Earth’s water doesn’t come from melting meteorites.

  The white dotted line in the figure shows the boundary between the inner solar system and the outer solar system, and the asteroid belt is roughly located between Mars and Jupiter. Bubbles near the top of the image show that water molecules are attached to rock fragments, indicating the type of objects that may bring water to the earth.

  Image source: Jack Cook/woods hole oceanographic institution

  Beijing Science and Technology Daily, March 16th (Reporter Zhang Jiaxin) Water accounts for 71% of the earth’s surface area, but no one knows how or when such a large amount of water arrived and existed on the earth. A new study published in the journal Nature on 15th brought scientists one step closer to answering this question. The researchers found that the water on the earth did not come from molten meteorites.

  The research team of the University of Maryland analyzed the molten meteorites that have been floating in space since the formation of the solar system 4.5 billion years ago. They found that the water content of these meteorites was extremely low. In fact, they are one of the driest substances ever measured. These results make researchers rule out that they are the main source of water on the earth, which is of great significance for finding water and life on other planets.

  The researchers analyzed seven molten meteorites, that is, spherulite-free meteorites, which split from at least five "planetesimals" and fell into the earth for billions of years. These planetesimals collided to form planets in the solar system. During the melting process, many of these micrometeoroids were heated by the decay of radioactive elements in the early solar system, causing them to split into layers with crust, mantle and core.

  Since these meteorites have only recently landed on the earth, this experiment measured their volatiles for the first time. The researchers used electron probes to measure their magnesium, iron, calcium and silicon levels, and then used secondary ion mass spectrometry to measure their water content.

  To reduce pollution, the researchers first baked their samples in a low-temperature vacuum oven to remove any surface water. The sample must be dried again before it can be analyzed in the secondary ion mass spectrometer.

  After analyzing the samples of non-chondrite, the researchers found that water accounts for less than two parts per million in its mass. In contrast, the wettest meteorite — — Carbonaceous chondrites contain up to 20% water (by weight), which is 100,000 times that of the meteorite samples studied by the team. This means that no matter where these micro-planets originated in the solar system, and no matter how much water they had in the beginning, the heating and melting of micro-planets will lead to almost all water loss.

  The researchers found that contrary to popular belief, not all extrasolar bodies are rich in water. This led them to conclude that water was probably transported to the earth through unmelted meteorites or chondrites.

What is culture?

What is culture? A topic that often lingers in my ears, but it is really difficult to make it clear. There is the concept of big culture and the understanding of narrow culture.

Some people on WeChat summarized a person’s cultural performance as "self-cultivation rooted in the heart; Consciousness without reminding; Freedom based on constraints; Kindness for others! "

Long Yingtai, a famous cultural person and former "Minister of Culture" of Taiwan Province, once wrote a book to answer this question, which is full of female cultural people’s understanding of culture: an excerpt from it: "Culture is actually reflected in how a person treats others, himself and his natural environment. In a society with a thick and deep culture, people know how to respect themselves-he disagrees, so he has taste because he disagrees; People know how to respect others-he is not overbearing, because he is not overbearing, so he has morality; Man knows how to respect nature-he does not plunder, because he does not plunder, so he has eternal intelligence. Taste, morality and intelligence are the sum of cultural accumulation. "

This is an explanation of cultural phenomena from a typical narrow cultural perspective.

According to our textbooks, culture is a social phenomenon, a product of people’s long-term creation, a historical phenomenon and a deposit of social history. To be exact, culture is condensed in the material and dissociated from the material, and the history, geography, customs, traditional customs, lifestyle, literature and art, code of conduct, way of thinking, values, etc. of a country or nation that can be passed down are generally recognized as an ideology that can be passed down in human communication.

There are two kinds of culture, one is production culture and the other is spiritual culture. Science and technology culture is production culture, and life ideology culture is spiritual culture. Corporate culture, university culture, office culture, etc. are institutional or systematic cultures. Any culture is used for life, and there is no culture that is not used for life. Any culture contains a theory, way, idea and understanding of life and existence.

The structural anatomy of culture is divided into two parts: material culture and spiritual culture; There are three levels, namely, material, system and spirit; There are four levels of theory, namely, material, system, customs, thoughts and values. There are six subsystems, namely, material, social relations, spirit, art, language symbols, customs and habits.

The internal structure of culture itself includes material culture, system culture, behavior culture and mentality culture. Theoretically, there is a lot to talk about, but generally speaking, changes in society itself bring about cultural changes. Mainly reflected in three aspects:

First, the vitality of culture comes from inheritance.

Any kind of culture is formed over time under the historical background of thousands of years, which is embodied in everyone. To some extent, culture is a kind of inheritance.

This kind of inheritance process, first of all, is to teach by example. Therefore, for everyone, family plays an important role, and parents play a central role. For students, school is an important platform for cultural inheritance, and teachers are the hub of cultural inheritance. For adults who have already worked, the institution where they work is the platform for cultural inheritance, and the person in charge of the institution is the core of cultural inheritance.

It is normal for everyone to have different feelings and views on culture at different ages. However, for culture, future generations are not qualified to comment on its advantages and disadvantages, which are the feelings of different ages and formed under the background of thousands of years of history. We are all unconscious inheritors and practitioners.

Second, the development of culture depends on communication and reference.

Culture is colorful because of communication, and civilization is enriched because of reference.

Culture is rich, even completely different, and the development process of culture is also a process in which various cultures constantly influence each other and learn from each other.

Indian Buddhism has been introduced to China for more than 1000 years. Compared with the original Indian Buddhism, it has been far away and has undergone many great changes. It has influenced China culture, and at the same time it has been completely influenced by China culture, and it has been mixed with Confucianism, Buddhism and Taoism in China, becoming an important pillar of China’s traditional cultural ideas and morality, and another bottom line of social governance.

During the early days of the founding of New China, we studied the Soviet Union, from architecture to running schools, broadcasting and movies, national governance, engineering technology, and specialty setting, and Soviet culture was everywhere.

In recent 40 years, in the process of reform and opening up, we have the shadow of western culture everywhere, from architectural style to school-running concept to film and television entertainment and social governance. Similarly, with the prosperity and increasing influence of China, China elements are increasingly appearing in the United States and other western countries, whether it is Spring Festival, Chinese characters, China Red, Chinese Dragon, and so on.

In the United States, it is normal to put schoolbags on the ground, because they think schoolbags are dirty. In China, schoolbags are often placed on the table because the ground is too dirty. These are all behaviors in different cultural backgrounds. When we are familiar with the reasons, we may learn from them and change.

Third, the innovative power of culture comes from the development of social productive forces.

Mankind has experienced agricultural revolution, industrial revolution and information revolution. Every industrial and technological revolution has brought great and profound influence to human production, life and culture.

Culture itself is also changing with the development of society, and shows the shadow of the development of the times. Especially in modern times, with the progress of technology, the culture of every country is undergoing tremendous changes, even subversive changes.

The improvement of transportation has promoted the development of economy to a great extent, and strengthened the connection between people, thus bringing more integration of regional language and writing architecture. The invention of electricity has also fundamentally changed the rules of people’s daily life and directly affected the formation of some related cultures, such as nightlife, movies and games. After the appearance of television, potato TV, a kind of special term, appeared to describe a certain state of life.

As one of the main bodies of culture, picture books were popular when we were young, and animation was already popular when my son was young, then games, and related industries, such as cosplay, had great influence among teenagers. Now, games have become one of the most important industries in the world. Although Sina has a great influence, its income is only 22% of Netease, which is mainly based on games.

But all these influences are not as far-reaching as the impact of the development of the Internet on our human culture.

Whether in the subway or on the bus, we can see the low-headed people everywhere, which is the cultural phenomenon brought by the mobile Internet. Of course, this is only a shallow impact.

A few years ago, a book called "The World is Flat" was popular. Now, the world is flat. The appearance of the Internet, starting from language conformity and communication, has gradually changed all systems of social relations, spirit, art, customs and habits. It has broken the traditional differences and distances between regions, time and space, classes, social structures and countries, and completely broken or even changed the inheritance of culture, learning from the way of integration.

For example, on FACEBOOK, WeChat, etc., people from different countries and religions are discussing the same issue in different groups. Different civilizations and cultures have also collided fiercely in the same time and space, which is unimaginable in the history of human civilization for thousands of years. Over the past two thousand years, culture has always been the social elite, and the strong are guiding it. Now, it is completely a group guidance.

The information technology represented by the Internet is changing with each passing day, which has led to new changes in social production, created new space for human life, expanded new areas of state governance, greatly improved the level of human understanding, greatly improved the ability to understand and transform the world, and improved the cultural space unprecedentedly.

Universities should play a leading role in culture.

As an important organization in a civilized society, universities have maintained a high social status and are enduring for a long time. University has not only inherited knowledge civilization, but also changed its times. Universities should play a leading role in culture. Academician Zhao Qinping of Beijing University of Aeronautics and Astronautics once made a special exposition. He pointed out: "The function of leading culture of universities is embodied in inheriting and carrying forward excellent traditional culture, drawing on and spreading advanced foreign culture, and creating and cultivating new culture of the times. Inheritance and reference are the basis of creation. Without the inheritance of traditional culture and the reference of foreign culture, it is difficult to create a new culture of the times. If it is said that inheriting and carrying forward excellent traditional culture is a universal function of all education, then it is mainly the function of universities, especially high-level research universities, to criticize and learn from foreign cultures, to spread advanced elements in society and to create, cultivate, reconstruct and develop new cultures. (Li Zhimin, the picture comes from the Internet)

Ding Yan Yuhang officially appeared! The first show scored 6 points, Nanjing Tongxi won 11 points, and the rookie broke out!

Nanjing Tongxi finally easily defeated his opponent 106-95, although Ding Yanyuhang scored only 6 points due to knee injury and his playing time was limited. However, the performance of new aid Abdul was excellent, and he scored 15 points. Xi Rejiang made some rotations in the lineup, but Blackney and Farr, both foreign AIDS, didn’t play.

Although he signed a contract with Nanjing Tongxi, Ding Yanyuhang was unable to participate in all competitions due to knee injury. However, in order to give back to the fans, he chose to play. Fortunately, the strength of the American explorer was relatively weak, and Ding Yanyuhang got many opportunities to shoot, and after making two three-pointers, he went off to rest.

Judging from the current situation, Ding Yanyuhang’s knee injury is still a big problem. He dare not exert himself when running, which makes it easy for his opponent to break through defensively. However, his 3-point shooting rate has remained at a high level, which can help the team.

The biggest surprise of this game is the new aid Abu Dhabi. His full name is Abdul Samaiti, and his playing style and appearance are very similar to Abdul Salamu of Xinjiang Men’s Basketball Team. He showed his comprehensive skills and contributed 15 points in the game.

Ma Guodong, an inside player, continues to perform well. He has been qualified for Sun Mingyang’s position and may even play better.

At present, the biggest hidden danger facing Nanjing Tongxi is the state of the West Thermal River. Gao Shumin, a mentor, used to help him, but now he often loses his temper for no reason and blames other players. Foreign teachers can’t help in time because of communication problems.

Nanjing Tongxi Team has become more attractive with the joining of Ding Yanyuhang. Although Ding Yanyuhang’s injury problem still exists, he can still contribute excellent three-pointers to the team. The addition of new aid Abu Dhabi has also brought new vitality to the team. However, we need to pay attention to some problems in the team, such as the state of the West Heating River and the communication problems of foreign teachers. I hope that Nanjing Tongxi team can make continuous progress and achieve better results.

Is it worth it? After Guashuai took over, Manchester City’s net transfer expenditure was 478 million pounds, and it won five Premier League titles in seven years.

Arsenal lost to Nottingham Forest and Manchester City locked in the Premier League title ahead of schedule. This is the fifth Premier League champion of Manchester City since Guardiola took the helm.

Guardiola officially became the coach of Manchester City in 2016. In the past seven years, Manchester City spent 1.074 billion pounds on transfer, 596 million pounds on transfer income and 478 million pounds on net expenditure, with an average net expenditure of about 68 million pounds per season.

In the past seven years, Gua-style Manchester City has won 12 championships (5 Premiership, 4 League Cups, 1 FA Cup and 2 Community Shield Cups), but it has not won the Champions League yet.

Real Madrid legend was hit in the face! After the 4-0 victory, Mr. 100 million of Manchester City replied: Shut up.

The dialogue between Real Madrid and Manchester City ended in the victory of Manchester City. On May 20th, Spanish and British media broke the news that Manchester City winger Grali, worth 100 million pounds, avenged himself and "banned" Real Madrid star Guti on social platforms.

Goody and Grali, what’s wrong with you?

In the first leg of the Champions League semi-final, Real Madrid drew 1-1 with Manchester City. After the game, Real Madrid star Guti visited the El Chiringuito program of Spain Channel 6 and commented on Manchester City. The "Golden Wolf" cast three perspectives: Grali can’t do anything, B-seat kicks the wing=Manchester City is short of one person, and Guardiola dare not change tactics.

If we only watch the first 90 minutes of the game, Guti still knows a truth: Grali’s breakthrough performance was not excellent, and Block B was completely blocked by Benisius and Camavanga on the right. Awkward; Guardiola’s 0-0 game involved substitution, with Alvarez, Foden and Mahrez sitting on the bench.

However, Guti and Real Madrid fans didn’t expect Manchester City to have an advantage in the second round, sweeping Real Madrid 4-0. Gurish, Sheet B and Guardiola criticized by Guti are all protagonists-

Grali is good at passing and controlling the ball.

2 points for seat B. Grali threatened to pass the ball three times, succeeded four times and was violated five times. Real Madrid can’t block the ball from the right. He is proficient in all 18 weapons.

Mr. Guti expressed his views on the plan of El Chiringuito, saying that Mr. Goreli could "endure" a week. It wasn’t until Manchester City won the final that Grali hit back at Guti. Under the information of the program, Grealish responded with a "shut up" expression.

Good people pull a long face

Grealish’s expressive response instantly detonated the social platform. It got more than 2 million views and 40,000 likes in just 8 hours. Guti never imagined that Real Madrid, the love of his life, would lose so badly. After the 0-4 defeat in the Champions League, Guti was silent for three minutes in El Chiringuito’s program, with a sad face …

0 tolerance! Guangdong players were criticized, and Du Feng showed his attitude.

0 tolerance! Guangdong players were criticized, and Du Feng showed his attitude.

In the Chinese Basketball Association Professional League (CBA), Guangdong team lost to Guangsha team. Losing was not terrible in itself, but the performance of the team made Guangdong head coach Du Feng very dissatisfied and criticized the players. He pointed out that the players lacked fighting spirit and didn’t try their best in the game, which led to the result of defeat. As the leader of the team, Du Feng has high requirements for the team’s performance, so he made it clear that he will take severe measures to evaluate and correct the players’ performance and will never tolerate such performance.

As a professional basketball player, everyone has the responsibility and obligation to fight for the team. Especially in difficult times, we should keep fighting spirit and fighting spirit. Du Feng believes that players should go all out in the game, not only for their own honor, but also for the team and fans. Therefore, he will not tolerate the players’ lack of fighting spirit and fighting spirit. Du Feng said that this is the philosophy and culture that the Guangdong team adheres to, and only in this way can it bring victory and honor.

Regarding the future of Guangdong team, Du Feng expressed his confidence in the team. He believes that the players can show better strength and mental outlook in the next game and win. Du Feng’s attitude and performance have been supported and recognized by the fans. His remarks show his concern and management ability for the team, and more importantly, he shows the quality of a good leader. Du Feng not only performed well on the field, but also had very high requirements and abilities in managing the team.

Du Feng’s performance also reminded other CBA teams and players. He told them that only by keeping fighting spirit and fighting spirit in the competition can they win. Not only the players, but also the coaches and management need to be strict in managing the team to ensure that the team can win and honor. This attitude and performance is a good example for the basketball circle in China and the whole sports circle in China.

In short, Du Feng expressed strict requirements for the performance of Guangdong team, and said that he would never tolerate players’ lack of fighting spirit and fighting spirit. His attitude and performance have been supported and recognized by the fans. This kind of attitude and performance is the quality that a good leader should have, not only to perform well on the field, but also to have very high requirements and abilities in managing the team. Du Feng’s criticism shows his concern and management ability for the team, and he firmly believes that only through fighting spirit and fighting spirit can we win. This attitude and performance is a good example for the basketball circle in China and the whole sports circle in China.

Guangdong team is one of the most successful teams in CBA history. They have won many championships and awards. However, the victory is not achieved overnight, and the players need to go all out in every game. Du Feng’s criticism reminds the players that they must keep fighting spirit and fighting spirit, which is the philosophy and culture that Guangdong team adheres to, and only in this way can they bring victory and honor. Du Feng’s attitude and performance will also inspire the players to work harder in future competitions and strive for more victories and honors for the team.

Sun Yingsha lost 4-0 to Chen Meng, which is abnormal? Don’t just watch the big score.

Some people watch the game and only watch the "big score".

In the WTT Macau Championship in 2023, Sun Yingsha lost 4-0 to Chen Meng in the women’s singles semi-final, and some people felt abnormal.

Last week’s WTT Xinxiang Championship was also a semi-final in women’s singles. Chen Meng lost 4-0 to Sun Yingsha. I wonder if they also felt abnormal?

In WTT Xinxiang Championship, Sun Yingsha scored 4-0 in Chen Meng, and the scores of the four sets were 11-5, 11-5, 11-7 and 11-6.

The score of four games failed to hit the key points, so it can be said that Chen Meng was completely defeated.

In the WTT Macau Championship, Sun Yingsha of Chen Meng scored 4-0, and the scores in four sets were 16-14, 11-6, 11-8 and 11-9.

Chen Meng and Sun Yingsha won the first game 10-9, and then Chen Meng tied the game and won five games in a row, only to win narrowly 16-14.

Sometimes, a small score per game is more telling.

Compare another women’s singles semi-final, although Manyu Wang won Wang Yidi 4-2, but this game is less suspense than Chen Meng’s 4-0 win over Sun Yingsha.

Manyu Wang 4-2 Wang Yidi, the score of six games: 7-11, 11-9, 11-9, 11-6, 5-11, 11-4.

Manyu Wang is tall and arm-length, and her movements will not be restored very quickly, which determines that her forehand and backhand cohesion will not be very smooth in the near stage. What Manyu Wang is afraid of is the players with fast convergence speed and not weak strength. In the face of fast players, she often has to quit the stage and exchange distance for reaction time.

Only with speed and strength, it is possible to penetrate Manyu Wang’s defense.

However, Wang Yidi is not a speed player, and her playing style also depends on the quality of her own veneer, which is similar to that of Manyu Wang.

However, compared with Wang Yidi, Manyu Wang has stronger rotation in returning the ball and higher veneer quality. From a fundamental point of view, Manyu Wang’s strength is higher than Wang Yidi’s.

Therefore, regardless of Manyu Wang’s four-to-several win, as long as it is a best-of-seven game, the chance of surprise is very small. Under normal circumstances, it is only a matter of time before Manyu Wang defeats Wang Yidi.

However, in the semi-final between Chen Meng and Sun Yingsha, after 9-9 in the fourth game, if it wasn’t Chen Meng’s serve wheel and Chen Meng’s serve, but Sun Yingsha reversed the game, the result of the following game would be hard to say.

Before the game, when analyzing the match between Chen Meng and Sun Yingsha, I said: Chen Meng was in a particularly good state this time, and Sun Yingsha experienced high-intensity events in a row, and her state declined, which may add a little suspense to this semi-final.

For players with equal strength, the recent competitive state of the players is very important, and the players’ improvisation has a great influence on the results of the game.

Fan Zhendong’s 3-2 reversal of Lin Shidong in the men’s singles quarter-final of WTT Xinxiang Championship last week is a typical example. Lin Shidong got the match point 10-8 in the fourth game, but Fan Zhendong tied the score. Finally, Fan Zhendong reversed 13-11 to win the fourth game and was tied with a big score. Fan Zhendong won the deciding game 11-8. Moreover, Fan Zhendong finally won the men’s singles championship in Xinxiang Championship.

A game, one or two key points, may lead to a world of difference.

In table tennis, besides paying attention to who wins and who loses, it is better to look at the score of each game.

I’m interested in going to see the players’ respective service wheels, return balls and so on. If you are still interested, then learn about various services, techniques and tactics, table tennis equipment and so on.

So, don’t stop at the level of "0-4 lost". Players are improving, should old fans keep pace with the times?

As for some "extreme fans", they think that the players they like can only win but not lose. Losing is abnormal and fishy. Don’t apply the "rice circle" to competitive sports. Isn’t it good to chase the stars in the entertainment circle?