Wikipedia, which went online in January, 2001, is now the greatest compendium of human knowledge ever assembled. Yet in the last four years, it has lost 25 per cent of its traffic—more than a billion monthly visitors. Since the site recruits its editors from its audience, this dip also threatens its growth and quality. Many users have been intercepted by A.I. “It’s a cruelly ironic fate,” Julian Lucas writes. Wikipedia was the single most important training corpus in the history of artificial intelligence. Now artificial intelligence is threatening its survival. Read Lucas’s report on the future of Wikipedia: newyorker.com/books/under-re…