Art 222
Megaliths and Earthworks

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MEGALITHS AND EARTHWORKS
February 5, 2001

In Europe, the Neolithic (or New Stone Age) period is associated with the cultural complex of ongoing agriculture, animal husbandry or maintenance of domesticated herds, and permanent, year-round settlements. In Europe, we can identify farming in Spain and France by ca. 5000 bce; the existence of plows by 4000 bce. While European settlements do not seem to feature the same sorts of monuments as we find in the Near East (walled cities, ziggurats and pyramids), there is large scale building with stone. Sometimes megalithic monuments can be identified as tombs. In other cases, however, alignments or circles of large stones have no purpose commonly agreed upon.

One consistent claim is that these structures are cosmically aligned, most often to the sunrise on the solstices or equinoxes. Gerald Hawkins calls Stonehenge a "neolithic computer," and an astronomical observatory, laid out according to a complex mathematics that allowed its creators to predict eclipses and other celestial events. Can we prove or disprove these theories? What do they tell us about neolithic peoples and their relationship to nature?

Problems of Reconstructing Celestial Phenomenon of the Past

Because of irregularities in the shape and motion of the Earth, the view of the sky from any fixed position will change over time. In some cases, movement follows a cycle. Due to the angle of the Earth's axis in relation to its orbital path around the sun, the sun does not rise at the same time every day, or over the same fixed point of the horizon. At the summer solstice (in the Northern Hemisphere), around June 21, the Sun attains its greatest declination north. At this time, daylight is at a maximum, and the Sun is directly over the Tropic of Cancer (at 23o, 27' N). At the winter solstice, the Sun is at its farthest point south, over the Tropic of Capricorn. This band through which the sun appears to "travel" is the ecliptic, and the twelve constellations of stars in it constitute the zodiac. The constellation that appears behind the sun as we view it from earth is the sign that it's in.

Diagram of Precession
From Activity for Precession of Equinoxes
Due to the circular motion of its axis, the Earth also changes its position with respect to the fixed stars in a phenomenon known as precession of the equinoxes. From the point of view of the Earth, the sun appears to move backwards through the zodiac at the rate of about one degree every 72 years, completing the entire cycle in about 26,000 years. Although we may not physically notice the slow precessional movement, there are cutural indicators of these long-term changes. For example, a person born on March 24, 2001 would be considered an Aries, but astronomers tell us that the sun is actually in Pisces. At the time of the Summer Solstice, the Sun is in Gemini, but earlier in history it lay in in the constellation Cancer, thereby resulting in our name for the Tropic of Cancer. Some people have speculated that the designation of Taurus, Leo, Scorpio and Aquarius as the fixed signs of the Zodiac reflect that around 4000 bce, the Sun would have risen in Taurus at the Spring Equinox.

The existence of computers to calculate star and planetary positions in the distant past has added those who want to reconstruct the skies at the time of the ancients. Originally, it was the Smithsonian Astrophysical Observatory housed in Cambridge Massachusetts that led the way in this kind of research. With the aid of the star charts (ephemerides) thus constructed, simple computer programs available for home use can allow amateurs to speculate on these matters. For available programs, check the list of Shareware and Freeware on the Sky and Telescope website.

Megalithic Sites

At Carnac, in Brittany,

Newgrange

The passage tomb at Newgrange

Stonehenge

http://merlin.alleg.edu/employee/a/acarr/art222/jan26b.html
Posted January 28, 2000