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  3. Cosmology is sometimes pooh-poohed as more philosophy than science. It asks d

Cosmology is sometimes pooh-poohed as more philosophy than science. It asks d

游客2023-12-17  58
问题    Cosmology is sometimes pooh-poohed as more philosophy than science. It asks deep questions about nature but provides unsatisfyingly vague answers. The cosmos may be 12 billion years old, but it could be as much as 15 billion. The stars began to shine 100 million years after the Big Bang, or maybe it’s a billion. "Our ideas," acknowledges Max Tegmark of the University of Pennsylvania, "have been kind of wobbly."
   But much of the wobble has been fixed, thanks to a satellite known as the Wilkinson Microwave Anisotropy Probe, or W. MAP. Since July 2001, WMAP has been orbiting in deep space, more than a million kilometers from Earth, studying the most ancient light in existence. And in a dramatic reminder that important space science is almost always done by machines, not fragile humans, it reported a series of precision measurements that will finally put cosmology on a firm foundation.
   What the satellite found, says Princeton University’s David Spergel, a theorist on the WMAP team, "is that the universe can be explained with five numbers. "First, the cosmos is 13. 7 billion years old, give or take a negligible couple of hundred million years. Second, the first stars turned on just 200 million years after the Big Bang, Finally, the universe is made of three things in the following proportions: 4% ordinary atoms; 23% "dark matter," whose nature is still unknown; and 73% "dark energy," the equally mysterious force whose antigravity effect is speeding up the cosmic expansion. "This," says astrophysicist John Bahcall, of the Institute for Advanced Study in Princeton, New Jersey, "is a rite of passage for cosmology, from speculation to precision science."
   WMAP learned this and more by scrutinizing the faint whisper of microwaves left over from the Big Bang. Hidden in that radiation are patterns of warmer and cooler spots, marking places where matter was a little more or less dense than average--spots that would eventually evolve into the clusters of galaxies and empty spaces that we see today. These patterns were first detected in crude form by the Cosmic Background Explorer satellite in 1992, But without enough detail for much to be said about them.     But with a resolution some 40 times as sharp as COBE’s, WMAP has plenty to say. "It’s a lot like matching fingerprints," says Spergel. "We ran computer simulations based on many different values for all of the numbers, generated patterns for each and found the one that best matched what we actually saw."
   WMAP also confirmed what earlier experiments had suggested about a basic characteristic of the milverse; the geometry of space-time, in the Einsteinian sense, is flat. That’s consistent with a theory called inflation, which posits that the cosmos underwent a period of turbocharged expansion before it was a second old. "I have to admit," says Bahcall, "that I was skeptical of the picture theorists had put together. Inflation, dark matter, dark energy--it’s all pretty implausible. But this implausible, crazy universe has now been confirmed with exquisite detail."
   That’s not to say that WMAP has answered every question. Nobody knows what dark matter and dark energy are, and the theory of inflation, while strengthened, is far from proved. Beyond that, there are some strange measurements in WMAP’s data that might be mere statistical flukes or might point to some major monkey wrench that could still throw cosmology into turmoil. "We should know better after we get in more data," says Charles Bennett of the Goddard Space Flight Venter, who is the V team leader.
   But cosmologists won’t be sitting around waiting. "You’re going to see a thousand papers based on these results," says Tegmark, who is already working on several. "It’s an exciting time to be in this field" [br] Which of the following statements is NOT true of the cosmos?
选项 A、Microwaves are the medium WMAP used to make measurements.
B、Warmer spots would finally develop into the clusters of galaxies.
C、Dark energy is a decisive factor in the cosmic expansion.
D、The nature of dark matter in space is unknown to scientists.
答案 C
解析 细节题。根据题目顺序及各选项内容定位至第三段。倒数第二句提到warmer and cooler spots:温度较高的区域密度大些，温度较低的区域密度小些，结果前者演化成了星群，后者成了空洞，[B]符合文意。倒数第三句提到WMAP的发现过程：scrutinizing the faint whisper of microwaves．．．，可见microwaves是它的研究介质，[A]符合文意。第四句中的“dark matter，whose nature is still unknown”与[D]意思一致。而提到dark energy时指出：“它也是一种神秘的力量，其反地球引力会加速宇宙扩张”，[C]是对该处内容的夸大，故为答案。
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