From Research in Review Magazine, Florida State University, Spring 2006:
- Almost all the lightning we see hitting the ground is in fact coming from the ground and heading for a cloud. But this is the bright “return stroke” triggered by an invisible first bolt that does emanate from a cloud, typically milliseconds beforehand.
- Most lightning is a negatively charged bolt hitting a positively charged object, either on the ground or in the air—most often another cloud. Positive lightning makes up only about 5 percent of all lightning, and is by far the most powerful and thus the most lethal and destructive.
- A leading theory suggests that lightning is initially triggered by cosmic rays striking air molecules and releasing a burst of extremely energetic electrons that set off a chain reaction with other air molecules, thereby creating a highly conductive plasma between oppositely charged objects.
- Ball lightning—described as a solid, floating ball of fire sometimes as big as a basketball that can penetrate window, doors, even walls and behave erratically—was long thought to be the stuff of local lore, but this bizarre phenomenon is in fact the rarest of all forms of lightning. Scientists still do not have a generally accepted theory that adequately explains what ball lightning is or how it works.
- More than twice as many people were killed by lightning in Florida (428) between 1959 and 2004 than in any other state. The deadliest months are May through August; the deadliest holiday is the Fourth of July; the deadliest day, Wednesday.
- “Heat lightning” is nothing more than flashes of normal lightning seen from a distance, typically at night over water.
- Sprites are a spectacular form of lightning that emanate high above thunderclouds and reach the ionosphere, 50 miles above the earth. The phenomenon was first photographed by scientists at the University of Minnesota in July 1989.
- Texas is the number-two state in lightning deaths, behind Florida; but Pennsylvania leads the nation in total lightning damage.
- A study of lightning deaths that occurred between 1959 and 1994 revealed that 84 percent of the fatalities were male. Of the known locations where the deaths occurred, five percent were on golf courses, although 27 percent happened in other open areas, particularly those near water.
- Blue jets, named for their distinctive color, are lightning flashes that jump from the tops of thunderclouds in a cone-like fashion. Brighter than sprites, jets can also reach into the lower ionosphere and were discovered in 1989 by shuttle astronauts passing over Australia.
- Lightning can’t work in a vacuum, because it needs to break down molecules of gas to work. This is why lightning doesn’t exist in space, although it is quite common on other planets, e.g. Jupiter.
- In a thousandth of a second, a bolt of lightning can reach 50,000 degrees Fahrenheit, about five times hotter than the surface of the sun, and can carry the explosive power of a 1-kiloton bomb.
- Even though trees are popular targets for lightning, they aren’t the best conductors of electricity. Because it’s such a poor conductor, the sap of a pine tree, for example, turns to explosive steam with a lightning hit, often blowing large cracks into the tree’s trunk that leave enormous, permanent scars.
- Contrary to the old saying, lightning can—and often does—strike the same place twice, even multiple times. New York’s Empire State Building gets zapped at least 100 times each year.
- Half of all deaths caused by lightning occur after a storm passes.
- The lightning capital of the world is Rwanda, Africa. Each year, the country gets nearly two-and-a-half times more lightning than Florida does annually.
- Lightning rods don’t prevent lightning strikes; they merely divert the bolts to earth, thereby preventing most damage to structures and harm to residents.