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科学家发现银河系中或拥有许多黑洞双星系统

       ①据国外媒体报道,黑洞碰撞、合并会产生强大的时空涟漪,科学家发现当两个黑洞合并时,会释放出巨大能量的引力波,这个预言由来已久。根据计算,黑洞合并释放出的能量相当于10的23次方个太阳的能量,如此巨大的能量超出了我们的想象力。双黑洞宛如引力的定时炸弹,它们通过引力爆炸来宣布自己的存在。炸弹的倒计时由黑洞间的最初距离决定;唯有引力波天文学可以揭示它们的存在。

       ②由两个黑洞构成的天体系统可通过几种方式形成,其一是由成对诞生的恒星产生,宇宙中只有三分之一到二分之一的恒星符合这种条件。在仅仅一百万年的时间内,双恒星演化、爆炸、坍塌,最终形成双黑洞。双黑洞像打蛋器一样互相环绕,它们的质量是太阳质量的20到100倍,这样的双黑洞系统也被称为共生双黑洞。共同排列旋转是双黑洞的主要标志,可以通过引力波信号对其进行测量。

       ③双黑洞系统也可以通过两个分属于不同稠密星团的黑洞互相捕捉形成,在此过程中,弹弓效应发挥了巨大作用。早期宇宙中的黑洞在恒星经过时散发能量,缓慢地向星团中心移动;久而久之,导致恒星与黑洞的距离相当于太阳到冥王星之间的距离。在这种情况下,黑洞相互通过引力作用捕捉,形成“捕捉双黑洞”;和共生双黑洞不同,由于它们是分别产生的,旋转轴的方向不固定。

       ④远距离黑洞双星系统的能量会受到其他恒星之间的弹弓效应而减少,因此合并的时间也相应缩短。这些通过不同方式形成的双黑洞,一些在星系中心附近被捕捉,一些停留在原地,另一些在浩瀚的宇宙中漂流了数十亿年。无数双黑洞将在宇宙的海洋产生引力波的涟漪;当它们合并时,释放出的巨大能量将触发一场宇宙海啸。

       ⑤黑洞系统近似于倒计时器,起始状态不同,导致倒计时时间差异。不同的形成过程将产生不同的时间设定;一些时间比宇宙更为久远,另一些则仅为宇宙中的一瞬。只有符合我们对时间和地点的要求的双黑洞才能为我们所用,可以通过LIGO(引力波天文台)引力波探测器探测其释放的能量,获得有关数据。据我们所知,能够为我们所得知的双黑洞数量是足够的,在银河系中未来将发现更多的黑洞双星,它们产生的引力波也会被我们所探测到。

                                                                                                                                                                                            (选自《腾讯太空》)

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同类题4

根据短文内容及首字母提示,填写所缺单词,使短文意思完整。每空限填一词。

    Lan Lan, a student of Grade Seven in Lushan, was taking a drawing class in a tent on April 23. Guess what she drew—a house with wings. When the teacher asked why she did so, Lan said if her house could f____ , it wouldn't fall down in an earthquake.

    Lan's hometown was hit by a s____earthquake on April 20. At least 196 people were killed and more than 11,000 were injured. Many people became homeless. Soldiers and doctors q____arrived in the area, saving people and rebuilding homes. Lots of money was sent there to help all those in need.

    Although we can't prevent (阻止) an earthquake from happening, we can use some methods to r____harm. During an earthquake, do not jump out of high buildings because it is very d____. Another method is to cover your head and neck u____a strong table or desk. If there is no shelter (躲避处) nearby, you can also stay by a wall, and cover your head and neck with your arms and hands. And then you must keep calm and stay there u____ the shaking stops.

    Japan is a c____ which lies on the earthquake belt (地震带) and it is very good at dealing with earthquakes. From a very young age, the Japanese are already taught how to survive (幸存) them. Students often receive earthquake training. Almost in every Japanese family you can find a survival kit (救生装备) with a flash-light, a radio, water and enough food for several days. This helps people to stay a____after an earthquake.

    "There should be more safety t____at schools in our country," said Xu Jiannong, an education expert in Beijing. There is no more truth than this when one's life is the most important of all.