Gravity never zero

Discussion in 'Astronomy, Exobiology, & Cosmology' started by Ivan, Dec 18, 2011.

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  1. Trippy ALEA IACTA EST Staff Member

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    I got the impression that they were actually simultaneous measurements - the momentum and position are being measured in the same place at the same time.

    A quantum take on certainty (Nature)

    Observing the Average Trajectories of Single Photons in a Two-Slit Interferometer (AAAS).

    As I understand it, the approach is to make a strong measurement of position and a weak measurement of the momentum of a single photon, in a cross-section. This experiment is then repeated many times, so that at each location an average momentum can be determined.
     
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  3. OnlyMe Valued Senior Member

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    Perhaps, I don't have access to the full paper. A camera is used as the detector, assuming a digital camera. This gives a position accurate to the pixel density of the CCD. The momentum is estimated based on a change in polarization. So the camera records polarization, as well as pixel position? The articles are not clear on that.

    If you have access to the published paper and say the CCD in the camera is detecting both position and polarization, it would seem to be a simultaneous measurement. But, I don't get that from the press releases. Call me a skeptic...
     
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  5. Syne Sine qua non Valued Senior Member

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    No straw man, and no, no reference on the subject supports your already admittedly philosophical claim that it is only a measurement issue.


    You keep making this assertion and then outright refusing to support it with anything other than philosophical arm waving.
     
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  7. OnlyMe Valued Senior Member

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    There you go again! Where have I said it is only a measurement issue. Yes I did use only and measurement in the same sentence, but you don't get to rearrange my words.

    And again, in the future I will try to remember you cannot follow two thoughts at a time. I even said the philosophical comment had nothin to do with the UCP. You should be able to expand that to more than one philosophical comment. If not initially, at least after I have explicitly made the distiction.
     
  8. OnlyMe Valued Senior Member

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    Trippy,

    I found one comment paper on arXiv, Comment on “Observing the Average Trajectories of Single Photons in a Two-Slit Interferometer”. Here is a quote from near the end of the paper,

    From the experimental results above no one would claim that photons actually traversed these trajectories, since the momentum was only measured on average and the pixel size of the CCD is still quite large.​


    This was part of what I was trying to get at earlier, measuring both position and momentum, for a single particle does not work. The comment paper suggests that the momentum was averaged.
     
  9. Trippy ALEA IACTA EST Staff Member

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    They used a combination of a thin slice birefringent material (calcite) and a quater wave plate to encode the momentum data as intesity. The only thing the camera then needs to be able to measure is the location of the beam on the slice and the intensity of the light.

    Source:
    Kocsis, S. et al. Science 332, 1170-1173 (2011).

    Here's an ArXiV paper that examines the results from the above work, and compares the results to the computed Bohm Trajectories, and confirms the results - IE that they reconstructed the photons trajectories without destroying the interference pattern:
    Comment on "Observing the Average Trajectories of Single Photons in a Two-Slit Interferometer"
     
  10. OnlyMe Valued Senior Member

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    Last edited: May 29, 2012
  11. Syne Sine qua non Valued Senior Member

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    The only thing you have been harping on for pages now is how it is a measurement issue. And still without any support for how that can be so in contradiction to every reference on the subject. You can keep dodging this all you like, but no amount of accusing me of misrepresenting you will make it go away.

    I've already tried to give you an out by assuming you agree with every credible reference on the subject. Anything else is you wanting to introduce philosophy where it is not needed and cannot be supported.
     
  12. OnlyMe Valued Senior Member

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    From Wiki
    In quantum mechanics, the Heisenberg uncertainty principle states a fundamental limit on the accuracy with which certain pairs of physical properties of a particle, such as position and momentum, can be simultaneously known. In layman's terms, the more precisely one property is measured, the less precisely the other can be controlled, determined, or known.​


    Syne, the only way to know anything about the particle is by measuring, what ever it is you wish to know. The UCP says you cannot know two related things about a quantum particle/wave with certainty, for both. Since to know anything about it in the first place you have to measure it, the uncertainty you discover is still observed by measuring it. Thus it remains an issue of measurement. In the above quote from WiKi those portions in bold can only be known and make any sense, when measured.

    In the case of the UCP the uncertainty is not in the measurement itself, though in some interpretations it is the act of measuring that introduces the uncertainty. If I measure a particle's momentum, it disturbs its momentum and likewise in the reverse. At times making one measurement may even prevent any further measurement.

    The weak or indirect measurement in the photon double slit experiment comes close and may statistically be equivalent to an at the same time measurement. But even there, there seems to be some disagreement among those who should know.

    And it still can only be demonstrated by measuring or attempting to do so.

    Do you not understand this?
     
  13. Trippy ALEA IACTA EST Staff Member

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    OnlyMe.

    Were/are you aware that at one stage, one of the fundamental debates of QM (IIRC) was whether uncertainty was an inherent property of particles, or an artifact of the instruments used to measure them? Either way, it was regarded as being insurmountable.

    I think this is why Syne takes issue with you refering to it as "an issue of measurement". Because when you make that statement, you appear to be coming down on the side of it being an instrumental artifact, rather than an inherent property.
     
  14. OnlyMe Valued Senior Member

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    Yes. I have even read several of the historical discussions on the issue.

    I cannot help what Syne thinks or believes.

    Using the word measurement in itself does not make it an instrument issue. I think you know that.

    I admit that I all too often over talk an issue. And what seems to have happened here is he early on decided he knew what I was saying and after that he read nothing with an objective ear.

    There is likely some personal issue going on also, as he began mostly talking at me, rather to the subject. A lot of.., colorful personal comments, that have no place in a serious discussion.

    I probably did not help things by throwing in tangents like the occassional philosophical comment or the relativistic mass issue. But well there it is. Enough has already been said here.
     
  15. Syne Sine qua non Valued Senior Member

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    So now you seem to be saying that the uncertainty is a measurement issue simply because all science is, in essence, an issue of measurement. Sounds like a cop-out to me, as that doesn't address what reality the measurements reflect.
     
  16. Gary A Registered Senior Member

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    Gravity's Decline, Galaxy M-Sigma Relation & Anomalous Stellar Velocity Dispersion


    Gravity's Decline, Galactic M-Sigma Relation and the Anomalous Stellar Velocity Dispersion ​


    Inverse gravitational decline versus inverse square decline

    Analyzing the implications of a black hole singularity with near infinitely tight curvature close to the center and what this means to the mathematical form of the gravitational field, one concludes that a postulated singularity requires that black hole gravity declines as 1/r, not as 1/r[sup]2[/sup]. This effective infinitely deep gravitational “point-mass” geometrically implies a hyperbolic gravitational field profile. So, the concept has some bizarre twists.

    But, general relativity does not permit a 1/r gravitational field in 3-D + t spacetime. However it does allow a hyperbolic field in 2-D + t spacetime. So, it is posited that there exists a 2-D, hyper-spinning centripetally induced disk singularity in all central galactic SBHs. Having mass probably concentrated nearer to the singularity center but being of spacetime in nature, this entirety of the disk singularity is immune to the event horizon of the black hole. It can therefore extend outward to far beyond the galactic rim even to nearby galaxies within a cluster or supercluster.

    This gravitational field is also quantum renormalizable. It is well known that items in a 3-D space can be projected perfectly onto a 2-D surface – the holographic principle. Might this be a simple route toward validatable, falsifiable quantum gravity?

    Mathematically, the constant velocity distribution observed in spiral galaxies is explicitly derived. This means that the Mbh Sigma relation is explained. Also, Milgrom’s MOND constant, ao , is derived. No modification of Newton’s law is required. But, Newton must be regarded in the context of a 2-D hyperbolically curved spacetime. So, gravity for black holes declines as 1/r and is not an inverse square relation. Newton’s law and Kepler’s laws are all easily adjusted to accommodate the hyperbolic 1/r G-field in two dimensions plus time. G is hyperbolic when its equal gravitational force contour lines are drawn with spacing in such a way that a 1/r relation is followed. If the contour lines are then plotted having a z axis, Flamm’s hyperboloid is the result. No inner galactic bulge stellar orbits need be fitted to raw Kepler. Kepler does not define these orbits. Kepler’s laws are used merely to analyze them. The orbits are what they are.

    All the other effects that have been observed that have been traced to Dark Matter are also explained in this way. These include the anomalous velocity dispersion in spiral galaxies and in clusters, the weak gravitational lensing, the Sunyaev-Zel’dovich, the Sachs-Wolfe and the Bullet Cluster effects.

    The hyperbolic G-field parsimoniously explains these phenomena without appeal to any unfalsifiable hypotheses of exotic dark matter. Weakly interacting massive particles and other alien perpetrators of Dark Matter effects have been researched avidly for a very long time. They must be regarded now as unfalsifiable hypotheses because it has become clear that there is no way to prove or disprove their existence or it would have been done by now.

    The hyperbolic SBH singular ultra-spin disk G-field might have mass, perhaps like Alan Guth’s inflaton field in the false vacuum. Its mass, but not its hyperbolic gravitational spacetime configuration, could be confined to below the event horizon. The horizon itself could be greatly distorted - including any surrounding plasma or photon sphere. So, a photon passing through the expansive hyper-spin singular spacetime disk would experience therein an enhanced gravitational field, just as if it had passed through a Dark Matter “halo”.

    The open cell foam, network or spiderweb structure of the large scale universe is also explained by the extensiveness of the hyperbolic field and its form as a 2-D saddle shape “hyperboloid of one sheet” embedded in 3-D space. Galaxies and galactic clusters will be expected to align so that the hyperbolic surfaces of their 2-D fields tend to coincide. So, even the initial structure of the nascent universe would be influenced by supermassive BHs therein which could have formed very quickly at that time.

    They might have been there from t = 0 + an instant, for all we know. After all, if the inflaton particle was like an unstable subatomic particle, it may have decayed into smaller particles including many SBHs. Some have said that the inflaton particle must have decayed all at once. Under these extreme initial conditions, what experimentally validated physical law or fundamental principle is quoted thereby? So, it decays all at once. To what?

    In short, the hyperbolic 1/r SBH galactic G-Field explains all the phenomena that have ever been traced to Dark Matter. The hyperbolic G-field IS Dark Matter. Its potential energy profile is generally higher than the profile of an equivalent inverse square G-field. Since m = E/c[sup]2[/sup], it accounts for the unseen and unseeable missing mass of Dark Matter. The HBHG field is mathematically derived rigorously and satisfies the mathematical requirements of all observations.

    I have written a paper on gravitational decline with distance, but I need a reviewer to help check my mathematics. kentgen1@aol.com
     
  17. hebeyl Registered Member

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    We locally they tell me we are heading toward the centre of the Milky Way. ..
     
  18. stc Registered Member

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    I really love all this talk of the "ATTRACTIVE FORCE" of gravity, I remember that when I first tinkered with vehicle electronics that many cars were wired NEGATIVE EARTH, because at their date of manufacture the flow of electrons wasn't understood, sooner or later people will begin to realise that gravity too is completely misrepresented as a pull rather than a thrust from the fabric of space itself.
    To my knowledge no one has yet managed to explain gravity, so my theory must be considered as valid as any others that have been offered,I think the chances of a graviton existing are about the same as the Higgs boson being a reality "ZERO"
    Anyone out there want to debate this one?
     
  19. prometheus viva voce! Moderator

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    It's your knowledge thats deficient here. Well, you're only a century behind...

    When your theory can model things like the precession of perihelion of Mercury, gravitational lensing, gravitational redshift etc as well as or better than general relativity then we'll talk. Until then, move along.
     
  20. AlexG Like nailing Jello to a tree Valued Senior Member

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    Your knowledge is very limited. General relativity explains gravity, and has been well tested. The idea of gravity as a repulsive force has been presented by several others and been sell and truly debunked.
     
  21. stc Registered Member

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    Gravitational red shift ???????????? What planet do you live on?
    If you would like to cross swords on the subject of gravitational lensing, I would be pleased to shoot you down in flames.
    as for the comment on general relativity....you may have read a little about it , but I doubt very much that you understood it .BY THE WAY......Its called THE "THEORY" OF GENERAL RELATIVITY, not the FACT of general relativity, because that is exactly what it is THEORY.
     
  22. AlexG Like nailing Jello to a tree Valued Senior Member

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    And you've just showed you don't know the meaning of the word theory in the sciences.

    And who mentioned anything about gravitational redshift? (although it has been verified, see the Rebka-Pound experiment.

    Cross swords? Maybe when you graduate from high school.
     
  23. stc Registered Member

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    You obviously don't understand the English language. the word theory means an unproven concept.
    it doesn't matter what the subject matter is , a theory is just that UNPROVEN.
    I look forward to your teaching me all you know about gravitational lensing, I'm sure I have a couple of seconds to spare. As for gravity itself.....Could you please give me some facts on what it is because neither Newton or Einstein Knew, the world has been waiting for a genius like you ( and I don't mean the warping of space/time "Theory".)
     
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