The polymath series is a universal reference publication that conveniently and clearly presents the main achievements of all areas of knowledge. Fascinating and accessible thematic material includes information of a high scientific level and contains a large number of tables, diagrams, photos, drawings, which greatly facilitate the assimilation of the material by schoolchildren and applicants. The books in this series are indispensable for students; in addition, they contain a huge encyclopedic material necessary for any educated person.