❓ why
Why is the cosmic microwave background everywhere in the sky?
Quick Answer
It is leftover radiation from the early universe, released about 380,000 years after the Big Bang, and it now fills all of space.
The Full Story
The cosmic microwave background, or CMB, is the afterglow of the hot early universe. About 380,000 years after the Big Bang, the universe cooled enough for atoms to form and light to travel freely, leaving behind a nearly uniform microwave glow. This radiation was first detected accidentally by Arno Penzias and Robert Wilson in 1965. Small temperature differences in the CMB later helped scientists study the universe’s age, composition, and structure.
Key Facts
1.Released about 380,000 years after the Big Bang
2.Detected in 1965 by Penzias and Wilson
3.The CMB fills all directions in space
YouTube Angle
Suggested video title for this topic:
"The universe still glows with its baby picture."
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