Cosmic Microwave Background Anisotropies

COBE's DMR instrument detected the first confirmed anisotropies (temperature fluctuations) in the cosmic microwave background (George Smoot, 1992) -- the primordial density fluctuations that seeded all later large-scale structure. Real, on-topic precedent literature exists back to the 1970s-80s (earlier, less-definitive ground/balloon-based anisotropy measurement attempts), confirmed via OpenAlex noise test. Smoot shared the 2006 Nobel Prize with Mather.