 In his spare time, he popularized science by writing science fiction. With his brother, he started a column in a Polish magazine for young people interested in science and engineering, Młody Technik (Young Technician), in which they proposed various futuristic gadgets. In 1961 Młody Technik published Zajdel's science-fiction debut, the short story "Tau Ceti" (Polish: Tau Wieloryba). Other stories by him soon appeared in several other Polish magazines.
