OPTI 200 Lecture Notes - Lecture 4: Electric Light, Incandescence, Illuminance
Document Summary
Sources of light fire: heat and light are emitted in the process of rapid oxidation of a combustable material. Flame visible light-emitting part of fire. Complete combustion - blue : incomplete combustion - yellow. Incandescence is the emission of visible light from a hot body due to its temperature. Means to (cid:1688)glow white(cid:1689), heat and light are emitted in the process, yellow color = incandescence, blue color = atomic emission. Incandescence produces a blackbody spectrum of energy. Incandescence, heat is generated ex. fire, toaster, etc. Doppler shift works for both sons wave and em waves. Output of our sun is best decreed by a planck function for t = 5800 k. Wavelength max x temperature = 3000 (micron x k degrees) The spectrum for the sun (above our atmosphere) is very close to the spectrum of a blackbody source at this temperature.