Neolithic Astronomy in Britain
|Perhaps the most mysterious ancient astronomy is that practiced by the neolithic
people of Britain and Western Europe. Beginning around 3000 B.C. the people
of this region began accumulating giant stones called megaliths and placing
them in specific shapes with special orientations. The most famous example
of this is Stonehenge, a site on a plain in southern England (see picture
below). This monumental feat was begun five thousand years ago, and was continually
reconstructed and added on to for two thousand years. The large stones weigh
about 30 tons each, and were probably dragged by oxen from a site 20 miles
away, while the central volcanic stones come from Wales, over 130 miles away.
The astronomical orientations of these stones are generally without question,
although archaeoastronomers believe in different levels of the people's scientific
capability. What makes Neolithic astronomy more mysterious is the fact that
only the monuments remain; the people had no writing system at that time with
which to record their motivations.
|At Stonehenge, astronomical alignments are hard to judge because
stones were placed next to each other sometimes hundreds of years apart. However,
it is commonly accepted that Stonehenge recorded the rising and setting positions
of the Sun and Moon at the height of each season. In addition, the oldest
stone at the site, called the Heel Stone, was placed at the entry to Stonehenge
in such a position that sighting it from the center of the monument points
directly to the summer solstice. It has also been suggested that the outer
series of holes could have acted as a computer to predict lunar eclipses.
This use is the most advanced stage of neolithic astronomy, and is still debated
among archaeoastronomers. The picture below shows a schematic of the astronomical
orientations at Stonehenge.
|Studies of other neolithic sites throughout Britain and France
show that many sites have a mathematical significance as well. At the Avebury
stone ring, 17 miles north of Stonehenge, the common neolithic unit of distance,
called the megalithic yard, is highlighted. The circumferences of the circles
of stones are significant: 25 or 50 megalithic yards (a megalithic yard is
2.71 feet). Many of the circles have diameters of 4, 8, 12, 16, or 32 megalithic
yards. In an effort to achieve a value of pi which was an integral number,
some of the circles are flattened at the top. It is also evident that these
people were aware of the geometric relation that we call Pythagorean's theorem
for a right triangle. Several shapes are constructed based on an interweaving
of circles and right triangles. Some of the stones could be used as sights
to distant mountain ranges, where astronomical events could be pin-pointed.
REFERENCES FOR THIS
Anthony Aveni, Stairways
to the Stars, John Wiley & Sons, 1997.
Evan Hadingham, Early
Man and the Cosmos, Walker and Company, 1984.
Stonehenge Photo Gallery. http://www.sacred-destinations.com/england/stonehenge.htm.