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 Rajchman the first cousin of Ludwik Hirszfeld, a Polish microbiologist. Ludwik Rajchman is the father of Jan A. Rajchman, a Polish computer scientist, inventor of magnetic-core memory. Rajchman grew up in Warsaw in the difficult conditions of the Russian occupation. At an early age, he and his sister Helena became keenly aware of the social injustices in their "country" (Poland did not officially exist at the time) and were involved as teenagers in teaching young workers. As an adult, he joined the Polish socialist party (PPS) and was involved in the 1905 uprising and even arrested. After several months in prison