If you have a basic understanding of ancient astronomy in China, you will find that ancient astronomy in China is actually very developed. After consulting the literature, it is found that there are three main worldviews in ancient China, namely, the theory of covering the sky, the theory of muddy sky and the theory of revealing the night. We might as well walk into these three views of celestial bodies one by one, and have a deep understanding of their views of heaven and earth and the wisdom of the ancients.
First, the sky is round:
Second, Huntian said:
The basic view of Huntian theory is that all the stars in the sky are distributed on a "celestial sphere", while the sun, moon and stars are attached to the celestial sphere and keep running. From this point of view, it is undoubtedly similar to modern spherical astronomy.
Third, Michelle Ye said: Heaven has no quality.
From the first two astronomical viewpoints, whether it is the theory of covering the sky or the theory of muddy the sky, the celestial body is regarded as a sphere, that is, an entity concept. Compared with these two concepts, Michelle Ye Theory is undoubtedly an ideological revolution. Michelle Ye said, "The sun, the moon and the stars naturally float in the void, and when they stop, they will be alive." That is, the whole celestial body floats in gas. In fact, the viewpoint in Michelle Ye's Theory originated very early. For example, Zhuangzi Xiaoyao thinks that "the sky is gray, and its positive color is evil? Is it distant, omniscient and extremely evil? " That is, the whole world is made up of qi, which is infinite. Later, Song Shuo and Yin Wen inherited Zhuangzi's view of vitality and traced the origin of everything in the world to "vitality". Later, Keiko, a famous artist, put forward the famous "Ten Historical Events" in the history of China's philosophy. One of his viewpoints is that "no one who surpasses the greatest is called a freshman;" To the smallest, it is called small. " The idea that the universe is infinite and infinitesimal has become the ideological basis of Michelle Ye's theory.
After talking about the ancient world view, what is the difference between the modern world view?
2 1 century has come, the century has changed, and the Millennium carnival has taken place, but people have not forgotten those problems that have plagued mankind for a long time. People are eager to learn more about nature by finding the answers to these questions. Is the universe eternal? How big is the universe? When was the universe born? How did the matter in the universe come from? There are too many questions about the universe, and people have raised many such questions since ancient times.
When man looked up at the sky for the first time and saw the vast sky and twinkling stars, he couldn't help wondering how it all happened. Every nation and every era has various legends about the formation of the universe. But they are all beautiful fairy tales based on thinking and fantasy.
Today, with the development of science and technology, human beings have a powerful tool to understand nature, but the cause of the universe is still inconclusive and still in the hypothesis stage. To sum up, there are roughly the following assumptions.
The first hypothesis is "the universe is eternal". This hypothesis holds that the universe is not unstable. The stars in the universe, their number and distribution and their spatial movement have been in a stable state since the beginning of time, and the universe is eternal. Astronomers who hold this hypothesis divide the matter in the universe into several categories, such as stars, asteroids, meteorites, cosmic dust nebulae, radio sources, pulsars, quasars and interstellar media. It is considered that these substances are in a state of balance between force and matter on a large scale. In other words, some stars are annihilated in one place, while others must be born in another place. The universe as a whole is stable, and even if it changes, it is only a local change.
The second hypothesis is the "layered theory of the universe", which holds that the structure of the universe is hierarchical, the stars are hierarchical, the galaxies formed by the collection of stars are hierarchical, the galaxy clusters formed by the combination of several galaxies are hierarchical, and some galaxy clusters form super galaxies to become higher levels.
The third hypothesis is the "big bang" theory that many scientists agree with so far. This view was put forward by famous American astrophysicists Gamov and Friedman. They believe that about 20 billion years ago, all the celestial bodies we saw today were concentrated together, forming a primitive fire with a huge density and a temperature as high as 65.438+0 billion degrees. Ball. During this period, the sky was full of radiation, and stars and galaxies did not exist. Later, for some reason, the original fireball exploded, and the substances that made up the fireball were sprayed in all directions, gradually cooled down and the density began to decrease. Two seconds after the explosion, protons and neutrons are generated at the high temperature of 1000 billion degrees, and in the following 1 1 minute, the free neutrons decay, thus forming the nuclei of heavy elements. After about/kloc-0.0 million years, hydrogen atoms and atoms were produced. In this 1 10,000 years, the substances scattered in space began to combine locally, and these substances condensed into stars of nebulae and galaxies. Most gases become stars during the development of nebulae, and some become interstellar media due to the gravity of stars.
Since then, scientists have built a space telescope and named it Hubble, hoping to use it to determine the Hubble constant. Hubble constant is the expansion rate of the universe named after Hubble, which has been the most important number in the universe for many years. The physical meaning of Hubble constant is the ratio of the speed and distance of stars moving away from each other. The larger the constant value, the shorter the time for the universe to expand to today's size, and the younger the universe. It relates to the age of the universe now, not only to the past of the universe, but also to the future of the universe. If the universe has a beginning, will it have an end? The universe originated from nothing. Is the final destination also "nothing"?
From the beginning, people have had a heated debate about Hubble constant. According to Hubble's own measured values, it can be inferred that the age of the universe is about 2 billion years old, but the earth is 4 billion years old, which is obviously impossible. Obviously, the universe should have been born before the planets in it. Since 1970s, scientists have been measuring Hubble constant by various means and obtained different results. However, the age of the universe calculated by people based on these values is quite different. On the one hand, scientists argue endlessly about Hubble constant, on the other hand, scientists have determined the ages of some stars more accurately. At present, astronomers have measured that some of the oldest galaxies in the Milky Way are about 65.438+0.6 billion years old. Based on this, it is speculated that the BIGBANG can only occur before 65.438+06 billion years, and according to some recent observations made by scientists with Hubble telescope, it is estimated that the age of the universe is about 65.438+02 billion years. This conclusion proves that the universe is indeed younger than the ancient galaxies that exist in it. If the calculation result is correct, it can only show that the original hypothesis is wrong, and the universe may not have been born from an explosion.
The age of the universe is so "small" that once again a person's life experience becomes mysterious in people's eyes. 1999 In September, the famous Indian astronomer Nal Licar and others challenged the Big Bang theory and put forward a new theory of the origin of the universe. They named their research achievement "metastable cosmology", which is the most important point in the new concept jointly put forward by Nal Licar and three other scientists. They believe that the universe was not formed by a big explosion, but by several small-scale explosions. This new theory holds that the universe is a huge energy pool from the beginning, which is called "creation field", while the Big Bang theory describes a starting point without time and space. In this energy field, successive explosions gradually formed the embryonic form of the universe. Since then, small-scale explosions have occurred continuously, leading to the expansion of local space, which is fast and slow, and together forms the expansion of the whole universe. People used to think that the universe had no beginning or end in time and no end in space. Later, in the observation, people found that the universe was still expanding, but the speed slowed down, which formed a brand-new concept of finite universe, which almost completely replaced the old concept of infinite universe. According to observations, cosmologists have calculated that it takes about 80 billion years for the universe to explode at a small point in hyperspace, expand first and then contract, and finally die and dissipate. Now it is only about1600 million years, and everything in the universe will gradually converge to the center in the next 60 billion years. By then, space will come to an end and the universe will cease to exist. Just as Supergiant star burns completely in a thermonuclear, gravity collapses, and all matter instantly shrinks to the center, forming a black hole that we can't see now and becoming an invisible metamaterial. Maybe this is the model of the death of the universe.