Using polymerizable cholesteric liquid crystal (CLC) paints, we prepare circularly polarized freestanding films that enable students to acquire a basic understanding of circular polarization and molecular chirality. The polymerized helical structures of CLC films can exhibit brilliant structural colors by selective reflection of visible light…

The current pandemic era demands distance learning, including physics experiments on the topic of optics. One of the optical phenomena that needs to be explained in optic courses is fluorescence. This study offers a simple home experiment regarding the application of fluorescence, namely to identify the purity of olive oil using simple…

Nowadays, technologies involving nanoparticles, colloids, sensors, and artificial intelligence are widespread in society, media, and industry. It is thus mandatory to integrate them into the curricula of students enrolled in chemistry and materials science. To this purpose, we designed a simple assay for the detection of glutathione (GSH) using…

Nanoparticles are an increasingly important tool in chemistry research, but currently there are few opportunities for chemistry students to work with nanoparticles in undergraduate analytical courses. In this exercise, designed for an analytical or instrumental analysis lab course, students have the opportunity to work with solutions of silver…

The complex approximation is widely used in the framework of the Ligand Field Theory for explaining the optical properties of crystalline coordination compounds. Here, we show that there are essential features of these systems that cannot be understood with the usual approximation that only considers an isolated complex at the correct equilibrium…

A simple but physically intuitive double-source model is proposed to explain the interferogram of a laser-capillary system, where two effective virtual sources are used to describe the rays reflected by and transmitted through the capillary. The locations of the two virtual sources are functions of the observing positions on the target screen. An…

A sticky capture thread from the spiral element of spider orb-webs is formed of almost regularly spaced droplets that surround a supporting axial fibre. From the perspective of physical optics it represents a periodic linear array of scattering elements that acts as a diffraction grating. This is a novel aspect, which is of vital importance for…

We study the misconceptions about colour that most people hold, determining the general phenomenological laws that govern them. Concept mapping was used to combat the misconceptions which were found in the application of a test specifically designed to determine these misconceptions, while avoiding the possible misleading inductions that could…

This paper reports on a simple experiment which enables splitting incident light into two different modes, each having a colour exactly complementary to the other. A brief historical development of colour theories and differences in a physicist's point of view with respect to an artist's one is discussed. An experimental system for producing…

Colour science is based on the sensation of monochromatic light. In contrast to that, surface colours are caused by reflection of wide sections of the daylight spectrum. Non-spectral colours like magenta and purple appear homologous to colours with spectral hue, if the approach of mixing monochromatic light is abandoned. It is shown that a large…

Explains the physical principles which result in various colors of the sky. Topics addressed include: blueness, mystical properties of water vapor, ozone, fluctuation theory of scattering, variation of purity and brightness, and red sunsets and sunrises. (DH)

Briefly describes a physics course for nonmajors which focuses on light and color. (PEB)

Describes how the color of an object is related to its chemical structure. (CP)