SRT and relative velocities addition

[Xgen]

There is something that bothers me about SRT. The recent threads in SciForums about Simultanity and Reciprocity only more deepen my concern.

In all SRT equations the terms include only V - the relative velocity between 2 frames, not the their absolute velocities. All problems seem to arise from this. If we know only V we cant know which frame is moving and which is stationary. And I doubt that we can calculate propertly the relativity effects in local units if we know only the relative velocity between them. I had obtained two different sets of equations for the time dilation of a frame. The first is based on SRT and the second of the notion for Absolute Space. The problem stands and in SRT only.

1. Time Dilation in SRT

Lets Have two frames A nd B with velocities wrt frame in rest - C (which I will denote as Absolute Space /AS/) - Vac and Vbc,

then their relative velocity will be:

Vab = (Vac + Vbc) / ( 1 + (Vac * Vbc) / c ^2)

the time dilation of say A in the units of B will be

Eq 1: dta = dtb / sqrt (1 - v^2/c^2),


this equation is the same if we represents dilation in B with units of A, which is the first problem - the problem with Reciprocity, we cant know which frame is moving faster and which slower, dtb is always bigger then dta.

2. Time dilation based on the notion of Absolute Space

dta = dt * sqrt (1 - vac^2/c^2)
dtb = dt * sqrt (1 - vbc^2/c^2)

then dilation in B with units of A:

Eq. 2 : dta/dtb = sqrt (1 - vac^2/c^2) / sqrt (1 - vbc^2/c^2)

this equation is not anymore reciprocal and has nothing to do with obtained before equation. dta can be not only bigger but smaller then dta. I dont know if it can at all be expressed with the relative velocity v between frames. I couldn't obtain Eq1 from Eq1.

Does any of you has some idea how to solve this? How relative velocities addition equation had been obtained anyway?

[Pete]

In all SRT equations the terms include only V - the relative velocity between 2 frames, not the their absolute velocities. All problems seem to arise from this. If we know only V we cant know which frame is moving and which is stationary.

Yes - that's the whole point.

And I doubt that we can calculate propertly the relativity effects in local units if we know only the relative velocity between them.

Why do you doubt it? Have you examined the theory in detail?

[Pete]

The rejection of absolute space is based on false assumptions of there only being two referances in the universe

Mac, are you seriously maintaining that SRT can't be applied over more than two frames?

Is this a ploy, or do you really believe it to be true?

[James R]

An off-topic post about GPS has been deleted.

[MacM]

Mac, are you seriously maintaining that SRT can't be applied over more than two frames?

Is this a ploy, or do you really believe it to be true?

It is a fact that SRT only considers relative veloicty between two observers at a time. Since the universe consists of more than two observers the calculations using all available (or sufficient information) to actually discern who has what magnitude of relative motion is an asset and removes the reciprocity consequence of just looking at two.

Instead of claiming what is wrong with looking at just two, you should be asking "what is wrong at looking at three or more".

If there is no reason to not consider such informtion it makes no sense to limit our understanding to just two points of view. That distorts reality.

Why not claim that all physics must be computed in total isolation. That is every observer stands alone. Now we have no velocity etc upon which to even concern ourselves. Physics would become so much more simple don't you think?

Of couse that is stupid but not much more stupid than rejecting the reality of more than two referance points which yields even greater information from which to make analysis.

[James R]

Why not claim that all physics must be computed in total isolation. That is every observer stands alone. Now we have no velocity etc upon which to even concern ourselves. Physics would become so much more simple don't you think?

Of couse that is stupid...

Yes, it is stupid, because obviously we see objects moving around us.

[Pete]

It is a fact that SRT only considers relative veloicty between two observers at a time.

I suggest you check that again, Mac. You seem to be stuck in the first half of the Beginner's Guide to Special Relativity, where only two-body situations are discussed.

Don't you recall our tedious analysis of the three-clocks problem? The one that bogged down into your attempt to prove that simultaneity is absolute?

[MacM]

Yes, it is stupid, because obviously we see objects moving around us.

My point exactly. It is equally stupid to describe the universe and phenomena claiming the motion between two observers must be treated in absence of other information which shows a different perspective and eliminates the reciprocity inherent in such a arbitrary and false two point view of the universe.

Just as there is more than one object in the universe, there is damn well more than two. Using more than two suggests a totally different picture of the universe than SRT. By what basis do you claim a superiority of views using the restricted two point assumption?

NONE.

[MacM]

I suggest you check that again, Mac. You seem to be stuck in the first half of the Beginner's Guide to Special Relativity, where only two-body situations are discussed.

Not at all. It is however, this view which creates the initial error. The multiple point view is further clouded by Velocity Addition. Once you admit that there is no reciprocity as inherent and advocated by SRT (hence SRT is falsified) then we will move onto the next step.

If SRT is falsified at the primary level it is assinine to suggest it is valid in multiple views isn't it.

Don't you recall our tedious analysis of the three-clocks problem? The one that bogged down into your attempt to prove that simultaneity is absolute?

Not at all. Have you forgotten that the Three Clock Paradox was my thread? Further it became bogged down because participants such as chroot refused to follow the computations once the result became clear by claiming simultaneity precluded any such expeiment from being done.

Further do you recall that I have shown it can be done using preset, precalculated simultaneity offsets and timers. Not to mention the fact that I have shown that such synchronization need not be part of any test of the concept since tick rates are not subject to simultaneity, only accumulated time in a given period is subject to simultaneity.

So in stark contrast to your innuendo, I am very much still in control of this issue. You nor anyone has effectively rebutted the issue. You have simply chosen to try and dodge, distort and leave the playing field in a huff.

The experience has been good for me in that it has helped me focus on the key issue and to find ways around the dubious arguements posted against me.

Now perhaps you would like to prove your superior view by posting example data of bonafide cases of reciprocity proving SRT for the first time. You might even get the nobel for that.

[James R]

Using more than two suggests a totally different picture of the universe than SRT. By what basis do you claim a superiority of views using the restricted two point assumption?

There is no "two point assumption" in SR.

The Lorentz transformations tell us how to translate physical quantities between any two reference frames. They can be applied to translate physical quantities of 1 billion different objects between 2 reference frames, if you like.

Do you want 3 reference frames? No problem. The Lorentz transformations will allow you to translate the physical quantities for your billion objects between frames A and B, or A and C, or B and C. Knowing the quantities in any one of the three frames, you can calculate what they will be in the other two frames?

3 frames not enough? Why not try 1 million frames, with a billion objects? No problem for SR. If you measure some physical quantities of your billion objects in just ONE frame, SR can tell you what values those quantities will have in all of the other 999,999 frames.

SR is not restricted. MacM just doesn't understand it.

[MacM]

There is no "two point assumption" in SR.

The Lorentz transformations tell us how to translate physical quantities between any two reference frames. They can be applied to translate physical quantities of 1 billion different objects between 2 reference frames, if you like.

Do you want 3 reference frames? No problem. The Lorentz transformations will allow you to translate the physical quantities for your billion objects between frames A and B, or A and C, or B and C. Knowing the quantities in any one of the three frames, you can calculate what they will be in the other two frames?

3 frames not enough? Why not try 1 million frames, with a billion objects? No problem for SR. If you measure some physical quantities of your billion objects in just ONE frame, SR can tell you what values those quantities will have in all of the other 999,999 frames.

SR is not restricted. MacM just doesn't understand it.

Stop trying to transform between multiple two point referances and compare such referances to determine who has what component velocity in the total relative velocity as depicted by SRT two referance points.

It has already been shown that a direct two point referance DOES NOT compute a proper time dilation except in cases where such view is a special case of three points where one of the two are at rest to the third point.

Why do you insist on misapplying that which does work in SRT so as to destroy SRT altogether. Your method leads to inherent reciprocity which not only has never been observed or detected but clearly is a physical impossibility. Give it up and move one.

[James R]

It has already been shown that a direct two point referance DOES NOT compute a proper time dilation except in cases where such view is a special case of three points where one of the two are at rest to the third point.

Nothing of the kind has been shown.

If you want to discuss that idea, consider a simple example, below. I am introducing this to avoid bringing in complicating factors, such as occur in your favorite case - GPS, which you don't understand properly, and which requires both GR and SR.

Clock A is "stationary" on an asteroid, somewhere in deep space.
Clock B moves at 0.6 c, away from Clock A.
Clock C moves at 0.8 c, also away from clock A, and on the same line of motion of clock B.

At a certain time, all three clocks are located at the same point in space (at the asteroid). At that time, they are set to zero time.

All clocks run in A's reference frame until A has ticked off 1 million seconds. At precisely 1 million seconds, as recorded on A's clock, all clocks are stopped simultaneously (according to A). The clocks are then brought back together and their displayed times compared on the asteroid.

Question: What are the readings on clocks A, B and C?

Answer from special relativity:

A: 1,000,000 seconds.
B: 800,000 seconds.
C: 600,000 seconds.

What is MacM's answer? Are these results a "proper time dilation", in MacM terms? Or not? If not, what's wrong?

[MacM]

Nothing of the kind has been shown.

Question: What are the readings on clocks A, B and C?

Answer from special relativity:

A: 1,000,000 seconds.
B: 800,000 seconds.
C: 600,000 seconds.

What is MacM's answer? Are these results a "proper time dilation", in MacM terms? Or not? If not, what's wrong?

Thanks for making my point. Your "A" is the third point which is common at rest to B & C. In this scenario you cannot reverse views and claim B or C is at rest. Time dilation will progressively be B slower than A and C slowest of all three.

You cannot reverse the sequence and claim C at rest, B at 0.2c and A at 0.8c.

1 - That causes such clocks to be required to accumulate multiple times because these observations are "Relative" hence must be concurrent.

2 - You would object to the velocity distribution based on Velocity Addition based on A's perspective. C vs B would not then still be 0.2c.

You have a whole host of problems in that reciprocity does not occur and cannot exist.

3 - Relabling the experiment is stating a new set of facts. A seperate problem, not a different view of the inital problem. Who has the greater velocity has been established or can be established by assuming a third point of referance.

4 - Only in gendankens can one arbitrarily assume such relationsips. The facts of physics are that one can only know the true relationsip of moving bodies by looking at the respective time dilation of the clocks. That is the physics and that disallows reciprocity.

Your calculations are correct for the gammas of the described motions but unfortunately that is not the complete SRT picture. You have not demonstrated SRT at all. Only gamma and using my third point technique.

In the case of GPS this scenario is not assumed it is physical fact. A is the ECI referance, (or other rest frames), B would be a surface clock (perhaps on a pulsar but not earth, C would be the orbiting sat. In this actual physical world you can no longer claim C at rest.

Game over. SRT is a mind game played in absence of physical realities and limitations.

[Pete]

Mac, you need to read the second half of Beginner Relativity. Your ignorance is profound.

[MacM]

Mac, you need to read the second half of Beginner Relativity. Your ignorance is profound.

I will only note that this response is hollow and does not address the issue. You attempt to avoid the issue by claiming nonexistant superiority.

http://www.daviddarling.info/encyclo...idalforce.html

Read this and get back to me. Your ignorance is profound.

Now either post proof of SRT, or acknowledge the truth.

[2inquisitive]

by James R:

All clocks run in A's reference frame until A has ticked off 1 million seconds. At precisely 1 million seconds, as recorded on A's clock, all clocks are stopped simultaneously (according to A). The clocks are then brought back together and their displayed times compared on the asteroid.
================================================== ============

Got a question. Same scenario as James described, except after all clocks are stopped
(simultaneously according to A), clock C is brought to a halt (0 velocity relative to the
asteroid) and clocks A and B are brought to C's location. As described by James, they
are not running during the phase they are brought back together. Are the displayed
times the same in this new location in space?

[2inquisitive]

See how simple it is to use the International Celestrial Reference Frame? If the asteroid
was 'stationary' relative to the 'fixed stars' (determined by Doppler readings of the KNOWN stars which comprise this frame of reference), the time dilations hold. If the
asteroid was moving at a certain speed and direction relative to the 'fixed stars' (ICRF)
still no problem calculating time dilations, you just take the velocity of the asteroid into account. And the positions and velocities relative to Earth are easily calculated
even if the Earth is not visible.

[Xgen]

Nothing of the kind has been shown.

If you want to discuss that idea, consider a simple example, below. I am introducing this to avoid bringing in complicating factors, such as occur in your favorite case - GPS, which you don't understand properly, and which requires both GR and SR.

Clock A is "stationary" on an asteroid, somewhere in deep space.
Clock B moves at 0.6 c, away from Clock A.
Clock C moves at 0.8 c, also away from clock A, and on the same line of motion of clock B.

At a certain time, all three clocks are located at the same point in space (at the asteroid). At that time, they are set to zero time.

All clocks run in A's reference frame until A has ticked off 1 million seconds. At precisely 1 million seconds, as recorded on A's clock, all clocks are stopped simultaneously (according to A). The clocks are then brought back together and their displayed times compared on the asteroid.

Question: What are the readings on clocks A, B and C?

Answer from special relativity:

A: 1,000,000 seconds.
B: 800,000 seconds.
C: 600,000 seconds.

What is MacM's answer? Are these results a "proper time dilation", in MacM terms? Or not? If not, what's wrong?

James, you seem to understand the math behind SRT? I asked 2 simple questions:

1) How velocity addition equation had been proved by the theoty? (in all sites I had found it had been given without any profe)

2) How second equation which I gived at the beggining converges to the first? (Which is requiered with and without the notion of Absolute Space, take C the frame of the asteroid if you like, but what we had computed by these two methods should give the same even only in SRT)

I am still waiting for your replies. The simple questions had simple answers.

[Pete]

http://www.daviddarling.info/encyclo...idalforce.html

Read this and get back to me. Your ignorance is profound.

I'm guessing that you think there's a point in there for you somewhere.

In my ignorance, I don't see it. Care to point it out?

[Pete]

by James R:

All clocks run in A's reference frame until A has ticked off 1 million seconds. At precisely 1 million seconds, as recorded on A's clock, all clocks are stopped simultaneously (according to A). The clocks are then brought back together and their displayed times compared on the asteroid.
================================================== ============

Got a question. Same scenario as James described, except after all clocks are stopped
(simultaneously according to A), clock C is brought to a halt (0 velocity relative to the
asteroid) and clocks A and B are brought to C's location. As described by James, they
are not running during the phase they are brought back together. Are the displayed
times the same in this new location in space?

Yes they are (SRT predicts they are, anyway).