Permittivity of free space

Permittivity of free space, often called "epsilon-zero," is a fundamental constant that measures how easily an electric field can establish itself in a vacuum. It essentially describes the ability of empty space to permit electric forces to exist and influence charges. Higher permittivity means electric fields can develop more easily, while lower permittivity means they are more difficult to form. This constant is key in understanding how electromagnetic waves, like light and radio signals, propagate through the vacuum of space or air and forms a basis for many equations in electromagnetism.