What is the relationship between light intensity and distance?

The relationship between light intensity and distance from a light source is accurately described by the principle that light intensity decreases with the square of the distance from the source. This is known as the Inverse Square Law, which states that as you move away from a point light source, the intensity of the light decreases as the distance squared.

For example, if you double the distance from the light source, the light intensity becomes one-fourth of what it was at the original distance. This happens because light spreads out uniformly in all directions, so the same amount of light energy is distributed over a larger area as distance increases.

Understanding this relationship is crucial in fields like astronomy, photography, and physics, as it affects how we perceive brightness and how light behaves in different environments. This principle is foundational in optics and provides insights into many practical applications involving light.