Teaching at its best, with a perceptively planned book to stimulate classroom experience of lecture cum demonstration: an introductory course in the principles of physics, their discovery and their inter-relation, climaxing with a brilliant (conceptually, visually) chapter on the quantum theory. With a minimum of well-chosen words (""stillness does not mean serenity""), Mr. Wilson explores balance of forces, motion, the states (or stages) of matter, light, color, electricity, the electron and electronics, and heat; in these sections he prepares the reader for the investigation of the atom and its consequences, prepares the reader also to question ""common sense"" and the evidence of his eyes. Consider the beaver, he asks; on land, he appears to be a land creature; in water, a creature of the sea--so has light a dual nature, expressed in the photon theory of light, extended in the quantum theory of matter and energy. ""How does this work out in practice""--depicted in vividly colored illustrations increasing gradually in scale to atomic dimensions. Mr. Wilson was trained as a physicist, taught the subject, knows his trade--it's equally useful as first view or refresher.