【Military Martial Subplane】Author: Military Mushroom
If so, congratulations, you may have found a low-end version of a directed energy weapon.
What's going on here?
When it comes to square dancing, many people's first reaction is that the noise disturbs the people, and the more they take a break, the more the music begins to drill into their ears indiscriminately, and the more they listen, the more irritating they become.
But after all, this square dance is an entertainment activity for the common people, and some people engage in some extreme measures to confront the uncles and aunts who dance the square dance, which often intensifies the contradictions, and even ends up with more than worth the loss.
We know that sound travels through the air, and generally speaking, when the sound source vibrates, the sound waves will spread along the air, which is why a square dance in one place is noisy for the neighbors around it.
If you want not to disturb the people with square dances,The best way is to let the sound only spread to the people who need to hear,It has also been reported before that the uncle and aunt wear headphones to dance the square dance to avoid disturbing the people,But people dancing the square dance picture is debauchery and love freedom,Wearing headphones is not enough to let go of yourself,Then at this time,Directional square dance speakers come in handy。
At present, there are three main technical means that can realize the directional transmission of sound.
The first is the condenser technology, which adds a hemispherical cover to the tweeter to block the free spread of sound waves. The sound can be heard clearly under the sound enclosure and almost inaudible outside the sound condensement, and the appearance of this device is similar to that of a desk lamp.
The second is speaker array technology, that is, a large number of speakers are first formed into an array, by extracting the sound signal of each speaker, and combining the sound signals in a certain way, and finally processing these signals to enhance the sound signal of a specific position or a specific direction. This technology is often used in sonar, radar, and other equipment.
The third is an ultrasonic-based directional audio propagation technology, which is a new type of audio technology that allows sound to propagate in a certain direction in the form of a beam.
The basic principle is to modulate the sound to the ultrasonic wave through intelligent means, and the sound wave is emitted into the air through the ultrasonic transducer, because the ultrasonic waves of different frequencies propagate in the air, interaction and nonlinear self-demodulation will occur, and then a new sound wave with a frequency of the difference between the original ultrasonic frequency (differential frequency) will be generated.
If the ultrasound is selected correctly, the newly generated differential frequency sound wave can fall on the audible sound area, and with the help of the high directivity of the ultrasound itself, the new sound wave can be successfully delivered to the designated object.
This allows the music to be heard clearly in the directional area, while in the non-directional area, the sound will fade rapidly, so as to achieve the effect of not disturbing the people, this technology is simple and reliable, and the effect is also the best.
So how is this a directed energy weapon? It has to start a long time ago.
In 1929, the Leerick Theatre in London, England, wanted to stage a historical drama that "traveled" back 150 years, and in order to arouse the audience's emotions and make them immersive, the director turned to the experimental physicist Robert Wood for help.
Wood used the organ to create a long, deep sound, and as soon as the organ began to play, the glass on the theater's chantel began to click, the doors and windows shook, and the audience felt uncomfortable and panicked, and the performance had to be stopped.
The reason for this effect is that Wood used organ pipes to create infrasound, and we know that there are countless "inaudible sounds" in nature, such as wind blowing trees, waves hitting the shore, lightning and thunder, etc., which can produce sound wave oscillations with a frequency of less than 20 Hz, and these sound waves are infrasound.
Because the wavelength of infrasound waves is very long, so when the infrasound waves encounter obstacles, diffraction phenomena will occur, and its influence range will be particularly wide, infrasound waves below 10 hertz can travel to a distance of thousands of kilometers, such as in 1983, Indonesia's Karacato volcano erupted, strong sound waves circled the earth three times, lasted for 108 hours before slowly disappearing.
And the infrasound wave is not easy to attenuate, nor is it easy to be absorbed by water and air, because the frequency of the infrasound wave and the human nervous system and various organs are fixed vibration frequency is similar, so when it resonates with the human body, the human body will have dysfunction, displacement and deformation or tremor rupture, so that people have difficulty breathing, blurred vision, nervous confusion, loss of consciousness, shock fainting and even fall to the ground and die.
As early as World War II, Nazi Germany secretly developed infrasonic weapons, trying to use them to produce a resonant reaction to destroy entire cities, but in the end it was unsuccessful.
However, in 1940, the German army recorded some special records, added infrasound to them, and got the signatures of famous musicians on them, hoping to release these records to Britain to cause panic, terror and other mental disorders in the listeners, so as to cause riots, but later found that the effect was not good.
In the 50s of the last century, he led a team responsible for the development of robots that can fight nuclear wars, and found in an experiment that when the frequency of sound waves emitted by the laboratory motor is less than 20 Hz, the sound waves will resonate with human organs, causing discomfort to the human body.
For example, the resonance frequency of the heart is about 6 Hz, the eyes 40 to 100 Hz, the head 20 to 30 Hz, the arms 2 to 5 Hz, the stomach 2-3 Hz, the intestines 2-4 Hz, and the vestibular organs 0.5-13 Hz.
So he began to focus on the secret development of sonic weapons from the mid-60s of the 20th century, and finally succeeded in developing the first infrasonic generator in 1972, which was classified as top secret by the French military at that time.
It was not until April 1986 that due to technical negligence, infrasound rushed out of the laboratory outside Marseille, France, causing 20 people in the room 16 kilometers away and 10 people working in the field to lose consciousness at the same time and die of cerebral blood vessel rupture.
In addition to infrasonic weapons, people have also developed strong sonic weapons, ultrasonic weapons, noise wave weapons, and cluster sonic pulse weapons according to the frequency range corresponding to sound waves.
Among them, strong sonic weapons are mainly used for short-term deterrence, which can make people palpitate or lose mobility, but they are unlikely to cause long-term harm to the human body. Ultrasonic weapons use the powerful sound pressure or acoustic thermal effects generated by high-energy ultrasonic waves to impact or damage people. Noise weapons mainly use high decibel noise to stimulate and affect people's physical and mental state, making people irritable, and even dizzy, tinnitus, and flustered. Cluster acoustic pulses can use fluid compression technology to give sound waves high energy characteristics, and the power is even more amazing.
In 1995, the United States secretly carried out infrasonic attacks on Serbian positions in Bosnia and Herzegovina, reportedly causing Serbian soldiers to faint, vomit and fall into confusion within seconds. In 1998, the United States developed a hand-held sonic pistol with an action range of up to 200 meters.
▲ Sonic pistol
In 2000, after the U.S. destroyer "Cole" was bombed by a suicide boat, the U.S. military selected the Long Range Accoustic Device (LRAD) as one of the systems for the ship's near-zone defense.
This kind of equipment can focus 150 decibels of noise and project it at an angle of 15 or 30 degrees to the target area tens or even hundreds of meters away, which is equivalent to putting a person under the turbofan engine of a jet airliner, making the enemy 100 meters away miserable and incapacitated, and making the forced personnel incapacitated immediately.
The sound propagation distance of the traditional tweeter is about 50 meters, while the propagation distance of LRAD is hundreds of meters, and the high-power LRAD can reach 3-9 kilometers.
Britain has developed an ultrasonic weapon as an underwater frogman protection system, which can form a strong sound pressure shock wave in the water to detect and prevent underwater intrusive frogmen from approaching.
With the popularization of the concept of directional sound wave and the continuous expansion of the application field, directional sound wave is increasingly used as an acoustic deterrent means.
On December 9, the China Coast Guard released an official announcement that the Chinese Coast Guard had implemented control measures in accordance with the law against three Philippine Fisheries and Aquatic Resources Bureau official vessels that had intruded into the waters adjacent to Scarborough Shoal in the Nansha Islands.
In fact, the non-lethal law enforcement equipment we use on Philippine ships is not only water cannons but also long-range directional sound wave dispersion devices, which can amplify the noise to 160 decibels, far exceeding the hearing tolerance limit of 100 decibels for the human ear, and can be "bombed" with sound waves at a distance of 3 kilometers.
In fact, this is not a new piece of equipment, according to the "People's Liberation Army Daily" report, as early as 2010, the escort ships of the fifth batch of escort formations of the Chinese Navy have used directional sonic weapons.
The structural principle of directional sonic weapons is not too complicated, and it is generally composed of signal processing circuits, power amplifiers, transducers, and control circuits. The signal processing circuit is responsible for modulating the input audio information, the power amplifier is responsible for amplifying the modulated electrical signal, the transducer is responsible for turning the amplified electrical signal into a sound wave signal and sending it out, and the control circuit is responsible for controlling the whole system.
Although the specific design is much more complicated, it is not something with high technical barriers, after all, even the phased array radar can be dried into cabbage over the years, and installed on the roof of the temple, this directional sonic device is naturally no problem.
In recent years, as some domestic enterprises have carried out the research and development and production of directional sonic dispersal equipment, the sonic dispersal equipment market has gradually taken shape, and has been widely used in the field of military and police anti-terrorism, warning, dispersal, strike, airport bird repellent, maritime surveillance law enforcement, etc., like in recent years, there are many manufacturers in each military and police equipment expo to launch related equipment.
In addition to the military and police field, directional sound wave removal equipment is also used in bridge collision prevention, emergency rescue, traffic diversion and other fields, and some hydropower station reservoirs are even equipped with directional sound wave strong sound removal equipment to drive away illegal fishing.
In order to expand sales, some manufacturers also combine directional acoustic wave dispersion equipment with infrared, thermal imaging, monitoring, radar and other perception systems to form a control platform integrating monitoring, early warning and dispersal of strikes.
It may be because this track is too volatile, after all, there are so many domestic military police and law enforcement units, and some manufacturers have found another way to make this directional sound wave dispersion equipment into sound wave directional broadcasting equipment.
To put it bluntly, they are all the same kind of things, all of which use parametric array technology, that is, based on the interference and phase control of sound waves in the propagation process to achieve directional and focused propagation of sound, and there is no technical threshold between them.
This thing can not only be used as a square dance directional sound, effectively solving the problem of square dance noise disturbance, but also can be used as a museum ultrasonic directional speaker, school playground directional broadcasting system, high-speed directional speaker, digital signage sound directional communicator, etc.
Therefore, as long as the pattern is opened, there will always be unexpected results, and technology diffusion is like this, didn't the U.S. military never imagined that the equipment used to prevent suicide boats would be used as an entertainment facility by Chinese aunts?
Isn't this a symbol of national strength?