第46篇 How the First Stars in the Universe Came into Existence
　　Researchers believe that our universe began with the Big Bang1 about 13 billion years ago, and that soon after that event, matter began to form as small dust grains and gases. How the first stars formed from this dust and gas has been a burning question2 for years, but a state-of-the-art3 computer simulation now offers the most detailed picture yet of how these first stars in the universe came into existence.
　　The composition of the early universe was quite different from that of today, and the physics that governed the early universe were also somewhat simpler. Dr. Naoki Yoshida and colleagues in Japan and the U. S. incorporated these conditions of the early universe, sometimes referred to as the "cosmic dark ages," to simulate the formation Of an astronomical object that would eventually shine its light into this darkness.
　　The result is a detailed description of the formation of a protostar4 the early stage of a massive primordial star of our universe -and the researchers' computer simulation sets the bar5 for further investigation into the star formation process. The question of how the first stars evolved is so important because their formations and eventually explosions provided the seeds for subsequent stars to come into being.
　　According to their simulation, gravity acted on minute density variations in matter, gases, and the mysterious "dark matter" of the universe after the Big Bang in order to form this early stage of a star - a protostar with a mass of just one percent of our sun. The simulation reveals how pre-stellar gases would have actually evolved under the simpler physics of the early universe to form this protostar. Dr. Yoshida's simulation also shows that the protostar would likely evolve into a massive star capable of synthesizing heavy elements, not just in later generations of stars, but soon after the Big Bang.
　　"This general picture of star formation, and the ability to compare how stellar objects form in different time periods and regions of the universe, will eventually allow investigation into the origins of life and planets," said Lars Hernquist, a Professor of Astronomy at Harvard University. "The abundance of elements in the universe has increased as stars have accumulated," he says,"and the formation and destruction of stars continues to spread these elements further across the universe. So when you think about it, all of the elements in our bodies originally formed from nuclear reactions in the centers of stars, long ago."
　　Their simulation of the birth of a protostar in the early universe signifies a key step toward the ambitious goal of piecing together the formation of an entire primordial star and of predicting the mass and properties of these first stars of the universe. More powerful computers, more physical data, and an even larger range will be needed for further calculations and simulations, but these researchers hope to eventually extend this simulation to the point of nuclear reaction initiation when a stellar object becomes a true star.
　　詞匯：
　　astronomical adj. 天文的；天文學(xué)的 pre-stellar adj. 前恒星的 synthesize v.合成，綜合
　　protostar n.原恒星 stellar adj.恒星的；星球的 primordial adj. 原始的
　　注釋：
　　1. the Big Bang：宇宙大爆炸，創(chuàng)始大爆炸。這是天體物理學(xué)關(guān)于宇宙起源的理論。根據(jù) 大爆炸理論，大約在 130 億年前，宇宙所有的物質(zhì)都高度密集在一點(diǎn)，有著極高的溫度 ， 因而發(fā)生了巨大的爆炸。大爆炸以后，物質(zhì)開始向外大膨脹，就形成了我們今天看到的 宇宙。但是，宇宙大爆炸僅僅是一種學(xué)說，是根據(jù)天文觀測(cè)研究之后得到的一種設(shè)想。
　　2. burning question：最吸引人的問題，亟待解決的問題。
　　3. state-oe-the-art：形容詞，意思是“最新的”、“達(dá)到最高技術(shù)水平的”、“代表當(dāng)前科 技發(fā)展水平”。
　　4. protostar 原恒星，就是處于“原始狀態(tài)”（處于慢收縮階段的天體）的恒星。原恒星由 “大爆炸”后產(chǎn)生的星際云演變而來。
　　5. sets the bar：制定標(biāo)準(zhǔn)
　　練習(xí)：
　　1. What can the state-of-the-art computer simulation tell us about?
　　A How matter began to form the first stars after the Big Bang.
　　B How the Big Bang marked the beginning of our universe.
　　C How the Big Bang took place about 13 billion years ago.
　　D How dust grains and gases form after the Big Bang.
　　2. What does the "astronomical object" (paragraph 2) refer to?
　　A The early universe. B Cosmic dark ages.
　　C The first star formed in the universe. D Dust grains and gases.
　　3. What does the word "minute" mean in the expression "minute density variations"?
　　A A unit of time equal to one sixtieth of an hour. B A short interval of time.
　　C Exceptionally large. D Exceptionally small.
　　4. According to paragraph 4, what is NOT true about a protostar?
　　A It had a mass of one percent of the sun.
　　B It was developed into a massive star before the Big Bang.
　　C It began to combine heavy elements after it evolved into a massive star.
　　D It was evolved from pre-stellar gases.
　　5. All except one of the following indicate the goals of the simulation project. Which one is it?
　　A To know more about the mass and properties of the first stars of the universe.
　　B To apply the simulation to the study of nuclear reaction initiation.
　　C To know how a stellar object becomes a true star.
　　D To obtain a detailed picture of the early universe before the Big Bang.
　　答案與題解：
　　1. A 第一段最后一句告訴我們說，最先進(jìn)的計(jì)算機(jī)模擬能詳細(xì)描述 how these first stars in the universe came into existence。該段第一和第二句告訴我們，大爆炸 后，粉塵和氣體開始聚集成物質(zhì)，這些物質(zhì)形成了宇宙中的星球。其他三選項(xiàng)都是錯(cuò)誤 的理解。
　　2. C 根據(jù)上下文，astronomical object 指的是上段第二句中的“first stars”，即下面 一段第一句中的“protostar”。
　　3. D minute 在這里是形容詞，意思是“極其細(xì)微的”，讀作：/mai'nju:t/。
　　4. B A、C 和 D 的表述都可以在本段中找到。從上文和該段的最后一個(gè)句子可以得知，原 恒星進(jìn)化的過程不是在宇宙大爆炸之前發(fā)生。所以，應(yīng)該選擇 B。
　　5. D A 是最后一段第一句句子的表述內(nèi)容，B 和 C 是文章最后一句的表述內(nèi)容。D 是對(duì)文 章的錯(cuò)誤理解。