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黑洞也有聲音？聽起來像什么? 近日，美國國家航空航天局發(fā)布了一段”黑洞的聲音”，有美國網友表示聽完“毛骨悚然（creepy）”，也有人認為“美得縹緲（ethereally beautiful）”……

（視頻戳這里）

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.

據《華盛頓郵報》報道，當地時間8月22日，美國國家航空航天局（NASA）在推特發(fā)布了一段音頻片段，該音頻是根據2億光年外的英仙座黑洞的壓力波而合成的，由錢德拉X射線天文臺制作，最初于今年5月4日發(fā)布于NASA官網。

NASA官網5月4日發(fā)布了這段音頻

NASA推特配文解釋稱：“太空中沒有聲音的誤解，源于大多數空間是真空，因此聲波無法傳播。” 但星系團中“有大量的氣體包圍著內部的數百甚至數千個星系，為聲波傳播提供了介質。” 


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.

據《華盛頓郵報》報道，這段聲波是在2003年被發(fā)現的。當時，美國國家航空航天局錢德拉X射線天文臺的研究人員在經過53個小時的觀測后，“發(fā)現黑洞發(fā)出的壓力波在星系團的熱氣體中引起漣漪，這些漣漪可以轉化為聲音。”

因此，美國國家航空航天局提取到了英仙座星系團中黑洞釋放出的壓力波。

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，黑洞中聲音的頻率太低了——大約在中央C以下57個八度音階，人耳無法聽到?？茖W家們通過音頻技術提升波形頻率，從而使人們能夠聽到黑洞的聲音。

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.

科學家表示，假如你真的站在黑洞旁邊，聽到的聲音與NASA這段“黑洞混音版”的聲音并不完全相同。因為人的耳朵沒有靈敏到能接收到這些聲波。“但這個聲音確實存在，如果我們把它放大，就能聽到。” 英國肯特大學天文學教授邁克爾·史密斯告訴《華盛頓郵報》。

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.

綜合來源：華盛頓郵報，央視新聞，NASA官網