# Application of Virtual Reality in Learning Quantum Mechanics
## 2 Virtual Teaching Modules  
In this study, virtual reality technology is used to develop the teaching modules of quantum mechanics, which embody and visualize the wave-particle duality of microscopic matter for learners to see the particles and wave phenomena of electrons and photons by conducting virtual experiments to understand quantum theory. This study analyzed the learning content according to the \"Curriculum Guidelines of 12-year Basic Education\" proposed by the Ministry of Education, Taiwan [29] and the textbooks of quantum phenomena in the field of natural sciences in senior high schools, and designed the learning objectives and virtual teaching modules based on the analysis results. After completing the virtual teaching modules, this study conducted a teaching experiment to explore the learning effectiveness, learning motivation, and cognitive load of applying virtual reality in learning quantum mechanics as well as learners' satisfaction with the teaching modules, which can be revised according to the questionnaire results and suggestions from teachers to facilitate the subsequent promotion activities. The research method and steps adopted in this study are shown in Figure 1.  
The virtual teaching modules developed in this study combined the situated learning theory and the knowledge of quantum mechanics by integrating the particles and wave phenomena of electrons and photons into observation activities, allowing learners to understand quantum theory by conducting virtual experiments. The goal is to enhance their learning motivation and understanding of quantum theory. This study analyzed the course content first and then planned and designed teaching modules based on the teaching objectives. The designers used the Windows 10 operating system and Unity 3D Game Engine as development tools. The latter has a cross-platform function, which can develop and execute stand-alone games on PC or Mac OS. It can also support multiplayer online games. This study used Adobe Photoshop to draw the textures required for virtual objects and virtual scenes and built 3D models with Autodesk 3D Studio Max. After completion, the models were exported to Unity 3D, and then JavaScript and C# were used to write programming languages to design interactive user interfaces for the quantum mechanics virtual experiments. Unity 3D provides a hierarchical environment and a visual editing interface for designers, including the property editor and the dynamic preview function. It is a popular development tool for building cross-platform 2D and 3D games and interactive environments. In this study, Unity 3D is used to import all objects in the teaching modules into the virtual experiments. The visual effect was enhanced through the built-in API and light source projection settings, and then the user interface was designed according to the operation process of the virtual experiment, which was published through Unity 3D. Finally, the  
Figure 1: The research method and steps adopted in this study. project was converted into an executable file in the Android environment, including the HMD and mobile devices (tablets and smartphones). This study referred to the quantum mechanics textbooks in high schools and colleges for developing virtual teaching modules. Before designing the 3D models of the experimental equipment, the size and resolution of the models must be determined. Then, 3 ds Max was used to edit the model designed by hand or scanned by a 3D imaging system. Textures and light sources were set to increase the sense of reality. In order to maintain execution efficiency when performing the virtual experiment, a low-polygon design method was adopted in this study to save storage space and calculation time required in real-time simulation. In the following, the (1) Cathode-ray tube experiment, (2) Oil drop experiment, (3) Photoelectric effect experiment, (4) Gold foil experiment, and (5) Electron diffraction experiment are shown as examples to illustrate the design principles and operation procedures of these virtual teaching modules.