宇宙探索中的十大極限物質(上)

Cosmic discoveries are important because they expand our understanding of nature and allow us to test reality against our mathematical theories. Here are 10 objects which reach the extremes we need to test the limits of our calculations—and our imaginations.

宇宙探索極爲重要，因爲它不僅可以拓展人們對大自然的認知，而且人們可以利用它對數學理論進行驗證。以下的十大物質考驗了我們計算能力和想象力的極限。

est Planet

10.最微小的行星

Earlier this year, the Kepler Observatory discovered a star system with three planets, including the smallest expolanet found to date. The Kepler telescope is conveniently located in space, allowing it an unobstructed view to the stars without that pesky atmosphere thing in the way. Dubbed Kepler 37-b, this baby planet is smaller than Mercury and only about 200 kilometers (124 mi) larger in diameter than our own Moon. Unfortunately, it's also sitting uncomfortably close to the threshold that saw Pluto demoted from full-time planet.

今年初，開普勒天文臺發現了帶有三顆行星的恆星系統，其中包括了迄今爲止天文學家所發現的體積最小的太陽系外行星。開普勒望遠鏡被安置於太空中，沒有討厭的大氣層的阻擋，可清楚地觀測到星際狀況。這顆編號爲開普勒37b的小行星比水星還要小，直徑僅僅比月球大200公里。不幸的是，它就位於從九大行星中降級的冥王星附近。

One of the few ways astronomers can locate exoplanet candidates is by observing a star and waiting for the light output to dim ever so slightly. This happens when the planet transits across the face of the star, so it's much easier to detect larger bodies. Most of the exoplanets we've found are much larger than Earth, usually around the size of Jupiter. The dimming effect produced by Kepler 37-b would be barely perceptible, which makes the discovery all the more amazing.

天文學家查找行星候選者的方法之一就是通過"凌日法"觀察恆星，行星經過其母恆星表面的時候，會造成恆星亮度的略微降低，因而此法更容易發現較大的行星。目前我們所發現的大多數系外行星都比地球要大，大小一般和木星差不多。開普勒37b所產生的暗光效果幾乎不易察覺，使得這次發現更加驚喜萬分。

Milky Way's Fermi Bubbles

9.銀河系的費米氣泡

The Milky Way galaxy looks absolutely immense when viewed flat, as we're accustomed to seeing it in illustrations. When viewed edge-on, however, it's underwhelmingly wispy and scrawny looking. Or at least it was, until we looked at it in the extremely short end of the spectrum: X-rays and gamma rays.

從平面看，銀河系非常龐大，就像我們經常在圖片上所看到的畫面一樣。但從側面看，它卻十分普通，纖細瘦小。或者至少在我們通過光譜的極短端（X射線和伽瑪射線）觀察它以前，它是這樣的。

The Fermi Bubbles jut out perpendicularly to our galaxy's disc and encompass a length of 50,000 light years, or about half the diameter of the Milky Way. Not even NASA knows for sure where the bubbles came from, but they could be leftover emissions from the supermassive black hole in our galactic core, because gamma radiation is only produced by incredibly energetic events.

費米氣泡垂直銀河系盤面沿伸50000光年，相當於銀河系直徑的一半。甚至連美國宇航局都不清楚這兩個巨大氣泡從何而來。然而他們也許是銀河系中心特大質量的黑洞所產生的殘餘放射物，因爲只有巨大的高能事件纔會產生伽瑪射線。

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8.行星"忒伊亞"

Over four billion years ago, the early Solar System was horrible and extremely dangerous, full of planetoids at different points of development. Our cosmic neighborhood was littered with chunks of rock and ice, so collisions were frequent. The largest of these collisions accounts for one of the more popular theories of how our Moon came about. The primordial Earth was impacted by an object about the size of Mars, named Theia. The two bodies met at a very specific angle, and it is believed that the leftover debris coalesced inside Earth's orbit to form what is now the Moon.

在四十億年前，早期的太陽系非常恐怖也極端危險，佈滿了在不同發展階段的小行星。我們的宇宙附近到處都是石頭和冰塊，所以碰撞也十分頻繁。其中最大的一次碰撞解釋了一種人們更加認可的月球形成學說——大碰撞說。原始地球和火星大小般的忒伊亞行星發生了碰撞。它們在一個特殊的角度相撞，據說碰撞後所產生的殘骸進入地球軌道，最終合併形成了現在的月球。

Had the impact been slightly more direct, either closer toward the poles or the equator, the results would have been drastically different and the young Earth could have been obliterated completely.

如果撞擊稍微再正面一些的話，要麼更靠近兩級要麼更靠近赤道，那麼結果將會大不相同，撞擊很可能會徹底毀滅年輕的地球。

n Great Wall

7.史隆長城

The Sloan Great Wall is mind-bogglingly large and seems absolutely unreal in lieu of the types of size comparisons we humans are accustomed to dealing with. The Great Wall is one of the largest structures in the universe, and is made up of a string of galaxies that stretch for 1.4 billion light years.

與平常我們人類接觸過的天體結構相比，史隆長城龐大到令人難以置信，看起來十分不真實。它是宇宙中最大的結構之一，由一連串的星系組成，長達十四億光年。

It contains hundreds of millions of distinct galaxies, most of which form superclusters within the overall structure. It appears that the clusters have formed in accordance with regions of differing densities that were a direct result of the Big Bang, and are observable in the cosmic microwave background. Some argue that the Sloan Great Wall should not be considered a single structure, due to the fact that not all of the galaxies are gravitationally bound to one another.

史隆長城包含了數以億計的不同星系，其中大多數在整體結構中形成了超星系團。這些星系團似乎是依照宇宙大爆炸造成的不同密度區形成的，在宇宙微波背景下也可以觀測得到。一些人認爲史隆長城不應被當成一個單一的結構，因爲事實證明並不是所有的星系都是有傾向性地連接在一起的。

est Black Hole

6.最微小的黑洞

Nothing in the universe inspires as much fear as the mighty black hole. In video game terms it's the "final boss" of the universe. It has enough pull to ensnare light itself, which moves at almost 300,000 kilometers per second (186,000 mi/s). We've seen black holes that are impressively large, at billions of times the mass of our sun, but now for the first time we found one that's impressively puny.

在宇宙中，沒有什麼能比巨大的黑洞更嚇人的了。用電子遊戲中的術語來說，它就是宇宙的"終極巨獸"。黑洞產生的引力場如此之強，甚至連以每秒30萬公里的速度移動的光也無法逃逸。我們已經目睹過無比巨大的黑洞，他們的質量是我們太陽的數十億倍。但是現在我們第一次發現如此微小的黑洞。

The previous record holder for smallness was still around 14 times the mass of the Sun, which is quite large for our standards. The new kid, IGR, is only about three times as massive as the Sun. IGR comes in at around the bare minimum of mass necessary to cause a star to fall in on itself when it dies. If it was any smaller it would have gone out as our own Sun will, slowly bloating up before shedding its outer layers and most of its material into space.

在此之前微小記錄的保持者大約是太陽質量的14倍，用我們的標準來衡量的話已經相當之大了。這顆最新發現的小黑洞IGR僅是太陽質量的三倍。它接近黑洞穩定存在的質量下限，當它死去時便會自動墜落。如果它更小一些，便會和我們的太陽一樣熄滅，漸漸膨脹，最後外層和大多數內部物質脫落，散落在宇宙中。

翻譯:高陳影 來源：前十網