O presente trabalho utiliza a chamada “concepção semântica” das teorias físicas para examinar o estudo realizado por Descartes sobre o fenômeno do arco-íris. Essa concepção parece ser a mais adequada para esse caso, tendo em vista o privilégio dos modelos na abordagem cartesiana. Nesse sentido, não parece ser possível concluir que esse estudo se configure como uma teoria física, como estimam alguns autores, embora Descartes tenha obtido valores corretos para o raio do arco-íris,ao fazer uso da lei de refração.

Batterman has recently argued that fundamental theories are typically explanatorily inadequate, in that there exist physical phenomena whose explanation requires that the conceptual apparatus of a fundamental theory be supplemented by that of a less fundamental theory. This paper is an extended critical commentary on that argument: situating its importance, describing its structure, and developing a line of objection to it. The objection is that in the examples Batterman considers, the mathematics of the less fundamental theory is definable in terms (...) of the mathematics of the fundamental theory and that only the latter need be given a physical interpretation---so we can view the desired explanation as drawing only upon resources internal to the more fundamental physical theory. (The paper also includes an appendix surveying some recent results on quantum chaos.). (shrink)

Greco-Roman meteorology will be described in four overlapping developments. In the archaic period, astro-meteorological calendars were written down, and one appears in Hesiod’s Works and Days; such calendars or almanacs originated thousands of years earlier in Mesopotamia. In the second development, also in the archaic period, the pioneers of prose writing began writing speculative naturalistic explanations of meteorological phenomena: Anaximander, followed by Heraclitus, Anaxagoras, and others. When Aristotle in the fourth century BCE mentions the ‘inquiry that all our predecessors have (...) been calling meteorology’ (338a26), he is referring to these writers. In the third development, the first two enterprises were combined: empirical data collection about meteorological phenomena began to be married to naturalistic theoretical explanation. This innovation was prompted by Democritus and synthesised in its most influential form by Aristotle. At this point more sophisticated techniques of both short-term weather forecasting and long-term speculation about global climate change were also developed. In the fourth development, the wider implications of the naturalistic explanation of meteorological phenomena were contested. The views of ‘meteorologists’ had been controversial since the archaic period because they were perceived, and sometimes intended, to displace the divine prerogatives and undermine traditional religion. These controversies intensified throughout the classical and Hellenistic periods. (shrink)

We apply a physical and historical analysis to a passage by the medieval scholar Michael Scot concerning multiple rainbows, a meteorological phenomenon whose existence has only been acknowledged in recent history. We survey various types of physical models to best decipher Scot’s description of four parallel rainbows as well as a linguistic analysis of Scot’s special etymology. The conclusions have implications on Scot’s whereabouts at the turn of the 13th century.

“Although up to now the [visual] image has been [understood as] a construct of reason,” Kepler observes in the fifth chapter of his Ad Vitellionem Paralipomena, “henceforth the [visible] representations of objects should be considered as paintings [ picturae ] that are actual[ly projected] on paper or some other screen.” While not intended as a historical generalization, this claim nonetheless reflects historical reality. Virtually all visual theorists before Kepler did, in fact, conceive of optical images as subjective, not objective constructs (...) – or, to put it in modern terms, as virtual rather than real entities. By current lights, of course, the distinction between virtual and real images is both obvious and common-place: whereas the latter can be physically projected upon a screen, the former cannot. (shrink)