Curiosity is the quality that is inherent in the vast majority of the descendants of Adam and Eve; curiosity is the main driving force behind great scientific discoveries and outstanding cultural achievements, grandiose financial enterprises and brilliant achievements in any field of human activity. The three-volume edition brought to your attention, addressed to the curious. This is not a reference book, much less a textbook. Its main task is not so much to inform the reader about various interesting and little-known facts, but to arouse active interest in a particular area of knowledge. Its goal is to help each of you realize your talent in time and awaken the musician, artist, poet, businessman, politician, astronomer, economist in you. The book is intended not only for schoolchildren and students, but also for mature people, for whom it will become a reliable means of renouncing everyday worries and realize the inexhaustible diversity of the surrounding world. The first volume of the publication, unique in its scope, is dedicated to astronomy, astrophysics, geography, biology and medicine.