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.
Hysteresis in a simple V-shaped spring-mass system
89(7), p. 663
Students are often introduced to hysteretic behavior by studying ferromagnetism or non-linear elastic materials. But hysteresis can also occur in exceedingly simple systems, such as the mass-spring system analyzed by the author. The simplicity of the analysis may allow instructors to introduce this important topic in introductory mechanics courses, and a physical model of the system could be used as a demonstration or laboratory apparatus. The link above will also take the reader to the article's video abstract.
Rock and roll of an ellipse
G. R. Heppler and G. M. T. D'Eleuterio
89(7), p. 666
A small disturbance from equilibrium causes an ellipse on an inclined plane to rock back and forth. A larger disturbance causes it to roll smoothly down the plane and eventually jump off of the surface. Students and instructors of advanced classical mechanics courses will be surprised that a system that is so simple can exhibit such rich dynamics.
Oscillation of a balanced hollow cylinder on an inclined plane
R. De Luca
89(7), p. 677
The author studies the behavior of a thin-walled cylinder lying on its side atop an inclined plane. The cylinder is balanced against rolling by a mass attached to its inner rim. The system's stable and unstable equilibria are found using geometry and trigonometry, while oscillations about equilibria are examined using a Lagrangian approach. The former presents a challenging exercise for introductory physics students, while the latter is suitable for an upper level mechanics class. The system is simple and inexpensive to construct, making it ideal for experimental verification of the results. The link above will also take the reader to the article's video abstract.
The true story of Newtonian gravity
89(7), p. 683
Under pressure of time we often teach the law of universal gravitation F = GmM/r2 as if it emerged fully formed out of the mind of Isaac Newton, perhaps with brief nods to the contributions of Kepler, Huygens, and Halley. But physically motivated theories of mass and force go back to at least the thirteenth century and involve many players, both pre- and post-Newton. This paper, which is accessible to readers at all levels, traces the development of this famous expression.
Scattering problems via real-time wave packet scattering
M. Staelens and F. Marsiglio
89(7), p. 693
In quantum mechanics classes, we typically present the time-independent theory of scattering. This approach is mathematically simpler than showing the time dependence of wave packets scattering from a barrier, but it can be conceptually confusing to students. Considering time-dependent scattering of wave packets within a tight-binding model allows the introduction of wave packets that do not spread as they propagate. The paper presents animations of these wave packets scattering from simple defects in a 1-D solid and shows how the dynamics can be calculated using a straightforward numerical diagonalization. The link above will also take the reader to the article’s video abstract.
An interactive gravitational-wave detector model for museums and fairs
S. J. Cooper, A. C. Green, H. R. Middleton, C. P. L. Berry, R. Buscicchio, E. Butler, C. J. Collins, C. Gettings, D. Hoyland, A. W. Jones, J. H. Lindon, I. Romero-Shaw, S. P. Stevenson, E. P. Takeva, S. Vinciguerra, A. Vecchio, C. M. Mow-Lowry, and A. Freise
89(7), p. 702
Instructions are given for the construction of a gravitational-wave model for both permanent use (exhibits) and portable use (demonstrations). You'll also find many practical tips on the use of the device and the set-up of exhibits and demonstrations.
Integrating numerical modeling into an introductory physics laboratory
Diana Sachmpazidi, Manuel Bautista, Zbigniew Chajecki, Claudio Mendoza, and Charles Henderson
89(7), p. 713
This paper shows how computational physics can be introduced into an introductory laboratory using Excel and documents student and instructor reactions to the new curriculum.
Haidinger–Michelson rings in white light
Youssef El Azhari and Saïd Tagmouti
89(7), p. 721
The bulls-eye pattern typically seen at the output of a Michelson interferometer cannot be observed when the input is white light. However, inserting a glass slide into one of the arms not only allows Haidinger–Michelson rings to be observed, but also enables the measurement of the index of refraction of the glass.
Rubidium isotope shift measurement using noisy lasers
Theodore J. Bucci, Jonathan Feigert, Michael Crescimanno, Brandon Chamberlain, and Alex Giovannone
89(7), p. 730
An inexpensive laser diode can be used to study hyperfine splitting in rubidium using saturated absorption spectroscopy, without the need for an external cavity diode laser, allowing students to directly see the effect of the nucleus through both motional and nuclear-size effects.
Energy and Entropy: A Dynamic Duo. Harvey S. Leff.
Eric Johnson, Reviewer
89(7), p. 739