Great power of resonance. Resonance is a physical phenomenon

We often hear the word resonance: "public resonance", "the event that caused the resonance", "resonant frequency". Quite familiar and common phrases. But can you tell exactly what resonance is?

If the answer bounced off your teeth, we are truly proud of you! Well, if the topic "resonance in physics" raises questions, then we advise you to read our article, where we describe in detail, clearly and briefly about such a phenomenon as resonance.

Before talking about resonance, you need to understand what vibrations are and their frequency.

Oscillation and frequency

Oscillations are the process of changing the states of the system, repeating in time and occurring around the point of equilibrium.

The simplest example of vibrations is swinging. We cite it for a reason, this example will still be useful for us to understand the essence of the phenomenon of resonance in the future.

Resonance can occur only where there are vibrations. And it doesn't matter what kind of vibrations they are - vibrations of electrical voltage, sound vibrations, or just mechanical vibrations.

In the figure below, we describe what fluctuations can be.

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Oscillations are characterized by amplitude and frequency. For the swing already mentioned above, the vibration amplitude is the maximum height to which the swing takes off. We can also swing the swing slowly or quickly. Depending on this, the vibration frequency will change.

Oscillation frequency (measured in Hertz) is the number of oscillations per unit of time. 1 Hertz is one oscillation in one second.

When we swing a swing, periodically swinging the system with a certain force (in this case, the swing is an oscillatory system), it makes forced vibrations. An increase in the amplitude of oscillations can be achieved by acting on this system in a certain way.

By pushing the swing at a certain moment and with a certain frequency, you can swing it quite strongly, making very little effort. This will be a resonance: the frequency of our impacts coincides with the frequency of the swing's vibration and the amplitude of the vibrations increases.

The essence of the resonance phenomenon

Resonance in physics is a frequency-selective response of an oscillatory system to a periodic external influence, which manifests itself in a sharp increase in the amplitude of stationary oscillations when the frequency of an external influence coincides with certain values ​​characteristic of a given system.

The essence of the phenomenon of resonance in physics is that the amplitude of the oscillations increases sharply when the frequency of the action on the system coincides with the natural frequency of the system.

There are cases when the bridge, along which the soldiers marched, entered into resonance from the marching step, swayed and collapsed. By the way, that is why now, when crossing the bridge, soldiers are supposed to walk at a free pace, and not in step.

Examples of resonance

The phenomenon of resonance is observed in a variety of physical processes. For example, sound resonance. Let's take a guitar. By itself, the sound of the guitar strings will be quiet and almost inaudible. However, the strings are installed above the resonator body for a reason. Once inside the body, the sound from the vibrations of the string is amplified, and the one who holds the guitar can feel how it begins to "shake" slightly, vibrate from striking the strings. In other words, resonate.

Another example of resonance observation that we encounter is circles on the water. If you throw two stones into the water, the passing waves from them will meet and increase.

Microwave action is also based on resonance. In this case, resonance occurs in water molecules, which absorb microwave radiation (2.450 GHz). As a result, the molecules come into resonance, vibrate more, and the temperature of the food rises.

Resonance can be both beneficial and harmful. And reading the article, as well as helping our student service in difficult learning situations, will only benefit you. If during the course of the coursework you need to deal with the physics of magnetic resonance, you can safely contact our company for quick and qualified help.

Finally, we suggest watching a video on the topic of "resonance" and make sure that science can be exciting and interesting. Our service will help with any work: from an essay "The Internet and Cybercrime" to a course on the physics of vibrations or an essay on literature.

under the hooves of a cavalry squadron

collapsing Egyptian bridge over the Fontanka river in St. Petersburg.

Imagine that you are standing on a swinging wooden slatted bridge. It is clear that if you begin to sway yourself in time with the swinging of the bridge, the bridge will begin to swing even more.

Real modern bridges also, in fact, sway imperceptibly to the naked eye. Architects know that the phenomenon of resonance (that is, the coincidence of a natural frequency with the frequency of an external stimulus) can lead to catastrophic consequences.

Egyptian chain bridge over the Fontanka

So, on February 2, 1905, the Egyptian Bridge collapsed in the city of St. Petersburg, when a cavalry squadron passed through it. It is believed that the cause of the incident was the fact that the riders, prancing on horseback, fell into resonance with the natural vibrations of the bridge.
At school physics lessons, when they study the phenomenon of resonance, they often give an example of this destruction, when a squadron of the Horse Guards regiment walked "in step" across the bridge in one direction, and 11 sledges with charioteers in the opposite direction.
Usually a detachment of the military makes 120 steps per minute, and this frequency (2 Hz) coincided with the frequency of the natural vibrations of the structure. With each step, the span of the span's oscillations increased, and, finally, the bridge could not stand it. The bridge resonated and collapsed. It was one of five suspension bridges in the city.
The entire flooring of the bridge, together with the railings and fastenings, breaking the chains and breaking part of the cast-iron support, broke the ice and ended up at the bottom of the river.
Fortunately, there were no casualties, everyone managed to get ashore. According to official information, there were no serious casualties.
Subsequently, the military was forbidden to cross the bridges in leg. There was even a special command: "Step out of time!"

Egyptian bridge over the Fontanka river. The bridge got its name from its peculiar design.

Currently, the sphinxes are all that remains of the first bridge. Now this bridge is neither chain nor suspended.

And in 1940, due to resonant vibrations, the Tacoma Bridge in the United States collapsed. The photo shows how he was "twisted".

In the school physics course, it is said that soldiers, passing in formation across the bridge, must stop marching and walk at their usual pace. What are these precautions for? This command is given to the soldiers so as not to destroy the bridge. The fact is that if the frequency of the bridge coincides with the frequency of the marching step, then the bridge may collapse as a result of the resulting resonance. And this sometimes happens ...

THE MOST ORDINARY RESONANCE

So what is resonance? In a simplified form, resonance is a harmonious relationship between different vibrations. So, with vibration of machines and mechanisms, spontaneous unscrewing of the nuts occurs. Or if two guitars are tuned in unison, then it is worth striking the string of one guitar, as the same string of the other guitar will immediately begin to vibrate without any intervention, making exactly the same sound. In order to be convinced of the resonance phenomenon, such an experiment was carried out. At a certain distance from each other, two pianos were installed and connected with a metal wire. Then one or another piece of music was performed on one of them. And the second grand piano began to repeat the same melody, although no one touched it.

The famous Fyodor Chaliapin sang in such a way that bulbs shattered in the concert hall. This was because the frequency of vibration of his voice coincided with the frequency of vibration of glass bulbs. Resonance does not obey the laws of space or time. He seems to be from some other world, not subject to earthly laws. Resonance does not occur because objects are next to each other, because they have a certain harmonic connection. These objects may be thousands of kilometers apart, but the invisible connection between them will remain.

Moreover, scientists and researchers working in this branch of physics argue that everything that is both in the Universe and in its individual structures, for example, on Earth, is subject to the laws of resonance. Here's an example of how resonance works in human relationships. A person most often communicates with people like himself - intellectuals with intellectuals, drunkards with drunkards, etc. By the same principle, people find themselves a life partner.

The principle of operation of resonance in ancient times was formulated by the Greek thinker Hermes Trismegistus, without even knowing what law he discovers: "Like attracts like to itself." In resonance with the vibrations of the Earth, there are only those structures that are made of natural, natural materials, i.e. made of wood, stone, etc. These include, for example, all the pyramids of the Earth. Therefore, in case of global cataclysms or a shift of the poles, they can withstand and persist, while all objects made of artificial material will be completely destroyed.

There are many mysterious sides to resonance. So, if we talk about parallel worlds as an objective reality, then we sometimes feel and even feel the presence of representatives of these worlds on ourselves. One of the signs of the parallelism of the worlds is that the parallel lines do not intersect, however, it is sometimes not observed, and their worlds with our earthly world nevertheless intersect. Apparently, this is due to the fact that on the border of the two worlds a certain resonant vibration occurs and violates the principle of parallelism.

RESONANCES OF TESLA AND SCHUMAN

One of the discoverers of the amazing and previously unexplored properties of resonance was the famous American scientist and inventor Nikola Tesla. The principle of resonance and vibrations lay literally in all of Tesla's discoveries and inventions. New York, 1898. Conducting another experiment, Nikola Tesla turned on the device and began to observe how the water supply vibrated under the influence of ultrasound, then the vibration spread to the walls, then the whole building vibrated. It vibrated more and more! It became clear to the scientist - another moment, and the irreparable will happen. There was no time left to think, and Tesla, grabbing a hammer, hit his brainchild with it. Later it dawned on Nikola that he almost destroyed the whole block. He realized that even the smallest vibration, if not allowed to die out, can cause the most terrible destruction. So the electoral resonance was opened!

After this incident, Tesla told reporters: "To learn the secrets of the Universe, one must think in terms of energies, frequencies and vibrations. Applying the principle of resonance, in a few weeks I can cause such vibrations in the earth's crust that it will fall and rise hundreds of feet, throwing rivers from the channels ... ". Later, Tesla argued that if you start a resonance corresponding to the vibrations of the earth's crust, then it can smash the whole planet to shreds. In 1915, Tesla reported that his device was capable of causing destruction at any distance. "I have already built a wireless transmitter with which we can send electrical energy in any quantity over any distance." So one of the versions of the Tunguska explosion can be safely called the result of the experiment of Nikola Tesla with his favorite resonator. But could Tesla direct the energy to a specific place? Doctor of Technical Sciences Dmitry Strebkov is sure that this is quite realistic - having two radars, you can fix any object on Earth.

After half a century of research, the German physicist Otto Schumann continued. In collaboration with the physician Herbert Koenig, he discovered the so-called standing electromagnetic waves located between the ionosphere and the Earth's surface. By the way, in 2011, Schumann waves were recorded by a space satellite at an altitude of 850 km. This space is the Earth, a huge spherical resonator. Subsequently, these waves were called Schumann waves. If this wave, having made a revolution around the globe, again coincides with its phase and enters into resonance with it, then it will exist for a very long time. Herbert of Kenya also stated that the frequency of this wave coincides with the range of alpha waves of the human brain.

Thus, a person lives, as it were, inside such a resonator, due to which Schumann waves stabilize his biological rhythms and normalize vital activity. These waves, so necessary for us, are excited by magnetic processes on the Sun, lightning discharges. The absence or weak activity of waves can cause disorientation, dizziness, headache. This is especially acute for the elderly and chronic patients.

Due to the deterioration of the Earth's ecology, which is happening today, the Schumann frequency may change for the worse. And then the physical body of a person can lose contact with the frequency radiation of the Earth, which is fraught with disastrous consequences. But as long as people observe universal moral and moral values, they will not have a negative impact on the programs laid down in them, they will be in resonance with the radiation of the Earth, with the Schumann waves. With the regular fulfillment of such conditions, the Golden Age mentioned by Nostradamus may begin on Earth.

CHAERONIMUS'S MACHINE

A rather unique device was invented by Gallen Haeronimus, an American electronics engineer. It consists of an endovibrator and a metal plate. The Gallen Haeronimus apparatus received US patent No. 2482? 773 in 1948. The essence of his invention is that the "operator" tunes his brain to this or that person and, causing resonance, runs his fingers along a special rubber diaphragm.

Haeronimus took turns inserting photographs of the Apollo 11 astronauts heading to the moon into a special device of his "time machine". Thus, he could monitor the state of the astronauts throughout the flight. From the report: “... the most important and frightening thing is that the Moon is surrounded by a belt that emits lethal doses of radiation. It extends about 65 miles from the surface of the Moon and begins 15 feet from it. activity. This state lasted until they were on the surface of the moon. "

"I INVENTED A THOUGHT RESONATOR!"

Georges de la Varre, professor of physics from Oxford, staging his mysterious experiments, sometimes for months did not leave the walls of the laboratory. Finally, the time came when he solemnly exclaimed: "I have invented the resonator of thoughts!" The resonator's capabilities were not just unique - they were not limited by either time or space!

At one time, the scientist came to the conclusion that almost all objects spread electromagnetic radiation around them. Moreover, the frequencies of a part of this object are identical to the frequencies of the whole object. This primarily indicated that the connection between them does not disappear, no matter how far from each other they are. In the same way, a photograph of this or that person is closely related to its original.

And de la Varre found a way to take photographs of objects together with their radiation - for this purpose he invented a special camera. Studying the photographs obtained, the professor drew attention to the fact that under certain conditions these objects contain insignificant differences from their photographic image. “The photographs show the state of objects in time,” the thought flashed through him, “and if you also apply a resonator, then the photographs will turn out to be timeless!” Unique experiments began. During one of them, de la Varr filmed ... his own wedding day. he filled two test tubes with his blood and the blood of his wife and, sitting comfortably, mentally imagined the distant year 1929 - the year of their wedding and clicked the shutter ...

The photograph showed himself and his wife - young and happy. And inspired by his success, de la Varr began to place drops of blood of those who suffered from serious illnesses into the resonating field. After photographing, I looked through the pictures of the affected organs. Now this invention has been adopted by doctors and is called magnetic resonance imaging.

Here is what the inventor himself says about this: "Blood is the only operating time machine, and it is controlled by human thoughts. Our thoughts are electromagnetic radiation of certain frequencies, and human hearts, embryos have similar frequencies. Everything that is in the flow of time, responds to our thoughts. " I must say that his discovery made a significant contribution to forensic science. By photographing the blood of the suspect and his victim in the resonator field, you can get detailed photographs of the crime.

UNIVERSAL LAW OF SPACE RESONANCES

The Universe with its countless galaxies, stars and planets is a single electromagnetic environment, and one of its laws is the Law of simple and complex resonances. Often, the main cause of terrestrial cataclysms and catastrophes lies in the resonance of two or more cosmic cycles. It is generally accepted that these cycles are in sharp resonance if they are shifted in time by no more than 3 hours. On resonance days, earthquakes, volcanic eruptions, hurricanes, epidemics, as well as sudden and abrupt weather changes begin on Earth. In addition, the number of aviation, railroad and sea accidents is increasing, and the work of computers is disrupted. As for people, they experience malfunctions of the brain and psyche.

On April 10, 2010, a plane with Polish President Kaczynski and his wife crashed at a military airfield in the Smolensk region. A total of 96 people were on board the Tu-134 - none of them survived. Lech Kaczynski was going to visit the Katyn cemetery near Smolensk that day.

Vladimir Pleskach, a specialist in resonance and biorhythms, is sure that this catastrophe is a consequence of a powerful resonance that arose due to the special ratio of biorhythms of the passengers of the airliner and all sincerely mourners. In other words, there were passengers on board the President's plane, whose hearts and souls were overwhelmed with grief and pain for their compatriots who died in the spring of 1940 in Katyn. But what happened - it happened! Vladimir, however, made every effort to defend the honor of the victims, along with all the pilots who turned out to be extreme in this tragedy. Here the crashed plane can be compared to the collapsed bridge.

Vladimir LOTOKHIN

TO MAIN

Physicists have developed a model that can be used to estimate the critical number of pedestrians walking on the bridge, which will lead to a sharp swing. According to the authors of the study published in Science Advances, the model proposed by them will allow the construction of safer pedestrian bridges in the future.

Despite the fact that the design of pedestrian suspension bridges is now using the most advanced computer simulation packages, there are still situations where, due to the large number of pedestrians on the bridge, it suddenly begins to sway violently. Sometimes these vibrations can be so strong that they cause unsafe situations and the destruction of part of the structures. Most notable examples are the opening of the Solferino Bridge in Paris in 1999, or the regularly swinging Millennium Bridge in London, which had to be rebuilt soon after its opening.

The swinging bridge is a classic oscillatory system in which walking pedestrians are sources of external periodic force. When the natural frequency of the bridge oscillations coincides with the frequency of the external force, the system comes into resonance, and the oscillation amplitude increases sharply. If there are many sources of external force and all of them have the same frequency (that is, pedestrians take the same number of steps in the same time intervals), then phase synchronization may still occur between them, when everyone starts to step at the same time. It is the phase synchronization that is commonly referred to as the main unaccounted for in design, which leads to the occurrence of resonant oscillations on real bridges. Despite the urgency of the problem, all previous models describing such a mechanism could not explain the threshold effect of this phenomenon: when the number of pedestrians is less than the critical one, the bridge almost does not swing, but as soon as the number of pedestrians walking in leg exceeds a certain value, a sharp increase in the amplitude of the cross hesitation.

A group of physicists from the United States and Russia led by Igor Belykh from Georgia State University proposed a new model that, among other parameters, takes into account the biomechanics of the human body at the time of the step. In the system under consideration, the bridge itself is an oscillatory system in which damped vertical oscillations occur under the action of walking pedestrians. To describe a walking person, two biomechanical models (a more complete and its simplified analogue) were considered, which take into account that in response to the vertical oscillation of the bridge, the person tilts to the side and thus excites lateral oscillations.

Diagram of the physical system under consideration. On the left is a bridge in which walking pedestrians excite its vibrations, on the right - a person who reacts to the movement of the bridge, thereby causing its lateral vibrations

I. Belykh et al. / Science Advances

There is no exact analytical solution for the resulting system of equations; therefore, to find solutions, the authors used numerical methods. Unlike all the previous ones, the proposed model led to the emergence of a threshold effect. If all pedestrians walk in step, then as the number of people on the bridge increases, instability can suddenly occur. To confirm the model's work, physicists tested it to describe the wobbling of London's Millennium Bridge, for which the exact number of people that caused the resonance is even known - 165.

At the same time, the same effect was observed in the case when the cadence of different pedestrians varied slightly, which brings the model closer to reality even more. In addition, it turned out that the presence of phase synchronization is critical only for the oscillation of very heavy bridges (like the same Millennium bridge, which weighs about 130 tons) with a large amplitude. Excitation of oscillations with a small amplitude is possible even without phase synchronization. Such cases have also been observed in reality, and one of the possible mechanisms of excitation of vibrations, even the only source, scientists call a change in the speed of a step when moving along a bridge.

In their work, physicists expressed the hope that their proposed model will be used in the future for more accurate design of safe suspension and pedestrian bridges.

Various methods are now used to diagnose damage that appear on large bridges, based on the study of mechanical characteristics and the identification of defects using ultrasound. Recently, drones were used to inspect bridges, including their underwater parts.

Alexander Dubov

Before embarking on an acquaintance with the phenomena of resonance, one should study the physical terms associated with it. There are not so many of them, so it will not be difficult to remember and understand their meaning. So, first things first.

What is amplitude and frequency of movement?

Imagine an ordinary yard, where a child sits on a swing and waves his legs to swing. At the moment when he manages to swing the swing and they reach from one side to the other, you can calculate the amplitude and frequency of movement.

Amplitude is the longest deviation from the point where the body was in equilibrium. If we take our example of a swing, then the amplitude can be considered the highest point to which the child swung.

And frequency is the number of vibrations or vibrational movements per unit of time. The frequency is measured in Hertz (1 Hz = 1 oscillation per second). Let's return to our swing: if a child passes only half of the entire swing length in 1 second, then its frequency will be equal to 0.5 Hz.

How is frequency related to resonance?

We have already found out that frequency characterizes the number of vibrations of an object in one second. Imagine now that an adult helps a weakly swinging child swing by pushing the swing over and over again. Moreover, these shocks also have their own frequency, which will increase or decrease the swing amplitude of the "swing-child" system.

Suppose an adult pushes a swing while they are moving towards him, in this case the frequency will not increase the amplitude of the movement.That is, an external force (in this case, jerks) will not enhance the oscillation of the system.

If the frequency with which the adult swings the child is numerically equal to the swing frequency itself, a resonance may occur. In other words, an example of resonance is the coincidence of the frequency of the system itself with the frequency of forced oscillations. It is logical to imagine that frequency and resonance are interrelated.

Where can you see an example of resonance?

It is important to understand that examples of the manifestation of resonance are found in almost all areas of physics, from sound waves to electricity. The meaning of resonance is that when the frequency of the driving force is equal to the natural frequency of the system, then at that moment it reaches its highest value.

The next example of resonance will give an understanding of the essence. Let's say you are walking on a thin board thrown across a river. When the frequency of your steps coincides with the frequency or period of the entire system (board-man), then the board begins to oscillate strongly (bend down and up). If you continue to move in the same steps, then the resonance will cause a strong amplitude of vibration of the board, which goes beyond the permissible value of the system and this will ultimately lead to inevitable breakdown of the bridge.

There are also those areas of physics where you can use the phenomenon of useful resonance. The examples may surprise you, because we usually use it intuitively, without even knowing the scientific side of the issue. So, for example, we use resonance when we try to get a car out of a hole. Remember, the easiest way to achieve results is only when you push the car as it moves forward. This example of resonance enhances the range of motion, thereby helping to pull the car out.

Examples of harmful resonance

It is difficult to say which resonance occurs more in our life: good or harmful to us. History knows a lot of the horrific consequences of the phenomenon of resonance. Here are the most famous events in which one can observe an example of resonance.

1. In France, in the city of Angers, in 1750, a detachment of soldiers walked in step across a chain bridge. When the frequency of their steps coincided with the frequency of the bridge, the swing (amplitude) increased sharply. There was a resonance, and the chains broke, and the bridge collapsed into the river.
2. There have been cases when in villages a house was destroyed due to a truck driving along the main road.

As you can see, resonance can have very dangerous consequences, which is why engineers should carefully study the properties of building objects and correctly calculate their vibration frequencies.

Useful resonance

Resonance is not limited to disastrous consequences. With a careful study of the surrounding world, one can observe many good and beneficial results of resonance for a person. Here is one vivid example of resonance that allows people to receive aesthetic pleasure.

The device of many musical instruments works on the resonance principle. Take a violin: the body and the string form a single oscillatory system, inside which there is a pin. It is through it that the vibration frequencies are transmitted from the upper deck to the lower one. When the Luttier moves the bow along the string, the latter, like an arrow, overcomes the friction of the rosin surface and flies in the opposite direction (begins to move in the opposite region). Resonance is generated and transmitted to the cabinet. And inside it there are special holes - f-holes, through which the resonance is brought out. This is how it is controlled in many stringed instruments (guitar, harp, cello, etc.).