Preferred Frame Theory indistinguishable from SR
in [Math]
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From: harald on 5 Jul 2010 06:14 On Jul 5, 3:00 am, stevendaryl3...(a)yahoo.com (Daryl McCullough) wrote: > harald says... > > >On Jul 4, 2:02=A0pm, stevendaryl3...(a)yahoo.com (Daryl McCullough) wrote: > >> It's hard for me to see how the "twin paradox" is a paradox in any > >> sense other than being a surprising result. > > >Just study Einstein's solution and see if you agree - or if you smell > >a dead cat. ;-) > > I'm not sure what "Einstein's solution" is, but for any problem > involving traveling clocks, the prediction of GR or SR is this: > > elapsed time on clock = Integral along the path > of square-root(|g_uv dx^u dx^v|) > > In SR, we can always choose coordinates so that g_uv is constant > and diagonal, with g_00 = 1, g_11 = g_22 = g_33 = -1. Then the > above expression reduces to: > > Integral along the path of square-root(1 - v^2/c^2) dt > > In General Relativity, or in SR with noninertial coordinates, > g_uv may in general vary from point to point, so there is an > apparent position-dependence to the rates of clocks. > > I really don't understand how the twin paradox is a consistency > challenge for GR. The fact that Einstein himself may have worried > about it doesn't mean anything to me. We're not dealing with holy > scripture, and Einstein is not a prophet. GR is a theory that stands > or falls independently of its creator. Einstein is not the last word on GR. > > What do you consider to be the *real* twin paradox? > > -- > Daryl McCullough > Ithaca, NY The one that Einstein was confronted with - the first "twin" or "clock" paradox that we know of. Harald
From: harald on 5 Jul 2010 06:20 On Jul 5, 1:55 am, Cosmik de Bris <cosmik.deb...(a)elec.canterbury.ac.nz> wrote: > On 5/07/10 00:40 , Daryl McCullough wrote: > > > > > whoever says... > > >> "Koobee Wublee" wrote > > >>> So, it is a > >>> really a moot point to go further with SR. However, the math involved > >>> is the Lorentz transform where it specifies WITHOUT EXCEPTION that any > >>> moving frame regardless in acceleration or not will be observed to be > >>> time dilated by anyone, anywhen, and anywhere.<shrug> > > >> Totally wrong. The transform says the exact opposite. > > > This is what is completely weird about anti-relativity cranks > > (and it is a characteristic that is shared by mathematical cranks, > > as well): If you give them a completely explicit list of rules > > for deriving results in some theory such as SR, the cranks are > > of course unable to derive a contradiction. But rather than taking > > that as evidence that the theory is correct, they take it that > > your presentation of the theory is *incorrect*. > > > Basically, there are two different theories: > > > SR_crank: the version of SR that is used by cranks to derive a > > contradiction > > > SR_noncrank: the version of SR that is used by noncranks. > > > The cranks don't come right out and say it, but by their silence > > they seem to agree that SR_noncrank is consistent---they don't even > > attempt to derive a contradiction from it. Instead, they criticize > > it on other grounds: (1) It's not what Einstein *REALLY* meant, or > > (2) You're cheating by carefully crafting the rules to hide the paradox.. > > > They are so used to dealing with nonsense, that they feel like > > anything that is consistent is somehow cheating. But I can't get > > a crank to explain what could possibly be WRONG with using the > > consistent SR_noncrank. > > > The only explanation I can come up with for why they reject a > > completely consistent theory is that there are certain ways of > > reasoning that the crank knows MUST be correct. Let's call this > > "crank reasoning". When you add this reasoning to SR_noncrank, > > you get SR_crank, which really is inconsistent. > > > So we have the equation: > > > SR_noncrank + crank reasoning == SR_crank > > > Since SR_crank is inconsistent, the crank must either reject > > SR_noncrank or reject their beloved crank reasoning. > > They can't do the latter, so they reject SR_noncrank. > > > -- > > Daryl McCullough > > Ithaca, NY > > Ain't that the truth. Yes - and as shown in parallel, it's not limited to cranks! Harald
From: Daryl McCullough on 5 Jul 2010 07:04 harald says... > >On Jul 5, 4:18=A0am, stevendaryl3...(a)yahoo.com (Daryl McCullough) wrote: >> harald says... >> >> >Einstein explained how a paradox arose with the inception of GRT: >> >> It's athttp://tiny.cc/kz0uq >> >> I read the dialog, and I do not agree with your description of it, >>as a paradox of GR. The fact is, as I said, the "GR description" is >>actually not GR at all, it's SR being expressed in noninertial coordinates. > >That's wrong: SRT does not *have* such concepts as "induced >gravitational fields". Yes, it certainly does. If you are in a rocket that is accelerating upwards, and you drop a ball, it will fall to the floor. That's true in Newtonian physica, and it's true in SR. That's all that is meant by an induced gravitational field. >> The use of the term "gravitational field" is picturesque and suggestive, >> but nothing that Einstein says about interpreting the twin paradox from >> the point of view of the traveling twin is in any way dependent on >> Einstein's theory of gravity. > >Indeed it's not! Then it's not GR. It's SR in noninertial coordinates. So you are mistaken in calling a paradox of GR, for two reasons: (1) It's not a paradox, and (2) it's not GR. >That is well known - and it misses the point (again). I think it is because you have not made it very well. I still have no idea what your point is. I admit to mistaking your discussion about the General Principle of Relativity as a discussion about GR, the theory of gravity. If your point is about the General Principle of Relativity (that the laws are covariant under generalized changes of coordinates), that has no physical content, and Einstein was mistaken to think otherwise. You can always rewrite the laws so that they are covariant. However, I don't see how the twin paradox is a "consistency challenge" for the principle of relativity or for GR, the gravitational theory. >1. I brought to your attention what history tells us about how the >clock paradox started for Einstein, information that was kept hidden >for the non-German speaking community for many decades >2. The information conflicts with what you "know" (what you learned >and believed for a long time) >3. From that you conclude that point 1 must be wrong. I have no idea what you are talking about. I certainly have never made claims about history. My point is about the logical relationships among Special, General Relativity, and the twin paradox. -- Daryl McCullough Ithaca, NY
From: Daryl McCullough on 5 Jul 2010 07:10 harald says... > >On Jul 2, 4:25=A0pm, stevendaryl3...(a)yahoo.com (Daryl McCullough) wrote: >> harald says... >> >> [quoting Newton] >> >> >"It is indeed a matter of great difficulty to discover, and >> >effectually to distinguish, the true motion of particular bodies from >> >the apparent; because the parts of that immovable space, in which >> >those motions are performed, do by no means come under the observation >> >of our senses. [...] >> >But how we are to collect the true motions from their causes, effects, >> >and apparent differences; and, vice versa, how from the motions, >> >either true or apparent, we may come to the knowledge of their causes >> >and effects, shall be explained more at large in the following tract. >> >For to this end it was that I composed it." >> >> It's not completely clear what he means by "true motions" and "apparent >> motions", but if he meant that there was an absolute standard of rest, th= >en >> he was just mistaken---there is no evidence of such a thing. > >Evidently the education system withheld this information from you, What information? The fact that Newton said the above things? Why is that relevant? Physics is a study of the world, it's not a study of the writings of famous physicists. What Newton believed has no more relevance than what you are I believe. What's important is the physics. And the physics of Newton has no need for any absolute rest frame. >just as it also happened to me. But he does present evidence there. >And it's not just a detail, but the postulate to which Newton's >equations of motions relate. If you believe that Newtonian physics requires an absolute standard of rest, then why don't *YOU* post an argument to that effect? The fact that Newton thought so is not relevant. Not to me, anyway. What's relevant is the argument and the evidence, not what famous people thought about it. -- Daryl McCullough Ithaca, NY
From: Daryl McCullough on 5 Jul 2010 07:18
harald says... > >On Jul 5, 3:00=A0am, stevendaryl3...(a)yahoo.com (Daryl McCullough) wrote: >> What do you consider to be the *real* twin paradox? >The one that Einstein was confronted with - the first "twin" or >"clock" paradox that we know of. I meant: what do you consider paradoxical about it? Can you say that in your own words? I don't want you to quote Einstein. I want you to describe the paradox and why in the world you consider it paradoxical. You complain that I miss your point, but it seems to me that you have scrupulously avoided making one with any clarity. If you want to make a point, lay it out in detail and give your arguments in your own words. -- Daryl McCullough Ithaca, NY |