Search results for "History of Physics"
showing 10 items of 65 documents
Comment on “Indications of aT=0Quantum Phase Transition inSrTiO3”
1998
A Comment on the Letter by Daniel E. Grupp and Allen M. Goldman, Phys. Rev. Lett. 78, 3511 (1997). The authors of the Letter offer a Reply.
Chronology and Outlook
2018
The following chronology places emphasis on the basics and on interpretations of quantum physics; it should not be considered to be a history of quantum physics as a whole. In particular, the special developments within quantum field theory, and the advances in particle physics which grew out of them, are not included. However, along with the interpretations which were given a detailed treatment in earlier chapters (Copenhagen, GRW, Everett, Bohm), a number of other approaches are briefly mentioned here. They could not be treated in detail in the rest of the book.
Exploring Historical Scientific Instruments by Using Mobile Media Devices
2022
We describe an educational activity that can be completed with mobile media devices in order to understand the working principle of a pair of tuning forks, from the Historical Collection of Physics Instruments of the University of Palermo, and how they were used to explain acoustic interference and beats with the Lissajous optical method. This approach can be used with any tuning fork and it is a valuable teaching strategy that does not require specific laboratory equipment.
The Dunkl–Williams constant, convexity, smoothness and normal structure
2008
Abstract In this paper we exhibit some connections between the Dunkl–Williams constant and some other well-known constants and notions. We establish bounds for the Dunkl–Williams constant that explain and quantify a characterization of uniformly nonsquare Banach spaces in terms of the Dunkl–Williams constant given by M. Baronti and P.L. Papini. We also study the relationship between Dunkl–Williams constant, the fixed point property for nonexpansive mappings and normal structure.
Coxeter on People and Polytopes
2004
H. S. M. Coxeter, known to his friends as Donald, was not only a remarkable mathematician. He also enriched our historical understanding of how classical geometry helped inspire what has sometimes been called the nineteenth-century’s non-Euclidean revolution (Fig. 35.1). Coxeter was no revolutionary, and the non-Euclidean revolution was already part of history by the time he arrived on the scene. What he did experience was the dramatic aftershock in physics. Countless popular and semi-popular books were written during the early 1920s expounding the new theory of space and time propounded in Einstein’s general theory of relativity. General relativity and subsequent efforts to unite gravitati…
Coherent states: a contemporary panorama
2012
Coherent states (CS) of the harmonic oscillator (also called canonical CS) were introduced in 1926 by Schr?dinger in answer to a remark by Lorentz on the classical interpretation of the wave function. They were rediscovered in the early 1960s, first (somewhat implicitly) by Klauder in the context of a novel representation of quantum states, then by Glauber and Sudarshan for the description of coherence in lasers. Since then, CS have grown into an extremely rich domain that pervades almost every corner of physics and have also led to the development of several flourishing topics in mathematics. Along the way, a number of review articles have appeared in the literature, devoted to CS, notably…
Directly probing the chirality of Majorana edge states
2021
We propose to directly probe the chirality of Majorana edge states in 2D topological superconductors using polarization selective photon absorption. When shining circularly polarized light on a 2D topological superconductor in disk geometry, the photons can excite quasiparticles only when the polarization of the light matches the chirality of the Majorana edge states required by the angular momentum conservation. Hence, one can obtain the chirality of the Majorana edge states by measuring the photon absorption rate. We show that the polarization selective photon absorption can also serve as smoking gun evidence of the chiral Majorana edge mode.
Distinguishing Majorana Zero Modes from Impurity States through Time-Resolved Transport
2019
We study time-resolved charge transport in a superconducting nanowire using time-dependent Landauer-B{\"u}ttiker theory. We find that the steady-state Majorana zero-bias conductance peak emerges transiently accompanied by characteristic oscillations after a bias-voltage quench. These oscillations are absent for a trivial impurity state that otherwise shows a very similar steady-state signal as the Majorana zero mode. In addition, we find that Andreev bound states or quasi-Majorana states in the topologically trivial bulk phase can give rise to a zero-bias conductance peak, also retaining the transient properties of the Majorana zero mode. Our results imply that (1) time-resolved transport m…
Continuity and Change in Cosmological Ideas in Spain Between the Sixteenth and Seventeenth Centuries: The Impact of Celestial Novelties
2010
The star which became visible in 1572 in the constellation of Cassiopeia (identified by twentieth-century astronomers as a Type I supernova), and the works and polemics to which it gave rise, marked an important stage in the abandonment of Aristotelian and medieval cosmology and their replacement by the idea of the infinite—or indefinite—universe of modern physics and astronomy.
Quantum Field Theory
2018
Quantum field theory (QFT) shares many of its philosophical problems with quantum mechanics. This applies in particular to the quantum measurement process and the connected interpretive problems, to which QFT contributes hardly any new aspects, let alone solutions. The question as to how the objects described by the theory are spatially embedded was already also discussed for quantum mechanics. However, the new mathematical structure of QFT promises new answers, which renders the spatiotemporal interpretation of QFT the pivotal question. In this chapter, we sketch the mathematical characteristics of QFT and show that a particle as well as a field interpretation breaks down.