Cosmos - Carl Sagan [25]
Human beings are good at understanding the world. We always have been. We were able to hunt game or build fires only because we had figured something out. There was a time before television, before motion pictures, before radio, before books. The greatest part of human existence was spent in such a time. Over the dying embers of the campfire, on a moonless night, we watched the stars.
The night sky is interesting. There are patterns there. Without even trying, you can imagine pictures. In the northern sky, for example, there is a pattern, or constellation, that looks a little ursine. Some cultures call it the Great Bear. Others see quite different images. These pictures are not, of course, really in the night sky; we put them there ourselves. We were hunter folk, and we saw hunters and dogs, bears and young women, all manner of things of interest to us. When seventeenth-century European sailors first saw the southern skies they put objects of seventeenth-century interest in the heavens—toucans and peacocks, telescopes and microscopes, compasses and the sterns of ships. If the constellations had been named in the twentieth century, I suppose we would see bicycles and refrigerators in the sky, rock-and-roll “stars” and perhaps even mushroom clouds—a new set of human hopes and fears placed among the stars.
Occasionally our ancestors would see a very bright star with a tail, glimpsed for just a moment, hurtling across the sky. They called it a falling star, but it is not a good name: the old stars are still there after the falling star falls. In some seasons there are many falling stars; in others very few. There is a kind of regularity here as well.
Like the Sun and the Moon, stars always rise in the east and set in the west, taking the whole night to cross the sky if they pass overhead. There are different constellations in different seasons. The same constellations always rise at the beginning of autumn, say. It never happens that a new constellation suddenly rises out of the east. There is an order, a predictability, a permanence about the stars. In a way, they are almost comforting.
Certain stars rise just before or set just after the Sun—and at times and positions that vary with the seasons. If you made careful observations of the stars and recorded them over many years, you could predict the seasons. You could also measure the time of year by noting where on the horizon the Sun rose each day. In the skies was a great calendar, available to anyone with dedication and ability and the means to keep records.
Our ancestors built devices to measure the passing of the seasons. In Chaco Canyon, in New Mexico, there is a great roofless ceremonial kiva or temple, dating from the eleventh century. On June 21, the longest day of the year, a shaft of sunlight enters a window at dawn and slowly moves so that it covers a special niche. But this happens only around June 21. I imagine the proud Anasazi people, who described themselves as “The Ancient Ones,” gathered in their pews every June 21, dressed in feathers and rattles and turquoise to celebrate the power of the Sun. They also monitored the apparent motion of the Moon: the twenty-eight higher niches in the kiva may represent the number of days for the Moon to return to the same position among the constellations. These people paid close attention to the Sun and the Moon and the stars. Other devices based