Whilst everyone is familiar with the process of blowing up a balloon, few of us have gone further to quantify the actual pressures involved at different stages in the inflation process. This paper seeks to describe experiments to fill some of those gaps and examine some of the apparently anomalous behaviour of connected balloons. (Contains 12…

This article aims to describe how to visualize surface tension effects in liquid jets. A simple experiment is proposed using the liquid jet flow from a mains water tap/faucet. Using a modern digital camera with a high shutter speed, it is possible to visualize the instabilities (capillary waves) that form within the jet due to the action of…

Misconceptions about sinking and floating phenomena are some of the most challenging to overcome (Yin 2005), possibly because explaining sinking and floating requires students to understand challenging topics such as density, force, and motion. Two scientific principles are typically used in U.S. science curricula to explain sinking and floating:…

A simple model is developed that predicts the coefficient of rolling friction for an undriven laboratory cart on a track that is approximately independent of the mass loaded onto the cart and of the angle of inclination of the track. The model includes both deformation of the wheels/track and frictional torque at the axles/bearings. The concept of…

In his scholarly and thoughtful article, "Interesting Times: Practice, Science, and Professional Associations in Behavior Analysis," Critchfield (2011) discussed the science-practice frictions to be expected in any professional organization that attempts to combine these interests. He suggested that the Association for Behavior Analysis…

This paper presents a critical analysis of the accepted educational use of the method performed by Eratosthenes to measure the circumference of Earth which is often considered as a relevant means of dealing with issues related to the nature of science and its history. This method relies on a number of assumptions among which the parallelism of sun…

Causality in electrodynamics is a subject of some confusion, especially regarding the application of Faraday's law and the Ampere-Maxwell law. This has led to the suggestion that we should not teach students that electric and magnetic fields can cause each other, but rather focus on charges and currents as the causal agents. In this paper I argue…

A simple pipe whistle can be made using pieces of PVC pipe. The whistle can be used to measure the resonant frequencies of open or closed pipes. A slightly modified version of the device can be used to also investigate the interesting dependence of the sound frequencies produced on the orifice-to-edge distance. The pipe whistle described here…

Charges and fields in a straight, infinite, cylindrical wire carrying a steady current are determined in the rest frames of ions and electrons, starting from the standard assumption that the net charge per unit length is zero in the lattice frame and taking into account a self-induced pinch effect. The analysis presented illustrates the mutual…

During the first decade of the twenty-first century, neopositivist claims made about the nature and validity of knowledge in the debates about scientifically based research were countered by educators who, decades earlier, had made various turns away from positivism and were surprised by its resurgence. In those debates, positivists often used…

This article recounts the story of the development of pangenesis, a principle proposed by Charles Darwin to describe the rules of inheritance and the source of new variation, two concepts vital to his proposal of evolution by natural selection. Historical accounts such as this are infrequently included in texts and classroom discussions but can…

As global average temperatures rise, there has been an increase in the frequency and magnitude of meteorological natural hazards. To survive in the world and thrive in the work place, students need to utilize educational skills (such as creative thinking, non-routine problem solving, collaboration and systems thinking) and become independent…

The purpose of this study is to explore how an online-structured dialogue environment supported (OSDE) collaborative learning about the nature of science among a group of trainee science teachers in the UK. The software used (InterLoc) is a linear text-based tool, designed to support structured argumentation with openers and "dialogue…

The purposes of the present study are to elicit pre-service elementary science teachers' scientific and pseudoscientific beliefs about earthquake and to make inferences about their understandings of science. Although the subject of earthquake is not a pseudoscientific area, some pseudoscientific beliefs related to earthquake were used in this…

The Next Generation Science Standards (NGSS) are composed of three intertwined dimensions--disciplinary core ideas, science and engineering practices, and crosscutting concepts--that provide a foundation for what students should know and be able to do at various grade levels. The eight science practices outlined in the NGSS are critical components…