Waves are not only in water. They consist of sound, light, etc. How can this be and what are waves in general?
Essence
This term is used in various scientific fields, but primarily in physics. According to the terminology of this discipline, the process of propagation of oscillations is a wave. The definition is simple, but in reality it is not so simple. In this case, individual particles do not move, but only move near their equilibrium positions. What follows is the property of waves: they are a means of energy transfer without changes in matter. Sometimes this happens, but only as a side effect. Those who have been at sea at least once have a good idea of ββwhat a wave is.
A definition, however, is not the only thing you need to know when confronted with this phenomenon. It is important that it is extremely closely interconnected with oscillations, therefore their study occurs jointly both in theory and in practice.
Origin
Waves can be generated in various ways. The cause of their occurrence is always the excitation of particles and their removal from equilibrium. This can be done using special devices such as antennas or emitters. In addition, the cause may be the occurrence of instabilities, as in the case of a strong wind, due to which ripples run through the water.
History of the study of the phenomenon
The study of the mechanism of the emergence and propagation of waves in various scientific disciplines, such as oceanology, seismology, mechanics, acoustics, medicine and, of course, physics in general, as well as many others, was carried out by many famous scientists. It is believed that the German researcher Heinrich Hertz made the most significant contribution . He established some laws and discovered previously unknown phenomena associated with the interaction of electromagnetic waves, for example, interference, diffraction, and polarization. His research was subsequently used to create radio communications. Of course, there were other scientists who studied this phenomenon and made a significant contribution to the development of science, for example, Maxwell, but it was Hertz's name that was immortalized in the unit of measurement of wave frequency.
Types of waves
There are a huge number of classifications on various grounds. First of all, this is the direction of wave oscillations. Types of waves according to this criterion: longitudinal, transverse, mixed. There are completely different ways of grouping them: description by equations, geometry, physical environment, etc.
It is important that when this phenomenon occurs, nothing fundamentally new appears in matter, only the organization of particles changes, which gives rise to certain events. From the point of view of perception, this can be expressed as light, color, sound, radiation, as well as invisible energy to the eye, etc. In turn, they can also be classified.
In addition, mechanical and electromagnetic waves are still distinguished. Types of waves from the first category can also be divided into elastic and those that arise on the surface of the water. This classification involves consideration of the distribution environment. In general, the main and most popular division includes only sound and electromagnetic waves. About them in the future and will be discussed in more detail.
general description
Any wave has a number of properties and parameters with which it can be described. The first is its length, which is denoted by Ξ» (lambda). In addition, it has a frequency, period and speed. Separately, a wave front or surface is distinguished, that is, a plurality of points located in the same phase, and a ray or vector showing the direction of propagation.
The last two parameters are related to yet another classification. Depending on the type of front, the waves can be spherical and plane. For simplified calculations and solving some problems, the surface can be considered flat, but only if it is significantly removed from the source. Based on all these characteristics, different types of waves are distinguished.
Examples
In addition to the most obvious things, such as the sound of a string or waves at sea, you can also think of circles on the water appearing from an abandoned stone, explosions, sleep on a soft mattress and many other phenomena. Ultraviolet or infrared rays, as well as what is not audible to the human ear, are all manifestations of the same phenomenon, wave propagation. The types of waves are so diverse, and they themselves are so diverse that it is really difficult to believe that such different things, in fact, have one nature.
Sound waves: features
Hearing gives a person a huge amount of information about the world around him. But without waves, this would be impossible. Sound variety refers to elastic. Their feature is that the length of such waves and, accordingly, the frequency are such that the height is within earshot. For humans, this range is from 20 to 20,000 hertz. Everything below is called infrasound, and above is called ultrasound. The first is still poorly understood, but the second is widely used in science, medicine and many other fields. These are the types of sound waves. Their characteristics are determined by such parameters as length, frequency and a combination of different types of vibrations. Volume, pitch, and timbre, respectively, depend on this.
Like any other wave, sound is naturally caused by vibrations. This can be felt, for example, standing at a concert near the speaker. Waves can propagate in many types of media, including liquid and solid. In a vacuum, it is believed that no sounds are heard. That is why so often there are reproaches towards Hollywood directors who shoot scenes with large-scale and loud explosions in airless space. The study of sound vibrations and waves is engaged in a fairly extensive section of physics - acoustics. This extremely interesting science has many applications in life. For example, using acoustic knowledge, concert and opera halls are designed so that the performances are clearly audible anywhere.
Sounds are perceived by humans and animals by converting mechanical vibrations into electrical signals. This mechanism is rather complicated, but its value cannot be overestimated. However, the same can be said about sounds in general. With their help, you can communicate, transmit information, change the mood. They affect people, even if they are out of earshot. That is why, for example, there is the concept of "noise pollution". The unit of sound volume is white, named after the scientist A. Bell, the inventor of the telephone.
Properties and types of electromagnetic waves
But there is a special type of vibrations, without which it is difficult to imagine modern life. Mobile phones, wireless, radio, microwave ovens and many other devices would not exist if electromagnetic waves were not discovered. It would also be impossible to perceive color, and light would not exist. How can you imagine this?
Unlike sounds, this type of oscillation can propagate in any medium, including in a vacuum, and their speed is equal to the speed of light. In fact, this type of wave is the propagation of electromagnetic fields in space and time. Their structure is extremely interesting because it consists of two parts. Magnetic and electric fields alternately generate each other and propagate along mutually perpendicular vectors. One of the main properties of such a wave is that it is always transverse. In addition, it always spreads with acceleration.
There are different types of electromagnetic waves depending on their length. There are 6 main ranges from the longest to the shortest:
- radio waves;
- infrared radiation, in other words, heat;
- visible light and colors;
- ultraviolet;
- X-ray
- gamma radiation (including radiation).
After all, it is really practically impossible to imagine the world without all these phenomena.