Sound, ultrasound, infrasound and their use. Presentation "ultrasound and infrasound in nature" Presentation on the topic ultrasound and infrasound
Drawings. Decipher the rebus. Frontal survey. Reflection. Is it possible to create a perpetual motion machine? General lesson on physics in 7th grade. Perpetual motion machines. Problem solving. Physics Experience Work. Woodward. Org. moment. Archimedes screw. The law of equilibrium of forces on an inclined plane. What do you understand by the term “perpetual motion machine”? The ideal engine. Task 1. “Strive to comprehend science more and more deeply, pine for the knowledge of the eternal. A perpetual motion device based on a magnet.
“Structure of matter physics” - Practical application of diffusion. Lesson No. 1 “What physics studies. What if the candles are heated? 2. Explain the action of glue and solder. Drawing on students' life experiences. Reliance on knowledge from natural history and primary school. Educational tasks. Basic material: The phenomenon of diffusion. Taking into account the characteristics of the class. Wetting and non-wetting. Differences in the molecular structure of solids, liquids and gases. Thematic planning.
“Physics of diffusion” - Solids. BALASHOV - 2010 S of the internal surface of the human intestine - 0.65 sq. M; due to the villi it reaches 4-5 square meters. Dependence of the rate of diffusion on temperature. What does diffusion depend on? Diffusion and human security. Identical. Lao-Tse. The most powerful thing in the world is what is not seen, not heard and intangible. The smallest particles that make up various substances. Human breathing and digestion. Continue the sentence. Different. Liquids. Water vapor
“Mechanical movement 7th grade” - 300 m. Trajectory of movement. Trajectory. Curvilinear movement (skier on the track). Mechanical movement. Rails Table Wheels of the carriage. Relative to which bodies is the book at rest? Rectilinear movement (elevator). Choose the correct answer. A change in the position of a body in space relative to other bodies over time. There is a book on a table in the carriage of a moving train.
“Pressure 7th grade” - How to increase blood pressure How to reduce blood pressure. Elastic force. Physical break. Attached to a support or suspension. Lesson on learning new material, grade 7. It's time to go on a diet! 300000 kPa. P=F/S. Test. Look out the window into the distance for 1 minute. The formula for finding the force of gravity is Ft = mg. Strength. Why am I failing? Animal claw. Increased pressure in nature.
“Physics 7th grade Mechanical work” - Seven people drag uphill, and one pushes downhill. What types of forces do you know? Formula for calculating work. It is not the oven that feeds, but the hands. The sled moves under the influence of muscle power. Why? A = F thrust ·s. If the force and direction of movement coincide, then A>0. Take it together, it won't be too heavy. 1 m. Rest friction force. 1 kJ = 1000 J 1 MJ = 1000 kJ = 1,000,000 J 1 mJ = 0.001 J. Experiment 2. The loaded cart moves 1 m. We increase the load and repeat the experiment.
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SOUND Man lives in a world of sounds. Sound is what the ear hears. We hear the voices of people, the singing of birds, the sounds of musical instruments, the noise of the forest, thunder during a thunderstorm. The sounds of running cars, moving vehicles, etc. What is sound? How does it arise? How do some sounds differ from others? People wanted to know the answers to these questions. The branch of physics that studies sound phenomena is called acoustics. Having heard a sound, we can usually establish that it came to us from some source. When we examine this source, we will always find something wavering in it. If, for example, sound comes from a loudspeaker, then a membrane vibrates in it - a light disk fixed around its circumference. If a sound is produced by a musical instrument, then the source of the sound is a vibrating column of air and others.
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Sound waves Elastic waves that cause the sensation of sound in humans are called sound waves. 16 – 2 10 4 Hz – audible sounds; less than 16 Hz – infrasounds; more than 2 10 4 Hz – ultrasounds. A prerequisite for the occurrence of a sound wave is the presence of an elastic medium. The mechanism of occurrence of a sound wave is similar to the formation of a mechanical wave in an elastic medium. Vibrating in an elastic medium, the vibrator affects the particles of the medium. Sound is created by long-term periodic sound sources.
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The speed of sound depends on the medium and its state, as for any mechanical wave: ύ = λν = λ/T. At t = 0 ºC water = 1430 m/s, steel = 5000 m/s, air = 331 m/s. Physical characteristics of sound 1. Sound pressure is the pressure exerted by a sound wave on an obstacle standing in front of it. 2. Sound spectrum - decomposition of a complex sound wave into its component frequencies. 3. Sound wave intensity: I = W/St, where S – surface area; W – sound wave energy; t – time; I = 1 J/m² s = 1 W/1 m²
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The volume, like the height, of a sound is related to the sensation that arises in the human mind, as well as to the intensity of the wave.
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The pitch of the sound depends on the vibration frequency: the > ν, the higher the sound. The timbre of a sound allows you to distinguish between two sounds of the same pitch and volume produced by different instruments. It depends on the spectral composition.
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WHAT IS SOUND? What is sound? Sound is mechanical vibrations propagating in elastic media: gases, liquids and solids, perceived by the organs of hearing. Let's look at examples that explain the physical essence of sound. The string of a musical instrument transmits its vibrations to surrounding air particles. These vibrations will spread further and further, and upon reaching the ear, they will cause the eardrum to vibrate. We will hear the sound. Thus, what we call sound is a rapid change, the particles of air do not move, they only oscillate, alternately shifting to one side and the other over very short distances. But isolated vibrations of one body do not exist. In each medium, as a result of interaction between particles, vibrations are transmitted to more and more new particles, i.e. Sound waves propagate through the medium.
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Another simple example of oscillatory motion is the oscillation of a pendulum. If the pendulum is deflected from its equilibrium position and then released, it will oscillate freely. Under the influence of gravity, the pendulum returns to its original position, by inertia it passes the starting point and rises upward, while the force of gravity will slow down its movement. At the point of maximum deflection, the pendulum becomes and after a moment begins to move in the opposite direction. The cycles of pendulum oscillations are continuously repeated. Oscillations can be periodic, when changes are repeated after an equal period of time, and non-periodic, when there is no complete repetition of the change process. Among periodic oscillations, harmonic oscillations play a very important role. Depending on the process, vibrations are mechanical, electric current and voltage of sound vibrations.
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The most visible waves are on the surface of the water. If you throw a stone into the water, first a depression will appear, then a rise of water will appear, and then waves will appear, which are successively alternating ridges and depressions. Increasing along the front, they spread in all directions, but individual particles do not move along with the waves, but oscillate only within small limits around a certain constant position. You can verify this, for example, by watching a piece of wood bouncing on the waves. It will rise and fall, i.e. oscillate, letting a running wave pass underneath it. Waves are longitudinal and transverse; in the first case, the oscillations of the particles of the medium occur along the direction of propagation of the wave, in the second - across it. The human ear can perceive vibrations with a frequency of approximately 200 to 20,000 vibrations per second. Accordingly, mechanical vibrations with the indicated frequencies are called sound, or acoustic. The issues that acoustics deals with are very diverse. Some of them are related to the properties and characteristics of the hearing organs.
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In warm air, the speed of sound is greater than in cold air, which leads to a change in the direction of sound propagation.
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General acoustics studies the origin, propagation and absorption of sound. Physical acoustics deals with the study of sound vibrations themselves, and in recent decades has also embraced vibrations that lie beyond the limits of audibility (ultraacoustics). At the same time, it widely uses various methods of converting mechanical vibrations, electrical vibrations and vice versa. In relation to sound vibrations, the number of tasks of physical acoustics includes the study of physical phenomena that determine certain qualities of sound that are distinguishable by ear. Electroacoustics, or technical acoustics, deals with the acquisition, transmission, reception and recording of sounds using electrical devices. Architectural acoustics studies the propagation of sound in rooms, the influence on sound of the size and shape of rooms, the properties of materials covering walls and ceilings, etc. etc. This refers to the auditory perception of sound.
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Musical acoustics examines the nature of musical sounds as well as musical moods and systems. We distinguish, for example, musical sounds (singing, whistling, ringing, sound of strings) and noises (crackling, knocking, creaking, hissing, thunder). Musical sounds are simpler than noises. A combination of musical sounds may produce the sensation of noise, but no combination will produce a musical sound. Hydroacoustics (marine acoustics) deals with the study of phenomena occurring in the aquatic environment associated with the emission, reception and propagation of acoustic waves. It includes issues of development and creation of acoustic devices intended for use in the aquatic environment. Atmospheric acoustics studies sound processes in the atmosphere, in particular the propagation of sound waves, the condition for ultra-long-range sound propagation.
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Underwater sound channel in the ocean: a) speed of sound at different depths; b) the trajectory of sound rays created by the source at point A; At a depth of minimum speed of sound zk, a concentration of sound rays occurs - this is the axis of the sound channel.
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Physiological acoustics studies the capabilities of the hearing organs, their structure and action. She studies the formation of sounds by the speech organs and the perception of sounds by the hearing organs, as well as issues of speech analysis and synthesis. Creation of systems; capable of analyzing human speech - an important step in the design of machines, especially robotic manipulators and electronic computers, that obey the verbal instructions of the operator. A speech synthesis machine can provide great economic benefits. If, through international telephone channels, not the speech signals themselves are transmitted, but codes obtained as a result of their analysis, and speech is synthesized at the output of the lines, then the same channel can transmit several times more information. True, the subscriber will not hear the real voice of the interlocutor, but the words will be the same as those spoken into the microphone. Of course, this is not entirely suitable for family conversations, but it is convenient for business conversations, and they are the ones that overload communication channels. Biological acoustics examines the issues of sound and ultrasonic communication of animals and studies the location mechanism that they use, and also explores the problems of noise, vibration and their struggle to improve the environment.
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ULTRASOUND Recently, technological processes based on the use of ultrasound energy have become increasingly widespread in production. Ultrasound has also found application in medicine. Due to the increase in unit powers and speeds of various units and machines, noise levels are increasing, including in the ultrasonic frequency range. Ultrasound is the mechanical vibration of an elastic medium with a frequency exceeding the upper limit of audibility - 20 kHz. The unit of sound pressure level is dB. The unit of measurement for ultrasound intensity is watt per square centimeter (W/s²). The human ear cannot perceive ultrasound, but some animals, such as bats, can both hear and produce ultrasound. It is partially perceived by rodents, cats, dogs, whales, and dolphins. Ultrasonic vibrations occur during the operation of car engines, machine tools and rocket engines. In practice, to produce ultrasound, electromechanical ultrasound generators are usually used, the action of which is based on the ability of certain materials to change their dimensions under the influence of a magnetic (magnetostrictive generators) or electric field (piezoelectric generators), while the generators produce high-frequency sounds.
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Due to its high frequency (short wavelength), ultrasound has special properties. Thus, like light, ultrasonic waves can form strictly directed beams. Reflection and refraction of these beams at the boundary of two media obeys the laws of geometric optics. It is strongly absorbed by gases and weakly by liquids. In a liquid, under the influence of ultrasound, voids are formed in the form of tiny bubbles with a short-term increase in pressure inside them. In addition, ultrasonic waves accelerate the processes of diffusion (interpenetration of two media into each other). Ultrasonic waves significantly affect the solubility of a substance and, in general, the course of chemical reactions. These properties of ultrasound and the peculiarities of its interaction with the environment determine its wide technical and medical use. Ultrasound is used in medicine and biology for echolocation, for identifying and treating tumors and some defects in body tissues, in surgery and traumatology for cutting soft and bone tissues during various operations, for welding broken bones, for destroying cells (high power ultrasound). In ultrasound therapy, oscillations of 800-900 kHz are used for therapeutic purposes.
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INFRASOUND The development of technology and vehicles, the improvement of technological processes and equipment is accompanied by an increase in the power and dimensions of machines, which determines the tendency for low-frequency components in the spectra to increase and the emergence of infrasound, which is a relatively new, not fully studied factor in the production environment. Infrasound refers to acoustic vibrations with a frequency below 20 Hz. This frequency range lies below the threshold of audibility and the human ear is not capable of perceiving vibrations of these frequencies. Industrial infrasound occurs due to the same processes as noise of audible frequencies. The greatest intensity of infrasonic vibrations is created by machines and mechanisms that have large surfaces that perform low-frequency mechanical vibrations (infrasound of mechanical origin) or turbulent flows of gases and liquids (infrasound of aerodynamic or hydrodynamic origin). The maximum levels of low-frequency acoustic vibrations from industrial and transport sources reach 100-110 dB.
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Having completed this work - collecting, processing and summarizing a large amount of material on this problem, I learned a lot about the nature of sound. About the danger that it can pose to the human body, and about how widely it can be used on the farm. I took this particular topic because... I believe that this is a relevant topic in our time and it will be easier for students to study it visually. As an advocate for peace, I am concerned about information about the convenience, ease and success of developing mass impact weapons using ultra and infrasound. It was very pleasant and interesting for me to work on this topic, since I consider it promising and extremely poorly covered for a wide range of people. Ultra and infrasound are the power of nature that man has put to his service! Students can test their knowledge on a test.
InfrasoundInfrasound Infrasound (from Latin infra below, under) – mechanical waves similar to sound waves, but having a frequency of less than 20 Hz. They are not perceived by the human ear. Infrasound is characterized by low absorption in various media, so it can spread over vast distances in air, water and the earth’s crust.
Infrasound in the water “Voice of the Sea” can warn of an approaching storm. Jellyfish are unique indicators of a storm. At the edge of the “bell” of jellyfish there are primitive auditory cones capable of perceiving infrasounds with a frequency of 8-13 Hz. They hear the storm hundreds of kilometers away and 20 hours before it reaches the area, and go deeper.
Under certain conditions, when the frequency of the ship’s hull and the infrasonic waves acting on it coincide, the ship itself becomes a source of these waves, and significantly amplified ones. The rats, hearing the voice of the sea, rush to leave the ship, the resonant frequency of which coincides with the frequency of the storm waves. They feel that such a ship may not be happy. Under certain conditions, when the frequency of the ship’s hull and the infrasonic waves acting on it coincide, the ship itself becomes a source of these waves, and significantly amplified ones. The rats, hearing the voice of the sea, rush to leave the ship, the resonant frequency of which coincides with the frequency of the storm waves. They feel that such a ship may not be happy.
Natural sources of infrasound waves are not only storms, but also tsunamis, earthquakes, hurricanes, volcanic eruptions, and thunder. Natural sources of infrasound waves are not only storms, but also tsunamis, earthquakes, hurricanes, volcanic eruptions, and thunder.
The main man-made sources of infrasound include powerful equipment (machines, boiler rooms, transport), underwater and underground explosions, wind power plants and even ventilation shafts. The main man-made sources of infrasound include powerful equipment (machines, boiler rooms, transport), underwater and underground explosions, wind power plants and even ventilation shafts.
Infrasound in medicine Modern medicine uses quite a lot of equipment that uses infrasound for treatment. Infrasound is mainly used in the treatment of cancer and eye diseases. The difficulty of using infrasound in medicine is due to the fact that it has a detrimental effect on the human body. It is necessary to conduct a large number of tests and spend many years of work to find suitable exposure parameters.
The influence of infrasound on humans Infrasound negatively affects people's health, especially mental health. Our brain, when working, oscillates at different frequencies, depending on the type of activity. The brain of a sleeping person oscillates with a frequency of 0.3-4 Hz, the brain of a waking person - with a frequency of 9-13 Hz. If our brain is affected by vibrations of the same or very similar frequencies, then a malfunction of the brain will occur, accompanied by hallucinations. Infrasound can affect the central nervous system, so people under the influence of infrasound experience unpleasant sensations: from depression to panic.
Another unusual phenomenon has been attributed to it: the “Flying Dutchman” - the legendary ghost ship. Our eyeball vibrates at a natural frequency of 18 Hz. When resonance occurs, visual acuity deteriorates and color sensitivity decreases. A visual hallucination occurs, seeing phantoms. This influence of infrasound on the human psyche could be the reason for numerous cases of the disappearance of the crew while the ship was completely intact and the weather was excellent. But it is still unknown whether it was in fact the infrasound that forced people to throw themselves off the ship, experiencing wild, inexplicable horror. Infrasound can This influence of infrasound on the human psyche could be the cause of numerous cases of the disappearance of the crew while the ship was completely intact and the weather was excellent. But it is still unknown whether it was in fact the infrasound that forced people to throw themselves off the ship, experiencing wild, inexplicable horror. Infrasound can
Seasickness is also caused by the influence of infrasound: a wave with a frequency of 12 Hz causes severe dizziness in a person, as it causes his vestibular apparatus to resonate. High-intensity infrasound, which entails resonance, due to the coincidence of vibration frequencies of internal organs and infrasound, leads to disruption of the functioning of almost all internal organs, and death is possible due to cardiac arrest or rupture of blood vessels. (Infrasound with a frequency of 7 Hz is fatal) Seasickness is also caused by infrasound: a wave with a frequency of 12 Hz causes severe dizziness in a person, as it causes his vestibular apparatus to resonate. High-intensity infrasound, which entails resonance, due to the coincidence of vibration frequencies of internal organs and infrasound, leads to disruption of the functioning of almost all internal organs, and death is possible due to cardiac arrest or rupture of blood vessels. (7 Hz infrasound is lethal)
Weapons, affecting the entire body, disable it. The United States has developed 4 types of infrasonic weapons (the picture shows a type of infrasonic weapon intended for a single fighter). It is planned that infrasonic weapons will come into military use and become an attribute of American police officers. Infrasonic weapons Infrasonic weapons are one of the types of weapons of mass destruction (WMD), based on the use of directed radiation of powerful infrasonic vibrations. This radiation can penetrate even concrete walls and metal barriers. This
Ultrasound is a mechanical wave similar to sound, but with a frequency ranging from 20 kHz to a billion Hz. (Waves having a frequency of more than a billion Hz are called hypersound). Scientists have known about the existence of ultrasound for a long time, but its practical use began only in the 20th century. At the moment, ultrasound is widely used in a variety of fields. UltrasoundUltrasound
Echolocation Echolocation (from the Greek echo - echo and from the Latin locatio - position, placement) is a method of determining the distance to an object by means of emission and perception of reflected ultrasonic signals. Echolocation helps some animals navigate in space, detect objects and hunt in conditions of absolute darkness: in the depths of the ocean, underground, in caves.
Bats are one of the animals that use echolocation to navigate in space. They extract ultrasonic waves with a frequency of 40 to 100 kHz. When these waves are emitted, the muscles in the bats' ears close their ears to prevent damage to the hearing system. The waves produced by the mouse are reflected from obstacles, insects, and other objects. The mouse picks up the reflected waves and estimates in which direction the obstacle or prey is located from it. Bats are one of the animals that use echolocation to navigate in space. They extract ultrasonic waves with a frequency of 40 to 100 kHz. When these waves are emitted, the muscles in the bats' ears close their ears to prevent damage to the hearing system. The waves produced by the mouse are reflected from obstacles, insects, and other objects. The mouse picks up the reflected waves and estimates in which direction the obstacle or prey is located from it. Ultrasound in nature. Echolocation.
Dolphins also use echolocation. They are capable of emitting and receiving ultrasonic waves with frequencies up to 300 kHz. Thanks to this, they can explore space, detect obstacles, search for food, communicate with each other and even express their emotional state.
The method of determining the distance to objects under water using ultrasonic signals is called sonar. An ultrasound emitter and receiver are placed at the bottom of the vessel. The emitter sends short ultrasonic signals to the bottom. The time of sending each signal is recorded by the device. Reflecting from the seabed, the signal reaches the receiver after some time. The moment the signal is received is also recorded. Thus, during the time that passes from the moment the signal is sent to the moment it is received, the signal travels a path equal to twice the depth of the sea. The method of determining the distance to objects under water using ultrasonic signals is called sonar. An ultrasound emitter and receiver are placed at the bottom of the vessel. The emitter sends short ultrasonic signals to the bottom. The time of sending each signal is recorded by the device. Reflecting from the seabed, the signal reaches the receiver after some time. The moment the signal is received is also recorded. Thus, during the time that passes from the moment the signal is sent to the moment it is received, the signal travels a path equal to twice the depth of the sea.
Hydrolocation is of great importance in navigation for detecting invisible underwater obstacles, in fishing for detecting schools and individual large fish, in oceanology for exploring the bottom, searching for sunken ships, and also for military purposes: for detecting submarines or ships, monitoring them, to determine the coordinates of an object when using torpedo or missile weapons. Hydrolocation is of great importance in navigation for detecting invisible underwater obstacles, in fishing for detecting schools and individual large fish, in oceanology for exploring the bottom, searching for sunken ships, and also for military purposes: for detecting submarines or ships, monitoring them, to determine the coordinates of an object when using torpedo or missile weapons.
Ultrasound is used to detect defects in cast parts. A stream of short ultrasonic signals is directed to the part being examined. In those places where there are no defects, the signals pass through the part without being registered by the receiver. If there is a crack, an air cavity or other inhomogeneity in the part, then the ultrasonic signal is reflected from it and, returning, enters the receiver. This method is called ultrasonic flaw detection.
Ultrasound in medicine Ultrasound is widely used in medicine: both for diagnostic purposes and as a therapeutic agent. It has an anti-inflammatory and absorbable effect, reduces the feeling of pain. Ultrasonic waves with a frequency of 0.5 to 15 MHz are capable of passing through body tissues, partially reflected from the boundaries of tissues of different composition and density. Thus, it is possible to recognize pathological changes in organs and tissues without surgical intervention. Ultrasound therapy is based on the fact that ultrasonic waves of certain frequencies have a mechanical, thermal, physicochemical effect on tissue, as a result of which metabolic processes and immune reactions are activated in the body. In laboratories and in production, ultrasonic baths are used to clean laboratory glassware and parts from small particles. In the jewelry industry, jewelry is also cleaned of small particles in ultrasonic baths. They are also used to clean root vegetables from soil particles. Some washing machines use ultrasound to wash clothes particularly thoroughly. Ultrasound is widely used to prepare homogeneous mixtures. If two immiscible liquids (for example, oil and water) are poured into one flask and irradiated with ultrasound, an emulsion is formed. Such emulsions are used to produce creams, hair dyes, cosmetics, pharmaceutical products, etc. There are many areas of application of ultrasound. In laboratories and in production, ultrasonic baths are used to clean laboratory glassware and parts from small particles. In the jewelry industry, jewelry is also cleaned of small particles in ultrasonic baths. They are also used to clean root vegetables from soil particles. Some washing machines use ultrasound to wash clothes particularly thoroughly. Ultrasound is widely used to prepare homogeneous mixtures. If two immiscible liquids (for example, oil and water) are poured into one flask and irradiated with ultrasound, an emulsion is formed. Such emulsions are used to produce creams, hair dyes, cosmetics, pharmaceutical products, etc. There are many areas of application of ultrasound.
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What is infrasound? Infrasound is sound waves, vibrations in air, liquid or solid media with a frequency less than 16 Hz, perceived by the human ear. These sound waves are completely silent; in principle, they obey the same laws as ordinary sound waves and have a similar mathematical model.
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Infrasound obeys the general laws characteristic of sound waves, but has a number of features: infrasound travels much further in the air, since its absorption in the atmosphere is negligible. Thanks to the long wavelength of infrasound, it easily penetrates rooms and bends around obstacles that block audible sounds. Infrasound causes large objects to vibrate due to resonance.
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Effect on humans Infrasound cannot be heard by humans, but is felt; it has a destructive effect on the human body. It causes nervous tension, malaise, dizziness, changes in the activity of internal organs, especially the nervous and cardiovascular systems.
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Propagation of infrasound “Voice of the Sea” is infrasound waves that arise above the sea surface during strong winds as a result of vortex formation behind wave crests. Infrasound is characterized by low absorption in various media, as a result of which infrasound waves in air, water and in the earth's crust can propagate over very long distances, which can cause natural disasters - tsunamis. The "voice of the sea" can serve to predict storms in advance.
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Storm Indicators Jellyfish are storm indicators. At the edge of the “bell” of the jellyfish there are primitive eyes and organs of balance - auditory cones the size of a pinhead. These are the “ears” of a jellyfish. They hear infrasounds with a frequency of 8 - 13 hertz. The storm is still unfolding hundreds of kilometers from the coast, it will arrive in these places in about 20 hours, and the jellyfish already hear it and go into the depths.
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Natural sources: Man-made sources: Infrasound sources The main man-made sources of infrasound include powerful equipment: machines, boiler rooms, transport, underwater and underground explosions. Occurs during earthquakes, storms and hurricanes, and tsunamis. Whales communicate with each other using fairly strong infrasounds (more than 60 dB).
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Sound sources and their range The development of industrial production and transport has led to a significant increase in sources of infrasound in the environment and an increase in the intensity of the infrasound level. For a person, noise of 20–30 dB is practically harmless, the acceptable limit is 80 dB, 130 dB causes pain, 150 dB is already unbearable.
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Killer infrasound In 1890, the sailing ship Marlborough, loaded with frozen lamb and wool, sailed from New Zealand to England. He did not arrive at his destination port. The sailboat was written off as lost. 23 years passed, and suddenly the Marlboro was discovered off the coast of Tierra del Fuego. The question arises: are infrasounds involved in these strange events? In fact, we already know that powerful infrasound with a frequency of 7 hertz is lethal. Meanwhile, infrasound waves that occur during stormy weather are close to this frequency in their frequency. It is quite reasonable to assume that the “voice of the sea” can have an oscillation frequency of 6 - 7 hertz. And so, when such a wave “covers” the ship, it kills everyone in seconds. However, a thorough investigation will not reveal any poisoning or contagious disease. The invisible killer “only” paralyzes the heart.
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Infrasound and animals In 1948 in Ashgabat (1), two hours before, the horses of the stud farm neighed loudly and broke free from their leashes. Many hours before the catastrophic earthquake in Yugoslavia, the animals of the zoo showed great concern. First, the hyena howled loudly, then tigers, elephants, and lions joined it. And in Japan, special fish are reliable predictors of earthquakes. Already a few hours before the first earthquake, they begin to rush about in the aquarium. The animal world perceives some signals, perhaps coming from the source of a future earthquake. Suspicion here also falls on infrasounds. We already know quite well what happens in the bowels of the earth before an earthquake. An unstable state of rocks is gradually created in the source, which ultimately leads to ruptures and sudden sudden displacement of large masses. Thus, residents of the northern outskirts of Tashkent, even before the 1966 earthquake, repeatedly heard an underground rumble. One might think that in an unstable state, constant small vibrations of rocks occur at the source of a future earthquake. And such vibrations give rise to infrasounds. Tashkent 1966 Ashkabad 1948
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Study of infrasound Work on the study of infrasound waves is being carried out all over the world nowadays; it has not yet been possible to tame sound waves completely, but progress is becoming more successful. The human intellect begins to conquer the obstinate waves. One would only like to hope that this discovery will not become a starting point for all living things and will only serve for the benefit of all humanity.
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Infrasound is sound waves having a frequency lower than that perceived by the human ear, and ultrasound is correspondingly higher, both of these phenomena are quite interesting and have always accompanied humanity in nature, and with the advancement of progress, people have learned to use them quite widely.
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Infrasound (from Latin infra - below) is sound waves with a frequency lower than that perceived by the human ear. The human ear is capable of hearing sounds in the frequency range 16-20,000 Hz; 16 Hz is usually taken as the upper limit of the infrasound frequency range.
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Features of infrasound
Since the absorption of infrasound by the atmosphere is insignificant, infrasound travels much further in the air. Due to its long wavelength, infrasound easily penetrates into rooms and goes around obstacles that block audible sounds; Infrasound causes vibration of large objects as it resonates with them. And as a result of all of the above, it is capable of spreading over vast distances in the air, in water and in the earth’s crust.
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Infrasound in water: “Voice of the sea.”
Infrasound in water Infrasound can be generated by the sea as a result of periodic compression and rarefaction of water. In this case, infrasound is called the “voice of the sea.” This phenomenon can warn of an approaching storm. Jellyfish, which are capable of perceiving infrasounds with a frequency of 8-13 Hz, are unique indicators of a storm. They hear the storm hundreds of kilometers away and 20 hours before it reaches this area, and go to the depths
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The sources of infrasonic waves in nature are not only storms, but also earthquakes, hurricanes, volcanic eruptions, and thunder. The main man-made sources of infrasound include powerful equipment, underwater and underground explosions, wind power plants and even ventilation shafts.
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Although medicine uses equipment that uses infrasound for treatment (Infrasound is mainly used in the treatment of cancer and eye diseases). Infrasound negatively affects people's health, especially mental health. The brain of a waking person vibrates with a frequency of 9-13 Hz. If our brain is affected by vibrations of the same or very similar frequencies, then a malfunction of the brain will occur, accompanied by hallucinations. People under the influence of infrasound experience unpleasant sensations: from depression to panic.
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Ultrasound
Ultrasound is a mechanical wave similar to sound, but with a frequency ranging from 20 kHz to a billion Hz. Its practical use began only in the 20th century. And unlike infrasound, ultrasound is widely used in a variety of fields.
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Properties of Ultrasound
The main and most used property of ultrasound is “elasticity”. Significant acoustic currents develop in the ultrasonic field. Therefore, the impact of ultrasound on the environment gives rise to specific effects: physical, chemical, biological.
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The method of determining the distance to objects under water or in the environment using ultrasonic signals is all using the “Elasticity” of ultrasound. Let’s say an ultrasound emitter and receiver are placed at the bottom of a vessel. The emitter sends short ultrasonic signals to the bottom. The time of sending each signal is recorded by the device. Reflecting from the seabed, the signal reaches the receiver after some time (this is called sonar). There are still a great many areas of application of ultrasound. It has firmly entered human life and is a wonderful example of humanity harnessing nature for the good.
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