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I have this question in mind because I read that the frequency of light depends only on the source of light.

If we consider a source of white light then it emits light of different colours also. Then is the frequency of other coloured lights like blue and red same and equal to the white light?

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closed as unclear what you're asking by Carl Witthoft, John Rennie, AccidentalFourierTransform, Peter Diehr, ACuriousMind May 6 '16 at 9:46

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • $\begingroup$ I don't understand your question. "White light" doesn't have a single frequency, while blue and red light can have only one. What are you actually trying to ask when asking whether those frequencies as "equal"? $\endgroup$ – ACuriousMind May 6 '16 at 9:46
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The other answers are not strictly true, as "whiteness" is a neurological perception. We can perceive a neutral color when the red, green, and blue retinal cones have roughly equal stimulation, but that color is only "white" when it exceeds some magnitude. Otherwise it's what we call 'gray.'

Further, in very dim conditions, only the retinal rods respond, and we perceive all input as white or gray.

And, finally, any sufficiently bright source, whether monochromatic or multispectral, appears white due to retinal overload.

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  • $\begingroup$ So is the frequency of red and blue light emitted from whire light source the same or not? $\endgroup$ – user1825567 May 5 '16 at 16:11
  • $\begingroup$ @user1825567 That question makes no sense. You need to understand that each photon has its own frequency, and that a "white light source" emits lots of different frequencies. $\endgroup$ – Carl Witthoft May 5 '16 at 19:45
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No, each color in the spectrum has a characteristic frequency. Every light source has a so called spectrum of frequencies. The relative intensity of these frequencies determines what color you see (or not). For example, the sun looks yellow because it's peak intensity is in the yellow wavelength. White light comes from a source consisting of a very broad spectrum of colors. It does not have a "frequency" of it's own. Furthermore, the observation of white light is purely the response of our brains to a stimulus. "White" is not a physical, measurable property like the frequency. If a given source has an emission spectrum with the required characteristics we call it white, but this is simply nomenclature.

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White light is made of visible photons of many colors (frequencies). Our eyes mix the different frequency and interpret it as white. Photons come in all frequencies and through evolution our eyes have evolved to register visible photons from red to violet. Blue photons are higher frequency than red photons. White light is not a photon but a mix of photons

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  • $\begingroup$ So is the frequency of red and blue light emitted from whire light source the same or not? $\endgroup$ – user1825567 May 5 '16 at 16:11
  • $\begingroup$ The frequency of red Photons is always the same no matter what the source and the frequency a blue Photons is always the same no matter what the source. Of course different shades of the color will be slightly different frequencies. $\endgroup$ – Bill Alsept May 5 '16 at 18:47

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