Cosmic Microwave Background Simulator

The cosmic microwave background is the oldest light in the universe — the afterglow of the Big Bang, released when the universe cooled enough for atoms to form, about 380,000 years after the beginning. This simulator renders the whole sky as a temperature-colored sphere, the same way missions like COBE, WMAP and Planck map it: a near-uniform 2.725 K background overlaid with tiny anisotropies from primordial density fluctuations, plus a dipole caused by our own motion through space. Adjust the anisotropy amplitude, angular scale and dipole strength to see how each shapes the map, and watch the blackbody spectrum confirm the CMB's thermal origin.