Jyotish. Andrew Mason

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      Precession of the equinoxes and the circumnavigation of Polar Stars

Nicolaus Copernicus proposed three planetary motions. First the Earth spins upon its own axis, second it completes an annual orbit about the Sun and third it inscribes a rotational axis upon the heavens at the celestial pole, completing a single revolution every 25,920 years. This third motion, now called nutation, was thus termed ‘The Great Year’ and featured heavily in the mystery schools25 of the ancient world.

      The phenomenon of precession plays a pivotal role in the history of astrology and astronomy yet, to date, its explanation still remains an unsolved mystery; and while its effect might be simulated in sophisticated computer models, mechanically they remain untenable.

      Although there are some interesting theories that seek to account for precession, none really seem to put the issue to bed. Arguments for and against various mechanisms are basically ‘big science’ and well beyond the scope of this work; however, presented here for readers’ interest are three interesting possibilities. Which explanation ultimately proves correct remains to be seen; but for now the jury is out.

      Chandler’s wobble (polar motion)

Seth Carlo Chandler Jr (1846–1913), an amateur astronomer and businessman, first proposed his ‘wobble’ theory in 1891, having the Earth akin to a spinning top whose lessening momentum develops a slight destabilisation of spin axis. This might be likened to a child’s spinning top that develops similar properties prior to toppling or ‘when gyroscopic forces can no longer resist the hand of gravity’. He reasoned that geographically the Earth has a greater land mass north of the equator and that this subtle pear-shaped26 profile would cause its more ‘pointed’ end (or southern hemisphere) to subtly displace the Earth’s centre of gravity, producing an incremental ‘wobble’ effect.

Chandler proposed that Earth’s North Pole moved in an irregular circle of 4–16 metres in diameter over a period of about 1.2 years. This ‘eigenmode’27 was reckoned to have a six-year cycle, during which two spiralling extremes were attained – one small and one large with a 3.5-year break in between. Since its proposal, the amplitude of the effect appears to have remained inconsistent, performing a number of surprises (referred to as phase-jumps) in the last 100 years. One significant jump occurred in the 1920s followed by a similar episode in 2000.

This ‘wobble’ had been predicted to subside after a number of decades, unless some unseen force worked upon it to reinvigorate motion. This, JPL28 believed, it had uncovered in July 2000 in the form of fluctuating oceanic pressures, coupled with changes in water temperature, ocean salinity and weather patterning. The totality of these influences were proposed to contribute to at least two-thirds of the observable phenomenon.

      Although this new theory looked tenable, events in November 2005 cast doubts upon this line of enquiry as further monitoring of the smaller spiralling cycles saw Earth’s spin-axis veer rather sharply at a right angle to its normal circular motion. This anomaly was completely unexpected and not predicted in any of the computer simulations.

To date, the 124-year-old free nutation model remains unexplained. The most current revision of Polar Motion was published in August 2009,29 with its investigators concluding that the historical phase-jumps were not likely to be unique and that the accrued data (so far) should be revisited and reprocessed to attain clarity in predicting future cycles.

      Binary Companion Theory

A more recent, ‘extraterrestrial’, proposal by Walter Cruttenden and Vince Dayes30 draws largely upon a popular theory called luni-solar causation. This sees the Sun’s gravitational force (along with the Moon) torqueing upon Earth’s equatorial bulge, resulting in axial gyration.31 Though the original luni-solar precession model dealt largely with near and visible objects, Binary Companion Theory is an upscaled hybridisation of the effect, working in tandem with distant unseen forces. Its protagonists claim that this alternative model of the solar system (and beyond) better accommodates the observable data whilst nicely trimming away a whole swathe of previously annoying loose ends.

      One troublesome factor for the luni-solar causation camp had been the prolonged and unrelenting torque exerted upon the Earth’s axial tilt. This, over longer periods, predicted a displacement of the seasons, that is, our seasonal routine eventually swapping hemispheres. To date, however, no noticeable switching has occurred as the equinoxes occur right on schedule – requiring only minor adjustments in the form of leap years to synchronise calendars.

      Supporters of the original luni-solar causation had attempted to account for this annoying oversight with complex mathematics, concluding that equinoxes were attained slightly earlier each year – along Earth’s orbit. This idea was eventually defeated by observable phenomena such as the lunar cycle, which showed Earth to complete the entirety of its equinoctial year. This again cast doubts on the accuracy of the luni-solar model.

All was not lost, however, as luni-solar causation was about to get a shot in the arm; this time in the form of a new dark stellar companion to our Sun some 2–4000 A.U.s32 distant. This twinning effect was proposed to have a warping effect on our Sun’s great orbit about the galactic centre, forcing it to accommodate the demands of its distant binary.

      In this revised model of precession, the Earth is constrained to a near-perfect circular orbit whereas our Sun now takes on a vastly accentuated elliptical orbit about its twin. The outcome for Earth is the effect of precession, which according to the laws of celestial mechanics predicts that objects in elliptical orbits accelerate to periapsis and decelerate toward apoapsis.

      This last prediction has proved to be the theory’s most promising indicator of correctness, as the rate of precession is anything but constant and does indeed appear at this time to be accelerating. See Section 1.10.

      Earth nodes