American Journal of Physics February 2017

AAPT announces that Richard Price, Massachusetts Institute of Technology, will assume the position of Editor for the  American Journal of Physics in 2017, following the term of David P. Jackson.
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February 2017 Issue, Volume 85, No. 2

 

Weight of an hourglass—Theory and experiment in quantitative comparison by Achim Sack and Thorsten Pöschel. DOI: 10.1119/1.4973527

A flowing hourglass changes its weight in the course of time because of the accelerated motion of its center of mass. While this insight is not new, it is frequently said that the effect is tiny and hardly measurable. Here, we present a simple experiment that allows the monitoring of weight as a function of time, and that shows that there are different stages of the weight variation. The experimental result is in quantitative agreement with theory.

Editorial

Video abstracts now available. DOI: 10.1119/1.4973116

Papers

Weight of an hourglass—Theory and experiment in quantitative comparison by Achim Sack and Thorsten Pöschel. DOI: 10.1119/1.4973527

Sliding down an arbitrary curve in the presence of friction by Felipe González-Cataldo, Gonzalo Gutiérrez, and Julio M. Yáñez. DOI: 10.1119/1.4966628

Kepler and the origins of pre-Newtonian mass by Eugene Hecht. DOI: 10.1119/1.4972044

The motion of a ball moving down a circular path by Diego C. de Souza and Vitor R. Coluci. DOI: 10.1119/1.4972177

Interactions between uniformly magnetized spheres by Boyd F. Edwards, D. M. Riffe, Jeong-Young Ji, and William A. Booth. DOI: 10.1119/1.4973409

Thermodynamically reversible processes in statistical physics by John D. Norton. DOI: 10.1119/1.4966907

The generalized scattering coefficient method for plane wave scattering in layered structures by Yu Liu, Chao Li, Huai-Yu Wang, and Yun-Song Zhou. DOI: 10.1119/1.4965884

LETTERS TO THE EDITOR

Quantum Measurements by Art Hobson. DOI: 10.1119/1.4967925
Feynman and Bell's Theorem, and the Pronunciation of  "Quark by N. David Mermin. DOI: 10.1119/1.4969073

NOTES AND DISCUSSIONS

A preprint by Jeremy Bernstein. DOI: 10.1119/1.4972526

BOOK REVIEWS

The Quantum Handshake: Entanglement, Nonlocality, and Transactions. DOI: 10.1119/1.4966111

The Hunt for Vulcan…And How Albert Einstein Destroyed a Planet, Discovered Relativity, and Deciphered the Universe. DOI: 10.1119/1.4968558

Additional Resources