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
2011-01-02
25
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 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 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, 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 bole 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
短文的第一和第二段提供了答案。第一段第一句说,特大质量的黑洞能够撕裂靠近它们的恒星;第二段的第二句说,由于它们之间力量的悬殊,恒星内部会发生核爆炸。第五段提及黑洞吞噬恒星的问题。C的内容文章中没有找到,所以应该选择C。
转载请注明原文地址:https://kaotiyun.com/show/G8Ld777K
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
Thepolarregionsaregenerallycoveredwithiceandsnow.
ScientistsDevelopWaysofDetectingHeartAttackGermanresearchershavecomeupwithanewgenerationofdefibrillators(除颤
ScientistsDevelopWaysofDetectingHeartAttackGermanresearchershavecomeupwithanewgenerationofdefibrillators(除颤
ScientistsDevelopWaysofDetectingHeartAttackGermanresearchershavecomeupwithanewgenerationofdefibrillators(除颤
ScientistsDevelopWaysofDetectingHeartAttackGermanresearchershavecomeupwithanewgenerationofdefibrillators(除颤
WhyDon’tBabiesTalkLikeAdults?Overthepasthalf-century,scientistshavesettledontworeasonabletheoriesrelatedto
随机试题
ProblemsCausedbyUsingComputersLonghoursatthescreencancause【C1】______(ache)eyes,【C2】______(blur)visionandheada
患者,男,45岁,乙型肝炎30年,近2个月来,乏力腹泻,睡眠倒置,性格与前不同,易急躁。化验:ALT为125U,A/G:2.5/3.2;B超显示:肝回声不均匀、增强,门静脉内径为1.6cm,少量腹水。下列哪项是最正确的()。
企业在进行现金清查时,查出现金溢余,并将溢余数记入“待处理财产损溢”科目。后经进一步核查,无法查明原因,经批准后,对该现金溢余正确的会计处理方法是()。
利润表是反映企业在一定会计期间经营成果的报表,属于静态报表。()
(上海招警2010—62)王先生从家里出发开车去朋友家,两家相距100千米。前往目的地时的平均车速为60千米/时。第二天早晨回家时,王先生希望把往返两地的平均车速提高到65千米/时,那么在回程中应该达到的平均车速约是多少?()
下列现象中不属于同一认知心理的是()
冰岛首都雷克雅未克是世界上著名的“无烟城市”,满足当地居民的能源需求主要靠利用()资源。
在SQL语句中,与表达式“供应商名LIKE”%北京%””功能相同的表达式是()。
Manyteachersbelievethattheresponsibilitiesforlearningliewiththestudent.【C1】______alongreadingassignmentisgiven,
A、Shepassedtheterribletest.B、Shewroteaperfectprogram.C、ShegotconfusedaboutItaliangrammar.D、Shememorizedthever
最新回复
(
0
)