"According to the current level of scientific and technological development and the restrictions of relevant policies and regulations, it is difficult for us to mine faith on a large scale on the earth, and since the sinking road has been blocked, then the company only has the option of going to sea."

Xu Mengyuan said, "Next, let Hephaestus introduce you to the basic theoretical knowledge related to interdimensional travel." ”

"Willing to help." The handsome half-race guy also found a chair and sat down, rubbing his hands and said, "Where do we start, hmm...... You've heard of string theory, buddy. ”

"I've heard a few."

"Well, I'll try to make a long story short, according to the theory of eternal inflation proposed by Soviet physicists Alexander Vilenkin and Andrei Linde, the universe we live in is like a bubble, triggered by quantum fluctuations.

"And there are infinitely many similar bubbles. It is constantly coming into being, and it is constantly dying, with no beginning and no end. To help you better understand this theory, you can imagine a bottle of Coca-Cola being shaken wildly, where one bubble is the universe we live in, and the other bubbles are other universes. ”

"Most of the time, our universe is stable and lonely, growing and expanding on its own, but there are times when we bump into other bubbles, a phenomenon that we researchers call interference.

"Normally, interference is silent, and the vast majority of beings in both universes do not feel it at all, and they do not know when it began or ended. Interference has little effect on the universe.

"Until the founders of the Tertiary Age unravel the secrets behind those ancient myths and discover that we can use interference to travel to another universe, a technology now known as the Arrival."

"Coming in the early days is very, very dangerous, and it's like sticking your head into a crocodile pool full of crocodiles. Because of the different Calabi-Yau manifolds, the physical rules of the different universes are likely to vary greatly.

"Going to a universe with a different Calabi-Khu manifold is basically the same as committing suicide. Fortunately, there were enough bubbles, and later researchers, after trial and error, gradually developed a way to find the same Calabi-Chu manifold universe after paying an extremely high price.

"Then the filter was narrowed down even further, and eventually we picked out a new world that was less than ours."

"What do you mean by being about the same?" Li Yu asked.

"To quantify it, the world with a deviation of less than 5% has those climates, geographical environments, flora and fauna that we are familiar with...... The most important thing is that classical physics is fully applicable. "We call these worlds the Pure Land. ”

"But it's not enough to just find the right plane and master the technique of coming," Xu Mengyuan interjected, "It's like you've set your destination and prepared a ship to sail, but in the end you need someone to pilot it."

"—Captain, that's the key to it all."

"That's right, only a very small percentage of people in this world have the ability to cross the universe and descend from one universe to another." Hephaestus continued, "I've always dreamed of going to another universe, and I won't regret it even if it costs dying there in the next second, but I don't have that chance in my life. ”

The handsome half-race man sighed, looking very sorry, "An ordinary person like me is destined to rely only on his own barren imagination and your descriptions to feel its magnificence, and pray to meet it in dreams." ”

"It's a pretty place," Li Yu said, "It's a bit like medieval Europe, with a bit of fantasy, the most powerful empire was built by orcs, humans, and gnomes, but there was no magic or magicians. ”

"Orcs? It's like the one in "The Lord of the Rings" or ......"

"There are animal ears, and the appearance is not very different from humans."

“damn！！！” Hephaestus let out a rare foul mouth, "The only thing I can't refuse in this world is furry!" Now a world full of furry is in front of me, and I can't even look at it, it's not fair! It's not fair at all!! ”

"We can talk about your sexual fetishes later." Xu Mengyuan glanced at the time, "The next advent will start soon, you'd better pick up the key points first." ”

"Okay." The handsome half-breed guy had to suppress the urge in his heart, "I'm going to introduce you to a few guidelines related to the Advent next, but I'm sure some of them have already been noticed. ”

"First of all, you can bring things from this world with you."

"But only what my body can reach?" Li Yu said.

“bingo！ Wow, buddy, you're very observant," Hephaestus praised, "and at this stage, you can't bring anything more than five kilograms combined." It can't be a living thing, not an uncooked seed. ”

The words of the mixed-race handsome guy also explained why Li Yu came for the first time before, his mobile phone, watch and clothes on his body were all there, but the wallet and tissues in his pocket were missing.

Fortunately, the latter two things were still in the room when he returned.

"What about germs," Li Yu asked again, "the bacteria and viruses I carry can't always disappear with them, what will they do there?" ”

"It's an interesting question, and I've seen similar discussions on a lot of forums before, and I think most people are more or less overestimating the power of modern germs, even though many people like to use the Indians of the American continent as an example.

"But these people ignore the premise that smallpox, brought by the European colonizers, is itself the most devastating infectious disease in human history, as well as the flu virus, the Black Death, and the coronavirus that is now raging, and our old friend AIDS, and so on......

"But if you are a healthy person, the germs you carry will have a very limited impact on a similar new environment. In fact, Eurasians arrived in the Americas long before the great geographical discoveries, and the germs they brought with them did not destroy them. ”

Seeing that Li Yu had no other questions, Hephaestus continued.

"Second, you can't bring anything back from that world, whether it's real or photographed, and you can't stay in that world for more than seven and a half hours at a time.

Of course, you must also be aware that time flows at different speeds in different universes. Our seven and a half hours are not equal to seven and a half hours over there......"

"Three to one." Li Yu said.

"What?"

"The speed of time on both sides is almost three to one, and the first time I came in, I spent almost a day there."

"You've been to a universe for a long time? That's good and means you have more time to act. While there hasn't been enough research to prove why this is the case, your watch and phone will still show the real-world time, and by taking advantage of that, you'll be able to grasp the timing of your return. ”

"Is the return a natural occurrence, or is it ......," Li Yu asked again.

"It happens naturally, you are like a guest to that universe, and once the reception time is over, you will be invited out of the house by the host."