"All right, now let's talk about that symbol of yours."
Professor Mei Yiqiu finally got to the point.
He picked up a pen and drew an equilateral triangle on the paper. "This triangle represents the space we inhabit." Then he drew another equilateral triangle above it, upside down, with the vertices of the two triangles touching. "This triangle represents another space. Now, although these two spaces are connected, there is no passage between them. What's more, the connection between the spaces consists of only a single point."
"Do you know what a 'point' means in mathematics and physics?" The professor answered his own question. "In geometry, a 'point' cannot be defined. Any attempt to define a point will plunge you into an abyss of circular and logically backward definitions. But in spatial terms, we can consider a point a zero-dimensional object."
"Zero dimensions means having no dimensions, not even the lowest dimension. Remember, the singularity of the universe is not a point in the mathematical sense. A singularity can have any number of dimensions; it is not zero-dimensional," the professor emphasized. "Matter and energy exist throughout the various dimensions of the universe, but not in zero dimensions. If the two triangles were connected not by a point but by an edge, we would have no way of determining how they affected each other, because we couldn't be certain whether these two triangles represented planes or three-dimensional spaces. But one thing would be certain: there would have to be extensive exchanges of matter and energy between them. Now, however, the two triangles are connected only through a 'point.' This is a dimensionless space, and no matter can pass through this point."
"It would seem that the two triangles could have no interaction at all. Then what is the significance of connecting them?"
At the crucial moment, Mei Yiqiu fell back into his old habit of keeping people in suspense.
Helplessly, Qingmu offered a meaningless response. "Well, there must be some significance to connecting them!"
"Yes, of course there is." The professor seemed pleased that someone was listening seriously to his theory. "Because if they were separated, they would become two isolated universes, and then there really would be no significance. Though no matter can pass through when they are connected only by a 'point,' they still form a whole and belong to the same universe. And as long as they are in the same universe, no two spaces can fail to affect each other."
"Then how exactly do they affect each other?" Since the professor had not criticized Mei Ziqing for interrupting earlier, she grew bolder now.
The professor said, "As living beings, neither of you should forget that our universe also contains something called 'consciousness,' similar to what metaphysicians call the soul. Consciousness has no mass and exists independently of matter. We possess it, yet know nothing about how it works. Only something without mass can pass through a zero-dimensional point and reach another space."
"Oh, I understand." Like a student, Mei Ziqing treasured her chance to speak. "You mentioned dreaming earlier. Are you saying that a person's dream is also another real space, with a connecting 'point' between it and our real space, and that only our consciousness can pass through this dimensionless point into the dream? So when we dream, it isn't actually an illusion, but our consciousness crossing into another space?"
"Mm, you could understand it that way." The professor seemed to weigh his words, considering how to make them easier for his student to understand. "But dreams are still illusory to us, because our consciousness doesn't leave our bodies entirely to go elsewhere. If it did, we wouldn't wake up. Just like a quantum superposition, when we dream, our consciousness should exist in two spaces simultaneously."
"Of course, some people may be exceptions." The professor gave Qingmu a mysterious wink.
Mei Ziqing clearly did not quite understand this, but the professor seemed unwilling to go any deeper. Instead, he picked up his pen and added a vertical line through the vertices inside the two triangles.
"If we view this symbol as an hourglass, this line undoubtedly represents the passage of time. But this so-called passage is only relative to a single space. If you regard the two spaces as a whole, you will find that the total amount of time neither increases nor decreases."
As he spoke, he picked up the hourglass on the table, turned it upside down in his hands, then turned it back again. The sand inside flowed from one end to the other, then back again, but no matter what, there was only that much of it. It would never change.
"Are you saying that time in dreams and time in reality can be exchanged?"
"Not just time, but space and everything else as well. Like this hourglass: the sand inside represents the time this space possesses, as well as all the matter that fills it. When time runs out, not a single grain of sand remains here. Unless the hourglass is turned over, this space loses its meaning as well."
"Just as every one of us must die at some point, death means that 'my' time has reached its end. In other people's eyes, the world still exists, but to the dead, the world no longer has any meaning, and this space collapses."
"But consciousness enters another space that is already 'full,' and only by turning the hourglass over can it all begin again?" Mei Ziqing found it wondrous. "So that's why those pharaohs in Egypt thought of building two identical pyramids, waiting for some mysterious power to turn the 'hourglass' over?"
"This is only a deduction about the Mirror Pyramid and this symbol. You could call it a hypothesis. Perhaps the priests of Ancient Egypt had mastered some method of controlling dreams and drew inspiration from them, which led them to build things like pyramids," the professor replied. "Once I return from Copenhagen, I may have more useful information and evidence."
"Then was this symbol passed down by the priests of Ancient Egypt?" Qingmu asked.
"It's difficult to determine when the symbol originated," the professor said. "We can only determine what it symbolizes: space, time, and our consciousness. If we exclude legendary worlds such as the underworld and heaven, then apart from the reality we inhabit, dreams are the only independent spaces currently known to humanity that consciousness can reach."
"So it must have something to do with dreams?"
"At least with the imagery of dreams."
"Anything more specific, such as a connection to some organization or religion?" Qingmu knew how learned the professor was. After some thought, he made his question more specific. "Have you ever heard of an alliance connected to dreaming and awakening? There also seems to be a profession called a dream mentor."
The professor shook his head. "Before this, I had never seen this symbol, nor have I heard of the kind of alliance you're talking about. But now that you mention it, it does remind me of a few things."
The professor took several puffs in succession, gathering his thoughts.
"In fact, people proposed the concept of the collective unconscious long before Jung. If we trace it further back, shamans in China and Europe were already adept at using group consciousness for mind control. In ancient legends, people were bewitched by night spirits, and after falling asleep, everyone had the same dream. This dream could continue, and afterward, people could no longer distinguish reality from dreams."
"To prevent this from happening, certain wise people stepped forward to teach others how to tell reality from dreams. They and their followers called themselves The Awake People. Their task was to protect humanity from being drawn into the same dream. It was said that they did not need to know one another. They met only in dreams, teaching disciples and fulfilling their mission."
Mei Yiqiu's large pipe was still burning, and the smoke he exhaled had already filled the room.
Through the gray haze, Qingmu seemed to glimpse a new world. Between that world and him lay a zero-dimensional point of connection. His consciousness needed only to pass through it for him to see everything there clearly.