This would mean that the universe was only half the size and age that Sandage believed—ten billion years. Matters took a further lurch1 into uncertainty2 when in 1994 a team from the Carnegie Observatories3 in California, using measures from the Hubble space telescope, suggested that the universe could be as little as eight billion years old—an age even they conceded was younger than some of the stars within the universe. In February 2003, a team from NASA and the Goddard Space Flight Center in Maryland, using a new, far-reaching type of satellite called the Wilkinson Microwave Anistropy Probe, announced with some confidence that the age of the universe is 13.7 billion years, give or take a hundred million years or so. There matters rest, at least for the moment.
这意味着,宇宙的大小和年龄只有桑德奇认为的一半──100亿年。1994年,情况突然变得更不确定,加利福利亚州卡内基天文台的一个小组根据哈勃天文望远镜的测量结果,提出宇宙的年龄只有80亿年──连他们也承认,这个年龄比宇宙里某些恒星的年龄还要小。2003年2月,一个来自美国国家航空和航天局及马里兰州高达德太空飞行中心的小组,利用一种名叫威尔金森微波各向异性探测器的新型卫星,信心十足地宣布,宇宙的年龄为137亿年,误差1000万年左右。事情被搁置下来,至少在一段时间里。
You are of course entitled to wonder what is meant exactly by "a constant of 50" or "a constant of 100." The answer lies in
astronomical4 units of measure. Except
conversationally5,
astronomers6 don't use light-years. They use a distance called the parsec (a
contraction7 of parallax and second), based on a universal measure called the stellar parallax and equivalent to 3.26 light-years. Really big measures, like the size of a universe, are measured in megaparsecs: a million parsecs. Thus when astronomers refer to a Hubble constant of 50, what they really mean is "50 kilometers per second per megaparsec."
(注:你当然有权知道“常数为50”或“常数为100”到底是什么意思,答案在于天文量度单位,除了在交谈中,天文学家不用光年,他们用的距离单位是“秒差距”基于一种普遍使用的、名叫恒视差的量度方法,相当于3.26光年。确实大的尺度。那个常数以每百万秒差距每秒公里数来表示,因此,哈勃常数为50的意思是“每百万秒差距每秒50公里”)。
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收听单词发音
1
lurch
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n.突然向前或旁边倒;v.蹒跚而行 |
参考例句: |
- It has been suggested that the ground movements were a form of lurch movements.地震的地面运动曾被认为是一种突然倾斜的运动形式。
- He walked with a lurch.他步履蹒跚。
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2
uncertainty
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n.易变,靠不住,不确知,不确定的事物 |
参考例句: |
- Her comments will add to the uncertainty of the situation.她的批评将会使局势更加不稳定。
- After six weeks of uncertainty,the strain was beginning to take its toll.6个星期的忐忑不安后,压力开始产生影响了。
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3
observatories
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n.天文台,气象台( observatory的名词复数 ) |
参考例句: |
- John Heilbron, The Sun in the Church: Cathedrals as Solar Observatories, 3-23. 约翰.海耳布隆,《教会里的太阳:教堂即太阳观测台》,第3-23页。 来自互联网
- Meteorologists use satellites, land observatories and historical data to provide information about the weather. 气象学家使用卫星、上天文台和历史资料来提供有关天气的信息。 来自互联网
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4
astronomical
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adj.天文学的,(数字)极大的 |
参考例句: |
- He was an expert on ancient Chinese astronomical literature.他是研究中国古代天文学文献的专家。
- Houses in the village are selling for astronomical prices.乡村的房价正在飙升。
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5
conversationally
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adv.会话地 |
参考例句: |
- I am at an unfavourable position in being conversationally unacquainted with English. 我由于不熟悉英语会话而处于不利地位。 来自《现代汉英综合大词典》
- The findings suggest that happy lives are social and conversationally deep, rather than solitary and superficial. 结论显示,快乐的生活具有社会层面的意义并与日常交谈有关,而并不仅仅是个体差异和表面现象。 来自互联网
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6
astronomers
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n.天文学者,天文学家( astronomer的名词复数 ) |
参考例句: |
- Astronomers can accurately foretell the date,time,and length of future eclipses. 天文学家能精确地预告未来日食月食的日期、时刻和时长。 来自《简明英汉词典》
- Astronomers used to ask why only Saturn has rings. 天文学家们过去一直感到奇怪,为什么只有土星有光环。 来自《简明英汉词典》
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7
contraction
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n.缩略词,缩写式,害病 |
参考例句: |
- The contraction of this muscle raises the lower arm.肌肉的收缩使前臂抬起。
- The forces of expansion are balanced by forces of contraction.扩张力和收缩力相互平衡。
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