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This book is a collection of essays written by those who have led, and continue to lead, the search for extraterrestrial intelligence. It reviews the history of the subject, details present-day science and technology, and looks ahead to the future.

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This book is a collection of essays written by the very scientists and engineers who have led, and continue to lead, the scientific quest known as SETI, the search for extraterrestrial intelligence. Divided into three parts, the first section, ´The Spirit of SETI Past´, written by the surviving pioneers of this then emerging discipline, reviews the major projects undertaken during the first 50 years of SETI science and the results of that research.

In the second section, ´The Spirit of SETI Present´, the present-day science and technology is discussed in detail, providing the technical background to contemporary SETI instruments, experiments, and analytical techniques, including the processing of the received signals to extract potential alien communications.

In the third and final section, ´The Spirit of SETI Future´, the book looks ahead to the possible directions that SETI will take in the next 50 years, addressing such important topics as interstellar message construction, the risks and assumptions of interstellar communications, when we might make contact, what aliens might look like and what is likely to happen in the aftermath of such a contact.

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Dedication.- Foreword: Looking Back.- Preface.- Part I: The Spirit of SETI Past.- 1 A half-century of SETI science.- 2 Project Ozma : The birth of observational SETI.- 3 Project Cyclops : The greatest radio telescope never built.- 4 "Wow!", A tantalizing candidate.- 5 SETI: The NASA years.- 6 From HRMS to Phoenix: Up from the ashes.- 7 Seeking SERENDIP: The Berkeley SETI Program.- 8 Millions and billions of channels.- Part II: The Spirit of SETI Present.- 9 ATA: A cyclops for the 21st century.- 10 Optical SETI: Moving toward the light.- 11 Distributed processing of SETI data.- 12 Project Argus : Pursuing amateur all-sky SETI.- 13 Gravitational lensing extends SETI range.- 14 Detection algorithms: FFT vs. KLT.- 15 Implementing the KLT.- 16 A sentry on the Universe.- 17 Pondering the Fermi Paradox.- Part III: The Spirit of SETI Future.- 18 Focusing the Galactic internet.- 19 SETI in science fiction.- 20 What´s past is prologue: Future messages of cosmic evolution.- 21 METI: Messaging to extraterrestrial intelligence.- 22 A contrarian perspective on altruism.- 23 Where the L are we?.- 24 What will they look like?.- 25 Being technological.- 26 After contact, then what? Epilogue Hungarians as Martians: The truth behind the legend.- Afterword Looking forward.- Index.

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