首页
财务会计
医药卫生
金融经济
考公考编
外语考试
学历提升
职称考试
建筑工程
IT考试
其他
登录
职称考试
Black Holes Trigger Stars to Self-destruct Scientists have long understood...
Black Holes Trigger Stars to Self-destruct Scientists have long understood...
admin
2020-12-24
31
问题
Black Holes Trigger Stars to Self-destruct
Scientists have long understood that supermassive (超大质量的) 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 (巴黎天文台) in Meudon, France,carried out computer simulations of the final moments of such an unfortunate star’s life,as it veered (改变方向) towards a supermassive black hole.
When the star gets close enough,the uneven forces flatten it into a pancake (薄饼)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 一 it will be completely destroyedBrassart says. Although the
explosion obliterates (使消失)the star,it saves some of the star’s matter from being devoured (吞没) 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 今 tarts swirling (旋动)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, US. “It may make it possible to see the disruption of that star immediately if it gets hot enough,” he says.
According to paragraph 3, researchers differed from each other as to
选项
A whether nuclear reactions would occur.
B whether the star would increase its density.
C whether shock waves would occur.
D whether the uneven forces would flatten the stars.
答案
A
解析
转载请注明原文地址:https://ti.zuoweng.com/ti/idsQKKKQ
相关试题推荐
共用题干 Scientistsworkingonaproblemdonotknowandsometimescan'teveng...
共用题干 Scientistsworkingonaproblemdonotknowandsometimescan'teveng...
共用题干 Scientistsworkingonaproblemdonotknowandsometimescan'teveng...
共用题干 Scientistsworkingonaproblemdonotknowandsometimescan'teveng...
ScientistsDevelopWaysofDetectingHeartAttack Germanresearchershaveco...
ScientistsDevelopWaysofDetectingHeartAttack Germanresearchershaveco...
ScientistsDevelopWaysofDetectingHeartAttack Germanresearchershaveco...
ScientistsDevelopWaysofDetectingHeartAttack Germanresearchershaveco...
ScientistsDevelopWaysofDetectingHeartAttack Germanresearchershaveco...
ScientistsDevelopWaysofDetectingHeartAttack Germanresearchershaveco...
随机试题
以下不属于预激综合征的治疗的是 A、抗心律失常药物 B、射频消融 C、外科
现浇钢筋混凝土楼盖施工中,梁的跨度为6m,板的跨度为4m,当设计无特别要求时,楼
企业选择招聘渠道的主要步骤有:①选择适合的招募方法②确定合适的招聘来源③分
某项目设计生产能力为年产5000台,每台销售价格500元,单位产品可变成本350
咨询机构提供的合同管理服务主要在于前期管理,其内容包括()。
学校的中心工作是()。A.思想品德教育工作B.教学工作C.校外活动D.教师的培养工作
下面可破坏胃黏膜屏障的药物是A:三钾二枸橼酸铋B:法莫替丁C:吲哚美辛D:雷尼替丁E:西沙必利
男性,62岁,饮酒后夜间突发左足背、第一妬关节剧烈疼痛1天,无发热,査关节局部红肿、皮温髙,化验血尿酸57μmol/L。该患者最可能诊断是A.痛风B.化脓性关
某年夏季,某县中心小学47名学生相继出现剧烈呕吐、上腹部剧烈疼痛、腹泻等症状,少数患者有低热。调査得知发病学生在当天上午均吃过学校供应的课间餐(外购的奶...
根据《标准施工招标文件》,承包人可同时索赔工期和费用的情形有(??)。A.承包人遇到不利物质条件B.法律变化引起价格调整C.发包人要求向承包人提前交付工