See Professor Sir Michael Berry's website for more details.

Many incompletely understood phenomena lurk in the borderlands between physical theories - between classical and quantum, between rays and waves... These borderlands - the domain of physical asymptotics - are my intellectual habitat, with an emphasis on geometrical aspects of waves (especially phase) and chaos.

A source of delight is uncovering down-to-earth or dramatic and sometimes beautiful examples of abstract mathematical ideas: the arcane in the mundane. Examples are:

• mathematical singularities in rainbows and the patterns on the bottom of swimming-pools;
• a laser pointer shone through irregular bathroom-window glass, illustrating abstract aspects of wave interference;
• optics with transparent overhead-projector plastic sheets, illustrating polarization singularities, matrix degeneracies, and quantum measurement, and Anderson localization;
• a levitating spinning-top, illustrating adiabatic stability and geometric phases;
• twists and turns with a belt, illustrating the behaviour of identical particles in quantum mechanics, responsible for the impenetrability of matter, lasers, superconductivity...
• Oriental magic mirrors, directly displaying the Laplacian.
• Tsunamis, which are caustics in spacetime, and, when focused, spacetime caustics on a cusped caustic