The phrase “lightning never strikes the same place twice” is a popular idiom suggesting that a rare or unfortunate event will not happen again. Scientifically, however, the opposite is true: lightning can and frequently does strike the same location multiple times. The intense electrical discharges that occur during a thunderstorm follow predictable physical laws, meaning certain spots become preferred targets repeatedly. The location of a lightning strike is not a matter of chance, but rather a function of physics.
Dispelling the Common Idiom
The notion that lightning avoids previously struck areas is an inaccurate piece of folklore. Nature has no mechanism to remember where a previous strike occurred. In reality, any structure or geographic feature available to the storm’s electrical forces will be repeatedly chosen. The Empire State Building in New York City, for instance, experiences an average of 20 to 25 strikes annually because of its immense height and isolation. This frequent contact proves the old saying is a myth.
How Lightning Chooses Its Target
A cloud-to-ground lightning strike begins when a massive electrical charge differential builds up between the storm cloud and the earth. This process initiates with a negatively charged channel called the “stepped leader” that descends from the cloud in a series of rapid steps. The stepped leader searches for the path of least electrical resistance as it zigzags toward the ground. As the leader approaches, the ground below responds by generating a positively charged electrical spark known as an “upward streamer.” The strike occurs when the descending leader connects with an upward streamer, completing a highly conductive circuit.
Why Certain Objects Are Struck Repeatedly
The reason some objects are struck repeatedly relates directly to the path of least resistance. Taller objects, such as skyscrapers, transmission towers, or isolated trees, shorten the distance the stepped leader must travel, making them the most likely point for the upward streamer to launch. Sharp, pointed features on these structures concentrate the electric field at their tips. This concentration lowers the voltage required to initiate the upward streamer. Furthermore, objects made of or connected to highly conductive materials, such as metal frameworks, offer a low-resistance pathway for the current to discharge into the earth.
Mitigating High-Risk Locations
Engineers use the understanding of lightning’s preference for height and conductivity to protect high-risk structures. The first component is the air terminal, commonly known as a lightning rod, which is a pointed metal object placed at the highest point of a structure to intercept the strike. Once intercepted, the current is directed through highly conductive down conductors, typically made of copper or aluminum. These conductors run down the exterior of the building, bypassing the internal structure to channel the electrical energy. The system is completed by a grounding network, which uses buried metal rods or plates to dissipate the electrical charge into the earth.