Quantum electrodynamics was described by Feynman as the ‘jewel of physics’ [1985 QED: The Strange Theory of Light and Matter (Alix G. Mautner Memorial Lectures) (Princeton, NJ: Princeton University Press)] because of its ability to precisely describe the interaction of light and matter. It embodies the key concepts of quantum physics and yetalso describes classical optics. It is normally considered to be too advanced for use in schools. Here we show that through the use of novel learning tools called phasor wheels, it is possible to make quantum electrodynamics accessible to students from middle school and higher. Our graphical approach is based on the summation of all possible paths (formally known as Feynman path integrals). It uses graphical vector addition, and gives students a deep understanding of vectors. It offers insights into the quantum world in which observations represent quantum probability density, while correctly describing the laws of classical optics. The phasor wheel is a tactile tool that allows students to compute the probability of photons arriving at a point in space and to explore phenomena such as matter–wave interference, diffraction, and reflection without any distinction between quantum or classical. To make it accessible, we combine the phasor tool with real-life analogies, and videos of single quanta interference. Needing only elementary mathematics, the approach is suitable for middle/upper secondary schools as well early undergraduate students.

量子电动力学被费曼描述为“物理学的宝石”[1985 QED: The Strange Theory of Light and Matter (Alix G. Mautner Memorial Lectures) (Princeton, NJ: Princeton University Press)] 因为它能够精确地描述光与物质的相互作用。它体现了量子物理学的关键概念，同时也描述了经典光学。它通常被认为太先进而不能在学校使用。在这里，我们展示了通过使用称为相量轮的新型学习工具，可以让中学及更高年级的学生了解量子电动力学。我们的图形方法基于所有可能路径的总和（正式称为费曼路径积分）。它使用图形向量加法，让学生深入了解向量。它提供了对量子世界的见解，其中观察代表了量子概率密度，同时正确描述了经典光学定律。相量轮是一种触觉工具，可让学生计算光子到达空间某一点的概率，并探索物质波干涉、衍射和反射等现象，而无需区分量子或经典。为了使其易于使用，我们将相量工具与现实生活中的类比和单量子干涉视频相结合。该方法只需要小学数学，适用于初中/高中以及早期本科生。