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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answer

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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answer

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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answer

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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See more comments

The best way to enrich yourself: exercise.

Some time ago, "More than half of adults in China are overweight or obese.The hot search quietly climbed to the top, causing many netizens to resonate.

Many people leave messages in the comment area:

Sit and sit, and your stomach will grow.

I ate a lot of takeout food and didn’t move much. I watched my stomach grow bigger and bigger.

I’m tired from work, so I lie down when I get home from work and gradually get fat.

Nowadays, the extreme convenience of life makes many people ignore the importance of sports.

After "coveting comfort", the body gradually lost its original vitality.

On the other hand, those who like sports around them are not only physically strong, but also have a positive mental state every day.

Exercise and no exercise lead different lives.

I don’t like sports. What’s the difference?

There is a hot question on the Internet: "How about a person who doesn’t exercise for a long time?"

There is a high praise answer below:

I haven’t exercised for about three years, and my physical fitness is getting worse and worse. I feel like I’m falling apart after walking for a while.

It turns out that because the answer master is busy with work, all his food comes from online shopping, and he also lies down most of the time on weekends, and the number of times he goes out is getting less and less.

I can’t control my mouth, I can’t open my legs, and my original healthy body is "swallowed up" by obesity.

People who don’t have time to exercise pay the price for their laziness to varying degrees.

A 10-year-old boy in Huai ‘an, because he doesn’t like sports, weighs five times as much as ordinary children, and his abdominal fat is 10 cm thick. He suffered from severe fatty liver at an early age.

A woman in Changchun, Jilin, used to go to bed after dinner and almost never exercised.

The weight actually reached 320 kg, and the stomach was three times larger than ordinary people.

Because of obesity, her blood pressure and heart function were seriously affected, so she had to have part of her stomach surgically removed.

People who don’t like sports indulge their health, but squander their health.

There is a saying on the Internet:

You have to carve whatever you want.

Beating inertia and strengthening exercise are the best ways to have a good body.

A netizen named "Fat Brother" got fat because he was ill and took hormone drugs.

The deterioration of his condition prevented him from losing weight. At one time, Brother Pang’s weight increased from 75 kg to more than 150 kg.

Later, he went to Sanjiang, Guangxi to teach.

Because of its remoteness, it takes half an hour to go shopping, and frequent home visits to children require mountains and mountains.

Unexpectedly, because of this periodic exercise, his weight kept falling, and after one year of teaching, his weight returned to 75 kilograms.

The body is honest, and it will treat you as you treat it.

People who like sports will naturally get feedback and rewards for a healthy lifestyle.

Exercise is a person’s best nourishment.

The body is 1, and the rest are 0.

Without a healthy body, work, life, wealth, fame and fortune are meaningless.

As the old saying goes, if you exercise your bones and blood, your qi will be strong.

Keep exercising, and your body and life will undergo positive changes.

1. improve your mood.

A doctor from a German university once did an experiment:

The experiment tracked 12 people with severe depression and asked them to exercise on the treadmill for 30 minutes every day, and gradually increased the amount of exercise.

After 10 days, the depression of 6 patients was greatly improved.

Studies have found that the brain will secrete neurochemicals such as endorphins during exercise, which will make people happy physically and mentally and help to get rid of negative emotions.

As the writer Haruki Murakami said:

When I am criticized by others or feel wronged, I always run farther than usual.

Running can consume negative emotions and make people more confident.

Life is not easy, and when you are in a bad mood, you might as well go out and exercise for 30 minutes.

Eliminate the troubles in life by exercise and welcome a happy life.

2. Strong physique.

"Compared with my peers, I have no pain in my body. I slept well after exercise, my blood pressure has been normal, and I have never had a serious illness. "

Uncle Huang Xujin, born in Xi ‘an in 1940, is 82 years old this year, and his body is very strong, which is mainly due to his love of sports since he was a child.

At school, he likes running and long jumping. After work, he often goes out for a run early in the morning.

After retiring in 2000, he fell in love with the 400-meter race. Today, he has been running for 22 years.

Persistence for decades has brought him healthy body and abundant energy.

There is a good saying:

Every drop of sweat you shed is shaping a healthier body.

When people reach middle age, they are old and young, and you need to bear a lot at work and family.

If the body collapses, everything will cease to exist.

So no matter how busy life is, take some time to exercise.

Only by having a healthy body can we be more confident in dealing with all problems.

3. delay aging.

Actor Carman Lee once launched a fitness punch-in activity on the Internet, sharing various slimming and fitness actions with netizens every day.

Everyone not onlysubdueBecause of her young appearance, she is also surrounded by her self-discipline life.

Carman Lee began to exercise at the age of 34, and running, skipping and flat support have always been her persistent projects.

Even when filming, I will take a yoga mat and jump rope and do some simple exercises.

Today, although she is 55 years old, she still looks like she is in her thirties.

Exercise is the best cosmetic and skin care product.

Scientific research shows that exercise can increase the oxygen consumption of the body, thus promoting metabolism, strengthening the nutritional supply of the skin and helping to delay skin aging.

People who move are racing against time, and every step you take will make you younger and younger.

4. Exercise your brain.

A research report from the University of Illinois shows that:

After sitting for two hours, people’s brains are basically in a rigid state, and their thinking ability and creativity almost stop.

After walking for 20 minutes, the cranial nerves become extremely active.

In other words, exercise can make the mind healthier and more flexible, and help to improve work efficiency.

A study published in Frontiers of Aging Neuroscience also found that:

If the healthy elderly people stop exercising for about 10 days, the blood flow in the important areas of the brain responsible for thinking, learning and memory will decrease significantly.

Moving is the best way to strengthen your body and exercise your brain.

Use fragmentation time to get up and walk around every once in a while.

A small habit, stick to it, will also produce huge benefits.

Learn to exercise correctly

The book "The Power of Habit" writes:

Exercise every day will not only make you feel happy, but also affect other details in your life. For example, make you energetic, so that you can work more efficiently and get more happiness.

The world is secretly rewarding those who love sports.

Today, readers put moderate exercise"1357 principle"Share with everyone, I hope everyone can develop good exercise habits.

1. Do aerobic exercise at least once a week.

Do aerobic exercise with moderate intensity or above at least once a week, such as running and swimming.

It can not only enhance immunity, slow down aging, release stress, but also help sleep.

If you feel painful during exercise, you can give yourself some positive psychological hints.

Focus on the fun of exercise, such as enjoying the roadside scenery and breathing the fresh air in the morning when jogging.

2. Each continuous exercise shall be no less than "30" minutes.

If the exercise time is too short, it will not achieve the expected effect and the purpose of keeping fit.

Even if your work is busy and your life is trivial, you should set aside more than 30 minutes for exercise at a time.

I suggest that when you go to work at ordinary times, you cansuitableSet aside a distance and walk slowly.

Climbing stairs intermittently at work; Do yoga during lunch break; Take a walk together after dinner.

As long as the amount of exercise is up, every drop of sweat you shed will not live up to your future self.

3. If you can’t exercise every day, you should exercise at least "5" days a week.

Perseverance can play the role of exercise and fitness.

If you are worried that you can’t get into exercise habits, you can set an alarm clock for yourself.

After receiving the reminder, don’t find any excuse to delay, and start exercising immediately.

Stick to it and get into the habit, and exercise will become extremely easy for you.

4. When exercising, the maximum heart rate should not exceed "170 minus your age".

As the saying goes, everything goes too far, so does sports.

Excessive exercise can easily burden people’s heart and body.

Healthy exercise should be gradual.

Take the first step first, and then gradually increase the amount of exercise, so that the body can gradually adapt.

In order not to cause harm to the body, the maximum heart rate of each exercise must not exceed 170 MINUS the age.

Grasp the degree of exercise and do it in a timely and appropriate manner, so that exercise is more beneficial to health.

The quality of life is determined by everyone’s lifestyle and habits.

As Socrates said:

The health of the body is destroyed by immobility and maintained for a long time by exercise.

For your own physical and mental health, for a better living condition, let’s go to exercise together while the sun is just right!

Even the smallest change, multiplied by 365 days, will become the strength that others can’t envy.

illumine"like"From today on, let’s keep self-discipline, keep exercising, have a good body and pursue the life we yearn for.

Author: You Shu Tian Xin, Source: You Shu.

What is culture? On the word culture

Image source network

The word "culture": its appearance in China can be traced back to the Western Han Dynasty. "Culture" is not only a system of civilizing and educating, but also a system of rites and music. This understanding has been maintained in our country until modern times. The meaning of the word "culture" that we use today is obviously different from that of ancient times. It was introduced from the west through Japanese translation at the end of the 19th century. At that time, there was no definition of the word, and people only used the word "culture" according to their own understanding and needs. According to analysis, there were about three meanings at that time; First, it is synonymous with "civilization"; Second, in a broad sense, it includes spiritual and "civilization" contents; Three, narrow sense, refers to the spiritual content. To this day. The meaning of culture is broader; There are also many people who agree that culture refers to "ideology", and everything outside politics and economy is among them; Others make a broader understanding that everything created by human beings (that is, the integration of material civilization and spiritual civilization) is culture; Besides, some people have other explanations.

In view of the fact that scholars at home and abroad have different opinions on the concept of "culture", it has been suggested that the word "culture" may be a vague concept naturally, and it is difficult to make a clear and complete definition. Instead of pursuing a simple and precise definition, people should determine a flexible range from the perspective of set.

Although there are many definitions of culture, I personally think that it should be the same in many aspects, and we can roughly summarize it into the following three aspects;

First, ideology (also known as ideology) means people’s world outlook, way of thinking, religious beliefs, psychological characteristics, values, moral standards, cognitive ability and so on.

Second, the way of life, that is, people’s attitude towards their food, clothing, housing and transportation, marriage, birth, illness, family life and social production activities, and some forms taken in these aspects.

Third, spiritual materialized products, that is, from the formal point of view, are some material things, but through the material form, they can reflect people’s differences and changes in ideas.

From the above three parts, the scope of culture is basically outlined. But we should pay attention to: the word culture; It should be an organic whole, which is not only the simple addition of the contents of these three parts, but also the mutual influence and premise of the contents of these three parts, and should be organically combined according to a specific sequence.

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 …