4 ms·

What?

• gradschool 16y ago
  Light, by definition, is visible. "Ultraviolet radiation" would be a preferable usage.
  • whyenot 16y ago
    Nonsense. Light, as defined by dictionary.com: 2. Physics a. Also called luminous energy, radiant energy. electromagnetic radiation to which the organs of sight react, ranging in wavelength from about 400 to 700 nm and propagated at a speed of 186,282 mi./sec (299,972 km/sec), considered variously as a wave, corpuscular, or quantum phenomenon. b. a similar form of radiant energy that does not affect the retina, as ultraviolet or infrared rays.