Measuring White Light
can white light be measured in wavelengths? Or is this the
wrong type of question for this site?
White light is a mixture of light of wavelengths between 400 and 800 nm. So
it can certainly be reported as the distribution of the number of photons at
each wavelength (this will usually be a smooth curve). But no single
wavelength will characterize or specify white light.
Richard E. Barrans Jr., Ph.D
PG Research Foundation, Darien, Illinois
White light contains many different wavelengths, all around .5 micron.
"White" light is a mixture of all colors of light. As such it does not have a
wavelength. You can separate the white light into its component colors and
each color would have a wavelength associated with it.
Asking for the wavelength of white light is like asking for the height of a
forest. The forest has trees of many different heights. To assign a single
number to the height requires selecting a single tree and measuring it. But
that doesn't really tell you much about the forest overall.
white light can be separated by a prism into a whole rainbow of different
wavelengths. So its really a mixture of lots single colors. So white light
could be said to have a RANGE of wavelengths, say from 0.4 microns to 0.7
microns. And of course in the end, these are just the wavelengths of light
that a human eye is sensitive to.
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Update: June 2012