Our universe is a wonderful existence. From the sun, moon and stars in the sky, to the flowers and trees on the ground, insects, fish, birds and beasts, including everything created by human civilization, together constitute this colorful world. From the macro to the micro, everything is exceptionally delicate and beautiful, and everything is running in an orderly manner.
But this beauty will eventually turn into nothingness, because the universe operates according to a fundamental law: everything will move from order to chaos, unless there is an influence of external energy. In other words, the "entropy" of the entire universe is always increasing. "Entropy" is a term in thermodynamics, and it represents the degree of chaos of things. That is, the entire universe will become more and more chaotic until it is finally in a state of thermal equilibrium. And this process is a process of orderly to disorderly diffusion. In the martial arts novels we are familiar with, there is a martial arts secret book, which opens with two sentences, but it can explain this truth very well, these two sentences are: "The way of heaven, the damage is more than enough to make up for the deficiency." Therefore, the false is better than the real, and the lack is more than enough. "Surplus" is order, and "insufficient" is chaos, which shows that the process of transforming orderly energy into disordered energy is similar.
To understand how "entropy" is increasing, let's look at the following phenomena.
The sun will not shine forever, and billions of years from now, when the fuel is exhausted, the sun will become a Death Star; life will not exist forever, whether it is animals or plants, they will eventually die and turn into disorderly dust; without human maintenance, the cities built by humans will eventually collapse and become a ruin; a broken cup will not automatically return to its original state; and the water that is spilled will be difficult to recover from the basin. All of this reflects what the entire universe is doing: destroying order, gradually turning it into a disordered state of chaos, which are some good examples.
So why is the universe we see now so beautiful and orderly? That's because there was more order in the universe before that. The output of energy from other systems, or ordered output, can maintain order in another system.
For example, a person re-pasting a shredded map consumes a person's calories in the process. Although the map is pasted, people consume a lot of organic matter to generate energy to complete this thing, which creates more disorder. Overall, disorder has increased.
The reason why our earth is thriving, animals and plants continue to survive and reproduce, that is because they absorb the energy of the sun, plants rely on photosynthesis to convert inorganic molecules into organic molecules containing energy, and animals rely on these organic foods to survive. The source of energy for their survival is the sun. The sun is constantly consuming its own hydrogen energy, transforming order into disorder before it can release energy into space. Among them, the earth receives only a very small amount of energy to maintain its own beauty. Overall, disorder has still increased.
With the help of human power or mechanical power, human beings have built roads and bridges, afforested and cultivated fields, and built an orderly and brilliant human civilization, which also depends on the energy of the sun. Man's own energy comes from food, organic energy molecules such as ordered proteins in food come from photosynthesis; mechanical energy comes from oil, electricity, oil comes from the orderly combination of organic molecules in animal and plant remains, electricity comes from coal, water, wind or solar energy, and all of this ultimately comes from the sun.
The sun is our source of energy, and without it, everything on Earth would quickly turn into chaos. The sun's energy, on the other hand, is fundamentally a highly "ordered": the aggregation of hydrogen produces a nuclear reaction that releases the energy. The aggregation of hydrogen is a highly ordered existence.
From the cosmic point of view, all isolated systems are constantly changing from order to disorder, which is what the second law of thermodynamics tells us. The universe itself, as the largest isolated system, is constantly moving from order to chaos, which is exactly what is happening in the universe, and all the movements of the universe can be summed up as such. Chaos is the ultimate destination of the universe.