December 2018 issue of American Journal of Physics

December 2018 Issue,
Volume 86, No. 12


Free falling inside flattened spheroids: Gravity tunnels with no exit

A “gravity tunnel” is the name given to a fictitious deep shaft drilled inside the Earth so that objects dropped from the surface of the Earth would free fall without ever touching the walls. It is well known that because of the rotation of the Earth, such tunnels are not straight lines but instead they emerge westward of the antipodal point, when the Earth is approximated as a rotating sphere. In this article, we determine the shape of gravity tunnels by taking into account the polar flattening of the Earth resulting from its rotation.


Guest Editorial

Feynman—Schwinger duality by S. Deser.  DOI: 10.1119/1.5078511


Evolution of quasi-history of the Planck blackbody radiation equation in a physics textbook by J. R. Persson.  DOI: 10.1119/1.5054005

Rebounding motion of a highly elastic ball between two parallel matte plates by Songling Liu, Guoye Guan, Shuting Peng, and Fang Lin.  DOI: 10.1119/1.5058511

Using history to foster critical scientific thinking: Aristotle and Galileo's debate resolved through high-speed motion tracking in the classroom by Josef M. Stadlbauer, Lukas Kehrer, and Siegfried Bauer.  DOI: 10.1119/1.5062167

A matrix exponential approach to radioactive decay equations by Edmond Levy.  DOI: 10.1119/1.5064446

Classical realization of the quantum Deutsch algorithm by Yohan Vianna, Mariana R. Barros, and Malena Hor-Meyll.  DOI: /10.1119/1.5065506

Free falling inside flattened spheroids: Gravity tunnels with no exit by Richard Taillet.  DOI: 10.1119/1.5075716

Will my student evaluations decrease if I adopt an active learning instructional strategy? by Charles Henderson, Raquib Khan, and Melissa Dancy.  DOI: American Journal of Physics 86, 934 (2018);

Apparatus and Demonstration Notes

An apparatus for measuring a material's photomechanical response by Elizabeth A. Bernhardt, Chad M. Garrison, Nathan F. Rasmussen, Joseph T. Lanska, and Mark G. Kuzyk.  DOI: 10.1119/1.5050927

Book Reviews

Foundations of Quantum Mechanics: An Exploration of the Physical Meaning of Quantum Theory by Tim Maudlin.  DOI: 10.1119/1.5050194

Emmy Noether's Wonderful Theorem (rev ed.). by Peter Olver.  DOI: 10.1119/1.5054300

What is Real? The Unfinished Quest for the Meaning of Quantum Physics by Christopher A. Fuchs.  DOI: 10.1119/1.5053411

Signatures of the Artist: The Vital Imperfections That Make Our Universe Habitable by Don Lincoln.  DOI: 10.1119/1.5078509

Books Received

American Journal of Physics 86, 960 (2018); DOI: 10.1119/1.5068772


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