Einstein's Special Relativity Fails?

[quantum quack]

The problem I see is that to accommodate what we think is the nature of light rest frames are necessary.

 

SRT is a natural outcome based on the invariance of velocity postualte. If we accept that lights velocity is invariant to all observers then the rest must follow. I can accept that that is the way it is, IF we accept that lights velocity is invariant. And at this stage there is no reason to think other wise.

 

But I wonder if the problems with SRT are simply because we do not understand the nature of light properly, just as we do not understand the nature of gravity either.

If someone came along and proved that light was a local effect and had no velocity per se, then all this problem dissappears.

[Mac]

There is a difference between absolute rest and an chosen rest frame. The absolute type is a frame that has no motion at all against which all else is measured. Its like a perfect measuring rod with absolute time being some perfect background clock against which all else is measured. A chosen rest frame can have motion even though being chosen it becomes the frame against which other frames are measured as if it was some rest frame. The first as far as we can tell in nature does not exist. Though there has been some debate about prefered frames which is a bit different. But the debate is one area in which relativity has been questioned a bit as of late. Some of the subtile difference on this shows up in the fact that an absolute rest frame under Newton was considered a prefered frame. Yet, in most of the modern debate it would be a non-rest frame that is seen as a prefered frame.

 

One reason most of us try and refer people to books is there may be a lot of net sources, but there is also a lot of garbage on the net also, which one can get misstatements, etc from. However, I believe one can access most of Einstein's own published works on both STR and GR on the net through some of the educational Institute sites out there which would also be a good source. Another site I know has a lot of decent relativity explination on is: http://www.geocities.com/zcphysicsms/sr.htm for SRT and http://www.geocities.com/zcphysicsms/ for GR. He is decent and even goes into an explination of some of the more odder aspects out of GR as well as being a co-author on a few papers out there himself. The way his site is designed is as a teaching aid.

 

 

I think Article XII and XIII are of greater interest but then I prefer new information to recitations of old speculations.

 

 

http://www.physicsnews1.com/articles.html

[paultrr]

Lorentz transformations cannot be globally defined except on Minkowksi spacetime, and cannot be locally defined except on locally flat spacetimes that have vanishing Riemann

tensor. An artifically engineered frame that is at rest artificially, here and in orbit to each other with more than one rest frame, is not a Minkowski spacetime.

 

A frame of reference is a purely kinematical device, for the geometrical description of motion without regard to the masses or forces involved. We use frame of reference as a standard relative to which motion and rest may be measured; any set of points or objects that are at rest relative to one another enables us, in principle, to describe the relative motions of bodies. But again it is a kinematical device only. The GPS case has both the orbital frame and the earth frame as at rest relative to each other via the programming. In effect there is now no way to distinguish between frames in this system as long as the programming remains in effect. Both frames have become the at rest frame from the different clock perspectives.

[TeleMad]

Mac: You are looking at "Angular Velocity" (period) as being the relative velocity.

 

False. Let me explain.

 

Here’s the general setup for relative motion. There are 3 observers: one, whose frame of reference we are considering things from originally, is at rest and the other two are in uniform motion relative to the first. We’ll use R, F, and S for the observers, indicating Rest, Faster, and Slower observers. We know the velocities for F and for S relative to R, but we don’t know the relative velocity between F and S: that’s what we need to find. When we obtain the answer for relative velocity, it will tell us how fast observer S would measure observer F to be moving: that is, the velocity of F from S's frame of reference.

 

Here’s a quote from a college physics text (this is in the front portion of the book, before relativity’s effects are taken into consideration: but the relativistic version does the same thing).

 

3.6 Relative Velocity

Observers in different frames of reference may measure different displacements or velocities for an object in motion. That is, two observers moving with respect to each other would generally not agree on the outcome of a measurement.

 

For example, if two cars were moving in the same direction with speeds of 50 mi/h and 60 mi/h, a passenger in the slower car would measure the speed of the faster car relative to the slower car as 10 mi/h. Of course, a stationary observer would measure the speed of the faster car as 60 mi/h. This simple example demonstrates that velocity measurements differ in different frames of reference.

 

We solved the previous problem with a minimum of thought and effort, but you will encounter many situations in which a more systematic method for attacking such problems is beneficial. …

 

We want to know Vfs, which is the velocity of the faster car with respect to the slower car.” (College Physics: Fifth Edition, Raymond A Serway & Jerry S Faughn, Harcourt College Publishers, 1999, p66)

 

Again, the setup is that we know the velocities of F and of S relative to R, but not the relative velocity between F and S. When we find it, the relative velocity between S and F tells us how fast S would measure F to be moving: that is, the velocity of F from S's frame of reference.

 

In the GPS example, we were given the velocities of a surface clock and a satellite clock and needed to determine the relative velocity between them. The answer - the relative velocity between the surface clock and the satellite clock in the GPS example - will tell us how fast an observer at the surface would measure the satellite clock to be moving: that is, the satellites velocity from the surface clock's frame of reference.

 

With that standard usage of the term relative velocity, your statements, Mac, that the relative velocity between the surface clock and the satellite clock would be the same no matter what angle the satellite’s path takes relative to the equator is wrong.

 

Now, if you used a different meaning for relative velocity, you should have explicitly stated what your non-standard usage of the term was.

 

 

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And let me point out again that if one wants to consider SPECIAL relativity then one should look at frames of reference that are moving in a straight line at constant speed relative to one another. This is NOT the case with the GPS system.

[TeleMad]

Now for the third time:

 

"What is the relative velocity between any surface point and a geosynchronous orbiting satellite.?'

 

That question is irrelevant to any of the points I am making. That's why I am ignoring that question of yours.

 

See my last post just above to see two of the main points I am making.

[TeleMad]

TeleMad: Neither has it been shown to NOT occur. The results are consistent with reciprocity considering the predictions of special relativity (once one takes into account the fact of the relativity of simultaneity).

 

Mac: Simultaneity has nothing to do with reciprocity.

 

Sure it does. It solves the APPARENT paradox you keep harping on. Did you forget about this?

 

"There seems to be a big problem with time dilation: "Moving clocks run slow", but who's to say which clock is moving? If clock B sees clock A move by and concludes that clock A is "running slow", why can't clock A claim to see clock B go by and conclude that B is "running slow"? It can! There's no contradiction, because of another remarkable implication of the principle of relativity: Two events that are simultaneous (i.e., that occur at the same time) in one frame of reference are not simultaneous in another frame moving relative to the first. It is this relativity of simultaneity that allows two observers in relative motion to see each other's clocks "run slow", without contradiction." (Einstein's Relativity and the Quantum Revolution: Modern Physics for Non-Scientists: 2nd Edition)

 

But of course you just pretend that a solution doesn't exist.

 

Mac: Reciprocity is the equal relavistic affect upon two observers having relative velocity.

 

Right, so, simply put, observer A sees observer B’s clock to run slow, and observer B sees observer A’s clock to run slow. A paradox? Nope, just an APPARENT one, resolved once one takes into account the fact that two events that are simultaneous in one frame of reference are not simultaneous in a second frame moving uniformly between the same two events. See the above quote from Professor Richard Wolfson.

 

 

Mac: Time dilation has been recorded in jet airplanes (H&K Atomic Clock Tests).

 

So what human was inside of those atoms?

 

Did you not want two different observers to actually measure time dilation from within the two different frames of reference in a single experiment?

 

There was no human observer in the atoms, there was no human observer in the muons used in the Mt. Washington experiment, and there are no human observers inside particles speeding through particle accelerators.

 

Now, do you have an actual way that we could directly measure time dilation from both of two different frames of reference moving in a straight line at constant speed with respect to one another, in a single experiment?

 

 

Mac: Please explain how such experiments are consistant with reciprocity when they infact their results invalidate it? They are consistant only with the gamma function, NOT Special Relativity.

 

So the experiments show that the laws of physics are NOT the same in all uniformly moving frames of reference? And you’ve shown this? Please point it out again because, gee, I must have missed it! :-)

[TeleMad]

Mac: You started your replies in this thread arguing that SR and GR were part of and required for GPS to function.

 

Now you're stooping to stuffing words into my mouth. Tsk tsk, for shame Mac.

[TeleMad]

Mac: Why on earth would anybody spend 13 cents much less $13 to be filled with stupid arguements.

 

I wouldn’t expect anyone to do that. But then again, that is not what I am suggesting. I am suggesting the pay $13.95 to learn why Einstein and the physics community at large is right, and you are wrong. That’s useful information.

 

Mac: Not to mention others (I at least) have already read such books …

 

So why don’t you actually explain what is wrong with Wolfson’s resolution of the APPARENT contradiction? Well?

[TeleMad]

TeleMad: [The resolution to the APPARENT contradiction is] based on the relativity of simultaneity, just as I've been saying all along.

 

And, anyone who wants to know badly enough to spend a mere $13.95 can find a clear and detailed explanation of the way out of the APPARENT contradiction by buying Richard Wolfson's Simply Einstein: Relativity Demystified" and reading chapter 10 The Same Time?, just as I've been pointing out repeatedly.

 

So why don't you read that explanation and tell us why it is (in your opinion) flawed, instead of pretending it doesn't even exist?

 

Mac: Unfortunately you are blowing smoke. Simultaneity has nothing what-so-ever to do with reciprocity.

 

Nope, wrongo!

 

"There seems to be a big problem with time dilation: "Moving clocks run slow", but who's to say which clock is moving? If clock B sees clock A move by and concludes that clock A is "running slow", why can't clock A claim to see clock B go by and conclude that B is "running slow"? It can! There's no contradiction, because of another remarkable implication of the principle of relativity: Two events that are simultaneous (i.e., that occur at the same time) in one frame of reference are not simultaneous in another frame moving relative to the first. It is this relativity of simultaneity that allows two observers in relative motion to see each other's clocks "run slow", without contradiction." (Einstein's Relativity and the Quantum Revolution: Modern Physics for Non-Scientists: 2nd Edition)

[TeleMad]

quantum quack: So how can we justify claiming artificially that a frame is at rest when it is obviously not at rest.

 

Because all objects in that frame share the same motion.

 

For example, I am at my computer. There are a slew of books strewn across the floor in a circle around my chair. I observe them to be at rest. I also observe my TV to be at rest. In addition, I observe my stereo system, my lamp, my DVD player, my couch, my walls, my ceiling, my floor, my washing machine, and so on, all to be at rest. And relative to them, I too am at rest. From within this frame of reference I and everything I mentioned in it in it are at rest. From this perspective, it makes perfect sense to say this frame of reference is at rest. After all, isn't that what the phrase "at rest" implies?

 

quantum quack: in fact SRT will even tell you that absoilute rest is impossible to determine yet in a two object system we declare one frame as at rest which is the same as claiming an absolute rest position in a two object universe.

 

No it's not.

 

A two-object "universe"? Let's see, (1) me sitting here at my computer and (2) a car driving down the road. I am at rest. I am not at absolute rest. So the problem is?????

 

Or, (1) me stting at my computer and (2) the rest of the Universe. I am at rest. I am not at absolute rest. So the problem is????

 

quantum quack: and no book is going to be able to show how non-simultaneousness can be proven ...

 

Huh? I demonstrated the relativity of simultaneity earlier in this thread using both "non-relativistic, mere mechanical" and relativistic examples.

 

quantum quack: BTW you don't need to buy a book to get all the info on this issue, there are thousands of free net resources to read.

 

So which one demonstrates exactly what the chapter I referenced does? Well?

 

I tried doing Google searches using different keywords and different keyword combinations, but the needle is lost in the haystack of hits. Yet I can point directly to the resolution of the APPARENT contradiction in the book I referenced. I've found the needle - I've shown you guys where it is.

[TeleMad]

Mac: Now to answer yours. Since time dilation is a function of the orbital (or perpheral) velocity an object in circular orbit at any angle has the same velocity relative to the common local preferred rest frame (the central axis of orbit) and hence a satellite in a polar orbit will have the same dilation to any surface clock (regardless of location) as does an equatorial orbit.

 

Why are you pretending to answer my question? Why are you answering a different question than the one I asked?

 

 

TeleMad: Now for the second time:

 

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Mac: The two perepheral velocities are infact subtractable regardless of angle.

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TeleMad: Care to support that such is how one finds the relative velocity between the ground clock and the satellite?

 

The relative velocity between the ground clock and the satellite tells us what an observer at the ground clock would measure the velocity of the satellite to be: it's the velocity of the satellite from the ground clock's frame of reference. The relative velocity between the ground clock and the satellite differs depending upon the path and direction the orbit takes.

 

If you used a different definition of relative velocity in your original calculation you should have explicitly stated what your non-standard usage was.

[TeleMad]

Mac: Are you getting a commission?

 

Nope. It's just a good book, directly relevant to the topics of discussion, that, as a bonus, explains in detail why you are wrong.

 

Mac: Now for the record. You have taken several different positions here. Which is it now?

 

1 - SR is required and part of GPS or;

 

2 - SR does not apply in GPS?

 

Your "record" is wrong.

 

For the record, I have not stated your #1 at all in this thread.

 

For the record, I have not stated your #2. You must be confusing what I actually said with what you claim I said, overlooking the fine points that separate the two positions.

[quantum quack]

the thing is when you talk of relative velocity it isn't really a true method, relative to rest only is a lopsided relativity.

 

In SRT a frame can only have another frame relatively faster and not relatively slower, so therefore it is not true relativity.

 

Sitting aat your computer you may claim other objects are at rest with you but that rest frame is a revolving planet that is orbiting a star.

 

Claiming another object is sharing teh same velocity is not teh same as claiming a rest frame. Sort of saying Iamj at rest to myself is no big deal, but when you extrapolate that onto oither moving objjects that don't share the same v then you develop a problem of lopsided relativism.

 

If your frame is deemed the slowest frame there can be then you are no longer in the real world but in one of abstraction.

[quantum quack]

I think it's quite reasonable to consider your self as an absolute frame, in that all things a relative to you...however to claim that you are the slowest entity or observer is falacious IMO.

[TeleMad]

Mac: Unfortunately you are blowing smoke. Simultaneity has nothing what-so-ever to do with reciprocity.

 

TeleMad: Nope, wrongo!

 

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"There seems to be a big problem with time dilation: "Moving clocks run slow", but who's to say which clock is moving? If clock B sees clock A move by and concludes that clock A is "running slow", why can't clock A claim to see clock B go by and conclude that B is "running slow"? It can! There's no contradiction, because of another remarkable implication of the principle of relativity: Two events that are simultaneous (i.e., that occur at the same time) in one frame of reference are not simultaneous in another frame moving relative to the first. It is this relativity of simultaneity that allows two observers in relative motion to see each other's clocks "run slow", without contradiction." (Einstein's Relativity and the Quantum Revolution: Modern Physics for Non-Scientists: 2nd Edition)

******************************

 

Let’s take a first look at how the relativity of simultaneity resolves the APPARENT contradiction.

 

First, we have to acknowledge the relativity of simultaneity: here, two events that are simultaneous in one inertial reference frame are not simultaneous in a second inertial frame moving in a straight line at constant speed between those same two events. How does this come into play? That will take a bit of explaining.

 

We have two inertial reference frames and two events. In the example that will appear in the quote, there is a spaceship traveling from Earth to a star. The two reference fames are the Earth-star frame and the spaceship frame. In the Earth-star frame the two events are the spaceship leaving Earth and the spaceship arriving at the star; in the spaceship frame the two events are the Earth leaving and the star arriving.

 

Let's start by considering things from the Earth-star frame. In the Earth-star frame, the spaceship is moving from one event to the other, so needs only one clock to measure elapsed time, because it’s one clock is present at both events. No problem with synchronizing one clock with itself. However, since in the Earth-star frame the Earth and star are at rest with respect to each other and with the two events, which are spatially separate – one at the Earth and the other at the star - two different clocks are needed: one at each event. Now, in order to measure the elapsed time between the two events the two clocks need to be synchronized. This can be achieved in a number of ways, one of which is to position a light source half-way between the two clocks and send out a flash of light: when a clock receives the light it sets it’s clock to 0, and since the distance to both clocks is equal and no length contraction occurs, the light travel time will be the same to both clocks … precise synchronization. So synchronizing the two clocks is not a problem … or is it? It is!

 

Let's switch to considering this from the spaceship's reference frame. The spaceship's one-clock is moving in a straight line at constant speed relative to and between the two events, therefore, because of the relativity of simultaneity, the two events involved in synchronizing the two clocks in the Earth-star reference frame cannot be simultaneous in the spaceship's reference fame. Consequently, the two clocks in the Earth-star frame, though synchronized in the Earth-star frame itself, cannot be synchronized from the spaceship’s reference frame.

 

With that setup …

 

“Turn back to Figure 10.4, where (a) shows the situation in the Earth-star frame when the ship passes Earth and (:eek: shows the situation in this frame when the ship passes the star. In this frame all the clocks read 0 as the ship passes Earth (Figure 10.4a). Later, as the ship passes the star, its clock reads 15 years while Earth and star clocks – which are synchronized in the Earth-star frame – both read 25 years (Figure 10.4b). The interpretation of the clock readings in the Earth-star frame is that 25 years have elapsed in that frame but only 15 years have elapsed in the ship frame because the ship clock runs slow.

 

Now look again at Figure 10.5, where (a) shows the situation in the ship frame when Earth passes the ship and (B) shows the situation in this frame when the star passes the ship. As in the Earth-star frame, both ship clock and Earth clock read 0 as Earth and ship pass. But in the ship frame, the clocks in the Earth-star frame aren’t synchronized; in fact, the star clock already reads 16 years when Earth and ship pass. Later, as the star and ship pass, the ship clock has advanced from 0 to 15 years. The star clock, running slow from the viewpoint of the ship frame, has advanced only 9 years. But since it was [16 years] ahead to begin with, it now reads 25 years. The interpretation of the clock readings in the ship frame is that 15 years have elapsed in that frame while only 9 years have elapsed in the Earth-star frame.

 

Yet observers in both frames agree about what the clocks actually read whenever two clocks are right next to each other so observers can unambiguously compare times. In particular, observers in both frames agree that 15 years elapse on the ship's one clock. They also agree that the reading of the Earth clock at the Earth/ship passing differs by 25 years from the reading of the star clock at the star-ship passing. What they disagree about is the interpretation of this 25-year interval. To observers in the Earth-star frame the clocks at Earth and star are synchronized, so 25 years is a legitimately measured time between two events. To observers on the ship, Earth-star clocks are running slow, and advance only 9 years between the two events. The 25-year difference in clock readings occurs because the star clock is ahead of the Earth clock by 16 years.” (Simply Einstein: Relativity Demystified, Richard Wolfson, W. W. Norton, 2003, p136-137)

[Mac]

Lorentz transformations cannot be globally defined except on Minkowksi spacetime, and cannot be locally defined except on locally flat spacetimes that have vanishing Riemann

tensor. An artifically engineered frame that is at rest artificially, here and in orbit to each other with more than one rest frame, is not a Minkowski spacetime.

 

A frame of reference is a purely kinematical device, for the geometrical description of motion without regard to the masses or forces involved. We use frame of reference as a standard relative to which motion and rest may be measured; any set of points or objects that are at rest relative to one another enables us, in principle, to describe the relative motions of bodies. But again it is a kinematical device only. The GPS case has both the orbital frame and the earth frame as at rest relative to each other via the programming. In effect there is now no way to distinguish between frames in this system as long as the programming remains in effect. Both frames have become the at rest frame from the different clock perspectives.

 

I think you are principally correct but perhaps the wording is not properly defined. In GPS the clocks are not at rest to each other. They have an absolute (local) velocity relative to a common preferred rest frame the ECI and ECEF. They each have a gamma function relative to that point but the orbiting clock always has the larger gamma (hence appears dilated relative to the surface) and hence no reciproicty exists.

[Mac]

I think it's quite reasonable to consider your self as an absolute frame, in that all things a relative to you...however to claim that you are the slowest entity or observer is falacious IMO.

 

QQ, remember if you assume yourself as at rest any motion in any direction by any other object is a positive motion not a negative. You can ascribe +/- relative to other objects but one going east and one going west may be labled + and - velocity but it is in vector not magnitude.