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BOOM in B flat please

  1. Sep 10, 2003 #1
    Very interesting.
     
  2. jcsd
  3. Sep 10, 2003 #2
    I was reading the article looking
    for the frequency of this "sound".
    How long does one cycle take? Any
    one know enough about this to
    explain how they pegged that very
    irregular looking wave as a B-
    flat?
     
  4. Sep 10, 2003 #3
    More here, http://chandra.harvard.edu/photo/2003/perseus/. Where they say the central 'cavities' are 50 thousand light years wide. So the waves must be thousands of light years peak to peak. At that long a wavelength, does it matter what note it is.
     
  5. Sep 13, 2003 #4
    Not to me. Apparently it matters
    to them because they give it the
    unbelievably specific designation
    of a B-flat. I'm curious as to
    how they could say it is any specific note.
     
  6. Sep 13, 2003 #5
    I've had an idea about this. Differences in octaves are logarithmic. Though the difference between B and Bb is small, it is magnified by 57 orders of magnitude. Spread over that large a difference the wavelengths will be, hand waving, hundreds of light years apart. Large enough to put a putative tone of Bb on this wave.

    Tell you what, let's call it A# instead.
     
    Last edited by a moderator: Sep 13, 2003
  7. Sep 13, 2003 #6
    Yes, but that's going to put it
    into a different key.
     
  8. Sep 13, 2003 #7

    marcus

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    LOL
     
  9. Sep 13, 2003 #8

    marcus

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    What pitch is sunlight?

    IIRC the average photon in sunlight is 1 eevee

    that is an infrared energy, visible photons have above average energies

    1 eevee translates into 2.4 E14 herz

    so how many octaves above middle C is sunlight?

    Basically it just means taking log (base 2) of E12
    because sunlight is E12 higher frequency than middle C.
    and an octave is a jump by a factor of 2
     
  10. Sep 13, 2003 #9

    Hurkyl

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    Going down a semitone represents a 6% increase in wavelength... I don't know what the relative error bars are on their measurements, but 6% is a sizable difference.
     
  11. Sep 13, 2003 #10

    marcus

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    Amen to that, and you can see where the 6 percent comes from if your calculator will take the twefth root of two

    21/12 = 1.0595

    A piano tuner might use 0.0595 but call it six percent so as not to put too fine a point on it.

    I took the log-base-two of 1012 (since it was clear nobody else would except maybe Hurkyl!) and got 40

    So I conclude that typical sunlight frequency is 40 octaves above middle C.


    If those astronomers can say that their black hole burp
    is 57 octaves below middle C, then I can point out the window
    and say the sunlight is 40 octaves above. Or?
     
  12. Sep 13, 2003 #11
    Or you could say:

    We hear the Sun's soprano
    with our eyes,

    But the Black Hole's bass...



    And I couldn't think of a
    finish for that. Dip your
    quills and finish this pome.
     
  13. Sep 13, 2003 #12

    Hurkyl

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    Well, they were talking about sound waves, not light waves...
     
  14. Sep 13, 2003 #13

    marcus

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    both waves though :wink:
    illustrating general idea of frequency

     
  15. Sep 13, 2003 #14
    Marcus gave me the right push.
    This is where I had wanted to
    go:


    We hear the Sun's soprano
    with our eyes,
    But Black Hole's bass carves
    ripples in the skies,
    A roar so deep no human ear
    will know
    A single beat of Black Hole's
    demon crow


    Iambic pentameter. Two rimes. It's
    a couple 'o cosmological couplets.
     
  16. Sep 13, 2003 #15

    hypnagogue

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    Awesome, zoobyshoe. Take a bow.
     
  17. Sep 13, 2003 #16
    Thank you, Hyp, for enjoying my
    scribbles.
     
  18. Sep 13, 2003 #17

    hypnagogue

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    The scribbles of this pauper be
    To kings a chamber symphony


    :smile:
     
  19. Sep 13, 2003 #18
    That's nice. What's that from?
     
  20. Sep 13, 2003 #19

    hypnagogue

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    Spontaneous random electrochemical processes in my brain. Or something like that.
     
  21. Sep 13, 2003 #20
    That was very fast. You
    must have been channeling some
    departed poet or else you're in the habit of writing alot yourself
    so that you're never far from
    Dylan Thomas' "Well of Poetry"
    where he went every day to pull
    up two lines.
     
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