The Arduino microcontroller is currently one of the favorite tools of makers, and many teachers have used it in teaching or experiments. In addition, light-emitting diode (LED) smart lighting is the worldwide trend in lighting. There are many teaching demonstrations or applications of color addition using LEDs. Furthermore, the Internet of Things…

We demonstrated that an optimally designed pinhole camera can be used as an astronomical tool to observe the libration and apparent diameter change of the Moon at night. The libration and apparent diameter change of the Moon were observed using a handmade pinhole camera with a diameter of 0.65 mm and a focal length of 400 mm. It was found that the…

In many introductory physics classes, diffraction of light is introduced first, then more advanced diffraction topics such as x-ray diffraction, Bragg's law, and crystallography are covered. Since using x-rays raises safety concerns and atomic spacing in a crystal is not easy to change, microwaves with macroscopic crystals have been used to study…

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…

The wave nature of light has been widely demonstrated in a double-slit experiment, which has played a special role in physics teaching. When monochromatic light passes through the double-slit sheet, the diffraction and interference fringes can be observed in the far-field regime. The interference of light causes the beams passing through the two…

Shadows produced by sunlight reflected from convex surfaces can be very well defined. This article provides an explanation for this phenomenon as well as a demonstration/lab activity for students to investigate properties of shadows made from sunlight reflected by a curved surface.

The interference pattern between two harmonic oscillations with slightly different frequencies are called beats. The beats, as a combined motion, have two different periods, one approximately equal to the period of the original oscillations, and another that is significantly longer and is related to the variable amplitude of the motion. The main…

Light and its spectrum are central concepts in many introductory physics, astronomy, geology, and conceptual physics courses. The Sun and its spectrum are usually primary examples, likely due to the Sun's everyday familiarity and the full spectrum it generates when dispersed. To enhance such discussions with a hands-on student activity, we've…

Student misconceptions of the double-slit experiment (Fig. 1) are abundant. The most common ones that we observe include: (1) belief that constructive interference requires both pathlengths to be integer multiples of the wavelength ("L[subscript 1] = n[subscript 1][lambda]" and "L[subscript 2] = n[subscript 2][lambda]") rather…

Crystallography is a fascinating subject and an argument of great importance in the study of structure of matter and fundamental physics. Moreover, many characteristics of crystals, as well as other organic and inorganic substances, are analyzed with x-ray diffraction. In order to introduce at a basic level the above mentioned subjects, and also…

This paper proposes a simple method to design experiments for drawing the light paths at a lens to find its effective focal length and principal planes. In the designed experiments, long-exposure photography was used to record the light scattered using a moving sheet of paper, thus revealing the light path. According to the proposed experimental…

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…

White light refracted by a glass edge or a prism might be split into the colors of the rainbow but, when restricted by a suitable arrangement of edges, might also yield a sequence of colors complementary to the rainbow. We studied the creation of these color fields experimentally with a setup consisting of RGB light-emitting diodes that cover all…

Nowadays, electronic devices (especially smartphones) are developed to use as an alternative tool for recording experimental data in physics experiments. This is because of the embedded sensors in a smartphone such as the accelerometer, gyroscope, magnetometer, camera, microphone, and speaker. These sensors were used in physics experiments, such…

In this study, we describe a method to employ a conventional compound light microscope, usually available in laboratories, to obtain fluorescence. In particular, two pieces of colored acrylic plastic were utilized to assist the microscope in filter performance. We also attempted to examine the applicability of the setup by staining onion cells…