Correspondence with John Nye concerning fast and slow evolving caustics Correspondence discussing various aspects of evolving caustics in two and three dimensions. Includes correspondence with Vladimir Igorevich Arnold, discussing his research and the English translation of his 'Catastrophe theory' book. Also some later correspondence with Ian Stewart and James William Bruce discussing their research on the same topic, and drawing comparisons with Arnold's work. The file contains various manuscript notes by Nye, largely relating to papers by Arnold, and some relevant reprints with minor annotation. 1981-1987