on 3/16/2002 7:27 PM, Joseph B. Reid at [EMAIL PROTECTED] wrote: > I had not noticed that 555 nm and 540 x 10^12 hertz are equivalent > statements.
That's true only for for electromagnetic waves, such as light, in vacuum. The relationship depends on the speed of the waves. Since the speed of light in vacuum is constant, any given wavelength of light (in vacuum) will always give the same corresponding frequency. The relationship is: f = c / L where I've used c for the speed of light in vacuum f for frequency (lower case Greek nu is often used instead) L for wavelength (lower case Greek lambda is more common) Naturally, to use this for numerical calculations, the quantities must be expressed in SI units, L in metres, c in metres per second, f in hertz. Thus, converting 555 nm to 555 x 10^-9 m, and substituting, the equation gives: f = (3.00 x 10^8) / (555 x 10^-9) f = (0.00541) x (10^17) Hz f = 541 x 10^12 Hz Your 540 and my 541 differ slightly, probably due to rounding off somewhere.
