The birth and death of the Sun: Stellar evolution and subatomic energy (Repost)

Preface:
How did our Sun come into being, what keeps it hot and luminous, and what will be its ultimate fate? These are questions that should be of interest to all the inhabitants of our globe, whose life and prosperity are entirely dependent upon the radiant energy coming from the Sun.
Since the beginning of scientific thought, the problem of solar energy sources has been one of the most exciting, but also one of the most difficult puzzles of nature. But only during the last decade has it become possible to tackle the problem of solar energy generation with any hope of a correct scientific solution, and thereby to answer questions concerning the past, present, and future of our Sun. It has finally been demonstrated that the tremendous amounts of energy radiated by the Sun are generated by the transformation of chemical elements taking place in its interior, precisely those "transmutations of elements" in fact, that had been so unsuccessfully pursued by medieval alchemists.
As our Sun represents only one member of the numerous family of stars scattered through the vast spaces of the universe, the answer to this solar problem necessarily involves also the question of the evolutionary history of stars, and this brings us back to the fundamental puzzle concerning the creation of the stellar universe.
In this book, the author, who has been closely connected with the progress of research on these problems, attempts to give, in the simplest terms of which he is capable, an outline of the fundamental discoveries and theories that now permit us a general view of the evolution of our world. Many of the views touched on in this work have been so recently arrived at that they have never before been discussed in popular literature.