1. Originally Posted by Quantum Quack
Pete,with all due respect,

Only a clock that has endured acceleration can record physical dilation when compared to a clock that hasn't endured accelleration.

You record two clocks moving at 0.8c (with respect to you). One of them fires its rockets and comes to rest (with respect to you).
SR says that the tick rate of the clock that is still moving is dilated with respect to the clock that accelerated.

2. Originally Posted by Pete
What? You just said "correct", indicating that you agreed that SRT doesn't allow a clock to be dilated without cause, but then you just repeat that exact complaint?

Let me say it again:
SRT does not allow a clock to be dilated without cause.
I've started another thead on this issue to lift it out of this complex ego rambling that has been going on in this one...
my answer to your post is that you are using only theory to provide cause and not reality..

3. Originally Posted by MacM
... The view from "B" that "A" "Appears" dilated is in fact just an illusion of motion. This view is supported by emperical data. To suggest that "A" actually changed tick rate and accumulated a different time as a physical reality is simply nutty. It would require that every clock in the universe have an infinite number of tick rates so as to be physically correct to all observers over all relative velocities...
(B was the clock that accelerated away from A which is still in the "common rest frame.")
Originally Posted by MacM
... A clock remaining at rest has absolutely no cause factor to change. A mere relative velocity cause is ludricrus and physically impossible.
First let me agree with one of the ambiguous ways of interpreting you imprecise statements above:

It is true that the physical tick rate of both clocks A & B is unchanged by the existence of some other clock moving in another inertial frame. I.e. a just made pregnant lady can expect nine months to pass by her clock before the baby is born.

However assuming I am not in her frame but another inertial frame moving wrt hers I can measure that it takes her longer to make the baby. This is because I will use my clock, not hers to determine the rate the fetus is growing just as I will use my clock to determine the speed that her house is moving away from me. In fact I am very stubborn about this - I always compute ALL rates the same way no matter what they are or where they are or how they are moving wrt to me and my clocks.

I determine a rate of x change as follows:
The value of x at some initial time t1 is noted and is x(t1). Then later x(t2) is recorded. Then the rate of x change is [x(t2) -x(t1)] / (t2-t1)

The pregnant lady would do exactly the same but use her clocks. For example her time interval is (T2 -T1) and her X1 is my x1 event. To take a specific example, For both of us X1 & x1 are touching a lighted match to a fire cracker fuse, and for both of us, X2 & x2, are the fire cracker exploding. There are two identical firecrackers, one stationary in each frame. (I light mine, she lights hers. We do not even attempt to do this simultaneously as that will just lead to arguments in this discussion.)

I might add that if we ever had what you call a "common rest frame" it was for both of us many years ago and neither she nor I were old enough to have any clocks or firecrackers back then.* In fact the clocks and fire crackers have never been at rest in the common rest frame as all were only made a few weeks ago. I.E. NEITHER the clocks nor the firecracker were ever accelerated so they cannot be affected by acceleration that was in the distant past, long before they even existed.

You will agree that at least (T2 -T1)' > (t2-t1) or (T2 -T1)' < (t2-t1) as you do not deny "one way" time dilation, but refuse to be both are true and that is correct as the prime I added to the right side quantities is to indicate that (T2 -T1)' is the time her fuse burns by my clocks and I cannot belief it both longer and shorter than the time (t2-t1), my identical fuse took to burn by my clock.

Exactly the same for her either: (T2 -T1) > (t2-t1)* or (T2 -T1) < (t2-t1)* but not both. Where an asterisk is added to time interval for my fuse to burn as measured by her clock.

SR states time is dilated in the frame moving wrt you. She and I both accept that. I.e. she believes (or measures) (T2 -T1) < (t2-t1)* and I believe (or measure) (T2 -T1)' > (t2-t1). Or in the less well defined words you use:

Both measure the others identical fuse as burning more slowly. You MacM assert that this is not physically possible. So you go on to conclude that since what SR asserts is nonsense, SR must be at least partially wrong.

I.e. you say it is not possible for her to measure my time interval (t2 -t1)* as longer than hers (T2 - T1); and also for me to measure her time interval (T2-T1)' is longer than mine (t2-t1). But it is as (t2 -t1)* IS NOT THE SAME AS (T2-T1)' Your lack of (actually your refusal to use) well defined symbols to aid clear thinking is at the heart of your belief that SRT is wrong, I think.

There is nothing impossible here; again:
(t2 -t1)* IS NOT THE SAME AS (T2-T1)'

It only seems to be the same when imprecisely expressed in your words as follows:

"Both CANNOT measure the others identical fuse as burning more slowly. THAT IS NONSENSE"

Probably all but you can see what the problem is: (Lack of precise terminology.)

Possibly even QQ can or else he believes that (t2 -t1)* IS THE SAME AS (T2-T1)' since he believes time dilation is an inertal effect and in this example no clock or firecracker was ever subjected to any acceleration. I would like to know what he thinks.

---------------
*Actually neither of use even existed back then (more than 150 years ago) when the acceleration took place - see post 425 for more details.

4. so Uhm BillyT how did you get to be moving at relative V to the pregnant lady in the first place if not for acceleration?

also as far as the lady is concerned she would give a rats ar*s it's still a bloody long time [ and SRT will inevitably make it the pregnancy, longer for the father and not her...oh no!!]

5. Originally Posted by Quantum Quack
Ok ..so if we focus only on this complaint without any further compexity being added we should see a result yes?

Only a clock that has endured acceleration can record physical dilation when compared to a clock that hasn't endured accelleration.
Unfortunately "NO". They will insist that acceleration has no causeal effect. They refuse to acknowledge that "Switching Frames" requires acceleration. Different frames means trhey have differentv inertial velocities, which means they share a relative veloicty to each other.

It is the velocity difference (an energy state in my opinion) that causes dilation and the reality is that you only get changes in velocity by accelerating.

Indeed the correct total time dilation must also include a gamma integration of velocity during acceleration period because there also exist periods of differing velocity (Frames).

But they will dance all around this issue and refuse to acknowledge the linkage. James R will argue that relative veloicty is the cause and that reciprocity is physically real. Even though it is physically impossible and has never been tested and appear is untestable. There is absolutely NO emperical data to support such ludricrus concept ad mere relative velocity a a cause of physical change.

Just as you have relative velocity between different frames there exists the "Apparent" relative acceleration. That isas the train pulls out from the station the statin appears to be accelerating in the opposite direction.

There is however a very important distinction in the two observations.

People on the train are being subjected to F = ma and are undergoing v = at. The people at the station have no "F" and have no actual "V".

That is why their clocks do not physically dilate.

.

6. It is the velocity difference (an energy state in my opinion) that causes dilation and the reality is that you only get changes in velocity by accelerating.
we agree....

7. Originally Posted by Quantum Quack
so Uhm BillyT how did you get to be moving at relative V to the pregnant lady in the first place if not for acceleration?...
One of our great grandparents was accelerated 150 our years ago. - More than a century before the clocks or firecrackers even existed. They NEVER were accelerated, but are made of identical chemicals and materials last week in accordance with exactly the same plans. (Our grand fathers got the plans from our great grandparents and then gave them to our fathers. Not to follow them exactly brings a terrible curse on our families for next seven generations so I assure you: the clock and firecrackers ARE IDENTICAL!)

I still wish to know what you think. Which is it:
(t2 -t1)* IS NOT THE SAME AS (T2-T1)'
or
(t2 -t1)* IS THE SAME AS (T2-T1)'

There are only these two alternatives - chose one.

My bed time now - hope I can sleep, but not knowing until tomorrow which you will choose may make that tough.

8. Originally Posted by Billy T
One of our great grandparents was accelerated 150 our years ago. - More than a century before the clocks or firecrackers even existed. They NEVER were accelerated, but are made of identical chemicals and materials last week in accordance with exactly the same plans. (Our grand fathers got the plans from our great grandparents and then gave them to our fathers. Not to follow them exactly brings a terrible curse on our families for next seven generations so I assure you: the clock and firecrackers ARE IDENTICAL!)

I still wish to know what you think. Which is it:
(t2 -t1)* IS NOT THE SAME AS (T2-T1)'
or
(t2 -t1)* IS THE SAME AS (T2-T1)'

There are only these two alternatives - chose one.

My bed time now - hope I can sleep, but not knowing until tomorrow which you will choose may make that tough.
nighty nite!

9. Originally Posted by Pete
Mac, I really wish you'd just take the time to understand what SR does and doesn't say. You too, QQ.
And I'd hope you will one day understand I do understand. What I am combating is James R and others assertion that what respective clocks "see" while in relative motion is the physical reality, not that SR says it is.

SR (actually LR) properly considers acceleration or who has "Actual Velocity" and ignores relative velocity when predicting physical time dilation of particles in the lab. Relative velocity measurements without consideration of who accelerated or who remained at rest simply address appearances or illusions of motion and not physical change.

QQ is correct when he points out that there is simply no cause for physical change in a resting clock.

10. Originally Posted by MacM
And I'd hope you will one day understand I do understand. What I am combating is James R and others assertion that what respective clocks "see" while in relative motion is the physical reality, not that SR says it is.

SR (actually LR) properly considers acceleration or who has "Actual Velocity" and ignores relative velocity when predicting physical time dilation of particles in the lab. Relative velocity measurements without consideration of who accelerated or who remained at rest simply address appearances or illusions of motion and not physical change.

QQ is correct when he points out that there is simply no cause for physical change in a resting clock.
thus we have a theoretical violation of physical C&E [Cause and Effect]

11. Originally Posted by MacM
And I'd hope you will one day understand I do understand.

It's abundantly clear that you don't. I've checked. Repeatedly. I really don't know where you get the hubris to think that your understanding is beyond reproach. You might as well be a creationist.

12. Originally Posted by Pete
It doesn't. SR says that the tick rate of a clock is a relative property, a property of not just the clock but of the frame of reference in which the tick rate is considered.
And the problem here is that you do not distinguish between such appearance while in motion vs emperical data of clocks compared in a common rest frame subsequenct to having had relative velocity.

It is this later case that is at issue and not the "Apparent" dilation caused by relative velocity. When you stop the relative motion only one will be dilated relative to the other and it will be the most accelerated clock even though during relative velocity each "Sees" the other dilated.

Emperical data does not support the relative velocity view as being physically real.

I have shown in my radioactive decay clock scenario that it does not matter which frame you compare the clocks in after having had relative velocity the results remain the same only the clock with the greatest v * t is dilated and not vice-versa as a matter of frame perspective.

13. Originally Posted by Quantum Quack
To be honest I am puzzled as to why something so simple and obvious can not be understood or dealt with. The complaint is very simple and should be very easy to deal with...as a trivial lack of understanding somewhere in the chain of causes and effects
You and me both. I understand the POV where each observer "Percieves" the other dilated but why they refuse to acknowledge that the only "TRUE" time dilation is that which causes permanent change in accumulated time when there is no longer relative velocity simply amazes me.

They want to argue about what SRT says or claims but not what common sense and emperical data suports.

14. Originally Posted by Pete
I don't understand why you think it is a complaint.
Do you think it is a problem that Newton treats velocity as relative but not acceleration?
Pete,

As QQ has said this has nothing to do with who has said what. It has to do with what is emperically supported as physically real and what is simply ludricrus nonsense based on extrapolated matematics of a flawed physical concept.

15. So, do you think that Newtonian mechanics is a reasonable description of reality at non-relativistic speeds?
Do you think it is a problem that reality treats velocity as relative but not (the direction of) acceleration?

16. Originally Posted by Pete
What? You just said "correct", indicating that you agreed that SRT doesn't allow a clock to be dilated without cause, but then you just repeat that exact complaint?

Let me say it again:
SRT does not allow a clock to be dilated without cause.
Reminds me of a former President saying "It depends on what your interpretation of what "Is" "Is".

The problem with your statement Pete is you and SRT want to claim "Mere Relative Velocity " is a cause. As QQ has rightfully pointed out there has been no physical basis for a resting clock to physically change.

Further SR doesn't even compute that way they consider who accelerated by claiming "Switched Frames" or who has actual velocity in the relative velocity pair when predicting who is dilated which is more LR than SR.

It is interesting that they use Lorentz formulas and now Lorentz preferred frame view but still claim it is SR.

17. Originally Posted by Pete

You record two clocks moving at 0.8c (with respect to you). One of them fires its rockets and comes to rest (with respect to you).
SR says that the tick rate of the clock that is still moving is dilated with respect to the clock that accelerated.
To get to that point you had to accelerate the clock to establish a common rest reference.

If you spot two clocks moving relative to each other and you, you have no way of predicting what there respective tick rates actually are based on your perspective of their relative velocity.

18. Originally Posted by Billy T
In fact I am very stubborn about this - I always compute ALL rates the same way no matter what they are or where they are or how they are moving wrt to me and my clocks.
So if you retain the physically dilatedcondition of your clock after having accelerated away cnad compute v = ds / dt, you can only get a correct answer matching you accumulated time for the trip if distance remaind unchanged.

The velocity you will compute increases if your clock is ticking slower.

End of arguement. Anyother assertion requires that you ignore your prior stipulation that the accelerated clock is dilated.

19. Originally Posted by Pete

It's abundantly clear that you don't. I've checked. Repeatedly. I really don't know where you get the hubris to think that your understanding is beyond reproach. You might as well be a creationist.
Don't call me names - He He. How dare you object to my holding pat to my view. Do you and other relativists not hold to yours?

Seems the pot calling the kettle black.

Your comments would carry more weight if you just provided a sound physics rebuttal and stopped trying reciting the very theory that is being challenged.

You could sttart by pointing out specifically how my car trip between two cities is not an accurate description of what is actually happening in SRT.

Keep in mind I could have Bob stationed at rest in city "B" and have him just look at the radar readings to conclude that Bill was driving 60 Mph all the way.

If so then you would agree that Bob predicts that Bll's watch would be running slow. So how is it then when Bob considers Bill's trip time he ignores the dilated clock he just predicted and computes distance changed because he accumulated less time.

He has to ignore his prediction that Bill's watch is dilated.

20. Originally Posted by Pete
So, do you think that Newtonian mechanics is a reasonable description of reality at non-relativistic speeds?
Do you think it is a problem that reality treats velocity as relative but not (the direction of) acceleration?

I don't see that what anybody has said affects the reality being discussed.