cosmic microwave background

Cultural  

1. The microwave radiation that arrives at the Earth from every direction in space. The detection of this radiation played an important role in acceptance of the Big Bang theory.

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This radiation is sometimes referred to as the “echo” of the Big Bang.

Example Sentences

They used measurements of the cosmic microwave background to estimate how matter was distributed shortly after the Big Bang.

From Science Daily • Mar. 6, 2026

They’ve measured the cosmic microwave background, or leftover radiation from the Big Bang, with extremely high precision to help paint a picture of the first nanoseconds of the universe.

From Salon • Jan. 17, 2025

Or it could be a relic of the Big Bang, akin to the cosmic microwave background, which led to fundamental discoveries about the structure of the universe to within 400,000 years of its beginning.

From New York Times • Jun. 28, 2023

The light from this epoch, now stretched to microwave wavelengths because of the universe’s subsequent expansion, is detectable as the all-pervading cosmic microwave background.

From Scientific American • Apr. 18, 2022

Another strong indication of the big-bang is cosmic microwave background radiation.

From Textbooks • Jan. 1, 2017