字神帝國英語天地

 今日主題：Billion Sun–Bright Events Leave Radio Wave Clues  光束活動留下無線電波線索

 洪欣老師推薦：托福聽力最好的課外教材：60-Second Science
 康康精選托福會考的主題，堅持每天精聽一定會進步的哦!!

 建議方法：
1. 先聽兩三遍 (不看文稿)
2. 再一句一句聽寫 (每句都要聽寫數遍，直到寫出85%以上的字)
3. 最後check文稿，看哪聽不出來，單字沒背過，還是發音不熟。
4. 堅持天天聽，就能每天進步哦。

 MP3音檔 (按右鍵可下載聽)：喜歡的同學，幫忙推或按讚哦~~
http://online1.tingclass.net/voaspe/…/20160324sa_science.mp3

 只有音檔怎夠，聽不懂地方，不用怕，康康幫你準備好中英文稿了：

 中英文稿：
Radio waves are invisible to our eyes. But if you could see them, the sky would dance with random tiny flashes. Thousands of what are called “fast radio bursts” are estimated to occur every day. And though each pinprick flash lasts only a thousandth of a second, they represent a faraway source briefly shining a billion or more times brighter than our sun.
我們的眼睛看不到無線電波。如果你看到了無線電波，天空就會有隨機閃爍的微小光束。據估計這些所謂的“快速無線光波”。儘管，每個閃光指持續千分之一秒，但他們代表了遙遠的光源，這些光源的亮度要比太陽亮十億倍。

Fast radio bursts have been known for nearly a decade, but scientists have struggled to determine exactly where they come from. And they'd like to know. Because finding their origins would help astronomers use the bursts as probes to map the history and structure of the universe in unprecedented detail.
近十年來，大家已經熟悉快速無線電波，但是科學家一直在努力確定這些光束的來源。並且科學家們迫切知道答案。因為發現來源有助於科學家利用這些光束詳細描述宇宙的歷史和結構。

Now researchers have found the source of one particular burst. They used radio telescopes in Australia and the giant Subaru optical telescope in Hawaii to trace a burst observed last April. And they determined it came from an old elliptical galaxy full of exhausted, dying suns some six billion light-years away. The findings are in the journal Nature.
現在，研究人員已經發現了一個特定的光束源。去年四月，他們利用澳大利亞射電望遠鏡以及夏威夷巨大的斯巴魯望遠鏡跟踪觀察到的光源。研究人員認為這些光束來自一個古老的橢圓星系，這些星系充滿了枯竭、垂死的恆星，距離約為60億光年遠。研究結果發表在《自然》雜誌上。

Identifying the source galaxy provides crucial clues. For one thing, such a galaxy is short on some of the objects expected to cause bursts, such as supernovae or rapidly spinning and flaring pulsars, suggesting this burst came from something else. And, although the burst in question lasted only milliseconds, astronomers were able to witness its faint, fading radio afterglow for about six days. That's the sort of afterglow expected from a colliding pair of ancient neutron stars, which would be a relatively common occurrence among an elliptical galaxy's geriatric suns .
確定光束來源的星係將提供重要的線索。一方面，這樣的星系缺乏引發爆炸的物體，例如超新星或者快速旋轉的脈衝星，這意味著爆炸原因來自其他方面。儘管，未 知的爆炸僅持續了數毫秒，但天文學家能夠6天觀看到爆炸的微弱餘光。這可能是古代中子星碰撞的餘暉，這在橢圓星係是一個比較常見的問題。

Even though this particular burst has probably been explained, many mysteries remain—not all bursts seem to come from the same cosmic source. Fortunately, most possible burst sources could be distinguished by the gravitational waves they emit, like those recently seen by the Laser Interferometer Gravitational-Wave Observatory, or LIGO. That means researchers may soon be searching the skies for both radio and gravitational waves for these bursts, to help draw an ever more detailed map of the cosmos.
即使這個爆炸問題得到了解決，但是仍存在很多疑團——似乎並不是所有的爆炸都來自同一個宇宙。幸運的是，可以通過其發射的引力波來區分爆炸源，例如，最近 通過激光干涉引力波天文台觀測到的爆炸源。這意味著，研究人員可以利用無線電以及引力波來確定爆炸源，這樣有助於繪製詳細的宇宙圖。