Unless you left town to avoid the cicadas, you know that Nashville has experienced a string of impressive thunderstorms this spring. At one point last week a severe storm warning actually grew into a tornado warning. In checkout lanes and at water-coolers, even people who hadn’t really suffered from the storms were complaining of tossing and turning through the late-night fireworks. They had no patience with weirdoes who regard lightning and thunder as glorious free entertainment.

Of course, even storm fans have to admit that, entertaining or not, thunderstorms can wreak havoc. Many Nashvillians have experienced power outages of varying durations. The accompanying rains have caused flooding. And then there’s the wind damage.

But even without rain or high winds, thunderstorms can be dangerous. They’ve proven this twice recently. Back in mid-April, Belmont University soccer player Jeremy Littlejohn was struck by lightning while helping clear the field during the approach of dark clouds (not to mention what turned out to be a couple of tornadoes). And just last week, St. Patrick’s Catholic Church on Second Avenue S. was struck by lightning and lost its steeple. As a result of this crime spree, lightning keeps showing up in the Nashville news media, right alongside murderers and real estate developers.

With more thunderstorms undoubtedly on the way, this seems a good time to take a look at them—at how they work and what you can do about them.

The distant rumble

“What is the cause of thunder?”

— King Lear

Was it Mr. Wizard who used to place inflated balloons in a refrigerator, then take them out and watch them expand as they warmed up? He could have answered King Lear’s question about thunder. When air is heated, the molecules spread out. When electrical charges in clouds build up enough force, a flash of lightning heats the air to more than 50,000 degrees Fahrenheit in a fraction of a second. The air molecules literally explode. The result is a shock wave—in this case, thunder.

By the way, it was also Lear who called thunder “all-shaking.” The familiar dish- and window-rattling occurs because most of the energy in a thunderclap is in the range below what we hear. You can experience precisely the same phenomenon any time one of those boosted-bass cruisemobiles drives by your house.

The closer you are to lightning the louder the thunder is. If you’re close enough, you hear a sudden clap followed by a rumble. Thunder growls and rumbles because what appear to be single lightning flashes are actually multiple bolts. They occur so quickly that we notice only a flickering flash. These repeated flashes may cover a distance of miles, so some of them sound much louder than others. They also bounce and echo.

We see lightning before we hear thunder because light travels many times faster than sound. For that reason, as Boy Scouts have always claimed, it really is possible to estimate the distance between you and the lightning. If you measure the time between the flash and the beginning of the thunder, and allow five seconds for each mile (or one second for each thousand feet), you can roughly estimate your distance from the lightning. High school physics teachers couldn’t ask for a handier demonstration.

That also explains what most of us call “heat lightning.” It’s simply lightning that occurs so far away that the actual flashes aren’t visible. The light is here in an instant, but sometimes the sound waves of the thunder scatter until you never even hear them. All you get is the experience Vladimir Nabokov described as “heat lightning taking pictures of a distant line of trees in the night.”

In case there are any budding scientists out there looking for projects, it’s worth mentioning that even the experts don’t truly understand why so much electricity builds up in the atmosphere during a thunderstorm. They theorize that electrification is associated with rain because it’s involved in the formation of ice crystals and water droplets. But like everything else in nature, it needs more study. There could be grant money in this for somebody.

Thor's Day

“Thunder is good, thunder is impressive; but it is lightning that does the work.”

— Mark Twain

Meteorologists estimate that at any given moment there are roughly 2,000 storms in progress around the Earth, producing roughly eight to nine million lightning flashes daily. That’s why you should be wary whenever anyone claims something is “about as likely as being struck by lightning.” The odds are not so good as they seem.

In 1963 lightning struck a jetliner, apparently igniting vapors in an empty fuel tank. Eighty-one people died. Six years later, lightning struck Apollo 12 less than a minute after lift-off. The electronic guidance system was zapped, but NASA finally regained control, and the crew went on to perform the second Moon landing. As recently as 1987, lightning struck an unmanned Atlas rocket, which lost control and had to be blown up. But perhaps the most damaging strike on record occurred in 1926, when lightning blew up a Navy ammunition magazine in New Jersey, killing 16 people and hurling debris as far as 22 miles.

Belmont’s Jeremy Littlejohn is in good company. Every year many people—people simply minding their own business, neither piloting rockets nor guarding ammunition—are struck by lightning. Frequently, they’ve remained too long on a golf course or sought shelter under a solitary tree. Many of the victims survive; some do not. Sometimes they are seriously injured but pull through, as Littlejohn did. After a long hospital stay, he survived to point out the hole left by the lightning’s exit route through his soccer cleats.

A Virginia park ranger named Roy Sullivan has the dubious honor of holding the world record of lightning strikes. He was struck seven times between 1942 and 1977. In 1942 he lost a toenail and in 1969 he lost his eyebrows.

No wonder lightning is such a widespread symbol of power, the tool of every old god, symbolized in tridents and arrows. You can show your children an example of this in Disney’s Fantasia, in which Zeus flings thunderbolts at picnickers. A Choctaw myth tells how the Great Sun Father assigned two dimwitted birds the task of warning his people of oncoming storms. By accident the birds created thunder and lightning.

One Hindu text makes the deep-sounding but not particularly useful claim that “in the thunder flash is Truth.” And here’s a useful tidbit to cheer up lighting victims: Some shamans claim that being struck by lightning bestows instantaneous enlightenment. Presumably this higher state requires that you survive the lightning strike. However, some people have found a way around that little detail by insisting that, if you are killed by lightning, you will be instantly transported to heaven.

One day of the week has particular associations with lightning. The venerable Norse god Thor was the bringer of rain. That made him essential to farmers—which, at the time, included practically everyone. His very name meant “thunder,” and his rolling chariot created the sound. The fifth day of our week is still called Thor’s Day. Here’s a tidbit, perhaps irrelevant, to worry the superstitious: Both Jeremy Littlejohn and St. Patrick’s Catholic Church were struck by lightning on a Thursday.

Dodging the wrath of God

St. Patrick’s isn’t the first church to be struck by lightning. As steeples aspire to heaven, they also dare the elements. Throughout history churches have been lightning’s favorite target. In the Middle Ages this common circumstance tested the ingenuity of priests who had to explain why, just as churchgoers died of plague alongside whores, the house of God was not a refuge from storms. An 18th century German account reported that lightning had struck 386 steeples in the preceding three decades, killing 103 bell ringers. St. Mark’s in Venice was struck 12 times in a 400-year period and burned down four times.

St. Mark’s sad history refutes the misconception that lightning never strikes twice in the same place. In fact, the reverse is true. If a stationary object has been struck once, the odds are good it will be struck again. Lightning is lazy. Like everything else in nature, it takes the path of least resistance. Air is a poor conductor of electricity, and anything that offers lightning an easier way “attracts” it.

That’s why a lightning rod works. Metal is the best conductor of electricity. A lightning rod reaches up into the air and invites the lightning to follow its metal path safely away from houses and other structures. Back in the 18th century, when lightning rods were the latest high-tech safety equipment, some people thought they worked by defusing storm clouds and preventing lightning. Actually they channel the electricity into the ground.

Lightning rods disproved the ancient adage that it was futile to seek a defense against the lighting. But some people still regarded the life-saving technology as an attempt to dodge God’s wrath. Benjamin Franklin, who invented the lightning rod, ran an advertisement in Poor Richard’s Almanack in 1753 that began, “How to Secure Houses Etc. from Lightning.” Religious authorities denounced such blasphemy, but Franklin calmly replied, “Surely the thunder of heaven is no more supernatural than the rain, hail, or sunshine of heaven, against the inconveniences of which we guard by roofs and shades without scruple.”

To do or not to do

We can’t go around wearing lightning rods on our clothes. What if we’re not at home and safely grounded when a thunderstorm arrives? When in doubt, ask the experts.

Like most others in his field, WKRN-Channel 5 weather forecaster Davis Nolan is quick to point out safety measures regarding thunderstorms: “You don’t want to stand underneath tall objects. You shouldn’t be near steel-framed windows and doors. Any time you can, get below the level of the ground, even if you’re out in a field and there’s just a little bitty ditch. Anything that gets you below the profile of the ground is good. If you’re inside a car and the doors are closed, you’re OK.”

Many of the traditional rules your mother taught you are wise. You should avoid bathing during a storm, because both metal and water are good conductors of electricity. Stay off tractors and riding mowers. Talking on the telephone during a storm used to be more dangerous than it is now. “Cordless phones are better,” Nolan says. “You don’t have that wire traveling from a telephone pole outside right to your ear.

“One thing that a lot of people don’t realize,” he adds, “is that a thunderstorm might be several miles away, and you can still get a bolt of lightning ahead of it, out of some of the forerunner clouds—a ‘bolt from the blue,’ as they call it.” One physicist described those familiar towering black thunderclouds as “a lightning bolt waiting to happen.”

According to Nolan, it’s difficult to determine whether Nashville’s recent storms are the result of El Niño. “The forecast of it being a warmer-than-normal winter pretty much panned out. We had some cool, dreary days, but at night the temperature wouldn’t even drop below freezing because of those same clouds. In an El Niño year, normally the Weather Service predicts for our part of the country a wetter-than-normal spring. This recent rain may be a little bit late though.”

Nolan says that the El Niño-related forecast for the next few months predicts that Nashville may experience a drier-than-normal summer. However, he adds, “From what I’ve heard from the experts, El Niño is starting to diminish out in the Pacific. How much longer these forecasts are valid, I don’t know.”

Another anniversary

On the Fourth of July, while celebrating the 222nd anniversary of the founding of the United States, you can remember the 246th anniversary of the single most important event in the history of studying thunderstorms. On July 4, 1752, Benjamin Franklin went out to fly a kite. During the thunderstorm he proved that lightning is a form of electricity.

But don’t try to reproduce Franklin’s kite experiment. Believe it or not, several people have died trying.