In video games, if you shoot a high-speed sniper rifle at a thin wooden wall, the game engine faces a severe mathematical crisis. Standard physics engines only check the position of the bullet once per frame. If the bullet is moving so fast that it exists on one side of the wall in frame 1, and completely on the other side in frame 2, the engine assumes it never hit the wall at all. The bullet simply phases through solid matter. This infuriating glitch is known as "tunneling." To fix it, software engineers developed Continuous Collision Detection (CCD). This advanced algorithmic architecture forces the physics engine to calculate the exact mathematical trajectory of the bullet between the frames, sweeping a geometric tunnel through the 3D space to guarantee an intersection with the wall. This book breaks down the massive processing cost of true digital physics. We explore why developers must ruthlessly limit which objects use CCD to prevent the CPU from instantly overheating under the weight of trigonometric calculations. Master the laws of digital physics. Learn how programmers manipulate time and space to stop high-speed objects from breaking reality.