Recombination Era

The Recombination Era occurred about 380,000 years after the Big Bang when the universe cooled enough for protons and electrons to combine and form hydrogen atoms. Before this, the universe was a hot, dense plasma opaque to light. Once atoms formed, it became transparent, allowing photons to travel freely. This event released the Cosmic Microwave Background radiation, which we can observe today. The Recombination Era marked the transition from an opaque, ionized universe to a transparent, neutral one, enabling the formation of stars and galaxies in subsequent cosmic history.