多普勒效应是为纪念奥地利物理学家克里斯琴·约翰·多普勒而命名的,他于1842年首先提出了这一理论,其主要内容为:由于波源和观察者之间有相对运动,使观察者感到波频率变化的现象.在声波上体现为我们所听到的声音是否变得尖锐,一个常被使用的例子是火车的汽笛声,当火车接近观察者时,其汽笛声会比平常更刺耳; The Doppler effect was named after the Austrian physicist Christian Doppler, who first proposed this theory in 1842. The main contents are as follows: Due to the relative movement between source and observer , So that the observer felt the phenomenon of changes in the frequency of waves reflected in the sound waves to hear whether we become sharp, a common example is the train whistle, when the train approached the observer, the whistle will be More harsh than usual;