As I thought, there is somebody who believes that the arrow of time is not a consequence of the second law of thermodynamics, but it is exactly the opposite:

https://www.amazon.it/Now-Physics-Time-Richard-Muller/dp/0393285235

In my opinion, time comes first and thermodynamics later. In the standard big bang model both come simultaneously. But I tend to think that after the unification of electromagnetic force and the weak force, photon or light cannot exist independently. All our thermodynamics is based on property of light. In my theory it happens around 10^(-21) sec. after big bang. So between Planck time and electroweak epoch, one cannot talk about heat transfer or entropy. Time in my theory is a period between two events like the period of a wave which begins at the Planck time 10^(-43) sec. Before this time one cannot talk about time because the particle collapse when it gains energy more than the planck energy. Particle crosses the limit of the Compton wavelength.

https://www.researchgate.net/post/Can_electroweak_force_transfer_heat

Dear Vikram, thanks for your skillful response!

I will read with interest your post.

What is time? While answers abound for this question, many physicists and philosophers continue to work on it tirelessly. Our common experience leads us to think of time as flowing forward, but the equations that describe our physical universe do not require that time move forward.

There are, however, indications of a preferred direction based on thermodynamic considerations. Recently two scientists published a paper that describes the criteria for a memory model and an argument that “the psychological arrow of time (memory) should align with the thermodynamic arrow of time (entropy) where the arrow is well defined.”

Time is a dimension (or coordinate) and a measure that helps us order events. Time is also used to describe the duration of events and the intervals between events. Some philosophers of science believe that time is independent of the events, and events occur sequentially through time, as if the events flow through time.

Other philosophers believe that only the present is real (presentists) or, conversely, that all events, past present and future, are equally real (eternalists). There are many different philosophical and scientific views of time.

Without doubt, time is important to us. Our modern, global world demands precise and consistent measures of time, and the best clocks are ones that have some periodicity (an event that occurs at regular intervals).

We began with clocks based on the Earth rotating about its own axis such as sundials. We devised time durations based on Earth’s rotation about the Sun and the Moon rotating about Earth. There have been clocks built based on pendula, and oscillations of quartz crystals.

One of the most recent clocks created at the National Institute of Standards and Technology is the NIST-F2 atomic clock that is so precisely periodic that this clock will neither gain nor lose a second within 300 million years

It should be noted that statement "between Planck time and electroweak epoch, one cannot talk about heat transfer or entropy" makes sense only for the entropy in the classical thermodynamic sense. And statement "the particle collapse when it gains energy more than the planck energy. Particle crosses the limit of the Compton wavelength" implies a point of view on the particles as independent from space-time structures that near the singularity under consideration (point at the arrow of time after which we can speak of our universe as an entity), most likely, is not fair enough.

In this sense, the first part of the sentence "Before this time one cannot talk about time" is true, to what can be added: one cannot talk about particles as well as one cannot talk about our space-time continuum.

But we can talk about the information always, even before the singularity under consideration. Accordingly, we can talk of entropy.

Entropy viewed in the slice of certain physical processes is not sufficiently informative value. "This is because the traditional notion is based on partitioning of a system into independent parts (which allows summation over local entropy)" (as rightly recently noticed by our colleague Maria Koleva in another discussion).

Incidentally, even from this (in the causality context) follows that the time is primary (preceding) to the arrow of thermodynamics (as isolated branch of physics). From what does not follow that thermodynamics does not affect the time.

A very interesting discussion! thanks to both for your insights!

Therefore, you think that time preceeds the arrow of thermodynamics.  This is an inmportant statement.  Thanks again!

 @ Vasiliy Fedorovich Komarov

"a point of view on the particles as independent from space-time structures that near the singularity under consideration (point at the arrow of time after which we can speak of our universe as an entity), most likely, is not fair enough."

My earlier post is with respect to a quantum gravity theory (given below) in which concept of space time of general relativity is treated as imaginary concept not a physical concept. The physical reality is based on wave lengths and periods of the wave particle duality. Therefore time as a period of the wave does not have any arrow but the imaginary linear time of general relativity does have an arrow. Because time is strictly periodic in nature therefore one can never build a time measuring device without an oscillator. Secondly in Periodic quantum gravity and cosmology (PQG), there is no geometrical singularity as in general relativity. So before planck time we can neither talk about space time nor the entropy but the singularity in PQG is defined in a different way which is perfectly motionless without any mass gap and therefore doesnot carry any information either.

Another point is that the equations of standard model of big bang are not reversible because they are in bits and pieces where as the equations of PQG are reversible. So when the universe expands the arrow of entropy is in forward direction and when the universe contracts, the direction of arrow is reversed.

Article Periodic quantum gravity and cosmology

Arrow of time is a scientific fiction. Firstly, time as an entity has to exist and no one can define what it is without reference to changing objects which change at different relative rates in different conditions (gravity,speed).

The natural occurrence of any process is a product of many physical processes. Entropy characterizes the behaviour of sets of molecules. Positive entropy reflects the naturally observed direction of thermodynamic processes and calling entropy the arrow of time is tautology. People think entropy exists but it is a mathematical function of state. The way states change determines entropy not the other way round. It is like saying that the lung cancer is caused by yellow teeth not by smoking. It is a mistake to take an indicator as a cause. Can economical indicators cause economic crisis or the processes affecting economy affect indicators?

The seemingly reversible Newtonian mechanics is also a good arrow of time. The Earth is orbiting the Sun in a particular direction and it is highly unlikely it will ever turn around. This is a better arrow of time as the calendar is based on this unidirectional circulation governed by seemingly time reversible equations.

Dear Vikram Zaveri, I dare to disagree with you regard to quantum gravity and the relationship to the particles. You and I are only talking about concepts (models) in which different axiomatic basis, not about reality.

"motionless" means a privileged frame of reference, it can not help you to answer my three favorite philosophical question, alas. Any model built based on this assumption will have uncertainty, which does not allow to state unequivocally the periodicity of everything in nature (this is not refutable and not provable within the model, if one of the axioms is like your, where two scenarios for evolution, at least). Even if you drop it (what allows to send the creationist challenge to the background), from a mathematical point of view it makes sense to talk about the potential periodicity only. It is epistemologically correct.

By the way, you can not oppose anything to my assertion that in an open system (you also generally can do nothing counter hypothesis of openess) I can always choose another subsystem, potential period of which exceeds the periodicity of any processes which currently under consideration.

I have a different axiomatic basis and view on the singularity and the arrow of time, respectively, I will not argue about it.

The world is more materialized for you, information/energy and dynamics of processes is primary for me. I must note, not only "mass" contains and transports information. Accordingly, I do not care about "mass gap", it is not a priority of interest. The information contains in any connected sequence of changes of anything. My statement concerning the entropy for me remains valid (dear Andrew Wutke), because I'm talking about information, and entropy is only a functional relation between the observer/model and rest of information, of course.

Entropy: A concept that is not a physical quantity

https://www.researchgate.net/publication/230554936_Entropy_A_concept_that_is_not_a_physical_quantity

This seems to be a religious question. According to Maimonides, who questioned the assumption of Aristotelian eternal matter, time was injected into thermodynamic space. In this physical understanding (of created matter), thermodynamics is first and not in need of time as variable; from this follows, that light and time are interconnected for biological clocks, which appeared or evolved in thermodynamic space. To better explore your question, the deeper interplay between thermodynamics and chronobiology has to be investigated or an alternative road would be astrobiology. Our species lives in a temporal gap of the thermodynamic universe by generational pro-creation.