Others suggest that the growth is flattening naturally because articles that could be called "low-hanging fruit"—topics that clearly merit an article—have already been created and built up extensively.In November 2009, a researcher at the Rey Juan Carlos University in Madrid found that the English Wikipedia had lost 49,000 editors during the first three months of 2009; in comparison, the project lost only 4,900 editors during the same period in 2008.Nupedia was initially licensed under its own Nupedia Open Content License, but even before Wikipedia was founded, Nupedia switched to the GNU Free Documentation License at the urging of Richard Stallman.Nupedia and Wikipedia coexisted until the former's servers were taken down permanently in 2003, and its text was incorporated into Wikipedia.As a result, any article could contain inaccuracies such as errors, ideological biases, and nonsensical or irrelevant text.Due to the increasing popularity of Wikipedia, some editions, including the English version, have introduced editing restrictions in some cases.Its most popular versions are leading the slide: page-views of the English Wikipedia declined by 12 per cent, those of German version slid by 17 per cent and the Japanese version lost 9 per cent." Varma added that, "While Wikipedia's managers think that this could be due to errors in counting, other experts feel that Google's Knowledge Graphs project launched last year may be gobbling up Wikipedia users." When contacted on this matter, Clay Shirky, associate professor at New York University and fellow at Harvard's Berkman Center for Internet and Security indicated that he suspected much of the page view decline was due to Knowledge Graphs, stating, "If you can get your question answered from the search page, you don't need to click [any further]." In January 2013, the 274301 Wikipedia asteroid was named after Wikipedia; in October 2014, Wikipedia was honored with the Wikipedia Monument; and, in July 2015, Wikipedia became available as 7,473 books for 0,000.In April 2019, an etched copy of Wikipedia is now on the Moon after surviving a crash landing of Beresheet, a failed Israeli lunar lander, according to experts.
The "History" page of each article links to each revision.On January 20, 2014, Subodh Varma reporting for The Economic Times indicated that not only had Wikipedia's growth stalled, but that it "had lost nearly 10 per cent of its page views last year.There was a decline of about 2 billion between December 2012 and December 2013.It started almost entirely open—anyone could create articles, and any Wikipedia article could be edited by any reader, even those who did not have a Wikipedia account.Modifications to all articles would be published immediately.