Gravitational Waves Detected for First Time (Stephen)

Thanks for Stephen for posting this important scientific news

Off topic but fantastic news about the detection of Gravity waves by LIGO.


“Scientists are claiming a stunning discovery in their quest to fully understand gravity. They have observed the warping of space-time generated by the collision of two black holes more than a billion light-years from Earth.
The international team says the first detection of these gravitational waves will usher in a new era for astronomy.
It is the culmination of decades of searching and could ultimately offer a window on the Big Bang.”

Some 35 years or so ago when I was still in High School I was given a book on Gravity Waves authored by P.C.W Davies. I think the project was mentioned in that book even back then. That book was was a huge inspiration for me and stimulated my permanent fascination with new Science and Technology especially less known aspects.

Perhaps there is a lesson for LENR here, with persistence eventually good results come.

  • I’m sure that I must be missing something, but I have a bit of difficulty understanding the principle of measurement. Perhaps someone can explain?

    The laser interferometer (LIGO) apparently consists of a laser beam that is split by a half silvered mirror into two beams, each of which is sent down one of two long tubes mounted at 90 degrees to one another, and bounced back by a fully silvered mirror at the far end to return to a common photon detector. The theory seems to be that a ‘gravity wave’ passing through the apparatus should upset the delicate balance between the two beams by red or blue -shifting one beam to a different degree to the other, causing variation in the combined intensity of the returning beams – a phase difference.

    However my understanding is that any distortion of spacetime will also affect light, because photons will simply follow the new geodesics momentarily created, in just the same way that they follow an apparently curved (to an external observer) trajectory when following a spacetime geodesic distorted by the presence of mass. It seems to me therefore that while the long tubes are expanded or contracted by a ‘gravity wave’ then light travelling within the tubes will be affected 100% equally, becasue they share exactly the same frame of reference, giving a null result under all conceivable directions and intensities of any gravitational waves passing through. It shouldn’t matter if the device has two or twenty ‘arms’ pointing in all direction.

    Surely this is like trying to measure the length of a steel tube using a steel tape measure as both get hotter. An outside observer using an optical measuring device would see both expanding at the same rate, while the local observer sees no change in the measured length.

    Enlightenment would be welcomed.

    • Andreas Moraitis

      As far as I understood it, both beams are not equally affected by the G-wave (except if the wavefront would arrive exactly from above or below).

      • Andreas Moraitis

        Regarding the other part of your question, since the speed of light remains the same (which is certainly a miracle), the time that the beams need to travel through the arms of the interferometer will change corresponding to the length differences that are caused by the G-wave, which eventually results in a detectable phase shift.

        • Omega Z

          Andreas Moraitis,

          I<—-Laser Light injected into vacuum tube & split to the Front and Back

          This may be wrong, but I think it's the basic concept.
          The Gravity Wave traveling towards me would compress space/time in front of me shortening the time the Laser Light takes to reflect back while behind me it would cause an expansion of space/time lenghtening the time the Laser Light takes to reflect back.

          With the exception of a precise broadside(a null effect) to both tubes, there would be a detectable difference in the time of reflectance regardless of whether the tube was straight on to the Gravity Wave or not.

          Note: Rather then space/time being compressed/expanded, maybe it is merely a ripple in space/time given it is a Gravity "Wave", but detectable regardless. Or have I got this confused with another concept.

        • “the interferometer will change corresponding to the length differences that are caused by the G-wave”

          That’s the part I’m having difficulty with. It seems to me that there is some confusion of the local reference frame with the behaviour of the detection system as observed by an all-seeing observer located outside of this local reference frame.

          While one of the tubes might lengthen from the POV of an observer outside of the local reference frame, from inside the RF, i.e., the area affected by the G-wave as it passes, nothing should change because from the local POV both the distance between mirrors and the speed of light will remain constant. Any distortion of one will apply equally to the other, because space and time are locked together, so the reflected light should remain in phase in both arms of the detector despite the momentary distortion.

          The original Michelson-Morely experiments, and all subsequent replications, demonstrate that the speed of light is unaffected locally by local distortions of spacetime (in this case resulting from the orbital speed of the Earth combined with the speed of the sun resulting from galactic rotation), so I am having difficulty understanding why a similar distortion due to a ‘gravity wave’ should be any different.

          • Andreas Moraitis

            I think it is exactly the constancy of the speed of light in vacuum that makes the measurement possible. If that speed would change when space-time is compressed or expanded – as the length of the steel tape in your above example – I’d say you were right.

            Let’s consider the ideal case that the front of the G-wave approaches one of the arms of the interferometer in a 90 deg angle. As long as it runs through that arm, neither the other arm nor the detector will be affected (to simplify a bit). That is, at least for that moment the detector is not part of the ‘system’ (= the first arm) of interest, thus it may act as a ‘neutral’ observer.

            Note that these are only my guesses. Somebody like Pekka could explain it certainly much better.

  • Jonnyb

    Just ripples in the aether.

  • Curbina

    My issue with this confirmation is the same issue with the mainstream reject of LENR. For most mainstream theorists gravity waves must exist, therefore, they will cling to any result or observation that supports that prediction and call it a confirmation. But when a result hints that LENR exists, but theory says its impossible or does not even consider a possibility, no amount of experimental result will be enough to confirm. So, I will wait until something more contundent of a confirmation is produced.

    • Charles

      Curbina, politics – meet science. Virtually nothing in science that is arguable is every “accepted”. Socialism has been repeatedly proven wrong and a failure, but it still has millions of adherents.

      Wonder it this proves my supposition that black holes get overloaded and explode as a new universe of some DETERMINATE STARTING SIZE instead of that hard to believe big bang from an infinitely small load of energy followed by in inexplicable sudden expansion in size that defies the speed of light limit.

  • Gerrit

    But will they be able to detect the gravitational waves caused by the jaw dropping of 99% of the world’s population when the LENR paradigm change happens ?

    • Jonnyb

      It’s going to be a wonderful time, a ‘I told you so’ moment to enjoy.