Electricity is a strange phenomenon. Since Benjamin Franklin’s time, we have learned a great amount about it.

Lightning results from electrical charge buildup due to friction between ascending and descending ice crystals in a cumulonimbus thunderhead.

Air is an excellent insulator and holds the charges separated like a giant capacitor until the stored charges become too great and the insulating air breaks down.

Lightning is an electrical fluid composed of electrons that flows between the ground and clouds, from cloud to cloud, or within a single cloud.

Although rare in Hawaii, lightning is common globally. On average lightning occurs about 100 times per second somewhere on Earth.

Lightning strikes account for a large number of forest fires, but strikes on humans are rare. Lightning kills only about 10 percent of people struck, leaving 90 percent with various degrees of disability. From 2006 to 2015, the U.S. averaged 31 lightning fatalities, which makes your chance of being struck by lightning in a given year in the U.S. about one in a million — in an 80-year lifetime about 1 in 13,000.

There have been no deaths recorded in Hawaii since 1959, but the National Lightning Detection Network does not keep track of lightning ground strikes for Alaska and Hawaii.

The effects of a lightning strike are impossible to predict. On one hand, lightning kills a man walking his dog with a leash while the dog is unaffected. On the other hand, a single ground strike kills 323 caribou in Norway.

A single lightning bolt can have 100 million to 1 billion volts of electron energy. Most current measurements have been in the range of 5,000 to 20,000 amps, but a lightning bolt may carry as much as 300,000 amps.

To get a sense of the magnitude, one ampere of current represents a flow of 6.2 billion billion electrons per second per ampere. Household circuit breakers limit current to 20 amps.

Power is voltage times current, and thus a typical bolt of lightning lasting 0.2 second releases about 350 kilowatt-hours of energy.

In the future, capturing the electrical energy stored in clouds could provide a significant boost to renewable alternatives. Researchers are working on exactly that idea.

Voltage and current both affect the way lightning equalizes electric charge. Voltage is the energy per electron and current is the number of electrons. The electron is the smallest unit of negative electric charge. It is very small indeed. Thought to be a fundamental particle consisting of no smaller particles, it has no measurable size.

In some cases, the flow of electrons in a lightning bolt is limited to a thin conductor such as an umbrella, a tree or a person to get to the ground. In others, if the current is high, the lightning can strike the ground. In this case, electrons flow like a liquid and spread out over the surface as the current dissipates while the ground sucks up the excess electrons.

When lightning strikes the earth, electrons fan out from the strike center in a tendril pattern. The lightning can be fatal up to 100 feet away from the point of strike.

This is probably the explanation for the recent caribou deaths. The animals huddle during rainstorms for protection and warmth.