Book excerpt: Rapid Penetration into Granular Media: Visualizing the Fundamental Physics of Rapid Penetration introduces readers to the variety of methods developed to visualize, observe, and model the rapid penetration of natural and man-made projectiles into earth materials while providing seasoned practitioners with a standard reference that showcases the topic's most recent developments in research and application. There has been a flurry of recently funded research both in the U.S. and Europe on studying the behavior of projectiles in granular media. This book compiles the findings of recent research on the subject and outlines the fundamental physics of rapid earth penetration, and assembles a comprehensive collection of experimental and numerical techniques to study the problem.