How was the cosmic microwave background discovered?
Quick Answer
It was found accidentally in 1964 by Arno Penzias and Robert Wilson with a radio antenna at Bell Labs. The faint microwave glow comes from the early universe and is visible in every direction.
The Full Story
In 1964, Arno Penzias and Robert Wilson detected an unexplained background hiss in a microwave antenna in New Jersey. After ruling out equipment issues and even pigeon droppings in the antenna, they learned that the signal matched a prediction for leftover radiation from the hot early universe. The cosmic microwave background, or CMB, was first predicted by George Gamow, Ralph Alpher, and Robert Herman in the 1940s. It was later mapped in detail by COBE, WMAP, and Planck. The CMB is one of the strongest pieces of evidence for the Big Bang model.
Key Facts
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Suggested video title for this topic:
"The accidental discovery that changed cosmology forever"
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