# Inverse-square law

## Description

The inverse-square law, in physics, is any physical law stating that a specified physical quantity or intensity is inversely proportional to the square of the distance from the source of that physical quantity. The fundamental cause for this can be understood as geometric dilution corresponding to point-source radiation into three-dimensional space.

Mathematically it can be expressed as shown.

Related formulas## Variables

intensity_{1} | intensity of a physical quantity from source 1 (dimensionless) |

intensity_{2} | intensity of a physical quantity from source 2 (dimensionless) |

distance_{2} | distance from source 1 of that physical quantity. (dimensionless) |

distance_{1} | distance from source 1 of that physical quantity. (dimensionless) |