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.
Regular readers will note the temporary increase in the length of the journal as we try to decrease the backlog of manuscripts.
The sun diver: Combining solar sails with the Oberth effect
Coryn A. L. Bailer-Jones
89(3), p. 235
By deploying a large gossamer sail, a spacecraft can exploit the Sun's radiation pressure to reduce the amount of fuel required to travel beyond the Solar System. But when and where should the sail be unfurled and the rocket fuel burned? The answer may surprise you and intrigue your undergraduate students.
Different scenarios of shrinking surface soap bubbles
Mattéo Clerget, Alexandre Delvert, Laurent Courbin, and Pascal Panizza
89(3), p. 244
Understanding the shrinking of a spherical cap bubble on a wetted surface involves several areas of physics applied to analysis, computation, and experiment. This article points out how related problems can be used for instruction or projects by advanced undergrads or grad students. The link above will also take the reader to the article's video abstract.
High-speed visualization of soap films bursting dynamics
Arseny A. Volodko and Alexander E. Dubinov
89(3), p. 253
The propagation of bursts in soap films can be studied in the teaching laboratory or demonstrated in classes. High speed digital video shows the evolution of a rupture in a soap bubble, which is explained at a level appropriate for introductory college or high school physics courses.
Mechanical approach to surface tension and capillary phenomena
89(3), p. 261
Although surface tension and capillary action are typically introduced via thermodynamics, a mechanical approach can also be used. This paper corrects errors that are often made in such an approach, but also shows that it can be instructive for undergraduate students beyond introductory courses.
Understanding and enhancing the impact-induced tension of a falling chain
89(3), p. 267
The mechanism of greater-than-g acceleration of a falling chain is elucidated through theory and experiments. Further investigations appropriate for undergraduate instructional labs and research are proposed.
Resolving tensions surrounding massive pulleys
D. J. Durian, J. Kroll, and E. J. Mele
89(3), p. 277
Tension in a string, which is redirected by a pulley, is usually idealized by treating the magnitude of the tension as being constant throughout. In this paper, which is appropriate for an intermediate or advanced mechanics class, the authors examine the tension profile in situations where the pulley or string elastically deforms.
Eddy currents in multilayer coils
Igor N. Gorbatyy and Iana P. Zhura
89(3), p. 284
An example of eddy current behavior in multilayer coils is described, which dramatically increases the active resistance of the coil with increasing frequency. This behavior is due to the “proximity effect”-namely, the interaction of currents in closely related conductors. Appropriate for intermediate or advanced circuits labs.
How much electric surcharge fits on … a “white dwarf” star?
Parker Hund and Michael K.-H. Kiessling
89(3), p. 291
A failed white dwarf star turns out to be an elegant stage for working out a number of pedagogically interesting problems, all aiming towards the goal of determining the limits of surplus charge it can accommodate. Instructors in statistical mechanics, quantum mechanics, solid state physics, and, of course, stellar astronomy, can all find interesting examples to incorporate into their courses.
Transport through quantum dots: An introduction via master equation simulations
Robert A. Bush, Erick D. Ochoa, and Justin K. Perron
89(3), p. 300
A master equation approach is presented for simulating transfer through single-electron transistors and quantum dots. By using simulations, students can build a strong understanding of transport through quantum dots without the financial overhead associated with experimental studies. Suitable for an undergraduate independent study or computational physics project.
Quantum composer: A programmable quantum visualization and simulation tool for education and research
Shaeema Zaman Ahmed, Jesper Hasseriis Mohr Jensen, Carrie Ann Weidner, Jens Jakob Sørensen, Marcel Mudrich, and Jacob Friis Sherson
89(3), p. 307
A freely-available simulation and visualization tool aids the understanding of quantum mechanics. Appropriate for quantum mechanics at all levels, including some research problems.
Active learning in a graduate quantum field theory course
G. Peter Lepage
89(3), p. 317
Despite the demonstrated success of active engagement techniques on student learning, it remains less common to see such techniques employed in advanced courses than at the introductory level. This article provides a first-hand account of a redesigned course on quantum field theory with an emphasis on active learning. The article will be of interest to educators who desire a fresh approach to learning in their advanced courses.
Physically significant phase shifts in matter-wave interferometry
Chris Overstreet, Peter Asenbaum, and Mark A. Kasevich
89(4), p. 324
Physical intuition about phase shifts in a matter-wave interferometer is developed by analogy with a classical accelerometer. Using the midpoint theorem, the authors show that the analogy holds when the spatial-dependence of the potential energy is degree 2 or lower on the scale of the wavepacket separation. For higher order potentials, the phase contains a nonlocal term with no classical counterpart. Useful to novices and experts in the fields of atom interferometry and quantum sensing.