In this book, Professor Anatoly Buchachenko gives a brief and informative description of the most striking achievements and discoveries made in the major natural sciences at the turn of the century - in the late twentieth and early twenty-first centuries. The author has a rare ability to describe scientific discoveries so that these achievements and their significance are understandable not only by professionals and scientists of all specialities, but for any reader interested in modern science, its role in the existence of mankind, and its impact on human society. Originally published in Russian, Professor Buchachenko's book describes the interaction of natural sciences with social ones-philosophy and history-as well as the part played by the human factor in the development of science, especially the role of the great scientists.