We analyze the interference of individual photons in a linear-optical setup comprised of two overlapping Mach-Zehnder interferometers joined via a common beam splitter. We show how, in this setup, two kinds of standard interference effects -- namely, single-photon Mach-Zehnder interference and two-photon Hong-Ou-Mandel interference -- interfere with one another, partially canceling each other out. This new perspective, along with the overall pedagogical exposition of this work, is intended as an intuitive illustration of why quantum effects can combine nontrivially and, moreover, of the fundamental notion that quantum interference happens at measurement. This work can serve as a bridge to more advanced quantum mechanical concepts. For instance, analyses of this setup in terms of entanglement have a rich history and can be used to test the predictions of quantum mechanics versus local realism (e.g., as in Hardy's Paradox).
The Laplace transform is a valuable tool in physics, particularly in solving differential equations with initial or boundary conditions. A 2014 study by Tsaur and Wang (2014 \emph{Eur.~J.~Phys.} \textbf{35} 015006) introduced a Laplace-transform-based method to solve the stationary Schrödinger equation for various potentials. However, their approach contains critical methodological flaws: the authors disregard essential boundary conditions and apply the residue theorem incorrectly in the inverse transformation process. These errors ultimately cancel out, leading to correct results despite a flawed derivation. In this paper, we revisit the use of the Laplace transform for the one-dimensional Schrödinger equation, clarifying correct practices in handling boundary conditions and singularities. This analysis offers a sound and consistent framework for the application of Laplace transforms in stationary quantum mechanics, underscoring their educational utility in quantum mechanics coursework.
The International Conference on Auditory Display (ICAD) is a significant event for researchers and practitioners interested in exploring the use of sound in conveying information and data. Since its inception in 1994, the conference has served as a vital forum for exchanging ideas and presenting research findings in the field of auditory display. While the conference primarily focuses on auditory display and sound design, astronomy has made its presence felt in the proceedings of the conference over the years. However, its not until the current ICAD conference where astronomy features a dedicated session. This paper aims to provide an statistical overview of the presence of astronomy in the ICAD conference's history from 1994 to 2022, highlighting some of the contributions made by researchers in this area, as well as the topics of interest that have captured the attention of sound artists.
Capitalizing on the enthusiasm about space science in the general public, our goal as an interdisciplinary group of scholars is to design and teach a new team-taught interdisciplinary course, "Philosophy and Science of Space Exploration (PoSE)" at the University of Texas at San Antonio (UTSA) where we currently teach. We believe that this course will not only help overcome disciplinary silos to advance our understanding of space and critically examine its ethical ramifications, but also will better educate the public on how science works and help overcome the science skepticism that has unfortunately become more prominent in recent years. In what follows, we first juxtapose two seemingly contradictory trends: increased interest in space science on the one hand and increased skepticism about and distrust in science on the other. We then turn to how our anticipated Philosophy and Science of Space Exploration (PoSE) course will develop tools that could dismantle distrust in science while also enhancing the scientific and philosophical understandings of space science. We explain the content and the questions we will examine in POSE and conclude with how we will measure our success and progress.
We present an intuitive, conceptual, but semi-rigorous introduction to the celebrated Markov Chain Monte Carlo method using a simple model of population dynamics as our motivation and focusing on a few elementary distributions. Conceptually, the population flow between cities closely resembles the random walk of a single walker in a state space. We start from two states, then three states, and finally the setup is fully generalized to many states of both discrete and continuous distributions. Despite the mathematical simplicity, the setup remarkably includes all the essential concepts of Markov Chain Monte Carlo without loss of generality, e.g., ergodicity, global balance and detailed balance, proposal or selection probability, acceptance probability, up to the underlying stochastic matrix, and error analysis. Our teaching experience suggests that most senior undergraduate students in physics can closely follow these materials without much difficulty.
This paper compares two cases of a Teacher Professional Development (TPD) focused on astronomy education: the San Antonio Teacher Training Astronomy Academy (SATTAA). The central question here is: How do in-service teachers' perceptions of the logistics and key benefits of SATTAA compare across two cases: the 2019 fully face-to-face (f2f) iteration in 2019, and the fully online iteration in 2020. Participants in both iterations equally indicated that they thought of their experiences as valuable and the program effective with two exceptions: (1) field trips that took place f2f were ranked higher than virtual options; and (2) technology was highlighted as benefit in the 2020 online iteration, but not in the 2019 f2f program.
This Physics Today article discusses why the physics community needs to embrace the challenge of educating students with diverse educational backgrounds to meet future research and workforce demands and outlines some of the efforts underway.
Alexander Rudolph, Gibor Basri, Marcel Agüeros
et al.
The purpose of this white paper is to provide guidance to funding agencies, leaders in the discipline, and its constituent departments about strategies for (1) improving access to advanced education for people from populations that have long been underrepresented and (2) improving the climates of departments where students enroll. The twin goals of improving access to increase diversity and improving climate to enhance inclusiveness are mutually reinforcing, and they are both predicated on a fundamental problem of inequality in participation. This white paper has been endorsed by the Board of Trustees of the AAS.
Pedro Russo, Edward Gomez, Thilina Heenatigala
et al.
Hundreds of thousands of astronomy education activities exist, but their discoverability and quality is highly variable. The web platform for astronomy education activities, astroEDU, presented in this paper tries to solve these issues. Using the familiar peer-review workflow of scientific publications, astroEDU is improving standards of quality, visibility and accessibility, while providing credibility to these astronomy education activities. astroEDU targets activity guides, tutorials and other educational activities in the area of astronomy education, prepared by teachers, educators and other education specialists. Each of the astroEDU activities is peer-reviewed by an educator as well as an astronomer to ensure a high standard in terms of scientific content and educational value. All reviewed materials are then stored in a free open online database, enabling broad distribution in a range of different formats. In this way astroEDU is not another web repository for educational resources but a mechanism for peer-reviewing and publishing high-quality astronomy education activities in an open access way. This paper will provide an account on the implementation and first findings of the use of astroEDU.
In recent centuries the world has become increasingly dominated by empirical evidence and theoretic science in developing worldviews. Advances in science have dictated Roman Catholic doctrine such as the acceptance of Darwinian evolution and Big Bang cosmology. Albert Einstein created an indelible impact on the relationship between science and religion. The question is whether or not his work was deleterious for church doctrine or whether it was compatible with, or even advanced, church dogma. It's my contention that Einstein revived the relationship between science and theology and did not create a bifurcation between the two. Despite his personal religious beliefs, his work has helped to reinforce the harmonious conjunction of science with religion, which cannot be ignored by succeeding scientists and theologians.
We present the proposal of an elective for engineering courses, designed to train professionals with a solid foundation in Physics of the Atmosphere interested in environmental and sustainability issues broadly. We propose four chapters that contain a variety of topics but strongly interrelated, which correspond to three main areas: nature of the atmosphere and meteorology relevant to contaminant transport, the dispersion of air pollutants and climate in general. We conclude that it is possible train engineers who understand the basic mechanisms that led to the current atmosphere, atmospheric processes related to local and global climate, the dispersion of air pollutants and key concepts such as solar activity, climatic change and climatic variability, even in one semester. It also discusses the relationship with other subjects and proposes and illustrates a method of course approval based on the performance of work directly applicable to engineering problems.
Assuming a constant mass-decrease per unit-surface and -time we provide a very simplistic model for the dissolution process of spherical candies. The aim is to investigate the quantitative behavior of the dissolution process throughout the act of eating the candy. In our model we do not take any microscopic mechanism of the dissolution process into account, but rather provide an estimate which is based on easy-to-follow calculations. Having obtained a description based on this calculation, we confirm the assumed behavior by providing experimental data of the dissolution process. Besides a deviation from our prediction caused by the production process of the candies below a diameter of 2 mm, we find good agreement with our model-based expectations. Serious questions on the optimal strategy of enjoying a candy will be addressed, like whether it is wise to split the candy by breaking it with the teeth or not.
Craig McDonald, Matthew McPherson, Craig McDougall
et al.
The increasing number of applications for holographic manipulation techniques has sparked the development of more accessible control interfaces. Here, we describe a holographic optical tweezers experiment that is controlled by gestures which are detected by a Microsoft Kinect. We demonstrate that this technique can be used to calibrate the tweezers using the Stokes Drag method and compare this to automated calibrations. We also show that multiple particle manipulation can be handled. This is a promising new line of research for gesture-based control that could find applications in a wide variety of experimental situations.
A simple physical model differentiates effective from ineffective teaching and identifies elements that make teaching productive, with specific implications concerning training of teachers.
A rule to assign a physical meaning to Lagrange multipliers is discussed. Examples from mechanics, statistical mechanics and quantum mechanics are given.