SETI: A Critical History: Introduction
In 1959 Giuseppe Cocconi and Philip Morrison wrote a short paper arguing that sending radio messages would be a logical choice for any being wishing to communicate across interstellar distances. They based their argument on the fact that radio waves can travel vast distances, even if "pushed" by very little energy, with little dissipation. Radio astronomy was still in its infancy and radio astronomers were excited by the prospect of a new project that captured the public's attention; they rushed to their telescopes to search for patterns in the radio waves reaching Earth. Today this enterprise is known as SETI, or the search for extraterrestrial intelligence. When interest in the American SETI project was at its peak the National Academy of Sciences (NAS) endorsed it and the National Aeronautics and Space Administration (NASA) funded a multi-million-dollar SETI program. SETI changed the way extraterrestrials (ETIs) were depicted in the popular culture, spawning a large number of blockbuster movies and popular television programs. The publication of popular-science texts about SETI surged. SETI's public face, Carl Sagan, became the best known scientist in the world.
This year we celebrate SETI's fiftieth anniversary. Its institutional support has disappeared. It is lampooned in blockbuster movies, and film ETIs tend to be silly beings with little narrative significance. SETI has become, to many, simply a cool screensaver.
Most importantly, after fifty years of searching SETI has found no messages.
What happened? Why did an idea that generated so much public and institutional interest eventually evanesce?
After millennia of speculation about whether ETIs exist, SETI's pioneers claimed to be establishing the question on a rigorously scientific basis for the first time. By assuming that intelligent beings would send us radio messages that we could detect, they believed they were able to experimentally answer the question of whether ETIs exist. Eager to get on with their experiment, they hastily developed a rationale for SETI based on bold assumptions about the likelihood that life would originate and evolve into intelligence similar to our own. They spent little time pausing to reach out to the scientific community at home or abroad to discuss their project. Scientists normally engage in a process known as peer review, in which they expose their assumptions, methods, and mission to the critical scrutiny of the scientific community. SETI's organizers behaved differently, steering the conversation toward the implications of a successful search and away from the details of the search itself. Moreover, they simply ignored much of the feedback volunteered by other scientists.
Their behavior is not altogether surprising. Almost as soon as the idea of SETI appeared, the NAS explored the possibility of establishing a SETI project in NASA, as part of the space agency's mission to search for extraterrestrial life (SETL). NASA was already busy with plans to land men on the Moon and probes on Mars, and more than a decade passed before it finally turned its attention to SETI. The delay was frustrating, but from an early point in the history of SETI its organizers were justifiably confident that they could secure an institutional home for their project and, thus, did not appear to feel particularly motivated to win the approval of their peers in the scientific community.
At the same time this distance began to open between SETI and the scientific community, SETI swept into prominence in the popular culture. Almost as soon as SETI appeared, a Cold War-weary American public latched onto the project as a powerful symbol of hope and the possibility of communicating with even the radically Other, provided only that one was willing to listen long and hard enough. This warm public welcome paved the way for the Congressional funding NASA projects required. Because early radio astronomers found the idea of a SETI-style search so intuitively compelling, SETI almost certainly would have arisen in the form that it did, when it did, and possibly even due to the efforts of the same people, if there had not been a Cold War. But its impact on the popular culture, SETI's most significant legacy, would have been muted.
In addition to the events and actors of the SETI project, this narrative has another equally important focus: the ETI discourse. ETIs are, obviously, hypothetical. We construct ETIs, and the site at which this occurs is the ETI discourse, or the universe of ideas that are expressed about ETIs. The ETI discourse provides critical context for SETI because it is where we imagine what the objects of SETI's searches might be like. In a fateful irony, the ETI discourse began to undergo a profound change at virtually the same historical moment that SETI's architects began their project. The ETI discourse was traditionally constructed around a single question: whether extraterrestrial intelligences exist. Contributors to the discourse simply assumed that the intelligences in question were essentially like our own. SETI's architects conceived of their project from within this traditional ETI discourse. One of their most important assumptions was that ETIs are humanoid; i.e., that ETIs have cognitive structures, consciousnesses, and intelligences that are similar enough to our own that we could communicate with them, or at least recognize that their messages were messages.
By the time NASA's SETI effort began to crystallize, however, contributors to the ETI discourse regularly raised questions about the nature of extraterrestrial intelligence in addition to the traditional question of whether ETIs exist. Evolutionists from a variety of fields questioned the traditional assumption that ETIs were humanoid. They argued that human intelligence is the product of an evolutionary chain-of-events so long and complex that it is unlikely to be repeated elsewhere. Other scientists, using the concepts of the emerging multi-disciplinary field of cognitive science, suggested that ETIs might have evolved cognitive structures, consciousnesses, and intelligences that are quite different from ours. Indeed, they regularly noted that ETIs' "natures" could be so different that we might find it difficult or impossible to communicate with, or even detect, them.
The SETI scientists, both culturally and by training, were deeply invested in the traditional ETI discourse and its assumption of humanoid ETIs. Moreover, they did not want to risk disrupting their projectís trajectory within NASA by acknowledging that serious questions existed about its most basic assumption. As a result, they exhibited a kind of blind spot toward the changes taking place in the ETI discourse. To be fair to them, it was not easy to observe these changes. There are no journals or professional conferences that discuss ETIs. There were two options available to the scientists, philosophers of science, and science writers who wished to circulate a fact-based idea about ETIs. They could publish their idea in a popular exposition of ETI science, a long-standing non-fiction genre that discusses the status of the scientific debate about whether ETIs exist. Or they could write a "hard" science fiction story or novel. This genre is different from fantasy science fiction in that it analogizes from accepted science to create scientifically plausible characters and plots. SETI was so popular that it crowded out the voices springing up in both of these primary sources to speak of the non-humanoid ETIs that SETI ignored. It is considerably easier to "hear" these voices today because, with the perspective afforded by the passage of time, it is possible to pry these isolated voices loose from the SETI-dominated ETI discourse in which they were embedded and examine them in the aggregate.
This is, in fact, what I have tried to do. My claim is that one cannot truly understand the history of the SETI program except in the context of this expansion of the ETI discourse to ask the "nature" question as well as the "whether" question. Indeed, the two questions are mutually constitutive: one can no longer hold an opinion about "whether" without acknowledging the assumptions being made about "nature," in much the same way that a description of the observed has become fused, in quantum mechanics, with a description of the observer. By chronicling the decoupling of SETI from the ETI discourse, I have produced the first critical history of SETI. SETI astronomers look through a very small keyhole: they look for humanoid ETIs – which evolutionists think are unlikely – but do not look for the non-humanoid ETIs that are increasingly thought to be possible. The charge is, essentially, a failure of imagination on the part of the SETI scientists: the scope of their project is too narrow.
SETI was conceived in 1959 and a number of narrowly-defined searches began in 1960. Because its Apollo and Viking programs took priority during the 1960s, NASA delayed undertaking its ambitious SETI project until the mid-1970s. By this time SETI was already in the process of becoming disconnected from the ETI discourse. NASA could no longer ignore the critiques of SETI that arose from the new "nature" segment of the ETI discourse. Moreover, acknowledging these shortcomings in SETI's conceptual foundation forced NASA to establish a new status for SETI. Instead of the conventional institutional science project originally envisioned by its architects, or the popular science to which SETI's critics condemned the project, NASA settled on something in between. SETI represented a kind of lottery ticket to NASA, a project whose conceptual flaws could be overlooked because it was a relatively low-cost project with potentially enormous returns.
At the same time criticism of SETI mounted in the scientific community, the enormous popular support it enjoyed began to dissipate. The dissolution of the Soviet Union robbed SETI of its value as a Cold War symbol, the early enthusiasm for the Space Age was waning, and thirty years of SETI searches failed to produce results. The depiction of SETI in both popular expositions of ETI science and contemporary films reflected this growing public disillusionment with the project. Congress cancelled NASA's SETI funding in 1993, less than a year after the project began searching.
Before SETI's founders began to fade from the scene, they abandoned the original claim that their project was rigorously scientific. Instead of experimentation they asked that SETI be thought of as exploration. They found a source of funding more appropriate to their project's new status – private patronage – and SETI itself began to fade from view in both the scientific community and the popular culture.
This narrative is divided into three parts. Part I examines the early construction of SETI both by its organizers and in the popular culture. Part II examines the rise of the "nature" segment of the ETI discourse, out of which a number of critiques were leveled at SETI. Part III examines the responses of SETI's architects to these "nature"-based critiques and the consequences the critiques ultimately had for the project.
It is important to note that this is primarily an examination of the government-sponsored American SETI project. Astronomers in the Soviet Union mounted a similar effort, which is more properly known as CETI or communication with ETI. I will follow the convention in the SETI literature and use "SETI" to generically refer to any search for evidence of intelligence using radio telescopes. Where necessary I try to make it clear when I am referring to the U.S. SETI program or the Soviet CETI program. In addition to the Soviet searches, search programs much less ambitious than NASA's were periodically commissioned in the United Sates and elsewhere during the period being examined, typically by university-sponsored observatories.
1. The historiography of the ETI discourse was pioneered by Steven J. Dick and Michael J. Crowe. See the former's Plurality of Worlds – The Origins of the Extraterrestrial Life Debate from Democritus to Kant (New York: Cambridge University Press, 1982), and Professor Crowe's The Extraterrestrial Life Debate, 1750-1900 (Cambridge: Cambridge University Press, 1986; republished, Toronto, ONT: Dover, 1999).