First things first: I personally don’t believe that the Earth has yet been visited by intelligent beings from another planet. Not that I doubt such beings exist. In a universe of 100 billion or so galaxies, each consisting of 100 billion or so stars, anything—no, everything—is possible. But have they come here? More to the point, have they started coming here in the last sixty-odd years, since the outbreak of UFO sightings that began in the late 1940s?
These were also the years, remember, that many more airplanes were flying in the skies of this country. With advances in high-altitude and nighttime operations developed during World War II, many more airplanes—and suddenly helicopters, too, with their great whirling rotors—were moving high overhead, some leaving condensation trails, and all flashing strange patterns of landing and navigation lights. These were the years when researchers were experimenting with weather balloons and other high-flying objects like the surveillance device that came back to earth in Roswell, New Mexico.1 Advances in astronomy were feeding a growing public awareness of other planets, and science fiction writers were speculating about their alien cultures. And finally, the horrors of world war were still ringing in our heads, and the growing threat of a new Cold War was feeding a climate of suspicion and paranoia. All told, it was time for Americans to expect to see the aliens.
So why don’t I buy into the irresistible fantasy that Earth has been visited repeatedly, endlessly—practically buzz-bombed and harassed—by hairless little people with big slanting eyes riding in silver saucers?
Because they never announced themselves. They did not, to anyone’s knowledge, ever land like Klaatu in a public park2 and say “Take me to your leader.” Of course, conspiracy theorists contend that the first government they approached—ours—put them under wraps, declared them a state secret, and have been dealing with them in private ever since. But is this reasonable, considering the huge number of supposed sightings? Even though the aliens are not human and cannot be expected to have human motivations, we should be able to attribute some intention to any being we might meet and describe as intelligent.3 If there is intention, then we can also predict how an intelligent being will respond to that intention being foiled, as by a paranoid local government.
Any interstellar trip is going to take time and effort, regardless of how much energy the traveler has at his disposal. Even the starship Enterprise, with its limitless matter-antimatter conversion reactor and space-bending warp technology, represents a significant investment in shipbuilding effort in order to whisk humans from one star to another in a vessel filled with science labs, state rooms, and cocktail lounges. One undertakes the trip with a purpose in mind: curiosity and exploration in the case of Star Trek, conquest and colonization in many other scenarios.
In neither case would the traveler be likely to give up his purpose because the locals were either paranoid or hostile. Fear of a United States or Soviet Union armed with fusion bombs wouldn’t occur to any being equipped with the energy resources to travel dozens or hundreds or thousands of light years. Even if the conspiracy theorists are right and the travelers were initially bought off, warned off, or scared off, then why do they endlessly return to abduct isolated individuals and perform experiments on them?
One could theorize that these travelers have some benign intent that prefers to remain secret. Thus they would have reasons for not making formal presentations in the U.S. Congress and at the U.N. General Assembly. They might, for example, want to work behind the scenes to bring humans quietly and peacefully up to a level where we can join some kind of Council of Planets (per Klaatu’s mission). Or they might want to study us while their ethics require them to let us develop culturally and technologically in our own unique way (per the Star Trek Prime Directive). But neither intent would account for this clumsy sneaking around, creating crop circles, mutilating cattle, and leaving light sleepers with dreamlike, half-remembered episodes of abduction and rape.
The aliens as depicted by the UFO theorists are a mix of clever and stupid: clever enough not to make public demands and present hard evidence of their arrival, but too stupid to cloak and shield themselves effectively. They are also too disturbingly humanoid, with homeobox segmentation4 and tetrapod limbs, to be the product of an evolution that started out among the stars.
No, I am dissatisfied with any evidence and explanations of extraterrestrial intelligence that we’ve seen so far. There is one explanation that does fit, however, although it is even more improbable than that hairless bipeds would come thousands of light years to butcher cattle and give rectal exams to agricultural workers.
The aliens as depicted might very well be from around here, but not from this time. They might be travelers from our own distant future, come back to study their history, take samples from their ancestral genome, or influence our development. That would explain the humanoid resemblance but with differences in size and appearance: future evolution and environment suits. That would explain the secrecy: protecting the awareness of the civilization that will one day evolve into themselves. It would also explain the persistence: if you could go back and study the past, wouldn’t you do it more than once? And it might explain some of the clumsiness: if you have lots of people applying for grants and permission to travel back in time, you’re bound to have a few comedians with the urge to drop their pants and scare the locals.
Of course, travel in time is even more improbable than travel over distances of light years. We know perfectly well how to travel through space by accelerating and expending of some kind of reaction mass, whether chemical propellants or ionized particles.5 We don’t have more than a few untested theories about the structure of space and time to support notions about how a physical body might travel backwards and forwards from one timespace to another.
Personally, my bet is that all the alien sightings are attributable to weather balloons and other identifiable effects salted with human imagination, yearning, and paranoia. But that doesn’t make such a good story, does it?
1. One of the reasons I don’t believe the Roswell event represents the recovery of a crashed spaceship is that the believers usually couple it with the development of solid-state transistors in that same year, 1947. These people claim that integrated circuits were found in the crashed spacecraft and secretly exploited to create all of our marvelous modern electronics. My father was a mechanical engineer at Bell Labs at about the same time that William Shockley and other physicists were experimenting with transistors. He once brought home one of these devices that I could hold in my hand as a child: a copper cup the size of a bottle cap filled with opaque material from which three wires stuck out. The first transistors were single gates, which would conduct an electric current across two wires, or not, based on the input of current through the third wire. They operated in printed circuits just like their predecessors, the vacuum tubes. It took a while—a major developmental step, actually—for human designers to stop soldering those wires together and start integrating them as collections of gates etched directly on the silicon substrate. No alien spaceship traveling the stars would have used single transistors; they would have advanced to integrated circuits much denser than even our current models. If humans had discovered integrated circuits in the debris at Roswell, I never could have held that single bottle cap in my hand.
2. The alien hero of The Day the Earth Stood Still played by Michael Rennie in the original 1951 version and Keanu Reeves in the 2008 remake.
3. Referring to science fiction stories in which scaly or tentacled aliens try to have amorous relations with Earth females, Carl Sagan said it would be much more likely for a human to have sex with a petunia than mate with a being from another planet. At least humans and plants share the same basic organizing principle, DNA. Given the huge possibilities for other forms of entropy-reversing energy conversion, or life, out among the stars, I think that to expect aliens to have tentacles, eyes, intentions, or anything we might recognize as intelligence is pure anthropomorphizing. When we actually are visited by beings from another planet, it’s likely we won’t recognize them as life at all, let alone try to communicate with them. Their organic processes, their time scales and attention spans, and their cerebral processes may simply be too strange, in human terms, for us even to notice them.
4. The homeobox, or hobox, gene sequences define bodily segmentation during embryonic development. They are why human beings share with fish, whales, crocodiles, cockatoos, fruit flies, and wasps a body shape that generally includes a head with clusters of sensory organs, a thorax with the mechanisms of respiration and circulation, an abdomen with mechanisms of digestion and reproduction, and various articulated limbs attached to the thorax. (Think of it: your pelvis and legs attach directly to the spine which supports the ribs; your belly hangs from this structure like an afterthought separated from the lungs by the diaphragm.) Most of the advanced, DNA-based animal life on Earth shares these features. Products of an alien evolution would not.
5. More exotic technologies like warp drive—where some kind of “generator” extends a “field” that bends and compresses the “fabric” of space—are not even the stuff of physics theory. They are literature with less scientific basis than fairytales.