Eigenstates of a quantum mechanical system reflect one to one correspondence with energy level. However, in some systems more than one or a group of eigenstates correspond to a single eigenvalue. To introduce more than one eigenstate corresponding to single energy eigenvalue in 1D-harmonic oscillator, we introduce a new perturbation term and find…

Based on a publication of Assis, where the most straightforward and oldest motor is described, first constructed by Ampère, a simple experiment is added to demonstrate once again, why published explanations about its principle of operation and especial the kind how Newton's 3rd principle is used has to be rejected. Ampère's description of his…

Column chromatography of photosynthetic plant pigments is a common experiment in introductory laboratory courses for science majors and nonscience majors alike. We report a simple, rapid, reproducible, and small-scale solid--liquid extraction of photosynthetic pigments from inexpensive, store-bought dried herbs that affords a dark-green extract…

Distance learning requires the combined use of techniques because it is more complicated to keep the students' attention. This exercise is designed to explain the inactivation of the x-chromosome in humans and is intended to complement the theoretical explanations. It is estimated that it lasts two hours and makes use of different web resources.…

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…

Throughout the long history of astronomy, scientists have repeatedly written fictional stories, which often lend themselves to use in the classroom thanks to the authors' in-depth knowledge and an appealing storyline. This article uses the novel 'The Black Cloud', written by the well-known astronomer Fred Hoyle, to show which physical-astronomical…

When it comes to winning the hearts of children, it is sometimes hard for plants to compete. How do teachers make plants exciting for children? The answer lies in the ancient practice of hydroponics. Hydroponics may seem like complicated, cutting-edge technology, but, in fact, it has been around for centuries. Using hydroponics in the classroom…

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.…

The durability and variety of plastics mean that they can take an age to break down (or biodegrade) in the environment. Plastic carrier bags will be around for 50 to 100 years, plastic bottles for 600 years, and Styrofoam/polystyrene containers for a whopping 5000 years. As more of these plastic items are added to the ocean, they just build up and…

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…

While a mutually agreed-upon definition of STEM education remains elusive, there is no doubt that instructional models and ideas put forward with the STEM label have had a tremendous impact on thinking, debate, and practice in schools worldwide. At issue is the degree to which some or all the STEM disciplines must be taught in a concurrent or…

This study seeks to understand how different scientific practices in high school science classrooms are associated with student situational engagement. In this study, situational engagement is conceptualized as the balance between skills, interest, and challenge when the reported experiences are all high. In this study, data on situational…

Learning standards for K-12 science education emphasize the importance of engaging students in practices that scientists perform in their profession. K-12 teachers are expected to engage students in scientific modeling, which entails constructing, testing, evaluating, and revising their own models of science phenomena while pursuing an epistemic…

This article describes a simple and inexpensive "shock and awe" classroom demonstration for understanding the importance of carbon dioxide (CO[subscript 2]) in acid-base regulation. Before class, a solution was prepared by adding sodium bicarbonate and universal indicator solution to a sample of distilled water contained in a standard…