the rate of transmission of luminous energy: expressed in lumens.
flux capacitorRead more in this article about some frequently asked questions and fun facts related to our definitions.
If you see an odd glow in the sky tonight, here’s what it’s called and its causeYou’ve heard of the northern lights? The next few days you may be able to see lights even if you aren’t that far north. The sun erupted on Sunday, spewing plasma, “a highly ionized gas containing an approximately equal number of positive ions and electrons” right in our direction. There’s no reason to freak out; solar storms are relatively common, and the most significant impact they have on …
- luminous efficacy,
- luminous efficiency,
- luminous emittance,
- luminous energy,
- luminous exitance,
- luminous flux density,
- luminous intensity,
- luminous paint,
- luminous range,
Origin of luminous flux
First recorded in 1925–30
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
a measure of the rate of flow of luminous energy, evaluated according to its ability to produce a visual sensation. For a monochromatic light it is the radiant flux multiplied by the spectral luminous efficiency of the light. It is measured in lumensSymbol: Φ v
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
[ lōō′mə-nəs ]
A measure of the radiant power of light emitted from a source without regard for the direction in which it is emitted. It is measured in lumens. See also luminous intensity.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.