This book aims to prove that the so-called "energy crisis" is really an entropy crisis. Since energy is conserved, it is clear that a different concept is necessary to discuss meaningfully the problems posed by energy supplies and environmental protection. This book makes this concept, entropy, accessible to a broad, nonspecialized audience.Examples taken from daily experiences are used to introduce the concept of entropy in an intuitive manner, before it is defined in a more formal way. It is shown that the entropy increase due to irreversible transformations (or "unrecoverable" energy) simul