How the First Stars in the Universe Came into
Existence
How the first stars formed from this
dust and gas has been a burning question for years, but a state-of-the- art
computer simulation now offers the most detailed picture yet of how these first
stars in the universe came into existence, researchers say. 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 protostar-the early stage of a massive primordial star of
our universe, and the researchers' computer simulation, which has been called a
"cosmic Rosetta Stone." sets the bar for further investigation into the star
formation process. The question of how the first stars evolved is so important
because their formations and eventual 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 geneal
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 originsof life and planets, " said Lars Hernquist, a
Professor of Astronomy at Harvard University and a coauthor of this latest
report. "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. "Dr.
Yoshida has taken the study of primordial star formation to a new level with
this simulation, but it still gets us only to the halfway point towards our
final goal. It is like laying the foundation of a skyscraper, " said Volker
Bromm, Assistant Professor of Astronomy at the University of Texas, Austin and
the author of a companion article. "We must continue our studies in this area to
understand how the initially tiny protostar grows, layer by layer, to eventually
form a massive star. Buthere, the physics become much more complicated and even
more computational resources are needed."
单选题
According to the first two paragraphs, the early universe ______.
单选题
What does the state-of-the art computer simulation tell us about?
A. How the Big Bang occurred about 13 billion years ago.
B. How "cosmic dark ages" came into existence.
C. How dust grains and gases were formed after the Big Bang.
D. How the first stars came into being after the Big Bang.
【正确答案】
D
【答案解析】[解析] 根据第一段内容“but a state—of-the—art computer simulation now offers the most detailed picture yet of how these first stars in the universe came into existence”可知，一种最先进的电脑模拟系统可以提供宇宙中最初的星辰产生的最详细的图片，由此可知，答案为D。
单选题
What does the "astronomical object" in paragraph 2 refer to?
A. cosmic dark ages.
B. dust grains and gases.
C. a protostar.
D. the early universe.
【正确答案】
C
【答案解析】[解析] 根据第二段内容“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.”可知，这一时期有时也被称为“宇宙的黑暗时代”，模拟了最终在夜空中闪耀的天体的形成过程，所以选C。
单选题
According to paragraph 4, what is NOT true about a protostar?
A. It developed into a massive star during the Big Bang.
B. It evolved from pre-stellar gases.
C. It was able to integrate heavy elements when evolving into a massive
star.
D. It had a mass of one percent of the sun.
【正确答案】
A
【答案解析】[解析] 根据第四段内容“the mysterious 'dark matter' of the universe after the Big Bang”可知，A项说法错误，所以答案为A。
单选题
According to the last paragraph, all of the following are goals of the
simulation project EXCEPT ______.
A. to know more about the mass and properties of the first stars of the
universe
B. to simulate the process of how the early universe began
C. to apply the simulation to the study of nuclear reaction initiation
D. to discover the truth about the formation of a protostar
【正确答案】
B
【答案解析】[解析] 根据最后一段内容“taken the study of primordial star formation to a new level with this simulation, ”We must continue our studies in this area to understand how the initially tiny protostar grows, layer by layer, to eventually form a massive star”可知，只有选项B没有提到，所以答案为B。