The real gem of this article -- is its chart: https://en.wikipedia.org/wiki/File:Commutative_diagram_of_harmonic_wave_properties.svg https://en.wikipedia.org/w

The real gem of this article -- is its chart: https://en.wikipedia.org/wiki/File:Commutative_diagram_of_harmonic_wave_properties.svg https://en.wikipedia.org/wiki/File:Commutative_diagram_of_ha... And the following terms it defines: o Linear Wavenumber o Angular Wavenumber o Linear Frequency o Angular Frequency o Linear Wavelength o Angular Wavelength o Linear Period o Angular Period Also... The next time someone uses the word "Frequency", "Wavenumber", "Period" or "Wavelength" on you -- your immediate follow-up question should be: Linear or Angular? ?