Review: Contact with Alien Civilizationsby Kenneth Silber
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| His analysis suggests that contact is a serious—and not necessarily pleasant—possibility. |
One might wonder why such things aren’t happening already (or at least not with scientifically respectable evidence), given the eons in which alien societies could have arisen and expanded. This question, known as Fermi’s Paradox after physicist Enrico Fermi, has many possible answers. Smart aliens may be rare or nonexistent. They may be signaling us in ways we do not understand, or lack all curiosity about worlds beyond their own. Perhaps their messages or probes have not arrived yet, or passed through long ago. Maybe extraterrestrials regard our solar system as a nature reserve, or avoid it as a slum.
Perhaps they are here, making themselves known only to government conspirators or other segments of the population. Surveying reports of UFOs and alien abductions, Michaud finds insufficient basis to believe these are genuine extraterrestrial encounters. He worries, however, that scientific attitudes on such topics are reflexively dismissive. Plus, as he mentions, aliens could be in our solar system—mining the asteroid belt, say—without having anything to do with reported UFO phenomena.
Michaud analyzes assorted factors that play into the likelihood of whether intelligent aliens exist in the first place. Vast numbers of stars produce the heavy elements needed for life as we know it, and planets appear to be an astronomical commonplace, with hundreds already detected beyond our solar system. The galactic “habitable zone” thus does not seem to be prohibitively small. The origin of life may be an important bottleneck, if it requires a rare accident or miracle; however, life’s emergence very early in Earth’s history could signify it was not so improbable. The diversity of life’s niches on our planet suggests similar adaptability may occur elsewhere.
Once life takes hold, how likely is intelligence to arise? Perhaps cognition is a probable or inevitable outcome of evolution, as suggested by signs of smarts in dolphins and other non-human animals; or intelligence may be an evolutionary fluke, inferior to the survival strategies of bacteria and plants. Michaud acknowledges such uncertainties, adding that it is unclear whether intelligent beings necessarily develop technology.
Another question involves the longevity of technological societies. Maybe they destroy themselves promptly through nuclear war or environmental damage; however, as Michaud notes, this explanation for alien absence was often voiced in the 1970s and ‘80s amid concerns about imminent human self-destruction that turned out to be overblown. Then again, evidence has grown in recent decades of space-based dangers—asteroid impacts, gamma-ray bursts, and so on—that could shorten the life spans of civilizations.
Michaud takes a moderately enthusiastic stance toward SETI. The search for alien signals, he observes cogently, has been too recent and limited to draw conclusions that no one is out there transmitting. SETI projects thus far have focused on several thousand stars and particular segments of the radio spectrum; there also have been some efforts to detect signals in visible or infrared light. In the next couple of decades, as facilities and search techniques are upgraded, the number of stars covered will jump to about a million.
| The intentions of aliens are hard to guess, particularly for those who have never met any. |
SETI also is a notable example of large-scale science operating without major dependence on government funding. The search was conducted briefly as a NASA program in the early 1990s before being cancelled by Congress as too expensive (the program cost $12.5 million in its last year) or just too weird. Subsequently, the search was revived by the non-profit SETI Institute and other groups, and has been financed mainly by private benefactors (plus a few government grants). The Allen Telescope Array, under construction in California, was funded by Microsoft co-founder Paul Allen and others; individuals can sponsor one of its 350 radio dishes for $100,000.
While calling for the search to continue, Michaud takes a skeptical approach to a number of hopes and assumptions that have fed into the SETI effort. It is, he points out, an open question whether intelligent aliens will be interested in communicating with us, or comprehensible if they try to do so. Their brains, or equivalent, may be radically different from ours. Expectations that they will have common concepts with us in science and math might underestimate different possible ways of looking at the universe.
Moreover, there has been a tendency in SETI circles to suggest extraterrestrials are likely to be benevolent, even helpful in solving humanity’s problems. Astronomer Carl Sagan, a high-profile SETI proponent, wrote that an alien message might include “detailed prescriptions for the avoidance of technological disaster” and tell us “which pathways of cultural evolution are likely to lead to the stability and longevity of an intelligent species.” Michaud rightly worries about the utopian strain in such ideas, and wonders whether aliens’ social solutions would be applicable to Earth anyway.
The intentions of aliens are hard to guess, particularly for those who have never met any. Perhaps extraterrestrials will be wise and peaceful (and would have destroyed themselves otherwise). But evolution’s tendency to channel intelligence to predators could mean that savvy aggressors sit atop food chains throughout the cosmos. Extraterrestrials, Michaud notes, might be technologically advanced without being ethically so, or they may be benign by their own standards but not by ours.
Nor is there any guarantee that distance would protect us if the aliens turned out to be hostile. No known principle of physics or engineering rules out interstellar travel. Extraterrestrials may be spreading through the galaxy, as well as chatting on the radio.
Other imponderables abound. The aliens may be experienced at communicating with other worlds, or this might be their first time. A message may come addressed specifically to humanity, or to whom it may concern, or we may intercept some routine piece of alien business such as a mortgage approval. The senders might be top officials or scientists of an alien culture, or they may be the otherworldly equivalent of ham radio operators. Perhaps, since such long-distance messaging suggests a strong motivation, the extraterrestrials we are most likely to hear from will be religious proselytizers.
Should humans be sending our own signals to possible listeners out there? To a degree, this already occurs routinely, as radio and television broadcasts, plus military and civilian radar pulses, leak into space; such signals, though, may be too weak to detect at astronomical distances (depending on how sensitive their receivers are). There also have been a few efforts to send more detectable transmissions, as in 1974 when astronomers used the huge Arecibo radio telescope to beam toward a distant star cluster a pictogram showing our solar system, the DNA molecule, a human stick figure, and more.
Michaud is wary of such “active SETI,” noting that its goal is to elicit a reaction from aliens whose capabilities and intentions are unknown. Similar to many in the SETI community, he prefers listening to transmitting; the latter is costlier as well as riskier. Michaud also raises the possibility of requiring international consultations for any transmission above the signal strength of ordinary radio, television, and radar. The need for such regulation is dubious, however, given that active SETI is rare, its recipients may or may not exist, and they might already be getting American Idol and other programs.
| How humans would react in the event of contact is almost as unpredictable as the nature and likelihood of the contact. |
While much SETI thinking has assumed that any aliens detected would be vastly ahead of us in science and technology, Michaud interestingly suggests that this may not be the case. Our search techniques may be more likely to turn up civilizations relatively close to our own in development, while any that are far more advanced stay undetectable. Moreover, straight-line projections of scientific and technological progress might be wrong; there could be inherent limits on such advances, such that even a civilization a million years older than ours would be just a few centuries ahead (whatever that entails).
How humans would react in the event of contact is almost as unpredictable as the nature and likelihood of the contact. Possibly, many people will not believe that the contact has occurred, or that it is what it seems; Michaud invokes a scenario of religious fundamentalists denouncing an alien message as demonic. Perhaps the evidence will be so ambiguous—a garbled radio signal, say, or an eroded chunk of ancient metal—that there will be long scientific debate as to whether it is indeed of intelligent origin. If an information-rich message arrives, some people might be inspired by evidence of a more advanced society (if that is what it is); others might be demoralized. Some people might want to emulate alien ways; others might engage in a terrestrials-first backlash.
The SETI community has developed some protocols for how to react if an extraterrestrial message is received. Their thrust is: verify the message in cooperation with other searchers; release the information publicly once verified; consult with national and international authorities about whether and how to reply. A few researchers have sketched out principles for direct contact, such as giving alien visitors diplomatic status and convening the UN Security Council if they seem to pose a threat. Michaud argues that such contingency planning is valuable, given how consequential contact could be; he laments that governments show little sign of taking the subject seriously in advance.
Space exploration, Michaud suggests persuasively, is a way of spreading humanity’s bets amid the current uncertainty as to who else might be out there. If intelligent extraterrestrials are detected, then being a spacefaring civilization will place us in a stronger position to deal with them, whether cooperatively or not. And if no contact occurs, then expanding beyond Earth could help ensure the survival of at least one civilization—our own—in a universe where civilized life is rare and hard to find.