OT (sort of) Lowest B-flat whistle in the Universe...

[amanderthad]

and it's a Black hole.

Just thought this was interesting... read the article below for details.


Big black holes sing bass. One particularly monstrous black hole has probably been humming B-flat for billions of years, but at a pitch no human could hear, let alone sing, astronomers said Tuesday.

"The intensity of the sound is comparable to human speech," said Andrew Fabian of the Institute of Astronomy at Cambridge. But the pitch of the sound is about 57 octaves below middle C, roughly the middle of a standard piano keyboard.


This is far, far deeper than humans can hear, the researchers said, and they believe it is the deepest note ever detected in the universe.


The sound is emanating from the Perseus Cluster, a giant clump of galaxies some 250 million light-years from Earth. A light-year is about 6 trillion miles (10 trillion km), the distance light travels in a year.


Fabian and his colleagues used NASA's orbiting Chandra X-Ray Observatory to investigate X-rays coming from the cluster's heart. Researchers presumed that a supermassive black hole, with perhaps 2.5 billion times the mass of our sun, lay there, and the activity around the centre bolstered this assumption.


Black holes are powerful matter-sucking drains in space, and astronomers believe most galaxies, including our own Milky Way, may contain black holes at their centres. Black holes have not been directly observed, because their gravitational pull is so strong that nothing, not even light, can escape it.


SOUND WAVES


So researchers have concentrated on what happens around the edges of black holes, just before matter is pulled in. When scientists trained the Chandra observatory on the centre of Perseus last year, they saw concentric ripples in the cosmic gas that fills the space between the galaxies in the cluster.


"We're dealing with enormous scales here," Fabian said in a telephone interview. "The size of these ripples is 30,000 light-years."


Fabian said the ripples were caused by the rhythmic squeezing and heating of the cosmic gas by the intense gravitational pressure of the jumble of galaxies packed together in the cluster. As the black hole pulls material in, he said, it also creates jets of material shooting out above and below it, and it is these powerful jets that create the pressure that creates the sound waves.


To scientists, he said, pressure ripples equate to sound waves. By calculating how far apart the ripples were, and how fast sound might travel there, the team of researchers determined the musical note of the sound.


Fabian said the notion of singing black holes might well be extrapolated to other galaxies, but not necessarily to the Milky Way.


Chandra has looked at X-ray emissions from the Milky Way's centre, and astronomers believe there is a black hole there, but because it is a young, rambunctious galaxy with lots of activity at its heart, this may interfere with any note our black hole might sing, Fabian said

[chas]

For anyone wondering, this wave would vibrate once every 17.85 million years. I myself believe that the concept of a sound wave should cease when the vibration is much more than a million years in period.

Speaking of this, has anyone else heard about the John Cage piece that's being performed in Germany? The original score said it should be playes "as slowly as possible," which he took to mean the piece would last about half an hour. Some guys in Germany decided that they'd rig something together so that it could be played on an organ in a performance that will last 400 years (which is the age of similar organ to the one they're using, so they're confident they can have it play that long). The opening rest lasted awhile, now the first not is gonna last 17 months.

I'm certainly familiar with the motto, "If it's worth doing it's worth overdoing," but even I find this a little odd.

[glauber]

Yes, very interesting. The organ keys are held down by lead weights. I think the opening rest lasted for 6 months. I actually think it's a nice idea, though odd. It's an optimistic idea, thinking that there will still be people around to listen 400 years from now. They think of it as a kind of sound monument.

I hope they thought through issues of power supply, redundancy for the compressors and other components. Ideally they should have fully redundant systems, that is, at least 2 complete organs. I hope the whole thing doesn't come to an end because of a power grid failure or some other such thing.

[skh]

I hope they thought through issues of power supply, redundancy for the compressors and other components. Ideally they should have fully redundant systems, that is, at least 2 complete organs. I hope the whole thing doesn't come to an end because of a power grid failure or some other such thing.

If that happens, the organ will just have had to snap a quick breath in the middle of a phrase. Happens to the best of us, doesn't it?

Sonja

[Nanohedron]

I just read this this morning. The universal drone? This may account for pipers' flat sets and the pitch of the highland pipes.

[Jerry Freeman]

What's interesting to me is the idea of what's a short or long period of time.

Who's to say that 17.85 million years is a long time? I find it completely plausible that some form of consciousness can hear (or sing) that note as naturally as I can hear the notes of my favorite whistle.

Reminds me of an episode of the cartoon, Frank and Ernest.

One of them is having a conversation with God. He says, "God, is it true that to you a million years is like a second?

God says, "Yes."

Frank or Ernest, as the case may have been says, "And is it true that a million dollars is just like a penny to you?"

God says, "Yes."

"Well, then. Could I have a penny?"

"Sure. Just a second."

Best wishes,
Jerry

[chas]

A theory proposed by Frank and Ernest:

"I think the universe is contracting. At least, I'm bumping into things more often."

[Jack]

Quote @ Jerry Freeman

Who's to say that 17.85 million years is a long time? I find it completely plausible that some form of consciousness can hear (or sing) that note as naturally as I can hear the notes of my favorite whistle.

Wow, I totally agree. Also, to some form(s) the song that lasts 400 years is sound just lovely about now.

[Charles]

What's interesting to me is the idea of what's a short or long period of time.

Yes, and there's a group of people advocating the use of five-digit years starting, well, in the year 01996:

http://www.longnow.org/

If they can make any impact on the "it'll be someone else's problem after I'm out of office/retired/dead" mentality, then they will have done a great service.

[The Weekenders]

I thot soundwaves relied on atmosphere to make actual sound. But I ain't scientific.

But there was another story a few days ago that mentioned that inaudible low frequencies created by earth movement and other large objects create the sensations associated with perceptions of ghosts and haunted places. That was very interesting.

A spooky black hole and it's not even my teenager's bedroom.

[The Weekenders]

Ha. Stewart Brand is still around??? He's the Whole Earth catalogue guy who wore a hard hat on Johnny Carson, as I recall. A media darling of the groovy 60s.

Takes all kinds to make the world interesting.....

[Steven]

I thot soundwaves relied on atmosphere to make actual sound. But I ain't scientific.

The compression waves travelling through the cosmic dust and gas are equivalent to (ie, same mechanism as) sound waves travelling through air. That's why they were able to equate the two. Of course, with the medium being so thin and sparse, the sound would be very quiet in addition to being very low....

(If none of this is at all clear, sorry -- I trained as a biologist, not a physicist.)


Steven