I Time Measurement in Extremely Curved Space Regions

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The discussion centers on the definition of time and clocks in the context of extreme spacetime curvature. The Caesium standard for measuring time may become problematic in such regions, as the geometry could affect its properties, leading to ambiguities in defining proper time. Proper time is fundamentally linked to the geometric structure of spacetime, suggesting that even if the Caesium clock fails, the concept of proper time remains valid. The conversation also highlights the importance of comparing different types of clocks based on their agreement and utility, rather than seeking a metaphysical "right" time. Ultimately, the definition of time and the choice of clocks are influenced by both theoretical models and empirical data, which may evolve with advancements in technology and understanding.
  • #91
DanMP said:
Maybe I'll open a new thread for it.
Yes, that would be appropriate.
 
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  • #92
Dale said:
I think this is wrong. Classical mechanics (including Newton Cartan) is self consistent considering clocks as measuring t.
Sorry, i cannot see how with the interpretation you propose makes Newtons theory at all usable.

Consider a clock ##r_1## on earths surface and another one ##r_2## in orbit, and a last one ##r_3## passing earth with relativistic speed, all of them measuring the time it takes earth spin one full turn. You will get 3 different results. The interpretation you apply will map those 3 different values to 1, the very same absolute time, so you have a contradiction right in your interpretation. If you cannot determine even the most basic initial conditions for you model, like how fast earth initially spins, how are you supposed to work with that? This problem will be the same for every single value you need for your model - and in terms of astronomy the different methods may yield significant deviances without relativistic corrections. You cannot work with a theory that has contradictions!

Even if Newtons theory is not relativistic, it doesn't mean it is not workable. But that requires to first establish a method of interpreting measurements in terms of the model, and if in reality it turns out that we have two devices that are supposed to measure the same thing but yield different results in practice, we have to work that out first. This very case has been discussed in this thread extensively: metrology suggest to figure out what is differenten about the devices/the conditions they are in and at very least establish a corrective function in between those to make them consistent - at very least empirically (e.g. fit the bias via regression). It is that corrective function, deducted from compares between measurements, that turns your time measuring devices to be able to measure a coordinate time.

During Newton's time, the different measuring techniques were all but consistent and as i read the relative time concept, it accounts for the problems this practicality entails.
 
  • #93
Killtech said:
i cannot see how with the interpretation you propose makes Newtons theory at all usable.

Consider a clock … with relativistic speed
Newton’s theory is not useable at relativistic speed.

Killtech said:
You will get 3 different results.
Not according to Newtonian mechanics. Newtonian mechanics predicts that all three produce the same result.

Killtech said:
the very same absolute time, so you have a contradiction right in your interpretation
That is a contradiction with experiment, not a contradiction in the interpretation.

If your model + interpretation does not produce this same contradiction with experiment then it is clearly not Newton’s theory. This is a well known contradiction between Newtonian theory and experiment.
 
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  • #94
Killtech said:
Consider a clock on earths surface and another one in orbit, and a last one passing earth with relativistic speed, all of them measuring the time it takes earth spin one full turn. You will get 3 different results. The interpretation you apply will map those 3 different values to 1
No. I have already pointed this out more than once, and so has @Dale. You are confusing the interpretation of the theory with the fact that it makes wrong predictions.

Newtonian theory predicts that all three of these clocks will measure the same time for the Earth spinning one full turn. This prediction is wrong. It's not that Newton's theory takes these three actual experimental results that are different and tries to adopt some "interpretation" to gerrymander them into one theoretical value of ##t##. It's that these actual experimental results falsify Newtonian theory. You appear unable to grasp this essential point.
 
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  • #96
After moderator review, this thread will remain closed.
 
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