cosmic microwave background

noun

: background radiation

Examples of cosmic microwave background in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
And this should be reflected in the cosmic microwave background radiation. — Manon Bischoff, Scientific American, 23 May 2026 Having established that the cosmic microwave background is symmetric on large scales, variations in this relic radiation from the big bang have been found. — Subir Sarkar, Space.com, 5 Jan. 2026 There are some proposals to use loop quantum gravity to make sense of signatures in the cosmic microwave background radiation that’s left over from the Big Bang. — Zack Savitsky, Quanta Magazine, 29 Oct. 2025 And there was even an anti-Big Bang argument put forth just a few months ago that the cosmic microwave background might not be of cosmic origin, but that it might merely be reflected light emitted from galaxies. — Big Think, 12 Nov. 2025 See All Example Sentences for cosmic microwave background

Word History

First Known Use

1981, in the meaning defined above

Time Traveler
The first known use of cosmic microwave background was in 1981

Rhymes for cosmic microwave background

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Browse Nearby Words

cosmic dust
cosmic microwave background
cosmic noise
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Cite this Entry

“Cosmic microwave background.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cosmic%20microwave%20background. Accessed 7 Jul. 2026.

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