Length Contraction and what not

[swansont]

I have performed an extremely thorough analysis of the special theory of relativity' date=' and the inescapable analytical conclusion is that both the Lorentz contraction formula, and the time dilation formula are [i']false[/i] in all inertial reference frames.

 

I even showed you how to prove it in some other thread.

 

Don't be mad at the messenger.

 

Kind regards Dr. Swanson

 

Every time you've attempted this, you've "proved" it by assuming the answer. Don't be mad if I'm not impressed.

[BlackHole]

Is the velocity 4-vector a physical velocity?

 

1. How do we give (physical) meaning to this component; seconds per second is not very usable?

 

2. Why does the time component go to infinity, while it is clear that proper time goes to zero?

[Tom Mattson]

If the clocks are ticking at different rates in different frames of reference' date=' then the physics is not the same in all inertial reference frames and necessarily, using your rules space and time aren't relative they are absolute.

[/quote']

 

Again: That's precisely backwards.

 

If you start from the posultates of SR, and apply them to Maxwell's equations (thus insisting that the laws of electrodynamics remain the same for all inertial observers), then you arrive at the Lorentz transformation. Insisting that the laws of classical/quantum mechanics/field theory also be covariant leads to relativistic versions of those theories that are experimentally known to be more correct (that is, more in agreement with experiment) then their nonrelativistic counterparts.

[geistkiesel]

Again: That's precisely backwards.

 

If you start from the posultates of SR' date=' and apply them to Maxwell's equations (thus insisting that the laws of electrodynamics remain the same for all inertial observers), then you arrive at the Lorentz transformation. Insisting that the laws of classical/quantum mechanics/field theory also be covariant leads to relativistic versions of those theories that are experimentally known to be more correct (that is, more in agreement with experiment) then their nonrelativistic counterparts.[/quote']

I notice you said the laws of

electrodynamics

remains the same for all observers, but apparently clock tick rates aren't of such physical significance that mere mechanical physics need not be considered important enough to maintain consistency in all reference frames. Did you intend to restrict the SRT to electrodynyamics only?

 

The post begins with an assumption that the postulates of of SR are correct when clearly they are mere mathematical contrivances. In fact the post I am responding to here is a statement of facts, assumptions, and is void of scientific content. To insist on maintaining the structure of Maxwell's equations by the convoluted dynamics of SR seems rather slothful, scientifically, indeed the statement is void of any physical value at all, in fact the opposite is true, SRT is an albatross clinged to so desparately by those few finding comfort with the insistance on the utility of nonsense.

 

I suppose that having to argue against a statement that "something is more in agreement with X than is Y", requires an infinitiely difficult task to perform. The postulates of light, however, some of them, are true, some aren't. This is probably why the statement was made in the first instance, a distraction to meander down the path of illusion picking apart SRT that has tar feathered the brains of so many.

 

When we recognize that the relative velocity of frame and photon are measurable as c + v and c - v, the simplicity of physics is exposed as a creature of magnificent complexity. Maintaining support for a mathematical structure steeped in contradiction, physical impossibility amd convenient definition is nonsense.

 

Geistkiesel

[geistkiesel]

And the laws of physics say that time depends on your frame of reference, so that the tick rates are not the same in all frames.

Actually the physics says the converse. It is SRT that says the tick rates are not the same in all frames. Tick rates may be a function of forces applied to the timing mechanisms such as crystal oscillators and in this sense the measure "time" may have changed - relying on the technological accuracy of "the clock" is dangerous. However, the application of accelerating force on timing measurement systems does not alter time in the slightest, this is too obvious,

 

Geistkiesel

[swansont]

Actually the physics says the converse. It is SRT that says the tick rates are not the same in all frames. Tick rates may be a function of forces applied to the timing mechanisms such as crystal oscillators and in this sense the measure "time" may have changed - relying on the technological accuracy of "the clock" is dangerous. However' date=' the application of accelerating force on timing measurement systems does not alter time in the slightest, this is too obvious,

 

Geistkiesel [/indent']

 

Yes, you can apply forces to clocks and alter their performance. But when you eliminate that effect, you are still left with relativity, which occurs independent of the type of clock. It's been observed in hydrogen masers and cesium and rubidium clocks. A given physical perturbation should affect different types of clocks in different ways, but that is not what is observed in measurements of relativity.

 

What physical mechanism can possibly be perturbed in radioactive decay, for example? And despite the interaction strength being different for the nuclear force, show the exact same effect for various atomic transitions?

[swansont]

When we recognize that the relative velocity of frame and photon are measurable as c + v and c - v' date=' the simplicity of physics is exposed as a creature of magnificent complexity. Maintaining support for a mathematical structure steeped in contradiction, physical impossibility amd convenient definition is nonsense.

 

Geistkiesel [/indent']

 

To realize it you have to demonstrate it. Until you do, you have something that is void of any physical value at all.

[Tom Mattson]

I notice you said the laws of

electrodynamics

remains the same for all observers' date=' but apparently clock tick rates aren't of such physical significance that mere mechanical physics need not be considered important enough to maintain consistency in all reference frames. Did you intend to restrict the SRT to electrodynyamics only?

[/quote']

 

Of course not. That's why I mentioned mechanics and field theory. It turns out that in order for mechanics to conform to experimental evidence, it must be relativistic. This is true in both the macroscopic and the quantum regimes.

 

The post begins with an assumption that the postulates of of SR are correct when clearly they are mere mathematical contrivances. In fact the post I am responding to here is a statement of facts, assumptions, and is void of scientific content.

 

Incorrect. This line of discussion started out with the following false statement by you:

 

"If the physics inall inertial frames is the same, identical, equivalent, then a tick rate in frame A is the same as the tick rate in frame B. This is what equivalence of physical law in inertial frames means to me."

 

I did not start out with the assumption that the postulates of SR are correct. I corrected you by saying that

if

they are correct (that is, if inertial frames are experimentally indistinguishable), then the tick rate of a clock

cannot

be the same in any two different inertial frames.

 

As for the rest of your post, it is not worth responding to. It's a pity that you didn't learn a thing from your brief stay at Physics Forums.

[Tom Mattson]

Johnny is right. The velocity 4-vector is not a physical velocity. Check out Lorentz invariant[/url'].

 

How does the statement "4-velocity is not a physical velocity" follow from Lorentz invariance?

[geistkiesel]

Yes' date=' you can apply forces to clocks and alter their performance. But when you eliminate that effect, you are still left with relativity, which occurs independent of the type of clock. It's been observed in hydrogen masers and cesium and rubidium clocks. A given physical perturbation should affect different types of clocks in different ways, but that is not what is observed in measurements of relativity.

 

What physical mechanism can possibly be perturbed in radioactive decay, for example? And despite the interaction strength being different for the nuclear force, show the exact same effect for various atomic transitions?[/quote']

How do you eliminate the effect of acceleration that is the force placing SATS in orbit in the GPS system? Do you have some references to the hydrogen maser, cesium and rubidium clock experiments? I would appreciate looking at this.

 

Every piece of physical matter containing the observed event of radioactivity in beta decay, for instance, is affected by acceleration. Vibration rates for one attribute are affected, not time. Certainly an object moving uniformly feels no forces by the mere virtue of its uniform motion; the causal affect cannot be uniform velocity can it?

 

Radioactivity is not a closed loop of physical knowledge. There are some still applying QM in its present form only, and trying to rationally model radioactive activity. Good luck.

 

Geistkiesel

[swansont]

How do you eliminate the effect of acceleration that is the force placing SATS in orbit in the GPS system? Do you have some references to the hydrogen maser' date=' cesium and rubidium clock experiments? I would appreciate looking at this.[/quote']

 

The cesium and rubidium clocks are in GPS satellites, among others. The hydrogen maser experiment summary.

 

Every piece of physical matter containing the observed event of radioactivity in beta decay' date=' for instance, is affected by acceleration. Vibration rates for one attribute are affected, not time. Certainly an object moving uniformly feels no forces by the mere virtue of its uniform motion; the causal affect cannot be uniform velocity can it?

[/quote']

 

You appear to be approaching this from a mistaken vantage point. It's not due to the physical clock mechanism feeling some force, because (as you say) there is no force. It's a consequence of the constant speed of light. Clocks run slow because time runs slow.

[Johnny5]

Where in some other thread did you prove this Johnny5? : That time dilation and Lorentz contraction are false.

 

Geistkiesel

 

Actually' date=' I didn't prove it here. Swansont would remember that. I wanted to see what he would say about me claiming to prove it here. I expected him to say that I didn't prove it, all I proved here was that:

 

If the speed of light is the same in all inertial frames then (the length contraction formula is true and the time dilation formula is true).

 

I actually haven't shown anyone here how to falsify the antecedent, because it is ridiculously easy, but for some reason PhD's don't know how to do it.

 

Regards

 

PS: The answer in how to falsify the antecedent, is obvious on logical grounds alone.

 

Here is the link to the statement which I did prove here:

 

See post 79: discussion of light clock

 

 

In that post, you will see the following highly important statement proven:

 

Theorem:

 

If the speed of a photon is the same in any inertial reference frame then

 

(Dt` = Dt/ [1 - (V/c)2 ]1/2 AND L = L0 [1 - (V/c)2 ]1/2)

 

QED

 

So, the question now, is can the antecedent be falsified deductively?

 

The answer is yes, and I explained to them how, but it seems to have been over their heads.

 

I will just re-explain, though you must decide for yourself.

 

 

We have a statement of the following form, which we are convinced is true:

 

If A then (B AND C).

 

Therefore, the following statement must be true on logical grounds alone:

 

If A then B.

 

Also, the following statement must be true on logical grounds alone:

 

If A then C.

 

In our case here, B is the time dilation formula, and C is the length contraction formula, and A is the fundamental postulate of the theory of special relativity.

 

Now, the statement about time dilation confuses everybody, so disregard it, and focus only upon the length contraction formula.

 

If you can now construct an argument, whose first and only assumption is that the length contraction formula is true, and which reaches contradiction, you can then negate your only assumption.

 

Thus, you will conclude, deductively, that the Lorentz-Fitzgerald length contraction formula is false.

 

 

That having been accomplished, you already knew that the following statement was true:

 

If the fundamental postulate of SR is true then the Lorentz-Fitzgerald length contraction statement is true.

 

The previous statement is logically equivalent to the contrapositive which is:

 

If the Lorentz-Fitzgerald length contraction formula is false, then the fundamental postulate of SR is false.

 

So now, since you just concluded that the Lorentz formula is false, you can conclude that the fundamental postulate of SR is false.

 

And then furthermore, you can now finally conclude that the time dilation formula is false as well.

 

So all these conclusions rest upon your being able to falsify the Lorentz contraction formula, and nothing else.

 

Regards

 

 

 

Here is the secret to doing it...

 

Forget about the Lorentz formula, and focus on all formulas which state that length of bodies in relative uniform motion contract.

 

We have two metersticks which have identical lengths, when at rest relative to one another.

 

We can make them coincide as follows:

 

AXXXXXXXXXXXXXXXXXXXXB

A`XXXXXXXXXXXXXXXXXXXB`

 

The ends of the rulers coincide when they are at rest relative to one another.

 

Now, suppose that the length of a ruler is dependent upon its speed v, in someone elses frame of reference, inertial or otherwise.

 

Let ruler AB be at rest in an inertial reference frame.

 

Let ruler A`B` be in uniform relative motion to ruler AB, from left to right, and make only one assumption, which is that it's length is a function of its speed v in ruler AB's frame.

 

(since AB is in an inertial frame, and A`B` is moving at constant speed through an inertial frame, it follows that the rest frame of A`B` is also inertial)

 

This can be proven, and in another post somewhere I proved it.

 

(Also, ruler AB cannot be rotating, but I've stipulated that).

 

So there is translational motion of the center of mass of ruler A`B` in the rest frame of AB only, there is no rotation of either ruler, in the rest frame of the other.

 

Assume the formula, which is a function of v, says that ruler A`B` should shorten, in the rest frame of AB.

 

Therefore, eventually there will come a moment in time, at which the state of the universe will be as follows:

 

______AXXXXXXXXXXXXXXXXXXXXB

A`XXXB`

 

Then later:

 

______AXXXXXXXXXXXXXXXXXXXXB

______A`XXXB`

 

Then later:

 

______AXXXXXXXXXXXXXXXXXXXXB

________________________A`XXXB`

 

And this analysis was carried out in the rest frame of ruler AB, which is inertial by stipulation.

 

 

So there is a necessary order to moments in time.

 

There is no way in hell that B` coincided with B before A` coincided with A.

 

 

From the state diagrams, the order of moments in time can be marked as follows:

 

There is a moment in time, at which B` coincides with A.

 

That is followed by a later moment in time, at which A` coincides with A, and then that is followed by a moment in time at which B` coincides with B.

 

[A` would have coincided with A simultaneously to B` coinciding with B, had it not been for our single assumption that length contracts as a function of relative speed v]

 

yet we must reason under that assumption for awhile.

 

So this is the order of things:

 

A` coincides with A before B` coincides with B.

 

 

Now, frame switch into the other inertial frame.

 

You are now analyzing the relative motion of the two rulers, from the rest frame of ruler A`B`.

 

Using whatever formula for length contraction you concocted, you must also use it here, hence the length of ruler AB is shorter.

 

So in this frame ruler AB is moving from right to left, and we have this:

 

 

_________________________AXXXXB

A`XXXXXXXXXXXXXXXXXXXXB`

 

Then later we have this:

 

___________________AXXXXB

A`XXXXXXXXXXXXXXXXXXXXB`

 

Then later we have this:

 

AXXXXB

A`XXXXXXXXXXXXXXXXXXXXB`

 

Therefore, the order of moments in time is as follows:

 

B` coincided with B before A` coincided with A.

 

So the following two statements are true, in global reality:

 

X before Y and Y before X.

 

The state diagrams should be sufficient to convince you, that there is an error in any formula which has length dependent upon relative speed v, in the manner here, where the contraction isn't due to an applied force.

 

 

Now, all you have to do, is construct a mathematical proof.

 

Which can be done.

 

Regards again.

 

PPS: If either of the rulers is being subjected to a force, then it's rest frame would be non-inertial, and its length would change, but that was not the case here.

 

Furthermore, length of a real ruler depends upon temperature, but again, we can stipulate that the rulers have the same temperature throughout their passing by each other, where that temperature is measured by a thermometer in their rest frame.

[geistkiesel]

Originally Posted by geistkiesel

When we recognize that the relative velocity of frame and photon are measurable as c + v and c - v' date=' the simplicity of physics is exposed as a creature of magnificent complexity. Maintaining support for a mathematical structure steeped in contradiction, physical impossibility amd convenient definition is nonsense.[/quote']

 

 

 

 

To realize it you have to demonstrate it. Until you do, you have something that is void of any physical value at all.

Try this for proof, if you haven't already. Caveat Emptor Swansont.

 

Geistkiesel

[J.C.MacSwell]

The cesium and rubidium clocks are in GPS satellites' date=' among others. The hydrogen maser experiment summary.

 

 

 

You appear to be approaching this from a mistaken vantage point. It's not due to the physical clock mechanism feeling some force, because (as you say) there is no force. It's a consequence of the constant speed of light. Clocks run slow because time runs slow.

 

Just a thought

 

Could a force be felt subatomically?

[swansont]

Try this for proof' date=' if you haven't already. Caveat Emptor Swansont.

[img']

http://www.scienceforums.net/forums/showthread.php?t=11074

[/img]

 

Geistkiesel

 

 

If I haven't already? I posted in that thread, and you responded, beofre you posted this.

 

Flawed arguments do not constitute proof.

[swansont]

If you can now construct an argument' date=' whose first and only assumption is that the length contraction formula is true, and which reaches contradiction, you can then negate your only assumption.

[/quote']

 

Did you use absolute simultaneity in your argument?

[swansont]

Just a thought

 

Could a force be felt subatomically?

 

 

In general, or in this context? A force felt subatomically that is not felt on a macroscopic scale? Because you can certainly exert forces on subatomic particles.

[Johnny5]

Did you use absolute simultaneity in your argument?

 

Actually no, I used beforeness.

[swansont]

Actually no, I used beforeness[/i'].

 

As in, if X happens before Y in one frame, it must be true in another frame, too?

[J.C.MacSwell]

In general, or in this context? A force felt subatomically that is not felt on a macroscopic scale[/b']? Because you can certainly exert forces on subatomic particles.

 

Yes, in the sense that a macroscopic body "blindfolded" would not feel the force. (no internal stresses one would feel in acceleration other than, say, gravitational acceleration is somewhat what I am getting at, with the idea that perhaps gravitational force could affect the workings subatomically).

 

Sorry if that's less than clear (awkwardly worded). I know that a macroscopic result is produced as time flows at a different rate.

[Johnny5]

As in, if X happens before Y in one frame, it must be true in another frame, too?

 

 

Not quite.

 

As in if X is a moment in time, and Y is a different moment in time, and X before Y, then in all reference frames, at all moments in time, X before Y.

[swansont]

Not quite.

 

As in if X is a moment in time' date=' and Y is a different moment in time, and X before Y, then in all reference frames, at all moments in time, X before Y.[/quote']

That is an assumption that contradicts relativity. By assuming that, you have assumed relativity is incorrect. One of the consequences of c being constant is that different observers won't necessarily agree on the order of events (that aren't causally related, at least)

 

So you have two assumptions, and a contradiction. If you assume A and assume (not A) you cannot assign the contradiction to any other cause. Your conclusion is invalid. And we've been through this before, so it shouldn't be too surprising that the rules of logic haven't changed in the last couple of months.

[swansont]

Yes' date=' in the sense that a macroscopic body "blindfolded" would not feel the force. (no internal stresses one would feel in acceleration other than, say, gravitational acceleration is somewhat what I am getting at, with the idea that perhaps gravitational force could affect the workings subatomically).

 

Sorry if that's less than clear (awkwardly worded). I know that a macroscopic result is produced as time flows at a different rate.[/quote']

 

If you put an atom in an electric field you can induce a dipole, even though the atom istelf is neutral and feels no net force. Something like that? The problem is that you can test for this to make sure there is no field.

[Johnny5]

That is an assumption that contradicts relativity. By assuming that' date=' you have assumed relativity is incorrect. One of the consequences of c being constant is that different observers won't necessarily agree on the order of events (that aren't causally related, at least)

 

So you have two assumptions, and a contradiction. If you assume A and assume (not A) you cannot assign the contradiction to any other cause. Your conclusion is invalid. And we've been through this before, so it shouldn't be too surprising that the rules of logic haven't changed in the last couple of months.[/quote']

 

It isn't an assumption, it is a conclusion.

 

The assumption of the argument is that the lorentz contraction formula is true. The conclusion of the argument is that simultaneity is absolute.

 

Regards

[swansont]

It isn't an assumption' date=' it is a conclusion.

 

The assumption of the argument is that the lorentz contraction formula is true. The conclusion of the argument is that simultaneity is absolute.

 

Regards[/quote']

 

You can't both assume it and conclude it.