Entropy & Time Reversal Symmetry: Breaking Symmetry?

[jimmy.neutron]

Does the ever increasing nature of entropy violate time reversal symmetry?

 

[Naty1]

Most, I think, believe it generally does. Yet "most" scientists have been repeatedly wrong over time..in other words, more often than not, the consensus has been proved wrong...from Ptolomy,Copernicus, Galileo, Newton, Einstein,Hubble, all upset widely held beliefs.

It is generally believed increasing entropy sets the direction of time. But in some respects entropy is not fully understood and time is certainly one of the most ambiguous, least understood, entities known. Hence many still disagree on the possibility of time travel, and if it's possible at all, might it be for both past and future. I don't think anyone knows how to relate entropy and time in a rigorous mathematical formulation.

Mathematical formulations generally don't break time's symmetry. +t and -t seem allowed. After Claude Shannon's information based formulation of entropy, it was realized perhaps information offers a more general insight: nature tries to dissipate information just as it tries to increase entropy,an alternative view setting a possibly fixed direction of time..
In DECODING THE UNIVERSE, Charles Seife discusses these entropy/information concepts for about 20 pages or so.

 

[sir-pinski]

Entropy is a measure of the disorder or randomness in a system. It is often associated with the concept of time, as it is commonly observed that systems tend to become more disordered over time. This raises the question of whether the ever-increasing nature of entropy violates time reversal symmetry.

Time reversal symmetry refers to the idea that the laws of physics should be the same in both forward and backward directions of time. In other words, if we were to reverse the direction of time, the physical processes and interactions between particles should still follow the same rules. This symmetry is a fundamental principle in physics and is supported by many experimental observations.

So, does the increase in entropy violate time reversal symmetry? The answer is no. The increase in entropy over time is a result of the second law of thermodynamics, which states that the total entropy of a closed system will always increase or remain constant. This law is not violated when we reverse the direction of time. In fact, if we were to reverse the direction of time, the second law of thermodynamics would still hold true, and entropy would continue to increase.

The concept of time reversal symmetry is more relevant at the microscopic level, where the laws of physics are governed by quantum mechanics. In this realm, there are some processes that are not time-reversible, such as radioactive decay. However, these processes do not violate time reversal symmetry, as they still follow the laws of physics in both the forward and backward directions of time.

In summary, the increase in entropy does not violate time reversal symmetry. The second law of thermodynamics, which dictates the increase of entropy over time, is still valid regardless of the direction of time. Time reversal symmetry remains a fundamental principle in physics and is not broken by the concept of entropy.