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 Leibler Engineering, recipient of CNRS Silver Medal, France IBM Prize in Material Science, the Polymer Physics prize of the American Physical Society (2006) and the Polymer Chemistry Award of the American Chemical Society (2007). Ludwik Leibler Ludwik Leibler, born in 1952 is a Polish physicist. He is Professor of École supérieure de physique et de chimie industrielles de la ville de Paris (ESPCI ParisTech) and member of the National Academy of Engineering. Ludwik Leibler received his PhD in 1976 in Theoretical Physics from Warsaw University, and then spent two years as a post-doctoral fellow at the Collège de France in Paris