At first, you may think this question is simple; But when you organize your own language and try to give an answer, you may feel at a loss and don't know how to use words.
This contradiction between intuition and truth reflects most people's vague view of time.
However, no matter how people feel and know, time is always accompanied by our daily life and social production activities. Spectacular dawn, beautiful sunset, maple leaves changing from green to red, geese flying from south to north, the formation and evolution of celestial bodies, the life and death of human beings are all bound by time.
Time is also a basic physical quantity, which is closely related to the development of science and technology. Since ancient times, human beings have used various periodic movements as the standard to measure time, and have created many exquisite instruments for measuring time-watches and clocks.
How to define time
In human's perception and abstraction of the objective world, the most elusive entity is probably time. It can't be seen or touched, it always flows and stubbornly moves forward. People are born and grow in the long river of time, and they are also aging and dying in this long river. Some important experiences in life: childhood, marriage, career failure and success, are all divided by time. "Time flies" and "Time waits for no man". Some people are good at using time and saving time; Some people will waste time and lose time. Therefore, how to make more beneficial achievements and create the highest value of life in a limited time has become an important reason why people attach great importance to time.
In the long-term struggle with nature, human beings not only knew how to make calendars, arrange years and days according to the changing laws of astronomical phenomena and stars, and use them to record important events including their own experiences, but also gradually learned to make various clocks and watches to provide time for daily life. With the progress of science and technology, human's ability to control and control time is constantly improving.
But strangely, for a long time, human beings have not found a scientific definition of time. In other words, people don't know what time is. Psychologists describe time as human consciousness; Physicists believe that time is a measure of movement; For some philosophers, time is another matter. Although they can all write books about time, no one can define time with mutually satisfactory words.
The difficulty of defining time was first put forward by Augustine, Bishop of ancient Greece and Western Rome, more than 500 years ago. He said, "What is time? If someone asks me, I know; If I can explain, I don't know. "
Augustine did a lot of research on time, and he also made some other specious remarks. It can be inferred that what Augustine knows may be people's consciousness or feeling of time; I'm afraid what he doesn't know is the objective time entity that produces these consciousness or feelings.
In science and daily application, the word "time" contains two different but interrelated meanings: time and time interval. The former represents a moment in the long river of time, and the latter represents a time interval. For example, someone asks, "When does the first class start?" He refers to the present; "How long is the first class?" Refers to the time interval.
Time and time interval are expressed in the same units-days, hours, minutes, seconds, etc. But they are different, not the same thing. Time and time interval can express time concretely, but they are not helpful to understand the nature of time.
"What is time?" In the final analysis, this question is related to the answers to some basic questions in epistemology. These basic questions include: Is human feeling a response to objective existence, or is objective existence a combination of human feelings?
Almost all the statements of idealist writers about time are based on the latter. Although they can also describe some characteristics of time in considerable detail, they can't reveal the essence of time after all; When it is difficult for them to find an arguable destination for their views in the fog of time created by themselves, they often have to turn to the gods or describe time as an unknown monster.
After the birth of Marxism, the essence of time began to be truly solved. Marxism holds that the essence of time lies in its materiality, and it is an objective existence that is independent of human will. Time is the most basic form of material existence and movement, which has the basic attributes of the universe and the relationship between the universe and observers. "The existence outside time and space is also absurd." (Engels, anti-Turin, 1970, p. 49) The eternity of material movement and change endows time with infinity. The exposition of the essence of time by Marxist philosophy has opened up a correct way for people to understand time more deeply.
Human sense of time
People and all creatures in nature live in a certain time and space, and all of them develop and change with the passage of time. But unlike other creatures, people can not only perceive time, but also control and control it.
How do people rely on various sensory organs to perceive time? After a long period of development, how did the abstract concept of time come into being?
Just as writers turn their own experiences into literary works, they can recall the past and foresee the future through memory. It is said that memory and foresight are the elements of human intelligence. Whether this is the case or not, we will not discuss it for the time being, but it is people who have learned from the past and created brilliant scientific civilization for their ability to engage in current activities in the future.
Of course, there are also many animals that have little response to time. Someone has done experiments with white rats. He asked the mouse to press the springboard. It was found that if mice were given some food within 25 seconds after pressing the springboard, they would continue to press the springboard repeatedly in order to get paid again. However, if you don't give it food after pressing the springboard for 30 seconds, the mouse will be at a loss, and then it will never be able to associate the future reward (getting food) with the current action (pressing the springboard).
Monkeys are smarter than mice, and their ability to handle time is one step ahead of mice. If we bring two identical opaque cups, one is empty and the other is for food, let the monkey have a look first, and then let it choose later. As a result, you will find that as long as the interval is not more than 90 seconds, monkeys can always find out the cups containing food; If the time exceeds 90 seconds, the monkey's ability to search for food will be greatly reduced, which is completely equivalent to groping.
For human close relative orangutans, its "time consciousness" has taken another big step forward. Not only in the wild, but even in the laboratory (the situation here is very different from that in the wild), orangutans sometimes show amazing ability to control the present in order to achieve future goals. For example, in order to get bananas from high places, chimpanzees will build wooden boxes one by one as ladders to climb up. In fact, the ability of orangutans to cope with the future is close to the edge of human ability, and they can even make "tools"! People see that orangutans in nature sometimes peel off leaves from branches and use them as "probes" to lead them out of termite holes. Of course, orangutans only do this when they see termite caves; If you can't see termites entering the hole, it won't make such a "tool". This shows that orangutans can only deal with the recent and visible future, so half of their "time consciousness" is in the "present" state.
About 10 thousand years ago, slightly clever apes began to learn to make tools. In order to meet the needs in the near and foreseeable future, they use stones as cutting tools and probes like orangutans. After a long time, the harsh natural environment made apes gradually learn to improve their tools. Judging from the many stones with certain shapes excavated from deep sediments in the earth's crust, apes have at least enough foresight to make stones into useful shapes.
Due to the growth of intelligence, the ability to foresee has also been enhanced. About 500,000 years ago, primitive ancients living in China began to learn to use fire for the first time. The use of fire shows that Chinese apes have a certain sense of time and foresight, and began to work by hand, such as collecting dead branches and leaves to keep the fire burning.
About this time (perhaps earlier), human beings invented language. Language is not only a tool for primitive people to transmit information to each other, but also provides conditions for the further development of human time consciousness.
Feel abstract time from time
Man's understanding of time has a very long history. Our understanding of all aspects of time today is the result of the long-term development of this understanding history.
However, human understanding of the nature of time has not been correctly reflected from the beginning. This is determined by some characteristics of the time object itself. Time is one of the basic problems of world outlook. Due to the limitation of people's understanding of the law of material movement in the objective world, in ancient times when science and technology were underdeveloped, people had all kinds of distorted understanding of the nature of time. Even in modern times, even for a long time in the future, some problems involving the nature of time have always been a mystery. Looking at the development process of human understanding of time, there is a feeling that "I don't know the true face of Lushan Mountain, but I am only in this mountain". In the early stage of understanding time, such as the description of "circulation theory" and "finiteness theory", these concepts are ultimately caused by the limitations of intuitive feeling. There is no doubt that intuitive feeling is the basis for people to know things, but we can't really know the true colors of things by this alone. It needs "from image intuition to abstract thinking, from abstract thinking to practice" (Lenin's Philosophical Notes, 1956, page 155), in order to obtain a more correct concept and grasp the laws of things, so as to understand the true colors of things more completely, deeply and scientifically. The emergence of concepts such as day, month and year and the establishment of the theory of uniform time flow indicate that human understanding of time has reached the stage of rational thinking from experience. Concepts such as relativistic effect and curvature of spacetime further deepen this rational thinking.
People's understanding of time stems from the needs of their own development.
It is difficult to discuss this point in the prehistoric stage of human development. What the predecessors left behind was the "fruit", and the "cause" itself can only be speculated by us. It can be inferred from the current data that there are at least three reasons that lead to people's understanding of time and constantly push this understanding forward and deepen.
The first is the need for survival. In ancient times, people lived a nomadic life of fishing and hunting in primitive groups, and used the simplest tools to obtain food through gathering and fishing and hunting, so as to continue their survival. Under smooth circumstances, the food you get every day is barely edible; In case of disaster, we will have to starve. In order to shelter from the wind and rain, they often take natural places such as forests and caves as their fixed places of residence, "work at sunrise and rest at sunset." For the needs of struggle for existence, people in this period had to have the most superficial understanding and familiarity with the time changes caused by the rising and setting of the sun. For example, when to start and how far to hunt, so as to get back to the residence before sunset. It is very dangerous for them not to return to the cave before sunset. It can be inferred that this is the beginning of human understanding of the alternation of day and night and the length of day. Of course, the understanding at this time is very superficial, and it can even be said that it is not much better than the understanding of some animals. Because people in this period have a narrow range of activities, their brains are poor in abstract thinking and judgment.
The second is the need to develop production. With the development of production, primitive humans who lived by gathering, fishing and hunting gradually transitioned to an agricultural society. In the production of agriculture and animal husbandry, the sowing, cultivation, harvesting and storage of crops should be closely coordinated with the seasonal changes. You can get a bumper harvest at any time, and a slight mistake will lead to a poor harvest. If the primitive society is inseparable from the concept of "day", then the agricultural society is inseparable from the knowledge of months, seasons and years. The ancients initially determined the months and seasons according to phenological phenomena such as withered vegetation, birds and animals, and guided the production of agriculture and animal husbandry. Phenological changes and changes in the natural environment are repeatedly printed in everyone's mind, and the periodic changes of astronomical phenomena have also left a deep impression on people. The interdependence between them will undoubtedly be gradually understood by people. Therefore, it is natural to determine these longer time units (months, seasons and years) than the sun by observing the movement changes of the sun, moon and stars.
The third is the need to establish a materialistic world outlook. As mentioned above, time is one of the two basic components of human understanding of the universe (the other is space). In other words, it is the main content of people's world outlook. As far as the world outlook is concerned, there is a difference between idealism and materialism. Since the emergence of classes in human society, the ruling class has always fabricated various absurd theories on the issues of time and space to deceive the people and consolidate its rule. And all people who study natural phenomena objectively, although unconsciously standing on the position of materialism, admit the objective reality of time and can understand things according to their true colors. So in a sense, the scientific understanding of time is established in the struggle with idealism (religious superstition). This is a very important stage in the history of scientific development. I like older scientific knowledge such as astronomy, biology, geology, anthropology, etc. The scientific knowledge of time germinates and grows in a harmful jungle-the jungle of witchcraft and superstition, and this harmful jungle always destroys the seedlings of knowledge again and again and prevents it from growing. This is a historical fact that the history of scientific development shows people.
Myths and legends about time
We can also rely on myths and legends handed down from distant times to find their rarity and infer the ancients' understanding of time. Studying scientific problems from myths or legends seems difficult to understand at first glance. Myth and science are opposites, which is correct in modern times. But in ancient times, especially in distant ancient times, myth, as an ideology, reflected primitive people's simple imagination of transforming nature and their understanding of nature.
There are many legends about the myth of time concept at home and abroad. Are related to the myth of the origin of the universe. In our country, the so-called origin of time is included in Pangu's creation myth. According to "Thirty-five Calendars", "Heaven and earth are chaotic like chickens, and Pangu was born in them." Later, Pangu chiseled the sun, the moon and the stars from the chaotic cliff, saying that "Yang Qing is the sky and cloudy is the earth", thus creating the universe, and time began to flow. Pangu accompanied the ancestors of animals-dragon, wind, turtle and snake. After Pangu's death, his body became the whole earth: his head became a mountain, his muscles became soil, his blood became rivers and lakes, the wind was the breath after his death, and the bugs that crawled over him became people. According to legend, it was about 18000 years ago.
There are many legends about He in China myths and legends. According to "Yao Dian of Shangshu", He is in charge of "observing the sun, the moon and the stars and respecting people", and is the official in charge of observing time and determining time. He lived in the 22nd century BC. This reflects the important position of observation time in the agricultural society at that time. Until today, we still call the work of determining, maintaining and providing time service. The origin of the word "timing" probably comes from this.
Similar to myth, there are legends about Chang. "Shan Hai Jing Ye Xi Jing" contains: "There is a woman bathing in the wild. The emperor's wife often gave birth twice in ten months, so she began to take a shower. " It is worth noting that Di Jun's wife often gave birth to 12 moons! This just shows that the lunar calendar has twelve moons a year.
There is also a little story that is not taken seriously in China's myths and legends. In fact, it has a deep relationship with the emergence of calendars. This story can be found in History of Weft (Volume 9) and Qiu Tianzi. "Yao is the son of heaven, born in the court. Emperor is a calendar. " Yi Shu Ji also said: "Yao is the king of benevolent government ... He was born in the grass." The so-called pod or grass here refers to a kind of grass that grows on the edge of the steps. From the beginning of each month, it bears 1 pod every day and 15 pods every half month. From 16, drop 1 pod every day. If it is a big month (30 days), it will be over; If it is an abortion (29 days), there will be 1 pod that will not wither. This myth reflects the ancient people's understanding of the moon, and its implication is also very obvious. So in the Han Dynasty, Zhang Heng actually made a wooden pod as a calendar.
In ancient Egyptian myths and legends, the earth is the body of Xibu, a male god wearing plants, and the sky is the elegant goddess Benjamin Luthi. It is said that at first, the west and Benjamin Luthi were closely connected with still water. Later, a new atmospheric spirit emerged from the original water, separating them and creating heaven and earth. From the day of creation, Sotheby's, the god of time, began to calculate time. In the Egyptian calendar year, the first month of the year is named after Sos. The ancient Egyptians also believed that Saussure had the power to dominate the soul after death. It holds the symbol of human life in its left hand and depicts the soul after death with an iron pen in its right hand.
In the most popular Greek myth, the earth is supported by a god named Atlas. He is the brother of Prometheus, and Prometheus is the god who stole fire from the world. Because he offended Zeus, the king of the gods, he was punished and became a "Tianzhu". Ancient Greece also had the idea that heaven and earth were based on chaos. Hissiad's "Divine Spectrum" describes the primitiveness of the world as that the earth "produced darkness and night from chaos, and after it mated with darkness, it produced day and night from night". Due to the emergence and development of agriculture, the ancient Greeks initially regarded Cronus as the father of time. Kronberg is the youngest son of Juranas and Gaia. He overthrew his father and gained the dominant position, but he was afraid that his descendants would follow his example. So he tried to eat the children when they were born, and the result was unsuccessful. Later, his other son Zeus followed in his footsteps, overthrew him and became the head of the gods. After Zeus ruled the gods, he put his youngest brother in charge of time, fate and agriculture. The sickle in his brother's hand is a tool to cut the year into pieces.
In ancient Babylon, people thought that the earth was a flat plate with land in the middle and oceans around it. There are steep mountains outside the ocean supporting the round sky, and the stars are listed in the round sky. The change of day and night is because there is a giant tube under the earth. The sun is in the sky during the day and the curtain is in the west in the evening. At night, it dives into the pipe and runs to the other end. Rosty Yi reappeared at the east entrance. The ancient Babylonians lived on the flat plains of the Euphrates River basin. When they observe the distant scenery, they often only see the scene disappearing on the horizon, which leads to the above idea.
There are many myths about time in ancient Chinese and foreign nationalities, and these legends are generally semi-intuitive and semi-mythical. Today, they may find it ridiculous. But this is an insurmountable stage in the history of human cognition. It reflects people's desire to conquer and dominate natural forces with imagination and with the help of imagination, which has positive significance in the early days. However, with the emergence of class society, the ruling class used this myth to mix with the consciousness of the exploiting class, making it a tool to poison and deceive the working people. This completely lost its original meaning and became a reaction to science.