字幕列表 影片播放 由 AI 自動生成 列印所有字幕 列印翻譯字幕 列印英文字幕 In 1929, astronomer Edwin Hubble noticed that almost all galaxies had a red shift to their 1929年,天文學家埃德溫-哈勃注意到,幾乎所有的星系都有一個紅移到它們的 color, and the farther away they were, the redder they appeared. 顏色,而且離得越遠,越顯得紅豔。 He concluded that the waves of light from the galaxies had been stretched as they traveled 他的結論是,來自星系的光波在行進過程中被拉長了。 to us, meaning space itself was expanding in all directions. 對我們來說,意味著空間本身在向四周擴展。 This observation literally shaped our image of the universe, but now some researchers 這一觀察結果確實塑造了我們對宇宙的印象,但現在一些研究人員 think that shape may be a bit lopsided. 覺得這個形狀可能有點歪斜。 The idea that space looks pretty much the same everywhere is known as the cosmological 空間在任何地方看起來都差不多的想法被稱為宇宙論。 principle. 原則。 Sure, close up there are variations. 當然,近看有變化。 The structure of star systems, galaxies, or even galaxy clusters are going to be different. 星系、星系、甚至星系團的結構都會有所不同。 But on an extremely zoomed-out scale of many billions of light years, it's believed the 但在極度放大的幾十億光年的尺度上,人們認為 universe looks and behaves the same way in every direction. 宇宙的每一個方向看起來和行為都是一樣的。 In other words, it's isotropic. 換句話說,它是各向同性的。 We think it started with a big bang 13.8 billion years ago, and like a balloon, has expanded 我們認為它始於138億年前的一次大爆炸 就像氣球一樣,一直在膨脹著 more or less evenly in every direction since. 此後,在各個方向上都或多或少地均勻。 A good piece of evidence supporting the notion that the universe is isotropic is the cosmic 支持宇宙各向同性這一觀點的一個很好的證據是宇宙的 microwave background, the afterglow left by the big bang, which looks pretty smooth and 微波背景,大爆炸留下的餘暉,看起來很平滑,很 uniform. 統一。 An isotropic universe is convenient. 一個各向同性的宇宙是方便的。 If everything is behaving the same and expansion is happening evenly, then we can assume dark 如果一切都表現得一樣,而且擴張是均勻的,那麼我們就可以假設暗色的 energy, what we think is driving the accelerating expansion, acts the same everywhere, and has 我們認為推動加速膨脹的能量,在任何地方的作用都是一樣的,並且具有以下特徵 been since the big bang. 自大爆炸以來,一直。 But what if somewhere along the way the rules changed, and the universe isn't expanding 但是,如果某個地方沿途的規則發生了變化, 宇宙並沒有膨脹,怎麼辦? evenly anymore? 均勻的了嗎? Some astronomers decided to double check using X-ray emissions from galaxy clusters, and 一些天文學家決定利用星系團的X射線發射來進行雙重檢查,並。 have concluded that the universe may not be as isotropic as we thought, in other words, 已經得出結論,宇宙可能並不像我們想象的那樣是各向同性的,換句話說。 it could be “anisotropic.” 它可能是 "各向異性"。 The researchers looked at data from almost 850 galaxy clusters. 研究人員考察了近850個星系團的數據。 Using their X-ray emissions, the astronomers estimated each cluster's temperature, and 天文學家利用它們的X射線輻射,估計了每個星團的溫度,並且 thus its luminosity. 是以其光度。 Keep in mind that luminosity is how much light a celestial object gives off, meaning it's 請記住,光度是指一個天體發出的光的多少,也就是說它的 an intrinsic property and should be the same no matter how you measure it. 是一種內在屬性,無論你如何衡量它都應該是一樣的。 Once they had used x-ray observations to determine the clusters' luminosities, they cross-checked 一旦他們利用X射線觀測確定了星團的光度,他們就交叉核對了X射線。 the numbers using another method that relies on the rate we assume the universe is uniformly 使用另一種方法來計算數字,這種方法依賴於我們假設宇宙是均勻的。 expanding. 擴大。 When they compared the two values, they found two areas of the night sky where the numbers 當他們比較這兩個數值時,發現夜空中有兩個區域的數字。 didn't match up. 不符合。 In these regions, the clusters were as much as 30% brighter or dimmer than predicted, 在這些區域,星團比預測的亮度或暗度高達30%。 meaning they were closer or farther away than they should be if the universe were isotropic. 意思是說,如果宇宙是各向同性的,他們比應該的距離更近或更遠。 That would throw a serious wrench into our understanding of the cosmos. 這將嚴重影響我們對宇宙的理解。 Why would the cosmic microwave background be so smooth when the recent universe isn't? 為什麼宇宙微波背景會如此平穩,而近代宇宙卻不平穩? Would this mean the laws of physics are different in certain areas? 這是否意味著物理定律在某些領域是不同的? Is it possible dark energy affects some regions more strongly than others? 是否有可能暗能量對某些地區的影響比其他地區更強烈? It's hard enough finding an explanation for dark energy when it behaves uniformly. 當暗能量表現均勻的時候,為它找到一個解釋已經很困難了。 These are the questions an anisotropic universe would raise, and their answers may be unknowable. 這些都是一個各向異性宇宙會提出的問題,其答案可能是不可知的。 But one possibility suggested by one study doesn't overturn all of our assumptions about 但是,一項研究提出的一種可能性並不能推翻我們關於的所有假設。 isotropy. 同向性; These researchers are looking to explain the findings in ways that gel with the cosmological 這些研究人員希望用與宇宙學相吻合的方式來解釋這些發現。 principle. 原則。 One explanation is some clusters could be caught in a “bulk flow” where even more 一種解釋是,一些集群可能會被捲入 "大宗流 "中,在那裡,甚至有更多的 massive clusters farther away drag them off. 巨大的集群更遠的地方把它們拖走。 Or there's the possibility that the data the conclusions are based on are just plain 也有可能是結論所依據的數據只是普通的 wrong. 錯。 One astronomer pointed out that one region the researchers deemed particularly lopsided 一位天文學家指出,研究人員認為有一個區域特別片面。 is also near an area where the Milky Way's gas and dust are thickest. 也是在銀河系氣體和塵埃最濃厚的區域附近。 It's possible that's absorbing x-rays and throwing off the luminosity calculations. 有可能是吸收了X射線,把光度的計算給丟了。 But the researchers do take the effect of the Milky Way into account. 但研究人員確實考慮到了銀河系的影響。 Even if their results were due to an absorption effect, it would mean some new kind of super-dust 即使他們的結果是由於吸收效應,那也意味著某種新的超級塵埃 was scrambling the emissions (which gives me serious Golden Compass vibes). 是擾亂排放(這給我嚴重的金羅盤的氛圍)。 The researchers intend to follow up with infrared observations to take another 研究人員打算通過紅外觀測進行後續工作,再拍攝一次。 stab at determining the clusters' luminosities. 嘗試確定星團的光度。 Maybe their future results will show that their assumptions based on x-rays were off 也許他們未來的結果會表明,他們基於X射線的假設是錯誤的。 and the universe is the same in all directions. 而宇宙的各個方向都是一樣的。 Then again, maybe their results will change everything we know about the history and shape 不過話說回來,也許他們的結果會改變我們對歷史和形狀的一切認識。 of the cosmos. 的宇宙。 If ever a topic needed more research, this is it. 如果說有什麼課題需要更多的研究,那就是這個了。 One instrument that will help map out the dark energy of the universe and answer this 有一種儀器可以幫助繪製出宇宙的暗能量,並回答這個問題。 riddle is ESA's Euclid telescope. 謎底是歐空局的歐幾里德望遠鏡。 Amanda has a Countdown To Launch episode on that here. 阿曼達有一個倒計時啟動的情節,在這裡。 Be sure to subscribe, thanks for watching, and I'll see you next time on Seeker! 一定要訂閱,謝謝大家的觀看,我們下期《求是》見!