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…

Data from the Kepler satellite were analysed using the Mikulski Archive for Space Telescopes database. With the participation of 53 students, we determined the parameters of the HAT-P-7b (Kepler-2) exoplanet system (transit duration, planet-to-star radius ratio, orbital period, semi-major axis and star mass). We used approaches that are easy to…

A simple measurement of the refractive index of a liquid has been performed using a spherical lens. This lens is a spherical shape flask containing the liquid under study. Parallel pointer laser beams are directed to the lens to obtain the back focal length of the lens. The focal point is determined visually or using the Tracker software to…

From ancient times, the different features of planets and moons have created a huge interest. Aristarchus was one of the first to study the relative relations among Earth, Moon, and Sun. This interest has remained until today, and therefore it is always relevant to make this knowledge more appealing to the younger generations. Nowadays, smartphone…

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…

Pinhole camera photography is explored using a set of entomology pins due to their known pin diameters and availability in a variety of sizes. A procedure to prepare removable-lens digital cameras for pinhole photography is described. A video is included showing a set of ten insect pins and how to fit the camera with pinhole apertures. Formulas…

For conducting laboratory experiments on Fresnel diffraction, the use of a simple point light source from an LED and the application of a modern smartphone for photographing the diffraction patterns are proposed. The developed devices allow the experiments to be carried out under normal laboratory lighting.

Light rays refract when passing through pockets of transparent fluids with different indices of refraction such as ordinary air pockets of varying temperature. This phenomenon makes night stars twinkle, distorts views above hot asphalt roads and hot barbeque grills, and provides an opportunity for visualizing the normally invisible movement of…

Your body is not a point particle. The nature and direction of the forces counteracting gravity influence your experience of uniform rectilinear motion--as does your own orientation in relation to the force of gravity. Sensors in smartphones or other devices can capture these forces, and help establish a connection between the personal experience…

We propose the use of a laptop with a program generator and a transistor power amplifier to control the frequency, duration and amplitude of the LED stroboscope flashes. Examples of the stroboscopic photographs are given.

This research aims to develop a falling chain experiment apparatus using kitchen scales and digital cameras (smartphones). Digital cameras were used to observe and record changes in the mass of falling chains measured using kitchen scales. Video recordings from observations of falling chain masses were analysed using Tracker 5.1.1 software. The…

Students are amazed when I show them a zoo photo of an animal behind a fence and then a zoomed-in photo where the fence has disappeared. They ask 'Where did the fence go?' This paper will explore this magical phenomenon which draws from concepts in photography (angle of view, depth of field) and physics (convex lenses, focal length, real images).…

Recently, infrared cameras have become available as smartphone accessories. Being less expensive than regular infrared cameras they are readily affordable for schools and many teachers may even privately own one due to their potential to visualize all kinds of thermal phenomena in physics teaching. Any science teacher who wants to use such a…

This paper describes ten simple thermal imaging experiments designed primarily for upper secondary students, but usable with younger pupils as well. The author's primary motivation was to come up with a meaningful use for a thermal imaging camera even if the teacher only has a short time to work with it--in the extreme case, only one lesson in…

In this article we present simple and low-cost experiments about the polarization of light. We use an LCD monitor or an RGB LED light bulb with a Polaroid as a source of polarized radiation, a polarizer sheet as an analyzer, and a smartphone camera to measure light intensities. Thus, using a digital camera to acquire videos students can explore in…