万物简史 第184期:爱因斯坦的宇宙(27)
Combining Leavitt's cosmic yardstick 1 with Vesto Slipher's handy red shifts, Edwin Hubble now began to measure selected points in space with a fresh eye. In 1923 he showed that a puff 2 of distant gossamer 3 in the Andromeda constellation 4 known as M31 wasn't a gas cloud at all but a blaze of stars, a galaxy 5 in its own right, a hundred thousand light-years across and at least nine hundred thousand light-years away. The universe was vaster—vastly vaster—than anyone had ever supposed. In 1924 he produced a landmark 6 paper, “Cepheids in Spiral Nebulae” (nebulae,from the Latin for “clouds,” was his word for galaxies 7), showing that the universe consisted not just of the Milky 8 Way but of lots of independent galaxies—“island universes”—many of them bigger than the Milky Way and much more distant.
哈勃把莱维特测量宇宙的标准和维斯托·斯莱弗的红移结合起来，开始以焕然一新的目光有选择地测量空间的点。1923年，他证明，仙女座里一团代号为M31的薄雾状的东西根本不是气云，而是一大堆光华夺目的恒星，其本身就是一个星系，直径有1万光年，离我们至少有90万光年之远。宇宙比任何人想像的还要大——大得多。1924年，哈勃写出了一篇具有划时代意义的论文，题目为《旋涡星云里的造父变星》（“星云”源自拉丁语，意为“云”，哈勃喜欢用这个词来指星系），证明宇宙不仅仅有银河系，还有大量独立的星系——“孤岛宇宙”——其中许多比银河系要大，要远得多。
爱因斯坦珍贵照片
This finding alone would have ensured Hubble’s reputation, but he now turned to the question of working out just how much vaster the universe was, and made an even more striking discovery. Hubble began to measure the spectra 9 of distant galaxies—the business that Slipher had begun in Arizona. Using Mount Wilson’s new hundred-inch Hooker telescope and some clever inferences, he worked out that all the galaxies in the sky (except for our own local cluster) are moving away from us. Moreover, their speed and distance were neatly 10 proportional: the further away the galaxy, the faster it was moving.
仅仅这一项发现就足以使哈勃名扬天下，但是，他接着把注意力转向另一个问题，想要计算宇宙到底大了多少，于是有了一个更加令人瞩目的发现。哈勃开始测量远方星系的光谱——斯莱弗已经在亚利桑那州开始做的那项工作。他利用威尔逊山天文台那台新的254厘米天文望远镜，加上一些聪明的推断，到20世纪30年代初已经得出结论：天空中的所有星系（除我们自己的星系以外）都在离我们远去。而且，它们的速率和距离完全成正比：星系距离我们越远，退行速率越快。
- This is a yardstick for measuring whether a person is really progressive.这是衡量一个人是否真正进步的标准。
- She was a yardstick against which I could measure my achievements.她是一个我可以用来衡量我的成就的准绳。
- He took a puff at his cigarette.他吸了一口香烟。
- They tried their best to puff the book they published.他们尽力吹捧他们出版的书。
- The prince helped the princess,who was still in her delightful gossamer gown.王子搀扶着仍穿著那套美丽薄纱晚礼服的公主。
- Gossamer is floating in calm air.空中飘浮着游丝。
- A constellation is a pattern of stars as seen from the earth. 一个星座只是从地球上看到的某些恒星的一种样子。
- The Big Dipper is not by itself a constellation. 北斗七星本身不是一个星座。
- 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。
- The Russian Revolution represents a landmark in world history.俄国革命是世界历史上的一个里程碑。
- The tower was once a landmark for ships.这座塔曾是船只的陆标。
- 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。
- 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。
- The infra-red spectra of quinones present a number of interesting features. 醌类的红外光谱具有一些有趣的性质。
- This relation between the frequency and the field spectra was noted experimentally. 实验上已经发现频率和场频谱之间的这种关系。