weak force


Definition of weak force 

: a fundamental physical force that governs interactions between hadrons and leptons (as in the emission and absorption of neutrinos) and is responsible for particle decay processes (such as beta decay) in radioactivity, that is 10-5 times the strength of the strong force, and that acts over distances smaller than those between nucleons in an atomic nucleus

called also weak interaction, weak nuclear force

— compare electromagnetism sense 2a, gravity sense 3a(2), strong force

Examples of weak force in a Sentence

Recent Examples on the Web

In universes with a weaker weak force, neutrons would decay more slowly, leading to more helium. Charles Q. Choi, Space.com, "Why Alternate Universes Might Also Host Life Around their Stars," 26 Sep. 2018 Previous research found that a universe where the weak force is entirely absent could still be habitable. Charles Q. Choi, Space.com, "Why Alternate Universes Might Also Host Life Around their Stars," 26 Sep. 2018 But some researchers have proposed a type of neutrino that doesn't interact via the weak force, leaving its only interactions to come via gravity. John Timmer, Ars Technica, "Weird neutrino excess won’t go away, hints at new physics," 8 June 2018 One class of hypothetical objects that might be dark matter do interact via the weak force, a phenomenon that also controls some sorts of radioactive decay. The Economist, "Particle physicsFundamental physics is frustrating physicists," 13 Jan. 2018

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

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First Known Use of weak force

1968, in the meaning defined above

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4 Dec 2018

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The first known use of weak force was in 1968

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More from Merriam-Webster on weak force

Britannica.com: Encyclopedia article about weak force

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