Dear Azzam AlMosallami,

As I suspected the only similarity between your paper and my essay is that we discuss gravitation. You regard gravity as a force, whereas I stressed in my essay that not only general relativity but most importantly the experimental evidence (discussed in the essay) demonstrate that no gravitational force is involved in the gravitational phenomena.

Thank you for your comments and good luck in the contest.

Dear Vesselin Petkov,

I'm really appreciate your comment. I named it as a gravitational force according to the classical concept of the force. But actually it is a field, and this field strength is not constant, it is changing according to the distance from the center of mass. In my theory http://fqxi.org/community/forum/topic/1272 the meaning of force is different from the classical meaning, it produced when the particle is transformed from a state to another state with different vacuum energy. The concept of vacuum energy in my theory is same as interpreted in quantum field theory, and thus what I proposed in the gravitational field is agreed with what is resulted in quantum field theory, which leading to unifying between GR and quantum gravity. according to my My MGRT I could solve the Pioneer anomaly exactly http://vixra.org/abs/1109.0058 According to my MGRT I could solve the faster than light in cosmology (wormholes) with violation to the Lorentz transformation or causality http://vixra.org/abs/1208.0018 and thus unifying quantum theory with relativity

Hi Vesselin:

I enjoyed reading your paper and agree with your conclusion: "...quantum gravity as quantization of gravitational interaction is Impossible.."

However, I do not completely agree with your reason that gravity is not an interactive force just because general relativity says so. Since general relativity has failed to predict 96% (dark energy and dark matter) of the universe and has been paralyzed with the Big Bang singularity, it can hardly be acclaimed as a universal theory and it would be not only be premature but also incorrect to declare the Newtonian interaction as non-existent. Also, I have demonstrated in my posted paper - " From Absurd to Elegant Universe", that integrating the missing physics of spontaneous decay of particles with Newtonian gravitational energy plus specific relativity, the ills of general relativity can be cured and observed expansion of the universe and galaxies as well as quantum/classical behaviors can be predicted without any singularities. This approach also resolves quantum mysteries and explains inner workings of quantum mechanics eliminating the need for quantum gravity.

I would greatly appreciate your comments on my posted paper -" From Absurd to Elegant Universe".

Best Regards

Avtar Singh

    Hello Avtar,

    Thank you for your comments. It seems it is now my turn to disagree with what you wrote:

    "I do not completely agree with your reason that gravity is not an interactive force just because general relativity says so."

    My argument is not at all that "general relativity says so." It is the ultimate judge (the experimental evidence) that says so and I tried to stress it as strongly as possible in the essay and also on this page (above):

    "We have unambiguous experimental evidence that gravity is not a force - falling bodies DO NOT RESIST their (apparent) acceleration, which proves that no gravitational force is accelerating them downwards; a force would exist only if the bodies resisted their fall (the force would be needed to overcome that resistance).

    So any theory that explicitly or implicitly treats gravity as a force contradicts the existing experimental evidence."

    So Newton's view of gravity as a force is directly contradicted by the experimental evidence and I think Newton would understand and accept that fact since it is based on the very essence of the concept of force introduced by Newton himself in his second law - by the second law a force is only necessary to OVERCOME the resistance a body offers to its acceleration (by overcoming the resistance the force accelerates the body); the experimental fact that a falling body does not resist its fall (acceleration) proves that no force is accelerating it, because a force would be present only if the body resisted its acceleration (the force would be solely needed to overcome that resistance; briefly: no resistance => no gravitational force).

    Now your essay is also on my "to read" list, but as I explained in my answer to Israel's post above it would take some time.

    Best wishes and good luck.

    Hi Vesselin:

    Thank you for your comments.

    If you read my paper, you will know that my model has been vindicated by several sets of data from quantum to galactic to cosmic scale observations. Hence, you cannot prejudge it to be wrong just based on the isolated example of falling bodies. Then again, you are discounting all the numerous well-known data that supports Newtonian gravity model including the solar system motion.

    Moreover, if there was no resistance to motion provided by mass inertia, the experienced acceleration of falling bodies would be infinite (due to zero mass inertia) and not limited to a constant gravitational acceleration.

    I would welcome your reading and commenting on my paper.

    Regards and best of Luck

    Avtar

    Dear Vesselin Petkov,

    I am just now reading your essay. I feel certain that I need to re-read it to be certain that I understand your arguments. However, with regard to this quote:

    "What is crucial for testing both the geodesic hypothesis and the generalized definition of a free particle in spacetime and for determining the true nature of gravitational phenomena is the experimental fact that particles falling towards the Earth's surface offer no resistance to their fall. This essential experimental evidence has been virtually neglected so far, which is rather inexplicable especially given that Einstein regarded the realization of this fact - that "if a person falls freely he will not feel his own weight" - as the "happiest thought" of his life which put him on the path towards general relativity [8].

    This experimental fact unambiguously confirms the geodesic hypothesis be-cause free falling particles, whose worldtubes are geodesics, do not resist their fall (i.e. their apparent acceleration) which means that they move by inertia and therefore no gravitational force is causing their fall. It should be particu-larly stressed that a gravitational force would be required to accelerate particles downwards only if the particles resisted their acceleration, because only then a gravitational force would be needed to overcome that resistance."

    Selecting out just this portion: "the experimental fact that particles falling towards the Earth's surface offer no resistance to their fall. This essential experimental evidence has been virtually neglected so far, which is rather inexplicable especially given that Einstein regarded the realization of this fact -that "if a person falls freely he will not feel his own weight" - as the "happiest thought" of his life which put him on the path towards general relativity [8]."

    Concentrating on:

    "if a person falls freely he will not feel his own weight"

    We do not feel acceleration if it is applied evenly to a body. Any object would show no significant indication of the force of gravity so long as it is applied very close to evenly. The force of gravity does closely approximate the condition of applying a force evenly. Therefore, in my opinion, your reference does not support your argument that gravity is not a force. We do feel the effects of a force that is un-equally applied. The effects are un-equal compression causing bodily distortion.

    Your rebuttel is of course welcome. Thank you.

    James

      Hello Avtar,

      Thanks again for your comments.

      I can't believe you questioned an experimental fact - that falling bodies do not resist their acceleration. In my essay I even gave a concrete example - a falling accelerometer reads zero acceleration, i.e. zero resistance. This experimental evidence proves that gravity is not a force (whose anticipation led Einstein to general relativity) and no other experiment could prove the opposite (that gravity is a force). Nature does not contradict herself. Indeed, none of what you called "the numerous well-known data that supports Newtonian gravity model" proves that gravity is a force.

      All the best.

      Dear James Putnam,

      Thank you for your comments and for taking the time to read carefully my essay.

      Unfortunately, what you wrote - "We do not feel acceleration if it is applied evenly to a body" - is simply not so, if by "We do not feel acceleration" you mean "We do not feel resistance" (what you wrote after this sentence indicates to me that you meant precisely that).

      Not only does this statement contradict all existing experimental evidence, but it contradicts even everyday experience. For instance, the acceleration of a car is evenly applied to the body of a person in the car, but the person tangibly feels the acceleration, i.e. the resistance his/her body offers (sometimes in cases of sudden deceleration that feeling is tragically tangible).

      A piece of all existing experimental evidence (mentioned above) is the resistance individual particles (e.g. electrons) offer when accelerated in particle accelerators.

      Good luck in the contest.

      Vesselin Petkov,

      "Unfortunately, what you wrote - "We do not feel acceleration if it is applied evenly to a body" - is simply not so, if by "We do not feel acceleration" you mean "We do not feel resistance" (what you wrote after this sentence indicates to me that you meant precisely that). ..."

      Yes I did mean that.

      "... Not only does this statement contradict all existing experimental evidence, but it contradicts even everyday experience. For instance, the acceleration of a car is evenly applied to the body of a person in the car, but the person tangibly feels the acceleration, i.e. the resistance his/her body offers (sometimes in cases of sudden deceleration that feeling is tragically tangible). "

      We feel a push in the back or front because it causes uneven acceleration resulting in deformation of our shapes. The example given is not an example of evenly applied force or acceleration. It is an example of unevenly applied force and acceleration.

      "... A piece of all existing experimental evidence (mentioned above) is the resistance individual particles (e.g. electrons) offer when accelerated in particle accelerators."

      This resistance demonstrates that particles have mass. We also have mass. My point is that objects with mass will not feel force or acceleration if it is applied equally over the entire body. The experience of undergoing evenly applied force or acceleration will not cause a feeling by which to know it.

      I can let this go. It is your blog. I made my point and I stick by it. Good luck to you also.

      James

      Dear James Putnam,

      Exactly because this is my blog I have to reply.

      If every single atom of the body of a person in an accelerating car accelerates with the car's acceleration (in your terminology acceleration is evenly applied) the person will still feel the resistance due to the acceleration.

      Evenly or unevenly applied accelerations have nothing to do with the resistance bodies offer to their acceleration. And you yourself state that: "This resistance demonstrates that particles have mass." This is so because since Newton mass has been defined as the measure of the resistance a body offers to its acceleration (naturally, there is no mentioning of how acceleration is applied).

      The experimental fact that falling particles do not resist their fall confirmed the geodesic hypothesis in general relativity, which in turn explained why the particles do not resist their fall - the particles' acceleration in the curved spacetime surrounding the Earth is zero, which means that no force is acting on them and they move by inertia. The observed apparent acceleration of falling particles is relative, which is caused by the fact that the particles worldlines and the Earth's worldline converge toward one another (this is called geodesic deviation). Therefore the observed apparent (relative) acceleration of falling particles is caused by the non-Euclidean geometry of spacetime in the Earth's vicinity and is not caused by a force.

      When a falling particle hits the ground it is prevented from moving by inertia and it resists its curved-spacetime acceleration (that is why the force of weight is inertial in general relativity in full agreement that there is no gravitational force). The measure of that resistance is the particle's (passive gravitational) mass. So general relativity also nicely explains why inertial and passive gravitational masses are equal.

      Best regards.

        Vesselin Petkov,

        "If every single atom of the body of a person in an accelerating car accelerates with the car's acceleration (in your terminology acceleration is evenly applied) the person will still feel the resistance due to the acceleration."

        No they are not accelerating evenly. The car pushes against the back. The body transfers the force forward to the other parts of the body. That transfer is not instantaneous. Right from the beginning the acceleration was not evenly applied. If it was evenly applied there would be no distortion of the body. If there is no distortion, then, there is no feeling. Gravity makes this point clear.

        Thank you for your reply.

        James

        James, I think that all one needs to understand Vesselin's reply is that " ... the particles' acceleration in the curved spacetime surrounding the Earth is zero ..." which is simple Galilean physics. That is, there is no other source of particle acceleration than gravity. How do we know? -- because we can test it.

        An observer in an airplane that drops an unpowered bomb and travels without accelerating for a certain distance while the bomb falls will find that the bomb remains directly beneath the plane for the total time of its fall. In other words, there is no horizontal acceleration component acting on the bomb; the plane and the bomb are both experiencing zero acceleration in the curved spacetime. Another way to test this hypothesis is to fire a cannonball in a flat trajectory, and drop another cannonball from the same height simultaneously. One will find that the fired projectile and the dropped projectile impact the ground at the same moment, even though the fired projectile follows a curved trajectory in its descent, and the dropped projectile a straight trajectory -- again illustrating that there is no horizontal acceleration to the common plane, only the acceleration of gravity acting on each cannonball.

        Now when this Galilean theory is extended to Newtonian mechanics and finally to relativity, one gets not only the beautiful mathematics by which we understand relative motion, one can also physically *feel* what it means to have no resistance to motion. I know this from long years of studying Einstein, and have known that one cannot truly grasp relativity without having this sensation. Vesselin brings the subject to life by reminding us that unquantized motion is one continuous quantum, that every particle is as free of resistance as every other.

        Tom

        Tom, I understand those things. They do not address the question of why does the freely falling person not feel the force of gravity. It is not because gravity is no force. The persons feeling is not evidence for that conclusion. I gave the reason why there is no feeling. The reason is because there is almost equal application of force to all parts of the body and almost equal acceleration for all the parts of the body. There is no reason to feel pulled or pushed whatever.

        The orbiting example does involve acceleration in the vertical direction. The reason it accelerates toward the Earth is because is is being acted upon by the force of gravity. That force is acting in the vertical direction.

        The Relativity arguments do not apply to solving this matter because of the level at which you are using them. It is the assumptions and choices that led to the development of the theory of relativity that apply. It is at that level, I can diffuse concepts such as space-time. When you use space-time as the crux of your argument, you are relying upon a theoretical concept as if it is real.

        My point in addressing what Vesselin said regarding Einstin's elation about no feeling of force of gravity is that that recognition is not an example of some great discovery. The lack of the feeling of being pulled or pushed down is exactly what anyone sould expect to be the case.

        James

        James,

        "I understand those things. They do not address the question of why does the freely falling person not feel the force of gravity."

        Yes they do. No particle or system of particles is in a privileged inertial frame. Think about it.

        "It is not because gravity is no force. The persons feeling is not evidence for that conclusion. I gave the reason why there is no feeling."

        A person is a system of particles. The external evidence is not contradictory of the internal evidence.

        Tom

        Thank you Tom for trying to help to clarify this issue. I should stress two things - (i) I have no intention to argue with James that gravity is not a force since that is an established fact of modern physics (not just my personal opinion), and (ii) my true motivation for trying to respond promptly to the messages on this page (despite the extremely time consuming launching of a new academic publisher other deadlines) is to share the many-year struggle to understand this really difficult issue (since it is quite counter-intuitive) with everyone genuinely interested in gravitation.

        James (if I may),

        What you say about unevenly applied acceleration is irrelevant for the issue of resistance due to acceleration. I will make one last attempt to explain.

        A falling accelerometer reads zero acceleration, that is, zero resistance (that is an experimental fact). If there were gravitational force that accelerated the accelerometer downwards it would resist its acceleration. Your argument, I guess, is that acceleration is evenly applied to all of its atoms and that is why the accelerometer does not resist its fall. The reason I said this argument is irrelevant is, I think, obvious - because every single atom (electron, quark, etc.) of the accelerometer would resist its acceleration, if that acceleration were caused by a gravitational force, then the whole accelerometer would also resist its fall. But it does not - so no gravitational force is causing its fall.

        Let me summarize again the explanation given by general relativity (GR). GR showed that only spacetime physical quantities adequately represent the world. The four-dimensional (curved-spacetime) acceleration of the falling accelerometer is zero; that is why it is not subject to any force (as Tom nicely stressed) and moves by inertia (the observed apparent acceleration of the falling accelerometer is relative and is not caused by a force either since it is a manifestation of the spacetime curvature as explained in my post above). When the accelerometer hits the ground, it is prevented from moving by inertia and its four-dimensional curved-spacetime acceleration becomes different from zero and a resistance (inertial) force arises in the accelerometer as a reaction to the force with which the ground disturbs the inertial motion of the falling accelerometer.

        You seem to be depriving yourself from properly understanding the general relativistic explanation since you regard spacetime as nothing more than a theoretical concept (as you clearly stated it above). The best way to see why such a view is not just wrong but contradicts the experimental evidence, assume that you are right - that spacetime is indeed a theoretical concept and what exists is the three-dimensional world that appears to follow from our perception data. Then analyze rigorously all kinematical relativistic effects and most importantly the experiments that confirmed them. You will see that those experiments are impossible in a three-dimensional world. I would suggest that you start with the Master - with Minkowski's explanation of length contraction shown in Fig. 1 of his famous paper "Space and Time" (it is contained in the free version of a book H. Minkowski, Space and Time: Minkowski's papers on relativity; the pdf file is available at: http://minkowskiinstitute.org/mip/books/minkowski.html).

        If you decide to follow my suggestion, feel free to ask any questions about Minkowski's explanation or about Einstein's explanation of gravitation in GR.

        Best wishes.