We all know about solar eclipses but they are rarely seen, since the shadow of the moon (at one of its two orbital nodes) creates a cone of darkness which only covers a small part of the earth’s surface which travels from west to east, taking hours. For the megalithic to have pinned their knowledge of eclipses to solar eclipses, they would have instead studied the more commonly seen eclipse (again at a node), the lunar eclipse which occurs when the earth stands between the sun and the moon and the large shadow of the earth envelopes a large portion of the moon’s surface, as the moon passes through our planet’s shadow.
This phenomenon of eclipses is the result of many co-incidences:
Firstly, if the orbit of the moon ran along the The path of the Sun through the sky along which eclipses of sun and moon can occur, traditionally divided into the 365¼ parts of the solar year, each part then a DAY in angle rather than time.: there would be a solar eclipse and a lunar eclipse in each of its orbits, which are 27 and 1/3 days long.
Secondly, if the moon’s orbit was longer or shorter, the angular size of the sun would not be very similar. The moon’s orbit is not circular but elliptical so that, at different points in the lunar orbit the moon is larger, at other points smaller in angular size than the sun. This is most visible with solar eclipses where some are full or total eclipses, and others eclipse less than the whole solar disc, called annular eclipses.
Thirdly, the ecliptic shape of the moon’s orbit is deformed by gravitational forces such as the bulge of the earth, the sun and planets so that its major axis rotates. When the moon is furthest away (at apogee), its disc exceeds that of the sun. And when the moon is nearest to the earth (at perigee), its disc is smaller than that of the sun. This type of progression is called the precession of the lunar orbit where the major axis travels in the same direction as the sun and moon. This contrasts with the precession of the lunar nodes which also rotate (see later).
The rotation of the elliptical major axis of the lunar orbit causes the apogee and perigee points to advance relative to the stars so that these points take 27.554 days (longer than the 27 1/3rd day orbital period) to complete. That is, the opposite larger moon and smaller moon extremes are advancing, to create this orbital phenomenon: called the Anomalistic Month. It is this which lies behind the so-called “supermoons“, where the moon’s disc seems larger, especially during its full phase of illumination by the sun. At that point the disc is 14% larger and 30% brighter [says NASA] than the full moon at perigee.
The sun has to be at one of the lunar nodes for there to be an eclipse, either solar with the moon at the same node or lunar with the moon at the opposite node to the sun. And the average time taken for the sun to travel between the lunar nodes is 173.31 days so that both nodes are visited after 346.63 days, a period called the the time taken (346.62 days) for the sun to again sit on the same lunar node, which is when an eclipse can happen.. This reveals another strange coincidence of the eclipse phenomenon on earth, that is, if one creates a circle of diameter equal to four times the anomalistic month (110.216 days) then times π (or π: The constant ratio of a circle's circumference to its diameter, approximately equal to 3.14159, in ancient times approximated by rational approximations such as 22/7.) the circumference is 346.254 days. An approximate to pi of The simplest accurate approximation to the π ratio, between a diameter and circumference of a circle, as used in the ancient and prehistoric periods. gives an eclipse year of 346.4 days whilst exactness would involve an approximation for pi of 3.1448 to give an exact 346.62 days.*
*This relationship has come to light through the work of Peter Harris and Norman Stockwell, through his pamphlet, but more recently in a new book sent me by by Thomas Gough and Peter Harris called A New Dimension to Ancient Measures.
This relationship between the Eclipse year is to me significant since it shows conformance, for whatever reason, to these two cycles within the primal geometry of pi,
The following post explores this diagram for its geometrical significance and relevance to megalithic methods.