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
考研
Compared with their cosmologist(宇宙学家) colleagues, cosmogonists(星源学家) can sound a little old-fashioned. Edgar Allen Poe turned to
Compared with their cosmologist(宇宙学家) colleagues, cosmogonists(星源学家) can sound a little old-fashioned. Edgar Allen Poe turned to
admin
2010-01-13
72
问题
Compared with their cosmologist(宇宙学家) colleagues, cosmogonists(星源学家) can sound a little old-fashioned. Edgar Allen Poe turned to the mysteries of cosmogony in an 1848 public lecture, just reprinted by Hesperus Press. And we encountered a reference to cosmogonists most recently in a new edition of Poe’s prose poem Eureka.
What’s the difference between cosmologists and cosmogonists? Just two letters and a few billion light years. Cosmologists worry about where the Universe came from, cosmogonists with how the Solar System formed. The interesting thing is that one-and-a-half centuries after Poe, they still can’t reach agreement on what happened in the nearest 5 light years of space.
What’s the problem? It turns out that there are a couple of competing explanations for why our neighbourhood is the shape it is, as well as several bizarre anomalies in the data. Cosmogonists know that the Solar System is essentially flat. With the exception of two tiny outliers, Mercury and Pluto, the orbits of all the other planets lie in very nearly the same plane. And most cosmogonists agree that this is because the planets themselves formed from a nebular(星云状的)disc orbiting the early Sun, which had itself coalesced out of the same cloud of gas and dust.
But there’s a catch. If the planets and the Sun came from the same nebular disc, then the Sun’s equator should lie in the planetary plane. It doesn’t. The Sun leans over at an angle of 7.25° The majority of cosmogonists insist that the angle is so close to zero that it really doesn’t matter. Anyway, they add, the Sun has been losing mass for most of its life, and may have slipped a little.
The remaining minority aren’t having this. How can 7.25° be the same as zero? The Sun and the planets did come from cosmic dust, they say, but not from the same cloud of material. The Sun took shape somewhere in the Galaxy. Then it sailed along and picked up the planets—or perhaps the gas and dust that gave birth to them—elsewhere.
Is a tilting Sun the cosmogonists’ only headache? Not at all. It’s also hard to agree on how the outer planets formed. Far out in the nebular disc, matter would have been so spread out that it couldn’t quickly have dumped together. Some suggest planet-sized gravitational instabilities, others can find no reason for Uranus and Neptune to have formed yet.
The closer you get to home, it seems, the deeper the mysteries.
Most cosmogonists believe that ______.
选项
A、the Sun’s equator lies in the planetary plane
B、the Sun leans over because of loss of mass
C、the Sun and the planets have different origins
D、the Sun took shape somewhere in the Galaxy
答案
B
解析
从本文的第4段可以了解到,大多数星源学家把太阳有7.25度倾斜度这一事实归因于太阳物质的损失:Anyway,they add,the Sun has been losing mass for most of its life,and may have slipped a little.
转载请注明原文地址:https://kaotiyun.com/show/ejmi777K
0
在职申硕(同等学力)英语
相关试题推荐
关于先天性髋关节脱位的叙述,下列哪项不正确
A.类风湿因子B.碱性磷酸酶较高C.组织相容抗原(HLA-B27)D.酸性磷酸酶较高对强直性脊柱炎具有诊断意义的指标是
IfyoureadCanadianEnglishDictionaries,youAcertainlyfindbothAmericanandBritishspellingsBlisting,andthefirstword
Revengeisoneofthosethingsthateveryoneenjoys.Peopledon’tliketotalkaboutit,though.Justthesame,thereisnothing
HowmanydollarsdidMissJoanhandtoMr.Greenly?Thephrase"subjecttochangewithoutnotice"suggests______
WhatdoTimeWarnerandMatsushitahaveincommon?Whichofthefollowingistrueofthemedia?
Woman:I’mreallybehindwithmyproject.Canyouhelpme?Man:I’mafraidyoubitoffmorethanyoucouldchew!Question:What
A:CanIborrowyourgeographynotesfromProfessorJohnson’sclass?.B:______
Ihaveaninfatuation(迷恋)withautumn.Thecolorsoftheseason,andthesmells,havealwaysthrilledme.Ihavealwaysfoundjoy
GermanChancellorOttoVonBismarckmaybemostfamousforhismilitaryanddiplomatictalent,buthislegacyincludesmanyoft
随机试题
加强腹股沟管前壁的疝修补方法是()
顺铂的英文名为环磷酰胺的英文名为
如患者平时疲倦乏力,常白日汗出不止,活动后加重,辨证时应诊为()
预应力可使混凝土构件在使用荷载作用下不致开裂或推迟开裂,或者使裂缝宽度减小。()
在图4-74中,将圆环的惯性力系向O点简化,其主矢F1和主矩MIO的数值为()。
国内某公司在海外直接投资取得并汇回的利润,应计入国际收支平衡表中经常账户的()项目。
下列叙述中正确的是
Astheglobalvillagecontinuestoshrinkandculturescollide,itisessentialforallofustobecomemoresensitive,moreawa
TheF.B.I.TheF.B.I,istheFederalBureauofInvestigation./ItisthemaininvestigatingagencyoftheDepartmentof
TopicOnTeacher-studentRelationshipForthispart,youareallowed30minutestowriteashortessayentitledOnTeacher-st
最新回复
(
0
)