Comment by westurner

Quantum Hall effect: https://www.quantamagazine.org/inside-the-proton-the-most-co... https://news.ycombinator.com/item?id=39374020 :

> Despite this difference in complexity, an electron has a charge of -e and a proton has a charge of +e. They are exactly complementary regarding charge (if I am understanding right, I am not a smart person).

> my question is... why? why must protons and electrons be perfectly complementary regarding charge? if the proton is this insanely complex thing, by what rule does it end up equaling exactly the opposite charge of an electron? why not a charge of +1.8e, or +3e, or 0.1666e, etc? Certainly it is convenient that a proton and electron complement each other, but what makes that the case?