With a top speed of some 200 mph, Japan's 500 Series Shinkansen bullet train is one of the fastest in the world. To enable it to run quietly at high speeds, designers emulated one of the quietest birds, owls. By designing small serrations similar to those on owl feathers, they were able to reduce the noise generated by the train's pantograph—the component that connects to overhead electrical wires. The most obviously biomimetic design element is the train's nose cone, which is modeled after a kingfisher's beak. This allows the bird to dive from air into water with a minimal amount of resistance. On a train, the aerodynamic design reduces the sonic boom that occurs when the train passes from a tunnel back into the open air, reducing noise pollution.