MacM's Closure to a Length Contraction Thread

[worzel]

Originally Posted by MacM

I think we are getting symantical here. I never said simultaneity was not part of relativity. I said it is not part of this test.

SR says that what are simultaneous events are different for different observers moving as in your thought experiment. So if the rel. of sim. is not part of your test then you are not testing SR, and can not conceivably hope to show SR to be inconsistent in doing so.

Look Ma! Pythagoras was wrong! See 2² + 3² = (13^1/₂)² but where's the right angle?

[Tensor]

Originally Posted by Celestial Mechanic

Get thee to a library! And if you do, be sure to read a real textbook on special relativity, not some potboiler by Herbert Dingle.

May I suggest "Spacetime Physics" by Taylor and Wheeler?

[MacM]

Originally Posted by Celestial Mechanic

"Pearls" indeed, clj4!

A quick review for MacM. For velocity v we have:

gamma(v) = 1/sqrt(1-v²/c²)

Doppler redshift in frequency for object moving away from observer at velocity v:

redshift(v) = gamma(v)*(1-v/c) = sqrt((1-v/c)/(1+v/c)).

For the velocities in your gedankenexperiment:
gamma(sqrt(3)/2)=2
redshift(sqrt(3)/2) = 2-sqrt(3)
gamma(4*sqrt(3)/7)=7
redshift(4*sqrt(3)/7) = 7-4*sqrt(3).

In my gedankenexperiment:
gamma(3/5)=4/5
redshift(3/5)=1/2
gamma(15/17)=8/17
redshift(15/17)=1/4.

If you cannot understand the calculation and meaning of the quantities above you should not be criticizing special relativity. Get thee to a library! And if you do, be sure to read a real textbook on special relativity, not some potboiler by Herbert Dingle.

Excellent post. It lays out the issue. I have not claimed doppler does not occur. I have claimed that doppler is not part of this test and I specified the gamma function and the standard formula as presented by SR.

t' = t / gamma where "v" is not differentiated as to vector, hence is red and blue shifted blind.

I do not object to your formulisim, I do object to the publication and claims that t' = t / (1 - v^2/c^2)^1/2. "v" has vector but "v" is just "v" and speed does not change with vector. Relative velocity does not change with vector.

The basic formula of SR as presented are physically invalid. It would seem that "v" should have some other symbol or notation to differentiate it in the gamma formula such that vector and doppler is imposed and not state t' is merely a function of relative velocity. Mere relative velocity IS NOT consistant with time dilation.

Unless others have further comment I am satisfied with the conclusions of this thread and hope it is of service to others.

[Tensor]

Originally Posted by MacM

I think we are getting symantical here. I never said simultaneity was not part of relativity. I said it is not part of this test.

You can say that all you want, but it is part of the test. Whenever your frames are in relative motion.

[MacM]

Originally Posted by Tensor

You can say that all you want, but it is part of the test. Whenever your frames are in relative motion.

You are still missing the point. Please read the balance of my post. The test specified it was based on "Relative Velocity" and the assertion by SR that t' = t / (1 - v^2/c^2)^1/2 which is blind to doppler shift.

[clj4]

Originally Posted by MacM

Excellent post. It lays out the issue. I have not claimed doppler does not occur. I have claimed that doppler is not part of this test and I specified the gamma function and the standard formula as presented by SR.

t' = t / gamma where "v" is not differentiated as to vector, hence is red and blue shifted blind.

I do not object to your formulisim, I do object to the publication and claims that t' = t / (1 - v^2/c^2)^1/2. "v" has vector but "v" is just "v" and speed does not change with vector. Relative velocity does not change with vector.

The basic formula of SR as presented are physically invalid. It would seem that "v" should have some other symbol or notation to differentiate it in the gamma formula such that vector and doppler is imposed and not state t' is merely a function of relative velocity. Mere relative velocity IS NOT consistant with time dilation.

Unless others have further comment I am satisfied with the conclusions of this thread and hope it is of service to others.

Go to post 79.
And stay there.

[clj4]

Originally Posted by MacM

You are still missing the point. Please read the balance of my post. The test specified it was based on "Relative Velocity" and the assertion by SR that t' = t / (1 - v^2/c^2)^1/2 which is blind to doppler shift.

Go to post 79
And stay there.

[clj4]

Originally Posted by MacM

More to the point what possible connection do you make between your post and the fact that accumulated time on a clock is t' = t / gamma*. t' is strictly a function of t, not t1 or t2 or t3 as functions of simultaneity views due to motion of observers 1, 2, or 3 at differing velocities.

The only thing being tested is how many tick does each clock do during an equal test period. The equal test period is to mimic relative velocity.

Relative velocity must be simultaneous to be relative but the only attribute that affects comparative accumulated time on the clock is the equal physical duration of the test.

Red or Blue shift are features of measurement between frames "During Motion". This test is blind and the only thing being done is comparing clocks in a common frame subsequent to a common test period.

*where gamma = 1 / (1 - v^2/c^2)^1/2

1. Go to post 79
2. Loop on 1

[MacM]

Originally Posted by clj4

1. Go to post 79
2. Loop on 1

Lets try post #95.

Stay there.

[Ken G]

Originally Posted by MacM

Synchronization is irrelevant to the test or its results. The only physics involved is to insure the interval between informational Start/Stop signals is 36,000 seconds according to clock Am to verify the gamma function and the accumulated times.

Again, all you have done is restate your position. It is not wise to simply restate an incorrect position, you must either show that I am incorrect in citing the relevance of synchronization in the incorrect interpretation you give to your results, or you must just take my word for it. If you prefer to carry around falsehoods in your brain for the rest of your life, that is your prerogative. Just don't try to spread the misconceptions.

By the way, you are correct that time dilation is only a part of Doppler shifts. Perhaps understanding this may help you:
A Doppler shift is what you get when you correct simple time-of-flight effects to account for time dilation. This is why the relativistic formula is different from the formula used for the Doppler shifts of sound-- the latter is not corrected for time dilation. As to the role of vectors, the direction of v does affect the time-of-flight piece of the calculation, but not the time dilation piece. The former can give red or blueshifting, the latter is always a redshifted correction. How do you intend to make that correction without time dilation?

[clj4]

Originally Posted by MacM

Lets try post #95.

Stay there.

Loop on 79. Until you get it.
Meaning for the rest of your life

[clj4]

Originally Posted by MacM

You are still missing the point. Please read the balance of my post. The test specified it was based on "Relative Velocity" and the assertion by SR that t' = t / (1 - v^2/c^2)^1/2 which is blind to doppler shift.

I don't need to read any of your nonsense. You THOUGHT that you found three errors. Yes, you did: all three belong to ....you!

[MacM]

Originally Posted by Ken G

Again, all you have done is restate your position. It is not wise to simply restate an incorrect position, you must either show that I am incorrect in citing the relevance of synchronization in the incorrect interpretation you give to your results, or you must just take my word for it. If you prefer to carry around falsehoods in your brain for the rest of your life, that is your prerogative. Just don't try to spread the misconceptions.

By the way, you are correct that time dilation is only a part of Doppler shifts. Perhaps understanding this may help you:
A Doppler shift is what you get when you correct simple time-of-flight effects to account for time dilation. This is why the relativistic formula is different from the formula used for the Doppler shifts of sound-- the latter is not corrected for time dilation. As to the role of vectors, the direction of v does affect the time-of-flight piece of the calculation, but not the time dilation piece. The former can give red or blueshifting, the latter is always a redshifted correction. How do you intend to make that correction without time dilation?

As pointed out above I have not argued that doppler shift doesn't occur. I have posted, and I thought clearly indicated, that the test was to demonstrate the falicy of the formula as advocated by virtually all books that t' = t / gamma. Where gamma = (1 - v^2/c^2) and is blind as to doppler shift or the vector of the velocity.

[Celestial Mechanic]

MacM:

Forget about post #79. Go to posts #74, 75 and 76. Read and re-read until you understand. I made them as entertaining and enlightening as I possibly could.

And also read the book recommended by Tensor.

[MacM]

Originally Posted by clj4

I don't need to read any of your nonsense. You THOUGHT that you found three errors. Yes, you did: all three belong to ....you!

The only nonsense here is the effort to take comments out of context. I clearly stated that the thread was based on the claim of t' = t / (1 - v^2/c^2)^1/2 and that neither doppler nor simultaneity were part of the test.

The data I correct as errors used doppler shifted "Observed" velocities and not "Source" velocities. As I stated several times in this thread doppler and simultaneity are illusions of motion measurements. My thread and calculations are based on "Source" velocity and the claim for t' as stated above and the fact that only two issues determine the accumulated time of a clock.

1 - Tick rate and,

2 - Duration of test.

[DOOMMaster]

MacM it is you who do not understand Relativity, not the other posters in this argument. You don't just get to take out the part of Relativity you don't like and substitute in your own version. Synchronization is very important and if not done, you will end up with incorrect results. Celestial Mechanic's #74, #75, and #76 posts are exactly what you need to learn how to do this correctly.

Originally Posted by MacM

The basic formula of SR as presented are physically invalid. It would seem that "v" should have some other symbol or notation to differentiate it in the gamma formula such that vector and doppler is imposed and not state t' is merely a function of relative velocity. Mere relative velocity IS NOT consistant with time dilation.

You claim that the basic forumla is physically invalid, yet all you show to support your position is incorrect assumptions and alteration of equations that are correct before you decided to change them. I'm no expert on Relativity, but I understand it enough to know that what you have done is wrong. As has already been stated, you really need to learn about Relativity from correct sources. Just because you don't like or understand something does not make it invalid.

[Celestial Mechanic]

MacM:

I hope that the following exposition might put an end to your confusion.

Let A and B be two bodies in relative motion with another and velocity v. Consider the inertial reference frame K in which A is at rest and B is moving with velocity +v in the x direction. The world-lines of the two bodies are then:

A(c*t, x) = (c*t, 0)
B(c*t, x) = (c*t, v*t).

Let K' be the inertial reference frame in which B is at rest. Let the coordinates in K' be denoted x' and t'. Let K and K' have the same origin. Then these coordinates are related to t and x of K via a Lorentz transformation:

c*t' = g*c*t - b*g*x
x' = g*x - b*g*c*t.

Here I'm being lazy and writing b for beta and g for gamma. The world-line in K' where B is at rest must have x' = 0 and thus x = b*c*t. Comparison with x=v*t yields v=b*c so that b=v/c.

Now consider this: c*t' = g*c*t-b*g*x everywhere, and x=b*c*t along the world-line of B, so along the world-line of B:

c*t' = g*c*t-g*b²*c*t so
c*t' = (1/g)*c*t.

This is true, but only on the world-line of B.

What is the world-line of A in K'? Along the world-line of A we have x=0 and using the Lorentz transformation we find

c*t' = g*c*t
x' = -b*g*c*t = -b*c*t' = -v*t'.

Thus the world-line of A in K' is A(c*t', x') = (c*t', -v*t'), just as we would expect since we can consider B at rest and A to be moving at -v.

But wait a minute! Here we have c*t' = g*c*t, and before we had c*t' = (1/g)*c*t. What gives?

The expression c*t' = g*c*t is only valid along the world-line of A. c*t' = (1/g)*c*t is only valid along the world-line of B. The only way they can both be valid is if g*c*t = (1/g)*c*t which implies (g - 1/g)*c*t = 0 which means either t (and thus t') equals zero (the intersection of A and B) or g = 1, in which case A and B coincide. There is no contradiction.

[MacM]

I refuse to get into an abusive verbal contest even if some post here have been borderline insults. Most have not so I will continue.

At this juncture I simply want to point out that there has been absolutely no basis to alter the terms of the test or thread. It was designed specifically to KISS (Keep It Simple St....).

I specifically pointed out it omitted doppler and simultaneity.

If relative velocity alters time, then it alters time in a one way test as I have laid it out. There was no basis to add confusion of turn arounds and return trips and to change from "Source" velocities to Doppler "Observed" velocities.

All clocks in the test accumulate time in the redshifted mode. Now if you like post the accumulated times for these clocks using your doppler shifted data.

If you choose to not do so that is fine, I will. At best using measurements altered by illusions of motion will shift the absolute values of the inconsistancies.

Arguements that you cannot break the test into such an increment is to argue that physics do not exist over that part of the relative motion frames. It is a ludricrus and unsupportable position to take.

I have not claimed doppler shift does not occur. I have not claimed relativity of simultaneity does not exist. I have claimed, and do claim, that if you reduce this issue to simple physics, the failure (and it is a failure) becomes apparent.

What you in effect are attempting to do is to alter the arguement to claim that to disprove SR you must use all of SR's manipulations. That is no longer a proper challenge.

That would be no different than me claiming that 10 x 10 = 1,000 instead of 100 because you MUST multiply by k = 10. I am saying this k = 10 is bogus physics.

The only valid arguement to the contrary would be for relativists to actually post emperical data to support the reciprocity asserted by the relative velocity view. Not to regurgitate the theory as its own proof.

At least they should not post in a manner suggesting I have overlooked something or do not understand something, when infact I have pointed out the conditions are irrelevant to the test.

Once again. Please demonstrate that to show (or test) time dilation due to relative velocity requires more than two clocks accumulating time over an equal test period. Or that physics only function if you make a round trip or use one form of velocity over another.

It is your arguement that my test does not demonstrate a conflict. Since you choose to work in "Observed" doppler shifted terms due to measurements in motion post your data for the test as described for the following clocks.

Am = 36,000
Abp =
Acp =

Bm =
Bap =
Bcp =
Bac =

Cm =
Cap =
Cac =
Cbp =

I don't think you dare.

[Nereid]

Originally Posted by MacM

I refuse to get into an abusive verbal contest even if some post here have been borderline insults. Most have not so I will continue.

At this juncture I simply want to point out that there has been absolutely no basis to alter the terms of the test or thread. It was designed specifically to KISS (Keep It Simple St....).

I specifically pointed out it omitted doppler and simultaneity.

And several folk pointed out that if you do that, you are not testing SR.

If relative velocity alters time, then it alters time in a one way test as I have laid it out. There was no basis to add confusion of turn arounds and return trips and to change from "Source" velocities to Doppler "Observed" velocities.

Again, several folk (Celestial Mechanic in particular) have pointed out that the 'turn arounds' and 'return trips' in no way alter what the three observers record.

All clocks in the test accumulate time in the redshifted mode. Now if you like post the accumulated times for these clocks using your doppler shifted data.

But there are only three (independent) clocks!

If you choose to not do so that is fine, I will. At best using measurements altered by illusions of motion will shift the absolute values of the inconsistancies.

Arguements that you cannot break the test into such an increment is to argue that physics do not exist over that part of the relative motion frames. It is a ludricrus and unsupportable position to take.

Again, the (primary) objections to your Gedankenexperiment aren't so much what you say the clocks will record, as that the test - as you have described it - is not a test of SR.

I have not claimed doppler shift does not occur. I have not claimed relativity of simultaneity does not exist. I have claimed, and do claim, that if you reduce this issue to simple physics, the failure (and it is a failure) becomes apparent.

What you in effect are attempting to do is to alter the arguement to claim that to disprove SR you must use all of SR's manipulations. That is no longer a proper challenge.

Let's accept this, for now.

It follows, then, that your Gedankenexperiment has little to do with SR.

It follows that your Gedankenexperiment is a test of "MacM physics".

Perhaps you could lay out for us what the key components of this physics are? That way we can mount challenges that make sense (in terms of what the test you propose is, in fact, a test of).

That would be no different than me claiming that 10 x 10 = 1,000 instead of 100 because you MUST multiply by k = 10. I am saying this k = 10 is bogus physics.

The only valid arguement to the contrary would be for relativists to actually post emperical data to support the reciprocity asserted by the relative velocity view. Not to regurgitate the theory as its own proof.

[snip]

Well, we've been over this before too.

If the test you describe cannot be conducted, with today's technology, then we will need to find another way to test SR or MacM physics, won't we?

SR has been subject to many tests, in the lab, and it has passed all with flying colours.

Can we test MacM physics in the lab too? What experimental setup can you describe for us that is, in principle, feasible with today's technology, that would test MacM physics?

But let me start with the MacM Gedankenexperiment.

If A, B, and C all send out, in all directions, a signal, using light, every second by their own clocks, what will each record (between the MacM start and MacM finish, each according to her own determination of these events)?

For clarity, let's require that each signal each of A, B, and C sends be a faithful image of the dial of the clock (A, B, and C have only one clock each).

What will be the time encoded in the last signal A sends? B? C?

What will be the time encoded in the last signal that A receives from B and C? that B receives from A and C? that C receives from A and B?

(for avoidance of doubt, this may serve as the 'videolink' I mentioned in my earlier posts).

[Ken G]

MacM, we realize that you are trying to distinguish Doppler shifts and synchronization issues from the time dilation effect. You think that when you only consider time dilation by itself, you reach a contradiction, and these other issues are just distractors. What we have tried to show you is that they are all intimately related, such that if you don't understand one, you can't understand any. For example, you cannot understand the formula for Doppler shifts unless you include time dilation. You keep saying you are not denying that Doppler shifts occur, but the issue is, is the formula correct? If it is, you will find that there is no way to derive it without time dilation.

But how is the reciprocity issue answered? You have an important gedankenexperiment there, and in it lies the ability to understand special relativity. It is true that the station clock will read 36,000 seconds when the shuttle clock reads 18,000 seconds, according to the way the people in the space station define simultaneity. But this is different from the way the people in the shuttle define simultaneity, and that's why they think the station clock only reads 9,000 seconds when their clock reads 18,000 seconds. This apparent paradox is all about the meaning of simultaneity, despite your oft repeated claim to the contrary. The issue is, when clocks are separated by distance, the way time and distance are interrelated in special relativity means you must pay very close attention to how simultaneity, or synchronization, is being defined in the various different frames. The equation is, separation in distance, plus a difference in velocity, equals a difference in simultaneity/synchronization. End of story. Until you understand this, you will keep thinking that there is a contradiction, when no one who understands it does.

Let me explain the twin paradox to you from this perspective (I know you think this has nothing to do with the twin paradox, but again, until you understand that you won't understand anything). When the shuttle is flying away, it thinks that very little time is elapsing on the station. When it gets to its turnaround point, it thinks this moment is simultaneous with a time very early on for the station. But when it suddenly changes velocity to return, it concludes in that very instant that its moment is now suddenly simultaneous with a moment much later in the life of the station-- a huge amount of time has passed on the station in the blink of an eye for the shuttle. For its return trip, very little time passes in the station, just as it did on the way out, so the aging of the space station crew will mostly have happened in the change in simultaneity during the turnaround. So you see, you can never understand the twin paradox, or the remote passage of time, by time dilation alone. The role of simultaneity is huge-- time dilation by itself is very incomplete, and leads to these kinds of paradoxes if you think time dilation can do all the heavy lifting.

[publius]

MacM,

I just read throught this whole thread (I can't believe I read the whole thing......where's my Alka-Seltzer ), and I'm trying to figure out just what is the brick wall you're hitting in understanding what's going on. I'm not going to try to argue with you about all the details others are making, mainly because my SR math is so rusty, I'd have dig out my EM textbooks just to get back in the game. The others here can do that better.

Your brick wall is this business about "reciprocity" or how A thinks B's clock is running slow compared to his, while B thinks A's clock is running slow, and A think B's yardstick is shorter and vice-versa, and how that must be impossible.

To get through that wall, you've got to understand that time and space are not distinct things, but become "mixed" into one thing, generally called "space-time". One observer's time is a "mixture" of the distance and time of another observer in relative motion. You will balk at that statement I'm sure, but this is the brick wall to your understanding of SR. Your trouble is you want to think of time as something distinct from distance (and possibly absolute). That is a big hurdle, but that's the way the universe works. Many others banged their heads about this, so you're not alone.

We have three dimensions of distance and you can easily how different coordinate systems basis vectors become "mixed" with other coordinate systems basis vectors. Now, you just have to accept that time has to be thrown in this same mix.

Imagine a 2D coordinate system, the familiar x-y plane. Now image a second coordinate system, the x'-y' plane, sharing the origin, but rotated at a 45 degree angle with respect to the x-y axes. Consider 1 unit of lenght alone the x' axis. That reflects to 1/sqrt(2) units along the x axis (and the same along the y-axis). Now consider one unit of length along the x axis. That corresponds to 1/sqrt(2) units along the x' axis, (and the same along the -y' direction).

Now, imagine that in that plane, we somehow want to think of x and y coordinates as being two different, distinct measures, say "time" or something. Well, as you can easily see from the geometry, 1 unit of time in the x-y frame is just 1/sqrt(2) units of x'-y's "time", and "reciprically", 1 unit of time in the x'-y' frame is just 1/sqrt(2) units of "time" in the x-y frame.

x-y thinks x'-y' clock is slow, but x'-y' sees x-y's clock as slow, "at the same time" (sorry, I couldn't help that)

If you read the links about Dingle, you'll recognize this rotated 2D system.

4D space-time is a little different, because it is *non-Euclidian*. There is a minus sign on the time coordinate in the norm, and "distances" in 4D can be either positive (space-like), negative (time-like), and zero (light-like).

This is usually called Minkowski space, and there are countless textbooks with various ways of geometrically visualizing it (using 1 space coordinate with time, the x-t plane) and how two frames are related with respect to gamma. It is different from the orthogonal 2D system above because of the non-Euclidian nature, but you will still see that the t' axis is at an angle to the t axis in a similiar way, and one unit along either has a shorter projection along the other.

-Richard

[MacM]

Originally Posted by Nereid

And several folk pointed out that if you do that, you are not testing SR.

First let me say yours, and the two that follow, posts are completely acceptable and I think educational regardless of any outcomes.

We simply disagree. I agree that I am not following your mathematical manipulations used in SR but then to restrict ones challenge to finding a formula error or derivation error is a completely different subject than understanding a physical flaw or contradiction. The later requires looking outside the formal structure and considering the physics issues, not some theoretical mathematical issue.

SR has been subject to many tests, in the lab, and it has passed all with flying colours.

But NONE have been to demonstrate reciproicty and in fact data suggests that reciprocity does not exist.

Can we test MacM physics in the lab too?

Absolutely. Take every test ever done and MacM physics will predict the results you have recorded for that test but MacM physics further predicts that none will demonstrate reciprocity and that reciproicty cannot be demonstrated hence it is unfalsifiable and hence further that makes SR unqualified to even be called "Theory". Theories must be falsifiable.

[MacM]

Originally Posted by Ken G

MacM, we realize that you are trying to distinguish Doppler shifts and synchronization issues from the time dilation effect. You think that when you only consider time dilation by itself, you reach a contradiction, and these other issues are just distractors.

True to an extent. The primary point being that time dilation due to relative velocity is a physics response to motion. Time only changes if it permanently alters the accumulated time of the clock.

That purportedly is due to relative velocity, not doppler shift or relativity of simultaneity. That is not to say these things do not occur but that they are illusions of motion measurements and do not permanently change the accumulated time by any clock and hence merely add complexiety to any analysis.

But how is the reciprocity issue answered? You have an important gedankenexperiment there, and in it lies the ability to understand special relativity. It is true that the station clock will read 36,000 seconds when the shuttle clock reads 18,000 seconds, according to the way the people in the space station define simultaneity.

Here we disagree. Only tick rate, test duration and subsequent comparison in a common frame (either physically or mathematically) affect accumulated time by a clockhence time, not some remote observers perspective of the clocks reading what - when.

But this is different from the way the people in the shuttle define simultaneity, and that's why they think the station clock only reads 9,000 seconds when their clock reads 18,000 seconds.

You have stopped talking about physical time dilation and are now talking about perceptions.

Will you agree that the 9,000 seconds is bogus and that clock Am will never record less time than clock Bm in my scenario? If so we have no disagreement because that is the physical reality; which isn't what SR predicts.

The role of simultaneity is huge-- time dilation by itself is very incomplete, and leads to these kinds of paradoxes if you think time dilation can do all the heavy lifting.

No. I think it is required mathematically to appease those that would want to keep SR alive but I thnk it has absolutely nothing to do with physical time dilation due to motion. It affects only perceptions or illusions of motion measurements, not realities.

[MacM]

Originally Posted by publius

MacM,

I just read throught this whole thread (I can't believe I read the whole thing......where's my Alka-Seltzer ), and I'm trying to figure out just what is the brick wall you're hitting in understanding what's going on.

I would only disagree with your conclusion that I am hitting a brick wall. I do believe I understand the various functions in SR; howver, I reject some of the conclusions and basis.

That doesn't make me right (or wrong) but it is a different issue.

Your brick wall is this business about "reciprocity" or how A thinks B's clock is running slow compared to his, while B thinks A's clock is running slow, and A think B's yardstick is shorter and vice-versa, and how that must be impossible.

In part but much more. I am firmly convienced that spatial length contraction does not occur. It is created artifically and mathematically only. There is an alternative. This has been discussed somewhat before but deviates from the scope of this thread.

We have three dimensions of distance and you can easily how different coordinate systems basis vectors become "mixed" with other coordinate systems basis vectors. Now, you just have to accept that time has to be thrown in this same mix.

I see 3D space as energetic and time as a property, not a 4th dimension. I do not accept the concept of time-space period.

[clj4]

You are mixing up "denying to death" with "making valid arguments".
You are right on one thing: the first approach makes peoples not to want to talk to you after a while. So you end up arguing with yourself.

"If two people tell you you are drunk, then you should go to bed" (old Aussie proverb)

MacM's Closure to a Length Contraction Thread

I do not accept the concept of time-space period.

Then please return your GPS systems, stop using the cellular phone and don't watch any sattelite TV.

[MacM]

Originally Posted by clj4

Then please return your GPS systems, stop using the cellular phone and don't watch any sattelite TV.

Sorry but pure bunk. GPS precalibrates the orbiting clock to run 45us/day slower for GR affects and 7.2us/day faster for "Absolute" orbit velocity to the ECI frame affects, or a net ~ 38us/day adjustment.

A calculation of relative velocity between a clock at the equator on the surface of the earth due to earths rotational speed and an orbiting GPS clock results in a -5.8us/day value. Incorrect.

The correct value is -7.2us/day due to orbit velocity with the center of the earth as a common local preferred frame.

Ouch! Relative velocity (SR) is not used in GPS. Only the one way gamma based on an absolute velocity to a preferred frame.

Preferred frame? Wash my mouth with soap.

[clj4]

Originally Posted by MacM

Sorry but pure bunk. GPS precalibrates the orbiting clock to run 45us/day slower for GR affects and 7.2us/day faster for "Absolute" orbit velocity to the ECI frame affects, or a net ~ 38us/day adjustment.

A calculation of relative velocity between a clock at the equator on the surface of the earth due to earths rotational speed and an orbiting GPS clock results in a -5.8us/day value. Incorrect.

The correct value is -7.2us/day due to orbit velocity with the center of the earth as a common local preferred frame.

Ouch! Relative velocity (SR) is not used in GPS. Only the one way gamma based on an absolute velocity to a preferred frame.

Preferred frame? Wash my mouth with soap.

Whatever.I would give you a link to a very good paper on SR/GR effects (not GR "affects") on GPS but I know it would be a waste. You will end up arguing with yourself about it. Right on, "space-time" does not exist. Because you say so.

[worzel]

KenG has hit the nail on the head several times over, MacM (and others have made very good points too). You can't just ignore the relativity of simultaneity if you want to understand what SR actually predicts, let alone if you want to have a feel for SR "means".

What you believe about 4D spacetime is completely irrelevant to your claim that SR is inconsistent. When you claim that dilation is just the maths and not physical reality you demonstrate a complete lack of understanding about what science is. SR is a mathematical model; or, two postulates and their necessary implications. The model makes predictions. Those predictions have been tested. Those tests have all been passed.

The data for the test you ask for could never been done because you won't allow the clocks to turn around and you won't accept that time dilation is real unless the clocks are brought back side by side. Nevertheless, the model predicts time dilation and all the experimental evidence supports that model and thus transitively supports that prediction.

The real problem with your thought experiment is that you are claiming that you are measuring physical time dilation and reaching a contradiction while all that is actually being measured is the passage of time in each frame. Your extra clocks really are just calculations in one frame of how time is progressing in another according to SR. The supposed contradiction you reach is to then insist that the relativity of simultaneity is not relevant when resolving the supposed paradox you pose. So you use SR to predict time dilation for each observer according the other but won't allow SR to be used to resolve your paradox!

If you want to acutally measure something physical between the observers then you need to have them observe each other and take into account doppler effects as well, just as CM was kind enough to spell out for you.

Your stop time is defined in A's frame. You then compare all clocks from As frame and conclude that time dilation is one way - but that's just cos you're only doing it one way. The other way is to see what happens in B's and C's frames. Whether you believe time dilation is symmetric or not, doing the calculations only from one frame of reference and then claiming that that demonstrates that it only happens that way is completely circular logic.

As KenG has said repeatedly, to understand the problem you need to think about the relativity of simultaneity. As A and B seperate their notion of what is now both "here" and "there" diverges and that is the resolution to the supposed paradox of reciprical time dilation. You can deny it all you want, but you can't show that it leads to any inconsistencies within the theory and you haven't shown any evidence showing that the theory might be wrong (where we can ignore gravitional effects, that is).

[tusenfem]

Indeed, Worzel makes good points.
IMHO what MacM does is exactly what my Relativistic Professor warned for. MacM is looking from the God perspective, a frame (where A may be at rest) in which he can observe all spacecraft at the same time (simultaneously). However, this frame does not exist. After said 36000 time units, all clocks are read off by the timonauts, and probably will show in their own frame 36000 and 18000, but they have no way of knowing what the other spacecraft have as a value UNLESS they communicate with eachother, and then we need a definition of simulteneity and we need doppler. Otherwise, there is no way this experiment can be done, there is no God frame.

Thus MacM's results are a paradox (used in its true meaning, not the popular one).

[MacM]

Originally Posted by worzel

KenG has hit the nail on the head several times over, MacM (and others have made very good points too). You can't just ignore the relativity of simultaneity if you want to understand what SR actually predicts, let alone if you want to have a feel for SR "means".

It is not a matter of what it predicts but how it achieves the purported internal consistancy.

What you believe about 4D spacetime is completely irrelevant to your claim that SR is inconsistent. When you claim that dilation is just the maths and not physical reality you demonstrate a complete lack of understanding about what science is. SR is a mathematical model; or, two postulates and their necessary implications.

Yes a mathematical model but unrestrained by common sense and untested in its extremes.

The model makes predictions. Those predictions have been tested. Those tests have all been passed.

In another post above I have been accused of simply repeating my arguement. It is time to point out that relativists are doing the same thing. This arguement is about as lame as it gets. As pointed out reciprocity has not been tested, observed or emperically demonstrated. The thousands of tests done do not support the theory in its complete form (consequences of the relative velocity view) but only tests and demonstrates a function which does not differentiate from affects which can also be accounted for in an absolute view.

All that can be said about test data is that it is not entirely "Inconsistant" with SR, not that it supports SR because it also supports the absolute view and suggests the relative velocity view is incorrect in that recorded permanent differential times by a clock violates the reciprocity advocated by SR.

i.e. - Where is the data that shows the pilots view in H&K atomic clock tests, that the earth bound clocks ran slower (were time dilated) vs the airborne clocks.

The data for the test you ask for could never been done because you won't allow the clocks to turn around and you won't accept that time dilation is real unless the clocks are brought back side by side.

Note my scenario was desinged to cut to the chase and up hold the principle of KISS. Others have commented here that the round trip does not alter the conclusion. I am inclined to agree that when properly done the round trip should not alter the conclusion.

Nevertheless, the model predicts time dilation and all the experimental evidence supports that model and thus transitively supports that prediction.

And so does an absolute view. See GPS.

The real problem with your thought experiment is that you are claiming that you are measuring physical time dilation and reaching a contradiction while all that is actually being measured is the passage of time in each frame. Your extra clocks really are just calculations in one frame of how time is progressing in another according to SR.

Absolutely. And is being done in a simple straight forward manner without all the usual complexiety to get from one to the other.

The supposed contradiction you reach is to then insist that the relativity of simultaneity is not relevant when resolving the supposed paradox you pose. So you use SR to predict time dilation for each observer according the other but won't allow SR to be used to resolve your paradox!

I repeat. Does simultaneity or doppler produce permanent recordable changes or are they an illusion of motion measurement? Only permanent changes in accumulated time can be real physical time dilation.

If you want to acutally measure something physical between the observers then you need to have them observe each other and take into account doppler effects as well, just as CM was kind enough to spell out for you.

We are not and do not want to "Observe" illusions of motion. We want only to record permanent changes in accumulated time due to relative velocity in accordance with SR. If these other aspects of SR do not affect that then there is no reason to include them.

Your stop time is defined in A's frame. You then compare all clocks from As frame and conclude that time dilation is one way - but that's just cos you're only doing it one way. The other way is to see what happens in B's and C's frames. Whether you believe time dilation is symmetric or not, doing the calculations only from one frame of reference and then claiming that that demonstrates that it only happens that way is completely circular logic.

I repeat where is the clock data that supports the expectations of the H&K pilots that the earth bound clocks ran slower than their airborne test clocks?

This is not a calaculation it is physical test. You must address the issue that ONLY the accelerated frame has ever demonstrated time dilation. Never the resting frame which defies the SR reciprocity (equality of frames) arguement.

As KenG has said repeatedly, to understand the problem you need to think about the relativity of simultaneity. As A and B seperate their notion of what is now both "here" and "there" diverges and that is the resolution to the supposed paradox of reciprical time dilation. You can deny it all you want, but you can't show that it leads to any inconsistencies within the theory and you haven't shown any evidence showing that the theory might be wrong (where we can ignore gravitional effects, that is).

I have considered simultaneity. I would hope that it becomes apparent that these are not pot shots from the hip. But simultaneity and doppler are only present during the motion of the moving frame and do not contribute to and result in the permanent recorded differential of accumulated time by clocks.

If you can show that they ultimately permanently change time recorded such that it agrees with ALL predictions of SR and not merely one half of the prediction then I will gladly conceed. Failing to do that I will steadfastedly maintain that SR is invalid and that data suggests an absolute view rather than the relative velocity view.

Yours was a good post as well.