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      VOA英語學習網 > 科學美國人 > 2019年科學美國人 > 科學美國人60秒科學系列 >
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      科學美國人60秒: 南極雪中掩埋的宇宙秘密

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      Secrets of the Universe Trapped in Antarctic Snow

      南極雪中掩埋的宇宙秘密

      In the summer of 2015, a strange delivery arrived in Munich, Germany: 25 boxes of still-frozen snow—sent all the way from Antarctica. The reason for shipping 1,100 pounds of snow halfway around the world? Scientists were hunting for interstellar dust—which might hold clues about our place in the universe.

      2015年夏天,德國慕尼黑收到了一份奇怪的快遞:25箱仍然冰凍的雪從南極洲一路送到這里。為什么要把1100磅的雪運送半個地球?科學家們一直在尋找星際塵埃——這可能為我們在宇宙中所處的位置提供線索。

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      First, scientists melted the snow and then filtered it for fine particles. Analyzing the remaining dust with mass spectrometry, they found traces of the isotope iron-60, which is primarily produced in two ways: by exploding supernovas or by cosmic rays zapping interplanetary dust. But it’s also produced in nuclear reactions here on Earth, by bombs or nuclear reactors.

      首先,科學家把雪融化,然后過濾出細小的顆粒。通過質譜分析剩余的塵埃,他們發現了同位素鐵60的蹤跡,鐵60主要通過兩種方式產生:超新星爆炸和宇宙射線撞擊星際塵埃。但它也在地球上通過炸彈或核反應堆的核反應中產生。

      So to determine how much of the stuff was truly interstellar—from beyond our solar system—the researchers used other isotopic clues to screen out quantities of iron-60 produced by nuclear reactions and cosmic rays. And they still had some iron-60 left over to account for—the stuff produced by supernovas.

      因此,為了確定有多少物質是真正——來自太陽系之外——研究人員利用其他同位素線索篩選出了由核反應和宇宙射線產生的鐵60的數量。他們還剩下一些鐵60來解釋超新星產生的物質。

      “Just by looking at something which is on our own planet to learn something which is so far away and happened so many millions of years ago—I mean, that’s pretty amazing. And that’s why I really like this work.” Dominik Koll, an experimental nuclear physicist at the Australian National University. His team reported the results in the journal Physical Review Letters.

      “僅僅通過觀察地球的一些東西,就能了解到一些遙遠的、發生在數百萬年前的事情——我的意思是,這非常令人驚奇。這就是我喜歡這份工作的原因。澳大利亞國立大學的實驗核物理學家多米尼克·科爾說。研究結果發表在《物理評論快報》上。

      Koll says this iron-60 might be showering down on us from the Local Interstellar Cloud, the patch of space the solar system is moving through right now. And if the cloud contains material produced by supernovas, Koll says, it could be the ancient remnants of exploding stars—a clue to the structure and formation of the universe. Luckily, we can investigate it all by hunting for dust, right here on spaceship Earth.

      科爾說,鐵60可能是從太陽系正在穿越的局部星際云中向我們傾瀉而下的。科爾表示,如果星云中含有超新星產生的物質,那么它可能是古代爆炸恒星的殘留物——這是宇宙結構和形成的線索。幸運的是,我們可以通過尋找塵埃來研究這一切,就在地球飛船上。

      Secrets of the Universe Trapped in Antarctic Snow

      In the summer of 2015, a strange delivery arrived in Munich, Germany: 25 boxes of still-frozen snow—sent all the way from Antarctica. The reason for shipping 1,100 pounds of snow halfway around the world? Scientists were hunting for interstellar dust—which might hold clues about our place in the universe.

      First, scientists melted the snow and then filtered it for fine particles. Analyzing the remaining dust with mass spectrometry, they found traces of the isotope iron-60, which is primarily produced in two ways: by exploding supernovas or by cosmic rays zapping interplanetary dust. But it’s also produced in nuclear reactions here on Earth, by bombs or nuclear reactors.

      So to determine how much of the stuff was truly interstellar—from beyond our solar system—the researchers used other isotopic clues to screen out quantities of iron-60 produced by nuclear reactions and cosmic rays. And they still had some iron-60 left over to account for—the stuff produced by supernovas.

      “Just by looking at something which is on our own planet to learn something which is so far away and happened so many millions of years ago—I mean, that’s pretty amazing. And that’s why I really like this work.” Dominik Koll, an experimental nuclear physicist at the Australian National University. His team reported the results in the journal Physical Review Letters.

      Koll says this iron-60 might be showering down on us from the Local Interstellar Cloud, the patch of space the solar system is moving through right now. And if the cloud contains material produced by supernovas, Koll says, it could be the ancient remnants of exploding stars—a clue to the structure and formation of the universe. Luckily, we can investigate it all by hunting for dust, right here on spaceship Earth.


      內容來自 VOA英語學習網http://www.tg377.com/show-8762-241826-1.html
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