Close Encounters of the Third Kind and E.T. suggest that UFOs are space vehicles piloted by extraterrestrials. This simplistic solution to the UFO prob lem is summarily rejected by most physical scientists--and with good reason: Even the most sophisticated propulsion devices could not cover the astronomical distances involved in any reasonable length of time. In addition our sophisticated surveillance systems have yet to detect any UFOs approaching or departing from Earth.

And having come from vast distances, UFOs make such poor use of their short visits. So unlike us! We would land prominently, bearing gifts and papers to establish our credibility. They favor lonely roads, late-night hours, and few witnesses.

Though these factors argue against an extraterrestrial explanation, they do not demolish the reality of the UFO phenomenon. UFO sightings continue to be reported from all over the world by military and commercial pilots, engineers, technicians, and other people judged sane and responsible. UFOs just won't go away.

The inconsistency of the situation of course begs some questions: Why are there UFO reports in the first place? Why not reports of pink elephants, for instance, or fiery dragons? What sorts of people make UFO reports? Under what conditions were tbe UFO sightings made? And how can we explain UFO photographs, inexplicable radar blips, and other bits of physical evidence?

The questions are so diverse that research could be conducted by any number of professionals: physicists, astronomers, sociologists, psychiatrists, or theologians.

The best person to investigate these questions, however, might be the ufologist -- someone who applies his particular expertise to the study not of UFOs (we have none in captivity) but to the myriad reports of UFO encounters.

As far as I'm concerned, studying such reports may open a whole new arena of which we are only dimly aware. The key to this alternate reality might lie in the ephemeral nature of UFOs. Much like the Cheshire Cat in Alice's Adventures in Wonderland, UFOs appear spontaneously within a limited area, remain visible for a short time, and then disappear without a trace. This peculiar behavior reminds us of the duality of light, which acts either as a wave or a particle, depending on the particular situation.

Can the UFO likewise have two aspects? Can it be an interface between our reality and a parallel reality, the door to another dimension? Surely we haven't had our last revolution in scientific thought; twenty-first-, twenty- fifth-, or thirtieth-century science may well hold concepts as unintelligible to us as nuclear energy would have been to the caveman.

Oberg: "We can account for decades of UFO sightings without resorting to supernatural explanations."

J. Allen Hynek says that intergalactic travel is physically impossible, arguing that UFOs could not be craft carrying emissaries from space. Instead he suggests that unidentified flying objects may represent an alternate reality, or even "doors" connecting our universe to some parallel dimension.

I would like to counter that theory with the "null hypothesis," which holds that we can account for decades of UFO sightings without resorting to extraordinary explanations. Under this hypothesis, put forth by skeptical UFO theoretician Robert Sheaffer, there would still be innumerable UFO reports, including some seemingly unexplainable cases. There would still be hypnotically extracted stories of abductions by flying-saucer beings. There would be close encounters of the first, second, and third kind.

There just wouldn't be any UFOs.

Proof of this hypothesis lies in a simple thought experiment. Ufologists now claim that of all UFO reports, 90 percent can be explained, while 10 percent are "true" UFOs. But imagine that all true UFOs go away for a period of time, leaving the UFO reports caused by readily explainable misperceptions, pranks, and hoaxes. Since it is unreasonable to expect amateur UFO investigators to solve all such prosaic cases, we would be left with a residue of false UFO cases, indistinguishable from what pro-UFO investigators present as true UFOs. The obvious implication is that the real world doesn't have real UFOs after all.

Ufologists such as Hynek refute this argument by pointing to the credentials of witnesses. But witnesses need not be drunk, uneducated, myopic, hysterical, or psychotic to succumb to limitations in human perception and memory. In fact studies suggest that the better educated an individual is, the more likely he or she is to fill in the blanks unconsciously.

An excellent example is a set of cases endorsed by Hynek himself. Astronomers in the Caucasus and Volga regions of the U.S.S.R. reported sighting UFOs throughout 1967. The men were actually seeing tests of space-to-Earth orbital thermonuclear warheads, but their reports were interpreted by leading American ufologists as proof that even highly educated people see UFOs. Until pro-UFO researchers grapple with the reality of human perception and self-deception, alternate universes and interdimensional communication are destined to remain hypotheses in search of data.

Maybe alien starfaring civilizations who have mastered the secrets of intergalactic travel are observing our planet. Such beings would, in Arthur C. Clarke's words, be capable of feats "indistinguishable from magic" and could thus conceal themselves from us. Having done so, they may even now be searching for the identity of the UFO pilots, since they know it isn't they!