The paper is about the appearance of space charge in an ohmic conductor moving in a magnetic field, as pointed out in this journal by Lorrain (1990 "Eur. J. Phys." 11 94-8) and earlier by van Bladel (1973 "Proc. IEEE" 61 260-8). The phenomenon is reinvestigated here in the light of energy balance considerations, in the particular case of a…

A recent paper in this journal describes an experimental demonstration of the conservation of total momentum before, during, and after an elastic collision between two bodies. The experiment also appears to show that total kinetic energy is conserved in the process, including "during" the collision. There is a danger that this may give rise to…

A recent article in "The Physics Teacher" describes a method for analyzing a systematic error in a Boyle's law laboratory activity. Systematic errors are important to consider in physics labs because they tend to bias the results of measurements. There are numerous laboratory examples and resources that discuss this common source of error.

Noticing the presence of colourless crystals in a glass of white wine was the starting point for some simple experiments to identify their chemical nature. The author did not succeed in identifying the chemical, but learned about the presence of an acid-base indicator. In retrospect, he was aware of the special chemical way he had considered the…

Floating and sinking might be common phenomena, encountered on a daily basis, but still represent conceptually complex scientific topics. Research has shown that most students have certain experiences and their own "theories" that explain why objects sink or float. Unfortunately, many of these "theories" are either misconceptions or are valid only…

Electromagnetic resonators are often used to detect foreign materials. Here we present a simple experiment for the measurement of liquid level. The resonator, consisting of a coil and a capacitor, is brought to resonance by an external magnetic field source, and the corresponding resonance frequency is determined using Fourier analysis combined…

This article discusses improvements to two "classic" demonstrations of the interaction force between a magnet and a current-carrying conductor, which it is hoped will both interest and delight readers. Creating new demonstrations of fundamental phenomena in physics is the most rewarding activity for the keen demonstrator. A close second is the…

An experiment is described in this test that was designed to study the role of the cyclin B protein in a cell-free system. The work was performed in the lab of Tim Hunt who, together with Hartwell and Nurse, received the Nobel Prize in Physiology or Medicine in 2001 "for their discoveries of key chemicals that regulate the cell division cycle." It…

A multiple day activity for students to create large-scale plastic objects from the biopolymer chitin (major component of lobster, crab, and shrimp shells) is described. The plastic objects created are durable and made from benign materials, making them suitable for students to take home to play with. Since the student-created plastic objects are…

There is an increasing focus across all educational sectors to ensure that learning objectives are aligned with learning activities and assessments. An attractive approach previously published is that of curriculum alignment projects. This paper discusses the use of the fun and famous "Elephant's Toothpaste" experiment as a customizable…

The purpose of this study is to investigate the effect of designing problem-based experiments (DPBE) on the level of metacognitive skills of prospective science teachers. For this purpose, pre test-post test design, without control group, was used in the research. The research group of the study comprised 113 second-grade prospective science…

Bioprocess engineering is a highly interdisciplinary field of study which is strongly benefited by practical courses where students can actively experience the interconnection between biology, engineering, and physical sciences. This work describes a lab course developed for 2nd year undergraduate students of bioprocess engineering and related…

Fluorescence quenching is an analytical technique and a common undergraduate laboratory exercise. Unfortunately, a typical quenching experiment requires the use of an expensive fluorometer that measures the relative fluorescence intensity of a single sample in a closed compartment unseen by the experimenter. To overcome these shortcomings, we…

In recent years, nanoscience and nanotechnology have been drawing enormous attention due to the numerous applications of nanomaterials. In an attempt to nurture interest towards these areas in young minds and to develop the next generation of environmentally conscious scientists and engineers, this new laboratory module focuses on the green and…

Everyone enjoys seeing the cloudy white fog generated when solid carbon dioxide (dry ice) is placed in water. Have you ever wondered what physical and chemical processes occur to produce this fog? When asked this question, many chemical educators suggest that the fog is produced when atmospheric water vapor condenses on cold carbon dioxide gas…