A symposium on Turning points in solid-state, materials, and surface science (to celebrate the 75th birthday of Sir John Meurig Thomas) will be held at Fitzwilliam College, on 14 and 15 December. The Opening Lecture, entitled 4D microscopy and diffraction in space and time, will be given by Professor Ahmed Zewail, Nobel Laureate. Many other experts from around the world will also be on the programme. The symposium opening ceremony begins at 10.45 a.m. on 14 December. Registration is free. Further details can be found at http://www.jmt75.org/.