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Re: speed of light of different colours

what you write is the (and your) common experience. However, it isn't always so, and then is called anomalous dispersion (a misnomer carried over from the 19 cent.). Its classical explanation is the medium is a damped oscillator (or series
thereof) driven by the light. The index value is the result of the direct and reradiated waves phases as determined by the difference in the incident frequency and the frequency of the oscillator. At frequencies greater than the oscillator's the
disperssive behavior is opposite to the common experience. (The index may even be less than one!) Numerous texts discuss this. e.g. Jenkins & White Ch. 23; Hecht & Zajac Ch. 3.3+.

bc

P.s. The "correct" QM explanation results in the same dispesion equation, but with a different interpretaion of the terms.


julie wrote:

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Dear all,
why is the speed of light for red bigger that , say, blue, when both are in an optcally denser medium? I know the refractive indices for both of them are different, and wavelengths are also different, but what actually causes the "difference" ?

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<DIV><FONT face=Arial size=2>Dear all,</FONT></DIV>
<DIV><FONT face=Arial size=2>why is the speed of light for red bigger that ,
say, blue, when both are&nbsp;in an optcally denser medium? I know the
refractive indices for both of them are different, and wavelengths are also
different, but what actually causes the "difference"
?</FONT></DIV></BODY></HTML>

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