Physics Textbooks Don’t Always Tell the Truth

Anyone who studies the history of physics quickly realizes that the history presented in physics textbooks is often inaccurate. I will discuss three episodes from the history of modern physics: (1) Robert Millikan’s experiments on the photoelectric effect, (2) the Michelson-Morley experiment, and (3) the Ellis-Wooster experiment on the energy spectrum in β decay. Everyone knows that Millikan’s work established the photon theory of light and that the Michelson-Morley experiment was crucial in the genesis of Albert Einstein’s special theory of relativity. The problem is that what everyone knows is wrong. Neither experiment played the role assigned to it by physics textbooks. The Ellis-Wooster experiment, on the other hand, is rarely discussed in physics texts, but it should be. It led to Wolfgang Pauli’s suggestion of the neutrino. I will present a more accurate history of these three experiments than those given in physics texts.     

弗兰克和赫兹对原子能级存在的实验研究

概述了弗兰克和赫兹的生平，正是他们用电子轰击原子，发现其中存在着非弹性碰撞，且原子仅接受一定量的能量，从而证明原子能级存在，并由此而获得1925年诺贝尔物理学奖，他们密切协作，不断改进实验，正确处理理论和与实践间的关系，研究工作不断创新，这些研究工作经验给人们以有益的启示。     

智能弗兰克-赫兹实验测量仪的研制

采用AT90S 8535单片机研制了一种智能弗兰克－赫兹实验测量仪，能测量10^-9-10^-12A微电流，提供0－50V线性程控稳压电源，模糊控温，图形液晶显示中英和曲线，曲线数据打印，具有测量快、精度高、体积小、成本低、使用方便等优点。本介绍了该测量仪的硬件组成、典型电路工作原理、软件设计，分析了实验结果。     

Optical scheme to demonstrate state-independent quantum contextuality

The contradiction between classical and quantum physics can be identified through quantum contextuality, which does not need composite systems or spacelike separation. Contextuality is proven either by a logical contradiction between the noncontextuality hidden variable predictions and those of quantum mechanics or by the violation of noncontextual inequality. We propose an experimental scheme of state-independent contextual inequality derived from the Mermin proof of the Kochen-Specker (KS) theorem in eight-dimensional Hilbert space, which could be observed either in an individual system or in a composite system. We also show how to resolve the compatibility problems. Our scheme can be implemented in optical systems with current experiment techniques.     

The <Emphasis Type="Italic">Bild</Emphasis> Conception of Physical Theory: Helmholtz,Hertz, and Schrödinger

Hermann von Helmholtz (1821–1894) criticized the objective conception of physical theory, denying that theoretical concepts are images of physical objects. Heinrich Hertz (1857–1894) and Erwin Schrödinger (1887–1961) used the term Bild to designate their conception of physical theory, meaning an intellectual construct whose relationship to phenomena was to be analyzed. The main features of their Bild conception were an outspoken anti-inductivism and an affirmation of a partial separation of physical theory and experimental observations. Once accepted, the Bild conception loosened the bonds that still justified the attempts at the end of the nineteenth century, such Helmholtzs and Hertzs, to unify physics through a generalized form of mechanics and opened the way to the innovations of Einsteins theory of relativity.Salvo DAgostino is Professor Emeritus, Committee on the History of Science, Accademia delle Scienze detta dei Quaranta, Rome, Italy.     

Repelling,binding, and oscillating of two-particle discrete-time quantum walks

In this paper, we investigate the effects of particle–particle interaction and static force on the propagation of probability distribution in two-particle discrete-time quantum walk, where the interaction and static force are expressed as a collision phase and a linear position-dependent phase, respectively. It is found that the interaction can lead to boson repelling and fermion binding. The static force also induces Bloch oscillation and results in a continuous transition from boson bunching to fermion anti-bunching. The interplays of particle–particle interaction, quantum interference, and Bloch oscillation provide a versatile framework to study and simulate many-particle physics via quantum walks.     

Quantum phase transition for the BEC-BCS crossover in condensed matter physics and CPT violation in elementary particle physics

We discuss the quantum phase transition that separates a vacuum state with fully gapped fermion spectrum from a vacuum state with topologically protected Fermi points (gap nodes). In the context of condensed-matter physics, such a quantum phase transition with Fermi point splitting may occur for a system of ultracold fermionic atoms in the region of BEC-BCS crossover, provided Cooper pairing occurs in the non-s-wave channel. For elementary particle physics, the splitting of Fermi points may lead to CPT violation, neutrino oscillations, and other phenomena.     

Attempt to Resolve the EPR-Bell Paradox via Reichenbach's Concept of Common Cause

Reichenbach's common cause principle claims that if there is correlation betweentwo events and none of them is directly causally influenced by the other, thenthere must exist a third event that can, as a common cause, account for thecorrelation. The EPR-Bell paradox consists in the problem that we observecorrelations between spatially separated events in the EPR experiments whichdo not admit common-cause-type explanation, and it must therefore be concludedthat, contrary to relativity theory, in the realm of quantum physics there existsaction at a distance, or at least superluminal causal propagation is possible; thatis, either relativity theory or Reichenbach's common cause principle fails.By means of closer analyses of the concept of common cause and a more precisereformulation of the EPR experimental scenario, I sharpen the conclusion wecan draw from the violation of Bell's inequalities.     

Integral Equation Method for Electromagnetic Wave Propagation inStratified Anisotropic Dielectric-Magnetic Materials

We investigate the propagation of electromagnetic waves in stratified anisotropic dielectric-magnetic materials using the integral equation method (IEM). Based on the superposition principle, we use Hertz vector formulations of radiated fields to study the interaction of wave with matter. We derive in a new way the dispersion relation, Snell's law and reflection/transmissioncoefficients by self-consistent analyses. Moreover, we find two new forms of the generalized extinction theorem. Applying the IEM, we investigate the wave propagation through a slab and disclose the underlying physics, which are further verified by numerical simulations. The results lead to a unified framework of the IEM for the propagation of wave incident either from a medium or vacuum in stratified dielectric-magnetic materials.     

Bose–Einstein condensation in dilute atomic gases: atomic physics meets condensed matter physics

Bose–Einstein condensed atomic gases are a new class of quantum fluids. They are produced by cooling a dilute atomic gas to nanokelvin temperatures using laser and evaporative cooling techniques. The study of these quantum gases has become an interdisciplinary field of atomic and condensed matter physics. Topics of many-body physics can now be studied with the methods of atomic physics. Many long-standing predictions of the theory of the weakly interacting Bose gas have been verified, including thermodynamic properties of the phase transition and dynamic properties such as shape oscillations and sound propagation. Stimulated light scattering was used to determine the dynamic structure factor both in the phonon and free-particle regime. Atomic Bose condensates show a variety of novel phenomena which include multi-component spinor condensates, magnetic domain formation, miscibility and immiscibility of quantum fluids, and finite-size effects.     

Pion,pion-pion,and pion-nucleus interactions

This survey is devoted to describing the early studies of I.I. Gurevich on pion physics that were performed by the photoemulsion method and the studies of the pion-pion interaction that were made by his colleagues on the basis of the hydrogen-bubble-chamber and the magnetic-spectrometer method (as well as on the basis of the photoemulsion method). Two approaches—an extrapolation of experimental data from the physical region to the pion pole and a theoretical calculation based on the Roy integral equations—are used to deduce information about the pion-pion interaction. The first results obtained for pion-pion and pion-nucleus interactions in the experiments that are being currently performed in Brookhaven and at CERN (ππ interaction) and at TRIUMF (Canada) and in Brookhaven (pion-nucleus interaction) are presented, along with the existing theoretical concepts in these realms of physics.     

Solitons and helices: The search for a math-physics bridge

We present evidence for an undiscovered link between N=2 super-symmetric quantum field theories and the mathematical theory of helices of coherent sheaves. We give a thorough review for nonspecialists of both the mathematics and physics involved, and invite the reader to take up the search for this elusive connection.Supported in part by Fannie and John Hertz Foundation.     

Ultrasound wave propagation in glass-bead packing under isotropic compression and uniaxial shear

The axial-stress dependence of sound wave velocity in granular packing is experimentally investigated with tri-axial and uni-axial devices. Preparing samples by repetitive loadings and unloadings in a range of 20 kPa–1000 kPa, we find that the axial-stress dependence of sound wave velocity approaches the Hertz scaling with an exponent of 1/6 for large axial stresses( 400 kPa). Weak deviation from the Hertz scaling is seen at low stresses. Repetitive axial loadings slightly reduce this deviation, and sound velocities increase nonlinearly approaching some saturated values. Velocities for uni-axial case are found slightly to be bigger than those for tri-axial isotropic compression case. These effects are discussed in the frameworks of granular solid hydrodynamics(GSH) and effective medium theory(EMT), which indicate that they cannot be explained with density nor Janssen ratio only. Dissipation occurring during wave propagation may be a non-negligible factor.     

Computationally efficient recurrence relations for one-dimensional Franck–Condon overlap integrals

Calculations based on analytical expressions for the harmonic oscillator Franck–Condon factors often yield numerically unstable and erroneous results for large values of the oscillator quantum numbers. This instability arises from inherent machine precision limits and large number round-off associated with the products and ratios of factorial and gamma functions in these expressions; the analytical expressions themselves are exact. This paper presents, first, efficient, exact recurrence relations to evaluate Franck–Condon factors for the harmonic oscillator model. The recurrence relations, which are similar to those originally found by Manneback, Wagner and Ansbacher avoid the direct use of the factorial and gamma functions. Second, a variational strategy for the evaluation of Franck–Condon factors for the Morse oscillator is proposed. The Schrödinger equation for the Morse model is solved variationally with a large enough basis set of one-dimensional harmonic oscillator functions to get good agreement with the analytic eigenvalues of the Morse potential itself. The eigenvectors of this analysis are then used together with the associated harmonic oscillator Franck–Condon overlap matrix elements to evaluate the overlap for the Morse potential. This approach allows one, in principle, to estimate Franck–Condon overlap up to states near to the dissociation limit of the Morse oscillator.     

On the Continuous Extension of States on the Ccr Algebra

The algebra CCR (E) of the CCR depends sensitively on the choice of the one boson test-function space E. Here the unique extension of certain continuous states, resp. representations, to the extended CCR algebra CCR E corresponding to an enlarged test-function space E is studied. Various applications in statistical physics, QED, quantum optics, solid state physics, and quantum chemistry are pointed out.     

The Historical Roots of ‘‘Foundations of Quantum Physics’’ as a Field of Research (1950–1970)

The rising interest, in the late 20th century, in the foundations of quantum physics, a subject in which Franco Selleri has excelled, has suggested the fair question: how did it become so? The current answer says that experiments have allowed to bring into the laboratories some previous gedanken experiments, beginning with those about EPR and related to Bells inequalities. I want to explore an alternative view, by which there would have been, before Bells inequalities experimental tests, a change in the views shared by physicists concerning the intellectual status of that issue. I will take three cases which will serve as the threads of our story: the connections between Bohms causal interpretation and Bells inequalities; Wigners ideas on the measurement problem; and finally Everetts relative states formulation. In the end, I will discuss how those threads were gathered together by creating foundations of quantum physics as a field of research.     

AnomalousE1 conversion in octupole-deformed nuclei and muon shake-off in prompt fission

It has been shown that the coexistence of octupole and quadrupole deformation in nuclei gives rise to strong penetration effects in internal conversion for theE1 transitions. This idea has been applied for evaluating the muon shake-off probabilityW _sh. The value obtained,W _sh/–0.5% per prompt fission, is in good agreement with the experimental result. Possibilities for further experimental studies of this effect are discussed.The author would like to acknowledge fruitful discussions of the problem together with Prof. Yu.P. Gangrsky, Dr. V. Yu. Denisov and Prof. D.F. Zaretsky. He is also grateful to Prof. G.Ye. Belovitsky, Prof. P. David and Dr. Ch. Rösel for discussions of the experimental situation. This work was completed at the University of Bonn in the frame of a fellowship from the Heinrich Hertz Foundation.     

Correlations due to localization in quantum eigenfunctions of disordered microwave cavities

Statistical properties of experimental eigenfunctions of quantum chaotic and disordered microwave cavities are shown to demonstrate nonuniversal correlations due to localization. Varying energy E and mean free path l enable us to experimentally tune from localized to delocalized states. Large level-to-level inverse participation ratio ( I2) fluctuations are observed for the disordered billiards, whose distribution is strongly asymmetric about . The spatial density autocorrelations of eigenfunctions are shown to spatially decay exponentially and the decay lengths are experimentally determined. All the results are quantitatively consistent with calculations based upon nonlinear sigma models.     

Exploring classically chaotic potentials with a matter wave quantum probe

We study an experimental setup in which a quantum probe, provided by a quasimonomode guided atom laser, interacts with a static localized attractive potential whose characteristic parameters are tunable. In this system, classical mechanics predicts a transition from regular to chaotic behavior as a result of the coupling between the different degrees of freedom. Our experimental results display a clear signature of this transition. On the basis of extensive numerical simulations, we discuss the quantum versus classical physics predictions in this context. This system opens new possibilities for investigating quantum scattering, provides a new testing ground for classical and quantum chaos, and enables us to revisit the quantum-classical correspondence.