Optical depth facts for kids
Optical depth is a measure of transparency. It is defined as the fraction of radiation (or light) that is scattered or absorbed on a path. One way of visualizing optical depth is to think of a fog. The fog between a person and an object that is immediately in front of them has an optical depth of zero. As the object moves away, the optical depth increases until it reaches a large value and the object is no longer visible.
Optical depth Facts for Kids. Kiddle Encyclopedia.