Is time universal? NO (and its proof)

I agree your calculations were correct for the light clock oriented to emitt the photon in the direction of travel. The mirror receeded from the event, which was the emission of the photon that was fixed in spacetime. The motion of the frame had no effect on the photon's travel.

Now, remember the orientation of the light clock where the photon was emitted 90 degrees orthogonal to direction of travel? In the rest frame of the light clock, the photon simply travels to the mirror and back to the laser/detector. How do you make the light clock work when viewed from the distant rest frame? The mirror and the detector/laser would both move if the emission of the photon, the event, was fixed in spacetime. The photon would neither 'hit' the mirror, which has moved forward 10 meters during the flight of the photon, nor be reflected back to the laser/detector, which has moved forward 20 meters during the same period.

 

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Well, I don't think that the light clock being perpendicular to the direction of travel is the same as the photon being emitted perpendicularly in any given frame. Even if they were baseballs or some other material object they would not be emitted perpendicularly. I think the photon has to be emitted at an angle of arctan(4/3) in order to hit the mirror and bounce back. Since it is just a transformation of variables if everything is lined up correctly in one frame so that it doesn't miss then everything has to be lined up correctly in all other frames so that it doesn't miss, otherwise you did your coordinate-transformation incorrectly.

Did you ever play the game "Pong" on the old Atari video-game console? For some reason I have a sudden mental picture of the inertial frame spinning one of those paddle wheels.

-Dale

 

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Yes, I used to play 'Pong' quite a bit in bars and such, ahem.

I guess you can anticipate my next question. If the photon is emitted at 90 degrees perpendicular to the direction of things passing by the observer in his 'rest' frame, how can it be emitted at a different angle in the distant observer frame unless the photon is 'carried along' by the frame, i.e. not independent of the motion of the frame? I'm not trying to disagree with you personally, DaleSpam, just pointing out what seems to me to be philosophical errors in STR gedankins.

 

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Hello?
You are calculating velocity using a clock in one frame and a ruler in another!

Correct... so why do you want to combine a clock in one frame with a ruler in another?

What do you mean?
Of course the velocity of the spaceship frame is different in different frames. Velocity isn't meaningful unless specified with respect to some frame.

In the spaceship frame, the velocity of the spaceship frame is zero.
In the Earth frame, the velocity of the spaceship frame is 0.866c.

This isn't SRT.. this is basic Galileo and Newton.

Your assumption that the meter markers are spaced one meter apart in the spaceship frame is an unnecessary assumption, and conflicts with the postulate that c is frame invariant.

You agreed before that we we must use clocks and rulers in the same frame. Why not try applying that rule?

 

Of course he won't. MacM doesn't work that way.

That's why he stopped arguing that his Doomsday device scenario earlier in the thread produced an explosion in one frame but not the other.

 

I have made a graphic representation of the Train and the Embankment, including rows of clocks that are synchronized in each frame. There are also some interesting observations pointed out on the drawing. Please click on this ClockGraphic.pdf for a PDF file. You will have to print it out, or adjust the the zoom in and out (the magnifying glass tool) in order to see everything clearly.

After studying the drawing, it will become clear that synchronized clocks are really only synchronized in their own rest frame. From other frames, the clocks are not synchronized. The drawing also demonstrates time dilation and length contraction (Gamma=2).

The actual light beams emitted from the center of the train, and the firecrackers at the front and rear of the train, are not shown. I think showing them would make the diagram even more difficult to read than it already is. If someone wishes to attempt to draw these things in to complete the diagram, perhaps these calulations from earlier in this thread might be of help:

Effective speed of signal toward rear firecracker (in frame E):
Vr = (c + v)/2 = (1.866c)/2

Effective speed of signal toward front firecracker (in frame E):
Vf = (c - v)/2 = (0.134c)/2

(1.866c/2) : (0.134c/2) = (1.866c) : (0.134c) = (14:1) approx.

(In other words, in the embankment frame, clocks would elapse approximately 14 times as many ticks between the emission time and the "front-of-train" firecracker going off, comapred to the number of ticks elapsed between the emission time and the "rear-of-train" firecracker going off.)

There are also some other interesting notes pointed out on the drawing. Special thanks to Pete for his original idea, "Pete's Table" earlier in this thread, which helped me to understand these concepts.

 

What do you mean by independent of the motion of the frame?
The direction of travel of the photon is dependent on the motion of the emitter, which is dependent on reference frame.

The speed of the photon is frame independent, but not it's direction of travel.

I'm not sure why you consider this to be a philosophical error?

 

Nice work, Neddy. Quite impressive.

 

Funkstar,

Really? Since you either didn't or cannot read:

********************** Extract **************************
http://www.mathpages.com/home/kmath307/kmath307.htm

A Primer on Special Relativity


An inertial coordinate system is a system of space and time coordinates with respect to which inertia is homogeneous and isotropic. Homogeneity implies that every material body free of external influence moves at constant speed in a straight line, and isotropy implies that if two identical material objects initially adjacent and at rest act to repel each other, they acquire equal speeds in opposite directions. Given one inertial coordinate system we can construct infinitely many others by means of arbitrary fixed translations and spatial rotations, which leave the speed of every object unchanged. Such an equivalence class of inertial coordinate systems is called an inertial reference frame. It's important to recognize that the definition of an inertial reference frame not only identifies inertial motion with straight paths of constant speed, it also establishes an operational definition of simultaneity (i.e., the synchronization of times at spatially separate events), because inertial isotropy implies that we can use identical physical objects acting against each other to synchronize clocks equidistant from their center of mass.

Given this definition of inertial reference frames, the principle of relativity asserts that for any material particle in any state of motion there exists an inertial reference frame - called the rest frame of the particle - with respect to which the particle is instantaneously at rest (i.e., the change of the spatial coordinates with respect to the time coordinate is zero). This principle is usually extended to include reciprocity, meaning that for any two systems S1 and S2 of inertial coordinates, if the spatial origin of S1 has velocity v with respect to S2, then the spatial origin of S2 has velocity -v with respect to S1. The existence of this class of reference frames, and the viability of the principles of relativity and reciprocity, are inferred from experience. Once these principles have been established, the relationship between relatively moving inertial coordinate systems can then be considered

*********************************************************
Either (both) clocks can assume inertial rest and it is the other clock which has all velocity and undergoes all relavistic affects. This creates the enviornment where clock A ticks slower than clock B at the same time as clock B ticks slower than clock A.

The only time dilation affects EVER recorded in 100 years of relativity shows only ONE clock time dilated (i.e. - accumulates less time hence was ticking slower than the other over the same test period).

There is no evidence to support the reciprocity advocated by SRT, nor is it a reasonable proposition.

“ Posted by MacM:"Now smart ass. Suppose you justify the claim of spatial length contraction. You mix frames by stipulating the velocity in your frame for the moving frame when it is grade school arithmatic to show that is not the actual case. ” (Highlited in red by Funkstar)

Herein lies your problem. You seem to have no ability to read and think. This means just what it says. You assume your velocity and apply it to another frame when in that frame the velocity would measure differently.

As demonstrated by the presence of meter markers along side the travel path of the moving observer.

On the grounds that you ignore the prior physical fact as supported by emperical data, that the moving observer clock is ticking slower than the rest clock and you then use the accumulated time of the slow clock to compute d = vt and claim "d" has changed.

"d" did not change. "t" changed because of time dilation. "d" and "t" are seperate physical entities. Acknowledging that fact then there is no basis to assume spatial length contraction.

The physical fact is to the observer in the moving frame the rate of meter markers passing by stipulates a higher velocity than the one seen in the rest frame.

You have no basis to claim length contraction at all. It is nothing more than an AD HOC assumption to cause relativity to become superfically mathematically consistant.

Oh, yea. On more careful consideration you will find your support for your arguement for length contraction is based on the very assumption of length contraction. You are basing your 0.866c velocity on the assumption of contracted space as measured by the ships ruler. Funny how you seem to think you can use assumptions of a theory to prove the theory.

Nice trick but it doesn't fly.

Meter markers are passing (as you have agreed) at the rate of 5.196E⁸/second. There is no basis for contracted space upon which to determine the markers are no longer the same physical 100 cm apart as compared to the rest frame or that the velocity is not 1.732c in the moving frame.

That is the assumption made using the rest frame velocity combined with the moving frame clock. You have to mix frames to fabricate a false illusion of length contraction.

Try again.

As I said you are a joke. You want to assume length contraction to create an arguement for length contraction. Try again. Stick with physics this time and not rhetoric.

Really. Then show that fact. Forget your 0.866c claim from the rest frame and show that the 5.196E⁸ meter markers/second does not equate to 1.732c. Rembember you cannot ignore the dilated tick rate of the clock and use d = vt.

"v" is not measured the same in the moving frame and you cannot ignore that t does not equal t' tick rates. The differance in time of the trip is completely accounted for by the dilated tick rate - NOT a contraction of spatial distance.

Correct. The meters and the seconds must be from the same frame, just as the meters/second must be from the same frame and you use meters/second from the rest frame to define velocity of the moving frame ignoring what the moving frame physics dictate, such as a dilated tick rate when computing the d = vt.

Sorry you need a course in simple arithmatic and basic physics. You need to be debriefed from the rhetoric you have been fed. There is no length contraction without mixing frame data. That assumption violates the evidence of the moving frame.

More appropriately there is no reason for him to assume, or even see a differance in such measurement. It only exists because you have attempted to force it to exist by mixing rest frame velocity with moving frame tick rate.

I am not making any such claim. I am showing the falicy of SRT claims of length contraction.

However, based on the emperical findings of time dilation of an accelerated clock (but not of an inertial clock that didn't accelerate) in cases of relative velocity, it would appear that is the case and we need to rethink our physics views.

Frankly that is no more odd than the assumption of "Velocity Addition", "Reciprocity" , "Relavistic Mass" or "Curved" or "Contracted" time-space; which is further stipulated to not exist in any fabric form. How does "Nothing" have physical properties and can be contracted and/or curved?

You might try actual physics.

“ Posted by MacM:"Now stick your superority complex up your ass. ”

I have made no such assumptions. The assumptions are being made by you. Those assumptions are that it matters not what basic physics principles dictate only the masters can be correct and not having a brain of your own you dare not attempt to apply any reason.

I dispute your assertion. As the extract posted above shows reciprocity infact requires precisely what I have merely quoted.

 

Pete,

Hardly. Try the moving clock and the moving ruler and a fixed and unchanged spatial dimension.

What have you missed about the rulers are the same and space has not changed dimension. You have no basis to claim it has. The only basis is to use the rest frame velocity combined with ignoring the dilated tick rate of the moving frame.

I hope you are just being deliberately obtuse.

We are talking about the moving frame velocity towards the original rest frame. (as seen by an inertial moving frame as being the original rest frame now moving toward him at 1.732c). Shssssh.

This issue is no different than the original rest frame having zero velocity and seeing the craft approaching at 0.866c. You are using your clock, your ruler and the rate at which the craft is passing the meter markers.

In my scenario the craft frame is using his clock, his ruler and the rate meter markers and the earth are moving closer to him.

Hardly. Please demonstrate how an invariant 'c' causes meters to change dimension for one frame and not the other.

Also that postulate is not valid to the exclusion of alternative explanations.

I.e - it is an illusion caused by there being different photons in the different frames and not the same photon having different scale velocity to satisfy the invariance to all observers regardless of relative motion.

I have. You haven't.

 

WHAT? Not hardly. Others stopped posting since they had no valid rebuttal to the issue of different photons in different frames view where the explosion would hence become simultaneous in all frames but not the view of light activation of the detonators.

 

Nice work granted. However, it must be noted that it is based on the assumption of recipocal time dilation and spatial length contraction (Reciprocity).

Which simply has not ONCE been demonstrated. I have never argued that SRT didn't advocate such results. I have argued such results have not been demonstrated and are nonsensical.

We should also note that the respective clocks claimed to have accumulated 1/2 the amount of time are Ta & Ed in the Embankment Frame and it is Td & Ea in the Train Frame.

This is not Clock A slower than clock B and clock B slower than clock A.

Further if you look at the 12:00 O'clock position of Ta in the Embankment Frame at the start and its 6:00 O'clock position at the end of the test.

That is in complete disagreement with the Train Frame where Ta starts at 12:00 O'clock and ends at 12:00 O'clock in the same physical test period.

You now have specific physical clocks recording two distinctly different accumulated times in the same test period. :bugeye:

WHICH DO YOU WANT TO CLAIM THE CLOCK WILL DISPLAY AT THE END OF THE TEST? IT CANNOT AND WILL NOT DISPLAY BOTH WILL IT.

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So the problem is as I have claimed. Not as to the mathematics of SRT and what it advocates but as to the physical reality of what it advocates.

The later is physically impossible. Thanks for making this even more clear to readers.

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Your meter markers are an Earth-frame ruler.
The spaceship clock is a spaceship-frame ruler.

I do not accept that a fixed and unchanging spatial dimension is a necessary assumption.

I do not accept your assertion that length is frame-independent.
Can you support this assertion?

It follows from the postulate of invariance of c.

How can one frame move towards another? A frame (any frame) is a coordinate system that encompasses all time and space.

The frames move relative to each other, or past each other or through each other if you want to visualise it that way.

So the spaceship has v=0.866c in the Earth frame, meaning the spaceship frame has v=-0.866c in the Earth frame.

In your scenario, you are explicitly using the spaceship clock and an Earth ruler. The meter markers are at rest in the Earth frame.

If you wish to determine the rate the Earth is moving in the spaceship frame, you need to determine how often they pass meter markers which are at rest in the spaceship frame.

 

Consider a Michelson-Morley type device:

A light emitter/detector is connected to two mirrors by two meter sticks at 90° to each other. One meter stick points to the North, the other to the West. The mirrors at the end of the meter sticks are aligned to reflect light back to the emitter/detector. The detector is rigged so that if it receives the reflections of two flashes at the same time (one from each mirror), it pops up a flag.


The emitter emits a flash of light.

Our postulate suggests that the speed of light is constant in all directions in the frame of the device as long as it's not accelerating. So if the postulate is true, the two flashes do in fact return at the same time, and the flag pops up.

OK so far?



Now, what about in a different reference frame? What if the device is proceeding North at some high speed v? If our postulate is true, what does that imply?

We know that the flag pops up. This is an unambiguous event that must be true in all reference frames. Therefore we know that the flashes return to the emitter/detector at the same time. We also know that the emitter fired a single time, so the flashes left the emitter/detector at the same time.

Therefore we know that the time taken for the flash to proceed along the North-meter-stick and back must be the same as the time taken for the flash to proceed along the West-meter-stick and back.


Now, is there any way that this could happen if the two meter sticks are the same length in the moving frame?

I'll give you a chance to work through the maths before I do it for you.

Deciphering your sentences is awfullly difficult sometimes. I think you mean that the constancy of the speed of light is possibly an illusion?

If so, then I'm sure you are correct. I'm sure there are all kinds of models that predict the same observations as SRT. I haven't examined Dr Dowdye's idea... it could be one of them for all I know.

 

Pete,

Hardly. Meter markers are distance markers in both frames. Clocks are time markers in both frames. Your assumption of a dilated clock being a ruler shows the falicy of SRT.

And that results in your acceptance of nonsensical physics.

Can YOU support SRT's assertion that it is frame independant? Certainy not by using velocity of one frame imposed on another frame where velocity is a mathematical function of m/s and you use a dilated clock to compute d = vt.

Without any question or hesitation it is most obvious that it is "t" that changed in this formula and not "d".

Not so. It follows from the distortion of basic physics by mixing data from frames and ignoring the emperical demonstrated fact of time dilation and the impact of that on the calculation using a common d = vt formula.

The correct method here is to first compute "v" of the frame using the local proper "t" and "d", not a distorted "d" using data from another frame.

What is your point. You are making no sense what-so-ever. Just as you assert that the craft is moving toward the earth at 0.866c and passing meter markers and the earth is at rest. In the craft frame the earth is moving toward the craft and meter markers are passing the craft while the craft is at rest.

Ah but that is a claim based on what?. Logic of relative velocity? Or physics based on emperical data considering actual physical time dilation?

Just as it has rightfully been pointed out in this forum, physics (nature) does not have to conform to our view of logic. That is the arguement made for the assertions of SRT.

I use the same basis here to argue that the only real physics that we have to work with says that your statement is false. That velocity defined as distance/second using local proper data says that when the earth observer sees the craft moving at 0.866c toward it, the craft sees the earth moving at 1.732c toward it and that distance remains unchanged.

But the only physics available upon which to make judgements indicates no change in the rulers between the rest ruler and the moving ruler.

That is merely a distortion created by SRT mixing frames (using d = vt as a standard between frames ignoring that the "t" component is known to have changed rates - measurement standards). "d" didn't change the "t" standard changed. You switched rulers when you switched frames and try to hide that fact.

No I don't. Because basic physics shows there is no differance in spatial seperation of the meter markers. They are an invariant standard.

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I will skip your exercise above since the answer exists in your concessions here.

The conclusion regarding the invariance of the SOL and its relavistic consequences are nothing more than assumptions about the measured invariance and is made without any consideration of alternative causes for such observations.

Relativity is a theory developed from a set of measured data (and limited to unilateral assumptions) in complete defiance of its illlogical and/or impossible consequences.

It seems far more rational to step back and realize that there are alternatives which are potentially equal if not perhaps superior to the antiquated conclusions from yester year.

But regardless of ones final opinion about the invariance of the SOL it makes no sense to continue to ignore the mixing of frame data that is being done to create SRT.

ONE way time dilation is physically real and that frankly is the complete and total extent of proof for any part of SRT based on emperical data. Spatial contraction and Reciproicity are not supported, nor are they logically acceptable.

Relavistic mass is indicated only indirectly but not to the exclusion of a decreased efficiency energy transfer view.

Overall there is very little support of the whole of SRT.

 

Yes. SR is indeed a model that relies on the invariance of light.
Yes, people do in fact think about other models.

Which is of course, the entire point of our discussions.
I think that you are wrong when you suggest that SR leads to impossible and/or illogical consequences.

Back to the exercise:

You argue is that SRT relies on length contraction to prove length contraction.
I argue that you are wrong again, that length contraction follows directly from the postulate of the invariance of c.

If you want to reject the postulate, then you are welcome to your opinion and I bid you good day.

Otherwise... do the exercise. Length contraction follows from invariance of c... like it or not.

Potentially equal. Forgive me if I leave the testing of potentially better models to those who are paid to do so, and stick with SR model unless and until:
1) Someone shows that it leads to impossible and/or illogical consequences, or
2) Someone shows that a new model is shown to produce more accurate experimental results.

You seem to think that no scientist wants to advance the state of human knowledge?
Do you really think that all the theoretical physicists of the world are twiddling their thumbs in complacency because they know everything?

 

Typo.
Your meter markers are an Earth-frame ruler.
The spaceship clock is a spaceship-frame clock.

If you want to calculate velocity, you need to use clocks and rulers from the same frame... as you agreed.

Typo, I think. SRT suggests that length is frame dependent. This follows directly from the postulate of the invariance of c, as shown.

It is not necessary to make that assumption, Mac.
And in fact, if c is frame-invariant, then length must vary between frames, as shown. Or as will be shown, if you bother trying the exercise.

What particular "basic physics" principles do you invoke? Or are you simply asserting that length is frame invariant?

 

Look closer, Mac. Pick any Train clock and any embankment clock. Compare the time that elapses on each clock over any duration. Do this in each frame, and tell us what you find.

Mac, you're trying to impose absolute simultaneity again. If the test ends when clock Te meets clock Ee, the time shown on the other clocks simultaneously with this event is frame-dependent according to SRT.

Come on, this is basic stuff.

 

Pete,

You don't seem to have given an appropriate amount of consideration to this fact.

*********************** Extract ***************************

[post=958782]Post[/post]

Further if you look at the 12:00 O'clock position of Ta in the Embankment Frame at the start and its 6:00 O'clock position at the end of the test.

That is in complete disagreement with the Train Frame where Ta starts at 12:00 O'clock and ends at 12:00 O'clock in the same physical test period.

You now have specific physical clocks recording two distinctly different accumulated times in the same test period. :bugeye:

WHICH DO YOU WANT TO CLAIM THE CLOCK WILL DISPLAY AT THE END OF THE TEST? IT CANNOT AND WILL NOT DISPLAY BOTH WILL IT.

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No but I do think the progress to that end is being damaged by block heads that refuse to think for themselves and depend on appeal to authority as a cover for their ignorance and arraogance.

No there are a few that speak out and actually consider alternatives.