Chapter 49: The Impossible Staircase

  "What's Penrose stairs?" Zhao Yang asked.

  "The Penrose stairs were proposed by British mathematician Roger Penrose and his father, geneticist Lionel Penrose, in 1958." I had just said that when Xian nodded slowly and said: "En, this is a famous geometric paradox, referring to a staircase that always goes up or down but cycles infinitely, can be seen as a variant of the Penrose triangle, on which it is forever impossible to find the highest or lowest point."

  "Right!" I looked at Xian Xian with relief, didn't expect that this kid not only has extraordinary skills, but also extensive knowledge!

  As others urged me on, I continued: "I saw a wonderful picture in which people were always climbing up stairs but always remained at the same level. If Pat was amazed by the existence of such fixed points, he would be even more amazed by these stairs. He could keep going round them forever, always climbing upwards and yet always returning to his original position!"

  "Is this possible?" Not only was Wang Yi stunned, but many people here were also filled with incredulity.

  "Of course it's impossible." Xianxian curled up her lips and smiled, flatly rejecting the idea.

  It's actually quite absurd even for me to say it out loud, let alone for others to hear, but the words that came out of my mouth still turned into a question: "Then why do you believe in ghosts? What kind of existence are ghosts anyway? If ghosts exist, then why not four dimensions..."

  "Does it exist or not?" Wang Yi's hair was almost scratched into a bird's nest, looking very entangled.

  "I don't know either!" I was almost driven mad, and had to resort to randomly spouting out someone else's summarized theory: "As for this phenomenon, there is an explanation that says it's because our eyes are deceived by the painting and think that such a staircase exists, and these impossible shapes are just its visual analogues."

  "College student, can't you say something normal?" Wang Yi scratched his head, looking somewhat annoyed at my verbatim repetition of what I had read.

  "Alright, to be honest I'm not really sure." I shrugged and continued reluctantly: "I've only heard of the Penrose stairs, although I don't really believe it, this kind of situation is fundamentally impossible in our three-dimensional world, unless... unless..."

  "What's wrong?" Wang Yi asked hastily.

  I didn't respond immediately, but instead looked at Xian Xian, and coincidentally he also turned to look at me. His eyes were as black as coal, shining like natural black gemstones. Although we had met several times before, the smile in his eyes never reached the bottom of them, which always seemed calm and unruffled, as if nothing could ever bother him. But now, I saw unreserved shock and incredulity in his eyes, mixed with a complex and strange glow!

  "What if something happens?" The nearsighted man also urged and asked.

  "Unless it's a four-dimensional world!" Xianxian and I said in unison, saying it lightly, but it was difficult to accept in our hearts.

  "The Penrose stairs cannot exist in three-dimensional space, but as soon as they are put into a higher-order space, this impossible staircase can be easily realized!" But does this world, the three-dimensional world we live in, have four-dimensional space?...

  This is something I didn't even dare to think about! It's not a matter of believing or not believing, it's just that people are certain and definite about it, only... they don't dare believe it, and neither do I...

  To others here, perhaps the views that Xianxian and I are putting forward at this moment are extremely mysterious and unimaginable. However, many unsolved mysteries become mysterious and unimaginable because we are unwilling or dare not to face them. This is because humans do not want to confront their own insignificance and fragility in the vast universe.

  She let out a silent sigh in her heart, and when she lifted her head again, except for Xianxian, everyone else's expression was still puzzled. There was a moment of silence around us, and suddenly, Xianxian stared at me with an extremely complex gaze and asked: "You didn't appear out of thin air back then, what exactly happened to you?"

  "It's strange when I think about it..." Next, I told him everything that had happened after entering the cave, no matter how big or small. At this point, keeping any information from each other wouldn't be beneficial, and there were many things I needed an explanation for.

  After I finished speaking, Xian Xian stroked his chin and fell into deep thought. Seeing that he wasn't saying anything, I had to temporarily set aside the issue of whether or not four-dimensional space existed, and asked: "I'm really curious, why is it that Red-Haired Glutinous Rice Ball only chases me? This is too abnormal, and also unscientific!"

  "There's nothing strange about that." Xian Xian looked at me like I was an idiot, but smiled elegantly and said: "Didn't you say you were injured by that little dumpling? That female dumpling has such a big grudge, if she doesn't chase you after smelling the dead air left on your body, who will she chase?"

  After hearing this, I suddenly realized and looked at the place on my leg that was re-treated by Gao Liang. Just then, I heard Gao Liang say calmly beside me: "Don't worry, the inflammation has been cleared up, and the corpse energy will disappear soon."

  I looked at him gratefully, if I really ran around with this wound, I'm afraid it wouldn't be just one dumpling chasing me, this special "aura" would be equivalent to exposing myself under the enemy's eyelids no matter where I hide!

  "Just now you mentioned that four-dimensional world, it seems to be a wonderful thing." One person looked at me with a curious face and said. The others also nodded one after another, as if they had all forgotten that we were already trapped to death, but instead became enthusiastic about scientific speculation.

  "Xian Xian, you also know very well, you explain it." I said to a certain someone who was sitting next to me and had suddenly become carefree again.

  "Who told you that this handsome guy is very knowledgeable? I just happened to glance at it, and I only know a little bit."

  "Alright." I curled up the corner of my mouth, not knowing whether he was telling the truth or just trying to placate me. Seeing a group of people's puzzled eyes, I had no choice but to play the role of teacher and explain: "One dimension is a line, two dimensions are a plane, three dimensions are a three-dimensional space, four dimensions are curved space, that is, length, width, height plus one time axis, which is what we often call the universe. Of course, this is just a way of speaking, not to say that the fourth dimension is the universe."

  I suddenly realized that I'm not a complete waste of space after all. At least my knowledge, which I acquired from reading about various strange and unusual things to pass the time when I was bored, wasn't completely useless. Even something as far-fetched as multidimensional space can be mentioned in a place like this. However, I still dare not imagine that such a thing could really happen. I don't know if I'm underestimating the abilities of the ancients or if I'm just afraid to face and accept the unknown. Perhaps it's both...

  "Relative to the universe, since we live on a slow-moving Earth where time runs extremely slowly, we can't feel the existence of the timeline. However, once our speed reaches or approaches the speed of light, time will shorten or reverse, and we'll be able to feel the existence of the timeline. This means that we can swim freely in spacetime, go back to the past, or reach the future..."