Aliens are big in America. Whether they've arrived via rocket, flying saucer, or plain old teleportation, they've been invading, infiltrating, or inspiring us for decades, and they've fascinated moviegoers and television watchers for more than fifty years. About half of us believe that aliens really exist, and millions are convinced they've visited Earth. For twenty-five years, SETI has been looking for the proof, and as the program's senior astronomer, Seth Shostak explains in this engrossing book, it's entirely possible that before long conclusive evidence will be found. His informative, entertaining report offers an insider's view of what we might realistically expect to discover light-years away among the stars. Neither humanoids nor monsters, says Shostak; in fact, biological intelligence is probably just a precursor to machine beings, enormously advanced artificial sentients whose capabilities and accomplishments may have developed over billions of years and far exceed our own. As he explores what, if anything, they would tell us and what their existence would portend for humankind and the cosmos, he introduces a colorful cast of characters and provides a vivid, state-of-the-art account of the past, present, and future of our search for extraterrestrial intelligence.

This milestone extensive work combines the essentials of history – biography, chronology, political and economic background – with the observations, theories, principles, laws and equations that constitute the specifics of science. The 5800-page Encyclopedia arises from the conviction that the optimal perspective on science is through the lens of history, setting aside traditional divisions of discipline and specialty, and rising above geopolitical boundaries. Reaching from 4,200 BCE to the 21st century CE, the Encyclopedia tells (as the author himself puts it) "not only who did it and when it was done but also precisely what was done." The author, Ari Ben-Menahem, surveys 100 generations of great thinkers, offering 2070 detailed biographies of scientists, engineers, explorers and inventors, who left their mark on the history of science and technology. The span of coverage is all-encompassing: mathematics, philosophy, logic, physical and environmental sciences (including physics, chemistry, astronomy, earth and space sciences and cosmology), life sciences (biology, medicine, physiology, botany, zoology and biochemistry), associated engineering disciplines, and the social sciences (among them economics, psychology, sociology, anthropology, linguistics and more). The six-volume Encyclopedia also includes 380 articles summarizing the time-line of ideas in the leading fields of science, technology, mathematics and philosophy, plus useful tables, figures and photos, and 20 ‘Science Progress Reports’ detailing scientific setbacks. Interspersed throughout are quotations, gathered from the wit and wisdom of sages, savants and scholars throughout the ages from antiquity to modern times.