The magnetic switch is part of common low-cost devices such as window alarms. Its operation is based on magnetic properties of ferromagnetic material. The paper describes our experience with using window alarm device in a course called 'How things work', which is elective course for first year physics majors. Specifically, we report on the…

It often falls to a physicist to teach a conceptual astronomy course. It is easy to justify a treatment of general relativity in the context of massive stars, black holes, and cosmology. There are a number of good books available to serve as texts or references, including Thorne's "Black Holes and Time Warps: Einstein's Outrageous…

In this article, the dynamics of a traditional toy, the yo-yo, are investigated theoretically and experimentally using smartphone sensors. In particular, using the gyroscope the angular velocity is measured. The experimental results are complemented thanks to a digital video analysis. The concordance between theoretical and experimental results is…

Motivated by widespread concerns for representation and equity in physics education, this study investigates negotiations of identity positions of master's students in physics. The goal is to explore how sociocultural features of physics can structure the possibilities for becoming a physicist. Interviews with international master's students in…

In many high school teaching materials the force on a current-carrying wire in a magnetic field is discussed using an idea based on a so-called "catapult field" (cf. Fig. 1), an engaging depiction of magnetic forces, albeit one which, to the best of our knowledge, has neither been used in college-level educational material or scrutinized…

Transistors are semiconductor devices that form the basis of today's electronic technology. Following the first step of developing a point-contact transistor developed by Walter Brattain and John Bardeen in 1947, the development of the junction transistor by William Shockley in early 1948 opened the way for rapid progress in electronic technology.…

In this study, the tilt of the Earth's axis was measured during a lunar eclipse using a telescope based on the angle between the lunar orbit and ecliptic planes being considered as approximately zero. The presented method not only offers a practical and reliable way of measuring the axial tilt of the Earth during a lunar eclipse but also helps in…

Purpose: To assess changes in criterion validity when modifying cut-points for use in different epoch lengths. Method: Simulated free-living data came from 42 adolescents (2-hr each) and 29 adults (6-hr each) wearing a hip-worn accelerometer and portable indirect calorimeter (Cosmed K4b[superscript 2]). K4b[superscript 2] data were classified as…

The Michelson interferometer is one of the key experiments in modern physics when it comes to the topic of interference (Box 1). Experiments using interferometry have a high historic relevance as well as uses in current areas of research (quantum erasers, gravitational wave detection) and are used in higher education. Because of the high cost of…

This paper is intended to foster conversations about stereotypes, prejudice, and our day-to-day work in the classroom. The focus is on sexism and how it can affect our teaching, particularly looking at physics textbooks. Maybe you are already familiar with debates around feminist movements, gender studies, patriarchy, performance, and all of those…

In early January 2018, after days of subfreezing temperatures, a 20 m waterfall became mostly frozen with supercooled water pouring over the top of the frozen parts of the fall. A video was taken of the waterfalls and supercooled turbulent water flowing on the frozen surface as it turned into frazil ice right before our eyes. Frazil ice consists…

We propose an experimental analogy to verify Kepler's second law using a spherical pendulum. We made a movie of a closed elliptical orbit of the pendulum and extracted the data position using the Tracker software. Analyzing the data, we measured the areas that the position vector sweeps showing the validity of Kepler's second law.

This work presents an experiment that seeks to simulate human color vision through electronic components in an attempt to build, together with the students, a cybernetic 'eye'. The limitation of the cybernetic eye developed here in relation to the standard human chromatic vision, which makes it a 'colorblind eye', is an argument to be explored by…

When we travel in a train moving at a certain velocity, we observe the stationary objects outside are moving backwards. These stationary objects seem to move due to a relative velocity. Consider that the stationary object outside the train is a man standing on the stationary floor watching a woman moving on a train. The woman on a train will see…

A new device for teaching the physics of sound, specifically demonstrating the wavelengths of standing sound waves, is here described. I define a "Lincoln's Tube" as any hollow tube that uses lights (LEDs typically) to demonstrate the presence of sound standing waves. The name is chosen intentionally to recall a Ruben's Tube or a Kundt's…