Sound from Perseus cluster is 57 octaves below middle C

Post #117,325 by lincoln 9/10/03 8:34:49 AM Reply	Sound from Perseus cluster is 57 octaves below middle C The voice of a black hole is a deep, deep bass, 57 octaves below middle C and far beyond the hearing range of humans. The Chandra X-ray Observatory has picked up sound waves for the first time from a cluster of galaxies 250 million light years away. [...] Andy Fabian, a professor at the institute, said a study of the fine detail collected by Chandra shows ripples in the X-ray pattern caused by sound waves excited by the energy from the black hole. He said the sound produced by the black hole is a B flat, the same pitch as a key near middle C on the piano. But the song of the Perseus Black Hole is 57 octaves below that middle C. This is a tone frequency more than a million, billion times deeper than the limits of the human ear, said Fabian. [link\|http://www.chron.com/cs/CDA/ssistory.mpl/front/2090936\|link] lincoln "Windows XP has so many holes in its security that any reasonable user will conclude it was designed by the same German officer who created the prison compound in "Hogan's Heroes." - Andy Ihnatko, Chicago Sun-Times [link\|http://users3.ev1.net/~bconnors/resume.htm\|VB/SQL resume] [link\|http://users3.ev1.net/~bconnors/tandem_resume.htm\|Tandem resume] [link\|mailto:bconnors@ev1.net\|contact me]
Post #117,377 by Arkadiy 9/10/03 5:33:40 PM Reply	Is it still a sound? Or series of pulses separated by looong time intervals? -- One Buffalo Bill And one Biffalo Buff
Post #117,428 by Ashton 9/11/03 12:46:03 AM Reply	Depends on the size of WHO'S Listening . . .
Post #117,455 by drewk 9/11/03 9:03:08 AM Reply	Dunno, did it fall in a forest? === Implicitly condoning stupidity since 2001.
Post #117,640 by Arkadiy 9/12/03 1:14:11 PM Reply	In the forest of the night -- One Buffalo Bill And one Biffalo Buff
Post #117,463 by andread 9/11/03 9:26:57 AM Reply	Not a sound would be a sound if it was going through the air A Play I Some Music w/ Papa Andy Saturday 8 PM - 11 PM ET All Night Rewind 11 PM - 5 PM Reggae, African and Caribbean Music [link\|http://wxxe.org\|Tune In]
Post #117,708 by pwhysall 9/13/03 2:04:30 AM Reply	No A sound is pressure waves going through any medium at all. The medium in this case is X-ray radiation. Peter [link\|http://www.debian.org\|Shill For Hire] [link\|http://www.kuro5hin.org\|There is no K5 Cabal] [link\|http://guildenstern.dyndns.org\|Blog]
Post #117,715 by Another Scott 9/13/03 9:16:53 AM Reply	No. The sound is a pressure wave in the plasma. The X-rays are a separate issue - changes in the X-rays give an indication of the sound, but aren't the medium for the sound. [link\|http://antwrp.gsfc.nasa.gov/apod/ap030912.html\|Here]: At right, the panel shows the x-ray image data specially processed to enhance contrasts and reveals a strikingly regular pattern of pressure waves rippling through the hot gas. In other words, sound waves, likely generated by bursts of activity from the black hole, are ringing through the Perseus Galaxy Cluster. Emphasis added. Or, in [link\|http://chandra.harvard.edu/press/kits/perseus/blackhole_sound.html\|more detail]: How is the Chandra X-ray Observatory able to detect these sound waves? The gas that pervades the Perseus cluster is very hot, with temperatures of millions of degrees, so it glows in X-rays. If the gas is directly visible, then pressure waves, if they are large enough, will also be visible, as "ripples" in the cluster gas. This is what is happening in the Perseus cluster. The scientists are able to see the sound waves, rather than hear them. By contrast, sound waves are not seen in the earth's atmosphere because our eyes are only sensitive to light at optical wavelengths, and air is much too cool to glow at these wavelengths. If air is invisible, the pressure waves (sound) passing through it will also be invisible. Cheers, Scott.
Post #117,718 by pwhysall 9/13/03 10:18:26 AM Reply	Thanks for the correction :) Peter [link\|http://www.debian.org\|Shill For Hire] [link\|http://www.kuro5hin.org\|There is no K5 Cabal] [link\|http://guildenstern.dyndns.org\|Blog]
Post #117,733 by Ashton 9/13/03 4:56:02 PM Reply	So then.. any sentient creature possessing an ear-drum analogue capable of Hearing this Peta-dBm *Aaaaaaauuuuummmmm .. mmmmm* - one had best address as, Ma'am? No?

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