As I suspect most people, I have always associated Bremsstrahlung with the breaking energy release of moving charged particles.

However, a little thought opens up many questions. As the following link points out Breaking Bremsstrahlung occurs due the interaction of the EM field associated with a charged particle in motion with other particle fields.

http://www.astro.utu.fi/~cflynn/astroII/l3.html

The problem is this.

1 - If I place EM detectors around an isolated charged particle (static electricity) and then accelerate another particle then there exists a relative velocity between such particles.

According to Relativity it doesn't matter which particle we look at each now has velocity and hence should have an associated EM field.

The facts are however, that only the particle which underwent the physical acceleration (F = ma and forces) has such an EM field. The detectors around the static charge will not see any pulse of EM during the acceleration of the other particle nor any field due to relative velocity between particles.

The concept of "Relative" velocity is therefore a flawed view of motion. There exists "Apparent" motion and "Actual" motion. While it is not obvious to an observer which is which, there does exists the ability to distinguish between such types of motion and that is where SRT failed.

2 - Einstein arugued that there is total equivelence between uniform acceleration and being restrained in a accelerating gravity field.

The absence of Bremsstrahlung of static charged particles in a gravity field disputes that view.

Comments welcome. :D

1 - If I place EM detectors around an isolated charged particle (static electricity) and then accelerate another particle then there exists a relative velocity between such particles.

According to Relativity it doesn't matter which particle we look at each now has velocity and hence should have an associated EM field.

Charged particles always have an associated electric field, regardless of their motion. If in motion, they also produce a magnetic field.

The facts are however, that only the particle which underwent the physical acceleration (F = ma and forces) has such an EM field. The detectors around the static charge will not see any pulse of EM during the acceleration of the other particle nor any field due to relative velocity between particles.

The detectors won't detect any change in the field from the charge which is stationary with respect to the detectors. However, they will detect effects from the charge which accelerates relative to the detectors.

The concept of "Relative" velocity is therefore a flawed view of motion.

How so?

There exists "Apparent" motion and "Actual" motion. While it is not obvious to an observer which is which, there does exists the ability to distinguish between such types of motion and that is where SRT failed.

I don't know what you're talking about.

2 - Einstein arugued that there is total equivelence between uniform acceleration and being restrained in a accelerating gravity field.

That's a very rough wording of what Einstein said. I hope you understand what he said, but somehow I doubt it, since you've always had trouble coping with reference frames.

The absence of Bremsstrahlung of static charged particles in a gravity field disputes that view.

Huh?

James R,

“ 1 - If I place EM detectors around an isolated charged particle (static electricity) and then accelerate another particle then there exists a relative velocity between such particles.

According to Relativity it doesn't matter which particle we look at each now has velocity and hence should have an associated EM field. ”

Charged particles always have an associated electric field, regardless of their motion. If in motion, they also produce a magnetic field.

If you believe you have stated something different or new here then please clarify. Otherwise you are repeating my post.

“ The facts are however, that only the particle which underwent the physical acceleration (F = ma and forces) has such an EM field. The detectors around the static charge will not see any pulse of EM during the acceleration of the other particle nor any field due to relative velocity between particles. ”

The detectors won't detect any change in the field from the charge which is stationary with respect to the detectors. However, they will detect effects from the charge which accelerates relative to the detectors.

Correct. And in case you have missed it that is the point. You have actual motion and you have apparent motion. They are not the same and Relative velocity is apparent motion. The only actual motion is that which has accelerated.

“ The concept of "Relative" velocity is therefore a flawed view of motion. ”

How so?

Read read and re-think above.

“ There exists "Apparent" motion and "Actual" motion. While it is not obvious to an observer which is which, there does exists the ability to distinguish between such types of motion and that is where SRT failed. ”

I don't know what you're talking about.

No real surprise here is there?

“ 2 - Einstein arugued that there is total equivelence between uniform acceleration and being restrained in a accelerating gravity field. ”

That's a very rough wording of what Einstein said. I hope you understand what he said, but somehow I doubt it, since you've always had trouble coping with reference frames.

Note:

1 - "Equivelence Principle" : Uniform acceleration and an accelerating gravity field.

Anybodyelse have trouble understanding the correlation here or is this just a James R problem?

2 - Your habit of interjecting negative innuendo when you have no physics response is well known.

“ The absence of Bremsstrahlung of static charged particles in a gravity field disputes that view. ”

Huh?

See # 2 above.

Happy New Year James R. :D

Correct. And in case you have missed it that is the point. You have actual motion and you have apparent motion. They are not the same and Relative velocity is apparent motion. The only actual motion is that which has accelerated.

But the Bremmstrahlung example doesn't show that. Does it?

1 - "Equivelence Principle" : Uniform acceleration and in a accelerating gravity field.

Anybodyelse have trouble understanding the correlation here or is this just a James R problem?

Correlation between what and what? You're not being very clear.

2 - You habit of interjecting negative innuendo when you have no physics response is well known.

Pardon me?

You have claimed that Bremmstrahlung somehow disproves relativity. However, your reasoning (if any) for that claim is impenetrable, as I have helpfully pointed out for you.

I suggest you try to explain yourself so people can understand what you claim is evidence for your view.

James R,

For anyone not already entrenched and deliberately being obtuse it is obvious that time dilation due to "Relative Velocity" is no different than Bremsstrahlung.

The only place any physical affect occurs is in the object which actually physically accelerated and is not due to relative velocity where one object may not have accelerated or moved at all. :bugeye:

If you had looked at the link I provided it would be clear:

********************** Extract ******************
1 Radiation from accelerated, charged particles

A charged particle undergoing an acceleration radiates photons.
************************************************** *****
Your memory must be failing so let me remind you. You have argued that when a train accelerates away from the station that the station indeed accelerates away from the train. (I and any rational person knows better).

let me try and clarify. mac, is it your argument that one particle will produce a magnetic field and the other will not, no matter what frame of reference you choose?

James R,

For anyone not already entrenched and deliberately being obtuse it is obvious that time dilation due to "Relative Velocity" is no different than Bremsstrahlung.

The only place any physical affect occurs is in the object which actually physically accelerated and is not due to relative velocity where one object may not have accelerated or moved at all. :bugeye:

If you had looked at the link I provided it would be clear:

********************** Extract ******************
1 Radiation from accelerated, charged particles

A charged particle undergoing an acceleration radiates photons.
************************************************** *****
Your memory must be failing so let me remind you. You have argued that when a train accelerates away from the station that the station indeed accelerates away from the train. (I and any rational person knows better).

Mac, the radiation is due to acceleration *relative* to the detector. If you keep the detectors stationary relative to the other particle, you will see radiation coming from the "stationary" particle.

>> The concept of "Relative" velocity is therefore a flawed view of motion.

absolutely.... The Universe is "preferred frame" referenced.
The Sun is our centre of spin, the Earth is the Moons centre


and the galactic centre is the Suns centre of spin.

let me try and clarify. mac, is it your argument that one particle will produce a magnetic field and the other will not, no matter what frame of reference you choose?

No the frame does matter but that is where SRT fails. It holds that both have accelerated and both have velocity. Time dilation and Bremsstrahlung seem to dispute that since only the one that physically accelerates has any physical affects.

Mac, the radiation is due to acceleration *relative* to the detector. If you keep the detectors stationary relative to the other particle, you will see radiation coming from the "stationary" particle.

That is not the arguement. Read the definition again. An accelerating charged particle radiates photons. Now you want to argue that it radiates photons in one frame but not another.

No the frame does matter but that is where SRT fails. It holds that both have accelerated and both have velocity. Time dilation and Bremsstrahlung seem to dispute that since only the one that physically accelerates has any physical affects.

No Mac, SRT holds no such thing. SRT says that in one frame one of the particles has accelerated, and in another frame, the other particle has accelerated. Accordingly in one frame one of the particles is radiating, and in the other frame, the other particle is radiating.

No Mac, SRT holds no such thing. SRT says that in one frame one of the particles has accelerated, and in another frame, the other particle has accelerated.

I understand very well what relativity says. You don't seem to realize the consequences in physical terms.

Accordingly in one frame one of the particles is radiating, and in the other frame, the other particle is radiating.

Incorrect. That makes a nice rhetoric, however, you seem to forget that even in a "Rest" frame if the particle is accelerating then the EM field must be changing and any such change would be detectable in that frame.

Incorrect. That makes a nice rhetoric, however, you seem to forget that even in a "Rest" frame if the particle is accelerating then the EM field must be changing and any such change would be detectable in that frame.

Mac, just how the hell can a particle be accelerating in its own rest frame?

This is entertaining. After several years on this forum, MacM still doesn't understand rest frames.

I commend you for your non-conformance (even if caused by ignorance).

Mac, just how the hell can a particle be accelerating in its own rest frame?


Try asking that of James R since he claims the train station accelerates aways from the train. Keep in mind that I agree that an EM detector would not measure a static field and at a given velocity (inertial) the field would be static (i.e. - equivelent to rest).

HOWEVER, that is not true of an accelerating frame. In an accelerating frame the EM field is changing and would be measureable. Otherwise no transformer would work since the secondary and primary windings are in a common frame. The changing signal in the primary is the equivelent of the changing EM field of a charged particle due acceleration.

Therefore if SRT were valid and the train station indeed accelerates away from the train and each actually has velocity such that relative velocity affects are bonafide, then a change in the EM field must become present during the "Relative Acceleration" between particles which constitute the "Relative Velocity" upon which SRT is based.

If you wish to talk of acceleration
you can only refer it to the absolute field in that spin system.

It is meaningless to try and relate it to another body.

It is meaningless to try and relate it to another body.

If I understand this comment I think we agree. It is meaningless to suggest that when a train accelerates aways from the station that (according to relativists) the train station is accelerating away from the train .

I am still a bit fuzzy on the original gedanken experiment. I think you are mixing frames again.

Incorrect. That makes a nice rhetoric, however, you seem to forget that even in a "Rest" frame if the particle is accelerating then the EM field must be changing and any such change would be detectable in that frame.
could you explain how this makes sense? how do you accelerate and remain at rest simultaneously?

I am still a bit fuzzy on the original gedanken experiment. I think you are mixing frames again.


could you explain how this makes sense? how do you accelerate and remain at rest simultaneously?

Certainly. The same way James R and relativists claim the resting particle has velocity without having accelerated. :D

I do believe you are starting to get the point.

If it didn't accelerate then it doesn't have velocity. AND if it has velocity (SRT) then it must have accelerated and hence a changing EM filed and Bremsstrahlung would have been detected.

Also, if indeed uniform linear acceleration and acceleration of gravity are "Equivelent" then static charges would be Bremsstrahlung while at rest relative to the gravitating body.

Try asking that of James R since he claims the train station accelerates aways from the train.

You're confusing issues again. The train station does accelerate with respect to the train. That's completely irrelevant in this scenario though. The thing that determines if a particle radiates or not is whether or not it accelerates with respect to the frame you are measuring from.

HOWEVER, that is not true of an accelerating frame. In an accelerating frame the EM field is changing and would be measureable.

That's wrong. Radiation occurs when the particle is accelerating relative to the frame. It has nothing to do with whether or not the frame is inertial.

Otherwise no transformer would work since the secondary and primary windings are in a common frame. The changing signal in the primary is the equivelent of the changing EM field of a charged particle due acceleration.

What do transformers have to do with anything in this thread?

Therefore if SRT were valid and the train station indeed accelerates away from the train and each actually has velocity such that relative velocity affects are bonafide, then a change in the EM field must become present during the "Relative Acceleration" between particles which constitute the "Relative Velocity" upon which SRT is based.

In the frame where one of the particles is accelerating, that particle will radiate. In the frame where the other particle is accelerating, the other particle will radiate. In a frame where both are accelerating, both will radiate. There is no problem for SRT here, other than in your imagination.

If I understand this comment I think we agree. It is meaningless to suggest that when a train accelerates aways from the station that (according to relativists) the train station is accelerating away from the train .

It's not meaningless at all. It's just a simple fact. Acceleration is defined as change in velocity. Velocity is defined as change in displacement. The station's velocity relative to the train is changing, therefore it is accelerating relative to the train.



Certainly. The same way James R and relativists claim the resting particle has velocity without having accelerated.

I do believe you are starting to get the point.

If it didn't accelerate then it doesn't have velocity. AND if it has velocity (SRT) then it must have accelerated and hence a changing EM filed and Bremsstrahlung would have been detected.

Where do you come up with this ridiculous ideas? This is a gedanken. The particle can start the scenario with velocity and have never accelerated. Anyway, in every frame where the particle is observed to have accelerated, radiation is observed as well. So your complaint is utterly baseless.

Also, if indeed uniform linear acceleration and acceleration of gravity are "Equivelent" then static charges would be Bremsstrahlung while at rest relative to the gravitating body.

This is a misunderstanding of the General Equivalence Principle. It does not state that gravitation is equivalent to acceleration. It states that an accelerated frame is equivalent to a frame with a graviational field. In an accelerated frame, you still will not see radiation from a particle at rest in that frame. Accordingly, you will not see radiation from a particle at rest in a graviational frame.

>> The particle can start the scenario with velocity and have never accelerated. >>

not in the real world.

All particles with velocity are intrinsically always undergoing acceleration. All motion is orbitally referenced.

This acceleration maybe 'inertial acceleration' in your thoughts
inertial acceleration is always and solely in respect to the field spin (as in an orbit).

What most call acceleration is over and above this... it is non inertial acceleration.

But it is important to realise everything is accelerating at all times.
[nothing is inertial as per Newtonian inertia]

GMontag ,

An awfaul lot of double talk here. I'll see if I can correct it.

Try asking that of James R since he claims the train station accelerates aways from the train.

]You're confusing issues again. The train station does accelerate with respect to the train.

Thank you we now know your mentality and what to expect. The station "Does Not" accelerate . There are no forces of acceleration, no Bremsstrahlung, etc. Your arguement and James R, etc are oversimplified nonsense.

That's completely irrelevant in this scenario though. The thing that determines if a particle radiates or not is whether or not it accelerates with respect to the frame you are measuring from.

More nonsense. Acceleration is not a matter of measurement. Acceleration has with it a component of F as in F = ma. You and others like to ignore this simple physics fact and pretend that if you can't feel uniform motion then you are at rest. That is frankly assinine and leads to the total corruption of physics.

The error being made is to assume that equivelence in some respects means equivelent in all respects. It is not.

HOWEVER, that is not true of an accelerating frame. In an accelerating frame the EM field is changing and would be measureable.

That's wrong.

There is nothing incorrect in my statment. Your response is assinine.

Radiation occurs when the particle is accelerating relative to the frame. It has nothing to do with whether or not the frame is inertial.

And your response has nothing to do with my comment.

Otherwise no transformer would work since the secondary and primary windings are in a common frame. The changing signal in the primary is the equivelent of the changing EM field of a charged particle due acceleration.

What do transformers have to do with anything in this thread?

If you don't understand that, you don't understand physics or electronics.

Therefore if SRT were valid and the train station indeed accelerates away from the train and each actually has velocity such that relative velocity affects are bonafide, then a change in the EM field must become present during the "Relative Acceleration" between particles which constitute the "Relative Velocity" upon which SRT is based.

In the frame where one of the particles is accelerating, that particle will radiate. In the frame where the other particle is accelerating, the other particle will radiate. In a frame where both are accelerating, both will radiate.

And you have convieniently left out if an object accelerates in any frame it has with it an associated changing field which would be detectable in it's frame regardless of it's inertial status.

There is no problem for SRT here, other than in your imagination.

The problem is there and your deliberate effort to ignore it or bury it show your lack of imagination and understanding of actual physics.

If I understand this comment I think we agree. It is meaningless to suggest that when a train accelerates aways from the station that (according to relativists) the train station is accelerating away from the train .

It's not meaningless at all. It's just a simple fact. Acceleration is defined as change in velocity. Velocity is defined as change in displacement. The station's velocity relative to the train is changing, therefore it is accelerating relative to the train.

Again with the half assed physics. You left out the crucial aspect of acceleration which is F = ma. Relative velocity of a non-accelerting body caused by one object accelerating is only "Relative" acceleration, not real acceleration.

When you and other relativists eventually understand you are equating illusion with reality perhaps physics will once again begin to actually define the mechanics and why and how things occur.

Certainly. The same way James R and relativists claim the resting particle has velocity without having accelerated.

I do believe you are starting to get the point.

If it didn't accelerate then it doesn't have velocity. AND if it has velocity (SRT) then it must have accelerated and hence a changing EM filed and Bremsstrahlung would have been detected.

Where do you come up with this ridiculous ideas?

And where do you get off disregarding certain real physical facts because they are inconvenient to your concept of reality?

This is a gedanken. The particle can start the scenario with velocity and have never accelerated.

Agreed. And it has nothing to do with the discussion.

Anyway, in every frame where the particle is observed to have accelerated, radiation is observed as well. So your complaint is utterly baseless.

Only if you chose to ignore physics.

Yes or no. If a charged particle accelerates it has a changing EM field?

Yes or No. When you have a changing EM field is it detectable in the same frame? (i.e. - transformers)

Also, if indeed uniform linear acceleration and acceleration of gravity are "Equivelent" then static charges would be Bremsstrahlung while at rest relative to the gravitating body.

This is a misunderstanding of the General Equivalence Principle. It does not state that gravitation is equivalent to acceleration. It states that an accelerated frame is equivalent to a frame with a graviational field.

Double talk.

In an accelerated frame, you still will not see radiation from a particle at rest in that frame.

Then transformers do not work and we must start the industrial revolution all over.

Accordingly, you will not see radiation from a particle at rest in a graviational frame.

You will not see radiation if the "Equivelence Principle" is incomplete or incorrect.

I am not going to enter into the confusion errors here, but the title of thread is a little strange. MacM will just agrue with me and I am tired of that, no longer willing to expend effort to convence him SRT and relativity are the best model of many experimental results.

Cosmic bremstrahlung is one of the three types of experimental data that confirms relativity. It is surely the hardest to understand why this is true, but I can at least hint at why. The bending of light (gravitational lensing) and gravitational red shifts are relatively easy to see why they support / confirm relativity.

Bremstrahlung, as anyone knowing German might guess, occurs when a charged particle is violently deacelerated in a collision. The intensity of the cosmic Bremstrahlung is thus directly proportional to the density of both "stopping particles" and charged particles, which can be measured. I.e. there are other means of knowing the density of charged particles (most of ordinary matter is in space is ionized.) and line radiation is the path for this independent measurement of the charged particle density.

There is too much Bremstrahlung so there is some other non ordinary matter doing some of the "stopping" at this point is gets too complex for me, but this "dark matter" and relativity (I think) related to star velocities and thus get tied together, and only if relativity is correct does the measured Bremstrahlung data agree. (or something like that)

GMontag ,

An awfaul lot of double talk here. I'll see if I can correct it.

I'm sure your attempt will be a laugh riot.

Thank you we now know your mentality and what to expect. The station "Does Not" accelerate .

Of course it does, as I already showed you. Acceleration is simply the second derivative of displacement. It is non-zero for the station with respect to the train, therefore it is accelerating.

There are no forces of acceleration,

Irrelevant.

no Bremsstrahlung, etc.

If the station is charged, the train certainly will see the station radiate.

More nonsense. Acceleration is not a matter of measurement.

Honestly, Mac, have you ever even taken a Physics course? This is Mechanics 101. Acceleration is nothing more and nothing less than the second derivative of displacement.

Acceleration has with it a component of F as in F = ma.

Just because a force *can* be a cause of acceleration does not mean that every acceleration must have a force causing it.

There is nothing incorrect in my statment. Your response is assinine.

There was quite a bit wrong with your statement. You were implying that you would see radiation in a non-inertial frame from a particle that is at rest in that frame, which is simply wrong.

If you don't understand that, you don't understand physics or electronics.

I understand how transformers work perfectly fine. They still are completely irrelevant to the topic at hand.

And you have convieniently left out if an object accelerates in any frame it has with it an associated changing field which would be detectable in it's frame regardless of it's inertial status.

Once again, you simply have the physical facts utterly wrong. You will *never* see radiation due to an accelerating charge in a frame that is accelerating along with that charge. And btw, frames aren't associated with particles, they are associated with frames. The fact you don't seem to get is that electric and magnetic fields are not frame-invariant.

The problem is there and your deliberate effort to ignore it or bury it show your lack of imagination and understanding of actual physics.

Your continued imagination of a problem has no effect on reality.

Again with the half assed physics. You left out the crucial aspect of acceleration which is F = ma.

F=ma is not a part of the definition of acceleration at all. Seriously, Mac. Go pick up a vector based physics text and read through the first chapter.

Relative velocity of a non-accelerting body caused by one object accelerating is only "Relative" acceleration, not real acceleration.

*All* acceleration is relative. You have to specify some other point for displacement (and its derivatives) to have meaning.

When you and other relativists eventually understand you are equating illusion with reality perhaps physics will once again begin to actually define the mechanics and why and how things occur.

Since there is no way to differentiate this "illusion" from reality, it is silly to talk about it as if there is a difference.

And where do you get off disregarding certain real physical facts because they are inconvenient to your concept of reality?

And just what physical fact am I disregarding? The one you just made up off your ass? Particles don't start at rest just because you want them to, Mac. If you didn't observe it accelerate, directly or indirectly, you have absolutely no reason to believe it ever accelerated.

Yes or no. If a charged particle accelerates it has a changing EM field?

This question is meaningless for two reasons.

First, you didn't specify what the particle is accelerating relative to. The frame? Some other particle? Santa Claus?

Second, particles don't have fields. Frames have fields. Particles have charges.

To answer what I think what you would have asked if you actually had some idea of what you were talking about:

If a charged particle is accelerating in a frame, then yes, that frame's field will be changing.

If you are in the rest frame of a charged particle, inertial or not, then you will never see that frame's field change without another charged particle moving in that frame.

Yes or No. When you have a changing EM field is it detectable in the same frame? (i.e. - transformers)

Another unparseable question. Detectable in the same frame as opposed to what?

Certainly you can detect if a frame's field is changing at any given point in that frame by placing a detector at that point at rest in the frame. But a detector will only ever detect the field of its rest frame, not some other frame.

Double talk.

Translation: I didn't understand it.

Then transformers do not work and we must start the industrial revolution all over.

Do you even think about what you post before you type it, or do you just enjoy talking out your ass? Here's a hint, Mac. The electrons in the transformer windings aren't at rest relative to the transformer.

Bremstrahlung, as anyone knowing German might guess, occurs when a charged particle is violently deacelerated in a collision.

I guess you skipped my introductory comments about most jpeoiple believing Bremsstrahlung being only breaking energy.

I guess you also skipped clicking on the link I provided which gives a more full description regarding Bremstrahlung.

Where relativity is valid it is quite accurate. However, that does not alter nor excuse the fact that it is completely invalid in its overall presentation which includes reciprocity.

Once that is understood it becomes clear that emperical data only demonstrates an absolute view and invalidates the relative velocity view.

You have some catching up to do.

Bremstrahlung, as anyone knowing German might guess, occurs when a charged particle is violently deacelerated in a collision.

I guess you skipped my introductory comments about most people believing Bremsstrahlung being only breaking energy.

I guess you also skipped clicking on the link I provided which gives a more full description regarding Bremstrahlung.

Where relativity is valid it is quite accurate. However, that does not alter nor excuse the fact that it is completely invalid in its overall presentation which includes reciprocity of time dilation and mixes frames to claim length contraction. (i.e. - disregards physical conclusion of one frame and relables the affect in another frame).

Once that is understood it becomes clear that emperical data only demonstrates an absolute view and invalidates the relative velocity view.

You have some catching up to do.

Hi MacM, I read the reference you posted. It was quite interesting, but I don't see the conflict with (my limited understanding of) relativity. I certainly didn't get the impression that the authors of the reference thought they had something as groundbreaking as a proof against relativity would be.

One really interesting thing about the reference you provided was the formula for the cutoff frequency of the Bremstrahlung radiation, this was calculated as the inverse of the "interaction time". In the case of a massive charged particle accelerated by free-fall on earth the interaction time would be quite long and so the cutoff frequency would be very low. I think a careful experiment could probably detect it, but I don't know if any such experiment has been done.

In any case I don't think that the Bremstrahlung radiation has much to do with relativity. I think relativity just says that it doesn't matter if the detector is at rest on the groud and you drop the charged particle or if you drop the detector and the particle is on the ground. You should observe the same radiation in each case. You should also observe the same radiation if you are in orbit and accelerating (e.g. with a string) the detector relative to the particle with a=g or vice versa.

-Dale

Although this thread doesn't seem to me to be a proof against relativity it does bring up a point that I had not considered and that I find very confusing.

If the Bremstrahlung radiation is frame-dependent then it would seem that the existense of particles is also frame-dependent. In other words, lets say that I perform an experiment in my rest frame. I have an accelerating charged particle and a co-accelerating detector. I also have a stationary detector. The stationary detector will detect radiated energy and will therefore say that Bremstrahlung photons were produced while the accelerating detector will not detect any radiated energy and will therefore say that Bremstrahlung photons were not produced. I knew that different frames could disagree on time, distance, wavelength, and frequency, but I thought that all frames agreed on the existence of particles.

I think that all inertial frames in SR will agree if a given particle is accelerating and they will agree on the existence of the photons. They will disagree on the magnitude of acceleration, the rate of photon production, the wavelength, etc., but not the existence of the photons. In GR, however, it seems to me that not all inertial frames will agree if a given particle is accelerating since some inertial frames are mutually accelerating due to the spacetime curvature. This then should lead to a disagreement on the existence of the photons in addition to the other disagreements from SR.

Could someone with GR experience please explain what I am missing according to GR? Are these somehow "frame photons" similar to "frame forces" like the centripetal force? Or do you need to introduce "frame anti-photons" in non-inertial frames? How do mutually accelerating inertial frames affect the situation? Do the missing photons just get redshifted to zero in some frames and can be therefore considered to exist in all frames?

-Thanks
Dale

To DaleSpam:
Perhaps ths will help:
Imagine a long line of uniformly-spaced parallel bar magnets, but the "N up" ones alternate with the "S up" ones. Now cosider two observers, one, A, is at rest WRT the bar magnets and B traveling just above the tops of the magnets at such a high speed that the electric field (due to the dB/dt term in maxwell's equations) has the same energy content as the magnetic field for B. I.e. for B a photon exists and for A only a static magnet field.

The classical particle nature/concept that photon can display is creating in your mind (I think) the confict: either the particle does or does not exist.

Truth is (I think) the if you could travel with a photon, it cease to exist. All you can find are orthogonal static E and B fields - no photon. Now slow down a little -see the radio wave passing you? etc. Slow down greatly - see the photon zip by? etc. Note it die and eject an electron by Photo electric effect.

I don't have time now to clearly think thru your questions but hope these comments may hit some of the problem.

Hi MacM, I read the reference you posted. It was quite interesting, but I don't see the conflict with (my limited understanding of) relativity. I certainly didn't get the impression that the authors of the reference thought they had something as groundbreaking as a proof against relativity would be.

I did not intend to suggest that the authors of this in any way were applying it to relativity.

In any case I don't think that the Bremstrahlung radiation has much to do with relativity. I think relativity just says that it doesn't matter if the detector is at rest on the groud and you drop the charged particle or if you drop the detector and the particle is on the ground. You should observe the same radiation in each case. -Dale

My point had to do with the physics of acceleration affect on a charge.

Acceleration of a charged particle causes a changing EM field. A changing EM field is detectable in a rest frame of the particle (the basis for the referance to transformers where the field is changing and couples across the primary to secondary winding which are at rest to each other.)

It follows therefore that if you claim the station accelerated away from the train (an SRT view) then Bremsstrahlung must occur and be measuraeable since it would have a changing field. Since it doesn't then it suggests the view is flawed and "Relative Acceleration" and "Relative Velocity" are illusionary and not actual motion.

Physics should conclude the only actual acceleration and hence actual velocity is held by the object which under went the F = ma force.

If anything is ficticious (referance relativity and centrifugal force) it is relativity's claims of velocity for an object which has had no F = ma associated with relative velocity to some other object.

Acceleration of a charged particle causes a changing EM field. A changing EM field is detectable in a rest frame of the particle (the basis for the referance to transformers where the field is changing and couples across the primary to secondary winding which are at rest to each other.)

It follows therefore that if you claim the station accelerated away from the train (an SRT view) then Bremsstrahlung must occur and be measuraeable since it would have a changing field. Since it doesn't then it suggests the view is flawed and "Relative Acceleration" and "Relative Velocity" are illusionary and not actual motion.You are mixing too many metaphors for me to follow here. Is the train the particle or the detector? Similarly, is the transformer supposed to be the detector? Or perhaps the primary winding is the particle and the secondary winding is the detector? It would be helpful (to me) if you could dispense with the metaphors for a moment and just clearly describe the experiment you are proposing and the results you expect.

By the way, with all the metaphors I am not 100% sure if this is a point of confusion for you or not, but the train station and the train example is not symmetrical according to SR. In other words, any two inertial frames are symmetrical, but the train's rest frame is not inertial while it is accelerating away from the station. While the train is accelerating a dropped ball will appear to be pulled to the back by a "frame force". The same effect will not occur in the station's rest frame which is inertial.

That said, even though the situation is not symmetrical it is perfectly valid to talk about the frame force accelerating the station in the train's rest frame. In fact, it is necessary in order to properly describe the motion of the station in the train's rest frame.

The symmetry in GR is that a train in flat space accelerating at g is symmetrical with a person standing on the earth. Both are in a non-inertial frame which is accelerating at g and so dropped balls will appear to be pulled by a frame force. In other words, any two frames with identical frame forces are symmetrical and gravity is considered a frame force. The accelerating train and the inertial station do not have identical frame forces and are therefore not symmetrical according to GR either (at least according to my fairly weak understanding).

-Dale

Or perhaps the primary winding is the particle and the secondary winding is the detector?

Correct.

By the way, with all the metaphors I am not 100% sure if this is a point of confusion for you or not, but the train station and the train example is not symmetrical according to SR. In other words, any two inertial frames are symmetrical, but the train's rest frame is not inertial while it is accelerating away from the station. While the train is accelerating a dropped ball will appear to be pulled to the back by a "frame force". The same effect will not occur in the station's rest frame which is inertial.

We agree and this is not a point of confusion for me. It is however, for those that want to claim that the station accelerated away from the train - which is what James R and others have argued saying its changing relative velocity means it is accelerating.

My position is it is neither accelerating nor has velocity as a consequence of any other body's motion, only it's own and F = ma is required to have acceleration and consequently actual velocity change.

That said, even though the situation is not symmetrical it is perfectly valid to talk about the frame force accelerating the station in the train's rest frame. In fact, it is necessary in order to properly describe the motion of the station in the train's rest frame.

Here we disagree. It is where physics begins to go wrong. It is best to recognize the station status as a consequence of the trains motion. The inability to sense the trains inertial motion does not and has not altered the fact that it was the train that actually accelerated and under went F = ma.

The symmetry in GR is that a train in flat space accelerating at g is symmetrical with a person standing on the earth. Both are in a non-inertial frame which is accelerating at g and so dropped balls will appear to be pulled by a frame force. In other words, any two frames with identical frame forces are symmetrical and gravity is considered a frame force. The accelerating train and the inertial station do not have identical frame forces and are therefore not symmetrical according to GR either (at least according to my fairly weak understanding).-Dale

I have no dispute with this. But given the mandated reciprocity one MUST expect Bremsstrahlung of any charged particle under acceleration, be it uniform linear or gravitational (if you want to claim equivelence). I do not.

Acceleration of a charged particle causes a changing EM field.

The field will only change in frames where the particle actually accelerated. In the particle's rest frame, the field will not change. And btw, any motion causes a changing field, not just acceleration.

A changing EM field is detectable in a rest frame of the particle (the basis for the referance to transformers where the field is changing and couples across the primary to secondary winding which are at rest to each other.)

Wow, are you this dense naturally, or do you have to work at it? As I already pointed out to you, the electrons in the primary winding are not at rest relative to the secondary winding, or the electrons in it. The electrons in the primary windings are accelerating, moving back and forth, due to the AC current.

It follows therefore that if you claim the station accelerated away from the train (an SRT view) then Bremsstrahlung must occur and be measuraeable since it would have a changing field. Since it doesn't then it suggests the view is flawed and "Relative Acceleration" and "Relative Velocity" are illusionary and not actual motion.

In the frame where the station is accelerating relative to the frame, the station *is* radiating.

That said, even though the situation is not symmetrical it is perfectly valid to talk about the frame force accelerating the station in the train's rest frame. In fact, it is necessary in order to properly describe the motion of the station in the train's rest frame.Here we disagree. It is where physics begins to go wrong. It is best to recognize the station status as a consequence of the trains motion. The inability to sense the trains inertial motion does not and has not altered the fact that it was the train that actually accelerated and under went F = ma.Ok, maybe this will help. Lets consider an inertial frame X and an accelerated frame X* where x* = -1/2 g t² + x. In other words the frames are co-incident at t=0 and X* is accelerating relative to X in the positive direction at an acceleration of g.

Now, if we have particle A (aka the station) at rest on the orgin of X then, since X is an inertial frame, there are no forces acting on the particle. We can also express the motion of A in the X* frame. In particular, x_A*(t) = -1/2 g t² + 0. Because A is accelerating in X*, with a_A* = -g, and there are no real forces acting on A we must postulate a "frame force" of f_A* = -m_A g in order to explain its motion according to Newtons laws in X*: a_A* = f_A*/m_A = -g.

Now if we have a second particle, B (aka the train), starting at rest on the origin and we apply a constant force, f_B = m_B g, which is sufficient to accelerate it with an acceleration of g then we will have x_B(t) = 1/2 g t². We can translate x_B into the accelerating frame by x_B*(t) = -1/2 g t² + x_B(t) = 0. So B is at rest on the origin of the non-inertial frame X*. Because B is at rest in X*, so a_B* = 0, and B is experiencing an applied force of f_B we must postulate a frame force of f_B* = -f_B = -m_B g in order to explain its motion according to Newton's laws in X*: a_B* = (f_B + f_B*)/m_B = 0.

So in summary, in the reference frame X we see that A is stationary and B is accelerating at a_B = g. In the reference frame X* we see that B is stationary and A accelerates at a_A = -g. Since the choice of coordinate system is completely arbitrary the description of the motion is equally valid in each case. So it is just as valid to talk about A accelerating in X* as it is to talk about B accelerating in X.

Despite this, the situation is not symmetric because the frame forces only exist in X*. In X only a single force is needed to describe the motions, while in X* three forces are needed. Also, note that the presence of the frame forces dramatically changes the results of even simple physics experiments like throwing a ball, again highlighting the lack of symmetry. I don't know the original context of the train-station example, but I suspect that the knowledegable posters on this forum did not mean that the situation was symmetric simply because the acceleration can be validly described in either frame.

-Dale

Bremsstrahlung is associated with acceleration of charged particles. Accelerated charged particles produce radiation.

Take an electron travelling around a synchroton ring, for example. In the ground frame, the electron is accelerated, and so radiates. MacM seems to be asking - what happens if we go to the rest frame of the electron? Does it radiate or not? Because in its own rest frame, the electron isn't accelerating.

The answer is: in the electron's frame, it still radiates. Obviously, this must be true, since the radiated photons are detected in every frame. They can't exist in one frame and not exist in another.

Next question: WHY does the apparently unaccelerated electron radiate, in its own rest frame?

In the particle's rest frame, the field will not change. ... In the frame where the station is accelerating relative to the frame, the station *is* radiating.
in the electron's frame, it still radiates. Obviously, this must be true, since the radiated photons are detected in every frame. They can't exist in one frame and not exist in another.You two disagree. This is related to my post above (Today 06:46 PM EST). I don't know the answer and would appreciate some insight.

-Thanks
Dale

Wow, are you this dense naturally, or do you have to work at it?

I'll pass on the opportunity to return the negative innuendo in that James R seems to be hedging his bet slightly and I prefer to respond to him since he is sticking to physics.

As I already pointed out to you, the electrons in the primary winding are not at rest relative to the secondary winding, or the electrons in it. The electrons in the primary windings are accelerating, moving back and forth, due to the AC current.

You pointed out to me that electrons are moving in the primary? Nice. Since you are fairly new here let me educate you just a tad.

My background education and experience is mechanical, electrical and nuclear engineering, specialized in Process Control Intrumentation Systems. i.e. - Electronics, Pneumatics, Hydraulics, etc.

My point is the moving electrons provide a changing EM field, the same as an accelerating charged particle. The primary winding simulates an accelerating charged particle. The secondary winding which happens to in the same frame of referance, hence at relative rest with the charged particle (winding) is a detector. Get it now?. Or should I schedule more classes for you. Some people are naturally slower than others.

I don't know the original context of the train-station example, but I suspect that the knowledegable posters on this forum did not mean that the situation was symmetric simply because the acceleration can be validly described in either frame.-Dale

I appreciate all the effort you just put forth, however, it was not necessary.

My only point is I dispute the view where acceleration is defined in terms of a changing velocity in absence of the physical requirement for their to be the F = ma relationship.

I dispute the view which attribute an object to having velocity affects due to relative velocity caused by another object having accelerated.

Bremsstrahlung is associated with acceleration of charged particles. Accelerated charged particles produce radiation.

Take an electron travelling around a synchroton ring, for example. In the ground frame, the electron is accelerated, and so radiates. MacM seems to be asking - what happens if we go to the rest frame of the electron? Does it radiate or not? Because in its own rest frame, the electron isn't accelerating.

The answer is: in the electron's frame, it still radiates. Obviously, this must be true, since the radiated photons are detected in every frame. They can't exist in one frame and not exist in another.

Next question: WHY does the apparently unaccelerated electron radiate, in its own rest frame?

Well I'll be damned. :o You were the last one I expected to address the actual physics issue. However, my question isn't really why it radiates in it's own rest frame.

A particle in accelerated motion radiates. While in inertial motion it also radiates but that radiation is static and undectectable in it's frame. But while accelerating the EM is changing and during acceleration the EM becomes detectable in it's own frame.

My concern is the absence of detectable radiation of static charges under the acceleration of a gravity field "IF we are to accept the Equivelence Principle".

Or in your prior example, why one does not measure radiation from static charges in the train station, if indeed it physically accelerates away from the train as you have previously claimed.

My contention is simple. There is physics differances between acceleration via F = ma and apparent acceleration due to changing relative velocity by another object actually undergoing physical acceleration.

That physics makes a fatal error by not recognizing the differance. They are not equivelent and should not be treated equivelent as they are in relativity.

My contention is simple. There is physics differances between acceleration via F = ma and apparent acceleration due to changing relative velocity by another object actually undergoing physical acceleration.

Yeah, that's right.


That physics makes a fatal error by not recognizing the differance. They are not equivelent and should not be treated equivelent as they are in relativity.

Here's where you went wrong. Physics does recognize the difference. In particular, special relativity recognizes the difference. Any good undergrad physics book discusses exactly this issue in the context of the twin paradox.

From the Feynman Lectures on Physics, Vol. I, Section 16-2, "The Twin Paradox":

"[...]consider a famous so-called "paradox" of Peter and Paul, who are supposed to be twins, born at the same time. When they are old enough to drive a space ship, Paul flies away at very high speed. Because Peter, who is left on the ground, sees Paul going so fast, all of Paul's clocks appear to go slower, his heart beats go slower, his thoughts go slower, everything goes slower, from Peter's point of view. Of course, Paul notices nothing unusual, but if he travels around and about for a while and then comes back, he will be younger than Peter, the man on the ground! That is actually right; it is one of the consequences of the theory of relativity which has been clearly demonstrated. Just as the mu-mesons last longer when they are moving, so also will Paul last longer when he is moving. This is called a "paradox" only by the people who believe that the principle of relativity means that all motion is relative; they say, "Heh, heh, heh, from the point of view of Paul, can't we say that Peter was moving and should therefore appear to age more slowly? By symmetry, the only possible result is that both should be the same age when they meet." But in order for them to come back together and make the comparison, Paul must either stop at the end of the trip and make a comparison of clocks or, more simply, he has to come back, and the one who comes back must be the man who was moving, and he knows this, because he had to turn around. When he turned around, all kinds of unusual things happened in his space ship - the rockets went off, things jammed up against one wall, and so on - while Peter felt nothing.

So the way to state the rule is to say that the man who has felt the accelerations, who has seen things fall against the walls, and so on, is the one who would be the younger; that is the difference between them in an "absolute" sense, and it is certainly correct. "

Yeah, that's right.



Here's where you went wrong. Physics does recognize the difference. In particular, special relativity recognizes the difference. Any good undergrad physics book discusses exactly this issue in the context of the twin paradox.

From the Feynman Lectures on Physics, Vol. I, Section 16-2, "The Twin Paradox":

"[...]consider a famous so-called "paradox" of Peter and Paul, who are supposed to be twins, born at the same time. When they are old enough to drive a space ship, Paul flies away at very high speed. Because Peter, who is left on the ground, sees Paul going so fast, all of Paul's clocks appear to go slower, his heart beats go slower, his thoughts go slower, everything goes slower, from Peter's point of view. Of course, Paul notices nothing unusual, but if he travels around and about for a while and then comes back, he will be younger than Peter, the man on the ground! That is actually right; it is one of the consequences of the theory of relativity which has been clearly demonstrated. Just as the mu-mesons last longer when they are moving, so also will Paul last longer when he is moving. This is called a "paradox" only by the people who believe that the principle of relativity means that all motion is relative; they say, "Heh, heh, heh, from the point of view of Paul, can't we say that Peter was moving and should therefore appear to age more slowly? By symmetry, the only possible result is that both should be the same age when they meet." But in order for them to come back together and make the comparison, Paul must either stop at the end of the trip and make a comparison of clocks or, more simply, he has to come back, and the one who comes back must be the man who was moving, and he knows this, because he had to turn around. When he turned around, all kinds of unusual things happened in his space ship - the rockets went off, things jammed up against one wall, and so on - while Peter felt nothing.

So the way to state the rule is to say that the man who has felt the accelerations, who has seen things fall against the walls, and so on, is the one who would be the younger; that is the difference between them in an "absolute" sense, and it is certainly correct. "


I see you know how to mimic the comments of others but you seem to lack any ability to actually think. Invoking GR into the Twin Paradox does not resolve the debate over SR claims in the situation. Try again.

I see you know how to mimic the comments of others but you seem to lack any ability to actually think. Invoking GR into the Twin Paradox does not resolve the debate over SR claims in the situation. Try again.
If you read carefully, it didn't actually state anything about GR. In fact, the only thing needed to explain it is that Paul changes inertial frames when he turns around. No GR necessary, not even if we conceed that this requires an acceleration phase.

If you read carefully, it didn't actually state anything about GR. In fact, the only thing needed to explain it is that Paul changes inertial frames when he turns around. No GR necessary, not even if we conceed that this requires an acceleration phase.

Boy are you desperate. I would love to see you make such a turn around without GR.

I see you know how to mimic the comments of others but you seem to lack any ability to actually think. Invoking GR into the Twin Paradox does not resolve the debate over SR claims in the situation. Try again.

Riiiight... do you even read people's posts before you respond? The whole point was that SR can't predict the outcome of experiments designed to measure time dilation, since reference frames will need to accelerate relative to one another. You can phrase the experiment however you want, but at the end of the day you're always going to need a general theory to make the prediction. That's why the one is called the "special" theory and the other is called the "general" theory. One needn't "invoke" GR; it's obvious from their names that SR is only to be considered in the larger context of GR.


Boy are you desperate. I would love to see you make such a turn around without GR.

Exactly.

Moreover, you don't need much in the way of a general theory of relativity to resolve the twin paradox; all that is required is that the guy in the rocket feels the acceleration when he launches and turns around.

You have no business trying to "debunk" relativity if you don't already understand this stuff. The ideas you've been attacking are not relativity, but rather a set of common misconceptions about relativity, you fucking knucklehead.

I appreciate all the effort you just put forth, however, it was not necessary.

My only point is I dispute the view where acceleration is defined in terms of a changing velocity in absence of the physical requirement for their to be the F = ma relationship.

I dispute the view which attribute an object to having velocity affects due to relative velocity caused by another object having accelerated.My point is that both descriptions are internally consistent and both descriptions accurately calculate the motion. You may prefer one frame for any or no reason at all, but you need to realize that your preference is only a preference and not a proof against the validity of your non-prefered frames. Mathematically they are equivalent as shown. Since this thread is so thick with metaphors I think I will throw my own in.

You are saying, "The glass is half-full". GMontag, quadraphonics, and I think James R are saying "The glass is half-empty". I am saying, "The glass is equally well described as being half-full and half-empty and I can show it mathematically". URI is saying, "If I spin the glass real fast over my head the H2O2 stays in" but everyone ignores him. You then say, "It is silly to call the glass half-empty because you can only drink out of the full half". Everyone else pulls their hair out and says, "Just because we can call it half-full or half-empty doesn't mean that the empty half is the same as the full half". Meanwhile URI asks, "Can I get some ice? This stuff burns my throat."

Hmm, kind of long for a metaphor, but I had fun writing it anyway :D

-Dale

PS You may want to re-think your insistence on only using inertial frames since that means that you are agreeing with BillyT who also dislikes accelerating frames and frame forces.

My point is that both descriptions are internally consistent and both descriptions accurately calculate the motion. You may prefer one frame for any or no reason at all, but you need to realize that your preference is only a preference and not a proof against the validity of your non-prefered frames. Mathematically they are equivalent as shown. Since this thread is so thick with metaphors I think I will throw my own in.

You are saying, "The glass is half-full". GMontag, quadraphonics, and I think James R are saying "The glass is half-empty". I am saying, "The glass is equally well described as being half-full and half-empty and I can show it mathematically". URI is saying, "If I spin the glass real fast over my head the H2O2 stays in" but everyone ignores him. You then say, "It is silly to call the glass half-empty because you can only drink out of the full half". Everyone else pulls their hair out and says, "Just because we can call it half-full or half-empty doesn't mean that the empty half is the same as the full half". Meanwhile URI asks, "Can I get some ice? This stuff burns my throat."

Hmm, kind of long for a metaphor, but I had fun writing it anyway :D

-Dale

PS You may want to re-think your insistence on only using inertial frames since that means that you are agreeing with BillyT who also dislikes accelerating frames and frame forces.

I think we are talking past each other. A changing relative v does not mean something is accelerating. It may or may not be. It depends on if it is undgoing the F = ma. If not then it is neither accelerating or undergoing a change in velocity in universal terms. It means something else you are measuring against is accelerating and changing velocity.

The whole point was that SR can't predict the outcome of experiments designed to measure time dilation, since reference frames will need to accelerate relative to one another.

Completely false.

You can phrase the experiment however you want, but at the end of the day you're always going to need a general theory to make the prediction.

False.

That's why the one is called the "special" theory and the other is called the "general" theory. One needn't "invoke" GR; it's obvious from their names that SR is only to be considered in the larger context of GR.

False.

You have no business trying to "debunk" relativity if you don't already understand this stuff. The ideas you've been attacking are not relativity, but rather a set of common misconceptions about relativity, you fucking knucklehead.

See above jerk. Go troll somewhere else or go learn a bit about the subject before pretending to know it all.

Whoops, what I meant to write was not that SR can't predict the outcome of experiments to measure time dilation, but that it can't predict the outcome of experiments that would resolve the twin paradox. Which is exactly what you're hung up on here, with all of the stuff about distinguishing between apparent acceleration and the actual application of a force.

There is surely no more compelling method of argument than simply shouting "nuh-uh!!". Particularly when the person you're shouting at agrees that you have the basic ideas right, but have simply misunderstood the way in which the standard theories accomodate them. But then, it's pretty obvious that you're more interested in being an ass than contributing to anyone's understanding of physics, particularly your own.

I think we are talking past each other. A changing relative v does not mean something is accelerating. It may or may not be. It depends on if it is undgoing the F = ma.You are just plain wrong here. A changing v is the definition of acceleration: a = dv/dt (http://hyperphysics.phy-astr.gsu.edu/hbase/acca.html#c1 http://en.wikipedia.org/wiki/Acceleration http://scienceworld.wolfram.com/physics/Acceleration.html http://mathworld.wolfram.com/Acceleration.html http://dictionary.reference.com/search?q=acceleration) Newton's second law defines force, not acceleration.

By the way, did you miss the "frame forces" in the X* frame? I also am a big fan of Newton's second law, so I thoughtfully included frame forces in order to make sure that F = m a would be satisfied in the X* frame too.

-Dale

You are saying, "The glass is half-full". GMontag, quadraphonics, and I think James R are saying "The glass is half-empty". I am saying, "The glass is equally well described as being half-full and half-empty and I can show it mathematically".

The glass is full. Half of the composition of the contents of the glass is water, and the other half is air. Failure to recognize the existance of that which is not easily seen is a common error when examining the glass.

But, don't ask me how this applies to SR. :)

The glass is full. Half of the composition of the contents of the glass is water, and the other half is air.


Assume a glass in a vaccuum, half full of ice...

(You know how air introduces awkward complications to simple scenarios :p )

Boy are you desperate. I would love to see you make such a turn around without GR.
Desperate? Why?

Oh, and here: clicky. (http://math.ucr.edu/home/baez/physics/Relativity/SR/acceleration.html)

Whoops, what I meant to write was not that SR can't predict the outcome of experiments to measure time dilation, but that it can't predict the outcome of experiments that would resolve the twin paradox.

Why on earth would you say that?

Which is exactly what you're hung up on here, with all of the stuff about distinguishing between apparent acceleration and the actual application of a force.

Funny I'm not hung up on anything. I have presented certain physics claims and facts and have posed a question which you apparently either don't understand or can't answer. Which is it?

There is surely no more compelling method of argument than simply shouting "nuh-uh!!". Particularly when the person you're shouting at agrees that you have the basic ideas right, but have simply misunderstood the way in which the standard theories accomodate them.[/quoute]

I really don't understand where you are getting all this stuff.

[quote] But then, it's pretty obvious that you're more interested in being an ass than contributing to anyone's understanding of physics, particularly your own.

I responded above in that most of your post was acceptable. This close is typical of what started this pissing contest but I choose to ignore it this time and see where that leads.

Why on earth would you say that?

Because any such experiment would require acceleration, putting it out of the reach of SR. Or so I thought; FunkStar's link seems to say otherwise. I will review some references, but at the end of the day the biggest mistake I could've made is to refer to as GR what is actually part of SR, which actually strengthens my original point that SR doesn't have the flaw you imagine it to.


Funny I'm not hung up on anything. I have presented certain physics claims and facts and have posed a question which you apparently either don't understand or can't answer. Which is it?

James R answered your initial question satisfactorily in the second post of this thread. I have nothing to add to his explanation beyond the fact that relativity DOES distinguish between apparent acceleration due to choice of reference frames and the actual application of force. Thus, you are attacking a strawman.

Because any such experiment would require acceleration, putting it out of the reach of SR. Or so I thought; FunkStar's link seems to say otherwise. I will review some references, but at the end of the day the biggest mistake I could've made is to refer to as GR what is actually part of SR, which actually strengthens my original point that SR doesn't have the flaw you imagine it to.

Considering that you don't seem to understand what is GR and what is SR and/or how to seperate them as to function and/or testing, I find your evaluation of my understanding to be of little value.

James R answered your initial question satisfactorily in the second post of this thread. I have nothing to add to his explanation beyond the fact that relativity DOES distinguish between apparent acceleration due to choice of reference frames and the actual application of force. Thus, you are attacking a strawman.

You don't seem to understand the issue. The strawman as you put it is infact a very important physical consideration and that is that a definition of acceleration which is devoid F = ma as to its origin is a ficticious acceleration and should not be considered to create velocity affects.

Relative velocity is not physical velocity and that is where SRT has gone wrong. Emperical data does not support any time dilation affects occuring due to relative velocity alone. Emperical data only supports time dilation for relative velocity in an object that has actually accelerated and undergone F = ma.

There is not ONE case of the non-accelerated clock showing any relative velocity affect.

Considering that you don't seem to understand what is GR and what is SR and/or how to seperate them as to function and/or testing, I find your evaluation of my understanding to be of little value.Come off your high horse, MacM :rolleyes:. Quadraphonics is at least acting reasonably and willing to investigate the limits of his own knowledge. He will actually learn something. You, on the other hand, will continue in your stupidity (e.g. trying to use F = m a as the definition of acceleration). I think his willingness to study and learn is commendable while your deliberate ignorance is disgusting.

-Dale

You don't seem to understand the issue. The strawman as you put it is infact a very important physical consideration and that is that a definition of acceleration which is devoid F = ma as to its origin is a ficticious acceleration and should not be considered to create velocity affects.

Relative velocity is not physical velocity and that is where SRT has gone wrong. Emperical data does not support any time dilation affects occuring due to relative velocity alone. Emperical data only supports time dilation for relative velocity in an object that has actually accelerated and undergone F = ma.

There is not ONE case of the non-accelerated clock showing any relative velocity affect.

For fuck's sake buddy, I agree everything you've said except the assertion that SRT conflicts with it. That Feynman quote, from the "Relativistic Mass and Energy" chapter in the Feynman Lectures, can be considered as definitive. If you'd read it, you'd have noticed that he's emphatic on the point that the clock that the force was applied to is the one that runs slow. Please point me to one single reference on relativity that says otherwise or drop your contention that relativity conflicts with these facts.

And before you ask, no, further unsupported assertions by yourself that "only relative velocity matters in SRT" will not cut it. And no more weak-suck ad-hominems instead of substantiative answers. Ad-hominems are only funny if you put them at the end of reasoned posts, you witless piece of shit.

... you witless piece of shit.You should refrain from this type of comment, as I did, when MacM repeatedly called me much worse. - I was, among many other things, a full “sack of shit,” not just a piece. :D

I suggest restraint in this area because this area is MacM's only field of expertise, but in "DUCK and WEAVE" responce he is also very good.

Come off your high horse, MacM :rolleyes:. Quadraphonics is at least acting reasonably and willing to investigate the limits of his own knowledge. He will actually learn something. You, on the other hand, will continue in your stupidity (e.g. trying to use F = m a as the definition of acceleration). I think his willingness to study and learn is commendable while your deliberate ignorance is disgusting.

-Dale

Actually I cut him a lot of slack because he was admitting his errors and insufficancy. But those facts invalidated anything he had to say regarding my understandings.

Your assertion that requiring F = ma to be part of any acceleration is ignorant and disgusting is amusing. It certainly limits the value of your post as well.

...Your assertion that requiring F = ma to be part of any acceleration is ignorant and disgusting is amusing....I like to agree with you MacM when I can, so I state that you are correct if speaking of the acceleration of an object with mass. It is strange, as DaleSpan has noted, that your strong inclination to dispute anything I say has made you inconsistent.

You said (In the rest & motion thread):
"Frankly I reject those views and your arguement against centrifugal force."

My main argument against "centrifugal force" force is that to accept it as a force, would require making a list of exceptions to Newton's three laws, even in the very classical realm where they are valid.

This is very same argument you advancing here! I.e. In effect you are saying that if there is a non zero "a" then there is a non-zero force. Just as I say that if there is a force, then there is an 'equal and opposite" force (acting on the agent that applies the first force.)

I am consistent in this adherence to Newton. You, however, are not. When it suits you, you say I am wrong to reject centrifugal and Coriollis effects as forces on the grounds that they would require being listed as exceptions to Newton's three laws.

As it is not much trouble, I will try, once more, to educate you. (I remain convinced that you are smart, just ignorant.) As several have already tried to tell you, acceleration “a” is the second time derivative of position, BY DEFFINITION. Mass is (at least for me, although some more modern young guys may resort to complex GR math, and others may start to babble about Higgs bosons, etc.) an empirical net of relationship between an intrinsic characteristic of matter (and probably inertia is same also). - For example, roughly speaking, four normal hydrogen atoms have same amount of this intrinsic characteristic as one helium atom. Once you know these relative relationships, anyone can be set to unity or 10,000 etc. and you have "absolute masses" (numerical values with units) in that set of units. (Historically not this way, but related to pieces of metal, etc.)

OK so we have independent definitions of both the “m” and the “a” in Newton’s first law, F = ma.

Congratulations! You guessed it! (Before I got there, in my usual long-winded way.) This is the definition of “force.”

"Force" is a little bit messy as requires a known test mass and careful measurement of its dynamics, but soon you forget all about that and are weighing the fish you caught on a calibrated spring balance, etc.

Unfortunately, you seem to think F =ma defines acceleration, but a lot of your thinking is based on ignorance, so this is not surprising.

Your assertion that requiring F = ma to be part of any acceleration is ignorant and disgusting is amusing.That must be nice. I wish your deliberate ignorance were amusing to me instead of disgusting. It would sure make reading and responding to your posts more enjoyable.

Since you apparently missed it the first time:
I think we are talking past each other. A changing relative v does not mean something is accelerating. It may or may not be. It depends on if it is undgoing the F = ma.You are just plain wrong here. A changing v is the definition of acceleration: a = dv/dt (http://hyperphysics.phy-astr.gsu.edu/hbase/acca.html#c1 http://en.wikipedia.org/wiki/Acceleration http://scienceworld.wolfram.com/phy...celeration.html http://mathworld.wolfram.com/Acceleration.html http://dictionary.reference.com/search?q=acceleration) Newton's second law defines force, not acceleration.

By the way, did you miss the "frame forces" in the X* frame? I also am a big fan of Newton's second law, so I thoughtfully included frame forces in order to make sure that F = m a would be satisfied in the X* frame too.
-Dale

My main argument against "centrifugal force" force is that to accept it as a force, would require making a list of exceptions to Newton's three laws, even in the very classical realm where they are valid.Just to summarize for those that may not have read the other thread. Your objection to using non-inertial frames was that the required frame forces (a.k.a. ficticious forces: http://en.wikipedia.org/wiki/Fictitious_force) do not satisfy Newton's 3rd law. These frame forces (e.g. centrifugal force) are required in order to satisfy Newton's first two laws in the accelerated frame, but there is no reaction force to the frame force.

MacM's specific objection to the linearly accelerating frame is less clear. From his recent posts it seems to have something to do with Newton's first two laws (F = m a), but those laws are satisfied in the accelerated frame.

-Dale

MacM's specific objection to the linearly accelerating frame is less clear. From his recent posts it seems to have something to do with Newton's first two laws (F = m a), but those laws are satisfied in the accelerated frame.-Dale

Not in the case of relative velocity being generated by another object. That is two objects A and B at relative rest and then A accelerates undergoing F=ma.

It is inappropriate to claim that B is accelerating just because the relative velocity to A is changing. The relative velocity is not actual velocity regrdless of what current physics and relativity claim.

Emperical data nor logic support such conclusions. Your tendancy to call such solidly founded views ignorance, etc., only deminishes your own character.

My main argument against "centrifugal force" force is that to accept it as a force, would require making a list of exceptions to Newton's three laws, even in the very classical realm where they are valid.

I must admit that I haven't closely read the thread you refer to, but do you really not accept centrifugal force as a genuine force? As I understood it during classical mechanics, the fictitious forces arise merely by the way F = ma looks in the general (translated and rotated) case. They're no less real than other forces, though the name suggests otherwise.

...Your {Billy T's (my)} objection to using non-inertial frames was that the required frame forces I do not object to use of non- inertial frames. Only object to considering the "fictitious forces" to be real forces. I prefer to call them frame effects, because they do not satisfy Newton's 3rd law (or F = ma, see my next reply).

...These frame forces (e.g. centrifugal force) are required in order to satisfy Newton's first two laws in the accelerated frame, ...You may have a point wrt "A body at rest tends to remain at rest unless acted upon by an outside force" (see footnote) if one is unknowingly* using a rotating frame, sort of as I am while writng this on rotating Earth, but I completely miss understand you for the F = ma law. "m" is a scalar. "a" is a vectory pointing at the center of rotation. The centrifugal "force" is in the opposite direction to "a." I do not think Newton forgot the minus sign and meant to write F = - ma, do you? :confused:

I like all of his three laws, just the way they are, with no list of exceptions which includes Coriollis and “centrifugal“ forces.
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*If while I sleep tonight, I am magically transported to a fast spinning planet an placed in bed in a room that looks just like my bedroom (but unknown to me everything is glued in place), then when I awaken and pull the covers back, (surprisingly hard to do), and start to "float" slowly towards the ceiling, I also notice that the lose part of the cover is now standing straight up, I think I would suspect the truth, not that some unknown real force was pulling me and the lose end of the cover toward the ceiling, but I am not sure. Perhaps I would wonder what was the mysterious force acting on me for a while, at least at first, but most likely I would wonder: “What the hell has happened to the gravity force - I am following a straight line, off towards space - thank God, for the ceiling!” For a few horrible moments, I might even think “My God, MacM may be right and we are running out of uniKEF flux.” :eek:

Not in the case of relative velocity being generated by another object. That is two objects A and B at relative rest and then A accelerates undergoing F=ma.

It is inappropriate to claim that B is accelerating just because the relative velocity to A is changing.

No, it isn't. That is what acceleration means, by definition. Relative to A, B's acceleration is defined as the time derivative of its velocity (as a function of time) wrt. A. It doesn't matter that B isn't undergoing acceleration due to some force, such as A is relative to B, because neither the definition of position, velocity nor acceleration has anything to do with force.

The relative velocity is not actual velocity regrdless of what current physics and relativity claim.

Whadaya mean, not "actual" velocity? You mean, relative to A, B isn't moving? If so, I suggest you go outside, throw a few balls in the air, and convince yourself that from their position you aren't moving, especially when you have to walk twenty meters to pick them up.

Or is there also a MacM definition of velocity being something other than the first time derivative of the position function?

Emperical data nor logic support such conclusions.

You mean "Empirical data and logic supports such conclusions." As indeed they do.

Your tendancy to call such solidly founded views ignorance, etc., only deminishes your own character.
For a man now disputing Galilean relativity, obviously struggling with simple coordinate system changes, such insults hold no more weight than being character assasinated by a spoilt five-year old.

Quit your whining and come back when you've learnt something. Anything.

Hi Billy,

You may have a point wrt "A body at rest tends to remain at rest unless acted upon by an outside force" (see footnote) if one is unknowingly* using a rotating frame, sort of as I am while writng this on rotating Earth, but I completely miss understand you for the F = ma law. "m" is a scalar. "a" is a vectory pointing at the center of rotation. The centrifugal "force" is in the opposite direction to "a." I do not think Newton forgot the minus sign and meant to write F = - ma, do you? :confused:
In the rotating frame, the acceleration due to the centrifugal force is away from the center of rotation. If something at rest in the rotating frame (except at the centre) is not acted on by any other force, it will accelerate outward.

*If while I sleep tonight, I am magically transported to a fast spinning planet an placed in bed in a room that looks just like my bedroom (but unknown to me everything is glued in place), then when I awaken and pull the covers back, (surprisingly hard to do), and start to "float" slowly towards the ceiling, I also notice that the lose part of the cover is now standing straight up, I think I would suspect the truth, not that some unknown real force was pulling me and the lose end of the cover toward the ceiling, but I am not sure. Perhaps I would wonder what was the mysterious force acting on me for a while, at least at first, but most likely I would wonder: “What the hell has happened to the gravity force - I am following a straight line, off towards space - thank God, for the ceiling!” For a few horrible moments, I might even think “My God, MacM may be right and we are running out of uniKEF flux.” :eek:
If while you sleep tonight, you are magically transported to room that looks identical to your own bedroom but is inside the outer wall of a huge spinning space station, so large that the curvature of the floor is not measureable (like the curvature of the Earth), and spinning just fast enough that your actual centripetal acceleration is equal to the acceleration due to gravity, would you notice anything different?

If you drop a ball, which way does it accelerate in your frame?

....Whadaya mean, not "actual" velocity? ...MacM has special magical powers. He just knows when things actually occur or actually move. I have twice asked him to share them with us. He told me I did not know when the explosions (in thread "is time universal No and its proof") just because adjacent to the explosion was a stop watch stopped by the explosion.

Likewise, just because you carefully measure the rate of position change in your frame of reference, and think that is the velocity, it is not, if that results disagrees with MacM's current* special powers results for what is the Actual velocity. Don't think MacM is one of those fools who believes in an absolute reference frame. He will assure you that he does not and then argue as if he does.
____________________________________
*You must be a little sympathetic to MacM. He has been posting here for years, and it is hard to avoid being inconsistent, when you are making it up as you go along, instead of using physical laws and standard definitions. :D

PS get him to explain an “elastic scattering collision” to you some time for some real fun. Last time I heard, it was when the incident particle did not lose any energy, but that may have changed by now. Only the inelasting scattering events of uniKEF flux heat stars as the flux passes thru, but they are rare and “elastic scattering” events dominate. Etc.

...In the rotating frame, the acceleration due to the centrifugal force is away from the center of rotation. If something at rest in the rotating frame (except at the centre) is not acted on by any other force, it will accelerate outward....As usual, you are right Pete. I should have made it clear that I was still speaking of the case MacM brought up earlier. He had suggested that the "equal and opposite force" to the real centrifugal force was the wall pressing against my body as I was pressed against the rim of a rotating cylinder, or something like that. Thus according to MacM my dislike for centrifugal "forces" violating the third law was unfounded, but he put it a little more strongly than that. (I forget his exact terms, fortunately.)

I.e. what I said, and was talking about, was only this case with NO* motion in (wrt) the rotating frame. I.e. object is, to use your words, "acted on by any other force" that supplies its real acceleration, or keeps it motionless wrt rotating frame.
___________
* this critical word was accidently left out priot to edit. (I am tired and dyslexic. going to bed now.)

...If while you sleep tonight, you are magically transported to room that looks identical to your own bedroom but is inside the outer wall of a huge spinning space station, so large that the curvature of the floor is not measureable (like the curvature of the Earth), and spinning just fast enough that your actual centripetal acceleration is equal to the acceleration due to gravity, would you notice anything different?

If you drop a ball, which way does it accelerate in your frame?On first guestion, I strongly doubt it if still in bed, but possibly if I stand up, certainly if I can carefully jump to the ceiling and touch it.

On second ball question, it will not fall straight down as it should, but hit the floor a little behind that spot, by {1- (r/R)}R, I think, quickly done, so may not be correct. R is the floor distance from center of rotation, and r that of the ball when released.

As I understood it during classical mechanics, the fictitious forces arise merely by the way F = ma looks in the general (translated and rotated) case. They're no less real than other forces, though the name suggests otherwise.

I could accept that but the relativists seem to want to declare it is non-existant.

No, it isn't. That is what acceleration means, by definition. Relative to A, B's acceleration is defined as the time derivative of its velocity (as a function of time) wrt. A. It doesn't matter that B isn't undergoing acceleration due to some force, such as A is relative to B, because neither the definition of position, velocity nor acceleration has anything to do with force.

Whadaya mean, not "actual" velocity? You mean, relative to A, B isn't moving? If so, I suggest you go outside, throw a few balls in the air, and convince yourself that from their position you aren't moving, especially when you have to walk twenty meters to pick them up.

Or is there also a MacM definition of velocity being something other than the first time derivative of the position function?

Now if you are through babbeling, THINK. You just said the magic words "first time derivative of the position function".

Make a graph showing A & B at rest (position A1 and B1). Now plot A & B after A has undergone F = ma acceleration and where A and B have had relative velocity.

Hmmm. We now have A2 and B2. Guess what B1 and B2 are in the same location. B did not move. Yet you want to argue that it accelerated and that it had velocity. That defies your own criteria.

More importantly I know and don't care what is the commonly accepted view. I'm trying to educate you and others to think. Only when you have enough knowledge and understanding to form your own opinions independant of what anybody else says can you claim to understand reality. You may or may not be right but you will at least be stating your own view and not merely being a parrot.

You mean "Empirical data and logic supports such conclusions." As indeed they do.

They damn sure do not. Please post for us ONE case of recorded reciprocity of time dilation. Please post evidence, much less proof of length contraction.

The fact is if I place meter markers between earth and Alpha Centuri (4.3 lyr) and then fire a rocket and accelerate to 0.866c. (Note 0.866c = 259,620,268.6 m/s).

You would argue (if you accept Special Relativity) that the clock aboard the rocket was only ticking at 1/2 the rate of your earth based clock.

According to your earth clocks it would take the rocket 4.965 years to make the trip (excluding acceleration and deceleration times). But the clock aboard the rocket would have recorded only 2.4826 years and you claim since he was traveling at 0.866c that he therefore could only have traveled 2.15 lyr. Hence space was contracted by 1/2.

That however is not logical nor justified since you are ignoring the dilated clock tick rate used to measure the distance via d = vt.

The reality is that if you observed the meter markers along the way and with the rocket moving at 0.866c relative to earth observers, since the rocket clock was ticking slow he would see markers passing by at the rate of 519,240,537.3 m/s. That means the rocket pilot would conclude he was moving at 1.732c!!!.

That is what actual physics and logic support. Not spatial contraction per SRT. At v = c space does not contract to zero, velocity aboard the rocket appears to be infinite and travel to anywhere instantaneous because clocks have stopped. That is what any rational person should conclude and why relativity should be abandoned (or substantially modified).

Quit your whining and come back when you've learnt something. Anything.

Ditto. Lets see you satisfactorialy argue length contraction to the contrary.

Now if you are through babbeling, THINK. You just said the magic words "first time derivative of the position function".

Actually, no, I didn't. But no matter.

Make a graph showing A & B at rest (position A1 and B1).

Ok. So the coordinate system we're in has A & B at rest. Fine.

Now plot A & B after A has undergone F = ma acceleration and where A and B have had relative velocity.

Hmmm. We now have A2 and B2. Guess what B1 and B2 are in the same location. B did not move. Yet you want to argue that it accelerated and that it had velocity. That defies your own criteria.

No, it doesn't, because you conveniently left out the final, and vital part of the sentence: "wrt. A". Come on, Mac. This is Galilean relativity - a simple coordinate change. You must be able to understand this. And in the coordinate system that has A at rest (which is what "wrt. A" means) B of course accelerated.

More importantly I know and don't care what is the commonly accepted view. I'm trying to educate you and others to think. Only when you have enough knowledge and understanding to form your own opinions independant of what anybody else says can you claim to understand reality. You may or may not be right but you will at least be stating your own view and not merely being a parrot.

MacM, this isn't philosophy. There's no value to be gained in arguing over such simple concepts as position, velocity and acceleration functions. If you want to abandon the usual definitions, fine, but don't presume that anybody will agree that they are somehow "wrong", because of your personal (and strange) dislike of them.

They damn sure do not. Please post for us ONE case of recorded reciprocity of time dilation. Please post evidence, much less proof of length contraction.

Nobody has been able to get you to conjure up a definition of this reciprocity, so I'll merely remind you that I have in fact posted an article (from PRL) on length contraction in the past.

The fact is if I place meter markers between earth and Alpha Centuri (4.3 lyr) and then fire a rocket and accelerate to 0.866c. (Note 0.866c = 259,620,268.6 m/s).

You would argue (if you accept Special Relativity) that the clock aboard the rocket was only ticking at 1/2 the rate of your earth based clock.

According to your earth clocks it would take the rocket 4.965 years to make the trip (excluding acceleration and deceleration times). But the clock aboard the rocket would have recorded only 2.4826 years and you claim since he was traveling at 0.866c that he therefore could only have traveled 2.15 lyr.

No. In my frame of reference he traveled 4.3 light years.

Hence space was contracted by 1/2.

The space that was moving at 0.866c with respect to the rocket is contracted to half it's rest length, correct.

That however is not logical nor justified since you are ignoring the dilated clock tick rate used to measure the distance via d = vt.

See, you keep bringing this up as if it's profound. It's not; it's just wrong. Here's the thing: Even in Galilean relativity, mixing measures between coordinate systems is nonsensical. Let's go back to the A/B example. Your using the dilated clock time in the frame it doesn't belong to is equivalent to me stating that since from A's viewpoint A has no velocity, B can't possibly have A moving, because d = 0*t = 0. It's nonsense, nothing more.

The reality is that if you observed the meter markers along the way and with the rocket moving at 0.866c relative to earth observers, since the rocket clock was ticking slow he would see markers passing by at the rate of 519,240,537.3 m/s. That means the rocket pilot would conclude he was moving at 1.732c!!!.

Only if he accepts that those markers are a meter apart, something that he could easily measure to be false - in his frame. See, you're implicitly assuming that length is absolute, and that simply isn't true.

That is what actual physics and logic support. Not spatial contraction per SRT. At v = c space does not contract to zero, velocity aboard the rocket appears to be infinite and travel to anywhere instantaneous because clocks have stopped. That is what any rational person should conclude and why relativity should be abandoned (or substantially modified).
I'll not argue the wrong points here. MacM, when will you get it through your thick skull that nature doesn't care how you think it ought to behave?!

Now if you are through babbeling, THINK. You just said the magic words "first time derivative of the position function

Actually, no, I didn't. But no matter.

************************* Extract *************************
Oh really? Here

Or is there also a MacM definition of velocity being something other than the first time derivative of the position function?
************************************************** *******

No, it doesn't, because you conveniently left out the final, and vital part of the sentence: "wrt. A". Come on, Mac. This is Galilean relativity - a simple coordinate change. You must be able to understand this. And in the coordinate system that has A at rest (which is what "wrt. A" means) B of course accelerated.
No it doesn't. What about your view is invalid physics do you not understand. I am not saying it is not what is generally done or accepted. I am saying it is BS and needs to be changed.

MacM, this isn't philosophy. There's no value to be gained in arguing over such simple concepts as position, velocity and acceleration functions. If you want to abandon the usual definitions, fine, but don't presume that anybody will agree that they are somehow "wrong", because of your personal (and strange) dislike of them.

You can lead the horse to the water but you cannot make him drink. Your refusal to acknowledge the merits of the arguement doesn't alter the merits.

Nobody has been able to get you to conjure up a definition of this reciprocity,

I have posted the Special Relativity description of "reciprocity" many times. You can choose to continue to ignore it but that doesn't make it go away.
so I'll merely remind you that I have in fact posted an article (from PRL) on length contraction in the past.

Yes, having to do with changes in magnetic fields as I recall. What does that have to do with "Spatial Contraction"? Remember I maintain dimensional contraction of material objects even in my own work. It is spatial contraction which is not valid.

No. In my frame of reference he traveled 4.3 light years.
Yes. I said that. But your assertion that distance contracted because he clocked the trip in one half the time is bogus.

If you maintain that clock A ticks at 50% the rate of your clock and you are computing distance by d = vt, where "t" is the accumulated time indicated on the clock then it is assinine to not retain the respective tick rates of the clocks.

The correct formula must be d = v * t*gamma; in which case it can be seen distance did not change at all and the differance is indeed in the tick rate of the clocks.

The space that was moving at 0.866c with respect to the rocket is contracted to half it's rest length, correct.

Not correct. As I have stated above. It is the error advocated by SR but it is not correct.

See, you keep bringing this up as if it's profound. It's not; it's just wrong. Here's the thing: Even in Galilean relativity, mixing measures between coordinate systems is nonsensical. Let's go back to the A/B example. Your using the dilated clock time in the frame it doesn't belong to is equivalent to me stating that since from A's viewpoint A has no velocity, B can't possibly have A moving, because d = 0*t = 0. It's nonsense, nothing more.

What? Try again. This is nonsense.

Only if he accepts that those markers are a meter apart, something that he could easily measure to be false - in his frame. See, you're implicitly assuming that length is absolute, and that simply isn't true.

It is true and length only changes in your theory because you alter the units of measure (time) and disregard that you did so. Call time a ruler, now artifically expand the ruler compared to the standard against which you are comparing. Certainly the distance measurement changes but distance didn't. Don't be so thick headed.

I'll not argue the wrong points here. MacM, when will you get it through your thick skull that nature doesn't care how you think it ought to behave?!

Ditto. One day you and many others will have to wipe the smirk off your faces when it becomes apparent SR can no longer be sustained becuase of its internal construct conflicts.

Actual physics doesn't have infinite densities, singularities, reciproicty of time dilation, relavistic mass changes or spatial dimenional change (spatial length contraction). It all works just fine (in fact far better) without them.

I must admit that I haven't closely read the thread you refer to, but do you really not accept centrifugal force as a genuine force? As I understood it during classical mechanics, the fictitious forces arise merely by the way F = ma looks in the general (translated and rotated) case. They're no less real than other forces, though the name suggests otherwise.You are exactly correct about the source of the frame forces (http://en.wikipedia.org/wiki/Fictitious_force).

As to wether or not the frame forces are "real" that is a bit more difficult to pin down. On the other thread 2inquisitive made the excellent point that frame forces are required to explain some very real physical effects in the accelerated frame (e.g. earth's equatorial bulge or stress in turbine blades). In the accelerated frame they can accelerate objects, do work, cause stress and strain, etc. All very real and measurable effects. Therefore 2inquisitive (and NASA) did not like the term "ficticious" force. (That is why I have been using the term "frame" force because it emphasizes the source without de-emphasizing the very real effects it can have.) Can something that is not "real" be used to explain such real effects?

On the other hand BillyT made the equally excellent point that frame forces do not follow Newton's third law. In other words, they accelerate objects, do work, cause deformations, and otherwise follow F = m a like real forces do, but they do not have an equal and opposite reaction force. Can you call something a "real" force if it does not follow all the laws governing forces?

I can see the argument either way, however, as an engineer I am very fond of coordinate transformations. They vastly simplify so many problems that I would not want to get rid of them. So I prefer to treat the frame forces as real in the non-inertial frame, with the understanding that "all forces are real but some are more real than others". Although BillyT does not like the idea of making this list of "reaction exempt" forces, I think it is not too difficult since the list has only one entry: frame forces. In any case, if you are talking only about the acceleration of two non-interacting bodies then there are no reaction forces to consider so there is no conflict (other than semantics) between BillyT's and 2inquisitive's positions.

-Dale

You may have a point wrt "A body at rest tends to remain at rest unless acted upon by an outside force" (see footnote) if one is unknowingly* using a rotating frame, sort of as I am while writng this on rotating Earth, but I completely miss understand you for the F = ma law. "m" is a scalar. "a" is a vectory pointing at the center of rotation. The centrifugal "force" is in the opposite direction to "a." I do not think Newton forgot the minus sign and meant to write F = - ma, do you? :confused:No Newton did not miss a minus sign. The point is that in the non-rotating frame the centripetal force causes you to accelerate towards the center of rotation. There is an acceleration and there is no centrifugal force. But in the rotating frame the situation is different: you are not accelerating at all. Therefore in the rotating frame there must be a centrifugal force in the opposite direction to balance out the centripetal force. This is the source of the minus sign for the centrifugal force. If you look at http://en.wikipedia.org/wiki/Fictitious_force you will see the general derivation of the minus sign in the "general definition" section.

-Dale

If while you sleep tonight, you are magically transported to room that looks identical to your own bedroom but is inside the outer wall of a huge spinning space station, so large that the curvature of the floor is not measureable (like the curvature of the Earth), and spinning just fast enough that your actual centripetal acceleration is equal to the acceleration due to gravity, would you notice anything different?

If you drop a ball, which way does it accelerate in your frame?The Coriolis force could eventually give it away, but with a sufficiently large and slowly rotating space station it would be very difficult to detect inside a normal-sized bedroom. I haven't done the math, so I could be wrong, but I believe that there would be one particular radius that would even give the exact same Coriolis force as experienced at any given lattitude. Then you could be completely fooled into thinking that you were still in your room on earth.

Hmm, sounds like great fodder for an alien-abduction novel. The protagonist woke up during the abduction and is having flashbacks. Meanwhile everyone thinks he is crazy and he is trying to prove he is right. You would have to do some real literary work to make the physics experiments interesting.

-Dale

MacM has special magical powers. ... I have twice asked him to share them with us.
You just said the magic words "first time derivative of the position function".Hmm, perhaps he has shared them with us. I don't know if any blood or hair etc. is required for the spell, bu