Absolute Time Clock Experiments: Einstein's Special Relativity

[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.

 

[roineust]

ghwellsjr,

I went over the text and animations several times.
I think it is an estimable effort to make SR more accessible to non-mathematicians...

My problem is that for me personally, it is still too complicated to understand.
Maybe it is because the of use animated forms such as circles and ellipse...isn't it possible to explain SR using animations of rectangular and straight lines?

Thanks,
Roi.

 

[ghwellsjr]

ghwellsjr,

I went over the text and animations several times.
I think it is an estimable effort to make SR more accessible to non-mathematicians...

My problem is that for me personally, it is still too complicated to understand.
Maybe it is because the of use animated forms such as circles and ellipse...isn't it possible to explain SR using animations of rectangular and straight lines?

Thanks,
Roi.

If you are going to limit the illustrations to straight lines, then you don't need an animation. That's what normal spacetime diagrams do. They show time on the vertical axis and one spatial dimension (corresponding to the direction of motion) along the horizontal axis. A century ago, that was all that technology could support, but nowadays, why not show time as time and allow for two dimensions of space?

Perhaps if you were to think of these animations as showing the progression of waves on the surface of water, would that help you understand them? If not, why don't you take them one at a time and describe what it is about them that makes them too complicated to understand. I want them to be simple to understand and you could help me improve them. I'd really appreciate it if you could help me do that.

 

[roineust]

I will go over it again and see if I am able to ask a particular question.

It is not that easy for me to do - the way I ask questions regarding SR is a sort of a stronghold that enables me not to end up with 'magical' or a paradoxical conclusions. You are asking me to open up my mind in a way that most likely will end up again with what is for me a conclusion that is 'falling through the rabbit hole'.

I think what is not clear for me at this point, and that I am not sure I will understand by this way of using animation of circular forms, has to do with why the two postulates of 1. The C velocity invariance and 2. Invariance of the laws of physics - Do not contradict with each other.

1: C invariance seems a very narrow, specific and testable postulate that I can trust, but, 2: The invariance of the laws of physics, seems to me a very broad, general, unreliable postulate, that is prone to amendments, especially regarding contradictions that arise from no.1 postulate.

 

[nismaratwork]

I will go over it again and see if I am able to ask a particular question.

It is not that easy for me to do - the way I ask questions regarding SR is a sort of a stronghold that enables me not to end up with 'magical' or a paradoxical conclusions. You are asking me to open up my mind in a way that most likely will end up again with what is for me a conclusion that is 'falling through the rabbit hole'.

I think what is not clear for me at this point, and that I am not sure I will understand by this way of using animation of circular forms, has to do with why the two postulates of 1. The C velocity invariance and 2. Invariance of the laws of physics - Do not contradict with each other.

1: C invariance seems a very narrow, specific and testable postulate that I can trust, but, 2: The invariance of the laws of physics, seems to me a very broad, general, unreliable postulate, that is prone to amendments, especially regarding contradictions that arise from no.1 postulate.

You may be running into issues that are solved through the relativity of simultaneity... give that material a read, and it may help.

 

[ghwellsjr]

I will go over it again and see if I am able to ask a particular question.

It is not that easy for me to do - the way I ask questions regarding SR is a sort of a stronghold that enables me not to end up with 'magical' or a paradoxical conclusions. You are asking me to open up my mind in a way that most likely will end up again with what is for me a conclusion that is 'falling through the rabbit hole'.

I think what is not clear for me at this point, and that I am not sure I will understand by this way of using animation of circular forms, has to do with why the two postulates of 1. The C velocity invariance and 2. Invariance of the laws of physics - Do not contradict with each other.

1: C invariance seems a very narrow, specific and testable postulate that I can trust, but, 2: The invariance of the laws of physics, seems to me a very broad, general, unreliable postulate, that is prone to amendments, especially regarding contradictions that arise with no.1 postulate.

Forget about Relativity. Forget about Einstein's two postulates. The text for my first animation says to get into the mindset of the scientists before Einstein came along. I'm sure you have tossed a pebble into a pond and seen the ever expanding ring of waves that emits from where the pebble entered the water. The first two animations are no more complicated than that, are they?

 

[nismaratwork]

Forget about Relativity. Forget about Einstein's two postulates. The text for my first animation says to get into the mindset of the scientists before Einstein came along. I'm sure you have tossed a pebble into a pond and seen the ever expanding ring of waves that emits from where the pebble entered the water. The first two animations are no more complicated than that, are they?

I'm not new to this, but they seem extremely clear to me, and I think they would were I new and you had given me a similar introduction.

 

[roineust]

The problem arise as soon as I try to understand the things that happen with the moving source of light.

 

[nismaratwork]

The problem arise as soon as I try to understand the things that happen with the moving source of light.

What is the very first issue that puzzles you once the source begins to move?

 

[ghwellsjr]

The problem arise as soon as I try to understand the things that happen with the moving source of light.

If you dropped a pebble into a quiet pond from a bridge, the ringlets expand around the point of entry, correct? But if you throw a pebble into a pond while you are standing on the shore, do the ringlets expand around the point of entry just as if you could have reached way out over the water and dropped the pebble in, or do the ringlets move away from you with the same speed that the pebble hit the water?

 

[roineust]

What do you mean by "...in just the right place at just the right time..." in:

"... 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: ..."

You mean that at that stage you want to learn how to put the mirrors in a way that for the moving guy it will be reflected so that it doesn't seem to him as if he were stationary, but rather as if he actually was in a water pond?

 

[nismaratwork]

I'm stumped... ghwellsjr seems to be answering your question. I guess I don't know the material well enough to teach it... sorry.

 

[roineust]

If the rock hit the water while flying away from me... Do you mean if the ringlets move in relation to the shore away from me, or do you mean that each time the rock bounces over the water, also the new ringlets that will be created of course will become more and more distant...?

 

[ghwellsjr]

What do you mean by "...in just the right place at just the right time..." in:

"... 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: ..."

You mean that at that stage you want to learn how to put the mirrors in a way that for the moving guy it will be reflected so that it doesn't seem to him as if he were stationary, but rather as if he actually was in a water pond?

Homer is stationary in the pond so if we place reflectors in a circle around him, the expanding ringlets will all hit the reflectors (in the case of water, we would want to do this in a circular pool) at the same time and change the expanding ringlet into a contracting ringlet which will collapse on Homer simultaneously from all directions. Remember, Homer can't see the waves like we can, he's only aware of when they start, and later, when they collapse on him and that makes him believe that he is stationary with respect to the medium that is propagating the waves.

In the case of Rover, he is moving through the water at one-half the speed that the waves move, although we have to stipulate that not only can he not see the waves, he cannot feel the water, nor does his motion create any additional waves. He doesn't even know that he is moving.

Now we put Rover in an oval-shaped pool and when he gets to the blue dot shown on the animation, he creates a wave that starts expanding outward from the blue dot. The elliptical shape of the pool causes the expanding ringlet to collapse on the red dot at the exact moment that Rover arrives there and so he, too, concludes that he is stationary with respect to the medium that is propagating the waves, that is, if he thought, like Homer that he was in the middle of a circular arrangement of reflectors.

 

[ghwellsjr]

If the rock hit the water while flying away from me... Do you mean if the ringlets move in relation to the shore away from me, or do you mean that each time the rock bounces over the water, also the new ringlets that will be created of course will become more and more distant...?

I'm assuming that the pebble does not skip across the water, it enters the water with some horizontal velocity and I was asking if that horizontal velocity causes the ringlets to move away from you (and the shore) or if they expand outward from the stationay point of entry?

 

[roineust]

I am not sure. I guess there will be some sort of movement of the ringlet not only by way of expanding from a center, but also of the center itself moving away from the shore.