Browsing the Journals

Carl Mungan, United States Naval Academy
mungan@usna.edu

The mysterious behavior of a short piece of PVC pipe spun on a table is investigated theoretically and experimentally on page 85 of the February 2019 issue of the American Journal of Physics (http://aapt.scitation.org/journal/ajp). In the same issue, the deformation of the lower portion of a bicycle tire is analyzed on page 102. Further, I added Lost in Math: How Beauty Leads Physics Astray to my summer reading list based on the Book Review on page 158. A helpful discussion of the concept of added mass for an object moving through a fluid is on page 165 of the March issue. A sealed bottle containing a little liquid nitrogen is placed at the bottom of a garbage can full of ping-pong balls; why does the can jump high in the air when the bottle explodes? See the article on page 255 of the April issue. In the same issue on page 264, Pearson discusses how “finely tuned” uranium-235 is for a fission chain reaction, with the usual humorous commentary about whether God had a choice in the matter. Finally, the editorial calling for high school physics teachers on page 328 of the May issue might be worth posting on a bulletin board in your department. I also enjoyed the treatment of a seesaw made by pivoting a candle through its midpoint and lighting the wick at both ends on page 370.

Adam Neat has an accessible analysis of questions such as “Can we see objects having faster-than-light recessional velocities?” and “How far out into a spatially expanding universe can we see?” on page 80 of the February 2019 issue of The Physics Teacher (http://aapt.scitation.org/journal/pte). Scott Rubin numerically models a snowball rolling down a snowy slope (and getting bigger in radius as it does so) on page 150 of the March issue. The simultaneous equilibrium of forces and torques on a Roberval balance is worked out on page 166 of the same issue. In the April issue, Kelley Sullivan points out that a superball is considered more bouncy than a steel ball, even though the latter is actually more elastic, because the coefficient of restitution crucially depends upon the nature of the surfaces off which the balls are bounced.

Article 025401 in the March 2019 issue of the European Journal of Physics reviews the quantum mechanical problem of an elastic ball bouncing vertically off a table and its connection with the equivalence principle. In the same issue, a concept inventory developed for the kinetic theory of fluids is discussed in article 025704. I do not recall having seen Editorials in this journal previously, but a pointed one worth a look is Bohren’s “The curse of knowledge” in article 030201 of the May issue. Article 035008 of the same issue entertainingly considers the effects of gravity if the earth were flat. Article 023006 in the March 2019 issue of Physics Education proposes a simple demo of two water bottles connected by a string with one sliding on a tabletop and the other hanging over the edge. With the right amount of water in the two, the sliding bottle will just stop at the edge when the other bottle is released. A simple model of a vacuum bazooka which considers only two forces (the pressure difference on the two faces of the projectile and residual air drag) fits the observed speed versus time data well in article 033002 of the May issue. Article 035005 in the same issue shows that the rise of water in a capillary tube depends on the draft of the submerged portion of the tube, an effect which is normally neglected. Both journals can be accessed online starting at http://iopscience.iop.org/journalList.

An interesting article on page 575 of the May 2019 issue of Resonance reviews the question of where the water on earth’s surface came from, particularly in light of the the relative deuterium/hydrogen abundance ratio. It can be freely accessed at http://www.ias.ac.in/listing/issues/reso.

The model of a particle in a quantum corral is discussed on page 82 of the January 2019 issue of the Journal of Chemical Education. A simple method to synthesize fluorescent carbon quantum dots is explained on page 540 of the March issue. Finally, an article on page 873 of the May issue discusses whether student responses to clicker questions should appear as polling progresses, or only after polling closes. The same issue also has an interesting analysis on page 926 of why the high-temperature heat capacities of gaseous nitrogen and fluorine are so different from each other. The journal archives are at http://pubs.acs.org/loi/jceda8.

The inaugural issue of the journal The Physics Educator discusses the use of tonic water and phosphorescent paper to make laser light rays visible for demonstrations in article 1950006. The journal homepage is at https://www.worldscientific.com/worldscinet/tpe.

Article 010120 in Physical Review Physics Education Research at https://journals.aps.org/prper/pdf/10.1103/PhysRevPhysEducRes.15.010120 considers how physics instruction about potential energy can help students understand electrostatic bonding energy between two oppositely charged ions in a subsequent chemistry course. Also see article 010103 at https://journals.aps.org/prper/pdf/10.1103/PhysRevPhysEducRes.15.010103 which shows that when measured values have more decimal places, students are less able to gauge the significance of the numerical differences between them; in other words, they think that if two numbers differ, it must reflect a physical difference, irrespective of the measurement uncertainty.

Disclaimer – The articles and opinion pieces found in this issue of the APS Forum on Education Newsletter are not peer refereed and represent solely the views of the authors and not necessarily the views of the APS.