Standing Wave: Is It So Simple?

Any wave is an oscillation. Fluid, electromagnetic field or any other medium can fluctuate. In everyday life, every person faces with every day the manifestation of fluctuations. But what is a standing wave?

Imagine a capacious tank, in which water is poured - it can be a basin, a bucket or a bath. If now to slap the liquid on the liquid, then from the center of the collision wavy crests will run in all directions. By the way, they are called - running waves. Their characteristic feature is the transfer of energy. However, by changing the frequency of claps, it is possible to achieve an almost complete apparent disappearance of them. It seems that the mass of water becomes jelly, and the movement occurs only down and up. Standing wave - this is the offset. This phenomenon occurs because each wave that has left the center of the impact reaches the walls of the container and is reflected back where it intersects (interferes) with the main waves traveling in the opposite direction. A standing wave appears only if the reflected and straight lines coincide in phase but are different in amplitude. Otherwise, the above interference does not occur, since one of the properties of wave disturbances with different characteristics is the ability to co-exist in the same volume of space without distorting each other. It can be argued that a standing wave is the sum of two oppositely directed runners, which leads to a drop in their velocities to zero.

Why, in the example given, does the water continue to oscillate in the vertical direction? Very simple! When waves are applied with the same parameters at certain instants of time, the oscillations reach their maximum value, called antinodes, while in others they completely damp (knots). Changing the frequency of cotton, you can both completely quench horizontal waves, and increase the vertical bias.

Standing waves are of interest not only for practitioners, but also for theorists. In particular, one of the models of the structure of the universe says that any material particle is characterized by a certain frequency of vibration (vibration): the electron oscillates (trembles), the neutrino oscillates, etc. Further, within the framework of the hypothesis, it was assumed that the above-mentioned vibration is a consequence of interference of some, still not open disturbances of the medium. In other words, the authors claim that where those amazing waves form a standing wave, matter arises.

No less interesting is the Schumann Resonance phenomenon. It is that under certain conditions (none of the proposed hypotheses has yet been accepted as the only true one), standing electromagnetic waves arise in the space between the earth's surface and the lower boundary of the ionosphere, the frequencies of which lie in the low and ultralow ranges (from 7 to 32 hertz ). If the wave formed in the interval "surface-ionosphere" will go around the planet and get into resonance (coincidence of phases), then it can exist for a long time without damping, self-sustaining. Schumann's resonance is of particular interest because the frequency of waves practically coincides with the natural alpha rhythms of the human brain. For example, not only physicists are involved in research of this phenomenon in Russia, but also such a large organization as the "Human Brain Institute".

On standing electromagnetic waves drew attention to the genius inventor Nikola Tesla. It is believed that he could use this phenomenon of wave interference in some of his devices. One of the sources of their appearance in the atmosphere is considered to be thunderstorms. Electric discharges excite the electromagnetic field and generate waves.