So Terrence McKenna was a botanist and pop-philospher who dropped a lot of acid, so the "theory" is more a loose collection of ideas. Think :jesse-wtf: posting, but it's the 70's and the vibes are right.

So basically it posits history comes in cycles of novelty. New ideas, new memes, new structures and power dynamics, that will eventually stagnate out until the next cycle. But these cycles are getting shorter and shorter as time goes on, so time isn't a flat circle, it's an inward spiral.

The zero-point is when the spiral winds so tight there is no longer a distinction. The cultural singularity. A point of infinite novelty that goes nowhere at all.

He predicted it would hit in 2012.