The plan selected for this book is that of a trilogy dealing first with things our size, secondly with things muchsmaller, and finally with things much larger than ourselves.In the first part the reader will find a discussion of phenomena that are more or less familiar to him from hiseveryday experience: the motion of the pendulum in agrandfather's clock, the boiling of water in a teakettle,rainbows in the sky, the electric current in a telephonewire, etc. This is the field of so-called "classical physics,"which is not very exciting and challenging for our imagination but is absolutely necessary for an understanding ofthe events that take place in the physical world to whichwe belong.In the second part, the reader will be taken into thewonderful world of modern physics and chemistry. Down will he gothrough the crowds of molecules that restlessly rush about without anyorder in gases and that form most unusual architectural structures incrystals. He will meet the atoms and learn how they stick together tomake different chemical substances, from such simple ones as table saltto such complex, and still to a large extent mysterious, ones as proteins.He will enter the interior structure of the atom with its swarms of unrulyelectrons, and finally the atomic nucleus itself. He will become acquaintedwith newly discovered particles with such strange names as "muons,""pious." and "hvperons," some of which may well be the ultimate building blocks of matter.Leaving this microcosmic world, the reader will now be taken intothe world of things that are much larger than himself. He will see theinterior structure of our globe, the depths of the ocean, and the outerfringes of the atmosphere. He will get acquainted with the planets ofthe solar system, the sun, the stars, and the giant stellar systems knownas galaxies. And at the end he will learn about the history of the universe,about the origin of the earth, stars, and galaxies, and also about theorigin of the tiny atoms of the various chemical elements of which ouruniverse is made.