The American John Griggs Thompson and the Belgian Jacques Tits will receive this year the Abel prize, the most important mathematical award of all years. His works have contributed to the development of group theory. According to this theory, any complex symmetry is a combination of basic symmetries, as any color is a combination of basic colors. And, of course, the theory sets out what these basic symmetries are. Among other things, it helps to understand the arrangement of atoms in mineral crystals.