Can LIGO actually work ?

Discussion in 'Physics' started by mattbullet, Apr 4, 2015.

  1. mattbullet

    Thread Starter Member

    Nov 29, 2008
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    I had first read of the plan to build a fantastic piece of equipment to detect gravity waves in about 1981 or so. The Laser Interferometer Gravitational-wave Observitory at first seemed like a great idea. After thinking about it for a while I realise this experiment is only an overly sensitive seismometer.
    This is an interferometer with two "legs" at 90 degrees to each other. The thought is if one leg is north/south and the other is east/west then a gravity wave coming from the zenith would make one leg expand while the other would contract and thus be detected by the laser lights change in respective path length.
    That would be possible in a universe that had only massive objects interacting and space.
    The universe I know also has time. As a gravity wave travels through space-time it should deform space AND time. Giving photons in each leg their nature given right to travel at the speed of light.
    The time dilation would negate any length change in this interferometer. This is why I think it's not a useable observitory.
    Any thoughts?
     
    Last edited: Apr 4, 2015
  2. Papabravo

    Expert

    Feb 24, 2006
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    This experiment has nothing to do with the Earth's gravity. It has to do with the arrival on the earth of waves from binary stars, pulsars, and other objects. If they exist, which according to Einstein, they do, then it should work eventually.

    What exactly is your point?
     
    Last edited: Apr 4, 2015
  3. mattbullet

    Thread Starter Member

    Nov 29, 2008
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    Yes Papa, this experiment has nothing to do with the Earth's gravity.
    This was desigined to detect incoming gravity waves from massive objects in the universe.
    My point exactly is, using light traveling through space-time should not be able to detect gravity waves because the change in space would be countered by the change in time.
    I hope that was more clearly stated.
     
  4. Papabravo

    Expert

    Feb 24, 2006
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    The experiment is not using light traveling to earth. It is using the laser light on Earth to detect the effect of the incoming gravity wave on the apparatus. In particular it is looking for differences in arrival time between the Louisiana facility and the Hanford facility.
     
  5. mattbullet

    Thread Starter Member

    Nov 29, 2008
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    I'm sorry. I thought my last post would be understood. I'll try again.
    My point MORE exactly is, using light traveling through space-time in each leg of an interferometer should not be able to detect gravity waves, because the change in space (which would make one leg of the interferometer a tiny bit longer than the other), would be countered by the change in time in the same leg. This would apear (to the interferometer) as no change at all.
    This should be most easily understood as, A laser interferometer is blind to gravity waves.
    I hope this was an easier to understand explanation.
     
  6. BR-549

    Well-Known Member

    Sep 22, 2013
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    To my way of thinking......to have a wave, you have to have symmetry.

    We haven't been able to find symmetry in gravity like we can in electricity.

    I tend to think of gravity as a static weak electric mono-field.

    I think that gravity is electrically generated by neutral atoms.

    How can someone assign a property (gravity) to an entity (mass or matter), without knowing what that entity is, and why or how the entity has the property?

    The only way these equations work.....is if they let the equation change the length of length and the speed of time.

    EVEN when they do this......they STILL can't explain the path of matter.

    And so now we have dark matter to explain this.

    This will go on and on.

    A gravity field attracts matter like an electric field attracts charge......only much weaker. And of course always attractive.

    And like charge.....matter moves in a helical fashion.....not in straight lines or ELLIPSES.

    Right now the study of gravity is like the early study of charge.

    When they first studied charge, they found coulomb densities and inverse square law.

    Later it was found that charge also had another term.....the magnetic.

    This magnetic term causes the charge to follow a helical path.

    Gravity also has another term that causes a helical path.

    Once you apply that term.....the classic theory works and everything fits.

    True classic physics is Weber based, not Maxwell.
     
  7. nsaspook

    AAC Fanatic!

    Aug 27, 2009
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    Do you understand how the detector works? Time dilation is not a factor in the detection system on earth. They also need dual detectors for locating the signal direction in they sky and for local noise signal elimination.

    http://www.ligo.org/science/overview.php
     
    Last edited: Apr 4, 2015
  8. alfacliff

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    Dec 13, 2013
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    perhaps if they made the distinction between waves, like ocean waves and light waves. it would work if light has weight. the confusion is that "gravity waves" might mean waves like electromagnetic waves to some people, and waves like changes in gravity to others.
     
  9. cmartinez

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    Jan 17, 2007
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    I'm under the impression that Ligo doesn't just work by measuring time dilation between light signals, but by also measuring its frequency, which should change if it traveled across a gravity wave.
     
  10. nsaspook

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    Aug 27, 2009
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    I haven't looked at the complete detector details but what they basically measure is extremely small length changes between two points on two separate angled detector lines caused by the gravity wave as it passes through the earth. So while time dilation between points might happen and the frequency between the source and earth might change, the source of data is the compression and stretching effect of gravity waves on a large mass like the earth.
     
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  11. cmartinez

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    :eek: I cannot possibly even begin to imagine all of the sources of noise affecting their experiment that they have to keep on monitoring and rule out...
     
  12. BR-549

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    Sep 22, 2013
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    There are only 3 physical dimensions, x, y, z.

    This experiment compares the length of x to the length of y.

    This experiment has shown that the length of x is constant with the length of y.

    If Einstein was right, then they would be constantly changing.

    Mass can not effect dimension, because mass is an allusion.
     
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