宇宙中最有趣的 galaxies

English | EPUB | 2018 | 163 pages | ISBN : 164327001X | 29.17 MB

Prior to the 1920s it was generally thought, with a few exceptions, that our galaxy, the Milky Way, was the entire Universe. Based on the work of Henrietta Leavitt with Cepheid variables, astronomer Edwin Hubble was able to determine that the Andromeda Galaxy and others had to lie outside our own. Moreover, based on the work of Vesto Slipher, involving the redshifts of these galaxies, Hubble was able to determine that the Universe was not static, as had been previously thought, but expanding. The number of galaxies has also been expanding, with estimates varying from 100 billion to 2 trillion. While every galaxy in the Universe is interesting just by its very fact of being, the author has selected 51 of those that possess some unusual qualities that make them of some particular interest. These galaxies have complex evolutionary histories, with some having supermassive black holes at their core, others are powerful radio sources, very few are relatively nearby and even visible to the naked eye, whereas the light from one recent discovery has been travelling for the past 13.4 billion years to show us its infancy, and from a time when the Universe was in its infancy. And in spite of the vastness of the Universe, some galaxies are colliding with others, embraced in a graceful gravitational dance. Indeed, as the Andromeda Galaxy is heading towards us, a similar fate awaits our Milky Way.

When looking at a modern image of a galaxy, one is in awe at the shear wondrous nature of such a magnificent creation, with its boundless secrets that it is keeping from us, its endless possibilities for harboring alien civilizations, and we remain left with the ultimate knowledge that we are connected to its glory.

在20世纪之前，人们普遍认为，除了极少数例外情况外，我们所在的银河系——即银河宇宙——就是整个宇宙。基于赫丽埃特·里维斯特与米纳德星变量的工作，天文学家艾尔登·哈勃能够确定仙女座星云及其他星云实际上位于我们的银河之外。此外，基于维尔多斯·塞尔弗利的工作以及这些星云的红移现象，哈勃推断出宇宙并非静止不变的，而是处于扩张之中。 据估计，目前已知的星系数量也在不断增长，范围从100亿到2万亿个。虽然每颗宇宙中的星系本身因为其存在而具有非凡意义，但作者从中选择了51颗拥有某些独特特性，使得它们尤其引人注目的星系进行研究。这些星系拥有复杂的演化历史，有些拥有位于中心的超大质量黑洞，其他则是强大的无线电波源，仅有极少数星系是相对较为接近且肉眼可见的，而从最近的一个新发现中发出的光已穿过134亿年的时间才到达我们的眼睛，展示出它的幼年时期，以及在宇宙初生之时的情况。尽管宇宙广阔无垠，但仍然有一些星系正在与其他星系发生碰撞，并以优雅的引力舞蹈形式缠绕在一起。 确实，当仙女座星云朝向我们靠近时，银河也面临着同样的命运。 当我们凝视现代星系的影像时，我们会为之惊叹于这伟大创造中蕴含的非凡之妙与它对我们所隐藏的秘密。宇宙可能孕育着外星文明的无限可能性，而我们始终无法得知这些秘密。无论如何，我们都深知自己与它的荣耀之间存在着联系。

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