In this paper, a simple method is described for visually demonstrating that the wavelength of light reduces when entering a medium of higher refractive index. When a violet laser (405 nm) is reflected off the surface of a Blu-ray disc (track spacing 320 nm) diffraction cannot occur since the wavelength is greater than the track spacing. However,…

Diffraction is an important phenomenon in physics. This paper describes using a scanning electron microscope (SEM) to produce cross-sectional images of iridescent seashells. When seashell cross-sections are viewed in a SEM, regular structure is seen. Seashells are a good example of a biocomposite material and good natural objects for introducing…

Huygens' principle in which every point on a propagating wave acts like a point source of radiation is a foundation principle of physics. Normally, Huygens' principle is demonstrated by passing a wave, for example a water or light wave through an aperture comparable in size to the wavelength. In this paper, an experiment is described in which a…

STEM is about the integration of science, technology, engineering and mathematics. To teach STEM effectively, students need practical examples of subject integration. A good example is the use of an electron microscope in teaching physics and biology. An electron microscope is an instrument in which the operation depends on electromagnetism and…

This paper describes the use of a tabletop electron microscope in teaching college level physics. The workings and use of an electron microscope encompass many aspects of science, technology, engineering and mathematics (STEM). A sequence of activities was constructed to compliment the instructional material in the physics course of the University…

This article describes a method for making a spectroscope from scrap materials, i.e. a fragment of compact disc, a cardboard box, a tube and a digital camera to record the spectrum. An image processing program such as ImageJ can be used to calculate the wavelength of emission and absorption lines from the digital photograph. Multiple images of a…

This paper describes a simple activity for plotting and characterizing the light curve from an exoplanet transit event by way of differential photometry analysis. Using free digital imaging software, participants analyse a series of telescope images with the goal of calculating various exoplanet parameters, including size, orbital radius and…