Cosmic Microwave Background
For approximately 380,000 years after the Big Bang, the universe existed in an extremely hot and dense state. During this period, photons were present but could not travel freely, as they were repeatedly scattered by free electrons. As a result, the universe was opaque and unobservable. As cosmic expansion continued, the temperature dropped, allowing electrons to combine with atomic nuclei to form neutral atoms in an event known as recombination. This process drastically reduced interactions between light and matter, enabling photons to propagate freely through space for the first time. The light released at this moment has continued traveling through the expanding universe, with its wavelength gradually stretched over billions of years. Today, this ancient radiation is observed as microwave radiation known as the cosmic microwave background. This work depicts that primordial light, emitted when the universe first became transparent and still reaching us from the distant past.
