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Identical Particles: the Platonic Ideal lives!

Plato taught something along these lines: every "real" chair is merely an "imprint" of (or an imperfect approximation to) a single "ideal" chair. Similarly for tables, glasses and certainly for the wine in the glass!

As things turned out, when it came to elementary particles Plato didn't go quite far enough. When physicists talk of " The electron..." or " The neutron..." they are not referring to one particular electron or neutron; they are expressing their (experimentally verified) belief that every electron is exactly identical to every other electron! Not just very similar, but indistinguishable even in principle. That is, every electron is a perfect "imprint" of the "ideal" electron - it is, in fact, the ideal electron! This is true of all elementary particles, and in quantum field theory reaches its ultimate expression: the number of ( e.g.) electrons in existence is just another "quantum number" of the unique and solitary "electron field." All evidence suggests that this description is "true" - i.e. it predicts what is observed, and its negation would predict things that are not observed.

Jess H. Brewer - Last modified: Mon Nov 23 13:58:11 PST 2015