Gregory9

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Trouton-Rankine Experiment

Hi! And allow me to welcome you to Wikipedia, too! I noticed that you had been editing Trouton-Rankine experiment, and it seems you have a clear grasp of the subject. Perhaps you might be able to rephrase the fourth paragraph (the one containing "Four rectangular coils were wound..."). It is an obvious copyvio from here. It was originally added by User:Ati3414, who you seem to know from elsewhere, and it has been hard to explain the concept of plagiarism to him. I would do it myself, but I haven't got access to the original article, and I fear I would mess it up. Thanks, and again: Welcome. Rasmus (talk) 08:11, 14 March 2006 (UTC)

I wasn't aware of his plagiarism in this case (yes he can be a handful at times). I will try to change the wording there. And thank you for the encouragement, as it is nice to hear from someone besides User:Ati3414. Actually, I am worried about another editting war from him over this article. Do you have any suggestions on how to prevent this? Gregory9 08:40, 14 March 2006 (UTC)

Thanks for that. It looks nice! Do you perhaps know why Trouton and Rankine believed the resistance would change? User:Ati3414 explained it in terms of resistivity, but why did they believe the resistivity would not change? As for editing wars, I am probably not the best person to ask. I tend to take a confrontational path too often. But I have the page on my watch-list and will back you up. If he insists on an edit war, he will probably run into a block fast. If you remind them about it, administrators are good at encouraging good editors and discouraging the bad. Rasmus (talk) 09:41, 14 March 2006 (UTC)

You asked: "Do you perhaps know why Trouton and Rankine believed the resistance would change?" I gave the beginnings of their arguement in the article. Yes it is flawed, but that is easy for us to say in hindsight. How material was built up from positive and negative charges was not fully known at the time, and even the form of Maxwell's equations and the electric/magnetic force laws in other frames was still being debated. So such questions can be difficult to answer from our perspective and I'll have to leave that to a science historian to answer. (Especially when one considers the fact that resistance of a material is hard to calculate even with modern theories and techniques as it is essentially an 'effective' macroscopic quantity by averaging over many scattering events... resistance is a messy thing.) Sorry I can't be of more help here. Gregory9 10:18, 14 March 2006 (UTC)

Thanks. User:Ati3414 gave the impression that their reasoning was obvious. While I didn't take him at his word, I wondered what their actual reasoning was (and whether they had considered the point at all). Rasmus (talk) 10:31, 14 March 2006 (UTC)

I gave a very detailed explanation, more detailed than most posts. You only needed to read the external link that User:Gregory9 dutifully removed. It is back, so all the people that can't afford paying 30$ a pop for old papers can read and understand the complete explanation, inclusive of derivation.User:Gregory9 simply copied a few paragraphs from the link I wrote into the wiki article. Ati3414 18:10, 15 March 2006 (UTC)

How dare you accuse me of plagarism. I did not simply copy a few paragraphs from you work. I was not even referring to your paper when writing that, so any resemblence to your paper is due to the fact that: 1) it is about the same experiment, 2) I left fragments of your previous edits in the article.

Let's look at who is really plagarising, okay? You write in http://www.wbabin.net/sfarti/sfarti19.pdf

"Assuming that FitzGerald was right in his contraction hypothesis, Trouton sought for more positive evidence of its truth. In 1908 with A.Rankine, an old student appointed assistant in 1904, an attempt was made to measure the change of resistance of a wire when parallel and transverse to the ether drift. Four rectangular coils were wound, mounted on a common stand and connected in such a way that they formed a Wheatstone network, the wires forming opposite arms of the bridge being parallel. The bridge was balanced when the wire in two of the coils was at right angles to the resultant drift and then the whole assembly was rotated through 90 degrees and the change of balance tested. Once again every realizable precaution was taken only to lead to a negative result as recorded in Proc. Roy. Soc. 80A, 420-435, 1908."

And here is where you copied it from: http://www.phys.ucl.ac.uk/department/history/BFox1.html#Fox140

"Assuming FitzGerald was right in his contraction hypothesis, Trouton sought for more positive evidence of its truth. In 1908 with A.O.Rankine, an old student appointed Assistant in 1904, an attempt was made to measure the change of resistance of a wire when parallel and transverse to the ether drift. Four rectangular coils were wound, mounted on a common stand and connected in such a way that they formed a Wheatstone network, the wires forming opposite arms of the bridge being parallel. The bridge was balanced when the wire in two of the coils was at right angles to the resultant drift and then the whole assembly was rotated through 90 degrees and the change of balance tested. Once again every realizable precaution was taken only to lead to a negative result as recorded in Proc. Roy. Soc. 80A, 420-435, 1908."

I will be removing your paper from the external links again not only because of plagarism, but because it is an incorrect informations source and you are posting links to your own writing (self-promotion). Gregory9 00:42, 16 March 2006 (UTC)

Kevin, before you try to remove it you will need to prove your words: that "it is an incorrect informations source" (in your own attrocious grammar). This is not self-promotion as you'd want people to believe, it is a free way for people who don't have the 30$ to find out about these long forgotten experiments. So, I challenge you to prove your statement that the math/physics of the paper is incorrect.While you are at it, I challenge you to prove that the many other papers you removed are also wrong. You'd need to prove this to all the readers that are not as rich as you and who are being deprived by your continous deletions from getting free descriptions of the experiments. I dare you in front of all these wiki readers. And no cheating this time, there are some very good physicists (including the students that you teach and take money from) watching.Ati3414 04:49, 16 March 2006 (UTC)

First, stop posting without signing. This is annoying that people have to add that for you.

Second, yes it is self promotion. If your main concern really was to educate people, then you would be adding information to Wikipedia where you feel it is lacking, like normal people do. Instead, you just spam links to your papers. And yes, your views on the Lorentz-Fitzgerald contraction hypothesis are wrong ... as Lorentz showed himself, this should not be measureable in the rest frame of the object. But when Trouton-Rankine fail to find an effect in the rest frame of the object you keep claiming it shows the hypothesis is wrong. It only shows that Trouton and Rankine's Aether ideas (which included the contraction hypothesis) were wrong. It does not show the hypothesis itself is wrong (again, Lorentz himself showed that no effect should have been measureable here). This hypothesis was used in creating the Lorentz transformations that are in Special Relativity to this day. You need to get over your belief that "time dilation" is real but somehow "length contraction" is not. Quite a few people are following this at UIUC and your repeated false and egotistical claims are just making you a laughing stock. We do enjoy the show, but I'd prefer if you just learned your errors. Gregory9 05:12, 16 March 2006 (UTC)

Kevin, as usual, you offer only words but no math. You also show your ignorance: the paper is about the Lorentz-FitzGerald contraction, not about the Lorentz contraction. If you knew physics history you would have known the difference. FitzGerald, Kevin, FitzGerald. Learn how to read. So, is the math correct? yes or No? Ati3414 05:22, 16 March 2006 (UTC)

So now you are claiming that calling it the "Lorentz-FitzGerald contraction" is a "misnomer" because they are two different contractions? Lorentz, FitzGerald, Poincare, and Einstein all suggested that a moving object would be contracted in the direction of its motion. This is all the Lorentz-FitzGerald contraction is. Their views on what this "meant" in some metaphysical sense differed as did their theories that used this effect. As for physics history, I referr you to "A History of the Theories of Aether and Electricity" (volume I and II) by Whittaker which I got from the library to double check my claims. He describes the developement of electromagnetism in history all the way up to Einstein. No such distinction is made between "Lorentz-FitzGerald contraction" and just "Lorentz contraction" like you are trying to claim. In the same sense that a moving clock "really does" run slow, a moving object "really is" contracted in its direction of motion.

If you want to show me that I am wrong, you are more than welcome to come out here and give your speech. I look forward to it. Otherwise I am not interested in continuing discussing this with you since I have seen others explain it to you and you have shown an inability to admit your mistakes. Gregory9 06:04, 16 March 2006 (UTC)

You are handwaving , Kevin. Try reading here (and no, I didn't write these pages): [1], [2]

While you are at it, why don't you read paragraph 8 of Lorentz's "Electromagnetic Phenomena in System Moving with any Velocity less than that of Light" Proceedings of the Academy of Sciences of Amsterdam 1904. It is bound to give you nightmares (and a lesson in physics history).

So, one last time, is the math right or not? You haven't answered the question. Do you have difficulty in understanding it? Ati3414 06:12, 16 March 2006 (UTC)

Your physics is wrong because you are applying the length contraction in the rest frame of the object, yet still assuming Maxwell's equations / Lorentz force law work without modification in such a strange coordinate system. You can do either of the following:

1] Apply length contraction to the object as if it was moving at velocity v, and apply Maxwell's equations / Lorentz force law in the frame in which the object IS moving at velocity v. (Basically "force" yourself to do all the calculations in some arbitrary "aether frame".)

OR

2] Do the calculations from the rest frame of the object with no length contraction and apply Maxwell's equations / Lorentz force law in this frame.

OR

3] If you insist on the length contraction in the rest frame of the object, Maxwell's equations / Lorentz force law are not invarient to this change. So you need to modify Maxwell's equations / Lorentz force law to account for this. This is very messy but ends up being equivalent to just doing #1.

You can't mix and match. You are trying to apply length contraction to the object in its rest frame, and then use Maxwell's equations / Lorentz force law unmodified in this frame. This faulty logic does not disprove the Lorentz-Fitzgerald contraction. It only shows your logic was incorrect. Gregory9 06:53, 16 March 2006 (UTC)

"Your physics is wrong because you are applying the length contraction in the rest frame of the object,.."

Nope, you are not reading it correctly. I'll help you, it is case 1 above. The frame is based somewhere in the Sun and v is the Earth revolution speed. Remember, Trouton was an aetherist.Ati3414 07:05, 16 March 2006 (UTC)

Wait, let me get this straight - you really believe you did the calculations according to case 1 and showed that a change in resistance should be measured in the experiment... thereby disproving case 1?

Are you serious? Oh my gosh. If you can't see the error in this, there is no use in talking to you. I really do look forward to you coming out here and explaining that to everyone. Have you considered the offer? Gregory9 07:11, 16 March 2006 (UTC)

Looks like you have serious comprehension issues. Let's try again : the paper is about what Trouton thought, about HIS calculations and HIS expectations. He:

1. calculated the predicted contraction effect as viewed from an absolute reference frame (placed in the Sun)

2. infered that a galvanometer deflection should ocurr as viewed from the frame at point 1

3. expected to detect the deflection in the lab frame

4. found none of the above and reported it accordingly

Capisci? Ati3414 07:19, 16 March 2006 (UTC)

Do you believe that in those calculations you are applying Maxwell's equations / Lorentz force law in the "absolute reference frame"? And if so, do you believe these calcuations support the conclusion in 'step 2'. Since you did the calculations yourself, you seem to be claiming yes. Gregory9 07:29, 16 March 2006 (UTC)

Uh-oh. I didn't get the nod "yes, I understand, I was wrong about your use of reference frame, it is indeed case 1". So I am not going to answer until you answer my question above. And remember, in the paper, I am just explaining Trouton's point of view, not mine. Like in all the other papers, I am producing a free copy of a paper that would cost you 30$ and would also be very hard to understand. So all the calculations are from HIS point of view and from the POV of the epoch (1904). Ati3414 07:44, 16 March 2006 (UTC)

The calculations are NOT being done according to case one, otherwise a null result would be predicted for the experiment. If you are saying "Trouton incorrectly believed that he was doing the calculations according to case 1" and you merely reproduced these, then fine ... we are actually getting somewhere. Gregory9 07:50, 16 March 2006 (UTC)

Simpler formulation of the same question as above: is the frame of reference an aether frame as specified by case 1? Ati3414 07:53, 16 March 2006 (UTC)

I already told you, the calculations in your paper are NOT being done according to case 1, otherwise a null result would be predicted for the experiment. Are you saying "Trouton incorrectly believed that he was doing the calculations according to case 1" and that you merely reproduced these calculations? Gregory9 08:10, 16 March 2006 (UTC)

Prove it, Kevin. With math, not repeating incessantly the same old tired song. The uiuc students are watching and waiting.This one too tough for you? Want to work with your buddy Rasmus on the Transverse Doppler Effect? We are waiting...Ati3414 16:18, 16 March 2006 (UTC)

Prove what? You don't believe that if the calculations are done according to case 1 that you will get a null result? I have stately explicitly my opinion on this. If you state explicitly yours (commit unabiguously to an answer), I will show you your error. As a reminder, case 1 is:

Apply length contraction to the object as if it was moving at velocity v, and apply Maxwell's equations / Lorentz force law in the frame in which the object IS moving at velocity v. (Basically "force" yourself to do all the calculations in some arbitrary "aether frame".)

So what is your answer? Then we can get to the math. Gregory9 16:38, 16 March 2006 (UTC)

All the equations are in the paper. Prove them wrong. Give me equation number and reason why it is wrong. I did all my calculations, it is time you did yours. Ati3414 16:42, 16 March 2006 (UTC)

Above you wrote: "And remember, in the paper, I am just explaining Trouton's point of view, not mine." So I want to be absolutely sure what your opinion is. You claim the calculations ARE done according to case 1. And you claim the calculations DON'T give a null result. So it appears you ARE claiming that if the calculations are done according to case 1 that you will NOT get a null result.

So again: You don't believe that if the calculations are done according to case 1 that you will get a null result? If you commit unabiguously to an answer, I will show you your error. Gregory9 17:05, 16 March 2006 (UTC)

You have the paper in front of you. You see the premises, they are stated clearly in the intro, everybody can see them (well, unless people take it down). So, stop waving your hands, we are waiting for your calculations. You know "tex", don't you? So , post your calculations. We have been waiting for almost a day now. Ati3414 18:09, 16 March 2006 (UTC)

Why won't you state your belief unambiguously? Afraid to be shown wrong later? As I told you: if, and only if, you commit unambiguously to an answer will I show you your error.

So again: You don't believe that if the calculations are done according to case 1 that you will get a null result? Gregory9 18:15, 16 March 2006 (UTC)

The rules are very clear:

1. Use only length contraction

2. Calculate results from the point of view of a inertial frame anchored in the SUN

3. Translate the results into the lab frame.

We're waiting.....Ati3414 21:54, 16 March 2006 (UTC)

There is no way I am answering the question until you commit to a response. I am not going to waste my time to just have you flip flop and claim "that isn't me, that is Trouton". I will solve this for case 1 if you commit to an answer. This is an easy request here Sfarti, just answer it so we can move on.

So again, answer unambiguously: Do you believe that if the calculations are done according to case 1 that you won't get a null result? Gregory9 22:16, 16 March 2006 (UTC)

I gave you the exact case, Kevin, several times.It is in print, on the website. Your task is to prove the paper wrong. Work with the paper.Ati3414 22:26, 16 March 2006 (UTC)

You wrote: "And remember, in the paper, I am just explaining Trouton's point of view, not mine." So I refuse to answer the question until you commit to a response. This is an easy request here Sfarti, just answer it so we can move on.

So again, answer unambiguously: Do you believe that if the calculations are done according to case 1 that you won't get a null result? Gregory9 22:30, 16 March 2006 (UTC)

Kevin, you don't set the rules, they were set by history. Refute the paper or shut up. Ati3414 22:59, 16 March 2006 (UTC)

Why do you feel my request is unreasonable? It is a simple question.

So again, answer unambiguously: Do you believe that if the calculations are done according to case 1 that you won't get a null result? Gregory9 23:09, 16 March 2006 (UTC)

Your request is unreasonable because you are trying to prove something that is plain stupid,your request is a nonstarter. Trouton was a very smart physicist and a fantastic experimentalist, if he for a second anticipated that his calculations would give a null result do you think that he would have devised and undertaken the experiment? His calculations anticipated a non-null result and this is what I am showing in my two page recreation. So don't give me this shit about the calculations being wrong. They are wrong the same exact way Trouton was wrong. They have to be in order to recreate his thinking. This is a paper about the history of a famous experiment, it is not a modern day analysis. You are simply showing your lack of respect and knowledge about the history of physics (see your blunders about the Lorentz-FitzGerald contraction, have you read the papers I recommended? Are you having some nightmares about Lorentz's explanation of the Michelson-Morley experiment? But this is a digression)So, using the SAME constraints and knowledge as descrbed in Trouton's paper (or in mine), show us how you get a null result.I'll tell you: you can't. Because he didn't. Neither did Tomascheck in 1924,5,6,7. Show some respect, these were smart people, they knew what they were doing, they were after non-null results because their calculations predicted non-null results. You are still thinking current day SR, you can't step out of your little box. I challenged you for 2 days now. Show us your calculations. We have been waiting, you have a big audience now.Ati3414 06:51, 17 March 2006 (UTC)

You are still missing the main points.

1) A moving object IS contracted in the direction of motion, and Maxwell's equations / Lorentz force law ARE correct (for macroscopic descriptions). Therefore if the calculations are done correct in "the sun's frame" or whatever, you should get the correct answer: no current flow through the galvanometer / a null result.

2) You are contradicting yourself. You even admit your calculations are wrong: "... don't give me this shit about the calculations being wrong. They are wrong the same exact way Trouton was wrong." Yet you still maintain this experiment kills off length contraction. This experiment shows more about their incorrect calculations than it does about length contraction. (I do have respect for them. Everyone makes errors including me and including you. They were working in earnest. They made mistakes.)

I will show you some errors in your paper if you answer my questions. Since you have brought this to a standstill, I will be gracious and go first. After this you must answer my questions, or this discussion is over. As it is not even a discussion if one party refuses to state their position.

Now, onto an example of your errors: For those interested in following along, here is his paper Sfarti spam.

Notice that the only thing he talks about when doing the calculations is resistance. Where are Maxwell's equations? He doesn't even specify in what frame he is applying Maxwell's equations and he implicitly assumes the electric fields are unaffected by the fact that this whole assembly is travelling at velocity v. I know some of the physics students taking electrodynamics this semester have enjoyed watching the antics of Sfarti, so in case you are following along, what does the electric field of a moving charge look like according to Maxwell's equations? That is correct, it is no longer isotropic and there is also an associated magnetic field now.

In other words, he is NOT doing the calculations in the "sun rest frame". Instead he is applying the length contraction AND Maxwell's equations in the rest frame of the circuit.

And while it doesn't matter now, I will also show how he is not even consistent in applying his arguements. He says $R_{2}'=\gamma ^{2}R_{2}$ because in rotating 90 degrees, L "uncontracts" and A "contracts". Alright, then $R_{1}'=R_{1}/\gamma ^{2}$ because in rotating 90 degrees, L "contracts" and A "uncontracts". (He states instead $R_{1}'=R_{1}/\gamma$.) The fact also holds similarly for $R_{4}'$. Again keep in mind that this change doesn't make his calculations correct.

So in summary, this paper has major errors which we can quickly see before even getting into the nitty gritty of applying Maxwell's equations to moving charges in a moving circuit.

And now it is your turn Sfarti.

Answer unambiguously: Do you believe that if the calculations are done according to case 1 that you won't get a null result? Gregory9 13:07, 17 March 2006 (UTC)

Ati3414's continual refusal to answer direction questions

As I stated above, I consider the discussion on Trouton-Rankine finished unless my simple direct question is answered. Until that time, all of Sfarti's stalling will be moved to this section. Gregory9 15:28, 27 April 2006 (UTC)

You must mean, your own errors, Kevin.

1. You seem unable to even quote the correct link to the paper. It is

here and here

2. Again, you can't even quote my formulas correctly.

3. The Maxwell equations that you keep clamoring for are embedded in the text. You need a much better knowledge of physics to recognize them.

So, Kevin, you have your answers. Ati3414 15:09, 26 April 2006 (UTC)

Quick reply. 1) The dead link is not my fault as you removed your incorrect paper after I pointed out errors. 2) I did quote the formulas correctly when I wrote that. You CHANGED your paper after I showed that your logic wasn't even consistent. 3) Resistance comes from Ohm's law (J=σE) - a phenomenological theory which is NOT Maxwell's Equations (it is a separate idea). You are only exposing more of your incorrect knowledge. If you are not willing to answer the simple question above, attempts at continuing the conversation will be moved here OR DELETED. You have been warned. Gregory9 15:28, 27 April 2006 (UTC)

Trouton did not use Ohm, you definitely don't know electromagnetism. He used some other form of Maxwell's equations but you wouldn't know. They are right in front of your nose but you can't see them, Kevin. Take a remedial class. Ati3414

They did indeed use Ohms law as you did in your paper as well. Here are Maxwell's equations:

${\vec {\nabla }}\cdot {\vec {E}}=\rho /\epsilon _{0}$

${\vec {\nabla }}\times {\vec {E}}=-{\frac {\partial {\vec {B}}}{\partial t}}$

${\vec {\nabla }}\cdot {\vec {B}}=0$

${\vec {\nabla }}\times {\vec {B}}=\mu _{0}{\vec {j}}+\mu _{0}\epsilon _{0}{\frac {\partial {\vec {E}}}{\partial t}}$

Note that they do not contain conductivity (or resitivity). That only comes from Ohm's Law ${\vec {j}}=\sigma {\vec {E}}$, a phenomenological theory. So it is not me that needs "a remedial class".

If you are not willing to answer the simple question above, attempts at continuing the conversation will be moved here OR DELETED. You have been warned. Gregory9 16:15, 27 April 2006 (UTC)

Pay the 25 pounds and get the original Trouton paper. You also need to retake Electromagnetism 101. Ati3414

Those are Maxwell's equations that I wrote above. That is Ohm's Law. You deny this and you claim that _I_ need to retake Electromagnetism 101? Your misconceptions run quite deep, and you are unwilling to actually learn or answer questions so that people may help you learn. So this is a waste of everyone's time. As I warned you, I will now start deleting any comments of yours that keep repeating the same incorrect physics as well as you stalling to answer any questions. Gregory9 18:37, 27 April 2006 (UTC)

I also see you keep trying to go back and change several previous comments. I will be reverting those as well. Make new posts. Do not just add to an older comment several back in the "thread" to "sneak in" an arguement or something. Gregory9 18:37, 27 April 2006 (UTC)

Trouton did not use Ohm,he was a much better phycist than you give him credit (and than you'll ever be). You definitely don't know electromagnetism. He used some other form of Maxwell's equations but you wouldn't know. It is NOT Ohm, it is another form, directly derived from Maxwell and invariant under transformations. But you are so fixated as in all cases that you can't see it. They are right in front of your nose but you can't see them, Kevin. Take a remedial class, Electromagnetism 101 would be good. Ati3414

Again, Maxwell's equations DO NOT HAVE RESISTIVITY OR CONDUCTIVITY IN THEM. Let this sink in: resistance is not in Maxwell's equations. Resistivity/conductivity comes from the phenomenological theory that is Ohm's law.

Trouton did indeed use Ohms law. The university library allows free access for anyone to almost any scientific paper. I have indeed seen Trouton's paper. His very first equation is referring to resistance, and the following equations are modifying this. Again, resistance is a concept from Ohm's law, not Maxwell's equations.

I went back in the history and saw that at one point you wrote "Hint: ever heard of Kirchoff's "laws"?" claiming that this somehow explained that Trouton did not use Ohm's law. I'm sorry to tell you, but Kirchoff's laws are just examples of conservation of charge (in equilibrium, the amount of charge entering a point equals the amount of charge leaving it) and conservation of energy for magnetostatics (closed path integral of the electric field is zero). Kirchoff's laws need to be used WITH OHM'S LAW to say ANYTHING about resistance.

You can deny it all you want, but Ohm's law is indeed used here and you are indeed misunderstanding electrodynamics at a fundemental level. Gregory9 19:28, 27 April 2006 (UTC)

Congratulations!, it took you several days and multiple hints to finally get the right name but you still don't get the elementary stuff, i.e. Kirchoff is a direct derivative of Maxwell. Obviously you don't know that (and you "teach" electromagnetism?). Two can play this game, Kevin. Get the remedial class. Soon As long as you edit out my pertinent comments and you put up your slanderous ones, I'll keep correcting your lies. Take the shit you have put up down and I will stop correcting you. Ati3414

1- Did you even read what I wrote? Kirchoff's laws are NOT about resistance. OHM'S LAW is what brings resistance into the equations. You are wrong for claiming otherwise. That is not slander, that is not lies, that is fact.

2- I am not editting out pertinent comments. I move your comments to the correct section, and I revert things that you try to add to old comments which then make the replies not totally related. As I said, add new comments, do not try to sneak stuff into old ones. Gregory9 20:41, 27 April 2006 (UTC)

You are so stuck up on your beliefs. Go back and check on Kirchoff. While you are at it, check out that there is a relativistic form for Ohm's law as well (though it isn't necessary in the Trouton experiment). I don't think that you are able to make the connections, this may be your problem. Try taking the blinders off, Kevin. Trouton was a VERY good physicist (you will never come close to that because of your narrow-mindedness) Ati3414

Then don't edit out my captions. You put up captions, I put up captions as well. You take them down, I will take them down. Ati3414

Kirchoff's Laws only show charge conservation and energy conservation. It says NOTHING about resistance without using OHM'S LAW. Your continued refusal of this even though it is so obvious (since Maxwell's equations don't even contain resistance), is just ridiculous.

My caption is correct. You are indeed continuing to refuse to answer a simple direct question. Your caption is not correct, for it is quite obvious that you are the one misunderstanding electromagnetism, not me.

If you admit that Ohm's law is indeed what brings resistance into the equations, as well as answering my simple question that you keep avoiding, then I will not only remove the caption, I will remove this whole section as it would no longer be pertinent. It is your choice. Keep refusing to answer questions or admit your mistakes and your comments will keep being moved here. Gregory9 05:06, 28 April 2006 (UTC)

The Ohm law is a red herring in this discussion, Kevin. By now you have at least figured out after many days where the Maxwell equations are in the paper. Trouton figured out an invariant under Lorentz laws, one that you are unable to see because you can't seem to take your blinders off, this is a "null" experiment (do you know what it means?). Not everyone in the world has free access to all the papers ever published like you do. That was the whole point of adding the interpretation of how Trouton reasoned. The interpretation that you removed out of spite because you were caught cheating (playing "sock puppets') on the wiki website (as "Gregory9" and as "Socrunchy" and as "quoi" and "gregory" here. You continue to argue that Trouton had it wrong, actually he was much smarter and subtler than you give him credit. He was a full professor of physics (he taught electromagnetism, see his bio) and at the time he did the experiment with Rankine he had already staged his other famous similar experiment with Noble. Other than throwing statements about his correct application of Maxwell's laws what have you done so far? We all know. Ati3414

Stop making accussations, and stop trying to "reason" by insult upon insult and ad hominem attack. I have clearly shown you that resistance is introduced into the equations from Ohm's law, and it must be so BECAUSE RESISTIVITY ISN'T EVEN IN MAXWELL'S EQUATIONS. The result of Trouton's experiment is correct - it agrees with Special Relativity, no one is arguing about the experimental result. The issue is that he makes incorrect calculations which lead him to expect that length contraction would produce a measureable effect in the rest frame of the object ... he did this despite even Lorentz (with his ether theory) showing that length contraction is not measureable in the rest frame of the object, and despite Poincare showing similarly (before SR), and despite Einstein stating so earlier as well with his theory of special relativity.

You continue to make accusations and insults instead of answering direct questions. You are not here for a scientific discussion, you appear to be here just to hurl insults. This is unacceptable. Gregory9 16:46, 28 April 2006 (UTC)

Yes, it is the Lorentz-FitzGerald Contraction Hypothesis that: "...lead him (Trouton) to expect that length contraction would produce a measureable effect in the rest frame of the object". It is not his incorrect application of the Maxwell's laws as you kept harping on. Trouton understood electromagnetism and relativity very well (he even taught it after 1905). Remember, the Trouton-Rankine experiment was executed in 1908.

If you read the intro to my paper it is stated clearly that Trouton "set to prove the FitzGerald hypothesis correct". This comes straight from Trouton's bio. The Lorentz-FitzGerald hypothesis was the cornerstone of both the Trouton-Noble experiment and of the Trouton-Rankine experiment. Now, I need to correct you on another mistake: if you read the Lorentz paper of 1904, as late as 1904 Lorentz still thought that length contraction is measurable in the rest frame of an object. Lorentz changed his opinion later, under the influence of Poincare and Einstein (the two Trouton experiments had a major contribution as well). Ati3414

No, you still do not get it. This experiment does not disprove the Lorentz-FitzGerald Contraction Hypothesis. The Lorentz-FitzGerald Contraction Hypothesis is in agreement with special relativity - moving objects contract in the direction of motion by the ratio $1:{\sqrt {1-v^{2}/c^{2}}}$.

You are quoting wiki, Kevin. I take it that you are reading this. If this is the case, read again. The Lorentz-FitzGerald contraction is the "length contraction (that) would produce a measureable effect in the rest frame". Of all people you should know that the Lorentz contraction (SR,due to relative motion) and the Lorentz-FitzGerald contraction (the one that is supposed to happen in the proper frame) are two different things, you are trying to teach this subject, aren't you?Ati3414

And Trouton DID misapply Maxwell's equations. Maxwell's equations are correct, Trouton's application of them (along with Ohm's law) is not. Gregory9 17:14, 28 April 2006 (UTC)

of course Maxwell equations are correct. You still don't get that Trouton knew his stuff, you are regressing again. Trouton did not need the Ohm equations explicitly (though a relativistic invariant form of the Ohm equation exists, you keep missing this one). Trouton discovered an invariant and used it to full extent. I'll let you discover what it is, it might take you a long time but you eventually get these things. Ati3414

You continue to bring up points that I have already shown to be incorrect. You continue to refuse to answer my questions, or accept your errors when they are shown to you. Thus it is obvious that: This is leading nowhere, please do not post on my talk page again. Please abide by this simple request. Gregory9 00:49, 30 April 2006 (UTC)

Guidelines for Wikipedia lists of ethnic groups

Please may I draw your attention to

http://en.wikipedia.org/wiki/Wikipedia:Village_pump_(policy)#Guidelines_for_Wikipedia_lists_of_ethnic_groups

Your contributions would be very welcome. -- Brownlee 11:52, 11 April 2006 (UTC)

Center of mass = center of momentum

Finding the center of mass (CM) of a system (which is a position vector, sometimes moving with a velocity v) is done with the standard equation. For a given system, if the CM has a velocity, it is v = sumP/sumM. The reference frame chosen to make the VELOCITY of the center of mass zero, usually referred to as the center of mass frame, is therefore also the center of momentum frame (since in this frame VsumM = sumP so grand total sumP = 0). So either term is fine, and both are used frequently in physics. No need to go stomping around labeling one of them "wrong." Neither is "wrong." Both are used. Center of momentum is a bit more descriptive, and is what I happen to like best. SBHarris 19:54, 13 August 2006 (UTC)

True, it is apparrent from context what is meant by the center of mass frame. However, I feel there are situations when the term "center of mass" is incorrect. For example, consider a system consisting of just two photons, with momentums in different directions. There is a frame with a zero net momentum. In this frame, there is a non-zero invarient mass (as in every frame), but where is the center of mass? It is undefined. Go into another frame with non-zero net momentum. Sure, there is a net momentum, and there is still a non-zero invarient mass ... so are you arguing that there is a center of mass and that it is moving at a particular velocity? There isn't. The center of mass is undefined in these situations.

I fully understand what you mean when you say the "center of mass frame". But a whole debate and editting war got started about the careful wording of what we were attributing mass to. Therefore, I felt it was best to remove "center of mass frame" and instead use something like "center of momentum"/"zero net momentum" frame.

I hope that didn't cause any problems. -- Gregory9 01:44, 14 August 2006 (UTC)

Well, I suppose you can say that the center of mass of a two photon system is "undefined" because you can't use the standard equation with masses of each particle to define it. However, by analogy with situations involving massive particles, the center of mass of a two-photon system (which system does have mass) is the same point that is the origin point of the center of momentum frame for two photons. There is nothing really undefined about the center of mass point--- if the two photons originate from an anihilation event, or decay of some particle like a π⁰, the event happened at that point. It's well defined. You might not like it, but you have to call it SOMETHING. And yes, in other frames, that point moves with a certain velocity, and yet the invariant mass remains the same. Just as the original particle which has that rest mass moves at that particular velocity, when seen from other frames. What's not to like? You'll see center-of-mass energies calculated for 2 photon systems from a decay ALL THE TIME. SBHarris 05:37, 14 August 2006 (UTC)

You can use the term "center of mass" frame instead of "zero net momentum" frame and I'm sure almost everyone will know what you mean. So it's kind of silly to argue about this. Heck, I often use the term myself.

However, the point is, as you say "you can't use the standard equation with masses of each particle to define it". But even more, there is no way to extend this definition with SR in order to unambiguously define the center of mass of two photons because 1) the invarient mass of the system being non-zero doesn't allow us to associate a mass with each component of the system and 2) even if we resort to some kind of "center of relativistic mass" the photons are delocalized. A photon is an inherently quantum mechanical object. So, unlike massive particles, there is no classical picture with positions and energies being specified simultaneously.

Your way of getting around this by trying to refer to the photons' histories to find some common point and call that a center of mass will not work either. First, because this would require us to know the history of all photons (instead of a mathematical definition). Second, it is possible to create the same physical state with different histories (again showing the center of mass for these system is not uniquely defined). Third, it doesn't make physical sense with more complicated histories (as an extreme case, a plasma with countless creation, annihilation, and scattering of photons).

You state: "You might not like it, but you have to call it SOMETHING." Unfortunately, just because there is a mass, doesn't mean you can say WHERE the mass is. It is this very same subtle point that was upsetting some people with the photon article. -- Gregory9 09:45, 14 August 2006 (UTC)

It's not my purpose to be argumentative, but there are very many situations in which you can detect two outgoing photons and infer their point of origin. That point is the COM of the system. This is how a PET scanner works, for example. For the breakup of an extreme relativistic particle like a π⁰ from a synchrotron products, the technique works just as well. Rest masses of many heavy particles are inferred from pairs of high energy photons, moving at acute angles.

What you say about photons being QM objects is of course exactly true of EVERY particle, and all the things you say applies equally well to any particle you can name. There's nothing special about photons, particularly comparing photons to other particles in the extreme relativistic region in which most of the particle energy is kinetic. Nevertheless, subject to those constraints, tracking particles (including photons) and where they come from, is still big business in medicine and high energy physics. In PET scanners, the resolution is down to mm range. And yes, the mass of a photon-pair system is delocalized. However, the center-of-mass of such a system isn't delocalized, or else a PET scanner simply would not work.SBHarris 15:16, 14 August 2006 (UTC)

"And yes, the mass of a photon-pair system is delocalized. However, the center-of-mass of such a system isn't delocalized, or else a PET scanner simply would not work." I'm not sure where you got this idea from. The positron annihilation into two photons gives a LINE of coincidence. So each pair of photons does not tell the imaging machine the "center of mass" point. Many of these lines of coincidence need to be considered together to reconstruct a 3-D image. Even after reconstruction, you can not return to the recording of an individual pair of photons and state their "center of mass".

"Rest masses of many heavy particles are inferred from pairs of high energy photons". Yes, a system of more than one photons can have a non-zero invarient mass (as we both know). But the point is that we can not say WHERE this mass is. This is the important subtle point.

"What you say about photons being QM objects is of course exactly true of EVERY particle, and all the things you say applies equally well to any particle you can name." You got the point backwards. The point was that we can discuss massive particles classically (and we can discuss electromagnetic fields classically), but we can't discuss photons classically as they are inherently quantum mechanical. If you want to ignore photons and consider instead classical electromagnetic fields, then you probably could indeed define some kind of "center of relativistic mass".

I just don't understand this strong need to know where the mass is. It just means the origin in this frame is arbitrary. And none of the things you want to calculate in this frame depend on the location of the origin. So why the strong need to know where the mass is?

Here, let's look at a specific example. Let's say we have an "atom" of positronium in an excited state, and it decays into three photons. Considering just two of those photons as a separate system (any two), how do you define the center of mass for that system of particles? If we are still in disagreement, maybe thinking over this simple case can help resolve some of the problems. -- Gregory9 21:11, 14 August 2006 (UTC)

If you give me any two photons AND tell me their directions and energies, the invariant mass/energy is calculable by the standard 2 photon formula, and the center of mass frame is of course the one in which both photons have equal energy and momenta. Center of mass moves with the center of mass frame. If you don't tell me the information about energies, of course I can't do the problem because the 3rd photon can carry off any arbitrary energy/momentum (up to a limit) so I don't have enough information to do the problem. I can't tell you about the electron and proton from a beta decay unless you tell me what the neutrino took, either. No photons involved. But I don't see what your point is. If you don't give enough information, the problem can't be solved for beta decay, either, and this has nothing to do with photons.

As for your point about PET scanners, you nailed me there. I was thinking that they routinely measure time of flight but they only use that as a veto on events to avoid the collimation problem of gamma cameras, so you are quite right that modern scanners only find an incidence line (line of response = LOR), and work from there like a SPECT or CT. They can't resolve where the event is, along that line, but have to do statistics. However, this is a technical problem only, due to the fact that our best detectors have a response time of 40 ns and you need 2 ps detector resolution to tell what voxel the decay happened in, to 1 mm. But if you HAD the detector, and nothing in physics prevents its existance, a TOF (time of flight) PET which told you about the 3-D location of every single event, is perfectly possible in theory[3]. SBHarris 00:24, 15 August 2006 (UTC)

"If you give me any two photons AND tell me their directions and energies, the invariant mass/energy is calculable by the standard 2 photon formula, and the center of mass frame is of course the one in which both photons have equal energy and momenta." We are not disagreeing on these points. All you did was describe the zero net momentum frame. None of this specifies the location of the "center of mass".

In your TOF PET example, you are implicitly giving the photons a position (localizing them). It is only because of your knowledge of their history that you define a center of mass. We're right back to where we were: your "definition by history" of a center of mass for two photons.

I made the three photon example because it removes this "define by history" escape route. And no, I don't need to specify the photon momentums... that is the point, they are practically arbitrary. We can mathematically define the center of mass for an arbitrary system of massive classical particles. 1] So: How do you define the center of mass for two photons of arbitrary momentums of unknown history?

The whole point is, you can't. You can't say what the position of a photon is and what its energy is. Therefore you can't calculate a "center of mass" for a system of photons. 2] I assume we agree on this, correct? This is similar to trying to answer: "Photons individually have zero invarient mass, but a system of them can have non-zero invarient mass, so in this system, where is the mass located?" 3] Do we agree this does not have a definite answer as the question itself is subtly flawed? 4] Do you agree, for those reasons just stated, that the question "Where is the center of mass?" has similar flaws?

If instead we treated particles and electromagnetic fields classically, then we could define some kind of "center of relativistic mass" if we really wanted to (even if the system contained only electromagnetic energy). 5] I assume we agree on this as well, correct? (And is that all you really want to show?)

You really seem to want to treat the photon as a "particle" of energy, with a definite position travelling away at the speed of light. I know you realize that is incorrect, so please fight the temptation to treat it as such just to maintain the notion of "center of mass" which does not really apply here.

If you'd like to continue this discussion, to prevent it from going in circles, please answer the five questions above. Thanks. -- Gregory9 06:47, 15 August 2006 (UTC)

Tag

I removed the sockpuppet tag. Sorry, I forgot all about that when I closed the investigation.
I'll explain my comments on the indef a little later when I have a bit more time. It's a moot point though because his current account got blocked and now that I've had time to review this more I would probably block his socks on sight.--Isotope23 12:27, 2 March 2007 (UTC)