6B-2 The Electromagnetic spectrum
As shown in Figure 6-3, the electromagnetic spectrum encompasses an enormous range of wavelengths and frequencies (and thus energies). In fact, the range is so great that a logarithmic scale is required. Figure 6-3 also depicts qualitatively the major spectral regions. The divisions are based on the methods that are required to generate and detect the various kinds of radiation. Several overlaps are evident. Note that the visible portion of the spectrum to which the human eye is sensitive is tiny