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2012 AAPT Award Citations at the Winter Meeting, Ontario, California

American Journal of Physics -- June 2012 -- Volume 80, Issue 6, pp. 465

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01.10.-m

Announcements, news, and organizational activities

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Oersted Medal Address 2012: Narrative and Witz in Physics

Charles H. Holbrow

American Journal of Physics -- June 2012 -- Volume 80, Issue 6, pp. 468

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Physics is the syntax and grammar of science; it is the rules. Therefore, you must learn physics to write, speak, or do good science. But knowing the rules of physics won’t make you a good physicist or a good physics teacher any more than knowing grammar will make you a good writer. To bring physics alive you need strong narratives and interesting content. I will describe three examples: A course—“The Physics of Living in Space”; a textbook—Modern Introductory Physics; and a project—Astronomy’s Discoveries and Physics Education. I will also show examples of what I mean by “Witz” and why it is important in physics.

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01.10.-m	Announcements, news, and organizational activities
01.40.-d	Education

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Resource Letter ALIP–1: Active-Learning Instruction in Physics

David E. Meltzer and Ronald K. Thornton

American Journal of Physics -- June 2012 -- Volume 80, Issue 6, pp. 478

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This Resource Letter provides a guide to the literature on research-based active-learning instruction in physics. These are instructional methods that are based on, assessed by, and validated through research on the teaching and learning of physics. They involve students in their own learning more deeply and more intensely than does traditional instruction, particularly during class time. The instructional methods and supporting body of research reviewed here offer potential for significantly improved learning in comparison to traditional lecture-based methods of college and university physics instruction. We begin with an introduction to the history of active learning in physics in the United States, and then discuss some methods for and outcomes of assessing pedagogical effectiveness. We enumerate and describe common characteristics of successful active-learning instructional strategies in physics. We then discuss a range of methods for introducing active-learning instruction in physics and provide references to those methods for which there is published documentation of student learning gains.

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01.30.Rr	Surveys and tutorial papers; resource letters
01.40.G-	Curricula and evaluation

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Fizeau’s “aether-drag” experiment in the undergraduate laboratory

Thierry Lahaye, Pierre Labastie, and Renaud Mathevet

American Journal of Physics -- June 2012 -- Volume 80, Issue 6, pp. 497

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We describe a simple realization of Fizeau’s “aether-drag” experiment. Using an inexpensive setup, we measure the phase shift induced by moving water in a laser interferometer and find good agreement with the relativistic prediction or, in the terms of 19th century physics, with Fresnel’s partial-drag theory. This appealing experiment, particularly suited for an undergraduate laboratory project, not only allows a quantitative measurement of a relativistic effect on a macroscopic system but also constitutes a practical application of important concepts of optics, data acquisition and processing, and fluid mechanics.

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01.50.Pa	Laboratory experiments and apparatus
03.30.+p	Special relativity

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Jacobi elliptic functions and the complete solution to the bead on the hoop problem

Thomas E. Baker and Andreas Bill

American Journal of Physics -- June 2012 -- Volume 80, Issue 6, pp. 506

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Jacobi elliptic functions are flexible functions that appear in a variety of problems in physics and engineering. We introduce and describe important features of these functions and present a physical example from classical mechanics where they appear: a bead on a spinning hoop. We determine the complete analytical solution for the motion of a bead on the driven hoop for arbitrary initial conditions and parameter values.

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02.00.00	Mathematical methods in physics
45.00.00	Classical mechanics of discrete systems

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Thermodynamics of combined-cycle electric power plants

Harvey S. Leff

American Journal of Physics -- June 2012 -- Volume 80, Issue 6, pp. 515

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Published data imply an average thermal efficiency of about 0.34 for U.S. electricity generating plants. With clever use of thermodynamics and technology, modern gas and steam turbines can be coupled, to effect dramatic efficiency increases. These combined-cycle power plants now reach thermal efficiencies in excess of 0.60. It is shown how the laws of thermodynamics make this possible.

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05.70.-a	Thermodynamics
89.00.00	Other areas of applied and interdisciplinary physics

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Why no shear in “Div, grad, curl, and all that”?

Joseph D. Romano and Richard H. Price

American Journal of Physics -- June 2012 -- Volume 80, Issue 6, pp. 519

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Are there good reasons for the absence of shear and gradients of vectors in the undergraduate curriculum, or have we simply been negligent by not explicitly introducing students to these concepts early on? In this paper, we (i) remind the reader that div and curl are not the entire story when it comes to vector derivatives and (ii) ask the reader to consider whether the missing information—shear or the more general vector gradient—should be included in the undergraduate curriculum. In an attempt to address this last point, we give a list of hypothetical responses to the question “Why no shear?,” along with some arguments both for and against teaching it. We leave it to the readers to choose among these reasons or to come up with one of their own when deciding whether or not to include shear and vector gradients in their undergraduate teaching.

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02.00.00

Mathematical methods in physics

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Quantum phase analysis with quantum trajectories: A step towards the creation of a Bohmian thinking

A. S. Sanz and S. Miret-Artés

American Journal of Physics -- June 2012 -- Volume 80, Issue 6, pp. 525

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We introduce a pedagogical discussion on Bohmian mechanics and its physical implications in connection with the important role played by the quantum phase in the dynamics of quantum processes. In particular, we focus on phenomena such as quantum coherence, diffraction, and interference, due to their historical relevance in the development of the quantum theory and their key role in a myriad of fundamental and applied problems of current interest.

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03.65.-w

Quantum mechanics

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An uninvited guest: The positron in early 1930s physics

Matteo Leone and Nadia Robotti

American Journal of Physics -- June 2012 -- Volume 80, Issue 6, pp. 534

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A few months before its “official” discovery in September 1932 by Anderson at Cal Tech in Pasadena, the positron was almost simultaneously observed by no less than two additional research teams: one at Cavendish Laboratory in Cambridge, England, and one at Institut du Radium in Paris, France. In this paper, we examine this curious case of multiple independent observations by studying the primary literature. This study identifies the motivations that led these researchers to independently design the experiments suitable for the detection of this novel particle and shows that none of these teams were looking for a positive electron.

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01.65.+g

History of science

Select this Article		Experiencing conceptual change about teaching: A case study from astronomy Janelle M. Bailey and Kentaro Nagamine American Journal of Physics -- June 2012 -- Volume 80, Issue 6, pp. 542 Full Text: Read Online (HTML) \| Download PDF
	+ -	Show Abstract Understanding faculty motivations for and barriers to change is an important component of facilitating instructional reform efforts to improve student learning. This case study describes the process of adoption of learner-centered instructional strategies by an astronomy faculty member, Ken, as viewed through the lens of conceptual change. Specifically, we applied the Cognitive Reconstruction of Knowledge Model (CRKM) to understand why Ken was willing to change his instructional strategies, what barriers to and supports for change existed, and how he and his students were impacted by this change. Ken’s statements and actions represented characteristics consistent with the CRKM. Notably, dissatisfaction, considered the primary motivator in many conceptual change models, was not of high importance in this case. Upon implementing learner-centered strategies, Ken’s students performed better on a measure of knowledge about stellar properties, which served to reinforce his motivation to continue with learner-centered methods.

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Visualizing Poynting vector energy flow in electric circuits

Noah A. Morris and Daniel F. Styer

American Journal of Physics -- June 2012 -- Volume 80, Issue 6, pp. 552

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According to standard Poynting vector arguments, energy in a circuit flows from the batteries to the resistors, not through the connecting wires, but through empty space between the wires. The computer simulation CircuitSurveyor helps to visualize this counterintuitive fact. The simulation also demonstrates the electric fields present near a circuit.

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01.50.hv	Computer software and software reviews
41.00.00	Electromagnetism; electron and ion optics

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The Quantum Universe (And Why Anything That Can Happen Does)

Brian Cox, Jeff Forshaw, and James Trefil, Reviewer, Reviewer

American Journal of Physics -- June 2012 -- Volume 80, Issue 6, pp. 555

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01.30.Vv	Book reviews
03.65.-w	Quantum mechanics

Select this Article		BOOKS RECEIVED American Journal of Physics -- June 2012 -- Volume 80, Issue 6, pp. 556 Full Text: \| Download PDF
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