1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Quick 'n' easy question about doppler effect

  1. Dec 4, 2004 #1
    Doppler effect revisited

    Am I right when I say that the doppler effect formula "f=f0((v+vo)/(v+vs))" is derivated from the classical theorem of speed addition and this is why the doppler effect for light and EM waves is different?
    Last edited: Dec 4, 2004
  2. jcsd
  3. Dec 4, 2004 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Because light does not behave as a classical particle, it has a constant speed for all observers. It is frequency and wavelength which undergo a Doppler shift in light.
  4. Dec 4, 2004 #3
    I'm a little confused here...

    I don't get how on this page: hyperphysics they get the first equation... I don't see the relativistic doppler effect written that way anywhere and I don't understand how they get ot that equation and how to expand it with maple...Anybody can help?
  5. Dec 4, 2004 #4

    Doc Al

    User Avatar

    Staff: Mentor

    That equation is just the relativistic Doppler formula rewritten in a form convenient for deriving the low speed approximation. They took something that usually appears in a form like:
    [tex]\sqrt{\frac{1 + x}{1 - x}}[/tex]
    And rewrote it like:
    [tex]\frac{\sqrt{1 - x^2}}{1 - x}[/tex]
    These expressions are equivalent.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Quick 'n' easy question about doppler effect