According to the standard view, the so-called ‘Copenhagen interpretation’ of quantum mechanics originated in discussions between Bohr and Heisenberg in 1927, and was defended by Bohr in his classic debate with Einstein. Yet recent scholarship has shown Bohr’s views were never widely accepted, let alone properly understood, by his contemporaries, many of whom held divergent views of the ‘Copenhagen orthodoxy’. This paper examines how the ‘myth of the Copenhagen interpretation’ was constructed by situating it in the context of Soviet Marxist (...) critique of quantum mechanics in the 1950s and the response by physicists such as Heisenberg and Rosenfeld. (shrink)

A prominent way through which wave-particle duality has been ascribed to photons is by illustrating their “wave-like” behaviour in the Mach-Zehnder interferometer and “particle-like” behaviour in the anti-correlation experiment. This duality has been formulated in two ways. Some have based the claim on the complementarity principle. This formulation, however, has already been shown to be problematic. Others have made a much simpler duality claim by considering that single-photons are analogous to waves and particles in the above experiments. I criticise this (...) formulation by arguing that the analogies cannot be distinctly established. Thus, this duality claim is found to be unsubstantiated. (shrink)

Příspěvek se zaměřuje na zavádějící příběh o tzv. kodaňské interpretaci kvantové mechaniky, již jako údajně nerozpornou či jednotnou vytvořili a sdíleli na základě tzv. kodaňského ducha kvantové teorie její tvůrci v roce 1927. Článek bude vycházet z role, kterou v tomto příběhu sehráli především N. Bohr a W. Heisenberg. První část příspěvku seznamuje s variacemi toho, co se v literatuře považuje za kodaňskou interpretaci. Druhá část odhaluje, že zatímco kvantová mechanika vznikla ve dvacátých letech 20. století, kodaňská interpretace je veskrze (...) problematickým a především Heisenbergovým produktem z let padesátých. Jednou z hlavních motivací, kvůli níž vystoupil s tzv. kodaňskou interpretací, byla obrana vůči množícím se kritikám obhájců kvantové teorie. Jelikož mezi členy tzv. kodaňské školy nepanovala žádná jednotná či nerozporná interpretace kvantové mechaniky, zaměřuje se poslední část příspěvku na několik vybraných rozdílů hlavně mezi Bohrovým a Heisenbergovým výkladem kvantové teorie. (shrink)

The laser, first operated in 1960, produced light with coherence properties that demanded explanation. While some attempted a treatment within the framework of classical coherence theory, others insisted that only quantum electrodynamics could give adequate insight and generality. The result was a sharp and rather bitter controversy, conducted over the physics and mathematics that were being deployed, but also over the criteria for doing good science. Three physicists were at the center of this dispute, Emil Wolf, Max Born’s collaborator on (...) a canonical text on optics as a branch of classical electromagnetism, Roy J. Glauber, a student of Julian Schwinger and a high-energy particle theorist, and Leonard Mandel, both experimentalist and theorist and versed in the physics of photodetection. The story told here is thus one of three distinct research trajectories and of the explosion that occurred when, pushed into the well-financed field of laser studies, these trajectories collided. (shrink)

As the theory of the atom, quantum mechanics is perhaps the most successful theory in the history of science. It enables physicists, chemists, and technicians to calculate and predict the outcome of a vast number of experiments and to create new and advanced technology based on the insight into the behavior of atomic objects. But it is also a theory that challenges our imagination. It seems to violate some fundamental principles of classical physics, principles that eventually have become a part (...) of western common sense since the rise of the modern worldview in the Renaissance. So the aim of any metaphysical interpretation of quantum mechanics is to account for these violations. (shrink)

: This paper examines the transformation which occurs in Heisenberg's understanding of indeterminacy in quantum mechanics between 1926 and 1928. After his initial but unsuccessful attempt to construct new quantum concepts of space and time, in 1927 Heisenberg presented an operational definition of concepts such as 'position' and 'velocity'. Yet, after discussions with Bohr, he came to the realisation that classical concepts such as position and momentum are indispensable in quantum mechanics in spite of their limited applicability. This transformation in (...) Heisenberg's thought, which centres on his theory of meaning, marks the critical turning point in his interpretation of quantum mechanics. (shrink)

This paper re-evaluates the formative year of quantum mechanics—from Heisenberg’s first paper on matrix mechanics to Schrödinger’s equivalence proof—by focusing on the role of radiation in the emerging theory. We argue that the radiation problem played a key role in early quantum mechanics, a role that has not been taken into account in the standard histories. Radiation was perceived by the main protagonists of matrix and wave mechanics as a central lacuna in these emerging theories and continued to contribute to (...) the theoretical development and conceptual clarification of quantum mechanics. Studying the interplay between quantum mechanics and radiation, the paper provides an account of (a) how quantum mechanics was able to connect to its empirical basis in spectroscopy and (b) how Schrödinger’s equivalence proof emerged from his explorative calculations on the emission of radiation. (shrink)