[ti:NASA Releases New Black Hole ‘Sounds’] [by:www.51voa.com] [00:00.00]更多听力请访问51VOA.COM [00:00.04]The American space agency NASA [00:03.60]has released sounds it created with data [00:08.00]collected from black holes. [00:10.88]The sound production process is called sonification. [00:17.12]NASA says it used astronomical data [00:21.76]recorded by its Chandra X-ray Observatory. [00:26.24]Special equipment then translates the data [00:30.60]into audible sound. [00:33.12]NASA says the Chandra orbiting observatory [00:37.76]is the world's most powerful X-ray telescope. [00:42.28]One of the black holes studied sits at the center [00:47.08]of the Perseus galaxy cluster, or group. [00:51.00]The Perseus cluster is home to hundreds of galaxies. [00:56.52]They are 240 million light years from Earth. [01:01.12]Black holes are areas in space where gravity is so strong [01:07.80]that nothing – not even light – can escape them. [01:11.92]They are believed to be formed by collapsed stars. [01:17.20]The presence of black holes affects the surrounding environment [01:22.60]in extreme ways. [01:24.92]But black holes are not easy to capture with a camera. [01:30.08]This is because they are surrounded [01:32.60]by thick dust and extremely hot gases. [01:36.96]NASA says it discovered in 2003 that the black hole [01:43.04]deep inside the center of the Perseus galaxy cluster was linked to sound. [01:50.24]Astronomers had earlier found [01:53.40]that "pressure waves" sent out by the black hole [01:57.36]caused ripples in the cluster's hot gas. [02:01.72]Astronomers found that they could translate [02:05.68]those ripples into a note of sound. [02:09.36]But the note was at a very low range that humans cannot hear. [02:15.20]Using new sonification methods, NASA says it was able [02:20.96]to produce sounds from the ripples that we could hear. [02:32.28]In a statement, the space agency said that in some ways, [02:37.12]the latest sonification was "unlike any other done before." [02:43.60]This is because the process "revisits the actual sound waves [02:49.52]discovered in data" from the Chandra telescope. [02:53.64]NASA explains that there is a popular misconception [02:59.60]that there is no sound in space. [03:02.68]It notes that it is true that most of space exists in a vacuum, [03:09.24]meaning it is separated from outside events or influences. [03:14.84]But a galaxy cluster contains large amounts of gas [03:20.00]that surrounds the many galaxies within it. [03:23.36]This, NASA says, "provides a medium for the sound waves to travel." [03:30.64]For the new sonification of the Perseus black hole, [03:35.56]the NASA team used the sound waves they had collected in the past. [03:41.44]But the astronomers then had to put the signals into a range [03:46.96]that the human ear could hear. [03:49.76]To do this, they greatly raised the pitch of the waves [03:54.72]to a level far above their own frequency. [04:02.32]NASA published the sounds on its website. [04:06.12]They are contained in videos that show visual representations [04:12.12]of the X-ray data collected by Chandra. [04:15.96]The video images can be used to follow the waves, [04:21.28]which NASA says were sent out in different directions. [04:26.24]The space agency also released a new sonification [04:31.08]of a black hole that became famous in 2019. [04:35.92]That black hole sits at the center of the Messier 87 galaxy, [04:42.88]about 55 million light years from Earth. [04:47.36]It gained fame when astronomers announced [04:51.48]they had successfully produced the first image of a black hole. [04:57.20]NASA says that sonification [05:00.96]was based on X-ray data collected by Chandra, [05:05.36]light captured by the Hubble Space Telescope, [05:09.12]as well as radio waves from the Atacama Large Millimeter Array in Chile. [05:26.40]The black hole sounds were released as part of NASA's Black Hole Week. [05:32.72]As part of that event, the agency also released [05:37.12]new "data visualizations" of black holes [05:41.32]based on telescope observations. [05:44.96]I'm Bryan Lynn. 更多听力请访问51VOA.COM