LIGO Violins in the Milky Way

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ML1
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15 Oct 2007 13:10:32 UTC
Topic 193224
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    As described on this page by Bruce, the S3 LIGO data suffers false candidates due to violin modes from the components suspensions adding noise into the data.

    So why does that noise appear to follow a pattern across the sky tracing out the Milky Way?

    Are we picking up gravitational waves due to the violin modes acting like a super-regenerative receiver?...

    Regards,
    Martin

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    tullio
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    LIGO Violins in the Milky Way

    15 Oct 2007 14:29:49 UTC
    Message 73824
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      A musician friend of mine told me that researchers at Genoa University have analyzed wires once belonging to a violin used by Niccolo' Paganini and were able to understand much about Stradivarius violins from these wires. Maybe we should ask them to analyze also the wires used in LIGO, VIRGO and GEO600.
      Tullio

      peanut
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      Maybe Einstein should have

      19 Oct 2007 1:32:37 UTC
      Message 73825
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        Maybe Einstein should have asked "What instrument does the Creator play" rather than state that the all powerful one does not play dice.

        tullio
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        RE: Maybe Einstein should

        19 Oct 2007 2:37:22 UTC
        Message 73826 in response to message 73825
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          Quote:
          Maybe Einstein should have asked "What instrument does the Creator play" rather than state that the all powerful one does not play dice.


          Einstein played the violin rather well, so maybe he thought the Creator would do the same. But, as Pauli said to Einstein, "not even you can tell God what He can or cannot do".
          Tullio

          Bikeman (Heinz-Bernd Eggenstein)
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          RE: As described on this

          20 Oct 2007 8:52:40 UTC
          Message 73827
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            Quote:

            As described on this page by Bruce, the S3 LIGO data suffers false candidates due to violin modes from the components suspensions adding noise into the data.

            So why does that noise appear to follow a pattern across the sky tracing out the Milky Way?

            Are we picking up gravitational waves due to the violin modes acting like a super-regenerative receiver?...

            Regards,
            Martin

            As to the original question, the "noise belt" does not coincide with the milky way, but (see the following page of the presentation you quoted):

            Quote:

            It's now easy to see why instrumental artifacts which are sinusoidal functions of time mimic pulsars located near a particular great circle in the sky. Any pulsar located in the plane defined by the directions to pulsars #2 and #3 produces a signal at the detector in which the annual frequency modulation is either absent or very small during S3. This plane is perpendicular to the average line from the Earth to the Sun during S3. So instrumental artifacts which are at a fixed frequency appear to lie in this plane, and the intersection of this plane with the celestial sphere is a great circle centered on the line from the Earth to the Sun.

            CU
            Bikeman

            ML1
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            RE: RE: As described on

            22 Oct 2007 15:30:43 UTC
            Message 73828 in response to message 73827
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              Quote:
              Quote:

              As described on this page by Bruce, the S3 LIGO data suffers false candidates due to violin modes from the components suspensions adding noise into the data.

              So why does that noise appear to follow a pattern across the sky tracing out the Milky Way?

              As to the original question, the "noise belt" does not coincide with the milky way, but (see the following page of the presentation you quoted):

              Quote:

              It's now easy to see why instrumental artifacts which are sinusoidal functions of time mimic pulsars located near a particular great circle in the sky. Any pulsar located in the plane defined by the directions to pulsars #2 and #3 produces a signal at the detector in which the annual frequency modulation is either absent or very small during S3. This plane is perpendicular to the average line from the Earth to the Sun during S3. So instrumental artifacts which are at a fixed frequency appear to lie in this plane, and the intersection of this plane with the celestial sphere is a great circle centered on the line from the Earth to the Sun.


              Thanks for highlighting that.

              Rereading, very slowly, in the cold light of day, elucidates ( :-) ) that description as an instrumental effect that the false positives show up along that particular curve.

              It would have been quite a difficult coincidence if that artifact curve followed the curve of the Milky Way... Are the detectors deliberately oriented to avoid that?

              Or even, are the detectors oriented to give optimum sensitivity along our galactic plane?

              Regards,
              Martin

              See new freedom: Mageia Linux
              Take a look for yourself: Linux Format
              The Future is what We all make IT (GPLv3)

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