There are three main directional types of lightning: cloud to air; cloud to cloud; and cloud to ground. In the first type, the difference between the positive charges at the top of a storm cloud and the air around it create a lightning bolt. With cloud-to-cloud lightning, the positive charges atop one cloud meet with the negative charges at the bottom of another, causing lightning between the two. Finally, there is the cloud-to-ground lightning, in which the negative charges invisibly zigzag toward the ground, and positive charges zoom up in that space.

As for the shape of lightning, scientists have named several types: streak lightning, which looks like a jagged or wiggly line; forked lightning, which has electrical streams coming off the sides; sheet lightning, which is actually the affect of lightning seen at a far distance; and ball lightning, a glowing sphere that either fades away or explodes with a bang.

## Human lightning rods

Seeing as 40 million lightning bolts are estimated to hit the ground in the United States alone each year, it’s not surprising that people are often struck. Luckily, most people survive: Lightning kills only about 1 in 10 victims. The survivors often wake up dazed and confused and some are even naked. The negatively charged energy can blow a person’s clothes off.

Golfers are particularly vulnerable to lightning. The sport is played in a mostly open field by humans holding metal clubs – making those players “ready lightning rods” according to Frank Lidz at Golf.com. The surrounding tress and water also attract lightning. In fact, five percent of lightning deaths happen on golf courses, the site says. Golfer Lee Trevino has been hit by lightning more than once. One of those instances was during the 1975 Western Open in Illinois. Trevino said at the time that he “should have held up a one-iron. Not even God can hit a one-iron.” Instead, the lightning bolt passed through Trevino’s bag and up his arm, then exited out his back.

If you’re caught outside in a thunderstorm, the best thing to do is to make yourself as small as possible. Crouch down (don’t lie down) and try to balance on just the balls of your feet. You want to avoid being the conduit for the lightning to reach the ground. And do stay away from trees. The sap in trees is a great conductor of electricity, so trees naturally attract lightning.

According to Inside Lightning, many ancient civilizations had somewhat heavenly ideas about lightning. For instance, the Aztecs believed that Tlacloc, the god of rain and water, used lightning to make people ill. In ancient China, it was thought that Tian Mu, the wife of thunder god Lei Kung, made lightning using mirrors. Egyptian god Set, Greek god Zeus, Mesopotamian god Adad, and Scandinavian god Thor each controlled weather and lightning. Set used an iron spear to make the bolts, while Adad used a staff. Zeus’s bolts were made especially for him by the Cyclops. And Thor’s lightning streaked across the sky whenever he threw his hammer.

Even as we began to learn more about science, lightning was still seen as otherworldly. In the Middle Ages, monks often tried to dispel the evil spirits thought to be contained within storms by ringing bells. These bell ringers were often struck by lightning. And as late as the 1700s, people in Europe believed that lightning was associated with poisonous gasses.

## Something good

It’s interesting to note that the earliest humans probably used lightning to make their first fires. So, in a way, lightning helped humans survive. Another plus: When lightning heats up the air, nitrogen and oxygen combine to form the fertilizer nitrous oxide. This chemical makes our soil richer.

Finally, if you’re more than just a little wary of thunder and lightning there are words for you. A person who has a heightened fear of thunderstorms is said to be suffering from brontophobia; those who are abnormally afraid of lightning are keraunophobics. We all know that it’s OK to be somewhat afraid.