|A book by|
William H. Calvin
UNIVERSITY OF WASHINGTON
SEATTLE, WASHINGTON 98195-1800 USA
How the Shaman Stole the Moon|
Copyright ©1991 by William H. Calvin.
You may download this for personal reading but may not redistribute or archive without permission (exception: teachers should feel free to print out a chapter and photocopy it for students).
Picturing the Eclipsed Sun
Totality. The very word brings up an image of an eerie scene, accompanied by paradoxical phrases such as darkness at noon. The total solar eclipse is usually a once-in-a-lifetime event for the person lucky enough to see it at all. Everyone who gets to see a total solar eclipse also gets to see a partial eclipse, the process of the moon slowly covering up the sun and then slowly uncovering it. Most people, however, get to see only a partial eclipse because they arent in the 160-mile-wide path of the moons shadow: the moon only partly covers the sun before reversing, when you arent in the path of totality.
When the moon doesnt quite manage to obscure the sun, the eclipse is hard to see, even if you know that it is going to happen and are alert for it. Even a crescent sun can be too bright to look at. The only partial solar eclipse that Ive ever viewed directly happened to occur just before sunset, as the sun and the new moon together sank lower and lower into the western sky, and finally into the Olympic Mountains as viewed from Seattle.
You can sometimes study the suns shape just before it sets, if you are careful. The suns brightness is dimmed by the long path taken by the light through the atmosphere; sometimes it becomes dim enough to allow a brief glimpse. That evening, as the sun neared the horizon, the moon could be seen just in front of it, obscuring the suns lower left. The three-dimensionality was quite striking. The moon was, literally, backlit. You could see how the notion that the moon did it would have arisen as an explanation for solar eclipses, even though the new moon is ordinarily invisible in the suns glare for a day or two.
The sun is too bright (and too dangerous) to view when higher in the sky. Observers rarely study its shape. Should the partial eclipse occur in the middle of the day, the sky may darken only about as much as if some high overcast had dimmed the sun a little and then, because you are seldom in the path of totality, the sunshine brightens again, just as if the high cloud had drifted away. Hardly a big occasion. The important thing about viewing partial solar eclipses is that you can get an hours warning of the potentially frightening totality.
ANY FAN OF ECLIPSES has heard of pinhole cameras, which use a hole in a card to produce
an inverted image of the eclipsing sun on a screen. Pinhole images are far easier to produce than
you might think; you dont need a darkened tent with a hole in the roof, plus a nice white
surface for a screen. Pinhole images occur in nature, as you can discover lounging in the shade
of a tree whose leaves have been perforated by insects. Likely, someone remembered those little
round spots of light that had inexplicably turned into crescents before the world darkened. Odd-shaped spots, all facing the same way, are certainly striking, evoking a sense of warped reality.
Even if you cant articulate whats different, you feel as if something is
If you are watching for a solar eclipse, just hold a perforated leaf at arms length toward the sun, the way that a child instinctively does to backlight an autumn leaf. Look down at your chest to the leafs shadow and see the little crescent of light in the midst of the shadow. The leaf is probably the worlds first portable pinhole camera. As you move the leaf farther away, the light spot changes from the shape of the insects hole to the shape of the eclipsing sun. The smaller the hole, the sharper the image.
Once you get the idea that the holes the thing, you may no longer require the assistance of a leaf-cutting insect or a plant species with naturally perforated leaves, such as the philodendron species commonly called Swiss Cheese. Just punch a hole with a twig. Or, if leafless, merely cross your fingers (for good luck?) to produce a small opening and inspect your hands shadow for a little crescent.
I almost didnt see the midday eclipse in Seattle that got me started on nonstandard pinhole methods; the path of totality was over Canada, and the calculations showed that it would be less than half-total in Seattle. Furthermore, at the hour of the eclipse, it was overcast in Seattle, though the sun seemed on the verge of reappearing from behind a high, thin layer of moisture. I peeked through the window shades of a south-facing window, and thought the prospects of seeing anything quite poor. The clouds were so bright that I couldnt even distinguish the sun, much less its shape. Yet the sun was casting modest shadows of the window frame across the desktop.
Then I noticed the spots of light on the ceiling. Obviously, they were reflections of the sunlight, off of something on the desktop. The spots moved ah, my wristwatch was reflecting the sunlight. I tried covering the crystal face of the watch with two fingers, and the large, round spot on the ceiling disappeared.
Yet the small ones remained. And they seemed crescent-shaped. Nothing was crescent-shaped on my watch. I tried covering each little shiny patch of chrome at the bracket where the wrist strap attaches. And the crescent on the ceiling suddenly disappeared.
The chrome patch was a small rectangle, not crescent. And then it finally dawned on me: the crescent on the ceiling is the shape of the sun when partially eclipsed. Even though I couldnt see the sun looking out the window because the nearby clouds seemed so bright, the image was amazingly sharp. The chrome rectangle was simply acting like a pinhole camera, combined with a mirror.
Once I had the idea (one that has probably been invented by many a school teacher over the years, trying to keep the children from looking directly at the sun), I took off the watch and propped it up on the desk, repositioning it so as to lower the crescent from the ceiling to the far wall of the room, where it was darker. Now I could walk up to the wall, take off my glasses, and closely examine the crescent. The nick that the moon had taken out of the sun was quite visible. Over the course of the next hour, it changed; the sun was never more than half-covered before the nick began to retreat.
I had some time to play around with the size of the mirror. When I used a small rectangular mirror, borrowed from my wifes purse, I only saw a rectangle on the wall. Similarly, when I used a small dental mirror, I saw only a round spot and not the crescent shape of the partially eclipsed sun. I used some bandage tape to mask most of the little mirror, leaving only a small hole unobscured. And finally the crescent shape appeared on the wall. The size of that facet on my watch seemed just about right, close enough to a pinhole for the shape to be that of the light source, rather than the reflector.
Crystals, at least those with many small-but-flat reflecting surfaces, also ought to be useful for viewing eclipses; a small facet serves to combine the pinhole with a mirror. Pull the shades except for a small opening, lay your crystal or jewel on the window sill in the sunlight, and walk up to inspect the crescent spots reflected onto the walls. A square millimeter seems about the area needed for a mirror to function as a pinhole; little spangles embedded in a plaster wall would work nicely. A cave with a ray of sunlight coming in the smokehole, touching a shiny piece of mica, could have been the first movie theater, entertainment for the dozens if you dont mind giving away your secret of eclipse forecasting.
Either leaf or crystal or crossed fingers would allow an alarm for a total solar eclipse, were this technique routinely used during the day of the new moon. The knowledgeable would likely warn the others to start praying. Its another entry-level eclipse forecasting method, simple enough not to require planning or antecedent techniques. It gives an hours warning of possible totality rather than the many-months-ahead prediction of the counting-by-sixes clenched fist method.
So eclipse Method #2 might be called the Holy Leaf or Crossed Fingers. And the crystal (or jewel or piece of broken mica) is its slightly-harder-to-discover corollary. Since prehistoric peoples probably wouldnt have understood the principle by which the holy leaf and the crystal were related, I suppose that Id better just call it Method #3 (The Crystal), rather than merely a corollary, since they were likely to be discovered independently of one another.
Since that day with the wristwatch, each time that Ive been in a cathedral observing rays of sunshine illuminating a jeweled altarpiece, Ive wondered if the architecture and the jewel facets were influenced by an ancient practice of just that sort.
WHY DO WE CALL THEM NEW MOONS, anyway? I can see why the first little crescent
seen after sunset might be called new, but new moon on your calendar is an astronomical
abstraction. You cant see them; theres a night or two when no thin crescent of
moon can be seen (because of the suns glare near sunrise, and then sunset), then the
moon reappears above sunset.|
But prehistoric peoples concerned about eclipses might find the exact day of new moon just as real as the day of full moon. Nothing may ordinarily happen on the exact day of the new moon, but solar eclipses occasionally happen. If youre aware that something might happen during the daytime when the moon can no longer be seen at twilight, new moon might be a significant time of the month, when a careful watch has to be kept with a crystal or holy leaf or crossed fingers. Good luck might be the avoidance of a solar eclipse.
WINDOWS IN A ROCK WALL are one of the more spectacular features of the canyon country. They do not, alas, qualify as pinholes in most cases. Rock arches are the most graceful forms, one of the nicest being Delicate Arch at Arches National Park north of Moab, Utah.
The first time that I hiked up to see it was on a summer evening. Delicate Arch is situated on the rim of a giant bowl, almost a funnel, carved in the sandstone. The arch itself rises, crests gracefully at about four stories high, and then drops like a Roman column to rest on a little pedestal, a platform of sorts on the edge of the bowl: imagine a delicate V-shaped coffee cup whose finger loop has been displaced to the top of the cups rim. Beyond the edge of the bowl, the rock drops away steeply into a little valley, on the far side of which is the end-of-the-road viewpoint from which most visitors look up to view Delicate Arch. But they miss seeing the bowl, on whose edge the arch seems suspended.
I sat atop the far edge of the bowl, where the trail ends, and looked across the bowl at the arch, and beyond to the distant mountains. The shadows were lengthening. The sun was behind me in the western sky, heading northwest, and the shadow line was creeping up the bowl toward Delicate Arch.
Down at the bottom of the bowl, I noticed a spot of light in the midst of the shadow. Soon it had moved, angling up the bowl. And I realized that there must be a window in the rock somewhere behind me.
I picked my way carefully along the edge of the bowl to the south and, sure enough, there was a large opening in the rock, big enough for a few people to stand in. As I stood there, I could see the diffuse shadow that I created in the midst of the spotlight on the other side of the bowl below Delicate Arch.
The bowl, and Delicate Arch, and the distant mountains were all very dramatic even without the spotlight. The bowl is almost a natural amphitheater, its rim below the arch a natural stage, visible both for people sitting around the bowl and for any viewers on the other side of the little valley where the end of the road viewpoint now is. And here we had a spotlight, angling up toward the stage as the sun set in the northwest sky.
The elevated pedestal at the foot of Delicate Arch had plenty of room for someone to stand, a natural speakers platform in the midst of all this natural seating for the multitudes. If the ancient Greeks had such a setting, they wouldnt have needed to build that amphitheater at Delphi. While Delphi may have steam-emitting springs on occasion, it lacks a built-in spotlight.
Delicate Archs natural spotlight is not adjustable, however, being dependent on the suns path through the sky. Though, I suppose, if a dozen people stood in the window, they could turn the spotlight on and off via kneeling and standing up (inadvertently casting a shadow on the spotlit priest might have had more severe consequences than mere shouts of Sit down!). I looked back through the window in the rock and saw a cliff to the west that would block the sunlight from reaching the window except when the sun was well into the northwestern sky. This only occurs near the summer solstice, in the half-hour before sunset. So that spotlight doesnt exist most of the year.
Fortunately, I was there only a few days after the summer solstice, and thus saw the shadows and the spotlight going as far southeast as theyd ever go. And the spotlight was angling up the bowl toward the speakers platform. Weeks later, it would surely angle up to the middle of the adjacent pillar, not the speakers platform.
I snapped one picture after another, wondering whether the spotlight would wink out before ever reaching the little platform (which would ruin the best part of my theatrical theory). But about the time that the shadow line was approaching the top of Delicate Arch, the spotlight reached the platform. Someone standing there would have been bathed in a red-orange light (if Id been thinking, I would have asked one of the other hikers to run around the rim and stand there). And then the reddish light would creep up the person, finally illuminating only the headdress. Then it would dim out as the sun set.
A climactic performance, just for me and a few other hikers. Would the prehistoric Indians have come in greater numbers? The Paleo-Indians were hunter-gatherers (not tied down all summer by hauling water to the plants if the thunderstorms dumped their rain in the wrong place, as were the Anasazi) and hunter-gatherers have an important reason to hold big meetings. Each band was a closely interrelated group of perhaps 25 people. Incest prohibitions being what they are, prospective spouses came from another band.
Anthropologists have calculated that it takes a pool of at least 500 people (in other words, a tribe of 20 bands) for the unmarried to find more than one unmarried person of suitable age and opposite sex. So hunter-gatherers who wanted some choice in this important matter had a real motivation to get together regularly, even if they couldnt live together at that density for very long, food on the hoof being scattered the way it is. My guess is that Delicate Archs spotlight was used by the chief shaman of a preagricultural tribe, that this is one place where they held their summer meeting -- and that the transient nature of the spotlight gave them a reason to meet near the summer solstice.
IN THE OLD WORLD, the Stone Age sites have usually been built upon, repeatedly.
Whats worse, old materials have been re-used, confusing the archaeologist. And even
when the archaeologist finds a late neolithic construction, such as Stonehenge or Avebury,
relatively intact, one knows little about the cultural traditions of the people who built it. In the
New World, you can find undisturbed sites. Even better, there are Native Americans whose
cultural traditions have descended from Stone Age peoples, providing a glimpse of the culture of
the ancient builders.|
The Pueblo Indians of the American Southwest are a case in point. Their distant ancestors are among the Paleo-Indians who crossed over from Asia to the Americas perhaps 15,000 years ago and subsequently followed the ice-free corridor east of the Rockies when it opened about 12,000 years ago, allowing passage from Alaska to the mid-latitudes of North America. About 2,300 years ago, some of the bands in the desert southwest began to settle down to agriculture which is when one starts referring to them as Anasazi rather than Paleo-Indian. They may have acquired corn (maize) and squash from the natives further south, who were the first to domesticate corn. These two stapes for their diet enabled their population to double and redouble over what mere hunting and gathering would support.
The rains are fickle in this country, which is largely mountainous desert, and so the Anasazi continued to get a lot of their calories from nuts, cactus, rabbits, and bighorn sheep. Theyd have gotten into dietary troubles if they hadnt supplemented with such hunter-gatherer items, since corn and squash alone arent a nutritionally balanced minimal diet. When beans were later added, the three crops would have made them largely independent of the wildlife and nuts, but I suspect they treasured their traditional foods and continued to seek them out at least, on the occasions when they werent trapped, hauling water to their crops. The occasions when they had the leisure to forage must have been a pleasure, as some people today feel for going shopping.
The Pueblo peoples are largely descendants of the Anasazi who took refuge in those Pueblo settings at the time of the great droughts between A.D. 1130 and about 1300. So the word Anasazi refers to a culture that existed from 2,300 years ago up until a substantial isolation and mixing with adjacent tribes (such as the Sinagua) took place about 700 years ago; its last phase produced the cliff-dwellings at places such as Mesa Verde. Pueblo refers to the living descendants of the Anasazi, who now prefer to live atop mesas and farm nearby. The remaining Pueblo Indian tribes are the Hopi, the Zuni, and several dozen smaller Rio Grande Pueblos (the latter tribes were largely Christianized by the industrious Spanish priests who came to New Mexico with the Spanish governor).
The Pueblos have, of course, likely undergone their own changes in the last 700 years, particularly as a consequence of the European culture that invaded the region with the Spanish Entrada of 1540, with more rapid changes occurring as settlers moved west in the nineteenth and twentieth centuries. Historic Pueblo tends to refer to the Pueblo culture in the period 1880-1895, when a series of anthropologists and diarists (often Protestant missionaries) recorded much about the Pueblos, at least those aspects that the Indians would show them and discuss.
The previous three centuries of presumably literate and curious Catholic clerics did not produce such a literature; this lack is likely a consequence of the intellectual intimidation of the Spanish Inquisition (initiated in the thirteenth century, the Inquisition was not finally suppressed until 1834). Since the Hopi, living in northern Arizona on high mesas about 100 kilometers east of the Grand Canyon, had been least affected by the Spanish priests working out of Santa Fe, New Mexico, the late nineteenth century Hopi culture is often assumed to be the closest to the original Anasazi culture, to the elements of the hunter-gatherer culture that preceded agriculture. However, the Hopi are traditionally secretive about ritual matters; for all we know, the essence of their ritual practice went unrecorded.
Still, whatever the limitations, one thus achieves a rare glimpse of the word-of-mouth culture of a temperate-zone Stone Age people. There are no such survivors of the European and Middle Eastern Stone Ages -- for those long-gone cultures, one has only hard evidence, the stone tools and broken pottery that have survived better than the wooden spears, sandals, carrying bags, and verbal culture. For the Anasazi, one even has pictographs and all sorts of soft evidence in the form of wood tools and intact necklaces. Despite the problems of inference back across several transitions, Anasazi archaeology and Pueblo ethnography give the archaeologist a lot to go on.
The pre-Columbian Americas in general, when compared to the Old World, give a unique view of another way to develop a high civilization than those followed by the peoples of the Fertile Crescent. Though more advanced than the Old World in certain areas (the Mayans were using the number zero well before the Old World; the Paleo-Indians domesticated corn, etc.), the lack of metal tools prevented the American cultures from straying very far away from the essentials. We marvel at their road systems (even though they lacked both wheeled vehicles and horses), at their extensive cultivation without the plow. And their art.
WHILE ANASAZI ROCK ART is sometimes found out in the open, exposed to the weather,
what remains is usually found protected under an overhang of some sort. There, the sun
doesnt heat up (and expand) the surface rock every day, eventually causing it to soften
and flake off. Permanent shadows help posterity, whether the rock art is painted (pictographs) or
pecked into the rock surface (petroglyphs).|
The Anasazi lived in a land of long, temporary shadows. Canyon country. Some of those moving shadows slowly sweep across rock art. Much has been written about the potential astronomical significance of the art-shadowline combination. Fajada Butte is perhaps the best known of the examples. High up one side of this free-standing butte, at the southern entrance to Chaco Canyon in New Mexico, are some fallen slabs of rock. If you crawl beneath them, you can see the midday shadows, narrowed to leave only a slit of light, move slowly across a spiral pecked into an underlying rock: the Sun Dagger, as the moving slit has been named.
It is said to mark the summer solstice but one sees about the same thing for weeks. So far as I know, there is nothing that happens at Fajada which uniquely marks the exact day of the solstice. There is a lot of Anasazi rock art scattered around the Southwest that is specially shadowed near the solstices, so the illuminated spiral on the side of Fajada Butte probably was intended to celebrate the summer solstice. But it doesnt mark it, in the sense of specifying the day of turnaround. Watching the position of sunrise on the horizon would have worked better than the Sun Dagger.
More interesting are rock art depictions of the Crab Nebula supernova of A.D. 1054, the best of which is located at the other end of Chaco Canyon. There is little doubt that the Anasazi paid a lot of attention to the skies, especially at the solstices. So did they build a Stonehenge?