Quantum physicist Etienne Klein and astrophysicist Marc Lachieze-Rey present and comment on the successive unifications that have marked the fundamental advances in physics. A good deal of modern theoretical physics is lightly and gracefully explained, rooted in a philosophical examination of the motivations that drive physicists and physics. The book is a discourse on the nature of elegance and beauty in physics, seeking to explain how and why beauty is a reliable guide in the ongoing search for Truth in physics.

Over the past few decades we have learned a great deal about the behavior of such materials as liquid crystals, emulsions and colloids, polymers, and complex molecules. These materials, called "soft matter" ("matiere fragile" in French), have neither the rigid structure and crystalline symmetry of a solid nor the uniformity and disorder of a fluid or a gas. They have unusual and fascinating properties: some change their viscosity at our beck and call; others form layers of two-dimensional liquids; some are polarized, their molecules all oriented in the same direction and turning in unison at our command; others make up the foams, bubbles, waxes, gums, and many other items we take for granted every day. De Gennes, one of the world's leading experts on these strange forms of matter, here addresses topics ranging from soft-matter physics - the formation of rubber, the nature and uses of gum arabic, the wetting and de-wetting of surfaces, and the mysterious properties of bubbles and foams - to the activities of science: the role of individual or team work, the relation of discovery to correction, and the interplay of conscience and knowledge. In the best tradition of science writing, this book teaches us about both our world and ourselves."