#大學英語聽力#

In 2017, astronomers captured a mysterious signal from deep space.

2017年，天文學家從深空捕捉到了一個神祕的訊號。

For mere milliseconds, it flared brightly in the radio spectrum and fell away, and that seemed to be that. But it wasn't.

在僅僅幾毫秒的時間裡，它在無線電頻譜中明亮地閃爍，然後消失了，看起來就是這樣。但事實並非如此。

Follow-up observations have now revealed the signal repeating, nearly 600 times fainter than that first burst. The repetition suggests these weird radio flares we keep detecting from the cosmos could be more active and more complex than we ever knew.

現在，後續觀察發現訊號在重複，比第一次爆發微弱近600倍。這種重複表明，我們不斷從宇宙中探測到的這些奇怪的無線電耀斑可能比我們所知道的更活躍，也更復雜。

The flares are called fast radio bursts (FRBs), one of the most bewildering phenomena from deep space.

這些耀斑被稱為快速射電爆發(FRBs)，這是來自深空的最令人困惑的現象之一。

They show up in radio data, huge spikes of electromagnetic energy, as powerful as hundreds of millions of Suns, in a burst only milliseconds in duration.

它們出現在無線電資料中，電磁能量的巨大尖峰，與數億個太陽一樣強大，在短短几毫秒的爆發中持續。

We don't yet know what causes them, or even where most of them come from; of the over 150 bursts detected, only a handful have been traced back to their galaxies of origin.

我們還不知道它們的起因，甚至不知道它們大多數來自哪裡；在檢測到的150多個爆發中，只有一小部分被追溯到它們的起源星系。

Not all FRBs are the same, either.

也不是所有的FRBs都是一樣的。

There are differences such as the strength of the signal, the way the signal is twisted (polarisation), tiny differences in duration.

有一些不同之處，如訊號的強度，訊號扭曲的方式(極化)，持續時間的微小差異。

But one of the biggest differences is whether the signal repeats.

但最大的區別之一是訊號是否重複。

Some do. Most do not.

有些人會。大多數人都不會。

Or, at least, have not been detected to do so.

或者至少沒有被檢測到這樣做。

"One of the big open questions about FRBs is whether or not they all repeat. While over a hundred FRBs are known, up until recently only one had been found to repeat," astronomer Pravir Kumar of Swinburne University of Technology in Australia told ScienceAlert.

澳洲斯溫伯恩科技大學的天文學家Pravir Kumar告訴ScienceAlert：“關於FRBs的一個公開的大問題是它們是否都會重複。雖然已經知道有一百多個FRBs，但直到最近，只發現了一個重複的FRBs。”

To find FRBs and search for their repetitions, Kumar and colleagues had been using the Australian Square Kilometre Array Pathfinder (ASKAP) in Australia.

為了找到FRBs並尋找它們的重複，Kumar和他的同事一直在澳洲使用澳洲平方千米陣列探路器(ASKAP)。

"We found 20 FRBs and searched for repetitions with ASKAP for two years," he said.

“我們發現了20個FRB，並用ASKAP搜尋了兩年的重複，”他說。

"In over 12,000 hours we found none! However, could it be possible that repetitions were too faint for ASKAP to detect?"

“在超過12，000小時內，我們沒有發現！但是，有沒有可能重複太微弱，ASKAP無法檢測到？”