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
Familiar as it may seem, gravity remains a mystery to modern physics. Despite several decades of trying, scientists have failed
Familiar as it may seem, gravity remains a mystery to modern physics. Despite several decades of trying, scientists have failed
admin
2021-09-17
65
问题
Familiar as it may seem, gravity remains a mystery to modern physics. Despite several decades of trying, scientists have failed to fit Einstein’s general theory of relativity, which describes how gravity holds big objects together, with the quantum mechanics (an extension of statistical mechanics based on quantum theory) he pioneered, which describes the tiny fundamental particles of which matter consists and the forces by which they interact. Recent discoveries have highlighted further problems.
Many physicists are therefore entertaining the idea that Einstein’s ideas about gravity must be wrong or at least incomplete. Showing exactly how and where the great man erred is the task of the scientists who gathered at the "Rethinking Gravity" conference at the University of Arizona in Tucson this week.
One way to test general relativity is to examine ever more closely the assumptions on which it rests, such as the equivalence principle: that gravity accelerates all objects at the same rate, regardless of their mass or composition. This principle was famously demonstrated by Galileo Galilei some 400 years ago when he simultaneously dropped cannon and musket balls, and balls made of gold, silver and wood, from the Tower of Pisa. Each appeared to hit the ground at the same time.
A more precise test requires a taller tower. In effect, researchers are sending balls all the way to the moon and back. Tom Murphy, of the University of California, San Diego, and his colleagues fire laser beams from the deserts of New Mexico at reflectors placed on the moon by American and Russian spacecraft in the late 1960s and early 1970s. They use a telescope to capture the small fraction of the light that returns. Because the speed of light is known, they can calculate the distance between the Earth and the moon from the time taken for light to pass through it.
According to general relativity, because the Earth and the moon orbit the sun, they should "fall" towards it at the same rate, in the same way as Galileo’s balls fell to the ground. By repeatedly measuring the distance between them, scientists can calculate the orbits of the Earth and the moon around the sun relative to each other. If the equivalence principle were violated, the moon’s orbit around the Earth would not appear straight, either towards or away from the sun. So far, Dr Murphy told the conference, these experiments have merely confirmed the equivalence principle to one part in 10 trillion. Dr Murphy and his colleagues hope that even more precise measurements could ultimately show general relativity to be only approximately correct. This would usher in a new revolution in physics.
It is stated in Paragraph 1 that the theory of relativity
选项
A、is beyond all the current scientists’ understanding.
B、has failed Albert Einstein for years.
C、seems at odds with the quantum mechanics.
D、is useful in holding big things together.
答案
C
解析
根据题干定位在第一段。该段第二句讲到科学家们无法(failed to)将爱因斯坦的广义相对论和他开创的量子力学有机地统一起来(fit),C项符合。
转载请注明原文地址:https://kaotiyun.com/show/C41Z777K
0
考研英语一
相关试题推荐
【F1】Whenadiseaseofepidemicproportionsripsintothepopulace,scientistsimmediatelygettowork,tryingtolocatethesour
Asthebanksterphenomenonhassoeloquentlyillustrated,Homosapiensisexquisitelysensitivetoinjustice.【F1】Manypeoplegru
Inaddition,changesmadetotheconstructioncodesinLosAngelesduringthelast20yearshavestrengthenedthecity’sbuildi
TheU.S.SecretService,whichstudies"targetedviolence",providesinsightontheurgencyoftheneedinits2002"SafeSchool
【F1】Duringthepastgeneration,theAmericanmiddle-classfamilythatoncecouldcountonhardworkandfairplaytokeepitself
【F1】Duringthepastgeneration,theAmericanmiddle-classfamilythatoncecouldcountonhardworkandfairplaytokeepitself
Severalyearsintoacampaigntogetkidstoeatbetterandexercisemore,childobesityrateshaveappearedtostabilize,andm
Researchhasshownthat—inbothsexesandacrossnumerouscultures—attractivepeoplearejudgedtobesmarter,kinder,morehone
Expressionismisanartisticstyleinwhichtheartistseekstodepictnotobjectiverealitybutratherthesubjectiveemotions
随机试题
阅读《风波》中的片段,回答下列小题:临河的土场上,太阳渐渐地收了他通黄的光线了。场边靠河的乌桕树叶,干巴巴的才喘过气来,几个花脚蚊子在下面哼着飞舞。面河的农家的烟突里,逐渐减少了炊烟,女人孩子们都在自己门口的土场上泼些水,放下小桌子和矮凳;人知道,这已经
A.儿童B.老年患者C.妊娠期妇女D.哺乳期妇女E.更年期后的女性应用糖皮质激素易发生高血压的人群是()。
寒热往来,发无定时,可见于()。
根据《建设工程项目管理规范》,制定项目管理目标责任书的主要依据有()。
下列关于劳动仲裁的表述中,正确的有()。
大陆对台大政方针是坚持反对“台独”,坚持维护一个中国的原则,继续坚持()。
简述技能的概念、特点、类型以及作用。
甲、乙两人相约于某地在12:00~13:00会面,设X,Y分别是甲、乙到达的时间,且假设X和Y相互独立,已知X,Y的概率密度分别为求先到达者需要等待的时间的数学期望.
UML中的结构事物是模型中的静态部分,采用名词描述概念或物理元素。(46)________________属于结构事物,以此事物为主的UML模型图为(47)________________。
WhatdoestheManMean?
最新回复
(
0
)