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
Scientists have long understood that supermassive black holes weighing millions or billions of suns can tear apart stars that co
Scientists have long understood that supermassive black holes weighing millions or billions of suns can tear apart stars that co
admin
2017-06-30
35
问题
Scientists have long understood that supermassive black holes weighing millions or billions of suns can tear apart stars that come too close. The black hotels gravity pulls harder on the nearest part of the star, an imbalance that pulls the star apart over a period of minutes or hours, once it gets close enough. Scientists say this uneven pulling is not the only hazard facing the star. The strain of these unbalanced forces can also trigger a nuclear explosion powerful enough to destroy the star from within. Matthieu Brassart and Jean-Pierre Luminet of the Observatoire de Paris in Meudon, France, carried out computer simulations of the final moments of such an unfortunate star’s life, as it veered towards a supermassive black hole.
When the star gets close enough, the uneven forces flatten it into a pancake shape. Some previous studies had suggested this flattening would increase the density and temperature inside the star enough to trigger intense nuclear reactions that would tear it apart. But other studies had suggested that the picture would be complicated by shock waves generated during the flattening process and that no nuclear explosion should occur.
The new simulations investigated the effects of shock waves in detail, and found that even when their effects are included, the conditions favor a nuclear explosion. "There will be an explosion of the star — it will be completely destroyed," Brassart says. Although the explosion obliterates the star, it saves some of the star’s matter from being devoured by the black hole. The explosion is powerful enough to hurl much of the star’s matter out of the black hole’s reach, he says.
The devouring of stars by black holes may already have been observed, although at a much later stage. It is thought that several months after the event that rips the star apart, its matter starts swirling into the hole itself. It heats up as it does so, releasing ultraviolet light and X-rays.
If stars disrupted near black holes really do explode, then they could in principle allow these events to be detected at a much earlier stage, says Jules Hatpern of Columbia University in New York, US2. " It may make it possible to see the disruption of that star immediately if it gets hot enough," he says. Brassart agrees. " Perhaps it can be observed in the X-rays and gamma rays, but it’s something that needs to be more studied," he says. Supernova researcher Chris Fryer of the Los Alamos National Laboratory in Los Alamos, New Mexico, US3, says the deaths of these stars are difficult to simulate, and he is not sure whether the researchers have proven their case that they explode in the process.
According to the third paragraph, researchers differed from each other in the problem of______.
选项
A、whether nuclear reaction would occur.
B、whether the stars would increase its density and temperature.
C、whether shock waves would occur.
D、whether the uneven forces would flatten the stars.
答案
A
解析
定位第三段“some previous…nuclear reaction…but other…”可知关于核反应是否会发生的问题有两种观点,故选A。
转载请注明原文地址:https://kaotiyun.com/show/NSFO777K
0
考博英语
相关试题推荐
democracyimaginationdifferentflexibilityovercomeonlineoffertraditionalmodern
Insuchachanging,complexsocietyformerlysimplesolutionstoinformationalneedsbecomecomplicated.Manyoflife’sproblems
Priortothe20thcentury,manylanguageswithsmallnumbersofspeakerssurvivedforcenturies.Theincreasinglyinterconnected
Everymorning,Alliewakesupandaccompaniesherfriendtothewashroom.Sheturnsonthelight,soapsupawashcloth,andbegi
Everyoneitseemshasahealthproblem.AfterpouringbillionsintotheNationalHealthService,Britishpeoplemoanaboutdirty
Thereareanumberofformatsforreportingresearch,suchasarticlestoappearinjournals,reportsaddressedtofundingagenc
Oftensuchargumentshavetheeffectof______ratherthanclarifyingtheissuesinvolved.
IntheopinionofmanyAmericansandEuropeans,weonlybegantoreallyexploreourworldinthesixteenthcentury.Accordingto
ToliveintheUnitedStatestodayistogainanappreciationforDahrendorf’sassertionthatsocialchangeexistseverywhere.T
Inthe2006filmversionofTheDevilWearsPrada,MirandaPriestly,playedbyMerylStreep,scoldherunattractiveassistantfo
随机试题
投保人王某勾结鉴定人朱某故意提供虚假的证明文件,使得王某获得了巨额保险金对王某和朱某的行为如何处罚?( )
下列关于地图比例尺的说法中,正确的有()。
青铜器的冶炼和铸造技术达到很高水平是在()时代。
某选区在举行人民代表大会代表直接选举时,应参加选举的选民为25000人,实际参加选举的选民为12350人。该选区三位候选人甲、乙、丙最后实际获得选票依次为6250票、3500票、2600票。依照法律规定,选举结果是()。
中共十八大以来,以习近平为总书记的新一届中央领导集体,带领全党全国各族人民积极应对前进道路上的困难和挑战,更好落实发展这个党执政兴国的第一要务。经济发展进入新常态,要坚持以提高发展质量和效益为中心,切实()。
公路客运方面:10月5日共发送客车3546车次,发送旅客5.45万人次;抵达客车1472车次,抵达旅客1.88万人次。民航方面:10月5日共发送航班236班次,发送旅客3.25万人次;抵达航班233班次,抵达旅客2.83万人次。[img][/img]
“文化-历史”发展理论的创始人是
Tounderstandthemarketingconcept.itisonlynecessarytounderstandthedifferencebetweenmarketingandselling.Nottooman
AddisonHeardusesanimageofhiswifeandinfantsonforthebackgroundonhislaptop.AnMBAstudentattheUniversityofVir
A、Itcanbevalidforsevendays.B、Ayearlypasscostsonly$18.C、Itvariesindifferentseasons.D、Itisfreeforpeopleover
最新回复
(
0
)