progress is not linear br everything is not br based on all known before br br quantum leaps br eureka moments br spice scientific br br discoveries br wave oscillations br sine waves br br pendulum sways br periodic motions br propagate changes br br equilibrium vibration br earth violent quakes br balances tectonic plates br br physical systems br biological systems br human societies br br civilizations empires br expand contract br rise fall cyclic changesbr br Terence George Craddock (Spectral Images and Images Of Light)br br