Contemporary Physics Research Articles

Mechanika arystotelesowska a współczesna fizyka. Na tropach ciągłości wewnętrznej logiki rozwoju nauki

An analysis of two different reconstructions of Aristotelian mechanics in the language of contemporary physics reveals interesting aspects of the historical development of physics: (1) there exists a structural invariant in all physical representations of reality in the form of the Cartesian product and (2) all intertheoretical transitions to date, at each stage of unification, have occurred in accordance with the correspondence principle. This means that the historical development of physics can be regarded as rational in the sense that subsequent theories become ever more general and Aristotelian mechanics can be treated as a natural forerunner of Newtonian mechanics and, by extension, Einstein’s relativity theory.

Scientists suggest insertion of nanoscience and technology into middle school physics

Experts recommend that contemporary physics topics should be added to the middle and high school physics curriculum.

Hyperons - a strange key to the strong interaction

Hyperons provide new insights into two of the most challenging problems in contemporary physics: a coherent and quantitative description of the strong interaction, and the matter-antimatter asymmetry of the Universe. In these proceedings, I will demonstrate the merits of hyperons as a diagnostic tool using two recent measurements by the BESIII experiment as an illustrative example. Furthermore, I will highlight the prospect of future hyperon studies with the next-generation experiment PANDA at FAIR.

Only a unified ontology can remedy disunification

Contemporary theoretical physics is divided into diversified theories of different phenomena. These are characteristically frameworks for giving mathematical descriptions of perceptions, in the absence of understandable explanations or a unified worldview. This is not an optimal state of affairs, for people by nature desire to understand; this sets a major obstacle for an optimal progress rate of physics, for understandable explanations are more prolific of new predictions and applications than non-understandable explanations. Disunification in physics can be remedied only by discovering an understandable ontology and applying it as the basis of unifying explanations of phenomena that were earlier explained by different theories. Due to disunified physics and the nature of traditional analysis in philosophy, there is no consensus about central concepts such as time, possibility and truth. It is suggested that philosophical analysis would be more prolific of understandable and applicable concepts, were it complemented by a method of unification.

A geodesical approach for the harmonic oscillator

The harmonic oscillator (HO) is present in all contemporary physics, from elementary classical mechanicsto quantum field theory. It is useful in general to exemplify techniques in theoretical physics. In this work,we use a method for solving classical mechanic problems by first transforming them to a free particle formand using the new canonical coordinates to reparametrize its phase space. This technique has been used tosolve the one-dimensional hydrogen atom and also to solve for the motion of a particle in a dipolar potential.Using canonical transformations we convert the HO Hamiltonian to a free particle form which becomestrivial to solve. Our approach may be helpful to exemplify how canonical transformations may be used inmechanics. Besides, we expect it will help students to grasp what they mean when it is said that a problemhas been transformed into another completely different one. As, for example, when the Kepler problem istransformed into free (geodesic) motion on a spherical surface.

Tuning the Kondo effect via gating-controlled orbital selection in the LaAlO3/SrTiO3 interfacial d -electron system

The orbital degree of freedom plays a critical role in contemporary condensed-matter physics, with recent discoveries of orbital-dependent many-body effects including electron correlation and superconductivity. Nevertheless, these orbital-dependent many-body effects have mainly been observed in bulk materials, wherein the electrons' orbital attribute is challenging to tailor selectively. Here, by planar tunneling into the two-dimensional electron system (2DES) at the ${\mathrm{LaAlO}}_{3}/{\mathrm{SrTiO}}_{3}$ interface, we observed a Kondo resonance, a model many-body phenomenon. The observation of the Kondo resonance provides an ideal opportunity to quantitatively exploit the emerging interfacial Kondo physics. Furthermore, it was found that the Kondo coupling strength and resonance line shape can be effectively regulated by electrostatic gating and show a sharp transition at the Lifshitz point, where the orbital occupancy of the 2DES changes from only ${d}_{\mathrm{xy}}$ to both ${d}_{\mathrm{xy}}$ and ${d}_{\mathrm{xz}/\mathrm{yz}}$. This unusual behavior is attributed to the orbital selectivity effect in this unique multiple-$d$-band system, wherein the itinerant ${d}_{\mathrm{xy}}$ and ${d}_{\mathrm{xz}/\mathrm{yz}}$ electrons have different orbital symmetries and therefore different Kondo exchange coupling with the localized ${d}_{\mathrm{xy}}$ electrons. The present study may pave the way for manipulating many-body effects in 2D multiband materials via orbital engineering of itinerant electrons.

The Making of Contemporary Physicists: Figured Worlds in the University Quantum Mechanics Classroom

The Making of Contemporary Physicists : Figured Worlds in the University Quantum Mechanics Classroom

Concept of Absolutism - Comments on the Theory of Relativity and Quantum Mechanism

After reviewed the problems in science and the folk that were difficult to be scientifically explained by contemporary physics, the reason is analyzed and found that contemporary physics is based on the human vision and cognition to think the universe, not based on nature. Then the concept of Absolutism is proposed based on nature itself and its intrinsic property, absorbed folk experience and lessons as well as religious thoughts, and criticized the Theory of Relativity and Quantum Mechanism. It includes three axioms and four corollaries to set up core concept, and establish the absoluteness of the material world. As an original concept of physics, the concept of Absolutism will deliver a revolutionary concept and thinking style for contemporary physics, and give contemporary physics a jolt after the Theory of Relativity and Quantum Mechanism have been proposed one hundred years.

Hyperon Structure and CP tests at BESIII

Hyperons are a powerful diagnostic tool that can shed light on some of the most intriguing questions in contemporary physics. Electromagnetic form factors (EMFFs) are currently the best way to study hyperon structure. In the time-like region the EMFFs can be complex with a relative phase. A non-zero phase polarizes the final state even when the initial state is unpolarized. A dedicated data sample collected by the BESIII experiment allowed for a first complete reconstruction of Λ in the time-like region. The ratio, R and relative phase between the electric and magnetic form factor, ΔΦ are measured to be 0.96±0.14(stat)±0.002(syst) and 37°±12°(stat)±6°(syst), respectively. In addition, the BESIII experiment has collected the world’s largest J/ψ data sample. Due to symmetric excellent detector conditions and low hadronic background, the experiment offers a clean environment for CP-violation tests using . That hyperons can be polarized allows for a simultaneous measurement of angular distributions of hyperons and antihyperons and to test CP symmetry directly. This has been done for the process recently measured by the BESIII experiment. The experimental results showed that the asymmetry decay parameter α(Λ → ππ−) = +0.750±0.009±0.004, is nearly twenty percent larger compared to the old PDG tabulated value. The test on CP symmetry, is the most sensitive test for Λ CP-violation. Preliminary results are presented for the process . The asymmetry decay parameter and −0.015 ± 0.037 ± 0.008 are both measured for the first time.

Hyperon Physics with PANDA at FAIR

Hyperons provide new angles on two of the most challenging problems in contemporary physics: a coherent and quantitative description of the strong interaction, and the matter-antimatter asymmetry of the Universe. The production dynamics and the electromagnetic structure of strange hyperons, as well as hyperon spectroscopy, give insights into the strong interaction in the confinement domain. Furthermore, two-body decays of strange hyperons provide clean tests of CP symmetry, an essential piece to the matter-antimatter puzzle. The future experiment PANDA at FAIR offers unique possibilities to study different aspects of hyperons using antiproton beams. In particular, the hitherto almost unexplored multi-strange sector will be addressed. The expected large production cross sections of hyperons and the versatile, near 4πdetector design makes PANDA a veritable hyperon factory already from the first phase of operation. In these proceedings, the opportunities for hyperon physics with PANDA will be outlined. I will also address how we can benefit from the weak hyperon decays, that provide straight-forward access to the full spin density matrix.

What’s the Problem with the Cosmological Constant?

The “Cosmological Constant Problem” (CCP) is widely considered a crisis in contemporary theoretical physics. Unfortunately, the search for its resolution is hampered by open disagreement about what is, strictly, the problem. This disagreement stems from the observation that the CCP is not a problem within any of our current theories, and nearly all of the details of those future theories for which the CCP could be made a problem are up for grabs. Given this state of affairs, I discuss how one ought to make sense of the role of the CCP in physics and generalize some lessons from it.

O inconsciente coletivo e a física contemporânea

Este artigo apresenta o conceito de inconsciente coletivo postulado pelo Dr. Carl Gustav Jung e alguns conceitos da física contemporânea que culminaram com a idéia da elaboração de uma Teoria de Tudo (TdT). Pretende iniciar uma discussão sobre a semelhança desses conceitos e propõe a continuidade da discussão visando maior esclarecimento teórico do assunto e da possibilidade da inclusão de experimentos para verificação empírica. Esse artigo foi elaborado a partir de consulta bibliográfica e informações transmitidas nas aulas do curso de pós- graduação latu senso em psicologia analítica na Universidade Santa Ursula.

Diffusion Cloud Chamber in Education

Radioactivity and the accompanying ionizing radiations are important part of the environment. They cannot be observed by humans. However, with the cloud chamber everyone can easily see that the radiations are really present in our environment. Using cloud chambers in public education students are able to gain direct experiences in many fields like natural and artificial radioactivity, characteristics of the particles, features of the quantum world, random nature of the processes as well as the unity of classic and contemporary physics. Pictures, videos, descriptions and computer codes assisting the evaluation may be really useful in lessons and in different studies including university education.

Gravitational waves in Newton’s gravitation and criticism of gravitational waves resulting from the General Theory of Relativity (LIGO)

The most important conclusion from this article is that from the General Theory of Relativity do not result any gravitational waves, but just ordinary modulation of the gravitational field intensities caused by rotating of bodies. If the LIGO team has measured anything, it is only this modulation, rather than the gravitational wave understood as the carrier of gravity. This discussion shows that using too complicated mathematics in physics leads to erroneous interpretation of results (in this case, perhaps the tensor analysis is guilty). Formally, various things can be calculated, but without knowing what such analysis means, they can be attributedmisinterpreted. Since the modulation of gravitational field intensities has been called a gravitational wave in contemporary physics, we have also done so, although it is misleading. In the article it was shown, that from the Newton’s law of gravitation resulted an existence of gravitational waves very similar to these, which result from the General Theory of Relativity (GTR). The article shows differences between the course of gravitational waves that result from Newton’s gravitation, and the course of gravitational waves that result from the General Theory of Relativity, which measurement was announced by the LIGO (Laser InterferometerGravitational-Wave Observatory) [1–3]. According to both theories, gravitational waves are cyclical changes of the gravitational field intensities. The article proposes a method of testing a laser interferometer for gravitational wave measurement used in the LIGO Observatory. Criticism of results published by the LIGO team was also presented.

Spatio-temporal characterization of thermal fluctuations in a non-turbulent Rayleigh–Bénard convection at steady state

In this paper we present a detailed description of the statistical and computational techniques that were employed to study a driven far-from-equilibrium steady-state Rayleigh–Bénard system in the non-turbulent regime (Ra≤3500). In our previous work on the Rayleigh–Bénard convection system we try to answer two key open problems that are of great interest in contemporary physics: (i) how does an out-of-equilibrium steady-state differ from an equilibrium state and (ii) how do we explain the spontaneous emergence of stable structures and simultaneously interpret the physical notion of temperature when out-of-equilibrium. We believe that this paper will offer a useful repository of the technical details for a first principles study of similar kind. In addition, we are also hopeful that our work will spur considerable interest in the community which will lead to the development of more sophisticated and novel techniques to study far-from-equilibrium behavior.

Respostas de licenciandos em Física sobre aspectos relacionados aos exames de diagnóstico médico por imagem

Assumindo que uma das possíveis maneiras de trabalhar tópicos de Física Moderna e Contemporânea é abordando aspectos do funcionamento de artefatos tecnológicos contemporâneos, estruturamos este trabalho a partir de duas questões: como licenciandos em física produzem sentidos a partir de uma unidade de ensino sobre aparelhos e exames de diagnóstico médico por imagem? E como o desenvolvimento de uma unidade de ensino sobre aparelhos e exames de diagnóstico médico por imagem pode contribuir para as representações de licenciandos em física sobre alguns conceitos e noções associados à Física Moderna e Contemporânea? Para respondê-las, embasamo-nos em noções da Análise de Discurso divulgadas e/ou produzidas por Eni Orlandi e analisamos respostas dadas por dois licenciandos em física ao longo do desenvolvimento da referida unidade de ensino em sala de aula. As análises evidenciaram que a abordagem do tema aparelhos e exames de diagnóstico médico por imagem pode funcionar como condição de produção de sentidos sobre noções relacionadas à Física Moderna e Contemporânea, como as de radiação, radioatividade e spin, proporcionando aos licenciandos a produção de sentidos coerentes com as interpretações científicas atualmente aceitas.

Análise dos conteúdos de Física moderna e contemporânea presentes em quatro coleções de livros didáticos aprovadas no PNLEM 2009 e nos PNLDS 2012, 2015 e 2018

Considerando a crescente discussão iniciada no final do século passado sobre a inserção de conteúdos de Física Moderna e Contemporânea no Ensino Médio, as pesquisas da área têm indicado a necessidade desses conteúdos no currículo da Educação Básica e nos livros didáticos. A presente pesquisa busca verificar como tais conteúdos são apresentados em quatro coleções aprovadas no PNLEM 2009 e nos PNLDs 2012, 2015 e 2018. A partir de uma pesquisa qualitativa realizada por meio de um estudo bibliográfico, análise de livros do Ensino Médio e trabalhos publicados na área, investigou-se como tais conteúdos são apresentados nos livros aprovados e como ocorreram as mudanças em suas atualizações, tencionando saber quais temas vêm sendo contemplados e de que forma são apresentados. Os resultados mostram que tópicos de Física Moderna e Contemporânea aparecem predominantemente no final do volume 3 de cada coleção e que, em algumas delas, foram suprimidos alguns temas no decorrer de suas atualizações. As mudanças mais significativas ocorreram na atualização das coleções do PNLEM 2009 para o PNLD 2012, período em que foram realizadas as principais adequações, visando ao Exame Nacional do Ensino Médio.

Une nébuleuse sémantique : « le vide » en français et diverses langues

This contribution explores the complex semantics of vacuum (void / blank / gap / emptiness) in French and in various languages. It first examines the paradoxical aspect of this concept through its unsteady, wavering antonymy, focusing the illustrations (terminology, phrases, sentences) in two distant cultural areas and periods of time : Western contemporary physics on the one hand and traditional Chinese Taoism on the other. The research follows by a diachronic and synchronic outline of the notion, from Indo-European roots to uses in French. Several semantic fields are involved in its development : these are sketched out with particular references to the history of French. In order to shed more light on the concept, additional potential synonyms and antonyms are put forward, as well as metaphors, through various languages, and the material appears to be rich and relevant. Several symbolic representations of the notion, which tend to confirm its paradoxical character, are briefly discussed in the conclusion followed by a short summary of findings.

Conceptual Challenges on the Road to the Multiverse

The current debate about a possible change of paradigm from a single universe to a multiverse scenario could have deep implications on our view of cosmology and of science in general. These implications therefore deserve to be analyzed from a fundamental conceptual level. We briefly review the different multiverse ideas, both historically and within contemporary physics. We then discuss several positions within philosophy of science with regard to scientific progress, and apply these to the multiverse debate. Finally, we construct some key concepts for a physical multiverse scenario and discuss the challenges this scenario has to deal with in order to provide a solid, testable theory.

Chirped self-similar solitary waves for the generalized nonlinear Schrödinger equation with distributed two-power-law nonlinearities.

We investigate the propagation characteristics of the chirped self-similar solitary waves in non-Kerr nonlinear media within the framework of the generalized nonlinear Schrödinger equation with distributed dispersion, two-power-law nonlinearities, and gain or loss. This model contains many special types of nonlinear equations that appear in various branches of contemporary physics. We extend the self-similar analysis presented for searching chirped self-similar structures of the cubic model to a more general problem involving two nonlinear terms of arbitrary power. A variety of exact linearly chirped localized solutions with interesting properties are derived in the presence of all physical effects. The solutions comprise bright, kink and antikink, and algebraic solitary wave solutions, illustrating the potentially rich set of self-similar pulses of the model. It is shown that these optical pulses possess a linear chirp that leads to efficient compression or amplification, and thus are particularly useful in the design of optical fiber amplifiers, optical pulse compressors, and solitary wave based communication links. Finally, the stability of the self-similar solutions is discussed numerically under finite initial perturbations.