Researchers hope they may have solved the “tunnel boom” problem as they prepare to roll out China’s latest prototype magnetic levitation train. The newest version of the maglev train is capable of travelling at 600km/h (about 370mph). However, the train’s engineers have wrestled with the problem of the shock waves which occur as the train exits the mouth of a tunnel. When a high-speed train enters an enclosed space such as a tunnel, air in front is compressed, like in a piston. The resulting fluctuations in air pressure coalesce at…