At a lunch with Gell-Mann in 1963, Serber explained his idea, but when Gell-Mann challenged him to explain what electrical charge these hypothetical particles would have, Serber wasn’t sure. Gell-Mann started scribbling on a napkin and soon had the answer. The charges would be ⅔ or –⅓ of the charge on a proton. The answer seemed ridiculous. ‘That would be a funny quirk,’ Gell-Mann commented. Nowhere in physics had anything been observed that wasn’t a whole-number multiple of the charge on the electron or proton.
