Myths and Facts Revealed

When you were growing up, you probably heard all kinds of stories about lightning. In this post, we'll talk about some of the ideas you've probably heard. Some of the popular conceptions about lightning are true; others are not. We've talked about some of these beliefs in previous posts, so we'll link to other posts when appropriate.

Belief: Lightning never strikes the same place twice.
Status: FALSE

This is probably the most common of all beliefs about lightning. We dedicated an entire post to this belief here. The short version is: Lightning can and does strike the same place twice; in fact, the Empire State Building and other tall structures get hit many times a year.

Belief: Lightning can strike out of a clear blue sky, with no rain and no clouds overhead.
Status: TRUE

Everyone's heard of the "bolt out of the blue" that strikes with no warning when there's not a cloud in the sky. This can and does happen–quite frequently, in fact. Most lightning bolts come from the front and back edges of a storm system, and can travel for many miles before they touch the ground. Lightning can easily reach eight miles away from a storm cloud, and hit the ground in a spot that's under clear sunny sky. In rare circumstances, lightning can travel for very long distances indeed; the longest lightning bolt ever recorded, in October 2001, started from a storm in Waco, Texas, and hit the ground in Dallas, after traveling a total distance of some 110 miles!

Belief: You can tell if lightning is dangerous by counting the number of seconds between a lightning flash and the sound of thunder.
Status: FALSE

Many, many people are taught to believe that counting the time between lightning and thunder is a good way to tell if the lightning is close enough to be dangerous. This particular myth is especially dangerous, because lightning can reach many miles from a thunderstorm, as we just mentioned. Thunder can't be heard very far; depending on the landscape, you may not be able to hear thunder from any farther than two miles away or so. Even in ideal circumstances, it's hard to hear thunder from more than four miles. But lightning can often reach more than eight miles from a thunderstorm.

Belief: You are protected from lightning by wearing rubber-soled shoes, or by the rubber tires inside a car.
Status: FALSE

We've talked about this myth before as well. A car is a safe place to be, but not because of the rubber tires; the car's body acts as a Faraday cage to protect the people inside. Rubber-soled shoes, though, will not help you at all during a thunderstorm. A lightning bolt that can jump through miles of air can't be stopped by a few inches of rubber!

Belief: A lightning bolt is hotter than the sun.
Status: TRUE

The temperature of the sun's outer photosphere is about eleven thousand degrees Fahrenheit. A lightning bolt can heat the column of air around it to about fifty thousand degrees–nearly five times hotter.

Belief: Lightning is attracted to metal jewelry, metal hair clips, and personal electronic devices like iPods.
Status: FALSE

As a lightning bolt descends from the cloud, streamers begin rising from the ground in the area around the descending lightning bolt. These upward-rising streamers eventually touch the downward stroke, and the lightning bolt is complete.

Small metal items such as hair clips or the earphone wires from a music player don't make any difference at all; they're far too small to influence the formation of the streamers. Wearing an iPod or metal jewelry won't put you at greater risk of a lightning bolt.

However, metal objects can alter the flow of electricity if you are struck by lightning. One person who was struck while listening to an iPod suffered burns and damage to his ears when the current flowed up the headphone wires.

Very large electrical discharges tend to be most dangerous if they penetrate the chest, where they can disrupt the normal rhythm of the heart. For this reason, personnel who work with large electrical sources (such as army radios and photoflash devices) often work with one hand in their pocket. If they touch energized equipment with one hand, they may suffer burns, but touching energized equipment with two hands may cause the electrical surge to flow through their body from one hand to the other, stopping the heart.

Belief: A person who is struck by lightning is electrified and should not be touched.
Status: FALSE

This popular myth is based on a lack of understanding of the way electricity works. A lightning bolts lasts only a few microseconds, and a person's body can not store significant amounts of electricity. If someone is struck by lightning, give medical attention immediately!

Belief: A rubber raincoat or other insulating clothing will protect you from lightning.
Status: FALSE

As with rubber-soled shoes and rubber car tires, rubber rainwear poses no obstacle to lightning. The high voltage and high current of a lightning bolt can easily pass through such clothing.

Belief: Carrying an umbrella in a storm can increase the chance of being struck by lightning.
Status: TRUE

Anything which makes you taller can increase the odds that you'll be struck by lightning. Lightning doesn't always hit the highest point, but the odds are greater that it will strike tall targets–particularly if those objects are made of metal. The umbrella can act as a crude lightning rod, directing a lightning stroke right into you.

Belief: If lightning strikes the ground nearby, the stroke is "grounded" and harmless.
Status: FALSE

When lightning strikes the ground, the electrical discharge can travel for considerable distances through the ground, as we talked about here. The indirect "splash current" from nearby lightning strokes can still be dangerous even sixty feet or more from the point of discharge. In water, it's even worse; dangerous currents can travel for six hundred feet from the place where the bolt hits the water. This creates an area of about eleven thousand square feet on land, or a whopping million square feet in water, that can carry potentially lethal amounts of current. Every year, lightning is responsible for the deaths of thousands of farm animals and millions of fish. The USDA estimates that about 80% of all accidental livestock deaths are caused by lightning.

Belief: You should not take a shower or use a conventional land-line telephone during a thunderstorm.
Status: TRUE

Lightning strokes can travel for significant distances through the ground, and these distances are greatly increased if lightning strikes a conductive metal object such as a telephone line. In fact, many computers are destroyed every year by lightning strikes on telephone lines. People will often disconnect their computers from the wall during a storm, but may not consider disconnecting them from the telephone line or cable modem. Lightning that strikes the phone line or cable can travel through a phone, cable, or DSL modem and into the computer, destroying it. The same thing can happen if you are using the phone or taking a shower; a lightning hit a good distance away can travel through metal pipes or phone lines and into your house.

Surge suppressors are not always effective at protecting electronics in a house. They are good at defending against small surges, but a direct lightning hit on a power or telephone line near the house will easily overwhelm a surge suppressor and damage the equipment connected to it.

Belief: You should stay away from metal bleachers, guard rails, railroad tracks, metal sheds, and fences during a storm.
Status: TRUE

Metal is metal is metal. All metals conduct electricity, and large metal objects can conduct the energy of a lightning bolt for long distances. A lightning hit on a train track or a fence can be conducted down its length, and discharge into a person standing on or near it. Metal sheds and bleachers offer no protection from lightning, and may conduct a far-off lightning strike directly to a person seeking shelter under them.

Belief: Lightning rods protect buildings by "discharging" a storm cloud or draining the electricity out of it.
Status: FALSE

A lightning rod offers an easy point for a streamer to form, increasing the odds that a bolt of lightning will hit the rod and be conducted safely to the ground rather than hitting the roof of a building. Lightning rods do not drain the electricity out of a cloud; instead, they just offer an appealing place for a lightning bolt to hit.

Belief: "Heat lightning" is caused by hot air and poses no threat.
Status: FALSE

What people call "heat lightning" is really just the visible flashes of lightning too far away to hear thunder. Since lightning bolts can travel farther than you can hear thunder, "heat lightning" in the distance may still pose a threat.