远古光形久经探寻终被发现

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杂谈 |
分类: 科学与技术 |
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光从宇宙形成之初到被现代望远镜捕获经历了漫长而曲折的旅程。远古的光穿越几十亿年到达我们这里,一路上因物质引力而变形,呈曲折形态。
这种被称为B-型偏振光(B-modes)的曲形光现在终于被观测到。它是由美国国家科学基金会(U.S. National Science Foundation)南极望远镜(South Pole Telescope)在赫歇尔天文台(Herschel Space Observatory)的协助下发现。这项发现将有助于更好地绘制宇宙中物质的分布图。
上图为艺术家图绘,显示来自初始宇宙的光子,在穿越宇宙途中,在大质量天体引力透镜效应下呈折曲折形态。
科学家在很早已前就预测存在两种类型的B-型偏振光。最近观测到的光产生于宇宙形成后的几十亿年中。另一种叫做原始光的B-型偏振光,理论上被认为是在宇宙新生阶段,即宇宙大爆炸(Big Bang)后几分之一秒内产生。
9月30日发表在《物理评论快讯》(Physical Review Letters)网络版的一份新报告的主要作者、蒙特利尔(Montreal)麦吉尔大学(McGill University)的邓肯•汉森(Duncan Hanson)说:“这项最新发现是通向测量原始B-型偏振光的道路上的一个良好检查站。”
难以捕捉的原始B-型偏振光可能含有我们宇宙起源的线索。科学家目前正通过梳理来自普朗克使命(Planck)的数据来寻找它们。赫歇尔与普朗克均为欧洲航天局(European Space Agency)的使命。
有关寻找B-型偏振光的更多信息,请见美国航空航天局新闻发布。
Read more: http://iipdigital.usembassy.gov/st/chinese/inbrief/2013/10/20131023285060.html#ixzz2ihyXhWZi
Long-Sought Pattern of Ancient Light Detected
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The journey of light from the very early universe to modern telescopes is long and winding. The ancient light traveled billions of years to reach us, and along the way, its path was distorted by the pull of matter, leading to a twisted light pattern.
This twisted pattern of light, called B-modes, has at last been detected. The discovery, which will lead to better maps of matter across the universe, was made using the U.S. National Science Foundation’s South Pole Telescope, with help from the Herschel space observatory.
The artist’s impression above shows photons from the early universe being deflected by the gravitational lensing effect of massive cosmic structures as they travel across the universe.
Scientists have long predicted two types of B-modes. The ones that were recently found were generated a few billion years into the universe’s existence. The others, called primordial, are theorized to have been produced when the universe was a newborn, fractions of a second after its birth in the Big Bang.
“This latest discovery is a good checkpoint on our way to the measurement of primordial B-modes,” said Duncan Hanson of McGill University in Montreal, lead author of the new report published September 30 in the online edition of Physical Review Letters.
The elusive primordial B-modes may be imprinted with clues about how our universe was born. Scientists are currently combing through data from the Planck mission in search of them. Both Herschel and Planck are European Space Agency missions.
For more on the hunt for B-modes, see the NASA press release.
Read more: http://iipdigital.usembassy.gov/st/english/inbrief/2013/10/20131022284995.html#ixzz2ihyZrPuh