Terence McKenna's Timewave Zero was a "mathematical" model which purported to track the ebb & flow of novelty in & across the history of the universe. The funny thing about this, was, that novelty ramps up exponentially in our era, & reaches an infinite "end point".... This date was December 21 2012. Which coincided with the Mayan 'End of Days' date.... & voila, a millenarian phenomenon is off & running.
A lot of people put a lot of hope & expectations into this. It was believable because it contained self-evident truths: things have been getting exponentially more advanced, novel, & weird - no doubt about it. Speculation as to what would happen at the moment of the apocalypse was the main game being played by adherents of the 2012 phenomenon.
Some believed an "ascension" would occur, where all people of the planet would have their consciousnesses elevated to enlightened levels & all war, fighting, & ignorance would melt away in an instance. Others believed an alien or spirit-based race of Beings would enter into history & help us with our failings as a species & as individuals.
....So mostly a lot of "Crystal Muncher" nonsense.
What did Terence say would happen?
He considered a new law of the universe could come into effect, as must have happened in the past. When pressed, he would explain that the Timewave predicts novel events through history... at 2012, the novelty spikes to infinite: therefore, he would say, by definition we cannot predict what will happens after this point.
So he's saying that if you had the Timewave in 1940, you could roughly predict what history was going to hold... But that predictive ability ceases in 2012 because novelty spikes to infinity.
What would be a factor in our world that would make the events of history unpredictable from then onward, and would lead to an infinite spike in novelty?
Not aliens, not spiritual ascension...
But the Internet.
1/3 of the Earth's population had access to the Internet in 2012.
This could be seen as a "critical mass" of people required for the influence & effects of the internet to be an unpredictable, hyper-novel force on the world & history.
Just think of Pepe & the effects that "Meme Magic" have had on the 2016 election.
Who could have or would have predicted that in 2011?