UV (UltraViolet) The portion of the electromagnetic spectrum in the frequency range of 1–30 PHz and with a wavelength of 380–10 nm. UV light has no applications in telecommunications other than to make it possible for you to enjoy the full impact of psychedelic posters from the 1960s while you are con-templating what to do next. UV is the most dangerous portion of the spectrum in causing sunburn because the energy of a photon is proportional to its frequency (e = h × f), where h is Planck’s constant (6.6 × 10-34 joule-second). See also electromagnetic spectrum, frequency, Hz, and wavelength. 74570c22.qxd 9/12/07 12:48 AM Page 517 |