Remembering Ernst Specker (1920--2011) (Q452476)

This is an obituary for the important mathematician Ernst Specker. It includes personal notes and articles of colleagues and friends, and a list of his publications. The contributions are written by Johann A. Makowsky, Urs Stammbach, Hans Bühlmann, Erwin Engeler, Haim Gaifman, Norbert Hungerbühler, Gerhard Jäger, Ulrich Knellwolf, Simon Kochen, Karl Lieberherr, Bruno Scarpellini, Volker Strassen, Dirk van Dalen, Jörg and Irène Waldvogel, and Stathis Zachos. Ernst Specker spent most of his life in Zürich at the ETH (Eidgenössische Technische Hochschule). He was interested not only in various mathematical subjects, e.g. set theory, combinatorics and logic (42 articles are indexed in the database zbMATH), but also in literature, history, politics and sociology. Coauthor of one of his papers was Paul Erdős. Consequently he has the Erdős-number 1. Ernst Specker's lectures were not lectures as usual. He motivated the students to ask questions and to take an active part in his lessons. In the last years of his life he preached in the protestant-reformed church. Some of his sermons were published.