3 facts
Explore the Big Bang theory, the leading scientific explanation for how our universe began. Discover its origins, evidence, and the cosmic evolution that shaped everything.
This ancient light, a relic from the Big Bang, shows incredibly uniform temperatures across the sky, with tiny fluctuations that seeded the formation of galaxies and large-scale structures.
Even in the vacuum of space, there's a faint glow of microwave radiation leftover from the Big Bang, known as the Cosmic Microwave Background (CMB). This omnipresent radiation gives the universe a baseline temperature of approximately 2.7 Kelvin, just above absolute zero, meaning it's never truly 'empty' of heat.
This "cosmic microwave background" (CMB) is the oldest light in the universe, a leftover from the Big Bang when the universe was only about 380,000 years old. It's evidence supporting the Big Bang theory.
