SETI: peering into the future

Abstract

Fifty years of scanning the skies for signs of ET has produced nothing. But we mustn't give up, argues Alan Penny, and describes an exciting future for the search for extraterrestrial intelligence. The first Search for Extra-Terrestrial Intelligence (SETI) project of the modern era was done by Frank Drake in the spring of 1960, using the Green Bank 26 m telescope. He was looking for narrow-band radio emission from two nearby stars, t Ceti and ε Eri, over a frequency range of 400 kHz near the H i line. Since then there have been six major and many minor searches, made both on specific targets and also over the entire sky. The searches have extended to the optical and infrared, and to search for artefacts in the solar system and beyond. There have also been more than a thousand papers in the scientific press. The searches have all come up negative. What does this mean? Can future searches extend in a significant way the present area of the “ETI phase space” that has been searched for the existence of extraterrestrial intelligences (ETIs)? This article will briefly describe some of the component parts of SETI and put forward the case that SETI does indeed have an exciting future. SETI has two main aims. There is the expanding exploration of that phase space, always with the possibility of “contact” and the leap forward in our understanding of life in the universe and in many other fields of science and culture that would result. But SETI also addresses the future of humankind, looking for other civilizations that have trodden this path before us. If we find them, then we will know there is a possible way forward. If a particular SETI search comes up with a negative result, then we know that our future may not include the path that that search would have revealed. SETI activity has other components. It involves studies of: how evolution leads from the origin of life to intelligence; the rise and nature of technological civilizations; the problems of communications with fundamentally different entities; the possibilities of interstellar travel. It provides a logical extension to the growing field of astrobiology. Like all high-tech work, it has spin-offs, such as the Berkeley BOINC system of grid computing, originally designed to deal with the flood of SETI data from the Arecibo telescope with the SETI@home project, and which is now used in many fields, including medicine, molecular biology and climatology. And SETI provides a powerful forum for engaging with the public on the nature of scientific studies, using a subject in which the public is already interested.