Tom Rathz said:
I have been trying to understand some of the basic differences in the fundamental nature of leptons and quarks. One article on this issue compares leptons and quarks as "oranges vs apples" to which I basically agree except for one aspect. How can the charges of the quarks be 1/3 or 2/3 the "exact" value of the electron if the leptons and quarks are supposed to be so fundamentally different?? I don't think this is serendipity working.
I would not favor the oranges and apples analogy for leptons and quarks. An analogy more like screws, bolts, nuts and washers that come in three sizes each, or maybe different kinds of legos, might be more apt. Heck, even Pokemon types would be a better analogy.
Fundamental particles are subtly different interchangeable parts that can be transmuted into other kinds of interchangeable parts in the right interactions. All fundamental fermions have the same spin and propagate in essentially the same way, except for color charge, electrical charge and mass and behave in a very particular way with W bosons. The three generations of four fundamental fermions each are identical exception for the fact that they have normal hierarchy masses (with an increasingly improbable exception given experimental data of an inverted neutrino mass hierarchy) and different W boson transformations.
The nature of fundamental quantum physics is that lots of quantities come in discrete rather than continuous increments, Plank's constant, for example, measures that granularity.
The 1/3 and 2/3 increments, recall, are just reverse engineered from the fact that all hadrons have integer electric charges just as all leptons do. Three color charges (which are only stable if you have one of each or a color and an anticolor of the same type in a hadron, of both) and electric charges of +/- 1/3 and +/- 2/3 is the most parsimonious way to get there and happen to work.
Some of the intuitive ways to get a system of fermions and/or fundamental particles like this are preons (more fundamental subparts) or strings (where different twists or standing waves translate into fundamental particles of a single indivisible kind of fundamental particle) or different kinds of field excitations (resonnances) in a quantum field theory. It has also long been noted that various Lie groups/Lie algebras correspond rather neatly to the Standard Model particle spectrum, but this was mostly an after the fact realization rather than a predictive tool.
The trouble is that anything that explains the Standard Model particle spectrum and the properties of its "fundamental" particles is beyond our power to observe apart from the Standard Model that we observe. We haven't found the tool that allows us to look under the hood of this part of the Standard Model yet. At a minimum there is a big "desert" of new phenomena between the Standard Model particle electroweak scale and the next deeper "under the hood" energy scale at which phenomena revealing the nature of the mechanism behind this might be revealed.
To some extent, all possible combinations of a set of discrete properties are realized in fundamental particles with the notable exceptions of electrically neutral quarks, and particles with rest mass that do not interact via the weak force. The patterns hiding in the constants of the Standard Model are another set of clues. Those omissions and those constants are pretty much the best clues that we have to what is going on at a deeper level, and alas, they aren't a complete enough set of clues to solve the mystery.
