文图版权：NASA
翻译、译文版权：中国分布式论坛 Rojer
原文：
http://www.nasa.gov/mission_pages/hubble/news/dark_energy.html
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These snapshots, taken by NASA’s Hubble Space Telescope, reveal five supernovae, or exploding stars, and their host galaxies.
这些照片由 NASA 的哈勃空间望远镜拍摄，显示了五个超新星或者正在爆发的恒星，以及它们所在的星系。
The arrows in the top row of images point to the supernovae. The bottom row shows the host galaxies before or after the stars exploded. The supernovae exploded between 3.5 and 10 billion years ago.
上面一行图片中的箭头指出了超新星。下面一行显示所在星系在恒星爆发前或爆发后的的样子。超新星爆炸时间在35-100亿年前。
Astronomers used the supernovae to measure the expansion rate of the universe and determine how the expansion rate is affected by the repulsive push of dark energy, a mysterious energy force that pervades space. Supernovae provide reliable measurements because their intrinsic brightness is well understood. They are therefore reliable distance markers, allowing astronomers to determine how far away they are from Earth.
天文文学家用超新星来确定宇宙膨胀的速率以及测定暗能量（一种遍及宇宙的神秘能量）的斥力对该膨胀率的影响，超新星能提供可靠的测量是因为它们的固有亮度是已知的。它们因此成为可靠的距离标尺，使天文学家得以测定它们距离地球有多远。
Pinpointing supernovae in the faraway universe is similar to watching fireflies in your back yard. All fireflies glow with about the same brightness. So, you can judge how the fireflies are distributed in your back yard by noting their comparative faintness or brightness, depending on their distance from you.
在遥远的宇宙中精确定位超新星就像在你的后院中观察萤火虫。所有的萤火虫闪耀着差不多相同的光亮。那么，你就可以通过计算它们的比较亮度判断出萤火虫离你有多远，从而知晓在你的院子里是如何分布的。
Only Hubble can measure these supernovae because they are too distant, and therefore too faint, to be studied by the largest ground-based telescopes.
只有哈勃望远镜才能测量这些超新星，因为对使用地基的最大望远镜进行研究来说它们太远、太暗淡了。
These Hubble observations show for the first time that dark energy has been a present force for most of the universe's history. A spectral analysis also shows that the supernovae used to measure the universe’s expansion rate today look remarkably similar to those that exploded nine billion years ago and are just now seen by Hubble.
哈勃的这些观测第一次显示暗能量在宇宙的早期就已经成为一种影响力。光谱分析同样显示现今用来测量宇宙膨胀率的超新星与那些90亿年前爆炸的也就是现在被哈勃看到的超新星非常的相似。
These latest results are based on an analysis of the 24 most distant known supernovae, most of them discovered within the last three years by the Higher-z SN Search Team. The images were taken between 2003 and 2005 with Hubble’s Advanced Camera for Surveys. + Click for high resolution tif image (1.5 Mb)
最新的结果建立在对24个距离最确定的超新星的分析之上，这24颗中的大多数是在最近3年中由 Higher-z 超新星搜索组发现的。图片是使用哈勃的高级相机巡天于2003-2005年拍摄的。大图点击:-D
图片感谢： NASA, ESA, and A. Riess (Space Telescope Science Insitute)
The graphic above serves to illustrate the "cosmic tug of war" that has been going on since the beginning of the universe.
上图举例说明从宇宙诞生就开始的“宇宙拉锯战”。 |
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