René Barjavel (24 January 1911 – 24 November 1985) was a French author, journalist and critic who may have been the first to think of the grandfather paradox in time travel. He was born in Nyons, a town in the Drôme department in southeastern France. He is best known as a science fiction author, whose work often involved the fall of civilisation due to technocratic hubris and the madness of war, but who also favoured themes emphasising the durability of love.René Barjavel wrote several novels with these themes, such as Ravage (translated as Ashes, ashes), Le Grand Secret, La Nuit des temps (translated as The Ice People), and Une rose au paradis. His writing is poetic, dreamy and sometimes philosophical. Some of his works have their roots in an empirical and poetic questioning of the existence of God (notably La Faim du tigre). He was also interested in the environmental heritage which we leave to future generations. Whilst his works are rarely taught in French schools, his books are very popular in France.Barjavel wrote Le Voyageur imprudent (1943), the first novel to present the famous Grandfather paradox of time travel: if one goes backwards in time and kills one of their ancestors before he had children, the traveller cannot exist and therefore cannot kill the ancestor.Barjavel died in 1985 and was buried with his ancestors in Tarendol (commune) cemetery, opposite Mount Ventoux in Provence. He used these place names in his books; Mount Ventoux appears as the site of the space base in Colomb de la lune, for example, and Tarendol is the name of the hero in the eponymous novel.