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I cant believe im asking this

  1. Sep 11, 2009 #1
    So the speed of light C = 3x10^8 m/s right? it had me thinking, is this the speed of the visible light spectrum or any and all frequencies commute at the speed of "light"... when i think of light i think of the visible spectrum.... maybe speed of light should be called speed of frequecies??
  2. jcsd
  3. Sep 11, 2009 #2
    Speed of light in vacuum is the same for all frequencies, from visible light, infrared such as used in remote controls, from microwaves in your oven, radio waves of your favorite station, ELF (extremely low frequencies) don't use those unless you have an electric tooth brush. In the upper range we have UV (ultra violet) that tans you, x-rays that outline your bones, and gamma that would kill you if exposed too long.

    Speed of light is constant, the only parameters that vary is the frequency and wavelength as given by the relationship:

    [tex] f = \frac{c}{\lambda} [/tex]
    Last edited: Sep 11, 2009
  4. Sep 11, 2009 #3


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    Maybe it could be called the Speed of Electromagnetic Radiation since light really only refers to one portion of the Electromagnetic Spectrum.
  5. Sep 14, 2009 #4


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    As waht so correctly described above, the speed applies to every frequency. You are correct that it could be called "speed of electromagnetic radiation", but saying "speed of light" is ubiquitous. You may just get used to the term "The Big Bang", knowing that it was coined as a derogotory criticism, but it has stayed with us anyway.
    Last edited: Sep 14, 2009
  6. Sep 14, 2009 #5


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    Yes, it probably can't be changed now, but if a new unit of Speed of Electromagnetic Radiation was introduced, there would be enormous prestige available for someone it was named after. What an awesome unit that would be.
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