Two alternative versions of strangeness

The concept of strangeness emerged from the low energy phenomenology before the entry of quarks in particle physics. The connection between strangeness and isospin is rather accidental and loose and we recognize later that the definition of strangeness is model-dependent. Indeed, in Gell-Mann’s triplet quark model we realize that there is a simple alternative representation of strangeness. When the concept of generations is incorporated into the quark model we find that only the second alternative version of strangeness remains meaningful, whereas the original one does no longer keep its significance.