To investigate students' interest in physics, this study explores the impact of a brief teaching intervention on the increase of interest. The intervention focused on modern physics, specifically exploring Einstein's theory of gravity and the dual nature of light. A total of 325 Greek students participated in the survey, comprising 83 students in the 6 th grade (11-12 years old), 116 students in the 9 th grade (14-15 years old), and 126 students in the 11th grade (16-17 years old). Participants completed a questionnaire, which helped determine the average level of interest before and after the teaching. The findings indicate that teaching modern physics concepts contributes to the development of students' interest. However, there is an observed decline in interest as the educational level advances, a pattern persisting despite the introduction of Einsteinian physics concepts.