The moving system is not an inertial frame in 1905 Relativity
in [Relativity]
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From: valls on 1 Jul 2010 12:38 On 30 jun, 17:45, harald <h...(a)swissonline.ch> wrote: > On Jun 30, 10:03 pm, va...(a)icmf.inf.cu wrote: > > > In a recent thread we established that > > Centre of mass inertial frames are the unique ones in 1905 > > Relativityhttp://groups.google.com.cu/group/sci.physics.relativity/browse_frm/t... > > We cant have two (or more) of them at the same time, because the > > bodies belonging to all of them determine a unique centre of mass > > inertial frame. As a result, in 1905 Relativity the moving system (MS) > > can be only a body (or subset) belonging to the body set of the unique > > inertial frame (the stationary system). The MS can be moving with any > > velocity compatible with the same laws valid in every inertial frame, > > not being then in general an inertial one. > > As you (should) know by now, that's not true: > I say more than one thing in the text you are rejecting. As you (should) know by now, ANY body set determines a unique centre of mass inertial system. Then, you cant have two (or more) of them at the same time. As a result, you cant have never two (or more) 1905 Einstein stationary systems at the same time. The moving system must be then always part of the stationary system. This is very clear (at least for me) in the rotating Earth with the clocks at a pole and the equator. The moving system is in that case the clock at the equator, with a very clear gravitational centripetal acceleration in a circular path (I am waiting for your answer in the other thread, to talk about your totally imaginary non-uniform instantaneous velocity with zero acceleration entity, considered by you an inertial frame). > "Let us take a system of co-ordinates in which the equations of > Newtonian mechanics hold good. In order to render our presentation > more precise and to distinguish this system of co-ordinates verbally > from others which will be introduced hereafter, we call it the > ``stationary system.'' [...] Theory of the Transformation of Co- > ordinates and Times from a Stationary System to another System in > Uniform Motion of Translation Relatively to the Former [..] the axes > of the moving system are [...] parallel to the axes of the stationary > system." > The first reference is the 1905 Einstein definition of stationary system, a one where the equations of Newtonian mechanics hold good, but without all the infinite Newtonian imaginary non-massive inertial systems (remember that a 1905 Einstein system of co-ordinates has material lines associated with them, or an equivalent massive rigid body). The second reference put clear that when deriving the transformation equations from the stationary system to the moving one (the transformation is then ONLY in that direction), 1905 Einstein considers the moving system with a UNIFORM motion. That condition is clearly violated in his rotating Earth example with the moving system (clock at the equator) with an accelerated motion. But the 1905 Einstein assumption related with that violation is supported good by all the today experimental evidence! The assumption is the following: [If we assume that the result proved for a polygonal line is also valid for a continuously curved line,]. Then, 1905 Relativity seems to have a more wide application scope than the one established originally by 1905 Einstein himself. > > See the example at the end > > of paragraph 4 of the 30Jun1905 Einsteins paper (rotating Earth). > > And which you cannot understand. > Dont forget to talk about your totally imaginary non-uniform instantaneous velocity with zero acceleration entity (considered by you an inertial frame), in the place you consider more adequate. > For the sake of others I copy-paste my recent clarifications to you > which you apparently also cannot understand (and I won't try anymore): > > At the beginning of paragraph 2 in the 30Jun1905 paper, Einstein > writes: > > 1. The laws by which the states of physical systems undergo change > are not affected, whether these changes of state be referred to the > one or the other of two systems of co-ordinates in uniform translatory > motion. > This last is a second version of what 1905 Einstein denotes by first time Principle of Relativity (PoR) in the Introduction with the following text: [The same laws of electrodynamics and optics will be valid for all frames of reference for which the equations of mechanics hold good]. As we can see, here is not mentioned at all any UNIFORM motion between systems of reference. 1905 Einstein doesnt seem to realize when stating his second version, that the UNIFORM motion between inertial frames is related with the imaginary absolute Newtonian inertial frame and the also imaginary infinite ones moving with all possible UNIFORM velocities with respect to it. As he starts rejecting the imaginary absolute frame, his second version of the PoR is in contradiction with that primary decision. I am considering right the first PoR version and wrong the second one by the reasons pointed. > Those changes of state stem from classical (Newtonian) theory, > and he referred to Newtonian coordinate systems. That he had such a > physical consideration of systems along with the mathematical one is > essential for understanding his paper, and the part about moving > clocks in particular. > But it is essential to distinguish what parts of the Newtonian view remain valid in 1905 Relativity and what parts do not. > Probably it's best to first discuss the predictions from the older, > classical theory for this case; and then you will probably immediately > understand the prediction with the new one. > > First, take Newton's theory. You surely know that that theory > predicts > that uniform motion does not at all affect the rate of a clock as > determined in a "stationary" system; and as also Einstein emphasized, > the word "stationary" commonly doesn't mean anything special, it's > just a Newtonian system that we pick. Now take a clock that is moving > uniformly in another direction, starting with a physical > consideration. > We never see in the 1905 text a stationary system moving as a whole. > Surely you understand that it has qualitatively the *same* state of > motion; the direction of motion cannot make a difference for the > prediction. > > Thus logically, the same can be said for a clock that is moving along > a polygonal trajectory, since an infinitely quick change of direction > does not affect the indication of a good clock. > > Mathematically this physical understanding can be verified by > performing Galilean transformations at the turning points: the > time t is of course the same when we shift our coordinates, while > the time t' that we locally read cannot be affected by our change > of ruler position (please think this over). > The Galilean transformation is no more valid in 1905 Relativity. It is part of the Newtonian view that we must take apart from it. > *If* we next assume that also acceleration has no effect on clock > rate, > then we can extrapolate (by simple integration) this result to a > circular trajectory. As a matter of fact, this is what always *was* > assumed by everyone, based on Newtonian mechanics. > > Now take the new theory. This one has the following "physical > meaning": > > "The time marked by [a uniformly moving] clock (viewed in the > stationary system) is slow by 1 - sqrt{1-v^2/c^2} seconds per > second." > > Following the same *physical* logic as in the old theory, the > direction of motion cannot affect the physics; thus "It is at once > apparent that this result still holds good if the clock moves from > A to B in any polygonal line". > > This can be verified mathematically (which takes a little longer than > the immediate physical insight based on state of motion) by performing > Lorentz transformations at the turning points. Then we verify that > when switching to another location, the time t remains of course the > same. Also the corresponding t' at that point (a physical event) > cannot be affected by our change of ruler position, as that would > contradict with what is observed with the first ruler position. > > Next, "*If* we assume that the result proved for a polygonal line is > also valid for a continuously curved line", Einstein comes to his > prediction about a clock moving in a circular trajectory. > > [NOTE: just as as the earlier, Newtonian prediction, that prediction > has nothing to do with confusing non-inertial frames with inertial > frames!] > Of course that this prediction HAS to do with confusing non-inertial frames with inertial frames! When going from the polygonal line to the continuous one, the UNIFORM moving system (considered an inertial system in each of the parts of the path with different directions) is converted in a NON-UNIFORM moving system in ALL THE POINTS OF THE CIRCULAR PATH. This is a flagrant violation of the UNIFORM velocity condition supposed for the moving system when deriving the transformation equations. The clock at the equator moving system is NOT an inertial frame. We cant apply then to it formulas derived for inertial ones. Of course, if we take out the PoR version including the UNIFORM condition, we are then in a very different road, the one I am following. > Following that, he makes a prediction in which he lets go of his > overly simple example of Newtonian systems that are determined by > means of "stationary" clocks and rods on a fixed body; > instead he now refers to the ECI coordinate system which is in > nearly uniform motion but in which almost no reference matter is > perfectly in rest. As PD also pointed out, this was already well > understood in Newtonian mechanics and Einstein based himself on > the use of Newtonian reference systems. > ++++++++behaviour as a good inertial frame has nothing to do with any UNIFORM motion at all. Taking into account the presence of the Moon, the Earths centre of mass is following an almost circular trajectory around the Earth-Moon centre of mass (and the trajectory in the Solar System frame is even a very much complex one). The true explanation is a very different one. Fortunately for the GPS, all the external world of the ECI applies an almost equal ACCELERATION to all the bodies belonging to the ECI, sufficiently equal to obtain a good behaviour (I think the near Moon is the more critical instance). The similarity with a free falling elevator is evident, but now without applying GR, being also for this case a superfluous theory. > Best regards, > Harald RVHG (Rafael Valls Hidalgo-Gato)
From: BURT on 1 Jul 2010 18:06 On Jul 1, 5:41 am, stevendaryl3...(a)yahoo.com (Daryl McCullough) wrote: > In article <7ecc2746-829e-4e69-81d4-45d45530e...(a)e5g2000yqn.googlegroups.com>, > va...(a)icmf.inf.cu says... > > I have to give you credit---this is a brand *NEW* misunderstanding of > relativity. The usual misunderstandings that are the basis for discussion in > this newsgroup date back to Herbert Dingle back in the 1950s, more than 50 years > ago. > > Dingle would love this newsgroup. Too bad there was no internet back then.. > > -- > Daryl McCullough > Ithaca, NY A frame is always moving ahead in space. There is No Abolute Rest. Mitch Raemsch
From: PD on 1 Jul 2010 18:39 On Jul 1, 5:06 pm, BURT <macromi...(a)yahoo.com> wrote: > On Jul 1, 5:41 am, stevendaryl3...(a)yahoo.com (Daryl McCullough) wrote: > > > In article <7ecc2746-829e-4e69-81d4-45d45530e...(a)e5g2000yqn.googlegroups.com>, > > va...(a)icmf.inf.cu says... > > > I have to give you credit---this is a brand *NEW* misunderstanding of > > relativity. The usual misunderstandings that are the basis for discussion in > > this newsgroup date back to Herbert Dingle back in the 1950s, more than 50 years > > ago. > > > Dingle would love this newsgroup. Too bad there was no internet back then. > > > -- > > Daryl McCullough > > Ithaca, NY > > A frame is always moving ahead in space. There is No Abolute Rest. > > Mitch Raemsch Mitch, have you eaten today? I worry about you. Too much time on the internet in the library and not enough time panhandling. Take care of yourself.
From: valls on 1 Jul 2010 18:52 On 1 jul, 06:58, stevendaryl3...(a)yahoo.com (Daryl McCullough) wrote: > va...(a)icmf.inf.cu says... > > >You forget that the topic in this thread is 1905 Relativity, where an > >inertial frame, denoted by 1905 Einstein stationary system, is related > >with mass without any doubt at all. To help you the understanding of > >it, I will put here some text from the 30Jun1905 Einstein's paper > >(between [ ]): > >[Let us take a system of co-ordinates in which the equation of > >Newtonian mechanics hold good.]. A direct identification between > >inertial system with massive system of co-ordinates. > > I agree that the first sentence in [] is from Einstein, but the > second isn't. He doesn't define a "massive system of co-ordinates" > and he *certainly* doesn't, anywhere in the paper say that the only > inertial frame is that of the center of mass. > (The second sentence is mine, I put it out of the [ ]) You dont consider my first reference to Artful, I will repeat here between { }: {Almost at the end of the Introduction: [The theory to be developed is based like all electrodynamics- on the kinematics of the rigid body, since the assertions of any such theory have to do with the relationships between rigid bodies (system of co-ordinates), clocks, and electromagnetic processes.]. See here how 1905 Einstein identify systems of co-ordinates with rigid bodies. Can you conceive a rigid body without mass?} You dont consider a rigid body a massive one? The essential contribution of 1905 Einstein is precisely the rejection of all Newtonian non-massive inertial frames (the imaginary absolute inertial frame and all the derived also imaginary ones moving with all possible uniform velocities with respect to it). You conceive to disappear the first floor of a tall building and maintain all the others over it in the same original places? > >At the beginning of paragraph 3: [Let us in "stationary space" take > >two system of co-ordinates, i.e. two systems, each of three rigid > >material lines, perpendicular to one another, and issuing from a > >point.]. A single material point is already a massive entity, and we > >have here RIGID MATERIAL LINES associated with the inertial frames. I > >will suppose this is already sufficient for you to understand that to > >talk about a non-massive inertial frame in 1905 Relativity is a > >complete absurd. > > You are confused. The paragraph does not mention mass at all. I am taking for granted that the Newtonian concept material point is well known. A material point is the model of any massive body (or any set of them) with all its mass considered concentred in its centre of mass. A material line is one with all its points considered material ones. Of course, it is also a massive entity. See the material point concept present in the 30Jun1905 Einsteins paper (almost at the beginning of paragraph 1, between [ ]: [If a material point is at rest relatively to this system of co-ordinates, its position can be defined relatively thereto by the employment of rigid standards of measurements and the methods of Euclidean geometry, and can be expressed in Cartesian co-ordinates.] > The point of talking about "rigid material lines" is about > *setting up* a coordinate system. To set up a rectangular > coordinate system, you need three things: (1) Clocks, (2) rulers, > and (3) a standard for 3 orthogonal spatial directions (which might > be three orthogonal rods stuck together at a point). The clocks, > rulers and orthogonal standard should be thought of as material > objects in the sense that they have a definite location, orientation > and velocity at each moment. That's the only thing that is important > about them. Certainly their mass doesn't come into play, and it > is certainly irrelevant for Special Relativity that they be associated > with a center of mass. If there are other huge masses nearby, that > is only relevant to the extent that they would force the consideration > of gravity, which is not covered by Special Relativity. > The denotation Special Relativity is introduced by 1916 Einstein, after making many changes in his previous Relativity work, adapting it to his new General Relativity. As you correctly refer, gravity is considered excluded from Special Relativity. But the situation is totally different with 1905 Relativity (1905R). I know that almost all persons think that Special Relativity and 1905 Relativity is the same thing. This is a mistake. To convince you, read the real application example of 1905R at the end of paragraph 4 of the 30Jun1905 Einsteins paper. The real rotating Earth with a clock at a pole and another at the equator. The stationary system is here what today is denoted as the GPS ECI (the E is for Earth, the C for Centre of Mass, and the I for Inertial). In the today GPS (Global Positioning System) we can find a very huge experimental evidence supporting in all detail 1905 Relativity. The moving system is here the clock at the equator, moving with a gravitational centripetal acceleration in a circular path, obviously very far from what in 1905 (and also today) is considered an inertial frame. As you see, we have in 1905 Relativity not only the gravity excluded from Special Relativity, but also non-inertial frames with Relativity formulas applied to it. Is this that already sufficient for you to understand that 1905 Relativity is NOT Special Relativity? The ECI is a centre of mass inertial frame. Sorry, almost all your last comment is totally out of context. I recommend you to have at hand a copy of the 30Jun1905 and 27Sep1905 Einsteins Relativity papers if you decide to continue active in this thread (or other similar ones that I maintain open addressing 1905 Relativity topics in this same group). You can find the papers free in http://www.fourmilab.ch > -- > Daryl McCullough > Ithaca, NY RVHG (Rafael Valls Hidalgo-Gato)
From: whoever on 1 Jul 2010 19:24
wrote in message news:de60355e-94d5-4c19-aafc-35ab61249fc7(a)y4g2000yqy.googlegroups.com... >On 1 jul, 08:21, artful <artful...(a)hotmail.com> wrote: >> No .. know all that .. point particles are pretty basic. At least >> you've >> said something that makes grammatical sense >> >Don't confuse point particle with material point. Our whole Solar >System is modelled by a material point to describe its movement in the >Galaxy. The Earth-Moon system is modelled by a material point to >describe the ecliptic. Difference without distinction .. a piont particle is a mathematical abstraction where an object is able to be represented by a single point when modelling it .. that point may or may not correspond to some material (eg a system of two objects orbitting each other could be represented in a larger system by the point about which they orbit, and that point doesn't correspond to any material object. How is that different from a 'material' point .. and how is 'material' point in any way a better notion? --- news://freenews.netfront.net/ - complaints: news(a)netfront.net --- |