After hearing this explanation, Xiao Yu suddenly figured it out, and Weishenme himself would feel familiar when he listened to this voice.

Because...... This is clearly the age of the earth, your own voice!

"I come from the future, I will be 500,000 years later, because I have done something stupid now......" Xiao Yu's thinking had a tendency to be a little rigid at this moment.

This incident was too unexpected. Xiao Yu was mentally prepared, no matter who this unknown existence said he was, he would not be surprised. But in the end, it surprised itself.

Xiao Yu's first reaction was disbelief. Based on the scientific foundation of Liang Haode, Xiao Yu clearly understands how unreliable time travel is. Not to mention the faster-than-light motion of the physical shijie, in addition to the almost cheating method of curvature navigation, Xiao Yu really doesn't know how to achieve faster-than-light motion.

The limits of the theory of relativity still firmly bind all matter in flat space, making it impossible for them to overcome the speed of light barrier. Moreover, even if it was true that the speed of light was reached from the flat space without sailing through curvature, Xiao Yu did not believe that he would really go back in time. The reason is simple, because there is a paradox in this.

Assuming that faster-than-light motion can really turn back time, does this time-lapse only happen to this faster-than-light moving matter, or does it happen within the entire universe? If it happens on the whole universe, there is one thing that is hard to imagine, that is, why can an extremely small object move faster than the speed of light affect the whole universe?

If it happened to this single matter, causing it to travel into the time and space that had already passed, then since the universe did not go back in time, what place would it have traveled through the past?

In this case, it seems that only the Multiverse can be used. Infinite space-time to explain, that is, the parallel universe theory that was quite popular in the age of the earth. The theory is that the number of universes is infinite and that any tiny error can lead to the birth of a new universe. For example, if a person gets up in the morning to go to work, and when he goes out, whether he steps out of his left foot or his right foot first, such a difference will lead to the birth of a universe. In a universe, the first thing he steps out of the house is his left foot. In another universe, the first thing he stepped out of the door was his right foot.

As we all know, the position of electrons is uncertain, so according to this theory, the movement of an electron will also lead to the creation of a large number of parallel universes all the time. In a universe. An electron appears at point A, in another universe. This electron appears at point B. There is only one difference between these two universes.

The parallel universe theory can perfectly solve the time paradox, but the parallel universe theory still has a fatal flaw, as long as a very simple logical thinking can overturn this theory.

In the parallel universe theory, there are an infinite number of parallel universes in the true universe. Infinite, this is an important concept. This means that no matter how unlikely it is, there must be a universe where it happens. For example, a person eats a coin while eating. The probability of this happening is calculated in 1 in 10,000, and then this coin happens to be handed down from ancient times to the present, and it is worth a lot of money, and this probability is calculated in 1 in a billion. If you calculate comprehensively, the probability that this person will eat a priceless coin for a meal is 1 in 10 trillion, which is quite small, but because the number of parallel universes is infinite, then it is certain that among the countless parallel universes, there must be a universe where such a thing will really happen, that is, in this universe, there is really a person who eats a meal and eats a priceless coin.

A very interesting inference can be made from this, that is, if the probability of a civilization developing to the top technology level is 1 in 10 trillion, and the probability of the top civilization mastering the technology of traveling through different universes is 1 in 100 trillion, and the exit position of this civilization that shuttles through the universe is exactly in front of your computer, and because of their arrival, the chance of smashing your computer is 1 in 1 trillion, then the probability of your computer being smashed by the civilization that has traveled through is 1 in 1 trillion trillion. But don't forget that the number of parallel universes is infinite, and even if the chance of this happening is only one in a million trillions, even if there is only such a small probability, it will inevitably happen - because parallel universes are infinite, it's as simple as that.

But now, we are still sitting in front of the computer, and there is no sudden brain-dead civilization that smashes our computer. Then it can be disproved that there are no infinite parallel universes. Maybe parallel universes really exist, but it will definitely not be infinite, and its number will definitely be limited.

Since it is impossible to go back in time, at least it is impossible to speculate based on Xiao Yu's current level of technology, and because a guy who claims to be himself after 500,000 years has traveled from a limited parallel universe, it is unlikely that such a small probability event will happen, so where did this guy in front of him come from?

After hearing this guy's statement, Xiao Yu's first reaction was that this guy was a liar.

Xiao Yu's vigilance not only did not let go, but became more strict. Xiao Yu said coldly: "I can't believe you. Give me an explanation, and I won't believe everything you say until you give me this explanation. ”

"Oh? What explanation do you want? Xiao Yu soon received a message. There was a tone of interest in this message.

"It's very simple, explain how you will come here in 500,000 years, how did you do it. In my scientific and technological system, time travel is impossible, if I want to admit time travel, my existing theoretical system will be overturned, and relying on a set of wrong theories, I don't believe that in 500,000 years, I can still develop to the point where yours are. It's a contradiction, and I can't believe you until you explain it reasonably. Xiao Yu said.

"You're wrong. In ancient times, the earthlings believed that the earth was flat and the sky was round, which was obviously a wrong theory, but in the wrong theory, human beings still developed a brilliant civilization. The development of science and technology lies in constantly summing up the laws from the phenomena, and then using this set of laws to solve the rest of the problems. Science allows for errors, and the significance of scientific progress lies in the continuous correction of these errors. The unknown being replied.

"You haven't answered me yet, how exactly did you go back in time." Xiao Yu still refused to let down his guard, and asked with vigilance.

"Well, since you want to know, I'll tell you." The being replied, "Can't you turn back time?" ”

"It's simple, entropy increases." Xiao Yu replied.

"The entropy of independent systems only increases, not decreases, right? If there is external energy support, can the entropy be reduced? If the entropy is reduced, will time be turned back? ”

Xiao Yu was stunned. In fact, no matter whether this guy proposed the superluminal time rewind theory or the infinite parallel universe theory, Xiao Yu would refute it mercilessly, but Xiao Yu didn't expect that this guy would put forward such a statement.

Xiao Yu has no way to refute this statement. The reason is simple, because theoretically this statement is true, as long as the entropy can be reduced, time can be turned back. It's just, it's just, how can entropy be lowered? Is there really an external universe?

Xiao Yu didn't know these things, this was beyond Xiao Yu's cognition. But Xiao Yu was only confused for a moment before reacting.

Xiao Yu sneered.

"You're saying that you've turned back time in this universe with the help of the energy of the outer universe? So there's a question I'm interested in. Since you can travel through the universe and turn back the clock in a large universe, what else can't you do? Will you travel from 500,000 years ago to the present to come to me? ”

This doesn't make sense. Xiao Yu is facing this unknown existence with the greatest vigilance, whether from the scientific or logical aspects, Xiao Yu will raise the biggest doubts about every word it says. If its claims were flawless and strictly self-consistent, perhaps they would believe it 10 percent.

"I don't have that much power." The unknown being sighed and said, "In fact, even I am not sure if there are any other universes outside of our universe, let alone shuttle into the rest of the universe and borrow the energy of the rest of the universe. ”

"So, how did you get the entropy to be lower?" Xiao Yu asked in a very interested tone.

"It's very simple, use the energy of this big universe to reduce the entropy of this big universe." The unknown being replied.

"Ridiculous." Xiao Yu retorted mercilessly, "I haven't heard of anyone who can grab their hair and pick themselves up. ”

"Who said...... Have I reversed the time of the entire universe? The unknown being said slowly, "What do you think of the explanation for taking the Milky Way as an independent entity, and then extracting the energy of the rest of the galaxy to reduce the entropy of the entire galaxy, reversing the time of the entire galaxy, and returning the galaxy to the present of 500,000 years ago?" ”

"Huh?" Xiao Yu only felt that a sledgehammer hit his host, and he temporarily fell into a crash. (To be continued......)

PS: Finally updated on time...... Well, ask for a monthly pass, after all, it's still in the double monthly pass period.