Undergrad WIKI and Time Dilation: The Possible Error in Relative Velocity

[JesseM]

We are doing a 2nd calculation.Is this an intellectual challenge?



We are doing a new problem.



This is not reasonable to try to trap me in like this when I clearly said let's switch the context.

Why don't you stop lying, none of you're posts said "let's switch the context". Instead you repeatedly made nasty accusations that I was making "mistakes" and "errors" when I just took you at your word, and then you pretended like you hadn't said what you had in fact said. Read again:

Geez, please take the clock as the stationary frame wrt to the observer.

In that case there is only one frame to consider, the frame where both the clock and observer are at rest

Where in the WIKI article is the clock at rest with the observer? You make many mistakes.

Then in the only post of yours that used the word "context", you said that the context was still about "the clock at rest wrt to the observer":

I have the context.

I want to see your calculation with the clock at rest wrt to the observer. See i even followed your rules, as if that was the issue.

Then it's simple, in the observer's frame the light source is at rest so there is no aberration, therefore the light just travels on a vertical path of length L from the bottom to the top, so the time is \Delta t = \frac{L}{c} to go from bottom to top.

What?

The observer's frame does not have the light source, the clock does. This is an error.

So in both cases, you said the observer was at rest relative to the clock, I responded to that, and then you accused me of a mistake/error. There was nothing like "oh sorry, I know I said the observer was at rest relative to the clock but now I want to change the context and talk about an observer moving relative to the clock" (when I pointed out you had changed your story, your response in post #248 was "whatever"). So you are either confused or trolling, I'm thinking the latter looks pretty likely now. If you want to show you're not a troll you can acknowledge that you were incorrect to accuse me of mistakes in the two posts above, if you don't do that I will be pretty confident that you are trolling and will no longer respond to your posts (and will probably also report this thread to the mods in hopes they will lock it so others aren't fooled into wasting time responding as if your questions were asked in earnest).

We are trying to calculate the clock at rest and the observer is moving and calculate the time intervals between the frames in the view of the clock frame. Can you do this?

To calculate the "time intervals between the frames", one of the time intervals we must calculate is the time in the observer's frame. What the hell does it mean to calculate the time in the observer's frame "in the view of the clock frame"? Are you asking to apply the LT to the times in the clock frame? Are you asking to figure out the clock frame's view of the two clocks the observer uses to locally measure the time-coordinates of the light leaving the bottom mirror and the light hitting the top one? If the question is serious and not a trollish provocation, you need to explain precisely what it is you want calculated here.

 

[chinglu1998]

How is what you showed a difference at all? In both frames, events on the light cone that are not simultaneous are not at the same distance. And in both frames, events on the light cone that are simultaneous are at the same distance. So both frames are the same in that respect, not different.

Not true. The stationary frame will show the moving light sphere located at origin vt when applying LT to its own light sphere at time t.

The other frame will see the origin at -vt.

We have a difference.

Bit, we are talking about the difference in the context of one frame. That has been established in this thread as fact.

Another thing established in this thread is that light aberration is absolute based on the frame that contains the light source. Hence for the WIKI example, t'=tγ regardless of which frame is taken as stationary.

 

[chinglu1998]

Why don't you stop lying, none of you're posts said "let's switch the context". Instead you repeatedly made nasty accusations that I was making "mistakes" and "errors" when I just took you at your word, and then you pretended like you hadn't said what you had in fact said. Read again:

I am so sorry, you are never wrong.

Anyway, I made it clear I wanted to calculate time dilation from the context of the clock frame and that is a fact. You take the time to validate that. I said it several time.

Then in the only post of yours that used the word "context", you said that the context was still about "the clock at rest wrt to the observer":

You are in error. This is just a few.
Geez, please take the clock as the stationary frame wrt to the observer. #227
You people are so willing to accept the WIKI calculations and yet so reluctant to calculate from the clock frame. Why? #230
So what are the times when the clock frame is taken as stationary.#239

To calculate the "time intervals between the frames", one of the time intervals we must calculate is the time in the observer's frame. What the hell does it mean to calculate the time in the observer's frame "in the view of the clock frame"? Are you asking to apply the LT to the times in the clock frame? Are you asking to figure out the clock frame's view of the two clocks the observer uses to locally measure the time-coordinates of the light leaving the bottom mirror and the light hitting the top one? If the question is serious and not a trollish provocation, you need to explain precisely what it is you want calculated here.

This seems so complicated. You know which frame the WIKI use to calculate? Yea, use the other and do not forget light aberration.

 

[Dale]

Not true. The stationary frame will show the moving light sphere located at origin vt when applying LT to its own light sphere at time t.

The other frame will see the origin at -vt.

We have a difference.

I can't parse that sentence at all. But, if something is stationary in the unprimed frame then it is moving at velocity v in the primed frame, and if something is stationary in the primed frame it is moving at velocity -v in the unprimed frame. How is that a difference?

Bit, we are talking about the difference in the context of one frame. That has been established in this thread as fact.

Another thing established in this thread is that light aberration is absolute based on the frame that contains the light source. Hence for the WIKI example, t'=tγ regardless of which frame is taken as stationary.

Stationary wrt what? The clock or the observer? You really have a very bad habit of not specifying what you are measuring velocity relative to. I don't think that this thread has even established what you are asking, let alone what the answer is.

 

[chinglu1998]

If something is stationary in the unprimed frame then it is moving at velocity v in the primed frame, and if something is stationary in the primed frame it is moving at velocity -v in the unprimed frame. How is that a difference?

Stationary wrt what? The clock or the observer? You really have a very bad habit of not specifying what you are measuring velocity relative to. I don't think that this thread has even established what you are asking, let alone what the answer is.

Let's calculate time dilation from the clock frame using the light aberration argument of the WIKI artucle.

 

[Dale]

Let's calculate time dilation from the clock frame using the light aberration argument of the WIKI artucle.

1

 

[JesseM]

I am so sorry, you are never wrong.

Sarcastic non-answer doesn't cut it for me to see you as a non-troll. Do you acknowledge you changed your story in those specific posts I quoted, where first you said you wanted the clock and the observer at rest wrt each other, then when I dealt with that scenario you accused me of mistakes/errors? Yes or no? If you don't give a serious answer here (and if the answer is 'no', an explanation of what specific mistake I made about what scenario you had described in those posts), then as I said I'm writing you off as a troll and reporting the thread.

Anyway, I made it clear I wanted to calculate time dilation from the context of the clock frame and that is a fact. You take the time to validate that. I said it several time.

Yeah but I keep asking you what the hell that means and you never answer.

Then in the only post of yours that used the word "context", you said that the context was still about "the clock at rest wrt to the observer":

You are in error.

What am I in error about?

This is just a few.
Geez, please take the clock as the stationary frame wrt to the observer. #227
You people are so willing to accept the WIKI calculations and yet so reluctant to calculate from the clock frame. Why? #230
So what are the times when the clock frame is taken as stationary.#239

Hmm, none of this has anything whatsoever to do about my comment Then in the only post of yours that used the word "context", you said that the context was still about "the clock at rest wrt to the observer". That comment was about post #240, which was in fact "the only post of yours that used the word "context", and in that post you said the context "the clock at rest wrt to the observer". I never denied that you wanted to calculate something "from the clock frame", I just pointed out you had changed your story about whether the observer was moving or stationary relative to the clock frame, and I still don't understand what it means to calculate the observer's time interval "from the clock frame".

This seems so complicated. You know which frame the WIKI use to calculate?

Yeah, the wiki used both frames, and you are on drugs if you think it only used the observer's frame. This statement from the wiki is clearly discussing the perspective of the clock frame:

In the frame where the clock is at rest (diagram at right), the light pulse traces out a path of length 2L and the period of the clock is 2L divided by the speed of light:

\Delta t = \frac{2L}{c}

If you still think the wiki calculates everything from the observer's frame, why don't you explain in detail how you derive the equation \Delta t = \frac{2L}{c} "from the observer's frame", and maybe this will finally allow us to understand what the hell you are talking about when you ask to calculate the observer's time interval "from the clock frame".

 

[darkhorror]

No, the light source is with the clock and the observer is moving relative to the clock.


So, the question is, what time interval will each frame conclude.

In the observer's frame the clock will be running slower compared to the observer's time.

In the clock's frame the observer's time will be moving slower when compared to the clock.

 

[chinglu1998]

In the observer's frame the clock will be running slower compared to the observer's time.

In the clock's frame the observer's time will be moving slower when compared to the clock.

Can we show with with the light aberration argument of WIKI?

 

[chinglu1998]

Sarcastic non-answer doesn't cut it for me to see you as a non-troll. Do you acknowledge you changed your story in those specific posts I quoted, where first you said you wanted the clock and the observer at rest wrt each other, then when I dealt with that scenario you accused me of mistakes/errors? Yes or no? If you don't give a serious answer here (and if the answer is 'no', an explanation of what specific mistake I made about what scenario you had described in those posts), then as I said I'm writing you off as a troll and reporting the thread.

Fine, I'm done. I showed you at least three times where I wanted to look at the calculation from the view of the clock frame. There are many more. Then, you continue to call me a liar even after I have provided evidence in a thread you are supposed to be reading.


I do not want to be at a place where I have answered truthfully, provided evidence of what I said and am still called names by someone out of anger.

 

[JesseM]

Fine, I'm done. I showed you at least three times where I wanted to look at the calculation from the view of the clock frame.

And I never denied that you "wanted to look at the calculation from the view of the clock frame", smartass (I already mentioned this in my previous post when I said I never denied that you wanted to calculate something "from the clock frame", I just pointed out you had changed your story about whether the observer was moving or stationary relative to the clock frame). I just responded to your statement that you wanted the observer and the clock to be the same frame, then you accused me of mistakes and errors even though that was exactly what you just said.

Then, you continue to call me a liar even after I have provided evidence in a thread you are supposed to be reading.

Provided evidence of what? All you provided evidence for was that you had said you wanted to calculate things "from the clock frame", but this was irrelevant because I never said anything different. I guess you want to continue to avoid the issue I actually raised, namely that you had changed your notion of whether the observer was at rest or moving relative to the clock.

I do not want to be at a place where I have answered truthfully, provided evidence of what I said and am still called names by someone out of anger.

You certainly never "answered truthfully" about whether you had changed your story about whether the observer was moving or stationary relative to the clock, you seem to be doing everything possible to change the subject and avoid addressing this topic. Anyway, if finding new ways to avoid answering simple questions is getting tiring for you so you want to leave the thread instead, don't let the door hit your *** on the way out!

 

[IsometricPion]

Can we show with with the light aberration argument of WIKI?

If you had a light clock at rest in the primed frame, then yes, otherwise no (how could you measure the light aberration of a clock that doesn't exist?). (Note that this has no bearing on the applicability of Lorentz transforms as all that is needed is the relative velocity to transform from the coordinates of events in a given frame to their coordinates in another.)

 

[chinglu1998]

And I never denied that you "wanted to look at the calculation from the view of the clock frame", smartass (I already mentioned this in my previous post when I said I never denied that you wanted to calculate something "from the clock frame", I just pointed out you had changed your story about whether the observer was moving or stationary relative to the clock frame). I just responded to your statement that you wanted the observer and the clock to be the same frame, then you accused me of mistakes and errors even though that was exactly what you just said.

Provided evidence of what? All you provided evidence for was that you had said you wanted to calculate things "from the clock frame", but this was irrelevant because I never said anything different. I guess you want to continue to avoid the issue I actually raised, namely that you had changed your notion of whether the observer was at rest or moving relative to the clock.

You certainly never "answered truthfully" about whether you had changed your story about whether the observer was moving or stationary relative to the clock, you seem to be doing everything possible to change the subject and avoid addressing this topic. Anyway, if finding new ways to avoid answering simple questions is getting tiring for you so you want to leave the thread instead, don't let the door hit your *** on the way out!

I am sorry I did not handle your extreme emotion better.

I thought this is a debate with emotion.

I started out the thread that the article was wrong.

In my view it is. Others claimed the moving observer is not actually moving by at rest or something or whatever.

Many posts went in this direction.

So, I said fine, both cannot be correct. So, I made a change of direction and decided to view the clock frame as stationary since that is what I thought in the first place.

Now, you clearly understood how to calculate from the moving observer, but when I switched to the clock as the frame, you have expressed all this anger and hostility.

So, that was my thought process.

Now, are you going to calculate the time dilation with light aberration from the clock frame as the frame or no.

 

[JesseM]

So, I said fine, both cannot be correct. So, I made a change of direction and decided to view the clock frame as stationary since that is what I thought in the first place.

I'm not talking about which frame is "moving" or "stationary" because those are just arbitrary labels which have nothing to do with calculating anything. I'm asking whether you acknowledge that you changed your scenario, first saying the observer was at rest relative to the clock and then accusing me of an error when I discussed what would be true if the observer was at rest relative to the clock. This is a simple question, can you stop changing the subject and address it?

Now, are you going to calculate the time dilation with light aberration from the clock frame as the frame or no.

Not if you won't address the very simple question above, and also not if I can't understand what you are asking me to calculate. The time dilation involves the time intervals in two frames, what does it mean to calculate the time interval in the observer's frame "from the clock frame"? That seems like a meaningless request. It might help if you'd address the end of post #277 where I pointed out that the wiki article clearly uses both frames, using the clock frame to find the time interval in the clock frame, and the observer's frame to find the time interval in the observer's frame.

 

[darkhorror]

Fine, I'm done. I showed you at least three times where I wanted to look at the calculation from the view of the clock frame. There are many more. Then, you continue to call me a liar even after I have provided evidence in a thread you are supposed to be reading.

you continue to ask for what happens from the clocks frame, people have answered many many times that from the clocks frame the clock isn't dilated. Obviously the clock is going to tick at the normal rate in it's own frame since in that frame the clock isn't moving.

Do you want to know the time dilation in the observer's frame when looked at from the clock's frame of reference?

This is NOT the same thing as asking the clock's rate when it's at rest wrt the observer.

 

[chinglu1998]

If you had a light clock at rest in the primed frame, then yes, otherwise no (how could you measure the light aberration of a clock that doesn't exist?). (Note that this has no bearing on the applicability of Lorentz transforms as all that is needed is the relative velocity to transform from events in a given frame to their coordinates in another.)

I could ask you how does the observer that is moving in the WIKI artricle has any time.

Here is the calculation.

Assume the clock and light source are at reat. Let d be some mark on the y-axis of the clock frame. Then, it will t = d/c.

Now, in a frame in relative motion to the clock, it will see light aberration in the view of the clock frame since it is moving and the light is traveling in straight lines in the clock frame, they must travel at an angle in the moving frame.
Hence, c²t²' = (vt')² + c²t²

√ (c²t²' - v²t'²)/c = t²
t'√ (c² - v²)/c = t²

So, t'/γ = t.

The primed frame is the moving frame.

 

[darkhorror]

I am sorry I did not handle your extreme emotion better.

I thought this is a debate with emotion.

I started out the thread that the article was wrong.

In my view it is. Others claimed the moving observer is not actually moving by at rest or something or whatever.

That is exactly what the article says we are calculating from the observer's frame of reference the observer is moving at velocity v with respect to the clock. So when you calculate from the "moving observer's" frame of reference it is at rest in that frame of reference.

Many posts went in this direction.

So, I said fine, both cannot be correct. So, I made a change of direction and decided to view the clock frame as stationary since that is what I thought in the first place.

The clock's frame is only at rest in it's own frame of reference. In the observer's frame of reference it is not so in the observer's frame of reference the clock is moving at velocity v.

Now, you clearly understood how to calculate from the moving observer, but when I switched to the clock as the frame, you have expressed all this anger and hostility.

So, that was my thought process.

Now, are you going to calculate the time dilation with light aberration from the clock frame as the frame or no.

The time dilation of the clock? or the time dilation of the observer that's in another frame of reference?

 

[chinglu1998]

I'm not talking about which frame is "moving" or "stationary" because those are just arbitrary labels which have nothing to do with calculating anything. I'm asking whether you acknowledge that you changed your scenario, first saying the observer was at rest relative to the clock and then accusing me of an error when I discussed what would be true if the observer was at rest relative to the clock. This is a simple question, can you stop changing the subject and address it?

I said above I saw no chance of have the moving frame considered moving in this forum. I said that.

So, I decided to take the view of the clock frame. So, if you want to say I changed it, I did but did not. I still taking the clock frame as stationary as I did in the OP.

So, I have addressed it. What is your problem?

 

[chinglu1998]

That is exactly what the article says we are calculating from the observer's frame of reference the observer is moving at velocity v with respect to the clock. So when you calculate from the "moving observer's" frame of reference it is at rest in that frame of reference.



The clock's frame is only at rest in it's own frame of reference. In the observer's frame of reference it is not so in the observer's frame of reference the clock is moving at velocity v.



The time dilation of the clock? or the time dilation of the observer that's in another frame of reference?

OK, take all this and revert to the clock frame.

What is the calculation?

 

[darkhorror]

I said above I saw no chance of have the moving frame considered moving in this forum. I said that.

So, I decided to take the view of the clock frame. So, if you want to say I changed it, I did but did not. I still taking the clock frame as stationary as I did in the OP.

So, I have addressed it. What is your problem?

The point once again is that it doesn't matter which frame you call stationary or moving. All you have are two frames of reference A and B. where one or the other is stationary or moving, it doesn't matter which is which.

So you have two frames of reference A and B moving relative to each other at velocity v.

Here are two very simple questions can you answer them without any other information?

From frame of reference A does B's time move slower?

From frame of reference B does A's time move slower?

 

[JesseM]

So, I decided to take the view of the clock frame. So, if you want to say I changed it, I did but did not. I still taking the clock frame as stationary as I did in the OP.

So, I have addressed it. What is your problem?

I'm not talking about which frame you "took the view of". I'm talking about whether the clock is moving or stationary relative to the observer. If the clock is moving relative to the observer, then they are in relative motion regardless of whether you take the view of the clock frame or the observer frame. If the clock is stationary relative to the observer, then they are not in relative motion, again regardless of which frame you adopt. Are you going to acknowledge the fact that you said "the clock at rest wrt to the observer", then accused me of mistakes and errors when I talked about the scenario where the clock is at rest wrt to the observer?

 

[inflector]

Why does this thread give me deja vu?

Oh, that's right:

http://www.bautforum.com/showthread...eeds-light-to-travel-faster-than-c-to-be-true

 

[darkhorror]

OK, take all this and revert to the clock frame.

What is the calculation?

and I will ask again calculation of what? as I asked before

Are you asking
1. What is the time dilation of the clock in it's own frame of reference?

2. What is the the observer's time rate when looked at from the clocks frame of reference?

if you are asking 1. there is not time dilation it ticks at normal rate since it's velocity in that frame is 0.

if you are asking 2. the observer's time rate will be slower than the clocks since you are looking from the clocks frame of reference.

Now to add one more thing if you are looking from the observer's frame of reference then the clock ticks slower since it's moving with velocity v with respect to the observer.

 

[darkhorror]

chinglu1998

Would it make sense to you if the wiki article said this instead.

so instead of this "Observer at rest sees time 2L/c." they wrote this
"From the clocks frame of reference it sees time 2L/c."


and
instead of "From the frame of reference of a moving observer traveling at the speed v..."
"From the frame of reference of an observer with the clock traveling at velocity v..."

 

[IsometricPion]

I could ask you how does the observer that is moving in the WIKI artricle has any time.

There are many methods of measuring time. However, since this is an abstract physics problem I don't see why time can't be defined in a more abstract manner e.g. as one of the consitituent dimensions of space-time that can be given a more or less arbitrary unit duration (just like the spatial dimensions can be given arbitrary units of length).

Assume the clock and light source are at reat.

So, t'/γ = t.

The primed frame is the moving frame.

Yes, this is the conclusion of the calculation in the wikipedia article as well. If you have two light clocks, one at rest in the primed frame and one at rest in the unprimed frame, then you can use light aberration to show time dilation is symmetric. (Each clock will exhibit light aberration and time dilation from the other frame and the values will be equal in magnitude.)

 

[chinglu1998]

Why does this thread give me deja vu?

Oh, that's right:

http://www.bautforum.com/showthread...eeds-light-to-travel-faster-than-c-to-be-true

This has nothing to do with that thread. It was a spinoff and different issue.
But, it had is points that Baut cannot see.

I never got to the point.

You see, if an observer rides a light beam, the entire universe becomes a plane in the direction of travel to the observer.

Yet, from the non observer, (non-light observer), light does not traverse the entire universe instantly.

So, the two logical conclusions are not invertible and hence not mathematically viable as a complete theory.

 

[chinglu1998]

and I will ask again calculation of what? as I asked before

Are you asking
1. What is the time dilation of the clock in it's own frame of reference?

2. What is the the observer's time rate when looked at from the clocks frame of reference?

if you are asking 1. there is not time dilation it ticks at normal rate since it's velocity in that frame is 0.

if you are asking 2. the observer's time rate will be slower than the clocks since you are looking from the clocks frame of reference.

Now to add one more thing if you are looking from the observer's frame of reference then the clock ticks slower since it's moving with velocity v with respect to the observer.

Using light aberration as the WIKI article, calculate the time intervals in he different frames. Assume the clock is the frame you are calculating from.

 

[chinglu1998]

I'm not talking about which frame you "took the view of". I'm talking about whether the clock is moving or stationary relative to the observer. If the clock is moving relative to the observer, then they are in relative motion regardless of whether you take the view of the clock frame or the observer frame. If the clock is stationary relative to the observer, then they are not in relative motion, again regardless of which frame you adopt. Are you going to acknowledge the fact that you said "the clock at rest wrt to the observer", then accused me of mistakes and errors when I talked about the scenario where the clock is at rest wrt to the observer?

I am not even sure what to say with you.

The clock is at rest relative to the observer. I have said this and said this and said this and said this and said this and said this.

 

[chinglu1998]

chinglu1998

Would it make sense to you if the wiki article said this instead.

so instead of this "Observer at rest sees time 2L/c." they wrote this
"From the clocks frame of reference it sees time 2L/c."


and
instead of "From the frame of reference of a moving observer traveling at the speed v..."
"From the frame of reference of an observer with the clock traveling at velocity v..."

Yes, the above makes sense to me no matter how anything is calculated.

 

[chinglu1998]

There are many methods of measuring time. However, since this is an abstract physics problem I don't see why time can't be defined in a more abstract manner e.g. as one of the consitituent dimensions of space-time that can be given a more or less arbitrary unit duration (just like the spatial dimensions can be given arbitrary units of length).Yes, this is the conclusion of the calculation in the wikipedia article as well. If you have two light clocks, one at rest in the primed frame and one at rest in the unprimed frame, then you can use light aberration to show time dilation is symmetric. (Each clock will exhibit light aberration and time dilation from the other frame and the values will be equal in magnitude.)[/QUOTE]

No you cannot.

We have one light source and the clock is at rest with the light source.