首页
登录
职称英语
Cosmology is sometimes pooh-poohed as more philosophy than science. It asks de
Cosmology is sometimes pooh-poohed as more philosophy than science. It asks de
游客
2023-12-16
69
管理
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." [br] 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.tihaiku.com/zcyy/3277530.html
相关试题推荐
"Finagle"isnotawordthatmostpeopleassociatewithscience.Onereasonw
"Finagle"isnotawordthatmostpeopleassociatewithscience.Onereasonw
Acommonresultofbeingfrustratedisanactofaggression,sometimesviolen
Acommonresultofbeingfrustratedisanactofaggression,sometimesviolen
Intheevenings,theygotothemall.Onceaweekormore.Sometimes,theyeve
Intheevenings,theygotothemall.Onceaweekormore.Sometimes,theyeve
Intheevenings,theygotothemall.Onceaweekormore.Sometimes,theyeve
Perhapsit’stheweather,whichsometimessealsLondonwithagrayceilingfor
Perhapsit’stheweather,whichsometimessealsLondonwithagrayceilingfor
Perhapsit’stheweather,whichsometimessealsLondonwithagrayceilingfor
随机试题
1Weoftenhearpeopleasksuchaquestion:Whydobadthingshappentogo
根据支付结算法律制度的规定,单位、个人和银行在办理支付结算时,应当遵守的基本原则
在“0”、“1”等概率出现情况下,包含直流成分的码是:()A.AMI码 B
建筑内部装修工程的防火施工与验收,按照装修材料种类分为()及其他材料几类。这几
生产经营单位应当制定本单位生产安全事故(),与所在地县级以上地方人民政府组织制
A.食管静脉曲张破裂出血 B.反流性食管炎出血 C.食管贲门黏膜撕裂综合征
我国交易所市场对附息债券的计息规定有( )。 Ⅰ.全年天数统一按365天计算
气体灭火系统中选择阀有明显碰撞变形属于()缺陷(A)一般(B)严重
下图是正方体的外表面展开图,下面哪一项能由它折叠而成? A.如上图所示 B.
下列属于免征耕地占用税的是()。A.飞机场跑道占用的耕地 B.农村住宅占
最新回复
(
0
)