The inertial frame concept in 1905 Relativity
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From: valls on 21 Jul 2010 18:55 On 20 jul, 08:58, harald <h...(a)swissonline.ch> wrote: > On Jul 20, 1:24 pm, va...(a)icmf.inf.cu wrote: > > > > > > > On 19 jul, 18:16, artful <artful...(a)hotmail.com> wrote: > > > > On Jul 20, 9:03 am, va...(a)icmf.inf.cu wrote: > > > > > On 19 jul, 15:20, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > On Jul 19, 2:17 pm, va...(a)icmf.inf.cu wrote: > > > > > > > On 19 jul, 08:36, "Dono." <sa...(a)comcast.net> wrote: > > > > > > > > On Jul 19, 3:35 am, va...(a)icmf.inf.cu wrote: > > > > > > > > > On 16 jul, 16:39, "Dono." <sa...(a)comcast.net> wrote: > > > > > > > > > > On Jul 16, 11:31 am, va...(a)icmf.inf.cu wrote: > > > > > > > > > > > > > > Old fart, Tycho Brache already did that hundreds of years ago. > > > > > > > > > > > > > The ECI is a centre of mass inertial frame, in both the Newtonian view > > > > > > > > > > > > and the 1905 Relativity one, in both holding good the Newtonian > > > > > > > > > > > > mechanical laws. And you must know that it is absolutely impossible to > > > > > > > > > > > > describe a Sun moving with respect to an Earth at rest following > > > > > > > > > > > > Newtons laws (Tycho Brahes work precedes Newtons one). > > > > > > > > > > > > You are an imbecile, old fart. > > > > > > > > > > > > > To describe > > > > > > > > > > > > the Suns trajectory you need to consider the Galaxy centre of mass > > > > > > > > > > > > inertial frame (or maybe a greater one), > > > > > > > > > > > > No, old fart. You can use ANY frame. This is the whole point of > > > > > > > > > > > relativity. > > > > > > > > > > > If you insist, describe then the Sun's trajectory in the ECI. > > > > > > > > > > Old fart, Tycho Brahe already did this almost 600 years ago. How dense > > > > > > > > > are you? > > > > > > > > > We are talking here about inertial frames, the ones denoted by 1905 > > > > > > > > Einstein stationary systems, in which the equations of Newtonian > > > > > > > > mechanics hold good. I insist, describe the Sun's trajectory in the > > > > > > > > ECI using Newton's laws. > > > > > > > > Imbecile, Tycho Brahe already showed how this can be done 600 years > > > > > > > ago. See here :http://www.mathpages.com/rr/s8-01/8-01.htm > > > > > > > Incredible! Tycho Brahe using Newton's laws. Surely he made a time > > > > > > travel. > > > > > > I'm sorry, I don't understand. One can describe a trajectory by either > > > > > detailed observation or by theoretical prediction, and in fact one > > > > > should have both and compare them to see if the theory is any good. > > > > > But Brahe's data are quite good descriptions of the trajectories. > > > > > > Are you claiming that Newton's laws cannot describe motion from a > > > > > center-of-mass coordinate? > > > > > By the contrary, what I am claiming is that in 1905 Relativity the > > > > unique inertial frames are the centre of mass ones, > > > > And that is simply wrong. There is no support for that in the paper. > > > That it does an analysis on and pair of arbitrarily moving bodies does > > > NOT mean that it only applies to centre-of-mass frames. Simply that > > > associating a frame with an (imaginary) object makes it easier to > > > picture > > > In the Introduction of his 30Jun1905 paper, 1905 Einstein put out very > > clearly the Newtonian absolute inertial frame (and then also any > > other thing derived from it). > > No, he merely did not *include* it and like everyone else before him > he *kept* everything that was derived from it. > If that is true, then we must put out from 1905 Relativity all the things derived from the ones it excludes, in order to maintain a coherent interpretation. I really dont think that 1905 Einstein does that. Whatever the case, I will follow the behaviour expressed. > The text is the following: > > > [The introduction of a luminiferous ether will prove to be > > superfluous inasmuch as the view here to be developed will not require > > an absolutely stationary space provided with special properties, nor > > assign a velocity-vector to a point of the empty space in which > > electromagnetic processes take place.] > > Originally "insofar as" was emphasized - as you now know! > Don't you understand the meaning of that word? Don't you understand > the words "do not require", and "nor assign"? > Unfortunately English is not my mother language, my understanding of something cant depend on single words or even short phrases. I am still searching for what insofar means. I consider the essential point of the referred text the exclusion of the Newtonian absolute frame, fortunately already confirmed by you. > > If you dont have already empty inertial frames (not related with > > massive bodies) moving with absolute uniform velocities (nor assign a > > velocity-vector to a point of empty space), what remains to determine > > inertial frames? > > He explained that in the *same* paragraph - as he likely was taught: > "all frames of reference for which the equations of mechanics hold > good." > From that I interpret that 1905 Einstein is referring to the inertial frames compatible with the exclusion of the absolute inertial frame (and all the consequences derived from that fact). Starting with the exclusion of the absolute frame, I derived the exclusion of all the ones depending on it to maintain a coherent interpretation. And with all not related with massive bodies inertial frames excluded from 1905 Relativity, I realize that only the massive bodies themselves can determine inertial frames in it, being them the centre of mass inertial frames already present in the Newtonian mechanics. That interpretation is full compatible with the 1905 Einstein identification of systems of co-ordinates with rigid bodies (including the tree rigid material lines). His stationary system denotation for inertial frames can be related with a centre of mass inertial frame always with its centre at rest with respect to the body set that determines it. What do you think that has 1905 Einstein in mind when selecting the word stationary to denote inertial frames? Any denotation is always arbitrary, but very rare (for not to say never) using a word with a meaning not related with the denoted thing. By the way, 1905 Einstein uses a centre of mass inertial frame for the stationary system in the real example at the end of paragraph 4 of his 30Jun1905 paper. > [..] > > > If you have any other valid interpretation of > > the 1905 text, put it here to consider it. > > No you won't! > Have you one? Maybe you consider a valid interpretation one in which all the derived things from an excluded one are *kept*? That is against any logic. I cant conceive a 1905 Einstein (the same able to put out the absolute time) doing that. > > Put an explicit example for > > an inertial frame (a stationary system using 1905 Einstein denotation) > > that is not a centre of mass one corresponding to some body set. > > You should be able to do that yourself, as *any* one is suited (just > more complex to calculate)! Therefore this was the last time for me to > try to get through to you, as I'm quite sure that you will again not > hear what I say. > I request something that in my opinion (wrong or right) cant be done, waiting a counter-example to convince me wrong. Let me analyse your answer. You say *any* one (inertial frame) is suited. That answer is not compatible with a 1905 Einstein stationary system (always with some body related with it), because *any* includes the absolute inertial frame excluded already by 1905 Einstein. Then you fail to point a valid counter-example, increasing my conviction that centre of mass inertial frames are the unique ones compatible with the absolute frame exclusion. I know that 1905 Einstein says nothing about centre of mass inertial frames, but his systems of co-ordinates with three rigid material lines are more than sufficient to convince me that a stationary system can be never the absolute frame or any of the derived from it ones (with no body related with them). > Regards, > Harald Why you dont answer the question in the starting post of this thread? I just note that revising your posts. RVHG (Rafael Valls Hidalgo-Gato)
From: PD on 21 Jul 2010 18:55 On Jul 21, 5:29 pm, va...(a)icmf.inf.cu wrote: > On 21 jul, 15:50, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Jul 21, 3:33 pm, va...(a)icmf.inf.cu wrote: > > > > On 21 jul, 08:27, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Jul 21, 8:13 am, va...(a)icmf.inf.cu wrote: > > ........... > > > > > No. Perhaps you don't understand the meaning of "system" in physics.. > > > > You can draw an imaginary surface around any collection of objects and > > > > that is a system in physics. Some systems can be (for the purposes of > > > > the analysis at hand) be considered isolated and others not isolated. > > > > Conservation of momentum and conservation of energy are statements > > > > about such systems. > > > > > This in no way presumes that the system is the entire universe. > > > > When you have a center of mass inertial system, you can use it only to > > > describe the bodies taking into account when determining that centre > > > of mass. In your 16 balls system, you cant use it for example to > > > describe an added 17 ball, because the presence of the new ball > > > changes the centre of mass. > > > I'm not talking about adding a 17th ball. I'm talking about the fact > > that the laws of physics are the same in any frame in which the center > > of mass of the 16 balls has a nonzero constant velocity. There are an > > infinite number of such frames. > > I added a new body with the purpose to explain you the implicit > assumption in any center of mass inertial system about being its body > set the entire universe. Taking for granted that you understand it > already, I return to your original 16 balls center of mass inertial > frame. Now you want to put it with a non-zero uniform velocity. First of all, let's get the language right. The 16 balls is a *system*. It is not the entire universe. It is a physical *system*. Secondly, there is a frame of reference which is NOT the system, in which the center of mass of this system is at rest. This you can call "the center of mass frame" of this system if you like. Now, what I said is that the laws of physics governing this *system* are identical also in any other reference frame in which the center of mass of this system is moving with constant velocity. Note that I am not involving the entire universe in ANY of this. I have a system of 16 balls. This system has a center of mass. I can look at the coordinates of the center of mass of this system in a reference frame. In one particular reference frame, the coordinates of the center of mass of this system is constant -- the center of mass is stationary. In any other inertial reference frame, the coordinates of the center of mass of this system is moving with constant velocity. > OK, a > single question. In the model, with respect to what you pretend to put > the entire universe moving with a non-zero uniform velocity? Only in > the Newtonian mechanics (with absolute frame) you can do that, never > in 1905 Relativity (without absolute frame). > > RVHG (Rafael Valls Hidalgo-Gato)- Hide quoted text - > > - Show quoted text -
From: Inertial on 21 Jul 2010 19:52 wrote in message news:f5b7711e-79ca-4711-b99f-dc10261f6270(a)y11g2000yqm.googlegroups.com... >On 20 jul, 08:58, harald <h...(a)swissonline.ch> wrote: >> He explained that in the *same* paragraph - as he likely was taught: >> "all frames of reference for which the equations of mechanics hold >> good." >From that I interpret that 1905 Einstein is referring to the inertial >frames compatible with the exclusion of the absolute inertial frame There is no possible way one could rationally justify such a mis-interpretation Regardless .. the "frames compatible with the exclusion of the absolute inertial frame" is all inertial frames, as no inertial frame need to be defined in terms of some non-existence absolute frame [snip rest of nonsense from incorrect interpretation]
From: harald on 22 Jul 2010 11:57 On Jul 22, 12:55 am, va...(a)icmf.inf.cu wrote: > On 20 jul, 08:58, harald <h...(a)swissonline.ch> wrote: > > > On Jul 20, 1:24 pm, va...(a)icmf.inf.cu wrote: [..] Last remarks: > > > In the Introduction of his 30Jun1905 paper, 1905 Einstein put out very > > > clearly the Newtonian absolute inertial frame (and then > > > also any other thing derived from it). > > > No, he merely did not *include* it and like everyone else > > before him he *kept* everything that was derived from it. > > If that is true, then we must put out from 1905 Relativity all the > things derived from the ones it excludes, in order to maintain a > coherent interpretation. I really dont think that 1905 > Einstein does that. Clearly HE did not, but his mechanics teachers DID keep in mechanics all the things derived from the cause they omitted (just as my classical mechanics textbooks did). He simply took that for granted. > Whatever the case, I will follow the behaviour expressed.> The text is the following: > > > > [The introduction of a luminiferous ether will prove to be > > > superfluous inasmuch as the view here to be developed will not require > > > an absolutely stationary space provided with special properties, nor > > > assign a velocity-vector to a point of the empty space in > > > which electromagnetic processes take place.] > > > Originally "insofar as" was emphasized - as you now know! > > Don't you understand the meaning of that word? Don't you > > understand the words "do not require", and "nor assign"? > > Unfortunately English is not my mother language, my understanding of > something cant depend on single words or even short phrases. I > am still searching for what insofar means. It means that it is not an absolute statement, but merely related to the points he next mentions. Freely translated in other words: He did not need to introduce a "luminiferous ether" model with special properties such as a determined velocity because in his theory no frame has special properties that make it distinguishable from others by a velocity effect. > I consider the essential > point of the referred text the exclusion of the Newtonian > absolute frame, fortunately already confirmed by you. I did no such thing; see below. > > If you dont have already empty inertial frames (not related with > > > massive bodies) moving with absolute uniform velocities (nor assign a > > > velocity-vector to a point of empty space), what remains to determine > > > inertial frames? > > > He explained that in the *same* paragraph - as he likely was taught: > > > > "all frames of reference for which the equations of mechanics > > hold good." > > From that I interpret that 1905 Einstein is referring to the inertial > frames compatible with the exclusion of the absolute inertial > frame (and all the consequences derived from that fact). That's a self-contradictory interpretation! In an "absolute" inertial frame the equations of mechanics certainly hold good. Consequently an "absolute" inertial frame is included if it exists (which question he did not discuss). However, instead of using a frame that cannot be determined for the theory, any inertial frame may be taken for the operational definitions of the theory. In short: if I don't introduce chocolate or angels in a discussion because I don't have use for them in that discussion, I am *not* negating the existence of chocolate or angels!! [..] Bye, Harald
From: valls on 22 Jul 2010 12:15
On 21 jul, 17:55, PD <thedraperfam...(a)gmail.com> wrote: > On Jul 21, 5:29 pm, va...(a)icmf.inf.cu wrote: > > > > > > > On 21 jul, 15:50, PD <thedraperfam...(a)gmail.com> wrote: > > > > On Jul 21, 3:33 pm, va...(a)icmf.inf.cu wrote: > > > > > On 21 jul, 08:27, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > On Jul 21, 8:13 am, va...(a)icmf.inf.cu wrote: > > > ........... > > > > > > No. Perhaps you don't understand the meaning of "system" in physics. > > > > > You can draw an imaginary surface around any collection of objects and > > > > > that is a system in physics. Some systems can be (for the purposes of > > > > > the analysis at hand) be considered isolated and others not isolated. > > > > > Conservation of momentum and conservation of energy are statements > > > > > about such systems. > > > > > > This in no way presumes that the system is the entire universe. > > > > > When you have a center of mass inertial system, you can use it only to > > > > describe the bodies taking into account when determining that centre > > > > of mass. In your 16 balls system, you cant use it for example to > > > > describe an added 17 ball, because the presence of the new ball > > > > changes the centre of mass. > > > > I'm not talking about adding a 17th ball. I'm talking about the fact > > > that the laws of physics are the same in any frame in which the center > > > of mass of the 16 balls has a nonzero constant velocity. There are an > > > infinite number of such frames. > > > I added a new body with the purpose to explain you the implicit > > assumption in any center of mass inertial system about being its body > > set the entire universe. Taking for granted that you understand it > > already, I return to your original 16 balls center of mass inertial > > frame. Now you want to put it with a non-zero uniform velocity. > > First of all, let's get the language right. > The 16 balls is a *system*. It is not the entire universe. It is a > physical *system*. > Secondly, there is a frame of reference which is NOT the system, in > which the center of mass of this system is at rest. This you can call > "the center of mass frame" of this system if you like. > I dont call anything, I am not the one introducing the centre of mass inertial frame concept, it is already in Newtonian mechanics long before 1905 Einstein. Yes, you can call the body set (your 16 balls) a physical system, a closed one where you can apply conservation laws. If you want now to consider the centre of mass inertial system corresponding to that physical system, in the model exists the implicit assumption that the physical system is the entire universe. I explained in detail all this already to you, but you seem not understand it yet. I will try again. When the position of the centre of mass relative to the body set is determined, ONLY the 16 balls are taking into account, you are assuming then in the model that they are the unique existing bodies (that they are the entire universe). This is nothing new in Physics, when 1913 Bohr develops its H atom model, he consider a universe with only a proton and an electron, determining their centre of mass at rest. Corresponding to any body set exists a unique centre of mass inertial frame. You must consider always the exterior of the physical system empty, putting a single body there alters the centre of mass (I introduced the ball 17 with that purpose). > Now, what I said is that the laws of physics governing this *system* > are identical also in any other reference frame in which the center of > mass of this system is moving with constant velocity. > We are in agreement about the laws of physics being the same in all inertial frames. What you dont understand yet is that to have a centre of mass moving with a non-zero uniform velocity you need the Newtonian absolute inertial frame already put out by 1905 Einstein. The entire universe can be moving only in the absolute frame. > Note that I am not involving the entire universe in ANY of this. False. Once you talk about a centre of mass inertial frame, in the model the body set (or physical system) is already considered the entire universe, as I explained in detail to you already twice. > I have a system of 16 balls. > This system has a center of mass. Then, in your model the 16 balls have no other body in its exterior, because its presence alters the centre of mass (not exist a 17 ball or any other body). > I can look at the coordinates of the center of mass of this system in > a reference frame. In 1905 Relativity that reference frame must be the centre of mass inertial frame corresponding to your body set. You cant have never two different inertial frames derived from the same body set. And only in the Newtonian view you can have inertial frames independent from bodies. > In one particular reference frame, the coordinates of the center of > mass of this system is constant -- the center of mass is stationary. > In any other inertial reference frame, the coordinates of the center > of mass of this system is moving with constant velocity. > For a non-zero uniform velocity, only in the Newtonian view with absolute frame, never in the 1905 Relativity one without absolute frame. 1905 Einstein never assign a velocity-vector to a point of empty space in which electromagnetic processes take place (in the Introduction of the 30Jun1905 paper). Inertial frames are denoted by him stationary systems. Nothing more good to understand anything that to analyse a real example in our world. Consider the GPS ECI. The body set (physical system) corresponding to the ECI is only our real Earth and some satellites and atomic clocks in them (even the Moon is considered not existing in the model). Corresponding to that body set a unique centre of mass inertial frame is derived, denoted ECI (Earth Centred Inertial system). The rotation of the Earth, the orbit of the satellites, the clocks at the Earth surface, absolutely all relevant things that moves is described in the same unique inertial frame. And the centre of mass of it is considered at REST, and the delay on all clocks owed to velocity correspond exactly to the one predicted by the 1905 Relativity formula (the same one used by 1905 Einstein in his example at the end of paragraph 4 of his 30Jun1905 paper, precisely having as the stationary system the same today denoted ECI!). All of this with a huge experimental evidence. But the centre of the Earth is NOT at rest, anybody knows that it is moving with a gravitational centripetal acceleration around the Sun! (could say you). And you are right, but that view corresponds to a different body set, the Solar System one, with a different centre of mass inertial frame (with centre considered also at REST!). In the previous case I added the 17 ball to obtain a new centre of mass inertial frame, in this case I added to the Earth all the rest of the Solar System. The ECI and the Solar System are examples of what I denote (many years ago) a Hierarchical Inertial System (HIS). The ECI is part of the Solar System, low hierarchy HIS compose high hierarchy ones. 1905 Relativity lead us to a hierarchical view of our Universe. HIS (1905 Relativity stationary systems, inertial frames) are equivalent in the sense of the same Physics laws, but hierarchical in the sense of the entities described in it. > > > > OK, a > > single question. In the model, with respect to what you pretend to put > > the entire universe moving with a non-zero uniform velocity? Only in > > the Newtonian mechanics (with absolute frame) you can do that, never > > in 1905 Relativity (without absolute frame). > > > RVHG (Rafael Valls Hidalgo-Gato)- Hide quoted text - > RVHG (Rafael Valls Hidalgo-Gato) |