The wmap image, how can it be accurate?

[epsilonbeta]

I don't portent to really know what i am talking about, and I expect the answer to be obvious like there's not enough matter to distort the image enough so that the image on the scale that we are looking at could be that inaccurate.

 

but that is my question, so how can we know that the differences in temperature in the W map image are not just the by-product of gravitational distortion rather than actual differences in temperature.

 

I know the physics back up the finding of the Wmap image but its just a question, and i know a lot of people a lot smarter than my self have already discarded that as a possibility probably for the reason i stated at the top.

 

thank to any one who can explain this to me in 500 words or less pleas