1. Not finding help here? Sign up for a free 30min 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!

Another light question

  1. May 27, 2008 #1
    1. The problem statement, all variables and given/known data

    Light from distant stars is Compton scattered many times by free electronsin the outer space before reaching us.This shifts the light toward the red.How can this shift be distinguished from the Doppler red shift due to the motion of receding stars???

    2. Relevant equations
    3. The attempt at a solution

    When visible light [of colour other than red---like blue/yellow/green etc] is scattered off free electrons,the Compton shift is negligible...and what we observe is very nearly the original wavelength, somewhat reduced in intensity...

    But when the Doppler Effect is the concern,the colour (wavelength) is increased with respect to us due to relative motion.If we were flying at the same rate with the star, there would be no red-shift...In this case,light that reaches us, has long wavelength (red). Compton scattering does nothing but to change red to red itslef...So, from colour observation, we get the idea...

    Please let me know if you support this idea.
     
  2. jcsd
  3. May 28, 2008 #2
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Another light question
  1. Another wave question (Replies: 3)

Loading...