| Intro | Metre | Kilogram | kelvin | candela | mole | second | helen(joke) | Bibliography |
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The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540 × 1012 hertz and that has a radiant intensity in that direction of 1/683 watt per steradian.
Though up until recently the candela was based on the amount of light emitted by one square centimeter of glowing solidifying platinum this new definition is made to keep the old definition accurate.