First of all my respectful greetings to all the Hive.blog community, this time we continue to relate to the wonderful phenomenon of sound and each of the intrinsic phenomena that originate when sound propagates from a certain species-time to another, such is the case of the Doppler effect.

Introduction

Throughout this thematic series related to sound we have shown how this phenomenon can be perceived in any space-time where we are, therefore, when this happens we know that a certain vibration of the component particles of a certain object or body in our environment takes place, and thus this object becomes a source of sound generation.

So far my dear readers the journey has been long but full of learning related to any physical aspect of sound, and all this man has been able to put into practice thanks to the field of science-technology, and also with the wonderful and indispensable area of education to spread this knowledge through our academies.

Let us remember my friends that we have been related to the essential sound spectrum which has allowed us to classify the sound in relation to its frequency and this physical magnitude is closely related to the length of waves that carry the sound phenomenon, these will allow us to take our first step to enter the analysis of the recognized phenomenon of the Doppler effect.

The above mentioned phenomenon was perceived for the first time by the great physicist Christian Andres Doppler, this he was able to do by analyzing the sound of a train whistle, noticing that the sound was much sharper as the engine approached him, and when the train moved away the sound was becoming more serious.

Therefore, clearly in relation to the above described we must relate again with our acoustic spectrum in order to visualize the frequency behavior, and its relationship with the wavelength for the audible sounds to our ears as are the high and low, and thus this will allow us a better understanding in the further analysis of the Doppler effect and this in general, therefore observe the following figure 1.

_{Figure 1. Relationship between frequency and wavelength in sound}

As you could visualize my dear readers, in the previous figure 1, we see how the shorter the wavelength, the higher the frequency of a given sound, and this is clearly due to the fact that more cycles per second or Hz will be obtained.

We also identify with an ellipse the wavelengths related to our audible spectral fraction, and with this, the obtaining of low, medium or high-pitched sounds, this relationship will allow us to explain the phenomenon of the Doppler effect, which develops both in sound waves and electromagnetic waves responsible for the propagation of light.

The Doppler effect

Every person on this planet is a reliable witness of the Doppler effect, because our natural auditory systems (ears) constantly perceive some kind of sound from our environment, and as it has been expressed, these sound waves carry the vibrations that originate a certain sound, thus disturbing the medium through which it propagates in order to reach a receiver.

In this way we are relating to two important elements in the development of this physical phenomenon as the Doppler effect, which are the source emitting sound and the receiver of these waves, therefore it is important to note that the Doppler effect has application in both sound and light, since both as we have expressed are of wave nature, but, in this opportunity we will link with this phenomenon (Doppler) and its relation with the sound waves, as well as with the different positions of the elements involved, such as the emitting source and the receiver, since the understanding of this phenomenon will depend on it.

In the next installments we will be linking with the Doppler effect and its relationship with the different positions between the sound emission source and receiver.

Conclusion

Thanks to the understanding of sound, man has achieved the comprehension of other important intrinsic phenomena at the moment of its propagation, such is the case of the Doppler effect and we will continue to learn about it in the following sections in order to go step by step towards the understanding of it from the sound point of view.

Therefore, we can express in a general way that the Doppler effect is related to the change of the frequency of the sound waves perceived by a certain receiver and this characteristic is intrinsically linked to the relative movement between the sound emitting source and the receiver of the same, and we will check this in the following parts or deliveries.

Until another installment, my dear Hive.blog readers.