These brief summaries are designed to help readers easily see which articles will be most valuable to them. The online version contains links to the articles.

Edward F. Redish, 91(6), p. 415, https://doi.org/10.1119/5.0155772

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Joanna Behrman

91(6), p. 417

https://doi.org/10.1119/5.0131617

It is hard to imagine teaching physics or astronomy without a laboratory component, but that was the common state of affairs in the late 19th century in the United States.  Sarah Frances Whiting was among the first educators to make lab work central to the teaching of astronomy.  This article discusses the influences on her work, the challenges she faced, and the “hands-on” teaching philosophy she adopted as she launched laboratory instruction at Wellesley College.

Stephen Kaczkowski

91(6), p. 425

https://doi.org/10.1119/5.0114235

Say that you're traveling along a wide, straight road and suddenly realize that you want to be going the other direction. What's the fastest way to turn around, if you're constrained by the maximum acceleration due to friction with the road? This sort of constrained motion problem has a long history in physics. The solution, which shows the importance of choosing the right variables, could make a good starting point for student projects in mechanics.

Kelley D. Sullivan, Antara Sen, and M. C. Sullivan

91(6), p. 432

https://doi.org/10.1119/5.0068701

In upper-level electromagnetism, multipole expansions are one of the standard tools used to solve Laplace's equation. However, it's hard to gain a physical intuition for the higher order multipoles. This paper shows how students can gain understanding of multipole fields, while also gaining skills in numerical computation, simulation, data collection, and analysis, by measuring and modeling the magnetic fields of configurations of commercially available magnets. The measurements can be made using a smartphone sensor, and the open-source Python library Magpylib can be used to simulate the fields. The modular organization allows instructors to pick and choose among multiple activities according to the ability and interest of their students.

Chang Hyeon Lee and Byung-Yoon Park

91(6), p. 440

https://doi.org/10.1119/5.0062860

Dropping a magnet in a conducting pipe to visualize the eddy current-induced braking is a classic classroom demonstration of induction. Usually, the magnet is dropped in such a way that its magnetic moment is vertical. Here, the authors explore what happens if the magnetic moment is horizontal. Then, the eddy currents are not of cylindrical symmetry, so that things get more complicated. Rather than solving Maxwell's equations numerically, the authors show that the problem is equivalent to having the magnet fall in a quadrupolar magnetic field. They can then derive the expression of the drag force for various magnetic moment orientations. The model is validated through experiment. All or part of this combination of classical electromagnetism, modeling and experiment could be used as an undergraduate exercise, a student project, or a numerical physics problem.

Theodore A. Corcovilos

91(6), p. 449

https://doi.org/10.1119/5.0083069

This article presents a mathematical technique that can alter the direction of the optical axis for compound optical systems while still retaining the small angle approximation. The use of the homogeneous coordinates furthermore delivers a simplified procedure for computing image points for these compound arrangements. This can be of use both in undergraduate instruction and in the laboratory.

Lea Kopf, Markus Hiekkamäki, Shashi Prabhakar, and Robert Fickler

91(6), p. 458

https://doi.org/10.1119/5.0062128

It's notoriously difficult to develop intuition for quantum mechanical systems, but the need to train students to contribute to quantum technologies inspires us to try new approaches. This paper presents a card game that can be used to learn about basic quantum mechanical concepts such as randomness, superposition, interference, and entanglement while manipulating the quantum state of a virtual quantum computer. The game can be played by students at a wide range of levels and even by the general public.

Alessandro M. Orjuela and J. K. Freericks

91(6), p. 463

https://doi.org/10.1119/5.0083964

The spreading of a free Gaussian wavepacket as it evolves in time is a familiar problem to quantum mechanics instructors. But as is frequently the case, revisiting this problem with a different approach can yield significant new insights. This paper shows how the problem can be solved by mapping it onto the application of a squeezing operator on a simple-harmonic-oscillator ground state, providing students with a solution that uses very little calculus while also emphasizing the use of operators. This approach will be particularly useful in courses that emphasize quantum information.

David L. Tran, Paymon Shirazi, Mohanchandra K. Panduranga, and Gregory P. Carman

91(6), p. 470

https://doi.org/10.1119/5.0134187

This article presents the design of a cost-effective apparatus for magnetostrictive measurements on nanoscale thin-film samples. Magnetostriction is a property of magnetic materials that causes them to expand or contract during the process of magnetization. The measurement capability of the apparatus is investigated via the measurements on an amorphous 200-nm-thick Terfenol-D sample, where magnetostriction values up to approximately 100 parts per million are obtained. In addition, it is demonstrated that the acquired magnetostriction data can be used to produce a plot of the sample's normalized magnetization as a function of applied magnetic field. The article will be of especial interest to those teaching a magnetic materials and devices course.

J. W. Powell, L. Caudill, and O. Young

91(6), p. 478

https://doi.org/10.1119/5.0144906

Just as many experimentalists use sophisticated hardware to aid their research, computational physicists use efficient and complex software that has been developed by many people. However, it is important to have some insight into how the algorithms underlying the software work. This paper provides important insights into the nature of ChaNGa, which can be used to simulate the motion of gravitationally interacting sources and gas dynamics in cosmology.

Eric S. Thomson, Reviewer

91(6), p. 486

https://doi.org/10.1119/5.0149392