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!

Questions regarding redshift

  1. May 31, 2008 #1
    Hey! :smile:

    I have a few questions regarding redshift. Firstly are there example of a shift in frequency of light other than the one seen in redshift or blueshift. I mean are there experiments that have been conducted that prove that this noted shift to the red end of the spectrum mean that something is moving away relative to an observer?

    Secondly, would I be correct in saying that the noted redshift now is actually, and indication of the rate of expansion quite a while back, taking into account the speed that the light takes to reach the observer. How do we know that the rate of expansion has decreased or infact it has start to contract again? There must be a way to calculate the rate of expansion now.

    Thanks for any help!

  2. jcsd
  3. May 31, 2008 #2
    Last edited by a moderator: May 3, 2017
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook