I need a word or phrase, and I just can't seem to find the right one ... for when several "trends" converge - after which, everything changes and you cannot go backwards.
This is sort of like, for instance, if an asteroid, meteor, comet and planet were moving along their paths, behaving like an asteroid, meteor, comet and planet - and then somehow collided to form something new - say a white dwarf, or black hole ... that has a completely differet form and behavior. (Don't take me literally about collisions - and especially don't look for scientific accuracy in my example.)
Essentially I am trying to describe where several separate trends/concepts are progressing/advancing, to the point where they converge, and a totally new concept is formed - that isn't merely the sum of the parts. Synergy is not quite the word, because it still implies separate entities working together in unison.
Any suggestions? It doesn't have to be a single word. A phrase (for instance "Tipping Point") is just fine. The fate of my last chapter is in your hands. Thanks!