45223wc@mtuxo.UUCP (w.cambre) (11/06/85)
How many photons are there in one candlepower? - Bill Cambre P.S.: I'm just too busy to count them today.
levy@ttrdc.UUCP (Daniel R. Levy) (11/10/85)
In article <1095@mtuxo.UUCP>, 45223wc@mtuxo.UUCP (w.cambre) writes: >How many photons are there in one candlepower? > - Bill Cambre >P.S.: I'm just too busy to count them today. Is this a hoax?? I thought candlePOWER was an expression of a RATE of energy (luminous energy put out by a light source) while photons were little packets of energy. It would be possible to express candlepower in photons per unit time, but not in photons alone. And this would depend on the wavelength(s) in the light. -- ------------------------------- Disclaimer: The views contained herein are | dan levy | yvel nad | my own and are not at all those of my em- | an engihacker @ | ployer or the administrator of any computer | at&t computer systems division | upon which I may hack. | skokie, illinois | -------------------------------- Path: ..!ihnp4!ttrdc!levy
carl@aoa.UUCP (Carl Witthoft) (11/21/85)
In article <567@ttrdc.UUCP> levy@ttrdc.UUCP (Daniel R. Levy) writes: >In article <1095@mtuxo.UUCP>, 45223wc@mtuxo.UUCP (w.cambre) writes: >>How many photons are there in one candlepower? >Is this a hoax?? I thought candlePOWER was an expression of a RATE of energy Come on , guys. the definition of candlepower, or candelas these days is easily available in CRC books or any reference text on optics. PHOTON is a quantum of energy (ignoring all the wave-particle duality stuff) with a defined wavelength, momentum, etc. CANDLEPOWER is all the power in all wavelengths emitted (in all directions) by a standard source . This source was a candle long ago, but is now a black body at the solidification point (I think) of Platinum. If W.Cambre was really asking how to convert candela to photons, the answer is "it depends." That is, one needs to know what wavelength is involved, and then play nasty games with integrals over blackbody curves. And dont forget lumens to nits/stilb conversions...( :==>) Darwin's Dad ( Carl Witthoft @ Adaptive Optics Associates) {decvax,linus,ihnp4,ima,wjh12,wanginst}!bbncca!aoa!carl 54 CambridgePark Drive, Cambridge,MA 02140 617-864-0201x356 "Selmer MarkVI, Otto Link 5*, and VanDoren Java Cut."