When Kepler concluded that the orbit of Mars was not a circle, he was led to the belief that the orbit was an oval touching the circle at the apsides and lying within the circle at other points. In the definition of the oval, physical hypotheses played a primary role. Two forces were involved; a tractive force arising from the effect of the solar rays rotating with the sun, and a directing force arising from a natural instinct of the planet (...) itself. The former pushed the planet along the orbit while the latter enabled the planet to steer itself across the stream of the solar vortex in a small epicycle. In adopting this physical theory to determine the oval, Kepler was led into what he himself described as ‘a new labyrinth’. After several attempts to construct the oval, and by progressively eliminating the sources of error from his calculating procedures in order to arrive at an accurate mathematical formulation of the physical hypotheses, he was able to conclude that the oval was inconsistent with the empirical data and the physical theory in need of modification. (shrink)

This completes what I think one may state and defend on physical grounds concerning the foundations of Astrology and the coming year 1602. If those learned in matters of Physics think them worthy of consideration, and communicate to me their objections to them, for the sake of eliciting the truth, I shall, if God grants me the skill, reply to them in my prognostication for the following year. I urge all who make a serious study of philosophy to engage in (...) this contest. For it concerns our worship of God and the welfare of the human race. Meanwhile, I pray from the depths of my soul, through Christ our mediator, that for all and for each the coming year may be a very happy one. (shrink)

Innovatory advances by outsiders: The example of the amateur astronomer William Herschel. — Every scientific experience and perception has been gained from within a particular historical situation constituted by numerous components, both internal and external to a particular science, called praesentabilia (Präsentabilien). They enable and determine the scope and the experiental pale of any given science as well as its way and method of acquiring experience and knowledge. The interaction of such praesentabilia forms, what may be called the Historische Erfahrungsraum (...) (‘historical field of experience’), which each individual and/or (greater/smaller) group shares in respectively. A scientific (cultural, religious, social, disciplinal, etc.) community may be said to exist whereever the intersection of the various sets of praesentabilia making up its members' fields of experience comprises a minimum standard of praesentabilia that form this community, thus establishing its particular Historische(n) Erfahrungsraum. As long and as far someone outside the disciplinal community could acquaint himself with its praesentabilia in a selftaught manner, there will be outsiders and amateurs, who, while lacking any regular (and one‐sided) education and training, yet owning some extra praesentabilia, would be in a position to bring in novel methods of thinking and unconventional perceptions. There may be several reasons for this: (1) because they study fields that are not yet or no longer present in the disciplinal community, or (2) because they are not bound to the usual (uniform and standardized) instrumentation, or (3) because their social status does not seem from the professional scientific community (nor from the socio‐political community, conditional to the former's existence). Conversely they feel not being bound by the rules, the expectations and the aims posited by that scientific community. Since the disciplinal community lacks the praesentabilia that are prerequisite to fully understanding the outsider and amateur, he, in turn, has to overcome much more difficulties, till his innovatory perceptions are acknowledged. On the other hand, whenever his new methods, instruments or points of view prove to be helpful in solving an old problem of the disciplinal community, this solution will generally soon be acknowledged, in case its reproduction is sufficiently guaranteed by the traditional methods and by the usual instruments. Eventually the acknowledgement may lead to the approbation and the acceptance of the said methods, instruments and points of view, because the solution offered has by then become a praesentabile integral to the disciplinal community.The life and career of an outsider and amateur, like William Herschel, is a good instance of a whole range of potentialities of such innovatory advances. Considering these points, the paper deals with several aspects of Herschel's work: his new method of reviewing the heavens (Himmelsdurchmusterung) linked to his novel telescopes, — his discovery of the planet Uranus, — his discovery and verification of the existence of physical double stars, — his assumption of historicity and development of cosmic objects, — his determining the shape of the Milky Way by means of a primary method of stellar statistics, ‐ his discovery and determination of the sun's peculiar motion, ‐ and his discovery of the infra‐red radiant heat continuing the spectrum of the visible light. (shrink)