Recent discussions in TPT have considered the pros and cons of an early introduction of students to modern physics.1–4 In this regard, appropriate experiments with classical waves can help students understand some important but counterintuitive aspects of modern physics. I recently taught a summer course that introduced high school seniors who had graduated with some background in physics and algebra to aspects of quantum physics and relativity. In this paper I'll describe a simple experiment I used to introduce these students to uncertainty principles in quantum physics.