Talk:Gravitational attraction

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This article was nominated for deletion on 16 March 2007. The result of the discussion was redirect to Gravitation.

[edit] Gravitation with attraction instead of curvatures of spacetime?

From Jim's message on my talk page:

I just read your correction to gravitational attraction. You must realize that you are proposing a completely different theory of gravitation than Einstein's, so could you present a proof that timespace is (pseudo)Euclidean or it is just your guess? Are you aware that Wikipedia's policy is not to present your own theories unless they are published by a reliable publisher?

Do you seriously think that the space is flat and therefore infinite? I don't believe that, so I hope you have some valid point. I just don't know what it could be so I'd like to learn.

Dear Jim, I'm not proposing any new theory. I just added the description of gravity in the framework of quantum field theory which makes your conclusions such as "gravitational attraction is a myth" invalid (so I removed them). To see more details about this framework, and in particular about how gravity fits in, please take a look at the textbook I referenced. Yevgeny Kats 18:05, 12 March 2007 (UTC)

Dear Yevgeny, "gravity in the framework of quantum field theory" is a new theory called quantum gravity. In Einstein's gravitation, and therefore in the real world as we know it, since Einstein's gravitation is so far confirmed by all the experiments up to date, there are no gravitational forces of attraction acting at the distance. Conseqently in Einstein's theory, which is supposed to be described in Wikipedia as the only officially accepted theory of gravitation the gravitational attraction is a myth. For the time being the real world isn't compatible with a theory that uses gravitons to explain gravitational attraction since there isn't such attraction in the real world and consequently it does not need an explanation. The gravitational attraction is simulated by inertial forces acting on particles which wordlines deviate from geodesics in spacetime. So if you don't have any strong argument that suports an idea of "attraction" by means of gravitons, perhaps something from the book you peopose as a ref, which I don't have and so I can't take a look at it) I would have to revert the page for the time being to Einstein's version. Jim 23:46, 12 March 2007 (UTC)

Dear Jim, if you don't trust me, I insist that you do read the textbook I mentioned, which you can probably find in the physics library of your university. I can also refer you to the article where this kind of approach was originally suggested: S. Weinberg, Phys. Letters 9, 357 (1964). If you don't have online access to this paper, you can find it in the library too (or if you send me an email I can send it to you). Zee's textbook that I referred you to explains it on a much more elementary level, though. (The things I wrote are correct even without knowing the full theory of quantum gravity. Quantum gravity is required only at energies comparable to the Planck scale, and you're right that such a theory doesn't exist yet, even though string theory is a good candidate.) Yevgeny Kats 02:08, 13 March 2007 (UTC)

Hi Yevgeny, When you log in and go to my "User page", there will be "E-mail this user" item on the sidebar (it isn't visible without login in). After clicking on it you may send me a mesage that I get through e-mail and then we may start a conversation through e-mail. Then you could send me the article you are talking about. I'll try to find it in one of our libraries anyway. If I can't then I'll tell you. For the time being let's keep your edits there despite that they contradict Einstein's theory. But Wikipedia is full of such articles (most of them placed there by editors who don't understand Einstein's theory) so one more won't make much difference I guess.

My problem is that if possibilities are that gravitational force is F=F1+F2, where F1 is "gravitational attraction" and F2 is "inertial force", and Einstein's theory says that F1=0, and quantum gravity says that F1>0, then both theories can't be true. Of course it isn't possible to tell which one is true but the experiments don't show that Einstein's theory is false. I.e. F1=0 in all observed cases (which means that F=F2, since there is no experiment showing that F1>0).

On what basis we are going to believe that the quantum gravity is true? To answer this is a similr problem as with deciding whethere the next perpetual motion machine won't prove to be working. So theoretically I have to know the arguments presented in the texts that you recommend for reading, to show that they are false. You could facilitate my task by providing those arguments (as I think they must be rather basic). The alleged formal similarity between (alleged) "fundamental gravitational force" and real fundamental forces (like electromagnetic, weak, and strong) isn't a valid argument of course while we don't have any evidence yet that a "fundamental gravitational attractive force" exists, and Einstein's theory says that it doesn't. So basically you should prove that Einstein's theory is wrong since it is much easier than an impossible task of proving that Einstein's theory is right. Jim 10:15, 13 March 2007 (UTC)

Hi Yevgeny, I've seen both things that you recommended (Weinberg and Zee). Both of them just assume the existence of gravitons and consequently the gravitational attraction. Zee writes: We now associate a particle with each of the known forces: for example, the photon with the electromagnetic force and the graviton with the gravitational force [...] latter while it has not yet been detected experimentally hardly anyone doubts its existence. That hardly anyone doubts its existence is not a sufficient reason to anounce its existence in Wikipedia since its existence is still not confirmed by any reliable source as required by Wikipedia's policy. Threfore we should revert to original Einstein's theory at least until the existence of gravtational attraction is confirmed by a reliable source.

I may just add to the page that many scientists believe privately rather the gravitational attraction at the distance and in gravitons rather than Eintein's theory in which gravitational forces are purely inertial forces. Jim 18:29, 13 March 2007 (UTC)

Hi Jim, thanks for looking at these sources. Since the predictions of both approaches are the same for all things that can be measured experimentally with the tools available today, the concept of gravitons etc is as confirmed experimentally as the curved space interpretation. Things that are well-established in the particle physics community, and which even appear in textbooks, have no reason to be excluded from Wikipedia. Yevgeny Kats 19:28, 13 March 2007 (UTC)

Hi Yevgeny, they are not excluded since they are published under their names as e.g. quantum gravity and gravitons so anyone interested in them can read about them. A problem is when two theories contradict each other in their interpretation of the same results (as here). It is solved by Wikipedia by picking up an already established theory rather then what's prefered by some groups of scientists or even what's true (if it's known). Jim 22:20, 13 March 2007 (UTC)

Hi Jim, I'm very disappointed about the way you essentially ignore our whole discussion and keep insisting on your own non-standard and single-minded view as to how the term "gravitational attraction" should be presented to the reader. If this is the result of our discussion, I don't have time to argue with you any more, and I hope some other people will join the dicussion. I'd like only to point out that possibly Weinberg's paper that I mentioned above wasn't the first paper, because Feynman was teaching this stuff already in 1962-1963, as you can see in the book "Feynman Lectures on Gravitation". If two textbooks and a paper aren't enough to convince you (while 2 out of 3 authors are Nobel Prize Laureates), it's very sad. Yevgeny Kats 14:48, 14 March 2007 (UTC)

Dear Yevgeny, how did I ignore our whole discussion? I waited for you to present a legitimate support for your POV and you presented only two authors who both say that "they assume" (without any legitimate theory behind it yet) certain interpretation of gravitation which accidentally is not the standard relativistic interpretation. In standard relativity there is no "gravitational attraction at the distance" and the gravitational forces aren't even attractive but inertial. As a physics student, especially a graduate as you claim, you should know at least the basics. To know also that an assumption is differnt from a theory and to know that what you call my "own non-standard and single-minded view" is Einstein's view, which I just report, wouldn't be too much to ask you either, would it?. BTW, my view is different (a "third way") but unlike you I don't push it in regular Wikipedia pages (I'm just trying to convert it into my PhD thesis).

You have finally to realize that Wikipedia's policy doesn't allow to push your own POV regardless how strongly you belive in it. It has to be NPOV (please click on link to learn) accepted by science not only by some scientists, even Weinberg or Einstein.

You have a way of improving the situation by proving that "gravitational attraction" is not only your assumption but also a fact and that it may be proved, and then prove it and publish the proof in some respected scientific journal. So please prove it if you think that it exists as a fundamental force. At least I showed you Landau's proof that it is an inertial force. If you don't agree you may try to falsify the proof. Have you ever tried and showed that Landau and Einstein are wrong? If not, then how do you know? Just to believe, as you ask me to, is not sufficient in science. Jim 18:14, 15 March 2007 (UTC)

Jim - You have consistently demonstrated a total lack of comprehension of what general relativity is and is about. Please stop bothering us with your odd personal viewpoint of what Einstein really meant. --EMS | Talk 18:39, 15 March 2007 (UTC)

[edit] Reverted to redirect

I have reverted this article to a redirect since

1. This topic is adequate covered in the gravitation article, and
2. The material being placed here is totally errorneous.

Jim - If gravitational attraction is a myth, then kindly explain what keeps our feet on the ground. Gravity as the force that causes gravitation is banished in general relativity, having been replaced by spacetime curvature and geodesic motion within it. However, the acceleration due to gravitation remains in any case, as is required for consistency with observation. --EMS | Talk 16:19, 14 March 2007 (UTC)

EMS - I showed Landau's proof that it is a myth on the same page that you redirected to this silly "gravitation" that pushes only your POV with exclusion of Einstein's. Too bad you didn't read it before redirecting since now it becomes a little bit more difficult to read it. So to make it easier for you I try to revert your redirection to gravitational attraction (and even provide a link here which for a troll like myself is rather a kind gesture). Then you may redirect it again if you still think it is a right thing to do. But I hope at some point you become reasonable and stop suppressing Einstein's POV to promote yours. IMHO, the NPOV policy requires presenting also Einstein's POV on gravitation. Jim 18:44, 15 March 2007 (UTC)

Jim - I assure you that I am promoting that which I consider to be Einstein's view, or at least the view of his successors. Part of the issue here is that you are treating the word "attraction" as being synonymous with "force", whereas I see "attraction" as being an attribute of the phenomenon of gravitation independent of its cause. The result is that your statement that "gravitational attraction is a myth" is read by some people as denying the existance of gravitation itself, something that is a joke, and which I would hope is not at all what you mean.

Even more disturbing is your section entitled "Mechanism through which curvatures of spacetime simulate gravitational attraction". The mechanism that you describe is one that is akin to what Einstein proposed in 1911 for the bending of light. However, that is not at all the mechanism that Einstein used after 1912, which is geodesic motion in curved spacetimes. Your write-up does not make an mention of geodesic motion, and so fails to present Einstein's final and most authoritative view of the subject of gravitation.

As you may have noticed, I have reverted the article back. Plase leave it be. If you revert again, I will do an AfD on your version, which I fully expect will result in the rejection of your version outright and making the maintenance of the redirect a mandate of the Wikipedia community. --EMS | Talk 20:14, 15 March 2007 (UTC)

I noticed a similar story with the article Gravitational force that turned from a redirect into a POV fork. Reverted that too. Yevgeny Kats 21:59, 15 March 2007 (UTC)

At least Jim did a better job with that article that with this one. However, a rant about the force not existing is not NPOV, even if it is fundamentally correct. --EMS | Talk 22:34, 15 March 2007 (UTC)

Did a better job?? He wrote: Gravitational force is an inertial force with which an object is pushing at an obstacle....

A force with which an object is pushing at an obstacle is the normal force (electromagnetism + QM), not gravitational force. Yevgeny Kats 22:48, 15 March 2007 (UTC)

Perhaps I should have been a bit clearer, but "better job" does not equal "good job". I will admit however that I found that first sentence to be so odd that I chose to disregard it when I first looked at what he wrote instead of trying to parse it out. The rest of the article at least got the flavor of GR right, but the details are once again all messed up. The bottom line in any case is that Wikipedia is not a soapbox, and I wish that Jim would respect that. --EMS | Talk 01:32, 16 March 2007 (UTC)

Dear EMS - you should place AfD instead of deleting the page in the first place. You shouldn't push your POV against Einstein's POV neither since most likely you won't succeed even if you happen to be right. It is just a bad way of pushing your POV. And BTW, "attraction" is synonymous with "force" (you could just read the pages you link your items to) and that's why "attraction" doesn't exist in Einstein's gravitation that is a pure geometry when objects are not in contact with each other (when they follow geodesics in spacetime). Of course, when they are in contact it is a different matter (since they can't follow geodesics in spacetime) and we see gravitational forces then. Which are nether attractive nor repulsive but inertial. I hope that during this dispute you learn some elementary Einsteinian gravitation and your POVs get closer to the real world.

Dear Yevgeny - it goes for you as well.

For all those reasons I'll try to revert once more to give you guys a chance to follow Wikipedia's policy and to learn something in the process. Jim 07:13, 16 March 2007 (UTC)