Middle school student writing practice and examination

Author: Su Xiuyun
Publisher:
Publish Date: 2006-04-01
Features:
Sky is Not Empty
In Jiangsu, Xuning – When people mention the sky, they often think of the boundless and vast universe, evoking a sense of emptiness, as if the universe were a space devoid of matter. Is the universe truly empty? No! The universe itself is an objective material world that can be described. It is not only boundless in space and endless in time but also infinite in matter. It is the entirety of the vast expanse of space and the various substances and energies within it.
There are countless celestial bodies in the universe, and celestial bodies are composed of vast amounts of matter. The Earth, where humans reside, is also a celestial body. Our Earth is part of the solar system, which is composed of the Sun, planets, moons, asteroids, comets, meteoroids, and interstellar matter. It is an enormous spherical range with a radius of 590 billion kilometers. This vastness is difficult to imagine with ordinary, but this range is merely an extremely tiny part of the even larger Milky Way system, a celestial body system. The Sun is just one of the 130 billion stars within the Milky Way. It orbits the center of the Milky Way, located over 300 trillion kilometers away, leading the entire solar system.
Clearly, the Sun is just a speck of sand in the Milky Way, and the Earth is like dust within that speck. From this, one can imagine the immense amount and diversity of matter in the Milky Way! With the advancement of science and technology, humans have discovered many other extragalactic systems. Like the Milky Way, they contain numerous celestial bodies, meaning they contain vast amounts of matter. Perhaps, on the "bridge" beyond the Milky Way, another pair of stars like the Cowherd and the Weaver are meeting!
Additionally, besides stars, planets, and galaxies, the universe contains other types of matter, such as black holes, which are the final destinations of aging stars. They have extremely large masses and contain a tremendous amount of matter. There are also nebulae, which are clouds and mist composed of interstellar gas and dust.
However, observations have shown that the universe is expanding, and all galaxies are moving away from us at an astonishing speed. These galaxies resemble small spots on a balloon. As the balloon is inflated further, the distance between the spots increases, causing them to move farther apart. It is estimated that in a few hundred billion years, it will be difficult to observe other celestial bodies beyond the solar system. Yet even then, the sky will not be empty, because matter is eternal.
Review
Scientific knowledge can arm people's minds, helping them understand the complex and vast world and clarifying the structure and changes of the objective world we live in. The author of Sky is Not Empty uses the scientific knowledge he has acquired to explain the objectivity and infinitude of the universe, thereby proving the truth that "the sky is not empty."
In writing this expository essay, the author employs numerous scientific data and terminology. The concepts are accurate, the language is clear and accessible, and the logical order of the explanation is also very clear. From the Earth to the solar system, and from the solar system to the Milky Way, the scope expands from small to large, giving a clear impression. It is evident that the author has a thorough understanding of the knowledge he has learned before writing this article.
It is particularly noteworthy that the author uses vivid and appropriate metaphors when describing the vast universe, making the reading experience engaging and easy to understand.