When the ping-pong ball is hit at supersonic speed …

In animation, Japanese students usually have the power of conan the destroyer, and playing ball always feels like a high-tech war.
In reality, can humans play ball games so ferociously?
(All the articles are professional, please don’t imitate them at home.)
Although it is impossible to rely on manpower, we can use the power of air and machines, such as the "vacuum table tennis cannon."
A cannon is actually more like a pipe. When a cannon is fired, the speed of the accelerated table tennis can reach 450km/h, which is about one third of the speed of sound.
At this time, the table tennis directly crashed into the coke with air pressure, and this can was like a punch in the abdomen:
What if the speed of table tennis is increased to supersonic speed? Will it be more powerful? In fact, mythbusters, a well-known popular science team, made a similar attempt many years ago.
According to their test, the average adult can hit the ball at a speed of about 112.6 kilometers per hour after swinging.The speed of sound is 1224 kilometers per hour, which is an insurmountable gap.
Unless, of course, the table tennis player is a machine.
After several attempts, they successfully increased the speed of table tennis to 730 kilometers per hour by pressure jet, which directly penetrated the 2.5 cm cardboard, but this speed is still far from the speed of sound.
At this time, the "vacuum ping-pong cannon" appeared.
To put it simply, this device is to put a ping-pong ball at one end of a pipe and then seal both ends of the pipe:
Then, the air in the pipeline is drained to make it enter a vacuum state, and then the seal at one end is punctured, and the air will rush in wildly and then fill the vacuum space.
At this time, the table tennis in the middle will be pushed by the air and move to the other side at high speed, and there is no air obstacle on the road.
The power of this kind of vacuum cannon has been improved remarkably. With only a 1.8-meter-long pipe, the ejection speed of table tennis has reached 600 kilometers per hour.
And if we add a pressure chamber to the vacuum cannon and increase the length of the barrel, the speed will be upgraded again.
(Image from Purdue University of Technology)
But it is not as long as possible. Once the barrel was lengthened to 47 meters:
The acceleration effect is different. After firing, the human eye can’t see the ball moving at all, and the ball disappears directly:
However, when the table tennis flies out of the barrel, it has been squeezed out of the ball by resistance.
In the end, the barrel was reserved for 6 meters, which not only ensured the integrity of the ball, but also reached the speed of 1770 kilometers per hour, which properly exceeded the speed of sound.
So, "What destructive power will the vacuum table tennis cannon have now?The researchers set the shooting target-a thick pig elbow.
Fill in table tennis, adjust the pressure, pump out the air and fire!
Table tennis hit the surface of the pork completely, and the elbow suffered great damage. A round wound immediately appeared on the epidermis:
But the injury doesn’t stop there. Under this wound, there is a wound with a depth of nearly 4 cm:
However, this wave of injuries is difficult to subdivide how much table tennis can account for. After all, it broke at the moment it touched pork, and the subsequent injuries were more like air cannons.
But overall, it smells like animation.
There are still many people who use "table tennis vacuum cannons" to sabotage. They have chosen all kinds of strange targets for testing.
Mark French, a professor at Purdue Institute of Technology, and his students, combined a supersonic table tennis cannon with a pressure chamber and a vacuum gun, which is said to be faster than an F-16 fighter.
(All the articles are professional, please don’t imitate them at home.)
In the face of this kind of attack, the table tennis bat can do nothing at all and is directly penetrated:
When you hit a tape, it’s like hitting tofu:
Not only did the tape break a hole, but the carton at the back also broke a hole:
Carton:
The most cruel thing is to play a row of cans and disappear in an instant:
Look at the injury of cans, it should be destroyed by the group:
With such destructive power, it is no wonder that the professor emphasized on the whiteboard that he is a professional team and advised others not to try it at home.
Bruce Yeany, a physics teacher, also tried to play cans. From the effect point of view, he used more power:
But when he bombarded the watermelon, he encountered a problem, that is, the quality of table tennis was too small after all, and it broke directly in front of the watermelon:
Is this the only survivor in the table tennis test?
However, watermelon didn’t laugh for long. The teacher unhurriedly increased the weight of table tennis, not much, just filled it with water:
Now, watermelon immediately becomes watermelon juice:
Watermelon: Can’t you afford to play?
However, the most extravagant way to play table tennis vacuum cannon comes from anchors Dianna Cowern and Brandon.They aimed a cannon at an iPhone 11 Pro worth more than 6700 yuan:
How can I put it? The moment when table tennis hits the mobile phone is quite artistic. Maybe this is the happiness of being rich.
(All the articles are professional, please don’t imitate them at home.)
(Part of the picture material in this article comes from the Internet, only for learning and communication.)
References:
https://www.youtube.com/watch? v=bAKqzAzfXKQ
https://www.youtube.com/watch? v=msgfm4DHiyc
https://www.youtube.com/watch? v=-HfaLqmRO1k
https://www.youtube.com/watch? v=wBY3Z4F0dxk
https://www.youtube.com/watch? v=YYNCGZCul1Q Physics Girl https://www.youtube.com/watch? v=rk-6wHimbUs
https://www.youtube.com/watch? v=JYivWedGCKc
https://www.youtube.com/watch? v=ts7v07lXmTQ
https://www.youtube.com/watch? v=nIL3HN4PQlI
https://www.youtube.com/watch? v=Z52yCL3tSGQ
https://www.youtube.com/watch? v=whkCwx2axQM
https://www.youtube.com/watch? v=87Cpe4bJn0U
Source: Mad Pill Science
Editor: xx
Reporting/feedback
Everyone is searching.
The table tennis movement in the competition includes the table tennis falling from a height when it is advancing. The jumping height is the fastest table tennis attack speed, and the fastest table tennis attack technology is () Fast speed is one of the outstanding characteristics of table tennis. The table tennis rules stipulate that the ball should be thrown when serving.



issue

Wake up in the starry night

Please ban table tennis, because table tennis can cause unimaginable harm in some people’s hands, especially in the hands of water injectors, which can easily shoot people in the eyes.

2020-09-02

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Liyue 8l

Remember+

2020-09-05

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Single-player small game enthusiasts

Forgot to be funny. That’s it?

2020-09-04

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All 4 replies

Liu Fang the butcher

Vacuum pump is very expensive!

2020-09-02

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Meteor star gap

Mechanical vacuum pump can play, but it’s not that powerful. But it’s much better than vacuum cleaners

2020-09-03

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Liu Fang the butcher

To achieve the effect in this article, the Roots vacuum pump with a million rmb will start!

2020-09-02

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All 6 replies

Lever and his friends’ daily life

L: hey! A, I brought you …
L was used by A to play table tennis …? Killed)
(l was born again)
A: Er … Hug …
(A is eliminated by cause and effect)
(a is born again)
(A is eliminated by cause and effect)
(a is born again)
(A is eliminated by cause and effect)
(a is born again)
A: stop! I surrender! I surrender!

2020-09-02

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Lever and his friends’ daily life

L:……
L:A……
A: I don’t know. Don’t ask me.
L:U……
U: what is quantum?
L: Er … ……Sans, you explain.
Sans:zzzzzzzzzzzzzzzzz ……
L:SSSSSAAAAAANNNNNNSSSSSS! ! ! ! ! !

2020-09-04

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Natural selection region

Enthusiasts in science field

Is the quantum state macroscopic, and the collapse state is realized through self-observation?

2020-09-04

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All 4 replies

Azul ink rain

How are light particles produced?

2020-09-02

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Natural selection region

Enthusiasts in science field

As a result, you are trapped in the track of the curvature engine and can’t move.

2020-09-04

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Think about it.

Start my curvature engine quickly

2020-09-04

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All 4 replies

mp364m

What I lack are table tennis and cannons? What I lack is an Apple phone!

2020-09-02

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Maliania, the blade of Michella.

This kind of air cannon seems to be at the level of one million RMB.

2020-09-02

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T’s advantage lies in my T.

I thought, this air cannon may be more valuable.

2020-09-02

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Super snow leopard MVP

All the articles are professional, please don’t imitate them at home?

How to imitate? 1.8 joules into the orange!

2020-09-02

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Fengqi captain

And use interchangeable words. What is an orange?

2020-09-02

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0321426as

I just want to ask: how expensive is this table tennis? The inferior table tennis we used, the speed of which was only over 20 kilometers per hour, was smashed by our table tennis racket and split in half.

2020-09-02

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Bodhi shines all over.

However, Xiao Pang broke the ball with a backhand at the World Championships several times and flew directly in half.

But Zhou Yu’s time …

It’s almost a sense of sight after being shot.

2020-10-14

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Theoretical progress

More than 20 kilometers per hour is less than 10m/s, and nobody can run fast. You can smash the ball. . . 9.18 complain about the business!

2020-09-03

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All 5 replies

Tianxing lost his heart

Curvature can be used next time

speed up

2020-09-02

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Tianxing lost his heart

True light

Particle strike

2020-09-13

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Maybe it’s a tomahawk

Wait, why did the earth fall?

2020-09-02

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Kawakaze Jiangfeng z6

The quality of water-injected table tennis is 20g, and the known exit speed is 1600km/h, that is, about 440m/s, and the kinetic energy is equal to one-half mass times the square of speed, and its kinetic energy is about 20 * 440 2/2 coke, which is calculated to be 1.93 * 10 6 coke, which can be approximately counted as 2,000,000 coke watermelon: I thank you tm.

The kinetic energy of this table tennis ball far exceeds the upper limit of 1.6 joules, so

//

@ account has been cancelled.

This content is temporarily invisible.

2020-09-02

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Angry dung beetles

What did you say? I can’t understand it. Please be more specific.

2020-09-03

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Qingluan glazed lamp

An hour ago.

2020-09-02

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Drama loves z1.

Want to do it, is it illegal?

2020-09-06

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v_qiu

Well, the speed of leaving the chamber exceeds the standard. Whoever tries it in China is illegal.

2020-09-02

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Elegant skn0624

Mythbusters is a real popular science program.

2020-09-02

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Luoguodaren

The writer of the article must be a graduate student with severe internet addiction, and he is flying like a kite.

2020-09-02

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Yan’s terminator z fu soul Soviet shirt z

Bench (only after reading it)

Don’t spray funny.

2020-09-02

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luckgodmo

Won’t the air in table tennis explode under vacuum?

2020-09-03

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Subway planning designer

If you use billiards, the power is even harder to imagine.

2020-09-02

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Juesheng Nanmo

This is one of the reasons why the per capita consumption of resources in the United States ranks first in the world. Just like PINKRAY  Jr. knows what it’s like to have three tones a year, he wastes a lot of experimental props, sees foreign children doing domino experiments on TV, and there are a lot of things on the Internet that are similar to putting people into shredders.

2020-09-02

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Thunder and lightning doctor sheep call animals.

We China people, just addicted to mobile phones every day, laughing to death, China is silent?

2020-09-02

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eyrbxjeusus

Boy, I won’t watch the funeral film without this thing.

2020-09-02

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Damn dog

The martial arts in the world are only fast and unbreakable.

2020-09-02

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kn12A

Faster than F16, air defense ball

2020-09-02

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Random thoughts: a cost-effective way to travel: time-saving, labor-saving, worry-free and comfortable.

Sunset on Weizhou Island

Bi Shumin said:Travel is a blind herb that can cure the bitterness of life.

It is also said that traveling is from a place where you are tired of living to a place where others are tired of living. Spend your own money, make others rich, then go back to the place where you are tired of living and continue to live tenaciously.

Like most people, I like to go out and have a look every year. In the past few years, the travel environment has been affected, and every time I go out, the troubles caused by the epidemic are not satisfactory.

After the Spring Festival in 2023, the epidemic was suddenly unsealed, which made people excited.

Retirees’ lives include not only pots and pans, but also poems and distant places. Gradually drifting away from society, it is inevitable to produce some spiritual internal friction. It is much better to spend some money to eliminate internal friction than to spend money on medical treatment.

Time and tide wait for no man, travel plan, put on the agenda.

After years of practice and feeling, I still prefer the semi-self-help travel mode: harmony but difference, casualness and freedom.

You don’t have to worry about the itinerary and accommodation, and you don’t have to worry too much about the safety of traveling alone. You can not only enjoy the leisure of seeing the mountains and water, but also have the opportunity to meet like-minded travelers.

Yuandadu site

Near the end of the year, summarize your travel situation in 2023.

1. Travel and expenses

First stop: 14-day tour of Guangxi Panorama.

The time is from February 11th to February 24th, 2023.

The places we visited were: Guilin Collection: Elephant Trunk Mountain, Tianxin Village, Longji Terrace, Yangshuo, Yulong River, Cuiping Wuzhishan, Xianggong Mountain, Huangyao Ancient Town, Liuzhou, Bama Changshou Village, Baimo Cave, Bainiaoyan Cave, Jingxi Goose Spring, Old Street in Jiuzhou, Detian Waterfall, Mingshi Manor, Quyang Lake, Anping Xianhu, Nanning City, Beihai Yintan.

Hydrangea Street, the Old Street of Jiuzhou in Jingxi.

Sunset in Wuzhishan, Cuiping

Tianxincun champion bridge

Anping Xianhexiao Foshan

Mingshi manor

Fees: Guilin assembly, Beihai delegation.

Tour fare (including tickets): about 4700 yuan,

Round-trip transportation cost: 1760 yuan.

Departure: 580 yuan (sleeper+bullet train)

Return: 1180 yuan by plane.

Total: 6450 yuan.

Second stop: Nine-day tour of Daliangshan-Yinji of Yi people.

Time: May 20-May 28, 2023.

The places we visited are: Suji Ancient Town, Jinkouhe Town, Jinkouhe Grand Canyon, Guluo Village, Yele Lake, Yihai Scenic Area, Yi Museum, Xichang Launch Center, Huanglian Tulin, Luojishan 99-grade Hot Spring Scenic Area, Gukede, Sanhe Village, Cliff Village, Mahu Scenic Area and Lizhuang Ancient Town in Zhaojue County.

Luojishan hot spring

Xichang Satellite Launch Center

Jinkouhe Grand Canyon

Yihai

Cliff village

Fees: Chengdu assembly, break up.

The tour fee (including tickets) is 3680 yuan.

Transportation fee: None (the tour fare includes the return ticket from Xi ‘an to Chengdu).

Total: 3680 yuan.

Third stop: 10-day tour of Xilin Gol Great Ring Road. The time is from July 28th to August 7th, 2023.

The places we visited were: Hohhot, followed by Huanghuagou Scenic Area, Wulanhada Volcano Group, Grassland Volcano Scenic Area, Xilinhot Beizi Temple, Wulantai Scenic Area of Xiwuqi, Seoul Scenic Area of Mongolia, Bulinquan Scenic Area, Bingtuan Town, Wolf Totem Shooting Base, Shizhen Scenic Area of Ketengke Banner, Dali Lake Scenic Area, Yuanshangdu Site, Jining Campaign Memorial Hall, etc.

Shizhen scenic spot

Mongolia Hancheng scenic spot

Volcanic grassland exposed to the sun.

volcanic vent

Fees: Hohhot assembly, break up.

Tour fare (admission): 4280 yuan

Transportation: 580 yuan (going from Xi ‘an to Hohhot, returning to the sleeper).

Total: 4860 yuan.

The fourth stop, a four-day tour of the Qinling Mountains in the autumn. Time: October 24th to October 28th, 2023.

The tour fee (including tickets) is 1210 yuan. Transportation fee: Xi ‘an takes the bus.

The places visited are: Lingguan Gorge in Fengxian, Lover Valley, Shizigou Ranch, Liuba Old Town, Gao Jiang Road, the most beautiful highway in Qinling, and Longtou Mountain in Hanzhong.

Lingguanxia

Longtoushan

Gao Jiang Road, the most beautiful highway in Qinling Mountains.

The total amount of the above expenses is: 16,200 yuan (including breakfast only), totaling 37 days.

During the trip, some people watch the culture, some people watch the scenery, some people punch in and take photos here, and some people relax and take a stroll.

Either way, the picture is a happy and happy mood. After being happy, it is not surprising that the body is tired and exhausted. After a comfortable sleep, the next day I will still be an old man and full of energy.

Gukede

I like this kind of travel because:

one: The line arrangement is reasonable and comprehensive.

Urban scenery, natural scenery, historical sites and ancient towns, cultural heritage, historical sites, regional culture and other related places will be arranged in the route reasonably.

2:The accommodation is good.

According to the unique situation of each region, we will arrange the best hotel and live comfortably.

three: The service mode is intimate.

There are points for spending, signing in and writing travel notes, and the tour fee can be deducted. The team leader has high quality and strong sense of service.

fourThe most important point is that there is no consumption, pure tourism.

5. Various scenic spots, the time arranged is broad and general., high degree of freedom.

sixBecause I am traveling alone, consideringSafety factor.

Traveling alone, free, unaccompanied, but less lively. This kind of worry-free, labor-saving, time-saving and relaxing way of traveling is just right for me.

Lonely in the crowd at arm’s length,

Joy in like-minded mountains and rivers.

There is no best, only suitable. What suits you is the best.

Jingxi goose spring

new energy vehicle

# Article First Challenge # Will new energy vehicles replace fuel vehicles?

Different people have different views on whether new energy vehicles will replace fuel vehicles.

Wang Qing, deputy director of Market Economy Research Institute of the State Council Development Research Center, predicted that by 2025, the annual sales volume of new energy vehicles in China will reach about 17 million, and by 2030, the market share of new energy vehicles will exceed 90%. This means that in the next decade, the sales and influence of new energy vehicles will increase rapidly.

On the other hand, new energy vehicles and fuel vehicles have their own application scenarios. In the short term, new energy vehicles may not completely replace fuel vehicles. This is because there are still some problems in new energy vehicles, such as safety, charging and battery life. If these problems are solved, new energy vehicles may further expand their market share.

However, in the long run, it is an inevitable trend for new energy vehicles to replace fuel vehicles. With the continuous progress of technology and the enhancement of environmental awareness, new energy vehicles will be applied in more fields, including passenger cars and commercial vehicles. At the same time, the policy is also promoting the development of new energy vehicles. For example, some cities have gradually stopped selling fuel vehicles.

To sum up, new energy vehicles may replace fuel vehicles at some point in the future, but this process may take some time. In this process, fuel vehicles and new energy vehicles will

Coexist and compete with each other.

Three "magical" coincidences in history make people doubt that the world is a reincarnation.

In the ancient East, there seems to be a mysterious veil hidden in the long river of history, revealing some amazing strange coincidences from time to time. These coincidences seem to be legends woven by history itself, leaving future generations with deep thoughts, and these stories hover in my heart, making me feel the mystery of the world’s reincarnation between ink and paper.

Let’s focus on the experience of Emperor Gaozu Liu Bang. His life is full of legends, and his leap from Buyi to Tianzi has attracted worldwide attention. But also, an episode that happened in his escape career is even more incredible. According to the report, when Liu Bang passed through a mountain forest, he encountered an unusually white boa constrictor crossing the road, and he cut it in two with his sword without fear. This python can’t help being given symbolic meaning by later generations-it was the test and hint given to Liu Bang by the god of fate, and he declared to the world the possibility of his future success with courage and determination.

Then, we might as well compare the fate trajectories of Qin Shihuang and Emperor Wen of Sui in Sui Dynasty. Qin Shihuang helped the world, burned books to bury Confucianism, repaired the Great Wall, built Epang Palace and built water conservancy, which was a great achievement. However, the grievances created by his harsh and cool laws are like undercurrents. After his death, the Qin Dynasty declined rapidly and eventually collapsed after only a few short years. Hundreds of years later, Emperor Wen of Sui in the Sui Dynasty also created a prosperous era of reunification. However, after the second emperor Yang Guang ascended the throne, his extravagance and tyranny made Jiangshan once again step into the path of subversion. Two dynasties, after the death of the founder, ushered in a similar fate.

Finally, we turn to the story of Zhao Kuangyin in the Song Dynasty and the last son of heaven in the Southern Song Dynasty. Zhao Kuangyin, a general of the Zhou Dynasty, rose to fame in helping the imperial court to quell civil strife and expand its territory, and usurped the seven-year-old throne left by Zhou Shizong from humble origins through the Chen Qiao mutiny. A similar plot was staged again in the last years of the Southern Song Dynasty. When the Southern Song Dynasty was besieged by the Yuan Army and was on the verge of extinction, the young emperor Meng Gong chose to jump into the sea heroically to show his loyalty and loyalty. The two young emperors suffered different but similar fate twists and turns.

When we put these three sections of history together, it seems that we can perceive that the breath of reincarnation is slowly permeating the river of time. Every turn and coincidence is like a chess game arranged by God’s will, waiting for the chess pieces to perform.

But can we really assert that history is reincarnation? I’m afraid we still need to have reservations. Because history itself is made up of countless individual behaviors; It should be noted that although the waves are small, they can gather into an ocean, and people are small, but they can also affect the historical process. These seemingly "magical" coincidences are just a few fragments highlighted in countless events, which does not mean that all history follows a certain established pattern.

Perhaps we should learn wisdom from these stories and study the law: the extraordinary ambition of heroes often indicates extraordinary achievements; Authoritarianism leads to the boiling of national resentment and eventually to its demise; Power translocation is often accompanied by the fading of old forces and the birth of new forces.

To sum up, although history always gives us countless possibilities and associative spaces, every era that needs to learn from the past and diligently explore the true meaning of the laws behind them has its particularity and independence. Anyone can try his best to exert his style and contribute his strength in his position and become a small and powerful wave that pushes history forward.

Chinese and foreign scholars say cultural relics: capturing the "bright spot" of China culture in artifacts.

China news agency, Shanghai, November 25 th: Chinese and foreign scholars say cultural relics: capturing the "bright spot" of China culture in artifacts

China News Service reporter Wang Wei Kang Yuzhan

The World Congress on China Studies and the Shanghai Forum were held at the Shanghai International Conference Center from 23rd to 24th. At a sub-forum held on 24th, Wang Chunfa, director of the National Museum of China, presented a precious cultural relic in the museum-bronze rhinoceros statue with gold, silver and moire patterns in the Western Han Dynasty, from which he realized the unique charm of Chinese civilization.

This statue is in the shape of a rhinoceros, with its head held high and its eyes inlaid with black beads, which is the image of Sumen rhinoceros who lived in China in ancient times; The whole object is decorated with staggered gold and silver moire as thin as hairspring, which is exquisite and gorgeous, and it can be called a fine bronze ware in the Han Dynasty. The bronze statue made of animals shows the concept of harmony between man and nature and the nature of Taoism in ancient China.

"This precious cultural relic not only vividly narrates the past, but also profoundly affects the present and the future, enlightening us to respect history, respect our predecessors, respect nature and protect the environment." Wang Chunfa said that human knowledge is accumulated through exploration from generation to generation, and it should be passed down from generation to generation. Chinese and foreign scholars are welcome to the National Museum of China to feel the moving place of the bronze rhinoceros statue with wrong gold, silver and moire.

What are the China cultural relics that foreign scholars are interested in? In the face of a reporter’s question from China News Service, Han Yili, a former associate professor in the Literature Department of Moscow Humanities University, made a list on the spot-Oracle Bone Inscriptions, bronzes, silk books of Mawangdui … Some of them were related to the topic of Zhouyi he studied, and the other part was out of his personal interest.

In Han Yili’s view, the importance of ancient cultural relics and historical documents lies in helping people truly understand the ancient world outlook and living conditions. Compared with some subjectively recorded words, real artifacts can reflect a period of history more intuitively. "Many cities in China have their own museums, so that everyone can learn history and experience culture from ancient artifacts. How to better protect cultural relics and inherit culture is where we should learn from China. "

Yi Xin, an international student from Shanghai University in Mexico, immediately thought of blue and white porcelain. "I found that China’s blue and white porcelain is very similar to some artifacts I saw in Mexico. Later, I read the literature to know that these artifacts really came from China. Exploring how these artifacts arrived in Mexico from China and looking for connections between different cultures made me feel very interesting. "

Yi Xin told reporters that China has a long history and China culture has many "bright spots", which let her know the real China from different angles. "We will not stop exploring China, because there are many things worth studying here." (End)

What is culture?

Buffett said: "when evaluating a person, we should focus on four characteristics: kindness, integrity, intelligence and competence." If you don’t have the first two items, the latter two items will hurt you. "

I often hear people say: it’s terrible to have no culture.

But what is "culture"? -is it a degree? Experience? Experience?

Answer: Neither.

Today, I saw a very reliable explanation. "Culture" can be interpreted in four sentences:

1. Self-cultivation rooted in the heart,

2. Consciousness without reminding,

3. Freedom based on constraints,

4. Kindness for others …