1. Originally Posted by James R
Can't you read? Read post #15, then it's time to conceed. Or continue with more stupidity, which is the option you'll no doubt take.

I have just shown your failure to address issues and also your continued false allegations. Either shape up or give up because what you are doing is futile and making you look impotent.

2. We need to be quite clear about MacM's stupid claims before we can go any further.

Questions for MacM:

I start with 3 clocks, A, B and C, at rest with respect to one another and synchronised. I accelerate A in a direction away from C, to a final speed of 0.8c. For the following questions, A is now travelling at a constant speed v=0.8c in the frame of C.

Questions:
(a) When A is travelling at v relative to C, is A ticking slower than C in the frame of C? (Yes/no)? (If your answer is "no", then ignore the remaining questions. I'll have more questions for you. Otherwise continue.
(b) Is A ticking slower than C in the frame of A? (Yes/no)
(c) Explain how you arrived at your answers to (a) and (b).

I now accelerate B away from C, in the opposite direction to the direction A was accelerated. For the following questions, B is travelling at speed 0.8c in the frame of C, in the opposite direction to A.

(d) Is B ticking slower than C in the frame of C? (Yes/no)
(e) Is B ticking slower than C in the frame of B? (Yes/ no)
(f) Explain how you arrived at your answers to (d) and (e).

(g) Is A ticking at the same rate as B in the frame of A? (Yes/no)
(h) Is B ticking slower than A in the frame of A? (Yes/no)
(i) Is A ticking slower than B in the frame of B? (Yes/no)
(j) What is the speed of A relative to B?
(l) Is A ticking at the same rate as B in the frame of C? (Yes/no)

3. Originally Posted by James R
We need to be quite clear about MacM's stupid claims before we can go any further.

Questions for MacM:

I start with 3 clocks, A, B and C, at rest with respect to one another and synchronised. I accelerate A in a direction away from C, to a final speed of 0.8c. For the following questions, A is now travelling at a constant speed v=0.8c in the frame of C.

I note that at 0.8c Gamma = 1.666666n

Questions:
(a) When A is travelling at v relative to C, is A ticking slower than C in the frame of C? (Yes/no)? (If your answer is "no", then ignore the remaining questions. I'll have more questions for you. Otherwise continue.

(b) Is A ticking slower than C in the frame of A? (Yes/no)

Finally here is where we disagree (I think) my answer is "YES" but you are going to assert that relative velocity is a symmetrical function and therefore since v = ds /dt and t is dilated then ds = v * t.

That little move makes the dilated clock in "A" now tick at the same rate as "C" forcing distance to undergo Lorentz Contraction.

That is false physics and logic. The assumption of symmetrical relative velocity is prompted by a number of factors and happens to be in error.

1 - At every day velocities where there is no measureable time dilation relative velocity certainly appears symmetrical. That is if you are moving away from me at 30 Mph then I'm moving away from you at 30 Mph.

2 - In an absolute view they are symmetrical. That is if you apply a common time standard relative velocity is symmetrical at some universal level.

3 - But in a local view based on proper time in each frame relative velocity would not necesarily be symmetrical.

Given that we agree that "A" is time dilated relative to "C" and then retaining that dilation as being physical reality (Compared to the Appearance that "A" sees "C" and "B" dilated but they aren't actually). When you move to the "A" frame you must use a dilated "t" tick rate to compute velocity.

Recall that velocity is a "COMPUTED" value being the ratio of two physical parameters of ds/dt. Not something you should simply assert casually because that artifically resets "t" to unity (no longer dilated).

Such that when tc = 1.0, ta = tc/Gamma = 0.6 and ds = 1.0

Then:

vc = ds / tc = 1.0 / 1.0

va = ds / ta = 1.0 / 0.6 = 1.66666666n

In other words observers in a moving frame will compute velocity differently than a resting ovserver. It should be noted that retaining the dilated condition of ta the accumulated time on the clock for a trip is only correct is ds does not change.

(c) Explain how you arrived at your answers to (a) and (b).

The same answer applies to both. Emperical data and logic, puts time dilation as being the physical factor causing recorded time dilation, not lorentz contraction. If time dilation is physical then it exists the same in all frames. This is not a matter of perception by other otbservers moviign at different relative veloicties. Thsi is a matter of "A" having accelerated from "C".

I now accelerate B away from C, in the opposite direction to the direction A was accelerated. For the following questions, B is travelling at speed 0.8c in the frame of C, in the opposite direction to A.

Yes

(d) Is B ticking slower than C in the frame of C? (Yes/no)

Yes

(e) Is B ticking slower than C in the frame of B? (Yes/ no)

Yes] See explanation above for "A"

(f) Explain how you arrived at your answers to (d) and (e).

Same as for (a & (b)

(g) Is A ticking at the same rate as B in the frame of A? (Yes/no)

That is a trick question. What "A" thinks is "B's" tick rate and vice versa is not "A" or "B's" actual tick rate. So the answer "Physically" is Yes but they don't Percieve each other as a common tick rate but any direct comparisoon reveals the truth. Since you launched them at different times they are not in synch.[/color]

(h) Is B ticking slower than A in the frame of A? (Yes/no)

See (g) above.

(i) Is A ticking slower than B in the frame of B? (Yes/no)

Ditto as above

(j) What is the speed of A relative to B?

0.975609756c according to SR's velocity addition. I don't necessarily accpet that either but that is the current view.

I have. I have stated that there is a difference between what observers "See", Percieve", etc than what is supported by emperical data.

Emperical data ONLY support the view that they are "Actually" "Physically" ticking at the same rates and velocity addition would only change the rate not the fact of equality between "A" & "B".

(l) Is A ticking at the same rate as B in the frame of C? (Yes/no)
Yes

4. Ok. More questions.

I note that at 0.8c Gamma = 1.666666n
Where does this gamma factor come from, in your opinion? The definition of gamma that you appear to have used is the same one used in the theory of relativity, which you apparently think is false. So:

(a) In your opinion, is the "gamma" factor of Einstein's relativity correct?

Now, you say that A's time is slower in C's frame. I asked you to explain why you believe that A's clock ticks slower, but you didn't answer.

(b) What causes one clock to tick slower than another, physically?

(c) Can you give a mathematical justification of your answer to (b)?

(d) You appear to think that while A ticks slower than C in C's frame, you think that A ticks FASTER than C in A's frame. Is this correct? (Yes or no)

Now, consider the following scenario. A is travelling at 0.8c relative to C, as before. A now launches a probe, D, that accelerates in the opposite direction to A's motion, until the probe is at rest relative to C.

(e) Did D and A both start from a common rest frame (assuming that A carried the probe when it was originally accelerated away from C)? (Yes or no)

(f) D ends up moving relative to A, while it ends up stationary relative to C. Does D's clock run slower, faster or at the same rate as A's clock at the end of D's motion? Explain your answer.

(g) Do you agree that C was not in an absolute state of rest at the start of this whole process? If not, explain how you know that it was in an absolute state of rest.

(h) If at the end of the process A ticks slower than D, but D ticks at the same rate as C, explain how D knew to speed up its clock when it was launched from A, whereas A knew to slow down its clock when launched from C. How do we tell the difference between A and D?

Originally Posted by MacM
3 - But in a local view based on proper time in each frame relative velocity would not necesarily be symmetrical.

Given that we agree that "A" is time dilated relative to "C" and then retaining that dilation as being physical reality (Compared to the Appearance that "A" sees "C" and "B" dilated but they aren't actually). When you move to the "A" frame you must use a dilated "t" tick rate to compute velocity.
Originally Posted by MacM
In other words observers in a moving frame will compute velocity differently than a resting ovserver.
(i) Do you think that if A is travelling at 0.8c relative to C, then C is not necessarily travelling at 0.8c relative to A? (yes or no)

Originally Posted by James R
(g) Is A ticking at the same rate as B in the frame of A? (Yes/no)
That is a trick question. What "A" thinks is "B's" tick rate and vice versa is not "A" or "B's" actual tick rate.
I didn't ask what A thinks B's tick rate is; I asked whether A is ticking at the same rate as B. You appear to have answered the question:

Originally Posted by MacM
So the answer "Physically" is Yes but they don't Percieve each other as a common tick rate but any direct comparisoon reveals the truth.
(j) What tick rate do they perceive each other as having?
(k) How do you do a direct comparison of the tick rates of A and B?

Originally Posted by MacM
Since you launched them at different times they are not in synch.
(l) Is it true that the time of launch affects the tick rate of a clock? If so, please give the formula that you use to calculate the tick rate of a moving clock. Your formula will presumably involve the launch time T and the relative velocity v, from what you have said. I will be interested to compare your formula to the one from special relativity.

Originally Posted by JR
What is the speed of A relative to B?
0.975609756c according to SR's velocity addition. I don't necessarily accpet that either but that is the current view.
(m) You don't necessarily accept it? Do you accept it, or don't you, or are you not sure? (Accept, don't accept, not sure)

(n) If that you do not accept the velocity addition process of special relativity, how do you calculate the velocity of A relative to B? Please give the formula you would use in this example.

5. Originally Posted by MacM
Hi Pete,

Wondered where you were.

Sorry Pete this is not about simultaneity or any other aspect of relative motion or distance. It is strictly about a very limited condition.

When I said synched in a common frame I meant after first having been equally accelerated from a synchronized common rest frame and are once again in such a frame - not necesasrily the original rest frame but another common inertial frame.

Those clocks WILL be synchronized. To eliminate the affects you are attempting to interject is done by communicating accumulated information via digital means.

This becomes quite clear if you simplify and merely have the common frame be locally close and not introduce confusion by simultaneity and light signal travel or sight time between remote clocks.
Six years of experience suggests that we won't get past this, but here goes...

Mac, when everyone keeps saying "but that's not how SR works", don't you ever think that just maybe there's a chance that it is your understanding of SR that is the problem?

The whole way that you talk about reference frames and simultaneity just doesn't quite make sense - it's very clear to me that whatever you are thinking of when you say "reference frame" and "relative simultaneity" is quite different from what is actually intended in the SR model.

I fully agree that if SR worked the way you think it does, then it would be nonsense. I implore you once again to consider a different model, a model of SR that works the way that I, JamesR, and the vast majority of physicists think that it works, and look for inconsistencies in that model.

But I don't think that you will, because you can't seem to get over the hurdle of considering the possibility that perhaps time isn't absolute, that simultaneity might really be relative.

Anyway, getting back to the point...
The bottom line is that SR says that the clocks won't be synchronized except in the C's rest frame. Period. There is no way around this, unless you are using a model that is not SR.

6. Originally Posted by James R
Ok. More questions.

Where does this gamma factor come from, in your opinion? The definition of gamma that you appear to have used is the same one used in the theory of relativity, which you apparently think is false. So:
SO you would be advised to acknowledge the name of the formula "Lorentz" a concept developed before relativity and based on an ether. I'm not advocaing the original concept of ether but clearly something that can curve,bend expand and contract and has physical properties is based on some form of fabric or substance.

Nothingness has no properties, etc.

Originally Posted by James R
(a) In your opinion, is the "gamma" factor of Einstein's relativity correct?
Partially. When you apply it you must also recognize what is a gamma illusion vs gamma reality. So far you reject that and want to claim what I see is reality. I hope others atr least understand why that is not true.

Recall red glass does not mean the universe is red.

Originally Posted by James R
Now, you say that A's time is slower in C's frame. I asked you to explain why you believe that A's clock ticks slower, but you didn't answer.
If had had formal answers you would be teaching my work. But I speculate it has to do with an absolute change in energy at some universal level. That is why only an accelerated clock undergoes change. As you know energy comes in many forms both external and internal to a mass. Total energy may well establish the tick rate of material.

Originally Posted by James R
(b) What causes one clock to tick slower than another, physically?
Differential total energy.

Originally Posted by James R
(c) Can you give a mathematical justification of your answer to (b)?
No. But again "Absence of Evidence" is not the same as "Evidence of Absence".

Originally Posted by James R
(d) You appear to think that while A ticks slower than C in C's frame, you think that A ticks FASTER than C in A's frame. Is this correct? (Yes or no)
No. The physical tick rate is fixed universally. If "A" is physically ticking slower than "C" then "C" is physically ticking faster than "A" in all frames.

Originally Posted by James R
Now, consider the following scenario. A is travelling at 0.8c relative to C, as before. A now launches a probe, D, that accelerates in the opposite direction to A's motion, until the probe is at rest relative to C.

(e) Did D and A both start from a common rest frame (assuming that A carried the probe when it was originally accelerated away from C)? (Yes or no)
Yes and "A" & "D" are ticking slower than "C" until "D" is fired back at "C" and once it has come to relative rest with "C" it has been restored to the common initial rest reference frame "C's" tick rate (energy level) such that "C" & "D" now tick in synch and both tick faster than "A".

If in fact you take the position that "D" accelerating away from "A" means "D" is ticking slower than "A" you have just ran head on into the reciprocity problem of the mere relative velocity view.

Time dilation clearly cannot be based on such simple relative velocity or you now have the situation where "D" is ticking slower than "A" while "C" is ticking faster than "A" and both "D" and "C" are in a common rest frame.

Originally Posted by James R
(f) D ends up moving relative to A, while it ends up stationary relative to C. Does D's clock run slower, faster or at the same rate as A's clock at the end of D's motion? Explain your answer.
Did above. "D" and "C" tick in unison once re-united in the common rest frame.

Originally Posted by James R
(g) Do you agree that C was not in an absolute state of rest at the start of this whole process? If not, explain how you know that it was in an absolute state of rest.
Never claimed "An absolute state of rest". Such a condition may well never be identified. It is a local absolute rest reference, not some universal absolute reference. Every inertial condtion may become a rest refence.

Originally Posted by James R
(h) If at the end of the process A ticks slower than D, but D ticks at the same rate as C, explain how D knew to speed up its clock when it was launched from A, whereas A knew to slow down its clock when launched from C. How do we tell the difference between A and D?
Therein lies the great question. It is incumbient on us to seek that answer because clearly something is going on that we have no clue how that occurs, just as we have no clue how particle entanglement occurs.

Originally Posted by James R
(i) Do you think that if A is travelling at 0.8c relative to C, then C is not necessarily travelling at 0.8c relative to A? (yes or no)
Loaded question. You must ask who has the most "Actual" motion and who is computing velocity. The observer with a dilated clock will compute a higher velocity but on a universal level where you have a fixed time standard relative velocity is symmetrical.

It is the failure by SR to acknowledge the physical nature of time dilation and arbitrarily asserting that velocity between frames is symmetrical that creates the apparent lorentz contraction.

If you treat time dilation as a physical condition where "A's" clock IS ticking slower than "C's" then "A" will compute a higher velocity which accounts fully for the reduced accumulated trip time only if lorentz contraction did not occur.

Originally Posted by James R
I didn't ask what A thinks B's tick rate is; I asked whether A is ticking at the same rate as B. You appear to have answered the question:
Yes "A" and "B" have a commom tick rate even though they have a relative velocity. I jsut wanted to make sure you didn't once again try to interject the illusion of motion where each "Sees" the other as dilated.

Originally Posted by James R
(j) What tick rate do they perceive each other as having?

Gamma = 4.5555n or each appears to tick at 21.95% (this is assuming veloicty addition correction which may be bogus).

Originally Posted by James R
(k) How do you do a direct comparison of the tick rates of A and B?
Been there and done that. I sent "A" and "B" passed each other and they both had accumulated the same trip time which means they had to tick equally since they had symmetrical launches.

Originally Posted by James R
(l) Is it true that the time of launch affects the tick rate of a clock? If so, please give the formula that you use to calculate the tick rate of a moving clock. Your formula will presumably involve the launch time T and the relative velocity v, from what you have said. I will be interested to compare your formula to the one from special relativity.
No. I do not see how launch time affects tick rate. It does affect the displayed accumulated time on clocks being compared.

Originally Posted by James R
(m) You don't necessarily accept it? Do you accept it, or don't you, or are you not sure? (Accept, don't accept, not sure)
I'm rather sure velocity addition as proposed by SR is invalid. I'm not sure what replaces it if anything.

Originally Posted by James R
(n) If that you do not accept the velocity addition process of special relativity, how do you calculate the velocity of A relative to B? Please give the formula you would use in this example.
Recall that distance is fixed in this view so each would compute dv = ds / dt based on their own time standard or dilated condition of their clock. That results in FTL calculations but I have no problem with such results. because at some point we are going to learn what we do not now know and there will be other twists and turns in the physical process such that time dilation as we now compute it is not valid under some conditions.

That is we currently base our view on limited once clock (particle) accelerates away from a rest reference and we see the affect. We then make assumption about what that must mean and further assume that FTL is impossible since that would lead to negative time, etc.

The reality is more likely that our current formulas are only valid for the current test configurations.

BTW:

Nice to actually have a discussion for a change.

7. Originally Posted by Pete
Six years of experience suggests that we won't get past this, but here goes...

Mac, when everyone keeps saying "but that's not how SR works", don't you ever think that just maybe there's a chance that it is your understanding of SR that is the problem?

The whole way that you talk about reference frames and simultaneity just doesn't quite make sense - it's very clear to me that whatever you are thinking of when you say "reference frame" and "relative simultaneity" is quite different from what is actually intended in the SR model.

I fully agree that if SR worked the way you think it does, then it would be nonsense. I implore you once again to consider a different model, a model of SR that works the way that I, JamesR, and the vast majority of physicists think that it works, and look for inconsistencies in that model.

But I don't think that you will, because you can't seem to get over the hurdle of considering the possibility that perhaps time isn't absolute, that simultaneity might really be relative.

Anyway, getting back to the point...
The bottom line is that SR says that the clocks won't be synchronized except in the C's rest frame. Period. There is no way around this, unless you are using a model that is not SR.
Pete,

Thanks for the post.

I certainly have considered I might be wrong but when I thought I was wrong, I was mistaken -

Actually The problem isn't with my understanding. It is with getting others to understand my objections. That is I don't have a problem with how SR is actually being applied. That is relying on the frame switching conditon to determine time dilation. Because that is the correct view.

The problem is that they refuse to acknowledge that y doing that they are no longer simply using "Mere Relative Velocity" but are using a form of absolute motion. That is switching frames requires that a clock has accelerated to a new velocity. That is a change in absolute velocity universally.

You may not know what that absolute velocity is or even if there is an underlying velocity to the inertial condition used as the rest frame but failure to acknowledge this fact and the fact that ONLY the accelerated clock dilates results in James R and others asserting that what one "Sees" is the physical reality.

That view re-instates the inherent reciprocity of a relative velocity view and the nonsensical condition of each clock ticking slower than the other at the same time.

You have seen James R once again make that assertion right here in this thread. He stated what you see is physical reality. That is not sound physics and why I insist one MUST treat time dilation as a physical reality and keep the dilated clock in consideration when you switch frame views and compute velocity according to the respective observers.

Doing that and lorentz contraction (for which there has been NO emperical data to support in over 100 years of study and testing) does not occur.

8. Originally Posted by MacM
That view re-instates the inherent reciprocity of a relative velocity view and the nonsensical condition of each clock ticking slower than the other at the same time.
There's that hurdle again. Why is it nonsensical? The answer might seem obvious (ludicrously so!), but try spelling it out. Why, exactly, do you think it is nonsensical that two clocks can each tick slower than the other from different points of view?

Is it any more nonsensical than two things each moving slower than the other at the same time from different points of view?

Or two things each being further away than the other from different points of view?

9. Hi MacM.

Let me start by admitting you, Pete and James are much better informed in SR than I am but I do not understand why you say:
Originally Posted by MacM
... That is switching frames requires that a clock has accelerated to a new velocity. That is a change in absolute velocity universally....
I see no reason why any clock needs to be accelerated to switch from one frame to the other. Consequently I have no idea why there is any need for an absolute velocity or argument here supporting its existence.

Surely all the clocks in frame A can be synchronized among themselves. Likewise for all the clocks in frame B. By the defined limit of SR no clock stationary in Frame A is accelerating wrt any clock stationary in Frame B (and conversely of course.)

Let's agree that all clock are digital, (to avoid any motions even of their hands) and being very rich we have a tiny clock at nearly every point in the XY plane of both frame A & B. Also imagine that the two XY planes are exactly parallel with aligned X axis direction and separated in the Z direction by small separation ~10cm. I.e. an observer in either frame thinks the dense network of clocks in the other frame are only 10 cm away from his frame's clocks. He can photograph the display of the clocks in the other frame as the clocks face towards the other frame.

In this 10 space between the XY planes there are two dual lens cameras, C & D, which are similar to those used to make stereoscopic photos. One lens of each camera is 4 cm from plane A's XY plane and the other lens is 4 cm from B's XY plane. (There is a 45 degree mirror 1 cm in front of each of the four lenses which allows the cameras to photograph the digital display of clocks passing by on either X axis. I.e. Both cameras C & D are as close as possible to the X axis of plane A and B. From POV of observer not moving wrt to the cameras the clocks in A are rushing by at +0.9C and those in plane B are speeding by with -0.9C. Also that observer stationary wrt to the cameras measures the separation between the two cameras as 1km and has the single electronic shutter pulse generator exactly half way between the cameras, so at least from his POV they take their digital pictures at exactly the same time.

If I have failed to specify anything, then assume it is perfectly symmetrical also.

After taking many exposures the data from Camera C and D both agree that the clocks in frame A are always 17 minutes advanced compared to the clocks in frame B. There is also complete consistency in the photo graphic data that neither frame has correctly synchronized their clocks. For example the photo taken with exposure pulse M shows a lack of synchronization of E seconds between the camera C & D photos. Likewise the two photos produced by exposure pulse N also have E seconds of difference, for all possible M & N.

Now I did not give the numerical value of E as I am too lazy and probably would not get it correct, but I am confident that any and all of you three could. That value is not important, but by standard SR is not zero.

SUMMARY: With only the camera photographic records you can calculate what any clock shows in either frame when any particular clock in either frame is showing noon. I do not know what more there is to switching {time in one SR frame} time / clock readings from one SR frame to {to time on clocks in} another SR frame.

I went into all this detail as I cannot see any basis for need for acceleration of any clock as MacM has asserted.
So Mach can you tell me why "switching time / clock readings / from one frame to the other implies an accelerated clock"?

10. Originally Posted by Pete
There's that hurdle again. Why is it nonsensical? The answer might seem obvious (ludicrously so!), but try spelling it out. Why, exactly, do you think it is nonsensical that two clocks can each tick slower than the other from different points of view?

Is it any more nonsensical than two things each moving slower than the other at the same time from different points of view?

Or two things each being further away than the other from different points of view?
Pete,

You have missed the point again. I have not and do not object to two observers 'Seeing', 'Perceiving' or thinking they 'Observe' each other as dilated. That is the condition which I have claimed is nothing but an "Illusion of Motion" and is not the "Physical Reality".

The physical reality is that only the accelerted clock (one that switches frames if you insist) becomes dilated. That means mere relative velocity had no permanent physical affect on clocks but the acceleration (a change in some absolute veloicty - energy) universally did.

The issue is when James R and other want to insist the the "Perception" IS physical reality which then re-instates the relative veloicty view and reciprocity. It is not simply "Counter Intuitive" as they want to claim but a physical impossiblity for two clocks to both be ticking slower than each other simulataneously.

11. Hello Billy,

Originally Posted by Billy T
Hi MacM.

Let me start by admitting you, Pete and James are much better informed in SR than I am but I do not understand why you say:I see no reason why any clock needs to be accelerated to switch from one frame to the other.
OK. I'll leave it to you to explain just how you propose to generate a relative velocity between clocks "A" & "C" when both are initially side by side at rest in a common inertial rest frame. Leave either one at rest and tell me just how the other achieves relative velocity.

Originally Posted by Billy T
Consequently I have no idea why there is any need for an absolute velocity or argument here supporting its existence.

Surely all the clocks in frame A can be synchronized among themselves. Likewise for all the clocks in frame B. By the defined limit of SR no clock stationary in Frame A is accelerating wrt any clock stationary in Frame B (and conversely of course.)
You are starting out with two clocks already having relative velocity. Now are you an observer from either one of these frames or are you a remote observer from a third frame?

1 - how you propose to synchronize the moving clocks

2 - and what you expect the emperical data to show about such clocks respective tick rates.

Originally Posted by Billy T
Let's agree that all clock are digital, (to avoid any motions even of their hands) and being very rich we have a tiny clock at nearly every point in the XY plane of both frame A & B. Also imagine that the two XY planes are exactly parallel with aligned X axis direction and separated in the Z direction by small separation ~10cm. I.e. an observer in either frame thinks the dense network of clocks in the other frame are only 10 cm away from his frame's clocks. He can photograph the display of the clocks in the other frame as the clocks face towards the other frame.
Proceed. Assuming you sucessfully explain how they were synchronized and how you describe their relative velocity.

Originally Posted by Billy T
In this 10 space between the XY planes there are two dual lens cameras, C & D, which are similar to those used to make stereoscopic photos. One lens of each camera is 4 cm from plane A's XY plane and the other lens is 4 cm from B's XY plane. (There is a 45 degree mirror 1 cm in front of each of the four lenses which allows the cameras to photograph the digital display of clocks passing by on either X axis. I.e. Both cameras C & D are as close as possible to the X axis of plane A and B. From POV of observer not moving wrt to the cameras the clocks in A are rushing by at +0.9C and those in plane B are speeding by with -0.9C. Also that observer stationary wrt to the cameras measures the separation between the two cameras as 1km and has the single electronic shutter pulse generator exactly half way between the cameras, so at least from his POV they take their digital pictures at exactly the same time.

1 - I assume your cameras are considerd at inertial rest, if so.

2 - you have just arbitrarily asserted that each has a velocity of 0.9c +/- to the cameras (or 0.994475 to each other if you assume velocity addition). Doing so your results are already limited to a symmetrical result.

3 - They will not see each other as dilated but will see each other as tick synchronized. But that is only because you fixed that relationship in your scenario. The reality might be that the cameras are moving +0.05c, "A" is moving +0.95c and "B" is moving -0.85c.

in which case your emperical results will not be symmetrical in accordance with you simplified relative velocity view.

Originally Posted by Billy T
If I have failed to specify anything, then assume it is perfectly symmetrical also.
I have done both.

Originally Posted by Billy T
After taking many exposures the data from Camera C and D both agree that the clocks in frame A are always 17 minutes advanced compared to the clocks in frame B. There is also complete consistency in the photo graphic data that neither frame has correctly synchronized their clocks. For example the photo taken with exposure pulse M shows a lack of synchronization of E seconds between the camera C & D photos. Likewise the two photos produced by exposure pulse N also have E seconds of difference, for all possible M & N.
This is totally inconsistant with emperical data of time dilation tests and the math for a symmetrical scenario. In a symmetrical scenario "A" & "B" will tick in unison and having been synchronized will display equal accumulated time. Their times however will be equally less (dilated) relative to a clock stationed with your cameras.

Originally Posted by Billy T
Now I did not give the numerical value of E as I am too lazy and probably would not get it correct, but I am confident that any and all of you three could. That value is not important, but by standard SR is not zero.
I have no idea what you are saying here.

Originally Posted by Billy T
SUMMARY: With only the camera photographic records you can calculate what any clock shows in either frame when any particular clock in either frame is showing noon. I do not know what more there is to switching {time in one SR frame} time / clock readings from one SR frame to {to time on clocks in} another SR frame.
I have no objections to your setup but I do reject your conclusions as to what will be seen.

Originally Posted by Billy T
I went into all this detail as I cannot see any basis for need for acceleration of any clock as MacM has asserted.
So Mach can you tell me why "switching time / clock readings / from one frame to the other implies an accelerated clock"?
How was it that "A" & "B" have relative velocity if one or both have never been accelerated?

12. BTW: To whoever saw fit to move this thread.

13. MacM:

SO you would be advised to acknowledge the name of the formula "Lorentz" a concept developed before relativity and based on an ether.
I usually refer to the gamma factor as the Lorentz factor, as it happens, because Lorentz came up with it first. Of course, the ether theory is no longer necessary, and has been disproved.

(a) In your opinion, is the "gamma" factor of Einstein's relativity correct?
Partially. When you apply it you must also recognize what is a gamma illusion vs gamma reality.
How do you tell the difference between the illusion and the reality?

(b) What causes one clock to tick slower than another, physically?
Differential total energy.
This is so vague as to be useless. Essentially you're saying you have an undeveloped theory that is no better than a guess. (Yes, yes, UniKEF, I know. That theory has gone nowhere in 50 years.)

(c) Can you give a mathematical justification of your answer to (b)?
No. But again "Absence of Evidence" is not the same as "Evidence of Absence".
In other words, you just hope your guesses are right, but they're still guesses based on nothing.

(d) You appear to think that while A ticks slower than C in C's frame, you think that A ticks FASTER than C in A's frame. Is this correct? (Yes or no)
No. The physical tick rate is fixed universally. If "A" is physically ticking slower than "C" then "C" is physically ticking faster than "A" in all frames.
It seems to me your answer is "yes", not "no", but never mind.

You seem to believe that C is some kind of "special" frame. I still can't see why.

(g) Do you agree that C was not in an absolute state of rest at the start of this whole process?
Never claimed "An absolute state of rest". Such a condition may well never be identified. It is a local absolute rest reference, not some universal absolute reference. Every inertial condtion may become a rest refence.
You appear to contradict yourself. In my example of A launching probe D, why can't the "initial condition" of A and D at the launch become a "local absolute rest frame" in the same way that you have taken C as a local absolute rest frame? After all, you agree that C is not necessarily at universal absolute rest. Why could it not instead be the case that A happens to be at universal rest?

(h) If at the end of the process A ticks slower than D, but D ticks at the same rate as C, explain how D knew to speed up its clock when it was launched from A, whereas A knew to slow down its clock when launched from C. How do we tell the difference between A and D?
Therein lies the great question. It is incumbient on us to seek that answer because clearly something is going on that we have no clue how that occurs, just as we have no clue how particle entanglement occurs.
You're tying yourself in logical knots.

1. You claim an effect that is not observed. "Clearly something is going on", but it is only going on in your imagination.

2. You have no explanation for your imagined effect.

3. Therefore, your imagined effect has no basis in fact, but is simply part of a long-standing illusion that you refuse to let go because it's your imagining.

(i) Do you think that if A is travelling at 0.8c relative to C, then C is not necessarily travelling at 0.8c relative to A? (yes or no)
Loaded question. You must ask who has the most "Actual" motion and who is computing velocity. The observer with a dilated clock will compute a higher velocity but on a universal level where you have a fixed time standard relative velocity is symmetrical.
Loaded question? It's a perfectly straightforward question. If you watch me drive my car, and my speedometer says I'm going at 50 mph, then will your radar gun also say I'm doing 50 mph, or will it sometimes give a different speed reading? That's all I'm asking.

1. Who has the most "actual" motion when I drive my car along the road and your point your radar gun at it? You or me, or some imaginary space cadet at rest relative to the universal standard of rest? And how can you tell?

2. Correct me if I'm wrong here. According to you, "the observer with the dilated clock will compute a higher velocity". You would also agree that since my car started from rest and accelerated up to 50 mph from our "common local rest frame", that my clocks in the car must run slow. Therefore, according to your answer, my speedometer should compute a higher velocity than your radar gun. Is that right?

Of course, at the "universal level" the speeds would be the same. How do I find the "universal level" when I drive my car along the street? In which reference frame would your radar gun measure the same speed as the speedometer in the car?

Yes "A" and "B" have a commom tick rate even though they have a relative velocity. I jsut wanted to make sure you didn't once again try to interject the illusion of motion where each "Sees" the other as dilated.
Wouldn't you have to first ask who has the most "Actual" motion and who is computing velocity? That's what you said above. How do you know that the "actual" motions of A and B are the same? What universal standard are you comparing to, and how do you know that the motions of A and B are the same with respect to that special standard?

Gamma = 4.5555n or each appears to tick at 21.95% (this is assuming veloicty addition correction which may be bogus).
Do you agree that this appearance is what A and B would actually see? (Yes or no)?

Note: this is not a question about your "reality". What I am asking you is whether the special theory of relativity correctly predicts appearances of clock rates. Or, to put it another way, does relativity predict anything about clock rates correctly, or is it all wrong?

I'm rather sure velocity addition as proposed by SR is invalid. I'm not sure what replaces it if anything.
So, is the speed of light a universal speed limit, or isn't it?

SR says that if B moves at 0.8c relative to A, and C moves at 0.6c relative to B, then the speed of C relative to A is not 1.4c, but still less than the speed of light.

Do you disagree with this? Is a speed of 1.4c possible? (Yes or no)?

14. Originally Posted by MacM
Pete,

You have missed the point again. I have not and do not object to two observers 'Seeing', 'Perceiving' or thinking they 'Observe' each other as dilated. That is the condition which I have claimed is nothing but an "Illusion of Motion" and is not the "Physical Reality".
No Mac, I'm not talking about 'seeing', 'perception', or any kind of illusion.

The kind of "point of view" I mean has nothing to do vision. It's something like this:
From your point of view, Sydney is further away than Washington DC.
From my point of view, Washington DC is further away than Sydney.

Both are correct. Clearly, it is not nonsensical that Sydney and Washington can both be further away than each other from different points of view.

Why is it (the condition of each clock ticking slower than the other at the same time) nonsensical? The answer might seem obvious (ludicrously so!), but try spelling it out. Why, exactly, do you think it is nonsensical that two clocks can each tick slower than the other from different points of view?

Is it any more nonsensical than two things each moving slower than the other at the same time from different points of view?

Or two things each being further away than the other from different points of view?

15. Originally Posted by James R
MacM:

I usually refer to the gamma factor as the Lorentz factor, as it happens, because Lorentz came up with it first.
Correct and it was based on an ether theory of relativity.

Originally Posted by James R
Of course, the ether theory is no longer necessary,
Correct only if you arbitrarily eliminate inherent reciprocity of the relative velocity view by invoking frame switching which means acceleration or actual motion causes time dilation (Hint an ether view of time dilation) - Hmmmm

Originally Posted by James R
and has been disproved.
Totally false assertion.

Originally Posted by James R
How do you tell the difference between the illusion and the reality?
You look at 100 years of data and see what is supported by emperical results vs what is not and you apply some common sense physics which tells you that the inherent reciprocity of the relative velocity between clocks view is not a physical possibility.

Originally Posted by James R
This is so vague as to be useless. Essentially you're saying you have an undeveloped theory that is no better than a guess. (Yes, yes, UniKEF, I know. That theory has gone nowhere in 50 years.)
Funny I never mentioned UniKEF here. What is useless is a theory that declines to be honest and acknowledge that it is actually based on a physical change in velocity (an absolute function) and not on relative velocity between clocks.

UniKEF hasn't gone any where is not entirely true but unfortunately mostly true but that frankly is a negtive reflection on you and other indoctrinated persons that refuse to actually consider it and to explore the possibilities.

I've laid logical ground work now it is your job to formalize the real physical universe, be it UniKEF or not. You will never do that when you decline to look at alternatives to SR and ignore it's shortcomings.

Originally Posted by James R
In other words, you just hope your guesses are right, but they're still guesses based on nothing.
Not a valid comment.

1 - I hope for nothing.

2 - I have presented thoughts to explain what data actually indicates versus the dogma of SR.

3 - Logical thoughts are hardly guesses.

4 - UniKEF is based on re-evaluation of evidence and is supported by a number of successful priori's; as well as a slight bit of calculus.

Originally Posted by James R
It seems to me your answer is "yes", not "no", but never mind.

Posted by James R: “ “ (d) You appear to think that while A ticks slower than C in C's frame, you think that A ticks FASTER than C in A's frame. Is this correct? (Yes or no) ”

Macm Replied:No. The physical tick rate is fixed universally. If "A" is physically ticking slower than "C" then "C" is physically ticking faster than "A" in all frames. ”
Please re-read your post. You have "A" ticking slower than "C" in the "C" frame which would be correct.

But you then have "A" ticking faster than "C" in the "A" frame, which is false.

Originally Posted by James R
You seem to believe that C is some kind of "special" frame. I still can't see why.
Therein lies your problem. You fail to see why a clock running slower physically will be running physically slower in every frame. How it might "Appear" to tick from some other frame is not the issue.

Only the physical reality is the issue and the physical treality is that physical permanent time dilation is NOT a matter of observer perspective but a matter of actual motion induced by undergoing F = ma acceleration..

Originally Posted by James R
You appear to contradict yourself. In my example of A launching probe D, why can't the "initial condition" of A and D at the launch become a "local absolute rest frame" in the same way that you have taken C as a local absolute rest frame? After all, you agree that C is not necessarily at universal absolute rest. Why could it not instead be the case that A happens to be at universal rest?
Here is where the rubber meets the road. You unfortunately have become so convinced that relativity is a real physical theory that you fail to recognize that you are extrapolating emperical test data from limited frame testing into hypothetical scenarios with mathematical formulas and expect them to hold physically.

The simple truth is you only have data from i.e - a particle being accelerated from a lab machine, or cosmic particles impinging on earth, as emperical references. Both involve only two frames where one is always static or at rest.

You can only justify multiple frame affects if you apply the data you have correctly. That is set a scenario where two particle accelerators are used and particles are launched , as I did in my clock examples, both co-moving and in opposite directions.

Since we know the results of each particle test where they have been accelerted equally ,we know that both particles will be dilated relative to the lab clock equally and it matters not it they are co-moving (no relative velocity) or in opposition (have relative velocity to each other).

Such that we know from emperical data that any other prediction by SR is not a valid physical prediction. We also know from the data that it is always the accelerated clock that dilates.

That is all we know.

Originally Posted by James R
You're tying yourself in logical knots.
Not at all. Just being honest. I do not know the answer to how the universe works no more than you do - AND you don't. But of what we do know my assessment is far more consistant with physics than yours.

Originally Posted by James R
1. You claim an effect that is not observed. "Clearly something is going on", but it is only going on in your imagination.

2. You have no explanation for your imagined effect.

3. Therefore, your imagined effect has no basis in fact, but is simply part of a long-standing illusion that you refuse to let go because it's your imagining.
I could write a simular assement about your physics. The difference is mine is more consistant with observation and emperical data. You want to claim that what observers "See" is physical reality. That is completely inconsistant with emperical data from tests.

Originally Posted by James R
Loaded question? It's a perfectly straightforward question. If you watch me drive my car, and my speedometer says I'm going at 50 mph, then will your radar gun also say I'm doing 50 mph, or will it sometimes give a different speed reading? That's all I'm asking.
You don't seem to get it. If you are going 50 Mph and I'm parked along side the road then my radar will say 50 Mph. But if you are traveling 50 Mph and try to compute my relative velocity to you bby v = ds/dt (by my clock) you would not get 50 Mph (although at these speeds the difference would be immeasurable).

Originally Posted by James R

1. Who has the most "actual" motion when I drive my car along the road and your point your radar gun at it? You or me, or some imaginary space cadet at rest relative to the universal standard of rest? And how can you tell?
You shuldn't try mixing being cut with any serious inquiry. They don't mix. Assuming you and your radar gun are at rest then from the measuring device you have the motion but in any absolute terms one doesn't know that until they compare the accumulated time on respective clocks. I may be driving west at 50 Mph such that I am effectively moving east at 950 Mph while you apparently standing still are actually moving east at 1,000 Mph. I know this is a rotating frame but you still get my point..

Originally Posted by James R
2. Correct me if I'm wrong here. According to you, "the observer with the dilated clock will compute a higher velocity". You would also agree that since my car started from rest and accelerated up to 50 mph from our "common local rest frame", that my clocks in the car must run slow. Therefore, according to your answer, my speedometer should compute a higher velocity than your radar gun. Is that right?
That would be right IF the frames are correct. This is no different than the case you gave where a rocket fired a missle backwards such that it once again was at rest from the launch pad. Hypothetical scenarios have a problem. The universe doesn't, it's affect on clocks clarifies the reality. Your math merely predicts "Hypotehtically" without supporting emperical data.

Originally Posted by James R
Of course, at the "universal level" the speeds would be the same. How do I find the "universal level" when I drive my car along the street? In which reference frame would your radar gun measure the same speed as the speedometer in the car?
Already answered. And your problem is a problem in SR not merely mine. You apply =/- signs to your math indicating which vector ov motion the clock has and that determines if the clock is speeding up or slowing down BUT that math does not answer why you do that since unless you knew the clock was returning to some other initial rest frame then you would predict it is slowing down.

Your math has the same clock both slowing down or speeding up while leaving an initial rest position depending on which vector sign you apply. That is time dilation in SR is inconsistant with respect to relative velocity to an initial rest reference frame, all as a matter of applying some pre-known or assumed fact about either leaving a rest clock or rejoining a prior rest clock.

Clocks cannot physically both slow down and speed up their tick rates at the same time. This shows you math is strictly hyupothetical and does not describe physical reality.

Originally Posted by James R
Wouldn't you have to first ask who has the most "Actual" motion and who is computing velocity? That's what you said above. How do you know that the "actual" motions of A and B are the same? What universal standard are you comparing to, and how do you know that the motions of A and B are the same with respect to that special standard?
I think this is answered above.

Originally Posted by James R
Do you agree that this appearance is what A and B would actually see? (Yes or no)?
No. They may well see each other dilated but that view will not be supported by physical data.

Originally Posted by James R
Note: this is not a question about your "reality". What I am asking you is whether the special theory of relativity correctly predicts appearances of clock rates. Or, to put it another way, does relativity predict anything about clock rates correctly, or is it all wrong?
It seems it likely predicts the "Perception" correctly. As applied it predicts measured physical time dilation correctly but that is by eliminating the "Percetion" of each being dilated due to mere relative veloicty by considering who has an actual change in velocity from some common rest reference frame.

Originally Posted by James R
So, is the speed of light a universal speed limit, or isn't it?
I suggest it is not. I suggest it is more a limit of physical dimension linkage. That is Lorentz Contraction of mass in the direction of motion (not space) causes objects to cese to exist in your physical universe but they continue to exist but at a different energy level universe.

Originally Posted by James R
SR says that if B moves at 0.8c relative to A, and C moves at 0.6c relative to B, then the speed of C relative to A is not 1.4c, but still less than the speed of light.
Yep it sure does. It should since it was designed to do so. Just as Einstein wanted the universe to be static and generated math to show it was (until it was proven to be expanding), he also wanted v = c to be a limit so wrote math to make it so.

Originally Posted by James R
Do you disagree with this? Is a speed of 1.4c possible? (Yes or no)?
Yes and no. Not in your physical universe but at some absolute reference level yes. Such object would be at 0.4c in the higher level outside your universe.

16. Originally Posted by Pete
No Mac, I'm not talking about 'seeing', 'perception', or any kind of illusion.

The kind of "point of view" I mean has nothing to do vision. It's something like this:
From your point of view, Sydney is further away than Washington DC.
From my point of view, Washington DC is further away than Sydney.

Both are correct. Clearly, it is not nonsensical that Sydney and Washington can both be further away than each other from different points of view.

Why is it (the condition of each clock ticking slower than the other at the same time) nonsensical? The answer might seem obvious (ludicrously so!), but try spelling it out. Why, exactly, do you think it is nonsensical that two clocks can each tick slower than the other from different points of view?

Is it any more nonsensical than two things each moving slower than the other at the same time from different points of view?

Or two things each being further away than the other from different points of view?
The answer is rather tirval. The reality of a physical tick rate is NOT a matter of observer view. It is whatever it is and does not change with observer view point.

Observers may "Percieve" respective clocks each ticking slower than the other while having relative motion but that is not and can never be the physical tick rate reality.

17. James R,

Given "A" & "B" clocks are both at an inertial relative rest in the same general location and synchronized.

If "A" is launched away from rest and accelerates to a velocity 0.8c from "B" what is it's tick rate compared to "B"?

18. Originally Posted by MacM
The answer is rather tirval. The reality of a physical tick rate is NOT a matter of observer view. It is whatever it is and does not change with observer view point.
Not with view point, but with velocity. SR says that the reality of a physical tick rate is quite definitely a matter of observer velocity.

Observers may "Percieve" respective clocks each ticking slower than the other while having relative motion but that is not and can never be the physical tick rate reality.
Let us be quite clear: SR dictates that the physical tick rate reality is frame dependent. The physical reality according to SR is that clocks in relative motion each tick slower than the other, according to the chosen frame of reference.

SR says that tick rate is relative to velocity, just as 'further away' is relative to position.

19. MacM:

Originally Posted by MacM
Given "A" & "B" clocks are both at an inertial relative rest in the same general location and synchronized.

If "A" is launched away from rest and accelerates to a velocity 0.8c from "B" what is it's tick rate compared to "B"?
I assume you mean after the acceleration period, once the final speed is reached. Answer: It depends on which frame you're observing the tick rate in. The Lorentz factor for this speed is 1.666. In A's frame, A's clock runs at the normal rate and B's runs slower by a factor of 1.666. In B's frame, A's clock runs slower than B's by a factor of 1.666 and B's clock runs at the normal rate.

By the way, this scenario is indistinguishable from one in which A and B are originally at rest and B accelerates away, leaving A at rest, except that the direction of motion of B would be the opposite to your original scenario.

That is, once the acceleration is over, there's no experiment you can do to show that the acceleration ever happened. Examining current clock rates won't tell you anything about the acceleration history of A or B. Do you agree?

---

Originally Posted by MacM
What is useless is a theory that declines to be honest and acknowledge that it is actually based on a physical change in velocity (an absolute function) and not on relative velocity between clocks.
You're not talking about special relativity here, are you?

Because you DO know that special relativity ONLY considers relative velocities. There are no absolute velocities in the theory of relativity.

So, what theory are you thinking of, then?

Please re-read your post. You have "A" ticking slower than "C" in the "C" frame which would be correct.

But you then have "A" ticking faster than "C" in the "A" frame, which is false.
Ah, sorry. I was obviously letting true physics slip into my thinking, instead of going with what your fantasy physics says. My mistake.

Therein lies your problem. You fail to see why a clock running slower physically will be running physically slower in every frame. How it might "Appear" to tick from some other frame is not the issue.

Only the physical reality is the issue and the physical treality is that physical permanent time dilation is NOT a matter of observer perspective but a matter of actual motion induced by undergoing F = ma acceleration..
Ok. We're getting to the crux of this. Your statement in bold is very clear. Let me give you one more scenario, just so I understand your position.

You observe three clocks: A, B and C. At the time you observe them, you happen to be at rest relative to clock C. Note: I am not telling you that you are on Earth. For example, Clock C may be the clock you're carrying along with you in a spaceship travelling at unspecified speed v relative to Earth, for example.

So, you're at rest relative to C. From your reference frame, you measure the speeds of clocks A and B, which happen to be moving relative to C (you). You observe that clock A is travelling at 0.6c away from you. You observe that clock B is travelling at 0.6c away from you, but in the opposite direction to clock A. You have no information about how the three clocks might have accelerated (or not) before your observations.

Questions:

* Is it possible for you (C) to measure the tick rates of clocks A and B from your frame C?
* If so, what are the tick rates of clocks A and B?
* Are A and B synchronised? i.e. do they tick at the same rate?
* If you can, please specify how you might measure the tick rates of clocks A and B (assuming that such a thing is possible at all).

Originally Posted by MacM
Originally Posted by James R
Loaded question? It's a perfectly straightforward question. If you watch me drive my car, and my speedometer says I'm going at 50 mph, then will your radar gun also say I'm doing 50 mph, or will it sometimes give a different speed reading? That's all I'm asking.
You don't seem to get it. If you are going 50 Mph and I'm parked along side the road then my radar will say 50 Mph. But if you are traveling 50 Mph and try to compute my relative velocity to you bby v = ds/dt (by my clock) you would not get 50 Mph (although at these speeds the difference would be immeasurable).
I get what you're saying. You're saying that my speedometer, which does just such a computation of my car's speed, will NOT read 50 mph if your radar gun reads 50 mph. The difference might be very small, but it would be a real difference, according to you. Right?

Can you tell me what maths I'd have to build into my speedometer so that it would always read the same speed as your radar gun's measurement of the car's speed?

Or, are you saying that if I have my own radar gun in my car and I point it at you it will read your speed as something other than 50 mph?

Assuming you and your radar gun are at rest then from the measuring device you have the motion but in any absolute terms one doesn't know that until they compare the accumulated time on respective clocks.
So, speedometers are impossible?

I may be driving west at 50 Mph such that I am effectively moving east at 950 Mph while you apparently standing still are actually moving east at 1,000 Mph.
So, you stand still and your radar gun measures my speed at 50 Mph west. Let's assume, like in your example, that you are moving east at 1000 mph and my car is driving east at 950 mph.

Questions:

* Have I got it right that your radar gun would measure my speed at 50 mph west?
* What would the speedometer on my car say in this case?
* What would the radar gun in my car read when I point it at you?
* Is there any way I could tell from the measurements (radar guns and speedmeter) our actual speeds (1000 and 950 mph)? Bear in mind that the road may also be moving relative to something like the Sun.
* Actually, just to be clear, what are these 1000 and 950 mph speeds relative to? The road? A fixed point at the centre of the Earth? The Sun? Or what?

And your problem is a problem in SR not merely mine. You apply =/- signs to your math indicating which vector ov motion the clock has and that determines if the clock is speeding up or slowing down BUT that math does not answer why you do that since unless you knew the clock was returning to some other initial rest frame then you would predict it is slowing down.
I'm not entirely sure what you're saying here.

Your math has the same clock both slowing down or speeding up while leaving an initial rest position depending on which vector sign you apply.
My math has the clock speeding up or slowing down depending on the reference frame it is observed from.

Another example: I am driving along the road at 50 mph, east. You are driving your car next to mine, also at 50 mph east. Now, you slam on the brakes. What does your car do, in my reference frame? Answer: You started at rest in my reference frame, and when you slammed on the brakes you accelerated with increasing speed to the west. Agree?

Question: did you speed up or slow down when you hit the brakes? Answer: it depends on the reference frame we're looking at you from. From my car's frame, you sped up. From the point of view of a bystander on the road side, you slowed down.

Do you agree?

What I am asking you is whether the special theory of relativity correctly predicts appearances of clock rates. Or, to put it another way, does relativity predict anything about clock rates correctly, or is it all wrong?
It seems it likely predicts the "Perception" correctly.
How does it manage to do that? Surely if the maths is all wrong, it can't possibly work to even predict perceptions correctly. Is it just lucky?

So, is the speed of light a universal speed limit, or isn't it?
I suggest it is not.
Why have we never observed any massive object moving faster than light, then?

I suggest it is more a limit of physical dimension linkage. That is Lorentz Contraction of mass in the direction of motion (not space) causes objects to cese to exist in your physical universe but they continue to exist but at a different energy level universe.
Why have we never seen any object disappear from our universe into a different energy level universe, or any object suddenly appear in our universe from the other universe?

Originally Posted by MacM
Originally Posted by JR
SR says that if B moves at 0.8c relative to A, and C moves at 0.6c relative to B, then the speed of C relative to A is not 1.4c, but still less than the speed of light.
Yep it sure does. It should since it was designed to do so. Just as Einstein wanted the universe to be static and generated math to show it was (until it was proven to be expanding), he also wanted v = c to be a limit so wrote math to make it so.
You think? *sigh*

I thought you would have learned after all these years that the entire theory of special relativity (for a start) is derived from only TWO postulates. From these two simple postulates, we get time dilation, velocity addition, "reciprocity", length contraction, relativity of simultaneity, and all the other good stuff you can't bring yourself to believe.

What is certainly NOT true is that Einstein could just add ad hoc mathematics to make things the way he wanted them. The velocity addition formula of special relativity is not an "extra" add-on to the theory. It is a direct and simply-derived consequence of the same two postulates. There's no choice in the maths once the two postulates have been specified. And they are exceedingly simple.

And in all these years you have never been able to bring yourself to directly say that either of the postulates of special relativity is flawed. Which means, of course, that all your attacks on the mathematics and your comments about "reality vs. perception" are useless, because if the postulates are right then the maths must be right. If it wasn't, somebody would have shown the errors some time in the last 100 years.

Similarly, the v=c speed limit is not something ADDED to the theory of relativity. It is a derived consequence of those same two postulates.

I'm extremely disappointed that you do not know these things.

In short, what all this means is that to attack special relativity, you need to attack at least one of the two postulates - with reasons, of course. But you're not brave enough to do that, are you?

Do you disagree with this? Is a speed of 1.4c possible? (Yes or no)?
Yes and no. Not in your physical universe but at some absolute reference level yes. Such object would be at 0.4c in the higher level outside your universe.
So what you're saying is that the theory you wish to replace relativity with doesn't apply to our universe, but only to a different universe at a "higher level" - an unknown fantasyland MacM universe that we have no way of detecting.

Correct?

20. Originally Posted by MacM
The answer is rather tirval. The reality of a physical tick rate is NOT a matter of observer view. It is whatever it is and does not change with observer view point.
Welcome to the physics of 19th century. We're a bit further on, now, but thanks for playing!
Observers may "Percieve" respective clocks each ticking slower than the other while having relative motion but that is not and can never be the physical tick rate reality.
Philosophy. Oh, look, something else that is shiny and irrelevant!

If you ever graduate from 1st year mechanics, I dread to think how you would cope with quantum stuff: "'The superposition can never be the reality!' thundered MacM, as he spurred his trusty steed onward towards the windmill."