The making process of drinking birds

Teacher Yu said that many people advocate the promotion of China's traditional culture, and China's ancient toys are an excellent representative. There are many ancient toys with rich scientific knowledge in our country. Compared with video games, they are equally interesting, and they don't keep children indoors all day, which is good for health and character formation. Let children know some scientific knowledge while playing with these toys.

Since June 2005, I have been searching for clues tirelessly. According to the plan, the China Ancient Toys Exhibition will be held in August of the same year. As a member of the organizing committee, Yu has been busy collecting exhibits for this exhibition. By the beginning of July, most of the planned exhibits were ready, but I was still worried because a very important exhibit had not yet been made. What am I looking for? It turned out that he was looking for a toy called "water bird". The waterbird is a mysterious toy bird. It is said that as long as you put a little water in front of it, it will swing tirelessly. But for half a century, it has disappeared into the vast sea of people. No one has seen the true face of this toy bird, no matter Yu, his colleagues or others. My first impression of quenching thirst by drinking poison came from a Soviet physics book, Interesting Physics. The author of the book, Berandiman, a popular science writer in the Soviet Union at that time, recorded such a bird in the book: as long as there is water to drink, it can keep moving. So since the 1970s, we have embarked on the road to find this amazing bird. In the process of searching, he found that most of the records and descriptions about drinking poison to quench thirst came from foreign researchers, and they all explicitly called it "China drinking poison to quench thirst". What does this toy bird look like? Did it really originate in China, and was it the crystallization of the wisdom of the ancient people in China? If so, why is there no relevant historical record in China?

In the past 30 years, I have searched through a large number of ancient books, but I have never been able to find the exact birth date of drinking poison to quench my thirst. In the long chase, he heard another amazing thing. In the book Science and Toys written by a professor at Tokyo University, drinking birds is associated with Einstein. It is pointed out in the book that when someone gave Einstein a drinking bird, the wise master couldn't put it down and was surprised: "The perpetual motion machine appeared!" " Later, I also collected such drinking birds.

This bird, which is neither exquisite handicraft nor high-tech product, has attracted the attention of a modern physicist. This magical toy tossed and turned in Einstein's hands, so it got a famous nickname; A toy that also surprised Einstein. From then on, waterfowl became famous, and some people called it "perpetual motion machine from China".

As we all know, the principle of conservation of energy has been repeatedly verified by modern physics and has become a recognized principle. But the water bird sounds as if it is challenging this theory: it can keep moving without the help of external forces such as machinery or modern energy such as electricity and magnetism, as long as ordinary water is put in front of it. ...

What exactly do waterfowl do? Has the production process of quenching thirst by drinking poison been handed down? Can anyone else make this kind of toy in modern times? I have been troubled by such problems. Seeing the day of development approaching day by day, the search for this ancient toy has made no progress. I am really worried. Although his colleagues constantly advised him not to bother about this toy, he was still unwilling to give up. In desperation, I thought of a way to expand the search scope with the help of the internet, newspapers and other media.

Sure enough, the news of seeking to quench thirst with poison quickly got feedback, and a large number of letters and telephone calls poured in. The news of a netizen made Yu overjoyed. This netizen once saw a waterbird in the laboratory when he was studying at North China Electric Power University. So, the next day, I arrived at North China Electric Power University in Baoding, Hebei. In the physics laboratory of this university, he finally saw the bird in his dream.

The bird in front of you is very similar in shape and action to that described in historical materials. But is its internal structure consistent with that of ancient mockingbirds? Because North China Electric Power University has only one collection, teachers have been reluctant to open it, and its internal structure is naturally unknown. But I understand that only by knowing what is in the bird's stomach can we know the secret of the bird's constant swinging.

Although I am still puzzled, I am lucky to find such a toy bird. Since the school doesn't want the drinking birds to be taken away, it's ok to take a picture and bring it back to Beijing. But when Yu left North China Electric Power University and returned home, he received a phone call that made him both excited and surprised. An old teacher of North China Electric Power University provided such a clue: the drinking bird was bought by the school from an old craftsman named Sun Gui in Shenyang. Then, Sun Gui from Shenyang called and said that he made the water birds.

This is really another village! But is Sun Gui really a producer who drinks poison to quench thirst? What does he have to do with drinking poison to quench thirst that spread all over the world? Find him, and the secret of quenching thirst will be revealed to the world? The phone call from Shenyang left me with a grain of salt, but the day of the exhibition is imminent. In order not to give up any hope, he left for Shenyang early the next morning.

As soon as I entered Sun Gui's home, I seemed to have entered a world of toy birds. Inside and out, up and down, filled with colorful toy birds. Are they the legendary drinking poison to quench thirst? Is Sun Gui the producer of Bird Drinking Collection?

Sun Gui pointed to these toy birds and told Yu that these birds, like those he saw in North China Electric Power University, were all drinking birds he had made intermittently over the years. A wide variety of eating birds with different styles, a large number of written materials and Sun Gui's description of the production time all convince Sun Gui that he is the producer of these eating birds. But where did Sun Gui's craft come from?

Sun Gui told Yu that this craft came from his childhood memories of his father's craft. At that time, Sun Gui's house smelled of ether everywhere. With these memories, Sun Gui fumbled to make waterfowl while recalling them. Drinking water birds are by no means perpetual motion machines. In fact, they skillfully applied the principles of thermodynamics in physics. Because ether is volatile, the temperature difference between the two ends can change the distribution of ether vapor in the glass tube, thus changing the center of gravity of waterfowl. Waterbirds keep drinking water, at the same time, their heads will be wet with water, and the evaporation of water in their heads will absorb the heat of the surrounding air, which will lead to the temperature difference again, prompting waterfowl to keep moving.

In the subsequent experiments, Sun Gui also found that no matter adding ether or wine, or even ordinary water, water-drinking birds can keep moving. It's just that ether is more volatile and waterfowl exercise more frequently. It is easy to judge that the ancients probably made it with water or wine without ether.

Two glass tubes, a little ether and some ordinary cotton can make a tireless bird. It sounds simple, but it is not easy to keep it moving. In order to retrieve the bird from memory, Sun Gui made great efforts and overcame many difficulties. For example, the balance of drinking birds is difficult to grasp, and the amount of ether added is difficult to determine. The attempt at that time was very unsuccessful. Some of these birds' initial movements last for a short time, while others are completely immobile. In order to solve these problems, Sun Gui had to experiment repeatedly and ask some physics teachers for help to find the law and create balance.

After more than 20 years of hard work, Sun Gui finally mastered some production skills. To make the bird move, we must first master the amount of ether in the bird. Too much will make the body too heavy, too little will not drive the body to swing. The second is to find the balance point of the bird's body, and the best fulcrum can ensure the bird to move freely.

Because the change of humidity and temperature in the air will affect the evaporation rate of water in the head of drinking birds, this bird has also become a weatherman.

According to Sun Gui's memories and historical data collected in advance, it is inferred that drinking poison to quench thirst was born at least in the middle of Qing Dynasty. Knowing the specific structure of the bird's body and what is inside, all the mysteries seem to be gradually clear. The 1st19th popular science week opened, and the ancient China toy "Drink poison to quench thirst" appeared in Daxing Palace Square, which surprised many people who visited the site.

The reporter saw at the scene that the "water bird" was about 10 cm high. The bird body is made of glass, and the outside is painted green, so you can't see the inside. The head is wrapped in thin cotton cloth, with several yellow feathers on it and a small basin in front.

Experts wet the beak with their hands, and the bird immediately began to pitch continuously, and the amplitude became larger and larger. Then dive into the basin and drink water. After a while, I look up and lean back and forth, just like a perpetual motion machine. I thought there was a battery in the bird, but the audience didn't find it after careful inspection. "Is there really a perpetual motion machine in a bird?" Otherwise, how can it keep drinking water? "But perpetual motion machine is impossible in scientific theory, so what's going on?

Seeing that everyone was puzzled, the experts uncovered the mystery at the scene. The "water bird" is filled with volatile liquid ether. In the case of immobility, the lower part of the tail is liquid ether and the upper part is gas. When someone touches the cotton cloth layer on the bird's head with cold water, the bird's head is cold, absorbing the heat of the surrounding air, the air pressure drops, and the liquid at the tail rises along the neck due to suction. In this way, the weight of the bird's head is increasing, the weight of its tail is decreasing, and the position of its center of gravity is changing, so the pitching phenomenon appears. When the center of gravity exceeds the fulcrum of the tripod and moves to the head, the bird will bow its head. When the mouth touches the water, the water will rise to the head along the mouth, and the bird's head will get wet again. At this time, a part of ether liquid remains in the middle glass tube, separated from the liquid below, but its position is still inclined, and the liquid will flow down again, and the bird's body will stand upright. At this time, the bird's head has become wet, so the above scene will appear again, and so on, until the water in the basin is dried up by the bird, and the head can no longer be wet, so he will no longer bow his head to drink water.

It turns out that the heat of the surrounding air absorbed by the "water-drinking bird" head is the driving force for this wonderful "water-drinking bird" to move. It is precisely because it uses energy that people around it are unaware of, so it will be mistaken for a "perpetual motion machine." No wonder even Einstein was fooled by it at a glance.