# [CMB] Need some help

1. Dec 19, 2005

### vincentm

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

2. Dec 20, 2005

### Chronos

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