Testwiki:Articles for deletion/Gravitational attraction

The following discussion is an archived debate of the proposed deletion of the article below. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review). No further edits should be made to this page.

The result was Redirect to Gravitation. Cbrown1023 talk 01:39, 23 March 2007 (UTC)

Gravitational attraction

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This article used to be a redirect to gravitation. JimJast has created a new article here which fails WP:NPOV in its presentation and WP:OR in its description of how curvature mimics a force. From talk:gravitational attraction one finds that the purpose of this article is to present that which JimJast calls "Einstein's POV", but which in fact is Jim's personal opinion of what that POV is. This article needs to be returned to being a redirect. EMS | Talk 14:50, 16 March 2007 (UTC)

Sorry to jump to the top of the queue, but I think this quote should settle this "debate". The following is from the Feynman Lectures on Gravitation, page 3:

"we first define the mass as the inertia of the object, which we measure by applying known forces and measuring the acceleration. Then we measure the attraction due to gravitation, for example, by weighing, and compare the results." (emphasis mine).Flying fish 14:43, 22 March 2007 (UTC)

• Redirect to gravitation --EMS | Talk 14:50, 16 March 2007 (UTC)
• Redirect to gravitation Current article has many serious problems. It claims to be partly about the history/interpretation of gravity, but what it says is wrong and is not anchored in history. It then attempts a weak-field approximation to regain Newton's laws, and the derivation is just plain wrong. linas 17:27, 16 March 2007 (UTC)

• question to linas Don't you agree with Landau that total energy E doesn't change with the change of position of particle (and so there isn't any gravitational attraction involved in the movement of the particle)? Jim 09:13, 19 March 2007 (UTC)

• comment - The total energy E of a free-falling particle doesn't change in classical mechanics either. Are you claiming that this should mean that there is no force of gravity in Newton's view? --EMS | Talk 14:49, 19 March 2007 (UTC)

• comment The kinetic energy of the particle changes in a free fall (e.g. when particle "drops" its kinetic energy increaes). So from Newton's POV (and so also from POV of non relativistic classical mechanics) there was a need for an assumption of some kind of "gravitational attractive force" F=dE/dx (where E is this kinetic energy and x is distance) that could be responsible for this change of kinetic energy of the free falling particle. To keep the conservation of energy intact this energy has been assumed to be delivered form a source called "potential energy of the particle". And that's why it has been assumed in Newtonian physics and non relativistic classical mechanics that the sum of kinetic energy and potential energy of the particle is constant. In relativistic physics since the energy of the free falling particle doesn't change despite its changing kinetic energy (see Landau) there is no need for an assumption of any "gravitational attractive force" nor any "potential energy". That's why we say now that Einstein eliminated "gravitational attractive force" form physics. Jim 15:50, 19 March 2007 (UTC)

• comment - You did not write "kinetic energy" above, but instead wrote "total energy". You are going to have to learn that if your writing is subject to misinterpretation, the fault is yours and not the reader's. BTW - You still have a goof in the above as you wrote that the "energy of the free falling particle does not change despite its changing kinetic energy", yet the point of your write-up is that the change in c (as determined by a distant observer) keeps the kinetic energy constant in general relativity. --EMS | Talk 16:51, 19 March 2007 (UTC)

• comment - What do you mean You did not write "kinetic energy" above? I just started my last comment from The kinetic energy of the particle .... When I write "kinetic energy" I mean "kinetic energy", when I write "total energy" I mean "total energy". While the idea of "kinetic energy" is almost the same in Newtonian and relativistic physics, the idea of "total energy" is obviously different in relativity since in Newtonian physics it used to be "kinetic energy" plus "potential energy", the latter being usually "negative". The "potential energy" lost its meaning in relativity where "total energy" is $E=m{c}^2\sqrt{g_{00}}$. Could you explain more clearly what you mean by "keeps the kinetic energy constant in general relativity" since in relativity the total energy is constant. The "kinetic energy" isn't constant in neither physics unless in the reference frame of the free falling particle when it is a trivial zero. Jim 20:55, 19 March 2007 (UTC)

• comment - Interesting goof on my part, as you are correct that Newtonian physics lack any rest energy, and kinetic energy does not include that. My point remains that energy is conserved (locally) in any case. More important is that your question to linas can only be valid if potential energy is excluded, but there was nothing in the question to make that clear. You keep approaching things from your own perculiar POV, and have no respect for the knowledge base or the needs of others. More specifically to this case, you seem to think that the gravitational attraction article should be a pro-GR rant instead of an informative review of the topic itself. --EMS | Talk 21:14, 19 March 2007 (UTC)

• comment I'm just trying to explain gravitation based on the "needs of others" which I hope is as simple explanation as possible so it could be understood by a high school student. That's why I use just derivatives and not the tensor calculus which would turn off most people. However, as Einstein said, while everything should be made as simple as possible (and luckily physics is simple, even simpler than Newton's) the math shouldn't be made any simpler than possible. So I think I made it the simplest possible. If you can make it any simpler you are welcome to modify my stuff but I don't think that keeping old Newtonian stuff would do anybody any good. Jim 21:57, 19 March 2007 (UTC)

• additional comment - You seem to be one of the guys on the other side of the issue who understands the issue. So you might be able to turn the whole consensus from 9:1 (as it stands now) to 0:10 (as it should be if everybody understood clearly what the issue is). So I should probably explain the issue more clearly. But I had a feeling that I did it already in the "gravitational attraction" page and no one was interested enough to read it all. So if we could discuss, after reading the page, what are the real objections (not just "troll Jim pushing again his POV") I'd have an opportunity to clarify them and explain while in this case Jim's POV is also POV of the hard science that is taught in all universieties around the world, unfortunately only to graduate physics students. And I'd like it to be taught to high school students as well since they are perfectly well capable of understanding this hard science POV, when it is properly explained to them. So if I make dydactical errors, as you seem to suggest, please point thosse errors to me and we may clarify them. One isse that you pointed to already is "total energy". However I also modified this page to fit the contemporary state of affairs and it was reverted to some non invariant nonsens as well. So I just concentrate on the most important issue in my opinion, which is the faith in gravitational attraction. This faith has persisted already for over 300 years, and it is outdated for almost 100 years, but despite that it is taught to high school students around the world, as good enough for them. Which then it has all the features of a state religion (in this case even a world religion). It is tauht with a hope that when those students are interested in the truth then they may study physics and learn in due time what the truth is. Apparently they never do as it is shown by this consensus of educated people, most likely graduated from many high schools, and some even graduate students in physics at Harvard University. Jim 09:18, 20 March 2007 (UTC)

• Responded to at User_talk:JimJast#Teaching_gravitation --EMS | Talk 16:39, 20 March 2007 (UTC)

• Redirect to gravitation —Ruud 19:35, 16 March 2007 (UTC)

• comment Any reason for redirection? Jim 21:31, 19 March 2007 (UTC)

• Redirect to gravitation —Flying fish 23:40, 16 March 2007 (UTC) Just seeing the statement in the first sentence that "gravitational attraction is a myth" was enough to convince me that this is an example of someone pushing their own (probably nearly unique) POV. The inverse square law holds in everyday life, and is a great approximation to nature at the energies and in the fields that humans are accustomed to. As others have pointed out, the fact that you don't fly off into space is evidence that "something" is pulling you down. Whether that something is some kind of inverse square law, or quantum gravity, or the result of some field equations doesn't matter, in ordinary human life we observe that we are attracted to the Earth. Arguments about what general relativity means should take place on GR pages, not on a page designed to attack the normal understanding of gravitation. As a final point, consider someone creating a page called "Earth's Geography" and stating in the lead sentence that "the idea that the Earth is round is a myth. It's actually a bumpy elipsoid". Even if the point is true it's badly representing the normal person's worldview.

• comment - Your example with a round Earth is about approximation while sentence about gravitational attraction is about something not existing at all. It seems that almost a century after the gravitational attraction disppeared from physics the high school students might finally start reading encyclopedia's articles that tell them the same thing that physics students learn in their gravitation courses and to learn how gravitation really works instead of believing a nearly century old story. Jim 21:31, 19 March 2007 (UTC)

• comment - Science is about approximation and model building. The model of 1/r**2 attraction works very well (wihthin measurement uncertainties) for almost everything everyone does. Should we change the first sentence of "proton" to "The existance of protons is a myth! In reality the proton is a bound state of three quarks of individual color". (Of course in perturbative field theory "quarks" don't exist either, they're just excitations out of the vacuum, so one can go even further...) We teach high school physics students about friction - but "friction is a myth"! It's really an integral of electromagnetic interactions between atoms (uh oh) on each of the adjacent surfaces.

Models are used constantly in physics. Condensed matter physicists talk about "depletion forces" (really electromagnetic), electronics designers talk about the AC current through a capacitor (electrons don't actually flow), we even talk about electrons "flowing" even though individual electrons bounce all over the place in the wire, and don't really go in orderly circles through the loop. The model of gravitational attraction due a to 1/r**2 force is an exceedingly good model for everyday life, is VERY important in the history physics, and is a great teaching tool. If you want people to learn about general relativity then include a link to it on Gravitation (I assume it's there already), and mention that the 1/r**2 force law represents the old way of thinking about it. Done.Flying fish 20:58, 20 March 2007 (UTC)

• response - I did what you advise long time ago, and it was removed by someone who believes (without any proof so far, but he believes it is going to be proved in future) that masses attract each other through empty space and a sentence to this effect still opens, untouched, the "Gravitation" page. That's why I stopped editing for a while (as Feynman advised "no argument will convince the idiot" [1]) but then it occured to me that I may create a page about gravitational attraction and clarify this issue according to knowledge delivered by reliable sources. It might have the advantage that idiots can't blank it since it would make an act of vandalism according to Wikipedia's policy. Now you and EMS did just that and additionally you think that high school students should be shielded from contmporary knowledge about gravitational attraction. Apparently you believe that shielding brings them a lot of good. EMS even thinks that admitting that relativity is real might blow people minds (which he saw happening). So you guys think that telling the truth as we know it is bad and Wikipedia should protect inocent high school students from learing truth about the real world and do it through an administrative action. However it is probably against Wikipedia's policy and for sure against policy of Prof. Dumbledore who maintained that the best way to improve society is to tell the truth as it is known. The simple reason behind such policy is that one can't predict the results of the lies that people are fed with, for noble purposes, and sometimes those lies backfire and then one regrets that those people were ever lied to.

An example of backfiring of noble purpose might be very recent decision by Polish Government (one of the few Governments that helps us to win the Iraq War) to consider a death during surgery an assasination. It might have ben an attempt to raise the flagging popularity of the ruling party with the voters. One doctor whose patient died after the surgery has been accused of assasination by the Minister of Justice (even before the trial) and jailed after a squad of police, popularly known as Ninja Turtles for their gear, made a spectacular arrest at the hospital for patients to enjoy. However the noble idea of creating a "perfect tool" for improving hospital statistics backfired by refusal of some Polish doctors to perform surgeries, which the Government didn't foreseen. They meant well and yet the bad doctors turned the best intentions into a disaster for Polish people who now have difficulties with having surgeries since 20 years in jail is too big a risk for those cowardly doctors. Unfortunately there is no death penelty in Poland so 20 years for assasination is max the governmant can afford but the Government is working on improving Polish Constitution that would be more like in Texas. So soon if a patient dies so does his doctor. Apparently, Polish Government might assume that it "is an exceedingly good model for everyday life, [...] and is a great teaching tool" to teach doctors.

To warn anybody who might not know, to call the Polish President, Mr. Kaczynski (don't mix him with this twin brother who looks exactly the same but is a Prime Minister of Poland) by any disrespectful name, according to the Polish law, might carry a penelty of three years in jail, and one doesn't have to live in Poland to be punished, since this law similarly to the American law is universal and may reach you wherever you are. The ruling party is "Law and Justice", and it is dedicated to enforcing the law. So guys, don't jump publicly to conclusions about the Polish Government. Now they are going to help us also in Afghanistan, and even on the ground, they are so tough, with our support only from the air, so be rather gentle with them, and no Polish Jokes please. Except possibly something like "Jim himself is a polish joke", which might be justified because of not folowing Feynman's advice. Jim 14:21, 21 March 2007 (UTC)

• more response - Flying fish, the above story is about a 40 million nation in the middle of Europe, of average IQ as ours, and the purpose of the story is for you to realize that people are not rational creatures and feeding them un-truths make them even less rational and that's why telling the truth, even to idiots, is the best policy.

Even if you try to think everything over in every detail they always manage to screw up something and then they tell you "you said it yourself". And then your only defense is "well, I lied, since I thought that you are idiots and can't bear the truth since it might blow your minds". And this is a very weak defense. So if you can document the fact that three quarks together is a myth, say it. It is BTW what Feynman always did. When he knew that something isn't true he said so and then he explained what model we may use to work with it anyway. Because science is not about models, as you say, but suprizingly enough it is abobut finding what is false. Which can be done in all relevant cases through experiments. That's why we already know, and are sure of, a lot of myth. By an important epistemological rule we can find what is true only when it is just oposite to a myth that we already proved false. And unfortunately there are many possible things opposite to a given myth. That's why to find truth is so difficult but luckily not impossible in principle.

One of my professors who taught magnetism always started his lectures by saying: "Whatever I'll tell you isn't true. It is simplified to make it easier for you to calculate certain things and understand what you can't calculate with those methods and why". And so the students were warned that Maxwell Equations are only approximation and could accept the rest and become better physicists than those who believed in Maxwell Equations and thought that magnetic force can exists on its own (you just add one term to Maxwell...) and were looking for "magnetic monopoles" not even suspecting that "magnetic monopole" (a stick with one end) or a graviton (a carrier of inertial force, a.k.a. "gravitational force") might be a myth. Jim 16:53, 21 March 2007 (UTC)

• comment - If you feel that word "myth" is improper you might want to change it to more scientifically correct "urban legend". Jim 23:01, 21 March 2007 (UTC)

• comment Science is not the search for truth. There are no certitudes in science, only theories and models. Further, since you mentioned Feynman let me quote from page 3 of the Feynman lectures on gravitation: "First of all there is the fact that the attraction follows an inverse-square law... Then there is the fact that the force is proportional to the masses of the objects." Then later on the same page: "we first define the mass as the inertia of the object, which we measure by applying known forces and measuring the acceleration. Then we measure the attraction due to gravitation, for example, by weighing, and compare the results." (emphasis mine). I think this ought to settle this matter.Flying fish 14:43, 22 March 2007 (UTC)

• response - You say "Science is not the search for truth", making an impression that maybe I said that it is. I said: "science is [...] about finding what is false". Of course finding what is false is not the same as the search for truth since as you agreed there are no certitudes in science. So we agree on this point. Then as it turns out we agree also on a point that The inverse square law holds in everyday life, and is a great approximation to nature ... which you said yourself. So your example with Feynman is about a model that Feynamn explains and which is an approximation to nature. It is all independent of what Einstein discovered, since as Feynman says in section 7-8 (Gravity and relativity) of The Fenman lectures on physics "In spite of all the excitement it created, Newton's law of gravitation is not correct!" (exclamation is Feynman's). Now my POV is that we shouldn't present to high school students something about which we already know that it is false, which contrary to truth can be discovered by science and it's even the purpose of science to find what is false. Because we don't want to live in the world of illusions as lived the people of Dark Ages. So my purpose is to show to the high school students how easy it is to understand Einstein's gravitation (and if I didn't do it well enough you are welcome to help), and so they don't need to believe that the gravitational attraction is real. They should know that it is not real (as far as we know) because this knowledge makes them capable of discovering something on their own in physics. While this opportunity will be taken away form most of them when from the earliest years they are going to believe in urban legends which Newtonian gravitation claerly is as Feynman confirms. We differ then only in POV on the educational policy. The education of most people taking part in this debate is an evidence that the present policy on teaching gravitation starting from Newton's theory is wrong. IMO it should start from stating clearly that there is no such thing as gravitational attraction, how it is simulated (which as you can see from the disputed page, thanks to Landau, takes less than 45 minutes to explain) and only then, when students comprehend the physics of the real world, explaining how simpy we can solve problems involving gravitation with Newton's equations. Otherwise we create mentally challenged individuals who might believe that the real world can't be understood. And later in life have problems with explaining many cosmological puzzles since faith in gravitational attraction affects their clear judgment. Jim 18:08, 22 March 2007 (UTC)

• Redirect to gravitation JRSpriggs 06:14, 17 March 2007 (UTC)

• comment Any reason for redirection? Jim 21:31, 19 March 2007 (UTC)

• Redirect to gravitation the first sentence does it. there's an insightful quote (perhaps physicists could tell me from whom, is it the relativist Singe?) that goes something like "In GR gravity is part of the stage while, in Newton's theory, it is an actor." IMHO, this article looks like a badly erroneous interpretation of that quote. Mct mht 13:24, 17 March 2007 (UTC)
• Redirect to gravitation, obviously, and beware of further disruption from JimJast. Tim Shuba 22:23, 17 March 2007 (UTC)

• comment - JimJast is referring to other editors as vandals in a similar though less egregious content dispute. [2][3] Tim Shuba 00:36, 18 March 2007 (UTC)

• comment - according to Wikipedia, blanking someone else's page (which Tim Shuba did) is vandalism. If you don't like the page because it contradicts your particular POV, to proceed in a civilized manner, you should state your offended POV first and then if not satisfied by the response, to request the deletion of the page. E.g. I don't understand why you consider Newtonian physics and relativity (contained in classical mechanics) being the same. Unless you never heard about relativity being different than Newtonian physics, but even then it is not a good reason for blanking a page. Jim 15:48, 18 March 2007 (UTC)

• Keep it as it is since high school students shouldn't be fed majority opinion but they should be told what physicists (and apparently not many of them have time to edit Wikipedia) consider to be a true story. "Two masses do not attract each other, period." (Robert A. Mitchell 02:32, 26 December 2006 (UTC)) and yet read the first sentence of "Gravitation" page to which "Gravitational attraction" is going to be redirected). But even if Eddington wondered who might be the third person who understood Einstein's theory it still made a better theory than Newton's. It is rather a sad picture that now, almost a century later, so many people want to come back to the gravitational attraction as a reason for things not falling off the Earth. In nearly hundred years they couldn't managed to understand Einstein. It means that my job of popularizing Einstein's gravitation is urgently needed to keep Wikipedia from sinking in the see of ingnorance about the physics of the real world. I just see a need to explain at least what this physics isn't and why. At least to high school students who might not yet have their own prejudices about it and could learn physics as understood by physicists and not those who understand only the simplified Newtonian physics. Jim 23:43, 17 March 2007 (UTC)
• Redirect to gravitation. The article is very problematic:

1. It doesn't make any sense that people who want to read about the gravitational force would need to understand general relativity first. It would be a very non-standard pedagogical approach.

comment Apparently this non standard pedagogical approach is urgently needed since relativity is around already for about a century and as demonstratef by this voting list a lot of intelligent people still don't understand it and some don't even know the simplest things about it. Jim 16:39, 18 March 2007 (UTC)

2. The article includes many mistakes. For example, the text claims that gravitational force exists when the body "is prevented from its free movement" and that it doesn't exist when the body is free to move. With or without general relativity, this statement is wrong.

comment This POV is wrong according to your POV but it is right according to POV of any textbook on general relativity. So to be fair you might say that opinions are divided, and yours aren't supported by any relible source yet since reliable sources support general relativity's POV. Even the autors that you quoted in discussion with me admit that they don't know yet how to prove their POV so they say that existence of attractive force is just their hypothesis. General relativity's POV, on the other hand, has been confirmed by all experiments up to date. Which makes pretty clear choice for Wikipedia. Jim 16:39, 18 March 2007 (UTC)

3. The main claim of the article that "gravitational attraction is a myth" isn't the only existing interpretation of Einstein's equations, and maybe not even the dominant one. I tried to fix the article, included a reference to a textbook, provided additional discussion and references on Talk:Gravitational attraction, but User:JimJast reverted the changes and removed the reference, violating many Wikipedia policies just in order to keep his POV as the only way to look at the subject. The whole article has a very POV-ish style. It seems like it's the only reason why User:JimJast created this fork, after his ideas weren't accepted in existing articles on gravitation. Yevgeny Kats 00:23, 18 March 2007 (UTC)

comment Wikipedia policy is to promote present knowledge (coming from reliable sources). Presenting stuff that even its authors consider to be hypotheses that are going to be proved sometime in the future is not something that should be necessarily placed in an encyclopedia. It is however proper for page like "other hypohteses" (since they aren't even theories yet, if you understand the difference). Jim 16:39, 18 March 2007 (UTC)

• Redirect per EMS et al. above, with special attention paid to Yevgeny Kats's concerns. Anville 22:05, 18 March 2007 (UTC)

• question Which conerns would you pay this special attention to and why? Jim 22:08, 19 March 2007 (UTC)

• note for closing admin - Did'ja like reading this one? If you made it all the way through, I for one wouldn't blame you for flipping out and indef blocking everyone involved, and maybe also a few unrelated editors for good measure. Wheee!—The preceding insane comment was added by Tim Shuba (talk • contribs)

The above discussion is preserved as an archive of the debate. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review). No further edits should be made to this page.