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.

[MacM]

Originally Posted by publius

Well, let's apply the Lorentz transform:

Lets not shall we.

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

Lets stop wasting everybody's time and answer my question. If you can't then just say so.

[publius]

Mac,

Again, throwing up my arms in exasperation and running around tearing my hair out, what is this question you want me to answer. Why does a clock read something when it stops? That is about all the sense I can make out of your question.

And, okay, let's don't the Lorentz transform. Let's do the MacM transform. Now, if you'll just tell me what that MacM transform is.....................<sigh>


-Richard

[MacM]

Originally Posted by publius

Mac,

Again, throwing up my arms in exasperation and running around tearing my hair out, what is this question you want me to answer. Why does a clock read something when it stops? That is about all the sense I can make out of your question.

And, okay, let's don't the Lorentz transform. Let's do the MacM transform. Now, if you'll just tell me what that MacM transform is.....................<sigh>


-Richard

Sorry you are frustrated but it really is simple and straight forward.

1 - MacM does not have a transform.

2 - According to SR a moving clock at 0.866c will register 1/2 the time compared to a resting clock. We have emperical data which tends to confirm that prediction so we must accept that as a real physical affect.

That being the case then it is clear that when the resting clock says it took the moving clock 1 year to go 0.866lyr, the moving clock will have recorded 6 months.

t = 1yr, t' = 0.5yr

d = vt = 0.866c * 1yr = 0.866lyr.

All is well.

However, what you do in SR is to completely disregard the comparative tick ratio of the two clocks that SR just declared when you transfer to the moving frame.

You assert that:

d' = v * t' = 0.866c * 0.5yr = 0.433lyr.

The error here is that t and d are physical quantities and v is a calculated value based on the ratio of such quantities.

Therefore correct physics is v' = d/t' = 0.866lyr / 0.5 = 1.72c.

Now before you scream that nothing can go v = > c, I know that is part of your theory but the contention is that the theory uses incorrect physics and hence that limitation cannot be used to claim error.

Now that we have a correct calculated value of the moving frames view of velocity based on its slow ticking clock:

d' = v' * t' = 1.72c * 0.5yr = 0.866lyr.

In this universal view the universe does not contract or respond to the motion of an observer. The observer merely moves thorough the universal void at higher and higher velocities.

At v = c relative to the resting clock the moving clock would traverse the resting clocks universal frame in zero time or have an infinite calculated velocity.

What is interesting in this scenario is that one can get the idea that particle entanglement can be explained as moving at v = c to the communications medium of particles.


The bottom line question is:

How do you justify spatial contradtion when "If you do not disregard the emperically demonstrated fact of a moving clocks comparative dilated tick rate, its tick rate fully accounts for the accumulated trip time without any spatial contraction."?

BTW this would seem to be consistant between frames with the view of 4 momentum (relavistic mass).

Hence it is velocity which is frame dependant, not distance.

[Grey]

Originally Posted by MacM

Sorry. I now know hat you are referring to. Yes calculations were made but I was not party to them and they were not posted. The following is an excerpt from a public forum debate regarding the issue of superluminal distance change as a consequence of spatial length contraction:

That looks like an interesting thread. Since it's a public forum, can you provide a reference or a link? It would be nice to know who is speaking here.

Originally Posted by Someone

Now, while the Lorentz-Fitzgerald contraction does hold, the super-luminal velocities that bother you do not occur inside the event horizon. And after the acceleration period, the event horizon receeds at the speed of light, but when finally see the Earth again, you see it is moving away at a speed of 0.8 c. Thus you never see anything moving at superluminal speeds.
...
So now we jump a bit over into philosophy. It is true that space is contracting quickly, as perceived by the accelerating electron. (Remember that in spacetime there is no problem. The proper distance (rest time times the speed of light) is the same in all reference frames.) But you don’t see the distant object. And whenever you actually can see it, you find that it is well-behaved. This is all consistent with relativity. Relativity simply tells you how different observers will perceive a situation. (And perceive in this context isn’t some wishy-washy thing. It means time and position.)

So the bottom line is the electron will never see the Earth approach at superluminal speeds.

Note that the answer to your quandary is here as well. Although you might calculate that it would be travelling toward you at superluminal speeds, you'll never actually see it do that.

Originally Posted by MacM

But the results are the same once you cease acceleration and become inertial at the higher velocity you will once again see the earth and it will be closer than it was when you first began to accelerate "Away" from it, "IF" the original distance is substantial and the terminal velocity is relavistically high, this change in spatial dimension will have been at superluminal rates and the distance will have become reduced even though your vector is away from the earth.

Nope. Read the above more closely. "And after the acceleration period, the event horizon receeds at the speed of light, but when finally see the Earth again, you see it is moving away at a speed of 0.8 c." If you work out the math, you'll note that by the time you can see the Earth again, it will be farther away than it was when it started, and there will never be a point at which it needed to have moved at superluminal velocities to reach an observed location. By the way, this is exactly why it doesn't make sense to talk about these questions in vague generalities. There are plenty of conclusions that seem like obvious results from the basics of special relativity that do not in fact logically follow from special relativity if you work out the math. Often even setting up the problem is sufficient to see the mistake in reasoning. For example, in the classic twin paradox, you have two observers moving relative to each other, so you might naively suppose that they should see the other as younger. But even just setting up the problem without working it out, you'll quickly realize that there's an asymmetry in the problem, and that there are three reference frames involved, not two.

Originally Posted by MacM

You are mis-stating the case and what I have said.

1 - The data we have does not violate the prediction.

2 - Some predictions have never been tested or have emperical data support.

That is absolutely not what you said. You said, "SR's prediction of reciprocity has been inconsistant with data, observation and logic." You did not say it hasn't been tested, you said it is inconsistent with data and observation. That's a claim that there is data that directly contradicts those predictions. If you now acknowledge that there is no data that contradicts the predictions of special relativity, then please stop stating that there is.

Originally Posted by MacM

If there is experimental evidence that supports special relativity reciprocity or length contraction, please provide it. Or, if you agree that there is no such evidence, please acknowledge that, and stop waffling about it.

I have not waffled about that. Waffling means switching one's claims, as you did above, where, in the same message, you both acknowledged that there is no data that contradicts special relativity, and then claimed that there was data inconsistent with special relativity. My position has been clear from the beginning. I recently gave you an example of an entire class of experiments which verify length contraction and time dilation together. You said you were familiar with that type of experiment, but that you would like to look into it in more detail. Out of curtesy, I offered to wait to discuss them until you had a chance to do so. I'm perfectly willing to give you time to do that, but that does not mean that you can simply dismiss those results without examining them.

Originally Posted by MacM

I tought it was clear that synchronization was not done and is not required as demonstrated by the resulting agreement that gamma = 2 at 0.866c because B and C accumulated 18,000 seconds in a 36,000 second test period according to the resting clock.

I'm not certain what you mean by a lack of synchronization here. If you have a test period in frame A, and you want to know what the clock at B measured during that period, you have to have clock B start and stop at the same time as clock A, right? Isn't that synchronization? I've already pointed out that if you don't do that, and just start and stop the clocks when they reach certain values, then all you have is clocks that read values that you preset, with no way to tell whether they have any relation to each other at all.

Originally Posted by MacM

I did. The equal test period was in the rest frame, not some undefinable universal absolute frame.

Sure, but then you've stated that it wouldn't be valid to take B's perspective of when clock started and stopped. Why can't I do that?

By the way, you haven't responded at all to my comments about what is necessary to show an internal inconsistency or an experimental contradiction of theory, and I consider that a crucial point. Maybe it's because I didn't ask a specific question. I'll repeat that section here

Originally Posted by MacM

Simply a false concept. One must adhere to bonafide basic physics not the formalisim and conclusion of the theory in question. To apply such a standard makes it defacto unimpeachable regardless of any actual validity or lack thereof as long as the theory has been made mathematical consistant by fiat.

Originally Posted by Grey

No, I'm afraid you're mistaken about this. Suppose someone wants to show that theory X has a contradiction or that it is not consistent with experimental evidence. But instead of taking the postulates of theory X as the basis, he takes some other set of postulates (some of which may be similar to those of theory X, but the whole set is not the same; call this theory Y), and derives a contradiction. Does this show that theory X leads to a contradiction? Of course not. It shows that theory Y leads to a contradiction. Or, looking for contradictory experimental evidence, he makes a prediction based on theory Y, and finds that it disagrees with experiment. Does that show that theory X is inconsistent with observation? Again, of course not. That shows that theory Y is not consistent with observation.

If you want to show that theory X leads to either an internal contradiction or a disagreement with observation, you have to find out what theory X really says.

So, I'll ask a specific question. Do you still insist that it's not necessary to work within the rules of a theory in order to show either an internal or external contradiction?

[Celestial Mechanic]

Originally Posted by MacM

[Snip!]1 - MacM does not have a transform.

That's OK, Lorentz does.

Originally Posted by MacM

2 - According to SR a moving clock at 0.866c will register 1/2 the time compared to a resting clock. We have empirical data which tends to confirm that prediction so we must accept that as a real physical affect.

Something sensible at last.

Originally Posted by MacM

That being the case then it is clear that when the resting clock says it took the moving clock 1 year to go 0.866lyr, the moving clock will have recorded 6 months.

t = 1yr, t' = 0.5yr, d = vt = 0.866c * 1yr = 0.866lyr.

All is well. However, what you do in SR is to completely disregard the comparative tick ratio of the two clocks that SR just declared when you transfer to the moving frame. You assert that:

d' = v * t' = 0.866c * 0.5yr = 0.433lyr.

No, SR does not assert that. Here are coordinates for your three events in the (t, x) coordinate system:
F (0, 0)
G (1, 0)
H (1, sqrt(3)/2)

A is the clock that travels from F to G, it is at rest. B is the clock that travels from F to H, it has velocity (sqrt(3)/2 - 0)/(1-0) = sqrt(3)/2.

Now let's Lorentz transform by velocity sqrt(3)/2 in the -x direction. The transform is:

t' = 2*t - sqrt(3)*x
x' = -sqrt(3)*t + 2*x

In the new coordinate system F, G, and H have the following coordinates:

F (0, 0)
G (2, -sqrt(3))
H (1/2, 0)

Note that G and H are not simultaneous in this coordinate system. Since B is at rest here and A is moving, we can wait until t'=2 at event H'=(2,0) and find that the velocity of A is (-sqrt(3)-0)/(2-0) = -sqrt(3)/2, equal and opposite to the velocity of B relative to A.

When you compute a velocity, you must use the same coordinates for space as you do for time. You cannot mix coordinates. If you do not compare apples to apples and oranges to oranges you wind up with a lemon of a theory.

Lemon tree, very pretty,
And the lemon smell is sweet,
But the fruit of the lemon,
Is impossible to eat.

Edited to add: Well, we really don't have to wait for anything that B does, the coordinates of F and G are sufficient to yield the velocity of A relative to B in this coordinate system.

[worzel]

Originally Posted by MacM

No you wouldn't.

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

I presume the irony here was intended

Are you going to answer the question that has been asked by at least three of us in the last page? What do you mean by "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."?

[MacM]

Originally Posted by Grey

That looks like an interesting thread. Since it's a public forum, can you provide a reference or a link? It would be nice to know who is speaking here.

He is a particle physicist from Fermilab:

http://www.sciencechatforum.com/bull...pic.php?t=1038

Note that the answer to your quandary is here as well. Although you might calculate that it would be travelling toward you at superluminal speeds, you'll never actually see it do that.

Yes that is true.

Nope. Read the above more closely. "And after the acceleration period, the event horizon receeds at the speed of light, but when finally see the Earth again, you see it is moving away at a speed of 0.8 c." If you work out the math, you'll note that by the time you can see the Earth again, it will be farther away than it was when it started, and there will never be a point at which it needed to have moved at superluminal velocities to reach an observed location.

Excellent. I missed that point in the debate. However, that leaves you only partially correct also. Since portions of the universe are cntractiong superluminally and are outside the light cone and are unobserved then the observed universe is even smaller during that portion of the trip.

That is absolutely not what you said. You said, "SR's prediction of reciprocity has been inconsistant with data, observation and logic." You did not say it hasn't been tested, you said it is inconsistent with data and observation. That's a claim that there is data that directly contradicts those predictions. If you now acknowledge that there is no data that contradicts the predictions of special relativity, then please stop stating that there is.

Here we have a different understanding of word usage. To me the assertion that time dilation has reciprocity is inconsistant with observation and emperical data in that it has not been demonstrated in 100 years. I can however, see how you take that to mean emperical data disproves reciprocity. It does not. As I have said repeatedly it is not supported by emperical data . That is a different claim.

I have not waffled about that. Waffling means switching one's claims, as you did above, where, in the same message, you both acknowledged that there is no data that contradicts special relativity, and then claimed that there was data inconsistent with special relativity. My position has been clear from the beginning.

Covered above. This is not a case of waffeling.

I recently gave you an example of an entire class of experiments which verify length contraction and time dilation together. You said you were familiar with that type of experiment, but that you would like to look into it in more detail. Out of curtesy, I offered to wait to discuss them until you had a chance to do so. I'm perfectly willing to give you time to do that, but that does not mean that you can simply dismiss those results without examining them.

I did examin them. I am not convienced that the KT experiments do what they claim but in any case they still would not provide an acceptable answer to the basic question regarding accumulated time being accounted for by the dilated rate of the moving clock measuring the trip time.

That being the case one must take any assertions about KT with a grain of salt and conclude that certain assumptions are false.

I'm not certain what you mean by a lack of synchronization here. If you have a test period in frame A, and you want to know what the clock at B measured during that period, you have to have clock B start and stop at the same time as clock A, right?

Absolutely not. That is why the gedanken is formed as it is to eliminate the requirement hence simplify the analysis. "IF" B were to start and stop in absolute synchronization with A, I would think you would agree that the test period would be the same would you not?

That being the case A receiving start/stop information signals and computing the the timing A can determne that the test period in which B accumulated 18,000 seconds was the same period described by A as being 36,000 seconds and hence confirms the gamma for 0.866c veloicty of the test.

Isn't that synchronization?

Yep but it isn't required.

I've already pointed out that if you don't do that, and just start and stop the clocks when they reach certain values, then all you have is clocks that read values that you preset, with no way to tell whether they have any relation to each other at all.

Not so. The calculated time interval between the start/stop information signals transmitted confirm the tinerval and hence the gamma ratio between the clocks.

Sure, but then you've stated that it wouldn't be valid to take B's perspective of when clock started and stopped. Why can't I do that?

Because it involves a shift in simultaneity and creates a differential in the test time periods that destroys the gamma relationship being considered, creating a different gamma for an alternate view to make SR internally consistant .

I contend that when a clock stops it is stopped and cannot be considered to be continuing to tick .

So, I'll ask a specific question. Do you still insist that it's not necessary to work within the rules of a theory in order to show either an internal or external contradiction?

I thought I had answered that. Your formalisim is ony valid to show external errors. Following the formalisim and accepting assumptions of the theory make it impossible to demonstrate physics shortfalls. The only possible errors allowed in such a case would be mathematical contruction, etc. I had conceeded that SR is mathematically consistant if you subscribe to all its assumptions and assertions.

[MacM]

Originally Posted by worzel

Are you going to answer the question that has been asked by at least three of us in the last page? What do you mean by "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."?

I wanted to make sure that you understand that the accumulated time is by my gedanken and once accumulated and stopped it can be moved to any frame for evaluation and of course the nubmers do not change since the clock (unlike in SR) is stopped in all frames.

[clj4]

I did examin them. I am not convienced that the KT experiments do what they claim but in any case they still would not provide an acceptable answer to the basic question regarding accumulated time being accounted for by the dilated rate of the moving clock measuring the trip time.

That being the case one must take any assertions about KT with a grain of salt and conclude that certain assumptions are false.

Please prove this statement. Give us your take on the KT experiment and point out which "assumptions are false".

[worzel]

Originally Posted by MacM

I wanted to make sure that you understand that the accumulated time is by my gedanken and once accumulated and stopped it can be moved to any frame for evaluation and of course the nubmers do not change since the clock (unlike in SR) is stopped in all frames.

I understand that, and would have thought that you'd understand by now that having your clocks tick until a predetermined time, then stopped, then brought back together for comparison proves nothing.

It doesn't even prove gamme in one direction, as the stop times in your gedanken are predetermined according to SR in A's frame. So one could use a similar argument to insist that Newtonian absolute time is correct simply by stating (by fiat ) that the clocks all stop simultaneously after 10 ticks and are then brought back together to compare thus showing that time ticks at the same rate in all frames.

If the purpose of using gamma was to demonstrate anything about SR, then all it demonstrates is that according to SR, B's clock with have ticked more slowly according to A.

As you've now agreed that there are no internal inconsistencies within SR and there is no experimental data that contradicts SR (within it's domain of applicability) I am really hard pressed to see what your point is other than that one can chose a frame in SR and claim it is the one true frame by faith (for SR allows no distinction to be made).

Originally Posted by MacM

"IF" B were to start and stop in absolute synchronization with A, I would think you would agree that the test period would be the same would you not?

Well done for putting it capitals, that is a big "IF". According to SR there is no absolute synchronization between A and B, so your whole argument reduces to "if SR is wrong, then SR is wrong". Wow, that's got me scratching my head and woo wooing myself to sleep.

[MacM]

Originally Posted by clj4

Please prove this statement. Give us your take on the KT experiment and point out which "assumptions are false".

I think my post was quite clear. Based on the understanding that it does not address (resolve) the accumulated time conundrum which is the foundation for asserting spatial contraction "one must conclude some assumption made in KT are false".

I am not required to resolve the issue of what is false but clearly KT cannot prove spatial contraction IF spatial contraction does not exist and without properly resolving the question I have raised spatial contraction cannot exist.

Now if you should resolve the accumulated time issue then we would certainly be able to talk more rationally about the situation.

[clj4]

Originally Posted by MacM

I think my post was quite clear. Based on the understanding that it does not address (resolve) the accumulated time conundrum which is the foundation for asserting spatial contraction "one must conclude some assumption made in KT are false".

I am not required to resolve the issue of what is false but clearly KT cannot prove spatial contraction IF spatial contraction does not exist and without properly resolving the question I have raised spatial contraction cannot exist.

Now if you should resolve the accumulated time issue then we would certainly be able to talk more rationally about the situation.

Please don't answer a question with a question.
The KT experiment is a fundamental test of relativity. It has not been challenged by anyone in the mainstream.
Once again, please show us what is wrong with the KT experiment, its math is very simple, can you show mathematically where the error lies? And yes, you "are required to resolve the issue of what is false.." You made the statement, now back it up.

[MacM]

Originally Posted by worzel

I understand that, and would have thought that you'd understand by now that having your clocks tick until a predetermined time, then stopped, then brought back together for comparison proves nothing.

Well you clearly have not digested the whole of the gedanken or you simply choose to short sheet the issue. It I had not transmitted start/stop information signals from the shuttles such that frame A could determine the test interval duration you statement would be true. But I did and therefore your statement is absolutely false.

It doesn't even prove gamme in one direction, as the stop times in your gedanken are predetermined according to SR in A's frame. So one could use a similar argument to insist that Newtonian absolute time is correct simply by stating (by fiat ) that the clocks all stop simultaneously after 10 ticks and are then brought back together to compare thus showing that time ticks at the same rate in all frames.

False once again. The fact that they stop as directed by SR calculations is to assume SR valid. The one way gamma is verified by the calculation of the test interval proving that B accumulated 18,000 seconds during a 36,000 second test period according to A, hence gamma = 36,000/18,000 = 2.000 which is correct for the flight scheduled velocity of 0.866c. So how is gamma not validated?

If the purpose of using gamma was to demonstrate anything about SR, then all it demonstrates is that according to SR, B's clock with have ticked more slowly according to A.

Correct. And that C also ticked more slowly than A and by an equal amount as B such that B and C must be ticking "physically" at an equal rate, even though they have a relative velocity.

As you've now agreed that there are no internal inconsistencies within SR and there is no experimental data that contradicts SR (within it's domain of applicability) I am really hard pressed to see what your point is other than that one can chose a frame in SR and claim it is the one true frame by faith (for SR allows no distinction to be made).

It has nothing to do with faith. You could pick anyother frame and you will still have a mis-match of accumulated times on the clock if you use the equal duration test time method.

Arguing that we should not use equal test periods seems outright ludricrus. Certainly one will get different accumulated times and computed gammas if you vary the test duration.

Well done for putting it capitals, that is a big "IF". According to SR there is no absolute synchronization between A and B, so your whole argument reduces to "if SR is wrong, then SR is wrong". Wow, that's got me scratching my head and woo wooing myself to sleep.

While taking your nap please dream up an acceptable explanation to the core issue here. The fully accounted for accumulated trip time by the moving clock without spatial contraction.

[MacM]

Originally Posted by Celestial Mechanic

That's OK, Lorentz does.

Lucky for you.

No, SR does not assert that. Here are coordinates for your three events in the (t, x) coordinate system:
F (0, 0)
G (1, 0)
H (1, sqrt(3)/2)

A is the clock that travels from F to G, it is at rest. B is the clock that travels from F to H, it has velocity (sqrt(3)/2 - 0)/(1-0) = sqrt(3)/2.

Now let's Lorentz transform by velocity sqrt(3)/2 in the -x direction. The transform is:

t' = 2*t - sqrt(3)*x
x' = -sqrt(3)*t + 2*x

In the new coordinate system F, G, and H have the following coordinates:

F (0, 0)
G (2, -sqrt(3))
H (1/2, 0)

Note that G and H are not simultaneous in this coordinate system. Since B is at rest here and A is moving, we can wait until t'=2 at event H'=(2,0) and find that the velocity of A is (-sqrt(3)-0)/(2-0) = -sqrt(3)/2, equal and opposite to the velocity of B relative to A.

Your three coordinates and numbers don't seem to be any part of my post.

When you compute a velocity, you must use the same coordinates for space as you do for time. You cannot mix coordinates. If you do not compare apples to apples and oranges to oranges you wind up with a lemon of a theory.

So that is why you impose the calculated value of v in A's frame on the B frame? HeHe.

Seems to be valid v should use the ratio of physical quantities d/t of that frame v' = d /t' is all you have to work with since you have not provided any acceptable solution to the issue of the dilated tick rate of the moving clock (B) fully accounting for the measured trip time WITHOUT length contraction.

Lemon tree, very pretty,
And the lemon smell is sweet,
But the fruit of the lemon,
Is impossible to eat.

SR may be neat
but is to fleet
time on clocks
smell like week old socks
and contraction is some
fabricated contraption.



Now "How do you justify claiming spatial contraction when the dilated tick rate you claim for the moving clock and the accumulated time fully accounts for the trip time without spatial contraction"?

You must choose one. Clock B cannot be subject to both as physical realities. Don't claim time is one frame and distance is the other. The clock is physical in both frames and so is it's accumulated time.