The concept of "Baowei," which had crossed Jiang Yu's mind before, was similar to the situation with the Boötes Void: there was an expanse of four-dimensional space with a diameter of hundreds of millions of light-years that hadn't, or had only slowly, begun to fall into three-dimensional space.
There must be a higher-level four-dimensional civilization that had found a way to slow down or stop the downgrade in dimensionality.
Jiang Yu posed a question that had long lingered in his mind: "Since there are relatively stable four-dimensional spaces in the universe, could there be macroscopic five-dimensional or six-dimensional spaces?"
Thirty-Six Dao replied, "I think there should be, but they would exist in special forms.
"Maintaining four-dimensional space in a universe dominated by three dimensions would undoubtedly be very difficult, and the difficulty would increase exponentially with the maintenance of higher macroscopic dimensions.
"However, I believe a workaround is possible, like enclosing a space to make it independent from the effects of spacetime and light cones, thus creating a micro-universe of its own.
"This way, it could possibly avoid the downgrade in dimensionality of the macro-universe, although this method is also akin to sealing one's own civilization within a confined space, not much different from the 'Dark Domain.'
Jiang Yu was taken aback—the concept of a "micro-universe" was familiar to him: "The concept of a micro-universe that you mention, is it possible to realize?"
Thirty-Six Dao said, "Jiang Shiliu has conducted related proofs, and with humanity's current technological level, it seems like a fantasy. At the very least, we would have to understand and apply the dimension of time before it becomes possible."
He glanced at Jiang Yu: "I didn't expect you to be interested in micro-universes, that's not like you!"
A micro-universe might seem like a grand concept, but in reality, it signifies a civilization locked within itself, a passive way to cope with the Dark Forest Strike.
At that moment, Jiang Yu suddenly realized that his own efforts had already given many people the confidence to confront the Dark Forest directly.
Indeed, when facing the Dark Forest, one can never be too cautious.
But if caution turns to excessive fear, lacking the courage to face the Dark Forest, humanity would forever live like mice in fear of the Dark Forest.
Jiang Yu first felt some satisfaction, then smiled and said, "I just find the concept of a micro-universe quite intriguing. Please continue, what do you mean by 'upgrading at the micro-scale'?
"My wife studies this. I know a bit about dimensional theory, and aren't the dimensions at the micro-level from the fifth to the tenth dimensions? How can there be an upgrading?"
"The macroscopic dimensions are sliding into the microscopic, didn't you think of that?" Thirty-Six reminded him:
"Based on your idea, I think that the dimensions of the macroscopic and microscopic should be like a seesaw, with the macroscopic losing a dimension and the microscopic gaining one.
"Consider this: if the universe was in a ten-dimensional state, the entire universe would have no blind spots or enclosed areas for ten-dimensional beings, and they would be able to observe everywhere without any obstruction!"
Jiang Yu understood: "When the macroscopic ten dimensions become nine, the universe would, well, seem to have obstructions.
"Just like a three-dimensional safe in the four-dimensional world, that three-dimensional safe is totally open in the fourth dimension.
"But after a dimensionality downgrade, all those observational angles would completely disappear, making the safe become enclosed!"
Thirty-Six, wiping sweat, exclaimed, "That's the principle!
"Under a macroscopic ten-dimensional state, the microscopic level must be of lower dimensions, and when a downgrade occurs in the macroscopic, the microscopic must indeed upgrade!
"This also aligns with the conservation law in a broad sense; otherwise, after a downgrade in dimensions, the previously existing dimensions would simply vanish, which of course would be illogical.
"It's difficult to explain the downgrade from four dimensions to three, so let's take the downgrade from three dimensions to two as an example.
"A cube becomes a square when it downgrades dimensions. If it's said that the volume and thickness of the three-dimensional universe simply disappear, then such a downgrade would cause the universe to lose more than 99.99% of its energy and mass.
"Even if the area of a two-dimensional square expands more than the area of a three-dimensional cube, that explanation doesn't hold water. If it's the mass of the three-dimensional cube that causes the expansion of the two-dimensional square, then this falling process must be extremely slow!
"For a two-dimensional square, a three-dimensional cube has infinite height, and it may never fall from three dimensions to two.
"But according to our observations, Four-dimensional Fragment falls into the three-dimensional universe at a very fast pace, which contradicts the theory!
"So after dimension reduction, where does the mass and energy of the higher dimension that was extra go?"
Jiang Yu, despite being in a sauna, felt a chill: "I understand what you mean, it goes into the microcosm, right?"
The theories of dimension reduction in the original work were not comprehensive, and at this moment, Jiang Yu realized that Thirty-Six's thoughts might well be the true face of this damned universe.
"That's not entirely correct!" Thirty-Six Dao said: "The lower the dimension on the macroscopic level, the higher it becomes on the microscopic level.
"The dimension enters the microcosm, while the ruins of the higher dimensions become various forms of dark matter, and that aligns with the mass ratio of dark matter to three-dimensional matter!"
Thirty-Six took a deep breath: "The biggest takeaway from my contemplation is that I've found a way for humanity to escape in the Dark Forest!
"If humanity wants to be completely free from the Dark Forest Strike, then we must find the ladder upward, while also breaking the ladder downward!"
Jiang Yu immediately said, "Explain it more clearly!"
"Finding the ladder upward means that we can use the higher dimensions hidden in the microcosm to elevate the dimension of three-dimensional beings like humans," Thirty-Six Dao explained:
"This way, we can not only evade the Dark Forest Strikes from most three-dimensional beings but also assist our fellow beings in the three-dimensional universe from a higher dimension, achieving even greater accomplishments!
"Of course, after ascending to a higher dimension, we will face new Dark Forest Strikes, but for humanity as a whole, our strategic depth will have increased by one dimension!"
Thirty-Six's words enlighten Jiang Yu.
Thirty-Six paused before continuing: "What I mean by 'breaking the ladder downward,' I realized through the intelligence provided by Venus, that following the universe's downgrade in dimension is a very foolish strategy!
"At the beginning of a new dimension, it is possible to dominate for a while, but because of the many barriers and closed spaces in the new dimension, the advantage of first era beings like Venus will gradually be lost!
"Moreover, for a civilization to downgrade itself, the initial impact on the civilization's own life forms is enormous! This is like making yourself as fragile as paper before even harming the enemy!
"Most importantly, based on the situation on Venus, once the dimension reduction begins, it cannot be stopped!
"He has fallen from Six-Dimensional to Three-Dimensional, so what's left of him now?"
Thirty-Six continued gravely: "So in the future, we must not downgrade ourselves to adapt to the universe's dimensions. Starting now, we must look for ways to protect the three-dimensional universe and attack Two-Dimensional Space!"
Jiang Yu quickly asked, "Do you have a specific plan?"
"Jiang Shiliu has proposed a conservative plan and an aggressive plan!" Thirty-Six immediately replied: "Gravity is a force that is common across dimensions. We could achieve our goals through dark matter and gravity.
"The so-called conservative plan is to use a gravitational field to protect three-dimensional space. The specific method is to use a gravitational field to enclose Two-Dimensional Space or Three-Dimensional Universe!
"The goal is to ultimately block the expansion of Two-Dimensional Space or prevent the Three-Dimensional Universe from slipping away!
"The aggressive plan, on the other hand, is to find a way to turn the central part of Two-Dimensional Space into zero dimensions, so the expansion force of that Two-Dimensional Space becomes a contracting force!"