The theory is it's evidence of the Big Bang.
In this thread, it's evidence that SSDD is wrong about radiation not moving from cold objects to warm objects.
Like everything is evidence for the AGW hypothesis.. Some scientists at the Bell laboratories got a Nobel Prize for discovering that this background radiation was absolutely uniform in every direction. No matter which direction one looks in space, there it was and it was exactly the same. A dead flat, constant 2.75 degree Kelvin cold. They said that the fact that it was uniform in every direction was the final nail in the creationist coffin. It was proof of the big bang.
A few years later, some superior detectors that we placed in orbit that were more sensitive than those used by the Bell laboratory scientists by orders of magnitude found that the flat background radiation wasn’t really flat at all but had some significant undulations and unevenness. It was then determined that the fact that the radiation was uneven and variable was the ultimate proof of the big bang
The big bang is fading as an acceptable hypothesis....the big bang theory requires that one believe in more miracles than the creation story.
And again, the CMB was detected via a resonant radio freqency...not actual 2.7K thermal radiation. One can measure actual CMB but one must have an instrument that detects thermal radiation and that instrument must be cooled to a temperature below 2.7K