"Can a human voice shatter glass?"

After getting off work, Officer Zhao kept thinking about this question in his head.

When he was in middle school, Officer Zhao was fond of physics, and he won the first place in the whole grade group almost every semester.

After seeing Weiyang shatter the glass with his voice that day, he developed a strong curiosity about the matter.

When everyone thought that Weiyang had a special ability, and this special ability was likely to be a god's blessing, Officer Zhao still firmly believed in science and did not believe in evil.

When he was in high school, Officer Zhao learned all kinds of things about waves in physics books.

He knew that the so-called waves, according to their nature, were nothing more than those four, namely, electromagnetic waves, gravitational waves, material waves, and mechanical waves.

The waves emitted by the sheep are undoubtedly sound waves, which belong to the category of mechanical waves.

The so-called sound waves, in fact, are the form of sound propagation. A sound wave is a type of wave produced by the vibration of an object, i.e. the source of the sound. The space in which sound waves travel is called the sound field. When propagating in gaseous and liquid media, it is a longitudinal wave, but when propagating in a solid medium, it is possible to mix with transverse waves.

The human ear can distinguish the frequency of sound waves, which are generally between 20 Hz and 20,000 Hz. That is, the air vibrates between 20 and 20,000 times per second for the human ear to hear. The number of vibrations per second is less than 20 times is called infrasound, and more than 20,000 times per second is called ultrasound.

Thinking of this, Officer Zhao boldly concluded that the sound waves emitted by Weiyang were infrasound.

Because the natural frequency of most organs of the human body (including the ear) is similar to it, in this way, once the vibration frequency of the external infrasound wave is the same as the vibration frequency of the human organ, or when it is close, it will cause the resonance of the ear and other organs, and in severe cases, the human ear will be deaf or the organ will be damaged.

......

That night, the night sky was slightly cool, and the town was already sparsely populated. Officer Zhao thought a lot in his brain, and the more he thought about it, the more he felt that the 'Weiyang phenomenon' was very scientific and reasonable.

It wasn't until he thought of the concept of decibel that he subconsciously quickened his pace. Soon, Officer Zhao returned home, and without even bothering to eat, he ran to rummage through the old book box.

Officer Zhao is a nostalgic person, from junior high school to high school, and even to college, he did not throw away almost all the textbooks, or, like some students, he was busy selling them to the scrap yard as soon as he graduated, but collected them one by one. Now, his house has five or six boxes of those old books in stock.

Finally, with a lot of effort, Officer Zhao dug out a high school physics book from a box.

As for the knowledge of decibels, he was only scratching the surface at that time, but he still knew the general meaning.

From the last page of the book, Officer Zhao finally found an interpretation of the decibel knowledge.

"A decibel is a unit of measurement that measures the ratio of two quantities of the same unit, and is mainly used to measure the intensity of sound, and is often expressed in dB." 'Cent' refers to one-tenth of the decibels, and the single digit is 'Shell', and generally only decibels are used. The decibel was named after the American inventor Alexander Graham Bell.

The sound is below 40 decibels, which has no effect on the human body; When the sound is between 40 and 60 decibels, if the human body is in this environment for a long time, then the nervous system will be affected. At this time, the noise energy doubles by every 3 decibels of noise.

When the sound reaches 65 to 80 decibels, the cardiovascular damage of a person is more than 20% higher than that of a person living in an environment with noise at 50 decibels.

When the noise exceeds 80 decibels, it will cause great damage to people's hearing.

When the noise exceeds 100 decibels, it produces unbearable noise.

When the sound reaches more than 120 decibels, it is equivalent to a Boeing plane flying past you, and the health of the human body will be greatly harmed in a short time.

When the sound reaches 180 decibels, the human ear is immediately deaf. ”

......

When Officer Zhao saw this, he was so excited that he couldn't calm down, and he couldn't wait to prove this natural phenomenon to anyone immediately.

Closing the book, closing his eyes and pondering for a moment, Huo Di took out his phone from his trouser pocket.

At this time, Officer Liu was already lying in bed, and he decided to read the Sherlock Holmes detective novel for a while, and then naturally fell asleep.

"Jingle Bell ......"

Officer Xiao Liu had just opened the book, and before he could see a page, the phone rang.

"Uh, Zhao Ju called, it's so late, what's the matter! No, it can't be another emergency, right? Officer Liu thought of an emergency call.

In fact, there have been several nights so far without a restful night's sleep. Either I was woken up from my dream, or I didn't finish taking a shower, and I only ate two bites of food, and I pressed the pause button, and the next second, I ran to the police station as if I was flying.

"Hey, Zhao, Bureau Zhao," Officer Liu said reluctantly, "It's so late, what's the matter?" ”

"I think it's a natural phenomenon." Officer Zhao said in conclusion.

"Uh," Officer Liu looked confused, "you mean?" ”

"That's right, it's the 'Weiyang phenomenon', the deaf and dumb child who shattered the glass with his voice."

"What's the matter, it's been a few days!"

"I recently made a new discovery," Officer Zhao began to explain, "and I think Weiyang used sound waves to shatter glass. ”

"Yes! I also know it's shattered with sound waves. ”

"Well, that's right, you listen to me first."

"Okay, you say."

"He uses infrasound."

"What? Infrasound? I don't understand what you mean. ”

That is to say, sound waves with a frequency of less than 20 hertz will produce infrasound waves in nature, such as storms at sea, volcanic eruptions, large meteorite landings, tsunamis, lightning and thunder, etc. And in real life, the sailing of ships, the horns of cars, blowers, mixers, amplifiers, etc., can also produce infrasound, and of course, tigers can also produce infrasound, such as tiger roars. ”

"And then?"

"When the sheep makes a sharp and piercing sound, it is like a tiger roaring, and then, the NMR of this sound is generally below 20 Hz, and the shock wave generated by it will form an invisible force, which can be defined in physics as kinetic energy, that is, momentum, and then, hit the eardrum, as if an invisible force hit the eardrum."

"Uh......"

"Well, I'm going to explain to you, that is, the eardrum has its natural frequency, and this sound wave, that is, the sound wave emitted by the sheep, is basically the same frequency as the natural frequency of the eardrum, so it will resonate, which can cause damage to the eardrum...... I explain it this way, can you understand? ”

"Well, I understand, but I still don't understand what you're trying to say?"

"I mean, this sound made by the sheep is reasonable, normal, and there is no need to make a fuss."

"Well, then why can't you make that sound? Moreover, I have never heard anyone in Weijia Village make the same sound, so it is because everyone can't do it that I am curious! Besides, I don't think it's normal. ”

Officer Zhao calmed down for a moment, and then, word by word, said, "Actually, I'm just proving that there is such a natural phenomenon in this world, not what they say about the arrival of gods, ghost possession, etc., this is not superstitious." ”

"Well, I think it's reasonable for you to explain it like this, but everyone is still very confused about this matter!"

Officer Zhao fell into deep thought again, because he suddenly felt that this was not very reasonable, that is, he himself felt that he had not explained clearly, for example, why did Weiyang make such a sound?

This is the root of the problem.

Officer Zhao pondered for a while, and then said strangely, "There is something strange about this matter!" ”

"Huh?"