This book deals with the sun from a physico-chemical point of view rather than a cosmic one. The first half of the book takes the reader step by step from elementary chemistry and physics, through theories of heat and energy, the atomic theory up to the subject of radioactivity and the atom-smasher. And then, in the light of this, the author shows how the seemingly inexhaustible heat and energy of the sun is due to radioactivity or nuclear reaction on a large scale within the solar body. From that, he estimates the probable age and life span of the sun. Then, given a clarification of our ""stars"", Gamow goes on to other stars, and a picture of the universe...Not an easy book to read, but, with thoughtful absorption of the text, step by step, even the amateur can read it with profit. Technical terms are clarified before assuming they are understood, and summaries at intervals, throughout, help make each point. Informal passages, flashes of humor, lighten the whole, though they do not weaken the soundness of the treatment. Definitely a book for study, both by those approaching the subject with little background, and those with some training and knowledge.