The growing popularity of intelligent design (ID) has left most scientists baffled, even exasperated. From their perspective, the match-up between Darwin’s theory of natural selection and ID would be laughable were it not so worrisome. It pits one theory backed by tens of thousands of peer-reviewed articles and consistent with multiple lines of converging genetic, physiological, and paleontological evidence against an armchair conjecture that has flown under the radar of peer review and has yet to generate a single confirmed scientific prediction. If the contest were a boxing match, the referee would surely have stopped the fight seconds after the opening bell.

Yet, to the dismay of most scientists, large swaths of the American public not only harbor serious doubts about Darwinian theory but believe that ID should be taught in science classes. In a 2005 Gallup poll, 34 percent of Americans said they believed that Darwinian theory was false and 31 percent favored ID as an explanation for the development of species. As of this writing, at least forty states are considering initiatives to include ID in public school science curricula. Early this past November, the Kansas Board of education voted to adopt standards mandating teachers to raise questions about Darwinian theory. Echoing the language of ID advocates, these standards refer to unexplained gaps in the fossil record and other purported challenges to the scientific status of this theory. (Shortly after this article was written, U.S. District Judge John Jones ruled that ID could not be taught as an alternative to Darwinian theory in Dover, Pennsylvania, public schools. It is too early to tell whether this ruling will affect popular support for ID across the country.)

In response to such developments, many scientists have expressed disdain-even ridicule-for believers in ID. Nobel Prize winner James D. Watson, co-discoverer of the structure of DNA, was quoted recently in The New York Times as saying that only people who “put their common sense on hold” doubt evolutionary theory (Wade 2005). Still other scientists have attributed malevolent intent to ID advocates. Expressing bewilderment at the ascendance of ID among the American public, one of my academic psychology colleagues abroad recently asked me, “What has happened to good sense and decency in the USA?”

Nevertheless, from the standpoint of psychological science, the only thing about ID’s popularity that should surprise us is that so many scientists are surprised by it. Of course, much of the resistance to Darwinian theory is theological, and media coverage of ID proponents has accorded nearly exclusive emphasis to the intimate connection between ID and fundamentalist Christianity. Nevertheless, religion doesn't tell the whole story.

The other reason for the public’s embrace of intelligent design is its compatibility with intuition. Contra Watson, it is Darwinian evolution, not ID, that is glaringly inconsistent with common sense. Political commentator Patrick J. Buchanan’s (2005) recent statements are illustrative in this regard. Invoking “common sense,” “experience,” and “reason,” Buchanan asked rhetorically, “How can evolution explain the creation of that extraordinary instrument, the human eye?”

Indeed, from the vantage point of commonplace intuition, it is far more plausible to believe that complex biological structures like the peacock’s tail and elephant’s trunk were shaped by a teleological force than by purposeless processes of mutation and natural selection operating over millions of years. To many laypeople, the latter explanation seems hopelessly farfetched. ID theorists have capitalized on this “argument from personal incredulity,” as biologist Richard Dawkins (1995) terms it, using the sculpted presidential faces on Mount Rushmore as a thought experiment. If an alien visiting the earth were to happen upon these faces, they ask, would it regard them as the outcome of intentional design or of unguided physical processes? The answer is obvious.

The foremost obstacle standing in the way of the public’s acceptance of evolutionary theory is not a dearth of common sense. Instead, it is the public’s erroneous belief that common sense is a dependable guide to evaluating the natural world. Even some prominent scientists and science writers have missed this crucial point. In a widely discussed article, psychologists Joaquim Krueger of Brown University and David Funder of the University of California-Riverside recently urged their colleagues to accord more credence to common sense notions of human nature (Krueger and Funder 2004). And in a New York Times op-ed this past August, science writer John Horgan (2005) called for a heightened emphasis on common sense in the evaluation of scientific theories.

Yet natural science is replete with hundreds of examples demonstrating that common sense is frequently misleading. The world seems flat rather than round. The sun seems to revolve around Earth rather than vice-versa. Objects in motion seem to slow down on their own accord, when in fact they remain in motion unless opposed by a countervailing force.

In my own discipline of psychology, striking violations of our intuitions abound (Lilienfeld 2005). Memory seems to operate like a video camera or tape recorder, but research demonstrates that memory is fallible and reconstructive. Most people believe that shifty eyes are good indicators of lying, but research reveals otherwise. Many people believe that opposites attract in relationships, but research shows that opposites tend to repel. The same goes for scores of other common sense claims regarding human nature, such as the belief that expressing anger is typically better than holding it in, that raising children in similar ways leads to marked similarities in their personalities, that most physically abused children grow up to become abusers themselves, and that the levels of psychiatric hospital admissions, crimes, and suicides increase markedly during full moons.

Of course, none of this demonstrates that common sense is worthless. When it comes to gauging our long-term emotional preferences for people and products, research suggests that we are often better off trusting our gut hunches than engaging in dry, objective analyses of the pros and cons (Gladwell 2005; Myers 2002). Yet when it comes to discerning the workings of the outside world or the three-pound world inside of our cranial cavities, common sense is an exceedingly undependable barometer of the truth.

Ironically, if scientists took the implications of evolutionary theory more seriously, they would understand why. The human brain evolved to increase the probability that the genes of the body it inhabits make their way into subsequent generations. It did not evolve to infer general principles about the operation of the natural world, let alone to understand itself. It also did not evolve to comprehend vast expanses of time, such as the unimaginable tens or hundreds of millions of years over which biological systems evolved. Consequently, it is hardly surprising that many intelligent individuals, like Patrick Buchanan, glance at the remarkably intricate biological world and conclude that it must have been produced by a designer.

To a substantial extent, the fault in the current ID wars lies not with the general public, but with scientists and science educators themselves. Generations of biology, chemistry, and physics instructors have taught their disciplines largely as collections of disembodied findings and facts. Rarely have they emphasized the importance of the scientific method as an essential toolbox of skills designed to prevent us from fooling ourselves. As Alan Cromer (1994) and Lewis Wolpert (1992) have noted, science does not come naturally to any of us, because it often requires us to think in ways that run counter to our common sense (see also McCauley 2000). Mark Twain observed that education requires us to unlearn old habits at least as much as learn new ones. Nowhere is Twain’s maxim truer than in effective science education, which asks us to unlearn our reflexive inclination to uncritically trust our perceptions.

Moreover, scientists and the skeptical community at large have long been waging the battle against pseudoscience on only a single front. They have treated each dubious claim, whether it be ID, astrology, or the latest quack herbal remedy, as an isolated thinking error to be combated. In doing so, they have forgotten that the popularity of ID is merely one example of a far broader problem, namely the American public’s embrace of pseudoscience in its myriad incarnations. This one-claim-at-a-time approach helps to explain why scientists are losing not only the ID wars, but also the broader war against public belief in pseudoscience. About a quarter of Americans believe that astrology is scientific and about half believe in extrasensory perception despite the virtually wholesale absence of evidence for either assertion. Public acceptance of alternative medicine continues to mount despite controlled studies showing that most popular alternative remedies are ineffective. Slaying each pseudoscientific dragon as it emerges is laudable and at times necessary, but as a long-term strategy against irrationality it is destined to fail.

Indeed, to win the long-term battle against pseudoscience, scientists must look beyond the narrow battles against ID. The real war they must wage is in the classroom. Specifically, scientists need to effect a sea-change in how science is taught at the junior high, high school, and college levels. They must teach students not merely the core knowledge of their subject matter, but also an understanding of why researchers developed scientific methods in the first place, namely as an essential safeguard against human error.

To do so, they must inculcate in students a profound sense of humility regarding their own perceptions and interpretations of the world. They should teach students about optical illusions, which demonstrate that our perceptions can mislead us. They should show students how their common sense notions regarding the movements of physical objects, like the trajectory of a ball emerging from a spiral, are often incorrect. They should teach students that even highly confident eyewitness reports are frequently inaccurate. Most broadly, they must counteract what Stanford psychologist Lee Ross calls “naïve realism"-the deeply ingrained notion that what we see invariably reflects the true state of nature (Ross and Ward 1996). Scientists may well emerge victorious from the current ID battles. Given that the research evidence is overwhelmingly on their side, they certainly deserve to. Yet as Dawkins (1993) reminds us, ideas can mutate at least as readily as genes. Unless scientists institute a fundamental change in how science is taught, it may be only a matter of time before a new and even more virulent variant of Intelligent Design emerges. Then scientists will again be surprised at the public’s uncritical embrace of it, while shaking their heads in disbelief at the average American’s lack of common sense.

References

• Buchanan, P.J. 1995. What are Darwinists afraid of? Commentary, August 7, available online here.
• Cromer, A. 1994. Uncommon sense: The heretical nature of science. Science 265: 688.
• Dawkins, R. 1993. Viruses of the mind. Free Inquiry 13 (3): 34-41.
• —. 2005. Where d'you get those peepers. New Statesman & Society 16, 29.
• Gladwell, M. 2005. Blink: The Power of Thinking Without Thinking. New York: Little, Brown.
• Horgan, J. 2005. In defense of common sense. The New York Times, August 12, available online at www.johnhorgan.org/work11.htm.
• Krueger, J.I., and D.C. Funder. 2004. Towards a balanced social psychology: Causes, consequences and cures for the problem-seeking approach to social behavior and cognition. Behavioral and Brain Sciences 27, 313-327.
• Lilienfeld, S.O. 2005. Challenging mind myths in introductory psychology courses. Psychology Teacher Network 15(3): 1, 4, 6.
• McCauley, R.N. 2000. The naturalness of religion and the unnaturalness of science. In F. Keil and R. Wilson (eds.), Explanations and Cognitions (68-85) Cambridge, Mass.: MIT Press.
• Myers, D. 2002. Intuition: Its Powers and Perils. New Haven: Yale University Press.
• Ross, L., and A. Ward. 1996. Naïve realism: Implications for social conflict and misunderstanding. In T. Brown, E. Reed, and E. Turiel (eds.),Values and Knowledge (pp. 103-135). Hillsdale, New Jersey: Lawrence Erlbaum Associates.
• Wade, N. 2005. Darwin’s disciples, now friendly rivals. The New York Times, October 27, available online here.
• Wolpert, L. 1992. The Unnatural Nature of Science: Why Science Does Not make (Common) Sense. Cambridge, Mass.: Harvard University Press.

Pogo said it best (and Calvin and Hobbs later echoed)–“Either way, it’s a mighty soberin' thought.” We search because we want to know the answer to the question, not because we demand cosmic company.

In the mid seventies, Stu Bowyer (an X-ray astronomer with an exceedingly clever idea about how to conduct a piggyback SETI program) gave me a copy of the Cyclops Report, a NASA Ames/Stanford/ASEE engineering design study edited by Bernard Oliver and John Billingham. Bowyer wanted to entice me to join his team because I knew how to program an obsolete PDP8/S computer that he'd been given as surplus equipment to use in his search. I read the Cyclops Report and drew two conclusions that remain valid to this day. First, I was lucky enough to live in the first generation of humans capable of attempting to do a scientific experiment to answer the question that thousands of previous generations had been able to address only to their priests and philosophers. Second, this was, and is, the most important scientific exploration humanity can undertake. The first conclusion is self-evident, the second one was later poetically phrased by Philip Morrison, who said, “SETI is the archaeology of the future.”

The successful detection of a signal from an extraterrestrial technology requires that technologies (theirs and ours) survive for a long time-long, that is, in a cosmic sense, not in human terms. Detection of a signal therefore tells us that we (or at least our technology) can have a future. No other human endeavor today is capable of providing us with that information. This doesn't imply “extraterrestrial salvation"; how we get to that future will more than likely be up to us. But it does imply a proof of concept. Detection of a signal requires that we search. That is what I have been doing and will continue to do, and I am hopeful that my successors will do so as well. Quoting Morrison again (writing with Guiseppe Cocconi in Nature, vol. 184, p. 844 [1959]), “The probability of success is difficult to estimate, but if we never search, the chance of success is zero.”

Schenkel spends a lot of time on the Drake Equation and suggests that it has some predictive power; it doesn't. The Drake Equation is simply a way to organize our ignorance in order to permit rational discussion. R* is the only factor in this so-called equation that has any current observational bounds. Within the next decade or so, we may have an idea of the range of values for fp and ne. L is unknown and unknowable, in the absence of a successful SETI program. Today, we can say only that approximately 6 percent of stars like the sun host “hot Jupiters” in short-period orbits. While this is vastly more than we could say prior to 1995, when such objects were unknown and unexpected, it says little about the prevalence of terrestrial planets, or other bodies suitable for life. Schenkel has misinterpreted what is now known from the rigorous searches for extrasolar planets, and has confused observational bias (inherent to the current generation of instrumentation and techniques) with results to conclude that habitable planets are rare. So too, he has confused the interesting and important speculations of the Rare Earth volume with results. Given our sample of one, it is difficult to distinguish between the contingent and the truly necessary in the saga of evolution to a technological civilization on planet Earth today. The data are precisely consistent with life (indeed intelligent life) being rare or extremely abundant in the Milky Way Galaxy; as yet we have no data. Which brings us back to the size of the Cosmic Haystack.

Conclusions based on the examination of a small number of stars on our galactic door step, at a few frequencies within the radio and optical portions of the electromagnetic spectrum, during a few minutes of time, with detectors optimized for a limited class of signal types, cannot be very robust. Forty-six years may seem to Schenkel to be a long time to search without positive results. Indeed it’s longer than my professional career, during which I've worked very hard to conduct and improve those searches. However, it must be examined in a cosmic context-in light of the ten-billion-year history of our galaxy. For signals to be detectable, they must be co- temporal and that requires that technologies overlap (at least within the 100,000-year crossing time of our galaxy). We ourselves have just emerged as a technological civilization. Should we really be surprised that we haven't achieved instant success? Are we so confident that our current technology is the correct technology for the job? Are we still at the mercy of priests and philosophers, or will we use the power of our exponentiating technology to help us survive into old age, and perhaps along the way discover other long-lived technologies? Pogo was right, but we are a long way from having the data to draw the sobering negative conclusion.

The Allen Telescope Array is just beginning an exploration of the astrophysical universe and a search for signals from technological civilizations. As the first telescope to be designed for continuous SETI observations, it will immediately speed up current search strategies by orders of magnitude. Exploitation of Moore’s Law will make it faster yet throughout its lifetime. A new OSETI sky survey instrument at Harvard is about to be dedicated. All readers of the Skeptical Inquirer are encouraged to follow the developments of these projects and other ongoing SETI search programs and to contribute suggestions for their improvement or of alternative search strategies. However, if you are lonely and impatient, perhaps you need to consider an on-line dating service.

Success may be difficult to predict, but it’s too soon to rule it out.

The possible existence of extraterrestrial intelligence (ETI) has always stirred the imagination of man. Greek philosophers speculated about it. Giordano Bruno was burnt on the stake in Rome in 1600, mainly because positing the likelihood of other inhabited worlds in the universe. Kant and Laplace were also convinced of the multiplicity of worlds similar to ours. In the latter part of the nineteenth-century Flammarion charmed vast circles with his books on the plurality of habitable worlds. But all these ideas were mainly philosophical considerations or pure speculations. It was only in the second half of the twentieth- century that the Search for Extraterrestrial Intelligence (SETI) became a scientifically underpinned endeavor. Since the late 1950s distinguished scientists have conducted research, attempting to receive intelligent signals or messages from space via radio-telescopes. Hundreds of amateur astronomers, members of the SETI-League in dozens of countries, are scanning the sky, trying to detect evidence of intelligent life elsewhere in our galaxy. SETI pioneers, such as Frank Drake and Carl Sagan, held the stance that the Milky Way is teeming with a large number of advanced civilizations. However, the many search projects to date have not succeeded, and this daring prediction remains unverified. New scientific insights suggest the need for a more cautious approach and a revision of the overly optimistic considerations.

The standard argument for the existence of a multiplicity of intelligent life runs like this: There are about 200 to 300 billion stars in our galaxy and probably hundreds of millions, maybe even billions of planets in our galaxy. Many of these planets are likely to be located in the so-called “habitable zone” in relation with their star, enjoying-as Earth-favorable conditions for the evolution of life. The physical laws, known to us, apply also to the cosmos, and far-away stellar formations are composed of the same elements as our solar system. Therefore, it is assumed, many should possess water and a stable atmosphere, considered to be basic requisites for the development of life. Such planets must have experienced geological and biological processes similar to those on Earth, leading to the development of primitive life organisms. Then, in the course of time, following a similar course of Darwin’s theory of natural selection, these evolved into more complex forms, some eventually developing cognitive capacities and-as in our case-higher intelligence.

In other words, it is maintained, our solar system, Earth, and its evolution are not exceptional cases, but something very common in our Milky Way galaxy. Consequently it must be populated by a huge number of extraterrestrial civilizations, many of them older and more advanced than ours.

Considering the enormous number of stars and planets, these seem like fair and legitimate assumptions. It indeed appears unlikely that intelligence should have evolved only on our planet. If many of these civilizations are scientifically and technologically superior to us, contact with them would give mankind a boost in many ways.

These optimistic views are based mainly on the famous Drake formula N=RfpnefifjfeL. It considers the formation of stars in the galaxy, the fraction of stars with planetary systems, the number of planets ecologically suited for life, the fraction of these planets, on which life and intelligent life evolves, and those reaching a communicative stage and the length of time of technical civilizations. On the basis of this formula it was estimated that a million advanced civilizations probably exist in the galaxy. The nearest one should be at a distance of about 200 to 300 light-years from Earth. German astronomer Sebastian von Hoerner estimated a number between ten thousand and ten million such civilizations.

But because of many new insights and results of research in a number of scientific fields, ranging from paleontology, geology, biology to astronomy, I believe this formula is incomplete and must be revised. The early optimistic estimates are no longer tenable. A more realistic and sober view is required.

I by no means intend to discredit SETI; the search for extraterrestrial intelligent life is a legitimate scientific endeavor. But it seems prudent to demystify this interesting subject, and to reformulate its claims on a new level, free of the romantic flair that adorns it.

Years ago, I readily admit, I myself was quite taken in by the allegations that intelligence is a very common phenomenon in the galaxy. In books, articles, and on radio and television I advocated the idea that our world, beset by problems, could learn a lot from a civilization more advanced than ours. But, in the meantime, I became convinced that a more skeptical attitude would do reality better justice. There are probably only a few such civilizations in the galaxy, if any at all. The following considerations buttress this rather pessimistic appraisal.

First of all, since project OZMA I in 1959 by Frank Drake, about a hundred radio-magnetic and other searches were conducted in the U.S. and in other countries, and a considerable part of our sky was scanned thoroughly and repeatedly, but it remained disappointingly silent. In forty-six years not a single artificial intelligent signal or message from outer space was received. Some specialists try to downplay this negative result, arguing that so far only a small part of the entire spectrum has been covered, and that more time and more sophisticated equipment is required for arriving at a definite conclusion. Technological and economic criteria may thwart the possibility of extraterrestrial civilizations beaming signals into space over long stretches of time, without knowing where to direct their signals. Or, they may use communication methods unknown to us. Another explanation is that advanced ETI may lack interest in contacting other intelligences, especially those less developed. The argument of the Russian rocket expert Konstantin Tsiolkovski is often quoted: “Absence of evidence is not evidence of absence.”

But neither of these arguments, which attempt to explain why we have not received a single intelligent signal from space-is convincing. True, future search projects may strike pay dirt and register the reception of a signal of verified artificial origin. But as long as no such evidence is forthcoming, the possibility of achieving success must be considered remote. If a hundred searches were unsuccessful, it is fair to deduce that estimates of a million or many thousands ETI are unsustainable propositions. As long as no breakthrough occurs, the probability of contact with ETI is near to zero. The argument that advanced extraterrestrials may not be interested in contact with other intelligences is also-as I will show-highly implausible.

Second, as recent research results demonstrate, many more factors and conditions than those considered by the Drake formula need to be taken into account. The geologist Peter D. Ward and the astronomer Donald Brownlee present in their book Rare Earth a series of such aspects, which turn the optimistic estimates of ETI upside down.

According to their reasoning, the old assumption that our solar system and Earth are quite common phenomena in the galaxy needs profound revision. On the contrary, the new insights suggest, we are much more special than thought. The evolution of life forms and eventually of intelligent life on Earth was due to a large number of very special conditions and developments, many of a coincidental nature. I'll mention only some that seem particularly important: The age, size, and composition of our sun, the location of Earth and inclination of its axis to it, the existence of water, a stable oxygen-rich atmosphere and temperature over long periods of time-factors considered essential for the evolution of life-and the development of a carbon-based chemistry. Furthermore an active interior and the existence of plate tectonics form the majestic mountain ridges like the Alps, the Himalayas and the Andes, creating different ecological conditions, propitious for the proliferation of a great variety of species. Also the existence of the Moon, Jupiter, and Saturn (as shields for the bombardment of comets and meteorites during the early stages of Earth). Also the repeated climatic changes, long ice ages, and especially the numerous and quite fortuitous catastrophes, causing the extinction of many species, like the one 65 millions years ago, which led to the disappearance of dinosaurs, but opened the way for more diversified and complex life forms.

Though first primitive life forms on Earth, the prokaryotic bacteria, evolved relatively rapidly, only about 500 million years after the cooling off of Earth’s crust and the end of the dense bombardment of meteorites and comets, they were the only lifeforms during the first two billion years of Earth’s 4.6-billion-year history. Mammals-including apes and man-developed much later, only after the extinction of the dinosaurs 65 million years ago. The first human-like being, the Proconsul, emerged in the Miocene Period, just about 18 million years ago. The Australopithecus, our antecessor, dates only 5 to 6 million years. In other words, it took almost 4 billion years, or more than 96 percent of the age of Earth, for intelligence to evolve-an awfully long time, even on the cosmic clock.

In this regard we should note also the caveat of the distinguished biologist Ernst Mayr, who underscored the enormous complexity of human DNA and RNA and their functions for the production of proteins, the basic building blocks of life. He estimated that the likelihood that similar biological developments may have occurred elsewhere in the universe was nil.

The upshot of these considerations is the following: Because of the very special geological, biological, and other conditions which propitiated the evolution of life and intelligence on Earth, similar developments in our galaxy are probably very rare. Primitive life forms, Ward and Brownlee conclude, may exist on planets of other stellar systems, but intelligent life, as ours, is probably very rare, if it exists at all.

Third is the so called “Fermi Paradox” another powerful reason suggesting a skeptical evaluation of the multiplicity of intelligence in the galaxy. Italian physicist Enrico Fermi posed the annoying question, “If so many highly developed ETIs are out there, as SETI specialists claim, why haven't they contacted us?” I already expressed great doubt about some of the explanations given to this paradox. Here I need to focus on two more. The first refers to the supposed lack of interest of advanced aliens to establish contact with other intelligent beings. This argument seems to me particularly untrustworthy. I refer to a Norwegian book, which explains why the Vikings undertook dangerous voyages to far-away coasts in precarious vessels. “One reason,” it says, “is fame, another curiosity, and a third, gain!” If the Vikings, driven by the desire to discover the unknown, reached America a thousand years ago with a primitive technology, if we-furthermore-a still scientifically and technically young civilization, search for primitive life on other planets of the solar system and their moons, it is incredible that higher developed extraterrestrial intelligences would not be spurred by likewise interests and yearnings. One of the fundamental traits of intelligence is its unquenchable intellectual curiosity and urge to penetrate the unknown. Elder civilizations, our peers in every respect, must be imbued by the same daring and scrutinizing spirit, because if they are not, they could not have achieved their advanced standards.

A second argument often posited is that distances between stars are too great for interstellar travel. But this explanation also stands on shaky ground. Even our scientifically and technically adolescent civilization is exploring space and sending probes-the Voyager crafts-which someday may reach other stellar systems. We are still far from achieving velocities, near the velocity of light, necessary for interstellar travel. But some scientists predict that in 200 or 300 years, maybe even earlier, we are likely to master low “c” velocities, and once we reach them our civilization will send manned exploratory expeditions to the nearest stars. Automatic unmanned craft may be the initial attempts. But I am convinced that nothing will impede the desire of man to see other worlds with his own eyes, to touch their soil and to perform research that unmanned probes would not be able to perform. Evidently, civilizations tens of thousands or millions of years in our advance will have reached near c velocities, and they will be able to explore a considerable part of the galaxy. Advanced ETI civilizations would engage in such explorations not only out of scientific curiosity, but in their own interest, for instance for spreading out and finding new habitats for their growing population, or because of the need to abandon their planet due to hazards from their star, and also because with the help of other civilizations it may confront dangers, lurking in the universe, more successfully than alone. The Fermi Paradox should therefore put us on guard, and foster a sound skepticism. Lack of interest in meeting a civilization such as ours is the least plausible reason why we have not heard from ETI.

A little mental experiment illustrates this point. Carl Sagan held once that intelligent aliens would visit Earth at least once every thousand years. But such visits have not taken place. Even extending this period to a million years, we fare no better. Let us assume an extraterrestrial craft landed on Earth any time during the era of the dinosaurs, lasting about 140 million years. It is only logical to assume the aliens would have returned at reasonable intervals to study our world and these fascinating animals, but also to find out if any one of them evolved the capability of reasoning, higher math, and building a civilization. There would have been reason for much surmise. According to paleontologists, Drake stresses, the dinosaur sauronithoides was endowed with such a potential. It was a dinosaur resembling a bird of our size and weight and possessing a mass of brain well above average, and, Drake speculates, if it had survived for an additional ten or twenty million years, it might have evolved into the first intelligent being on Earth. But it didn't happen, because the dinosaurs went extinct due to a cosmic catastrophe. When Homo australopithecus, then Homo faber and habilis, and lastly Homo sapiens evolved, shouldn't that have provoked on the part of visiting extraterrestrials a high level of interest? But no such visits are recorded. Only a few mythological, undocumented and highly suspect accounts of alleged visiting aliens exist. It is fair to assume, if advanced aliens had visited Earth during the past 200 million or, at least, during the past 16 million years, they would have left some durable, indestructible and recognizable mark, probably on the moon. But nothing has been detected. The most likely explanation? No such visits took place! There are no advanced extraterrestrial civilizations anywhere in our vicinity. If they existed, they already would have responded to our world’s television signals, reaching some 60 light-years into space-another reason invalidating the claim that our galaxy is teeming with intelligence.

Another argument supporting the skeptical point of view sustained here is the fact that none of the detected planets around other stars comes close to having conditions apt for creating and sustaining life. Since Michel Mayor’s Swiss group discovered the first planet outside our solar system around the star 51 Pegasi ten years ago, about 130 other planets have been identified within a distance of 200 light-years. Research results show that most are of gaseous composition, some many times the size of Jupiter, some very close to their stars, very hot and with extremely rapid orbital cycles. So far, not one presents conditions favorable for the development of even the most primitive forms of life, not to speak of more complex species. Again it may be argued that only a very tiny fraction of planets were surveyed and future research might strike upon a suitable candidate. This may well be, and I would certainly welcome it. But so far the evidence fails to nourish optimistic expectations. The conditions in our universe are not as favorable for the evolution of life as optimists like to think.

Even if water or fossils of microorganisms should be found underneath the surface of Mars, the importance of such a finding for the theory of a multiplicity of inhabited worlds would be insignificant. Some astronomers think that Titan, the famous moon of Saturn, may have an ocean, possibly of methane. Primitive life forms may exist in it, but this remains to be seen. Even if it does, the evolutionary path from such primitive forms to complex life as human beings is-as we have seen-a long one, studded with a unique sequence of chance and catastrophes.

I am not claiming that we are probably the only intelligent species in our galaxy. Nor do I suggest that SETI activities are a waste of time and money. Though, so far, they have failed to obtain evidence for the existence of ETI, they enrich man’s knowledge about the cosmos in many ways. They helped develop sophisticated search techniques, and they contribute decisively to the perception of man’s cosmic destiny. Carl Sagan and Frank Drake, the two most distinguished pioneers of SETI, did groundbreaking work. That their efforts and those of other dedicated SETI experts on behalf of this great cause are tinged with a dash of too optimistic expectation is understandable and profoundly human.

However, in the interest of science and sound skepticism, I believe it is time to take the new findings and insights into account, to dampen excessive SETI euphoria and to adopt a more pragmatic and down-to-earth stand, compatible with facts. We should quietly admit that the early estimates-that there may be a million, a hundred thousand, or ten thousand advanced extraterrestrial civilizations in our galaxy-may no longer be tenable. There might not be a hundred, not even ten such civilizations. The optimistic estimates were fraught with too many imponderables and speculative appraisals. What is required is to make contact with a single extraterrestrial intelligence, obtaining irrefutable, thoroughly verified evidence, either via electromagnetic or optical waves or via physical contact, that we are not the only intelligent species in the cosmos. Maybe an alien spacecraft, attracted by our signals, will decide to visit us some day, as I surmised in my novel Contact: Are We Ready For It? I would be the first one to react to such a contact event with great delight and satisfaction. The knowledge that we are not alone in the vast realm of the cosmos, and that it will be possible to establish a fruitful dialogue with other, possibly more advanced intelligent beings would mark the biggest event in human history. It would open the door to fantastic perspectives.

But SETI activities so far do not justify this hope. They recommend a more realistic and sober view. Considering the negative search results, the creation of excessive expectations is only grist to the mill of the naysayers-for instance, members of Congress who question the scientific standing of SETI, imputing to it wishful thinking, and denying it financial support. This absolutely negative approach to SETI is certainly wrong, because contrary to the UFO hoax, SETI (as UCLA space scientist Mark Moldwin [2004] stressed in a recent issue of this magazine) is based on solid scientific premises and considerations. But exaggerated estimates fail to conform to realities, as they are seen today, tending to backfire and create disappointment and a turning away from this fascinating scientific endeavor. The dream of mankind to find brethren in space may yet be fulfilled. If it is not, man should not feel sorry for his uniqueness. Rather that circumstance should boost the gratitude for his existence and his sense of responsibility for making the most of it.

References

• Davies, Paul. 1992. The Mind of God. New York: Simon and Schuster.
• Drake, Frank, and Dava Sobel. 1992. Is Anyone Out There? New York: Delacourt Press.
• Moldwin, Mark. 2004.Why SETI is science and UFOlogy is not. Skeptical Inquirer 28(6).
• Greene, Brian. 1999. The Elegant Universe. New York: W.W. Norton.
• Sagan, Carl. 1973. Communication with Extraterrestrial Intelligence. Massachusetts: MIT Press.
• Schenkel, Peter. 1999. Contact: Are We Ready For It? London: Minerva Press.
• Ward, Peter D., and Donald Brownlee. 2000. Rare Earth. New York: Copernicus.

A couple of years ago, I saw an announcement for an astrology presentation to a local discussion group called Mingling of the Minds. My first reaction was, “Surely, nobody really believes in astrology anymore! At least not in my well-educated community.” I decided to go “mingle my mind” and find out.

I was appalled. These people had heard some of the arguments against astrology, but they entirely discounted them. Their personal experience was that astrology worked, and that’s all they cared about. The speaker had prepared charts for several members of the group, with scientific-looking symbols and calculations, and they seemed very impressed. I tried to introduce a bit of skepticism by asking questions like, “How did the first astrologers learn which human characteristics corresponded to which heavenly signs?” The speaker said that was an interesting question that could never be answered, because we lack any historical records. Of course, he didn't doubt that they had obtained their knowledge by some reliable means.

Sure they had. I heard about a woman who told a group of friends she had identified new constellations for a more up-to-date astrology; instead of names like Sagittarius and Pisces, the new constellations had names like Vacuum Cleaner and Telephone. She explained how those born under the Vacuum Cleaner are perfectionists who like everything to be neat and clean, and how those born under the Telephone sign are verbally oriented, good communicators, and have lots of friends. Her friends didn't get the joke. They asked where they could learn more about this great new system!

In retrospect, I probably should have told the astrologer I wasn't going to believe in astrology because my horoscope said I shouldn't be gullible.

Future “Mingling of the Minds” sessions were planned with psychics and other strange creatures. I decided that these people were in desperate need of a resident skeptic, so I appointed myself. I knew there was no hope of converting any true believers, but I thought there must be at least a few people who had not irrevocably made up their minds and might like to know the facts.

My skeptic friends tried to warn me: “Never try to teach a pig to sing; it wastes your time and annoys the pig.” I knew this, but I didn't think it applied here. I'm an optimist-these were nice, friendly, reasonable people, and I thought at least some of them would enjoy learning some of the things I had learned. I used to believe a lot of weird things myself, until evidence and reason persuaded me to change my mind. I find it intellectually satisfying to discard an error and learn a truth. I thought others might get the same satisfaction. My friends laughed at my naïveté; but I am a skeptic, so I had to find out for myself.

It was the beginning of an odyssey that introduced me to a strange race of people who believed in angels but not in germs. I can only compare it to visiting a carnival freak show of intellectual, rather than physical, anomalies. I observed how the average nonskeptic member of the public reacts to these anomalies. It almost destroyed my faith in human reason.

We heard from a feng shui practitioner. He explained that feng shui is a science, and he went into details like how you should position the head of your bed to the north. I asked him if he meant geographic north or magnetic north. I'm not sure he even knew the difference, but he guessed that it was probably magnetic north because feng shui has to do with forces that are sort of like magnetic forces. The magnetic north pole is in northeastern Canada; I asked him what he would tell a client who lived in northeastern Canada, directly north of the magnetic north pole-if the client put the head of his bed towards the magnetic north pole, it would be actually be pointing due south. His only answer was, “Gee, that’s an interesting question.” I thought so too. It’s an interesting science if it only applies to certain parts of the globe.

The feng shui guy also sells Chinese medicines. He always checks by opening each bottle and tasting or at least looking to be sure it contains what the label says, because sometimes he finds an entirely different herb in the bottle. That’s his idea of quality control. Nevertheless, he is quite confident that these herbal products are safe. One of the safe remedies he showed us was a Chinese pain reliever called Lemonin. I could see from the label that it was an overpriced mixture of paracetamol, caffeine, and vitamin C. He didn't know that paracetamol is the British name for acetaminophen (Tylenol), so of course, he couldn't warn his victims (oops, I mean clients) that taking Tylenol along with Lemonin could result in a fatal overdose.

A chiropractor insisted that newborn babies needed immediate chiropractic adjustment, because their necks are stretched to over twice their normal length during childbirth, even by C-section. I told him that I knew that was not true, because I used to deliver babies. It couldn't be true, because that amount of stretch couldn't happen without killing the baby. He assured us that, yes, it really does a lot of damage.

Another chiropractor explained that he doesn't believe in the germ theory, because if germs caused disease, we'd all be dead. The only reason some people get sick is because their spines are out of alignment. He has never been vaccinated, yet he is confident he could be exposed to any infectious disease without catching it. Next time we need volunteers to treat a case of Ebola, let’s call on him!

A third chiropractor told us how he diagnoses allergies. He has the patient hold a closed vial containing an allergen in one hand, and he tests the muscle strength in her or his other arm. If it is weaker than before, they are allergic to what’s in the vial. He thought one patient might be allergic to his workplace, and he didn't have a vial of “Boeing,” so he had the patient just think about Boeing, and that worked just as well. He found people were allergic to all kinds of things they had never imagined. He had all kinds of testimonials about miraculous cures. I pointed out that this method, called applied kinesiology, had failed all controlled tests and was rejected even by the majority of his own profession. I read him the words of a professor of chiropractic, who essentially said applied kinesiology was about the stupidest quackery any chiropractor had ever fallen for. He was not impressed: his method works.

I took out a small implement and handed it around the group. No one could guess what it was for. I explained that it was a fleam, a lancet used in bloodletting. The ancient Greeks believed there were four humors, and they balanced the humors by bleeding the patient for fevers and other illnesses. George Washington’s death was hastened (if not caused) by bloodletting. The treatment was in use for many centuries, until science finally tested it and found out it did more harm than good. I told the chiropractor that I could come up with more testimonials for bloodletting through the centuries than he had for muscle testing. If he rejected the scientific evidence that applied kinesiology didn't work, it would be consistent to reject the scientific evidence that bloodletting didn't work. If he accepted the evidence of testimonials for muscle testing, it would be consistent to accept the evidence of many more testimonials for bloodletting. Would he use a fleam? No, he wouldn't. A lady friend asked, “But what does his method hurt, as long as his patients feel better?” I reminded her that bloodletting also made lots of people feel better, and I offered to use the fleam on her to see if it made her feel better. She declined. I can't imagine why.

A massage therapist specialized in energy medicine. She could feel the energy fields around a patient’s body and twiddle them to help patients heal. She knew this was real, because a scientist had actually measured the human aura with some scientific instrument. What kind of instrument? Where were the data published? She didn't have the specifics, but she assured me I could learn about it in a book called The Isaiah Effect. I got that book and read every word of it, but couldn't even find the word aura, much less anything remotely scientific. It is arguably the worst book I have ever read, with an average of one and a half errors of fact or logic per page-I counted. I told her that I found nothing in the book about measuring auras, and her only answer was, “Oh.”

A couple of self-styled “intuitives” (i.e., psychics) spoke to us, and did some amateurish cold readings. One explained away apparent failures by saying that she might be seeing something in the future, and that her intuitions could not perceive time; she immediately contradicted herself by saying the next person would have a new job “within the next three years"! She “read” a hypochondriac man and apparently intuited that he wasn't worried enough already, so she told him she could see something terribly wrong in his abdomen that needed urgent care. Another psychic told us she could actually see angels beside each of us. (In psychiatry, this is called a hallucination and is a sign of mental illness.)

Here are just a few of the astounding comments I heard:

“A molecule made in a plant is natural, so it has to be better than the exact same molecule made in a lab.”

“I had to stop taking my homeopathic sleep remedy because it caused side effects.” (Water causes side effects?)

“I know my headache didn't go away because of any placebo effect, because I would be able to tell if it were just placebo.” (So why do you think scientists bother with placebo-controlled double-blind trials?)

“Truth doesn't matter.”

“What’s true for you may not be true for me; it’s okay if we disagree.”

“We create our own reality.”

I asked one woman what she would think of me if I still truly believed, at my age, that the Tooth Fairy really exists. She said, “I'd think that was really sweet!”

The last meeting I went to was a pro-and-con discussion of dowsing. The “pro” side consisted of “I saw it work; there are lots of dowsers.” I gave the scientific “con” side, explaining the ideomotor effect and the consistent failure of dowsers to find water beyond the level of chance when tested objectively. My information did not go over well. They wanted to hear more about how it works and less about how it doesn't work. The “pro” presenter explained to me that science just hasn't learned how to test dowsers to get a positive result; it doesn't know the right questions to ask. He also explained that science is based on assumptions, so he doesn't trust science; he trusts his intuitions more, even though he admits his intuition can be wrong.

The Pig Instructor Reconsiders

At this point, I had to recognize that these people did not inhabit my universe. They rejected the scientific method, they didn't care about objective truth, and they were happy in their superstitions. I tried hard to understand them, but I failed. I find science and reality far more exciting than superstition. I agree with Lily Tomlin that “the best mind-altering drug is the truth.” Why were the people at “Mingling of the Minds” so reluctant to give up their unfounded beliefs?

Maybe there was something wrong with me. Whenever I told my father I had changed my mind about something, he used to tell me, “If I had a mind like that, I'd change it too.” After being exposed to all these “minglers” who refused to change their minds, I began to wonder if I was the one who was abnormal. Maybe I lacked the gene for certainty. Maybe I am unduly prejudiced in favor of reality testing. Maybe they are right: personal experience and belief are all that matters. I was really beginning to get worried.

Then two things happened to reassure me. First, I read the list of obituaries in the Encyclopedia Britannica yearbook. Among the famous in all walks of life, the important people, the people who mattered, there were plenty of scientists who had contributed to human knowledge and welfare; there wasn't a single homeopath, astrologer, or psychic on the list. Second, I read Saturday, by Ian McEwan. Enough people are reading this novel to put it on the best-seller list, and its main character is a skeptic and critical thinker who says, ” . . .[belief in] the supernatural was the recourse of an insufficient imagination, a dereliction of duty, a childish evasion of the difficulty and wonders of the real, of the demanding reenactment of the plausible.” Maybe science and reason are slowly winning the war against superstition, even if they are losing some of the smaller skirmishes.

In a sense, the people I met at Mingling of the Minds were the norm and I was the anomaly. Minds are not meant to change easily. Absolute certainty based on authority and eyewitness accounts must have had some evolutionary survival value. Humanity has managed pretty well with instinct, magical thinking, and superstition for a very long time, and it will probably continue to muddle through. The scientific method is a recent innovation; it isn't easy, and it doesn't come naturally.

Time is money, and I finally had to admit that Mingling of the Minds was not a good investment. I cut my losses and resigned. I'm too stubborn to not get the last word in, so I wrote this little fable and sent it to Dan, my opponent in the dowsing debate.

Is the Tooth Fairy Real?: A Fable

Harriet told her little brother Dan that there was no Tooth Fairy; it was their parents who put the money under the pillow.

Dan refused to believe Harriet. He knew there was a Tooth Fairy. Every time he put a tooth under his pillow, there was money there the next morning. And all his friends said the Tooth Fairy brought them money too. And it couldn't be Mom and Dad because he'd wake up if they came in the room and lifted his pillow. Anyway, Mom and Dad said there was a Tooth Fairy, and they wouldn't lie.

Harriet asked him how he thought the Tooth Fairy found out about lost teeth, how she got into the house, where she got the money from, and what she did with the teeth. Dan said he didn't know, but wasn't it a wonderful mystery? Harriet pointed out that older kids all eventually stopped believing in the Tooth Fairy. Dan said that only proved that the Tooth Fairy would only bring money to those who still believed in her.

Harriet got several neighborhood kids to help test whether the Tooth Fairy would appear if the parents didn't know a tooth had been lost. It turned out that every time the parents knew about the tooth, there would be money under the pillow the next morning, and every time the parents didn't know about the tooth, there would be no money. Dan said the Tooth Fairy was just refusing to cooperate in those cases, because she wouldn't bring money if she knew she was being tested.

Harriet got out her Junior Detective kit and dusted Dan’s Tooth Fairy money for fingerprints. Sure enough, she found their parents’ fingerprints on it. Dan said that didn't prove anything, because there are lots of ways the Tooth Fairy could get hold of money the parents had previously touched. Or she could have magically put the evidence there to confuse us. And of course, the Tooth Fairy wouldn't leave any fingerprints of her own because she was magical.

The next time Dan lost a tooth, Harriet spread flour on the floor, and the next morning, she showed Dan their parents’ footprints between the door and the head of his bed. He said that didn't prove anything-his parents had probably just checked on him, and the Tooth Fairy had come later. There were no Tooth Fairy footprints, because fairies don't leave footprints.

The next time Dan lost a tooth, Harriet set up a video camera in Dan’s room and caught their parents in the act. (For those readers with dirty minds, I mean the act of removing the tooth and putting money under the pillow.) Dan told her that didn't prove a thing. Maybe the Tooth Fairy wouldn't appear when a camera was present. Maybe she is a shape-shifter who made herself look like their parents on videotape. Maybe she asked Mom and Dad to do the job for her just this once.

Harriet led Dan into their parents’ bedroom, opened a dresser drawer, and showed him a box containing all of Harriet’s and Dan’s baby teeth neatly labeled and dated. She said that was proof their parents were taking the teeth and leaving the money. Dan said it was no such thing; the Tooth Fairy probably passed the teeth on to parents for keepsakes, or maybe she sold teeth to parents to raise the money she put under the pillows. Hey, yeah, that would explain the fingerprints!

Harriet and Dan confronted their parents, who admitted they had been taking the teeth and leaving the money under the pillow. Dan said either they were lying before or they're lying now, and they're probably lying now. Why trust what anyone says? He was just going to ignore everything except what he knew: the tooth-under-the-pillow thing worked. The Tooth Fairy was real.

Harriet screamed in frustration and tore all her hair out. She left it under her pillow. It was still there in the morning.

For twenty-five years a remarkable group at Princeton University, the Princeton Engineering Anomalies Research (PEAR) group, has been pursuing a research program in what many would characterize as parapsychology. A recent article by this group, “The PEAR Proposition” (Jahn and Dunne 2005) summarizes this quarter-century effort. The bulk of the research has been to show that human intent can remotely affect mechanical and electronic devices in a manner consistent with their intention. They have also reported experiments in remote perception. However, in this article I will take a critical look only at the first group of experiments. I first came upon the work of PEAR while on sabbatical leave in 1992. While browsing in the library, I came upon an article in the journal of the Institute of Electrical and Electronics Engineers (IEEE) with the eye-catching title “The Persistent Paradox of Psychic Phenomena: An Engineering Perspective” by R. Jahn (1982). A number of things struck me about this article: it appeared in a reputable, peer-reviewed, credible scientific journal; its author was clearly a colleague with credible scientific credentials, being formerly a Dean of Engineering; and the work was conducted at an institution with impeccable standards, particularly in the sciences. Jahn’s article reviewed historical claims for parapsychology and justifiably rejected many of them for a host of obvious reasons, among them poor methodology, poor statistics, outright fraud, and so on. The last section discussed experiments conducted at Princeton whereby an electronic device was designed to produce a random series of pulses. These were counted in a pre-set time interval and it was established that the accumulated counts scattered around a mean and standard deviation, which conforms to a high degree to Gaussian statistics, i.e., the statistics of random numbers.

Figure 1. First formal results of one operator’s intentions on REG output count distributions, superimposed on theoretical chance expectation: a) baseline data; b) high- and low-intention data; c) best binomial fits to high and low data.

Some of the first results obtained using this device are shown in figure 1. The distribution of the numbers does seem to conform to the expected random distribution about a mean of 100 and with a standard deviation of around seven. A fit derived from the Gaussian distribution with these parameters is shown as the solid line and labeled theory. The word theory is used in the sense of modeled behavior-here the assumption being that in the absence of any extraneous effects the device behaves in a random manner. Theory is not used in the sense of being derivative of a set of physical principles. In their many publications the PEAR group use theory to imply fitting of experimental data to statistical expectations.

The data, as published, appear to show a small offset between the data derived when someone is ostensibly attempting to bias the mean to be higher than it would be in their absence (or, more precisely, in the absence of their mental efforts to produce a bias) and conversely a small offset in the opposite sense when someone attempts to bias the output to be smaller than it would be otherwise.

In attempting to underpin the claims for statistical significance with a theoretical basis, the PEAR group make frequent appeals to quantum mechanics and quote approvingly of Schrödinger, Wigner, etc. They argue, in a metaphorical sense, that the parameters of quantum systems can be mirrored by psychological correlates. Some of the claims advanced by the PEAR group are post-dictions, for example, the claims for gender bias, baseline bind, etc. None of these are actually predicted by any of the many interpretations of quantum mechanics.

Methodological Issues

Figure 2. REG Grand cumulative deviations: All operators.

I have conducted several experiments in collaboration with others in this field (Jeffers 2003). One characteristic of the methodology employed in experiments in which I have been involved is that for every experiment conducted in which a human has consciously tried to bias the outcome, another experiment has been conducted immediately following the first when the human participant is instructed to ignore the apparatus. Our criterion for significance is thus derived by comparing the two sets of experiments. This is not the methodology of the PEAR group, which chooses to only occasionally run a calibration test of the degree of randomness of their apparatus. We contend, although Dobyns (2000) has disputed our claim, that our methodology is scientifically more sound.

If the claims are credible, it should be possible for other groups to replicate them. To their credit, the PEAR group did enlist two other groups, both based at German universities (Jahn et al. 2000) to engage in a triple effort at replication. These attempts failed to reproduce the claimed effects. Even the PEAR group was unable to reproduce a credible effect.

Baseline Bind or Baseline Bias?

Figure 3. Cumulative deviations of all mean shifts achieved by the same operator as figure 2 over entire database of 125,000 trials per intention.

One favored way of analyzing and displaying data from experiments of this type is to calculate the accumulated deviation from normal expectations. If humans had successfully biased the data such that it now has a higher mean than in the absence of their efforts, then by forming successive differences in the data so biased with a data set in which there is presumably no bias, then one would get an ever-increasing sum. Similarly, if the subject had succeeded in biasing the data such that the data now had a lower mean, the accumulated sum would increment in the negative direction. No bias would result in a cumulative sum, which would hover around zero. Gaussian statistics allows one to assign a likely probability to the cumulative sum if no bias were present. Typically, if this probability, p value, is less than .05, then one concludes that a real bias is present. Inspection of the data in figure 2 appears to bear out the claims made. Curves labeled P+ (corresponding to efforts to bias the data to a higher mean value) do indeed accumulate to a running sum unlikely by chance at a p<.01, and curves labeled p- (corresponding to efforts to bias the data such that it has a lower mean) do accumulate in the negative sense with a p<.01. the baseline plot, bl, obtained from data in which no effort is made to bias the equipment does indeed, as per expectations, hover around zero.

In Jahn and Dunne’s book Margins of Reality, a short chapter is devoted to “Baseline Bind.” It is reported that “namely, of the seventy-six baseline series performed, seven or eight of the means would be expected to exceed the 0.05 terminal probability criterion, in one direction or the other, simply by chance. In fact not one of them does.” In other words, the baseline data are too good. The means of the baseline data conform to the means of the calibration data, but the variance of the baseline data is less than that of the calibration data. This baseline bind effect is attributed to “the conscious or unconscious motivation on the part of the operators to achieve a 'good baseline.'” It is instructive to compare the baseline behavior of the data shown in figure 3 with that in figure 4. The data presented in figure 4 show an accumulated deviation which actually achieves significance according to PEAR criteria, as the terminal probability lies just outside the p=.05 envelope. The data in figure 4 represent all the data accumulated in PEAR’s experiments.

When the data shown in figure 4 were first published, surprisingly there was no discussion about the behavior of the baseline data given the previous claims regarding “baseline bind.” The baseline data in figure 4 violate PEAR’s own criteria for significance (i.e., p<.05 terminal probability), and consequently-according to PEAR’s own standards-must be regarded as evidence for nonrandom behavior in the baseline data. This has to call into question the claimed statistical significance of the data labeled HI and LO in the same plot.

Conclusions

Figure 4. Cumulative deviations of all mean-shift results achieved by all 91 operators comprising a database of some 2.5 million trials.

In their book Margins of Reality Jahn and Dunne raise this question: “Is modern science, in the name of rigor and objectivity, arbitrarily excluding essential factors from its purview?” Although the question is couched in general terms, the intent is to raise the issue as to whether the claims of the parapsychological community are dismissed out of hand by mainstream science unjustifiably. This paper argues that in the light of the difficulties in replication (even by the PEAR group itself), the lack of anything approaching a theoretical basis for the claims made, and, perhaps most damaging, the published behavior of the baseline data of the PEAR group which by their own criteria indicate nonrandom behavior of the device that they claim is random, then the answer to the question raised has to be no. There are reasonable and rational grounds for questioning these claims. Despite the best efforts of the PEAR group over a twenty-five-year period, their impact on mainstream science has been negligible. The PEAR group might argue that this is due to the biased and blinkered mentality of mainstream scientists. I would argue that it is due to the lack of compelling evidence.

Acknowledgements

I thank all members of the PEAR team for all their encouragement and support, and Professor J. Alcock of York University for supportive interest and critical insights. Thanks also go to Professor Morris Freeman of the University of Toronto for his interest in the subject matter.

References

• Dobyns, Y. 2000. Overview of several theoretical models on PEAR data. Journal of Scientific Exploration 14(2): 163-194.
• Ibison, M., and S. Jeffers. 1998. A double slit experiment to investigate claims of consciousness-related anomalies. Journal of Scientific Exploration 12(4): 543-550.
• Jahn, R.G., and B. Dunne. 1987. Margins of Reality: The Role of Consciousness in the Physical World, New York: Harcourt Brace Jovanovich.
• Jahn, R.G. 1982. The persistent paradox of psychic phenomena: An engineering perspective. Proceedings of the IEEE 70(2): 136-170.
• Jahn, R.G., and B. Dunne. 2005. The PEAR proposition. Journal of Scientific Exploration 19(2): 195-246.
• Jahn, R., et al. 2000. Mind/Machine Interaction Consortium: PortREG replication experiments. Journal of Scientific Exploration 14(4): 499-555.
• Jeffers, S. 2003. Physics and claims for anomalous effects due to consciousness. In J. Alcock, J. Burns, and A. Freeman, eds. Psi Wars: Getting to Grips with the Paranormal. Exeter, U.K.: Imprint Academic: 135-152.

Set against the fact that SETI has not so far received a positive signal are a number of encouraging developments in astronomy and astrobiology. These include the detection, since the mid-1990s, of more than 150 extrasolar planets, and increasing signs from within the solar system that the conditions deemed necessary for the development of life as we know it (water, organics, and a suitable energy source) may arise on multiple worlds around a single star. Astrobiology is in the ascendancy. Mars, Europa, and Titan head a short list of locales in our neighborhood where scientists would not be at all surprised to find extant microbic life. We are detecting increasingly complex molecules in interstellar space and evidence that life might be able to survive trips between worlds aboard meteorites. As I explain in my book Life Everywhere (Basic Books, 2001), terrestrial life, from the outset-not just over the past few hundred million years-has shown a propensity to become increasingly complex and display the rudiments of intelligent behavior.

The rise of astrobiology and of exoplanetary astronomy has offered SETI researchers a new approach which the SETI Institute, in particular, has embraced. That is, it enables the attempt to make contact with other intelligences to be done from the bottom up rather than the top down. Within the next decade, increasingly powerful and sensitive instruments, based on interferometry, will allow us to detect Earthlike worlds that may orbit sunlike stars within a range of a few hundred light-years. These instruments and their successors will enable us then to analyze the light coming from these “alien Earths” to search for biogenic signatures, such as those of molecular oxygen and chlorophyll. If we are successful in demonstrating beyond reasonable doubt that certain known planets are life-bearing, we can then begin to study these worlds more closely to see to what heights their indigenous life has evolved. Are there signs of industrial contaminants in the atmosphere or stray artificially produced EM emissions? When we reach this stage of our investigations, astrobiology and SETI will join forces in an effort to determine if high intelligence is present.

Personally, I feel there’s only a slim chance that any time soon we'll make contact with another race in our galaxy that is at roughly the same technological level as ourselves. I suspect there is a technological window of about 500 years beyond which we would effectively be blind to another intelligent species. The galaxy may be swarming with advanced intelligence that is as invisible to us as satellite communications is to a native in the rainforest. Moreover, our galactic elders, if they exist, far from having any desire to communicate with us, would likely be interested in us only as biological or anthropological specimens. They may also have the wisdom to appreciate that any interference by them in our affairs would have the potential to destroy our culture, just as we in the West have harmed the less technologically advanced races on Earth with whom we've made first contact.

Today astrobiology has developed into an international multidisciplinary field, bringing together biologists, chemists, astronomers, geologists, and planetary scientists to seek common ground. There are two major professional journals in astrobiology, international meetings, several nascent professional societies, a NASA Astrobiology Institute (where I work), and an explosion of college courses and books on this topic. It is within this broader context that we should examine SETI programs and their scientific underpinnings.

Studies of life on our planet continue to broaden our understanding of the robustness of life, and its ability to survive and even thrive in seemingly extreme environments, ranging from boiling hot springs to Arctic sea-ice to the cooling water of nuclear reactors. But while life may be widespread, detecting it on other worlds is challenging. Within our solar system, we may need to return samples to Earth for detailed study that might reveal unambiguous signatures of past or present life. For planets around other stars, astronomical techniques are all we have. The problem here is to understand what global biomarkers (such as oxygen in an atmosphere) can be relied upon, and how we can develop the new instruments to make the required measurements. SETI presents us with an alternative approach to biomarkers. While the occurrence of a technological civilization is probably rare even on living worlds, the detection of a radio or optical signal from such a civilization would provide unambiguous evidence of life.

Peter Schenkel’s article “SETI Requires a Skeptical Reappraisal” mostly lacks the modern astrobiology perspective. His target is high expectations of the success of SETI based largely on philosophical positions that go back to Giordano Bruno. In fact, much of his article seems to be aimed at refuting his own past optimistic positions, making his reappraisal a personal statement of reduced expectations. Probably the truth about current ideas on SETI lies between these optimistic and pessimistic extremes.

One area in which I believe Schenkel is too negative is the matter of the prevalence of exoplanets-planets circling other stars. It has been common in evaluations of the Drake equation to set this number at between 10 percent and 100 percent, based until recently on little hard information, since no exoplanetary systems had been discovered. All this has changed in the past decade, with more than 150 exoplanets known today. Initial results were confusing and perhaps disheartening for SETI supporters, since the systems being discovered were dominated by giant planets very close to their suns. These “hot Jupiters” are incompatible with the presence of Earth-like planets. But these strange (to us) configurations are actually found in only about 10 percent of solar type stars. Recent improvements in detection technology are now revealing systems with giant planets in jovian-like orbits, which leave open the possibility of terrestrial planets like our own. Today these Earth-like planets are undetectable, but within three years the NASA Kepler observatory should be able to find analogues of Earth. Thus the new results, while inconclusive on the prevalence of Earths, are actually encouraging. Earth-like planets may be common in the universe, and we should soon know!

The “rare Earth” hypothesis is also used by Schenkel as an argument against the common presence of inhabited planets. He correctly lists several unusual features of Earth that seem to have been favorable to the evolution of advanced life. The exact duplication of such a situation in another planetary system is indeed rare. But are these elements of our past history really required? I do not think we know enough about the origin and evolution of life to define the range of conditions that are conducive to life and intelligence. Earth is rare, but it does not necessarily follow that inhabited planets are rare.

His note that it required “more than 96 percent” (I think he meant 99 percent) of the age of Earth for higher intelligence to evolve illustrates an interesting logical error. We always look at the past from our present perspective. I read Schenkel’s article only today, which represents less than one trillionth of the age of the Earth, but that really does not say anything about the probability of this article having been written and sent to me by the editor of SI. Besides, there are probably many Earth-like planets with up to twice the age of our solar system.

Is SETI likely to succeed in our lifetimes? I do not know. I hope so, of course, but I cannot assign a probability to such near-term success. I think the situation demands skepticism but not pessimism. I think that Schenkel would agree with this perspective.

There are two well-known SETI-related conclusions of which we can be confident, however. If we succeed, any civilization we detect will almost surely be far in advance of our own, and the message itself may be indecipherable. We should not, therefore, look to SETI for easy solutions to our current challenges on Earth. The second conclusion is that, while we may not succeed if we search, we are assured of failure if we do not search.