首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Cosmology is sometimes pooh-poohed as more philosophy than science. It asks deep questions about nature but provides unsatisfyin
Cosmology is sometimes pooh-poohed as more philosophy than science. It asks deep questions about nature but provides unsatisfyin
admin
2011-02-11
72
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 WMAP. 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% Jo "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 universe: 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."
What can we infer from Bahcall’s comment?
选项
A、WMAP’s findings are quite convincing and he accepted them.
B、WMAP will solve all the problems that have puzzled cosmologists.
C、WMAP’s findings accord with Einstein’s concept of space-time.
D、We may ignore some strange measurements in WMAP’s data.
答案
A
解析
推断题。由题干中的Bahcall定位至倒数第三段。倒数第三句提到Bahcall的说法:I have to admit... that I was skeptical of the picture theorists had put together.Inflation,dark matter,dark energy—it’s all pretty implausible.末句语气一转,指出:但是这个看似不合理的、疯狂的宇宙现在由那些精确的细节得到了证实。由此可以推断正是WMAP的测量结果打消了他对某些宇宙理论的怀疑,故A为答案。C符合首句内容,但该句并非Bahcall的评论,排除。
转载请注明原文地址:https://www.kaotiyun.com/show/dKeO777K
0
专业英语八级
相关试题推荐
1Divorceisoneofthosecreations,likefastfoodandliterock,thathavemorepeoplewillingtoindulgeinitthanpeople
1White-collarcopycatsmaybelessinclinedtopilferthewell-chosenwordsofothersnowthatsoftwaredesignedtoferret
AfaultlinerunsthelengthofNewZealand,whichmeansthatitoftenhas______.
WhichAmericanpresidentwitnessedthedisintegrationoftheSovietUnionandtheWesternizationofEastEuropeancountries?
______referstoasociolinguisticsituationtwovarietiesofalanguageexistsidebysidethroughoutthecommunity,witheach
Humanbeingsarecuriouscreatures,andinnothingmorecuriousthanintheformsofdiversionwhichtheydeviseforthemselves.
A、wheneverythinggoessmoothlyB、whenthesunstandsstillC、forpeople’sappreciationD、foreverydayaspectsoflifeD
Animalsperformmanyusefulandentertainingjobs.Dogsareparticularlyvaluableguidingtheblind,protectingproperty,
今天的老年人是昨天的劳动者。他们对物质文化的发展作出了许多贡献,理所当然应享受物质文化发展的成果。若全社会都把尊敬老人看作当代的美德,人们就会有一种安全感。这使得各个年龄层的人都感到他们将来的日子肯定也是愉快的,就会全力以赴地投入工作。去年,宣武医
然而,或是因为中国人与其他人太不一样,或是因为他们工作起来很有耐心,他们能成功地把表面看来毫无价值的开采地(miningclaim)变为有利可图的东西,这使他们成为爱嫉妒的竞争者们的眼中钉。他们受到了多种形式的骚扰。经常阻止他们在开采地上开矿;一些地区甚
随机试题
WhatdoesJeromesaywashismainworryayearpreviously?
倾转式自动化浇注的铸型到达浇注位置时,碰到(),电磁阀动作,液压缸驱动浇包,开始浇注。
下列说法错误的是()
不属于易化扩散过程的是
模型与原形采用相同介质,为满足黏性阻力相似若几何比尺为10,设计模型应使流速比尺为()。
开发、利用、节约、保护水资源和防治水害的统一规划分为()。
根据《中华人民共和国进出境动植物检疫法》及其实施条例规定,不论输往国家是否有特殊要求,出境货物的木质包装及动植物性铺垫材料均须依照规定实施检疫。( )
下列哪一项不属于外部监督体系?()
新闻编辑(复旦大学2013年研)
Somefuturologistshaveassumedthatthevastupsurge(剧增)ofwomenintheworkforcemayportendarejectionofmarriage.Manywom
最新回复
(
0
)