Paradigm shifts, at least in the Khunian sense, tend to happen over a generational scale, which means, firstly, that they take a considerable time to become rec

Paradigm shifts, at least in the Khunian sense, tend to happen over a generational scale, which means, firstly, that they take a considerable time to become recognised as the new paradigm, and secondly, that you tend not to see too many in a lifetime.