Notices
Page 1 of 2 12 LastLast
Results 1 to 100 of 153
Like Tree29Likes

Thread: Why Push Gravity Does Not Work

  1. #1 Why Push Gravity Does Not Work 
    Moderator Moderator Markus Hanke's Avatar
    Join Date
    Nov 2011
    Location
    Ireland
    Posts
    7,172
    Motivation

    Too many people seem to think that Push Gravity, or indeed any mechanical explanation, is a valid model for gravitation. This is erroneous, as these models are either not internally consistent, or require physically impossible assumptions.


    Basic premise of Push Gravity

    The model assumes that gravity is caused by particles impacting massive bodies from all directions, thereby providing a push force wish causes a tendency for massive bodies to move towards each other, also because the bodies themselves cause a shielding effect, leading to pressure differentials due to the collisions not being fully elastic. This is also posited as the reason for the inverse square law the incoming momentum flux is greater than the outgoing one. Further assumptions must be made to account for the fact that the gravitational force is primarily caused by total mass rather then surface area, namely that only a small number of particles actually interact with a massive body.


    Reasons why Push Gravity does not work

    1. The gravity particles are thought of classical particles with classical interactions. This notion is inconsistent with current understanding of particle physics there is no particle which could have all the characteristics required by PG without violating one or more physical laws
    2. The particle flux filling all space must be perfectly isotropic and of very high density. No known form of radiation of particle flux has these characteristics to the degree required by the theory
    3. The neutrino. Modern proponents of PG often posit the neutrino as the mediating particle of the theory. This has been conclusively disproved by Richard Feynman in 1995 [1].
    4. Transparency of matter. With increasing mass the change in gravitational shielding becomes mathematically less then the sum of the shieldings of the two bodies. To overcome this one has to place an extremely high lower bound on the flux density of these particles. This is inconsistent with experiments conducted to detect such flux energies [2]
    5. Drag. Any mechanical model of PG necessarily creates a drag force, or else there would be no interaction between the particles and a massive body. In order to reduce the amount of drag to levels consistent with observation, the speed at which these particles move must be in the region of 10^17 m/s, which is many orders of magnitude higher than the speed of light.
    6. Heat energy. If the particles of PG really move at superluminal speeds, which is in violation of basic physical principles, they would impart a heat energy onto any massive body sufficiently high to instantly incinerate any form of normal matter.
    7. Aberration. In any mechanical model of gravity, the gravitational force can only act with finite speed, creating an aberration effect. Such an effect has not been observed.
    8. Sources of gravity. As we know today, and as is experimentally well verified [3], all forms of energy are a source of the gravitational field, not just mass. This is not explainable by PG.
    9. Time dilation. PG has no consistent mechanism to explain the well verified phenomenon of time dilation.
    10. Deflection of light. PG cannot explain deflection of light rays while at the same time avoiding aforementioned problems with drag.
    11. Thermodynamics. The flux of particles in PG would be many orders of magnitude more energetic then mass at rest. However, not transmission of energy is observed, even though there must be a form of interaction with ordinary matter. This leads to a violation of the laws of thermodynamics.
    12. Perpetual motion. Due to shielding effects the existence of PG would make it possible to construct a perpetual motion machine. Again, this is in violation of the laws of thermodynamics.
    13. Binding energy. Binding energy of elementary particles contributes to their gravitational energy, which is not explainable by PG.
    14. Origin. There is no consistent explanation as to where those particles come from, why their flux never varies, why the field is perfectly isotropic, or why the total energy never decreases even if the universe is expanding.
    15. Mathematics. The mathematics of PG are not self-consistent, and do not produce the correct results. [4]
    16. Frame of reference. PG would create an absolute frame of reference, which means that the Theory of Relativity must be false. This is in contradiction to experiment and observation.
    17. Large scale structure. Due to the necessary isotropy of the PG medium, over very large distances the net forces would cancel out. This does not explain the large scale structure of the universe.
    18. Non-existence. No flux field or particle stream as needed by PG has ever been observed by experiment or observation.

    Conclusion

    PG was abandoned around 1900 due to some of the very serious problems listed above. It is not a viable model of gravitation, and even in its hey day ( around the time when LeSage was alive ) it had very few proponents, since even then it was recognized that there were serious problems with this model. It is in many ways in direct contradiction to empirical evidence, and would, in order to work, violate several fundamental laws of physics.
    In short push gravity is complete nonsense.


    References

    [1] ^ Feynman, R. P. (1995), Feynman Lectures on Gravitation, Addison-Wesley, pp. 2328

    [2] Bertolami, O. & Paramos, J. & Turyshev, S. G. (2006), General Theory of Relativity: Will it survive the next decade?, in H. Dittus, C. Laemmerzahl, S. Turyshev, , Lasers, Clocks, and Drag-Free: Technologies for Future Exploration in Space and Tests of Gravity: 2767, arXiv:gr-qc/0602016

    [3] Carlip, S. (1997), "Kinetic Energy and the Equivalence Principle", Am. J. Phys. 65: 409413, arXiv:gr-qc/9909014, Bibcode 1998AmJPh..66..409C, doi:10.1119/1.18885

    [4] Lesage's Shadows


    KALSTER and Kerling like this.
    Reply With Quote  
     

  2.  
     

  3. #2  
    Average Human guymillion's Avatar
    Join Date
    Apr 2012
    Posts
    187
    Wow! A very detailed post! I was not aware of this theory, I guess I am just not up to speed when it comes to "non-mainstream" science. I will have to give this a closer look.


    James Burroughs likes this.
    Reply With Quote  
     

  4. #3  
    Moderator Moderator Markus Hanke's Avatar
    Join Date
    Nov 2011
    Location
    Ireland
    Posts
    7,172
    Quote Originally Posted by guymillion View Post
    I was not aware of this theory, I guess I am just not up to speed when it comes to "non-mainstream" science. I will have to give this a closer look.
    The reason why you weren't aware of it is that it was abandoned a century ago, for good reasons. The model simply does not work. It is being dragged up out of its grave every once in a while by cranks and crackpots, just like geocentrism, flat earth etc etc.
    It's a waste of time. I wrote this thread so that I do not need to repeat myself every time it is resurrected by someone.
    Reply With Quote  
     

  5. #4  
    Time Lord
    Join Date
    Apr 2008
    Posts
    5,305
    Thanks. Prior to your post I'd had the encumbrance of entertaining Push Gravity as remotely possible.
    A pong by any other name is still a pong. -williampinn
    Reply With Quote  
     

  6. #5  
    Forum Freshman
    Join Date
    Sep 2012
    Posts
    60
    I don't like all these QFTs, because they don't seem to be addressing the problem, only pushing it further back.

    What is the force between masses and the push particles?


    Another example: How did Life originate on Earth. Oh, it came from an asteroid that crash landed.

    Such theories just serve to push the problem further back.


    In theoretical physics, we must ask ourselves, what is truly fundamental?
    Reply With Quote  
     

  7. #6  
    Suspended
    Join Date
    Apr 2007
    Location
    Pennsylvania
    Posts
    8,822
    Moved Bill Alsept and Forrests nonsense to the pseudo forum.
    Reply With Quote  
     

  8. #7  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    Markus Hanke,

    .......So which type of particles are they, exactly ? Tell us, and we shall then examine in detail what happens if you insert them into a PG model.
    Asserted problem PG #1 of OP

    I believe Number 1 above, has at least one interesting possibility concerning PG models.

    1. The gravity particles are thought of classical particles with classical interactions. This notion is inconsistent with current understanding of particle physics – there is no particle which could have all the characteristics required by PG without violating one or more physical laws
    I generally do not discuss alternative possibilities or hypothesis in a mainstream forum but make an exception to propose one alternative vector possibility concerning PG. Neutrinos move at close to the speed of light and this energy of motion is related to two facets of their character. One is that because of this energy they have a mass equivalence, thereby a mass potential upon rare impacts. Secondly there may be aether drag in a PG model as in #5 OP comment. Accordingly this drag would appear as something like (if not exactly) the Pioneer anomaly.

    In time accordingly the field would slowly act upon all matter in motion slowing it down via aether drag. This would also apply to neutrinos. We can presently detect neutrinos via their known occasional interactions with matter at known energy levels. Hypothetical slowed-down (aether drag) neutrinos might accordingly interact differently with matter. Such neutrinos, via their stellar productions, could collectively represent vectors in all directions. Such lower energy, lower velocity neutrinos might instead often interact (instead of seldom) with matter conceivably being the primary vectors of pushing gravity.
    Last edited by forrest noble; December 23rd, 2012 at 12:53 PM.
    pjg250 likes this.
    Reply With Quote  
     

  9. #8  
    Brassica oleracea Strange's Avatar
    Join Date
    Oct 2011
    Location
    喫茶店
    Posts
    16,540
    moved.
    Without wishing to overstate my case, everything in the observable universe definitely has its origins in Northamptonshire -- Alan Moore
    Reply With Quote  
     

  10. #9  
    Administrator KALSTER's Avatar
    Join Date
    Sep 2007
    Location
    South Africa
    Posts
    8,232
    Please continue with Forrest's comments in the new thread.
    Disclaimer: I do not declare myself to be an expert on ANY subject. If I state something as fact that is obviously wrong, please don't hesitate to correct me. I welcome such corrections in an attempt to be as truthful and accurate as possible.

    "Gullibility kills" - Carl Sagan
    "All people know the same truth. Our lives consist of how we chose to distort it." - Harry Block
    "It is the mark of an educated mind to be able to entertain a thought without accepting it." - Aristotle
    Reply With Quote  
     

  11. #10  
    Forum Senior bill alsept's Avatar
    Join Date
    Jul 2012
    Location
    Seattle, WA
    Posts
    386
    Quote Originally Posted by Markus Hanke View Post
    Motivation

    Too many people seem to think that Push Gravity, or indeed any mechanical explanation, is a valid model for gravitation. This is erroneous, as these models are either not internally consistent, or require physically impossible assumptions.


    Basic premise of Push Gravity

    The model assumes that gravity is caused by particles impacting massive bodies from all directions, thereby providing a push force wish causes a tendency for massive bodies to move towards each other, also because the bodies themselves cause a shielding effect, leading to pressure differentials due to the collisions not being fully elastic. This is also posited as the reason for the inverse square law – the incoming momentum flux is greater than the outgoing one. Further assumptions must be made to account for the fact that the gravitational force is primarily caused by total mass rather then surface area, namely that only a small number of particles actually interact with a massive body.


    Reasons why Push Gravity does not work

    1. The gravity particles are thought of classical particles with classical interactions. This notion is inconsistent with current understanding of particle physics – there is no particle which could have all the characteristics required by PG without violating one or more physical laws
    2. The particle flux filling all space must be perfectly isotropic and of very high density. No known form of radiation of particle flux has these characteristics to the degree required by the theory
    3. The neutrino. Modern proponents of PG often posit the neutrino as the mediating particle of the theory. This has been conclusively disproved by Richard Feynman in 1995 [1].
    4. Transparency of matter. With increasing mass the change in gravitational shielding becomes mathematically less then the sum of the shieldings of the two bodies. To overcome this one has to place an extremely high lower bound on the flux density of these particles. This is inconsistent with experiments conducted to detect such flux energies [2]
    5. Drag. Any mechanical model of PG necessarily creates a drag force, or else there would be no interaction between the particles and a massive body. In order to reduce the amount of drag to levels consistent with observation, the speed at which these particles move must be in the region of 10^17 m/s, which is many orders of magnitude higher than the speed of light.
    6. Heat energy. If the particles of PG really move at superluminal speeds, which is in violation of basic physical principles, they would impart a heat energy onto any massive body sufficiently high to instantly incinerate any form of normal matter.
    7. Aberration. In any mechanical model of gravity, the gravitational force can only act with finite speed, creating an aberration effect. Such an effect has not been observed.
    8. Sources of gravity. As we know today, and as is experimentally well verified [3], all forms of energy are a source of the gravitational field, not just mass. This is not explainable by PG.
    9. Time dilation. PG has no consistent mechanism to explain the well verified phenomenon of time dilation.
    10. Deflection of light. PG cannot explain deflection of light rays while at the same time avoiding aforementioned problems with drag.
    11. Thermodynamics. The flux of particles in PG would be many orders of magnitude more energetic then mass at rest. However, not transmission of energy is observed, even though there must be a form of interaction with ordinary matter. This leads to a violation of the laws of thermodynamics.
    12. Perpetual motion. Due to shielding effects the existence of PG would make it possible to construct a perpetual motion machine. Again, this is in violation of the laws of thermodynamics.
    13. Binding energy. Binding energy of elementary particles contributes to their gravitational energy, which is not explainable by PG.
    14. Origin. There is no consistent explanation as to where those particles come from, why their flux never varies, why the field is perfectly isotropic, or why the total energy never decreases even if the universe is expanding.
    15. Mathematics. The mathematics of PG are not self-consistent, and do not produce the correct results. [4]
    16. Frame of reference. PG would create an absolute frame of reference, which means that the Theory of Relativity must be false. This is in contradiction to experiment and observation.
    17. Large scale structure. Due to the necessary isotropy of the PG medium, over very large distances the net forces would cancel out. This does not explain the large scale structure of the universe.
    18. Non-existence. No flux field or particle stream as needed by PG has ever been observed by experiment or observation.

    Conclusion

    PG was abandoned around 1900 due to some of the very serious problems listed above. It is not a viable model of gravitation, and even in its hey day ( around the time when LeSage was alive ) it had very few proponents, since even then it was recognized that there were serious problems with this model. It is in many ways in direct contradiction to empirical evidence, and would, in order to work, violate several fundamental laws of physics.
    In short – push gravity is complete nonsense.

    Marcus, when I first saw this list I printed it and stuck it on my office wall. I thought great finally something that might prove PG wrong once and for all or even better yet maybe something I could argue against. Now that I have had time to go through it several times I find that most items on the list do not appear to describe PG in the way that I have always figured it. In some cases the arguments are too vague to tell. Would it be possible to be a little more specific as to how or why these items prove anything. Would it be possible to maybe start with the first five. For example in number (8) you say "all forms of energy are a source of the gravitational field, not just mass" What does that mean? Why are all forms of energy a source of gravity? Why can't kinetic energy be the source. Thanks
    Reply With Quote  
     

  12. #11  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    Marcus, when I first saw this list I printed it and stuck it on my office wall. I thought great finally something that might prove PG wrong once and for all or even better yet maybe something I could argue against. Now that I have had time to go through it several times I find that most items on the list do not appear to describe PG in the way that I have always figured it. In some cases the arguments are too vague to tell. Would it be possible to be a little more specific as to how or why these items prove anything. Would it be possible to maybe start with the first five. For example in number (8) you say "all forms of energy are a source of the gravitational field, not just mass" What does that mean? Why are all forms of energy a source of gravity? Why can't kinetic energy be the source. Thanks
    You're right Bill. This list generally only applies to Le Sage pushing gravity, as Marcus explained on our other thread at that time. None of these criticisms would necessarily apply to generic PG models in general -- not necessarily your ideas or model, nor mine. Since this is a mainstream site we can only discuss what's wrong with his listed criticisms concerning PG models, but we cannot promote any PG model(s) in particular in a mainstream forum.

    Muskus' criticism list:

    1. The gravity particles are thought of classical particles with classical interactions. This notion is inconsistent with current understanding of particle physics there is no particle which could have all the characteristics required by PG without violating one or more physical laws.
    Most PG models do not propose classical particles. Many or most propose neutral particles with a range of influence much smaller than electrons.

    2. The particle flux filling all space must be perfectly isotropic and of very high density. No known form of radiation of particle flux has these characteristics to the degree required by the theory.
    Isotropic is not a requirement. High-density depends upon how density is defined. As far as particles per volume, then I would expect most models would require a high density background field. As far as particulates as a portion of empty space then some or most models might be considered low-density aether model.

    3. The neutrino. Modern proponents of PG often posit the neutrino as the mediating particle of the theory. This has been conclusively disproved by Richard Feynman in 1995.
    Most propose such a field to be comprised of neutral particles but very few or none would propose classical neutrinos.

    4. Transparency of matter. With increasing mass the change in gravitational shielding becomes mathematically less then the sum of the shieldings of the two bodies. To overcome this one has to place an extremely high lower bound on the flux density of these particles. This is inconsistent with experiments conducted to detect such flux energies.
    This might apply to some PG models but certainly not those that I know of.

    5. Drag. Any mechanical model of PG necessarily creates a drag force, or else there would be no interaction between the particles and a massive body. In order to reduce the amount of drag to levels consistent with observation, the speed at which these particles move must be in the region of 10^17 m/s, which is many orders of magnitude higher than the speed of light.
    This might apply to some PG models but makes no sense in most that I am aware of. Most would seem to require high momentum particles, but none necessarily super-luminal. I expect the calculations relate to Le Sage PG. All such models would require some minuscule drag regarding matter in motion against a gravitational field. Maybe something like the Pioneer anomaly?

    6. Heat energy. If the particles of PG really move at superluminal speeds, which is in violation of basic physical principles, they would impart a heat energy onto any massive body sufficiently high to instantly incinerate any form of normal matter.
    This criticism applies to a superluminal PG particulates, which most PG models no not require. This also assumes that all particulates impact matter directly whereby most models propose that most of the field passes through matter, and those that do impact matter do not necessarily make direct contact because all particles and atomic matter would require a spinning aether vortex for most or all PG models.

    7. Aberration. In any mechanical model of gravity, the gravitational force can only act with finite speed, creating an aberration effect. Such an effect has not been observed.
    Aberration of starlight would be a requirement and consequence of "streaming" PG models.

    8. Sources of gravity. As we know today, and as is experimentally well verified, all forms of energy are a source of the gravitational field, not just mass. This is not explainable by PG.
    The bending of EM radiation, in the same way, is also explainable by many or most PG models. Both the energy of relative motion and internal kinetic energy of matter could also be factored into a modern generic PG model of gravity, as it could be factored into Newtonian gravity -- I would expect.

    9. Time dilation. PG has no consistent mechanism to explain the well verified phenomenon of time dilation.
    This is true. Since PG is another model of gravity, the equations of GR can't be used by PG models to explain time dilation. But it is very easily explained by some PG models as being a simple function of the observed redshifts.

    10. Deflection of light. PG cannot explain deflection of light rays while at the same time avoiding aforementioned problems with drag.
    I do not see this a problem with most PG models. Drag, if it exists, is seemingly be very small compared to the effects of gravity in general.

    11. Thermodynamics. The flux of particles in PG would be many orders of magnitude more energetic then mass at rest. However, not transmission of energy is observed, even though there must be a form of interaction with ordinary matter. This leads to a violation of the laws of thermodynamics.
    This might be a problem with superluminal PG models, which most are not.

    (continued in next posting due to length)
    Last edited by forrest noble; December 25th, 2012 at 02:16 PM.
    Reply With Quote  
     

  13. #12  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    bill alsept, Markus Hanke,

    (Continued from previous posting)

    12. Perpetual motion. Due to shielding effects the existence of PG would make it possible to construct a perpetual motion machine. Again, this is in violation of the laws of thermodynamics.
    If this is a valid criticism of Le Sage gravity, I don't see why. But it would not apply to any model that I could imagine.

    13. Binding energy. Binding energy of elementary particles contributes to their gravitational energy, which is not explainable by PG.
    This would not apply to any aether model of pushing gravity that I know of. If there is such a possible model I am not aware of it.

    14. Origin. There is no consistent explanation as to where those particles come from, why their flux never varies, why the field is perfectly isotropic, or why the total energy never decreases even if the universe is expanding.
    This, I think, is a valid criticism of only some PG models.

    15. Mathematics. The mathematics of PG are not self-consistent, and do not produce the correct results.
    There is no PG model that can explain the mechanics of gravity within our solar system as well as GR. But GR, at the galactic scale, greatly fails without the inclusion of dark matter which is entirely a hypothetical entity. Until all aspects of gravity are understood, including hypothetical dark matter, GR might someday be replaced.

    16. Frame of reference. PG would create an absolute frame of reference, which means that the Theory of Relativity must be false. This is in contradiction to experiment and observation.
    Yes. This would invalidate SR in favor of LT. There, however, is no mathematical difference between the two calculations.

    17. Large scale structure. Due to the necessary isotropy of the PG medium, over very large distances the net forces would cancel out. This does not explain the large scale structure of the universe.
    This might apply to Le Sage's model, but not to many or most other PG models.


    18. Non-existence. No flux field or particle stream as needed by PG has ever been observed by experiment or observation.
    This is true, nor has an aether field yet been recognized or flux field, other than the ZPF allegedly being evidence for an aether. But neither is there any direct evidence for dark matter or dark energy, only indirect evidence.


    None of the above 18 criticisms are necessarily valid or evidence against PG models in general because seemingly all can be explained away concerning generic PG explanations.

    BTW, happy holidays to all
    Last edited by forrest noble; December 23rd, 2012 at 01:07 PM.
    Reply With Quote  
     

  14. #13  
    Moderator Moderator Markus Hanke's Avatar
    Join Date
    Nov 2011
    Location
    Ireland
    Posts
    7,172
    Now that I have had time to go through it several times I find that most items on the list do not appear to describe PG in the way that I have always figured it.
    Well, I don't really know how you understand PG, but all of my points come from the literature available about LeSage's PG model.

    Quote Originally Posted by bill alsept View Post
    For example in number (8) you say "all forms of energy are a source of the gravitational field, not just mass" What does that mean? Why are all forms of energy a source of gravity?
    What it means is that it is not just massive objects which are being accompanied by the presence of gravitational fields. Any form of energy acts as a source of gravity, including the gravitational field itself ( since it contains energy it is self-coupling ). Other examples would be electromagnetic fields, massless particles with momentum, electric charges etc etc. In general, a source of the gravitational field is anything which can be described by a stress-energy-momentum tensor :

    Stress

    As far as I can see it the PG model relies solely on the presence of mass to work. If there is no mass, there is no "shadow" effect, and thus no net field. Any model of gravitation needs to explain how each of the energy forms mentioned in the link above leads to gravitational effects, and it needs to be able to do so giving the correct numbers.

    Would it be possible to maybe start with the first five.
    The first five are pretty much taken straight from here :

    Le Sage's theory of gravitation - Wikipedia, the free encyclopedia

    It would be advisable to have a thorough and careful read through this. I might write a bit more about these points myself, but since it is Christmas this will have to wait. I am sure you understand that I'd rather spend the festive season with my wife and kids than on an Internet forum arguing against push gravity.

    P.S.: I should stress again that my points are based on LeSage PG, being the classic PG model.
    Reply With Quote  
     

  15. #14  
    Forum Senior bill alsept's Avatar
    Join Date
    Jul 2012
    Location
    Seattle, WA
    Posts
    386
    Quote Originally Posted by Markus Hanke View Post
    Now that I have had time to go through it several times I find that most items on the list do not appear to describe PG in the way that I have always figured it.
    Well, I don't really know how you understand PG, but all of my points come from the literature available about LeSage's PG model.

    Quote Originally Posted by bill alsept View Post
    For example in number (8) you say "all forms of energy are a source of the gravitational field, not just mass" What does that mean? Why are all forms of energy a source of gravity?
    What it means is that it is not just massive objects which are being accompanied by the presence of gravitational fields. Any form of energy acts as a source of gravity, including the gravitational field itself ( since it contains energy it is self-coupling ). Other examples would be electromagnetic fields, massless particles with momentum, electric charges etc etc. In general, a source of the gravitational field is anything which can be described by a stress-energy-momentum tensor :

    Stress

    As far as I can see it the PG model relies solely on the presence of mass to work. If there is no mass, there is no "shadow" effect, and thus no net field. Any model of gravitation needs to explain how each of the energy forms mentioned in the link above leads to gravitational effects, and it needs to be able to do so giving the correct numbers.

    Would it be possible to maybe start with the first five.
    The first five are pretty much taken straight from here :

    Le Sage's theory of gravitation - Wikipedia, the free encyclopedia

    It would be advisable to have a thorough and careful read through this. I might write a bit more about these points myself, but since it is Christmas this will have to wait. I am sure you understand that I'd rather spend the festive season with my wife and kids than on an Internet forum arguing against push gravity.

    P.S.: I should stress again that my points are based on LeSage PG, being the classic PG model.
    Happy Holidays you guys
    Reply With Quote  
     

  16. #15  
    Moderator Moderator Markus Hanke's Avatar
    Join Date
    Nov 2011
    Location
    Ireland
    Posts
    7,172
    None of these criticisms would necessarily apply to generic PG models in general
    Ok then, back to the drawing board - what exactly are "generic PG models in general" ? Please describe in detail how and why such generic models work, what they are based on, what the mathematical description is, and whether they give the correct numbers. Once I have this information I will adapt my list accordingly. Once again, that list was based on LeSage.
    Mind you, the emphasise is on generic PG model, not your personal theories.
    Reply With Quote  
     

  17. #16  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    Markus Hanke,

    As far as I can see it the PG model relies solely on the presence of mass to work. If there is no mass, there is no "shadow" effect, and thus no net field.
    ..... "If there is no mass, there is no "shadow" effect, and thus no net field" gravitational effect .

    Any model of gravitation needs to explain how each of the energy forms mentioned in the link above leads to gravitational effects, and it needs to be able to do so giving the correct numbers.
    Yes, such a model would have to explain how different energies of matter can relate to increased gravitational effects.

    ....Ok then, back to the drawing board - what exactly are "generic PG models in general" ? Please describe in detail how and why such generic models work, what they are based on, what the mathematical description is, and whether they give the correct numbers......
    What is the meaning of a generic PG model?

    Of course this is a necessary question and explanation. Such possible explanations would be a matter of opinion since obviously the answer is speculative. I envision generic PG models to mean those PG alternatives that can overcome any method of dis-proving based upon known evidence to the contrary. I would expect generic models would not require faster-than-light particulates, for instance. Background fields of PG particulates would not necessarily have to be uniform in density or motion, as in the Le Sage model. Such fields might be deformed by matter causing high and low pressure background field volumes and field flow related to gravitational influences, and other non-uniform field alternatives. There are no PG models, that I know of, that can do any better mathematically than the inverse square law of gravity. Like GR, any successful new PG model of gravity would probably require a set of equations to make adjustments like GR, which uses 10 related equations.

    Once I have this information I will adapt my list accordingly. Once again, that list was based on LeSage. Mind you, the emphasise is on generic PG model, not your personal theories.
    Yes, last time when singular possibilities were proposed the thread was "thrown" into the abyss of Pseudo-Science, since specific singular examples of PG models and possible mechanics were then suggested/proposed. I will now stay with "generic versions" trying to give more than one possible alternative to Le Sage -- in those aspects where his model might seem to fail. If bill alsept only suggests one possibility, I will try to add more to his single possibility, or otherwise show where it may not be one of the generic PG possibilities -- since this is the mainstream part of the forum.
    Last edited by forrest noble; January 2nd, 2013 at 05:27 PM.
    Reply With Quote  
     

  18. #17  
    Moderator Moderator Markus Hanke's Avatar
    Join Date
    Nov 2011
    Location
    Ireland
    Posts
    7,172
    Such possible explanations would be a matter of opinion since obviously the answer is speculative.
    Yes, and that is why you guys need to first show me exactly what kind of PG model you consider "generic", and present it here. Once this is done I will respond with an appropriate list of reasons why it can't work. Perhaps you can get in touch with Bill Alsept via PM, and work something out together.
    As far as specifically LeSage PG is concerned, my list stands, and everyone of these points is a valid objection to LeSage. This is why his model was abandoned very quickly, because even in his own days the shortcomings were already obvious.

    There are no PG models, that I know of, that can do any better mathematically than the inverse square law of gravity.
    Correct. Bear in mind also that the inverse square law is only approximately correct for weak fields, and that the current standard against which any model of gravity is being compared will be GR, not Newton. There are a lot of subtle effects in GR which aren't compatible with Newton, and all of these need to be accounted for by whatever PG model you eventually propose.
    Reply With Quote  
     

  19. #18  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    Happy New Year Marcus

    For PG models to be generic I think only those most common characteristics would be considered. Such models must necessarily be modern to account for all known observations. As you stated, we cannot discuss particular models. We will generally be discussing unknown hypothetical, modern possible models, most not yet theorized.

    Such models must have pushing vectors from all sides according to what we observe concerning the effects of gravity. I believe such models must not have those characteristics that I named above. Possible characteristics of such models relate to variations of the field particulates, their forces, variations in physical characteristics and energies of motion, including uniform collective directional motions, and in my opinion probable field flows. The reason for these field and particle characteristics may be explained by some models but not by others. I think there are literally dozens of PG models that could not be disproved, that collectively could be called generic.

    Only basic details in-common can be given, otherwise we would not be describing a "generic model."

    For instance:

    1) As to number one above, I agree the particles cannot be conventional particles excepting for maybe slowed down conventional neutrinos that might interact much more readily and often than their nearly speed-of-light counterparts. Since these particles effects would be by direct contact, their mass could be anything like dark matter particulates or vastly smaller. I would expect that many of these PG models would also propose the same field and particles as being the source of particle mass. Such particles could be long lived, or conceivably short lived like the supposed Higgs. Also such models could be based upon hypothetical forces like dark energy, or based upon force-field theory like magnetism.

    2) The field could be isotropic in some models but not so in most other such conceivable models.

    3) see number one.

    4) matter of a certain size could be mostly transparent to such a field, but does not have to be transparent for larger masses, whereby upon impact particulates can transfer there downward vector forces upon, and within matter.

    5) Aether drag would be a consequence of most PG models, I would expect, but not necessarily all.

    6) Superluminal particles (SL) would not apply to most PG models, so I consider such PG SL models as not being generic.

    7) Aberration effect. Of course we know that stellar aberration exists, as well as gravity lensing -- so I don't know what the point of this criticism is. Any PG model involving field motions could seemingly predict the existence of stellar aberration and gravity lensing.

    8) For more accurate calculations, adjustments to mass outside a theory of gravity could be made based upon the energy of relative motion as well as kinetic energies of the various sorts included within GR.

    9) Time dilation is one of the simplest of calculations, being the redshift z plus 1, multiplied by the observed elapsed time of the event close by. t1 = (z + 1) t . Such a calculation could seemingly be justifiable by any generic PG model.

    10) Deflection of light would seemingly be a prediction of any PG model proposing field flow, and also might be justified by other hypothesis concerning other models.

    11) Thermodynamics: I think this is an easy one to justify for most PG models. For many particulate PG models, they could also be called aether models. Vortexes would surround matter so no direct contact would be needed with matter, only with the vortex that would contact the matter within it.

    For items 12) through 18) see my prior posting concerning how generic PG models would deal with these asserted criticisms, involving those characteristics that such models may or may not need to overcome your proposed criticisms.
    Last edited by forrest noble; January 2nd, 2013 at 05:14 PM.
    Reply With Quote  
     

  20. #19  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    bill alsept,

    Happy Holidays you guys
    You too Bill. Have a great 2013
    Reply With Quote  
     

  21. #20  
    Forum Senior bill alsept's Avatar
    Join Date
    Jul 2012
    Location
    Seattle, WA
    Posts
    386
    Quote Originally Posted by forrest noble View Post
    bill alsept,

    Happy Holidays you guys
    You too Bill. Have a great 2013
    Thanks Forest, and I agree with many of your points in post #18. Unfortunatly we now have two threads going on this subject because as you predicted in post#11 my post was highjacked and placed in the trash and is being continued from there.
    Reply With Quote  
     

  22. #21  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    bill alsept,

    .....Unfortunately we now have two threads going on this subject because .......................
    This may not necessarily be a bad thing if you receive the comments that might provide you with new insights

    The trash is not a common place to "play" for most members, but you have already had some good comments and commentators there. You can concentrate on your own model there, and maybe those aspects of it that might be generally generic if you wish. In this physics forum the thread must relate to the pros and cons of what might be wrong with PG models in general. No particular PG model should be advocated here since it is a mainstream site.
    Last edited by forrest noble; January 2nd, 2013 at 05:29 PM.
    Reply With Quote  
     

  23. #22  
    Moderator Moderator Markus Hanke's Avatar
    Join Date
    Nov 2011
    Location
    Ireland
    Posts
    7,172
    Quote Originally Posted by forrest noble View Post
    Happy New Year Marcus
    Same to you, thanks

    7) Aberration effect. Of course we know that stellar aberration exists, as well as gravity lensing -- so I don't know what the point of this criticism is. Any PG model involving field motions could seemingly predict the existence of stellar aberration and gravity lensing.
    What I actually meant is that we know by observation that static gravitational fields act instantaneously. In contrast, mechanical models like PG rely on pressure differentials, which can only propgate at finite speeds.

    9) Time dilation is one of the simplest of calculations, being the redshift z plus 1, multiplied by the observed elapsed time of the event close by. t1 = (z + 1) t . Such a calculation could seemingly be justifiable by any generic PG model.
    Ok, I don't get that - how do you get from pressure differentials in a particle field to gravitational time dilation ?

    11) Thermodynamics: I think this is an easy one to justify for most PG models. For many particulate PG models, they could also be called aether models. Vortexes would surround matter so no direct contact would be needed with matter, only with the vortex that would contact the matter within it.
    The end effect would be the same, because the energy needs to be transferred somewhere. I don't see how this results in no heating effects.
    Reply With Quote  
     

  24. #23  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    Markus Hanke,

    What I actually meant is that we know by observation that static gravitational fields act instantaneously. In contrast, mechanical models like PG rely on pressure differentials, which can only propagate at finite speeds.
    I think Einstein said gravity works at the speed of light. In the Newtonian model gravity acts instantaneously. Yes, in any mechanical PG model the actions or propagation of a gravitational field seemingly could not be instantaneous. But in PG models after a field has first developed/ propagated around a star, planet, etc., when something enters this field, it seemingly would almost immediately be acted upon by a pre-existing physical field condition. This would be more obvious for PG models that propose a different gravitational field surrounding matter than would exist in free space, proposing that matter by some method, accordingly would deform the characteristics of the field.

    Ok, I don't get that - how do you get from pressure differentials in a particle field to gravitational time dilation ?
    What I meant here is that the formulation is simple and could be justified by a different cosmological model, or by supplementary theory, rather than by the PG gravitational model itself.

    The end effect would be the same, because the energy needs to be transferred somewhere. I don't see how this results in no heating effects.
    I totally agree that additional heat cannot be avoided by such PG models. But not necessary by direct contact from pushing particulates, maybe just from molecular/ atomic vortexes being compressed and the resultant friction. The question would seem to be to what extent? In the case of the Earth, moon, and stars, for instance, such models might predict that most of the Earth, moon, and a planet's internal heat would be caused by gravity's inward vectors. As to stars the same prediction would probably be made: that a substantial portion of stellar heat and radiation would be related to heat produced by the compression of PG vectors, rather than nuclear fusion alone. Such PG models might predict, for instance, that stars could be older than present theory would assert since less "nuclear fuel" would accordingly be consumed per unit of time to produce the observed heat/ radiation, and therefore less neutrinos might be produced. Such a PG model might also predict that all matter including interstellar and intergalactic matter might be heated by inward pushing vectors supposedly accounting for the observed micro-wave background.
    Last edited by forrest noble; January 3rd, 2013 at 08:05 PM.
    Reply With Quote  
     

  25. #24  
    Quagma SpeedFreek's Avatar
    Join Date
    Jan 2011
    Location
    London, UK
    Posts
    2,786
    Quote Originally Posted by forrest noble View Post
    Markus Hanke,

    What I actually meant is that we know by observation that static gravitational fields act instantaneously. In contrast, mechanical models like PG rely on pressure differentials, which can only propagate at finite speeds.
    I think Einstein said gravity works at the speed of light. In the Newtonian model gravity acts instantaneously.
    This is what Markus was referring to:

    [gr-qc/9909087] Aberration and the Speed of Gravity

    The observed absence of gravitational aberration requires that “Newtonian” gravity propagate at a speed cg > 2 10^10 c. By evaluating the gravitational effect of an accelerating mass, I show that aberration in general relativity is almost exactly canceled by velocity-dependent interactions, permitting cg = c. This cancellation is dictated by conservation laws and the quadrupole nature of gravitational radiation.
    In the weak limit, gravity acts like an approximation of a static field, even if the gravitational source is uniformly accelerating. Only when a gravitational source changes its acceleration (known as "jerk"), does the extrapolation described in the above paper "miss", which is the source of gravitational radiation (gravitational waves).

    So, gravitational waves propagate at the speed of light, but the gravitational field, in of itself, does not act like it propagates at c. Hence, there is none of the aberration that led Newton to propose instantaneous gravity. This is why it is so hard to measure "the speed of gravity".

    Consequently, to all intents and purposes, the Earth is approximately falling around the extrapolated "instantaneous" position of the Sun, rather than where we see the Sun to be in the sky due to the propagation delay of light and gravity.
    Last edited by SpeedFreek; January 3rd, 2013 at 02:58 PM. Reason: clarification
    Reply With Quote  
     

  26. #25  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    double post
    Reply With Quote  
     

  27. #26  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    Quote Originally Posted by SpeedFreek View Post
    Quote Originally Posted by forrest noble View Post
    Markus Hanke,

    What I actually meant is that we know by observation that static gravitational fields act instantaneously. In contrast, mechanical models like PG rely on pressure differentials, which can only propagate at finite speeds.
    I think Einstein said gravity works at the speed of light. In the Newtonian model gravity acts instantaneously.
    This is what Markus was referring to:

    [gr-qc/9909087] Aberration and the Speed of Gravity

    The observed absence of gravitational aberration requires that “Newtonian” gravity propagate at a speed cg > 2 10^10 c. By evaluating the gravitational effect of an accelerating mass, I show that aberration in general relativity is almost exactly canceled by velocity-dependent interactions, permitting cg = c. This cancellation is dictated by conservation laws and the quadrupole nature of gravitational radiation.

    In the weak limit, gravity acts like an approximation of a static field, even if the gravitational source is uniformly accelerating. Only when a gravitational source changes its acceleration (known as "jerk"), does the extrapolation described in the above paper "miss", which is the source of gravitational radiation (gravitational waves).

    So, gravitational waves propagate at the speed of light, but the gravitational field, in of itself, does not act like it propagates at c. Hence, there is none of the aberration that led Newton to propose instantaneous gravity. This is why it is so hard to measure "the speed of gravity".
    OK. According to my understanding of what I read and what you wrote, I believe I answered this objection to PG

    Consequently, to all intents and purposes, the Earth is approximately falling around the extrapolated "instantaneous" position of the Sun, rather than where we see the Sun to be in the sky due to the propagation delay of light and gravity.
    Yes, I think some PG models would have the same conclusion for similar reasons. The mass would create/deform the gravity field as well as the direction of motion of the mass relative to the field. The field would propagate at the speed of light but gravitational actions would be almost instantaneous acting in the direction of propagation, where such relative motion or acceleration might exist. In GR you are talking about physical deformation of space surrounding matter, in PG you would be talking about the physical deformation of a particulate field, or maybe a deformation of a force field like dark energy, in other PG models.
    Last edited by forrest noble; January 3rd, 2013 at 08:07 PM.
    Reply With Quote  
     

  28. #27  
    Forum Senior bill alsept's Avatar
    Join Date
    Jul 2012
    Location
    Seattle, WA
    Posts
    386
    Quote Originally Posted by Markus Hanke View Post

    all of my points come from the literature available about LeSage's PG model.
    Yes I know but we are working on that.

    Quote Originally Posted by Markus Hanke View Post
    In general, a source of the gravitational field is anything which can be described by a stress-energy-momentum tensor :
    I agree, I think any PG especially my model fit that description even better than GR. PG Is 100% momentum or momentun tensor.



    Quote Originally Posted by Markus Hanke View Post
    As far as I can see it the PG model relies solely on the presence of mass to work.
    Yes, I don't see why anyone would consider a model of gravity that does not.

    Quote Originally Posted by Markus Hanke View Post
    If there is no mass, there is no "shadow" effect, and thus no net field.
    That is correct but I wouldn't say field, I would say gravity


    Quote Originally Posted by Markus Hanke View Post
    Any model of gravitation needs to explain how each of the energy forms mentioned in the link above leads to gravitational effects
    If it has enough kinetic energy to supply a push then it leads to a gravitational effect.
    Reply With Quote  
     

  29. #28  
    Forum Senior bill alsept's Avatar
    Join Date
    Jul 2012
    Location
    Seattle, WA
    Posts
    386
    Quote Originally Posted by forrest noble View Post



    Yes, I think some PG models would have the same conclusion for similar reasons. The mass would create/deform the gravity field as well as the direction of motion of the mass relative to the field. The field would propagate at the speed of light but gravitational actions would be almost instantaneous acting in the direction of propagation, where such relative motion or acceleration might exist. In GR you are talking about physical deformation of space surrounding matter, in PG you would be talking about the physical deformation of a particulate field, or maybe a deformation of a force field like dark energy, in other possible models.
    With a PG model every mass large, small or subatomic is being pushed and penetrated from all sides by what I call partrinos because I can never spell corpuscles correctly. Anyway depending on the density of the mass only a percentage of these partrinos completely penetrate the mass and continueon their way. The low percent of partrinos moving out and away from all sidesof the mass meet head on with a higher percent of partrinos coming toward the mass. The connection or effects between every mass has already happened and any two objects in the universe no matter how far apart are technically already shadowing each other by the inverse square law. They only come closer to each other because of the positive number of partrinos hitting each of their away sides. Just like in nature there is never a vacuum only an outside positive push.
    Take your hands and push them together. Consider your left arm a vector stream of partrinos impacting one side of a mass and your right arm a vector stream of partrinos impacting the opposite side. To represent a denser mass or stronger gravity you would press harder. Now lessen the push of your left arm only. this represent a reduced amount of partrinos coming from that side. Notice that the effect is instant or at least as fast as the chain reaction traveled up your arm. A mass in the middle where your hands meetwould have instantly moved. Notice the vectors were always connected. This isthe same for us standing here on Earth. The incoming partrinos outnumber the partrinos coming up through the Earth so we are pushed down. The vectors are pushing from the top and the bottom and the only reason we don’t move downward is because the imbalance of partrinos is offset by the Earth itself. Take the Earth away and we move. Instantly
    Last edited by bill alsept; January 3rd, 2013 at 09:26 PM.
    Reply With Quote  
     

  30. #29  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    Quote Originally Posted by bill alsept View Post
    Quote Originally Posted by forrest noble View Post

    Yes, I think some PG models would have the same conclusion for similar reasons. The mass would create/deform the gravity field as well as the direction of motion of the mass relative to the field. The field would propagate at the speed of light but gravitational actions would be almost instantaneous acting in the direction of propagation, where such relative motion or acceleration might exist. In GR you are talking about physical deformation of space surrounding matter, in PG you would be talking about the physical deformation of a particulate field, or maybe a deformation of a force field like dark energy, in other possible models.
    With PG every mass large, small or subatomic is being pushed and penetrated from all sides by what I call partrinos because I can never spell corpuscles correctly. Anyway depending on the density of the mass only a percentage of these partrinos completely penetrate the mass and continue on their way.
    ("partinos" coined to mean corpuscles)
    The low percent of partrinos moving out and away from all sides of the mass meet head on with a higher percent of partrinos coming toward the mass. Because no mass can just instantly appear or disappear there would never be a vacuum or wave etc to measure the speed of. The connection or effect between every mass has already happened and any two objects in the universe right now where ever they are technically are already shadowing each other by the inverse square law. They only come closer to each other because of the positive number of partrinos hitting each of their away sides. Just like in nature there is never a vacuum only an outside positive push.

    This could apply to some PG models but not others. I don't think your statement is generic enough.

    Take your hands and push them together. Consider your left arm a vector stream of partrinos impacting one side of a mass and your right arm a vector stream of partrinos impacting the opposite side. To represent a denser mass or stronger gravity you would press harder. Now lessen the push of your left arm only. this represent a reduced amount of partrinos coming from that side. Notice that the effect is instant or at least as fast as the chain reaction traveled up your arm. A mass in the middle where your hands meet would have instantly moved. Notice the vectors were always connected. This is the same for us standing here on Earth. The incoming partrinos outnumber the partrinos coming up through the Earth so we are pushed down. The vectors are pushing from the top and the bottom and the only reason we don’t move downward is because the imbalance of partrinos is offset by the Earth itself. Take the Earth away and we move. Instantly

    Again, your description applies to just some PG models. I understand that you are using the word patrinos as a synonym for corpuscles, but try your best to keep your postings here related to general PG models but advocating none in particular, either agreeing or disagreeing with the OP proposal, explaining why you may think that his proposal is valid or not concerning PG models in general. No model other than mainstream models can be advocated in a mainstream forum, only appropriate topic related general discussions are allowed.
    Last edited by forrest noble; January 3rd, 2013 at 09:43 PM.
    Reply With Quote  
     

  31. #30  
    Forum Senior bill alsept's Avatar
    Join Date
    Jul 2012
    Location
    Seattle, WA
    Posts
    386
    Quote Originally Posted by forrest noble View Post

    Again your description applies to just some PG models. I understand that you are using the word patrinos as a synonym for corpuscles, but try your best to keep your postings here related to generic/ general PG models but none in particular, either agreeing or disagreeing with the OP proposal, explaining why you may think that his proposal is valid or not concerning PG models in general.
    Your right, I get it. I keep trying to answer Marcus when he wants me to try and explain my PG. How else can I do that? I have to start some where.
    Reply With Quote  
     

  32. #31  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    You're right, I get it. I keep trying to answer Marcus when he wants me to try and explain my PG. How else can I do that? I have to start some where.
    I don't think he's asking about your particular model. I think he made a proposal of why pushing gravity does not work according to his OP proposal. If he or anyone refers to your own model based upon your comments, try not to make comments that might make them think that you are referring to your own model. Your job would be to explain why you think at least some of his/their points may not be valid in some conceivable PG models and why, without advocating your own or any other PG model in particular. You could refer to details within your own model that you think might contradict his point-for-point objections, but you should not mention of refer to your model in particular without being perceived as promoting it. You might say things like "a model that proposes .............. would not seem to have this same objection, or similar type wording, or question type wording such as: how about this or that to overcome this objection? where you might wish him to explain why he thinks a particular detail of a PG model (like yours) would not work.

    Also in a mainstream forum it's also best not to use non-mainstream words, or to use mainstream words in an unfamiliar or unknown way.

    The key is not to propose or promote anything non-mainstream in a mainstream forum since there are other forums that were created for such discussions. Generally you should not even discuss alternative non-mainstream models or possibilities in a mainstream forum unless they are the thread topic or directly related to the main topic, as in this thread.
    Last edited by forrest noble; January 4th, 2013 at 12:26 AM.
    Reply With Quote  
     

  33. #32  
    Moderator Moderator Markus Hanke's Avatar
    Join Date
    Nov 2011
    Location
    Ireland
    Posts
    7,172
    Quote Originally Posted by forrest noble View Post
    I think Einstein said gravity works at the speed of light.
    It is only changes in the gravitational field which propagate at the speed of light, but static fields act instantaneously ( obviously, since they are just geometry of space-time ).

    rather than by the PG gravitational model itself.
    I still don't understand - gravitational time dilation is a direct result of gravity, nothing else. They aren't distinguishable. Therefore, any model of gravity, be it mechanical or not, needs to be able to explain gravitational time dilation.

    The question would seem to be to what extent?
    Yes, that's the big question, and that is why I keep asking for specifics.
    Reply With Quote  
     

  34. #33  
    Moderator Moderator Markus Hanke's Avatar
    Join Date
    Nov 2011
    Location
    Ireland
    Posts
    7,172
    Quote Originally Posted by bill alsept View Post
    I agree, I think any PG especially my model fit that description even better than GR. PG Is 100% momentum or momentun tensor.
    I am starting to get the distinct feeling that you are confusing sources of the gravitational field with properties of the gravitational field. The stress-energy-momentum tensor acts as the source of the field, and contains terms for the following :

    1. Energy density
    2. Momentum density
    3. Energy flux
    4. Momentum flux
    5. Shear stress
    6. Pressure

    The total energy-momentum tensor will be the sum of the individual tensors for mass, EM fields etc etc. These are all sources of the field, not the field itself.

    Yes, I don't see why anyone would consider a model of gravity that does not.
    Because mass is not the only source of gravity, see above. For example, a electromagnetic field would be a source of gravity. So would a single photon, even though it doesn't have mass.

    That is correct but I wouldn't say field, I would say gravity
    Again, see above. If what you are saying is "no mass = no gravity", then this is clearly wrong. Mass is only one specific form of a gravitational source, but not the only one.

    If it has enough kinetic energy to supply a push then it leads to a gravitational effect.
    Refer to the abovel. You seem to be confusing sources of gravity with properties of the gravitational field.
    Reply With Quote  
     

  35. #34  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    I still don't understand - gravitational time dilation is a direct result of gravity, nothing else. They aren't distinguishable. Therefore, any model of gravity, be it mechanical or not, needs to be able to explain gravitational time dilation.
    Gravitational time dilation such as the slowing of time within a gravitation well or its speeding up in free space, is gravity related but separate equations could be used rather than those needed for gravitational influences on matter. The dilation of time due to relative motion, for instance, falls within the domain of SR. Time dilation of supernovas is something else again. How these formulations are derived, justified, and organized, I think is just a matter of the particular gravity theory or cosmological model as to how these equation fit in the whole scheme of the theory.
    Last edited by forrest noble; January 7th, 2013 at 03:16 PM.
    Reply With Quote  
     

  36. #35  
    Quagma SpeedFreek's Avatar
    Join Date
    Jan 2011
    Location
    London, UK
    Posts
    2,786
    That's not very convincing.
    Reply With Quote  
     

  37. #36  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    Quote Originally Posted by SpeedFreek View Post
    That's not very convincing.
    In PG a gravitational field involves vectors that change the course of relative motion of matter including its linear path, velocity, orbital motion, spin motion, etc. This is a mainstream site so to explain how this all relates to time dilation would be dependent on the particular PG model. Changing a fermion's spin rate, for instance, might be related to its longevity. Slow its spin rate down (angular momentum) by intense gravity you might increase its lifespan according to such models. This might be the principle of gravitational time dilation according to some PG models. No PG models can be promoted here, only discussions concerning the perceived problems, or not, with PG models.

    Details of theory and questions are being asked and "answered" in the Trash Can for those that might wish to get down and dirty.
    Last edited by forrest noble; January 7th, 2013 at 03:20 PM.
    Reply With Quote  
     

  38. #37  
    pmb
    pmb is offline
    Suspended
    Join Date
    Dec 2006
    Posts
    482
    Quote Originally Posted by Markus Hanke View Post
    Motivation

    Too many people seem to think that Push Gravity, or indeed any mechanical explanation, is a valid model for gravitation. This is erroneous, as these models are either not internally consistent, or require physically impossible assumptions.


    Basic premise of Push Gravity

    The model assumes that gravity is caused by particles impacting massive bodies from all directions, thereby providing a push force wish causes a tendency for massive bodies to move towards each other, also because the bodies themselves cause a shielding effect, leading to pressure differentials due to the collisions not being fully elastic. This is also posited as the reason for the inverse square law – the incoming momentum flux is greater than the outgoing one. Further assumptions must be made to account for the fact that the gravitational force is primarily caused by total mass rather then surface area, namely that only a small number of particles actually interact with a massive body.
    s
    Where on Earth did this idea come from? Who came up with it?

    The most obvious reason why this theory fails is that it implies that the force between two bodies is a function of the shape and/or orientations of the bodies relative to each other. Also it implies that two spheres while accelerating towards each other will not accelerate at the same rate but will be a factor of the radius size of the other sphere. Also push gravity predicts that the force on each sphere will be independant of the mass of the spheres, contrary to observation.
    Last edited by pmb; January 4th, 2013 at 03:59 PM.
    Reply With Quote  
     

  39. #38  
    pmb
    pmb is offline
    Suspended
    Join Date
    Dec 2006
    Posts
    482
    Quote Originally Posted by Markus Hanke
    I am starting to get the distinct feeling that you are confusing sources of the gravitational field with properties of the gravitational field. The stress-energy-momentum tensor acts as the source of the field, and contains terms for the following :

    1. Energy density
    2. Momentum density
    3. Energy flux
    4. Momentum flux
    5. Shear stress
    6. Pressure
    Quote Originally Posted by Markus Hanke


    Note: Momentum density = energy flux, sheer stress and pressure are both described in terms of the stress tensor. I.e. pressure is a particular kind of stress. That’s why this tensor is called the stress-energy-momentum tensor.
    Last edited by pmb; January 4th, 2013 at 03:53 PM.
    Reply With Quote  
     

  40. #39  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    Quote Originally Posted by pmb View Post
    Quote Originally Posted by Markus Hanke View Post
    Motivation

    Too many people seem to think that Push Gravity, or indeed any mechanical explanation, is a valid model for gravitation. This is erroneous, as these models are either not internally consistent, or require physically impossible assumptions.


    Basic premise of Push Gravity

    The model assumes that gravity is caused by particles impacting massive bodies from all directions, thereby providing a push force wish causes a tendency for massive bodies to move towards each other, also because the bodies themselves cause a shielding effect, leading to pressure differentials due to the collisions not being fully elastic. This is also posited as the reason for the inverse square law – the incoming momentum flux is greater than the outgoing one. Further assumptions must be made to account for the fact that the gravitational force is primarily caused by total mass rather then surface area, namely that only a small number of particles actually interact with a massive body.
    s
    Where on Earth did this idea come from? Who came up with it?

    The most obvious reason why this theory fails is that it implies that the force between two bodies is a function of the shape and/or orientations of the bodies relative to each other.
    PG models would use different wording. These models would not say the "force between two bodies." They would use the wording "the lack of pushing vectors between two bodies because of the shadow effect, will cause two bodies in proximity to each other, to be pushed together by surrounding pushing vectors." Although it seems possible that the shape or orientation of various shapes of two bodies of the same mass conceivably might be influenced differently by pushing vectors in a PG model, I am unaware of any such PG models that make such proposals or predictions.

    Also it implies that two spheres while accelerating towards each other will not accelerate at the same rate but will be a factor of the radius size of the other sphere.
    Formulation-wise generic PG models follow the inverse square law of gravity which formula and function-wise, purport to give the same results as Newtonian gravity. The smaller body will accelerated faster toward the larger body.

    Also push gravity predicts that the force on each sphere will be independent of the mass of the spheres, contrary to observation.


    Not for any PG models that I know of.
    Reply With Quote  
     

  41. #40  
    Moderator Moderator Markus Hanke's Avatar
    Join Date
    Nov 2011
    Location
    Ireland
    Posts
    7,172
    Quote Originally Posted by forrest noble View Post
    Changing a fermion's spin rate, for instance, is related to its longevity.
    Huh ? Since when ? A particle's life span is not a function of spin.

    In PG a gravitational field involves vectors
    That's exactly one of the problems. Using vector fields you can at best recover the inverse square law ( which we know to be an incomplete description ), and even that only if and when the field is a conservative one.

    This is the principle of gravitational time dilation.
    Errr...no.
    Reply With Quote  
     

  42. #41  
    Moderator Moderator Markus Hanke's Avatar
    Join Date
    Nov 2011
    Location
    Ireland
    Posts
    7,172
    Quote Originally Posted by pmb View Post
    Where on Earth did this idea come from? Who came up with it?
    This was courtesy of two gentlemen by the names of Nicolas Fatio de Duillier ( 1690 ) and Georges Louis Le Sage ( 1748 ). It was an attempt to develop a purely mechanical model of gravitation, but even in their own lifetimes it was never really accepted by the mainstream, since the problems with these models are rarther obvious.

    The most obvious reason why this theory fails is that it implies that the force between two bodies is a function of the shape and/or orientations of the bodies relative to each other.
    Very good point. This is so obvious that I didn't really think of it myself.

    Formulation-wise generic PG models follow the inverse square law of gravity
    Again, that would only be the case of the resulting vector field is conservative. Can you guys show that that is actually the case ? Because if it isn't, you won't get an inverse square law.
    Reply With Quote  
     

  43. #42  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    Quote Originally Posted by Markus Hanke View Post
    Quote Originally Posted by forrest noble View Post
    Changing a fermion's spin rate, for instance, is related to its longevity.
    Huh ? Since when ? A particle's life span is not a function of spin.
    Short-lived particles with spin live longer at higher speeds, according to some PG models. Time dilation, as to their longevity, occurs for these particles at high speeds. Their longevity can be equated to the amount of spins per lifetime (angular momentum muons), according to some models. When they have a longer lifetime due to their relative motion their amount of total spins will remain about the same per lifetime but their rate of spin will be less.

    Vacuum has friction after all - space - 11 February 2011 - New Scientist

    Time dilation occurs in the presence of a gravitational field, because of relative motion, and some extra-galactic phenomena such as type 1a supernova events.
    Last edited by forrest noble; January 7th, 2013 at 03:23 PM.
    Reply With Quote  
     

  44. #43  
    Quagma SpeedFreek's Avatar
    Join Date
    Jan 2011
    Location
    London, UK
    Posts
    2,786
    Quote Originally Posted by forrest noble View Post
    Time dilation occurs in the presence of a gravitational field, because of relative motion, and some extra-galactic phenomena.
    What?!?

    Please explain the relative motion or extra-galactic phenomena involved in the Pound-Rebka Experiment.

    ETA: Ahh, I see I misunderstood you.
    Last edited by SpeedFreek; January 5th, 2013 at 01:26 PM. Reason: Edited to add...
    Reply With Quote  
     

  45. #44  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    SpeedFreek,

    (my statement)
    Time dilation occurs in the presence of a gravitational field, because of relative motion, and some extra-galactic phenomena such as type 1a supernova events
    Please explain the relative motion or extra-galactic phenomena involved in the Pound-Rebka Experiment.
    I think you are misunderstanding my statement. "In the presence of a gravitational field" means that a gravitational field effects time dilation. Closer to the field one observes more time dilation, and farther away from the field's center one would observe less time dilation.

    In the other case time dilation based upon relative motion is one of the principles of Special Relativity.

    added: probably my fault in that my related statement could convey possible ambiguity.

    The Pound-Rebka Experiment seems to be totally unrelated to the meanings of my statement, but still very interesting to me. but I can't comment on it concerning pushing gravity models because I can not envision how a generic PG model might explain it, only speculation, but at least some PG model(s) might predict the results of the Pound-Rebka experiment before hand.
    Last edited by forrest noble; January 5th, 2013 at 03:20 PM.
    Reply With Quote  
     

  46. #45  
    pmb
    pmb is offline
    Suspended
    Join Date
    Dec 2006
    Posts
    482
    Quote Originally Posted by forrest noble
    Not for any PG models that I know of.
    Perhaps, but that's why I asked where it came from. I'd like to see where it originated. Was it from a legitimate physics journal or from crackpot?

    And you're stating that there are different models? What's the different between these models? Please explain how the shadowing is determined by the mass of the body.
    Reply With Quote  
     

  47. #46  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    Quote Originally Posted by pmb View Post
    Quote Originally Posted by forrest noble
    Not for any PG models that I know of.
    Perhaps, but that's why I asked where it came from. I'd like to see where it originated. Was it from a legitimate physics journal or from crackpot?

    And you're stating that there are different models? What's the different between these models? Please explain how the shadowing is determined by the mass of the body.
    All PG models that I have ever read were created during the time or after Newton. All were aware of the successes of the inverse square law of Newton before they proposed PG models. All of the generally known PG models formulate gravity via Newton's formula. A modern PG model may try to account for stellar rotation rates of spiral galaxies, maybe proposing a PG vortex formation for these galaxies.

    Shawdowing of PG models is based upon some PG particulate vectors passing through matter while some would interact with matter and their vectors absorbed. The more mass involved the more vectors would be absorbed and a lesser precentage would pass through the matter generally without effect.
    Last edited by forrest noble; January 6th, 2013 at 01:45 AM.
    Reply With Quote  
     

  48. #47  
    pmb
    pmb is offline
    Suspended
    Join Date
    Dec 2006
    Posts
    482
    Quote Originally Posted by forrest noble View Post
    All PG models that I have ever read were created during the time or after Newton.
    Instead of me asking you a million questions in order to try to understand these s-called "models" can't you simply point me to a place where I can find them for myself and read them? Otherwise this will take forever.

    Also, I asked you a question which you didn't answer - Where did these models originate from? From physics journals? From crackpots? When was the first one forwarded and byt whom? How many different ones are their? How do they differ? How are they the same?

    What is the nature of the scattering processes? What particle is scattering off what particle?
    Reply With Quote  
     

  49. #48  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    double post
    Last edited by forrest noble; January 5th, 2013 at 07:07 PM.
    Reply With Quote  
     

  50. #49  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    Quote Originally Posted by pmb View Post
    Quote Originally Posted by forrest noble View Post
    All PG models that I have ever read were created during the time or after Newton.
    Instead of me asking you a million questions in order to try to understand these s-called "models" can't you simply point me to a place where I can find them for myself and read them? Otherwise this will take forever.

    Also, I asked you a question which you didn't answer - Where did these models originate from? From physics journals? From crackpots? When was the first one forwarded and byt whom? How many different ones are their? How do they differ? How are they the same?

    What is the nature of the scattering processes? What particle is scattering off what particle?
    This is a mainstream forum. The OP relates to the problems PG models are accordingly asserted to have. My responses relate the generic PG models. For the purpose of this conversation I defined my meaning for the meaning of a generic Pushing Gravity model:

    Such possible explanations would be a matter of opinion since obviously the answer is speculative. I envision generic PG models to mean those PG tenets that can overcome any obvious method of dis-proving based upon known evidence to the contrary. I would expect generic models would not require faster-than-light particulates, for instance. Background fields of PG particulates would not necessarily have to be uniform in density or motion, as in the Le Sage model. Such fields might be deformed by matter causing high and low pressure background field volumes and field flow related to gravitational influences, and other non-uniform field characteristics.
    The history of PG models and general ideas of such models can be seen here: Le Sage's theory of gravitation - Wikipedia, the free encyclopedia

    There have been many pushing gravity models since that time, most generally unknown today by most in the mainstream. Such respected scientists had numerous published works in mainstream journals concerning PG, amongst which we have those of Lorentz, H. Poincare, F. Brush, Secchi, Leray, V. Thomson, Schramm, Tait, Isenkrahe, Preston, Jarolimek, Waachy, Rynsanek, S. Darwin, Majorana...within the last 150 years, and some after GR was proposed.

    A layman's explanation of a present day PG model can be seen here: http://www.keelynet.com/gravity/wright1.htm

    And this model (page 57A, pg. 119) : http://pantheory.com/PDFs/PanTheory.pdf#page=119

    In this thread we are talking about a "generic PG model" only without specific details which might apply to just one model, trying to present a summary of PG tenets, discussing those PG common traits which may or may not be readily disprovable.
    Last edited by forrest noble; January 6th, 2013 at 01:48 AM.
    Reply With Quote  
     

  51. #50  
    pmb
    pmb is offline
    Suspended
    Join Date
    Dec 2006
    Posts
    482
    Never mind. I think I'll be safe if I believe that the OP ws right. i.e. it's complete nonsense.
    Strange and Markus Hanke like this.
    Reply With Quote  
     

  52. #51  
    Moderator Moderator Markus Hanke's Avatar
    Join Date
    Nov 2011
    Location
    Ireland
    Posts
    7,172
    Quote Originally Posted by forrest noble View Post
    Short-lived particles with spin live longer at higher speeds. Time dilation, as to their longevity, occurs for these particles at high speeds. Their longevity can be equated to the amount of spins per lifetime (angular momentum muons). When they have a longer lifetime due to their relative motion their amount of total spins will remain about the same per lifetime but their rate of spin will be less.
    It seems you are mixing things up a little - the lifetime is a function of speed, not of spin. Also, quantum mechanical spin isn't the same as classical angular momentum, so measuring a particle's lifetime in "spin cycles" is rather meaningless, as it implies thinking of a particle as a rotating body, which isn't correct.
    Reply With Quote  
     

  53. #52  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    Markus Hanke,

    It seems you are mixing things up a little - the lifetime is a function of speed, not of spin.
    Yes, a short-lived particle's life is a function of its velocity, but its spin rate is also a function of its velocity.

    Also, quantum mechanical spin isn't the same as classical angular momentum, so measuring a particle's lifetime in "spin cycles" is rather meaningless, as it implies thinking of a particle as a rotating body, which isn't correct.
    (underline added)

    Yes, that particle spin is not real spin is the present belief/assertion of the standard model and quantum mechanics.


    edited; ammendment added: ...but its spin rate is also a function of its velocity, "in my opinion"
    Last edited by forrest noble; January 7th, 2013 at 02:14 PM.
    Reply With Quote  
     

  54. #53  
    Moderator Moderator Markus Hanke's Avatar
    Join Date
    Nov 2011
    Location
    Ireland
    Posts
    7,172
    Quote Originally Posted by forrest noble View Post
    Yes, a particle's life is a function of its velocity, but its spin rate is also a function of its velocity.
    I don't know what you mean by this. Quantum mechanical spin has nothing to do with classical rotational motion of a body; and even if it did, it still would not be a function of the particle's velocity.
    Reply With Quote  
     

  55. #54  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    Quote Originally Posted by Markus Hanke View Post
    Quote Originally Posted by forrest noble View Post
    Yes, a particle's life is a function of its velocity, but its spin rate is also a function of its velocity.
    I don't know what you mean by this. Quantum mechanical spin has nothing to do with classical rotational motion of a body; and even if it did, it still would not be a function of the particle's velocity
    I agree that this is the present belief of the standard model, and of quantum mechanics.

    .....and even if it did, it still would not be a function of the particle's velocity. .
    There is no way that I know of to determine the rate of a particle's spin/ angular momentum in transit. If particle spin were real then a particle's velocity would effect its spin rate since at certain velocities and directions, the spin rate would acceed the speed of light if it were real and not reduced by the particle's velocity at high speeds.

    (my quote)
    but its spin rate is also a function of its velocity.
    This quote is only theory, and not the consensus view. I added an ammendment to the above quote to reflect that this is my opinion based upon alternative theory.
    Last edited by forrest noble; January 7th, 2013 at 02:15 PM.
    Reply With Quote  
     

  56. #55  
    Quagma SpeedFreek's Avatar
    Join Date
    Jan 2011
    Location
    London, UK
    Posts
    2,786
    Quote Originally Posted by forrest noble View Post
    Yes, a particle's life is a function of its velocity, but its spin rate is also a function of its velocity.
    Can we please keep statements like this out of the hard science forums? You admit this view is neither part of the standard model or quantum mechanics, and that it is presently believed that a particles spin is invariant, regardless of velocity, so why did you say it?

    We shouldn't keep having to correct you like this.
    Reply With Quote  
     

  57. #56  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    Quote Originally Posted by SpeedFreek View Post
    Quote Originally Posted by forrest noble View Post
    Yes, a particle's life is a function of its velocity, but its spin rate is also a function of its velocity.
    Can we please keep statements like this out of the hard science forums? You admit this view is neither part of the standard model or quantum mechanics, and that it is presently believed that a particles spin is invariant, regardless of velocity, so why did you say it?

    We shouldn't keep having to correct you like this.
    The standard model used to believe spin was real. Theory has changed within the last maybe 30 years or so. Since this cannot be verified by experiment it is still alternative theory. Alternative theory can be discussed when subject related; in this case the whole thread relates to alternative theory. It was an oversight not to identify my statement as opinion or alternative theory which I usually always do. I made the ammendment to posting #52 as soon as I became aware of the omission.
    Reply With Quote  
     

  58. #57  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    double post
    Reply With Quote  
     

  59. #58  
    Suspended
    Join Date
    Apr 2007
    Location
    Pennsylvania
    Posts
    8,822
    Quote Originally Posted by forrest noble View Post
    Alternative theory can be discussed when subject related; in this case the whole thread relates to alternative theory. It was an oversight not to identify my statement as opinion or alternative theory which I usually always do. I made the ammendment to posting #52 as soon as I became aware of the omission.
    Forrest, this thread is not an excuse to post any nonsense you want. If you cannot post scientifically valid information, keep away.
    Reply With Quote  
     

  60. #59  
    Brassica oleracea Strange's Avatar
    Join Date
    Oct 2011
    Location
    喫茶店
    Posts
    16,540
    Quote Originally Posted by forrest noble View Post
    There is no way that I know of to determine the rate of a particle's spin/ angular momentum in transit.
    Well, apart from the fact that angular momentum is conserved so it can't change randomly as you would like, I guess you could measure the deflection of an electron by a magnetic field as one way of measuring the angular momentum at different velocities. I'm quite sure this has been done (I can't be bothered to try and find any results right now).

    If particle spin were real then a particle's velocity would effect its spin rate since at certain velocities and directions, the spin rate would acceed the speed of light if it were real and not reduced by the particle's velocity at high speeds.
    That makes no sense to me. Why would the spin rate of a particle depend on velocity? Why would it exceed the speed of light? The classic example of conservation of angular momentum is a spinning ice skater pulling her arms in and going faster. Do you think she would spin at a different speed if she were moving? But as velocity is relative, that would mean her rate of spin would depend on the speed of the people watching... which makes zero sense.
    Without wishing to overstate my case, everything in the observable universe definitely has its origins in Northamptonshire -- Alan Moore
    Reply With Quote  
     

  61. #60  
    Moderator Moderator Markus Hanke's Avatar
    Join Date
    Nov 2011
    Location
    Ireland
    Posts
    7,172
    Quote Originally Posted by Strange View Post
    I guess you could measure the deflection of an electron by a magnetic field as one way of measuring the angular momentum at different velocities. I'm quite sure this has been done (I can't be bothered to try and find any results right now).
    I don't disagree with you often Strange, but in this case I need to. The deflection of an electron in a magnetic field depends only on its charge and velocity, not on angular momentum, at least in the classical domain. On the other hand a magnetic field may have an effect on spin, but this would not affect the deflection of a moving electron.
    Reply With Quote  
     

  62. #61  
    Brassica oleracea Strange's Avatar
    Join Date
    Oct 2011
    Location
    喫茶店
    Posts
    16,540
    Quote Originally Posted by Markus Hanke View Post
    Quote Originally Posted by Strange View Post
    I guess you could measure the deflection of an electron by a magnetic field as one way of measuring the angular momentum at different velocities. I'm quite sure this has been done (I can't be bothered to try and find any results right now).
    I don't disagree with you often Strange, but in this case I need to. The deflection of an electron in a magnetic field depends only on its charge and velocity, not on angular momentum, at least in the classical domain. On the other hand a magnetic field may have an effect on spin, but this would not affect the deflection of a moving electron.
    Hmmm... Maybe you are right. I will have to think of a better (er, correct) example.
    Without wishing to overstate my case, everything in the observable universe definitely has its origins in Northamptonshire -- Alan Moore
    Reply With Quote  
     

  63. #62 Newtonian Gravity : docity.com 
    Forum Freshman
    Join Date
    Jan 2013
    Posts
    5
    Newton was the first one to study the applications and limitations of gravity, some of his findings are given in the following document, it might help you in your research

    EDIT: non-functioning link deleted
    adelady
    Last edited by adelady; January 9th, 2013 at 04:53 AM.
    Reply With Quote  
     

  64. #63  
    Forum Junior
    Join Date
    Sep 2011
    Location
    Manchester, UK
    Posts
    236
    There is a comment made on these explanations of gravity in Richard Feynman's book: "The Character of Physical Law". Feynman's objection seems very simple - quote from book: "If the earth is moving, more particles will hit it from the front than from behind. (If you are running in the rain, more rain hits you in the front of the face than in the back of the head, because you are running in the rain.)"

    Feynman points out that this would mean that any moving body would be subject to a retarding force. However, although he rejects the notion that gravity arises because of interactions with particles streaming through space in all directions, he does note that such an explanation would give rise to an inverse square law.
    Last edited by JonG; January 9th, 2013 at 05:58 AM. Reason: typographical error
    Reply With Quote  
     

  65. #64  
    Forum Senior bill alsept's Avatar
    Join Date
    Jul 2012
    Location
    Seattle, WA
    Posts
    386
    Quote Originally Posted by JonG View Post
    There is a comment made on these explanations of gravity in Richard Feynman's book: "The Character of Physical Law". Feynman's objection seems very simple - quote from book: "If the earth is moving, more particles will hit it from the front than from behind. (If you are running in the rain, more rain hits you in the front of the face than in the back of the head, because you are running in the rain.)"

    Feynman points out that this would mean that any moving body would be subject to a retarding force. However, although he rejects the notion that gravity arises because of interactions with particles streaming through space in all directions, he does note that such an explanation would give rise to an inverse square law.
    Considering the Earth is spinning and orbiting a solar system which is also orbiting a galaxy what is the front side? Add to that the clustering of galaxies and who knows what else. I'm not sure but has light been shown to hit the Earth faster on this so called front side?
    Reply With Quote  
     

  66. #65  
    Moderator Moderator Markus Hanke's Avatar
    Join Date
    Nov 2011
    Location
    Ireland
    Posts
    7,172
    Quote Originally Posted by bill alsept View Post
    Considering the Earth is spinning and orbiting a solar system which is also orbiting a galaxy what is the front side? Add to that the clustering of galaxies and who knows what else. I'm not sure but has light been shown to hit the Earth faster on this so called front side?
    No, the speed of light is always constant, independently of the emitter and receiver.
    Reply With Quote  
     

  67. #66  
    Brassica oleracea Strange's Avatar
    Join Date
    Oct 2011
    Location
    喫茶店
    Posts
    16,540
    Quote Originally Posted by bill alsept View Post
    Considering the Earth is spinning and orbiting a solar system which is also orbiting a galaxy what is the front side?
    Given that complex motion, how would a push gravity theory account for the fact that the "push" is the same in all directions?
    Without wishing to overstate my case, everything in the observable universe definitely has its origins in Northamptonshire -- Alan Moore
    Reply With Quote  
     

  68. #67  
    Forum Senior bill alsept's Avatar
    Join Date
    Jul 2012
    Location
    Seattle, WA
    Posts
    386
    Quote Originally Posted by Markus Hanke View Post
    Quote Originally Posted by bill alsept View Post
    Considering the Earth is spinning and orbiting a solar system which is also orbiting a galaxy what is the front side? Add to that the clustering of galaxies and who knows what else. I'm not sure but has light been shown to hit the Earth faster on this so called front side?
    No, the speed of light is always constant, independently of the emitter and receiver.
    Light is used to measure the expansion of the universe, why not the motion of the earth? You didn't answer the first part of my question what did Feynman consider the front? How would he test his idea?
    Reply With Quote  
     

  69. #68  
    Brassica oleracea Strange's Avatar
    Join Date
    Oct 2011
    Location
    喫茶店
    Posts
    16,540
    Quote Originally Posted by bill alsept View Post
    Light is used to measure the expansion of the universe, why not the motion of the earth?
    Expansion is isotropic and causes red-shift. The motion of the Earth can only be defined relative to something else.

    You didn't answer the first part of my question what did Feynman consider the front? How would he test his idea?
    I assume the "front" would be the side where gravity was greater because it is pushing against your "gravity particles". You could test this by looking for changing gravity throughout the day or year.
    Without wishing to overstate my case, everything in the observable universe definitely has its origins in Northamptonshire -- Alan Moore
    Reply With Quote  
     

  70. #69  
    Forum Junior
    Join Date
    Sep 2011
    Location
    Manchester, UK
    Posts
    236
    Quote Originally Posted by bill alsept View Post
    Considering the Earth is spinning and orbiting a solar system which is also orbiting a galaxy what is the front side? Add to that the clustering of galaxies and who knows what else. I'm not sure but has light been shown to hit the Earth faster on this so called front side?

    I don't know how Feynman would have answered the question "what is the front side?" I presume that this question refers to the absence of an absolute state of rest which would enable the direction of motion, and therefore the "front side", to be specified. However, it could be that he had in mind a state of rotational or orbiting motion such as was originally mentioned by Isaac Newton in his famous "rotating bucket" dilemma. A bucket which is half full of water and rotating about its vertical axis will differ from a non-rotating bucket in that the water in it will have a concave surface (due to rotation). This was originally put forward as evidence that there was such a thing as a state of absolute rotational rest. That matter was argued about for centuries, however it does show that all rotational states are not equivalent.

    Please note that I was quoting what Feynman wrote.
    Reply With Quote  
     

  71. #70  
    Forum Senior bill alsept's Avatar
    Join Date
    Jul 2012
    Location
    Seattle, WA
    Posts
    386
    Quote Originally Posted by Strange View Post
    Quote Originally Posted by bill alsept View Post
    Considering the Earth is spinning and orbiting a solar system which is also orbiting a galaxy what is the front side?
    Given that complex motion, how would a push gravity theory account for the fact that the "push" is the same in all directions?
    As with light the complex motion doesn't seem to effect it. I believe most PG models describe the particles coming from every direction in the same way we see light coming from every direction.
    Reply With Quote  
     

  72. #71  
    Brassica oleracea Strange's Avatar
    Join Date
    Oct 2011
    Location
    喫茶店
    Posts
    16,540
    Quote Originally Posted by bill alsept View Post
    I believe most PG models describe the particles coming from every direction in the same way we see light coming from every direction.
    There is a difference: these "gravity particles" are supposed to push against things - this, after all, is what you say causes gravity. How can they always come equally from all directions as the direction and speed of motion of the Earth changes?

    And, if they are coming from every direction, how come gravity always and only acts towards the center of mass? And why isn't it dependent on the shape, size or chemical composition of an object. It just depends on mass. Why is that?
    Without wishing to overstate my case, everything in the observable universe definitely has its origins in Northamptonshire -- Alan Moore
    Reply With Quote  
     

  73. #72  
    Forum Senior bill alsept's Avatar
    Join Date
    Jul 2012
    Location
    Seattle, WA
    Posts
    386
    Quote Originally Posted by JonG View Post
    Quote Originally Posted by bill alsept View Post
    Considering the Earth is spinning and orbiting a solar system which is also orbiting a galaxy what is the front side? Add to that the clustering of galaxies and who knows what else. I'm not sure but has light been shown to hit the Earth faster on this so called front side?

    I don't know how Feynman would have answered the question "what is the front side?" I presume that this question refers to the absence of an absolute state of rest which would enable the direction of motion, and therefore the "front side", to be specified. However, it could be that he had in mind a state of rotational or orbiting motion such as was originally mentioned by Isaac Newton in his famous "rotating bucket" dilemma. A bucket which is half full of water and rotating about its vertical axis will differ from a non-rotating bucket in that the water in it will have a concave surface (due to rotation). This was originally put forward as evidence that there was such a thing as a state of absolute rotational rest. That matter was argued about for centuries, however it does show that all rotational states are not equivalent.

    Please note that I was quoting what Feynman wrote.
    I'm not saying we could never figure out the Earths motion relative to the rest of universe but even if we did how would you use PG particles any different than photons to determine motion?
    Reply With Quote  
     

  74. #73  
    Forum Senior bill alsept's Avatar
    Join Date
    Jul 2012
    Location
    Seattle, WA
    Posts
    386
    Quote Originally Posted by Strange View Post

    There is a difference: these "gravity particles" are supposed to push against things - this, after all, is what you say causes gravity. How can they always come equally from all directions as the direction and speed of motion of the Earth changes?
    If you are really asking these questions then you do not understand the basic premise of PG or you are being intelletually dishonest. Maybe its because the descriptions that Forest and I have given are not clear enough. If that's the case then please excuse my inability to articulate but my hands are also tied. If I get to detailed I get banned from the forum.

    To directly answer your question and conform with the rules of the forum I would say the motion of the Earth is very very small compared to the speed of PG particles. Just like the speed of photons are. Also detecting these particles would be much harder than even detecting dark matter. Dark matter is just sitting there but PG particles are smaller and moving at an extreme speed. We see the effect of dark matter just as we see the effects of PG particles but so far neither have been physically detected. Also to correct your question, PG doesn't claim they always come equally from all directions. PG models involve shielding and in so doing reduce the number of these particles creating an imbalance on one side.

    Quote Originally Posted by Strange View Post
    And, if they are coming from every direction, how come gravity always and only acts towards the center of mass?
    Again if your asking questions like this you have not been keeping up.


    Quote Originally Posted by Strange View Post
    And why isn't it dependent on the shape, size or chemical composition of an object. It just depends on mass. Why is that?
    I believe it has a lot to do with levels of density and not just mass but I'm not sure of other models of PG. Again I could be more specific if I wanted to be banned. Are you baiting me?
    Last edited by bill alsept; January 10th, 2013 at 12:35 AM.
    Reply With Quote  
     

  75. #74  
    Universal Mind John Galt's Avatar
    Join Date
    Jul 2005
    Posts
    14,169
    Quote Originally Posted by bill alsept View Post
    . Maybe its because the descriptions that Forest and I have given are not clear enough. If that's the case then please excuse my inability to articulate but my hands are also tied. If I get to detailed I get banned from the forum.
    Who told you that and when? I'm probably prepared to untie your hands.
    Reply With Quote  
     

  76. #75  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    Quote Originally Posted by John Galt View Post
    Quote Originally Posted by bill alsept View Post
    . Maybe its because the descriptions that Forest and I have given are not clear enough. If that's the case then please excuse my inability to articulate but my hands are also tied. If I get to detailed I get banned from the forum.
    Who told you that and when? I'm probably prepared to untie your hands.
    The problem in a thread like this one, John, is that the subject, which in this case is the "perceived problems with Pushing Gravity," sometimes involves discussing alternative theory in a mainstream thread. To discuss this particular topic, alternative theory must sometimes be discussed in detail. If too much detail or defense concerning alternative theory is presented, then it might appear to be a promotion of that model, or something similar. There are dozens of PG models, many such discussions are modern. The problem is simply answering questions about Pushing Gravity models based upon one's statements, without being construed as promoting PG, or any PG model in particular. For this reason words are carefully chosen, details that might be misconstrued are omitted, a "hands tied analogy," to avoid misunderstandings, warnings, or suspensions. This seemingly would only apply to threads where alternative theory is an integral part of the topic in a mainstream forum.
    Last edited by forrest noble; January 10th, 2013 at 08:43 AM.
    Reply With Quote  
     

  77. #76  
    Brassica oleracea Strange's Avatar
    Join Date
    Oct 2011
    Location
    喫茶店
    Posts
    16,540
    Quote Originally Posted by forrest noble View Post
    To discuss this topic, alternative theory must be discussed in some detail.
    If you discussed it in detail, that would include the "detail" that it doesn't work. So: no problem.
    Without wishing to overstate my case, everything in the observable universe definitely has its origins in Northamptonshire -- Alan Moore
    Reply With Quote  
     

  78. #77  
    Moderator Moderator Markus Hanke's Avatar
    Join Date
    Nov 2011
    Location
    Ireland
    Posts
    7,172
    Quote Originally Posted by bill alsept View Post
    Light is used to measure the expansion of the universe, why not the motion of the earth? You didn't answer the first part of my question what did Feynman consider the front? How would he test his idea?
    The velocity of the earth is a vector quantity, the direction of which is tangential to the orbit. The "front" would be the semi-sphere which is oriented in the same direction as the velocity vector.
    Since according to PG space is filled with particles, the pressure at the "front" of a moving object would necessarily be higher than at the "back".
    Reply With Quote  
     

  79. #78  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    Quote Originally Posted by JonG View Post
    There is a comment made on these explanations of gravity in Richard Feynman's book: "The Character of Physical Law". Feynman's objection seems very simple - quote from book: "If the earth is moving, more particles will hit it from the front than from behind. (If you are running in the rain, more rain hits you in the front of the face than in the back of the head, because you are running in the rain.)"

    Feynman points out that this would mean that any moving body would be subject to a retarding force. However, although he rejects the notion that gravity arises because of interactions with particles streaming through space in all directions, he does note that such an explanation would give rise to an inverse square law.
    Yes, this seems like a valid criticism of PG models without field dynamics, i.e. no field motions to it. I think this might apply to Le Sage's model and some PG models of yore.
    Reply With Quote  
     

  80. #79  
    Universal Mind John Galt's Avatar
    Join Date
    Jul 2005
    Posts
    14,169
    Quote Originally Posted by forrest noble View Post
    The problem in a thread like this one, John, is that the subject, which in this case is the "perceived problems with Pushing Gravity," sometimes involves discussing alternative theory in a mainstream thread.
    My apologies. For some reason I thought this thread was in speculations. Also I see Harold's earlier admonition to you in this thread. We'd best stay with things as they are.
    Reply With Quote  
     

  81. #80  
    Forum Senior bill alsept's Avatar
    Join Date
    Jul 2012
    Location
    Seattle, WA
    Posts
    386
    Quote Originally Posted by Markus Hanke View Post
    Quote Originally Posted by bill alsept View Post
    Light is used to measure the expansion of the universe, why not the motion of the earth? You didn't answer the first part of my question what did Feynman consider the front? How would he test his idea?
    The velocity of the earth is a vector quantity, the direction of which is tangential to the orbit. The "front" would be the semi-sphere which is oriented in the same direction as the velocity vector.
    Since according to PG space is filled with particles, the pressure at the "front" of a moving object would necessarily be higher than at the "back".
    Any motion of the Earth would be to slow compared to light speeds to measure a difference between a front and back. I had already considered the tangential and the situation is still complex. Even if you take your readings from the equator looking east with Earth's rotation you would still need to time the reading so it pointed in the direction of Earth's orbit around the sun and then time it so it pointed in the direction of the solar systems orbit around the galaxy. And after all of that you may still be pointing in the wrong direction of the cluster movements and who know what larger systems come into play. And all this in an attempted to make differential readings of something moving as fast as light and smaller than dark matter?

    Keep in mind that most PG models especially mine is based on the shielding effect which is a percentage reduction in the number of PG particles coming through and NOT necessarily a reduction in their speed.
    Reply With Quote  
     

  82. #81  
    Suspended
    Join Date
    Jul 2012
    Posts
    613
    Quote Originally Posted by bill alsept View Post
    Any motion of the Earth would be to slow compared to light speeds to measure a difference between a front and back.
    Quite the opposite. First the speed of light is constant, thus even much smaller velocity change like the one of a Start wobbling around the center of mass with their own satellite (called planet) can be measured from the earth into the light doppler shift
    Orbit3.gif
    Seeing this animation I also think that push gravity does not explain the the sun is 'pushed' away from the planet. From this vantage point I see the planet shadowing the facing side of the sun, which should then wobble the opposite side of its orbit.

    I had already considered the tangential and the situation is still complex. Even if ...
    It is why it does not work. You cannot even describe a way to measure things, let alone compute it.
    Reply With Quote  
     

  83. #82  
    Forum Senior bill alsept's Avatar
    Join Date
    Jul 2012
    Location
    Seattle, WA
    Posts
    386
    Quote Originally Posted by Boing3000 View Post
    Orbit3.gif
    Seeing this animation I also think that push gravity does not explain the the sun is 'pushed' away from the planet. From this vantage point I see the planet shadowing the facing side of the sun, which should then wobble the opposite side of its orbit.
    No PG model would ever claim that the sun is 'pushed' away from the planet. And your second coment tells me you do not have an understanding of the basic premise of PG, either modern or LeSage's old model. Read a little about it and then see if the second part of your question still applies. Thanks
    Reply With Quote  
     

  84. #83  
    Suspended
    Join Date
    Jul 2012
    Posts
    613
    Quote Originally Posted by bill alsept View Post
    No PG model would ever claim that the sun is 'pushed' away from the planet.
    It is too bad, because it happens anyway. Is there any other mundane thing PG does not explain ? I think the tide opposite to the moon does not exist with PG.



    Quote Originally Posted by bill alsept View Post
    And your second coment tells me you do not have an understanding of the basic premise of PG,
    I hold PG "basic premise" in high regards, when I invented it at the age of 14 (like many thousands curious people probably do every year). But you see, it is basic, and it is primal. If you continue to think about it, it does not work.

    Quote Originally Posted by bill alsept View Post
    either modern or LeSage's old model.
    No I won't interest myself into modern PG, because the old one does not work, and the new one either. I think you should read a little that basic wiki page, and explain to me why my example does not apply. I am afraid the proof burden is on you. Thanks
    Strange and Markus Hanke like this.
    Reply With Quote  
     

  85. #84  
    Moderator Moderator Markus Hanke's Avatar
    Join Date
    Nov 2011
    Location
    Ireland
    Posts
    7,172
    I hold PG "basic premise" in high regards, when I invented it at the age of 14 (like many thousands curious people probably do every year). But you see, it is basic, and it is primal. If you continue to think about it, it does not work.
    No I won't interest myself into modern PG, because the old one does not work, and the new one either. I think you should read a little that basic wiki page, and explain to me why my example does not apply. I am afraid the proof burden is on you. Thanks
    Very well spoken, Boing3000. My respect
    Reply With Quote  
     

  86. #85  
    Moderator Moderator Markus Hanke's Avatar
    Join Date
    Nov 2011
    Location
    Ireland
    Posts
    7,172
    Allow me to quote from reference [4] as given in the OP - no one here has even attempted to properly address this, using appropriate mathematical detail. I invite comments from all proponents of PG ( sorry about the lines, can't get rid of them for some reason ) :


    Accepting for the moment that all these rather daunting requirements are met, and accepting the combined rationalizations regarding the densities and sizes of weighty particles, there are still some serious problems for shadow gravity, many of which can be traced back to the finite speed of the ultra-mundane particles. As a macroscopic body moves (relative to the frame with respect to which the ultra-mundane flux is isotropic) it will naturally encounter more particles on its leading face than on its trailing face, resulting in a net drag on the body. Quantitatively, if a series of equally-spaced ultra-mundane particles with speed vg are impinging on a stationary opaque object from two opposite directions, the object will be struck by particles at the same rate on both sides. (How all the independent ultra-mundane particles acquired this particular speed is not explained.) However, if the object moves with speed v in one direction along this axis, the rate of encountering particles on its leading face is increased in the ratio (vg + v)/vg, and the rate of encountering particles on its trailing face is decreased in the ratio (vg - v)/vg, so the original force balance F – F = 0 becomes
    The momentum transferred to an object by each ray of flux must be large enough to account for gravity, which implies that F in the above equation is not negligible. Since we do not observe any appreciable drag on (for example) the planets in their orbits around the Sun, we must impose some further restriction on the model to minimize this effect. To minimize the drag we must assume the speed vg of the ultra-mundane particles is extremely great. Thus, we find once again that a natural consequence of the model must be nullified by setting one of the parameters to an extreme value.
    To treat this more fully, let r denote a measure of the spatial density of the ultra-mundane particles absorbed by ordinary matter, defined such that rUdt equals the quantity of mass accretion by a sphere of a given radius from a given direction in an increment of time dt, where U is the relative speed between the ultra-mundane particles and the sphere along that direction. For a massive sphere in orbit around some center of mass with another body we will consider just the radial and tangential flows as shown below.
    The radiation density from the bottom (i.e., from the direction of the other orbiting body) is reduced by the factor (1-k) where k is a small number representing the fraction of the flux that was intercepted by the neighboring body. (Note that, since the gravitational constant does not change appreciably with distance from the Sun, we know that k for the Sun must be no greater than one part in a hundred million, i.e., 10-8). Beginning with a mass m and speed v, the orbiting body will absorb in an increment of time dt ultra-mundane particles with momentum in the horizontal direction equal to [r(vg-v)dt]vg and –[r(vg+v)dt]vg. The mass accreted from particles in the horizontal direction is equal to the quantities in the square brackets. In addition, during this same increment of time, the object will accrete from particles in the vertical direction quantities of mass equal to [r(vg)dt] and [(1-k)r(vg)dt]. Letting u denote the horizontal speed of the object at the end of this increment of time, the conservation of momentum requires
    Solving this for u, subtracting v, and dividing by the incremental time dt gives the rate of change of speed (i.e., the acceleration) in the horizontal direction
    We also know that the slight different in the radiation density in the vertical direction produces the force of gravity on the object, so we have
    where M is the mass of the other gravitating body and r is the distance between the bodies. Solving this for the density r and substituting into the previous equation gives the acceleration due to drag
    The radial acceleration is of course GM/r2, so the ratio of the tangential to the radial acceleration is
    The second term represents the effect of Bradley aberration resulting from the fact that the planet is moving perpendicularly to the incoming shadow, so vector addition causes the apparent direction of the shadow (i.e., the “attractive force”) to be slightly forward of the actual direction. This effect should not be confused with the aberration resulting from the motion of the source body during the finite time required for the shadow to traverse the distance between the source and the planet, which will be discussed below.
    In order for the orbits of the planets around the Sun to have persisted for hundreds of millions of years, the ratio of tangential to radial acceleration can be no greater than about 10-10, and we’ve already noted that the fraction k of ultra-mundane particles absorbed by the Sun can be no greater than 10-8, so the above relation implies that the speed of the ultra-mundane particles must be at least (6)1018 times the speed v of the planet. The planet Mercury has an orbital speed of about (4.8)104 m/sec, so the value of vg must be at least (2.9)1023 m/sec, which is about 1015 times the speed of light. Henri Poincare used more stringent limits on the shielding and acceleration ratios to conclude that vg must be about 1017 times the speed of light. In any case, it’s clear that the gravific corpuscles must be assumed to move at a speed far in excess of the speed of light. This may not have been considered an impossibility in the time of Fatio or Lesage (or even in the time of Kelvin and Maxwell), but it is surely known to be impossible today. This is true regardless of whether one adopts the Einsteinian or the Lorentzian interpretation of special relativity because, in either case, the momentum of a corpuscle of (rest) mass m moving with speed v is not p = mv but rather
    The modern laws of mechanics are solidly based on this fact, which has been confirmed to phenomenal accuracy by countless observations.
    Reply With Quote  
     

  87. #86  
    Forum Senior bill alsept's Avatar
    Join Date
    Jul 2012
    Location
    Seattle, WA
    Posts
    386
    Quote Originally Posted by Boing3000 View Post
    I think you should read a little that basic wiki page, and explain to me why my example does not apply. I am afraid the proof burden is on you. Thanks

    In post 81 you said

    "I also think that push gravity does not explain the the sun is 'pushed' away from the planet. From this vantage point I see the planet shadowing the facing side of the sun, which should then wobble the opposite side of its orbit."

    Neither statement makes sense to me could you be more specific? For example what does wobble the opposite side mean? How do you explain the sun pushing the planets away? Please re ask your question and I'm sure I can answer.
    Reply With Quote  
     

  88. #87  
    Brassica oleracea Strange's Avatar
    Join Date
    Oct 2011
    Location
    喫茶店
    Posts
    16,540
    Quote Originally Posted by Boing3000 View Post
    I think the tide opposite to the moon does not exist with PG.
    Good one. How could push gravity explain that?
    Without wishing to overstate my case, everything in the observable universe definitely has its origins in Northamptonshire -- Alan Moore
    Reply With Quote  
     

  89. #88  
    Forum Senior bill alsept's Avatar
    Join Date
    Jul 2012
    Location
    Seattle, WA
    Posts
    386
    Quote Originally Posted by Markus Hanke View Post
    Allow me to quote from reference [4] as given in the OP - no one here has even attempted to properly address this, using appropriate mathematical detail. I invite comments from all proponents of PG ( sorry about the lines, can't get rid of them for some reason ) :


    Accepting for the moment that all these rather daunting requirements are met, and accepting the combined rationalizations regarding the densities and sizes of weighty particles, there are still some serious problems for shadow gravity, many of which can be traced back to the finite speed of the ultra-mundane particles. As a macroscopic body moves (relative to the frame with respect to which the ultra-mundane flux is isotropic) it will naturally encounter more particles on its leading face than on its trailing face, resulting in a net drag on the body. Quantitatively, if a series of equally-spaced ultra-mundane particles with speed vg are impinging on a stationary opaque object from two opposite directions, the object will be struck by particles at the same rate on both sides. (How all the independent ultra-mundane particles acquired this particular speed is not explained.) However, if the object moves with speed v in one direction along this axis, the rate of encountering particles on its leading face is increased in the ratio (vg + v)/vg, and the rate of encountering particles on its trailing face is decreased in the ratio (vg - v)/vg, so the original force balance F – F = 0 becomes
    The momentum transferred to an object by each ray of flux must be large enough to account for gravity, which implies that F in the above equation is not negligible. Since we do not observe any appreciable drag on (for example) the planets in their orbits around the Sun, we must impose some further restriction on the model to minimize this effect. To minimize the drag we must assume the speed vg of the ultra-mundane particles is extremely great. Thus, we find once again that a natural consequence of the model must be nullified by setting one of the parameters to an extreme value.
    To treat this more fully, let r denote a measure of the spatial density of the ultra-mundane particles absorbed by ordinary matter, defined such that rUdt equals the quantity of mass accretion by a sphere of a given radius from a given direction in an increment of time dt, where U is the relative speed between the ultra-mundane particles and the sphere along that direction. For a massive sphere in orbit around some center of mass with another body we will consider just the radial and tangential flows as shown below.
    The radiation density from the bottom (i.e., from the direction of the other orbiting body) is reduced by the factor (1-k) where k is a small number representing the fraction of the flux that was intercepted by the neighboring body. (Note that, since the gravitational constant does not change appreciably with distance from the Sun, we know that k for the Sun must be no greater than one part in a hundred million, i.e., 10-8). Beginning with a mass m and speed v, the orbiting body will absorb in an increment of time dt ultra-mundane particles with momentum in the horizontal direction equal to [r(vg-v)dt]vg and –[r(vg+v)dt]vg. The mass accreted from particles in the horizontal direction is equal to the quantities in the square brackets. In addition, during this same increment of time, the object will accrete from particles in the vertical direction quantities of mass equal to [r(vg)dt] and [(1-k)r(vg)dt]. Letting u denote the horizontal speed of the object at the end of this increment of time, the conservation of momentum requires
    Solving this for u, subtracting v, and dividing by the incremental time dt gives the rate of change of speed (i.e., the acceleration) in the horizontal direction
    We also know that the slight different in the radiation density in the vertical direction produces the force of gravity on the object, so we have
    where M is the mass of the other gravitating body and r is the distance between the bodies. Solving this for the density r and substituting into the previous equation gives the acceleration due to drag
    The radial acceleration is of course GM/r2, so the ratio of the tangential to the radial acceleration is
    The second term represents the effect of Bradley aberration resulting from the fact that the planet is moving perpendicularly to the incoming shadow, so vector addition causes the apparent direction of the shadow (i.e., the “attractive force”) to be slightly forward of the actual direction. This effect should not be confused with the aberration resulting from the motion of the source body during the finite time required for the shadow to traverse the distance between the source and the planet, which will be discussed below.
    In order for the orbits of the planets around the Sun to have persisted for hundreds of millions of years, the ratio of tangential to radial acceleration can be no greater than about 10-10, and we’ve already noted that the fraction k of ultra-mundane particles absorbed by the Sun can be no greater than 10-8, so the above relation implies that the speed of the ultra-mundane particles must be at least (6)1018 times the speed v of the planet. The planet Mercury has an orbital speed of about (4.8)104 m/sec, so the value of vg must be at least (2.9)1023 m/sec, which is about 1015 times the speed of light. Henri Poincare used more stringent limits on the shielding and acceleration ratios to conclude that vg must be about 1017 times the speed of light. In any case, it’s clear that the gravific corpuscles must be assumed to move at a speed far in excess of the speed of light. This may not have been considered an impossibility in the time of Fatio or Lesage (or even in the time of Kelvin and Maxwell), but it is surely known to be impossible today. This is true regardless of whether one adopts the Einsteinian or the Lorentzian interpretation of special relativity because, in either case, the momentum of a corpuscle of (rest) mass m moving with speed v is not p = mv but rather
    The modern laws of mechanics are solidly based on this fact, which has been confirmed to phenomenal accuracy by countless observations.
    Thanks Markus, this is a much better way to have a discussion about PG. I have an afternoon of meetings scheduled but I will return to this and try to find away to comply with the forum rules and answer any of these questions without getting myself banned from the forum. For now I will say that SOME models of PG (the one I like) do incounter drag and when matter is accelerated there is inertia to prove it. Either acceleration by being pushed through the flux or an imbalance of flux coming down in the form of g. Either way we experience gravity as long as we are being accelerated. but never in free fall like most celestial bodies.
    Reply With Quote  
     

  90. #89  
    Moderator Moderator Markus Hanke's Avatar
    Join Date
    Nov 2011
    Location
    Ireland
    Posts
    7,172
    I have an afternoon of meetings scheduled but I will return to this and try to find away to comply with the forum rules and answer any of these questions without getting myself banned from the forum.
    Bill, you will not get banned from this forum if you give genuine answers to genuine questions, in other words, for having a genuine constructive discussion. You need not worry.
    Reply With Quote  
     

  91. #90  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    Quote Originally Posted by Markus Hanke View Post
    I have an afternoon of meetings scheduled but I will return to this and try to find away to comply with the forum rules and answer any of these questions without getting myself banned from the forum.
    Bill, you will not get banned from this forum if you give genuine answers to genuine questions, in other words, for having a genuine constructive discussion. You need not worry.
    No, in a mainstream forum like this thread, one cannot promote an alternative mainstream model in particular or you can get suspended on banned. Of course you can discuss the merits, or lack thereof, of such models or the mainstream model if it is directly subject related, discussing generalities of some models or others. But promotion or discussion of your own model is not allowed, only when alluding to details of it in a subject related context without overtly promoting any particular model. See postings #73, #74, #75, and #79.
    Last edited by forrest noble; January 11th, 2013 at 02:57 PM.
    Reply With Quote  
     

  92. #91  
    Moderator Moderator Markus Hanke's Avatar
    Join Date
    Nov 2011
    Location
    Ireland
    Posts
    7,172
    Quote Originally Posted by forrest noble View Post
    No, in a mainstream forum like this thread, one cannot promote an alternative mainstream model in particular or you can get suspended on banned. Of course you can discuss the merits, or lack thereof, of such models if it is directly subject related, discussing generalities of some models or others, but promotion or discussion of your own model is not allowed, only when alluding to details of it without promoting them in particular. See postings #73, #74, #75, and #79.
    I am only looking for a response to the quote I presented, not for a promotion of any model. The maths are clear - all I want is for someone who is a proponent of PG to show how PG could work in the face of the maths presented, or alternatively to just admit that PG is a non-runner, which it is. After all, I opened this thread and titled it "Why PG does not work"; I have presented a strong argument why it doesn't, so now I am looking for someone to address that very specific argument. It is you guys who said my 18 points don't refute PG, so now let's get down and dirty and show me why my points don't do the trick.
    The task is simple - refute the maths in post 85, using physically plausible counterarguments. I am not looking for your pet models, I am looking for a physically valid refutation of the maths. The author uses simple, classical mechanics, no magic involved here.

    As such, my comment stands - no one here will get banned for giving a genuine, straight answer to the quote. Again, I don't want personal theories, just a simple mechanical refutation.
    Harold14370 likes this.
    Reply With Quote  
     

  93. #92  
    Suspended
    Join Date
    Apr 2007
    Location
    Pennsylvania
    Posts
    8,822
    Quote Originally Posted by forrest noble View Post
    Quote Originally Posted by Markus Hanke View Post
    I have an afternoon of meetings scheduled but I will return to this and try to find away to comply with the forum rules and answer any of these questions without getting myself banned from the forum.
    Bill, you will not get banned from this forum if you give genuine answers to genuine questions, in other words, for having a genuine constructive discussion. You need not worry.
    No, in a mainstream forum like this thread, one cannot promote an alternative mainstream model in particular or you can get suspended on banned. Of course you can discuss the merits, or lack thereof, of such models or the mainstream model if it is directly subject related, discussing generalities of some models or others. But promotion or discussion of your own model is not allowed, only when alluding to details of it in a subject related context without overtly promoting any particular model. See postings #73, #74, #75, and #79.
    Forrest, what got you into trouble was posting gobbledegook about spinning vortexes, electrons spinning in atoms near the speed of light, and foolishness like that. As long as you stick to real science, you can post on this thread.
    Reply With Quote  
     

  94. #93  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    Quote Originally Posted by Markus Hanke View Post
    Quote Originally Posted by forrest noble View Post
    No, in a mainstream forum like this thread, one cannot promote an alternative mainstream model in particular or you can get suspended on banned. Of course you can discuss the merits, or lack thereof, of such models if it is directly subject related, discussing generalities of some models or others, but promotion or discussion of your own model is not allowed, only when alluding to details of it without promoting them in particular. See postings #73, #74, #75, and #79.
    I am only looking for a response to the quote I presented, not for a promotion of any model. The maths are clear - all I want is for someone who is a proponent of PG to show how PG could work in the face of the maths presented, or alternatively to just admit that PG is a non-runner, which it is. After all, I opened this thread and titled it "Why PG does not work"; I have presented a strong argument why it doesn't, so now I am looking for someone to address that very specific argument. It is you guys who said my 18 points don't refute PG, so now let's get down and dirty and show me why my points don't do the trick.
    The task is simple - refute the maths in post 85, using physically plausible counterarguments. I am not looking for your pet models, I am looking for a physically valid refutation of the maths. The author uses simple, classical mechanics, no magic involved here.

    As such, my comment stands - no one here will get banned for giving a genuine, straight answer to the quote. Again, I don't want personal theories, just a simple mechanical refutation.

    Even to express yourself as a proponent of a non-mainstream model may not be acceptable in a mainstream forum. What I think is wrong with your formulation is that they are not dynamic and do not include field motions and flows. Like we both agree , the best that such a conservative model could propose mathematically is the inverse square law of gravity. Since observation has shown that in some cases that the inverse square law in not totally accurate close to the sun, and in the galaxy as a whole it has no predictive power at all. In the absence of dark matter any model of gravity, especially aetherial models like PG, the mathematics would seemingly have to have dynamics to it (non linear flows) to be able to possibly explain spiral galaxy stellar rotation curves
    Reply With Quote  
     

  95. #94  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    Quote Originally Posted by Harold14370 View Post
    Quote Originally Posted by forrest noble View Post
    Quote Originally Posted by Markus Hanke View Post
    I have an afternoon of meetings scheduled but I will return to this and try to find away to comply with the forum rules and answer any of these questions without getting myself banned from the forum.
    Bill, you will not get banned from this forum if you give genuine answers to genuine questions, in other words, for having a genuine constructive discussion. You need not worry.
    No, in a mainstream forum like this thread, one cannot promote an alternative mainstream model in particular or you can get suspended on banned. Of course you can discuss the merits, or lack thereof, of such models or the mainstream model if it is directly subject related, discussing generalities of some models or others. But promotion or discussion of your own model is not allowed, only when alluding to details of it in a subject related context without overtly promoting any particular model. See postings #73, #74, #75, and #79.
    Forrest, what got you into trouble was posting gobbledegook about spinning vortexes, electrons spinning in atoms near the speed of light, and foolishness like that. As long as you stick to real science, you can post on this thread.
    PG models require a background field like an aether. . This is not mainstream theory so the details of PG models are not mainstream either and most cannot be explained using mainstream physic. In a PG aether model, spinning molecular matter can produce aether vortexes. This would require corpuscles like dark matter, gravitons, Higgs particles, etc. The details of PG models in general are not mainstream. When asked to explain time dilation according to PG models, I explained one PG possibility, forgetting the "in my opinion" part.. In my PG explanation I also forgot to mention that it was speculative and relating to PG models only, for those reading that might misinterpret alternative theory contentions as being mainstream.
    Reply With Quote  
     

  96. #95  
    Brassica oleracea Strange's Avatar
    Join Date
    Oct 2011
    Location
    喫茶店
    Posts
    16,540
    Quote Originally Posted by forrest noble View Post
    No, in a mainstream forum like this thread, one cannot promote an alternative mainstream model in particular or you can get suspended on banned.
    Alternatively, you could stick to discussing science (mainstream or otherwise) rather than the fetid outpourings of your imagination.
    Without wishing to overstate my case, everything in the observable universe definitely has its origins in Northamptonshire -- Alan Moore
    Reply With Quote  
     

  97. #96  
    Forum Senior bill alsept's Avatar
    Join Date
    Jul 2012
    Location
    Seattle, WA
    Posts
    386
    Quote Originally Posted by forrest noble View Post


    Even to express yourself as a proponent of a non-mainstream model may not be acceptable in a mainstream forum. What I think is wrong with your formulation is that they are not dynamic and do not include field motions and flows. Like we both agree , the best that such a conservative model could propose mathematically is the inverse square law of gravity. Since observation has shown that in some cases that the inverse square law in not totally accurate close to the sun, and in the galaxy as a whole it has no predictive power at all. In the absence of dark matter any model of gravity, especially aetherial models like PG, the mathematics would seemingly have to have dynamics to it (non linear flows) to be able to possibly explain spiral galaxy stellar rotation curves
    Forest, could you explain this one some more?
    Thanks
    Reply With Quote  
     

  98. #97  
    Suspended
    Join Date
    Dec 2011
    Location
    I live in Los Angeles but travel a lot and spend some time in Mexico.
    Posts
    1,509
    Quote Originally Posted by bill alsept View Post
    Quote Originally Posted by forrest noble View Post

    Even to express yourself as a proponent of a non-mainstream model may not be acceptable in a mainstream forum. What I think is wrong with your formulation is that they are not dynamic and do not include field motions and flows. Like we both agree , the best that such a conservative model could propose mathematically is the inverse square law of gravity. Since observation has shown that in some cases that the inverse square law in not totally accurate close to the sun, and in the galaxy as a whole it has no predictive power at all. In the absence of dark matter any model of gravity, especially aetherial models like PG, the mathematics would seemingly have to have dynamics to it (non linear flows) to be able to possibly explain spiral galaxy stellar rotation curves
    Forest, could you explain this one some more?
    Thanks
    Sure Bill. What Markus's math points out is that in what is called a conservative PG field, the field is the same everywhere, and the best math you can get out of it is the inverse square law of gravity. This was good in the times of Newton but nowadays with better predictions of GR, we realize that although intuitive and simple, the inverse square law cannot explain everything about gravity. Up until the 1970's it was thought that GR could accurately explain gravity in all venues. But soon-thereafter we realized we also needed dark matter, an ad hoc mechanism at the time, invented to explain how GR might still work at galactic scales. There have been many experiments since then to find dark matter but no so-called discovery has happened yet. This has led others to look for other models of gravity. One of the first of these models was MOND gravity, others followed.

    Gravity has shown to be non-linear in certain circumstances as mathematically modeled by GR. Gravitational forces do not act in a straight line. GR calls this the bending or warping of spacetime. MOND does not address this problem because it relates to motions of galaxies, whereby such considerations do not necessarily have to be addressed.

    For any successful model or gravity mathematically, including PG, it would have to also accept the dark matter hypothesis as did GR, or propose mathematically why dark matter is irrelevant and probably does not exist. It will have to explain the so called precession of the axis of rotation of the planet Mercury, while at the same time explaining with equal capability those things that GR has successfully explained.

    Presently there is only one consensus equation to PG, the inverse square law. GR has 10 such equations. PG might develop non-linearity through additional equations involving fluid dynamics, vortex equations, etc. but if one is interested in a correct model of gravity mathematically, all observations must be identifiably explainable.
    Last edited by forrest noble; January 11th, 2013 at 06:20 PM.
    Reply With Quote  
     

  99. #98  
    Moderator Moderator Markus Hanke's Avatar
    Join Date
    Nov 2011
    Location
    Ireland
    Posts
    7,172
    Quote Originally Posted by forrest noble View Post
    What I think is wrong with your formulation is that they are not dynamic and do not include field motions and flows.
    That's because there is no obvious source of such dynamics, and also if the field is not perfectly uniform then it couldn't give us the inverse square law.

    This is not mainstream theory so the details of PG models are not mainstream either and most cannot be explained using mainstream physic.
    Yes, now we are approaching the heart of the matter - PG simply isn't a valid, working model in the context of currently understood physics. It is a hypothesis which relies on assumptions which are contrary to scientific understanding.
    Which is pretty much all I was trying to point out when opening this thread. In the context of current scientific understanding, it simply does not work.

    PG models require a background field like an aether.
    Yes, just another assumption in a long list of assumptions in order to somehow get PG to work.
    And you guys complain about dark matter and dark energy ? Some cheek !

    but if one is interested in a correct model of gravity mathematically, all observations must be identifiably explainable.
    Absolutely right, forrest.
    KALSTER and Strange like this.
    Reply With Quote  
     

  100. #99  
    Suspended
    Join Date
    Jul 2012
    Posts
    613
    Quote Originally Posted by bill alsept View Post
    Neither statement makes sense to me could you be more specific? For example what does wobble the opposite side mean?
    Well, you'll have to excuse my sorry English again. All (or most of) the points Marcus had summarized are also explained in the wiki page of PG. Maybe some of these are too complex to be understood by you, that's why I try hard to keep this to layman's level, the level were I am expert in.

    Please click on the picture, it is animated. Fix you eyes on the red cross, and look at the sun, it is "pushed away" from the planet. Of course classic gravity even Newtonian explain that, PG don't. Instead for case as simple, PG predic's aberration, which does not exist.
    This picture also depict the earth and its moon, and the second tides only exist because of the centrifugal force superior on the earth surface in opposition of the moon. You have to understand this:
    -the center of rotation is NOT the center of the sun (or the earth) it is the red cross, the center of both masses. If anything it show's you gravity is pull not push.

    What your mind should click on is the fact that this observation is local, i does not depend on an aether like field, or absolute reference or time. Any explanation that need a non-local local mechanism is just always wrong, because it introduce had hoc fix that themselves needs more had hoc fix, ad infinitum.

    There is a fix for the second tide, a dark matter moon, in orbit opposite to the not-dark one. PG saved, for now...
    Markus Hanke likes this.
    Reply With Quote  
     

  101. #100  
    Forum Senior bill alsept's Avatar
    Join Date
    Jul 2012
    Location
    Seattle, WA
    Posts
    386
    Quote Originally Posted by Boing3000 View Post
    Quote Originally Posted by bill alsept View Post
    Neither statement makes sense to me could you be more specific? For example what does wobble the opposite side mean?
    Well, you'll have to excuse my sorry English again. All (or most of) the points Marcus had summarized are also explained in the wiki page of PG. Maybe some of these are too complex to be understood by you, that's why I try hard to keep this to layman's level, the level were I am expert in.

    Please click on the picture, it is animated. Fix you eyes on the red cross, and look at the sun, it is "pushed away" from the planet. Of course classic gravity even Newtonian explain that, PG don't. Instead for case as simple, PG predic's aberration, which does not exist.
    This picture also depict the earth and its moon, and the second tides only exist because of the centrifugal force superior on the earth surface in opposition of the moon. You have to understand this:
    -the center of rotation is NOT the center of the sun (or the earth) it is the red cross, the center of both masses. If anything it show's you gravity is pull not push.

    What your mind should click on is the fact that this observation is local, i does not depend on an aether like field, or absolute reference or time. Any explanation that need a non-local local mechanism is just always wrong, because it introduce had hoc fix that themselves needs more had hoc fix, ad infinitum.

    There is a fix for the second tide, a dark matter moon, in orbit opposite to the not-dark one. PG saved, for now...
    Does everyone else agree that the sun pushes planets away? I hope not. What your seeing is a rotation around a common center of gravity.
    Reply With Quote  
     

Page 1 of 2 12 LastLast

Similar Threads

  1. Does Gravity do any work
    By Joe L. Ogan in forum Physics
    Replies: 100
    Last Post: October 14th, 2012, 03:28 AM
  2. Pull gravity versus controversial Push gravity
    By LeavingQuietly in forum Physics
    Replies: 18
    Last Post: July 12th, 2012, 11:06 PM
  3. zero gravity magnatic's (-)(+)push factors
    By bryan in forum Pseudoscience
    Replies: 27
    Last Post: January 10th, 2012, 11:59 AM
  4. zero gravity magnatic's (-)(+)push factors
    By bryan in forum Physics
    Replies: 20
    Last Post: January 9th, 2012, 11:45 PM
  5. Does Gravity do any work?
    By Joe L. Ogan in forum Astronomy & Cosmology
    Replies: 7
    Last Post: March 8th, 2010, 06:55 AM
Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •