The idea that light attracts lightning is a common misconception that persists during thunderstorms. The simple, scientific answer is no: visible or artificial light does not attract lightning. Lightning is a massive, rapid discharge of static electricity that occurs between two electrically charged regions, typically a thundercloud and the ground. This natural phenomenon is driven entirely by electrical forces.
Light’s Relationship to Electrical Discharge
Light and lightning differ fundamentally in their physical nature. Light is electromagnetic radiation composed of photons that carry no electrical charge. These photons cannot influence the massive electrical field that develops between a storm cloud and the Earth’s surface. Lightning, conversely, is a flow of electrical current, specifically a surge of electrons through a channel of superheated, ionized air known as plasma.
For lightning to strike, it must find the path of least electrical resistance through the air. Light does not alter the electrical resistance or conductivity of the surrounding air in any meaningful way. Therefore, a lit-up city or an outdoor light fixture is not at increased risk simply because of the illumination. The electrical properties of the environment are the only factors that matter to the traveling current.
The Actual Process of a Lightning Strike
The mechanism of a lightning strike begins with the separation of electrical charges within a cumulonimbus cloud. Collisions between ice crystals and softer ice pellets, called graupel, cause positive ice crystals to rise while heavier, negative graupel collects in the cloud’s lower region. This charge imbalance creates an enormous electric field that the air must eventually break through.
To bridge the gap to the ground, the cloud initiates a faint channel of negative charge called the stepped leader. This leader propagates downward in discrete steps, pausing briefly to test the electrical resistance of the air ahead. The stepped leader’s search for the easiest route gives the lightning bolt its familiar jagged path.
As the negative stepped leader nears the ground, the strong electric field causes positive charges on the ground to surge upward from objects. These upward surges are called positive streamers, launching from any grounded object in the area. The strike is completed when a downward stepped leader branch connects with an ascending positive streamer, typically between 30 and 100 meters above the surface. This connection completes the circuit, allowing a massive surge of current to rush back toward the cloud. This intense, rapid upward surge of energy is perceived as the bright flash of the return stroke.
Physical Factors That Influence Strike Location
Instead of light, three specific physical factors determine where a lightning strike will terminate.
Height
The height of an object is the primary factor, as a taller structure reduces the distance the downward stepped leader must travel to make a connection. This is why objects like trees, skyscrapers, and broadcast antennas are frequent targets.
Conductivity
The second factor is an object’s electrical conductivity. Materials that conduct electricity well, such as metal or wet surfaces, provide an easier path for the electrical current.
Shape and Sharpness
The shape and sharpness of an object also play a significant role in determining the strike point. Pointed structures, like the tips of lightning rods, concentrate the electric field around them. This concentration makes it easier for the positive streamer to launch upward and intercept the descending stepped leader. These electrical and physical properties, not light, determine a lightning strike’s path.