TheoSea (for THEOry SEArch) is a Julia meta-program that discovers compact theories from data if they exist. It writes candidate theories in Julia and then validates: tossing the bad theories and keeping the good theories. Compactness is measured by a metric, such as the number of space-time derivatives. A theory can consist of more than one well-formed formula over a mathematical language. The underlying algorithm is optimal in terms of compactness, although it may be combinatorially explosive for non-compact theories. TheoSea is now working on re-discovering the source-free Maxwell equations and the wave equation of light. There are many applications.