Drop Tower Physics (DTP) is composed of a set of experiments using standard physics lecture demonstration equipment, such as a pendulum, mass spring oscillator, and so forth, while videotaping them as they fall freely in the Dryden Drop Tower in Portland, OR. An article published in "The Physics Teacher" illustrated the behavior of a…

A Finderscope is a low-power telescope with a relatively large field of view. It has the same line of sight as the main telescope, helping the main telescope easily find the target. One of the differences between a telescope and a finder is that the finder has crosshairs to aid in accurately pointing at a target. You can see the crosshairs and the…

Although ripple tanks have been used in the past to perform wave simulations for electromagnetic and acoustic phenomena, especially before the advent of computers, they are still often used to demonstrate wave propagation in high school and college physics classrooms. Usually ripple tanks have a rectangular shape. The wave propagating through the…

The Wilson cloud chamber is an apparatus used for detecting and observing the trails of alpha/beta rays or even cosmic rays in saturated gas conditions. The principle of this device is based upon the powerful ionization of the aforementioned rays within the medium. This article will provide instruction for creating a classic version of the cloud…

There are hundreds of satellites in orbit around Earth. Readily available data about them can be a treasure trove for investigations by students at all levels. Orbital parameters and energy changes can be explored. Many of these satellites transmit signals that can be detected by an inexpensive radio receiver--a scanner--designed to receive FM…

In this article, we present an intriguing experimental exercise that does not fall foul of improper use of instrumentation. The activity is designed as an electronics exercise where the role of the instruments in the measurement of the RC time constant is considered. Essentially, we study the accuracy and precision of a measurement of the RC time…

This article presents some simple calculations related to the Future Circular Collider (FCC), which is being studied at CERN as a potential future replacement for the world's largest particle accelerator, the Large Hadron Collider (LHC). The aim of this article is to bring particle physics into secondary school classrooms using the physics of the…

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…

We present a simple experiment that allows us to demonstrate graphically that the intensity of sound waves is proportional to the square of their amplitude, a result that is theoretically analyzed in any introductory wave course but rarely demonstrated empirically. To achieve our goal, we use an audio signal generator that, when connected to a…

The Ball Bearing High Voltage generator is a fairly simple and transparent apparatus that can serve as a tool to motivate conceptual descriptions and calculations in electrostatics that are normally presented to our students in a rather dry and matter-of-fact fashion. For example, instead of posing a problem in the typical textbook form of…

Photogates play an important part of many of today's physics laboratory experiments. They signal when an infrared (IR) beam is interrupted, thus supplying the experimenter with important timing information. Currently photogates use an infrared photodiode (IR transmitter) and a phototransistor (IR receiver). User-built photogates have a weakness…

The Leaning Tower is a long-time staple of the demonstration room. It can be traced as far back as apparatus catalogues from the 1850s. Some years ago, while teaching himself how to use a new wood lathe, Thomas B. Greenslade, Jr. made a replica of the original design. With the top removed, the tower is stable, but once the top is added, the line…

One of the memories of my freshman year at Amherst was a lecture in the required physics/calculus course in which Arnold Arons quoted Isaac Newton on standing on the shoulders of giants. Now that I have spent my physics career, I still use the same quote, but now apply it to the eponymous apparatus that has been designed by the giants in our field.

Recently, small computer fans have been demonstrated to be an effective method for teaching simple resistive circuits both qualitatively and quantitatively. The current through the fans is related to the rotational speed of the fans and allows multiple senses to be engaged (touch, sight, and hearing). Methods for learning simple circuits in an…

The ground-breaking image of a black hole's event horizon, which captured the public's attention and imagination in April 2019, was captured using the power of interferometry: many separate telescopes working together to observe the cosmos in incredible detail. Many recent astrophysical discoveries that have revolutionized the scientific…