R. Espinosa, I. Sánchez, A. Guirao

University of Murcia (SPAIN)
In any educational institution we find excellent instruments for teaching physics (particularly optics): displays. Beyond its role as an audio-visual device useful to expose the theory, a display is itself an experimental tool for teaching. We all sit today in front of monitors, but how many people know how they work? Exploring the science and technology behind displays may serve to attract the attention of students and to shorten the separation between the academic context and the real world. In this work we will present a series of experiments and demonstrations of optics by using displays that may be used both for secondary school and university level. Optics is a branch of physics in which one can find very easily lots of phenomena, materials and instruments very familiar. Demonstrations may be done directly at the classroom by the teacher as an important support for teaching and learning physics. This also motivates for doing experimentation at home so physics will appear nearer and nicer. Students will see physics is in everyday life. We will show how to study the colors superposition in RGB displays by using magnifying glasses or microscope eyepieces to see the on/off pixels when different colors are displayed on the screen; and how to observe the light spectrum emitted by different monitors (CRT, LCD, etc.) by means of simple homemade spectroscopes. Seeing at the screen in LCDs through polarizers allows us to check the linear polarized light and to study polarization. We will also explain how to use pixel size, resolution of displays, and refresh frequency in the context of visual perception; or to play with brightness and contrast to understand a digital image.