Har har har!! Dammit, here I've been awa' from this 'Cat for a long long time & then I saw this article (well, the AP version) & thought Ah HA! I'll post this on Mudcat. And of course yez beat me to it.

Well, no matter. I love it. B flat, albeit 57 octaves below middle C. See that? -- the Music of the Spheres is the Low Whistle. Hoo hah :)

Here (since cut/paste is invited above by the Threadmaker) is the AP article. Note the last paragraph. The Universe may sing many different songs. (Hi, Amos. :)


Low Note From A Celestial Object
Astronomers Detect Black Hole's Song

September 10, 2003
Associated Press

WASHINGTON -- 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 detected sound waves for the first time from a cluster of galaxies 250 million light years away.

Astronomers at the Institute of Astronomy in Cambridge, England, discovered the sound waves while analyzing the Chandra images of the Perseus cluster, an immense grouping of galaxies held in formation by the powerful tug of a supermassive black hole. The sound waves were detected passing through superheated gases in the cluster of galaxies.

Andy Fabian, a professor at the Institute of Astronomy, said that a close study of the fine detail collected by Chandra shows ripples in the X-ray pattern that are 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.

The voice of the black hole is detected by analyzing the pattern of X-rays coming from superheated gases in the Perseus galactic cluster, said Fabian.

Squeezed by the gravitational pull of the black hole and the galaxies in the cluster, gases are heated to 50 million degrees, hot enough to generate X-rays. A surge of sound waves adds heat energy, causing a slight change in the pattern of X-rays.

In effect, he said, the sound waves cause bright and dark emissions of X-rays moving in rings away from the black hole center like ripples on the surface of a pool.

"A three-dimensional analogy is when a child takes a straw and blows into a glass of water, producing a sequence of bubbles," said Fabian. "That is like a sequence of sound waves."

Fabian said that the discovery is prompting astronomers to look for telltale ripples in the superheated gas around other black holes.

It is possible, he said, that other galactic clusters are singing in other tones.

"We would expect that every cluster and group of galaxies has its own note," said Fabian. "So if you look at the whole universe, there are many tunes being played."