英語聽力 學(xué)英語,練聽力,上聽力課堂! 注冊 登錄
> 在線聽力 > 英語高級聽力 > 英語聽力:探索與發(fā)現(xiàn) >  第274篇

英語聽力:黑洞吞噬—8

所屬教程:英語聽力:探索與發(fā)現(xiàn)

瀏覽:

2017年07月12日

手機版
掃描二維碼方便學(xué)習(xí)和分享
https://online2.tingclass.net/lesson/shi0529/0009/9895/274.mp3
https://image.tingclass.net/statics/js/2012
But if you look carefully, stars aren't spread smoothly across the whole sky. They are gathered together into a band that loops around the sky which we call the Milky Way.

That bright strip across the sky with its extraordinary abundance of stars and clusters was a clue to the nature of our galaxy.

It was obvious to astronomers for quite a long time that most of the stars were gathered together into a flats, layer or disk and that we were within that disk. But we still don't know whereabouts in the galaxy we are. And then in the early 20th century an American astronomer, Harlow Shapley, hits on a way of trying to find out where the centre of the galaxy might be. He used objects called globular clusters, which are actually found all over the sky.

Bright sources containing thousands of stars, globular clusters are spread out in the sphere around the Milky Way's central disk. Shapley realized they were in effect signposts to where the centre of the galaxy could be found.

He plotted where the clusters were and he found although they were spread all over the sky, they were concentrated in a particular direction. And that told us that we weren't at the centre of the galaxy, but the centre of the galaxy was in this direction here. So at last, astronomers knew exactly where the centre of the galaxy was and they also knew pretty much how far away it was.

用戶搜索

瘋狂英語 英語語法 新概念英語 走遍美國 四級聽力 英語音標(biāo) 英語入門 發(fā)音 美語 四級 新東方 七年級 賴世雄 zero是什么意思包頭市萬順包百廣場英語學(xué)習(xí)交流群

網(wǎng)站推薦

英語翻譯英語應(yīng)急口語8000句聽歌學(xué)英語英語學(xué)習(xí)方法

  • 頻道推薦
  • |
  • 全站推薦
  • 推薦下載
  • 網(wǎng)站推薦