Notion of Absolute Clock Synchronization in SR
in [Relativity]
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From: Tom Adams on 9 Apr 2010 08:13 On Apr 9, 12:48 am, "Androcles" <Headmas...(a)Hogwarts.physics_x> wrote: > "Tom Adams" <tadams...(a)yahoo.com> wrote in message > > news:abfe6383-fc76-4a18-a06b-fc96d163a777(a)5g2000yqj.googlegroups.com... > On Apr 8, 8:23 pm, "Androcles" <Headmas...(a)Hogwarts.physics_x> wrote: > > > "Tom Adams" <tadams...(a)yahoo.com> wrote in message > > >news:7a85b85e-8e57-4e27-9407-a69b05d1b03b(a)r36g2000yqm.googlegroups.com.... > > On Apr 8, 4:04 pm, "Androcles" <Headmas...(a)Hogwarts.physics_x> wrote: > > > > "Tom Adams" <tadams...(a)yahoo.com> wrote in message > > > >news:a779de06-faa9-4cd0-85df-8ee04f9aedf7(a)r18g2000yqd.googlegroups.com.... > > > On Apr 8, 12:06 pm, "Androcles" <Headmas...(a)Hogwarts.physics_x> wrote: > > > > > "Tom Adams" <tadams...(a)yahoo.com> wrote in message > > > > >news:4512a6c4-1d93-40b6-bc7e-84b200f3c1fb(a)u31g2000yqb.googlegroups.com... > > > > On Apr 7, 10:05 pm, "Androcles" <Headmas...(a)Hogwarts.physics_x> wrote: > > > > > > "Tom Adams" <tadams...(a)yahoo.com> wrote in message > > > > > >news:3cfbbdd8-1c7e-4113-9ea9-d9ee6a4cf187(a)g30g2000yqc.googlegroups..com... > > > > > On Apr 7, 3:21 am, "Androcles" <Headmas...(a)Hogwarts.physics_x> > > > > > wrote: > > > > > > > "Tom Adams" <tadams...(a)yahoo.com> wrote in message > > > > > > >news:827aa470-d686-4b02-a943-ada1caebe193(a)g30g2000yqc.googlegroups.com... > > > > > > On Mar 11, 11:35 am, GSS <gurcharn_san...(a)yahoo.com> wrote: > > > > > > > > As per Newtonian notion of absolute space and time, clocks can > > > > > > > be > > > > > > > synchronized in absolute terms such that identical precision > > > > > > > atomic > > > > > > > clocks located anywhere within the solar system and in any state > > > > > > > of > > > > > > > motion, will read the same time t1 when a standard master clock > > > > > > > reads > > > > > > > t1. This notion of absolute clock synchronization implies the > > > > > > > notion > > > > > > > of absolute simultaneity. > > > > > > > > However, as per SR, spatial distance and time measurements have > > > > > > > been > > > > > > > rendered 'relative' and cannot be the same value for different > > > > > > > observers in different states of motion. As per SR the notion of > > > > > > > global 'absolute simultaneity' is fundamentally invalid for > > > > > > > different > > > > > > > observers in different states of motion. Therefore, the notion > > > > > > > of > > > > > > > global 'absolute clock synchronization' (in contrast to e- > > > > > > > synchronization) is no longer valid in SR. > > > > > > > > Since the term 'absolute clock synchronization' is often used in > > > > > > > discussions, I would like to request some Relativity experts to > > > > > > > kindly > > > > > > > clarify the precise definition of absolute clock synchronization > > > > > > > in > > > > > > > SR. Kindly illustrate the procedure, through some 'thought > > > > > > > experiment' > > > > > > > or 'gedanken', to achieve absolute clock synchronization for all > > > > > > > observers in different states of motion within our solar system. > > > > > > > > Further, I also need some expert opinion on the following > > > > > > > situation, > > > > > > > involving clock synchronization. > > > > > > > > Two identical precision atomic clocks are positioned side by > > > > > > > side > > > > > > > at > > > > > > > point A on the surface of earth and mutually synchronized to > > > > > > > ensure > > > > > > > that > > > > > > > (a) their clock rates or frequencies are exactly matched or > > > > > > > synchronized > > > > > > > (b) their instantaneous timing offsets are eliminated to ensure > > > > > > > that > > > > > > > a > > > > > > > common trigger pulse yields the same timing reading t1 from both > > > > > > > clocks. > > > > > > > > Assuming the inherent drift of the two atomic clocks is > > > > > > > identical > > > > > > > and > > > > > > > well within 100 ps per day, it can be demonstrated that while > > > > > > > the > > > > > > > two > > > > > > > clocks remain side by side, their synchronization, after a > > > > > > > period > > > > > > > of > > > > > > > one day, is retained at well within one ns accuracy. > > > > > > > > Let us shift one of the synchronized atomic clocks to a position > > > > > > > B > > > > > > > such that distance AB is about 30 km. > > > > > > > Stop right there. You are outside of the scope of SR. All > > > > > > acceleration > > > > > > is outside the scope. SR cannot address your question. > > > > > > > Strictly speaking, the twin paradox is not part of SR since in > > > > > > involves acceleration. The space-time paths that the twins take do > > > > > > involve different elapsed times in a reference frame, but taking > > > > > > one > > > > > > of the paths involves acceleration. > > > > > > =========================================== > > > > > > Stop right there. > > > > > > Strictly speaking, the twin paradox is very much part of SR since > > > > > > it > > > > > > does > > > > > > NOT involve acceleration. > > > > > > The outbound journey is at velocity v and the inbound is at > > > > > > velocity -v, > > > > > > the > > > > > > path is a two-sided polygon. > > > > > > Yes, but the twin has to go from v to -v. > > > > > ====================================== > > > > > Not relevant, v is squared in tau = t * sqrt(1-v^2/c^2), > > > > > so (-v)^2 = v^2. Cars go around oval race tracks without > > > > > changing speed all the time, reversing their velocity. > > > > > ====================================== > > > > > > > "If we assume that the result proved for a polygonal line is also > > > > > > valid > > > > > > for > > > > > > a continuously curved line, we arrive at this result: If one of > > > > > > two > > > > > > synchronous clocks at A is moved in a closed curve with constant > > > > > > velocity > > > > > > until it returns to A, the journey lasting t seconds, then by the > > > > > > clock > > > > > > which has remained at rest the travelled clock on its arrival at A > > > > > > will > > > > > > be > > > > > > 1/2 t v^2/c^2 second slow." -- Einstein, 1905, "On the > > > > > > Electrodynamics > > > > > > of > > > > > > Moving Bodies". > > > > > > Yeah, it's in the paper. But there is acceleration. > > > > > ======================================= > > > > > If there were then its duration and distance would be pertinent. > > > > > Unless you can state their relevance then acceleration is just so > > > > > much hand-waving, like Gordon Brown dog-paddling the economy > > > > > as he sinks, flapping his paws up and down and saying "No", > > > > > and "Should" without answering any questions. > > > > > > Einstein claims his result is proved for a polygonal line and a > > > > > continuous curved line, there is no change in SPEED (not velocity) > > > > > as the ship swings around the back of the star and returns to Earth. > > > > > He contradicts his own xi = x'/sqrt(1-v^2/c^2), eta = y, zeta = z, > > > > > but that's normal for his nonsense. > > > > > ======================================= > > > > > > > Thence we conclude that clock B (having travelled and being > > > > > > younger > > > > > > than > > > > > > clock A) meets clock A before clock A meets clock B. The clock are > > > > > > twin > > > > > > clocks, and in real physics A meets B when B meets A. That's the > > > > > > paradox. > > > > > > No, there is no real paradox. > > > > > ==================================================== > > > > > Oh yes there is, > > > > >http://www.merriam-webster.com/dictionary/paradox > > > > > > 2 a : a statement that is seemingly contradictory or opposed to > > > > > common > > > > > sense > > > > > and yet is perhaps true > > > > > b : a self-contradictory statement that at first seems true > > > > > c : an argument that apparently derives self-contradictory > > > > > conclusions > > > > > by > > > > > valid deduction from acceptable premises > > > > > > As the ship goes around turns 2 and 3 it travels at v = 0 when u = > > > > > <unchanged speed>, > > > > > so > > > > > eta = y'/sqrt(1-u^2/c^2) > > > > > and NOT > > > > > eta = y > > > > > Einstein wasn't bright enough to know the difference between speed > > > > > and velocity, he was too busy reading sci-fi in school. > > > > > ==================================================== > > > > > > One twin accelerated and the other did not. You can't just reverse A > > > > > and B. > > > > > =================================================== > > > > > > Einstein can! He can do as he likes, He's a god. He can defy the > > > > > laws > > > > > of > > > > > physics. He's holy, a genius. > > > > > The important thing is that *you* can't reverse A and B because they > > > > took > > > > different paths in space-time. No inertial frame will consider these > > > > two paths to be equivalent. > > > > > Einstein did not reverse them either. > > > > ================================================== > > > > > The important thing is > > > > "Take, for example, the reciprocal electrodynamic action of a magnet > > > > and > > > > a > > > > conductor. The observable phenomenon here depends only on the relative > > > > motion of the conductor and the magnet... > > > > Examples of this sort, yada, yada, yada... will hereafter be called > > > > the > > > > ``Principle of Relativity'' > > > > Ref: > > > > ON THE ELECTRODYNAMICS > > > > OF MOVING BODIES > > > > by A. Einstein > > > > June 30, 1905 > > > > Einstein does reverse A and B (when it suits him). > > > > > The important thing is Humpty Roberts has just told you SR can handle > > > > acceleration > > > > just fine and you've agreed with him, and here you claim acceleration > > > > is > > > > required. That's a paradox, and the PoR requires that A and B can be > > > > reversed. > > > > No, the PoR makes speed relative. It does not make acceleration > > > relative. > > > ==================================================== > > > Yes, the PoR makes speed relative. No, it does make acceleration > > > relative since acceleration is rate of change of velocity and velocity > > > is > > > relative. If the Earth goes away from the ship and then returns to > > > the ship, which is exactly what those aboard the ship see, then the > > > Earth changed its velocity and therefore accelerated. > > > The PoR requires the station to come to the train. > > > > ==================================================== > > > I agreed that SR calculations might be able to handle acceleration. I > > > meant that it might be able to handle some calculations or inferences > > > about acceleration. > > > > ==================================================== > > > No, "Might be" is handwaving. Humpty Roberts is very good at it but > > > hopeless > > > at mathematics. No, I do not agree that SR calculations might be able to > > > handle > > > acceleration, so where does that leave us? No, We should agree to > > > differ? > > > No, Not at all, you have the burden of proof, its your claim. No, This > > > is > > > physics and mathematics, not religion where faith applies. > > > > ==================================================== > > > I was not agreeing that the PoR applies to acceleration. It clearly > > > does not > > > apply to acceleration. > > > ==================================================== > > > > No, CLEARLY it DOES, as I've proven above. No, Acceleration is rate of > > > change of velocity and velocity is relative. No, The station comes to > > > the > > > train. > > > No, Do not confuse force with rate of change of velocity, in case you > > > are > > > thinking of doing so. No, In the frame of reference of the train, the > > > station > > > accelerates. > > > ==================================================== > > > All inertial frames will agree about which > > > clocks have accelerated and which clocks have not accelerated, the PoR > > > does not apply. > > > ==================================================== > > > No, A team of scientists working under the direction of researchers from > > > the > > > University of Sussex have recently discovered that Einstein did not say > > > "inertial". No, Here is a copy of their experimental results. > > > >http://www.androcles01.pwp.blueyonder.co.uk/inertial.JPG > > > > "If at the points A and B of K there are stationary clocks which, viewed > > > in > > > the stationary system, are synchronous; and if the clock at A is moved > > > with > > > the velocity v along the line AB to B, then on its arrival at B the two > > > clocks no longer synchronize, but the clock moved from A to B lags > > > behind > > > the other which has remained at B by 1/2 tv^2/c^2 (up to magnitudes of > > > fourth and higher order), t being the time occupied in the journey from > > > A > > > to > > > B. > > > It is at once apparent that this result still holds good if the clock > > > moves > > > from A to B in any polygonal line, and also when the points A and B > > > coincide. > > > > If we assume that the result proved for a polygonal line is also valid > > > for > > > a > > > continuously curved line, we arrive at this result: If one of two > > > synchronous clocks at A is moved in a closed curve with constant > > > velocity > > > until it returns to A, the journey lasting t seconds, then by the clock > > > which has remained at rest the travelled clock on its arrival at A will > > > be > > > 1/2 tv^2/c^2 second slow. Thence we conclude that a balance-clock at the > > > equator must go more slowly, by a very small amount, than a precisely > > > similar clock situated at one of the poles under otherwise identical > > > conditions." > > > > No, A continuous curve is not inertial by any stretch of the > > > imagination. > > > > No, "Inertial" isn't relevant, and Einstein did not mean inertial. > > > No, You are handwaving. > > > > =================================================== > > > > That is, given any curve or piecewise line in space-time, all inertial > > > frames > > > will agree on whether that line represents acceleration or not. > > > > Acceleration = the line is not straight in space-time. Simple as > > > that. > > > ============================================= > > > No, Einstein did not say "space-time" either. > > > No, The "space-time curve" of the station is reflected in the frame of > > > the > > > train. > > > No, In any event, a "spacetime diagram" is a distance/time graph with > > > the > > > axes reversed to promote bullshit. No, Simple as that. No, You are > > > handwaving. > > > > > > =================================================== > > > > > You can demonstrate the so-called "paradox" within SR by having the > > > > > clock traveling at v pass close to another clock traveling back at - > > > > > v. When they are close together they can synchronize. But when the > > > > > clock traveling at -v gets back to the clock at rest, it will now be > > > > > "younger" (less time ticked off) demonstrating that one path through > > > > > space-time gets to the future faster than the other. > > > > > ==================================================== > > > > > That's what I said, B meets A before A meets B. It's a whole lot > > > > > harder to do than mere instant acceleration in zero time. > > > > > > >http://www.merriam-webster.com/dictionary/paradox > > > > > > > 2 a : a statement that is seemingly contradictory or opposed to > > > > > > common > > > > > > sense > > > > > > and yet is perhaps true > > > > > > > b : a self-contradictory statement that at first seems true > > > > > > > c : an argument that apparently derives self-contradictory > > > > > > conclusions > > > > > > by > > > > > > valid deduction from acceptable premises > > > > > > > No need for any word salad about 'synchronized' or 'spacetime' or > > > > > > 'acceleration', the paradox is: B meets A before A meets B, > > > > > > contradictory > > > > > > to > > > > > > the acceptable premise that A meets B when B meets A. > > > > > > > ================================================ > > > The inertial frames > > =================================================== > > > No, it went right over the top your head, didn't it? > > No, A team of scientists working under the direction of researchers from > > the > > University of Sussex have recently discovered that Einstein did not say > > "inertial". No, Here is a copy of their experimental results. > > >http://www.androcles01.pwp.blueyonder.co.uk/inertial.JPG > > > "If at the points A and B of K there are stationary clocks which, viewed > > in > > the stationary system, are synchronous; and if the clock at A is moved > > with > > the velocity v along the line AB to B, then on its arrival at B the two > > clocks no longer synchronize, but the clock moved from A to B lags behind > > the other which has remained at B by 1/2 tv^2/c^2 (up to magnitudes of > > fourth and higher order), t being the time occupied in the journey from A > > to > > B. > > It is at once apparent that this result still holds good if the clock > > moves > > from A to B in any polygonal line, and also when the points A and B > > coincide. > > > If we assume that the result proved for a polygonal line is also valid for > > a > > continuously curved line, we arrive at this result: If one of two > > synchronous clocks at A is moved in a closed curve with constant velocity > > until it returns to A, the journey lasting t seconds, then by the clock > > which has remained at rest the travelled clock on its arrival at A will be > > 1/2 tv^2/c^2 second slow. Thence we conclude that a balance-clock at the > > equator must go more slowly, by a very small amount, than a precisely > > similar clock situated at one of the poles under otherwise identical > > conditions." > > > No, A continuous curve is not inertial by any stretch of the imagination. > > No, "Inertial" isn't relevant, and Einstein did not mean inertial. > > No, You are handwaving. > > Just read the wiki on the twin paradox. > ============================================== > The wacky on the twin paradox was written by the same bigots that > that used to spew nonsense on sci.physics.relativity. Do not appeal > to your idea of authority on the matter, I have quoted the lunatic that > started the whole shebang, Einstein himself. > This is about mathematics and logic, not "just read the wacky". > =============================================== > > A lot of your objections are > addressed in the wiki. If you can't understand it then you > need to backfill on basic stuff like the PoR for simultenaity. > =============================================== > I do not need the wacky to think for me, I have the original paper > athttp://www.fourmilab.ch/etexts/einstein/specrel/www/ > > If you can't understand it then you need to backfill on basic stuff like > kiddy algebra, kiddy calculus and kiddy logic, quit your useless > handwaving beliefs and debate in a logical manner. > > Inertial frames are Newtonian Mechanics. The bozo Einstein doesn't agree > with Newton, and you don't get to mix Newton's precise laws with the > crank's imprecise handwaving "laws of physics" and then say Newton > was wrong! The PoR in Einstein's paper is an EXAMPLE. > His chosen EXAMPLE is > "Take, for **example**, the reciprocal electrodynamic action of a magnet and > a conductor" > "The observable phenomenon here depends only on the relative motion of the > conductor and the magnet" > **Examples** like this ... yada yada yada ... > will hereafter be called the "Principle of Relativity") > > If you can't understand it then you need to backfill on basic stuff like > reading comprehension. > > 'Some men, reasoning preposterously, first establish some conclusion in > their minds which, either because of its being their own or because of their > having received it from some person who has their entire confidence, > impresses them so deeply that one finds it impossible ever to get it out of > their heads.'- Galileo Galilei > 'Faced with changing one's mind, or proving that there is no need to do so, > most people get busy on the proof.'- John Kenneth Galbraith > 'There is nothing so easy but that it becomes difficult when you do it with > reluctance.'- Marcus Tullius Cicero > > So STOP right there. > Strictly speaking, the twin paradox is very much part of SR since it does > NOT involve acceleration. > The outbound journey is at velocity v and the inbound is at velocity -v, the > path is a two-sided polygon. You don't seem to have a grasp of the most elementary things. Take your car up to 20MPH then go to -20MPH as fast as possible. Throw it into reverse or take a U turn. You think there is no acceleration involved in doing that?
From: GSS on 9 Apr 2010 12:50 On Apr 9, 1:24 am, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: > GSS wrote: > > [...] > > Bottom line: while one can take two clocks at rest on earth's geoid and > synchronize them in an inertial frame (e.g. the ECI), one CANNOT treat them as > if they were at rest in that inertial frame. Because they aren't. > Agreed. That is fair enough. > The method used by the GPS to synchronize clocks in the ECI works in a way that > relies on each clock moving at a constant speed wrt the frame, and at a constant > gravitational potential. For a set of clocks at rest on the geoid, those > conditions hold for the ECI frame. They do NOT hold for the BCRF frame, which is > why it is not possible to synchronize them in that frame. > That is if we 'set' or 'adjust' or 'synchronize' each of the two clocks to the 'coordinate' time of that frame (BCRF) then the two clocks will no longer remain mutually synchronized. If the individual clock times are not disturbed then these clocks will not display the coordinate time of that frame but will remain mutually synchronized. After all, when the two clocks A and B under consideration, are mutually synchronized to UTC time through GPS, these clocks are actually, physically located in (a) their local or lab frame, (b) ECI frame, (c) BCRF frame and the (d) Galactic reference frame. That is these clocks are simultaneously located in ALL of these frames ALL the time. Only when you have to force the application of the second postulate of SR in different inertial frames, perforce you have to bring in the notion of coordinate time and hence need to 'adjust' the clocks accordingly in each frame. > The other thing you are missing is the fact that neither the ECI nor the BCRF is > an inertial frame in the sense of SR -- they are LOCALLY inertial frames in the > sense of GR, in which the effects of gravitation have been approximately > canceled. In particular, the relative velocity between them is NOT constant -- > the ECI revolves around the origin of the BCRF. This is what invalidates your > attempts to apply notions of synchronization in SR to this different situation. >. The notion of 'locally inertial' frames does suffice for the purpose of mutual synchronization for a limited period, of the two clocks fixed on the surface of earth. >> (i) When two clocks under consideration are mutually synchronized, >> they represent a physical phenomenon which must not change with our >> arbitrary choice of a reference frame. > > This is just plain not true. Synchronization INHERENTLY depends on the frame > used. This is not "to protect the validity of [the] second postulate of SR", > this is OBSERVED FOR REAL CLOCKS (specifically, the GPS). There cannot possibly > be a "physical phenomenon" that represents a human's ARBITRARY decision of how > to set the offsets of clocks. > Let us suppose you have set the offsets of two precision clocks A and B so as to mutually synchronize them in some inertial reference frame say ECI. We can arrange to let their output in the form of 1PPS recorded in the associated computers. This 1PPS data from both clocks can be recorded for a 24 hour period for its detailed analysis later on. This recorded data is a physical record which CANNOT CHANGE whether we consider the clocks to be physically located in their lab frame, or ECI frame or BCRF or even the Galactic reference frame. Don't you agree that the digital recording of the clock outputs is a physical phenomenon which is not influenced by the fact that the two clocks are actually, physically located in ALL of the above mentioned frames ALL the time. GSS
From: Tom Adams on 9 Apr 2010 15:00 On Apr 8, 11:53 am, "Androcles" <Headmas...(a)Hogwarts.physics_x> wrote: > "Tom Adams" <tadams...(a)yahoo.com> wrote in message > > news:eb8a8b80-b069-45cd-a43b-ea3be0dcf897(a)g30g2000yqc.googlegroups.com... > On Apr 7, 4:42 pm, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: > > > > > > > Tom Adams wrote: > > > Stop right there. You are outside of the scope of SR. All acceleration > > > is outside the scope. SR cannot address your question. > > > This is just plain not true. SR can handle acceleration just fine. Of > > course an > > accelerated system is not an inertial frame, but the math is > > self-consistent, > > meaningful, and agrees with experiments. It is also complicated, so one > > must be > > careful. > > > SR is used to model particle ACCELERATORS all the time. > > > SR cannot handle gravitation -- in relativity that is modeled as a curved > > manifold, and the equations of SR require that the manifold be flat. > > Indeed, GR > > can be considered to be SR generalized to non-flat manifolds; the increase > > in > > complexity is enormous, and the change in ontology is significant.... > > > > Strictly speaking, the twin paradox is not part of SR since in > > > involves acceleration. > > > This is also not true, for the same reason. > > > Tom Roberts > > You are probably right. Just a matter of calculus. > ============================================== > Einstein did not understand calculus. > We establish by definition that Einstein got his knickers in a twist when > he said "we establish by definition that the "time" required by a ray to > travel from A to B equals the "time" it requires to travel from B to A" > and claimed > 1/2 [ tau(0,0,0,t) + tau(0,0,0,t+x'/(c+v)+x'/(c-v))] = tau(x',0,0, t+ > x'/(c-v)) > Ref: > http://www.fourmilab.ch/etexts/einstein/specrel/www/figures/img22.gif > > (It would have been far easier to write > tau(x',0,0, t+ x'/(c-v)) =tau(0,0,0, t+ x'/(c+v)) > and then differentiate that, but then that would make Einstein's silly spoof > rather too obvious.) > > Hence if x' be taken infinitesimally small, > > @tau/@x' + 1/(c-v) * @tau/@t = @tau/@0 + 1/(c+v)*@tau/@t > > Ref right-hand side of: > http://www.fourmilab.ch/etexts/einstein/specrel/www/figures/img23.gif > > There is no derivative @tau/@0 or @tau/@x', > Einstein confuse the coordinate (x',0,0) with the length x'. > ============================================== > > There are SR > effects and separate acceleration effects on the clocks. I learned > something for once on this group. > > Anyway, it's possible to show the "paradox" without acceleration. You > just have 2 clocks in 2 inertial frames pass each other close together > and you synchronize them when they are close. You can get sufficient > sychronization that way between a clock moving away from our clock and > the clock returning to our clock. In the idealized version, the two > clocks participate in the same event (somehow without colliding) and > are perfectly synchronized. > ================================================ > Turning the hands is allowed at departure, not on arrival. The paradox > is the PoR, you can't say which clock moved. You *can* say which clock was and which clock was not either stationary or uniformly moving from departure to arrival. > That was how > acceleration got into the act in the first place. > So which is it? The clock that accelerated loses time or acceleration > doesn't matter, each sees the other move away and come back again?- Hide quoted text - > > - Show quoted text -
From: eric gisse on 9 Apr 2010 15:28 Tom Adams wrote: [...] Androcles is insane and stupid. Good luck.
From: Androcles on 9 Apr 2010 17:19
"Tom Adams" <tadamsmar(a)yahoo.com> wrote in message news:ea4bfd46-651f-403f-ad98-773f446e40e1(a)q15g2000yqj.googlegroups.com... On Apr 8, 11:53 am, "Androcles" <Headmas...(a)Hogwarts.physics_x> wrote: > "Tom Adams" <tadams...(a)yahoo.com> wrote in message > > news:eb8a8b80-b069-45cd-a43b-ea3be0dcf897(a)g30g2000yqc.googlegroups.com... > On Apr 7, 4:42 pm, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: > > > > > > > Tom Adams wrote: > > > Stop right there. You are outside of the scope of SR. All acceleration > > > is outside the scope. SR cannot address your question. > > > This is just plain not true. SR can handle acceleration just fine. Of > > course an > > accelerated system is not an inertial frame, but the math is > > self-consistent, > > meaningful, and agrees with experiments. It is also complicated, so one > > must be > > careful. > > > SR is used to model particle ACCELERATORS all the time. > > > SR cannot handle gravitation -- in relativity that is modeled as a > > curved > > manifold, and the equations of SR require that the manifold be flat. > > Indeed, GR > > can be considered to be SR generalized to non-flat manifolds; the > > increase > > in > > complexity is enormous, and the change in ontology is significant.... > > > > Strictly speaking, the twin paradox is not part of SR since in > > > involves acceleration. > > > This is also not true, for the same reason. > > > Tom Roberts > > You are probably right. Just a matter of calculus. > ============================================== > Einstein did not understand calculus. > We establish by definition that Einstein got his knickers in a twist when > he said "we establish by definition that the "time" required by a ray to > travel from A to B equals the "time" it requires to travel from B to A" > and claimed > 1/2 [ tau(0,0,0,t) + tau(0,0,0,t+x'/(c+v)+x'/(c-v))] = tau(x',0,0, t+ > x'/(c-v)) > Ref: > http://www.fourmilab.ch/etexts/einstein/specrel/www/figures/img22.gif > > (It would have been far easier to write > tau(x',0,0, t+ x'/(c-v)) =tau(0,0,0, t+ x'/(c+v)) > and then differentiate that, but then that would make Einstein's silly > spoof > rather too obvious.) > > Hence if x' be taken infinitesimally small, > > @tau/@x' + 1/(c-v) * @tau/@t = @tau/@0 + 1/(c+v)*@tau/@t > > Ref right-hand side of: > http://www.fourmilab.ch/etexts/einstein/specrel/www/figures/img23.gif > > There is no derivative @tau/@0 or @tau/@x', > Einstein confuse the coordinate (x',0,0) with the length x'. > ============================================== > > There are SR > effects and separate acceleration effects on the clocks. I learned > something for once on this group. > > Anyway, it's possible to show the "paradox" without acceleration. You > just have 2 clocks in 2 inertial frames pass each other close together > and you synchronize them when they are close. You can get sufficient > sychronization that way between a clock moving away from our clock and > the clock returning to our clock. In the idealized version, the two > clocks participate in the same event (somehow without colliding) and > are perfectly synchronized. > ================================================ > Turning the hands is allowed at departure, not on arrival. The paradox > is the PoR, you can't say which clock moved. You *can* say which clock was and which clock was not either stationary or uniformly moving from departure to arrival. ============================================== Isaac Asimov wrote in "Quasar, Quasar, Burning Bright" , ISBN 0-380-44610-3 (concerning life after death) [ If you want to argue the point, present the evidence. I must warn you, though, that there are some arguments I will not accept. I won't accept any argument from authority. ("The Bible says so") I won't accept any argument from internal conviction ("I have faith it is so") I won't accept any argument from personal abuse ("What are you, an atheist?") I won't accept any argument from irrelevance ("Do you think you have been put on this Earth just to exist for a moment of time?) I won't accept any argument from anecdote ("My cousin has a friend who went to a medium and talked to her dead husband") And when all that, and other varieties of non-evidence are eliminated, there turns out to be nothing.] Present the evidence; all you need do is argue your case logically, based on acceptable axioms, and I'll accept what you say. When one teaches, two learn. I'm quite willing to listen, but I'll jump down your throat and rip your lungs out (metaphorically, of course) if you try to bullshit me. ============================================ > That was how > acceleration got into the act in the first place. > So which is it? The clock that accelerated loses time or acceleration > doesn't matter, each sees the other move away and come back again?- Hide > quoted text - > > - Show quoted text - |