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.

"What's old is new. 'Pope Leo XIII addressed the social question in the content of the first industrial revolution. Today, the Church offers her social teaching in response to another industrial revolution and artificial intelligence.'--Pope Leo XIV, First Address to the College of Cardinals, 2025. In 1891, as strikes paralyzed nations and socialist revolution loomed, Pope Leo XIII issued Rerum Novarum--a groundbreaking document that reshaped Catholic social thought. Confronting industrial capitalism's brutality while rejecting Marxism, Leo XIII charted a third way. 'When a man engages in remunerative labor, the impelling reason and motive of his work is to obtain property, and thereafter to hold it as his very own.' Leo XIII defended private property while demanding just wages, reasonable hours, and workers' dignity. He affirmed unions but rejected revolutionary violence. His vision inspired global labor reforms and founded modern Catholic social teaching. Published as Pope Leo XIV invokes this legacy to address AI and digital disruption, this edition features historical context, paragraph summaries, and illuminating footnotes for today's reader. Essential reading for understanding Catholic responses to economic injustice--then and now."--from the back cover.