(See also: The Newton)
Going from the theory that every action has an equal and greater reaction, The Apocalypse occurs as a result of a human male ejaculating at the exact same time that he releases a dump into the toilet.
But at the exact same time that this is occuring the man must punish himself so relentlessly that he begins to bleed, cry, and sweat as well as making himself vomit, burp, cough, sneeze along with every other form of bodily fluid coming forth from the bowels of his body.
All of this being done at the precise and exact same time, will certainly cause the destruction of Pluto, eventually causing the end of the world.
"Hey man, I don't feel like the world should be around anymore, I'll be in the bathroom attempting to Apocalypse."