Waves: types of waves and the definition of a wave. Types of electromagnetic and sound waves

Waves are not only in the 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. Definition is not difficult, but in reality everything is not so simple. In this case, individual particles do not move, but only move near their equilibrium positions. From what follows this property of waves: they are a means of transferring energy without changes in matter. Sometimes this happens, but only as an incident. Those who have ever been to the sea, perfectly imagine what a wave is.

Definition, however, is not the only thing you need to know when facing this phenomenon. What is important is that it is extremely closely related to fluctuations, and therefore their study takes place 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 with the help of special devices, such as antennas or radiators. In addition, the cause may be the occurrence of instabilities, as in the case of a strong wind, because of which ripples run along the water.

History of the phenomenon

The study of the mechanism of the origin and propagation of waves in various scientific disciplines, such as oceanology, seismology, mechanics, acoustics, medicine and, of course, physics in general, and many others, have been studied by many well-known scientists. It is believed that the most significant contribution was made by the German researcher Heinrich Hertz. He established some regularities 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 the wave frequency.

Types of waves

There is a huge number of classifications on various grounds. First of all, this is the direction of the wave oscillations. Types of waves by this criterion: longitudinal, transverse, mixed. There are also completely different ways of grouping them: the description of equations, geometry, the physical environment, and so on.

It is important that when this phenomenon occurs, nothing fundamentally new in the substance appears, only the organization of particles changes, which generates certain events. From the point of view of perception it can be expressed as light, color, sound, radiation, as well as energy invisible to the eye, etc. In turn, they can also be classified.

In addition, mechanical and electromagnetic waves are still distinguishable. Types of waves from the first category can also be divided into elastic waves and those that arise on the water surface. This classification implies consideration of the propagation medium. 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. First, this is its length, which is denoted as λ (lambda). In addition, it has a frequency, period and speed. A wavefront or surface, that is, a set of points that are in the same phase, and a ray or vector indicating the direction of propagation are separately isolated.

With the latter two parameters, another classification is related. Depending on the type of front, the waves can be spherical and flat. For simplified calculations and for solving some problems, the surface can be considered flat, but only if it is significantly removed from the source. Based on all these characteristics, and different types of waves are distinguished.

Examples

In addition to the most understandable things, like the sound of a string or waves on the sea, one might also think of circles on the water that appear from 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 - all are manifestations of the same phenomenon, the propagation of the wave. Types of waves are so diverse, and they themselves are so many-sided 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 it would be impossible. Their sound variety refers to elastic. Their peculiarity consists in the fact that the length of such waves and, accordingly, the frequency are such that the altitude is within earshot. For humans, this range is from 20 to 20,000 hertz. All that is lower is called infrasound, and above - ultrasound. The first is still poorly understood, but the second is widely used in science, medicine and many other areas. These are the types of sound waves. Their characteristics are determined by parameters such as length, frequency, and a combination of different modes. Dependent on this, respectively, the volume, pitch and tone.

Like any other wave, sound is naturally caused by fluctuations. This can be felt, for example, standing at a concert near the column. Waves can spread in many kinds of environments, including liquid and solid. In a vacuum, however, sounds are not heard. That's why so often there are accusations towards Hollywood directors who shoot scenes with large-scale and loud explosions in the airless space. The study of sound waves and waves deals with a fairly extensive section of physics - acoustics. This extremely interesting science has many uses in life. For example, with the use of acoustics knowledge, concert and opera rooms are designed so that presentations can be heard at any place.

The perception of sounds by man and animals is due to the conversion of mechanical vibrations into electrical signals. This mechanism is rather complicated, but its value can not be overemphasized. However, the same can be said about sounds in general. With their help you can communicate, transfer information, change your mood. They affect people even if they are out of earshot. That is why there is, for example, the concept of "noise pollution". A unit of loudness of sound is adopted in bel, named after the scientist A. Bell, the inventor of the phone.

Properties and types of electromagnetic waves

But there is also a special type of hesitation, without which it is difficult to imagine modern life. Mobile phones, wireless communications, radio, microwave ovens and many other devices would not exist if the electromagnetic waves were not open. And it would be impossible to perceive color, and there would not be light. Is it possible to imagine this?

Unlike sounds, this kind of oscillation can propagate in any medium, including in vacuum, and their speed is equal to the speed of light. In fact, this type of waves is the propagation of electromagnetic fields in space and time. Their structure is extremely interesting, because it consists of two parts. The 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 practically impossible to imagine the world without all these phenomena.