18#,Xly: Thumbs up, the theory of parallel universes is indeed a good solution to the problem of space-time paradox, but in fact, it is not an exaggeration to say that this theory is "sophistry", it is the result of human imagination, think about it, just use an illusory theory to successfully solve the problem that has plagued the proponents of space-time theory for a long time, isn't it great?

However, there is a fatal loophole in the theory of parallel universes! In the theory of parallel universes, the large universe has an infinite number of parallel universes, which means that no matter how small the probability of an event happening, as long as it conforms to the rules of the universe, it is possible to happen in one of the parallel universes.

Suppose we set a scale for the level of development of science and technology, and make the most developed civilization in the galaxy the "top", then the probability of a civilization developing to the top is 1 in a trillion, and the probability that this top civilization will master the technology of traveling through different universes is 1 in a trillion, and the probability that the exit of this civilization that has traveled through the universe is just in front of your computer is even more small, although the probability is extremely small, but in general it is still possible.

Since there are countless parallel universes, there will always be a universe that will produce a civilization with this kind of technology and appear in front of you.

But in fact, we don't see any civilization coming out of the computer, so we can prove that parallel universes do not exist, and even if they exist, they must not be infinite. Or, the technology that travels through parallel universes itself violates the rules of the universe and should not exist.

To sum up, the possibility that the landlord is from a parallel universe is theoretically almost zero.

19#, thumbs up: crooked! crooked! crooked!!

20#, 10,000 years at a glance: I don't know if the landlord is from a parallel universe. Perhaps, as Xly on the eighteenth floor says, the odds are so small that they are almost non-existent. But I know it. The landlord will definitely not come from the future!

21#, thumbs up: The twentieth floor is so sure of what is it. Ask for advice! Ask for advice! Ask for advice!!

22#, 10,000 years at a glance: the reason is very simple, because entropy increases!

23#, thumbs up: It seems to make a lot of sense.

24#, 10,000 years: The first law of thermodynamics is the law of conservation of energy, which tells us that all energy is conserved in the process of transfer and transformation, while the second law of thermodynamics tells us that heat cannot be transferred from a cold object to a high temperature object without other changes, in other words. That is, in a system, the system always develops in the direction of increasing entropy, which is an irreversible process!

……

Entropy, which refers to the state function of a system, indicates the degree of chaos in the system.

The second law of thermodynamics says that the entropy of an isolated system will only increase, not decrease, in other words, the system will only develop in the direction of increasing complexity and chaos, it will be like a ball of flour being thrown into a closed room. Once it is thrown away, it will only become chaotic and disorderly, which is a process of entropy increase. You can't get the flour that has been thrown out and become messy to retract back into your hands, which means that entropy reduction is unachievable.

Any object in the world has an entropy value. A cup, which has entropy, a broken cup. It also has an entropy value if you break an intact cup. Then the entropy of the broken cup is greater than that before it was not broken. This is because a broken cup is more messy than a cup that isn't.

The same. Since the entropy of an isolated system only increases, not decreases, it is impossible for the cup to spontaneously return from a broken state to a full state. The law of entropy increase, which clarifies the directionality of time from a timeline perspective, has irreversible properties.

Of course, it should be noted here that the law of entropy increase refers to an isolated system, if you artificially re-glue the broken cup back, then the additional energy is provided from outside the system, although the phenomenon of entropy reduction is achieved locally, it can stand on a larger scale, and it is still a process of entropy increase.

32#, 10,000 years at a glance: The landlord said that he came from 2030, that is to say, the time of the entire universe has been turned back, which means that countless stars and countless particles in the entire universe have all entered the process of entropy reduction, which is simply incredible, if the entire universe is an isolated system, then if you want to make it entropy reduction, where to get such a huge amount of energy?

A local entropy reduction will inevitably require a larger entropy increase! Here a question arises, our universe is too big, so where does the greater energy come from?

……

After a glance at Wannian's words, the entire forum seemed to digest his point of view, and was silent for a while.

Su Yuan in front of the computer also fell into contemplation, yes, if the entropy of this world will only increase, as Wan Nian said, then the moment before he traveled through time and space, and the moment he crossed into this world, wouldn't it be from more chaotic to relatively chaotic, which is a process of entropy reduction in essence?

As we all know, refrigerators can be refrigerated, and some low-temperature refrigerators can even reduce the internal temperature to minus 80 degrees Celsius or even lower. If the temperature is compared to the entropy value, then the entropy value inside the refrigerator is undoubtedly reduced, but it should also be noted that in the process of cooling the refrigerator, the heat is actually not dissipated, but discharged from the inside to the outside, and at the same time, in the process of exhaustion, electric energy is also needed to drive the compressor to do work, in a larger system, the heat is not reduced, but because the electrical energy is converted into heat energy, the total heat energy is increased.

So Su Yuan was also thinking that whether he was going back in time through [backtracking] or a time machine, it was actually a process of local entropy reduction, and according to the law of entropy increase, there must be greater "chaos" in the overall system.

The problem is that the boundary line of the world has jumped, and the value of the boundary line is a mathematical quantity that represents the entire world and the entire universe, that is to say, the time goes back, and the scope covers the entire universe.

So what is the force that drives the entropy of the universe down? At least in the face of this force, even the entire universe is just a relatively small isolated system.

What a majestic and great existence this must be!

For several days, the posts in this science and technology forum have remained silent, and there will be a few more meaningful speeches every day, but it always feels as difficult as squeezing toothpaste for Su Yuan. On the other hand, Alayer's posts on other forums show that some buildings have been flooded to hundreds or nearly 1,000 floors.

But no matter how hot it is over there. Su Yuan wasn't too interested, she urgently needed an answer now. As well as fishing out the owner of the diary, as for whether the fire on the floor is hot, it is really not what interests her.

This went on for several days, until the morning of December 24, when a post appeared:

68#, Rootless Duckweed: Is it difficult to understand the local entropy reduction? The jump in the boundary of the world means that the whole universe has become a "local" isolated system of local entropy reduction, although it is large enough, but you must know that the universe is finite and boundless. The meaning of this sentence tells us that although our universe has no boundaries, it is actually a finite individual.

The universe is not a simple three-dimensional space, it is a more complex "curved world", if a person walks in a straight line, it will never reach the edge of the universe, on the contrary, it will inexplicably come to its starting point from the opposite direction. Because in a three-dimensional perspective, you think you're walking in a straight line. But in fact, you are moving in a curved movement along with the space.

So, we don't know how big a space our universe is huddled in.

So, why can't it become a local isolated system in entropy reduction? As long as there is a larger system that provides energy to it, the phenomenon of entropy reduction can be produced!

With the sudden speech of the rootless duckweed. The whole forum came alive all at once. The question is, what kind of existence can provide the majestic energy that pushes the entire universe backwards? It's an incredible thing to think about.

Su Yuan glanced at Su Caiwei with interest. He said: "Mom, there is a premise for the statement of rootless duckweed. That is, the system to achieve entropy reduction must be an isolated system, and it must not have material communication with the outside world in the time span of time rewinding......"

Take the Milky Way, for example. If there is no intergalactic exchange between the Milky Way and other galaxies in the intergalactic belt for 100 million years, then theoretically, as long as there is a technique to turn back time and enough energy, the isolated system of the Milky Way can be turned back by 100 million years.

But if the Milky Way is constantly communicating with other galaxies, for example, the Milky Way's strong gravitational pull has been swallowing up a nearby satellite galaxy, or if there are always wandering stars in the Milky Way that break free from its constraints and fly towards the depths of the universe, then the Milky Way cannot turn back time.

Because you can't let things that are already in or out of the system disappear or pull back for no reason.

Su Caiwei nodded knowingly, "Listening to his tone, it seems to be sure that the universe is a closed individual." ”

78#, White Rabbit: So what kind of existence is providing the energy that pushes the entire universe backwards?

Su Yuan asked secretly with the help of Alayya's ability.

Rootless duckweed replied quickly, and his answer was only four words.

79#, rootless duckweed: the long river of time!

"Time is long, what does this mean?" Su Yuan looked at the computer screen in confusion, and was about to tap the keyboard to ask the confusion in his heart, but someone had already asked this question before her.

80#, thumbs up: What's the long river of time?

81#, 10,000 years at a glance: Yes, what is the long river of time?

82#, rootless duckweed: The long river of time is the endless past and the endless future, plus the river of time composed of the present being deduced, in the long river of time, space, matter, and energy are all "light and specific" things, they can exist in the long river of time, but they can never become the protagonist, or even insignificant existence!

The long river of time is always a large collection of timelines, whether complete or disordered, countless timelines exist in the long river of time, and the spatial fragments, material fragments, and energy fragments that depend on the existence of the timeline also have a reason to exist in the long river of time.

Rootless duckweed: The long river of time is so mysterious, and the universe of any time period there is a real universe, that is, if we can separate a part of the energy from the long river of time and apply it to the universe where we are, why is it difficult for it to reduce its entropy?

If we want to turn back our universe by one day, we only need to draw the timeline of one day, and if we go back a year, we can draw the timeline of one year, and as long as we find the right way to borrow energy from the long river of time, the whole process is as easy as drawing.

Our universe is just a drop in the ocean compared to the long river of time. (To be continued......)