There are many processes in our lives that are irreversible. For example, the water can't be collected when it is spoiled on the floor, this process is irreversible. It is not absolutely impossible for you to withdraw water, but you have to do a lot of work. For another example, after the bomb explode, you couldn't get the shrapnel back together and return to the state before. So these processes are irreversible. Entropy is a measure of these irreversible course.
If there are two cups A and B, A is filled with solution containing ingredients such as protein, sugar, fat, mineral salts, etc. There is a fish in B, and the water around the fish is pure water. Assume that the content of protein, sugar, fat, mineral salt, etc. in the fish's body is equal to that in solution of A, that is, if the two cups A and B are filled with exactly the same ingredients, what is the difference? The structure is different. The structure in A is symmetrical, the various components are evenly distributed in the cup, B is in symmetry broken, the structure of A is relatively simple, and the structure of B is very complicated. After the death of a living organism, the organ tissue in the body will rot and decompose, which is equivalent to changing from B to A. This is a kind of degradation, changes from a complex structure to a simple structure. The changes from simple to complex are evolution.
The second law of thermodynamics tells us that in an isolated system, no change can reduce the total value of entropy. In other words, the world can only degenerate and cannot evolve. From this theorem, it can be inferred that the universe is inevitably going to heat death. However, the fact we see is the evolution of the world. In the course of biological evolution, biology has evolved from a simple single cell to a variety of complex and diverse organisms. The non-living and human society also has a evolutionary process.
In fact, at the beginning of the universe, the state after the Big Bang was a state of heat death. Today's Universe is a result that comes step-by-step out of heat death and a result of constant entropy reduction. Clausius said that when the universe enters a state of heat death, no further change will occur. At this time, the universe will enter a state of eternal death. But in fact, the universe easily walked out of heat death and did not introduce any negative entropy from outside. Not only has the universe created its own negative entropy, but it has also been able to produce new particles. It has continuously created new symmetry broken of matter and energy, and the structure of the universe has become increasingly complex.
Hawking's explanation is that the entropy reduction comes from outside the system and cannot come from inside. But if this is the case, then the universe as a system can only increase the entropy, it is impossible to reduce the entropy, and the universe must move toward the most balanced state. If you say that in some places entropy decreases, while in some other places, the entropy increases, but after the Big Bang, the universe has been reached the maximum entropy, it is completely uniform, and how can it increase.
If there is a container, which is divided into two parts, A and B. There are some hot gases on the left and some low temperature gases with the same composition on the right. After a while, the high-temperature gas transfers heat to the low-temperature gas, and the temperature on the two sides tend to be the same. This change belongs to the increase of entropy, which is consistent with the second law of thermodynamics. Heat transfer from a low temperature object to a high temperature object is an entropy reduction. How can this system reduce entropy?
In order to solve this problem, Maxwell invented a goblin called Maxwell demon. He said that this little goblin is very clever, it can track the whereabouts of each molecule, and can identify their respective speed. Molecules in an air-filled container with a uniform temperature have non-uniform rate of motion, but the average velocity of molecules is uniform. Now suppose there is a small hole in the container boundary, and then imagine that Maxwell's demon can open or close that hole so that fast molecules run from A to B, while slow molecules run from B to A. In this way, without power consumption, the temperature of B increases, the temperature of A decreases, and there is a contradiction with the second law of thermodynamics. So symmetry breaking occurs, and as the entropy decreases, the world can evolve now.
Is Maxwell's demon the real cause of the evolution of the world? Impossible, because it consumes external information even if it does not consume energy when it creates non-equilibrium. The speed of movement of molecules is a kind of information. So it is still a worldwide puzzle to explain the evolution of the world.
So is there a Maxwell demon that does not consume energy and foreign information? Although the asymmetry of energy is not likely to occur spontaneously, the asymmetry of matter may occur spontaneously. Boltzmann tells us that the essence of energy symmetry is that the structure of matter tends to be symmetrical.
If there are two small balls A and B in two adjacent boxes and the partition in the middle of the box is removed, the symmetrical state has two possible distributions, one is A on the left with B on the right, the second is B on the left with A on the right. There is only one distribution of the two balls on the left or right side together, which is a state of symmetry broken. Therefore, the probability of occurrence of a symmetric state is large, and the probability of a symmetry broken state is small. Boltzmann defines the logarithm of this probability as entropy.
In the example above, if there are two balls in the box, they may be on one side, or they may be evenly distributed on both sides. The possibility of even distribution is big, and the possibility of being on one side is small. However, if we assume that there is an oxygen atom on each side of the box, they will certainly not be on two side and they will soon be combined into one oxygen molecule. In other words, the state with the highest probability we said is not the stable state, and the state of symmetry broken is the stable state. The state of low probability appears spontaneously, that is, the entropy decreases sponta- neously. The emergence of such symmetry broken does not consume energy nor consume external information, ie, no external input of negative entropy is required. This is a spontaneous entropy reduction process.
Who undermines the second theorem of thermodynamics? It is chemical bond. The chemical bond is a Maxwell demon, which can distinguish different atoms, the chemical bonds of oxygen atoms can recognize other oxygen atoms, and also can recognize hydrogen atoms, iron atoms, and so on. The recognize means that it contains information and negative entropy, but it is not input from outside the system and there is no intelligence.
There is no electromagnetic force between the gas molecules, so they tend to balance the structure. However, liquids and solids are different. The water molecules is polar. Other liquids and solids also rely on electro- magnetic forces to bring molecules together. When the temperature is high enough, the molecules will break free and become gas. When you put a few molecules of liquid water in a box, they don't spread evenly up and down spontaneously. That is, the number of micro states in the equilibrium state is zero, and the system will always maintain the symmetry broken state.
A famous scholar believes that the small balls mentioned in Maxwell's thought experiment refer to gas molecules and cannot refer to other molecules, and there is no electromagnetic force between them. However, I think that if we only consider gas molecules, then Maxwell's ideological experiment is not universal, so its conclu- sions cannot be generalized to the entire universe, and it cannot be used as a basis for discussing the theory of heat death in the universe. If we are going to discuss the problems of the entire universe, then the objects we think of in the ideological experiments should be universal, capable of representing any substance, and possibly having various attributes of matter.
Chemical bonds are electromagnetic forces. In addition to it, gravitation, strong nuclear force, and weak nuclear force can also destroy the second theorem of thermodynamics. They are all Maxwell demon. We can divide the space around the Earth into grids, the earth occupies one of the grids. The Earth is made up of many substance. These substance are not evenly distributed in these grids, but concentrate together. From the view of entropy reduction, the existence probability of this state is almost zero. What is the power to increase its probability of existence from zero to 100%? It is gravitation.
Theorem: Gravitation, electromagnetic force, strong nuclear force and weak nuclear force are the dynamics of the world's evolution toward complex and unbalanced directions.
Graph 2: Earth's constituent is not evenly distributed in space
The second Theorem of thermodynamics points out the inevitability of the degradation of the world. The Boltzmann principle points out the reason of the world's degradation, and the theorem now proposed points out the inevitability and the reason of evolution of the world. With this theorem, we can see that the entropy reduction can come not only from the outside of the system, but also from inside, and the second theorem of thermodynamics will not take the world to heat death.
Each substance has many attributes, including these four forces, and many other attributes that will affect the results of system movement and interaction more or less, prompting the emergence of complex, unbalanced systems. The chemical properties of the material, abiotic radiation, luminescence, conservation of kinetic energy, quantum mechanical properties, and all other physical properties, biological properties such as growth, metabolism, regeneration, phototaxis, reproduction, and mutation can be the driving force for the evolution of the world towards complex, non-equilibrium directions, as they all can bring about a stable symmetry broken.
Like all biological characters that can be the driving force of evolution, intelligence is also a biological character, and it has become the most important driving force for the creation of complexity and order.
Theorem: The various properties of matter may be the driving force for the evolution of the world towards complex and unbalanced directions.
In fact, everybody knows that even if the world is really going to die, it will be a matter of billions, or even trillions of years, and few people really care about it. The crux of the problem lies in the fact that if the global degenerative trend is universal, it will also dominate many things in our daily lives. Will our society become more and more chaotic, will humanity moral become more and more degenerate, will science and technology continue to develop, and will modern human civilization lead us into the abyss? With these two previous theorems, we can believe that the world has both spontaneous degenerative and evolutionary trends, and degradation is not the fate of the world.