"Very good!"

Peter Pan clapped his hands, nodded with admiration, and said, "This Zhang Heng's statement is very close to the current mainstream view of parallel universes......

"There have always been different opinions in the physics community about what a parallel universe is, and there are no less than dozens of conjectures and hypotheses, each with its own supporters, but since they are all hypotheses, it is difficult to say who is right and who is wrong. Pen @ fun @ pavilion wWw. ｂｉｑUｇE。 ｉｎｆｏ”

Peter Pan paused, and then continued: "Compared with all kinds of conjectures analyzed from a professional point of view, the general public's understanding of parallel universes may mostly come from fantasy novels, and they generally believe that the so-called parallel universe should exist independently of the universe that exists in us. Or in other words, in a different time and space......"

"The parallel universe theory that I am going to talk about today is the one I most agree with in the physics community...... It is possible to overturn this view. ”

"Now let's think about a question together...... Is it possible for the so-called parallel universe to be in the same time and space as me? ”

"Parallel universes are in the same space-time?" Zhang Heng frowned and shook his head: "Professor, I don't understand. ”

"It's okay if you don't understand, it may take some time to digest and understand." Peter Pan smiled kindly, and continued, "Then consider another question, when we look up at the night sky from an open plain, and assume that our eyes can reach an infinite distance...... Is it possible to observe the whole universe? ”

Looking at most of the confused students on the ladder seats, Peter Pan asked himself, "Impossible." ”

"The reason why it is impossible to observe the entire universe is not because the universe is infinite, but because it takes time for light to propagate, and only 13.7 billion years have passed since the birth of our universe, which means that even if the visual distance of our eyes can really reach infinity, at best, we can only see the universe within a radius of 13.7 billion light years......"

"But considering that space in the universe is still expanding, and the rate of expansion is accelerating, this radius may be a bit larger than 13.7 billion...... One says it's 41 billion light years. ”

"Interestingly, our universe is much larger than just 41 billion light-years, and at the rate of its expansion, the so-called three-dimensional space is growing exponentially......

"Let's go back to the previous question, for us, the observable universe is a sphere with a radius of 41 billion light-years, and since it is impossible for any object to move faster than the speed of light, we cannot observe the universe 41 billion light-years away, nor can we exert any influence on it, in this case, the universe outside of it and the universe that we can observe are independent of each other."

"At this point, you may have some questions...... How does this relate to what you understand as parallel universes? Peter Pan smiled: "The so-called parallel universe should be in another identical earth, and there is an identical 'me'...... But according to what I said before, the so-called parallel universe is just a space that exists under the same time and space and cannot be observed by each other, but if these spaces are inhabited by completely different people, then what kind of parallel universe is it? ”

"There's another issue here."

"In order to make it easier for you to understand what I am going to say, I need to find a student to volunteer and complete a game with me."

Peter Pan seemed to wander around the staircase hall for a while, and finally set his eyes on Gu Fan's body, and said, "This male classmate, can you please come to the stage to help me complete the game?" ”

Gu Fan opened his mouth, pointed at himself with some uncertainty, and said in astonishment: "Me? ”

"That's right, it's you!" Peter Pan nodded and smiled.

"Afraid of what? The soldiers will block the water and cover the earth, what are you afraid of what he can do? Xiao Zifan kept shouting in Gu Fan's ear: "With me covering you, don't be afraid, go on." ”

"Okay." Gu Fan nodded, his expression became calm, he stood up and left his seat, and strode down the stairs to the podium.

"Good." After a while, Peter Pan put a virtual console composed entirely of three-dimensional images in front of Gu Fan: "This is a virtual console, you can use it to do some relatively simple operations. You should have used it, right? ”

"Of course." What has been popularized in the real world, Gu Fan is naturally not unfamiliar, and nodded firmly.

"Now please turn on the calculator function in the virtual console. The game we are going to do is very simple, just guess the numbers......" Peter Pan lifted the golden frame and said seriously: "From now on, I will be incarnated as the predictor of the unpredictable, you will enter a set of numbers in the calculator at will, and at the same time, I will also enter a set of numbers in my console, and the numbers entered by the two of us will be the same." ”

"Any number you want?" Gu Fan asked rhetorically.

"Of course, you can do whatever you want." Peter Pan nodded.

"Okay, let's get started."

Gu Fan stopped talking nonsense, connected his fingers, and quickly entered a set of numbers on the calculator interface.

And Peter Pan also entered a set of numbers at the same time, and when he saw that Gu Fan was already standing with his hands down, he said: "Okay, now I will project all the numbers entered by the two of us onto the three-dimensional light curtain behind the podium......

Peter Pan operated for a while, and two sets of numbers appeared on the three-dimensional light curtain on the podium at the same time......

All the students in the staircase hall could clearly see these two sets of numbers, and the group of numbers near Peter Pan was "913452". And the number close to Gu Fan is "18302035275".

"Okay...... Maybe I should add some restrictions. Peter Pan touched his chin, smacked his lips, and said, "There are no rules like this, it's really hard to guess, next time, let's enter five digits and try it?" ”

Gu Fan shrugged his shoulders and signaled that he was fine.

The two repeated the previous practice again, and this time, the number given by Peter Pan was "12345". The number given by Gu Fan is "73128".

"I suddenly feel that five digits are a bit difficult to guess......" Peter Pan frowned, scratching his head with some distress: "It's better to change it to two digits." ”

“28”、“91”。

"This classmate, have you found anything?" Peter Pan exclaimed, "Even if we've narrowed it down to two digits, there's still only a 1 percent chance that we'll get the same number randomly!" Why don't you try the single digits? In this way, at least we can further narrow down the probability of guessing together! ”

Finally, after five or six more attempts, the two men finally typed the number "6" at the same time.

"It's not easy...... Peter Pan smiled bitterly, "It doesn't look like I'm very suitable for fortune telling......"

"However, all the students here......" Suddenly, he changed his words: "Have you ever thought about what kind of message I hope to convey to you through this game?" ”