In the modern world, people are increasingly talking about such a phenomenon as the Doppler effect. The unique discovery of this scientist not only glorified him, but also found application in various fields of science and life.
The history of the discovery of the Doppler effect
The Doppler effect is the change in the length and frequency of the waves recorded by the receiver, which causes the movement of their source or the receiver itself. The effect was named after Christian Doppler, who discovered it. Later, the Dutch scientist Christian Ballot succeeded in proving the hypothesis by an experimental method, who put a brass band in an open railway carriage and gathered a group of the most gifted musicians on the platform. When the carriage with the orchestra passed next to the platform, the musicians played a note, and the listeners wrote down what they heard on paper. As expected, the perception of pitch was directly related to the speed of the train, as stated by Doppler's law.
Doppler effect
This phenomenon is explained quite simply. The audible tone of a sound is affected by the frequency of the sound wave that reaches the ear. When a sound source moves towards a person, each subsequent wave comes faster and faster. The ear perceives the waves as more frequent, which makes the sound seem higher. But in the process of removing the source of the sound, subsequent waves are emitted a little further and reach the ear later than the previous ones, which makes the sound feel lower.
This phenomenon occurs not only during the movement of the sound source, but also of the person. "Running" on a wave, a person crosses its crests more often, perceiving the sound as higher, and leaving the wave - on the contrary. Thus, the Doppler effect does not depend on the movement of the sound source or its receiver separately. The corresponding sound perception arises in the process of their movement relative to each other, and this effect is characteristic not only of sound waves, but also of light and radioactive radiation.
Applying the Doppler effect
The Doppler effect does not cease to play an extremely important role in various fields of science and human life. With the help of it, astronomers managed to find out that the universe is constantly expanding, and the stars "run away" from each other. Also, the Doppler effect allows you to determine the parameters of the motion of spacecraft and planets. It also forms the basis for the operation of radars, which are used by traffic police to determine the speed of a car. The same effect is used by medical specialists who, using an ultrasound device, distinguish veins from arteries during injections.
