The Victorian era mathematician, Augustus de Morgan wrote,
“Great fleas have little fleas upon their backs to bite ‘em,
And little fleas have lesser fleas, and so ad infinitum.”
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Note: The origin of these terms is historical. Baryon comes from the Greek word “barys” or “heavy,” while meson comes from “mesos” or “middle.” When they were discovered, baryons (of which the proton and neutron are examples) were among the heaviest of the subatomic particles, while mesons tended to have a mass in the range of 10 to 40% of the proton. In contrast, particles of the class lepton (from “leptos” or “light”) were much lighter. The familiar electron is a lepton and it has a mass of approximately 1/2000 that of the proton. However, as described in the text, these names no longer have the same physical implication as they did when they were proposed.
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