[QUOTE=morls;1451268]Oh dear...
You talk of changes to the obliquity over the last 2000 years, well, I'll attach a figure charting temperature trends for the past 65 million years (Ma).
Hi Moris,
I refer to the last 2000 years of the obliquity by reason that we have a clear rate of the the constant decrease of the obliquity over this period and that the rate of decrease is known to be increasing. My objective is to demonstrate the existence of spiral planetary motion and how it has always controlled the continuous change in our planets climate.
To move on from the point where we could clearly identify that Earth's Orbit is a spiral that is responsible for the precession of the equinoxes. So we understand that in the first place the Spiral mode of of Earth's orbit is a very important important factor in the motion of our planet. Without the spiral factor what would we have Circular orbits? I think not - perpetual motion.
So the Spiral nature of our orbit takes on a very important place in Astronomy
and planetary motion. Then why we ask did Newton ignore it in the first place?
There is a very good reason for his decision, because it was being brought to his notice By Dr. Hooke in their correspondence in 1689. But Newton dared not recognise what Dr Hooke had hinted at in his own work that he had asked Newton to review, Where they discussed Hooke's contention of all matter 'moving to a centre' Hook sketched for him the elliptic spiral as the form of motion.
This was in fact the biggest step forward for astronomy since Kepler described the elliptical form of orbital motion. But the Hooke was disappointed and returned to other many scientific studies and activities. So the advance stagnated.
Hooke and Newton fell out over this but Newton In his Principia 1786 (after Hookes death he gave mention of the spiral but reduced the study of planetary motion to the study of curvature which continues to this day.
The reason why not only Newton but all of the revered principle characters in astronomy, ever since, all continue to ignore the natural spiral motion of our planets. To follow the spiral is a great adventure into the history of our planet to see where it leads.
Kepler gave us the elliptical form of orbital motion. If it is wished, We can discuss the foregoing before we pass on to the spiral effect of Earth's second form of motion it's rotation. There are some questions perhaps, this is a very simplified explanation but it is all based on historical fact and the constants of precession published in the astronomical almanacs.
Cheers, Alan D.