Progression of Time & Entropy: Is the Pass. Slowing?

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Discussion Overview

The discussion revolves around the relationship between the passage of time and entropy, exploring whether the rate at which time passes is influenced by changes in entropy and the cooling of the universe. Participants examine various concepts related to the directionality of time, including thermodynamic, cosmological, and memory arrows of time, and whether time can be measured independently of entropy changes.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • Some participants propose that the directionality of time is linked to increasing disorder, suggesting that the passage of time might slow down as the universe cools.
  • Others argue that the "passage" of time, understood as the "rate" at which time passes, can be measured by periodic processes that do not involve entropy change, thus separating it from entropy.
  • A participant questions the idea that time can be measured without changes that involve entropy, suggesting that some form of change is necessary for time measurement.
  • Another participant asserts that the periodicity of time measurement is not affected by entropy increase, challenging the initial claim about time slowing down with cooling.
  • There is a discussion about the nature of periodic processes, with some questioning what processes can occur without energy transfer and entropy change.
  • One participant introduces the concept of gravity as a potential periodic process that does not involve energy transfer in the same way as other mechanisms, suggesting a geometric interpretation of time's passage.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between time and entropy, with no consensus reached on whether the passage of time is affected by entropy changes or the cooling of the universe. The discussion remains unresolved with multiple competing perspectives presented.

Contextual Notes

Participants reference various "arrows of time" and their implications, but the definitions and relationships among these concepts remain unclear and are subject to interpretation. The discussion also highlights the complexity of measuring time and the assumptions underlying these measurements.

Paul Howard A
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The directionality of time seems to be linked to the process of increasing disorder.

Is the 'passage' of time similarly linked?

If so, it would seem that the passage of time would generally slow down as the universe cools. And perhaps time should pass more slowly in cooler regions of the cosmos; and pass more quickly during times of rapid expansion.

And, if true, could we even experience or measure it since our senses and instruments would be in sync with what we were trying to measure...unless we were looking into deep space...
 
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Paul Howard A said:
The directionality of time seems to be linked to the process of increasing disorder.

More precisely, this is one of several possible "arrows of time", the thermodynamic one. There is also a cosmological arrow (the "future" is the direction in which the universe is expanding) and the memory arrow (the "past" is the direction of time in which we can remember events, so the "future" is the other one). There are arguments for why two or even all three of these arrows must point in the same direction, but I don't think the question is settled.

Paul Howard A said:
Is the 'passage' of time similarly linked?

No, assuming that by "passage" you mean the "rate" at which time passes. The passage of time can be measured by periodic processes that are reversible and involve no entropy change, so there is no way to link the "rate of time flow" to entropy.
 
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PeterDonis said:
The passage of time can be measured by periodic processes that are reversible and involve no entropy change

Surely something must be changing to measure time. The clock must increment or the observer must accumulate memories of the past- these processes would involve entropy?
 
Cause and effect are the arrow of time.
 
bcrelling said:
Surely something must be changing to measure time. The clock must increment or the observer must accumulate memories of the past- these processes would involve entropy?

Good point. The recording of the passage of time does require some entropy increase. However, the periodicity of the process being recorded is not affected by the increase in entropy. So the "tick rate" of the clock would not change as entropy increases. So this inference in the OP...

Paul Howard A said:
it would seem that the passage of time would generally slow down as the universe cools

...is not correct.
 
PeterDonis said:
The passage of time can be measured by periodic processes that are reversible and involve no entropy change, so there is no way to link the "rate of time flow" to entropy.

What periodic process (other than a perpetual motion machine) involves no transfer of energy? (ie entropy change)
 
Paul Howard A said:
What periodic process (other than a perpetual motion machine) involves no transfer of energy? (ie entropy change)

Two clocks may keep the same time even though their mechanisms do different amounts of work in different ways ( steam vs wind-power say ).
 
Doug Huffman said:
Cause and effect are the arrow of time.
Paul Howard A said:
What periodic process (other than a perpetual motion machine) involves no transfer of energy? (ie entropy change)

gravity; (coordinate acceleration) and certainly requires spacetime.

I'd say Doug has it most "right" if we're to paint a geometric property as something of a "passing". It's via that "odd" geometric property that the properties of physical "entities" can "play out"...tick tick tick
 
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