Lowest Note in the Universe

[ned]

I was astounded to read in the newspaper this morning that astronomers have detected a sonic emission from a black hole in deep space that is a B flat - 57 octaves below middle C. Wow!  Too bad Horowitz didn't live to put that baby in one of his transcriptions. Consider the possibilities. Talk about music of the spheres.
Ned

[allchopin]

What is a sonic emmision? Because sound does not travel through medium-less space...

[NetherMagic]

allchopin I haven't learned about sound energy yet in my Physics class but isnt' sound a kind of energy?  The pitch depends on its frequency.  The lower the frequency, the lower the pitch.  And sonic means sound, so sonic emission pretty much means emitting sound waves.  Pardon me if I've got any wrong facts please correct me, not very sure  

[allchopin]

No, its not really a type of energy - its simply a wave (with a frequency) that subsequently pushes particles of a medium (laterally) which eventually reaches that ear.  However, in space, there isnt any medium for the emmision to travel through, so how could Earth microphones pick it up at all?  There must be some side effect of this sound wave that they are detecting.

[xenon]

Sound waves (mechanical) cannot use air molecules as a medium to "play" sound upon, but I believe that the energy from the sound wave (mechanical) can be picked up by some sort of sensitive (and expensive) recording device.

So, it's a B flat, eh?  Cool.  

[allchopin]

What do you mean they

cannot use air molecules as a medium to "play" sound upon

?
This is how sound travels (excpet through whatever type molecules, not only air)

[ned]

You might read the article
"A Deep Voice from Deep Space"
Washington Post, September 10, 2003
It's online.
Ned

[xenon]

allchopin> Whoops, i forgot to add a couple words.  It's supposed to read, "Sound waves (mechanical) cannot use air molecules as a medium to "play" sound upon in space."  Because these are mechanical waves, one cannot hear it in space, but it is still there.

[rachfan]

Well, the echos of the Big Bang can still be plainly heard through radio astronomy.  So why not a black hole's sound waves?  I believe an assumption being made about medium is that space is "empty".  Much of it appears visually to be empty, but actually it's not.  There is gas, dust, and other "dark matter" present, most of which is invisible to optical astronomy.  Perhaps those elements are sufficient to form a medium.   One thing is for sure though, the B flat at 57 octaves below middle C just pushed Bosendorfer's lowest bass note (F#?) on its Imperial Grand totally off the map.   They'll have to come up with a new gimmick now.

[ned]

Cool! RachFan.
And there's dark energy too.

They actually X-rayed these sonic waves, according to the article. You'll never hear them since it is apparently only one cycle every ten million years. So they said.
Ned

[rachfan]

Hi Ned,

Imagine, one cycle per 10 million years!  If we could be positioned at the  expanding  edge of the universe where time might be much faster than here in the Milky Way, maybe we could hear the black hole as if it were a string of 32nd note B flats played prestissimo.  Or if we could be inside the black hole itself, where we'd measure time with a yardstick and distance with a clock, then perhaps we'd have the sense that the B flat was one continuous, never ending tone.  And, if it could be sounding there on a Baldwin Synchatone string stretched all the way across the event horizon, so much the better!