Mac's Final Relativity Thread

[Quantum Quack]

You see my counter to the list below

Petes description

This description of SR is better:
1] The magnitude and direction of velocity is relative (will be different in reference frames with relative velocity)
2] Time elapsed between events is relative (will be different in reference frames with relative velocity)
3] The magnitude of acceleration is relative (will be different in reference frames with relative velocity)

would be:

1] You have relativity of observer velocity [can use either observer at rest ]
2] You have relativity of observer Time dilation [can use either observer at rest ]
3] You do not have relativity of observer accelleration [can not use either observer at rest ]

and of course I am confident that that would not be right either as all I am trying to do with the new version is explain the relativity function of placing any observer at rest

 

[Pete]

I take it that by "GR" you mean "galilean relativity", not "general relativity"? Maybe "BR" for basic relativity might be less subject to confusion?

Note that a combination of SR and BR gives SR.
There is nothing in BR that is not already included in SR; BR is the special case of SR when c has a value of infinity (this is a reasonable approximation for most situations in practice).

 

[Pete]

You see my counter to the list would be...

Yes, I can understand that better. Thanks!

 

[Quantum Quack]

I take it that by "GR" you mean "galilean relativity", not "general relativity"? Maybe "BR" for basic relativity might be less subject to confusion?

Note that a combination of SR and BR gives SR.
There is nothing in BR that is not already included in SR; BR is the special case of SR when c has a value of infinity (this is a reasonable approximation for most situations in practice).

nahh GR is supposed to have meant General relativity...what the hell is Galilean relativity any way - only kidding] I have edited my post to show General Relativity.

 

[Pete]

Ok ..First impressions when comparing the two posts are:
1] When discussing SRT we make the mistake of over simplifying what really is just an extension of GR [General Relativity] or vica versa.
2] In doing so we set the scene for over simplistic complaint against SR when in fact GR must be included before any complaint can be lodged.
3] Therefore all this arguement about SRT is really "kids fighting in a sandpit" type situation where by to really argue the case a full and complete understanding of GR is necessary so that SR is not over simplified.

A full and complete understand of general relativity is not required to discuss SR! All that is required is the patience to limit discussion to the simplest cases on which there is disagreement. As each simple case is resolved, then more complex cases can be addressed.

 

[Quantum Quack]

I am surpirsed at how It has taken me so many posts to this and other threads to realise that most arguement about SRT is simply that the theory is being taken out of context.

By over simplifying by using a given gedanken ie. two rel. v observers with out any other data and using this to demonstrate a small aspect of the whole picture has many dangers if theoretical context is not also included in the gedanken.
Of course people with out high end qualifications in GR [ general rel.] are going to get upset at obvious inconsistancies and counter intuitive results. Counter intuitive only because of a lack of theoretical context that is inclusive of all that makes a theory tick.
The arguement as I see it is simply that whilst observers can be deemed at rest for for velocity and time dilation calculations the application of the theory avoids the same treatment of accelleration thus the arguement comes up of what observer clock is actually dilated and length contracted and what is simply a mathematical convenience.
Hence the illusion of motion issue. Is the motion real or is it simply SRT abstraction? As accelleration is not able to be used in the same way as velocity and dilation for obvious reasons [ an observer at rest can not be at rest and accelerating simultanoeusly] then the question is an obvious one to raise. Yet flawed because of contextual issues IMO.

So in this sense the old saying "a little knowledge...... can be a confusing thing..."

 

[Quantum Quack]

A full and complete understand of general relativity is not required to discuss SR! All that is required is the patience to limit discussion to the simplest cases on which there is disagreement. As each simple case is resolved, then more complex cases can be addressed.

yeah sure...until a smart arse student such as myself gets stuck on the "illusion of motion" issue as this thread demonstrates...[ chuckle]

Ages ago I concurred with myself that SRT was entirely logically consistant and even though it does not make it correct it would have to be the most water tight self justifying theory ever devised and evolved by mankind.

It has however one weakness and as far as I can tell one weakness only and that is the presumption that light travels from A to B simply because we can not think of another way for light to arrive at it's destination with the delay that it demonstrates, which underpins just about every theory we have through all specialities.
and this, from your point of view most likely is such a weak arguement that it is hardly worth considering and yet to me it is the difference between traveling the stars or staying at home...

 

[Quantum Quack]

A full and complete understand of general relativity is not required to discuss SR! All that is required is the patience to limit discussion to the simplest cases on which there is disagreement. As each simple case is resolved, then more complex cases can be addressed.

well Pete, resolve the issue of how an observer at relative v can experience relative time dilation with out accelleration from rest? [ and not invoke GR to do it] I bet you can't which is why this MacMs complaint is unresolvable.

 

[Pete]

well Pete, resolve the issue of how an observer at relative v can experience relative time dilation with out accelleration from rest? [ and not invoke GR to do it] I bet you can't which is why this MacMs complaint is unresolvable.

I don't know what you mean by "experience relative time dilation", nor do I know why you think there is some issue to be resolved.

I strongly suspect that the issue is with your understanding of what SR does and doesn't say. I really wish you would take the time to learn.

 

[Billy T]

…There is and has been no problem with who "Measures" tick rate. You and James R seem to choose to repeatedly ignore the issue and that is not who "Sees", "Percieves", "Observes", etc but what is the physical reality when compared in a common rest frame

I (and reasonably sure James too) have no objection to computing Tick Rates as measured with clocks of a prior rest frame although I do prefer to speak of “time dilation,” TD, as not all clocks “tick” (and on this we agree, but as I try to be completely accurate I speak of TD, not tick rate.)

I try to avoid the words “see”, “observer” “perceive” etc. as they at least suggest the possibility of errors due to the propagation of light delays. Inherent in any measure of the TD of a clock from another frame than the clocks frame is that only one of two events (start & stop events of the interval being measure) can be adjacent to you in the other frame so one of them is at some distance from you and signal/ information/ light /etc. delays from it must be corrected for.

As far as for “physical reality” you assert /assume (whatever word you like) that it must be calculated for the clocks of the common rest frame (the most recent one, if more than one exists) and as there is only one actual / physical TD for clock A, or TDA. According to you, but not SR, all other frames would measure that same TDA, if they measure correctly. You accept the SR formula for calculating the TDA, provided that the velocity plugged into it is the velocity wrt this most recent common mutual rest frame, which I have started calling the CMRF or just frame C. I.e. you insist that one must insert VAc into the SR formula.

Pete, James and I disagree as we insert the velocity wrt any inertial frame, for example frame E’s velocity of clock A (VAe) into that same SR formula and so do not get the same result as the one you insist is the true physical unique TDA. For you, there is no need to call it TDAc as for you it is the unique physical TDA and all others that Pete, James and I calculate with for example VAe are just wrong / nonsense.

Because we disagree, think SR is correct, we cannot just speak of the TDA, but must use more careful notation which specifies the frame of the clocks used in the formula. If they are the clocks of CMRF or C, I speak of the TDAc. If they are the clocks of frame E, I speak of the TDAe, which is not the same as TDAc

I think you agree that when one tells what the rate of some changing observable is, they ALWAYS use their own clocks. For example if I want to tell the speed of a fast ball, bullet or train, I divide the distance it traveled by the number of seconds the trip took according to MY clocks. I do not divide by the seconds the trip took with seconds of the clocks of someone else’s frame, especially if I know that frame’s clocks are “running slow” wrt mine. (and you agree that such frames do exist.) Again: Everyone always uses their own clocks to measure or state the rate of anything, including the rate time is passing in some other frame. Why is TDA, for you, an exception to this rule? I.e. if I am at rest in frame E, why must I use the clocks of frame C (frame CMRF) to state correctly the TDA? Why can I not use my own clocks and find it is TDAe, which is different from TDAc? What is false about stating the rate of clocks in some other frame wrt MY clocks? Why must I state the rate of clock A which is not fixed in my frame E wrt to clocks of some other frame you specify?

Your insistence on the use of only the time / clocks of frame C for all other is based on what?

I think the answer to that is that you are sure there is only one physical TD and it must be computed only with the velocity wrt frame C. But MacM, that is what the entire discussion is about. Whether or not TD depends upon the clocks of the frame specifying what it “really is” is the question we are discussing. You are attempting to prove that TD does not depend upon the clocks of any frame but frame C (the CMRF) but that is just what you start by asserting or assuming. –Namely that TD does not depend upon the frame specifying what it truly is. Thus, as I stated before your reasoning is circular – You cannot assert /assume what you want to prove. Refusing to use TDAc or TDAe etc. only hides/ glosses over/ your assertion / assumption that there is only one true, physical, unique, TDA for all frames. You cannot prove anything with circular reasonin.

I don’t think, and certainly hope you are not really objecting to the use of algebra, by insisting that I only use words etc. I think you are really objecting to my introducing symbols, especially when they expose the fact you are ambiguous, not clear, with your words only. I.e. with the subscript, I specify which frames clocks are used. For example I used TDAe and you at best only use TDA, often only the words Time Dilation” never specifying wrt to which clocks. You just assume that it not matter and speak of the universal, unique, physical time dilation as you assume it is the same for all frames. Then you proceed from this starting point to argue that it is the same for all frames.

…Why do you only apply SR to an observer that has switched frames? …

I don’t do that. I apply SR to both frame from the other. SR is completely symmetrical with no special frames as you postulate the CMRF is unique. In fact I even told how each frame can measure the TD of the other frames clocks in post 195 as I remembered it having been done as follows:

“…an atomic clock was carried for a few hours in a supersonic jet years ago to measure the time between two events. The interval was also measured by synchronized ground clocks. I forget the details but perhaps at each event location there were high resolution pulse coded time patterns transmitted to the plane flying over head at constant altitude. I.e. the instant of arrival at the plane of a particular pattern was known to a tiny fraction of a micro second and these served as the start and stop pulses for the accumulator on the plane, as well as on the ground.”

SR can be applied even when there never existed a CMRF, but the “MacM SR” is useless then. As most of the clocks in the universe (I am sure your will agree) are natural clocks such as objects periodically orbiting a star or radioactive isotopes decaying, it is safe to say the far fewer than 1% of all the clocks that exist ever had a common rest frame in the last 10 billion years.

 

[Quantum Quack]

I think the list as mentioned before an dnow again below is pretty self explanitory as to what the problem is.

1] You have relativity of observer velocity [can use either observer at rest ]
2] You have relativity of observer Time dilation [can use either observer at rest ]
3] You do nothave relativity of observer accelleration [can not use either observer at rest ]

the simple fact that accelleration can not be treated in the same way as velocity relatively speaking is the key to what this issue is about.

Say we are in deep space and we have two observers with clocks attached. They are positioned back to back and in between them is a charge of special explosive material [ most likely a substance derived from ancient nuclear stockpiles - just to add color]
The ensuing explosion accelerates both observers equally and to an eventual separating velocity of .6c

By just applying common sense:

Which clock is dilated?
Are any of their clocks out of synch given that they are sharing the same acquired velocity from a point of rest?
have they ever broken their innitial inertial state? [ assuming perfection in accellerations and resultant velocity?

Now apply SRT and ask the questions again....
and you will get entirely different answers yet you know that they both have acquired the same velocity due to the same explosion.


so how is this reconciled, Reality vs SRT?
The only reason SRT would HAVE to be used is due to the need to support the NOTION that light travels invariantly across vacuum and to maintain that invariance of a TRAVELLING light wave or particle one observer has to be deemed capable of stating he is at rest relative to the other observer and NOT just to himself. If you DON'T apply SRT light is no longer invariant in its presumed Travelling.

 

[MacM]

So why, exactly, do you say that it is ludicrous that SR says that any inertial reference can be considered to be at rest?

Not in any limited view but for any physics application with regard to time dilation any inwertial rest also has a proper trick rate. That being the case nothing is actually at rest unless you accept some universal absolute rest concept.

Considering ones self at rest when predicting time dilation only works if you really did not move. Having moved and becoming inertial and claiming to be at rest does not alter the fact that you are now dilated relative to the one that remained at initial rest.

As far as I can tell, you are disagreeing with yourself, but I suspect that's because I'm not following what you're thinking.

Please, stay away from time dilation for the moment - I'm trying to be clear about what you mean by your concept of "actual velocity," to understand why you distinguish between "motion" and relative velocity, and hopefully to establish a common understand of a reference frame in the context of Galileo's relativity.

First actual velocity is also a relative term but it is only relative to some fixed rest reference. Relative velocity as advocated by original SR is just that relative velocity shared between two observers even if one has remained stationary.

The later case the resting observer has relative velocity but not actual velocity in the relative velocity pair.

 

[MacM]

Perhaps you should read what I said again. Some things (pseudo-forces) that occur in non-inertial reference frames are not real.

As is SR -

 

[MacM]

I don't regard him as exceptionally clever.

Missed this before.

Well this makes us even I haven't found you to be intelligent. I have found you to be a parrot reciting what you have read or been told. No capacity to actually think for yourself.

 

[James R]

Being intelligent, MacM, requires an ability to interact with other sources of information and to learn from them. Being stuck in a useless rut for 50 years because you're too stuck in your own imaginings to go looking for the truth is not a sign of intelligence. It is a sign of ego, and that's all.

 

[Billy T]

As I said above Billy, I'm not impressed. Acceleration isNOT excluded from SR. It is just more difficult to do. Your lack of actual understanding here should exclude you from commenting in such threads.

Acceleration certainly is excluded from standard SR, but not from MacM's version of SR.

Standard SR applies ONLY between inertial frames. It uses the current relative velocity and is not concern, as your SR is with the history of how one clock may have been in the distant past accelerated away from the other. Standard SR does not require any historical information to compute time dilation - your version of SR does require this information.

To illustrate assume two identical rocket ships a & b, now in inertial reference frames A & B with relative velocity V due to them earlier having left frame C in opposite direction, but with different accelerations and different final coasting speeds wrt the launch pad.

After the crews can get up from their chairs (the accelerations were strong) they open their tool boxes an find that their clocks are missing - must have been accidently left behind. "No problem" says the chief engineer "I will build a new one." and he does, both now have identical clocks (Made from the same emergency backup plan with identical spare parts.)

Please note that neither of these clocks were ever accelerated and they are not traveling at the same speed wrt to their common launch pad. Standard SR easily predicts how each will see the others new clock as time dilated. (Just plug V into the formula and calculate.)

POINT BEING:
SR does not need any acceleration to be applied as you falsely assert (or even use any accelerations). Only "MacM SR" needs one clock to be accelerated and the other to remain at rest to avoid being useless.

I am curious: What does MacM SR say about time their time dilation? Is the slower clock not dilated and the faster one is dilated? or what?

 

[MacM]

I try to avoid the ords “see”, “observer” “perceive” etc. as they at least suggest the possibility of errors due to the propagation of light delays.

Good but James R doesn't he likes to claim what you see is what you get.

As far as for “physical reality” you assert /assume (whatever word you like) that it must be calculated for the clocks of the common rest frame (the most recent one, if more than one exists)

Incorrect. In my radioactive decay clocks I show comparative % decay in the "C" and "A" frame. The "A" frame occured after the "C" frame common rest. "A" to "B" % decomposition was compared in the "C" and "A" frames.

Pete, James and I disagree as we insert the velocity wrt any inertial frame, for example frame E’s velocity of clock A (VAe) into that same SR formula and so do not get the same result as the one you insist is the true physical unique TDA. For you, there is no need to call it TDAc as for you it is the unique physical TDA and all others that Pete, James and I calculate with for example VAe are just wrong / nonsense.

SDo you want to assert you are absolutely correct and I am absolutely wrong even though you have absolutely no emperical data to suport your view that mere reltive velocity causes change in a resting clock. - Based on what some 100 year old text. :shrug:

I think you agree that when one tells what the rate of some changing observable is, they ALWAYS use their own clocks. For example if I want to tell the speed of a fast ball, bullet or train, I divide the distance it traveled by the number of seconds the trip took according to MY clocks. I do not divide by the seconds the trip took with seconds of the clocks of someone else’s frame, especially if I know that frame’s clocks are “running slow” wrt mine.

Precisely. Now back up and think about what you just said. Only and only if you disregard a physically dilated clock can you then compute trip time and claim distance contracted. The dilated condition of the traveling clock fully accounts for trip time only if distance remains fixed. Time dilation is either physical of ir is not.

(and you agree that such frames do exist.) Again: Everyone always uses their own clocks to measure or state the rate of anything, including the rate time is passing in some other frame. Why is TDA, for you, an exception to this rule?

It isn't. I hold a dilated clock to be physically dilated and his accumulation of less time for the trip simply means he will calculate v = ds/dt and find he traveled faster that a resting observer calculates using a different time standard.

Only by assuming hwe will calculate a common velocity (even though his tick rate is dilated) can you force distance to appear to have changed. I really hope you can remember back 24 hours where I gave a perfectly good analogy using traveling cars and radar.

A slow watch does not cuse distance to change it causes you to calculate a differnt veloicty.

Your insistence on the use of only the time / clocks of frame C for all other is based on what?

You seem to ignore the fact that I have used both thev "A" and "C" frame in my prior scenario and the time dilation between "A" & "B" does not change in different frame views.

SR can be applied even when there never existed a CMRF

Oh of course you can apply SR math but to what avail your predictions are just math, unsupported and unsuportable by emperical data.

 

[MacM]

Being intelligent, MacM, requires an ability to interact with other sources of information and to learn from them. Being stuck in a useless rut for 50 years because you're too stuck in your own imaginings to go looking for the truth is not a sign of intelligence. It is a sign of ego, and that's all.

Einstein (your favorite guy) once said "a sign of intelligence is having changed your mind on a major issue".

Since I grew up a believer and idolized Einstei,n but did grow, up I changed my mind. You on the other hand cling on to a 100 year old view with no ability to even consider it's flaws or shortcomings.

Why do you resist addressing the fact that you consider who switched frames when applying SR? Why don't you admit that is not a mere relative velocity concept? Why are you so adomate that reciprocity is a physical fact when to claim so makes you a complete fool.

And you want to slam me. I don't think so.

 

[James R]

No flaws have been found in 100 years.

 

[MacM]

Acceleration certainly is excluded from standard SR, but not from MacM's version of SR.

Billy, Billy, Billy. Why do you insist on making me show your ignorance?

******************************************************
http://math.ucr.edu/home/baez/physics/Relativity/SR/acceleration.html

Can Special Relativity handle accelerations?

It is a common misconception that Special Relativity cannot handle accelerating objects or accelerating reference frames. It is claimed that general relativity is required because special relativity only applies to inertial frames. This is not true. Special relativity treats accelerating frames differently from inertial frames but can still deal with them. Accelerating objects can be dealt with without even calling upon accelerating frames