Cosmic Microwave Background
Did You Know?
The CMB is leftover radiation from 380,000 years after the Big Bang!
What is the CMB?
The Cosmic Microwave Background (CMB) is the oldest light in the universe, leftover radiation from when the universe was only 380,000 years old. At that time, the universe cooled enough for atoms to form, and light could travel freely for the first time. This 'first light' has been traveling through space for 13.8 billion years and now appears as microwave radiation filling the entire universe.
Discovery
The CMB was accidentally discovered in 1965 by Arno Penzias and Robert Wilson at Bell Labs. They detected a persistent microwave signal coming from all directions in the sky. Initially thought to be interference, they realized it was cosmic radiation predicted by the Big Bang theory. This discovery earned them the 1978 Nobel Prize in Physics and provided strong evidence for the Big Bang.
Tiny Fluctuations
The CMB is remarkably uniform, but tiny temperature variations (about 0.00001°C) reveal the seeds of cosmic structure. These fluctuations represent density variations in the early universe that grew through gravity to form galaxies, stars, and planets. The pattern of these fluctuations tells us about the universe's composition, age, and geometry.
Amazing Facts
The CMB is visible in all directions
This fact reveals the incredible scale and wonder of our universe.
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CMB temperature is 2.725 Kelvin
This fact reveals the incredible scale and wonder of our universe.
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The CMB reveals the universe's age and composition
This fact reveals the incredible scale and wonder of our universe.
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Planck satellite mapped the CMB in detail
This fact reveals the incredible scale and wonder of our universe.
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Your Next Jump
Continue your journey through the cosmos