John, Einstein's conception of simultaneity follows a procedure. The first step in this procedure is to establish clock synchronization in one frame of reference in isolation from a moving system. However, it occurred to me that this first step is not necessary. Instead it is possible to imagine a method of clock synchronization that requires contact with a moving system.
Imagine four clocks which are wound up but not ticking. Two clocks A and B are separated by a given distance in a stationary frame and the other two clocks A' and B' are separated by the same distance in a moving frame aligned along a closely parallel axis. When the pairs of clocks brush past they all start ticking. Harry On Wed, Mar 12, 2014 at 6:58 PM, John Berry <berry.joh...@gmail.com> wrote: > I agree that video is not terribly useful. > > Here is an argument against Einstein's scheme of synchronization. > Please correct me if you think I am misrepresenting it. > > We have 3 points in a straight line labelled A, B and C with an equal > distance between B and it's 2 neighbours. > > A pulse of light from B travels to A and C, A and C are not considered > synchronized as far as B is concerned, if they both send a light pulse B > will see the light from them at the same moment. > > Why it is invalid: > > The method works fine for some purposes, but not for the purpose of seeing > if the speed of light is actually C, since the method of setting clocks in > sync uses light and includes any delay. > > Let's say the light too 0.5 seconds to move left from B to A, and 1.5 > seconds to move the same distance toward the right from B to C. > > Now the clock at C would be 1 second out of sync compared to A. > Next each sends a light pulse back in this faulty sync scheme idea of the > same moment, so light leaves A a second earlier, but now that light takes > longer, 1.5 seconds to get to B, but the light from C moving to the left > takes only .5 seconds. > > B sees the light from both at the same time and would conclude the > synchronization scheme was sound, and the speed of light was constant. > > Indeed we could do this test with sound in a wind tunnel, you would end up > with silly sync results and the idea that the speed of sound was constant. > > Other sync methods must be used if the speed of light is to be tested such > as testing the speed of light in a Sagnac loop. > > Light in a Sagnac loop is known to take more or less time as the loop is > rotated, the claim of SR is that while the time light takes to make a full > loop will vary and even exceed C from the rotating frames perspective, if > measured over a portion it will be found to be C under Einstein's methods > of synchronization. > > Well, I do agree, but only because the method entirely unsuited for > testing the constancy of the speed of light. > > If another method is used Relativists (some anyway) will agree that the > speed of light over a portion of the loop will not be C. > One such scheme is synchronization from the center. > > This means the speed of light could be found to be unequal in a portion of > a Sagnac loop. > > And if another scheme of synchronization must be accepted since Einstein's > method is rigged, then this would also apply to a spaceship that is moving > in a very subtle arc, an arc that would make a circle of any size even > larger than a galaxy. > > Since all real world motion is not perfectly straight, then even a > momentary subtle arc would have to behave as if it were part of a giant > Sagnac loop that. > > This quickly turns into the speed of light not being constant outside of > completely perfect inertial frames that do not exist in reality. > > John > > > > > > On Thu, Mar 13, 2014 at 6:32 AM, H Veeder <hveeder...@gmail.com> wrote: > >> John, >> Forget these videos. >> I just realized they are not a fair critique of special relativity >> because they don't factor in the the postulate of the constancy of light >> speed. >> >> Harry >> >> >> On Wed, Mar 12, 2014 at 12:53 PM, H Veeder <hveeder...@gmail.com> wrote: >> >>> Sorry, >>> I should have included section 1 _and_ 2 from Einstein's paper. The >>> second section is added below. >>> Harry >>> >>> On Wed, Mar 12, 2014 at 12:39 PM, H Veeder <hveeder...@gmail.com> wrote: >>> >>>> Of the six videos, this one is the most important one... >>>> >>>> [ The Neo-classical Theory of Relativity ] Einstein's incorrect method >>>> to synchronize clocks - case (A). >>>> http://www.youtube.com/watch?v=H2qYCvw1UiE&list=UUek3dPxFThe8FLl-ONbOeVw >>>> >>>> ...because it uses the same thought experiment described by Einstein >>>> his 1905 paper On the Electrodynamics of Moving Bodies.** >>>> The video shows that Einstein was wrong to conclude from this thought >>>> experiment that simultaneous events in a stationary frame cannot be >>>> synchronized >>>> with events in a moving frame. >>>> >>>> The criticisms in other videos could/will be ignored on the grounds >>>> that they don't include relativistic corrections. (Whether or not the >>>> corrections are sufficient to address all the criticisms doesn't actually >>>> matter as long as one can say there aren't any.) >>>> >>>> Harry >>>> >>>> **1. Definition of Simultaneity >>>> >>>> Let us take a system of co-ordinates in which the equations of >>>> Newtonian mechanics hold good.2 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." >>>> >>>> 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 measurement and the methods of Euclidean >>>> geometry, and can be expressed in Cartesian co-ordinates. >>>> >>>> If we wish to describe the motion of a material point, we give the >>>> values of its co-ordinates as functions of the time. Now we must bear >>>> carefully in mind that a mathematical description of this kind has no >>>> physical meaning unless we are quite clear as to what we understand by >>>> "time." We have to take into account that all our judgments in which time >>>> plays a part are always judgments of simultaneous events. If, for instance, >>>> I say, "That train arrives here at 7 o'clock," I mean something like this: >>>> "The pointing of the small hand of my watch to 7 and the arrival of the >>>> train are simultaneous events."3 >>>> >>>> It might appear possible to overcome all the difficulties attending the >>>> definition of "time" by substituting "the position of the small hand of my >>>> watch" for "time." And in fact such a definition is satisfactory when we >>>> are concerned with defining a time exclusively for the place where the >>>> watch is located; but it is no longer satisfactory when we have to connect >>>> in time series of events occurring at different places, or--what comes to >>>> the same thing--to evaluate the times of events occurring at places remote >>>> from the watch. >>>> >>>> We might, of course, content ourselves with time values determined by >>>> an observer stationed together with the watch at the origin of the >>>> co-ordinates, and co-ordinating the corresponding positions of the hands >>>> with light signals, given out by every event to be timed, and reaching him >>>> through empty space. But this co-ordination has the disadvantage that it is >>>> not independent of the standpoint of the observer with the watch or clock, >>>> as we know from experience. We arrive at a much more practical >>>> determination along the following line of thought. >>>> >>>> If at the point A of space there is a clock, an observer at A can >>>> determine the time values of events in the immediate proximity of A by >>>> finding the positions of the hands which are simultaneous with these >>>> events. If there is at the point B of space another clock in all respects >>>> resembling the one at A, it is possible for an observer at B to determine >>>> the time values of events in the immediate neighbourhood of B. But it is >>>> not possible without further assumption to compare, in respect of time, an >>>> event at A with an event at B. We have so far defined only an "A time" and >>>> a "B time." We have not defined a common "time" for A and B, for the latter >>>> cannot be defined at all unless we establish by definitionthat the "time" >>>> required by light to travel from A to B equals the "time" it requires to >>>> travel from B to A. Let a ray of light start at the "A time" from A towards >>>> B, let it at the "B time" be reflected at B in the direction of A, and >>>> arrive again at A at the "A time" . >>>> >>>> In accordance with definition the two clocks synchronize if >>>> >>>> We assume that this definition of synchronism is free from >>>> contradictions, and possible for any number of points; and that the >>>> following relations are universally valid:-- >>>> >>>> If the clock at B synchronizes with the clock at A, the clock at A >>>> synchronizes with the clock at B. >>>> If the clock at A synchronizes with the clock at B and also with the >>>> clock at C, the clocks at B and C also synchronize with each other. >>>> >>>> Thus with the help of certain imaginary physical experiments we have >>>> settled what is to be understood by synchronous stationary clocks located >>>> at different places, and have evidently obtained a definition of >>>> "simultaneous," or "synchronous," and of "time." The "time" of an event is >>>> that which is given simultaneously with the event by a stationary clock >>>> located at the place of the event, this clock being synchronous, and indeed >>>> synchronous for all time determinations, with a specified stationary clock. >>>> >>>> In agreement with experience we further assume the quantity >>>> >>>> to be a universal constant--the velocity of light in empty space. >>>> >>>> It is essential to have time defined by means of stationary clocks in >>>> the stationary system, and the time now defined being appropriate to the >>>> stationary system we call it "the time of the stationary system." >>>> >>>> from >>>> https://www.fourmilab.ch/etexts/einstein/specrel/www/ >>>> >>>> >>>> >>> >>> 2. On the Relativity of Lengths and Times >>> >>> The following reflexions are based on the principle of relativity and on >>> the principle of the constancy of the velocity of light. These two >>> principles we define as follows:-- >>> >>> 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. >>> Any ray of light moves in the "stationary" system of co-ordinates with >>> the determined velocity c, whether the ray be emitted by a stationary or by >>> a moving body. Hence >>> >>> where time interval is to be taken in the sense of the definition in § 1. >>> >>> Let there be given a stationary rigid rod; and let its length be l as >>> measured by a measuring-rod which is also stationary. We now imagine the >>> axis of the rod lying along the axis of x of the stationary system of >>> co-ordinates, and that a uniform motion of parallel translation with >>> velocity v along the axis of x in the direction of increasing x is then >>> imparted to the rod. We now inquire as to the length of the moving rod, and >>> imagine its length to be ascertained by the following two operations:-- >>> >>> (a) The observer moves together with the given measuring-rod and the rod >>> to be measured, and measures the length of the rod directly by superposing >>> the measuring-rod, in just the same way as if all three were at rest. >>> (b) By means of stationary clocks set up in the stationary system and >>> synchronizing in accordance with § 1, the observer ascertains at what >>> points of the stationary system the two ends of the rod to be measured are >>> located at a definite time. The distance between these two points, measured >>> by the measuring-rod already employed, which in this case is at rest, is >>> also a length which may be designated "the length of the rod." >>> >>> In accordance with the principle of relativity the length to be >>> discovered by the operation (a)--we will call it "the length of the rod in >>> the moving system"--must be equal to the length l of the stationary rod. >>> >>> The length to be discovered by the operation (b) we will call "the >>> length of the (moving) rod in the stationary system." This we shall >>> determine on the basis of our two principles, and we shall find that it >>> differs from l. >>> >>> Current kinematics tacitly assumes that the lengths determined by these >>> two operations are precisely equal, or in other words, that a moving rigid >>> body at the epoch t may in geometrical respects be perfectly represented by >>> the same body at rest in a definite position. >>> >>> We imagine further that at the two ends A and B of the rod, clocks are >>> placed which synchronize with the clocks of the stationary system, that is >>> to say that their indications correspond at any instant to the "time of the >>> stationary system" at the places where they happen to be. These clocks are >>> therefore "synchronous in the stationary system." >>> >>> We imagine further that with each clock there is a moving observer, and >>> that these observers apply to both clocks the criterion established in § 1 >>> for the synchronization of two clocks. Let a ray of light depart from A at >>> the time4 , let it be reflected at B at the time , and reach A again at the >>> time . Taking into consideration the principle of the constancy of the >>> velocity of light we find that >>> >>> where denotes the length of the moving rod--measured in the stationary >>> system. Observers moving with the moving rod would thus find that the two >>> clocks were not synchronous, while observers in the stationary system would >>> declare the clocks to be synchronous. >>> >>> So we see that we cannot attach any absolute signification to the >>> concept of simultaneity, but that two events which, viewed from a system of >>> co-ordinates, are simultaneous, can no longer be looked upon as >>> simultaneous events when envisaged from a system which is in motion >>> relatively to that system. >>> >>> >>> >>> >>> >>> >>> >>> >>> >>>> On Tue, Mar 11, 2014 at 7:54 PM, John Berry <berry.joh...@gmail.com>wrote: >>>> >>>>> http://www.neoclassicalrelativity.org/ >>>>> >>>>> There are 6 simple videos showing arguments against various parts of >>>>> Special Relativity. >>>>> >>>>> http://www.youtube.com/user/NeoclassicRelativity >>>>> >>>>> >>>>> >>>> >>> >> >
