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…

Behind the creativities and innovations in human history, there lie the humble practices of multidisciplinary studies that drive new revolutionary ideas and unconventional approaches. One such example is Leonardo da Vinci's "Mona Lisa"--one of the perennial portraits that bear witness to a transcendent level of creative art. It is one of…

The eye should have a particular focal length in order to see an object. As there are many things to see, the focal length of the eye must vary because these things are not all at the same distance from the eye. We explore the eye accommodation from a geometrical optics point of view and present our results in this paper; the study includes a…

Diffraction refers to a kind of optical phenomena which occurs when light approaches an element (object or aperture) whose features are in the range of the illuminating wavelength (small apertures, sharp edges). It can be explained by means of the undulatory nature of light or also geometrically by using simple ray optics. Diffraction phenomena…

We outline the physics involved in the use of scanning electron microscopy (SEM) and modernise the usual textbook treatment by explaining how one can now obtain high-quality images with non-conductive specimens. As a concrete example of an application in biology, we provide several magnification series of a flea obtained using SEM.

Research in physics education has revealed that students often have incomplete and incoherent ways to use the concept of photon. Most researchers in science education recommend photons to be taken in a realistic sense as existing entities of quantum objects. Furthermore, in science education literature it is often claimed that realistic stance to…

Spin crossover (SCO) materials that switch between two different spin states, that is, the high spin (HS) and the low spin (LS) state, with very different optical, magnetic, and structural properties offer a unique platform to understand the consequences induced by the different electronic configurations of transition metal complexes. Due to the…

On April 14, 1912, the British passenger liner R.M.S. "Titanic" struck an iceberg. The ship sank in a fraction of the time designers had estimated following a worst case scenario. The purpose of this article is to examine the atmospheric refractive phenomena that might have played a significant role in obscuring the iceberg from…

Recently I took a walk through the physics demonstration room at Kenyon College, where I first started teaching in 1964. On an upper shelf was the little home-built apparatus in Fig. 1. This was used for one of two short single-concept films that I made in the 1970s. Both "The Magnus Effect" and "Optical Barrier Penetration"…

Why does a raindrop on a window pane show an image of the environment that is turned upside-down? And why does vision go blurry underwater, but is perfectly clear with diving goggles? Our everyday life is rich in optical phenomena. Unfortunately, these phenomena often play a subordinate role in Optics teaching, compared to ray constructions or…

HOBIT, which stands for "Hybrid Optical Bench for Innovative Teaching and learning" is an educational platform that leverages the combination of numerical simulation and physical manipulation to facilitate learning of complex phenomena and motivate users about wave optics in practical work. HOBIT operates in real time and is…

The article describes a methodology for studying Fresnel diffraction with the active involvement of students in discussing the results of a demonstration experiment. To create a clearly visible model of Fresnel zones, a centimeter radio wave range was chosen, in which the first zone is about 10 cm in size. This makes visible the created…

Even though many physics teachers take their students on a calculation adventure through circular motion and Newton's universal law of gravity to determine Earth's velocity, most of us leave it at that. We present the final result and say, "Look, Earth is moving around the Sun at about 107,000 km/hr (66,000 mph), yet we can't feel the motion…

Possibly the greatest irony of physics education is the difficulty of demonstrating optics in a visible way. The two most common solutions to this conundrum are to either use "all-inclusive" optical apparatuses, like a large-format camera, or to rely on classic ray-tracing diagrams. While the former looks elegant while demonstrating the…