The dependence on the temperature of the population of the "i"th state, "P"[subscript "i"], in the Boltzmann distribution is analyzed by studying its derivative with respect to the temperature, "T." A simple expression is found, involving "P"[subscript "i"], the energy of the state,…

This paper extends the interesting work of a previous contributor concerning the analogies between physical phenomena such as mechanical collisions and the transfer of power in an electric circuit. Emphasis is placed on a mathematical function linking these different areas of physics. This unifying principle is seen as an exciting opportunity to…

An experiment with a mechanical black box containing unknown masses is presented. The experiment involves the determination of these masses and their locations by performing some nondestructive tests. The set-ups are inexpensive and easy to fabricate. They are very useful to gain an understanding of some well-known principles of mechanics.

"The viscosity of the blood in narrow capillary tubes" by Robin Fahraeus and Torsten Lindqvist ("Am J Physiol" 96: 562--568, 1931) can be a valuable opportunity for teaching basic hemorheological principles in undergraduate cardiovascular physiology. This classic paper demonstrates that a progressive decline in apparent…

A two-part demonstration was conducted in our first-semester organic chemistry course designed to introduce students to the formation of alcohols, regioselective reactions, and analysis of organic products by NMR analysis. This demonstration utilized the oxymercuration-demercuration sequence to prepare an alcohol from an alkene in a Markovnikov…

This study explores the development of a methodology to analyze how nature of science (NOS) and scientific inquiry (SI) are portrayed in mainstream films. We demonstrate this methodology using the films, "Contact" and "Twister," as they are commonly used in earth/space science classrooms. We investigate the following research…

This study explored the ways in which pre-service teachers' (PSTs) understanding of the nature of science (NOS) emerged in their experience of a socio-scientific inquiry-based (SSI) experience. In this study, an undergraduate science course with structured collaboration on a SSI-based inquiry between PSTs and campus scientists was intertwined with…

The "cis"-regulatory hypothesis is one of the most important claims of evolutionary developmental biology. In this paper I examine the theoretical argument for "cis"-regulatory evolution and its role within evolutionary theorizing. I show that, although the argument has some weaknesses, it acts as a useful example for the importance of current…

As part of a bone scan procedure to look for the spread of prostate cancer, I was injected with radioactive technetium. In an effort to occupy/distract my mind, I used a Geiger counter to determine if the radioactive count obeyed the inverse-square law as a sensor was moved away from my bladder by incremental distances. (Contains 1 table and 2…

How would a physicist describe the elastic properties of an apple or a banana? Physics students and teachers are familiar with the elastic properties of metal springs, but are likely to be less familiar with the elastic properties of other common materials. The behavior of a metal spring is commonly examined in the laboratory by adding masses to…

When an ice cube floating on water in a container melts, it is said in some textbooks that the water level does not change. However, as pointed out by Lan in a recent work, when the buoyant force from a less dense fluid resting above the waterline is taken into account, one should expect a detectable "increase" in the volume of water. Here in this…

With evolutionary biology relatively recently introduced into the South African school curriculum, the need arose to explore practising teachers' knowledge of the subject. A number of anticipated as well as unanticipated cognitive and affective barriers to the understanding of evolutionary biology were identified from a questionnaire with…

Even though density is taught in middle school, high school students often struggle to understand that the density of a substance is consistent regardless of amount. This is because many high school students know density = mass/volume, but do not have the conceptual understanding necessary to explain density-related phenomena. The scaffolded…

A novel procedure is described where students use COMU [(1-cyano-2-ethoxy-2-oxoethylidenaminooxy)dimethylamino-morpholino-carbenium hexafluorophosphate], as a nonhazardous partner, in the one-pot coupling of a carboxylic acid and amine producing N,N-diethyl-3-methylbenzamide (DEET). Fundamental principles of carbonyl reactivity are understood,…

In this article, we present two concrete applications of the concept of the human element to chemistry education; starting with a course and experimental project on blue pigment synthesis and concluding with cross-disciplinary lessons and experiments on blue photography. In addition to the description of the content of these courses, we explore…