The harm of infrasound?

Infrasound waves are sound waves with frequencies below 20 Hz. Generally speaking, the sound waves that the human ear can accept are between 20 and 20000Hz, and the sound wave frequency is higher than 20000 Hz, which is called ultrasound; Below 20 Hz is about infrasound. Infrasound waves are invisible, inaudible and intangible like ultrasonic waves, but they travel far because of their low frequency and long wavelength. Another important feature of infrasound is its strong penetrating ability, which can penetrate not only air, sea water and soil, but also aircraft fuselage, hull, tank and solid reinforced concrete structure. For example, infrasound with a frequency of 3.44 Hz and a wavelength of 100 m can penetrate the solid walls of buildings, and it is certainly not a problem for the human body.

It is reported that there are quite a few incidents of infrasound causing death. 1980, a sailboat named "Marpolo" suddenly disappeared mysteriously on the way from New Zealand to England. Twenty years later, it was found near Tierra del Fuego. Everything on the ship is intact. Even the crew members who have been dead for many years are in their posts and continue to work. Scientists paid great attention to their mysterious deaths. After long-term research, they finally found that they died of infrasound caused by a storm at sea.

1992165438+1On October 24th, there was an air crash over Guilin, and 14 1 people were killed, making it the worst air crash in China's civil aviation history. After many explanations failed to confirm the cause of the incident, experts from China Institute of Acoustics pointed out the possibility that the plane crashed due to infrasound. Guilin is a semi-hilly area, and the air mass floats up and down with the trend of the mountain, causing airflow vibration and generating a infrasound wave. When the aircraft encounters this clear-sky turbulence caused by infrasound, it will fall into the wind vortex, and under the action of various powerful external forces such as squeezing force and impulse, the aircraft will lose control and die. The recent research results show that infrasound has a "biological effect" on aircraft. According to this theory, when the frequency of infrasound is close to the human body frequency, "* * * vibration" may occur, and the pilot can't bear this strong effect, which is fatal. In other words, the murderer of this air crash is probably this kind of infrasound.

Then, why does infrasound cause serious casualties without bleeding? Scientific research shows that all internal organs of human body have their own natural vibration frequency, which is also between 0.0 1-20 Hz, which is similar to the frequency of infrasound. In this way, when the external infrasound, whether naturally formed or artificially made, once its vibration frequency is the same as or close to the internal organs of the human body, it will cause the vibration of various organs, making people fidgety, tinnitus, headache, insomnia, nausea, blurred vision, dysphagia and liver and stomach dysfunction; In severe cases, it can also make people feel numb in limbs and oppressive in the chest. Especially when it is consistent with the natural vibration frequency of abdominal cavity, thoracic cavity and cranial cavity, it will vibrate with internal organs and brain, and even endanger life.

These magical functions of infrasound, such as silent propagation, difficult attenuation of wavelength, easy mixing with infrasound in nature and difficult to be detected by people, have long attracted the attention of military experts. Some countries are developing infrasound weapons by using the characteristics of infrasound. The direction of using infrasound is infrasound generator and infrasound bomb.