When l is given in nanometers, K = 28,900,000. Wein's Law works for all the wavelengths of the electromagnetic continuum provided the correct constant for the units of wavelength are given. The consequences of this are that relationships worked out for one portion of the spectrum apply to the whole spectrum, and Color Temperature rises as wavelength decreases. Thus Infrared lamps are hotter than microwaves even though microwaves and Infrared have no visible color. A further consequence of this is the concept of Invisible Colors.
At this point I want to introduce the concept
of the "Visual Spectrum." which is simply the "Visible Spectrum" extended
in both directions to include both Infrared light, and Ultra Violet light.
Thus all the wavelengths that are labled as some kind of "light" will become
members of the same grouping. This of course does not make Infrared or Ultra
Violet light more visible, it merely puts all the visible and invisible colors
together into a single group.
The Visual Spectrum is the forrest we wish to
examine more closely. We also want to be able to compare this forrest with
another forrest that does not come from the electromagnetic continuum but is
very similar to the Visual Spectrum in many ways. That forrest is the
Audio Spectrum.
