How our view of "fundamental" has evolved over time

"In antiquity, many opined about "the elements" in combination. Around 2500 years ago, Leucippus and Democritus founded the idea of atoms. Perhaps everything, they opined, was composed of indivisible building blocks. In the late 1700s, hydrogen and oxygen were discovered. Circa 1804, John Dalton revived atomism to explain chemical behavior. Then in 1869, Mendeleev developed the periodic table: organizing the atoms."

"But radiaoctive decays, identified by Bequerel in 1896, suggested atoms weren't indivisible. Shortly thereafter, the electron (1897) and the atomic nucleus (1911) were discovered. The proton was isolated in 1920, followed by the neutron in 1932. With " fundamental " protons, neutrons, and electrons, normal atom-based matter made sense. But other particles soon emerged, whether wanted or desired. Pauli's neutrino, proposed in 1930, was detected in 1956. Antimatter - specifically the positron (anti-electron) - was proposed by Dirac in 1929 and discovered in 1932."

"Muons were unexpectedly found in cosmic ray data in 1936. Later particle physics experiments produced mesons, baryons, and antibaryons: composite particles. This led to our modern Standard Model: quarks, leptons, bosons, and antimatter. Dark matter's, dark energy's, and gravitation's underlying elementary structure remains unknown. The ongoing quest for reality's full, fundamental nature continues. Mostly Mute Monday tells a scientific story in images, visuals, and no more than 200 words."

Ancient thinkers proposed combinations of classical elements as the basis of matter. Around 2500 years ago, Leucippus and Democritus introduced atomism, positing indivisible building blocks. Late 18th-century chemistry identified elements like hydrogen and oxygen, and John Dalton revived atomism to explain chemical behavior. Mendeleev organized known elements into the periodic table in 1869. Discoveries of radioactive decay, the electron, and the atomic nucleus revealed atomic substructure, followed by identification of the proton and neutron. Subsequent particle discoveries — neutrinos, positrons, muons, mesons, baryons — culminated in the Standard Model of quarks, leptons, and bosons. The natures of dark matter, dark energy, and gravity remain unresolved.

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