In the seventeenth century, great physicists and mathematicians like Descartes and Newton made the first real progress in understanding the interplay of matter and force, and in the description of the motions due to this. It must have been a marvellous epoch: for the first time, the workings of Nature on a grand range of scales were encompassed by theories that actually predicted things correctly. Since then, four forces have been discovered, and at present we are in the middle of another monumental advance: for the first time, there is a real prospect of a theory that explains all forces on the basis of one mechanism. We live in a marvellous epoch, and if you miss out on this revolution, you deprive yourself of a big piece of the action in the twentieth century. That is why I wrote this book: to instruct myself and to share with you the delight of this wonderfully intricate and powerful view of Nature.

This book is about experiences in the world that you and I live in, but the action takes place in an extremely special corner, which is not the one of our daily life. Thus, in reading what I have to say, your belief will be put to a severe test. What are you going to accept of all the extraordinary explanations that lie here before you?