Prof. Dr. Klaus Hentschel

During Einstein’s lifetime, the special and general theories of relativity were quite frequently interpreted by philosophers. Most of these interpretations actually were misinterpretations. Even today interpretative statements about relativity theory are often false or highly misleading. Why is this so? In my Ph.D. dissertation (Hentschel 1990a), I analyzed (mis)interpretations by 10 different philosophical schools active in the early twentieth century which widely differed in their approaches, emphasis and blind spots. Many of these interpreters – including philosophers of high standing such as Ernst Cassirer, Moritz Schlick or Joseph Petzoldt – had studied the theory intensely and many even had close contact with Einstein himself or with one of the members of his “protective belt” of close friends and allies. Rather than declaring all of these (mis)interpreters as either luminaries or idiots (which would be implausible, if not downright silly), I show structurally how these misunderstandings arose and why they were kind of unavoidable, even for highly qualified and often well-informed interpreters. More popular texts about relativity theory were often second-order interpretations of these first-order accounts, thus multiplying the first-order errors of misinterpretations. I will give a few characteristic examples but my focus will rather be on structural characteristics of these misinterpretations. I will discuss how to analyze them historically by means of interpretational frames. A link will also be made to Ludwik Fleck’s thesis that socially and cognitively stabilized “thought collectives” (“Denkkollektive”) exert strong constraints on human thinking and interpretation (“Denkzwang”). My concept of interpretational frames is one method to formalize and analyze the complex interrelations between different assumptions and inferences within such a frame of thinking (“Denkstil”). Semantic frames and word clouds are also discussed as alternative approaches but both are discarded as unsuitable for the purpose of reconstructing interpretative frames.

This paper is a summary of my doctoral dissertation on philosophical interpretations of Einstein’s special and general theories of relativity, submitted to the Dept. for History of Science, Univ. of Hamburg, in 1989, which was recently published in the Series Science Networks at Birkäuser.2 After a brief overview of its content I will focus on a discussion of the method employed to analyse philosophical interpretations of a physical theory.My analysis is based- firstly on about 2500 contemporary published texts about the theories of relativity written both by scientists and philosophers. These texts have not been of particular interest to historians or philosophers of science up to now; this is understandable from the fact that many of diem contain gross oversimplifications, misinterpretations and incorrect statements about the theories of relativity.

Die Relativitatstheorien (RT) Einsteins gehoren zu den meistdiskutierten Theorien der Physik des zwanzigsten Jahrhunderts. Nach der Formulie­ rung der sog. 'speziellen Relativitatstheorie' (SRT) im Jahr 1905 nah­ men zunachst nur einige Spezialisten von ihr Kenntnis, bis mit ungefiihr fiinf Jahren Verspatung dann auch zunehmend Nicht-Physiker sich mit ihr zu beschaftigen begannen, angeregt durch populiirwissenschaftliche, all­ gemeinverstiindliche 'Einfiihrungen' von Kollegen Einsteins wie z. B. Paul Langevin in Frankreich oder Max von Laue in Deutschland. Diese Pha­ senverschiebung zwischen fachwissenschaftlichem Ausbau der Theorie und offentlicher Notiznahme wiederholte sich bei Einsteins 'allgemeiner Theorie der Relativitat und Gravitation' (ART). Zwischen 1913 und 1915 in ihren wesentlichen Ziigen ausformuliert, wurde sie erst nach einer spektakuliiren experimentellen Bestatigung im Jahr 1919 einem breiterem Publikum be­ kannt. In meiner Arbeit werde ich den Facettenreichtum der Ausdeutungen, die beide RT erfuhren, zunachst zu referieren und durch repriisentative Zi­ tate aus der Literatur der Zeit zu belegen haben. Der Umfang dieser Arbeit geht wesentlich auf das Konto dieser ausgewahlten Belege - davon verspre­ che ich mir, dafi nicht nur bislang unveroffentlichte Dokumente, sondern auch entlegene Texte hier in ihren zentralen Passagen leicht zuganglich ge­ macht werden. Fernerhin werde ich aber auch zu analysieren haben, warum derartig vielfaltige, einander mitunter diametral entgegengesetzte Interpre­ tationen einer wissenschaftlichen Theorie vorgelegt wurden.

This paper discusses facets of 19th-century scientific photography as a visual culture. The example of spectral research and documentation is particularly well suited, because prismatically diffracted light from the sun or from luminous gases was one of the most frequently examined phenomena of that century. The results were significant not only for physics but also for analytical chemistry and astrophysics. The spectrum also served as an ideal test object for checking the effectiveness of a wide array of photochemically sensitizable surfaces to the various color regions. Scientific photography became the most important experimental technique in the infrared and ultraviolet. H. A. Rowland's spectrum charts are discussed as an example of the transition from comprehensiveness in documentation to fetishism. The discussion of the Lippmann process, one of the first methods of color photography, addresses the associated training of the eye. Issues of authenticity and the much averred „mechanical objectivity” are raised with regard to retouching. The overriding theme of visual science cultures leads furthermore to unanticipated interdependencies with other scientific fields, such as geography, and draws the importance of practitioners into the foreground

This paper reconstructs what may have led the American professorof chemistry andnatural philosophy John William Draper to introduce a new kind ofradiation, whichhe dubbed `Tithonic rays''. After presenting his and earlierempirical findings onthe chemical action of light in Section 3, I analyze his pertinentpapers in Section 4with the aim of identifying the various types of argumentshe raised infavor of this new actinic entity (or more precisely, this newnatural kind of raybesides optical, thermal and perhaps also phosphorogenic rays).From a modernperspective, all of these obviously belong within theelectromagnetic spectrum,but not so for many thinkers of the 19th century. I close withremarks about whyDraper''s interpretation was abandoned in the second half of the19th century (hehimself recanting only in 1872), and why I think such a naturalhistory ofargumentation (as one might call my approach in Section 4) may beuseful for acomparison-oriented history of science.

The manipulation of materials, and to some extent also their systematic classification, form an integral part of the skills and culture of all societies. Yet it took long for proper sciences to develop out of many processing procedures, tapping the accumulated knowledge about specific material characteristics. In the late 20th century an overarching science of workable materials emerged: materials science. This concept and term originated from major boosts in materials research during WWII and the Cold War, first financed by the U.S. Department of Defense and the Advanced Research Project Agency. The COSMAT-Report from 1974, written by the American Presidential Science Advisory Committee’s „Committee on the Survey of Materials Science and Engineering" four years after its inception, and subsequent reports heralded in the second institutionalization phase of materials science in the USA and with some delay also elsewhere. As the field continued to expand, the demand grew from within in the late 1990s for disciplinary status. This article sorts these claims from the various camps and sets them in the context of unfolding institutional change. The developments within the German-speaking realm, thus far unduly neglected in these debates, are added. I close with a systematic discussion of eight indicator arguments for or against a convergence of this complex field of research into a single coherent discipline. Against Bensaude-Vincent’s thesis that materials science still is an “aggregation of fragments of knowledge", I argue that by 2010 materials science did indeed achieve disciplinary status in a historically rare and enduring process of discipline formation through “emergence by integration" rather than by differentiation.

A translator and her science consultant, who have worked together on many books, consider the problems of translating primary and secondary texts in science. Various problems encountered in translating an ongoing documentary edition in the history of science are discussed using the collected works of Albert Einstein as a test case. For instance, each language has its own preferred sentence structure; moreover, not every historical term finds a perfect equivalent in modern usage, and historical accuracy is contextually bounded.

This paper discusses a series of case studies on observations, experiments, and the theoretical interpretation between 1890 and 1960 of a shift of dark Fraunhofer lines in the solar spectrum. I argue for the use of flow charts to analyze interconnections and to identify sequences of research strategies. Also I advocate using a newly-developed tool called "block diagram" representation of experimental systems as an appropriate method to identify recurrent patterns in the interplay of instrumentation, experiment, and theory in research episodes

The ArgumentGravitational redshift of spectral lines as one of the three early-known experimental implications of Einstein's general theory of relativity and gravitation was intensively searched for by researchers all over the world, but around 1920 most of the contemporary evidence in the sun's Fraunhofer-spectrum conflicted with the predictions of relativity theory.In 1923 the American astrophysicist Charles Edward St. John announced that his own solar spectroscopic data would force him to retreat from his former skepticism concerning the existence of gravitational redshift. This statement was at the time widely interpreted by scientists and journalists alike as the open confession of a rapid conversion of one of the few remaining serious scientific opponents of Einstein's theory.This paper demonstrates that this illusion of a sudden “Gestalt switch” in St. John's evaluation of data can be dissolved by a careful step-by-step account of St. John's research practice between 1917 and 1923. After a fine-grained diachronic report of the development of St. John's interpretation of his and others' data, the second part of the paper consists in a systematic analysis of the heuristics and arguments used by St. John pro and contra gravitational redshift.

This paper describes a now widely forgotten tradition in the nineteenth century which - to borrow a simile used or implied by the actors themselves - may be described as 'spectroscopic portraiture'. Quite unlike the later obsession with numerical precision in wavelength measurement, and also in stark contrast to the contemporary vogue of photographic mapping which presumptuously claimed 'mechanical objectivity', that is avoidance of any human intervention in the recorded data, there was among some spectroscopists a much greater preoccupation with qualitative rather than quantitative aspects. The atlases of the solar spectrum by Cornu, Thollon, and Piazzi Smyth were supposed to convey the subjectively perceived Gestalt of the Fraunhofer lines, at the expense of precision. I shall argue that this was a systematic research programme addressed to a welldefined but small audience of specialists in the new subdiscipline of spectroscopy which was distinct from other practices such as spectrum analysis, which was directed mainly at chemists. Apart from this, the new tradition can also be identified by the dense net of cross-references in the publications of the various members, and by their critique of earlier work. This tradition of spectrum portraiture started with Kirchhoff's 1861-2 high-resolution chromolithographic plates of the solar spectrum, which were printed off a half-dozen different stones in order to render most faithfully the various line intensities. Focusing especially on the tension between representational goals and technical possibilities in the rapidly developing printing industry, I then trace the emerging tradition through its apogee to the close of the nineteenth century