What do a kingfisher and a high speed train have in common?

This small, colorful bird has inspired aerodynamics engineering from none other than Japan's bullet train. In the 1990s it was found that each time the train pulled out of a tunnel, the air pressure exerted on its 'nose' created a 'sonic boom' that bothered tremendously residents and wildlife of the area. The solution to this problem was found in the kingfisher. These birds dive into the water without distorting or big splashes. Engineers designed nose imitating Martin peak train, and the result was the elimination of noise in the tunnels and improving energy efficiency by 15% ...