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 >>> >>> >>> >> >
