The precession of the equinoxes

"The precession of the equinoxes has lost its importance for us; once, however, it was the one majestic secular motion that our ancestors could connect with a great cycle capable of influencing humanity as a whole. But then our ancestors were astronomers and astrologers. They believed that the shifting of the Sun along the equinoctial point influenced the structure of the cosmos and determined a succession of world ages under different signs of the zodiac. They had found great support for their conception of cosmic time, which gave all things a predestined order. Today that order has vanished, like the idea of a living universe. There is only history, which has been aptly defined as 'one damned thing after another'."

It is thanks to the careful and exhaustive study of myths from all over the world carried out by Giorgio de Santillana and Hertha von Dechend that today we are beginning to understand how far from primitive the civilizations that preceded us were. Not only were they aware of astronomical concepts that are hard to detect and understand, such as the precession of the equinoxes, but they were also able to grasp their meaning and importance and to track them through the construction of complex buildings such as the pyramids of Giza, the pyramids of Teotihuacan, Machu Picchu and Stonehenge.

In our present Eurocentric world, the discovery of the precession of the equinoxes has been attributed to Hipparchus (134 BC), but it had already been known for thousands of years, to Pythagoras, to Plato, to the ancient Sumerians, to the Egyptians and to the peoples of Central America. The concept is not easy to grasp; essentially, it is thought to be caused by the influence of the other planets of the solar system and of our Moon. Because of the gravitational pull of these celestial bodies, the Earth's axis "wobbles" as the Earth spins, just as a spinning top does when it slows down. The Earth's wobble is very slow. The base ellipse of the Earth's orbit rotates gradually at a rate of 0.3° per century, so the Earth's axis traces a huge complete curve across the sky over a period of 25,920 years. For the last 2,160 years we have therefore lived under the constellation of Pisces: it is Pisces that rises in the eastern sky just before sunrise. At present, however, we have almost reached the end of the influence of this so-called "house" and are about to move into a new one, that of Aquarius.