The case for True Length = Rest Length


by rjbeery
Tags: case, length, rest
ghwellsjr
ghwellsjr is offline
#361
Apr12-11, 12:15 PM
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Quote Quote by Mike_Fontenot View Post
At any rate, any decision you make to quote from that paper doesn't really have anything to do with me, since I had to sign the copyright over to them ... they own it ... it's just between you and the publisher.

Mike Fontenot
Is that the reason you would make this statement?

"Those elementary observations and elementary calculations are given, in detail, in my paper. I'm not willing to reproduce them here."
Mike_Fontenot
Mike_Fontenot is offline
#362
Apr12-11, 12:29 PM
P: 250
Quote Quote by ghwellsjr View Post
Is that the reason you would make this statement?

"Those elementary observations and elementary calculations are given, in detail, in my paper. I'm not willing to reproduce them here."
Well, I wouldn't do a long quote for several reasons: for one thing, because of the copyright agreement I signed, but also because I was only willing to do that much work ONCE, when I wrote the paper. ONCE is enough.

Mike Fontenot
ghwellsjr
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#363
Apr12-11, 01:19 PM
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Quote Quote by Mike_Fontenot View Post
Well, I wouldn't do a long quote for several reasons: for one thing, because of the copyright agreement I signed, but also because I was only willing to do that much work ONCE, when I wrote the paper. ONCE is enough.

Mike Fontenot
Are you suggesting that I could not adequately state your definition of "elementary observations and elementary calculations" without a long quote and much work?
GrayGhost
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#364
Apr12-11, 03:39 PM
P: 432
Mike_Fontenot,

Interesting subject it is.

There are a few issues here ...

1. what does twin B see as he goes?
2. does B see the heavens precisely as the co-located MSIRF observer does, at that instant?
3. why can the A-velocity per B go superluminal, while the co-located MSIRF observer disagrees (which is never superluminal)?
4. can the LTs be applied by twin B while non-inertial, and if so, how?
5. is there a way that twin B may make correct spacetime transformations using only his own measurements alone?

I've got answers of my own on these matters, however I'm not sure where to start.

BTW ... wrt 4) EDIT: I'm rethinking this for now :)

GrayGhost
GrayGhost
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#365
Apr12-11, 08:33 PM
P: 432
Quote Quote by Mike_Fontenot View Post
Just FYI:

... at any instant of his life, the traveler CAN, if he so chooses, decide to stop accelerating for more than a single momentary instant ... for some segment of his life ... before resuming accelerating again. He may not choose to ever do that, but he CAN if he wants. IF he does, he can make the SAME kind of observations and calculations that a perpetually-inertial observer who is (temporarily) co-located with him during that segment can make.
EDITs have been made in this post, and they are highlighted ...

Mike, let me ask you ...

What's the difference between going inertial for 1 quintillionth of a microsecond, versus considering the velocity at a point on the x vs t position plot while still non-inertial? I mean, from a standpoint of what twin B can do in that time, what's the diff?

On the one hand, I realize that while inertial, one is not dynamically changing in POV. On the other hand, there's not enough time for twin B to bounce any radar signals out and back off twin A, either way. Now, the LTs were designed for the all-inertial case, yes, however it seems to me that all heavenly bodies exist precisely where the co-located MSIRF observer says they do, including twin B. Why not? Twin B and the MSIRF observer are "at that instant" colocated and of zero relative v. They are both then receiving the same light signals from their surroundings, including from twin A, so they should then see the heavens the same at that instant. If the MSIRF observer says twin A is currently right there, then although twin B may not know such from his own classical calculations, there's no good reason that twin B should disagree, because the special theory is rock solid. If they were of differing v when colocated, I'd contend differently, however they are not.

If twin B's calculations based upon his own measurements tell him something differently, then something is amiss. What's amiss IMO, is the fact that the non-inertial twin B deduces the twin A velocity differently from observations and "calculations made in the classical way". Let's face it, he can't plug superluminal velocities into the LTs, nor should he try. His POV dynamically changes, which causes light's speed to appear variable across spatial expanse (but never at his own location). The reason he measures the A-velocity differently is because he (rather accidentally) accounts for length-contraction while ignoring dilation (and doppler effects). If he does not ignore said effects, and accounts for all of them, then he should obtain the relative A-velocity representing the current slope of the A-worldline. Events move in spacetime while non-inertial, and this cannot be ignored whether B is trying to determine the A-velocity from bounced radar signals, or determining the A-velocity from a space vs time plot after the fact, IMO.

Now I realize that you use the twin-A system as the reference for all future calculations as they go, so you do not have the superluminal problem. I'm just trying to nail down the reasoning as to why twin B should disagree with the MSIRF observer at their moiment of colocation, and how to justify a resolution of that matter in a way that all observers agree (as consistent with SR).

GrayGhost
Mike_Fontenot
Mike_Fontenot is offline
#366
Apr13-11, 11:47 AM
P: 250
Quote Quote by GrayGhost View Post
[...]
What's the difference between going inertial for 1 quintillionth of a microsecond, versus considering the velocity at a point on the x vs t position plot [B]while still non-inertial?
It turns out to be true that the traveler DOES agree with his MSIRF (about distances to, and ages of, remote people) at each and every instant of his life, even when he is stationary with that particular MSIRF at only that single instant. But to PROVE that, I needed to FIRST prove that it is true for an arbitrarily long segment of the traveler's life, and then prove it for a finite, but arbitrarily short segment, and then finally (by using a limiting argument) to prove that it is true even when the "segment" consists of only a single instant of time.

It's not possible to understand those proofs by trading "sound bites" on a web forum. If you really want to understand them, you're just going to have to spend a lot of "quiet-time" with my paper ... there's no other way.

(Most university libraries will either have the volumes of that journal, or can get them through inter-library loan. At least that's the case in the USA. I don't know about in other parts of the world, though ... in those cases, you may just have to "bite-the-bullet" and give the publisher his due. Otherwise, you'll just have to answer your questions on your own, or from sources other than me.)

[...]
I'm just trying to nail down the reasoning as to why twin B should disagree with the MSIRF observer at their moment of co-location [...]
[...]
I think you need to spend some more time with this posting:

http://www.physicsforums.com/showpos...&postcount=328 .

If that's not enough to answer your question (about WHY the traveler, whenever his acceleration is non-zero, doesn't agree with his MSIRF about their respective relative velocities wrt the home-twin), then I think it's possible that you might need some additional experience working with derivatives: exactly how they are defined, what they mean, and how they are used.

Mike Fontenot
DaleSpam
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#367
Apr13-11, 02:16 PM
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GrayGhost, this is Mike's pattern. Whenever he is asked for details he simply refers to his paper, and whenever challenged to justify a false assertion he simply avoids responding entirely. He is very passive-agressive.
GrayGhost
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#368
Apr13-11, 04:36 PM
P: 432
Mike Fontenot,

Derivatives are not a problem for me.

It sounds like we are in agreement far as twin A existing precisely where the co-located MSIRF observer says he does. Twin B will disagree based upon his own measurements and calculations assuming he makes them in the typical classical way, however twin B will be wrong in his assessment. My position is that twin B is incorrect because of 2 reasons ...

(1) because he (w/o knowing) accounts for contractions while (w/o realizing) ignoring dilations. IOWs, twin B fails to account for the fact that events move in spacetime while non-inertial, and such an event would be the B-departure-from-A. So, B's assessment is incomplete IMO.

(2) because while non-inertial, light's speed must appear to travel variantly because of one's own dynamically changing POV. This is analagous to measuring light's speed across an expanse of space which includes a very large and very strong gravity well, from the vantage of one far removed from the region. Yet, light's speed is always c when measured at the non-inertial observer, and it is always measured at c in any small locale of the gravity well.

In my mind, I see why twin B calculates things differently, and inconsistently with any co-located MSIRF observer. Instead of just saying they "should" disagree (given the special theory requires it), and reverse engineering the B side from the A side, my opinion is that the reasoning of their disagreement needs articulated, and then a transformation from B's assessment to the co-located MSIRF observer's assessment may be obtained (with fuller meaning). The hope would be that twin B does not have to consider everything from the A-side first to determine the state of the union from his own measurements and calculations.

As to whether there already exists any other methods (and conventions) that differ, while getting the job done (properly, and considtent with SR), I am not sure.

GrayGhost
GrayGhost
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#369
Apr13-11, 04:44 PM
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Quote Quote by DaleSpam View Post
GrayGhost, this is Mike's pattern. Whenever he is asked for details he simply refers to his paper, and whenever challenged to justify a false assertion he simply avoids responding entirely. He is very passive-agressive.
Well, it seems to me that in discussing a paper, it would promote folks to want to buy it. Imagine the 1905 OEMB paper was posted today for the first time in an online physics journal. No matter how much relativity is discussed online regarding OEMB, countless folks will always debate it ... mainly because they don't grasp it all. I'm quite confident that I'd buy that paper today, to obtain the story straight from the horse's mouth ... especially given all the debates about the details of the theory. That said, I would figure that detailed discussions of the key points of the paper would encourage increased sales.

GrayGhost
DaleSpam
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#370
Apr13-11, 04:53 PM
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Me too, which is partly why I believe it is simply a debate tactic when he knows he has an indefensible claim.
ghwellsjr
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#371
Apr14-11, 03:30 AM
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Quote Quote by ghwellsjr View Post
Quote Quote by GrayGhost View Post
Did buying Mike's paper help you in any respect?
Help me? You mean help me understand his position? Yes, I believe I understand exactly what his fatal mistake is.
I have posted my critique of Mike's scheme here:

http://www.physicsforums.com/showthr...78#post3245978

Please respond there, rather than here.
GrayGhost
GrayGhost is offline
#372
Apr16-11, 01:11 PM
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Quote Quote by GrayGhost to ghwellsjr View Post
OK, so wrt your comment here ... you are saying that neither observer can say anything about the current readout or rate of the other clock unless colocated, and that on 2nd relocation, the accelerated clock is (1/2)tv2/c2 sec slow on arrival. Yes?

I do realize that one cannot say anything about what the accelerated clock might record of the always-inertial clock while non-inertial "as he goes", from a standpoint of using the LTs as designed as they are applied in all-inertial scenarios. All anyone can say is that B cannot dispute his clock aged (1/2)tv2/c2 less than the always-inertial clock over the entire interval in collective. However ...

However ... can the always-inertial clock say the accelerated clock (which moves at constant v curvilinearly) always ticks slower by (1/2)v2/c2 as it goes? It seems to me he can declare such, however I will need to verify that first.
ghwellsjr,

I finally got to looking at this. I'm just curious .... Do you agree that-by-extrapolation-of-SR the accelerating clock will tick slower by the factor of 1/gamma over the entire interval, and at any point during its transit, per the inertial clock?

GrayGhost


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