World of quarks

The author describes how the idea of quarks as fundamental particles and constituents of protons and neutrons came to be established. One of the successes of the ideas behind the quark model has been the prediction and subsequent discovery of the omega minus particle. Observations on groups of hadrons led researchers to propose that quarks had fractional electric charges. 1/3 and 2/3 that of the electron in direct contravention of Faraday's experimental observations which had held sway for so long. Although controversial at firs, these three fractionally charged quarks (Known as up, down and strange) where shown to make up all the hadrons, or particles subject to the strong interaction when grouped together in threes. Pairs of quarks and antiquarks were shown to make up the meson family. Later studies revealed the existence of a fourth 'charm' quark and a fifth 'bottom' quark which added to understanding of high energy interactions. The search for the, as yet theoretical, sixth, or top quark continues. (author). 3 figs