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!

[CMB] Need some help

  1. Dec 19, 2005 #1
    Ok, i'm reading up on the Cosmic Microwave background radiation guys. And i'm at a part that confuses me (actually i kinda don't understand the whole thing, but i'm trying) regarding the uniformity or isotropy. If someone can put this in a simpler form so that i can understand it easier i'd highly appreciate it, thanks in advance for your help :smile:
  2. jcsd
  3. Dec 20, 2005 #2


    User Avatar
    Science Advisor
    Gold Member

    The intensity of radiation from objects within each concentric 'shell' decrease proportionate to the square of the distance [from earth], however, the average number of objects within each shell [assuming uniform density as indicated by observation] increases with respect to the cube of the distance [from earth]. Hence, the total background radiation [CMB] is dominated by contributions from distant sources. What they lack in intensity is more than made up by sheer numbers.
    Last edited: Dec 20, 2005
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: [CMB] Need some help
  1. Some CMB Clarifications (Replies: 25)

  2. Help with some Numbers (Replies: 4)

  3. CMB anisotropies (Replies: 3)