By 2007, most of the major Wikipedia articles - those which covered major topics, like central scientific concepts and big historical events - had been written. Since then, new articles have tailed off alarmingly, writes Rebecca J. Rosen in The Atlantic.
It might seem impossible for an encyclopedia of everything to reach completion, but according to Wikipedia editor and historian, Richard Jenson, the subject matter represented by the Universe, all of human history and all of human thought is, in fact, more or less finite: "After an encyclopedia reaches 100,000 articles, the pool of good material shrinks. By the time one million articles are written, it must tax ingenuity to think of something new. Wikipedia passed the four-million-article mark in summer 2012.