russ_watters said:
As you must know, this question is incomplete.
Speed is measured between two points and you've only listed one point for each of the two speeds you are looking for.
We have “two point”...
We have a orbit and thereby a circumstance of the milkyway (MW).
You can bend the orbit to a straight line.
So you do have “two points”.
A staring point that also is the final point when the orbit is completed.
You need to specify what you are measuring the speeds relative to and who is doing the measuring.
This is done too.
The Sun travels relative to a points of no motion, which is the center of the Milkyway.
The 2 clocks are according to the example mentioned above following the exact same orbit as the Sun.
Bjarne
Does both observer A and B agree the speed is the same ?
Maybe. But again, this isn't really all that important. What is important is this:
Russ
If both observers faithfully follow the principle of Relativity as stated in your title and, as it requires, ensure they are clear and consistent about what frames of reference they are doing the measurements from, or measure from one and properly transform to the other, they will agree on what is happening.
First at all notice we are only speaking about influence due to gravity (GR) not about SR
The orbits of the 2 clock’s are exactly the same (for all observers).
Observer A and B are doing the measurement from their own reference frame.
B's clock is really ticking slower as A's clock - because B is closer to the Sun as A and therefore comparable slower as A's clock.
Nothing prevent that A and B can compare time differences.
Think about; how do we determinate how long 1 meter is or what the speed of light.
Both obersver A and B would determinate that the exact same way, wouldn’t they?
Again: If they follow the principle of Relativity and are clear on the choices of reference frames (and the definition of a "meter") they most certainly will.
They might say: "From here, your meter looks smaller than mine,
If A's meter-stick is comparable shorter as B's it will not only "look" shorter.
B's reality is real, as well as A's (or our) reality also are real.
Therefore B's meter stick will really be shorter.
We are not speaking about "illusion" but about realities.
but since I know our relative speeds, I calculate that if I was to go over to you and measure your meter it would be the same as mine."
Now you are speaking SR
Both A and B is according to the example in the same SR-reference frame, since both exactly follows the motion of the Sun, hence SR do not apply, - only GR does.
Let me ask more simple and all-round.
Imaging you was orbiting the Sun with a meter stick 50 billion km from the Sun.
I was orbiting 150 billion km from the Sun also carry a meter stick.
Would both meter sticks comparable be the same length? .
What I am asking is 1 meter the exact same length if a observer far away ( not affected by gravity of the Sun) could se both meter stick and also was able to compare if our meter stick did have the exact same length, so long we are different places in the gravitational field of the Sun ?
Now let say that time in your orbit is 1 billion part slower for you, compared to my time rate.
Would your meter stick then
proportional to that be 1 billion-part longer ? (or shorter ) – or exactly the same as mine, - still seen from a observer C far away and not affected by the gravity of the Sun.
The wording of the question violates Relativity by mixing and matching observations from different reference frames without properly accounting for the differences.
Comparing relative differences, doesn’t matter whether we speak about time rate, speed or length, - is not necessary mixing these, and this is also not what I have done at all.
I am not mixing anything but asking what is the
speed and
distance /B] difference between A’s and B’s reality according to the example, - if any ?
There must be a very simple answer to that question.
If you would say there is no difference between the reality of A and B (accept time), simple math would show you a mathematical contradiction, since time multiplied with speed can impossible result to the same distance for A and B. (since time for B is shorter)
So I am in fact trying to separate relative differences.
Mathematical either speed or distance cannot comparable be the same.
So what is the mathematical answer here?
Is speed comparable larger - or is it distance that is proportional and comparable shorter (and therefore the meter -stick propositional longer) ?
If nothing proves that (comparable) speed is affected (and hence comparable different), and you multiply less time (for B) with the same (comparable ) speed that is valid for A, - you will get a shorter distances for B.
So if you have no objection that we assume that speed is (comparable) the same for A and B, - then it is mathematical proven that distance (circumstance of the MW) for A and B NOT is comparable the same for A.
If you do not agree speed is comparable the same, what is the correct comparable speed for B, ?.
Yours assumption that I am mixing realities is not true. – I am ONLY comparing realities, and do in fact try to keep factors separated, by asking what the differences except time .
Is speed and / or distance comparable different according to the very simple example mentioned?
Please try to keep it simple.