[guest39538]

I think if the observer spun  with an orbiting object there would be no contraction.

 [ Invalid Attachment ]

[timey]

imperceptibly

If the speed is a constant 3 mph, and the observer is relatively stationary, all the carriages will look the same length to the observer. If the train accelerates, there will be a variation length of the carriages, they will get ''shorter'' the faster the acceleration the more carriages going past at a faster rate.

No box, read the post again.  Changes in the gravitational field, change the 'rate' of time.  (Look up NIST ground level general relativity experiments 2010). This is synonymous to counting as a means of timing an event, one, one thousand, two, one thousand, etc, at a faster, or slower rate, ie: speaking the words faster or slower.  Do you get it?  Therefore a constant speed will take a longer or shorter amount of 'time' to cover the same unit of distance.

This having nothing to do with an acceleration of speed, and my question to Alan is:
How do the effects of special relativity have an effect on the general relativity observations of the observer?

[Space Flow]

Surely the special relativity effects only apply to the accelerated reference frame?

Timey, SR does not in any way address or describe any accelerated frame.
SR is only about constant relative speed between observers. It is a good way of describing relativistic time dilation and length contraction "principles" but does not actually apply to any known real situation in the Universe.
That is the reason that Einstein kept on working on and finally brought out GR as a way of applying the concepts that SR introduced to real world scenarios.

[Ethos_]

I understood length contraction in the first place, a meaningless parlour trick, relative to the object, the object does not contract it just appears to contract to the observation. 

OK, now that we can agree in part, we should examine how we can determine whether or not the object actually shrinks as it appears to. One thing we should also agree upon Mr. Box, is all the evidence we have to consider this question comes to us through observation and mathematical constructs.

You believe, if I'm not mistaken, that the object doesn't actually shrink, it only appears to shrink. What observational evidence or mathematical evidence do we have to support that conclusion?

Bare in mind, I'm not attacking you with this question, I am only presenting you with a thought experiment for us to think about.

[guest39538]

.  Changes in the gravitational field, change the 'rate' of time. 

Change the rate of time of what?

[timey]

.  Changes in the gravitational field, change the 'rate' of time. 

Change the rate of time of what?

LOL!

[guest39538]

I understood length contraction in the first place, a meaningless parlour trick, relative to the object, the object does not contract it just appears to contract to the observation. 

OK, now that we can agree in part, we should examine how we can determine whether or not the object actually shrinks as it appears to. One thing we should also agree upon Mr. Box, is all the evidence we have to consider this question comes to us through observation and mathematical constructs.

You believe, if I'm not mistaken, that the object doesn't actually shrink, it only appears to shrink. What observational evidence or mathematical evidence do we have to support that conclusion?

Bare in mind, I'm not attacking you with this question, I am only presenting you with a thought experiment for us to think about.

We have the evidence that if the actual object shrunk in length, that would be compression of the mass, it would then expand in height, applied force is needed for compression, space offers no resistance to motion.
i,e cars contract in length when they hit  a wall fast


i.e for something to contract the rear would have to be travelling faster than the front

 [ Invalid Attachment ]

Or vice versus and the front would have to slow down

[Ethos_]

We have the evidence that if the actual object shrunk in length, that would be compression of the mass, it would then expand in height, applied force is needed for compression, space offers no resistance to motion.

I understand your point Mr. Box and that would be the logical assumption. But remember, reality is not always logical and we need to look for evidence other than just logical assumption.

Leaving this question for a moment, how about time dilation. Can we agree that time dilation actually takes place? Taking into consideration that our GPS system must account for this factor to accurately map our earth and account for the time differences.

[Space Flow]

I think if the observer spun  with an orbiting object there would be no contraction.

Thebox, your eyes when you turn with the satellite are describing a circle that has a radius, circumference and speed. Those qualities when compared with the satellite's radius, circumference and speed, are not the same.
Whenever there is an observed difference in speed there will be an observed difference in time and length.
Whether you want to call that real or just illusionary is at this stage up to you. But the effect is there and it is measurable.
Maybe the reason you have not understood what we are saying so far is this "observation".
You see and I think you are finally taking the first steps to understanding, "Relativity" is about what is observed and measured from one reference frame to another. It does not claim that any change can ever be seen to one's own frame. No matter what you believe is causing those observations to be what they are, if you don't acknowledge them and make corrections for them, then two different frames could never coherently communicate.

Having said all that I better add for precision's sake that in your picture there are two effects in play and they are working against each other to give you the observations that you will measure and have to correct for.
One is the difference in observed speed and the other is the difference in the speed of the flowing spacetime, due to the inverse square law and the satellite being further from the centre of the system (Gravity).

Change the rate of time of what?

Not of what.
Change of rate of time. (See that character after the word time? That is a full stop.)

[guest39538]

We have the evidence that if the actual object shrunk in length, that would be compression of the mass, it would then expand in height, applied force is needed for compression, space offers no resistance to motion.

I understand your point Mr. Box and that would be the logical assumption. But remember, reality is not always logical and we need to look for evidence other than just logical assumption.

Leaving this question for a moment, how about time dilation. Can we agree that time dilation actually takes place? Taking into consideration that our GPS system must account for this factor to accurately map our earth and account for the time differences.

I can agree that there is a dilation of the timing mechanism synchronisation to gravity of mass that is situated in a timeless 5th dimension of space-time.


Taking into consideration that anything after 0 is history  and all mass including the satellites are travelling through simultaneous time that is timeless.

[guest39538]

Not of what.
Change of rate of time. (See that character after the word time? That is a full stop.)

Yes! change of time of what?


Answer the question please

[timey]

Surely the special relativity effects only apply to the accelerated reference frame?

Timey, SR does not in any way address or describe any accelerated frame.
SR is only about constant relative speed between observers. It is a good way of describing relativistic time dilation and length contraction "principles" but does not actually apply to any known real situation in the Universe.
That is the reason that Einstein kept on working on and finally brought out GR as a way of applying the concepts that SR introduced to real world scenarios.

OK, I'm following you.  But... what I am trying to understand is 'how' the maths from the concepts of SR: ie: length contraction for the observer, and distance contraction, plus velocity related time dilation for the accelerated frame, mesh with the general relativity time dilation considerations and the stretching of spacetime.  They appear to be entwined indistinguishably within the GR field equations amongst some very complex geometrical considerations.  I'd like to understand.

[Space Flow]

We have the evidence that if the actual object shrunk in length, that would be compression of the mass, it would then expand in height, applied force is needed for compression, space offers no resistance to motion.
i,e cars contract in length when they hit  a wall fast


i.e for something to contract the rear would have to be travelling faster than the front

Here you are making the classic mistake of visualising the length contraction as something that matter might do within the space it occupies, therefore occupying less space.
That is not the effect we observe or describe.
It is the contraction of the spacetime itself. Matter just keeps occupying the same amount of space it always has. It appears to contract because the space it occupies appears to contract.
Remember to focus on the word "Appears".
It is always how something behaves relatively when viewed from a reference frame other than its own.

[guest39538]

We have the evidence that if the actual object shrunk in length, that would be compression of the mass, it would then expand in height, applied force is needed for compression, space offers no resistance to motion.
i,e cars contract in length when they hit  a wall fast


i.e for something to contract the rear would have to be travelling faster than the front

Here you are making the classic mistake of visualising the length contraction as something that matter might do within the space it occupies, therefore occupying less space.
That is not the effect we observe or describe.
It is the contraction of the spacetime itself. Matter just keeps occupying the same amount of space it always has. It appears to contract because the space it occupies appears to contract.
Remember to focus on the word "Appears".
It is always how something behaves relatively when viewed from a reference frame other than its own.

You have not read what Ethos asked.  quote ethos - ''You believe, if I'm not mistaken, that the object doesn't actually shrink, it only appears to shrink. What observational evidence or mathematical evidence do we have to support that conclusion?''

[Space Flow]

Yes! change of time of what?


Answer the question please

Hang on I did answer the question.

Quote from: Thebox on Today at 08:36:01
Change the rate of time of what?
Not of what.
Change of rate of time. (See that character after the word time? That is a full stop.)

[guest39538]

Yes! change of time of what?


Answer the question please

Hang on I did answer the question.

Quote from: Thebox on Today at 08:36:01
Change the rate of time of what?
Not of what.
Change of rate of time. (See that character after the word time? That is a full stop.)

that is an incompleteness answer, I may have to quote Gobel.

Are you sure the answer is not  - a change in the rate of time of the caesium atom?

and should time not be timing or synchronisation?


 a change in the rate of synchronisation of the caesium atom relative to a gravitational field

[Space Flow]

You have not read what Ethos asked.

Thebox I am trying to directly answer your questions not everyone's.
Is that not what you keep asking for?
As far as anyone else's understanding if I address them I will do so by quoting them.

[guest39538]

You have not read what Ethos asked.

Thebox I am trying to directly answer your questions not everyone's.
Is that not what you keep asking for?
As far as anyone else's understanding if I address them I will do so by quoting them.

Yes I understand, But Ethos asked me a question about an actual object and asked how we could disprove the actual object shrank, which I answered.  You read it wrong and presumed I was saying an object shrunk .

[Space Flow]

that is an incompleteness answer, I may have to quote Gobel.

Are you sure the answer is not  - a change in the rate of time of the caesium atom?

and should time not say timing or synchronisation?

As you may have noticed and are obviously choosing to ignore the fact, I did not mention caesium atom or any matter based anything neither did I mention timing or synchronisation.
If that was what I meant, than that is what I would have said.
I am answering your direct question with a direct and complete answer and would appreciate it if you did not try to assume I ever mean anything other than what I say. I have a wife who has that kind of thing more than adequately covered.

[Space Flow]

You have not read what Ethos asked.

Thebox I am trying to directly answer your questions not everyone's.
Is that not what you keep asking for?
As far as anyone else's understanding if I address them I will do so by quoting them.

Yes I understand, But Ethos asked me a question about an actual object and asked how we could disprove the actual object shrank, which I answered.  You read it wrong and presumed I was saying an object shrunk .

If I took an answer of yours to someone else out of context, I apologize.
I am concentrating on you and the subject matter of this post.
Therefore any reference to contraction I took to be a reference to contraction as described by relativity.
I will check out what others have said at a more leisurely time and address any issues I perceive in their comments then. Right now it's about you.