Bullet trains can brake before humans feel an earthquake

When an earthquake strikes, it releases different types of energy that move through the earth at varying speeds. The first to arrive are primary waves, or P-waves, which travel fast but cause very little shaking. Japan's Shinkansen network uses a sophisticated early warning system that detects these harmless P-waves and automatically cuts power to the overhead lines. Because a bullet train traveling at 270 kilometers per hour covers about 75 meters every single second, these automatic reflexes are far faster than any human operator could manage.