Mac's Final Relativity Thread

[MacM]

MacM it is past my bed time so will be quick. I said SR Theory does not use require or applie to non-inertial frame cases. that is not the same as asserting it is correctr discription of realitiy. It is a simple statment about the theory. Where in the eqution of SR does any acceleration appear?
I will admit that for some case some one may have extended SR theory to allow it to be applied with small acclerations and little error or to slowig rotating frames etc. I do not know if that is the case or not but extended SRt is not SRT so my statment stands.

Refute it if you can by showing an equation of SR that includes an acceleration term.

Denial gets you no credit. You shold note that the link is xxxx.edu and that they say clearly "This is not true".

You sir are wrong. Just as James wants to assert that the stand alone formuas cannot and should not be sued (so why do they exist?) your rejection of acceleration is SR is equally flawed.

 

[MacM]

MacM:

Special relativity is based on only two postulates:

WEBSTER:

Poatulate - 2) to assume without proof to be true, real or necessary

Now that the basis for your theory are properly laid.

1. The laws of physics take the same form in all inertial frames.

2. The speed of light is the same in all inertial frames, regardless of the speed of its source.

Disregarding that the measured invariance may well be due to an illusion and does not mean every photon moves invariantly.

It is not possible that parts of SR are correct and other parts are wrong, unless one or both of the postulates above is wrong.[/'quote]
This is out and out Bulls___. There is simply no factual basis to claim because one aspect of something appears valid all aspects must be. That is utter nonsense and very unscientific.

In particular, it is not possible that reciprocity is wrong unless one or both of the postulates is wrong. It is not possible that length contraction is wrong unless one or both of the postulates is wrong. Velocity dilation cannot be correct unless one or both of the postulates is wrong, etc.

To the contrary the very fact of inherent reciprocity mandates that a postulate is wrong since physical reciprocity is an impossibility..

Unless you address this issue head on, you're really just wasting everybody's time.

Ditto.

Now, in this thread you have made a claim that you think that maybe postulate 2 is wrong. In fact, if your velocity dilation concept is correct, then postulate 2 presumably must be incorrect, since the speed of light relative to different observers cannot be the same if MacM fantasyphysics velocity dilation is correct.

That would appear to be the most logical answer.

Perhaps a good next step would be to give a formula by which you believe the speed of light can be calculated for different reference frames. Do you have such a formula?

What about "Appears to be invariant" do you not understand. In my view light is generated, produced or percieved at v = c which is some energy state that energy statev changes with relative veloicty of the observer.

Point beeg it is not the same photon moving invariantly but different generated photons.

To make this concrete, let's say clocks A and B start together, and B accelerates away to 0.6c. What is the speed of light measured by B after the acceleration, and what formula does B use to calculate it?

Covered above.

I have no idea what you're talking about here.

Then stop and think. When you apply frame switching you are dictating who has accelerated and hence has actually changed veloicty. You are ignoring the relative velocity of the resting observer and hnce are avoiding reciprocity by using a form of absolute motion.

I have no idea what you're talking about here. It doesn't matter if clock is a pendulum clock or a digital clock or a radioactive clock or a heartbeat. Relativity applies equally to all clocks.

Oh really. Perhaps you should read the scenario before trying in vain to rebut it. So I have a grandfather clock and a cesium clock in LA at rest, equally calibrated and sychronized. I move them to Denver. The cesium clock speeds up but the GF clcok slows down -


I

 

[MacM]

What's a "frame that has accelerated"? That sounds like a meaningless construction to me.

Do you know what a (reference) frame is?

Pathetic James R, really pathetic. An accelerated frame is a frame that has been subjected to F = ma and undergone dv = at. Simple basic physics Your denial gets you no grade points.

 

[MacM]

QQ:



Are you claiming, then, that the speed of light is not the same in all inertial reference frames?

If so, can you give me a formula for calculating the speed of light in different frames, as I asked MacM above?

What about light "Appears" invariant do you not understand?

 

[MacM]

1) It doesn't matter to me how long you've "been around" SR, if you haven't worked out the details and done the calculations, you haven't studied it, you've only glanced at it.

2) I don't know what an escape goat is, but where can I buy one?

Physicists don't claim SR only applies to motion through time and space. SR is what the title says, Special Relativity- a special case of the more general theory known as GR, specifically the case in which the spacetime metric is Minkowskian, i.e. gravity is absent.



Like I already said, SR doesn't say anything whatsoever about cosmology.



Looks like you never even bothered to ask what physicists mean by information. Faster than light signals can be exchanged between particles to produce statistical correlations between them. Those statistical correlations can only be spotted by exchanging and comparing the results at lightspeed or less, the usual ways. Because the quantum signal is chosen at random and not determined by the experimenters, the experimenters can't produce any controllable effects that would propagate faster than c, travel back in time and cause paradoxes. When we say information doesn't travel faster than c in quantum mechanics, we mean information that the experimenters can actually access and control.



This just proves what I was asserting earlier, you haven't properly studied SR, you're barely aware of the essential details. GR was introduced to explain gravity, that was the only reason Einstein needed it. SR handles accelerations just fine, you treat it by moving through a consecutive sequence of inertial reference frames, each frame moving at a different velocity. There are at least two easy ways I've seen of resolving the twins paradox using only basic SR reasoning. I wrote one of them up here about a year ago (see link). Einstein himself solved the paradox and used it as a means of illustrating the way SR is used and some of the counterintuitive results it describes. The conclusion is the same regardless of what method you use to solve it: the astronaut who went out into space comes back younger than his twin. The biggest thing newcomers forget when trying to show a contradiction in SR is that not only do you have to include time dilation in your calculations, but relative simultaneity also comes into play.

Pure babble, dogma and rhetoric. Meaningless in this discussion.

 

[MacM]

There's no "as if" about it. They have a relative velocity. Velocity is NOT the same as speed. Direction matters. And that's not relativity talking - it's basic week 1 undergraduate physics.

One thing I find absolutely ironic is that you reject to fervently the idea that an observer with a dilated clock will compute a different relative veloicty but you advocate with equal fervent the idea of veloicty addition where different observer compute different relative vleocities.

Shhhsh what a load of crap.

 

[MacM]

But the idea that photons don't travel from point to point is bizarre. What's the alternative? How do optic fibres carry information from point to point?

Not really. Take a rope and shake it in unison from both ends and set up a wave. The Rope is not traveling. A wave on the rope is produced. The rope just jiggles.

In my view that is the situation with photons they are the jiggles along the rope and there are virtually an infinite number of energetic ropes in the uinverse which lead to seeing jiggles at v = c regardless of you relative velocity to the clusters of ropes.

Shake a bowl of jello, the jello isn't traveling it jiggles. Photons are jiggles in the undetected fabric of space.

 

[MacM]

Wrong. The clocks were/are in sync only in the original reference frame. They are out of sync in the reference frame of either of the clocks, due to the relative velocity in either of those frames.

Correction. They "Appear" out of synch to the observers with relative velocity but they are in fact still in synch.

 

[MacM]

There's no need to know anything about acceleration data. Only the relative velocities are needed, and SR applies as usual. Any disagreement based on acceleration data is because some ignorant person doesn't know relativity.

Ignorant persons advocate realities that have not been and cannot be tested.

Please post one case of emperical data showing that relative veloicty caused a resting clock to dilate physically. I didn't say appears to be dilated but was dilated when compared to the traveling clock in a common rest frame.

 

[MacM]

Can you use any fixed reference?

You can compute that way but you may or may not be right and you will never know because the concept is untestable beyiond the first istance of motion to a known rest reference.

That is you cannot just spot two objects moving relative to you and factually conclude which has a higher or lower tick rate to each other because your vantage point is not necessarily their common rest reference.

You can calculate what you will "Percieve" to be each of their tick rates to you but that is not related to what their actual tick rates are.

 

[Pete]

You can compute that way but you may or may not be right and you will never know because the concept is untestable beyiond the first istance of motion to a known rest reference.

That is you cannot just spot two objects moving relative to you and factually conclude which has a higher or lower tick rate to each other because your vantage point is not necessarily their common rest reference.

You can calculate what you will "Percieve" to be each of their tick rates to you but that is not related to what their actual tick rates are.

So, you're saying you have no method of predicting what the tick rate of a moving clock will be?

 

[CptBork]

Pure babble, dogma and rhetoric. Meaningless in this discussion.

And yet you complain when people throw around Einstein's name in order to dismiss you without considering any of your own arguments. You're doing the same thing here with me, and it just reflects on your desperation to be seen as correct. Go ahead, I challenge you to refute any of the points I made in my last reply. I pointed out some very basic fallacies in your reasoning and understanding of relativity, so since you're so touchy about being told you haven't studied the subject, please feel free to prove me wrong.

Tell me what's wrong with my simple SR solution to the twins paradox, since you claim Einstein needed to invent GR to solve this specific problem. What aspect of this solution is so inconsistent with relativity that you can dismiss it in one sentence as irrelevant babble and dogma? If you just came here to rant about why you personally dislike relativity and to dismiss anyone who refutes you as a brainwashed lackey, then there are more appropriate subforums where you could have posted your rant. This place is for serious physics debate and discussion including, where necessary, details.

 

[Billy T]

Denial gets you no credit. You shold note that the link is xxxx.edu and that they say clearly "This is not true".

You sir are wrong. Just as James wants to assert that the stand alone formuas cannot and should not be sued (so why do they exist?) your rejection of acceleration is SR is equally flawed.

I am not denying -only asking you for even one formula of SR where the acceleration even appears.

I have been busy so have not gone to your "evidence link." Also because the last one you sent me to a link, it was just an Email one guy sent to another.

I'm still waiting for real evidence that standard* SR uses acceleration - namely an equation with place to insert acceleration of something into the equation.

-------------
*I understand that your version of SR does - infact requires one of two clocks to accelerate away form your "common rest frame."

 

[CptBork]

Billy, just to let you know, SR is fully equipped to handle any acceleration as long as it's not caused by gravity. If you know a rocket ship's position or acceleration or velocity as a function of time, that's really all you need to describe all the relativistic effects. Accelerations are handled in SR by setting up a series of reference frames moving at different velocities, so that at any given moment the rocket ship or whatever may be considered at rest in one of these frames, and then the calculations for that brief instant of time can be done from there before being converted back into the original frame.

 

[CptBork]

In fact, considering the laws of force and acceleration as revised by Special Relativity is one of the central arguments leading to $$E=mc^2$$, an energy-mass relationship that already had experimental support even before 1905 and is automatically derived as a consequence of relativity.

 

[Billy T]

... Light does not travel...across three dimensional space...

Can you make a new thread for this? IMHO this one already is clutter up with train's Doppler whistles and pilots falling etc already.

 

[Billy T]

... I have not changed my POV I have always said a simple absolute view does not work. You haven't pointed out anything I didn't already know. ...

Yes you have as no longer claim the both procedures you agreed to in your post 93 are correct. I.e. after my post 118 showing they give mutually self contradictory results, you said that both you and SR do not know how to compute Time Dilations correctly. Before post 118 you told how to correctly compute time dilations.

You have already said:
“I have always said a simple absolute view does not work." in prior post

And I have already replied:
"Neither I nor SR hold an "absolute view."

In fact SR & I refute that view and say only Relative Velocities are important. I also state there is no reason to think any frame is at absolute rest or even to be preferred (except your own frame, for convenience in most cases) over others. - I. e. there is nothing special about using velocities wrt your "last common rest frame."

I am beginning to lose faith in your creative powers as you again drag out this irrelevant comment about your always refuting the absolute POV.
Surely you could at least find a new non-relevant diversion.

What I have been trying to teach you is:

(1) To use symbolic notation that clearly defines what it is you are speaking of; which clock it is about; & which frame's clocks are measuring. For example when speaking of Time Dilation of clock B as measured by clocks in different frame C, I compactly indicate this by TDBc. You essentially never in your words only description tell what the subscript "c" is specifying as you assume it does not matter - I.e. you assume SR is wrong and that there is only one TDB. Then proceed in circular reasoning way to prove there is only one TDB.

(2) That in most case of clocks in the universe there never was a mutual common rest frame. Even for clocks now in two rocket ships that launched from the same launch pad at the same time they could not have a common rest frame if they were built in the rocket ships after they were in different inertial frames.

You are in the embarrassing position of saying that one clock in rocket ship A, which was accelerated from still resting clock B in their common mutual rest frame is dilated, but an identical one (say both are cesium atomic clocks) which was built in the rocket ship after it was coasting in an inertial frame and thus was never accelerated is not time dilated.

I.e. MacM's SR, which places all the time dilation effect on the prior acceleration* history of one clock wrt to the other predicts:
Two identical clocks, at sitting side, by side do run at different rate just because one of them (and only one of them) had a prior acceleration!

*If you want to say "no, it is not the prior accelration, but the velocity that produced, which causes the time dialtion, let assume the cesium for the "built in space" clock was collected by the rocket flying thru some cloud of cesium. Or perhaps there are two types of velocity? One produce by F=ma and another by the expansion of the universe effect on different locations? It realy is hard to pin you down to one unchanging POV. (You have abandon your POV you confirmed in post 93 after my post 118 and that is only one example of your "flexability.")

 

[Billy T]

actually BillyT I think the issue has already been pretty much nailed down and as yet there has been no adequate response. refer to post #291
and as your later posts are starting to reflect SRT does not adequately deal with accelerating frames without mixing theories....as far as I know.

At 291 I found:
"The simple fact that acceleration can not be treated in the same way as velocity relatively speaking is the key to what this issue is about." and some questions that you must ask again differently for me you get what you are asking.

It is not at all strange that std. SR does not treat acceleration in a reciprocal way like it does velocity. - Because Std SR does not ever consider acceleration at all - only "MacM SR" thinks the prior period of acceleration is important and symmetry breaking. So only one clock has time dilation, TD, as measured by the seconds of the other clock. MacM claims that reciprocal TD has never been verified (and also that std SR is false because it cannot be)

AFAIK, the only time a discussion of SR results (not SR itself) that acceleration is even mentioned, is in the "twin paradox" to tell which twin is younger when rejoined. In this case, as all others, Sr is only concerned with the inertial phases - no details about the accelerations even given usually.

I gave a test design with supersonic jet flying at constant altitude (for same transit delays of the start and stop pulses sent to the accumulator in the jet) over two well synchronized ground clocks (one on US east coast and other on the west coast) and other details such as pulse code timing patterns in the transmission to the plane, which can easily tell time to 0.001 micro second resolutions. So a test is possible despite what MacM says.

 

[Billy T]

... The initial frame is non-exstant since the explosion. ...

You seem confused as to what a frame is. It is not some wire grid that an explosion can destroy. It is only a mathematical coordinate system. Usually for SR discussions a Cartesian one so I can designate the origin of frame "C" as C(0,0) and the origin of frame E as E(0,0).

Assuming for convience that they have the same x-axis line and all motions are along it is also convenient. The speed of C(0,0) wrt E(0,0) then can be designated as Vce but that does not imply there must be anything in either frame an explosion can destroy anymore than an explosion can destory the math that states 1+2 = 3.

Working with speeds instead of vectors is easier for most but does require you to tell which way along the x-axis the motion is. (Some people get confused by fact one of a pair of symmetric opposite velocities is a negative vector - speed is always positive.)

I also fail to see any advantage to your explosion scenario. Why not just have the quite commen two rockets, A & B, leave C(0,0) simultaneously with equal accelerations oppositely directed along the common X axis until reaching speed VAc and VBc where they then foreever coast if you want to construct a symmetric scenario (one with VAc = VBc)?

This is not only easy for all to grasp (most have seen it before) and has almost self evident notation available, but also does not require imposible infinite forces and accelerations to give A & B their speeds in zero time as I understand your explosion between to observers un realistically assumes.

If two observers are accellerating in synch with each other at exactly the same rate what reference frame terminology would you refer to them as?

Answered above in my notational examples. I.e. use trailing sub script to refer to frames.

as regards to alternatives to photon traveling the thread in question is
Does light move and it is in pseudo science...$100usd is up for grabs [and has been for nearly a month] if any one can show effect evidence that clearly demonstrates a photon in transit and note the key words are "in transit" from any point A to B.

Thanks. I will definitely have a look at it as I have measured the length of some Sodium D photons by making changes in the path between source and a screen they fell on and died. (They were about 30cm long. I will describe how to measure later - but have have already some time ago.)

PS to Capt Bork -I am working my way forward and will read your "again" post when I come to it before reply, but think we only differ in symantics as to what is included in SR, not the ways it can be applied with zullions of sequential inertial and limiting increments of time to handled accelration case.

 

[CptBork]

AFAIK, the only time a discussion of SR results (not SR itself) that acceleration is even mentioned, is in the "twin paradox" to tell which twin is younger when rejoined. In this case, as all others, Sr is only concerned with the inertial phases - no details about the accelerations even given usually.

Again, there's no problem with treating accelerations in SR as long as they're not being caused by gravity. Newton's gravitational law doesn't fit into SR and doesn't even give consistent results when applied from different reference frames in this context, and that's the one and only reason Einstein invented GR. Of course for large distances and weak gravitational fields, GR reduces to the usual Newtonian picture. Like I said, acceleration is in fact so important in SR that its consequences actually lead to $$E=mc^2$$.

As far as acceleration in the twins paradox goes, there's no real need to consider it. If the spacefaring twin has a long journey (i.e. 20 years as seen from Earth) at speeds close to c, and by comparison their acceleration only takes a day or so, it makes almost no difference whatsoever to the end result. So one twin ages half as much as the other if the acceleration is instant, and you give or take at the very most a day depending on how they accelerated during that one day... big whoop.