Dear Ankur,

in the surface layer, where phenomena and social activities are taking place, entropy is created. Entropy continues increasing on Earth, but we never reach a thermal death, since Earth receives heat and light from the sun constituting an open system that discharges heat into space. Such an open system maintains a non-equilibrium stationary state by taking negative entropy from the environment and, at the same time, throwing the generated entropy into the environment (by environment we mean the one extended from Earth’s surface to the upper atmosphere). Since it throws entropy to space it constitutes a non-equilibrium stationary open system as well. Circulation is also important in the maintenance of Earth environment. Generally there are two kinds of stationary open systems. One is a system where a simple diffusion process takes place in. Examples for this type are flows of falling down water, electric conduction and heat conduction. The system is locally almost equilibrium and entropy does not increase any more. Such system is not related to life.

Another one is a system where a circulation exists and it is related to life. In fact life consists of various circulations. While maintaining a stationary open system on Earth, circulation plays an important role. Three types of circulations are worthwhile to be mentioned: the one of the atmosphere itself, the one of water and the one of living creatures.

How does Earth maintains its stationary open system? First of all, it exists an atmosphere kept by gravity linked to the surface of Earth wherein the circulations of atmosphere and water take place constantly by convection. The extra entropy is carried upward in the atmosphere by the convection of air together with thermal energy against gravity. Earth throws heat entropy to space as well. Water circulation is responsible for such processes. Heat entropy on the ground is absorbed by the water evaporation. The water vapour rises to the upper layer of the atmosphere because it is lighter than air. Then heat is radiated to space together with entropy and the water returns back to the ground (rain, snow…).

On the other hand, matter entropy by living organisms of Earth is transformed into carbon dioxide and water, through decomposition. These are reused for photosynthesis. Finally, the generated entropy of the abolition heat is radiated from clouds in the atmosphere to space as infrared rays by water circulation and by the mechanism of entropy emission from the Earth.

Among the solar energy that reaches Earth, the thermal energy Q that remains on Earth surface is, on average, approximately 77 kcal at one square cm per year. Considering an average temperature on the earth surface at about 288 K, the entropy received by Earth from the Sun at one square cm per year is 267 cal/K. On the other hand, the residual heat is thrown away to space under an infrared ray form. Considering the temperature in the upper layer of the atmosphere at, say, 243 K, the entropy discharged out of the Earth sphere is 316 cal/K.

Thus, the net entropy thrown by Earth at 1 square cm per year is about 49 cal/K through water cycle and convection in the atmosphere. In this way Earth maintains a low entropy level. However, burning fossil fuels, the atmosphere cannot throw the excess of entropy by water circulation and convection and, thus, entropy can increase in the Earth environment.

Mr. Towe.... The balance of net entropy may change, changing heat entropy at the ground and the thermal energy that remains on Earth surface. Changing in water circulation and convection also gives a change in the net entropy thrown by Earth, changing the amount of extra entropy which is carried upward in the atmosphere by convection. Processes are linked and we cannot consider a cooling or a warming of the Earth surface by itself.

Mr. Towe ... In this question/answer I have discussed about the processes which need to take place to mantain a low entropy level in a setting that does not violate the second law of thermodynamics. These processes need to perform physical and chemical work in order to create gradients to keep global cycling of matter going. Processes can be viewed into those that continuously perform work and create free energy, and the irreversible ones that dissipate it and continuously produce entropy. Fossile fuels burning (but not only) is simply in this second class.

I do understand that you may be more interested in the climate change debate and about the anthropogenic climate drivers, but I have not discussed about this huge matter in my answers whatever I think about climate change itself.

Best regards.

thanks guys for your time and effort..

the point where i am coming from when every process on earth is cyclic then how come entropy is anomaly.

according to milkowitch cycles.. earth tilt changes and been the reason for the destruction of past civilizations.

i need your help in establishing the fact that after maximum disorder/entropy with gravity in existence.. the entropy will either start reducing or reset to lowest level.

thanks

@Ankur,

I’ll try to point out some elements about links among gravity, thermodynamics and climate. You know that the second law of thermodynamics states that in any cyclic process the entropy will either increase or remain the same and entropy is a measure of disorder or multiplicity of a system, or the amount of energy unavailable to do work. For an isolated system, the natural course of events takes it to a more disordered and higher entropic state. Gravity, on the other hand, knows attraction only and thus tends to keep the things in an orderly state by keeping them close to one another and thus reducing the volume occupied as well as the possibilities of the possible states. Do gravity and entropy complement each other? Is gravity an entropic force and a consequence of physical systems tendency to increase the entropy? Remember that an entropic force in a system is a force that results from the entire system thermodynamic tendency to increase its entropy. In statistical mechanics, entropic force is an effective macroscopic force that originates in a system with many degrees of freedom by the statistical tendency to increase its entropy. Gravity tries to keep things together through attraction and thus tends to lower statistical entropy. The 2nd law of thermodynamics states that the entropy of an isolated system which is not in equilibrium will tend to increase with time, approaching a maximum value at equilibrium. At equilibrium, entropy change is zero.

It has been recognized that there are profound connections between gravity and thermodynamics It has been shown that the entropy can be taken as the Noether charge associated with the diffeomorphism invariance of the theory. Other authors have shown that the Einstein equation can be derived from the first law of thermodynamics. There are fundamental relationships between general relativity and ordinary thermodynamics. The equations of motion for modified gravity theories are equivalent to the Clausius relation in thermodynamics. It can also be argued that the Einstein–Hilbert action can be constructed by minimizing the free energy. Gravity has also been explained as an entropic force caused by changes in the information associated with the positions of material bodies. In the case of nonzero chemical potential the changes of temperature, entropy, particles, and chemical potential will result in gravitational force, or gravitational force will induce changes of temperature, entropy, particles, and chemical potential. For Newtonian approximation, the gravitational potential is related to the temperature, entropy, chemical potential, and particle number, which implies that gravity is entropic force only for systems with constant temperature and zero chemical potential. For general case, gravity is not an entropic force. Back to Newtonian fluids, consider a fluid system in a Benard cell. In this system, fluid is heated at the bottom and cooled at the top, and the resultant expansion and contraction lead to a density distribution that is gravitationally unstable. The potential energy in this distribution is generated by the differential heating and results from the conversion of the heat energy into the mechanical energy. When the temperature difference becomes larger than a certain critical value, the fluid is no longer stable against small perturbations, and convective motions tend to develop. This critical condition is related to the Rayleigh number. Once convection starts, the dynamic equation and conservation equations that govern the dynamics of the system become nonlinear. The fluid motion itself transports the heat energy, and thereby the total heat flux increases. The generated potential energy in this case is converted into the kinetic energy of the fluid and then dissipated into heat energy by viscous dissipation. The conversion process is related to the nonlinear dynamic equation. However, when the system can be seen to be in a steady state in a statistical sense, the generation rate of the potential energy has to be balanced by the viscous dissipation rate, so long as no part of the kinetic energy is stored in the system. Then, the inflow rate of heat should be equal to the outflow rate. Our climate system is a heat engine, absorbing solar radiation at a mean input temperature and emitting terrestrial radiation at a lower, mean output temperature. These mean temperatures, defined as the ratio of the energy to entropy input or output, determine the Carnot efficiency of the system. The climate system, however, does no external work, and hence its work efficiency is zero. The system does produce entropy and exports it to space. The climate system becomes less efficient, more irreversible, and features higher entropy production as it becomes warmer and changes in the intensity of the latent heat fluxes are the dominating ingredients.

Hence, we can say that the second law of thermodynamics is a fundamental principle for which there is no corresponding conservation law. Earth’s radiation exchange with space drives and maintains almost all the processes within the Earth system. The long-term mean exchange of incoming solar radiation and outgoing longwave radiation are the same, but the associated entropy fluxes are different. The outgoing entropy associated with longwave radiation is about 22 times larger than the incoming entropy associated with solar radiation resulting in a negative net entropy flux. This provides a measure of the overall activities within the Earth system including oceanic, atmospheric, and biological processes. Applying the maximum entropy production principle to turbulent fluid systems since it is a nonlinear system and tested on the climate system, accurate predictions of the long-term mean of the present global climate are found, but it does not prove that the Earth’s climate system transports heat to achieve a state of maximum entropy production. However, this hypothesis has shown consistency on several types of turbulent fluid systems in nature such as the Rayleigh-Benard convection and shear turbulence. Lorenz suggested that the Earth’s atmosphere operates in a way to generate available potential energy at a maximum possible rate. The available potential energy is defined as the maximum possible amount of potential energy available for kinetic energy. There was a discrepancy in his results, as he did not account for direct waste of energy by the irreversible process of latent heat transport. However, it has been shown that Lorenz’s hypothesis of maximum generation of available potential energy is identical to the maximum entropy production hypothesis. Ozawa et. al qualitatively discussed a possible mechanism by which a turbulent fluid system self adjusts to a state of maximum generation of available potential energy. Entropy production of Earth’s climate involves many dynamic and thermodynamic processes, and the maximum entropy production principle may provide a general insight on the overall system.

You will find lot of articles about these arguments in several journals of atmospheric sciences, general physics, nonlinear processes among others. There you will find much more cues than in this my quite long post: this is a very large but intriguing subject.

The so-called "entropy " doesn't exist at all.

During the process of deriving the so-called entropy, in fact, ΔQ/T can not be turned into dQ/T. That is, the so-called "entropy " doesn't exist at all.

The so-called entropy was such a concept that was derived by mistake in history.

It is well known that calculus has a definition,

any theory should follow the same principle of calculus; thermodynamics, of course, is no exception, for there's no other calculus at all, this is common sense.

Based on the definition of calculus, we know:

to the definite integral ∫T f(T)dQ, only when Q=F(T), ∫T f(T)dQ=∫T f(T)dF(T) is meaningful.

As long as Q is not a single-valued function of T, namely, Q=F( T, X, …), then,

∫T f(T)dQ=∫T f(T)dF(T, X, …) is meaningless.

1) Now, on the one hand, we all know that Q is not a single-valued function of T, this alone is enough to determine that the definite integral ∫T f(T)dQ=∫T 1/TdQ is meaningless.

2) On the other hand, In fact, Q=f(P, V, T), then

∫T 1/TdQ = ∫T 1/Tdf(T, V, P)= ∫T dF(T, V, P) is certainly meaningless. ( in ∫T , T is subscript ).

We know that dQ/T is used for the definite integral ∫T 1/TdQ, while ∫T 1/TdQ is meaningless, so, ΔQ/T can not be turned into dQ/T at all.

that is, the so-called "entropy " doesn't exist at all.

Why did the wrong "entropy" appear ?

In summary , this was due to the following two reasons:

1) Physically, people didn't know Q=f(P, V, T).

2) Mathematically, people didn't know AΔB couldn‘t become AdB directely .

If people knew any one of them, the mistake of entropy would not happen in history.

Please read my paper and those answers of the questions related to my paper in my Projects.

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