In April 2010, fifty years to the month after the first experiment in the Search for Extraterrestrial Intelligence (SETI), scholars from a range of disciplines—including astronomy, mathematics, anthropology, history, and cognitive science—gathered at NASA's biennial Astrobiology Science Conference (AbSciCon) for a series of sessions on the search for intelligent life. This book highlights the most recent developments in SETI discussed at that conference, emphasizing the ways that SETI has grown since its inception. The volume covers three broad themes: First, leading researchers examine the latest developments in observational SETI programs, as well as innovative proposals for new search strategies and novel approaches to signal processing. Second, both proponents and opponents of "Active SETI" debate whether humankind should be transmitting intentional signals to other possible civilizations, rather than only listening. Third, constructive proposals for interstellar messages are juxtaposed with critiques that ask whether any meaningful exchange is possible with an independently evolved civilization, given the constraints of contact at interstellar distances, where a round-trip exchange could take centuries or millennia. As we reflect on a half-century of SETI research, we are reminded of the expansion of search programs made possible by technological and conceptual advances. In this spirit of ongoing exploration, the contributors to this book advocate a diverse range of approaches to make SETI increasingly more powerful and effective, as we embark on the next half-century of searching for intelligence beyond Earth.

It is statistically unlikely that humans are the only intelligent species in the universe. Nothing about the others will be known until contact is made beyond a radio signal from space that merely tells us they existed when it was sent. That contact may occur tomorrow, in a hundred years, or never. If it does it will be a high-risk scenario for humanity. It may be peaceful or hostile. Relying on alien altruism and benign intentions is wishful thinking. We need to begin identifying as a planetary species, and develop a global consensus on how to respond in either scenario.

What will happen if (perhaps when) humanity makes contact with another civilisation on a different planet? In 1974 a message was beamed towards the stars by the giant Arecibo telescope in Puerto Rico, a brief blast of radio waves designed to alert extraterrestrial civilisations to our existence. Of course, we don't know if such civilisations really exist. For the past six decades a small cadre of researchers have been on a quest to find out, as part of SETI, the search for extraterrestrial intelligence. So far, SETI has found no evidence of extraterrestrial life, but with more than a hundred billion stars in our Galaxy alone to search, the odds of quick success are stacked against us. The silence from the stars is prompting some researchers to transmit more messages into space, in an effort to provoke a response from any civilisations out there that might otherwise be staying quiet. However, the act of transmitting raises troubling questions about the process of contact. In The Contact Paradox, author Keith Cooper looks at how far SETI has come since its modest beginnings, and where it is going, by speaking to the leading names in the field and beyond. SETI forces us to confront our nature in a way that we seldom have before – where did we come from, where are we going, and who are we in the cosmic context of things? This book considers the assumptions that we make in our search for extraterrestrial life, and explores how those assumptions can teach us about ourselves.

Astronomers around the world are pointing their telescopes toward the heavens, searching for signs of intelligent life. If they make contact with an advanced alien civilization, how will humankind respond? In thinking about first contact, the contributors to this volume present new empirical and theoretical research on the societal dimensions of the Search for Extraterrestrial Intelligence (SETI). Archaeologists and astronomers explore the likelihood that extraterrestrial intelligence exists, using scientific insights to estimate such elusive factors as the longevity of technological societies. Sociologists present the latest findings of novel surveys, tapping into the public’s attitudes about life beyond Earth to show how religion and education influence beliefs about extraterrestrials. Scholars from such diverse disciplines as mathematics, chemistry, journalism, and religious studies offer innovative solutions for bridging the cultural gap between human and extraterrestrial civilizations, while recognizing the tremendous challenges of communicating at interstellar distances. At a time when new planets are being discovered around other stars at an unprecedented rate, this collection provides a much needed guide to the human impact of discovering we are not alone in the universe.

Addressing a field that has been dominated by astronomers, physicists, engineers, and computer scientists, the contributors to this collection raise questions that may have been overlooked by physical scientists about the ease of establishing meaningful communication with an extraterrestrial intelligence. These scholars are grappling with some of the enormous challenges that will face humanity if an information-rich signal emanating from another world is detected. By drawing on issues at the core of contemporary archaeology and anthropology, we can be much better prepared for contact with an extraterrestrial civilization, should that day ever come.

Extraterrestrial Altruism examines a basic assumption of the Search for Extraterrestrial Intelligence (SETI): that extraterrestrials will be transmitting messages to us for our benefit. This question of whether extraterrestrials will be altruistic has become increasingly important in recent years as SETI scientists have begun contemplating transmissions from Earth to make contact. Technological civilizations that transmit signals for the benefit of others, but with no immediate gain for themselves, certainly seem to be altruistic. But does this make biological sense? Should we expect altruism to evolve throughout the cosmos, or is this only wishful thinking? Is it dangerous to send messages to other worlds, as Stephen Hawking has suggested, or might humankind benefit from an exchange with intelligence elsewhere in the galaxy? Would extraterrestrial societies be based on different ethical principles, or would we see commonalities with Earthly notions of morality? Extraterrestrial Altruism explores these and related questions about the motivations of civilizations beyond Earth, providing new insights that are critical for SETI. Chapters are authored by leading scholars from diverse disciplines—anthropology, astronomy, biology, chemistry, computer science, cosmology, engineering, history of science, law, philosophy, psychology, public policy, and sociology. The book is carefully edited by Douglas Vakoch, Director of Interstellar Message Composition at the SETI Institute and professor of clinical psychology at the California Institute of Integral Studies. The Foreword is by Frank Drake. This interdisciplinary book will benefit everybody trying to understand whether evolution and ethics are unique to Earth, or whether they are built into the fabric of the universe.

Originally published in Great Britain by Profile Books Ltd, 2016.