The historical development of solar theories in the late sixteenth and seventeenth centuries

Abstract

The main concern of this paper is to give a critical account of the historical development of planetary theories in their approaching process to the modern theory. Since in astronomy as in any other observational science each theory originates in a certain relation to the observations, the development of the theories may be traced as a function of an elementary observational quantity. The convergence of the historical theories towards the modern theory may be then represented as a decreasing process of the observational error range, which symmetrically extends over both sides of the modern values, if no systematic error source is involved. From the observed values of the planetary positions and the independent parameters like parallax, refraction, geographic latitude and others, the planetary positions in the orbit, generally called observations, arc computed. From these observations the theory, consisting of the hypothesis and the dependent parameters like mean longitude (L), longitude of perihelion (P) and eccentricity (e), is formed and reproduces the planetary positions (1), in the case of the modern theory, precisely as