Question about gravity
in [Physics]
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From: "Juan R." González-Álvarez on 15 Mar 2010 17:40 "Juan R." González-Álvarez wrote on Mon, 15 Mar 2010 21:36:18 +0000: > Tom Roberts wrote on Mon, 15 Mar 2010 14:40:41 -0500: > >> Juan R. González-Álvarez wrote: >>> First, recent research shows that GR does not reduces to NG, with >>> textbooks claims about this being wrong. >> >> This depends on the meaning of "reduce". Certainly the physicist's >> sense of this holds, > > The meaning of reduction of a theory to other is unambiguous for > theoreticians and, of course, all the physicists who studied this agree > with me on that "GR does not reduces to NG". > > Their quotes are cited in the report (in your reply you snipped all > references cited) > > E.g. Joy Christian (expert in limits of general relativity) openly > accepts that the original theory of gravity of Newton is not the > Galilean limit form of general relativity. > > Even Miguel Alcubierre who initially did some silly mistakes about this > work, has finally emphasized that: > > "Strictly speaking, Newton's theory is not contained in GR" > > If you disagree with our findings please give us the references where > you have proved the contrary. > > The same rigorous analysis was done over other theories of gravity, with > the result that other theories (more rigorous than GR) give us the > correct Newtonian limit > > For example, this is from an expert in Stuckelberg Feynman theory: > > "your paper looks good, and the main observation that the Stueckelberg > et. > al theory has the consistent Newton limit, and that it passes in other > respects, sounds very reasonable to me." > >> in that the experiments that support NG do not refute GR, but rather >> support it as well. > > And you continue talking about stuff that you did not even read! > > If you have the minimal honesty of doing comments about stuff that you > first took the time to read, you would know that claim about experiments > was also showed to be wrong in a pair of sections of the report devoted > to this (in your reply you snipped all references cited). > > Paraphrasing Dirac, we have at hand "one theory [GR] for dealing with > non-relativistic effects and a separate disjoint theory [NG] for dealing > with certain relativistic effect". Ooops, the paraphrase is we have at hand: "one theory [NG] for dealing with non-relativistic effects and a separate disjoint theory [GR] for dealing with certain relativistic effect". -- http://www.canonicalscience.org/ BLOG: http://www.canonicalscience.org/publications/canonicalsciencetoday/canonicalsciencetoday.html
From: mpc755 on 15 Mar 2010 18:04 On Mar 15, 5:40 pm, "Juan R." González-Álvarez <nowh...(a)canonicalscience.com> wrote: > "Juan R." González-Álvarez wrote on Mon, 15 Mar 2010 21:36:18 +0000: > > > > > Tom Roberts wrote on Mon, 15 Mar 2010 14:40:41 -0500: > > >> Juan R. González-Álvarez wrote: > >>> First, recent research shows that GR does not reduces to NG, with > >>> textbooks claims about this being wrong. > > >> This depends on the meaning of "reduce". Certainly the physicist's > >> sense of this holds, > > > The meaning of reduction of a theory to other is unambiguous for > > theoreticians and, of course, all the physicists who studied this agree > > with me on that "GR does not reduces to NG". > > > Their quotes are cited in the report (in your reply you snipped all > > references cited) > > > E.g. Joy Christian (expert in limits of general relativity) openly > > accepts that the original theory of gravity of Newton is not the > > Galilean limit form of general relativity. > > > Even Miguel Alcubierre who initially did some silly mistakes about this > > work, has finally emphasized that: > > > "Strictly speaking, Newton's theory is not contained in GR" > > > If you disagree with our findings please give us the references where > > you have proved the contrary. > > > The same rigorous analysis was done over other theories of gravity, with > > the result that other theories (more rigorous than GR) give us the > > correct Newtonian limit > > > For example, this is from an expert in Stuckelberg Feynman theory: > > > "your paper looks good, and the main observation that the Stueckelberg > > et. > > al theory has the consistent Newton limit, and that it passes in other > > respects, sounds very reasonable to me." > > >> in that the experiments that support NG do not refute GR, but rather > >> support it as well. > > > And you continue talking about stuff that you did not even read! > > > If you have the minimal honesty of doing comments about stuff that you > > first took the time to read, you would know that claim about experiments > > was also showed to be wrong in a pair of sections of the report devoted > > to this (in your reply you snipped all references cited). > > > Paraphrasing Dirac, we have at hand "one theory [GR] for dealing with > > non-relativistic effects and a separate disjoint theory [NG] for dealing > > with certain relativistic effect". > > Ooops, the paraphrase is we have at hand: > > "one theory [NG] for dealing with non-relativistic effects and a separate > disjoint theory [GR] for dealing with certain relativistic effect".. > > --http://www.canonicalscience.org/ > > BLOG:http://www.canonicalscience.org/publications/canonicalsciencetoday/ca... Or we realize the pressure associated with the aether displaced by massive objects is gravity.
From: Koobee Wublee on 15 Mar 2010 19:07 On Mar 15, 7:34 am, Uncle Al <Uncle...(a)hate.spam.net> wrote: > Metric gravitation postulates the Equivalence Principle Any serious gravity postulate has to abide by the principle of equivalence. <shrug> The principle of equivalence was first pointed by Galileo. Newton used that for the Newtonian law of gravity. After years of intensive studying, Einstein the nitwit, the plagiarist, and the liar finally understood Newtonian law of gravity. Through reverse-engineering, the nitwit was able to re-discover the principle of equivalence. <shrug> > (local centers > of mass in vacuum free fall pursue identical minmum action > trajectories independent of all measurable properties) The trick is to identify and justify what this minimum action is. <shrug> > in which the > effects of a massive body are geometrized as pseudo-Riemannian > spacetime curvature and manifested by bodies pursuing minimum action > geodesic paths (photons pursuing null geodesic paths). Self-styled physicists have claimed that the action to be extremized is spacetime. That might work fine for non-photons. Photons always have zero spacetime. Thus, all geodesic paths are already at minimal. Photons cannot possibly propagate within the concept of minimal spacetime. <shrug> The concept of geodesic paths following minimal spacetime is just plain wrong. The most basic issue must be addressed before one can go further. <shrug>
From: Koobee Wublee on 15 Mar 2010 19:08 On Mar 15, 12:40 pm, Tom Roberts <tjrob...(a)sbcglobal.net> wrote: > It's remarkable how simple questions like this generate a firestorm of responses > from people who know essentially nothing about the topic. Plus a few sensible > replies. That was not a useful remark as usual. <shrug> > It can be very difficult for people unfamiliar with the subject to distinguish > sense from nonsense. The only reliable way I know is that the fools and idiots > don't refer to textbooks, while the knowledgeable people often do. I recommend > you start with: > > Geroch, _General_Relativity_from_A_to_B_. A non-mathematical > introduction to the concepts of GR. If these textbooks are wrong in the first place, wouldnt you say it would be more fools and idiots follow blindly behind already full of fools and idiots. <shrug> > In General Relativity, gravitation is MODELED as being a geometrical effect > which is related to the mass and energy distributed in the universe. Energy and mass are observed quantities. They would vary from one observer to another where everything is relative to each other, and any quantity is relative to another quantity. Interpreting the energy momentum tensor this way is bound for trouble. <shrug> At least, Newtonian gravity uses intrinsic mass which is independent of any observers. <shrug> > In other theories, such as Newtonian gravity, gravitation is modeled as a force. Interpreting GR as no force is just a cult in interpretation. One can easily show mathematics that results in gravitational force under the concept of GR. <shrug> > And one of the hot topics in theoretical physics for the past 2-3 decades has > been the quest to unify GR with quantum mechanics, which has generated the > notion of gravitons and guesses of how they might interact. At present there is > no complete and believable theory containing gravitons, however, and they remain > primarily a bunch of guesses. I can confidently tell you that you are wrong. Riemann curvature tensor is a mathematical object. It was invented by Ricci. There is at least another arrangement of these coefficients for another so- called tensor (merely a matrix). On top of that, there is at least another to define the covariant derivative that satisfy within the frame work of the one Ricci invented. Trying to create a universe from a mathematical invention is called fantasy. <shrug> > At present, the best model we have of gravity that is generally accepted in the > physics community is General Relativity. But there are rather solid indications > that it is incomplete, and must be replaced by a better theory; unfortunately, > at present we don't know what that theory might look like, and seem to be > depressingly far from understanding even how to approach it. GR is just wrong right from the very start. Newtonian gravity still remains the only working, realistic model. <shrug> > This can be modeled either way. There are a number of measurements that imply GR > is considerably more accurate than Newtonian gravity. But don't think this > implies that your second description is "correct" just because GR models it that > way -- other "gravitational force" models can obtain equally-accurate agreement > with observations. GR predicts anything just under the sun. So, what good is it? As I have said before, for mere $99,999, I will design a universe of your choice that satisfies as a static, spherically symmetric, and asymptotically flat solution to the field equations. This, of course, includes the observed accelerating expanding universe so observed today through lack of understanding in a more accurate model of gravity to replace the Newtonian one. <shrug> > That's rather naive. Nature does whatever it is that she does, and presumably > that is just one thing (likely corresponding to neither of these models). We > humans try to figure out what nature does, but there are inherent limitations on > our ability to figure such things out, and there are inherent limitations on our > ability to make observations and perform experiments. This does not prevent you to call the metric invariant. It is the geometry that is invariant. For every set of coordinate system, one must apply the appropriate metric to conclude the observation of the invariant geometry. Calling the metric invariant is just stupid. Any grade school kids can understand the fallacy in that. Labeling the metric as the geometry is equally absurd. The metric is merely a connection between your choice of coordinate system to describe the invariant geometry. You are the ones who are trying to bend nature. <shrug>
From: Inertial on 15 Mar 2010 20:00
"kenseto" <kenseto(a)erinet.com> wrote in message news:bd2b0f8a-592e-429c-8c0d-9085f56314fc(a)v20g2000yqv.googlegroups.com... > On Mar 15, 10:09 am, "Inertial" <relativ...(a)rest.com> wrote: >> "kenseto" <kens...(a)erinet.com> wrote in message >> >> news:09cf23d5-351a-4602-adce-f4cfbf00034c(a)a18g2000yqc.googlegroups.com... >> >> >> >> >> >> > On Mar 15, 6:43 am, "Peter Webb" >> > <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: >> >> Not a whole lot to add to what Inertial in particular said. >> >> >> In GR, gravity is a virtual force in a similar way to centrifugal >> >> force >> >> in >> >> Newton. In both cases its really an acceleration, and the force is >> >> just >> >> the >> >> product (literally) of this acceleration and the mass of the object. >> >> >> Einstein in GR gave a geometric interpretation of what gravity is. >> >> This >> >> is >> >> very appealing, because it provides a mechanism for force at a >> >> distance. >> >> > Wrong it provides no such physical mechanism. It merely assumes the >> > existence of a physical entity caLLED the fabric of spacetime for the >> > interacting object to follow. >> >> Its just how things move. There no more need for there to be a 'physical >> entity' (and certainly not a material one) for that to happen, than there >> needs to be one in 3D Newtonian/Euclidean/Gaillean space to make objects >> follow a straight line (ie follow Newton's first law) > > Then why did you guys say that object follows the curvATURE in the > fabric of spacetime? Because its sounds nice. It gives one something to imagine .. its hard to imagine curvature of something that isn't a material substance. > What is that fabric of spacetime? It is a visual analogy (but not an accurate portayal as something material) of the geometry of the paths objects naturally take. You can, if you like, imagine lots of object moving freely in various directions, and their paths being like threads that weave a fabric. But its all just pretty analogy. Don't get so hung up on the word 'fabric' |