My intention in this book is to describe in simple language, using a minimum of mathematics but a maximum of numerical values, the most important developments of science dealing with matter and energy on cosmic and global scales. In the conventional literature all of these findings are distributed among books and journals on physics, astronomy, chemistry, geology, biology, energy, engineering, and the environmental sciences. The main purpose here is to attempt to give a unified description of Nature from the elementary particles to the Universe as a whole. This is used as a basis for analysing the future development of mankind. The future evolution of the Universe, galaxies, stars, and planets gives some hope for the destiny of mankind. The problem of matter and energy flow on the Earth appears soluble even for the distant future. There seems to be no reason why a long period of human development on this planet should not be possible. The book has been prepared based on my lectures at the Warsaw University from 1959 to 1968 and during the 15 years 1969-1983 at the Swiss Federal Institute of Technology (Eidgenossische Technische Hochschule) in Zurich and at the University of Zurich. I wish to give my sincere thanks to the Swiss Federal Institute for Reactor Research at Wurenlingen for their constant support. I am especially grateful to Mrs. Christine Stratton for setting up the English text and to Mr. R.W. Stratton and LG. McKinley for their helpful criticisms and remarks.