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
70
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.
What can we infer from the last paragraph?
选项
A、General relativity is actually ungrounded at all.
B、The calculation of the orbits shows that equivalence principle is violated.
C、More should be done to prove the correctness of equivalence principle.
D、A new revolution in physics has already arrived.
答案
C
解析
最后一段中作者指出现代科学家所做的试验“仅仅在10万亿分之一的概率上证实了等效原理”,也就是说还需要更多试验来检验该理论,C项与之相符。
转载请注明原文地址:https://kaotiyun.com/show/J41Z777K
0
考研英语一
相关试题推荐
Instudyingboththerecurrenceofspecialhabitsorideasinseveraldistricts,andtheirprevalencewithineachdistrict,ther
【F1】Despitethegeneralnegativefindings,itisimportanttorememberthatallchildrenwholivethroughadivorcedonotbehav
【F1】Americansnolongerexpectpublicfigures,whetherinspeechorinwriting,tocommandtheEnglishlanguagewithskillandg
【F1】Itistheworld’sfourth-most-importantfoodcrop,aftermaize,wheatandrice,whichprovidesmorecalories,morequickly,
AsGilbertWhite,Darwin,andothersobservedlongago,allspeciesappeartohavetheinnatecapacitytoincreasetheirnumbers
Twenty-sevenyearsago,EgyptreviseditssecularconstitutiontoenshrineMuslimshariaas"theprincipalsourceoflegislation
Theprovisionofpositiveincentivestoworkinthenewsocietywillnotbeaneasytask.【F1】Butthemostdifficulttaskofall
Researchhasshownthat—inbothsexesandacrossnumerouscultures—attractivepeoplearejudgedtobesmarter,kinder,morehone
Expressionismisanartisticstyleinwhichtheartistseekstodepictnotobjectiverealitybutratherthesubjectiveemotions
SowhyisGooglesuddenlysointerestedinrobots?That’sthequestioneveryone’saskingafteritemergedthismonththatthein
随机试题
CO2气体保护焊在立焊和横焊位置时的操作方法和要点是什么?
人们通常把管理幅度宽、组织层次少的组织结构称为()
某企业刚刚建立时,权益总额为80万元,现发生一笔以银行存款10万元偿还银行借款的经济业务,此时,该企业的资产总额为()。
至宝丹最适宜于哪种原因引起的窍闭神昏
尿路感染最常见的细菌是
中国传统城市土地使用制度的改革有一个发展过程。这个发展过程突出表现在()。
投资项目评价用的建设期是()所需的时间。
不参与电信管道、电信杆路、通信铁塔联合建设的电信业务经营者,原则上在()年之内,不得在同路由或同位置建设相同功能的电信设施。
ROM中的信息只能读出不能写入,只要关闭计算机电源,ROM中的信息将全部丢失。()
从信息加工的观点看,记忆就是人脑对外界输入的信息进行________、存贮和提取的过程。
最新回复
(
0
)