黑洞也有声音？听起来像什么? 近日，美国国家航空航天局发布了一段”黑洞的声音”，有美国网友表示听完“毛骨悚然（creepy）”，也有人认为“美得缥缈（ethereally beautiful）”……
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What does a black hole sound like? Both “creepy” and “ethereally beautiful,” according to people who’ve listened to an audio clip posted on Twitter by NASA.
据《华盛顿邮报》报道，当地时间8月22日，美国国家航空航天局（NASA）在推特发布了一段音频片段，该音频是根据2亿光年外的英仙座黑洞的压力波而合成的，由钱德拉X射线天文台制作，最初于今年5月4日发布于NASA官网。
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NASA官网5月4日发布了这段音频
NASA推特配文解释称：“太空中没有声音的误解，源于大多数空间是真空，因此声波无法传播。” 但星系团中“有大量的气体包围着内部的数百甚至数千个星系，为声波传播提供了介质。”
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The US space agency tweeted what it called a remixed sonification of the black hole at the center of a galaxy cluster known as Perseus, which lies about 240 million light-years away from Earth.
But the idea that there is no sound in space is actually a "popular misconception", the agency said. While most of space is a vacuum, with no medium for sound waves to travel through, a galaxy cluster "has copious amounts of gas that envelop the hundreds or even thousands of galaxies within it, providing a medium for the sound waves to travel," it explained.
据《华盛顿邮报》报道，这段声波是在2003年被发现的。当时，美国国家航空航天局钱德拉X射线天文台的研究人员在经过53个小时的观测后，“发现黑洞发出的压力波在星系团的热气体中引起涟漪，这些涟漪可以转化为声音。”
因此，美国国家航空航天局提取到了英仙座星系团中黑洞释放出的压力波。
The sound waves were discovered in 2003, when, after 53 hours of observation, researchers with NASA's Chandra X-Ray Observatory "discovered that pressure waves sent out by the black hole caused ripples in the cluster's hot gas that could be translated into a note."
然而，黑洞中声音的频率太低了——大约在中央C以下57个八度音阶，人耳无法听到。科学家们通过音频技术提升波形频率，从而使人们能够听到黑洞的声音。
But humans couldn’t hear that note because its frequency was too low — the equivalent to a B-flat, some 57 octaves below the middle C note of a piano, according to NASA. So astronomers at Chandra remixed the sound and increased its frequency by 57 and 58 octaves.
科学家表示，假如你真的站在黑洞旁边，听到的声音与NASA这段“黑洞混音版”的声音并不完全相同。因为人的耳朵没有灵敏到能接收到这些声波。“但这个声音确实存在，如果我们把它放大，就能听到。” 英国肯特大学天文学教授迈克尔·史密斯告诉《华盛顿邮报》。
Experts have cautioned that the sound in NASA’s remix isn’t exactly what you’d hear if you were somehow standing beside a black hole. Human ears wouldn’t “be sensitive enough to be able to pick up those sound waves,” Michael Smith, professor of astronomy at the University of Kent in England, told The Post. “But they are there, they’re the right sort of frequency, and if we amplified it … we would then be able to hear it,” Smith said.
综合来源：华盛顿邮报，央视新闻，NASA官网
