Source: wikibot/external-ray
= External ray
{wiki=External_ray}
An **external ray** is a concept in the field of complex dynamics, particularly in the study of Julia sets and the Mandelbrot set. It is used to describe a ray emanating from a point in the complex plane that enters or exits a fractal set. In more precise terms, external rays are typically defined in relation to a point on the boundary of a Julia set or the Mandelbrot set.