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
2016-02-26
57
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 mat 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.
Something destructive could happen to a star that gets too close to a black hole. Which of the following destructive statements is NOT mentioned in the passage?
选项
A、The black hole could tear apart the star.
B、The black hole could trigger a nuclear explosion in the star.
C、The black hole could dwindle its size considerably.
D、The black hole could devour the star.
答案
C
解析
事实细节题。选项A与文章首段第一句“Scientists…that supermassive black holes…can tearapart stars that come too close.”对应;选项B与第二段“The strain of these unbalanced forces canalso trigger a nuclear explosion powerful enough to destroy the star from within.”对应;选项D与第五段“The devouring of stars by black holes…”对应。选项C在文中没有提及。故答案为C。
转载请注明原文地址:https://kaotiyun.com/show/eHGO777K
0
考博英语
相关试题推荐
Whenmostpeoplethinkaboutchangingtheirbodyshape,theyusuallyfocusonjustlosingweight.Booksandmagazinesaboutdiet
Tofightagainstcomputercrimes,acomputersystemneedsasurewayofidentifyingitsrightusersandrejectingthosewhoare
Thedeclineinmoralstandards—whichhaslong-concernedsocialanalysts—hasatlastcapturedtheattentionofaverageAmeric
Billisanexampleofaseverelydisabledpersonwhohasbecome______atmanysurvivalskills.
Satellitecommunicationaresoup-to-datethatevenwhen______inthemiddleofthePacific,businessmencancontacttheiroffi
Itssubjectis"life-as-spectacle",forreaders,divertedbyitsvariousincidents,observeitsheroOdysseusprimarilyfromwit
Ifoundthesubjectverydifficult,andatonetimethoughtIshouldhavetogiveitup,butyoudirectionsaresoclearand____
Openupmostfashionmagazinesandyouwillseeincrediblythinmodelswithimpossiblehairandwearingunreasonablyexpensive,
Researchershavefoundthatmigratinganimalsuseavarietyofinnercompassestohelpthemnavigate.Somedirectthemselvesby
中国是世界文明的发源地之一,有五千年的文明史。在中国古代思想史上,涌现出了许许多多杰出的思想家,为中华民族乃至整个人类留下了丰富的思想遗产。这些思想成果独树一帜,在漫长的历史中又不断地被阐释、被发展,很多思想对于今天的中国乃至世界而言,仍然历久弥新。极具生
随机试题
BullyingandChildrenA)Whatyoursonisdescribingisbullying,plainandsimple.Althoughitislateintheschoolyear,
下列情况所引起的误差中,不属于系统误差的是()。
不属于颈外动脉的分支是【】
女性,25岁,平时月经规则,3个月前妇科检查有小肌瘤,现停经2月余,阴道流血10天。妇科检查子宫如妊娠14周大,软,轻压痛,双侧附件区触及5cm囊性包块,壁薄活动好,无压痛。血HCG增高明显。此例最可能的诊断是
专用发票适用于()。
中央银行降低法定存款准备金率时,商业银行( )。
当事人之间不存在管辖协议时,下列关于民事诉讼地域管辖的表述中,不符合民事诉讼法律制度规定的是()。
下列有关票据行为有效要件的表述中,符合票据法规定的有()。
人民公安机关是人民民主专政国家政权的重要组成部分,是武装性质的(),是关系国家安全和社会治安的要害部门。公安机关一旦脱离党的领导,就可能被坏人所掌握、所利用,蜕变成镇压人民的工具。
A、Men.B、Women.C、Olderpeople.D、Youngerpeople.C细节辨认题。短文最后一句Otherstudiesshowthatolderpeopleusuallyfinditeasiertore
最新回复
(
0
)