Inverskvadratlagen

Inverskvadratlagen, often translated as the inverse square law, is a scientific principle that describes how certain physical quantities, such as intensity or gravitational force, decrease in proportion to the square of the distance from their source. This means that if you double the distance from a source, the quantity you are measuring will be reduced to one-fourth of its original value. If you triple the distance, it becomes one-ninth.

This law appears in various areas of physics. In electromagnetism, the intensity of light or sound radiating from a point source follows the inverse square law. Similarly, Newton's law of universal gravitation states that the gravitational force between two objects is inversely proportional to the square of the distance between their centers. The electrostatic force described by Coulomb's law also adheres to this principle.

The inverse square law is a consequence of the conservation of energy and the geometric spreading of a quantity in three-dimensional space. Imagine a sphere radiating outwards from a point. The total amount of energy passing through the surface of the sphere must be constant, regardless of the sphere's radius. As the radius increases, the surface area of the sphere increases with the square of the radius. Therefore, to maintain a constant total energy flux, the energy per unit area, or intensity, must decrease with the square of the radius.