B Time dilation problem question

[Ibix]

Depends on the details of the camera. Is it a normal lens-based camera (which can be treated as a pinhole camera offset in the y direction) or a shadow camera that we have to treat as a plane close to the square?

 

[stevendaryl]

Sure as soon as he makes measurements by means of Einstein synchronized clocks. Because he arbitrarily synchronizes clock by Einstein. And everyone does the same.

Then what are you claiming about "acceleration"? Nobody sees any acceleration.

 

[Bartolomeo]

Depends on the details of the camera. Is it a normal lens-based camera (which can be treated as a pinhole camera offset in the y direction) or a shadow camera that we have to treat as a plane close to the square?

Obsura. Long enouh so as light would reach film an not to hit walls

 

[Bartolomeo]

Then what are you claiming about "acceleration"? Nobody sees any acceleration.

Look at the diagram again. Observer slows down himself and everything around appears running faster. Dilates that observer who moves in certain frame. All amount of relative time dilation belongs to him. Amount of time dilation is mutual.

 

[stevendaryl]

Look at the diagram again. Observer slows down himself and everything around appears running faster.

No, it does not. You are misunderstanding it. Herb does NOT see any clocks running faster while he is traveling at a constant speed. He sees John's clock run SLOWER.

 

[stevendaryl]

No, it does not. You are misunderstanding it. Herb does NOT see any clocks running faster while he is traveling at a constant speed. He sees John's clock run SLOWER.

In my humble opinion, it's clearer in my demo here: http://dee-mccullough.com/relativity/

• From the frame of the red clocks (Herb's), it is the green clocks that are running slowly.
• From the frame of the green clocks (John and Bob), it is the red clocks that are running slowly.
• Nobody sees anybody's clocks running faster than their own.

The gif here https://en.wikipedia.org/wiki/Time_dilation#/media/File:Time_dilation02.gif shows the same thing: In the frame in which the red clocks are at rest, the green clock runs slower. In the frame in which the green clocks are at rest, the red clock runs slower. (The diagram only shows one moving clock, but 4 stationary clocks.)

 

[Bartolomeo]

In my humble opinion, it's clearer in my demo here: http://dee-mccullough.com/relativity/

• From the frame of the red clocks (Herb's), it is the green clocks that are running slowly.
• From the frame of the green clocks (John and Bob), it is the red clocks that are running slowly.
• Nobody sees anybody's clocks running faster than their own.

The gif here https://en.wikipedia.org/wiki/Time_dilation#/media/File:Time_dilation02.gif shows the same thing: In the frame in which the red clocks are at rest, the green clock runs slower. In the frame in which the green clocks are at rest, the red clock runs slower. (The diagram only shows one moving clock, but 4 stationary clocks.)

I saw your diagram. Very nice! It shows what I have already told. Any chosen single clock dilates relatively to a set of synchronized cloks. Succesively looking at synchronized clocks single clock will see that they run faster. Why do you discriminate single moving clock and don't want to listen to it's opinion?

 

[stevendaryl]

I saw your diagram. Very nice! It shows what I have already told. Any chosen single clock dilates relatively to a set of synchronized cloks. Succesively looking at synchronized clocks single clock will see that they run faster. Why do you discriminate single moving clock and don't want to listen to it's opinion?

What are you talking about? There are two frames: the red frame, in which the red clocks are stationary, and the green frame, in which the green clocks are stationary. In the red frame, the green clocks are running slow. In the green frame, the red clocks are running slow. In no frame is any clock running faster than the clocks that are stationary in that frame.

More details:

According to the red frame:

• the right green clock is 45 minutes ahead of the left green clock
• Both green clocks advance at half the rate of the red clocks

According to the green frame:

• the left red clock is 45 minutes ahead of the right red clock
• Both red clocks advance at half the rate of the green clocks

Nobody sees anything running faster.

 

[Bartolomeo]

What are you talking about? There are two frames: the red frame, in which the red clocks are stationary, and the green frame, in which the green clocks are stationary. In the red frame, the green clocks are running slow. In the green frame, the red clocks are running slow. In no frame is any clock running faster than the clocks that are stationary in that frame.

More details:

According to the red frame:

• the right green clock is 45 minutes ahead of the left green clock
• Both green clocks advance at half the rate of the red clocks

According to the green frame:

• the left red clock is 45 minutes ahead of the right red clock
• Both red clocks advance at half the rate of the green clocks

Nobody sees anything running faster.

I am traveling in a train and have a clock on my wrist. I am traveling along a platfotm. There are posts with a clock on the platform every 100 yards. I see clocks succesively. First, second, third etc. I see that clock hands rotate much faster than my own. I have no more clock in posession. You insist that I would place another clock in next carriage or even in each carriage. But I have to have an assistant then in my train. Then we have to sinchronize our clocks by light. Then my assistant takes readings from any chosen clock on platform. If we sinchronize clocks by einstein, we will see that any chosen clock dilates. Bur neither my assistant nor I have never heared about Einstein. Even if we heared, we don't trust him. We are not sure that one way speed of light is c. Why do you insist so as I would hire an assistant? I have to make an assumption about synchronization, but I don't like to make assumptions.
Why do you insist so I have to introduce my own frame? Why platform's is not good?
Why should I employ the same synchronization procedure for my clocks as for those on platform?

 

[stevendaryl]

I am traveling in a train and have a clock on my wrist. I am traveling along a platfotm. There are posts with a clock on the platform every 100 yards. I see clocks succesively. First, second, third etc. I see that clock hands rotate much faster than my own.

No, you don't. You see the clocks on the platform running SLOWER than your clock.

 

[Ibix]

Why do you insist so I have to introduce my own frame? Why platform's is not good?
Why should I employ the same synchronization procedure for my clocks as for those on platform?

Because if you look at the clock 100m ahead and the one 100m behind you will see that they show different times. So they are either not synchronised, or the speed of light is anisotropic according to you. Which is just making your life difficult for the sake of it.

 

[Bartolomeo]

Because if you look at the clock 100m ahead and the one 100m behind you will see that they show different times. So they are either not synchronised, or the speed of light is anisotropic according to you. Which is just making your life difficult for the sake of it.

I look at a clock which is straight in the front. Straight in the front. just my nose separates us. In immediate vicinity as that should be done in Special Relativity and compare readings of my own clock and that clock. One after another. At each post in platform.

 

[Ibix]

No, you don't. You see the clocks on the platform running SLOWER than your clock.

He's not looking at one clock. He's looking at the clock infront of him - so he's comparing $t|_{x=0}$ and $t'|_{x=0}$. So he's using the Einstein synchronisation convention in someone else's frame, in short.

 

[stevendaryl]

Bur neither my assistant nor I have never heared about Einstein. Even if we heared, we don't trust him. We are not sure that one way speed of light is c. Why do you insist so as I would hire an assistant? I have to make an assumption about synchronization, but I don't like to make assumptions.
Why do you insist so I have to introduce my own frame? Why platform's is not good?
Why should I employ the same synchronization procedure for my clocks as for those on platform?

Without making any assumptions, you can't compare the rates of two clocks that are not side-by-side. What does it mean to say that one clock (Herb's) is running faster or slower than another clock (John's)? What you have is the following situation:

• When Herb's clock passes John's clock, they both show time 12:00. (Call this event e_0)
  
• At some time after e_0, Herb's clock shows time 12:30 (Call this event e_1)
• At some time after e_0, John's clock shows time 12:30 (Call this event e_2)

So to determine whose clock is running slow or fast, you need to know this: Did e_1 take place before or after e_2? How do you answer that question? You have to rely on a convention, or assumption.

 

[Battlemage!]

Suggestion: People should stop using the word "see" in this thread unless they mean visually. I think "measure" or "calculate" would be the better word for considering time dilation.

 

[Ibix]

I look at a clock which is straight in the front. Straight in the front. just my nose separates us. In immediate vicinity as that should be done in Special Relativity and compare readings of my own clock and that clock. One after another. At each post in platform.

And how were those clocks synchronised? The mechanism chosen contains the assumptions you are trying to hide by "not employing an assistant" and "not trusting Einstein".

 

[Bartolomeo]

And how were those clocks synchronised? The mechanism chosen contains the assumptions you are trying to hide by "not employing an assistant" and "not trusting Einstein".

In the rest frame of platform we synchronize clock by Einstein, admitting that velocity of light in all direction is the same. Space is isotropic, nothing surprising.

 

[Bartolomeo]

Suggestion: People should stop using the word "see" in this thread unless they mean visually. I think "measure" or "calculate" would be the better word for considering time dilation.

"Seeing" in special relativity means comparison of your clock with another clock in immediate vicinity, just in front of you, nothing else. Not turning you head up and down, left and right and observing distant material bodies.
Well, excuse me, we can also make pictures and measure frequency. But there are very important details in this case,

 

[stevendaryl]

In the rest frame of platform we synchronize clock by Einstein, admitting that velocity of light in all direction is the same. Space is isotropic, nothing surprising.

But not in the frame of the train?

 

[Ibix]

In the rest frame of platform we synchronize clock by Einstein, admitting that velocity of light in all direction is the same. Space is isotropic, nothing surprising.

Then a lightspeed measurement you make will not be isotropic. You can do that if you want, but you are just making life more difficult for yourself - throwing away symmetries that can simplify maths instead of using them.

"Seeing" in special relativity means comparison of your clock with another clock in immediate vicinity, just in front of you, nothing else. Not turning you head up and down, left and right and observing distant material bodies.
Well, excuse me, we can also make pictures and measure frequency. But there are very important details in this case,

That is not the common usage, at least not on this forum. It is used in the precise sense of the receipt of light signals by an observer, and sometimes in the sloppier sense of "what Minkowski diagram would someone draw".

 

[stevendaryl]

"Seeing" in special relativity means comparison of your clock with another clock in immediate vicinity, just in front of you, nothing else. Not turning you head up and down, left and right and observing distant material bodies.
Well, excuse me, we can also make pictures and measure frequency. But there are very important details in this case,

You cannot determine whether Herb's clock is running faster or slower than John's clock by only looking at nearby clocks.

 

[Battlemage!]

"Seeing" in special relativity means comparison of your clock with another clock in immediate vicinity, just in front of you, nothing else. Not turning you head up and down, left and right and observing distant material bodies.
Well, excuse me, we can also make pictures and measure frequency. But there are very important details in this case,

Two clocks separated by large distances cannot be compared in the way you describe, but you can certainly look at a clock far away. What will your eyes tell you? Is this the same as what the equations tell you?

If you don't calculate for the finite speed of light then what you see with your eyes will be incorrect, or at least ambiguous.

 

[Bartolomeo]

Two clocks separated by large distances cannot be compared in the way you describe, but you can certainly look at a clock far away. What will your eyes tell you? Is this the same as what the equations tell you?

If you don't calculate for the finite speed of light then what you see with your eyes will be incorrect, or at least ambiguous.

Yes! That's why observer takes readings in immediate vicinity. Observer in SR is not a "physical person". It is the whole reference frame, which is filled with many people and each of them has a clock. They synchronize clocks by light signals and make judgement then. John is certain point of reference frame K. John has a clock. Bill is far away. Bill has a clock too. John and Bill are the relativistic observer together. They synchronize clocks by light. Jim passes by John first and compares his clock with Johns at this moment in immediate vicinity. Then Jim passes by Bill. They again compare clocks in immediate vicinity. John and Bill together make conclusion, that Jim's clock runs slower.

https://en.wikipedia.org/wiki/Observer_(special_relativity)
https://arxiv.org/abs/physics/0512013

 

[Bartolomeo]

You cannot determine whether Herb's clock is running faster or slower than John's clock by only looking at nearby clocks.

It is the core of special relativity. Einstein's work of 1905. Observer introduces a reference frame and allocates AT LEAST two clocks in different spatial positions. AT LEAST two clocks.
Observer in SR is not a "physical person". It is the whole reference frame, which is filled with many people and each of them has a clock. They synchronize clocks by light signals and make judgement then. John is certain point of reference frame K. John has a clock. Bill is far away. Bill has a clock too. John and Bill are the relativistic observer together. They synchronize clocks by light. Jim passes by John first and compares his clock with Johns at this moment in immediate vicinity. Then Jim passes by Bill. They again compare clocks in immediate vicinity. John and Bill together make conclusion, that Jim's clock runs slower.

https://en.wikipedia.org/wiki/Observer_(special_relativity)
https://arxiv.org/abs/physics/0512013

 

[Battlemage!]

Yes! That's why observer takes readings in immediate vicinity. Observer in SR is not a "physical person". It is the whole reference frame, which is filled with many people and each of them has a clock. They synchronize clocks by light signals and make judgement then. John is certain point of reference frame K. John has a clock. Bill is far away. Bill has a clock too. John and Bill are the relativistic observer together. They synchronize clocks by light. Jim passes by John first and compares his clock with Johns at this moment in immediate vicinity. Then Jim passes by Bill. They again compare clocks in immediate vicinity. John and Bill together make conclusion, that Jim's clock runs slower.

https://en.wikipedia.org/wiki/Observer_(special_relativity)
https://arxiv.org/abs/physics/0512013

This doesn't really address the point that what you see with your eyes isn't necessarily the same thing as what is going on locally at what you are looking at, due to the finite speed of light. The Doppler effect needs to be taken into account if you're going by what you see.

 

[Battlemage!]

It is the core of special relativity. Einstein's work of 1905. Observer introduces a reference frame and allocates AT LEAST two clocks in different spatial positions. AT LEAST two clocks.
Observer in SR is not a "physical person". It is the whole reference frame, which is filled with many people and each of them has a clock. They synchronize clocks by light signals and make judgement then. John is certain point of reference frame K. John has a clock. Bill is far away. Bill has a clock too. John and Bill are the relativistic observer together. They synchronize clocks by light. Jim passes by John first and compares his clock with Johns at this moment in immediate vicinity. Then Jim passes by Bill. They again compare clocks in immediate vicinity. John and Bill together make conclusion, that Jim's clock runs slower.

https://en.wikipedia.org/wiki/Observer_(special_relativity)
https://arxiv.org/abs/physics/0512013

What does Jim conclude as he passes both? (or rather, as they pass him, given that he is justified in claiming he is at rest)

 

[Bartolomeo]

This doesn't really address the point that what you see with your eyes isn't necessarily the same thing as what is going on locally at what you are looking at, due to the finite speed of light. The Doppler effect needs to be taken into account if you're going by what you see.

"To see by eyes" can be interpreted in various ways. A scientist has tools. Rods, clocks, spectrometers, photo cameras. You can do no measurements without introducing a reference frame. Reference frame is synchronized clocks in different spatial positions.

 

[Bartolomeo]

What does Jim conclude as he passes both? (or rather, as they pass him, given that he is justified in claiming he is at rest)

That depends on how Jim will measure. He can introduce his own reference frame. He hires Jack and gives him a clock. Jack goes into another spatial position. He sends a beam of light to Jack. They adjust clocks , taking into account that speed of light was c. Now their clocks show the same time.
Tony and Bill fly towards them from the deep space. They chase each other. They have clocks too. Tony and Bill synchronize their clocks too with the same assumption.
Tony passes by Jack first and compare clocks. Let's their clocks show 12 o'clock each. Then Tony passes by Jim. Tony's clock show 3 PM and Jack's 7 PM o' clock.
Jim and Jack think, that Tony's clock runs slower. Tony thinks, that Jim's and Jack's clocks run faster.

Now upside down.

Jim passes by Tony. They compare clocks. For example, their clocks shows 12 each. Then Jim passes by Bill. Jim's clock shows 3 PM and Bill's 7 PM.
Tony and Bill together think, that Jim's clock runs slower. Jim thinks, that Tony's and Bill's clocks run faster.
https://en.wikipedia.org/wiki/Time_dilation#/media/File:Time_dilation02.gif

 

[Ibix]

Jim thinks, that Tony's and Bill's clocks run faster.

Only if Jim assumes Bill and Tony's clocks are synchronised. He has no reason to believe they are, though, since you seem to regard looking at anything not right in front of you as forbidden.

If he doesn't look, he's guessing. If he does look he's assuming. But what I do not understand is why you would choose to make anything other than an assumption of isotropy. You seem to pick one frame and let them assume isotropy, then force every other frame (edit: or rather, everyone not at rest in your chosen frame) to make a more complicated assumption. Why? Just to make things more complex?

 

[Bartolomeo]

Only if Jim assumes Bill and Tony's clocks are synchronised. He has no reason to believe they are, though, since you seem to regard looking at anything not right in front of you as forbidden.

If he doesn't look, he's guessing. If he does look he's assuming. But what I do not understand is why you would choose to make anything other than an assumption of isotropy. You seem to pick one frame and let them assume isotropy, then force every other frame to make a more complicated assumption. Why? Just to make things more complex?

Well, Jim is too stupid to assume something. He is very plain guy. He compares clocks and makes his own conclusions. I do not like or dislike certain synchronization procedures. I am a bit suspicious. Just in case. But I know, that another measuring technique of time dilation (transverse Doppler Shift) does not make any assumptions. And observations are not reciprocal. And that makes me even more suspicious.
Either Doppler effect and photo camera is rubbish or Einstein clock synchronization for every observer.

 

[Ibix]

Well, Jim is too stupid to assume something. He is very plain guy. He compares clocks and makes his own conclusions.

...thereby assuming that Bill and Tony's clocks are synchronised.

I do not like or dislike certain synchronization procedures. I am a bit suspicious. Just in case. But I know, that another measuring technique of time dilation (transverse Doppler Shift) does not make any assumptions. And observations are not reciprocal. And that makes me even more suspicious.

They aren't expected to be reciprocal in the Joe/alien example we discussed in the other thread because the situation you are examining is not symmetric betwen Joe and the aliens. As you yourself pointed out. If you reverse the experiment completely the results are reciprocal, as noted in the Wikipedia page you linked to in that thread.

 

[Bartolomeo]

...thereby assuming that Bill and Tony's clocks are synchronised.

They aren't expected to be reciprocal in the Joe/alien example we discussed in the other thread because the situation you are examining is not symmetric betwen Joe and the aliens.

Exactly. In no way they can be symmetrical. In no way. Green photon turns blue at the moving mirror. Not red. In no way red, whatever you do. Mirror dilates itself and concludes that source oscillates faster. Joe sees redshift (dilation), Aliens see blueshift (acceleration of time). Aliens see redshift (dilation), Joe sees redshift (acceleration of time). Joe makes picture of moving Aliens and see contraction. Aliens make picture of Joe and see stretching, since their photo - film contracts.

 

[Ibix]

Aliens see redshift (dilation), Joe sees redshift (acceleration of time). Joe makes picture of moving Aliens and see contraction. Aliens make picture of Joe and see stretching, since their photo - film contracts.

Not if they use the same experimental procedure. If they use different procedures it's hardly surprising that the results are different.

 

[Bartolomeo]

Not if they use the same experimental procedure. If they use different procedures it's hardly surprising that the results are different.

There are no procedures. What kind of procedures? Joe releases green photon straight up. The aliens have a mirror. Photon reflects and goes back to Joe "from the top". It comes back green again. What color was at mirror? Red? Blue! Only blue, newer red. For Joe the mirror is moving source, and photon which comes back to Joe from moving source redshifts, since moving source dilates. Blue and only blue! It is so simple. Never red!

 

[Ibix]

There are no procedures. What kind of procedures? Joe releases green photon straight up. The aliens have a mirror. Photon reflects and goes back to Joe "from the top". It comes back green again. What color was at mirror? Red? Blue! Only blue, newer red. For Joe the mirror is moving source, and photon which comes back to Joe from moving source redshifts, since moving source dilates. Blue and only blue! It is so simple. Never red!

If the aliens fire a green photon straight down so that it strikes Joe then bounces back you will find the exact same result with the roles reversed. They can't do it at the same time as Joe is doing his experiment because Joe is not in position to do so in their frame at that time - so they would be following a different experimental procedure if they try.

 

[Bartolomeo]

If the aliens fire a green photon straight down so that it strikes Joe then bounces back you will find the exact same result with the roles reversed. They can't do it at the same time as Joe is doing his experiment because Joe is not in position to do so in their frame at that time - so they would be following a different experimental procedure if they try.

Yes, but they have to take physical action and change direction of their tube. They can't look with one eye in two different direction at the same moment. But, so what? Yes, the Aliens will release green photon and it will be blue for Joe, Joe reflects it back and the Aliens see it red again. Now the photon is blue at Joe. Now Joe is in motion and his clock dilates. That what I told all this time. Who ascribes himself state of rest, sees dilation. Who ascribes himself state of motion, sees acceleration since he dilates himself.
But they can't ascribe themselves equal states of proper rest or motion.

 

[jbriggs444]

But they can't ascribe themselves equal states of proper rest or motion

This is unclear. What cannot be equal to what? And what is "proper rest".

Certainly two observers can each maintain that they are at rest and that their peer is not.

 

[Bartolomeo]

This is unclear. What cannot be equal to what? And what is "proper rest".

Certainly two observers can each maintain that they are at rest and that their peer is not.

Proper rest is a state, when you consider yourself as being at rest and interpret observations from the point of view observer at rest. Imagine that you stay at certain point at axis y, at point Y. You posses a long thin tube. You ascribe yourself a state of proper rest. You want to measure frequency of moving source - green monochromatic lamp. You turn the tube into the origin. You stay and wait. The lamp moves along x in negative direction. At certain moment you see a short flash, when the lamp passes the origin and a photon goes through you tube. The flash will be red in color due to Transverse Doppler Effect.
Then you ascribe yourself small velocity. You repeat the experiment but do nothing special in this case - just turn the tube a bit into front. Why? Because if photon flies along y-axis up, you approach the point of "intersection from the left" and you have to take aberration into account. You tilt tube so as the photon would be able to pass through it. You see a flash again. The photon will be a bit less red, than it was in the first experiment.
Then you repeat the experiment again, but ascribe yourself even larger proper velocity. You think that since your velocity increased, you tilt you tube even further an see that color of photon moved into blue range of spectrum.
In fact you do nothing, just turn you tube further an further into front and interpret every observation as transverse doppler effect, since photon according to you comes to you along y-axis and due aberration becomes more and more blue with each experiment.
So, ascribing yourself state of proper motion means that you simply turn your tube or gaze further and further into front.

If lamp emits dispersed light, you will always see it. But if the source emits narrow beam, the source will always have to adjust angle of emission at corresponding angle, so as the photon will go through your tube,
These angles are always tied with relativistic aberration formula. The more you tilt you tube into front, the less the source has to tilt his laser pointer back. At the moment, when these angles are the same, you will see no shift, neither dilation nor acceleration, because the source and you ascribe themselves equal velocities.
So, state of proper motion means, that you look into front but not straight down

 

[Ibix]

Yes, but they have to take physical action and change direction of their tube. They can't look with one eye in two different direction at the same moment. But, so what? Yes, the Aliens will release green photon and it will be blue for Joe, Joe reflects it back and the Aliens see it red again. Now the photon is blue at Joe. Now Joe is in motion and his clock dilates. That what I told all this time. Who ascribes himself state of rest, sees dilation. Who ascribes himself state of motion, sees acceleration since he dilates himself.
But they can't ascribe themselves equal states of proper rest or motion.

No. The result of Joe and the aliens isn't symmetrical because the circumstances aren't symmetrical. Joe fires the laser; the aliens do not. This is not the same as two people watching each other's clocks, which is a symmetrical situation and the results must be symmetrical, barring an absolute rest frame of some kind.

 

[jbriggs444]

Proper rest is a state, when you consider yourself as being at rest

So it's not a state at all. It's a decision about what reference frame to use.

 

[Bartolomeo]

So it's not a state at all. It's a decision about what reference frame to use.

Well, this decision looks like that. If you choose a frame, in which you move with equal velocities, the source and you have to turn tubes at the same angle. If you choose a frame, in which you at rest, you look at right angle to direction of motion of the source. Angle depends on chosen reference frame.

 

[Ibix]

Proper rest is a state, when you consider yourself as being at rest and interpret observations from the point of view observer at rest. Imagine that you stay at certain point at axis y, at point Y. You posses a long thin tube. You ascribe yourself a state of proper rest. You want to measure frequency of moving source - green monochromatic lamp. You turn the tube into the origin. You stay and wait. The lamp moves along x in negative direction. At certain moment you see a short flash, when the lamp passes the origin and a photon goes through you tube. The flash will be red in color due to Transverse Doppler Effect.
Then you ascribe yourself small velocity. You repeat the experiment but do nothing special in this case - just turn the tube a bit into front. Why? Because if photon flies along y-axis up, you approach the point of "intersection from the left" and you have to take aberration into account. You tilt tube so as the photon would be able to pass through it. You see a flash again. The photon will be a bit less red, than it was in the first experiment.
Then you repeat the experiment again, but ascribe yourself even larger proper velocity. You think that since your velocity increased, you tilt you tube even further an see that color of photon moved into blue range of spectrum.
In fact you do nothing, just turn you tube further an further into front and interpret every observation as transverse doppler effect, since photon according to you comes to you along y-axis and due aberration becomes more and more blue with each experiment.

So you are just saying that if you do different experiments you get different results. This is true (and frame invariant) but trivial.

 

[Bartolomeo]

So you are just saying that if you do different experiments you get different results. This is true (and frame invariant) but trivial.

Yes, outcome of experiment depends on how I make it. and what I think about my own state of motion. If I am at rest, I do not consider aberration. If I am in motion, I consder aberration. You told me in your very first post, that outcome of experiment does not depend on how it is done, don't you? And what I think about my motion. No, it does. The faster I move, the blueish source will be.

 

[jbriggs444]

Well, this decision looks like that. If you choose a frame, in which you move with equal velocities, the source and you have to turn tubes at the same angle. If you choose a frame, in which you at rest, you look at right angle to direction of motion of the source. Angle depends on chosen reference frame.

When asked what "proper rest" means, you give a longwinded and incorrect response. When this is objected to, you try to clarify by invoking aliens and laser pointers.

I conclude that "proper rest' is not a meaningful term.

 

[Bartolomeo]

When asked what "proper rest" means, you give a longwinded and incorrect response. When this is objected to, you try to clarify by invoking aliens and laser pointers.

I conclude that "proper rest' is not a meaningful term.

Especially for you I even posted a video.

 

[Ibix]

Yes, outcome of experiment depends on how I make it. You told me in your very first post, that outcome of experiment does not depend on how it is done, don't you?

No. I told you that the outcome of one experiment did not depend on which frame you use to describe it. See the second quote and my response in this post.

 

[Bartolomeo]

No. I told you that the outcome of one experiment did not depend on which frame you use to describe it. See the second quote and my response in this post.

I have nothing to say.

 

[Ibix]

I have nothing to say.

To expand a little - in the post I linked in my last, you wrote "And what will a co-moving inertial observer (an observer of a co-moving inertial frame of reference) see, who at some point in time ends up near one of the observers hurtling around the circle? This will depend upon what velocity it ascribes to itself." There is only one point in space where it makes any sense to compare the viewpoint of an instantaneously co-moving inertial observer and a circular orbiting observer: where the two are co-located and co-moving. At that point there is only one setting of the tube angle that will receive light, and the frequency that you measure is obviously frame invariant. It does not matter if the co-moving observer decides to use some other frame - they will conclude that the tube is set in the correct position to reveive light at the moment they co-move with the orbiter. If they move the tube they will be doing a different experiment (which may obviously have different results), an experiment which is irrelevant to the question at hand because it won't work when they are co-moving with the orbiter.

I now think you were referring to running multiple experiments which can, of course, have different results. But they are irrelevant to the circular motion thread as I just noted, and you are misapplying them in this one. When the two parties do the same experiment (i.e., set their receiving tube to the same angle to the other's direction of travel by their own local measurements) they receive the same frequency that the other received. This is the reciprocity that is expected, and is consistent with symmetric time dilation. The fact that, in any given realisation of the experiment, the two parties do not see the same frequency is not a counter-argument because there is no symmetry in that realisation. One of the parties is emitting a light pulse at a time of their choosing and the other is passively receiving. The symmetry is broken and no reciprocity is expected.

 

[Bartolomeo]

To expand a little - in the post I linked in my last, you wrote "And what will a co-moving inertial observer (an observer of a co-moving inertial frame of reference) see, who at some point in time ends up near one of the observers hurtling around the circle? This will depend upon what velocity it ascribes to itself." There is only one point in space where it makes any sense to compare the viewpoint of an instantaneously co-moving inertial observer and a circular orbiting observer: where the two are co-located and co-moving. At that point there is only one setting of the tube angle that will receive light, and the frequency that you measure is obviously frame invariant. It does not matter if the co-moving observer decides to use some other frame - they will conclude that the tube is set in the correct position to reveive light at the moment they co-move with the orbiter. If they move the tube they will be doing a different experiment (which may obviously have different results), an experiment which is irrelevant to the question at hand because it won't work when they are co-moving with the orbiter.

It is very difficult graphically demonstrate coincidence of commoving and rotating observer, we need spatial imagination. But I think you can understand that. Just try to move either observer relatively to rotating circle and central lamp or the whole rotating establishment relatively to resting observer.
Fig. 1 – Commoving observer moves in the reference frame of the lamp (blue shift)
Fig. 2 – Commoving observer and the lamp are at equal velocities to each other (no shift)
Fig. 3 – Lamp is in motion in the reference frame of commoving observer (reds shift)
Fig. 4 – Rotating observers in the same spatial positions as commoving ones.

Length of arrow V reflect "proper velocities"
http://[url=https://postimg.org/image/8mvqlxk0z/][PLAIN]https://s29.postimg.org/8mvqlxk0z/Fig_1.jpg

 

[Bartolomeo]

I now think you were referring to running multiple experiments which can, of course, have different results. But they are irrelevant to the circular motion thread as I just noted, and you are misapplying them in this one. When the two parties do the same experiment (i.e., set their receiving tube to the same angle to the other's direction of travel by their own local measurements) they receive the same frequency that the other received. This is the reciprocity that is expected, and is consistent with symmetric time dilation. The fact that, in any given realisation of the experiment, the two parties do not see the same frequency is not a counter-argument because there is no symmetry in that realisation. One of the parties is emitting a light pulse at a time of their choosing and the other is passively receiving. The symmetry is broken and no reciprocity is expected.

Relative velocity is the same in every give experiment. It doesn’t change.

Experiment is to show the independence of observations from the arbitrary choice of the reference system. Of course, if you do not change anything, nothing changes.

The purpose of any given experiment is to confirm or deny certain suggestions. Suggestion is the following: observation of clock rate of relatively moving clock does not depend of state of rest or motion of any relativistic observer. If Ibix and Bartolomeo conduct certain experiment, Ibix must measure dilation of Bartolomeo’s clock (to register redshift) and Bartolomeo has to measure dilation of Ibix’s clock (to register redshift) in any given experiment despite of what they think about their state of motion or rest.

Amount of redshift must depend on their relative velocity solely. Let’s say 0.9 c.

They conduct experiment at 10 AM and write a report. Ibix releases a photon along y axis, Bartolomeo reflects it and Ibix gets it back. Report claims, that Ibix measured redshift and Bartolomeo blueshift. Relative velocity was 0.9 c.

They conduct another experiment after lunch at 2 PM. Relative velocity was 0.9 c again. velocity solely. Let’s say 0.9 c. Bartolomeo releases a photon along y axis, Ibix reflects it and Bartolomeo gets it back. Report claims, that Bartolomeo measured redshift and Ibix blueshift.

They can conduct 1000 experiments or even 1000000 experiments. Relative velocity is still 0.9 c. They change angle of rotation of their tubes in every experiment at 0.01 degree. In any experiment, they cannot find, that Bartolomeo fixes redshift and Ibix redshift. It is ABSOLUTELY IMPOSSIBLE.

Amount of time dilation, which corresponds to relative velocity 0.9 c is the same in every experiment. It is mutual property. The more Ibix takes for himself, the less remains to Bartolomeo.

Time dilation and length contraction is like a short blanket. You cover your head but it is too short to cover legs and vice versa.

Well, Ibix had finally found THE brilliant solution! Ibix saw time dilation at 10 AM, Bartolomeo at 2 PM. They publish a report, that they both saw time dilation fully in accordance with SR.