Preferred Frame Theory indistinguishable from SR
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From: Tom Roberts on 26 Jun 2010 11:54 kenseto wrote: > On Jun 26, 12:41 am, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: >> This is just one of the theories that are equivalent to SR (i.e. they are >> experimentally indistinguishable from SR). [...] >> In all of these theories other than SR (which is the only member of this class >> without a preferred frame), > > This is not true....the PoR says that all frames are equivalent, > including the preferred frame. But in SR there is no "preferred frame". Indeed, that is a direct consequence of the PoR. > This allows every SR observer to use > the preferred frame to derive the math. But in SR there is no "preferred frame". An observer at rest in an inertial frame has a unique relationship to that specific inertial frame. But that frame is not "preferred" in any sense except by that observer. And the "preference" extends ONLY to simplifying the math, there is no effect whatsoever on the dynamics of the theory. We do not say "preferred frame" for this, because that phrase historically designates a frame in which the dynamics of a theory are different from all other frames. Such as in an aether theory, in which the aether rest frame is indeed given preferential treatment by the dynamics. > That's why every SR observer > claimed the exclusive properties of the preferred frame which are: all > the clocks moving wrt him are running slow and all the meter sticks > moving wrt him are contracted. Those are NOT the properties of any "preferred frame", in SR those properties apply to ANY INERTIAL FRAME WHATSOEVER -- no "preference" there. > To make SR complete, an SR observer must > include the possibility that an observed clock can run faster than his > clock by a factor of gamma. If one attempts to include that, it does not make the theory "complete", it makes it SELF-INCONSISTENT. It also gives a theory inconsistent with actual observations -- within the domain of SR it is never observed that a "moving clock runs fast" (speaking loosely, but in the same vein as you). Tom Roberts
From: Surfer on 26 Jun 2010 15:32 On 26 Jun 2010 07:16:52 -0700, stevendaryl3016(a)yahoo.com (Daryl McCullough) wrote: >Surfer says... > >>However suppose a frame of reference is identified in which the one >>way speed of light is 'truely' isotropic, referred to below as the >>'isotropic frame'. >> >>Suppose that relative to such a frame a radar system is moving with >>speed vi in the direction of a target, and that the target is moving >>towards the radar system with speed V relative to the radar system. >>(So vi, V and radar signals are collinear.) >> >> ------------ ------------ >> | Radar | ----------------c-vi------------>|Target | >> | System |<---------------c+vi------------ | | >> ------------- signal ----------- >> ---vi--> speeds <--V-- >> Radar system relative Target speed >> speed relative to radar relative to >> to isotropic system radar system >> frame >> >> >>To ensure consistent representation of distance and time, let time in >>the radar system frame be synchronized with time in the isotropic >>frame and let distance measurements be derived from the spatial >>coordinates of the isotropic frame. These conditions require the >>frames to be mapped to each other via Galilean transforms. > >[stuff deleted] > >Okay, I think what you are saying is that if >instead of the Lorentz-transformed coordinate system, > >x' = gamma (x-vt) >t' = gamma (t-vx/c^2) > >moving users use Galilean-transformed coordinates: > >x' = x-vt >t' = t-vx/c^2 > >then they will get different answers for values such >speed of light, Doppler shift, etc. > Well, suppose the isotropic frame provides a finely spaced set of clocks, so that at any time the radar system and the target can each read their position and time directly from an adjacent clock. Then there is no need to use Lorentz transforms and its possible to perform this analysis using the much simpler Galilean transforms. This provides a much better guaranttee of correctness. But doing so results in a radar Doppler formula which differs from the formula derived using SR. But why is this? The reason is that the Einstein clock synchonization protocol synchronizes clocks so as to provide the appearance that light propagates with a one way speed of c, in all inertial frames, but in reality it is only the two way speed of light that can actually be confirmed to be equal to c. But if a target is moving relative to a radar system, the Doppler shift will depend on the actual one way speeds of the radar signals rather than on the apparent speeds. The derivation I gave takes into account the possibility of actual one way speeds that differ from c, but SR derivations typically assume that actual one way speed = apparent one way speed = c. Hence the difference.
From: Daryl McCullough on 26 Jun 2010 15:48 Surfer says... > >On 26 Jun 2010 07:16:52 -0700, stevendaryl3016(a)yahoo.com (Daryl >McCullough) wrote: >>Okay, I think what you are saying is that if >>instead of the Lorentz-transformed coordinate system, >> >>x' = gamma (x-vt) >>t' = gamma (t-vx/c^2) >> >>moving users use Galilean-transformed coordinates: >> >>x' = x-vt >>t' = t-vx/c^2 >> >>then they will get different answers for values such >>speed of light, Doppler shift, etc. >> >Well, suppose the isotropic frame provides a finely spaced set of >clocks, so that at any time the radar system and the target can each >read their position and time directly from an adjacent clock. That doesn't matter. The point is that the moving observer is using a different set of coordinates than the "inertial coordinates" assumed by the Lorentz transformations. As I said, you don't need a preferred frame to do this. You can pick any frame you like, and *call* that the preferred frame, and use it for the basis of a set of coordinate systems related by the Galilean transformation. >But doing so results in a radar Doppler formula which differs from the >formula derived using SR. But why is this? There is no mystery here. If you define a coordinate-dependent quantity, then you will get a different answer for that quantity in different coordinate systems. >The reason is that the Einstein clock synchonization protocol >synchronizes clocks so as to provide the appearance that light >propagates with a one way speed of c, in all inertial frames, but in >reality it is only the two way speed of light that can actually be >confirmed to be equal to c. One-way speed depends on the coordinate system. Light only has speed c in all directions as measured from a special, inertial coordinate system. Why do we care about those coordinate systems? The main point is the principle of relativity: the laws of physics have the same form in all inertial coordinate systems. >But if a target is moving relative to a radar system, the Doppler >shift will depend on the actual one way speeds of the radar signals >rather than on the apparent speeds. > >The derivation I gave takes into account the possibility of actual one >way speeds that differ from c, but SR derivations typically assume >that actual one way speed = apparent one way speed = c. Your derivation doesn't have anything to do with preferred frames. You can pick any frame whatsoever, and *CALL* that the preferred frame, and things work out the same way. -- Daryl McCullough Ithaca, NY
From: kenseto on 26 Jun 2010 15:51 On Jun 26, 11:54 am, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: > kenseto wrote: > > On Jun 26, 12:41 am, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: > >> This is just one of the theories that are equivalent to SR (i.e. they are > >> experimentally indistinguishable from SR). [...] > >> In all of these theories other than SR (which is the only member of this class > >> without a preferred frame), > > > This is not true....the PoR says that all frames are equivalent, > > including the preferred frame. > > But in SR there is no "preferred frame". Indeed, that is a direct consequence of > the PoR. You are playing word game here....all frames are equivalent does not exclude the preferred frame. In fact the preferred frame is selected by every SR observer and that's why all frames are equivalent. > > > This allows every SR observer to use > > the preferred frame to derive the math. > > But in SR there is no "preferred frame". This is a bogus assertion. > > An observer at rest in an inertial frame has a unique relationship to that > specific inertial frame. But that frame is not "preferred" in any sense except > by that observer. And the "preference" extends ONLY to simplifying the math, > there is no effect whatsoever on the dynamics of the theory. Calling the preferred frame as an inertial frame does not exclude the existence of the preferred frame. > > We do not say "preferred frame" for this, because that phrase > historically designates a frame in which the dynamics of a > theory are different from all other frames. Such as in an > aether theory, in which the aether rest frame is indeed given > preferential treatment by the dynamics. Then give us the differences between a preferred frame and an inertial frame. Also give us the reason why the PoR does not include the preferred frame and at the same time uses the exclusive properties of the preferred frame. > > > That's why every SR observer > > claimed the exclusive properties of the preferred frame which are: all > > the clocks moving wrt him are running slow and all the meter sticks > > moving wrt him are contracted. > > Those are NOT the properties of any "preferred frame", in SR those properties > apply to ANY INERTIAL FRAME WHATSOEVER -- no "preference" there. Sure they are the exclusive properties of the preferred frame. SR claims that the observer's clock is the fastest running clock in the universe and that means that it is a preferred clock. > > > To make SR complete, an SR observer must > > include the possibility that an observed clock can run faster than his > > clock by a factor of gamma. > > If one attempts to include that, it does not make the theory "complete", Sure it does....it means that any SR observer is no longer claims the exclusive properties of the preferred frame and thus it makes SR complete. > it > makes it SELF-INCONSISTENT. You are talking nonsense....when comparing two clocks A and B the following possibilities exist: 1. If A is truly running faster than B 2. Then B is truly running slower than A. At no time does A predicts B is running slow and at the same time B predicts that A is running slow. Ken Seto >It also gives a theory inconsistent with actual > observations -- within the domain of SR it is never observed that a "moving > clock runs fast" (speaking loosely, but in the same vein as you). > > Tom Roberts
From: kenseto on 26 Jun 2010 15:55
On Jun 26, 10:40 am, PD <thedraperfam...(a)gmail.com> wrote: > On Jun 26, 8:40 am, kenseto <kens...(a)erinet.com> wrote: > > > > > This is not true....the PoR says that all frames are equivalent, > > including the preferred frame. > > Classic Setoism. > > Ken, the *meaning* of "preferred" in "preferred frame" is "not > equivalent to other frames". > Thus you are claiming that some theory says that "all frames are > equivalent, including the one that is not equivalent to other frames". Then give us the differences in properties between a preferred frame and an inertial frame. Ken Seto > > You are a champion at inventing meanings for words you do not > understand and immediately generating an oxymoron with your made-up > meaning. > It does not occur to you that if you stopped making up the meaning of > words, you would not immediately run into contradictions. > But it just rankles the heck out of you to even ask what words mean. > You HATE the idea of having to ask somebody a question about something > you do not understand. > > PD |