But according to the current accepted model of precession, the main source of precession is due to luni-solar forces and slowly increases (period decreases), has done so for who knows how long, and will continue to do so. In fact, from 1900 to 1975, Simon Newcomb’s formula for precession below was used to calculate the yearly increase in precession.
50.2564 + .000222 (year – 1900)
Note the table, below using Newcomb’s annual increase, 100,000 years ago, precession would have been around 28 arcsec/year for a corresponding period around 46,000 years – definitely out of sync with the Milankovitch cycle. And the further back we go in time, the greater the discrepancy.
|Year/Epoch||Value ("/year)||Period of Revolution|
|150 B.C.||49.8013 (-.4551)||26023|
|(-10,000 years)||48.0364 (-2.22)||26980|
|(-50,000 years)||39.1564 (-11.1)||33098|
|(-100,000 years)||28.0564 (-22.2)||46193|
Consequently, if precession does play a factor in global warming and cooling cycles then the evidence implies there must be some constraint that limits the rate to not go much below the current rate of about 50” per year or much above a rate of about 62” per year. Lunisolar precession theory mentions nothing about this for the first few hundreds years of its interpretation. It was only after noticing the rate was changing for a prolonged period of time that lunisolar theory was interpreted to include some factors that would cause the rate to increase and decrease. It is still not known if these later inputs are consistent with dynamical theory.
The binary model, which must conform to Kepler’s laws, forces natural constraints from the outset. The annual rate can never be faster than the rate at periapsis and can never be slower than the rate at apoapsis. The rate is now consistent with the binary orbit parameters set forth by the Indian astronomer, Sri Yukteswar in 1894, who gave us an orbit periodicity of about 24,000 years and apoapsis at about 500AD.
Additional information on this topic can be found at: