Is time universal? NO (and its proof)

[Billy T]

.... The local ether model which cannot be ruled out by experimental evidence does not say that the relativity of simultaneity is real or perception.

several times you have mentioned the "local ether model."
Is the same "aether drag model" that some hoped could explain the null results of the M&M experiement, until they were forced to "abandon all hope" by the results of the"stellar aberation observations"? or some new version. Say something so I will better understand what it is that you rae referring to by "local ether model"

(I assume that it is not the effect of breathing ether on your brain, but I am not always sure. in some of your posts. For example, you took me to task in approximately 10 of your posts because I find the rather widely used definition of "relativistic mass" useful, but you think nothing of coining/defining the term "irrational measurement" when you wanted to speak of physics and measurement instead of the purely math problem as to why π is irrational. I read a lot but never have seen anyone else use your defieniton of "irrational measurement" although some do speak of being irrational and measuring things, but I did not think you were trying to be irrational - I always give you credit for trying to be rational. )

 

[Billy T]

What I am saying is that you give up galilean transformation (that claims that simultaneity is absolute) to prove that simultaneity is relative.

I think I agree and that it is obvious that yes I give up claims to simultaneity when proving events that are simultaneous inone frame are not simultaneous in one moving wrt to it. (I don't see the need to speak of Galilean transforms or any other type in my simple, I think, irrfutable proof that time is not universal.) I like to keep it firm and simple. No propagation delays, No transformations, No use of equations, especailly not any from SR. etc.

If Galiliean transforms help you to agree with the conclusion that is fine with me, but I don't think I need them in my proof.

 

[1100f]

I think I agree and that it is obvious that yes I give up claims to simultaneity when proving events that are simultaneous inone frame are not simultaneous in one moving wrt to it. (I don't see the need to speak of Galilean transforms or any other type in my simple, I think, irrfutable proof that time is not universal.) I like to keep it firm and simple. No propagation delays, No transformations, No use of equations, especailly not any from SR. etc.

If Galiliean transforms help you to agree with the conclusion that is fine with me, but I don't think I need them in my proof.

No, you gave up absolute simultaneity (by giving up the galilean velocity addition) and then you gave an example, not a proof, that if you give up absolute simultaneity then simultaneity is relative.

 

[Aer]

several times you have mentioned the "local ether model."
Is the same "aether drag model" that some hoped could explain the null results of the M&M experiement, until they were forced to "abandon all hope" by the results of the"stellar aberation observations"? or some new version.

I would expect it is not the same version as it is explicitly stated in one paper's abstract regarding the local ether that:

Based on this local-ether model of wave propagation, a wide variety of earthbound, interplanetary, and interstellar
propagation phenomena are accounted for. Strong evidence of this new classical model is its consistent
account of the Sagnac effect due to earth’s motions among GPS, the intercontinental microwave link, and
the interplanetaryradar.

I cannot backup the accuracy of this claim, but can only state that I've not seen any rebuttals to it.

 

[Billy T]

No, you gave up absolute simultaneity (by giving up the galilean velocity addition) and then you gave an example, not a proof, that if you give up absolute simultaneity then simultaneity is relative.

I am still not following your logic well. Perhaps it would help me follow you if you to tell where "I give up the galilen transform" in the proof.

Are you assumng that somewhere in the proof I must use the unstated velocity of the train (v in your notation) to compute something? - I don't compute any thing !!!! So how can it be that I am giving up galilean or any other transform?

I even noted that compared to Pete's stamping time clock and the need to use SR theory (as he and James did) to calculate what is printed, My proof avoids all calculations. It only depends on the fact the train moves while the explosion triggering light flash is in flight towards the two explosive charges.

 

[1100f]

I am still not following your logic well. Perhaps it would help me follow you if you to tell where "I give up the galilen transform" in the proof.

If the flashlights have velocity +c and -c in the train reference frame, then if the train velocity is v wrt the ground, by galilean transformation the flashlight velocities should be v-c and v+c wrt the ground. By stating that the velocities of the flash lights wrt the ground are equal (and opposite) you have given up galilean transformation. and simultaneity.

 

[Billy T]

I would expect it is not the same version as it is explicitly stated in one paper's abstract regarding the local ether that: I cannot backup the accuracy of this claim, but can only state that I've not seen any rebuttals to it.

I note that the Sagna effect is one related to rotation while two light beams travel around in opposite directions of a closed path (BTW I have held in my hand the core of the US navy's equlateral triangle ring laser that is used to get the rotational rate ω directly - a beautiful piece of physics / optics machined into solid quartz.)

I do not use rotating frames in my conceptual demonstration. Assume that the train and station are both inertial frames. If I did not explicity state this, it was because it seemed obvious that the train was passing the station in a straight line, but perhaps you falsely, but reasonable, assumed on rotating Earth etc.

 

[Billy T]

... By stating that the velocities of the flash lights wrt the ground are equal (and opposite) you have given up galilean transformation. and simultaneity.

OK, I think I see your concern now.

I do need to claim the the speed of light is independant of the source motion. I.e. even though the flash bulb (not flash lights) is mounted on the train that the light it produces moves both ways along the tracks at equal speeds (any number you like, say 100,000m/sec) but I don't call this a transform (galilean or other wise.)

I think Maxwell's equations are valid for the velocity of light - all you need to calculate c is the vacuum magnetic permability and the vacuum dielectric constant. Neither has any motion associated with their measurement, so I think it OK to assume that both ways (up and down the track), that light speed, whatever it is, is the same and given by these two motion free measurements.

It is a little far fetched for a thought experiment, but it is true (if you are concerned) that the two beams are red and blue shifted and that the air does have slight dispersion but even with all that essentially negligible physics, I can just make the train longer so it remains true for the ground observers that the explosion at the rear of the train preceeds the one at the front, but they are simultaneous in the train's frame.

 

[Neddy Bate]

Neddy Bate:

What you have discovered is that everybody in two frames will agree unambiguously on what clocks in the two frames read at any particular location, provided all clocks in one frame are synchronised with each other, and all clocks in the other frame are synchronised with each other.

What you need to be careful about is to assert that therefore the clocks in one frame remain synchronised at all times with clocks in the other frame, because that does not happen.

JamesR is correct. The method for synchronizing clocks in one frame depends on the speed of light and the distance a light signal must travel from one clock to the next. From a different frame, the distance that the light signal travels (between the clocks) is shorter when the light signal travels toward the rear of the train, and longer when the light signal travels toward the front of the train. (According to BillyT's original example).

Thus the train clocks are not properly synchronized in the reference frame of the embankment (even after compensating for time-delay effects which cause distant clocks to show a reading that is actually from some time in the past). Assuming BillyT's original proof consists of inertial frames, the effect would reciprocal. Synchronized clocks along the embankment would not be properly synchronized according to passengers on the train.

Unfortunately, this just makes it even more difficult to understand what will be shown on the printed notepads. Each notepad represents simultaneousness at a certain point co-located in both frames, and there are an infinite number of possible points along the axis of motion to place these notepads. Therefore there is something simultaneous about the two frames everywhere.

So although I agree that time is relative in the sense that one frame can be dilated and not-synchronized when compared to another frame, somehow there is a universal aspect to it as well. Simultaneousness all along the axis of motion, or "proper time," or whatever it is, can be considered universal in a sense. For example, even if clocks tick slower on Jupiter than they do on Earth, neither one is ahead or behind the actual "time" of the solar system as told by the positions of the planets. (Neglecting perception delays).

 

[1100f]

You should state that you believe the relativity of simultaneity is a real effect. There is no experimental evidence to conclusively conclude that it is. The local ether model which cannot be ruled out by experimental evidence does not say that the relativity of simultaneity is real or perception.

What I meant here is that according to SRT all those effects are real. I stated there since some people think that even according to SRT, the effects are just a question of perceptions.

About evidences of SRT, there is no lack both theoretical and experimental of SRT

 

[Aer]

What I meant here is that according to SRT all those effects are real. I stated there since some people think that even according to SRT, the effects are just a question of perceptions.

Agreed.

About evidences of SRT, there is no lack both theoretical and experimental of SRT

You should say there is no evidence against SRT, both theoretical and experimental.

 

[1100f]

You should say there is no evidence against SRT, both theoretical and experimental.

At the moment, SRT is the most accurate theory (not including gravitation) for the space time structure. It has the most accurate predictions.

 

[Aer]

At the moment, SRT is the most accurate theory (not including gravitation) for the space time structure. It has the most accurate predictions.

No disagreement about the accuracy.

 

[Neddy Bate]

</em>At the moment, SRT is the most accurate theory (not including gravitation) for the space time structure. It has the most accurate predictions.

</em>No disagreement about the accuracy.

Sorry, but I have not yet seen an unambiguous set of predictions by SR in this thread. Perhaps you two understand GR so well that you have some way of sorting out the apparent paradoxes. Is it always taken for granted that the predictions only need apply to "our" (laboratory) frame?

May I ask for an SRT prediction of just a few samples of "notepad-clock" printed receipts? Here is the scenario (All clocks are identically constructed):

The embankment clocks are all synchronized (in the embankment frame only), and the train clocks are all synchronized (in the train frame only). Whenever a clock in one frame passes very close to a clock in the other frame, one printed receipt is generated.

Any arbitrary starting point will do. EmbankmentTime = 20, TrainTime = 400, it does not matter. Please give me a few examples of the SR predictions, such as:

EmbankmentTime = 20, TrainTime = 400, end of receipt.
EmbankmentTime = 21, TrainTime = 401, end of receipt.
EmbankmentTime = 22, TrainTime = 402, end of receipt.

I just am not getting it. Would it help if we stipulated that a long, long time ago one of the frames had to accelerate? Please help. Thank you.

 

[MacM]

Any arbitrary starting point will do. EmbankmentTime = 20, TrainTime = 400, it does not matter. Please give me a few examples of the SR predictions, such as:

EmbankmentTime = 20, TrainTime = 400, end of receipt.
EmbankmentTime = 21, TrainTime = 401, end of receipt.
EmbankmentTime = 22, TrainTime = 402, end of receipt.

I just am not getting it. Would it help if we stipulated that a long, long time ago one of the frames had to accelerate? Please help. Thank you.

At first glance it seems you are accumulating time at equal rates. I believe your example should show a ratioed change.

ET = 20, TT = 400.0
ET = 21, TT = 400.5
ET = 22, TT = 401.0

But then maybe I am missing the point.

 

[Neddy Bate]

At first glance it seems you are accumulating time at equal rates. I believe your example should show a ratioed change.

ET = 20, TT = 400.0
ET = 21, TT = 400.5
ET = 22, TT = 401.0

But then maybe I am missing the point.

Thanks for trying to help me, MacM. Are you giving me the SR answer or one from a different theory?

Because now I have to ask you why SR would predict that the Train clocks would tick "absolutely" slower than the Embankment clocks. What would cause that to happen in a case of uniform translational motion? Was it an acceleration from some time ago?

Don't forget that this paper trail would be audited from both reference frames at a later time.

 

[MacM]

Thanks for trying to help me, MacM. Are you giving me the SR answer or one from a different theory?

I am not sure thanks are in order. There is apt to be some disagreement with what I say.

Because now I have to ask you why SR would predict that the Train clocks would tick "absolutely" slower than the Embankment clocks. What would cause that to happen in a case of uniform translational motion?

I think it is evident from emperical data (and logic) that in fact IS the case, even though it defies the inherent reciprocity predicted by SRT.

Was it an acceleration from some time ago?

Precisely. There is no justification (nor emperical evidence) to claim or actually show that reciprocity occurs. That is the non-accelerated referance has no basis for physical change, while the accelerated frame has undergone a change in absolute energy.

Don't forget that this paper trail would be audited from both reference frames at a later time.

Correct and just as GPS, it will show that one (and only one) has an altered tick rate. The dilated clock will always be the one which has been accelerated relative to the other.

 

[Pete]

Because now I have to ask you why SR would predict that the Train clocks would tick "absolutely" slower than the Embankment clocks. What would cause that to happen in a case of uniform translational motion? Was it an acceleration from some time ago?

Mac's figures are a correct reflection of the predictions of SR, but he has only shown the receipts generated as a single train clock passes several embankment clocks. Since we're only assuming the embankment clocks to be synchronized in the embankment frame, this only demonstrates that the train clock is dilated by a factor of two in the embankment frame.

To see what's happening to embankment clocks in the train frame, we need to see the receipts generated as an embankment clock passes several train clocks.

 

[Pete]

Hi Neddy,

Sorry, but I have not yet seen an unambiguous set of predictions by SR in this thread.

Unfortunately SR can't speak for itself, so in this thread you'll only find what various people understand to be the predictions of SR. Unfortunately, misunderstandings abound. If you want a reliable description of SR, you need to work through a textbook or talk to a real physicist or physics lecturer.

Is it always taken for granted that the predictions only need apply to "our" (laboratory) frame?

No.

May I ask for an SRT prediction of just a few samples of "notepad-clock" printed receipts? Here is the scenario (All clocks are identically constructed):

The embankment clocks are all synchronized (in the embankment frame only), and the train clocks are all synchronized (in the train frame only). Whenever a clock in one frame passes very close to a clock in the other frame, one printed receipt is generated.

Any arbitrary starting point will do. EmbankmentTime = 20, TrainTime = 400, it does not matter. Please give me a few examples of the SR predictions, such as:

EmbankmentTime = 20, TrainTime = 400, end of receipt.
EmbankmentTime = 21, TrainTime = 401, end of receipt.
EmbankmentTime = 22, TrainTime = 402, end of receipt.

Firstly, here's the scenario with more detail. I've set it up so that the clocks are always at whole numbers when receipts are printed.

• Ten synchronized clocks are equally spaced 520m apart on the embankment, labeled EA to EJ.
• Ten synchronized clocks are equally spaced 520m apart on the train, labeled TA to TJ.
• The distance between embankment clocks in the embankment frame is equal to the distance between train clocks in the train frame.
• The train clocks are labeled in reverse order to the embankment clocks to make the problem easier for me (it makes it symmetrical).
• The first clocks to meet are EA and TA. They pass each other as EA reads 20 and TA reads 400.
• The relative speed of the train and the embankment is 86.6% of light speed, so that lengths are contracted by two and time is dilated by two.
• The unit of time is microseconds.

Here is a table of the receipts generated as each pair of clocks pass. The format is EmbankmentTime, TrainTime.

<table border=1 cellpadding=4 align=center><tr><td></td><td>EA</td><td>EB</td><td>EC</td><td>ED</td><td>EE</td><td>EF</td><td>EG</td><td>EH</td><td>EI</td><td>EJ</td></tr><tr><td>TA</td><td>20,400</td><td>22,401</td><td>24,402</td><td>26,403</td><td>28,404</td><td>30,405</td><td>32,406</td><td>34,407</td><td>36,408</td><td>38,409</td></tr><tr><td>TB</td><td>21,402</td><td>23,403</td><td>25,404</td><td>27,405</td><td>29,406</td><td>31,407</td><td>33,408</td><td>35,409</td><td>37,410</td><td>39,411</td></tr><tr><td>TC</td><td>22,404</td><td>24,405</td><td>26,406</td><td>28,407</td><td>30,408</td><td>32,409</td><td>34,410</td><td>36,411</td><td>38,412</td><td>40,413</td></tr><tr><td>TD</td><td>23,406</td><td>25,407</td><td>27,408</td><td>29,409</td><td>31,410</td><td>33,411</td><td>35,412</td><td>37,413</td><td>39,414</td><td>41,415</td></tr><tr><td>TE</td><td>24,408</td><td>26,409</td><td>28,410</td><td>30,411</td><td>32,412</td><td>34,413</td><td>36,414</td><td>38,415</td><td>40,416</td><td>42,417</td></tr><tr><td>TF</td><td>25,410</td><td>27,411</td><td>29,412</td><td>31,413</td><td>33,414</td><td>35,415</td><td>37,416</td><td>39,417</td><td>41,418</td><td>43,419</td></tr><tr><td>TG</td><td>26,412</td><td>28,413</td><td>30,414</td><td>32,415</td><td>34,416</td><td>36,417</td><td>38,418</td><td>40,419</td><td>42,420</td><td>44,421</td></tr><tr><td>TH</td><td>27,414</td><td>29,415</td><td>31,416</td><td>33,417</td><td>35,418</td><td>37,419</td><td>39,420</td><td>41,421</td><td>43,422</td><td>45,423</td></tr><tr><td>TI</td><td>28,416</td><td>30,417</td><td>32,418</td><td>34,419</td><td>36,420</td><td>38,421</td><td>40,422</td><td>42,423</td><td>44,424</td><td>46,425</td></tr><tr><td>TJ</td><td>29,418</td><td>31,419</td><td>33,420</td><td>35,421</td><td>37,422</td><td>39,423</td><td>41,424</td><td>43,425</td><td>45,426</td><td>47,427</td></tr></table>

It will be difficult to make sense of this table, so take it slowly.
Here are some questions that might help:

• TA and EA are the first clocks to meet. What are the second pair of clocks to meet?
• Look a the EB,TD receipt. Did this meeting happen at the same time as EC,TB? Did it happen at the same time as ED,TC?
• Think about how you discover from the receipts (if possible) just how fast a particular clock is ticking in each frame.
• What else can the receipts tell you? Can they tell you how far apart any pair of clocks is at any time in each frame?

I just am not getting it. Would it help if we stipulated that a long, long time ago one of the frames had to accelerate?

No, historical accelerations aren't relevant to the SR model.


EDIT: The distance between the clocks should be 520m, not 52m. Thanks to Raphael for pointing out this mistake.

 

[Pete]

This setup leads to a very interesting question, which I'm about to open another thread to address.