A Questao do Conhecimento na Ciencia Moderna

It is useful to re-examine the history of Physics and revalue under the present perspective its limitation and unlisted novelies; to value the Themata that were conducting threads of search. Investigatio in Physics is conducted today by ideas such as conservation, relativity, invariance, symmetry. Oythagorians sustained that "Nature is harmony and number" but for decades this thesis was considered obscurantist. It must be told that invariance and symmetry have a precise sense today because they are ideas develped within a rigorus mathematical formalism. Another example, greek astronomers developed models, whose admissibility before the experimental error they discussed. Today, in Particle Physics, searchers are awre that they are propounding models. In the first part of this dissertation, is described the evolution of the mevchanicist model and its culmination in Relativity Theory. It will be concluded that there is no science without observation-experimentation: a discourse that is not fed by them will soon degenerate in a science fiction tale, eventually interesting but without cognitive value. Afterwards data have to be unified into models. There are the comparatively small models of Experimental Physics and the wide models of Theoretical Physics. against what empiricists thoght, the latter encompass reality better than the experimentalists models. Thus, Kepler laws suggested to Newton an ulterior unification; if it was correct, Kepler laws would be sent to the rank of" reasonable approaches". The wider Newton system was more beautiful, and experience showed that it was more exact. The same happened in the transition from Classical Mechanics to Special Reality and from it to General Relativity. The second part consists of a review of Viena Circle philosophy and its rules for analyzing scientifical progress. accurate quantitative degree only holds in constructed languages, far away from the real science language; qualitative rules as Popper's verisimilitude degree are closer to the way physicians value their theories, but is imperfectly formalized. A feature to give prominence to, is that scientifical laws are utterly different from statements as "all raven are black" Physical concepts are quite different from "raven" and "black" as they are constructed with mathematical tools and as such, they stick to experience in a very indirect mode. Another feature to emphasize is that these philosophies of science conceive the question as if there were a choice between a finite number of theories only; however this number has at least the continuum potency and we don't see how to enlasrge those rules without enourmous changes. Concluding, the great scientific theories have the statute of hypothesis that describe approximately the real world. Scientific progress is well described in Novalis metaphor quoted by Popper - as a fishing net, theories embody always more (the net has a smaller mesh) and they adhere better to the real (they contact in abigger extension). When experience shows that there is no adjustment, it is necessry either to correct the old theory or to invent another completely new. The the standards of invariance, conservation symmetry enter the stage. These are the methodological rules - non formalized and inexprimable in quantitative parametrs -of Physics today. But physicists know that if an interesting turn starts to delineate, it will be supported by new ideasAvailable from Fundacao para a Ciencia e a Tecnologia, Servico de Informacao e Documentacao, Av. D. Carlos I, 126, 1200 Lisboa / FCT - Fundação para o Ciência e a TecnologiaSIGLEPTPortuga