He obtained his university degrees in Electronic Engineering and in Mathematics in 1964 and 1968, respectively. In 1969 he received a Ph.D. in Cybernetics and Information Theory and in 1975 became full professor of Information Theory at the Electronic Engineering Department of the University of Trieste, where he has been teaching courses on information theory and coding, a subject that he has introduced in Italy back in the Sixties.
He has taken part in many international conferences on information theory and related topics, reading papers and chairing sessions. He has carried out teaching and research activity in several universities and other scientific institutions in Europe, United States and Asia. On these topics he has also published many articles and volumes, such as the Information Theory manual (Boringhieri, 1980).
From 1970 to 1990 he directed the Information and Automation departments at the International Centre of Mechanics Science of Udine.
He also is an associate of the Veneto Institute of Science, Literature and Arts, the Lombardy Institute of Literature and Science and the Italian Association of Electrotechnical and Electronic.
Currently his scientific interests are mainly devoted to epistemology, artificial intelligence, communication, and the social impact of technology. He is very active in giving lectures and publishing papers on such topics. He has coordinated, and contributed to, several encyclopedic works of the Istituto dell'Enciclopedia Italiana, and writes regularly for the Corriere della sera, Technology Review, Pluriverso, Avvenire, L'Occidentale, Mondo Digitale, Prometeo and other newspapers and magazines. He published several books on the cultural and anthropological consequences of the new technologies: Il nuovo Golem: come il computer cambia la nostra cultura, (Laterza, Roma-Bari, 1998), Homo Technologicus (Meltemi, Roma, 2001), Il Simbionte: prove di umanità futura (Meltemi, Roma, 2003), Bit Bang. La nascita della filosofia digitale (con A. Vaccaro, Apogeo Education, 2013).
Besides being a scientist, Longo is also a prominent writer. The magazine Open City, based in New York City, has published several of his short stories. He published tree novels: Di alcune orme sopra la neve (Campanotto 1990, Mobydick 2000), L'acrobata (Einaudi 1994, tradotto in Francia da Gallimard) and La gerarchia di Ackermann (Mobydick 1998, Jouvence 2016, translated in french from A la Croisée), eleven collections of short stories, which were translated in many languages, and two collections of dramas: Il cervello nudo (Nicolodi, 2004) and La scienza va a teatro (EUT, 2017). He also participates in the programmes of the Italian Broadcasting Company (RAI) as many of his stories were broadcasted on the radio. Recently he has devoted himself to writing texts for the radio and for the stage, which have had a good reception. He also dedicated an essay to the relationship between Science and Literature: Il senso e la narrazione (Springer 2008). Some of his essays are Il gesuita che disegnò la Cina, Vita e opere di Martino Martini (Springer 2010), Homo immortalis (con N. Bonifati, Springer 2012). He collaborates with some newspaper such as Il corriere della sera and Avvenire.
He has translated 15 books (in 1991 he was awarded the "Monselice" prize for scientific translation). In 1996 and 1997 he performed as an actor, playing the main roles in plays by Ionesco (La leçon) and Pinter (Last to Go and Troubles in the Work). In 2014 he interpreted the role of Heisenberg in his very own Farm Hall 45 staging at the Puccini Theatre in Florence.