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Relational Mechanics

  1. Sep 28, 2010 #1
    Why has the book on Relational Mechanics, by Andre K.T. Assis, which claims to replace relativity, not been seriously considered and expanded upon?

    I search relation mechanics and this book is the only one I find, sitting on dark corners across the web.
     
  2. jcsd
  3. Sep 28, 2010 #2
    To quote an Amazon.com reviewer:
    It is not a question of to be "open minded" or "follower". It is just a question of comparison of theory and experiments. In this regard, relational mechanics is wrong: It does not explain nature as we see it by the experiments. It's simple. No big deal here about conspirations, followers or discriminated geniuses.

    I think that sums it up well.
     
  4. Sep 28, 2010 #3
    It is not proven by experiments, or experiments prove it wrong?
    Is there some experiment that proves Relational Mechanics wrong?
     
    Last edited: Sep 28, 2010
  5. Sep 28, 2010 #4
    Well, it is not in a dark corner, it is on my bookshelf. It is not "mainstream", so in the eyes of the mentors it has the same status as publications of Peter and Neal Graneau brothers. It touches some scared cows, therefore it is not being considered as "serious". The Amazon review is totally useless because it is not supported by a serious evidence. It's just a claim of an "anonymous cutomer'.
     
  6. Sep 28, 2010 #5
    Ok, but I am wanting to know, I don't know where else to find this out, but is there experimentation that proves it wrong, or is it simply lacking experimentation?
     
  7. Sep 28, 2010 #6
    Chapter 9.5 of the book is "Experimental Tests of Relational Mechanics". It ends with the following sentence: "Many other tests will appear in due course as more people begin working along these lines of research." But I doubt if there will be more people as this is not the "mainstream physics" and this line of research is being either strongly discouraged or, simply, ignored.
    As for whether what Assis considers to be a an experimental support of his ideas can be really understood as such - is debatable. This should not be a surprise since quite often a given experiment can be interpreted in several different ways - depending on the underlying theoretical and philosophical assumptions.
     
  8. Sep 28, 2010 #7
    Hm, well if there is no specific experiment that proves this theory wrong, then why is not not mainstream? (or part of mainstream) String Theory has no experimental support as well.
     
  9. Sep 28, 2010 #8
    But String Theory is very abstract - so it is not being considered as "dangerous". But, frankly speaking, I did not follow the development of relational mechanics for a number of years. So I do not know what is the present status. One would have to ask Assis himself.
     
  10. Sep 28, 2010 #9

    JesseM

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    A physics theory is just a mathematical model that makes quantitative predictions about experiments, "philosophical assumptions" should only be part of the "interpretation" of the theory, but not the theory itself. Does Assis have a mathematical model which makes different predictions about the results of some experiments than the mainstream theory?
     
  11. Sep 28, 2010 #10
    Let me give you an example from p. 242:

    "Another experimental test was suggested by Eby in 1979 [194]. Essentially, he calculated the precession of a gyroscope utilizing Weber's Lagrangian energy applied to gravitation (without being aware of Weber's electrodynamics). He obtained geodetic and motional precessions which differed from those of general relativity (the Lense-Thirring effect) by factors of 2 and 3/2, respectively. His analysis should first be checked independently, and then the experiments should be performed to distinguish these models. It is interesting to quote his discussion of these predictions (our words between square brackets):
    It is conceptually satisfying that in these theories [i.e., relational mechanics which he is constructing based on Weber's law] it is clear what the gyroscope is precessing with respect to, namely, the distant matter. This is not the case in metric theories of gravity [like Einstein's general theory of relativity] since there is no distant matter explicitly included in the Schwarzschild metric or its equivalent.​
    Another extremely important point to be tested directly is the existence of an exponential decay in gravitation. This is not necessarily connected with relational mechanics or Mach's principle, but as we have seen if we have an exponential decay in Newton's potential energy it is reasonable to suspect that an analogous term should exist which multiplies both terms of Weber's potential energy; see Eq. (8.5). Experiments to test the Seeliger-Neumann term have been performed since the last century, with some of them yielding positive results. We reviewed this subject in another study [35]. We suggest especially the repetition of Q. Majorana's many experiments on this effect ([47], [48], [49] and [50])."​

    It would be interesting to know what has happened since 1999 when the book was first published.

     
    Last edited: Sep 28, 2010
  12. Sep 28, 2010 #11
    No, it is not debateable. Crackpots like to make it sound like there is a debate, by outright rejecting every experiment that supports GR and clinging to the few (non repeatable mind you) experiments that didn't work.

    It's not enough for an experiment to see an effect (heck, a magnetic monopole was seen by one experiment). It needs to be repeatable. There have been many measurements testing GR (including frame dragging / geodetic precession, etc.). GR has been repeatably upheld by experiment.

    There is no real debate.

    Even worse is the claim of the long scale limit not being Newtonian gravity, but something that exponentially decays.

    We don't need "new" experiments to test any new theory. We can apply the results from a wealth of previous experimental data. We don't need to wait around. We already know theories radically changing relativity like this are incorrect.

    In mainstream literature when a theorist proposes a whole new theory or modifications to a well known one, one of the first things that are done is to check what limits of parameters in this theory would even allow it to match the stringent requirements of current experimental knowledge.
     
  13. Sep 28, 2010 #12
    Well the immense problem I am having is not getting solved, I am trying to learn enough physics to get to GR but people are telling me the answer does not lie in GR. I want a theory that explains the laws of physics in any reference frame.
    Does GR answer https://www.physicsforums.com/showthread.php?t=404650"?

    I have later found out my problem is a special case, and Newton and Ernst Mach both considered it, however Newton saying there is an absolute space, which there is not.
     
    Last edited by a moderator: Apr 25, 2017
  14. Sep 28, 2010 #13
    GR ends where QT begins, or even sooner. Different physical theories have different domains of validity. These domains are all the time being tested. Once in a while someone claims that the domain of application of a given theory is well known and makes an error- like it was with the high temperature superconductivity.
    But you absolutely should learn both GR and QT. Otherwise you will be lost.
     
  15. Sep 28, 2010 #14
    Well, that's what they get for being scared, huh?
     
  16. Sep 28, 2010 #15
    If you want to try to learn enough of physics I recommend you take the mainstream approach.
     
  17. Sep 28, 2010 #16
    I'm always suspicious when the only info on a theory is a book.

    Anyway, GR has been wildly successful. Any new theory has to explain the same results. So I suggest learning GR.
     
  18. Sep 28, 2010 #17
    Well of course, I wasn't planning on learning other theories before learning mainstream physics.

    But I had thought of that problem, (linked above) a long time ago and I am disappointed to find out that there is no obvious answer, nor is it for sure there even is an answer. I will learn GR and if it does not explain that issue, then there is something wrong with it, (General Relativity that is).
    I will explore other theories as well, I just wanted to know what you guys thought of Relational Mechanics, as it seemed to be the answer to my problem.
     
    Last edited: Sep 28, 2010
  19. Sep 29, 2010 #18
    If you are interested - you will easily find references to the papers published by the author of the book. There are 244 references altogether.
     
  20. Oct 1, 2010 #19

    Cleonis

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    OK, you have stated in an earlier thread what you are looking for. You started that thread in May, and it was called:
    https://www.physicsforums.com/showthread.php?t=404650"

    I have reread it, and there is nothing to add. Everything possible has been said.

    The answer you seek does not exist, just as much as the proverbial pot of gold at the end of the rainbow does not exist. It's not that we don't have the answer you seek because we're not looking hard enough, it's not there. The Universe isn't like that.

    Unfortunately my message to you is harsh: you are wrongfooting yourself in a very deep way.
     
    Last edited by a moderator: Apr 25, 2017
  21. Oct 1, 2010 #20
    This is how many people think today. But tomorrow the answer may well be different. As the history of science teaches us - that happened before, it may happen in the future.
     
  22. Oct 1, 2010 #21

    Cleonis

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    Of course, we expect that some day our current theories will be eclipsed by successors.

    Perhaps such a successor will be a theory in which no gravitational waves exist; a theory in which the observations of the behavior of binary pulsars is explained differently than GR does. That is possible.

    But suppose someone says: "We ought to have a theory that says that diamond is soft as butter." That is not going to happen.
     
  23. Oct 1, 2010 #22
    Back to relational mechanics. It has also a human side which may be interesting to know. Assis was asked how he came to think about inertia. He gave two reasons:

    1. He was never happy with Einstein relativity theories
    2. His study of the history of physics made him to study Mach.

    Thus warning: too much interest in the history of physics can damage your reputation.

    [Source: Peter Graneau and Neal Graneau, "Newton versus Einstein. How Matter Interacts with Matter"]
     
  24. Oct 1, 2010 #23

    bcrowell

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    GR's field equations have the same form in any reference frame, but GR nevertheless has certain frames (Lorentz frames, i.e., free-falling, non-rotating frames) that are preferred, and that can be defined without reference to any external object.

    You are basically expressing a dislike for this non-Machian feature of GR. There are other theories of gravity, such as Brans-Dicke gravity, that are more Machian than GR. In B-D gravity, it's quite possible that your two particles *will* collide. The theory was specifically constructed in order to give the "right" Machian behavior in cases similar to this one.

    We then have several possibilities: (1) B-D gravity is right, GR is wrong, and your aesthetic distaste correctly steered you away from the theory that was wrong. (2) GR is right, B-D is wrong, and the universe works that way without concern for your aesthetic distaste. (3) Neither GR nor B-D is correct within their common domain of applicability (i.e., above the Planck scale).

    The current empirical evidence leans toward #2, since the [itex]\omega[/itex] parameter in B-D gravity is constrained by solar-system measurements to be very large.

    Whether relational mechanics is a good candidate for #3, I can't say, not having studied it. Does it, for example, expose itself to falsification by making predictions of solar-system observation that differ from those of GR?
     
    Last edited by a moderator: Apr 25, 2017
  25. Oct 1, 2010 #24

    bcrowell

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    I spent some time this afternoon going through Assis's book on his relational mechanics theory. The book can be downloaded from his web site at www.ifi.unicamp.br/~assis/wbooks.htm[/URL] .

    The theory assumes absolute simultaneity, and therefore it's falsified by a vast number of high-precision tests of special-relativistic time dilation, as well as by empirical confirmations of gravitational time dilation such as the Hafele-Keating experiment.

    The theory is also incompatible with cosmological expansion, which forces Assis to resort to the "tired light" explanation for cosmological redshifts. But tired light is falsified by a vast amount of evidence from many different types of observations. One example is Blondin 2008.

    Blondin et al., "Time Dilation in Type Ia Supernova Spectra at High Redshift," ApJ 682 (2008) 724. [url]http://arxiv.org/abs/0804.3595[/url]
     
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  26. Oct 1, 2010 #25
     
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