How did entropy become associated with time? - by Mark John Fernee and by Assistant - Quora Question review

This document contains a review of the answer by Mark John Fernee on the question in Quora: "How did entropy become associated with time?
To order to read all the answers select: https://www.quora.com/How-did-entropy-become-associated-with-time?

• The text in italics is copied from the article.
  
• Immediate followed by some comments
  

Contents

• 1. Answer Review by Mark John Fernee

Reflection

• Reflection 1 - Question Review

1. Answer Review by Mark John Fernee

It's almost trivial.

Nothing is trivial (self evident?)

The second law states that the entropy can never decrease.

It is wrong to try to explain something by means of a law.

Moreover, entropy is really a statement of probability.

What does that mean?

Thus the second law can be reframed as, a system is most likely to be found in its most probable state (which is a trivial statement). Therefore a system changes by always tending towards its most probable state. This is an inherently asymmetric tendency, as if probability increases in one direction, it must decrease in the opposite direction. This intuitive flow of probability is how we immediately notice if a film is being played in the forward or reverse direction. Therefore, the change in entropy is naturally associated with the forward arrow of time.

Nevertheless, it is curious that the microscopic laws of physics are time symmetric.

What means time symmetric. In the physical world time cann't be reversed. An equation can be time symmetric: f(t) = a(t^2) with a>0

Macroscopic concepts such as entropy are based on probability rather than determinism.

Why the word 'rather'? Rather implies both, but the first more than the second.

Probabilities can be assigned when the underlying deterministic mechanisms are unknown.

Probabilities can be assigned when the outcome of a reaction or process (a vote) can have different concrete outcomes.

Therefore, the entropic arrow of time seems to be an emergent property associated with information loss.

Sentence not clear
What means arrow of time? The concept time has no specific direction. An arrow can above a plane, go in all directions.

However, there is another irreversible process lurking in the microscopic laws of physics, and that is the process of measurement. In quantum physics, measurements cause the “collapse of the wavefunction". This process is irreversible in all interpretations of the theory. Therefore, the arrow of time actually can be determined in the microscopic limit. Thus, time irreversibility does seem to be a more fundamental property.

2. Answer Review by Assistant

The connection between entropy and time is deeply rooted in the second law of thermodynamics. This law states that in a closed system, the entropy of the system tends to increase over time.

The emphasis is that entropy only makes a claim on a closed system. The problem is in the universe is neither an open or closed system. A closed system is typical a human related concept.

Entropy is a measure of the disorder or randomness of a system, and the second law of thermodynamics essentially tells us that natural processes tend to move towards states of higher entropy, or greater disorder.

The second law makes a claim about human created systems or products.

The reason why entropy is associated with time is because of the probabilistic nature of entropy increase. When we talk about the entropy of a system increasing, we are essentially saying that there are more ways for the system to be in a disordered state than in an ordered state. As time progresses, the system is more likely to evolve towards one of these higher entropy states simply because there are more of them.

This asymmetry in the probabilities of states evolving towards higher entropy over time is what links entropy with the concept of time's arrow. In a sense, the increase in entropy provides a directionality to time - from a state of lower entropy towards a state of higher entropy.

This connection between entropy and time has profound implications for our understanding of the universe and the directionality of processes that we observe in the world around us.

No it does not. The evolution of the universe, in its totality, is the reverse of chaos. The evolution of the universe is an example of order.

It is important to note that the association between entropy and time is a fundamental concept in physics and has been a subject of much study and discussion among scientists and philosophers.

The fundamental concept of study in physics and by scientists is order. Not the increase in entropy.

Go Back to Quora Question Review
Back to my home page Index