MacM's Closure to a Length Contraction Thread

[Ken G]

Originally Posted by MacM

or a deviation of 1/2,000,000 when the testing is comoving vs recessional.

You are correct in that if they should decide to actually look for the affect it should be detectable but it is so small that they must be very careful to insure other affects do not swamp the underlying motion affect.

MacM, on countless occasions you have denied the need for a master frame where time is running "correctly", and in this very post to worzel you cite the motion of the Earth with respect to the CMB as a measure of the absolute sense to which Earth clocks are dilated! Sure sounds like a master frame to me. Once and for all, which is it-- do you think that time dilation is merely a relative effect due to motion between observers, or do you actually think there is such a thing as "real time dilation" that accumulates relative to an absolutely undilated clock, and independently of any simultaneity issues?

This can all be condensed into a simple question, which is important to do given the volume of argumentation that has gone by already. Let's start with a clock that you would stipulate is not time dilated. Then take a second identical clock with an identical history, accelerate that clock so that it moves away from the first, then accelerate it back and return it to rest next to the first clock. The twin "paradox", if you will. You claim that the "F=ma" affects are why this second clock will read less time. We have explained at length the quantitative result you get from SR which you reject as an unphysical trick. So if you are going to reject the SR explanation, which succeeds completely in predicting the accumulated time differential given the known velocity history, then this is my final challenge to you before I leave you to the inferior quality of your alternative theory: tell me how to calculate the accumulated time differential, your way, and get the right answer by doing the calculation from the perspective of either observer.

If you can't, I say your approach is stillborn, because it requires a frame that is not directly accessible to every observer, but rather requires conversion into a preferred frame of some other observer. That's a terminal flaw.

[MacM]

Originally Posted by worzel

So if I take too clocks side by side, note that they are synchronized, then accelerate one away and back again, not only will it have elapsed less time than the one that didn't acclerate, but it will now be running slower than the other one when put back side by side because it has experienced more past acceleration. Is that what you're saying?

Of course not. It will have accumulated less time but will be ticking at the proper time rate for that frame.

[MacM]

Originally Posted by Ken G

MacM, on countless occasions you have denied the need for a master frame where time is running "correctly", and in this very post to worzel you cite the motion of the Earth with respect to the CMB as a measure of the absolute sense to which Earth clocks are dilated! Sure sounds like a master frame to me. Once and for all, which is it-- do you think that time dilation is merely a relative effect due to motion between observers, or do you actually think there is such a thing as "real time dilation" that accumulates relative to an absolutely undilated clock, and independently of any simultaneity issues?

While we cannot (yet) claim an absolute frame, it would appear that there must be one. It may or may not be the CMB. That is because the CMB is not at rest it is dynamic but our ansitrophy to it certainly suggests the existance of a universal rest frame.

As A.E. stipulated by fiat that there is no need for an ether, I stipulate there is no need for a master rest frame. Every inertial condition appears to be such a frame, except that motion to that frame becomes dilated and is not any part of a reciprocity (relative velocity) affect.

This can all be condensed into a simple question, which is important to do given the volume of argumentation that has gone by already. Let's start with a clock that you would stipulate is not time dilated. Then take a second identical clock with an identical history, accelerate that clock so that it moves away from the first, then accelerate it back and return it to rest next to the first clock. The twin "paradox", if you will. You claim that the "F=ma" affects are why this second clock will read less time. We have explained at length the quantitative result you get from SR which you reject as an unphysical trick. So if you are going to reject the SR explanation, which succeeds completely in predicting the accumulated time differential given the known velocity history, then this is my final challenge to you before I leave you to the inferior quality of your alternative theory: tell me how to calculate the accumulated time differential, your way, and get the right answer by doing the calculation from the perspective of either observer.

If I could do that I would invite you to Sweden. As I have said I don't have the answers. I do have valid questions. The primary question which is not being answered is the fact that the known dilated tick rate of the moving clock fully accounts for the accumulated trip time of the moving clock and hence the physical impossibility of actual physical spatial contraction.

If you can't, I say your approach is stillborn, because it requires a frame that is not directly accessible to every observer, but rather requires conversion into a preferred frame of some other observer. That's a terminal flaw.

And as is the above condition in SR. So where next?

[MacM]

My personal solution to this is to believe that there exists some form of energy background which creates space and it exists all along a spectrum such that every inertial energy condition has its own absolute rest frame referance.

That seems to be consistant with observation and emperical findings without requiring the unsupported and ubelievable portions of SR.

It would mean that the invariance of light is an illusion in that observers moving relative to the source of light are not seeing the same photon. Photon being the consequence of reaching the terminal velocity of v = c to that particular energy level. That is to think of standard light as just an excitation signal moving through the vacuum and being another form of Cerenkov Radiation in the fabric of universal space..

[publius]

Originally Posted by MacM

So now you want to assert that SR causes physics in one frame that are not in another?

Mac, Mac, Mac,

SR is not causing any physics. It is the *consequence* of the physics. The frame of the moving charge sees a charge separation and so experiences a force. However, transforming to the stationary frame, that charge separation disappears (because of the Lorentz contraction), but we still see a force on the charge. This is the principle of relativity. So in our frame, we deduce the force is something between moving charges. That is a moving charge induces a force on other moving charges. We call this magnetism.

If Lorentz contraction didn't occur, there would be no force in either frame, and we would NOT have a magnetism. IOW, magnetism is a relativistic effect of "distortions" of the coulomb field due to relative motion.

-Richard

[worzel]

Originally Posted by MacM

Of course not. It will have accumulated less time but will be ticking at the proper time rate for that frame.

Ok, for a moment there when you mentioned tick rates being the result of historical accumulation of acceleration I was thinking that maybe you thought acceleration itself could account for time dilation locally, with no consideration of a master frame. But for a clock to dilate (and stay dilated) upon departure from our earth clock, and then return back to the same tick rate upon being reunited, acceleration back to the initial frame would have to cause the clock to to speed up.

That is, according to your theory, the amount by which a clock slows down, or speeds up, due to acceleration is dependant on the difference between the before and after velocity of the clock relative to some initial, undilated, frame. KenG beat me to it, but you are just arguing for an absolute frame afterall.

I think KenG's request for the calculation for "how to calculate the accumulated time differential, your way, and get the right answer by doing the calculation from the perspective of either observer." is crucial, and I too don't see any point in going on with this discussion unitl you answer that request. Your response so far:

Originally Posted by MacM

The primary question which is not being answered is the fact that the known dilated tick rate of the moving clock fully accounts for the accumulated trip time of the moving clock and hence the physical impossibility of actual physical spatial contraction.

is totally inadequate. You respond to a question with a question. But you claimed that everything can be worked out by just using your theory of "time dilation against an absolute frame", and KenG's request is nothing more than a request for you to back up that claim by showing us how it all works out for both observers.

[MacM]

Originally Posted by publius

Mac, Mac, Mac,

SR is not causing any physics. It is the *consequence* of the physics. The frame of the moving charge sees a charge separation and so experiences a force. However, transforming to the stationary frame, that charge separation disappears (because of the Lorentz contraction), but we still see a force on the charge. This is the principle of relativity. So in our frame, we deduce the force is something between moving charges. That is a moving charge induces a force on other moving charges. We call this magnetism.

You are still advocating physics in one frame that does not exist in another.

If Lorentz contraction didn't occur, there would be no force in either frame, and we would NOT have a magnetism. IOW, magnetism is a relativistic effect of "distortions" of the coulomb field due to relative motion.

-Richard

I'll not debate your assertion but only point out that I have had mechanical, electrical and nuclear engineering; plus post grad training in process control instrumentation and I must have fallen asleep in the class that taught that magnetisim is the consequence of relativity's length contraction.

Care to explain just how all this babble resolves the issue about a dilated clock accounting for the accumulated time of the trip in complete absence of any spatial contraction? If not your comments above have no meaning.

[MacM]

Originally Posted by worzel

Ok, for a moment there when you mentioned tick rates being the result of historical accumulation of acceleration I was thinking that maybe you thought acceleration itself could account for time dilation locally, with no consideration of a master frame. But for a clock to dilate (and stay dilated) upon departure from our earth clock, and then return back to the same tick rate upon being reunited, acceleration back to the initial frame would have to cause the clock to to speed up.

Correct.

That is, according to your theory, the amount by which a clock slows down, or speeds up, due to acceleration is dependant on the difference between the before and after velocity of the clock relative to some initial, undilated, frame. KenG beat me to it, but you are just arguing for an absolute frame afterall.

I think KenG's request for the calculation for "how to calculate the accumulated time differential, your way, and get the right answer by doing the calculation from the perspective of either observer." is crucial, and I too don't see any point in going on with this discussion unitl you answer that request. Your response so far:is totally inadequate. You respond to a question with a question. But you claimed that everything can be worked out by just using your theory of "time dilation against an absolute frame", and KenG's request is nothing more than a request for you to back up that claim by showing us how it all works out for both observers.

You seemed to have missed or choose to ignore the fact that I have repeated several times "I have NO theory". I am merely raising a bonafide question about YOUR theory. If you have no answer then say so.

If you do then explain how you declare spatial contraction while dialted tick rate of the moving clock fully accounts for the accumulated trip time without spatial length contraction.

[worzel]

Originally Posted by MacM

Correct.

Right, absolute master frame it is then.

You seemed to have missed or choose to ignore the fact that I have repeated several times "I have NO theory". I am merely raising a bonafide question about YOUR theory. If you have no answer then say so.

That is rather ridiculous given that you have had countless explanations to the resolution of your supposed paradox which you have hand waved away because they use SR rather than the premises of your thought experiment.

If you do then explain how you declare spatial contraction while dialted tick rate of the moving clock fully accounts for the accumulated trip time without spatial length contraction.

So your question is really

Why is there length contraction in SR when it is not required to account for the elapsed time of a moving clock when analysed from one frame of reference

The answer is because it is required when analysing events from other points of view. If SOL is constant and people can use rulers to measure distances and clocks to measure time without having to adjust their measurements in accord with their velocity against some master frame, then reciprical time dilation, length contraction, and relativity of simultaneity are logically necessary.

You will no doubt reply that that is just a fiat statement. But that is just basic SR, if you don't understand that then your question belongs in Q & A, along with a willingness to try to understand the theory you are having difficultly grasping. You are in no position to refute a theory until you can already answer your own question.

[publius]

Originally Posted by MacM

You are still advocating physics in one frame that does not exist in another.



I'll not debate your assertion but only point out that I have had mechanical, electrical and nuclear engineering; plus post grad training in process control instrumentation and I must have fallen asleep in the class that taught that magnetisim is the consequence of relativity's length contraction.

Care to explain just how all this babble resolves the issue about a dilated clock accounting for the accumulated time of the trip in complete absence of any spatial contraction? If not your comments above have no meaning.

Yep, I believe you did indeed fall asleep during a lot of classes. Sorry, but you painted that big target right on yourself. Electrical engineering is but a subset of electromagnetic theory -- it depends on exactly what one specializes in, but many EEs never get into field theory beyond the very basics. The bible of EM theory is a tome dubbed "Classical Electrodynamics", by Jackson. Get a copy of that and read it -- you'll learn something. And you'll see my babble is repeated there, and most other texts of that level.

SR was born out of the womb of EM theory, Mac. The Lorentz transform is what makes Maxwell's equations invariant between intertial reference frames. That's how it came about. However, logically, one can start with the Coulomb field, postulate SR, and derive Maxwell's equations. That is magnetic forces are a relativistic effect on the coulomb field, that is they are due to things like length contraction and other things you object to. Or can one start with Maxwell, and derive SR. For magnetic forces to work the way they do, then SR comes out.

Jackson and any other "deep" text on the underpinnings of classical electrodynamics will go into this as well. Selected lectures of Schwinger, "Mr. Radar" himself, were compiled into a text of the same name as Jackson's "Classical Electrodynamics", and this goes into excellent detail of how Maxwell can be derived from relativity.

Write down a 1D wave equation. Transform it to a moving coordinate system using the Galiean transform. You get something different. In the simple case, you can show that the wave speed depends on the velocity of the moving frame, and a moment's though reveals the speed of the wave from the wave equation is therefore relative to the medium in which it propagates. Sound, and the vibrations of a guitar string are simple examples.

So, the notion of an "aether", the medium in which EM forces propagate , followed. However, 100 years ago, the notion of the aether collapsed, and as you put it before, "Houston, we have a problem".

Now, transform that 1D wave equation into a moving frame using the Lorentz transform. Voila! You get the same equation, saying the moving frame sees the waves at the same speed, c ( 1/c^2 = mu*epsilon, but hey, you know that, of course, but the EM highbrows will be using Gaussian units, where there are no mu's and epsilons).

The full, source form of Maxwell's equations is also invariant under the Lorentz transform, but it takes a lot more mathematical effort to show that in the traditional modern vector form of Maxwell. However, a far more elegant approach exists, and that is the four-vector formulation. The E and B fields become one thing, a 4-tensor called the Faraday tensor. Maxwell's equation in that form say simply the divergence of that tensor are equal to a 4-vector known at the 4-current density, the time-like component being the charge density, and the space like components being the 3 of the familiar current density vector. In the transforms of that 4-current, and the mixing of its time-like and space-like components, one learns indeed how magnetism can be seen as pure relativistic effect of the basic coulomb force.

The lesson you need to learn here is that by disagreeing or challenging SR or whatever the heck you are trying to do, you are going against over 100 years of EM theory. And like most people who attack SR, you don't have a clue about the classical EM theory behind it, and how it was developed. If you start picking apart SR's time and space mixing because you don't like it, the whole of EM theory comes apart. Statements like length contraction doesn't exist, is saying EM theory is wrong, but you don't understand enough about EM to see this. Far greater minds than I could ever wish to be in my dreams have gone over EM theory and found it to be consistent.

What you are actually arguing for, although you don't know it or appreciate it, is an aether theory, where the frame of that aether is your master frame, and the Lorentz transform is just a trick caused by an "aether drag" -- distances don't contract, yardsticks do, and time doesn't dialate, but clocks do. Lorentz himself was a proponent of this, and tried to show how something like an LC oscillator would slow down due to "aether wind", and how the distances between molecules held together by the EM forces between the charged constituents would shrink due to this same aether drag.

Take a few years to study classical EM theory, and you'll get up to speed on why this was abandoned in favor of Einstein's view. But in the meantime quit babbling yourself about something you don't understand. You may protest you understand SR, but you clearly don't understand the EM that underpins it.


-Richard

[MacM]

Originally Posted by worzel

The answer is because it is required when analysing events from other points of view.

False. And I would have hoped you at least would have realized by now that the accumulated time on the clock is the same in any frame.

If SOL is constant and people can use rulers to measure distances and clocks to measure time without having to adjust their measurements in accord with their velocity against some master frame, then reciprical time dilation, length contraction, and relativity of simultaneity are logically necessary.

Considering that this does not answer the question about accumulated time by the moving clock then the logical conclusion is that your system is broken, not logically required.

You will no doubt reply that that is just a fiat statement. But that is just basic SR, if you don't understand that then your question belongs in Q & A, along with a willingness to try to understand the theory you are having difficultly grasping.

The only difficulty here seems to be your being able to actually explain the issue being raised.

You are in no position to refute a theory until you can already answer your own question.

Wrong again. I nor anyone is required to provide an alternate theory to be able to point out the falicy of your theory.

[MacM]

Originally Posted by publius

Get a copy of that and read it -- you'll learn something. And you'll see my babble is repeated there, and most other texts of that level.

I'll do that the very minute you answer my question. How do you justify claiming spatial contraction when the dilated tick rate of the moiving clock fully accounts for the trip time without any change in distance?

Otherwise I would be merely wasting a lot of time, apparently as you have, reading it.

[worzel]

Originally Posted by MacM

False. And I would have hoped you at least would have realized by now that the accumulated time on the clock is the same in any frame.

What do you mean by that? That if a clock is allowed to run for 10 seconds and then stopped that everyone would agree that it read 10 seconds? That was the gist of your gedanken, but I don't see what that proves. Or do you mean that all frames can agree on the simultaneity of the clock's start and stop time? That is not what SR says, so if that is the premise of your question about SR then your question is based on a false premise. If you have some other theory that maintains simultaneity across all frames then please feel free to present it.

Considering that this does not answer the question about accumulated time by the moving clock then the logical conclusion is that your system is broken, not logically required.

My system? We're talking about SR, right? If the question is about SR then, as above, either the question is vacuous or it has a false premise We tried to explain the false premise from the SR perspective to you very early on and you dismissed any talk of simultaneity as irrelevant.

If you think that a mainstream theory is falsified if humbe ole me is unable to you educate you sufficiently in it then you are sorely mistaken: surely a gibbon could use the same logic to falsify arithmetic!

If you think that SR is broken (by which I presume you mean inconsistent) then perhaps you could demonstrate this inconsistency within SR.

The only difficulty here seems to be your being able to actually explain the issue being raised.

The issue still seems to be your inability to make up your mind as to whether you are simply asking a question about SR and are still unable to understand the answer, talking about an inconsistency you have found within SR and are unable to present, or your own pet theory that you are unable to present.

Perhaps you should just focus on your question about time dilation and all frames agreeing on the accumulated time of a clock. What do you mean by that?

Wrong again. I nor anyone is required to provide an alternate theory to be able to point out the falicy of your theory.

I simply said that if you can't even answer your own basic question about SR (which implies that you don't understand SR) then you are in no position to refute it. I'll add that if you can't demonstrate an inconsistency within SR then you are in no position to claim that it is inconsistent. The question of your alternate theory only crops up when you claim it can all be done without length contraction but refuse to show how.

[publius]

Originally Posted by MacM

I'll do that the very minute you answer my question. How do you justify claiming spatial contraction when the dilated tick rate of the moiving clock fully accounts for the trip time without any change in distance?

Otherwise I would be merely wasting a lot of time, apparently as you have, reading it.

Mac,

What do you mean by that? The dilated tick rate of the moving clock fully accounts for the trip time without any change in distance..... The dilated tick rate accounts for the trip time. What does that mean? IOW, a clock says what it says after a certain time has passed (which doesn't depend on how much distance it travelled in any frame)?? If I set one clock to run at half the rate of the other, then after a certain time, it will read one half of what the other clock says, and I say, "Aha, that is accounted for by the fact it is running at 1/2 the rate of the other"??

If I send one clock off at some velocity with instructions to stop it when it reads a certain time and come back, that it will read that time when it gets back?? And that somehow confirms it travelled whatever distance it did in my frame?

-Richard

[publius]

Mac,

I'm still stuck trying to figure out what you actually mean. Where is the problem with SR as you see it? Let's do a little SR distance/time scenario and you tell me where it's wrong (and an experiment that would show it).

Harry and Sally are our two test subjects. Harry's will be the stationary frame and Sally's the moving frame. Sally goes off, accelerates to velocity v in Harry's frame along a common x-axis and they start their stop watches when she passes a common origin, where we declare x = x' = 0. Standard conditions, (0, 0) corresponds to (0', 0').

Some time t passes in Harry's frame; *in Harry's frame*, Sally is at space-time point (event) of (vt, t). That is she has travelled a distance d = vt and the time is t. Harry's clock has ticked off t time units. In Harry's frame, (vt, t) and (0, t) are simultaneous events. They occur at the same time.....in Harry's frame.

Now, what are those events in Sally's frame, we ask. Well, let's apply the Lorentz transform:

x' = y(x - vt) (y = gamma, b = v/c)
t' = y(t - (b/c) x)

For x', we plug in x = vt. Hmmm, x' = 0. Well, Sally's origin is where she is, and that comfirms it. Now, t' = y(t - (b/c) vt) = y(t - (v/c)^2 t). Factoring out t, the term in parentheses is just (1/y)^2, so t' = t/y, which is just Sally's proper time along her world line.

I did this way to demonstrate that "reciprocity" doesn't work out like you think it does. dt'/dt(partial derivative) = y, but that doesn't mean t' = yt, because Harry's x coordinate comes in there. Here t' = t/y.

Now, what does that mean. *IN HARRY'S FRAME*, Sally's clock ticking t/y (Event (0', t' = t/y) (vt, t) is simultaneous with his clock ticking t (event (0, t). That ain't the case in Sally's frame.

Let's transform event (0, t) in Harry's frame into Sally's frame:

x' = y(0 - vt) = -y(vt)

t' = y(t - 0) = yt

So in Sally's frame, Harry's clock ticks time t well after her clock ticks t/y, and at that time, Harry has moved a distance y(vt) away from her. But wait, Harry moved a longer distance in Sally's frame at (0, t) in his frame, than she did in his frame. Longer by gamma. There's that simultaneity thing coming up here. Harry's events (0, t) and (vt, t) (when Sally reaches a "destination" of vt) are NOT simultaneous in Sally's frame. This is where you getting tripped up. You're trying to force Harry's simultaneity onto Sally.

But how far did Harry move at t' = t/y in Sally's frame. Well, Harry is moving at velocity -v in her frame, so he moved a distance x' = vt' = vt/y. There's the Lorentz contraction. When (and note this is indeed *when*) Sally travelled a distance d = vt in Harry's frame, Harry only travelled d/y in hers. Who travelled what distance and when depends on whether we are using Harry or Sally's concept of simultaneity.

You want to hold onto the concept of time and space as being separate things, and you just can't do it.

-Richard

[MacM]

Originally Posted by worzel

What do you mean by that? That if a clock is allowed to run for 10 seconds and then stopped that everyone would agree that it read 10 seconds? That was the gist of your gedanken, but I don't see what that proves.

No you wouldn't.

For the balance of our post. Nice dodge but I didn't think you had the answer.