Explore the challenges in searching for evidence of extraterrestrials. The book is the first to examine electromagnetic frequencies besides RF and microwave as signal sources, taking into consideration all the ways that extraterrestrials might communicate.

The author explores in detail the key problems in starting a search for extraterrestrial signals, the programs that have failed and those that continue. His book is the first book that treats electromagnetic frequencies besides RF and Microwave as possibilities for signal sources. The book includes the fundamental considerations and the physics of the necessary laser, UV, IR and RF technologies, as well as coding and information theory considerations. It explores future possibilities providing the reader with a comprehensive view of the many ways signals from aliens could be sent and explains why the search using RF leaves more than 99% of the electromagnetic spectrum unexamined. The book also demonstrates the many parts of the electromagnetic spectrum, considering the next likely steps in this unique enterprise. The ideas, concepts and approaches are clearly explained without the use of complex maths or physics.

First book that treats electromagnetic frequencies besides RF and Mictrowave as possibilities for signal sources Considers the whole electromagnetic spectrum for extraterrestrial signals Explains why pulsed lasers are good candidates for extraterrestrial signals Brings the search for signals up-to-date Explains ideas, concepts and approaches clearly without the use of complex maths or physics

Inhalt
The likelihood of extraterrestrial intelligence.- Vast distances and long travel times.- Stars, their evolution and types.- Planets and our Sun.- The many constraints on life.- Why would anyone transmit to us?.- The Drake Equation and habitable planets.- The basics of space communication.- Where to look in the electromagnetic spectrum?.- Receiver basics and how big is big?.- Noise and limitations on sensitivity.- Programs in SETI.- A brief history of SETI.- Radio-frequency and microwave SETI, including the Allen Telescope Array.- Early optical SETI and the all-sky Harvard system.- Possibilities in SETI.- The PhotonStar project.- Key issues for SETI.- Other parts of the spectrum, decoding the data and forming pictures.- Future systems for intercepting alien lasers.