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| Tags: circular, dilatation, motion, time |
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#141
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"Tom Roberts" escreveu na mensagem t... El Enrrabadore-mor wrote: "Tom Roberts" escreveu na mensagem ... [...] 1 - Your solution: \tau = sqrt(1-|v|^2/c^2) You're not paying attention, and you are MISQUOTING. I said "For circular motion, v(t) is constant," (TYPO: I of course meant |v(t)| is constant.) \tau = sqrt(1-|v|^2/c2) (T2 - T1) Just MISquoting the formula is not sufficient, you must also read the words that give the conditions under which the formula is valid. I didn't misquote your formula by propose. I just didn't realise that you've simplified that much the problem. Such simplification makes your solution ridiculous, that's all. So, I never realise that one could make such ridiculous simplification: What you say is that: 1 - The velocity v is constant. 2 - Hence, the sqrt(1-(v/c)^2) is a constant term K. 3 - Therefore, \integral K = K t Without such ridiculous simplification, to include "t" or not doesn't make any difference, since it is obvious that dt/dt = 1. Because dt/dt = 1 is so obvious, I didn't care about it. Hence, I didn't misquote your formula by propose. [...] Can't see what's wrong. What is wrong is that it is not possible to perform that integral without knowing the functional form of v(t). When |v(t)| is constant, the integral is trivial, and has the value given above. When |v(t)| is not constant, you must know its functional form in order to do the integral. That's the ridiculous part of relativity approach to the rigid disk. When |v(t)| is constant, it doesn't matter if it's circular motion or linear motion, you always got Lorentz equation. To compare, or to say, that circular motion is the same thing as linear motion, sounds ridiculous to me. I'm about to say that, relative to the XXI Century, relativity theory is in its Stone Age. ...and people stoned with it. Tom Roberts |
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#142
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"El Enrrabadore-mor" wrote in message
"Tom Roberts" escreveu na mensagem t... El Enrrabadore-mor wrote: "Tom Roberts" escreveu na mensagem ... [...] 1 - Your solution: \tau = sqrt(1-|v|^2/c^2) You're not paying attention, and you are MISQUOTING. I said "For circular motion, v(t) is constant," (TYPO: I of course meant |v(t)| is constant.) \tau = sqrt(1-|v|^2/c2) (T2 - T1) Just MISquoting the formula is not sufficient, you must also read the words that give the conditions under which the formula is valid. I didn't misquote your formula by propose. I just didn't realise that you've simplified that much the problem. Such simplification makes your solution ridiculous, that's all. So, I never realise that one could make such ridiculous simplification: What you say is that: 1 - The velocity v is constant. 2 - Hence, the sqrt(1-(v/c)^2) is a constant term K. 3 - Therefore, \integral K = K t Without such ridiculous simplification, to include "t" or not doesn't make any difference, since it is obvious that dt/dt = 1. Because dt/dt = 1 is so obvious, I didn't care about it. Hence, I didn't misquote your formula by propose. If you want to consider the general case where v(t) does not have a constant magnitude, then you must integrate over the actual function. This is obviously more difficult that assuming constant speed (either linear or circular motion). In fact, for most functions v(t) there will not be an easily obtained closed form solution, or perhaps no closed form solution. In such cases one usually resorts to numerical integration or an approximation method. When you did the integral you made the error of assuming that dv/dt = dt, which it won't be in general. If you have an integral such as \Integral _a^b U(t)dt, you cannot assume that dU(t) = t. You need to have U(t)du. [...] Can't see what's wrong. What is wrong is that it is not possible to perform that integral without knowing the functional form of v(t). When |v(t)| is constant, the integral is trivial, and has the value given above. When |v(t)| is not constant, you must know its functional form in order to do the integral. That's the ridiculous part of relativity approach to the rigid disk. Absurd. You're miffed because the math for the general case might be hard. When |v(t)| is constant, it doesn't matter if it's circular motion or linear motion, you always got Lorentz equation. Indeed. What a pleasing result! Wouldn't it be more strange if, despite the obvious analogs between the mathematical physics of linear and circular motion (v ~ w, T ~ F, L ~ momentum, etc., and the functional forms of rotational and linear energy), that relativity would predict different forms for the time dilation effect? To compare, or to say, that circular motion is the same thing as linear motion, sounds ridiculous to me. They are clearly not the same thing, as rotational and linear momenta are separately conserved. Yet the mathematical form for dealing with them run along parallel lines. I'm about to say that, relative to the XXI Century, relativity theory is in its Stone Age. ...and people stoned with it. Uh oh. |
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#143
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El Enrrabadore-mor wrote:
"Tom Roberts" escreveu na mensagem t... For circular motion, |v(t)| is constant: \tau = sqrt(1-|v|^2/c2) (T2 - T1) I just didn't realise that you've simplified that much the problem. Look at the subject of this thread. "simplifying" to circular motion is what is being discussed. Such simplification makes your solution ridiculous, that's all. It's not "ridiculous", it is what this thread is about. I gave a general equation (in response to an inquiry), and then applied it to the subject of this thread. shrug [...] To compare, or to say, that circular motion is the same thing as linear motion, sounds ridiculous to me. What is ridiculous is your "sound bite" approach to physics. Nowhere does anybody claim "circular motion is the same thing as linear motion". But when the formula in question depends only on |v|, and when one considers a constant |v| (which can apply to either linear or circular motion), then THE FORMULA gives THE SAME ANSWER for the two types of motion. This does not in any way imply the motions themselves are "the same". This is not limited to just linear and circular motion -- ANY motion with constant |v| obtains the same answer from this formula. I'm about to say that, relative to the XXI Century, relativity theory is in its Stone Age. ...and people stoned with it. Obviously you do not understand it, so your opinion is irrelevant. Tom Roberts |
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#144
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On May 9, 8:14 am, Tom Roberts wrote:
El Enrrabadore-mor wrote: "Tom Roberts" escreveu na mensagem et... For circular motion, |v(t)| is constant: \tau = sqrt(1-|v|^2/c2) (T2 - T1) I just didn't realise that you've simplified that much the problem. Look at the subject of this thread. "simplifying" to circular motion is what is being discussed. Such simplification makes your solution ridiculous, that's all. It's not "ridiculous", it is what this thread is about. I gave a general equation (in response to an inquiry), and then applied it to the subject of this thread. shrug [...] To compare, or to say, that circular motion is the same thing as linear motion, sounds ridiculous to me. What is ridiculous is your "sound bite" approach to physics. Nowhere does anybody claim "circular motion is the same thing as linear motion". But when the formula in question depends only on |v|, and when one considers a constant |v| (which can apply to either linear or circular motion), then THE FORMULA gives THE SAME ANSWER for the two types of motion. This does not in any way imply the motions themselves are "the same". This is not limited to just linear and circular motion -- ANY motion with constant |v| obtains the same answer from this formula. I'm about to say that, relative to the XXI Century, relativity theory is in its Stone Age. ...and people stoned with it. Obviously you do not understand it, so your opinion is irrelevant. Tom Roberts Yeah, In the past I equated 2x acceleration x radius = velocity squared. 2ar = V^2. and subbed a=GM/r^2 then V^2 = 2GM/r, where V is escape Velocity. Grist's hit me over the head when I done that. It's close enough ;-), but it really needs to reveal more subtle effects. Regards Ken S. Tucker |
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#145
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On May 9, 8:03 am, "El Enrrabadore-mor"
wrote: "Darwin123" escreveu na ... Do you agree with the above picture? At this point, I do not have a clear image of your apparatus. I also don't fully understand the deviation from theory that you claim to be seeing. I am a physicist, not an engineer. However, I can provide some hypotheses based on general engineering considerations. I am not saying that you are wrong, but have you looked into... Do you believe it's possible that a torque T3 can arise in the process, in order to spin up/down the gyro main angular velocity w3? Yes, in principal. I don't know if this is true in your system, but I will hypothesize some possible sources of T3. I think the general engineering approach is to assume the conservation laws and ignore dynamical laws like the Euler equations. The conservation laws have an amazing ability to police themselves regardless of mechanical detail. Dynamical laws require detailed information. However, since the dynamical laws are what you are questioning, you have to go into some of that detail. 1) Your electric motor. An electric motor is not a simple system in the sense of Principia because it uses electromagnetic fields. Some of the angular momentum is stored by the fields, which makes it a bit more complicated. No, I don't have direct experience with electric motors. Its one of the reasons I went into optics. For example, there is a magnet in your motor that applies a "static" magnetic field on the coils. What is the torque on that magnet? I seriously doubt that the third component on the magnet ic zero. The reason is that the motion of the coils has to drag the currents with them. If a wire is maintaining an electric current, and you move the wire in a direction orthogonal to that wire, you have created a component of current in the direction of motion. The charge carriers are confined to the wire, so they have to go where the wire goes. The magnetic field will apply a force to that component. So yes, I think an electric motor will apply torques where you don't expect them. 2) Elastic vibrations. One possibility is that T3 is being caused by elastic vibrations that couple T1 and T2 to your T3. The result may be beats between vibrations that appear to be precession or nutation, even if Euler's equations don't predict them. Euler's Laws are valid for rigid bodies. However, real things bend and even flow. Furthermore, the larger the object the less rigid the object becomes. The cube-square applies. So even if you made your apparatus out of invar-admantium alloy, out of a Marvel comic, if it is large it will act like a rubber band. I once was shopping for an optical table. Read a catalogue from a company that makes optical tables. The catalogues give specifications as to the resonances and vibrations these optical tables will generate. You will get to see that it is impossible to completely ignore vibration. The optical table manufacturers try damp one resonance and another pops up at a different frequency. That is one thing you can try. If it is a case of elastic vibration, you can try to damp particular modes of vibration. You may not get rid of the problem, but the system may deviate in a completely different way. If you try to damp a vibrational mode and your "nutation" changes amplitude, that would be a clue. Of course, you have to identify the possible modes of vibration first. 3) Displacement. Your apparatus may be bouncing up and down. But this I will not expand on. |
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#146
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On May 9, 8:03 am, "El Enrrabadore-mor"
wrote: "Darwin123" escreveu na ... Sorry, I took a lunch break. There is a fourth thing I would like you to consider. My point is that: T1 w1 = Tz wz = T2 w2 That is, T3 and w3 is out of the Energy Conservation problem. Maybe. But what about the power phase? You have some electrical engineering background. Have you considered that the is a phase difference between voltage and current? This is especially important if you use an electric motor. Electric motors have a power phase that changes with the work done by the electric motor. A phase difference will also apply to all mechanical counterparts to your system. For example, there may be a phase, which I designate as Ai (i=1,2,3), between your torques and your angular velocities. So maybe, T1 w1 cos(A1) = Tz wz cos(A2)= T2 w2 cos(A3) Maybe you can make an approximation A1=A2=A3. However, I doubt that Ai=0 in your system for all i. Your time averaged power has to have a phase correction in it. |
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#147
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Ken S. Tucker wrote:
Yeah, In the past I equated 2x acceleration x radius = velocity squared. 2ar = V^2. Your "2" looks wrong. In Newtonian mechanics, for any object moving uniformly in a circle, a=v^2/r. There is no "2". and subbed a=GM/r^2 then V^2 = 2GM/r, where V is escape Velocity. To compute the Newtonian escape velocity V as a function of radius R, simply set an object's kinetic energy to be equal and opposite to its gravitational potential energy at radius R from mass M: 0.5*m*V^2 = G*m*M/R = V^2 = 2*G*M/R Note there is no acceleration involved in this computation. All that is needed is that the object's total energy at r=infinity be zero. Grist's hit me over the head when I done that. It's close enough ;-), but it really needs to reveal more subtle effects. I have no idea what you are trying to say. If you mean that GR has more subtle effects than this Newtonian computation, then sure. Tom Roberts |
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#148
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"Darwin123" escreveu na mensagem ... On May 9, 8:03 am, "El Enrrabadore-mor" wrote: "Darwin123" escreveu na ... Do you agree with the above picture? At this point, I do not have a clear image of your apparatus. I also don't fully understand the deviation from theory that you claim to be seeing. I've the deviation from theory in a 42+20 pages long so far, but can be made much shorter once I finish the story. The problem looks very difficult to work here. I need a support Web page for that, otherwise describe 3 orthogonal coordinate system, Euler angles and math that most of the equations are a full line using dots for derivatives, that will be 4 lines long here. I've been lucky. On a search for gyroscopes I've found a book to download - looking for errors. It was a 10 Years old work from David Morin - Harvard professor - Now available by Cambridge press since January 2008. I've digested those pages deep down up to the minimum detail. The methods I've talked about are all there. The Newton method is fully solved. The Lagrangian method provides a clue on the equations, but misses the second potential T2 = - grad V. The required potential to solve the secondary axis of precession (nutation) was engineered by me. Most of the pages are the work about this, seen by all possible angles, on the Lagrangian solution. Both, Newton and Lagrange fully agree. The vectorial method is a footnote of 2 lines in the book. Nevertheless, such method pulled out of the hat work 99% perfect. Yes, not 100% perfectly. That has been a pain in the ass, since the vectorial method is by far the very best one can have to take a picture on what is going on. Each term of every equation is a vector (torque) that one can draw upon the coordinate system. I've already ****ed my head on that picture and I still have the feeling something escapes me. So, Convervation of Energy was my life save. Like I told you, I can't see any reason why the torque T3 should be involved in the process. No vector exists that can cause it. Only magic can do it. But gyroscopes are all about magic, and you know that. I'm very sure that T3 is out of the problem. The Harvard Book deviation is based on that. The book says dw3/dt = 0. Now the funny thing. If dw3/dt = 0 the conservation of power/energy is the solution I've told you: T1 w1 = T2 w2 = Tz wz The vectorial method gives a perfect match for energy conservation. The Newton/Lagrange doesn't, because includes the acceleration dw1/dt and somehow two of the terms got a number 2 multiplier, one due to the derivative of a squared term, the other due to the sum (I1 + I2) and I1 = I2. What is left out, the difference between Newton and vectorial methods, is a second order differential equation I've solved and gives the perfect behaviour of the secondary axis of precession (the one that is not usual to be described). Such new equation was very exciting, but in fact from the engineering point of view I'm working with peanuts. That is, the value of the torque that those terms amount are less then 1% of the big load involved in the process. So, I'm ****ed up and puzzled. The apparatus is a Wave Energy Converter. I want to run the gyroscope like a gearbox to speed up motion from Ocean Waves, up and down. I am a physicist, not an engineer. However, I can provide some hypotheses based on general engineering considerations. I am not saying that you are wrong, but have you looked into... That's very good, since this problem is basically related to Physics. The apparatus was investigated from the one University in the UK connected to the main manufacture of those devices, based on oil pumps and motors, which is only 25% efficient. They give up do to the lack of understanding of the gyroscope only, by written. Well, I've pressed then a little too, but they deserved, specially because they talk about complex conjugate control and don't have a clue on impedances. The gyroscope can mimic whatever impedance I desire. It can be a damper, a spring or a mass. Full spectrum control. Yep, that's a strange gearbox indeed. Thanks for the remarks, but this is not an engineering problem. No engineering problems exist besides the fact that gyroscope bearings can't handle the load, but I've fixed that too - many gyros in parallel, what else? The problem is the trial top / gyroscope problem from every text book. The question is, does the top in the process of precession and nutation, whatever you do to the top, increase or decrease its main angular speed? The speed decrease do to friction on the table, or friction on bearings, is out of the problem. I mean due to other sources different from what is trivial. Say, frame-dragging or so (kidding)? |
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#149
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Tom et al.
Best essay I've found on the subject under discussion is, Pauli's "Theory of Relativity" pg.150, *53 Simple deductions from the principle of relativity*. On May 9, 1:35 pm, Tom Roberts wrote: Ken S. Tucker wrote: Yeah, In the past I equated 2x acceleration x radius = velocity squared. 2ar = V^2. Your "2" looks wrong. V(e) = sqrt(2GM/r) is escape Velocity. g_44 = 1 - ( V(e)/c )^2 P= GM/r. In Newtonian mechanics, for any object moving uniformly in a circle, a=v^2/r. There is no "2". In that case use, P= 1/2 (wr)^2 which is the "centrifugal force potential". (w is angular velocity). and subbed a=GM/r^2 then V^2 = 2GM/r, where V is escape Velocity. To compute the Newtonian escape velocity V as a function of radius R, simply set an object's kinetic energy to be equal and opposite to its gravitational potential energy at radius R from mass M: 0.5*m*V^2 = G*m*M/R = V^2 = 2*G*M/R Note there is no acceleration involved in this computation. All that is needed is that the object's total energy at r=infinity be zero. Grist's hit me over the head when I done that. It's close enough ;-), but it really needs to reveal more subtle effects. I have no idea what you are trying to say. If you mean that GR has more subtle effects than this Newtonian computation, then sure. That's right, that's a weak field, small velocity calculation. In the quoted article Pauli writes, "the transverse Doppler effect and the time dilation produced by gravitation appear as two different modes of expressing the same fact". What do you think he means by that? Regards Ken S. Tucker |
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#150
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"Greg Neill" escreveu na mensagem m... "El Enrrabadore-mor" wrote in message When |v(t)| is constant, it doesn't matter if it's circular motion or linear motion, you always got Lorentz equation. Indeed. What a pleasing result! Wouldn't it be more strange if, despite the obvious analogs between the mathematical physics of linear and circular motion (v ~ w, T ~ F, L ~ momentum, etc., and the functional forms of rotational and linear energy), that relativity would predict different forms for the time dilation effect? Since time dilatation is something that is very hard for me to accept, I will say that maybe. Imagine that the original inquiry about the circular motion is a 100 seconds-light radius motion around Saturn. People here on Earth will see that circular motion from an external point of view of the circle. It will be like looking to a spinning wheel and compare clock rates from the point of view of a fixed external observer. The symmetry of the problem simply cancels out any possible time dilatation. Therefore, we have the same circular motion problem and two different inertial observer (one at the center of the circle, the other an external observer) that disagree on time dilatation. Which one is right? To compare, or to say, that circular motion is the same thing as linear motion, sounds ridiculous to me. They are clearly not the same thing, as rotational and linear momenta are separately conserved. Yet the mathematical form for dealing with them run along parallel lines. I'm about to say that, relative to the XXI Century, relativity theory is in its Stone Age. ...and people stoned with it. Uh oh. Indeed. My point, that you didn't comment so far, is that effects have consequences. Relative to the original inquiry of this thread, you didn't comment on the main issue. Both observers send electromagnetic signals to each other. The distance between observers doesn't change and light speed is isotropic and constant. Why the moving observer see all signals send by the central observer and the observer and the central observer can't ever receive any signal from the moving observer (at the limit)? Do you see the consequences of a wrong analysis? The right analysis is that time dilatation is a consequence of the speed of light and the DISTANCE travelled by light. That is, time dilatation only is required for observations made at distance, by means of light, like Einstein said. Not the actual bull**** that follows because physicists only have a stone hammer to work with. |
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