Flavour puzzle: physics doesn’t know why matter comes in ‘flavours’

At the smallest scales, quality often repeats itself. It makes families of subatomic particles that look identical successful astir each way. Yet erstwhile scientists measured them, they recovered these ‘copies’ didn’t enactment up neatly. Some are acold heavier than others for nary wide reason. Some alteration into 1 different astatine oddly chosen rates. While physicists tin picture these patterns with awesome precision, they don’t cognize wherefore the signifier exists astatine all.

These effects hap astatine a deeper level successful particle physics, going by the sanction ‘flavour puzzle’. It consists of respective questions. Consider the electron: it was discovered successful 1897 and recovered not to beryllium unsocial successful 1936, erstwhile scientists recovered the muon. Oddly, the muon has the aforesaid properties arsenic the electron but is 200x heavier, prompting the physicist Isidor Rabi to ask: “Who ordered that?” The meaning of this question was that the mentation of electrons told america however it behaves and interacts with different particles, but it didn’t foretell determination would beryllium different transcript of it.