Prof. Dr. Klaus Hentschel

An effort of proponents of relativity theory to find evidence for the so-called gravitational red-shift of spectral lines as one of the experimental consequences of Einstein's generalized theory of relativity is reconsidered with reference to hitherto unpublished documents. It is shown how much interest Albert Einstein in fact took, around 1920, in the data analysis of Leonhard Grebe and Albert Bachem, who tried to explain why most earlier efforts to find the gravitational red-shift had failed. They carefully measured the line profiles of the spectral lines both in the sun's Fraunhofer lines and in pressure-independent laboratory comparison spectra. Then they rejected all lines with strong neighbouring lines which could cause apparent shifts of the line centres; the remaining seven well-isolated lines showed the gravitational red-shift with acceptable accuracy. Nevertheless, their claim to have successfully isolated the relativistic effect never convinced the astrophysicists of their day—the reasons for the scientific community's scepticism, contrasted against the enthusiastic group of Einstein sympathizers, are also discussed

Summary The growing need for standardized units of measure led to major metrological reforms in the mid-nineteenth century. This paper focusses on their implementation in the Kingdom of Hanover and the involvement of C.F. Gauss. His papers reveal how much the success of his precision measurements hinged on the skill of his mechanic M. Meyerstein. A discussion of the regional weights and measures and the standardization procedure is followed by a description of various precision balances and the weighing methods employed as well as a review of the problems posed by reliable length calibration. The success of the enterprise rested not only on intellectual prestige and ministerial clout but also on the hands-on skill of the mechanical practitioner.

Loss of the Inner Core: Expectations and Fears for the Future of the History of Science. In this paper, I discuss the current state of history of science in Germany, a combination of strong interest in the field from various neighboring fields (including cultural history, media history, history of art, visual studies) and increasing fragmentation. Powerful institutions such as the Max Planck Institute for History of Science rather encourage this tendency to lose the inner core of the field, a kind of fluidization or vaporization.

ZusammenfassungBei der Durchsicht des Nachlasses von Rudolf Tomaschek (1895–1966) fand ich ein 30 Seiten umfassendes Typoskript seines damaligen Assistenten Hugo Watzlawek (1912–1995) aus dem Jahr 1944 mit dem Titel „Interatomare Energie“. Heute würde man eher von „inneratomarer Energie“, oder von „Kernenergie“ sprechen, da der Inhalt des Typoskripts „technische Kernphysik“ einschließlich ihrer potentiellen militärischen Anwendungen betrifft. Der Text bietet einen ungefilterten, erstaunlich kenntnisreichen, aber in vielem auch erschreckenden Einblick in die technokratische Gedankenwelt sowie den Wissensstand und Anwendungshorizont eines „technischen Kernphysikers“ im „Dritten Reich“, der unter Verweis auf konkurrierende amerikanische Forschungen 1944 nachdrücklich um weitere Mittel für kernphysikalische und -technische Forschung sowie für die Entwicklung von Kernwaffen bittet. Der vorliegende Aufsatz kommentiert und kontextualisiert das Typoskript; meine ebenfalls online gestellte annotierte Transkription des Typoskriptes bietet ungekürzten Zugang zum Originaltext samt knapper, für dessen Verständnis notwendiger historischer und technischer Erläuterungen.

Despite a renewed interest in the philosophical prehistory of logical empiricism, several texts by prominent figures such as, e.g., Moritz Schlick and Hans Reichenbach, published in non-standard journals, have escaped the notice of scholars. Here, a hitherto virtually unknown but significant review of Moritz Schlick's influential book Allgemeine Erkenntnislehre [1st ed. 1918] written by Hans Reichenbach in 1919/20 is reprinted together with comments about its background and the later development, relying on and citing from the unpublished correspondence between Schlick and Reichenbach in 1920. Since they later became the leading figures in the so called Vienna and Berlin circles respectively, this episode marks an important stage in the gradual emancipation of scientific philosophy from its Kantian roots

ZusammenfassungEs wird die wechselseitige Beeinflussung Einsteins und Schlicks anhand ihrer ab 1915 erhaltenen Korrespondenz in vier Schwerpunkten untersucht. Schlicks Selbstverständnis als Philosoph wie auch einzelne Themata seines Denkens (wie etwa das der Einfachheit) bildeten sich mit seiner Auseinandersetzung um die Relativitätstheorie Einsteins heraus, deren systematische Explikation durch Schlick auf Einsteins Beifall stieß. Als die Ursache für das Auseinanderdriften beider Denker nach 1925 werden fundamentale Differenzen im Wirklichkeitsverständnis und in der Interpretation des Kausalitätsprinzips aufgewiesen, die beide auch zu komplementären Formen der Wissenschaftsgeschichtsbetrachtung führten.

The main features of a new online database of scientific illustrators are portrayed. We list illustrators of scientific publications of all genres (especially atlases, articles, textbooks) who were active between 1450 and 1950, thus excluding illuminators of medieval manuscripts as well as illustrators still active. Currently (Sept. 26, 2012), we already have more than 3,461 entries, with particular emphasis on anatomy, dermatology, botany, zoology, mineralogy, astronomy, and general natural history. Access to the database with its 20 search fields is free and open to all interested users at www.uni-stu ttgart.de/hi/gnt/dsi/

ZusammenfassungBei der Durchsicht des Nachlasses von Rudolf Tomaschek fand ich ein 30 Seiten umfassendes Typoskript seines damaligen Assistenten Hugo Watzlawek aus dem Jahr 1944 mit dem Titel „Interatomare Energie“. Heute würde man eher von „inneratomarer Energie“, oder von „Kernenergie“ sprechen, da der Inhalt des Typoskripts „technische Kernphysik“ einschließlich ihrer potentiellen militärischen Anwendungen betrifft. Der Text bietet einen ungefilterten, erstaunlich kenntnisreichen, aber in vielem auch erschreckenden Einblick in die technokratische Gedankenwelt sowie den Wissensstand und Anwendungshorizont eines „technischen Kernphysikers“ im „Dritten Reich“, der unter Verweis auf konkurrierende amerikanische Forschungen 1944 nachdrücklich um weitere Mittel für kernphysikalische und -technische Forschung sowie für die Entwicklung von Kernwaffen bittet. Der vorliegende Aufsatz kommentiert und kontextualisiert das Typoskript; meine ebenfalls online gestellte annotierte Transkription des Typoskriptes bietet ungekürzten Zugang zum Originaltext samt knapper, für dessen Verständnis notwendiger historischer und technischer Erläuterungen.Among the papers of Rudolf Tomaschek I discovered a 30-page typescript from 1944 by his then assistant Hugo Watzlawek entitled “Interatomare Energie”. Nowadays one would rather say ‘inneratomic energy’ or ‘nuclear energy’ since the typescript treats issues of nuclear engineering including its potential military uses. It presents an unfiltered, surprisingly informed view into the technocratic mindset, state of knowledge and application horizon of a “technical nuclear physicist” in the Third Reich. Watzlawek in 1944 urgently petitions for more funding for research in nuclear physics and technology, citing analogous research underway in America. The present paper places the typescript within its historical and technical context. My succinctly annotated transcription of the original text—also made freely available online—provides full accessibility to this document.

Comparisons as a Bridge between History and Philosophy of Science. Both in history and philosophy of science, comparisons are looked upon with considerable skepticism. A widespread syndrome of casuitis, i.e., the tendency of historians of science to produce extremely narrow and local studies that do not present a case for any broader thesis of interest to philosophers, has widened the gulf between history and philosophy of science.This may be somewhat surprising to sociologists, philosophers, or general,legal and cultural historians, who have been using comparisons successfully for a long time–albeit not always without controversy. In the first part of this paper, I assess the status of comparisons in science studies, in order to explain why their systematic use is not nearly as natural as might elsewhere be expected. This critical section is followed by a very brief outline of the prerequisites for fruitful comparison as formulated by general and sociological historians in their detailed methodological discussions. To these are added some necessary conditions from the perspective of modern history of science. In the third part I present four examples of such systematic comparisons taken from my own research.

Die Korrespondenz der beiden Physiker und Wissenschaftshistoriker Ernst Mach und Pierre Duhem ist weitgehend, vielleicht mit Ausnahme nur eines Briefes, erhalten. Neben der Dokumentation dieser historischen Zeugnisse setzt sich der Autor in diesem Aufsatz zum Ziel, die jeweiligen Motive, die Mach resp. Duhem zur Beschäftigung mit Wissenschaftsgeschichte führten und die damit verbundenen Modelle der Wissenschaftsgeschichtsentwicklung beider gegeneinander abzugrenzen. Dazu wurden insb. die in der bisher vorliegenden Sekundärliteratur zu Mach und Duhem überhaupt nicht berücksichtigte Buchbesprechung der Machschen Mechanik durch Duhem sowie die ergänzenden Bemerkungen zu Duhem in späteren Auflagen der Werke und in der Korrespondenz Machs herangezogen, die eine recht detaillierte wechselseitige Kritik ihrer Methodik beinhalten. Den Abschluß meiner Betrachtungen bildet der Versuch einer Sondierung dessen, was in Duhems resp. Machs historischen Betrachtungsweisen über die nicht in Frage stehende Bedeutung als Meilensteine der Wissenschaftsgeschichtsschreibung hinaus noch heute von Relevanz ist.The preserved part of the hitherto unpublished Duhem-Mach correspondence, kept in the Archives de l'Académie des Sciences, Paris, and in the Ernst Mach Institut of the Fraunhofer Society, Freiburg im Breisgau, is documented and commented upon. Biographical, methodological, and philosophical analogies and differences between the points of view of Pierre Duhem and Ernst Mach are discussed, and a critical evaluation is given of their impact as historians of science

A brief biographical introduction to Snellius (Snel van Royen) and his geodetic work is followed by a discussion of the historical background of his Amsterdam manuscript on optics. Here I present the first translation of the Latin original into any living language. It is preceded by a heuristic reconstruction of the path Snellius very likely took in finding the law of refraction named after him. My reconstruction essentially consists in the following five steps: Because of his geodetic work in which he pioneered the method of triangulation, Snellius already had considerable experience with trigonometric functions; indicative of this are the two allusions to geodesics in the Amsterdam manuscript, one of them directly before the law of refraction (see prop. 7 and prop. 22 of his book I). Other remarks in the manuscript reveal that Snellius had studied the existing literature on optics, particularly on refraction; various passages in the manuscript are analogous in formulation and sequence to other treatises as shown by his marginal notes and occasional references to other texts interspersed throughout the manuscript. Snellius showed special interest in Ibn al-Haitam's experimentum elegans (mentioned in prop. 22 of book I). He sought a geometrical description of the refractaria, (idem, prop. 36–39). This search led him to find the law of refraction in the secant form (idem, prop. 23).