Believers Beware

[James R]

Moderator note: Thread moved to Physics & Math.

This discussion is about the truth or falsity of Einstein's theory of Relativity, which is of course a legitimate scientific theory.

 

[Pete]

I have just a little time, so I'm going to address the original post without attempting to wade through everything in between.

You are aware that the theory precludes travel faster than light (FTL).

I disagree.
The theory precludes any object having FTL velocity in any reference frame in flat space.

For casual conversation, this equates to precluding travel faster than light... but there are tricky thought experiments like this one which require a more precise look at exactly what it does and doesn't preclude.

In your thought experiment, for example, the distance between the chevy and the cosmic object changes at sub-light speeds in all inertial reference frames.
In the chevy's non-inertial rest frame, the distance changes at a much greater rate - but this is not prohibited by the theory.

If you really want to get crazy, you could try looking at what happens to the cosmic object's age in the chevy's rest frame as it accelerates.

 

[MacM]

James R,

As usual, you're tying yourself in logical knots.

Thanks for making my prior point. This is a false and absolutely worthless unsupported innuendo.

That statement is false. Which clock dilates depends on your frame of reference.

Two false comments in a row. Which clock "physically" dilates only depends on which clock accelerated. The dilation as viewed from respective frames is an illusion of measuremnt during relative motion and does not reflect the actual physical affects on clocks.

That's exactly what SR does. It tells you what a clock will read when you observe it from a frame other than its rest frame.

Three in a row. You going for some kind of record. As I have stated numerous times this issue has NOTHING to do with readings of observers in motion.

That's the whole point of relativity.

Not really. The main objective was to describe physical reality. Observations in motion are nice but they won't tell you which clock is physically accumulating less time.

Correct. But SR makes predictions that have been tested and verified over and over for 100 years and found to be correct.

I hve made no comment about the utility of the gamma function. Nothing wrong with that. It is it's application by Einstien in the erroneous assumptions about SR that is the issue.

So the fact that you can calculate properties of an accelerated particle that's great but that is only using the Lorentz gamma function which Einstien incorperated into SR. SR is only the extension of the relativity principle to declare equallity of frames and incorrectly advocating relative veloicty (not actual velocity due to acceleration) ass a cause.

The SR view that each clock loses time is false, only one loses time and it is the one that accelerated. The relative velocity affect is to only cause both to "Appear" to be losing time but only the one is actually losing time

If you still want to argue otherwisde I still await your posting of emperical data which shows that the inertial resting clock accumulated less time than the accelerated clock. To win this discussion that is all yo have to do - now produce or admit it is ONLY the accelerated clock which will lose time.

You use of the term "energy levels" sounds like how a new-age nut would use the term. I doubt you know what an "energy level" is. You're so vague that your statement is useless.

More worthless babble and innuendo. Energy level is a very appropriate term and is understood by virtually everyone but apparently you. We have been after all talking about object in motion and velocity, so just what do you think energy level might mean? Kinetic perhaps?

Now you're arguing against yourself.

Still more worthlews babble and innuendo. When you have no good rebuttal you just ramble on don't you.

You have previously agreed that the postulates of SR are correct, on multiple occasions.

Absolutely false. I have never agreed that the invariance of light is as described. I hae only agreed that it appears invariant but I have always qualified that as being an illusion of origin being a function of a specific energy. Thing of it like a phase change. When and ONLY when relative energy is a certain value does the EM become produced or measureable.

The difference is incredable. It means there is no relativity as curently assumed because different observers with different relative velocity to the source are not seeing the same photons.

Emperically the relativitvity principle is still present due to time dilation. That is a Lorentz gamma function but no SR reciproicty or spatial contraction nonsense. It isn't required and we are better off without it.

You can't have it both ways. Either the postulates are "rather stupid assumptions", or they are not. If you say they are rather stupid, you need to show that they lead to some kind of inconsistency or unphysical result. But if you agree with them, then you implicitly agree with all results that follow from them.

I do not and have not agreed with them as conventionaly advocated and I have posted the irratinal consequences of their erroneous application. I think that is made clear above so I'll not repeat myself here.

On the contrary, any introductory text on relativity explains exactly these things, carefully and explicitly.

If that is so then why do you and so many other purportedly educated individual continue to mis-represent simultaneity as the cure all for arguements against SR. It isn't. In fact it buttresses the point. Observed time dilation of both clocks is the consequence of reading their time at different times. What a lot of crap. The IRS code is more meaningful and coherent.

Your "common sense" has got you nowhere. And you have failed to show any deficiency in SR, despite your labelling it as "assinine".

More babble. I have gotten quite far and will be going much further - Thank You. And I have shown multiple assinine aspects of SR. As I have also said the mathematical consistancy is ONLY achieved through bad science.

That is the failure to retain different time standards when switching frames. While you claim time is dilated in a moving clock frame (and emperical data supports that but not physically dilated as a consequence of mere relative motion) but then you equate clock ticks in one frame to the ticks in the resting frame and because the clocks accumulate different time you falsely claim the clock with less time traveled less distance.

Now it either ticked slower and distance remained constant (my view) or it ticked the same and did travel less distance. Pick one but stop mixing standards when you do calculations.

This is your idea of simple, is it?

Yep. And I see you really have no rebuttal. It is more rational and doesn't have remote object get clooser the faster you fly away from them. What a relief eh?

I remind you again: you agree that the postulates are correct.

I remind you again the agreement is only to the measrement not the cause and affect.

Hence, you leave yourself no wiggle room. You are logically compelled to agree with all results derived from the postulates that you agree are correct.

Not hardly. Understanding that the imeasured invariance is actually measuring different photons which are being generated as a function of a specific relative energy level and are not the same photons existing at different times and places as is now assumed, is a major benefit to eliminating the hogwash caused by the narrow minded view currently held.

I have never agreed with your postulates. In fact, I don't think I've ever seen a clear statement of them.

No problem I don't expect to have you as a convert but neither will I allow you to distort what I've said or my views. Feel free to actually provide sound physics rebuttals but your rhetoric and innuendo are meaningless.

You're the one trying to overturn 100 years of accepted physics, not me.

Not so. I am merely pointing out for other the problems with current physics and making suggestions about possible alternatives. Your problem is you refuse to seriously consdier any alternative until it has been universally accepted. Sort of a coat tail ahnger on attitude. Afraid to be on the outside looking in I guess. Better to be in the in crowd and accepted by the masses. Doesn't matter just how entrenched your view is does it.

If you don't mind that every respectable physicist considers you to be a crank, that's fine. But do I wonder why you keep rabbiting on about something you say you don't care about.

Now that shows your bias if I've ever seen it. "Ever respectable physicist..."??? I suppose you get to choose who they are and they are only those that agree with you or at least disagree with me because I have several physicists that do agree with me much to your displeasure.

But as I recall you immediately referrred to them as cranks too even though you didn't even know who they were. So what should that tell everyone - Hmmmmmm?

 

[MacM]

First let me say I am completely surprised at the move of this thread. I think it is a good thing. lol Thanks James R.

I have just a little time, so I'm going to address the original post without attempting to wade through everything in between.

I disagree.
The theory precludes any object having FTL velocity in any reference frame in flat space.

Hello Pete, been a while. I have posted comments by a particle physicist and links he provided which show that indeed distance does change FTL BUT it is not seen by the observer. That is objects that reach v = c and then distance changes FTL beyond that become hidden behind an event horizon.

Things actually vanish until the acceleration dimenishes the change in distance to become sub-luminal again.. I find that interesting in that I predicted the same result in my own work (not formally mathematically of course but just ad libbed that conclusion).

For casual conversation, this equates to precluding travel faster than light... but there are tricky thought experiments like this one which require a more precise look at exactly what it does and doesn't preclude.

In your thought experiment, for example, the distance between the chevy and the cosmic object changes at sub-light speeds in all inertial reference frames.

In the chevy's non-inertial rest frame, the distance changes at a much greater rate - but this is not prohibited by the theory.

If you really want to get crazy, you could try looking at what happens to the cosmic object's age in the chevy's rest frame as it accelerates.

I have no objection to the balance of your post.

 

[MacM]

Moderator note: Thread moved to Physics & Math.

This discussion is about the truth or falsity of Einstein's theory of Relativity, which is of course a legitimate scientific theory.

I do have one technical question.

How is it we keep refering to SR as a theory? The rules are it must be testable and falsifiable to be considered a valid theory.

Aspects of SR are untested and are untestable - i.e the reciprocity and spatial contraction claims.

I suggest rather that SR is just a hypothesis.

 

[Pete]

Hello Pete, been a while.

And it shows - I just noticed a mistake in an important sentence in my last post. It should read:
The theory precludes any object having FTL velocity in any inertial reference frame in flat space.

So you see that the premise of your thread is a non-sequitur.
Yes, distance between the cosmic object and the chevy changes FTL in the chevy's rest frame.
No, this isn't precluded by SR.

I have posted comments by a particle physicist and links he provided which show that indeed distance does change FTL BUT it is not seen by the observer. That is objects that reach v = c and then distance changes FTL beyond that become hidden behind an event horizon.

This is a pretty irrelevant sidetrack, I think... it encourages confusion between what events the chevy is actually seeing and what events are happening simultaneously with the chevy in the chevy's frame.
Anyway, I don't have time to hunt through the thread to find those comments, but a couple of things are kind of interesting:

Firstly, the chevy's event horizon would be behind it. There would only be a horizon between the object and the chevy in the chevy's accelerating frame if the chevy is accelerating away from the cosmic object.

Things actually vanish until the acceleration dimenishes the change in distance to become sub-luminal again.

That's a pretty vague description... and I'm not sure that it's accurate, even for the case of the chevy accelerating away from the object.
Strictly speaking, the cosmic object will never completely disappear but will become more and more red-shifted - as you'd expect for something that you're accelerating away from.

I'm not sure exactly how the object's appearance would relate to the rate of change of it's distance away in the chevy's frame. I don't think any relationship would be trivial.

 

[James R]

Moderator note: Thread moved back to Pseudoscience, following a discussion among the moderator group.

The OP of this thread assumes without evidence that Special Relativity is false.

This decision was based on the following policies, outlined in a thread linked from the Physics & Math FAQ

...

3. Posters who are critiquing accepted physical or mathematical ideas should clearly point out what is wrong with those ideas, providing clear examples showing where the accepted theories are or may be incorrect. Preferably, such examples should be testable, backed by evidence of some kind or (in the case of mathematical criticisms) accompanied by proof.

4. Posters putting forward alternative theories should clearly explain the basic ideas of their theory, how their theory differs from conventional theories, and how their theory is likely to improve on accepted theories. Explanations should be backed by evidence. Theories should be testable and falsifiable. In short, alternative theories must be classifiable as science rather than pseudoscience.

5. Threads which are blatantly unscientific, which push ideas which are unfalsifiable (at least in principle), will be immediately moved to the Psuedoscience forum. Ideas which have been widely rebutted elsewhere, such as "pyramid power", alien visitations and so on, will be moved, as will discussions which are primarily religious in nature.

6. Threads which contain alternative ideas which have previously been effectively rebutted on this forum in replies to the particular poster concerned will be moved to the Pseudoscience forum. If a poster cannot accept legitimate criticism of his or her pet theory, discussion on this forum is not going to be of much value.

 

[James R]

MacM:

I have made no comment about the utility of the gamma function. Nothing wrong with that. It is it's application by Einstien in the erroneous assumptions about SR that is the issue.

So now you're claiming that while all the mathematics of special relativity is correct, the meaning of its mathematical results is somehow incorrect. How that could be the case is a mystery.

More worthless babble and innuendo. Energy level is a very appropriate term and is understood by virtually everyone but apparently you.

Define "energy level" for me.

We have been after all talking about object in motion and velocity, so just what do you think energy level might mean? Kinetic perhaps?

I have no idea what you mean by it.

You have previously agreed that the postulates of SR are correct, on multiple occasions.

Absolutely false. I have never agreed that the invariance of light is as described.

This is a change from your previous statements.

Let us be clear. Are you asserting that the speed of light is NOT invariant in all inertial frames of reference? A simple YES or NO, please.

The difference is incredable. It means there is no relativity as curently assumed because different observers with different relative velocity to the source are not seeing the same photons.

Relativity doesn't depend on observers seeing the same photons.

You can't have it both ways. Either the postulates are "rather stupid assumptions", or they are not. If you say they are rather stupid, you need to show that they lead to some kind of inconsistency or unphysical result. But if you agree with them, then you implicitly agree with all results that follow from them.

I do not and have not agreed with them as conventionaly advocated...

Then state your preferred modifications of them in a clear manner. What do you wish to replace them with? What are MacM's postulates of MacM relativity?

If that is so then why do you and so many other purportedly educated individual continue to mis-represent simultaneity as the cure all for arguements against SR. It isn't.

Straw man.

While you claim time is dilated in a moving clock frame (and emperical data supports that but not physically dilated as a consequence of mere relative motion) but then you equate clock ticks in one frame to the ticks in the resting frame and because the clocks accumulate different time you falsely claim the clock with less time traveled less distance.

I can't made any sense of this muddle.

Your problem is you refuse to seriously consdier any alternative until it has been universally accepted.

On the contrary, I spent a considerable amount of time seriously examining your efforts at creating a new theory, several years ago. At the time, I pointed out a number of reasons for why your theory was and is useless.

...I have several physicists that do agree with me much to your displeasure.

Then get them here and I'll argue with them instead. Perhaps they'll make more sense than you do.

 

[MacM]

And it shows - I just noticed a mistake in an important sentence in my last post. It should read:
The theory precludes any object having FTL velocity in any inertial reference frame in flat space.

So you see that the premise of your thread is a non-sequitur.
Yes, distance between the cosmic object and the chevy changes FTL in the chevy's rest frame.
No, this isn't precluded by SR.

Now if you had read carefully you would have seen I pointed out in fact that SR doesn't preclude the motion but hides in behind an event horizon.

This is a pretty irrelevant sidetrack, I think... it encourages confusion between what events the chevy is actually seeing and what events are happening simultaneously with the chevy in the chevy's frame.
Anyway, I don't have time to hunt through the thread to find those comments, but a couple of things are kind of interesting:

Firstly, the chevy's event horizon would be behind it. There would only be a horizon between the object and the chevy in the chevy's accelerating frame if the chevy is accelerating away from the cosmic object.

No actually there is another set of mathematics that deals with the FTL motion when aproaching approaching.

That's a pretty vague description... and I'm not sure that it's accurate, even for the case of the chevy accelerating away from the object.
Strictly speaking, the cosmic object will never completely disappear but will become more and more red-shifted - as you'd expect for something that you're accelerating away from.

I'm not sure exactly how the object's appearance would relate to the rate of change of it's distance away in the chevy's frame. I don't think any relationship would be trivial.

The mathematics states it is hidden by the event horizon (it only becomes red shifted upto v=c.

 

[Reiku]

Gee whiz... this thread moves about like a dizzy electron...

 

[Pete]

Now if you had read carefully you would have seen I pointed out in fact that SR doesn't preclude the motion but hides in behind an event horizon.

So you backed down from your stance in your original post.
Then I guess the main point of the thread is done, and we can sidetrack.

No actually there is another set of mathematics that deals with the FTL motion when aproaching approaching.
...
The mathematics states it is hidden by the event horizon (it only becomes red shifted upto v=c.

Perhaps you could show us the mathematics of which you speak?

Both results that I stated are pretty trivial from looking at a spacetime diagram of an accelerated particle (from Wiipedia):

The diagram shows the cosmic object's rest frame (the initial inertial rest frame of the chevy).
The curved line is the chevy's worldline.
The 45 degree line from the bottom left to the top right of the diagram is the accelerating chevy's event horizon.
The cosmic object's worldline will be a vertical line in that diagram.

If the chevy is approaching the cosmic object, the cosmic object will be off to the right somewhere. Clearly not behind the event horizon.

If the chevy is departing from the cosmic object, the cosmic object will be somewhere to the left of the chevy. Light that left the object before it crosses the horizon will continue to cross the path of the chevy indefinitely - only more and more red-shifted.


Looking at the debate you had with Don Lincoln (two years ago), I think the problem may come from this poorly phrased sentence:

Now while it is true that you do not see the Earth, because it is far away and outside the event horizon, there is a train of light in transit from the Earth. The light that was inside the event horizon continues to travel through space and arrives at the electron, with a Doppler shift that is appropriate for the velocity. There is nothing bizarre going on there.

What do you think Dr Lincoln actually means here?
He should have been more careful to clearly distinguish between what is visually seen right now (ie light arriving at an observer from past events) and what will eventually be seen of events happening right now.


This is a longish post, so let me briefly summarize so far:

• A moving event horizon forms behind an accelerating observer.
• Events that happen behind the event horizon will never be seen by that observer
• Objects which cross the event horizon (eg when the object begins accelerating) will not visually disappear. The accelerating observer will continue to see light that left the object in the past.

Now, consider your chevy.
The cosmic object it sees is an object from 3bn years past. That object might not exist in the present.
If it does exist in the present in some form, then the present object will disappear behind an event horizon if the chevy accelerates away from it. The chevy will never see the object in its present form as long as it continues to accelerate away.

However, the light from 3bn-years-in-the-past object will not be behind the horizon, and the chevy will still see it.

 

[MacM]

Pete,

So you backed down from your stance in your original post.
Then I guess the main point of the thread is done, and we can sidetrack.

Not sure what you think you read but I haven't backed down on anything. What do you think is different.

Perhaps you could show us the mathematics of which you speak?

The trailing event horizon link is posted. I'll have to go looking for the approaching math.

 

[Pete]

Your original post:

A theory that prohibits FTL travel actually creates it.

Your previous post:

Now if you had read carefully you would have seen I pointed out in fact that SR doesn't preclude the motion..

 

[MacM]

Your original post:


Your previous post:

I see no conflict here. Perhaps we speak in differernt languages.

SR does prohibit FTL travel and it is routinely cited by relativists.

But it also creates it under non-inertial conditions. Since relativists like to argue that SR is only valid for inertial conditions they ignore that consequence of the theory.

But ignoring physical realities or consequences of a theory is just plain stupid and bad science.

Further they ignore the fact that SR also applies to non-inertial conditions and that there are mathematics to deal with that which include FTL.

The original post was "Beware" and meant to inform those that aren't aware of these facts.

There is nothing in my position or posts that are contriversial or in conflict.

 

[Pete]

SR does prohibit FTL travel and it is routinely cited by relativists.

No, SR prohibits FTL travel in inertial frames in flat space.
You agreed only a post ago that SR doesn't preclude FTL travel in an accelerating frame.

Why do you contradict yourself?

 

[draqon]

pete is telling us all, screaming it to us, to make a wormhole of a sort to travel faster than light relative to flat space.

 

[MacM]

No, SR prohibits FTL travel in inertial frames in flat space.
You agreed only a post ago that SR doesn't preclude FTL travel in an accelerating frame.

Why do you contradict yourself?

No contridiction and why do you continue to distort the basis for this thread. SR DOES prohibit FTL in flat space and virtually every relativists tries to insist that SR is only valid in flat space.

My point and it is substantiated is that SR is also applicable in a non-inertial frame and in that frame FTL does occur. It is mathematically recognized and dealt with using SR.

The issue here is the double talk posited by relativists. I am making it clear to others that in spite of claims by relativists FTL does occur and futher that is IS NOT prohibited by SR since SR CAN also be applied to a non-inertial frame.

So the issue is NOT actually about SR but about the false representations of SR by relativists AND the consequences of SR in the real world universe, not just the artificial, theoretical world of an inertial frame.

Surely you recognize that there is NO known frame that is truely inertial. To be so would be to claim an area of the universe devoid of gravity.

 

[MacM]

James,

So now you're claiming that while all the mathematics of special relativity is correct, the meaning of its mathematical results is somehow incorrect. How that could be the case is a mystery.

No mystery what-so-ever. If you assume the theoretical basis for the mathematical formulas are false then the results are most certainly false or are correct only under special or limited accidental conditions.

Define "energy level" for me.

There are of course many forms of energy but all have units and the numerical value applied to those units represent level - i.e. 1,000 Watts/sec is certainly a different level of energy than 100 Watts/sec.

I have no idea what you mean by it.

Then you need to try harder and stop being closed minded.

This is a change from your previous statements.

Let us be clear. Are you asserting that the speed of light is NOT invariant in all inertial frames of reference? A simple YES or NO, please.

The answer is not a black and white - Yes or No. I have agreed that light measures invariant but that what we measure at different velocities to the source is not the same photon and hence has no emputus to mandate a relavistic principle.

Put in simple format for those of you that have trouble following:

If Bill and Joe are identical twins and drive identical cars except Bill's car is lighter blue than Joe's;

Bill is driving 30 Mph west on I10 and I am driving east on I10 at 30 Mph on Fri such that at mile marker 100 I measure Bill's relative velocity as we pass to be 60 Mph. I notice the shade of blue of his car.

But then on Sat while driving east on I10 at 40 mph and Joe is driving west on I10 at 20mph we pass at mile marker 150 and I measure Joe's velocity as 60mph but note that his car is more blue in color.

I may have noted that regardless of how fast I am driving the vehicle I pass (which appears to be the same but blue shifted in color) always has a velocity of 60 mph but passes at a different location and time.

NOTHING about this says anything about physics and that is the very situation with the invariance if that measured invariance is due to photon production as a function of observer energy to an EM excitation source.

I anticipate that excitation signal travels instantaneously just as in particle entanglement but the photon is only produced at the v = c energy level relative to that signal.

Relativity doesn't depend on observers seeing the same photons.

If they don't then it says absolutely nothing about spatial contraction or time dilation. See Bill and Joe above.

Then state your preferred modifications of them in a clear manner. What do you wish to replace them with? What are MacM's postulates of MacM relativity?

Suggested Postulates:

1 - EM Radiation production or measurement is a function of a specific energy (equivelent to v = c) to an entanglement type excitation source and hence photons are created at different times and locations as a direct function of observer velocity c+v or c-v, such that EM appears to be invariant between frames.

2 - The issue of the gamma function (hence the only relativity) for time dilation is a completely seperate issue based on actual motion not mere relative motion. That is the only observer to experience time dilation is the observer that has the greatest collective F = ma from their common rest origin.

3 - Spatial distance and proper length of massive object are fixed but measurement of physical dimensions of mass or matter contracts in the direction of motion by the gamma ratio of relative velocity to the observer making the measurement.

4 - There is NO unique enity known currently as space-time but only time and space. Simple physical principles with a gamma function for tick rate based on acceleration history universally.

Straw man.

I see you had no bonafide response.

I can't made any sense of this muddle.

Incredilbe.

1 - You claim physical time dilation and emperical data shows clocks that have been accelerated lose accumulated time. The relative tick rate is set by the gamma function as a function of relative velocity (note relative velocity of the accelerated clock is ACTUAL velocity whereas relative velocity of the resting inertial clock isn't and the resting clock suffers no recipocal loss even though it has the same RELATIVE velocity).

2 - If you accept time loss as a physical reality you must either contribute that to a dilated tick rate (which I prefer) OR to the clock having traveled less distance (which I reject)

3 - In SR you ignore the dilated clock tick rate in the moving frame and then assert that the accumulated time loss is due to traveling less distance. That is you have different physical affects for each frame.

Not only un-necessary but creates numerous "Counter Intuitive" conditions (polite words for ludricrus or impossible conditions).

4 - Velocity (V) IS the mathematical ratio of two physical parameters. D is distance and T is time. "d" is change or delta). V = dD /dT.

Given a measured time loss dilated tick rate to be T1 = 1; T2 = 0.5*T1 and retaining that tick ratio as a physical reality in all frames, where D=1 and is equal between frames, then what you have is:

V1 = dD / dT1 = 1 / 1 = 1.0

V2 = dD / dT2 = 1 / 0.5 = 2.0

While universally we can see that there is only one absolute universal velocity the observers will COMPUTE different velocities (V) because of their different proper times (time tick rate standards) used to compute the ratio dD/dT.

It is simply bad science to claim computed:

V1 = V2 hence:

D1 = V1 * T1 = 1 * 1 = 1

D2 = V2 * T2 = 1 * 0.5 = 0.5

while one T is ticking at a different rate than the other.

Since universal relative velocity is absolute and equal Einstein erroneously used that fact in lieu of measured or computed velocity thereby forcing distance to change.

It is really a very simple matter to envision that distance and time are the physical realities and the computed value V=dD/dT varies as a function of actual motion (motion due to F = ma acceleration - not mere relative velocity) and the gamma function produced by that motion (note no physical gamma function has ever been recorded for the inertial resting clock).

On the contrary, I spent a considerable amount of time seriously examining your efforts at creating a new theory, several years ago. At the time, I pointed out a number of reasons for why your theory was and is useless.

Sorry but you haven't once grasped the issues or how the alternative works. That is evident by your own stated inability to understand the concept. That may well be my shortfall in presentation but I really don't see how it can be presented differently.

 

[Neddy Bate]

Hi Pete,

The theory precludes any object having FTL velocity in any inertial reference frame in flat space.

Yes, distance between the cosmic object and the chevy changes FTL in the chevy's rest frame.
No, this isn't precluded by SR.

In your thought experiment, for example, the distance between the chevy and the cosmic object changes at sub-light speeds in all inertial reference frames.

This is news to me. I have never seen this mentioned in any of the basic SR lessons, or twin paradox resolutions. If it is an accurate statement, I sure wish someone would have told me this sooner. It might have helped me make sense of what is really supposed to be going on in SR.

It would seem to me that, in the Chevy's reference frame, the FTL (faster than light) velocity of the cosmic object is the result of length contraction of the entire reference frame of the cosmic object. This change in distance takes place during the time that the Chevy is accelerating, which can be an arbitrarily brief period of time.

Am I to understand that there is no length contraction of the Chevy's reference frame as realized from the cosmic object's reference frame, simply because the cosmic object does not accelerate by F=ma (to borrow MacM's terminology for real acceleration)?

If you really want to get crazy, you could try looking at what happens to the cosmic object's age in the chevy's rest frame as it accelerates.

I have been trying to understand this age puzzle by considering that, in the accelerated reference frame, the formerly-synchronized clocks throughout that frame begin to run at different rates (depending on their height in the pseudo-gravitational well caused by the acceleration) and that this is true in all reference frames including the accelerated one. This would mean that, after the acceleration is over, the clocks would have to be re-synchronized before we could re-establish this inertial frame as being on "equal footing" to the unaccelerated frame (in that clocks are synchronized in their own frame, at least). Only then can we say that each of the two inertial frames are just as valid, and eachj believes the other frame to have the slower ticking clocks, etc.

 

[MacM]

Hi Pete,


This is news to me. I have never seen this mentioned in any of the basic SR lessons, or twin paradox resolutions. If it is an accurate statement, I sure wish someone would have told me this sooner. It might have helped me make sense of what is really supposed to be going on in SR.

It would seem to me that, in the Chevy's reference frame, the FTL (faster than light) velocity of the cosmic object is the result of length contraction of the entire reference frame of the cosmic object. This change in distance takes place during the time that the Chevy is accelerating, which can be an arbitrarily brief period of time.

Am I to understand that there is no length contraction of the Chevy's reference frame as realized from the cosmic object's reference frame, simply because the cosmic object does not accelerate by F=ma (to borrow MacM's terminology for real acceleration)?



I have been trying to understand this age puzzle by considering that, in the accelerated reference frame, the formerly-synchronized clocks throughout that frame begin to run at different rates (depending on their height in the pseudo-gravitational well caused by the acceleration) and that this is true in all reference frames including the accelerated one. This would mean that, after the acceleration is over, the clocks would have to be re-synchronized before we could re-establish this inertial frame as being on "equal footing" to the unaccelerated frame (in that clocks are synchronized in their own frame, at least). Only then can we say that each of the two inertial frames are just as valid, and eachj believes the other frame to have the slower ticking clocks, etc.

Excellent post Neddy. I'll let Pete answer since you asked him the questions but I just wanted to emphasize the believes aspect of SR. This is where my argument has been for many years now.

"Relative Velocity" only causes the perception of slower ticking. The "Actual Velocity" by the accelerated clock "Actually" loses accmulated time.

And you are correct this FTL aspect of SR in the real world physics is generally ignored and even denied by most relativists.