Is Time Slowing or Are Processes Slowing Near High Gravity and Speeds?

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Processes occurring near high gravity or at near light speed appear to slow down, a phenomenon explained by general relativity as a result of time dilation. The discussion raises the question of whether this perceived slowing is due to the processes themselves slowing down rather than time itself. Some argue that the oscillation of atomic clocks or biological processes could be inherently slowed under such conditions. However, others emphasize that time is a measurement of the rate of change of processes, suggesting that the distinction between slowing processes and slowing time is nuanced and often interdependent. Ultimately, the conversation highlights the complexities of relativity and the interpretation of time and processes in extreme conditions.
  • #91
1977ub said:
It strikes me that the simplest and most paradoxical case in SR is the two-ships-passing-in-the-night version where A measures B's clock as slower and B measures A's clock as slower.
It seems a lot less paradoxial when you realize that statements about A's experience of B's clock are actually statements about coordinate assignments to points on B's world line made by a coordinate system that a standard procedure associates with A's world line.

The SR result that I find the most counterintuitive is that if you see something like a dot from a laser pointer move faster than c, and you start running after it, its speed relative to you will be larger when you're running, not smaller. (This is also a consequence of the definition of your experience using the comoving inertial coordinate system).

1977ub said:
...and that 'mechanism' would appear to be an interaction with the mysterious "Source of Inertia."
This I disagree with. No mechanism is needed.
 
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  • #92
Fredrik said:
This I disagree with. No mechanism is needed.

Something - mechanism or something else - is required to explain why one person experiences acceleration when another does not. This same something appears to be involved in cases where A & B bring their clocks together and one of them has run slower somehow.
 
  • #93
bobc2 said:
Here is why I think the slowing of the clock cannot be caused by some mechanism that affects the physical operation of the clock. That might be the case if it was just one of the clocks that is seen to be ticking more slowly. But, actually each observer sees the other’s clock as ticking more slowly. If red was at rest in aether, for example, and it was just the mechanism of the blue clock being affected (due to blue's absolute velocity in reference to aether), then both observers would always agree that it was the blue clock ticking more slowly. However, you can see in the sketch below that each observer sees the other’s clock displaying an earlier time (each sees the other’s clock ticking more slowly). This could not be the case if some mechanism of just the blue clock was affected. And if you wish to claim that both clocks were affected, then they would see no discrepancy, since both clocks would be affected the same way (assuming both moved with the same absolute speed with respect to the aether).

I personally have not been able to find in the literature a full account of any mechanism that predicts the results of Einstein's special relativity. It is recognized that there is disagreement with my position, so I don't want to claim expertise that establishes this view with some kind of finality--I would not want to deny others their views on this. I may be wrong here and would be very open to enlightenment on this point.

At one of the famous Solvay conferences, it is said that Poincare’ asked Einstein, “What is the mechanism accounting for time dilation and length contraction?” Einstein’s reply was simply, “There is no mechanism.”
Good stuff. I agree with these statements. It seems to me that the only way to make sense of the view that motion changes the properties of clocks is to label an arbitrary inertial coordinate system "the ether system", and then say that rulers and clocks with velocity v in the ether system are contracted/slowed by a factor of ##\gamma(v)##.
 
  • #94
1977ub said:
Something - mechanism or something else - is required to explain why one person experiences acceleration when another does not.
OK, that I can agree with.
 
  • #95
Fredrik said:
Good stuff. I agree with these statements. It seems to me that the only way to make sense of the view that motion changes the properties of clocks is to label an arbitrary inertial coordinate system "the ether system", and then say that rulers and clocks with velocity v in the ether system are contracted/slowed by a factor of ##\gamma(v)##.

Thanks, Fredrik. And I think the possibility of the ##\gamma(v)## resulting from an aether related effect, as you suggest, was the primary thrust of Fitzgerald, Lorentz, Poincare', et. al. My problem has been that for the past few weeks (off and on for months) I've tried to run that concept to ground and just haven't been able to find references that explicitly show how an observer moving relative to the aether can "see" a clock at rest in the ether as ticking slower by the same rate as the observer at rest in aetherr "sees" the clock in motion relative to the aether.

If red is at rest in aether, then his clock would be unaffected. If blue's clock, is affected due to his own motion, I have not seen the analysis that would show that blue "sees" red's clock to be affected in exactly the same way that red would "see" blue's. Whereas, with SR, each sees the other's clock tick slower by the same amount.

I probably just haven't found the right references and maybe someone here can provide an account of this mechanism that produces the same symmetric results as special relativity.

[edit] Just to add another note: It seems that the moving observer (his clock having a mechanistic slowing of his clock in an absolute physical sense) would "see" the at-rest-in-aether's clock ticking faster than his own. SR predicts just the opposite, i.e., the moving observer would "see" the at-rest-in-aether's clock ticking slower.
 
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  • #96
Fredrik said:
It seems a lot less paradoxial when you realize that statements about A's experience of B's clock are actually statements about coordinate assignments to points on B's world line made by a coordinate system that a standard procedure associates with A's world line.

Yes. It is a standard procedure, it is intuitive, it is practical. But it also, in a way, elaborate. It is certainly not the same thing as seeing or perceiving or knowing the other person's clock.
 
  • #97
1977ub said:
Something - mechanism or something else - is required to explain why one person experiences acceleration when another does not. This same something appears to be involved in cases where A & B bring their clocks together and one of them has run slower somehow.

1977ub, you can set up the experiment for two observers in relative motion showing differences in tick rates without any acceleration being involved. So, the acceleration is not a factor in the difference in clock rates (at least for special relativity). We can show examples if you wish.
 
  • #98
bobc2 said:
1977ub, you can set up the experiment for two observers in relative motion showing differences in tick rates without any acceleration being involved. So, the acceleration is not a factor in the difference in clock rates (at least for special relativity). We can show examples if you wish.

It relies upon construction of inertial frames. It could be understood that the "differences in tick rates" are an artifact of setting up these inertial frames in the first place. Until somebody accelerates, we don't end up with a difference that can't be chalked up to being such an artifact.
 
  • #99
1977ub said:
... It could be understood that the "differences in tick rates" are an artifact of setting up these inertial frames in the first place.
That is true.
Until somebody accelerates, we don't end up with a difference that can't be chalked up to being such an artifact.
Another way to put this is "Until their relative velocity changes, we don't end up with a difference that can't be chalked up to being such an artifact."

Only relative velocity enters the equations, through the γ factor.
 
  • #100
1977ub said:
It relies upon construction of inertial frames. It could be understood that the "differences in tick rates" are an artifact of setting up these inertial frames in the first place. Until somebody accelerates, we don't end up with a difference that can't be chalked up to being such an artifact.

The construction of the inertial frames does not produce artifacts. You seem to be familiar with the examples I referred to (difference in tick rates without acceleration), so could you show us one of those examples and explain how the artifacts were produced. I don't understand where the artifacts come from. Does the Minkowski metric produce artifacts? Please explain that.
 
  • #101
bobc2 said:
The construction of the inertial frames does not produce artifacts. You seem to be familiar with the examples I referred to (difference in tick rates without acceleration), so could you show us one of those examples and explain how the artifacts were produced. I don't understand where the artifacts come from. Does the Minkowski metric produce artifacts? Please explain that.

Which distant events are simultaneous with events at my location? The simplest and most direct answer is "I have no idea." There, done. If you were accelerating, you'd stop there. If you're not satisfied, you can send light pulses back and forth and time them. Seems reasonable enough, and it works well enough if the events of concern are in flat-enough space-time. But it is reasoning and not simple perception. And it breaks down if the space-time in the area of concern is not flat enough. But given all the caveats, you end up with this intuitive and practical creation: the inertial frame. And reality when filtered through this creation yields slower ticking of moving clocks etc.

Perhaps you could describe how a Minkowski metric of my environs is best experimentally constructed. Can it be done if I am accelerating?
 
  • #102
bobc2 said:
Not necessary. You can still find redemption if you will look into the Minkowski space-time diagram topic. Then you will see what I meant in the previous post about B taking a shorter path through space-time. The clock rates are not affected at all. B just simply took a shorter path that had fewer tick marks along his worldline in 4-dimensional space-time.

I only looked at the part about time dilation, and I accept it.

Probably off topic: How does one reconcile this? In the measure of time the two clocks will never synch again yet they recorded the same amount of time, yes?

If yes, then can one say that the re-united clocks are now in their own separate temporal dimensions forever even though subsequent observations shared from the same vantage point will be measured equally by both clocks?
 
  • #103
D English said:
Probably off topic: How does one reconcile this? In the measure of time the two clocks will never synch again yet they recorded the same amount of time, yes?

If yes, then can one say that the re-united clocks are now in their own separate temporal dimensions forever even though subsequent observations shared from the same vantage point will be measured equally by both clocks?
Huh? This is word salad.
 
  • #104
1977ub said:
Perhaps you could describe how a Minkowski metric of my environs is best experimentally constructed. Can it be done if I am accelerating?
Use a set of inertial rods and clocks where the clocks are synchronized using Einsteins convention. It can certainly be done if you are accelerating. You will not be at rest (other than momentarily) in such a frame, but there is no reason that you must use a coordinate system where you are at rest.
 
  • #105
DaleSpam said:
Huh? This is word salad.

I think because the whole notion is paradoxical. Yet, I know its a true phenomena.

The clocks measured the same amount of time, yet due to the motion of one, each according to the other is de-synced. Despite the de-syncing, neither is "wrong". Yes?
 
  • #106
DaleSpam said:
Use a set of inertial rods and clocks where the clocks are synchronized using Einsteins convention. It can certainly be done if you are accelerating. You will not be at rest (other than momentarily) in such a frame, but there is no reason that you must use a coordinate system where you are at rest.

I think over here I was discouraged from doing something like this. Einstein method doesn't agree with Rindler method, etc. Apples & oranges?

https://www.physicsforums.com/showthread.php?t=668580&highlight=pallen&page=6
 
  • #107
1977ub said:
I think over here I was discouraged from doing something like this. Einstein method doesn't agree with Rindler method, etc. Apples & oranges?

https://www.physicsforums.com/showthread.php?t=668580&highlight=pallen&page=6

DaleSpam is telling to you use an inertial frame in which you are accelerating; in that other thread you were being warned away from using a non-inertial frame in which you were at rest.

Confusions of this sort are the reason why I try very hard to avoid speaking of "the reference frame of <somethng>" or "the observer's reference frame" and the like
 
  • #108
Nugatory said:
DaleSpam is telling to you use an inertial frame in which you are accelerating; in that other thread you were being warned away from using a non-inertial frame in which you were at rest.

If I am accelerating, and if I will not be able to determine in a straightforward way which particular times and distances particular events have happened, not able to use any methods which operate in an IRF, how will I then be able to construct the Minkowski metric which describes the view from *any* IRF? It's all well and good for us *outside* of the situation, analyzing the motion from the perspective of a perfectly flat spacetime, and at rest.
 
  • #109
1977ub said:
If I am accelerating, and if I will not be able to determine in a straightforward way which particular times and distances particular events have happened, not able to use any methods which operate in an IRF, how will I then be able to construct the Minkowski metric which describes the view from *any* IRF? It's all well and good for us *outside* of the situation, analyzing the motion from the perspective of a perfectly flat spacetime, and at rest.
The question is a bit odd, since the metric is a property of spacetime, not a property of your world line. I'm guessing that what you have in mind is to apply the standard synchronization convention to a non-geodesic world line. The result will be a coordinate system that can't be defined on all of spacetime. It's a local coordinate system, not a global one. Nothing wrong with that though.

The suggestion that you've been given is to use the fact that the tangent your world line at any point on it is a geodesic, which can be taken to be the t axis of an inertial coordinate system. This coordinate system is certainly easier to work with.
 
  • #110
Fredrik said:
The question is a bit odd, since the metric is a property of spacetime, not a property of your world line. I'm guessing that what you have in mind is to apply the standard synchronization convention to a non-geodesic world line. The result will be a coordinate system that can't be defined on all of spacetime. It's a local coordinate system, not a global one. Nothing wrong with that though.

The suggestion that you've been given is to use the fact that the tangent your world line at any point on it is a geodesic, which can be taken to be the t axis of an inertial coordinate system. This coordinate system is certainly easier to work with.

Again, all of this seems to assume that I am floating above all of this information and know information about my world line, how to describe a tangent to it, etc. I asked about how to do this in the context of the conversation that was going on. Can you describe how to experimentally derive or construct the "minkowski space" from the POV of an accelerating observer making empirical observations?
 
  • #111
1977ub said:
I think over here I was discouraged from doing something like this. Einstein method doesn't agree with Rindler method, etc.
You asked how to experimentally construct a Minkowski metric, I answered. How you are accelerating is irrelevant, as is the Rindler method.
 
  • #112
1977ub said:
If I am accelerating, and if I will not be able to determine in a straightforward way which particular times and distances particular events have happened, not able to use any methods which operate in an IRF
I told you a straightforward way to use methods which operate in an IRF.
 
  • #113
1977ub said:
Can you describe how to experimentally derive or construct the "minkowski space" from the POV of an accelerating observer making empirical observations?
There are a number of ways. I already gave the most basic way. You can also use an accelerometer and radar. You can also use a GPS-like system. I am sure there are other ways.
 
  • #114
DaleSpam said:
Use a set of inertial rods and clocks where the clocks are synchronized using Einsteins convention. It can certainly be done if you are accelerating. You will not be at rest (other than momentarily) in such a frame, but there is no reason that you must use a coordinate system where you are at rest.

DaleSpam said:
I told you a straightforward way to use methods which operate in an IRF.

I am accelerating. How do I access "inertial" rods and clocks?
 
  • #115
Anyhow I barely recall the point I was trying to make. Thanks, everyone.
 
  • #116
1977ub said:
If I am accelerating, and if I will not be able to determine in a straightforward way which particular times and distances particular events have happened, not able to use any methods which operate in an IRF, how will I then be able to construct the Minkowski metric which describes the view from *any* IRF? It's all well and good for us *outside* of the situation, analyzing the motion from the perspective of a perfectly flat spacetime, and at rest.

The Lorentz interval between all pairs of "nearby" points determines the geometry.

There isn't any argument about how to choose a nearly inertial (and usually, co-moving) frame for _nearby_ events (which I'll call points from now on), which one can use to measure said interval. If the points are too far away from each other, you do start to see errors or ambiguities (depending on your interpretation) due to curvature. The solution to this dilemma is to choose points that are closer together, so these errors/ambiguities do not arise.

When you pick a coordinate system, then, you can choose some point with some coordinates (p,q,r,s), and some nearby point where one or more of the coordinates varies. You then determine the metric coefficients by fitting the measured Lorentz intervals to the ones you compute from the quadratic form of the metric.

This gives you the values of the metric coefficeints at the point (p,q,r,s). You repeat as desired at another point.

Sort of an aside, but while there are many methods to determine "distance in the large", one of the most intuitive is using Fermi Normal coordinates. But I suppose that would be material for another post, to treat it properly.
 
  • #117
1977ub said:
I am accelerating. How do I access "inertial" rods and clocks?
Take some rods and clocks and let go of them.
 
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  • #120
DaleSpam said:
Take some rods and clocks and let go of them.

Sounds like they're overboard then and I no longer know with certainty how far away they are...
 

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