Historical event

Cosmic Microwave Background Decoupling

Date: about 13.75 Billion Years Ago (approx. 380,000 years after Big Bang)

The universe cools enough for protons and electrons to combine into neutral hydrogen atoms, allowing photons to travel freely, creating the Cosmic Microwave Background radiation.

Tags: cosmic microwave background, cmb, recombination, decoupling, early universe, cosmology, physics, photons, big bang afterglow

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