We'd like to use analytics cookies to understand which symbols people look up, so we know what to research next. They are not used for advertising and we set none of them unless you say yes. What we store.
A theta with a c subscript, beyond which light cannot escape.
Also known as: Critical angle, Total internal reflection angle, Theta c
Past the critical angle light striking a boundary from the denser side is entirely reflected back — total internal reflection. It only exists going from a higher index to a lower one, which is the condition optical fibres and prismatic binoculars are built around.
Denotes the angle of incidence beyond which total internal reflection occurs at a boundary.
Contexts: Laboratory
Exists only for light passing from a denser to a less dense medium; there is no critical angle in the other direction.
Contexts: Laboratory
Is what confines light inside an optical fibre and what makes a prism in binoculars reflect without a mirror coating.
Contexts: Laboratory
A Greek lowercase theta — an oval crossed by a horizontal stroke — with a small lowercase c set below and to the right.