"What exactly is this thing?" Qingmu asked.
"Don't rush," Professor Mei said. "Let's get back to the pyramids."
He pointed at the interior of the pyramid on the drawing. "This is the known burial chamber layout. This is the queen's chamber, this is the pharaoh's chamber, and here are four ventilation shafts." The professor's finger kept moving over the drawing.
"I've heard these ventilation shafts point precisely toward certain constellations?" Qingmu recalled some rumors about pyramids he had read before.
"Oh, that theory exists, but it isn't widely accepted in academia. These passages are less than eight feet wide, and we don't know how people back then carved them out, though that isn't so surprising either. What I want to point out is that the inverted pyramid on the seabed near the Tubuai Islands also has a vertical shaft less than half a foot wide, running straight down from the main burial chamber to the pyramid's apex."
Only then did Qingmu notice that a line on the drawing connected the burial chamber to the pyramid's apex. It was so thin that he would never have noticed it without looking closely.
The professor said, "Since we've established that the two pyramids are mirror images, anything this inverted pyramid has should also exist in the one in Egypt. So someone conducted further scans of the Pyramid of Khufu using radiation, and sure enough, they found this vertical shaft in its upper section. The scans also showed that the top of the pyramid originally had an opening. That pointed cap must have been added later."
"Now it's perfect. The two pyramids are identical, down to the smallest detail." The professor puffed on his pipe and gave Qingmu a mysterious look. "Now, what comes to mind?"
"Ah, scholarship really does tax the brain!" Qingmu said, rubbing his disheveled hair. "Did that pharaoh think he could be buried on this side of the earth and crawl out on the other?"
"Hmm, now that's interesting. Go on," the professor encouraged him.
"Aha, was I right? But I was just guessing wildly! Professor, why don't you just tell me?"
Qingmu really couldn't be bothered to kill off a batch of brain cells. The old man was only keeping him in suspense anyway and would tell him soon enough. Didn't all learned people like doing this?
"Can't you use your brain a little more? It could help awaken your dormant memories!" Mei Yiqiu said in exasperation, then burst out laughing. "Never mind, never mind. You're already an eccentric genius. If your nervous system problems cleared up and all your memories returned, who knows what sort of monster you'd become!"
Mei Ziqing, who was replacing their tea, looked at Qingmu when she heard the professor's words, her eyes full of curiosity.
Mei Yiqiu took an hourglass from the bookcase behind him, shook it in his hand, then set it on the table.
This hourglass was, of course, not the crystal kind in the image Professor Silva had sent, but a conical one made of ordinary glass. Sand flowed through the tiny hole connecting the two cones, forming a fine thread.
"The most obvious meaning of an hourglass is time. The flowing sand is time passing," Mei Yiqiu said. "Think about it. Throughout history, what has been the greatest dream of emperors and kings?"
"Immortality!" Qingmu didn't need to rack his brains to come up with that.
Mei Yiqiu nodded. "Exactly. Immortality. But people always grow old. The hourglass of time never stops. Who can contend with time?"
The sand in the hourglass kept flowing without the slightest obstruction.
"But the greatness of civilization lies in struggling against the god of fate and creating miracles through that struggle. Every civilization has pursued immortality, but each has used different methods. The Chinese, for instance, have always tried to achieve it through alchemy and taking elixirs, while the civilization of Ancient Egypt naturally had its own methods-"
Mei Yiqiu suddenly turned the hourglass over. The sand that had just flowed out of one cone instantly began flowing back:
"Time flowing backward!"
Qingmu found it incredible. "You're saying the Egyptian pharaohs built the pyramids to make time flow backward?"
"At present, it's only a conjecture, and we need more archaeological evidence to support it, but it does have a certain logic to it. Look at these two pyramids." Mei Yiqiu put the two pyramid drawings together, their tips touching. "How much they look like an hourglass of time!"
Looking at them, Qingmu found that they did bear some resemblance to the image Professor Silva had sent. The vertical shafts leading to the pyramids' tips looked like thin streams of sand, while the pharaohs' burial chambers lay right at the centers of the hourglass's two compartments.
"We know that on a plane, the triangle is the most stable structure. By the same reasoning, in three-dimensional space, the triangular pyramid is the most stable structure. Using the most stable spatial structure to represent space itself-that is the metaphysical meaning of the pyramid: space."
Professor Mei Yiqiu's brow was tightly furrowed, as though he were refining his theory as he spoke.
"The pyramids were built in the desert. The desert represents this world, and the passing of sand represents the passing of time. The Egyptian pharaohs believed that one day the two cones of the hourglass of time would turn over. Then time would flow backward, and the pharaohs would come back to life."
Puzzled, Qingmu asked, "Then why build the other inverted pyramid so far away?"
The professor said, "Perhaps they knew something unforeseeable. For instance, one day in the future, North Africa might be swallowed by the ocean, while the submerged continent where the Tubuai Islands lie might rise and become a desert. Or perhaps someday other gravitational forces will affect the earth and change the direction of its rotation. Who knows!"
"There's another conjecture that seems even more absurd and more frightening. Professor Garcia, a geologist from Argentina, says that the Sahara Desert only began gradually forming after the pyramids were built. In other words, the Sahara region gradually became a desert because so many pyramids were built. Though no one in academia publicly agrees with him, in fact, the explanations for the Sahara's formation offered by meteorology and traditional geology are just as flimsy as his theory. It's merely the pot calling the kettle black."
"That's terrifying!" Mei Ziqing exclaimed beside them, then immediately covered her mouth. She knew full well that when Professor Mei was talking to someone, his assistant should not interrupt.
Mei Yiqiu wasn't angry, however. "There's nothing frightening about it. Compared with the entire universe, humanity doesn't even amount to a grain of sand."
Although Qingmu thought this theory was unlikely to be true, hearing such a version of the story for the first time still shocked him somewhat. He imagined a mummy crawling out of a pyramid's vertical shaft years in the future, shook his head, and said, "That's nothing but a dream!"
"Yes, who could say otherwise! But scientifically speaking, the space within dreams is also real space, and it has some sort of connection to our real world. Just like those two pyramids that mirror each other: one stands there in the Sahara Desert, plain as day, while the other lies hidden beneath the sea, influencing the other in a way we don't yet understand."
Holding his pipe in his left hand, Mei Yiqiu turned the hourglass on the table over again with his right.
"Perhaps one day, just as those pharaohs hoped, the two spaces will turn over, and like sand, we will fall out of this spacetime into that dream we once thought unreal."