Stonehenge Solved Its Three Observatories, Who built them, How and Why

As likely candidates there are only two bodies in the sky, the Sun and Moon, and the nature of the installation does not suit either. They reach their highest point in the sky to south, not southwest where the tallest mast is, furthermore there are low level spars to north and neither orb ventures there. Most incongruously there is a mast for high angles of elevation to north northwest!

From rise to set, Sun and Moon move symmetrically about a north-south line because this is the line of the Earth's axis of spin; the installation is also symmetrical about its own line but this is orientated 51 degrees east of north. However bizarre it may seem, this symmetry suggests the Earth's axis of spin at the time was located somewhere along an extension of this line (i). The question of how far along it is a matter of trial and error, but the choice, together with the concept, can be tested by discovering if the resulting paths in the sky have a meaningful relationship with the sighting windows we have identified.

The paths of both Sun and Moon would be different from those of today but they can't both be candidates, we have to choose. This is not difficult for several reasons: the Moon completes its orbit in approximately 28 days and the installation has 28 stations; it could not have been the Sun that was sighted because this would have led to blindness; lastly, the Moon is observable day and night where the Sun is not. The best fit of the Moon to the windows occurs when the Earth's axis of spin (EAS) is located at St Petersburg on Russia's Baltic coast, Fig 17.

Comprehension of how the paths are derived may be aided by contemplating Figs 18, 19, 20. At a) in figure 17 no paths are to be seen because the Moon is below the horizon in contemporaneous south, it first appearing at b). Successive days would see arcs crossing the dome of the sky, these at ever increasing maximum heights and decreasing curvatures. The arcs then morph into a mode of increasing tilts, their conjunctions with the horizon progressively advancing ahead of their seeming apogees, or maximum heights, until becoming a distorted near-ring hanging in the sky above the horizon to contemporaneous north, this after 14 days. Thereafter the ring unwinds and the paths continue their circuits in reverse sequence, returning to their start point at a), completing the lunar month of 28 days.

The consequence of these movements was for a path to pass through one or more of the henge's windows day or night every 24 hours.(This scenario needs confirmation with a computer model, but as will be seen, only after chapter 21 has been taken into account.) Having determined which window the Moon was approaching the appropriate spar could be readied and accurately placed, so that the notional centre of the Moon passed through its line of sight. 28 days later, with the spar setting preserved, the sighting would repeat, but not exactly; presumably it was the degree of difference that was the subject of concern.

There was a station for almost every day, there being 28 of them except on the northwest as noted earlier. The number of stations was important for several reasons: 28 days would have been a long time to wait before a comparison could be made, but with many stations operating simultaneously, conclusions could be reached in say, a day or so; cloudy weather would have placed a premium on the rapid utilisation of brief, cloud-free spells; there needed to be cover for equipment failures, notably of the lines, and for preventive maintenance.

The people of the time would have been well used to the regular cyclical movements of the Moon, whatever form they took. Consequently the implications are of them seeking to forecast other sorts of events known to have extremely serious outcomes, these being heralded by a change in the Moon's apparent behaviour. This implies foreknowledge. One aspect is certain: while the apparent changed behaviour of the Moon, and inevitably of the Sun, was a recent strange phenomenon, the instigators of the Stone henge strongly believed it had stabilised, to the point where it was worth their while embarking upon a lengthly project necessitating enormous efforts.