Preferred Frame Theory indistinguishable from SR
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From: Daryl McCullough on 26 Jun 2010 09:30 colp says... >Before I respond directly to the issue of the preferred frame, I again >raise the issue of need. The reason that the issue of need is pivotal >here is that necessity may be a reason for people to lie and deceive. I have no idea what you are talking about, and at this point I really don't care. I'm only discuss physics, not psychology. Goodbye. -- Daryl McCullough Ithaca, NY
From: kenseto on 26 Jun 2010 09:40 On Jun 26, 12:41 am, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: > Daryl McCullough wrote: > > There is a preferred frame, F, and there is an associated > > coordinate system such that > > > 1. Light travels in straight lines at speed c, as measured in F's > > coordinate system. > > 2. An ideal clocks in motion relative to F has an elapsed time > > given by dT/dt = square-root(1-(v/c)^2), where t is the time > > coordinate of F's coordinate system, and v is the velocity of > > the clock, as measured in F's coordinate system, and T is the > > elapsed time on the clock. > > 3. An ideal meterstick in motion, with the stick aligned in the > > direction of its motion, will have a length given by > > L = square-root(1-(v/c)^2). > > > I would think that anybody could see that rules 1-3 are consistent. > > You cannot deduce a contradiction from these rules. Note that the > > contradiction that so many anti-relativists think that they have > > found in SR, namely, mutual time dilation, is not present in these > > rules, because these rules only mention time dilation with respect > > to a specific, preferred frame. So there is no possibility of deriving > > a "twin paradox" that is a logical contradiction. Right? > > > Well, all the weirdness of SR, including mutual time dilation and > > the relativity of simultaneity *follows* logically from principles > > 1-3! You can prove that if 1-3 are true in the preferred coordinate > > system, then they are *also* true as measured in any coordinate system > > that is related to the preferred coordinate system through the > > Lorentz transforms. > > Yes. This is just one of the theories that are equivalent to SR (i.e. they are > experimentally indistinguishable from SR). This is one way of deriving the > equations of LET (Lorentz Ether Theory). Lorentz used a completely different > method in his 1904 paper. > > There is a much larger class of theories equivalent to SR, consisting of all > theories in which these two criteria apply: > a) the round-trip speed of light is isotropically c in any inertial > frame > and > b) the one-way speed of light is isotropically c in one frame > > Note that (a) is solidly established experimentally, and (b) is basically what > it means to have an aether frame, or any sort of "preferred" frame. > > If you work out the details, you find that all of these theories > have transforms between inertial frames that differ from the > Lorentz transform only in the way coordinate clocks are > synchronized in inertial frames. Note that except for SR and > LET, the synchronization method is ad hoc and artificial. > > In all of these theories except SR and LET, slow clock transport relative to a > moving inertial frame CANNOT be used to synchronize the coordinate clocks of the > frame. And the difference is PRECISELY what it takes to make experiments and > observations be identical to those of SR and LET. > > 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. This allows every SR observer to use the preferred frame to derive the math. 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. Also that's why SR and LET have the same math. It turns out that using the preferred frame to derive the math is the reason why SR is incomplete. 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. IRT is a new theory of relativity that includes such possibility. IRT includes SR and LET as subsets. However, unlike SRT, the equations of IRT are valid in all environments, including gravity. A paper on IRT is available in the folowing link: http://www.modelmechanics.org/2008irt.dtg.pdf Ken Seto >there is no possible experiment that can determine > which frame is the preferred frame. That is, no matter which frame you > arbitrarily select to be the "ether frame", the predictions for any experiments > or observations are unchanged. IOW: (b) can be applied to any inertial frame. > Only in SR does (b) apply to all inertial frames simultaneously. > > NOTE: the modern interpretation of this is that it is all > irrelevant. That's because these different "theories" merely > apply different coordinates to the underlying space-time > manifold, and use different transforms among them. Yes, except > for SR and LET those coordinates are pretty unusual.... The > uniqueness of SR is precisely that (b) applies to all frames. > SR is also the only theory that includes the PoR. > > I posted a much longer series of three articles on this 'way back in 1999 --http://groups.google.com/group/sci.physics.relativity/msg/15ceaad17be... > > Tom Roberts- Hide quoted text - > > - Show quoted text -
From: Daryl McCullough on 26 Jun 2010 10:16 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. I have two points to make about that: (1) This has *NOTHING* to do with the existence of a preferred frame. What it has to do with is describing coordinate-dependent quantities using a noninertial coordinate system. What I mean by an inertial coordinate system is a coordinate system where: 1. Light has the same speed c in all directions. 2. Meter sticks at rest in the coordinate system have length 1 meter. 3. Clocks at rest in the coordinate system have elapsed times T satisfying dT/dt = 1. If (x,t) is such an inertial coordinate system, and (x',t') is related to (x,t) through a Galilean transform, then (x',t') will *not* be an inertial coordinate system in the sense of 1-3. Meter sticks will have lengths different from 1 meter (and worse, the computed length will change when you rotate them), clocks will not tick at 1 second per second. Light will have different speeds in different directions. That doesn't have anything to do with the existence of a preferred frame. You can pick any frame you like, and devise an inertial coordinate system for that frame, and you can pick any frame you like, and devise a noninertial coordinate system for that frame. (2) The second major point is that to understand the *physics* of the situation, it often helps to avoid coordinate-dependent quantities, and instead use operationally defined quantities that are independent of the choice of coordinate system. For example, let's take lightspeed. That's a coordinate-dependent quantity, and so if you switch to a noninertial coordinate system, the speed of light might change. However, we can operationalize it to get a related quantity that is independent of coordinate systems. Here's one way of doing so: (1) Take two clocks at the same location, initially at rest, and synchronize them. (2) Keep one clock at rest, and slowly move the second clock to a known distance L away from the first. Then bring it to a stop. (3) At t=0 according to the first clock, send a light signal from the first clock towards the second clock. (4) Let T be the time on the second clock when the light signal arrives. (5) Then the empirically determined one-way speed of light is L/T. (If you are concerned about the fuzziness of the word "slowly" in step 2, you can try computing L/T for various speeds of the moving clock, and take the limit as the speed goes to zero) If you operationalize the definitions of things like lightspeed, Doppler shift, etc., then you will get the SR values, even if there IS a "preferred frame". -- Daryl McCullough Ithaca, NY
From: PD on 26 Jun 2010 10:40 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". 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
From: PD on 26 Jun 2010 10:45
On Jun 26, 2:47 am, colp <c...(a)solder.ath.cx> wrote: > > You claimed that you need a physics, but you didn't identify the > nature of the threat implied by that statement when I questioned you > on it. Until that threat is eliminated it is reasonable for me to > think that you may employ deception in order to maintain your own > sense of security. If this is the case it is pointless for me to > continue to argue with you, since it is reasonable to think that you > will introduce any point of contention necessary to maintain your > position and sense of security. > I'd like for you to look at the above paragraph again and reconsider your participation in a discussion group. What POSSIBLE value would you place on spending any time whatsoever in a discussion with someone that you inherently do not trust? Why would you attempt to wean out consensus or clarification or improve your understanding of anything by conversing with someone whose words do not mean anything to you at all? Try taking a brief break from your activity here, and ask yourself what you hope to accomplish with the ten minutes or so of your valuable time that you would invest next time you got on. PD |