Zamenhof Day 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 traced back to 17 December 1878, when at a birthday party for his 19th birthday he presented to his friends his "Lingwe uniwersala", the first version of his international language. By 1887, this language had evolved into what is now recognized as
Ludwik Leibler 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 under the direction of Pierre-Gilles de Gennes. He is a researcher in Centre National de Recherche Scientifique (CNRS) which he joined first in Stasbourg then in Paris where he worked on theoretical and