I checked the site you mention above, and I found a really neat section in it that is germane to a criticism of postmodern theory and its anti-scientific _epoche_ as to the character of objects:
***** Patterns and predictions
One of the successes of this model was the prediction of the omega-minus baryon and its properties: this "all-strange" baryon was clearly "missing" when a group of related baryons were laid out in a pattern, and its mass could be deduced from the masses of the other baryons within the pattern. The particle was found in due course, with the expected mass, proving, if not that quarks existed, then at least that the patterns of mesons and baryons which the quark model "explained" were real enough to be used to predict particles as-yet undiscovered.
Twenty of the currently-known baryons laid out in one of the patterns, called multiplets , which reflect their quark content and share various properties such as spin and a certain range of masses. In this case, the multiplet forms a tetrahedron or triangular pyramid.
When the quark model was put forward, only 9 of these particles were known - the particles in the "bottom triangle" containing only up, down, and strange quarks - with the omega-minus as a "missing corner" of the triangle.
The key discovery that showed that quarks themselves were real, and not "just" a convenient way to make sense of all the different hadrons, was made in the early 1970's. If a proton is struck by a high energy electron (or another proton, etc), a particle produced in the collision will sometimes "fly off" at a sharp angle to the incoming particle. If a proton behaved like a "point", or even like a solid "billiard ball", this behaviour would be expected, but there were far too many particles produced at large angles, as if there were some small, hard centre or centres within the proton which were scattering particles abruptly, provided the incoming particle energy was high enough to resolve them. (For the need to use high energy particles to probe the structure of matter, see the previous page.)
Detailed experiments and a check of "the numbers" are all consistent with the hard "centres" being the quarks. (It was especially appealing that quarks should be discovered using this technique: the nucleus of the atom was discovered in the same way, sixty years earlier.) While there are hundreds of hadrons, there seem to be only a handful of fundamental particles feeling the strong nuclear force - the quarks. *****
BTW, I'm happy to see you posting again.
Yoshie