本帖最后由 gohomeman1 于 2011-3-22 22:49 编辑
http://hubblesite.org/newscenter/archive/releases/1999/19/text/
Hubble Completes Eight-Year Effort to Measure Expanding Universe
The full news release story:
《哈勃持续8年的测量宇宙膨胀工程完工》新闻稿全文
The Hubble Space Telescope Key Project team today announced that it has completed efforts to measure precise distances to far-flung galaxies, a nessential ingredient needed to determine the age, size and fate of theuniverse.
哈勃太空望远镜重点项目团队今天宣布，他们已经完成了精确测量宇宙中广泛分布的星系距离工作，这是确定宇宙大小、年龄以及未来命运必不可少的一步。
"Before Hubble, astronomers could not decide if the universe was 10 billion or 20 billion years old. The size scale of the universe had a range so vast that it didn't allow astronomers to confront with any certainty many of the most basic questions about the origin and eventual fate of the cosmos," said team leader Wendy Freedman, of the Observatories of the Carnegie Institution of Washington. "After allthese years, we are finally entering an era of precision cosmology.Now we can more reliably address the broader picture of the universe'sorigin, evolution and destiny."
“哈勃太空望远镜上天前，天文学家甚至无法确定宇宙已经100亿岁还是200亿岁了。宇宙大小的变动范围是如此之大，以致于天文学家无法直面任何关于宇宙起源和未来命运的基本问题。”团队带头人、美国华盛顿卡内基研究院附属天文台的温蒂. 弗里德曼说。
The team's precise measurements are the key to learning about the expansion rate of the universe, called the Hubble constant. Measuring the Hubble constant was one of the three major goals for NASA's Hubble Space Telescope before it was launched in 1990.
团队精确的测量值是研究宇宙膨胀速率——哈勃常数的钥匙。测定哈勃常数是哈勃天文望远镜在1990年发射前就预定的三大重要目标之一。
For the past 70 years astronomers have sought a precise measurement of the Hubble constant, ever since astronomer Edwin Hubble realized that galaxies were rushing away from each other at a rate proportional to their distance, i.e. the farther away, the faster the recession. For many years, right up until the launch of the Hubble telescope - the range of measured values for the expansion rate was from 50 to 100 kilometers per second per megaparsec (a megaparsec, or mpc, is 3.26million light-years).
70多年前的过去，埃德温.哈勃发现星系彼此远离速率与它们间的距离成正比，也就是说，距离越远，后退越快。此后多年来，天文学家持续寻求更精准的哈勃常数。但直到哈勃望远镜发射前，哈勃常数的值还在每百万秒差距50~100km/s这么大范围内（百万秒差距缩写为mpc，相当于326万光年）。
The team measured the Hubble constant at 70 km/sec/mpc, with an uncertainty of 10 percent. This means that a galaxy appears to be moving 160 thousand miles per hour faster for every 3.3 light-years away from Earth.
团队测得哈勃常数是70km/sec/mpc,不确定性约10%。这意味着离地球每隔3.3光年，星系就以16万英里以上的（平均叠加）时速退离我们。
"The truth is out there, and we will find it," said Dr. Robert Kirshner,of Harvard University. "We used to disagree by a factor of 2; now we are just as passionate about 10 percent. A factor of two is like being unsure if you have one foot or two. Ten percent is like arguing aboutone toe. It's a big step forward."
“真相就在那里，而我们将发现它，”哈佛大学罗伯特.科什纳博士说。 “过去我们常常都不能确定因子是取1还是2，现在我们的不确定性只有10%了。是1还是2就像你搞不清自己有一只脚还是两只脚一样（糊涂），而10%就像在讨论脚趾头数目这种细节了。这是一个巨大的进步。”
Adds Dr. Robert Kennicutt of the University of Arizona, a co-leader of the team: "Things are beginning to add up. The factor of two controversy is over."
团队协同领导人、亚利桑那州大学的罗伯特.肯尼柯特博士补充说：“事情正在变得合乎情理，因子取1还是2的辩论已经结束了。”
The team used the Hubble telescope to observe 18 galaxies out to 65 million light-years. They discovered almost 800 Cepheid variable stars,a special class of pulsating star used for accurate distance measurement. Although Cepheids are rare, they provide a very reliable"standard candle" for estimating intergalactic distances. The team used the stars to calibrate many different methods for measuring distances.
团队使用哈勃太空望远镜观测了6500万光年外的18个星系。他们发现了差不多800个造父变星，一种用于准确测量距离的特殊变星。虽然造父变星数量稀少，它们是估计银河系间距离的一种非常可靠的“标准烛光”。团队使用它们校准各种不同的测距方法。
"Our results are a legacy from Hubble telescope that will be used in a variety of future research," said Dr. Jeremy Mould, of the Australian National University, also a co-leader of the team. "It's exciting to see the different methods of measuring galaxy distances converge, calibrated by the Hubble Space Telescope."
另一位团队协同领导人、澳大利亚国立大学杰里米.模特博士说：“我们的研究结论将成为哈勃遗产，在未来多种研究中有用。经哈勃太空望远镜校准，不同的测量星系距离的方法逐步汇集一点，真令人兴奋。”
Combining the Hubble constant measurement with estimates for the density of the universe, the team determined that the universe is approximately 12 billion years old - similar to the oldest stars. This discovery clears up a nagging paradox that arose from previous age estimates. The researchers emphasize that the age estimate holds true if the universeis below the so-called "critical density" where it is delicately balanced between expanding forever or collapsing. Or, the universe is pervaded by a mysterious force pushing the galaxies farther apart, in which case the Hubble measurements point to an even older universe.
结合哈勃常数和当前宇宙密度估值，团队确定宇宙大约有120亿岁了——与最老的恒星寿命一致。这个发现同时澄清了以前那些估值引起的似是而非的唠叨。研究者强调，如果宇宙刚好在“临界密度”之下，那么年龄估计有效；或者，星系被充斥宇宙各处的神秘力量推动而互相远离，那么哈勃望远镜观测结果将指向一个更古老的宇宙。所谓“临界密度”是指宇宙平均密度刚好在持续膨胀与最终收缩之间。
The universe's age is calculated using the expansion rate from precise distance measurements, and the calculated age is refined based on whether the universe appears to be accelerating or decelerating, given the amount of matter observed in space. A rapid expansion rate indicates the universe did not require as much time to reach its present size, and so it is younger than if it were expanding more slowly.
宇宙年龄的计算基于精准距离测量导出的宇宙膨胀速率，准确性同时基于根据空间物质数量观测结果——宇宙到底是在加速膨胀还是减速膨胀。一个快速膨胀的宇宙意味着宇宙不需要很多时间就能到达现在大小，自然比非常慢膨胀会更年轻。
The Hubble Space Telescope Key Project team is an international group of 27 astronomers from 13 different U.S. and international institutions.The Space Telescope Science Institute is operated by the Association of Universities for Research in Astronomy, Inc. for NASA, under contract with NASA's Goddard Space Flight Center in Greenbelt, MD.
哈勃太空望远镜重点项目团队是有来自13个国家、组织的27位天文学家组成的国际团队。太空望远镜科研所由美国大学天文研究协会（AURA，向NASA负责）负责运作，并与马里兰州格林贝尔市的美国航空航天局戈达德太空飞行中心长期协作。
CONTACT
联系人
Donald Savage
唐纳德.萨维奇 （野蛮人唐老鸭叔叔？）
NASA Headquarters, Washington, DC,
华盛顿特区 美国航空航天局总部
Phone: 202/358-1547)
Nancy Neal
南希.尼尔
Goddard Space Flight Center, Greenbelt, MD,
马里兰州 格林贝尔市 戈达德太空飞行中心 （绿化带市？）
Phone: 301/286-0039)
Ray Villard
雷·维兰德
Space Telescope Science Institute, Baltimore, MD,
马里兰州 巴尔的摩市 太空望远镜科研所
Phone: 410/338-4514)
PS：本文的人名、地名又比较特殊，有野蛮人Savage、有自由民（获释奴隶）Freeman，Mould虽然不是女模特的意思，但也是模具、模型的意思。至于Wendy，英文还有勇于冒险的少女之意。Donald，大家都知道唐老鸭吧。 Greenbelt，绿化隔离带。
我们现在知道，主流观点是宇宙充斥着暗能量，宇宙年龄大概137亿年，误差小于5%。
根据本文最后一句话，Space Telescope Science Institute将继续翻译为太空望远镜科学学会。——gohomeman1 |
显身卡
