background radiation


: the microwave radiation pervading the universe that exhibits a corresponding blackbody temperature of 2.7 K and that is the principal evidence supporting the big bang theory

called also cosmic background radiation

Example Sentences

Recent Examples on the Web Around this setup is a water tank that helps protect the experiment from background radiation. Robert Lea, Popular Mechanics, 29 July 2022 All qubits are fragile and susceptible to errors caused by interactions with environmental factors such as electrical noise from internal components, background radiation, other qubits, wiring, and much more. Paul Smith-goodson, Forbes, 2 June 2022 Regulatory limits on annual exposure around nuclear plants are less than a year’s background radiation from rocks and cosmic rays. Robert Hargraves, WSJ, 26 Jan. 2022 The background radiation in most of the 18-mile Exclusion Zone around the nuclear plant, after 36 years, poses scant risks and is about equivalent to a high-altitude airplane flight. New York Times, 8 Apr. 2022 The latency period for lung cancer from radiation is longer than five years and 74 mSv spread over four years is not enough dose to cause any health effects, being lower than background radiation in many many places on Earth. James Conca, Forbes, 12 Nov. 2021 Many factors contribute to errors in quantum systems, including the environment, noise from internal components, background radiation, cabling, and even noise caused by qubits themselves. Paul Smith-goodson, Forbes, 15 June 2021 The needle jumps, showing a reading 50% higher than the already elevated background radiation. Gavin Blair, The Christian Science Monitor, 26 Feb. 2021 The aircraft belong to the Energy Department’s National Nuclear Security Administration, which is testing naturally occurring background radiation levels ahead of the 2021 presidential inauguration. Gabriel T. Rubin, WSJ, 23 Oct. 2020 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'background radiation.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History

First Known Use

1968, in the meaning defined above

Time Traveler
The first known use of background radiation was in 1968

Dictionary Entries Near background radiation

Cite this Entry

“Background radiation.” Dictionary, Merriam-Webster, Accessed 29 Nov. 2022.

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