Reading the “Principia” of Newton is a joy

One important difference between me and Newton is when I am reading his famous “Principia ..” I am drinking a chilled diet coke but I don’t know what he was drinking when he derived his brilliant work. I am right away reading chapter 6** and here he is deriving moon’s variation and later it’s apsidal precession. apsidal prcession means the farthest or closest points of excursion of moon from earth center, precess due to perturbation, that is they make slight deviation from it’s earlier apogee/perigee or apoapsis/periapsis. Not described in this scientific marvel as yet, perhaps I just do not know, but to be found ultimately I guess, is earth’s precession of equinoxes, the slight deviation of the earth’s spin axis which in about 26000 yrs goes exactly reverse, that is the dates of arrival of summer and rain and winter seasons they change drastically, over a 26000 yrs because now the earth is upside down completely. Newton explained these precession but Einstein’s work explained such precessions for perihelion of mercury very precisely.

**Isaac Newton’s Natural Philosophy, edited by Jed Z. Buchwald and I Bernard Cohen