Hijack from Speed of Time

[studiot]

19 minutes ago, swansont said:

But, when combined with the first postulate, “Any ray of light moves in the “stationary” system of co-ordinates with the determined velocity c, whether the ray be emitted by a stationary or by a moving body” the result is that speed of light must be the same for all (inertial) observers, since any frame can be considered a stationary frame.

But Logicandreason isn’t challenging the postulates as being in error. 

Of course, the modern presentation is easier.

I think that someone (logic) who has made the effort to read the 1905 paper deserves a bit more if he will so allow himself.

Especially since quite a few posts back he declared that he did not want 'interpretations', but preferred to follow through the actual chain of reasoning as originally presented.

 

 

[swansont]

5 minutes ago, studiot said:

Especially since quite a few posts back he declared that he did not want 'interpretations', but preferred to follow through the actual chain of reasoning as originally presented.

Right. And we’re discussing the equation at the end of section 2, which Logicandreason just acknowledged as being correct, and why Einstein claims that clocks will not be synchronous between the two frames.

[Mordred]

2 hours ago, studiot said:

Of course, the modern presentation is easier.

I think that someone (logic) who has made the effort to read the 1905 paper deserves a bit more if he will so allow himself.

Especially since quite a few posts back he declared that he did not want 'interpretations', but preferred to follow through the actual chain of reasoning as originally presented.

 

 

Correct I'm still thinking of the easiest way to explain section 3. As section 3 gets more into the Lorentz transforms. Though naturally it will have to wait till after work (RL sux lol)

[studiot]

34 minutes ago, Mordred said:

Correct I'm still thinking of the easiest way to explain section 3. As section 3 gets more into the Lorentz transforms. Though naturally it will have to wait till after work (RL sux lol)

I was concentrating on why Einstein had to do simultaneity first, rather than how he deals with it.

This is particularly important since it takes him from page 8 to halfway down page 11 to complete that job, unlike say Semat who does the whole thing in a few lines.

However all power to Einstein and whoever follows him for he did it the hard way as pioneers usually have to.

[Mordred]

All good simultaneaity is highly important to understand. I certainly don't mind  assistance.

 Sometimes a different angle on any topic opens the light of day.

[Logicandreason]

2 hours ago, Mordred said:

Correct I'm still thinking of the easiest way to explain section 3. As section 3 gets more into the Lorentz transforms. Though naturally it will have to wait till after work (RL sux lol)

Sorry Mr Mordred, but I can progress to section 3 until the final conclusion of Einstein regarding the Rod experiment has been explained. He proposed an experiment, described the results and then made a concluding statement.

This is the reasoning that I am unable to follow.

Unless I can understand why he concluded that the clocks would become unsynchronized simply by noting the positions of their hands while counting an elapsed period, I cant just move to section 3.

Remember his exact words of conclusion were; "Observers moving with the moving rod would thus find that the two clocks were not synchronous, while observers in the stationary system would declare the clocks to be synchronous"

The conclusion doesn't seem to follow from the equation given. (which I admit is correct) 

And nothing even hints as to what physical process forced the clocks to become unsynchronized.

Math doesn't make clocks change the positions of their hands on the face. Everyone in Einstein's experiment first all agreed that the clocks were synchronous initially, they only became unsynchronized because the observers started to record elapsed time periods. 

 

7 hours ago, Phi for All said:

!

Moderator Note

This is NOT a tutorial, it's a science discussion, on a science discussion forum.

 

Whatever, discuss what ever you wish between other members, but, personally,  I am only able to concentrate on one persons argument at a time, and right now, that happens to be Mordred. And If he has agreed to explain it step by step to be tutorial fashion, then I can call it a tutorial if I so desire. Your big red alarming box is rather pointless.

[Mordred]

Fair enough we will stick to section 2.

Let's express what section two does not describe.

1) it does not describe time dilation.

2) it does not describe length contraction.

3) it does not describe the ticks from the face of the clock as being slower or faster.

What does it describe ?

It describes classical physics and Galilean invariance using relativity of simulaneaity.  Which existed since the late 1600's  section two does not present any new physics for the time period. 

He does use c as a constant but that's one of the postulates of the paper.

However the relevant math showing how that applies comes later in the paper. It is not contained in section 2.

Section 2 in essence shows that one does not require an eather to describe Galilean relativity. Nor relativity of simultaneaityThe end of section 2 covers what he showed in the section.

"So we see that we cannot attach any absolute signification to the concept of simultaneity, but that two events which, viewed from a system of co-ordinates, are simultaneous, can no longer be looked upon as simultaneous events when envisaged from a system which is in motion relatively to that system "

We already covered the math where you see that in the stationary setup. The synchronous readings of clock A and Clock B was right in the middle between them.

 We also covered that in the moving system this is no longer true.

That is what that quoted section is referring to.

 

Edited June 13, 2023 by Mordred

[swansont]

1 hour ago, Logicandreason said:

Sorry Mr Mordred, but I can progress to section 3 until the final conclusion of Einstein regarding the Rod experiment has been explained. He proposed an experiment, described the results and then made a concluding statement.

This is the reasoning that I am unable to follow.

Unless I can understand why he concluded that the clocks would become unsynchronized simply by noting the positions of their hands while counting an elapsed period, I cant just move to section 3.

Remember his exact words of conclusion were; "Observers moving with the moving rod would thus find that the two clocks were not synchronous, while observers in the stationary system would declare the clocks to be synchronous"

The conclusion doesn't seem to follow from the equation given. (which I admit is correct) 

If the tick of the clock is a round trip of light, the tick will be r/(c-v) + r/(c+v) in the moving frame.

In the rest frame (v=0) that same tick is 2r/c

They are not equal. Thus, the ticking of the clocks are not synchronous.

This can be easily checked for any value of v (less than c, of course)

 

1 hour ago, Logicandreason said:

And nothing even hints as to what physical process forced the clocks to become unsynchronized.

It’s a consequence of the constancy of c. There is no force.

1 hour ago, Logicandreason said:

Math doesn't make clocks change the positions of their hands on the face. Everyone in Einstein's experiment first all agreed that the clocks were synchronous initially, they only became unsynchronized because the observers started to record elapsed time periods. 

They tick at different rates, though they can both start at the same time

 

[Mordred]

Just a side, more for other readers but its also useful. You recall I stated that often the mathematics are more important than the words spoken. This is a good example.

in the first equation where he is defining synchronization he uses the equation

\(T_a-T_b=\acute{T}_b-\acute{T}_a\)

this immediately tells me that not only does this describe synchronization, it also shows the relation is commutative, and symmetric. What this means is the choice of observer A or observer B doesn't change the mathematics. Either observer A or observer B can be treated as at rest or alternatively the inertial frame of reference.

(it tells me far more than that in terms of related mathematics but that's outside the scope of the discussion)

Edited June 13, 2023 by Mordred

[Logicandreason]

12 minutes ago, Mordred said:

Fair enough we will stick to section 2.

Let's express what section two does not describe.

1) it does not describe time dilation.

2) it does not describe length contraction.

3) it does not describe the ticks from the face of the clock as being slower or faster.

What does it describe ?

It describes classical physics and Galilean invariance using relativity of simulaneaity.  Which existed since the late 1600's  section two does not present any new physics for the time period. 

He does use c as a constant but that's one of the postulates of the paper.

However the relevant math showing how that applies comes later in the paper. It is not contained in section 2.

Section 2 in essence shows that one does not require an eather to describe Galilean relativity. Nor relativity of simultaneaityThe end of section 2 covers what he showed in the section.

"So we see that we cannot attach any absolute signification to the concept of simultaneity, but that two events which, viewed from a system of co-ordinates, are simultaneous, can no longer be looked upon as simultaneous events when envisaged from a system which is in motion relatively to that system "

We already covered the math where you see that in the stationary setup. The synchronous readings of clock A and Clock B was right in the middle between them.

 We also covered that in the moving system this is no longer true.

That is what that quoted section is referring to.

 

Yep, we know that up to the conclusions about the Rod experiment, there is not yet any hypothesis about Time dilation or length contraction. 

Its all classical Physics and standard Math.

So on reviewing what's been said so far, my understanding is this:

Einstein is saying that if the measurements made by a moving observer of some event involving motion, (all inertial) are compared to measurements of that same event made by a stationary observer, then by the use of the rules of classical physics and standard Math, they will both be in full agreement about lengths and time periods, for any velocity, EXCEPT when light velocity is used. 

The confusing bit is of course, how come the finite speed of light gets to ignore the otherwise correct rules that apply to everything else? Not only that, but if stationary guy gets 186 for light speed measure, and moving guy also gets 186 for light speed, then what happened to the speed difference between the two observers? I can't just go away. Classical Physics fully accounts for it, but Einstein just seems to ignore the relative speed difference between the two observers .In this case setting it to zero when its clearly not zero.

[Mordred]

Your essentially correct so far. However as I mentioned showing light as constant he refers to two works by other physicists. Lorentz and Maxwell. In section 3 he applies the Lorentz transformations. In later sections he applies the Maxwell equations, which at this time has already been shown by other research papers to follow Lorentz invariance and not Galilean invariance.

 In essence he refers to other research papers that have already shown light being constant. One of those tests being the null results of the M and M experiment for Luminiferous Eather. In that test it also showed zero deviation from c due to velocity of emitter or observer.

[Logicandreason]

6 minutes ago, Mordred said:

Just a side, more for other readers but its also useful. You recall I stated that often the mathematics are more important than the words spoken. This is a good example.

in the first equation where he is defining synchronization he uses the equation

Ta−Tb=T´b−T´a

this immediately tells me that not only does this describe synchronization, it also shows the relation is commutative, and symmetric. What this means is the choice of observer A or observer B doesn't change the mathematics. Either observer A or observer B can be treated as at rest or alternatively the inertial frame of reference

That equation only covers how long light will take to cover a set distance in a forward and return fashion.

Einstein has previously set the exact conditions under which this this equation is valid, and that was, Quote:

"Let us take a system of co-ordinates in which the equations of Newtonian mechanics hold good.2 In order to render our presentation more precise and to distinguish this system of co-ordinates verbally from others which will be introduced hereafter, we call it the “stationary system."

So at this point, that equation is only applicable to the "stationary system", which has supplied the necessary frame to which ALL measured speeds are related.

We could call the "stationary system",  System Zylon, it's name is not important. Only that it is inertial.

So any observer, relative to his own attached frame, can take measures from his own frame, and that equation will apply to his own frame. 

Is this corect?

[Mordred]

It also applies to the statement the laws of physics are the same regardless of observer. The stationary system is a replacement from an absolute rest frame. Which Einstein also states isn't necessary. 

A simple example take observer A being stationary. Now observer B moves towards Observer A. You already know how to mathematically describe that.

Now switch observers Observer B is now stationary while Observer A moves towards observer B. The equation will be identical. ( symmetric). If a relation is symmetric it is also commutative.

Edited June 13, 2023 by Mordred

[Logicandreason]

3 minutes ago, Mordred said:

Your essentially correct so far. However as I mentioned showing light as constant he refers to two works by other physicists. Lorentz and Maxwell. In section 3 he applies the Lorentz transformations. In later sections he applies the Maxwell equations, which at this time has already been shown by other research papers to follow Lorentz invariance and not Galilean invariance.

 In essence he refers to other research papers that have already shown light being constant. One of those tests being the null results of the M and M experiment for Luminiferous Eather. In that test it also showed zero deviation from c due to velocity of emitter or observer.

I have no interest in section 3 at this stage.

Lorentz was concerning himself with figuring out how to calculate a doppler wave effect of anything that had wave propagation, and he came up with his transformation.

Maxwell mentions nothing about stationary or moving other than relative motion between say a coil and a carbon rod to generate an electric field.

Nothing about Lorentz or Maxwell demand a single measured value for light speed across any frame of reference, that was a postulate of Einstein, his "guess" so to speak.

I already admitted or am willing to believe that it may very well be that Light always moves with consistent velocity.

And I'm willing to accept that in Einstein's "stationary Frame" System Zylon, someone measured light and recorded 186 from where they were in System Zylon.  Anywhere in System Zylon, light will be measured as 186.

But so far its not been shown that 186 could ever be measured from any other frame unless it had the same state of motion to System Zylon.

So far, everything that Einstein has explained, is relative to System Zylon.  The stationary observer, and the moving observer are both in System Zylon, and most of the time Einstein uses System Zylon specific equations. Of course, the moving observer is free to take measures of anything from his own system that is moving along with him. System Zylon and the moving system have a known peed differential that needs to be considered in any comparisons. 

 

[Mordred]

Unfortunately your incorrect regarding the researches by Lorentz and Maxwell. The easiest way to show that is to compare the transforms That Lorentz developed that Einstein used in section 3.

Galilean transformations. the important 2 is time and travel along the x axis.

\[\acute{x}=x-vt, \acute{T}=T\] no time time dilation

Lorentz transformations

\[ \acute{x}=x\gamma(x-vt),\acute{t}=t-\gamma \frac{vx}{c^2}, \] time dilation and length contraction

 

Edited June 14, 2023 by Mordred

[Logicandreason]

11 minutes ago, Mordred said:

It also applies to the statement the laws of physics are the same regardless of observer. The stationary system is a replacement from an absolute rest frame. Which Einstein also states isn't necessary. 

A simple example take observer A being stationary. Now observer B moves towards Observer A. You already know how to mathematically describe that.

Now switch observers Observer B is now stationary while Observer A moves towards observer B. The equation will be identical. ( symmetric). If a relation is symmetric it is also commutative.

A "stationary frame" actually "System Zylon", is no more a replacement for an hypothetical "Absolute frame" than  any other frame, such as the moving frame, which I well give the name, "System Honda".  The ONLY thing to identify these systems that they both have in common is that they are inertial and moving or not in the same direction.( Orientated in the same plane)

Now your other statement "the laws of physics are the same regardless of observer."  needs fixing, it was supposed to read, "The Laws of Physics are applicable equally in all inertial frames".

And that is exactly what classical Physics does.

Therefore an object that possesses constancy of motion, inertial motion, will be seen to have constancy of motion when viewed from any relatively moving frame when that motion is also inertial.

That is the Law of Physics we are talking about correct?

 

2 minutes ago, Mordred said:

Unfortunately your incorrect regarding the researches by Lorentz and Maxwell. The easiest way to show that is to compare the transforms That Lorentz developed that Einstein used in section 3.

Galilean transformations. the important 2 is time and travel along the x axis.

 

x´=x−vt,T´=T

no time time dilation

 

Lorentz transformations

 

x´=xγ(x−vt),t´=t−γvxc2,

time dilation and length contraction

 

 

The Lorentz transformation is not showing that time is dilating and length is contracting, its just a mathematical calculation of the effect of Doppler shift and speed differences. 

If Lorentz had already proved time dilation and length contraction and the necessary Mass increase, then Einstein's 1905 paper was not required.

But regardless, none of this is explaining how Einstein came to the conclusion the clocks would get out of sync when they were used to record durations of events, or that the observers could possibly come up with different lengths for that Rod.

He alluded to Maxwell and maybe was referring to the Michaelson and Morley experiment, but never mentioned Lorentz.

But that had nothing to do with his Rod Experiment scenario. Those comments were simply introducing the concept that there was some chance that not all was right with the current understanding as there were un answered questions. That's all you can deduce from Einstein's reference to Maxwell and M&M.

So I would like you to focus on just the Rod Experiment as Einstein explained it. Which is completely contained in the Kinematic Part, in sections one and two.

About Lorentz, he was actually trying to also establish that there must be an aether for light propagation,  A belief he held for many years after 1905.  He thought that a medium was required because his doppler equation, the Lorentz transformation, which works for sound waves in mediums like liquid or gasses , was applicable for light but he could not understand how his equations gave the right results without the medium.

Lorentz equations do not shrink lengths of objects nor distort time.

Einstein applied the Lorentz equations in a different way, which did distort time and distance and mass.

He applied a wave equation to a objects. Thus getting weird results.

 

[Mordred]

Really he doesn't mention Lorentz funny he specifically notes the Lorentz transformations and even has a footnote directly referring to it on the bottom of page 8. he even goes through the related mathematics directly applying the Lorentz transformations in that paper. 

"The equations of the Lorentz transformation may be more simply deduced directly from the condition that in virtue of those equations the relation x2 + y2 + z2 = c2t2 shall have as its consequence the second relation "

 

Edited June 14, 2023 by Mordred

[swansont]

1 hour ago, Logicandreason said:

Yep, we know that up to the conclusions about the Rod experiment, there is not yet any hypothesis about Time dilation or length contraction. 

Its all classical Physics and standard Math.

At the end of section 2 he has shown that time is relative, owing to the constancy of c, which was not part of “classical” physics. If that had been applied to the problem, the light would have acquired the speed if the source rather than being constant, and the time in both frames would be simply r/c

[Logicandreason]

10 minutes ago, Mordred said:

Really he doesn't mention Lorentz funny he specifically notes the Lorentz transformations and even has a footnote directly referring to it on the bottom of page 8. he even goes through the related mathematics directly applying the Lorentz transformations in that paper. 

"The equations of the Lorentz transformation may be more simply deduced directly from the condition that in virtue of those equations the relation x2 + y2 + z2 = c2t2 shall have as its consequence the second relation "

 

He did not mention Lorentz in "the Kinematic Part, Sections 1 and 2, the section of our interest. That is all that matters at this moment.

[Mordred]

I see well its up to you if your going to accept c as being constant. That entails also time dilation and length contraction. As I mentioned before its not really our goal to force posters to believe in something.

[Logicandreason]

11 minutes ago, swansont said:

At the end of section 2 he has shown that time is relative, owing to the constancy of c, which was not part of “classical” physics. If that had been applied to the problem, the light would have acquired the speed if the source rather than being constant, and the time in both frames would be simply r/c

au contraire, we all know that light has constancy of velocity across all inertial frames, but he never showed that it was always measured as 186... across all frames. He specifically said that its speed was 186 (c) a determined velocity IN THE System Zylon.

1 minute ago, Mordred said:

I see well its up to you if your going to accept c as being constant. That entails also time dilation and length contraction. As I mentioned before its not really our goal to force posters to believe in something.

We were going through Einstein's rod experiment, and he specifically said that 186... (c) was determined in the System Zylon. He is using classical physics here in this explanation, (in an attempt to show that it s wrong) So far c is relative only to the System Zylon. Einstein now needs to prove with classical physics, that his apparently irrational claim that 186 can be also measured an System Honda, is possible. Given that there is a speed difference between Systems Zylon and Honda.

The only classical Physics and rational Mathematics situation where this is a true claim is when the difference in speed between the two systems = zero. Its therefore called a "special case".  Not universal.

[Mordred]

In your opinion, however you also choose to ignore relevant sections and materials for c being constant.

[Logicandreason]

Prove mathematically using classical physics only, that light speed is measured at 186... units, in both of two systems when there exists a speed difference between the systems of k velocity, given that light is independent of both systems.

That is what you must show, before we can proceed. This is not an unreasonable request.

Because this is what Einstein is claiming classical physics believes, but I think its not representative of classical physics at all. Before Einstein can claim that there is a problem with classical Physics, he must first give a correct account of what classical physics actually is.

4 minutes ago, Mordred said:

In your opinion, however you also choose to ignore relevant sections and materials for c being constant.

In his paper, is it not divided into several sections? Yes or No?

In section one and two, does he not make specific claims and then concludes with a specific statement claiming that classical Physics is in error? 

Why Yes he does.

So why do you consider that I must look outside this self contained section of the paper, the "proffered proof that classical physics is in error" section, for the explanation? 

Anyway, by any means, using classical Physics alone, (for this is Einstein's claim) show me how light speed results of measure can be obtained apparently without possessing any origin from which to begin the measurement.

Cant use the origin of system Zylon or Honda, because there will be a mathematical error UNLES there is no speed differential between those two Systems.

So I'm listening, and willing to learn, but you need to be concise and scientifically (rationally) minded in your approach. The Logic needs to be sound.

 

 

10 minutes ago, Logicandreason said:

Prove mathematically using classical physics only, that light speed is measured at 186... units, in both of two systems when there exists a speed difference between the systems of k velocity, given that light is independent of both systems.

That is what you must show, before we can proceed. This is not an unreasonable request.

Because this is what Einstein is claiming classical physics believes, but I think its not representative of classical physics at all. Before Einstein can claim that there is a problem with classical Physics, he must first give a correct account of what classical physics actually is.

In his paper, is it not divided into several sections? Yes or No?

In section one and two, does he not make specific claims and then concludes with a specific statement claiming that classical Physics is in error? 

Why Yes he does.

So why do you consider that I must look outside this self contained section of the paper, the "proffered proof that classical physics is in error" section, for the explanation? 

Anyway, by any means, using classical Physics alone, (for this is Einstein's claim) show me how light speed results of measure can be obtained apparently without possessing any origin from which to begin the measurement.

Cant use the origin of system Zylon or Honda, because there will be a mathematical error UNLES there is no speed differential between those two Systems.

So I'm listening, and willing to learn, but you need to be concise and scientifically (rationally) minded in your approach. The Logic needs to be sound.

 

 

Someone said that this belief was a "tough pill to swallow", obviously because its an irrational pill, and also very large with spikes all over, but before I swallow any pill, I need to know what's inside.

No one is explaining that to me so far.

[swansont]

23 minutes ago, Logicandreason said:

au contraire, we all know that light has constancy of velocity across all inertial frames,

We know this now, but that was not the state of physics in 1905. In “classical” physics, as you are calling it (it’s Galilean relativity and Newtonian physics), the speed of the source was added to the speed of whatever is being sent. The speeds added linearly. 

If c were acknowledged as being constant in Newtonian kinematics, there would have been no point in writing the paper.

23 minutes ago, Logicandreason said:

but he never showed that it was always measured as 186... across all frames. He specifically said that its speed was 186 (c) a determined velocity IN THE System Zylon.

None of this is mentioned in the paper (no numerical value for c, no Zylon), and I thought we were limiting ourselves to the paper.

23 minutes ago, Logicandreason said:

Prove mathematically using classical physics only, that light speed is measured at 186... units, in both of two systems when there exists a speed difference between the systems of k velocity, given that light is independent of both systems.

That is what you must show, before we can proceed. This is not an unreasonable request.

Because this is what Einstein is claiming classical physics believes, but I think its not representative of classical physics at all. Before Einstein can claim that there is a problem with classical Physics, he must first give a correct account of what classical physics actually is.

No, this is wrong. You are misinformed or misunderstand that state of physics before relativity.

The constancy of c is a postulate of relativity. It is taken as a given in the paper, to investigate the ramifications of this deviation from Galilean relativity. A problem here is that Einstein assumed readers of the paper would understand the state of physics at that time, and you don’t seem to.

[Mordred]

20 minutes ago, Logicandreason said:

Prove mathematically using classical physics only, that light speed is measured at 186... units, in both of two systems when there exists a speed difference between the systems of k velocity, given that light is independent of both systems.

 

Its not my job to prove anything to you. that isn't why I visit this forum. I visit this forum to help people that want to learn physics not force them to believe in something they choose not to accept. I offered numerous literature showing c as constant you chose to ignore those.