Absolute Time Clock Experiments: Einstein's Special Relativity

[ghwellsjr]

ghwellsjr,
So far so good,
Please continue.

Roi.

Good.

You're going to have to be patient with me. I'm working on some animations to illustrate the ideas I'm presenting so it will take me some time but I think in the long run this will be much more effective.

 

[Ymyk]

Ymyk, it is very difficult to understand your scenario. It appears that you are using some of your nomenclature to refer to absolute times (A0, Bu, A2?) and others for delta times (B1). But whatever you are doing, it is not legitimate. You cannot measure the one-way speed of light. You cannot tell how long it takes for light to go from A to B or B to A without some previously defined answer to the question. I'm sure that transponders are relying on a previously defined timing conventions and so cannot be used to measure the times of receipt/reflection as you are proposing. You should be able to figure out what is wrong with your idea if you understand Special Relativity. In fact, you wouldn't even attempt to find a way around the problem. You do realize that if what you are proposing is legitimate, that you have just dethroned Einstein and you will be able to take his seat. Is that what you really believe?

ghwellsjr, My clumsy language perhaps garbled what is a simple arrangement. Two tranbsponder are separated by a constant distance. A transponder is a device that substitutes fro air traffic control radar. Insted of bouncing the outbound sihnal off of an aircraft, the signal is coded and the 'reflected signal' has the time of arrival and reflection imbeded in the return signal - aircraft ID, azimuth and elevation and calculated distance are included.

The transponders are identical in all respects. My argument is straightgforward. A0 is the time imbeded in the outbound pulse in the direction of the B transponder. At A0 the B clock is unknown, or Bu, a recordwed vcalue. When the pulse arrives at B the B clock registers Bu + B1 , where both Bu and B1 are unbknown but their total clock value is recorded when the pulse arrives. In other words the pulse simple tells the clock to give out the current clock time, he Bu + B1. When the pulse returns to A at A2, the B clock now reads Bu + A2, again recorded as x1. Immediately emitting a pulse from A where the clock now is A2, arrives at B at Bu + A2 + B1 = x2 subtracting thye two x's x2 - x1 = Bu + A2 + B1 - Bu - A2 = B1, which is the time of flight of the pulse from A to B. There is no measure of the SOL which is presumed to be constant at unit SOL C = 1.

The two clock are ticking at the same rate and even thoughn there was initially no information of what the clock time on B happened to be when the A clock reas A0.

There is also the presumption that the motion of the [pulse is independent of the motion of the source of the light - I already knew what the SOL was before the pulse motions began.

The repeat of the round tripm trajectory was intended for the purpose of determining what the instantaneous clock time difference of the two transponders happened to be.

The transponders work as I have indicatedbut I am sure that the system disrfegards any relativity effects for the reason thagt the velocities are soi slow.

Look at it as two clocks separated by a constant distance. On clock emits a pulse at A0 when the B clock time is inknown or Bu, a time recorded when triggered by the arriving pulse.

We don't even need to imbed the time of arrival in the reflected pulse. As long as the A transponder has the A0 and A2 times recorded and the B clock has the Bu + B1 time recorded. Calculating the trajectory distances is then trivial and can be accomplished at the observer's pleasure.

You made a great deal claiming that I couldn't measure the one way sol. I didn't try to measure the sol. I already knew the sol as approximately 3x 10^8 km/sec which IO copied out of AE's book "relativity". AE didn't know about transponders in 1905.

I didn't violate any relativity concept. In fact I claim that determining the velocity of the transponder is determined soley from the three time-of -day events A0, A2, and B1. Which is NOT a measurement of the velocity NOR detection of motion. The three event times are carefully recorded.

 

[Dale]

You made a great deal claiming that I couldn't measure the one way sol. I didn't try to measure the sol. I already knew the sol as approximately 3x 10^8 km/sec which IO copied out of AE's book "relativity".

And how did you already know the SOL? You assumed it, that is what AE did.

If you set up the equations without that assumption then you will find that you always have more unknowns than equations.

 

[roineust]

ghwellsjr,
No problem,
I am here and waiting.

Roi.

 

[darkhorror]

ghwellsjr, My clumsy language perhaps garbled what is a simple arrangement. Two tranbsponder are separated by a constant distance. A transponder is a device that substitutes fro air traffic control radar. Insted of bouncing the outbound sihnal off of an aircraft, the signal is coded and the 'reflected signal' has the time of arrival and reflection imbeded in the return signal - aircraft ID, azimuth and elevation and calculated distance are included.

The transponders are identical in all respects. My argument is straightgforward. A0 is the time imbeded in the outbound pulse in the direction of the B transponder. At A0 the B clock is unknown, or Bu, a recordwed vcalue. When the pulse arrives at B the B clock registers Bu + B1 , where both Bu and B1 are unbknown but their total clock value is recorded when the pulse arrives. In other words the pulse simple tells the clock to give out the current clock time, he Bu + B1. When the pulse returns to A at A2, the B clock now reads Bu + A2, again recorded as x1. Immediately emitting a pulse from A where the clock now is A2, arrives at B at Bu + A2 + B1 = x2 subtracting thye two x's x2 - x1 = Bu + A2 + B1 - Bu - A2 = B1, which is the time of flight of the pulse from A to B. There is no measure of the SOL which is presumed to be constant at unit SOL C = 1.

The two clock are ticking at the same rate and even thoughn there was initially no information of what the clock time on B happened to be when the A clock reas A0.

There is also the presumption that the motion of the [pulse is independent of the motion of the source of the light - I already knew what the SOL was before the pulse motions began.

The repeat of the round tripm trajectory was intended for the purpose of determining what the instantaneous clock time difference of the two transponders happened to be.

The transponders work as I have indicatedbut I am sure that the system disrfegards any relativity effects for the reason thagt the velocities are soi slow.

Look at it as two clocks separated by a constant distance. On clock emits a pulse at A0 when the B clock time is inknown or Bu, a time recorded when triggered by the arriving pulse.

We don't even need to imbed the time of arrival in the reflected pulse. As long as the A transponder has the A0 and A2 times recorded and the B clock has the Bu + B1 time recorded. Calculating the trajectory distances is then trivial and can be accomplished at the observer's pleasure.

You made a great deal claiming that I couldn't measure the one way sol. I didn't try to measure the sol. I already knew the sol as approximately 3x 10^8 km/sec which IO copied out of AE's book "relativity". AE didn't know about transponders in 1905.

I didn't violate any relativity concept. In fact I claim that determining the velocity of the transponder is determined soley from the three time-of -day events A0, A2, and B1. Which is NOT a measurement of the velocity NOR detection of motion. The three event times are carefully recorded.

What exactly are you trying to get at? I am not sure what your trying to do here. Unless I am reading them wrong the math doesn't line up with what your saying. Why did you send it from A to B, back to A then back to B again? I am trying to go through it and see what your doing but it really doesn't make any sense. You are using A and B clocks in the same frame of reference, why not just synchronize them? Then when you send your signal from A to B you know the start time on A and the time that B gets it just subtract and you get the time it takes to go from A to B. But what does this tell us? I really have no idea what you are trying to get to at the end of all of this.

 

[NoDoubt]

Hello,


All we are trying to build is an Absolute time clock, let's follow the rules of Physics and see if it works,

We all know that light beam acts like a wave too, and it has some frequency.

And this frequency changes with the motion of the light source, (red shift or blue shift depending on the direction)

So let us place a light source and a frequency detector on both ends of a stationary train, and claculate the frequency of the light beam emitted from the light source, What ever this frequency is, Set the speed to zero. (Reletive to the Earth, of cource)

Now if the train starts to accelerate/travel to any direction the shift in frequency of the light beam should be detected and claculated to determine the speed of train.

Hence these calculated values can be added to a conventional clock onboard which is loosing time because of motion. And we get an Absolute clock for the Earth. (For the Universe it will be a whole new story)

I'm not sure, but this is my two cents.

 

[ghwellsjr]

No, there might be a momentary shift in the color of the light (frequency) during the acceleration but as soon as the effect of that is over, the detected light and the unboard clock behave just like they did before the acceleration. But you could use this or any number of other means to measure/calculate the speed of the train.

Now you have a situation where there are two clocks in relative motion. Each clock sees the other one as running slower than its own. Neither clock can be considered Absolute. In fact, you can view both clocks from any frame of reference, including one that is the "average" speed of the two clocks in such a way that they both appear to run at the same rate (both slow in that reference frame).

An Absolute clock is considered one that is stationary in the so-called, presumed, universal, at-rest ether which no one knows how to identify if it were to exist and so there is no hope to have an Absolute clock.

 

[ghwellsjr]

I have uploaded some animations to illustrate the scenarios in my previous post:

OK, good. Now the first thing we must do is put ourselves in the mindset of most of the great scientists of that era. They believed in an absolute ether rest frame in which light propagated at the same constant speed in all directions. Imagine a very brief bright flash of light being set off in this stationary frame. It will create an ever-expanding spherical shell of light, centered on its point of origin with respect to the stationary ether.

They believed that if the source of light were moving with respect to this stationary ether frame, the source would not remain in the center of this expanding spherical shell but would move off-center.

But the question is: how can we tell if the light source remains in the center of this expanding shell or moves off-center? By analogy, we could visualize what would happen if we were observing an expanding ring of waves on the surface of a pool after dropping a pebble in the water because we use light to observe the water, but how can we observe a lightwave once it has started moving away from us? Therein lies the problem: we cannot directly observe the propagation of light so we do the next best thing which is to set up an array of mirrors to reflect the light back to us.

Now the best way to "observe" an expanding spherical shell of light is to set up a whole bunch of mirrors, all an equal distance from the source and in all possible directions. Then when we set off the flash it will expand until it simultaneously hits all the mirrors which turn the expanding spherical shell of light into a contracting spherical shell of light which will eventually collapse on the source simultaneously from all directions.

For purposes of illustration, we will consider a two-dimensional subset of mirrors and an expanding ring of light, much like the expanding ring of waves on the surface of a circular pool of water as it simultaneously strikes the entire pool wall circumference, reverses direction and simultaneously collapses on the source in the center of the pool.

I realize this is pretty simple so far, but I want to make sure you grasp all the concepts before moving on so if there is anything that is ambiguous or confusing, please let me know before we continue.

 

[ghwellsjr]

Now it's really not practical to build a solid sphere of mirrors but all we really need is four mirrors that are placed 90 degrees apart and all equidistant from the observer. In this animation, I have used circular mirrors so that when the light strikes them, they create a new expanding circle of light.



I represent the stationary observer in green and I call him Homer (think green, green grass of home). I represent the original expanding circle of light in blue as well as a blue dot to represent its source, the mirrors in brown, the collapsing circles of light in green when they reflect off stationary mirrors.

Please note that just as in the previous post when the collapsing circle of light arrived simultaneously from all directions on the observer, the four reflections from the four mirrors all arrive simultaneously on the observer. Although this is not actually how the MMX was configured, it still represents conceptually exactly what the experiment was doing.

The MMX experimenters assumed that the previous animation would represent only what would happen if they were stationary with respect to the ether which they believed they never were. They believed that they were constantly moving with respect to the ether and also constantly changing their velocity through the ether as the Earth rotated on its axis and as it revolved around the sun. This constant acceleration was very small so for all practical purposes, they could assume that they were moving at a constant speed through the ether. This is how they thought the light would behave:



I represent the moving observer in red and I call him Rover (think Red Rover). The light that reflects off the moving mirrors is shown in red and a red dot is placed at the origin of each expanding reflection.

Note that when the light from the four mirrors arrives at Rover, it is not simultaneous, it first arrives from the top and bottom mirrors and then later arrives from the left and right mirrors. This is what the MMX experimenters expected to measure but instead, they got the same result as if they were stationary in the ether, the same result the Homer would have gotten.

So now the question is how can this happen? Well, Lorentz and others came up with an explanation and we will go through a process that will arrive at the same explanation.

First, we want to learn how we know where to put the mirrors so that the expanding circle of light can create a reflection that results in a collapsing circle of light in just the right place at just the right time. For Homer, it's easy:



Just note the intersection of the blue expanding circle and the green collapsing circle and in this animation, we draw a black dashed line to show where that intersection occurs:



Now for Rover, it's a little more complicated because his collapsing circle of light is not centered on the expanding circle of light but rather the location of where he will be later on, shown as a red dot. Try to visualize in this animation where the blue and red circles intersect:



And here we have the black dashed line to show the points of reflection:



Now this black dashed line shows the points of relection relative to the ether but we really want them relative to Rover, so here we show both for comparison:



Also, note that Lorentz realizes that everything contracts in the direction of motion so we now show Rover as being length contracted as well as his circular arrangement of mirrors. In addition, the time it takes for the light to traverse from Rover to the mirrors and back to Rover is longer than it was for Homer which illustrates time dilation. We can also see the issue of Relativity of Simultaneity because the reflections for Rover do not all occur at the same time whereas they do for Homer.



This illustrates how Lorentz believed MMX produced the null result. He believed that the experiment was moving through the ether and experienced length contraction, time dilation and relativity of simultaneity.

He also believed that Rover would measure the speed of light to be the same as Homer because even though time was going slower and stretching out (time dilation), it is the actual length that the light has to travel relative to the ether that is used to calculate the speed (length divided by time), so we need to use the lengths defined by the black dashed line, not the moving brown line representing the length contracted mirror. This length is dilated to the same extent that time is dilated and so the two dilations cancel each other out and give the same calculation for the speed of light.

However, Einstein put a new spin on the interpretation. He said that we could assume that MMX was actually stationary in the ether and everything else that was moving with respect to MMX was experiencing length contraction, time dilation and relativity of simultaneity.

 

[nismaratwork]

Now it's really not practical to build a solid sphere of mirrors but all we really need is four mirrors that are placed 90 degrees apart and all equidistant from the observer. In this animation, I have used circular mirrors so that when the light strikes them, they create a new expanding circle of light.



I represent the stationary observer in green and I call him Homer (think green, green grass of home). I represent the original expanding circle of light in blue as well as a blue dot to represent its source, the mirrors in brown, the collapsing circles of light in green when they reflect off stationary mirrors.

Please note that just as in the previous post when the collapsing circle of light arrived simultaneously from all directions on the observer, the four reflections from the four mirrors all arrive simultaneously on the observer. Although this is not actually how the MMX was configured, it still represents conceptually exactly what the experiment was doing.

The MMX experimenters assumed that the previous animation would represent only what would happen if they were stationary with respect to the ether which they believed they never were. They believed that they were constantly moving with respect to the ether and also constantly changing their velocity through the ether as the Earth rotated on its axis and as it revolved around the sun. This constant acceleration was very small so for all practical purposes, they could assume that they were moving at a constant speed through the ether. This is how they thought the light would behave:



I represent the moving observer in red and I call him Rover (think Red Rover). The light that reflects off the moving mirrors is shown in red and a red dot is placed at the origin of each expanding reflection.

Note that when the light from the four mirrors arrives at Rover, it is not simultaneous, it first arrives from the top and bottom mirrors and then later arrives from the left and right mirrors. This is what the MMX experimenters expected to measure but instead, they got the same result as if they were stationary in the ether, the same result the Homer would have gotten.

So now the question is how can this happen? Well, Lorentz and others came up with an explanation and we will go through a process that will arrive at the same explanation.

First, we want to learn how we know where to put the mirrors so that the expanding circle of light can create a reflection that results in a collapsing circle of light in just the right place at just the right time. For Homer, it's easy:



Just note the intersection of the blue expanding circle and the green collapsing circle and in this animation, we draw a black dashed line to show where that intersection occurs:



Now for Rover, it's a little more complicated because his collapsing circle of light is not centered on the expanding circle of light but rather the location of where he will be later on, shown as a red dot. Try to visualize in this animation where the blue and red circles intersect:



And here we have the black dashed line to show the points of reflection:



Now this black dashed line shows the points of relection relative to the ether but we really want them relative to Rover, so here we show both for comparison:



Also, note that Lorentz realizes that everything contracts in the direction of motion so we now show Rover as being length contracted as well as his circular arrangement of mirrors. In addition, the time it takes for the light to traverse from Rover to the mirrors and back to Rover is longer than it was for Homer which illustrates time dilation. We can also see the issue of Relativity of Simultaneity because the reflections for Rover do not all occur at the same time whereas they do for Homer.



This illustrates how Lorentz believed MMX produced the null result. He believed that the experiment was moving through the ether and experienced length contraction, time dilation and relativity of simultaneity.

He also believed that Rover would measure the speed of light to be the same as Homer because even though time was going slower and stretching out (time dilation), it is the actual length that the light has to travel relative to the ether that is used to calculate the speed (length divided by time), so we need to use the lengths defined by the black dashed line, not the moving brown line representing the length contracted mirror. This length is dilated to the same extent that time is dilated and so the two dilations cancel each other out and give the same calculation for the speed of light.

However, Einstein put a new spin on the interpretation. He said that we could assume that MMX was actually stationary in the ether and everything else that was moving with respect to MMX was experiencing length contraction, time dilation and relativity of simultaneity.

This is an explanation I think I'll modify for use with family members on this issue. Thanks ghwelljr, your posts are always very thoughtful.

Quick question... what's the point of trying to design a clock (I realize you're arguing against it, not for it) to measure something that modern physics tells us is NOT absolute and universal? I must be missing something critical... I thought that one of the central tenants of relativity was the inability to define the passage of time in absolute terms for anything other than an ether?

This thread seems like a backwards argument to get to that absolute frame of reference, but using time as the hook instead of relative motion.

 

[ghwellsjr]

This is an explanation I think I'll modify for use with family members on this issue. Thanks ghwelljr, your posts are always very thoughtful.

Quick question... what's the point of trying to design a clock (I realize you're arguing against it, not for it) to measure something that modern physics tells us is NOT absolute and universal? I must be missing something critical... I thought that one of the central tenants of relativity was the inability to define the passage of time in absolute terms for anything other than an ether?

This thread seems like a backwards argument to get to that absolute frame of reference, but using time as the hook instead of relative motion.

I'm not sure I understand your concern. Roi is the one who is trying to design an absolute clock which is the same as trying to identify an absolute ether rest frame. I'm trying to show him historically how Special Relativity treats each Frame of Reference as if it were an absolute ether rest frame, just so that he can understand SR. I believe that once a person understands how time dilation, length contraction and relativity of simultaneity work in explaining the null result of MMX in the context of the existence of ether, and how SR is merely a switch in concept where instead of the ether being out there somewhere unknown, we can treat it as if it is any inertial frame of reference, they will no longer search for the ether any more or search for a means to make an absolute time clock.

I have more animations to show how Homer and Rover both think they are in the center of the expanding circle of light and how they each see that the other one also thinks he is in the center, but I want to let this one sink in first.

 

[nismaratwork]

I'm not sure I understand your concern. Roi is the one who is trying to design an absolute clock which is the same as trying to identify an absolute ether rest frame. I'm trying to show him historically how Special Relativity treats each Frame of Reference as if it were an absolute ether rest frame, just so that he can understand SR. I believe that once a person understands how time dilation, length contraction and relativity of simultaneity work in explaining the null result of MMX in the context of the existence of ether, and how SR is merely a switch in concept where instead of the ether being out there somewhere unknown, we can treat it as if it is any inertial frame of reference, they will no longer search for the ether any more or search for a means to make an absolute time clock.

I have more animations to show how Homer and Rover both think they are in the center of the expanding circle of light and how they each see that the other one also thinks he is in the center, but I want to let this one sink in first.

I agree with you... and given the acceptance and sense of SR/GR... it seems odd to try and find an absolute rest frame, which as you rightly point out is not possible... or rather, not meaningful. I don't see why the switch as you put it, it something people seem to fight like mad though, and that's my concern.

 

[roineust]

ghwellsjr,

I need some time now to learn the text and animations.
If you have more, please let me know.

Thanks,
Roi.

 

[NoDoubt]

No, there might be a momentary shift in the color of the light (frequency) during the acceleration but as soon as the effect of that is over, the detected light and the unboard clock behave just like they did before the acceleration. But you could use this or any number of other means to measure/calculate the speed of the train..

Alright, alright, I agree with you.
So do you agree with me that this arrangement will work only while acceleration, but not in constent velocity situation? If yes, I can put another experiment to show that it is possible to build a clock that will not loose its time because of motion, In simple words, A clock that will keep time with my home clock, no matter what, even if you put it on a jet, a rocket, or any thing faster than that. It should keep its time. I'll give it a try, may be I'm missing something?

 

[Dale]

I can put another experiment to show that it is possible to build a clock that will not loose its time because of motion, In simple words, A clock that will keep time with my home clock, no matter what, even if you put it on a jet, a rocket, or any thing faster than that. It should keep its time.

Sure, in principle it is possible to take an accelerometer, a clock, and a computer and build a device which accounts for relativistic effects and measures coordinate time. That is essentially what GPS does. Such a device would confirm relativity.

 

[ghwellsjr]

Alright, alright, I agree with you.
So do you agree with me that this arrangement will work only while acceleration, but not in constent velocity situation? If yes, I can put another experiment to show that it is possible to build a clock that will not loose its time because of motion, In simple words, A clock that will keep time with my home clock, no matter what, even if you put it on a jet, a rocket, or any thing faster than that. It should keep its time. I'll give it a try, may be I'm missing something?

But as I said before:

An Absolute clock is considered one that is stationary in the so-called, presumed, universal, at-rest ether which no one knows how to identify if it were to exist and so there is no hope to have an Absolute clock.

Your home clock is not an absolute clock. And you don't need to actually construct a clock to keep track of Earth time, you can do it with Lorentz Transforms as long as you keep track of your accelerations. But even then, you have to be aware that even Earth time is not unique except to those stationary on earth. From any other reference frame, time is totally different.

I just don't understand what it is you are trying to "prove" by making a moving spacecraft clock read the same as a stationary Earth clock. Would you also try to have a clock on Earth keep track of the time on a clock on the moving spacecraft and consider that significant?

 

[NoDoubt]

Your home clock is not an absolute clock. ?

Of cource, I know that.

Would you also try to have a clock on Earth keep track of the time on a clock on the moving spacecraft and consider that significant?

This is exactly what I'm trying to do.

"DaleSpam"

I'm sorry, You missed the whole point.

 

[Dale]

I'm sorry, You missed the whole point.

So please try to explain your point.

 

[ghwellsjr]

Your home clock is not an absolute clock.

Of cource, I know that.

But your first post on this thread started off:

All we are trying to build is an Absolute time clock, let's follow the rules of Physics and see if it works...

And then you proceeded to propose something that I thought was supposed to be an Absolute time clock. Did you change your mind somewhere along the line without telling us? Please be clear and state what it is you are trying to do here.

 

[NoDoubt]

But your first post on this thread started off:

And then you proceeded to propose something that I thought was supposed to be an Absolute time clock. Did you change your mind somewhere along the line without telling us? Please be clear and state what it is you are trying to do here.

I think we are having some miscommunications here, Let me try to explain myself again. I'll try to keep it as simple as possible. Thank you.

My understanding is, take two identical clocks (atomic clocks), and put one on a jet or a spaceship for some time. when we bring them back togather, they are out of sinc. The one that was sent out has lost some time, (Time dilation).

And this does not happen to just the clocks, it happens to everything even biological clocks. Even people, (The twin age thing)

So the goal is to make two clocks again, but this time none should loose its time, even when one is send out to Mars or put near a black whole and when brought back, It should have the same time as the other one, that was left on the Earth. (No time dilation for this clock)

So the question is, is it possible? There will be no out side help, like GPS, transponders, etc. etc. It has to be just the clock itself.

I have tried to keep it as simple as I can. I hope it will help.

 

[nismaratwork]

But your first post on this thread started off:

And then you proceeded to propose something that I thought was supposed to be an Absolute time clock. Did you change your mind somewhere along the line without telling us? Please be clear and state what it is you are trying to do here.

You see why I'm so confused?

NoDoubt: You'll always be having to add more clocks until you have a smooth manifold of them covering the universe, and the ability to poll them all and make comparisons for where you are on that manifold. The very act of polling distant clocks would eventually be thwarted by galactic recession and spatial expansion, so even in this absurd fancy this doesn't work.

How can you measure something that doesn't exist except as a concept? The idea of an absolute clock is literally the antithesis of Relativity in my view, as much as absolute measure.

 

[darkhorror]

all this "absolute" time clock would measure is the time on earth. If you wanted to create a clock that measured Earth's time you would have to calibrate it for Earth's time and it would only be useful if you wanted to see how fast your time is moving vs the Earth's. Such that it calculates the time from gravity/acceleration/speed so that when you leave Earth it tells you the Earth's time.

But why bother? and how is this an "absolute" clock?

 

[Dale]

So the goal is to make two clocks again, but this time none should loose its time, even when one is send out to Mars or put near a black whole and when brought back, It should have the same time as the other one, that was left on the Earth. (No time dilation for this clock)

So the question is, is it possible? There will be no out side help, like GPS, transponders, etc. etc. It has to be just the clock itself.

As I said before, in principle it is possible to take an accelerometer, a clock, and a computer and build a device which accounts for relativistic effects and measures coordinate time. Such a device would not need any "outside help", but it wouldn't technically be a clock.

I don't know why you thought I missed the whole point since this is exactly what I already answered.

 

[NoDoubt]

Such that it calculates the time from gravity/acceleration/speed so that when you leave Earth it tells you the Earth's time.

But how will you build one? I'm having hard time putting one togather. Would you care to elaborate a bit? Thank you.

 

[nismaratwork]

But how will you build one? I'm having hard time putting one togather. Would you care to elaborate a bit? Thank you.

Thought. Experiment.

 

[Dale]

But how will you build one? I'm having hard time putting one togather. Would you care to elaborate a bit? Thank you.

Take the accelerometer, the integral of the accelerometer reading is the rapidity, the time dilation factor is a function of the rapidity, adjust the clock by the time dilation factor.

 

[ghwellsjr]

So the goal is to make two clocks again, but this time none should loose its time, even when one is send out to Mars or put near a black whole and when brought back, It should have the same time as the other one, that was left on the Earth. (No time dilation for this clock)

Dalespam, I think it is going to take much more than you described to meet these specs. They are a pretty tall order.

NoDoubt should also be aware that two identical perfect clocks on Earth will generally not even keep the same time unless they are located in the same
place. The standard clocks in Boulder Colorado and in Greenwich England don't even keep the same time.

 

[Dale]

Dalespam, I think it is going to take much more than you described to meet these specs.

Like what exactly?

NoDoubt should also be aware that two identical perfect clocks on Earth will generally not even keep the same time unless they are located in the same
place. The standard clocks in Boulder Colorado and in Greenwich England don't even keep the same time.

Sure. Because they are (nearly) ideal clocks and clocks measure proper time, not coordinate time. As I mentioned above, the device that NoDoubt is describing is not technically a clock.

 

[NoDoubt]

Take the accelerometer, the integral of the accelerometer reading is the rapidity, the time dilation factor is a function of the rapidity, adjust the clock by the time dilation factor.

This will be good only when the spaceship/jet/train is accelerating, Once it start travling at a constent speed, Time dilation will take over and the clock will start to lag.

ghwellsjr:You did a really god job with those animations. Thank you. And I know that a clock in Boulder Colorado should loose time when compared to the clock in Greenwich England.

So the question remains, is it possible to build such a clock?

 

[ghwellsjr]

Dalespam, I think it is going to take much more than you described to meet these specs.

Like what exactly?

How is an accelerometer going to distinguish between an acceleration that results in a speed change and an acceleration caused by gravity that does not result in a speed change? And how, without gyroscopes can the "clock" tell when the clock is rotated so that it knows if the next acceleration actually results in a speed change or merely a direction change?

 

[nismaratwork]

This will be good only when the spaceship/jet/train is accelerating, Once it start travling at a constent speed, Time dilation will take over and the clock will start to lag.

ghwellsjr:You did a really god job with those animations. Thank you. And I know that a clock in Boulder Colorado should loose time when compared to the clock in Greenwich England.

So the question remains, is it possible to build such a clock?

AFAIK it's impossible, without needing even more clocks, then more... etc. This is why I'm a little confused... the OP talked about light undergoing time dilation, which is the same as saying, "forget Relativity".

 

[Dale]

This will be good only when the spaceship/jet/train is accelerating, Once it start travling at a constent speed, Time dilation will take over and the clock will start to lag.

No. That is why you integrate the acceleration to get rapidity.

 

[Dale]

How is an accelerometer going to distinguish between an acceleration that results in a speed change and an acceleration caused by gravity that does not result in a speed change?

You are correct. If we are talking about SR then nothing more is needed, but if we are talking about GR then a map of the spacetime metric is needed. This is in principle similar to how cruise missiles work.

And how, without gyroscopes can the "clock" tell when the clock is rotated so that it knows if the next acceleration actually results in a speed change or merely a direction change?

Yes. When we talk about an accelerometer in relativity we are talking about the 6 degree-of-freedom kind that measures three axes of acceleration and 3 axes of rotation, so the gyroscopes are implied. It just gets too cumbersome to always specify all of those details. So "accelerometer" becomes shorthand for "six degree of freedom inertial guidance unit containing three orthogonal simple accelerometers and three orthogonal ring laser gyroscopes".

 

[nismaratwork]

You are correct. If we are talking about SR then nothing more is needed, but if we are talking about GR then a map of the spacetime metric is needed. This is in principle similar to how cruise missiles work.

Yes. When we talk about an accelerometer in relativity we are talking about the 6 degree-of-freedom kind that measures three axes of acceleration and 3 axes of rotation, so the gyroscopes are implied. It just gets too cumbersome to always specify all of those details. So "accelerometer" becomes shorthand for "six degree of freedom inertial guidance unit containing three orthogonal simple accelerometers and three orthogonal ring laser gyroscopes".

at bolded: Heh... I actually like that much more.

 

[ghwellsjr]

ghwellsjr,

I need some time now to learn the text and animations.
If you have more, please let me know.

Thanks,
Roi.

I do have more but I want to make sure you understand what I have uploaded so far before proceeding. Please ask if there are any points of confusion or anything you want more clarification on.