Basic Optics Discipline: Education RefractionLight travels through a vacuum at its maximum speed of about 3.0 × 108 m/s, and in a straight path. Light travels at slower speeds through different materials, such as glass or air. (A material through which light travels is called a medium, plural: media.) When traveling from one medium to another, some light will be reflected at the surface of the new medium.Tags: seeingfield of viewlight rayreflectionrefration
How Telescopes Work Discipline: Education This guide describes how telescopes work. Telescopes are the fundamental tool in observational astronomy, and understanding their capabilities and limitations is central to understanding what we can learn from them. Tags: spectraopticsseeingrefractingreflectingCCDspectrographfield of viewangular resolution
