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
Black Holes Trigger Stars to Self-Destruct Scientists have long understood that super massive black holes weighing millions
Black Holes Trigger Stars to Self-Destruct Scientists have long understood that super massive black holes weighing millions
admin
2011-05-18
65
问题
Black Holes Trigger Stars to Self-Destruct
Scientists have long understood that super massive black holes weighing millions or billions of suns can tear apart stars that come too close. The black hole’s 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, Francel, carried out computer simulations of the final moments of such an unfortunate star’s life, as it veered towards a super massive 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 e-nough 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 Halpern 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, USA, 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 fourth paragraph, which of the following is NOT true?
选项
A、No nuclear explosion would be triggered inside the star.
B、The star would be destroyed completely.
C、Much of the star’s matter thrown by the explosion would be beyond the black hole’s reach.
D、The black hole would completely devour the star.
答案
D
解析
第四段告诉我们,模拟实验发现,整个的条件会引起核爆炸,这将彻底毁灭恒星,但恒星的一些物质会被强力的爆炸抛出黑洞。所以,A、B、C三个选择的内容都是正确的说法,而D不是。
转载请注明原文地址:https://kaotiyun.com/show/UrLd777K
本试题收录于:
职称英语理工类A级题库职称英语分类
0
职称英语理工类A级
职称英语
相关试题推荐
A.becostlyB.harmfulC.savealifeD.stillopentodebateE.reducetheriskofradiationtriggeringacancerF.reducedto
CarMaintenanceOnceitwasconsideredgoodpracticetoletthecarengineidleaminuteortwofollowingcoldstarts.Todaywit
A.thevolunteersdoB.becauseshedoesnothaveaweightproblemC.becausethelifetherecanbeveryboringD.makepeopleo
TheHistoryoftheFridge1Thefridgeisconsideredanecessity.Ithasbeensosincethe1960swhenpackagedfoodfirstap
RecyclingAroundtheWorldRecyclingisoneofthebestenvironmentalsuccessstoriesofthelate20thcentury.Butwecoul
FemaleBullfightingItwasaunique,eye-catchingsight:anattractivewomaninashinybullfighter’ssuit,swordinhand,facin
HowWeFormFirstImpressionWeallhavefirstimpressionofsomeonewejustmet.【B1】______Whydoweformanopinionabouts
AthevolunteersdoBbecauseshedoesnothaveaweightproblemCbecausethelifetherecanbeveryboringDmakepeopleovere
AftertheviolentearthquakethatshookLosAngelesin1994,earthquakescientistshadgoodnewstoreport:Thedamageanddeath
TheindustrialrevolutionmodifiedthewholestructureofEnglishsociety.
随机试题
我国新疆吐鲁番境内的古城有()。
T68型镗床的照明灯由控制照明变压器TC提供交流24V的安全电压。()
简述国际经济法的科学含义。
酶的比活力越高表示酶()
建筑物细部点的平面位置的测设方法包括()
()是对投资产品和服务做出选择的行为和过程,它是整个投资者教育体系的基础。
根据技术来源的不同,可将企业的技术创新战略分为()。
青岛位于山东半岛,在山东处于领先的经济地位,对全国的影响力较大。作为一个沿海的旅游城市,酒店业比较发达,数量众多。但整体管理水平并不高,很多酒店目前还都处于手工操作的阶段。部分酒店管理者对酒店管理系统持有排斥态度,认为没有必要在这块进行投资。但随着市场环境
在名为Form1的窗体上绘制一个文本框,名为Text1;再绘制两个命令按钮,名称分别为Cmd1和Cmd2,标题分别为Hide和Display,如下图所示。请编写适当的事件过程,使得在运行时,若单击Hide按钮,则文本框消失,而如果单击Display按钮,则
Nobodyheardhimsing,______?
最新回复
(
0
)