And what, might you ask, is a neurobiologist doing writing a book about astronomy? I tell the astronomers that this is the neurobiologists’ revenge — the astronomer Carl Sagan did, after all, write a best-selling book about neurobiology. (Indeed, The Dragons of Eden sets a high standard for would-be interlopers.)

     Or what, for that matter, am I doing writing a book that is, in part, about shamanistic practices and the possible origins of religion? That’s a little harder to answer, even to myself; unlike astronomy, such are not among my hobbies. Yet while out hiking and admiring the views from ancient ruins such as Stonehenge, I stumbled on something interesting, a candidate for how the first shaman, the first priest, the first prophet — and maybe even the first scientist — might have gotten started in their part-time occupations, back in the hunter-gatherer days of the Ice Age. I have come to think of ancient astronomy as the first “knowledge-based industry,” that a shaman was also likely the first scientist.

     Still, I might not have gotten around to writing a book were it not for how well the discoveries illustrate something about how scientists really work (in contrast to the myths that build up). When I blunder into a series of simple discoveries that many a high school science student could have made, I am reminded that they had remained undiscovered over all those years of visitors to such sites marveling over the architecture, nearly always asking, “What was it for?” — but advancing no further. How does such a question ever achieve a tentative answer, susceptible to the better-known scientific processes of rationality and careful testing? We teach the rational part of science (at least to those students who go on to make up the six percent minority of the population that can pass a simple test of “scientific literacy”) but we seldom manage to get across the creative process that spans the time from the first “Isn’t that interesting?” to the scientific debates in learned journals. I suspect that the scientific creative process is little different from the creative process involved in writing a novel or composing a symphony.

     In the seventies, I’d read the Stonehenge books of Gerald Hawkins and Fred Hoyle — and was both fascinated and dissatisfied. Surely, I thought, there must be a simpler way to predict eclipses than those clever record-keeping schemes that they were proposing. From all the examples I’d seen of emergent properties, I was well aware that complex results often arose from simple rules. Perhaps, I mused, rules for eclipse prediction could be discovered without anyone understanding why they worked.

     Emergent rules is about all that this book’s subject matter has to do with my usual expertise. Archaeoastronomy started out as hobby, providing some vacation-time relief from those long days in a hot laboratory solving surgical and electronics problems, thinking about how brains work, how they evolve, and what abrupt climate change does to them. Fans of my throwing theory, or the Darwin Machine, or islands in the mind, will not find them elaborated here — though “evolutionary thinking” will be found, as well as my preoccupation with climate change. As every tourist at Mesa Verde soon learns, the Anasazi disappeared due to a great drought, rather like those abrupt climate changes elsewhere that may have helped to bootstrap our apelike ancestors into more human levels of intelligence (which I discussed in The Ascent of Mind: Ice Age Climates and the Evolution of Intelligence).

     While my earlier books have often used travels as a framework for discussing science, this one is a proper “journey of discovery.” It is about formulating a question, collecting contradictory evidence, occasionally seeing how to reconcile previously unconnected evidence, revising my theory on the spot and seeking out new data, suddenly feeling that I had begun to see the world as an ancient shaman had. I did have to make one compromise: in writing for general readers, I have rearranged the order of discovery in minor ways. For example, I left the precision measurement site in the Grand Canyon until the penultimate chapter, even though it was discovered first and motivated me to look at other Anasazi sites (which, it turned out, worked very differently and required me to find a whole new way of looking at things than I’d gleaned from the initial discovery). Personally, I suspect that most good stories about scientific discoveries have also been, consciously or unconsciously, edited and rearranged to improve the telling. Scientific problems start out confused and ill-defined, with motivations that are usually different from those that develop later when the solution is unfolding. The confusion I exhibit in this book is minor, compared to what I felt!

     The other rearrangement was more a matter of literary challenge than explanatory necessity. I have avoided giving the textbookish geometric explanation for eclipses (and for the northeast-to-southeast changes in sunrise and moonrise positions) in the first few chapters of the book, just to give the reader an opportunity to see how a hunter-gatherer might have approached the problem from a flat-earth viewpoint: what phenomena there were to notice, what use anyone could have made of the crude beginnings, how someone could have eventually backed into doing science without really intending to.

     Emerging scientific questions are especially useful for familiarizing nonscientists with the creative aspect of science; nonscientists often feel that, unlike literature and politics, science has no place for their opinions, that it is “all fact” that they cannot debate in a familiar manner, that to create a new contribution requires unimaginable years of specialty training (not true!). And so this is a book for those nonscientists who have always wanted to participate in a good quest, who are interested in seeing ancient ruins in a new light — and with those ruins, catching a glimpse of our pioneering ancestors who bootstrapped themselves up out of superstition.

          W.H.C.
               Woods Hole and Seattle