英语听力文摘 English Digest 434、人类听不见的声音
时间：2019-02-16 作者：英语课 分类：英语听力文摘 English Digest
The Lowest Note in the Universe
宇宙中的最低音
It's coming from a black hole in the Perseus Cluster, about two hundred fifty million light years away. A black hole？And outer space？That makes sound?
What’s happening out there is that intergalactic gas has concentrated around a cluster of galaxies 1, forming a cloud. A massive black hole is sending out jets of particles that crash into the cloud, causing pressure waves to ripple outward.
Some astronomers 2 interpret these as sound waves. Of course, even if you call it sound, it’s too low for anyone to hear. What note is it? They estimate the note to be a “B flat,” about fifty-seven octaves lower than middle C.
Researchers now think that many black holes may produce such waves, which can affect the way galaxies, and even galaxy clusters, behave.
宇宙中的最低音是由距地球约两亿五千万光年的英仙座星期群中的一个黑洞发出的。
那里的星际气体已集中在星系群周围形成了云层。一个巨大的黑洞正在释放粒子喷流，这些粒子喷流又撞向云层，然后就产生了压力波向外界发出潺潺声的情况。
有些天文学家把这种波解释成声波。当然，即使你称之为声音，但它也太低了以致没有人能听得到。他们估计这种声音属于降B调。比中央C低57个八度音阶。
研究者们现在认为很多黑洞都会发出这种可以影响星系甚至是星系群的表现方式。
- Quasars are the highly energetic cores of distant galaxies. 类星体是遥远星系的极为活跃的核心体。
- We still don't know how many galaxies there are in the universe. 我们还不知道宇宙中有多少个星系。
- Astronomers can accurately foretell the date,time,and length of future eclipses. 天文学家能精确地预告未来日食月食的日期、时刻和时长。 来自《简明英汉词典》
- Astronomers used to ask why only Saturn has rings. 天文学家们过去一直感到奇怪，为什么只有土星有光环。 来自《简明英汉词典》