Spectrum
Around light and other eletromagnetics: Some_physics_related_to_everyday_life#EM_spectrum
Around sound: Sound_physics_and_some_human_psychoacoustics#Frequency,_wavelength
Around light and other eletromagnetics: Some_physics_related_to_everyday_life#EM_spectrum
Around sound: Sound_physics_and_some_human_psychoacoustics#Frequency,_wavelength