Klaus Hentschel

Compendium of Quantum Physics

The role of operational quantum mechanics, quantum axiomatics and quantum structures in general is presented as a contribution to a compendium on quantum physics, its history and philosophy.

EINSTEIN'S ATTITUDE TOWARDS EXPERIMENTS: TESTING RELATIVITY THEORY 1907-1927

Contrary to the widespread Einstein legend, it is demonstrated that in many cases he was extremely curious about certain experimental results and that he could hardly wait for the moment when tests which he had suggested were actually done by skilled observers. I will show that this was the case whenever these empirically testable effects were closely linked to his newly proposed fundamental principles which still lacked empirical support, focussing on the examples of gravitational redshift (linked to the equivalence principle between gravitational and acceleration fields), of light deflection (linked to mass-energy equivalency and the curvature of space-time), and of interferometric experiments (linked to the two axioms of the special theory of relativity).

Erwin Finlay Freundlich and testing Einstein's theory of relativity

This article covers aspects of the life and career of ERWIN FINLAY FREUNDLICH, the first German astronomer to consider seriously Einsteins theory of relativity and gravitation. In doing so, he made himself so unpopular among his colleagues that nothing less than Einsteins powerful intercession was necessary for him to be able to continue his research on the experimental verification of this theory.

Die Korrespondenz Einstein-Schlick: Zum Verhältnis der Physik zur Philosophie

Zusammenfassung Es wird die wechselseitige Beeinflussung Einsteins und Schlicks anhand ihrer ab 1915 erhaltenen Korrespondenz in vier Schwerpunkten untersucht. Schlicks Selbstverstandnis als Philosoph wie auch einzelne Themata seines Denkens (wie etwa das der Einfachheit) bildeten sich mit seiner Auseinandersetzung um die Relativitatstheorie Einsteins heraus, deren systematische Explikation durch Schlick auf Einsteins Beifall sties. Als die Ursache fur das Auseinanderdriften beider Denker nach 1925 werden fundamentale Differenzen im Wirklichkeitsverstandnis und in der Interpretation des Kausalitatsprinzips aufgewiesen, die beide auch zu komplementaren Formen der Wissenschaftsgeschichtsbetrachtung fuhrten.

Visual cultures in science and technology : a comparative history

1. Introduction 2. Historiographic layers of visual science cultures 3. Formation of visual science cultures 4. Pioneers of visual science cultures 5. Transfer of visual techniques 6. Support by illustrators and image technicians 7. One image rarely comes alone 8. Practical training in visual skills 9. Mastery of pattern recognition 10. Visual thinking in scientic and technological practice 11. Recurrent color taxonomies 12. Aesthetic fascination as a visual cultures binding glue 13. Issues of visual perception 14. Visuality through and through

Measurements of gravitational redshift between 1959 and 1971

Summary The paper presents and discusses measurements of gravitational redshift (GRS) made between 1959 and 1971 by Pound and Rebka, Schiffer and Marshall, Brault, Blamont and Roddier, and finally by Snider. It emphasizes the importance of new measurement techniques such as wavelength modulation, electronic amplification, and scattering of atomic beams to the emergence of new tests of Einsteins GRS prediction, which were perceived by the scientific community as the first ‘clean’ verifications of GRS. In particular, the race to be the first to apply the Mossbauer effect to the GRS problem is described. As soon as the Mossbauer effect was stabilized, it was transformed into a measurement technology that in turn triggered new types of experimental tests of GRS.

Die Korrespondenz Duhem-Mach: Zur ‘Modellbeladenheit’ von Wissenschaftsgeschichte

Zusammenfassung 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 Beschaftigung mit Wissenschaftsgeschichte fuhrten und die damit verbundenen Modelle der Wissenschaftsgeschichtsentwicklung beider gegeneinander abzugrenzen. Dazu wurden insb. die in der bisher vorliegenden Sekundarliteratur zu Mach und Duhem uberhaupt nicht berucksichtigte Buchbesprechung der Machschen Mechanik durch Duhem sowie die erganzenden Bemerkungen zu Duhem in spateren Auflagen der Werke und in der Korrespondenz Machs herangezogen, die eine recht detaillierte wechselseitige Kritik ihrer Methodik beinhalten. Den Abschlus meiner Betrachtungen bildet der Versuch einer Sondierung dessen, was in Duhems resp. Machs historischen Betrachtungsweisen uber die nicht in Frage stehende ...

Gauss, Meyerstein and Hanoverian Metrology

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.

SPECTROSCOPY OR SPECTROSCOPIES

title SUMMARY /title One of the most intriguing questions posed to the participants of the Munich workshop was: Were the techniques similar enough from one field to another so as to facilitate communication between different groups? Or did they conversely vary so much that one cannot speak of a single community of spectroscopists? This paper discusses why - in my opinion - spectroscopy never made the transition to a separate discipline. It remained instead an albeit well-known and broadly applied research technology (Terry Shinn) - or should we rather say, a bundle of research technologies? Correspondingly, spectroscopic visuality was differentiated into more than a dozen spectro-scopic domains.

Heinrich Hertz’s Mechanics: A Model for Werner Heisenberg’s April 1925 Paper on the Anomalous Zeeman Effect

In this paper, I will show that Heisenberg’s last paper before his invention of matrix mechanics in the summer of 19251 contains striking parallels to Hertz’s Mechanics. Although other philosophical influences on the young Heisenberg, as well as his physics and mathematics background, have already been examined extensively,2 this particular Hertzian strand in Heisenberg’s writings at that specific time has not been pointed out in the pertinent secondary literature.3