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
49
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.
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
是非判断题。选项D的信息定位在文章第四段第三句话,爆炸尽管会摧毁恒星,但也会使恒星的一些物质免于被黑洞吞没。由此可知,答案为D。
转载请注明原文地址:https://kaotiyun.com/show/qHGO777K
0
考博英语
相关试题推荐
Bigcitiestodayareconfrontedwithveryseriousproblems.Transportisa【C1】______difficulty:someplannersbelievein【C2】____
Concernwithmoney,andthenmoremoney,inordertobuytheconveniencesandluxuriesofmodernlife,hasbroughtgreatchanges
Chooseoneappropriatewordfromthefollowingwordbanktofillintheblanknumberedfrom91to105inthepassagebelow.Chan
Chooseoneappropriatewordfromthefollowingwordbanktofillintheblanknumberedfrom91to105inthepassagebelow.Chan
Thepotentialofcomputersforincreasingthecontroloforganizationsorsocietyovertheirmembersandforinvadingtheprivac
InChristianwritersitisnaturalthatlogicalexplanationsofthegenerallawofstormsshouldcenterabouttheDevil.Clement
WheneverthepoliticallawsoftheUnitedStatesaretobediscussed,itiswiththedoctrineofthesovereigntyofthepeoplet
AstoutoldladywaswalkingwithherbasketdownthemiddleofastreetinPetrogradtothegreatconfusionofthetrafficand
Openupmostfashionmagazinesandyouwillseeincrediblythinmodelswithimpossiblehairandwearingunreasonablyexpensive,
TheEnglishlanguagecontainsa(an)______ofwordswhicharecomparativelyseldomusedinordinaryconversation.
随机试题
下列经济业务产生的现金流量中,属于“筹资活动产生的现金流量”的是()。
中度张口受限是上下切牙切缘间距在
室外台阶的坡度应比楼梯小,通常踏步高度为()。
一般而言,能更有效地激发学生的学习动机的是()
日常生活中有许多省电的技巧。以下做法,不能省电的是()。
为了处理参数及返回地址,在递归过程或函数调用时,要用一种称为()的数据结构。
结合材料回答问题:材料1实事求是这个词已经有2000多年历史了,但使它展现生机、广为人知的是我们党,把它提到马克思主义和毛泽东思想精髓、我们党思想路线核心高度的是邓小平。实践证明,什么时候坚持实事求是,我们的事业就顺利发展;什么时候背离实事求是
袋中有a只黑球,b只白球,现把球一只一只摸出,求第k次摸出黑球的概率(1≤k≤a+b).
A、 B、 C、 D、 B
根据维护的具体内容的不同,可对软件维护进行分类。______是指对文件或数据库中的记录进行增加、修改和删除等操作,通常采用专用的程序模块。
最新回复
(
0
)