From led light signboards to the Planck's constant

Recent studies have highlighted an alarming decline in young people's interest towards the study of scientific subjects, often considered interesting but not easily understood and appreciated by students. In particular, the introduction of Modern Physics (MP) key topics at secondary school level is a difficult and complex task because MP involves abstract ideas and requires a strong mathematical background. In this communication we present and discuss the results of an inquiry-based teaching/learning path aimed at surmounting the difficulties of an exclusively theoretical approach to the introduction of MP topics. In particular, we planned and realized an inquiry-driven learning environment where about 20 students, from a second-year class of a vocational school, were involved in the discovery of the Planck's constant and brought closer to MP. The work, carried out as a cross-disciplinary module, has involved Physics and Technological Laboratory. The task given to the students was the design of an illuminated sign, efficient from the energetic point of view, flexible and attractive. Through a 'guided inquiry', the students evaluated the different solutions, developed their critical thinking and decided to implement them with LED diodes. Planck's constant has been determined by two methods of analysis of the experimental data and satisfactory values have been obtained. Our results suggest that an inquiry-based teaching/learning path, can constitute a successfully teaching approach to effectively engage students into an active learning of the MP. The described learning activity provided students with opportunities to develop a large range of complementary skills such as working in groups, synthesis, interpretation and evaluation of the experimental data, experience of open-ended problems solving and other cross-disciplinary abilities.