READING TEST 7 PART 3

Prehistoric peoples most certainly took note of the recurring patterns of movements in the sky of such celestial bodies as the Sun, the Moon, the planets, and the stars, and they most certainly noted that events in their world, such as seasonal fluctuations in weather, which in turn had an effect on the lives of the plants and animals in their world, were often correlated with the movements of the celestial bodies. Because it was important for prehistoric people to have knowledge, for example, of when it was important for prehistoric people to have been migrating, early farmers and hunters took a great interest in the movements of celestial bodies. An understanding of the relationship between the movements of celestial bodies and recurring patterns of events on Earth was paramount in many cultures; thus, many cultures in widely separated areas of the world developed methods for monitoring astronomical events.

The field of archeoastronomy, which combines knowledge and expertise from the fields of archeology and astronomy, is dedicated to the study of the astronomical knowledge of prehistoric cultures. Archeoatronomers who have been studying prehistoric cultures in North America have been discovered various devices that made it possible for prehistoric people to study and record astronomical events. An alignment of stones in Wyoming that is known as the Bighorn Medicine Wheel, the remnants of a circular-shaped structure created with wooden posts at Cahoki in Illinois, and specially designed windows in structures of the Southwest that allowed the rays of the Sun to hit designated marks on inside walls are all believed to be constructions that serve the function of monitoring and measuring astronomical events.

One particular construction, which is located in the Chaco Canyon area of the state of New Mexico, has been the subject of considerable attention and discussion among archeologists and astronomers. This construction, which is at least 700 years old, consists of large slabs of rock located on top of the flat surface of a high butte that seem to form an observatory of sorts. What makes it appear to experts to be an observatory is that the slabs of rock are positioned so that shafts of sunlight fall between them and hit spiral markings carved into the side of a cliff. As the Sun changes positions with the progressions of the seasons, the shafts of light fall in different places on the markings in the cliff wall. Using this system, it must have been possible for early inhabitants of the area to predict upcoming seasonal changes and the events based on them.

One question that has been the focus of considerable discussion is whether the stones were actually placed in their current location by early inhabitants of the region or whether the stones forces of nature created the arrangement. While some scientists argue that the stones could not have fallen in the current arrangement by mere happenstance and must have been purposefully positioned, others find it harder to believe that the huge stones could have been moved and easier to believe that that the marks on the cliff wall were placed to reflect the positions where the slabs had fallen naturally. Whether or not the slabs were positioned by the local population, the structure correlating the positions of the slabs and the markings on the cliff wall represents a remarkably sophisticated method of following astronomical events.