<h1 class="pgc-h-arrow-right" data-track="1" > mysterious sound</h1>
In 1996, Professor Magnus Wahlberg of the University of Southern Denmark was taken into a very secret room at the Bergen Naval Base in Stockholm, where the military played a mysterious voice to him. The sound was detected by a submarine, containing a propeller-like noise, and the military suspected that soviet submarines had been working in secret, but the Soviet Union had been disbanded for many years, and Russia had no reason to provoke them in this way.
In fact, the signal was first received back in 1981, when a Soviet submarine ran aground off the coast of Sweden, only 10 kilometers from the Swedish naval base, after which sweden began to monitor the surrounding waters closely, and during this time they received this mysterious and mysterious sound.
In 1982, Sweden launched several submarines, ships and even helicopters to explore the place where the sound originated for a whole month in order to find the source of the mysterious sound, but found nothing. For more than 10 years after that, Sweden often received this mysterious voice, and this voice almost drove them crazy, after all, when you face a threat and don't know where the threat is coming from, and who is threatening you, you can also go crazy.
It is said that the Swedish prime minister also wrote a letter questioning The Russian prime minister at the time, Boris Yeltsin, which led to a period of tension between the two countries.
To find out where the voice came from, the Swedish military took Professor Magnus Wahlberg into a secret room and told him: "You are the first ordinary citizen to hear about him, and I hope you will keep it a secret."
After that, the Swedish military began playing the mysterious voice. Originally, Professor Magnus Wahlberg thought that the sound would be very shocking, but after listening to the voice, he said: Just this?
Professor Magnus Wahlberg said that I could reproduce the sound, and then the next time he came to the naval base, he showed the military the sound of a "Soviet submarine", and just when the military was highly nervous, Professor Magnus Wahlberg said: "This is the sound of atlantic herring farting."
<h1 class="pgc-h-arrow-right" data-track="9" > Atlantic herring fart? </h1>
We may not be familiar with Atlantic herring, but it is the raw material for the famous "canned herring".
We know that the reason why humans fart is because the human gut microbiome will release some gases in the process of decomposing food, such as: carbon dioxide, which causes the air pressure in the intestine to be higher than the air pressure outside the human body.
The farting principle of herring is different from that of humans, their farts do not come out of the digestive tract, but from the swim bladder. Their body has a very unique structure inside, after they swallow the air from the surface of the water, they will store a part of the gas in the swim bladder, the end of the swim bladder is connected to the anus, when they encounter danger, they will squeeze the gas in the fish out of the anus to form a "fart", but the Atlantic herring fart is fast and fierce.
<h1 class="pgc-h-arrow-right" data-track="13" > herring communicate with farts</h1>
Atlantic herring has a characteristic, that is, they like to live in groups, scientists once measured one of the herring populations found that the Atlantic herring school size of up to 4 cubic kilometers, about 4 billion fish.
While surviving in so many individuals, Atlantic herring evolved a form of communication called "fart language." Scientists have found that unlike the "poof" sound of human farting, herring farts are similar to high-frequency farts of "poof, poof", and the technical term is "a continuous pulse train".
The low frequency of herring farts can reach 1.7kHz, the high frequency is 22kHz, and the human hearing range is 20 to 2000Hz, which means that most of the frequencies of herring farts exceed the human frontal hearing range, so it is difficult for people to hear.
However, the study found that herring has a hearing range above 1kHz, which means that they can hear themselves farting, so scientists believe that they may communicate through farts.
This claim is not unfounded, in fact at night, or in the deep sea, the ocean lacks light, and herring needs to be in constant contact in order to find a companion. In addition, the rapid repetition of the signal emitted by herring is very frequent, beyond the hearing range of most meat-eating fish, so they communicate in this way without fear of predators hearing. But mammals living in the ocean can hear this frequency, so they are easily chased by animals such as whales and seals.
<h1 class="pgc-h-arrow-right" data-track="19" > summary</h1>
Herring farts, but that's not what makes canned herring stink. The reason why canned herring is so smelly is that an anaerobic bacteria release a lot of irritating and unpleasant gases when decomposing canned herring, which makes people smell very uncomfortable.