Black hole sings.

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alokmohan

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the dark heart of the Perseus galaxy cluster, 300 million light-years from Earth, a supermassive black hole has been singing the same note for 2.5 billion years. Its tone registers 57 octaves below middle C and, according to scientists at NASA's Chandra X-Ray Center, is a resounding B-flat. Yet, how is this possible in the vacuum of space?<br /><br />Sound requires a medium, such as water or air, to travel. Here on Earth a sound wave moves from its origin by causing the surrounding air molecules to vibrate. The vibrations pass from one molecule to another; when they hit an ear, they are understood as noise. But because neither air nor water nor much of anything else exists in the majority of vast reaches of space, it is difficult for sound to travel there.Scientific American wave.<br /><br /><br />
 
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adrenalynn

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In space, no one can hear you scream. (- "Alien") <div class="Discussion_UserSignature"> <p>.</p><p><font size="3">bipartisan</font>  (<span style="color:blue" class="pointer"><span class="pron"><font face="Lucida Sans Unicode" size="2">bī-pär'tĭ-zən, -sən</font></span></span>) [Adj.]  Maintaining the ability to blame republications when your stimulus plan proves to be a devastating failure.</p><p><strong><font color="#ff0000"><font color="#ff0000">IMPE</font><font color="#c0c0c0">ACH</font> <font color="#0000ff"><font color="#c0c0c0">O</font>BAMA</font>!</font></strong></p> </div>
 
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xmo1

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Just because the vibration exists does not mean that someone can hear it. Obviously at -57 octaves no one is going to hear it. It can, however, be measured. The question is, to me at least, what is causing the ringing. <div class="Discussion_UserSignature"> <p>DenniSys.com</p> </div>
 
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shadow735

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"Revenge is a dish best served cold, It is very cold in space" Star Trek 2 the wrath of Khan...<br />Opps.... <div class="Discussion_UserSignature"> </div>
 
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nexium

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We don't often think of radio waves with a frequency below 550 kilohertz, but they exist in space almost to zero hertz. This is possibly what the arcticle means by 'black hole sings' Does anyone know the details of how we detect and display one microhertz?<br />The 57 may have been a wild guess as Heizth 57 varieties. Neil
 
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pyoko

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edit: deleted. I got the joke. <div class="Discussion_UserSignature"> <p> </p><p> </p><p><span style="color:#ff9900" class="Apple-style-span">-pyoko</span> <span style="color:#333333" class="Apple-style-span">the</span> <span style="color:#339966" class="Apple-style-span">duck </span></p><p><span style="color:#339966" class="Apple-style-span"><span style="color:#808080;font-style:italic" class="Apple-style-span">It is by will alone I set my mind in motion.</span></span></p> </div>
 
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heyscottie

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microhertz? I wish. At 57 octaves down, this comes in at less than 2 femtohertz.<br /><br />Which means that one cycle takes 17 million years. Which makes me wonder how we can detect it.
 
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themage

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I do not know what 57 octaves below middle C would translate into frequency wise, but any frequency can be transmitted. While we tend to think that sound requires a medium to travel (which in a sense it does for us to hear it at least), these lower frequency can still travel. <br /><br />When trying to explain frequency to someone, I like to make this analogy. We have someone singing, and we have a light above them. Seeing the light and listening to the song may seem different, because we are using 2 different instruments to translate them. However, the song and the light are very much one in the same thing, its just light is at a higher frequency then sound. Imagine if we were able to see or hear X-rays, we would need another instrument to translate it into something we can understand.<br /><br />What’s a couple of wavelengths among friends <img src="/images/icons/laugh.gif" />.<br />
 
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dragon04

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It's an analogy.<br /><br />It emits energy at what would be a B Flat note that was audiologically detectable in atmosphere.<br /><br />In fact, that B Flat is a harmonic frequency far below what we can actually hear. In other words, even if we could produce that B Flat note at its resident frequency with a musical instrument on Earth, we couldn't hear it. <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>
 
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dragon04

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But it reminds me of the fact that our Universe is playing a symphony whether we can hear it or not.<br /><br />We could literally compose music based on the frequency emissions of the hundreds of billions of central massive black holes if we sequenced them to play their notes in the proper order.<br /><br />That is beauty. Awesome beauty. <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>
 
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alokmohan

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True .It sings we cant hear.Singing black holes would cause fear.
 
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adrenalynn

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Just trying to follow along... Middle-C in the scientific community (varies depending upon scale) is 256hz<br /><br />So 57 octaves down would be 256/(2^57) right? Each octave down is half the frequency, so half the frequency of 256hz, 57times. 1.77635684 e^-15hz. That seems right, right? <div class="Discussion_UserSignature"> <p>.</p><p><font size="3">bipartisan</font>  (<span style="color:blue" class="pointer"><span class="pron"><font face="Lucida Sans Unicode" size="2">bī-pär'tĭ-zən, -sən</font></span></span>) [Adj.]  Maintaining the ability to blame republications when your stimulus plan proves to be a devastating failure.</p><p><strong><font color="#ff0000"><font color="#ff0000">IMPE</font><font color="#c0c0c0">ACH</font> <font color="#0000ff"><font color="#c0c0c0">O</font>BAMA</font>!</font></strong></p> </div>
 
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siarad

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Gee the guy who measured that must be <i>really</i> old <img src="/images/icons/rolleyes.gif" />
 
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themage

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So its 1.77 femto Hertz. Yea.......thats a huge wavelength.<br /><br />So the wave is 5,649,717,514,125 meters long (estimate of course :p). I hope I did that right. If I remember correctly I just take the inverse of the frequency to get lamda.
 
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adrenalynn

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I get 1.687681502e+23 meters, I think.<br /><br />I guess the big question here is do we solve for the wavelength at the speed of sound, or solve for the wavelength at the speed of light? <br /><br />Depends on the type of radiation. Since they're calling it a "note" - I'd solve it for the speed of sound. <div class="Discussion_UserSignature"> <p>.</p><p><font size="3">bipartisan</font>  (<span style="color:blue" class="pointer"><span class="pron"><font face="Lucida Sans Unicode" size="2">bī-pär'tĭ-zən, -sən</font></span></span>) [Adj.]  Maintaining the ability to blame republications when your stimulus plan proves to be a devastating failure.</p><p><strong><font color="#ff0000"><font color="#ff0000">IMPE</font><font color="#c0c0c0">ACH</font> <font color="#0000ff"><font color="#c0c0c0">O</font>BAMA</font>!</font></strong></p> </div>
 
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themage

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I'm sorry but I am not familiar with the equations for solving wavelength at the speed of sound. What equation is that? Now that I think about it, with a frequency that low you might as well call it DC.
 
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themage

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Well, it has one hell of a bass drop. But nothing can compare to Barry White <img src="/images/icons/wink.gif" />.
 
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lukman

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<blockquote><font class="small">In reply to:</font><hr /><p> I also dont understand.But does it sing? <p><hr /></p></p></blockquote><br /><br />It is not even an audible sound, why bother. More, i beleive there is no proof of such low frequency, it was just a fancy speculation for sensation. What equpment can detect such low Hz? It shouldl be a Plank Hz. <div class="Discussion_UserSignature"> </div>
 
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themage

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I would imagine that they have some type of instrumentation to measure it. However being the wavelength that it is they can't directly observe it. It would have to be a computer calculated signal based off of observing it for a period of time and calculate the projected sine wave of how it should look like. Something like a precision oscilloscope with a very, very low frequency response would have to be used. Then pump in the info to a computer (or maybe even just using some trig could work also) and viola, you got a femto hertz signal. <br /><br /><br />EDIT: I should mention that the field of wave propagation, electronics, and the sort is what I do work wise. And to my knowledge nothing can take a measurement that low directly.
 
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adrenalynn

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The only way I'm familiar with to arrive at the frequency would be: Frequency=Speed of Wave/Wavelength<br /><br />So as we can see here, ((Freq = (Speed/c)) != ((Freq = (Speed / 340.29m/s)) [Where 340.29m/s is the speed of sound at sea level]<br /><br />This is exactly why I despise silly touchy-feelie pseudo-science. If it "sings", to me it implies that the wave moves at the speed of sound. But it stands to reason that it's just some low-band radiation moving at the speed of light since the vacuum of space doesn't give a medium for sound to move through.<br /><br />The only reason for saying that a blackhole sings is publicity. It is in no way a scientifically accurate or reproducible statement. <div class="Discussion_UserSignature"> <p>.</p><p><font size="3">bipartisan</font>  (<span style="color:blue" class="pointer"><span class="pron"><font face="Lucida Sans Unicode" size="2">bī-pär'tĭ-zən, -sən</font></span></span>) [Adj.]  Maintaining the ability to blame republications when your stimulus plan proves to be a devastating failure.</p><p><strong><font color="#ff0000"><font color="#ff0000">IMPE</font><font color="#c0c0c0">ACH</font> <font color="#0000ff"><font color="#c0c0c0">O</font>BAMA</font>!</font></strong></p> </div>
 
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themage

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"The only reason for saying that a blackhole sings is publicity. It is in no way a scientifically accurate or reproducible statement. "<br /><br />Exactly.<br /><br />"The only way I'm familiar with to arrive at the frequency would be: Frequency=Speed of Wave/Wavelength"<br /><br />That ones new to me. I just take the inverse of frequency to get the wavelength, and vice versa.<br /><br />http://en.wikipedia.org/wiki/Frequency
 
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