Hey guys, I have a question which I've been researching for a while and just can't find much on. The WMAP measures the CMB from the farthest regions of space. It has provided a map of the early universe. Scientists did some work on this and found that the universe is flat to within a 2% margin of error. My question is, HOW in the world did they figure this? What did they do, how did they do to prove the universe is near flat? What measurements did they take? Thanks in advance.