A significant goal when teaching at the secondary education level is to present the generality of the procedures that are being used to describe a wide range of different physical phenomena. However, this approach is abandoned by physics instructors in many cases since the general mathematical background needed to present the above generality is…

The photoelectric effect consists of electrons emerging from the region near the inner surface of a metallic solid toward the outside vacuum, when the metal surface is illuminated. The effect depends on the frequency of the light waves and the properties of the metal surface. In particular, a minimum or "threshold" frequency of light is…

In an earlier article I argued that much of what used to be called "modern physics" stems from the intersection of two earlier technologies: high vacuum and high voltage. In this article I will discuss the induction coil, invented in the 1830s, reinvented in the second half of the 19th century, and still used today to produce the high…

Nearly everyone, including physics students, finds rainbows to be fascinating and much has been written about them. For example, in a 2020 paper, Kenneth Ford sets forth the basic theory of rainbows created by water droplets at the level of geometric optics and uses a graphical approach to address the question of the relative intensities of the…

The most important question for anyone born in London is 'Are you a Cockney?' Only those born within the sound of Bow bells can truthfully answer the question with a resounding 'yes.' 'Cockney' is a term of pride in the heart of the East End, an area recently made internationally famous to a new audience due to the global success of the TV series…

Research-based assessments (RBAs) measure how well a course achieves discipline-specific outcomes. Educators can use outcomes from RBAs to guide instructional choices and to request resources to implement and sustain instructional transformations. One challenge for using RBAs, however, is a lack of comparative data, particularly given the skew in…

Currently there are no assessment instruments available for upper-division thermal physics, though several introductory assessments are currently available. Notably missing from these introductory assessment are items targeting statistical mechanics. This leaves a gap in the content that can be assessed by upper-division thermal physics faculty.…

Space telescopes are some of the most precise and complicated machines ever built. Not only must they survive the harshness of space travel, but they also need to be incredibly accurate: misalignments by fractions of a millimetre can have huge effects on the quality of the images they capture. In 1990, the Hubble Space Telescope became the first…

Chaos is a scientific approach that refers to the fact that systems or behaviors that are thought to be irregular, complex, impossible to predict actually occur in an orderly manner. The aim of this research is to determine what chaos and butterfly effect mean in terms of education, the importance of chaos and butterfly effect in education and its…

In this experiment we have first determined the focal length of an equiconvex lens. We have observed that a real image can be formed by the lens on the same side of the source if the source is sufficiently strong. This is due to the reflection from the concave surface of the lens. We have measured these image distances for different object…

Oblique angle collisions of two penny coins on a smooth, horizontal surface were filmed with a video camera to investigate the physics of the collision process. If one of the coins is initially at rest, then the two coins emerge approximately at right angles, as commonly observed in billiard ball collisions and in puck collisions on an air table.…

In introductory texts, some "special" rays are selected to draw the image produced by lenses and mirrors. After teaching special rays, students usually ask how to draw an arbitrary ray. One method for drawing an arbitrary ray is the "tilted principal axis." As an example, the tracing of an arbitrary ray in diverging lens is…

This article is about a famous physics course taken by thousands of students at Amherst College in the 1950s, designed and taught by its distinguished instructor, Arnold B. Arons. There are very few of us left who have taken the course. The youngest one would be, as the course was discontinued in 1968, about 72 years old!

The refractive index (RI) is probably the single most important parameter in optical systems. Chromatic dispersion, on the other hand, indicates how the RI depends on the wavelength and is central in, e.g., optical communication systems. Chromatic dispersion also plays an important role when teaching optics due to the captivating natural…

In this paper, we utilize the readily known theory of the ideal transformer to furnish a self-contained qualitative explanation on the AC-powered Thomson jumping ring (TJR) experiment.