Since 1674, the masons of Christian John's family in Salzburg, Austria have been thriving. They built a beautiful house by the river in Hannibal Square (now called Marquette Square), where Doppler was born. Of course, according to the family tradition, he will be allowed to take over the masonic business. However, his health has been very poor and quite weak, so he did not engage in the traditional family business.

Doppler finished primary school in Salzburg and then entered Linz Middle School. From 65438 to 0822, he began to study in Vienna Institute of Technology, and he showed an extraordinary level in mathematics. From 65438 to 0825, he graduated with honors in all subjects. After that, he returned to Salzburg, taught philosophy at Salzburg Middle School, and then went to Vienna University to study advanced mathematics, mechanics and astronomy.

When Doppler finished his studies at Vienna University in 1829, he was appointed as an assistant professor of advanced mathematics and mechanics, and he published four mathematical papers in four years. Later, I worked as an accountant in a factory, and then I taught in a technical middle school in Prague. I was also a part-time lecturer at Prague Institute of Technology. It was not until 184 1 that he officially became a professor of mathematics at the Institute of Technology. Doppler is a rigorous teacher. He was once investigated by the school because students complained that the exam was too harsh. Heavy academic affairs and heavy pressure make Doppler's health worse and worse, but his scientific achievements make him famous all over the world. 1850 was appointed as the first dean of the School of Physics of Vienna University, but died three years later in Venice, Italy, at the age of 49.

The famous Doppler effect first appeared in a paper published by 1842. Doppler deduces that when the wave source and the observer have relative motion, the wave frequency received by the observer will change. He tried to use this principle to explain the color change of binary stars. Although Doppler mistook light waves for longitudinal waves, the conclusion of Doppler effect was correct. The Doppler effect has only a slight effect on the color of binary stars. At that time, no instrument could measure these changes. But since 1845, some people have experimented with sound waves. They asked some musicians to play music on the train and others to write down the pitches they heard as the train approached and left the platform. The experimental results support the existence of Doppler effect. The Doppler effect has many applications. For example, astronomers can observe the red shift of the spectrum of distant stars and calculate the relative speed of stars and the earth. The police can use radar to detect the speed, etc.