Paul Bernays et la rénovation des fondements philosophiques des mathématiques

The history of the foundations of mathematics in the XX^th century leads to a revision of the meaning of traditional philosophical notions such as «evidence», «experience» or «rationality». This paper focuses on the influence of Ferdinand Gonseth's «open philosophy» on Paul Bernays' philosophical interpretations of the technical results in the foundations. Familiar with the ideas of Jacob Friedrich Fries and Léonard Nelson, the logician Bernays turns at the middle of the century more and more towards Gonseth's ideas. Quite before Thomas Kuhn, Bernays considers the revisions under consideration not simply as a problem of truth and falsehood, but as a task requiring the introduction of a new conceptual system. Indeed, in opposition to Kuhn, according to Bernays, the necessary change is less the consequence from a change of paradigm and methodological incommensurability as a epistemological necessity.     

Laboratory Notes,Laboratory Experiences,and Conceptual Analysis: Understanding the Making of Ohm's First Law in Electricity

Georg Simon Ohm's work in the field of electricity led to what is now considered to be the most fundamental law of electrical circuits, Ohm's Law. Much less known is that only months earlier, Ohm had published another law—one that differed significantly from the now accepted one. The latter entailed a logarithmic relation between the length of the conductor and a parameter that Ohm called “loss of force.” This paper discusses how Ohm came up with an initial law that he felt compelled to correct a few months later. We analyze Ohm's publication as well as his laboratory notes, relating them to our own laboratory experiences while using the replication method to study his work. We also discuss the conceptual background of Ohm's work. We conclude that he was significantly influenced by French studies in the field of electricity, most notably the ones by Charles Augustin Coulomb.     

Roman lead mining in Germany: its origin and development through time deduced from lead isotope provenance studies

High precision lead isotope analysis by Multi Collector Inductively Coupled Plasma Mass Spectrometry was applied to the investigation of more than 240 Roman lead objects from several archaeological sites in Germany, in order to obtain information on the pattern of Roman mining activity and ore processing in the area. Measurements of ore samples from German deposits east (Siegerland, Lahn-Dill, Ems) and west of the Rhine (Eifel, Hunsrueck) were made and supplemented with data from literature to create a data bank of lead isotope ratios of European lead occurrences. Comparing the isotope ratios of lead objects with those from German ore deposits shows that the source of over 85% of the objects is Eifel ore deposits, but that, in the early years, the Romans also imported lead from the Southern Massif Central and later from Britain.     

Ettore Majorana (1906—1938): Eine Bestandsaufnahme 64 Jahre nach seinem Verschwinden

Ettore Majorana probably belongs to the most mysterious and most fascinating personalities of the recent physics history. Majoranas work shows also nowadays more than 60 years after its appearance an amazingly fresh reference to present physics problems. A short representation of Ettore Majoranas life and scientific work will be given in this article.