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
39
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://kaotiyun.com/show/dKeO777K
0
专业英语八级
相关试题推荐
1White-collarcopycatsmaybelessinclinedtopilferthewell-chosenwordsofothersnowthatsoftwaredesignedtoferret
Anassumptionissomethingtakenforgranted.Everyonemakesassumptions--youhavetoinordertosayanything.Asacriticalre
Morethan360,000babiesareborneverydayontheplanet.WhichoneofthemwillgrowuptobeafutureShakespeare,findacur
Everyprofessionortrade,everyart,andeverysciencehasitstechnicalvocabulary,thefunctionofwhichispartlytodesigna
OncefoundalmostentirelyinthewesternUnitedStatesandinAsia,dinosaurfossilsarenowbeingdiscoveredonallsevencont
ThediscoveryoftheAntarcticnotonlyprovedoneofthemostinterestingofallgeographicaladventures,butcreatedwhatmigh
A、thereislittlesupplyB、thereisstillenoughsupplyC、thereisseveraldays’supplyD、thereisonlytwodays’supplyC听力原文中的
ThatLouisNevelsonisbelievedbymanycriticstobethegreatesttwentieth-centurysculptorisallthemoreremarkablebecause
Incrimenovelsthemysteriesseenindetectivestoriesareretained,buttheinvestigationfocusesmoreoncharacterthanonph
ItispossibleforstudentstoobtainadvanceddegreesinEnglishwhileknowinglittleornothingabouttraditionalscholarlyme
随机试题
耳部(颞骨)CT扫描合适的扫描参数是
引起产后出血最常见的原因是
A.脾虚温停B.寒实积滞C.脾虚泄泻D.脾虚食积E.阳虚寒积健脾丸主治的是
患者,女性,54岁。患肝硬化8年,近日出现大部分时间昏睡,可唤醒,有扑翼样震颤,肌张力增加,脑电图异常,锥体束征阳性。此时该患者处于并发症的
硝酸甘油控制心绞痛发作时,最佳的给药途径是()。
建筑群主干电缆(光缆)≤()m,建筑物主干电缆(光缆)≤()m。
有腐蚀建筑物、污染河流、造成土地酸化等危害的是()。
2012年4月,我国与邻国()在黄岩岛海域发生摩擦。
杜威是()的代表。
MicrosoftVisualBasic0包括三种版本,其中不包括______。
最新回复
(
0
)