I'm the convener of the "Q Seminars", which is a group of staff, students and exstudents, who meet fortnightly over dinner, to share their enjoyment of mathematics in a relaxed and friendly environment. Each year is devoted to a special theme:  1998: Galois Theory
 1999: Probability and Measure Theory
 2000: the Riemann Hypothesis
 2001: the Fundamental Theorem of Algebra
 2002: the Continuum Hypothesis
 2003: Group Representations
 2004: Celestial Mechanics
 2005: Nonstandard Analysis
 2006: Hilbert's Nullstellensatz
 2007: Quaternions and Octonions
 2008: Integer Partitions
 2009: The Mathematics of Voting
 2010: Google PageRank and the mathematics of the internet
 2011: Combinatorics of words
 2012: Arnold’s “Dynamics, Statistics and Projective Geometry of Galois fields”
 2013:
“Elliptic tales: Curves, Counting and Number Theory”, by Ash and Gross
 2014: Random Matrices, using Terry Tao's book
 2015: Graph colouring, using Alexander Soifer's "The Mathematical Coloring Book"
 2016: "Forcing for mathematicians", by Nik Weaver
 2017: "A Singular Mathematical Promenade", by Etienne Ghys
 2018: "Mathematical Omnibus: Thirty Lectures on Classic Mathematics”, by Dmitry Fuchs and Serge Tabachnikov
 2019: "Reverse Mathematics", by John Stillwell
 2020/21: Quantum Computing. We started in early 2020 but went into a long break because of covid; we're due to reconvene in late July 2021
