In 1980, to explain the conditions observed in the universe, astrophysicist Alan Guth proposed cosmic inflation. The term inflation refers to the explosively rapid expansion of space-time that occurred a tiny fraction of a second after the Big Bang. In another tiny fraction of a second, inflation slowed to a more leisurely expansion that continues to this day and is accelerating.
Major Discovery: 'Smoking Gun' for Universe's Incredible Big Bang Expansion Found
The earliest radiation astronomers can detect is called the Cosmic Microwave Background, or CMB. This is radiation that was released about 380,000 years after the Big Bang.
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