科学美国人60秒 SSS 2014-08-07
时间:2019-01-20 作者:英语课 分类:2014年Scientific American(八)月
英语课
How heavy is the Milky 1 Way in comparison to its neighbor galaxy 2, Andromeda? Well, depends how you calculate it. In 2006 one group of astronomers 3 figured the Milky Way was twice as massive as Andromeda. A 2009 estimate evened the score, calculating that the two galaxies 4 are equal in mass.
Now a new formula suggests we're only half the mass of Andromeda. To come up with that number, astronomers first measured the speed and distance of galaxies between three and 10 million light-years away. That allowed them to calculate the deformation 5 of spacetime, and thus the mass, of our stellar neighborhood, aka the Local Group—a group of more than 50 galaxies, in which the Milky Way and Andromeda dominate.
They deduced the center of mass between the two heavyweights and found that Andromeda may indeed be twice as massive as the Milky Way. The results are in the Monthly Notices of the Royal Astronomical 6 Society.
The researchers say this new model might be more accurate than past ones, because it accounts for dark matter far from each galaxy's center—assuming the data's right, that is.
"Well, I never bet money on anything. Because I'm aware of all the uncertainties 7 and approximations." Lead author Jorge Peñarrubia of the University of Edinburgh. "One year from now, two years from now, some clever guy will come and say, ‘Hey, you forgot to include this, actually when you do everything changes,’ and then you will have to accept that."
For now, we'll just have to accept that we live in the wimpier of the two galaxies. At least until the next weigh-in.
—Christopher Intagliata
adj.牛奶的,多奶的;乳白色的
- Alexander always has milky coffee at lunchtime.亚历山大总是在午餐时喝掺奶的咖啡。
- I like a hot milky drink at bedtime.我喜欢睡前喝杯热奶饮料。
n.星系;银河系;一群(杰出或著名的人物)
- The earth is one of the planets in the Galaxy.地球是银河系中的星球之一。
- The company has a galaxy of talent.该公司拥有一批优秀的人才。
n.天文学者,天文学家( astronomer的名词复数 )
- 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》
星系( galaxy的名词复数 ); 银河系; 一群(杰出或著名的人物)
- Quasars are the highly energetic cores of distant galaxies. 类星体是遥远星系的极为活跃的核心体。
- We still don't know how many galaxies there are in the universe. 我们还不知道宇宙中有多少个星系。
n.形状损坏;变形;畸形
- The deformation frequencies are not sufficiently distinctive.其变形频率不是十分明显的。
- The calculated deformation is almost equal to the real situation by measurement.经检测,计算变形量与实际情况基本一致。
adj.天文学的,(数字)极大的
- 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。
无把握( uncertainty的名词复数 ); 不确定; 变化不定; 无把握、不确定的事物
- One of the uncertainties of military duty is that you never know when you might suddenly get posted away. 任军职不稳定的因素之一是你永远不知道什么时候会突然被派往它处。
- Uncertainties affecting peace and development are on the rise. 影响和平与发展的不确定因素在增加。 来自汉英非文学 - 十六大报告