Zamenhof Day (but not the international English one), bore a special version of their logo (a Doodle) emblazoned with the Esperanto flag in honor of the occasion, which generated, on the 30 biggest Wikipedia languages, 1,750,000 page views on the articles "L. L. Zamenhof". Zamenhof Day Zamenhof Day (), also called Esperanto Book Day, is celebrated on 15 December, the birthday of Esperanto creator L. L. Zamenhof. It is the most widely celebrated day in Esperanto culture. On this day, Esperantists hold information sessions and cultural gatherings to promote literature in Esperanto. The history of celebrating Esperanto on Zamenhof's birthday can be
Ludwik Fleck Ludwik Fleck Ludwik Fleck (11 July 1896 – 5 June 1961) was a Polish and Israeli physician and biologist who did important work in epidemic typhus in Lwów, Poland, with Rudolf Weigl and in the 1930s developed the concepts of the ""Denkstil"" ("thought style") and the ""Denkkollektiv"" ("thought collective"). The concept of the "thought collective" defined by him is important in the philosophy of science and in logology (the "science of science"), helping to explain how scientific ideas change over time, much as in Thomas Kuhn's later notion of the "paradigm shift" and in Michel Foucault's concept of the "episteme".