Measurement length of an object will not be changed by motion

[Jeremy0922]

Just because you do not like or do not understand a concept does not mean that that that concept is wrong. It might just mean that you are wrong.

 

Which, by the way, is exactly what is going on here.

 

 

 

 

 

I like physics more than others, but never accept any theory that disobey nature and science rule.

Edited December 1, 2010 by Jeremy0922

[D H]

There is nothing in special or general relativity that disobeys the laws of physics. From all experiments to date, relativity is the best description of how the universe works. The only problem is that you don't like it. Tough.

[Jeremy0922]

There is nothing in special or general relativity that disobeys the laws of physics. From all experiments to date, relativity is the best description of how the universe works. The only problem is that you don't like it. Tough.

 

 

But disobey nature rule that time can never go back,

and disobey causality that evey thing must obey in nature.

Edited December 1, 2010 by Jeremy0922

[D H]

What, exactly, gives you such incredible insight into the laws of the universe?

 

This page, http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html lists some of the many tests of special relativity. This page, http://www.einsteins-theory-of-relativity-4engineers.com/tests-of-relativity.html, describes the of the many tests of general relativity. This page, http://einstein.stanford.edu/content/sci_papers/papers/Will.C_Relativity_Cent-PW2005.pdf, describes tests of the equivalence principle, which now stands as one of the most precisely tested of all concepts in physics.

 

You, as a proponent of anything-but-relativity, need to come up with some other explanation of all of these phenomena, and more. Relativity has been tested many, many times over. To date it has withstood all such tests. The very few alternatives to general relativity that are not falsified by these numerous tests differ from relativity only slightly. They all yield length contraction and time dilation, for example.

[ajb]

Certainly, Some experimental results seem to fit to some deduction from SR, but SR is not the unique theory to explain them.

 

Though special relativity is quite simple and explains a lot of phenomena in a unified way?

 

To date there is no experimental reason to doubt that special relativity is a good theory. Have a good look at the links DH provides and references therein.

 

But disobey nature rule that time can never go back,

 

What rule that time can never go backwards? In fact it is a very non-trivial question.

 

and disobey causality that evey thing must obey in nature.

 

You can still have causality in the context of general relativity. Space-times can have "good behaviour".

[Jeremy0922]

What, exactly, gives you such incredible insight into the laws of the universe?

 

This page, http://math.ucr.edu/...xperiments.html lists some of the many tests of special relativity. This page, http://www.einsteins...relativity.html, describes the of the many tests of general relativity. This page, http://einstein.stan...Cent-PW2005.pdf, describes tests of the equivalence principle, which now stands as one of the most precisely tested of all concepts in physics.

 

You, as a proponent of anything-but-relativity, need to come up with some other explanation of all of these phenomena, and more. Relativity has been tested many, many times over. To date it has withstood all such tests. The very few alternatives to general relativity that are not falsified by these numerous tests differ from relativity only slightly. They all yield length contraction and time dilation, for example.

 

I am not a proponent of anything-but-relativity, but one likes to search for and believes science truth.

I hope my question given above could be solved by physical expert like you, but not be censured.

 

Though special relativity is quite simple and explains a lot of phenomena in a unified way?

 

To date there is no experimental reason to doubt that special relativity is a good theory. Have a good look at the links DH provides and references therein.

 

 

 

What rule that time can never go backwards? In fact it is a very non-trivial question.

 

 

 

You can still have causality in the context of general relativity. Space-times can have "good behaviour".

 

 

Thinks for your kind suggestion,

but the basal conceptions are very important for any theory, but it is very difficult for me to accept the space-time conception of SR becaue of the contradiction with it.

[D H]

What contradiction, jeremy?

[Jeremy0922]

What contradiction, jeremy?

 

 

Shown in my first post and following.

[D H]

Your opening post is wrong, Jeremy. It contradicts very well-verified experimental results.

[Jeremy0922]

Your opening post is wrong, Jeremy. It contradicts very well-verified experimental results.

 

 

I disagree with your comment.

Edited December 1, 2010 by Jeremy0922

[swansont]

Relativity is self-consistent, mathematically. A thought experiment cannot show a contradiction in relativity, it can only show an error in the application of it, i.e. user error. The only way to contradict the theory is with physical evidence; you need to have an actual experiment which is inconsistent with prediction. Got any?

[Jeremy0922]

Relativity is self-consistent, mathematically. A thought experiment cannot show a contradiction in relativity, it can only show an error in the application of it, i.e. user error. The only way to contradict the theory is with physical evidence; you need to have an actual experiment which is inconsistent with prediction. Got any?

 

 

thanks swansont,

The most important thing for a theory is the basal conception with which some phenomena could be explained well.

the experiment in first my post is a real testing tech for high speed moving object while I research in shock wave by impact of two bodies.

Edited December 1, 2010 by Jeremy0922

[swansont]

I don't see how the experiment would have any hope of measuring length contraction, since it is not sensitive enough. That's a problem with the experiment, though, not with the theory. We can do other experiments, though, and they give results consistent with the theory.

[Jeremy0922]

I don't see how the experiment would have any hope of measuring length contraction, since it is not sensitive enough. That's a problem with the experiment, though, not with the theory. We can do other experiments, though, and they give results consistent with the theory.

 

 

Einstein's thought experiment also is a observation method for moving objest with system error.

 

space-time has not been changed by motion.

[D H]

Sorry Jeremy, but you are wrong. Relativity has been tested and re-tested, many times over. The universe does not behave the simplistic way you think it should. My advice: Get over it. Learn.

[Jeremy0922]

Sorry Jeremy, but you are wrong. Relativity has been tested and re-tested, many times over. The universe does not behave the simplistic way you think it should. My advice: Get over it. Learn.

 

 

Sorry D H, some phenomena has been explained many times with SR, but SR meet many serious problems that can not be settled down by itself.

[imatfaal]

Jeremy - are you positing your experiment as a real-world experiment that would disprove SR or as a thought-experiment that causes you to believe SR is incorrect. Both cases, by the way, have to battle against the huge amount of evidence that SR is correct as already given above.

 

If it is the former you will note the practising research physicists who cannot see a way to bring the experimental measurement to a level where it would not be swamped by experimental/measurement error. If it is the latter (which I think is your intended meaning) then you should make this clear and you will receive different responses (ie my first quesion would be how do you synchronise the clocks without some form of communication between them and the experimenter - at what speed does this information travel?)

[D H]

Sorry D H, some phenomena has been explained many times with SR, but SR meet many serious problems that can not be settled down by itself.

Name one.

 

 

 

[uncool]

"Time dilation" and "space contraction" are the important deductions from Einstein's special relativity(SR), based on "the principle of constant speed of light in vacuum" and the observation of moving objects in his thought experiment.

Actually, Einstein's thought experiment is one kind of observation of length for a moving object with an invariable velocity, and there are many methods for us to be selected to measure the length of a moving object. for an experimental measurement, the errors caused by the method and equipment must be considered and be applied to correct the results.

 

Lorentz's transformation from SR, which is only satisfied to the special example in Einstein's thought experiments, should not be understood as space-time transformation for any moving object, because a different result will be given by a different measurement.

 

Selecting two points (D1, D2) on the trajectory of the moving object, testing the times that the moving object reach at and leave these two points D1 and D2, separately, t1, t1' and t2, t2', the length (Lb) and the velocity (V) of the moving object will be gotten by the measurement results of these times and the distant (L) between D1 and D1, as shown in following figure.

 

 

 

the velocity V is:

V= L/(t2-t1) or

V=L/(t2'-t1')

the length Lb is:

Lb=V(t1'-t1)=L(t1'-t1)/(t2-t1) or

Lb=V(t2'-t2)=L(t2'-t2)/(t2'-t1')

Clearly, the measured result Lb does not relate to the velocity of the moving object V and light speed c by above measurement.

Why not? The velocity of the moving object could affect the times t1, t1', t2, and t2'. And that is precisely what special relativity predicts.

Therefor, Space would not be changed by motion.

Is that right ?

You are, in effect, asserting your conclusion.

=Uncool-

[Jeremy0922]

Jeremy - are you positing your experiment as a real-world experiment that would disprove SR or as a thought-experiment that causes you to believe SR is incorrect. Both cases, by the way, have to battle against the huge amount of evidence that SR is correct as already given above.

 

If it is the former you will note the practising research physicists who cannot see a way to bring the experimental measurement to a level where it would not be swamped by experimental/measurement error. If it is the latter (which I think is your intended meaning) then you should make this clear and you will receive different responses (ie my first quesion would be how do you synchronise the clocks without some form of communication between them and the experimenter - at what speed does this information travel?)

 

The precondition is that we should have a correct theory about the electromagnetic radiation of moving charged particle, because that is the foudation for us to measure and understand the electromagnetic phenomena. but we have not now.

 

Why not? The velocity of the moving object could affect the times t1, t1', t2, and t2'. And that is precisely what special relativity predicts.

 

You are, in effect, asserting your conclusion.

=Uncool-

 

 

times t1, t1', t2 and t2' are the measure times in rest frame

Edited December 1, 2010 by Jeremy0922

[D H]

The precondition is that we should have a correct theory about the electromagnetic radiation of moving charged particle, because that is the foudation for us to measure and understand the electromagnetic phenomena. but we have not now.

Yes, we do. It is called -- tada -- special relativity.

 

 

 

times t1, t1', t2 and t2' are the measure times in rest frame

What rest frame?

 

 

 

[Jeremy0922]

Yes, we do. It is called -- tada -- special relativity.

 

 

 

 

What rest frame?

 

 

 

 

 

lab

[uncool]

The precondition is that we should have a correct theory about the electromagnetic radiation of moving charged particle, because that is the foudation for us to measure and understand the electromagnetic phenomena. but we have not now.

 

 

 

 

times t1, t1', t2 and t2' are the measure times in rest frame

Which rest frame? The rest frame of the measuring devices? The rest frame of the bar?

 

ETA: You answered after I had been writing this question, so nm.

 

lab

So that means that the velocity of the bar does affect the times.

 

Hell, that's even true in Newtonian physics. Your original post applies exactly as well to Newtonian physics as it does to special relativity.

=Uncool-

Edited December 1, 2010 by uncool

[Jeremy0922]

Yes, we do. It is called -- tada -- special relativity.

 

 

It would be nice, if that will not meet or make new problems.

Edited December 1, 2010 by Jeremy0922

[John Cuthber]

It would be nice, if that will not meet or make new problems.

 

Name one.