The original description page was here. All following user names refer to en.wikipedia.
2007-12-03 13:58 User A1 580×200 (52643 bytes) [[SVG]] Illustration of the Numerical aperture for an Optic fibre. Interior of the fibre is causing coupled light to undergo Total internal reflection due to Snell's law.
2007-12-03 13:57 User A1 744×1052 (51885 bytes) Illustration of the [[Numerical aperture]] for an [[Optic fibre]]. Interior of the fibre is causing coupled light to undergo [[Total internal reflection]] due to [[Snell's law]].