background radiation

Cultural  

1. Low-level radiation at the surface of the Earth that comes from cosmic rays and from small amounts of radioactive materials in rocks and the atmosphere.

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Example Sentences

In the 1960s Stephen Hawking demonstrated the Big Bang in theory, while Arno Penzias and Robert Wilson had detected the background radiation that proved decisive evidence of the event.

From The Wall Street Journal • Apr. 16, 2026

Prof Krawczynski wants very thin, 0.8mm pieces of CZT for his telescopes because this helps to reduce the amount of background radiation they pick up, allowing for a clearer signal.

From BBC • Dec. 11, 2025

Researchers put detectors deep underground to shield them from cosmic rays and background radiation.

From Science Daily • Dec. 5, 2024

In recent years, the foundation has funded a new observatory in Chile’s Atacama Desert to observe microwave background radiation from the big bang, and created the Flatiron Institute, which applies computational methods to scientific research.

From Science Magazine • May 15, 2024

This is consistent with the observations of the microwave background radiation, which show that it has almost exactly the same intensity in any direction.

From "A Brief History of Time: And Other Essays" by Stephen Hawking