mu·​on | \ ˈmyü-ˌän How to pronounce muon (audio) \

Definition of muon

: an unstable lepton that is common in the cosmic radiation near the earth's surface, has a mass about 207 times the mass of the electron, and exists in negative and positive forms

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Other Words from muon

muonic \ myü-​ˈä-​nik How to pronounce muonic (audio) \ adjective

Examples of muon in a Sentence

Recent Examples on the Web

Megalodon, once the largest creature on earth, would have been a muon magnet. Jill Kiedaisch, Popular Mechanics, "Exploding Stars Might Have Brought an End to the Prehistoric Megalodon," 14 Dec. 2018 Harmless in small amounts, muons are 200 times heavier than electrons and can penetrate hundreds of feet of solid rock without interacting. Jill Kiedaisch, Popular Mechanics, "Exploding Stars Might Have Brought an End to the Prehistoric Megalodon," 14 Dec. 2018 Scientists discovered in 1912 that subatomic particles — the building blocks of matter, such as protons, electrons, muons, neutrinos, and quarks — hit the Earth every day. Brian Resnick, Vox, "10 science stories in 2018 that made us go, “Whoa, that’s awesome”," 18 Dec. 2018 After a supernova, everything on Earth would have been exposed to 20 times the normal muon load. Jill Kiedaisch, Popular Mechanics, "Exploding Stars Might Have Brought an End to the Prehistoric Megalodon," 14 Dec. 2018 Travelling at close to the speed of light, muons shower Earth from all angles. Elizabeth Gibney, Scientific American, "Muons: The Little-known Particles Helping to Probe the Impenetrable," 28 May 2018 There are three types of antineutrino just as there are three types of regular neutrino—electron, muon, and tau. Avery Thompson, Popular Mechanics, "New Experiment Hints at Why the Universe Is Made of Something Rather Than Nothing," 8 Aug. 2016 The MiniBooNE experiment shoots a beam of muon neutrinos toward a giant oil tank. Natalie Wolchover, Washington Post, "Evidence for a new fundamental particle thrills and baffles physicists," 18 June 2018 This would give an additional path by which muon neutrinos produced in the decays could oscillate into electron neutrinos, having spent a short bit of time as sterile neutrinos in between. John Timmer, Ars Technica, "Weird neutrino excess won’t go away, hints at new physics," 8 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'muon.' 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 muon

1951, in the meaning defined above

History and Etymology for muon

contraction of earlier mu-meson, from mu

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Dictionary Entries near muon



Muntz metal





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Last Updated

17 Apr 2019

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Time Traveler for muon

The first known use of muon was in 1951

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More from Merriam-Webster on muon

Rhyming Dictionary: Words that rhyme with muon Encyclopedia article about muon

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