In pheesics, the swawlenth o a sinusoidal swaw is the spatial period o the wave—the distance ower which the swaw's shape repeats.[1]

Wavelenth o a sine swaw, λ, can be measured atween ony twa pynts wi the same phase, such as atween crests, or troughs, or correspondin zero crossins as shawn.


  1. Hecht, Eugene (1987). Optics (2nd ed.). Addison Wesley. pp. 15–16. ISBN 0-201-11609-X.