Beyond Contact pdf epub mobi txt 电子书 下载 2026

"What do we need to know about to discover life in space?" --Frank Drake, 1961 In the early 1960s, Frank Drake, a young astronomer with the National Radio Astronomy Observatory (NRAO) in Green Bank, West Virginia, developed what is now known as the "Drake Equation" in an effort to determine how many intelligent, communicative civilizations our galaxy could harbor. For forty years, the Search for Extraterrestrial Intelligence (SETI) has combed the skies in search of signals from star systems within the galaxy. In Beyond Contact: A Guide to SETI and Communicating with Alien Civilizations, author Brian McConnell goes behind the scenes and examines what goes into the search for intelligent life. SETI is a four-step process. First we have to know where to look; then we must be able to send and receive signals to that star system. Once signals arrive, scientists then need to be able to interpret those signals into something that can be understood. And although we haven't yet received any signals (except for our own Earth-based transmissions), we'll eventually have to figure out a protocol for responding. Beyond Contact introduces you to:

<li type="disc">The history of SETI research, including the early searches of Project Ozma, traditional radio astronomy, the search for intelligence in optical wavelengths (known as Optical SETI, or OSETI), and the SETI@home project. <li type="disc">An overview of the Drake Equation and the Rare Earth Hypothesis, which scientists use to estimate the number of planets in our galaxy that could harbor intelligent, communicative life forms. <li type="disc">How signals are sent and received over interstellar distances. The author explains the principles of signal and image processing, and how SETI researchers identify and process analog signals using Fourier transforms to see how the power in a signal is distributed across different frequencies. <li type="disc">How to build a general-purpose symbolic language for sending signals, and even computer programs, with present-day SETI equipment. The ability to transmit computer programs enables us to let another civilization know about our knowledge and technological capabilities. The author also shows how SETI research--though often thought to be a mere flight of fancy--has spawned technological improvements in astronomy, computers, and wireless communications. Beyond Contact: A Guide to SETI and Communicating with Alien Civilizations sidesteps the "little green men" approach to take a hard, realistic look at the technologies behind the search for intelligent life in our universe.