We use apparatus based on two Geiger-Müller tubes, a simple electronic circuit and a Raspberry Pi computer to illustrate relativistic time dilation affecting cosmic-ray muons travelling through the atmosphere to the Earth's surface. The experiment we describe lends itself to both classroom demonstration to accompany the topic of special relativity…

Instructors often present Mendelian genetics and molecular biology separately. As a result, students often fail to connect the two topics in a tangible manner. We have adopted a simple experiment to help link these two important topics in a basic biology course, using red and white onions bought from a local grocery store. A lack of red coloration…

This study aimed at finding out how young children express their thinking about some of the themes in the early-grades school science curriculum. Foundation-phase children at a primary school in Soweto, Johannesburg, were interviewed after they had watched classroom demonstrations of the production of carbon dioxide gas, absorption of water and…

In this note we synthesize and extend expressions for the magnetic field at the center of very short and very long current-carrying coils. Elementary physics textbooks present the following equation for the magnetic field inside a very long current-carrying coil (solenoid): B[subscript sol] = µ[subscript 0] (N/L) I, (1) where I is the current, N…

In this time of concern over climate change due to the atmospheric greenhouse effect, teachers often choose to extend relevant classroom work by the use of physical models to test statements. Here we describe an activity in which inexpensive backyard models made from cardboard boxes covered with various household transparent materials allow…

In this article, Bryan Warnick discusses not so much whether creationism should be taught in schools, but how evolution should be taught. He contends that if we are going to prohibit the teaching of something like Intelligent Design (ID) in science classrooms because it is unscientific, what implications does that then have for how we teach…

This paper aims to clarify the misconception about the violation of the principle of floatation. Improper understanding of the definition of "displaced fluid" by a floating body leads to the misconception. With the help of simple experiments, this article shows that there is no violation of the principle of floatation.

Emergent processes, such as diffusion, are considered more difficult to understand than direct processes. In physiology, most processes are presented as direct processes, so emergent processes, when encountered, are even more difficult to understand. It has been suggested that, when studying diffusion, misconceptions about random processes are the…

I came up with a new way to introduce the concept of a constant gravitational field near the surface of the Earth. I made "g-field detectors" (see Fig. 1 ) and suspended them by strings from the ceiling in a regular spacing. The detectors are cardstock arrows with a hole punched out of them and the letter "g" in the center.

Teachers regularly use stories to amplify the concepts taught and to encourage student engagement. The literary form of a parable is particularly suitable for classroom use, and examples are given, including a longer one intended to stimulate discussion on the nature of quantum physics (and the wave-particle duality in particular).

The double-tangent construction of coexisting phases is an elegant approach to visualize all the multiphase binary systems that satisfy the equality of chemical potentials and to select the stable state. In this paper, we show how to perform the double-tangent construction of coexisting phases for binary systems modeled with the gamma-phi…

The molar entropy of mixing yields values that depend only on the number of mixing components rather than on their chemical nature. To explain this phenomenon using the logic of chemistry, this article considers mixing of distinguishable particles, thus complementing the well-known approach developed for nondistinguishable particles, for example,…

This is a classic classroom demonstration of resonance, nodes, anti-nodes, and standing waves that has been described elsewhere. The modern age twist that we are advocating is the coupling of this classic demo with free (or relatively inexpensive) sound analysis software, thereby allowing for quantitative analysis of resonance while experimenting…

Humans have evolved to follow their intuition, but as any high school physics teacher knows, relying on intuition often leads students to predict outcomes that are at odds with evidence. Over the years, we have attempted to make this intuition-outcome disparity a central theme running throughout our physics classes, with limited success. Part of…

We present a simple method to determine the refractive indices of transparent media using a laser distance meter. Indices of refraction have been obtained by measuring the speed of light in materials. Some speed of light techniques use time-of-flight measurements in which pulses are emitted by lasers and the time interval is measured for the pulse…