The NightStar flashlight Physics Guide is a comprehensive tutorial on the science and engineering of the NightStar flashlight. The 20 page Physics Guide (PDF Electronic Format only) contains numerous equations and diagrams to help explain the nature of magnetism, electrodynamics, energy, light and optics. The guide is ideal for high school level students, though much of the material can be understood by 6th graders and up. The Physics Guide is authored in the USA and published globally.