The residential buildings aboard the Polaris had also been almost completely dismantled and sent to Planet Three to be reassembled into civilian bases. Only a tiny portion remained as temporary housing for the spacecraft construction crews. All the residents had moved from the Polaris to Base Three, and once again, people felt the solidity of the ground beneath their feet. Although they lived in sealed bases, they could still feel the sun's warmth and familiarity in the sunlight passing through the thick special glass.
That year, the hard-working exploration team finally brought good news. They had discovered a ball of ice in a cold, silent region two hundred astronomical units from Tau Ceti. The small ice ball orbited Tau Ceti in that distant region, where there was no sunlight or heat, and it had been very well preserved. The furrow finally left Hu Yu's brow. Over the past two years, the fleet's water supply had dwindled, and industrial water in particular was severely scarce.
To ensure a supply of industrial water, the public had voluntarily cut back their domestic use once again. Apart from drinking water, they avoided using it wherever possible. Even so, it was a drop in the bucket. Planets Three and Five were not entirely without water, but it existed in molecular form in the rock and soil. Extraction was extremely slow, yielding less than a few dozen tons a day.
The exploration team's discovery of the small ice ball could not have come at a better time. After confirming that it was biologically safe, Hu Yu immediately dispatched two of the Polaris ships, which had been converted into heavily occupied transports, to the team's location. Their mission was to transport water.
Although the small ice ball was only a little over fifty kilometers in diameter, preliminary calculations put its water content at tens of billions of tons. The two Polaris ships flew toward the asteroid carrying enough engines to mount on it and propel it toward an inner orbit around Tau Ceti. Even with the engines installed, it would take more than a decade to travel over two hundred astronomical units and reach the vicinity of Planet Five. Without ordinary residents aboard, a Polaris could accelerate at a minimum of 5 G and make the round trip in just one year. After delivering the engines, the two ships would return carrying some water.
With the water problem solved, all that remained was to begin construction in an orderly fashion. Every day, hundreds of thousands of technicians in basic spacesuits worked outside the bases on Planets Three and Five. Watching it all, Hu Yu finally felt much more at ease. In less than a few decades, a brand-new fleet would set sail from Tau Ceti.
At the thought, Hu Yu could no longer sit still and hurried to the Academy of Sciences. The academy had also settled on Planet Three, where an enormous building, no less impressive than the other bases, towered over the surface. More than a hundred thousand scientists had gathered there, hard at work on all kinds of experiments.
"Academician Zeng," Hu Yu called as he entered Academician Zeng Zhaoyuan's laboratory.
"Oh, General Hu Yu. What brings you here today?"
"Academician, when the fleet set sail, the curvature travel you mentioned..."
"Ah, I boasted too much. I said I'd solve every problem by the time the fleet reached Tau Ceti, but it's already been two years since we arrived. I'm ashamed."
"Then, Academician, how far along are you now? When will it be finished? Academician, it's not that I'm in a hurry. I just can't help myself."
"I understand. But as of now, all the problems have been solved," Academician Zeng said, a little proudly. After fifty or sixty years of hard work, it was difficult for him not to feel happy.
"Really? Quick, Academician, tell me about it."
"Don't rush, don't rush. Let me explain," Academician Zeng said with a smile. "In the last two years of the voyage, we cracked the technology for directional control of magnetic field lines. We immediately tested using them to contain energy leakage, and it had some effect. The energy level within the magnetic confinement net also reached a new height, enough to propel a Polaris directly to 0.1 times the speed of light. A J-90 could travel directly at light speed."
"Then why didn't you tell me?"
"Ah, Comrade Xiao Hu, although that result was already quite good, have you forgotten how big our new residential spacecraft are? That energy level still wasn't enough. The spatial curvature had two problems: its range was too small, and the degree of curvature was too low. If the range was too small, it couldn't move a large ship. If the curvature was too low, the speed wouldn't be high enough."
"Oh, I understand. So you've spent the last few years continuing to work on it, Academician?"
"Yes. In the fleet, we lacked a large particle accelerator for the relevant experiments. While I was worrying about it, a chance occurrence gave me an idea. Since we could control magnetic field lines perfectly, why couldn't we use them to build an intangible high-energy accelerator?"
"An intangible high-energy accelerator?" Hu Yu interrupted, somewhat puzzled.
"Yes. We use magnetic field lines to create a conduit. It's actually not all that different from an ordinary particle accelerator, which also uses magnetic fields to control particles moving around a circular track. The difference is that we no longer need physical electromagnetic coils, and the conduit made from magnetic field lines fits the particles perfectly. It can even be as small as a particle, so it takes up very little space while providing a very long path. Look at this." As Academician Zeng spoke, he took out a disk the size of his palm.
"What is this?" Hu Yu took the disk Academician Zeng handed him and suddenly felt a tremendous magnetic pull surge toward him. He tried releasing his fingers, but the disk remained firmly stuck to his palm.
"This is a prototype curvature engine, and it's currently running at its lowest power. Don't underestimate it. The magnetic field line conduit inside is a full hundred thousand kilometers long, with countless particles moving at high speed through the circular magnetic conduit. If they were supplied with enough energy to reach maximum power, your whole body would be pulled against it, and you wouldn't be able to resist at all."
"Academician, wouldn't the bends in the conduit affect the particles' speed? Especially when the turns seem a bit too sharp."
"That's true. But since there's no friction between the particles and the conduit, very little energy is consumed in steering the particles, so it won't have much effect on the final result. Besides, this design was made for a curvature engine. The smaller, the better. Surely we can't carry an accelerator thousands of kilometers in diameter to accelerate a spacecraft."
"Academician, you really are..." Hu Yu happily gave Academician Zeng Zhaoyuan a thumbs-up.
"Don't rush. I haven't finished yet. You're already losing your composure over this? As a leader, you ought to be a little more reserved. Haha."
"Academician, how can I act reserved in front of you? You're my idol."
"All right, don't flatter me. This old man can't take too much praise. Let me continue. What you have there is a sample curvature engine. A real one will be much larger, depending on the circumstances, but at most it will be around a hundred meters. Any larger and its energy efficiency would drop greatly, so it wouldn't be worthwhile. According to the data, this kind of curvature engine is more than enough to propel the residential spacecraft we build in the future at 0.5 times the speed of light. Smaller warships will reach around three times the speed of light."
"That's great! We won't have to suffer through crawling along at a snail's pace anymore. Can it go a little faster, Academician?"
"That's the most conservative estimate. In practice, it should be a little faster, but not by much."
"That's already wonderful, wonderful. Compared to before, the residential ships will be almost twice as fast, and the warships' speed will increase severalfold. Most importantly, we won't need to spend so long accelerating. Before, it took ten years to accelerate the Polaris to 0.3 times the speed of light. Now it will only take a few seconds," Hu Yu said excitedly. Curvature travel did not require acceleration like conventional travel. As long as the engine curved the space in front of a warship, the ship would naturally fall forward. Space moved faster than light, and the greater the curvature, the faster the speed.
"There's just one more problem. All the high-energy particles in these magnetic engines must be Chong Element extracted from the bugs. Other particles produce less than a tenth of the effect. And the particles in the engines won't last forever. They need to be replenished with Chong Element particles at intervals, and our reserves are limited. They'll run out someday."
"Then how long will our current Chong Element reserves last?"
"If it's all used for travel, it should last about four to five hundred years, given the size of the new fleet."
"Wasn't this stuff meant for travel? Are there other uses for it?"
"Of course. A curvature engine bends space, which, to put it plainly, means it creates immense gravity. And gravity can be used to attack. With a few modifications, a curvature engine becomes a gravity bomb. The immense gravity it releases at close range can tear a warship to pieces with tremendous tidal forces. Besides gravity bombs, our warships will no longer need to rotate to produce simulated gravity. We only need to install curvature engines along the bottom of a warship and run them at low power to produce gravity. All of this consumes precious Chong Element. War in particular would be a bottomless pit of consumption if we encountered another civilization. The amount used for gravity, on the other hand, would be negligible."
"It can do that too?"
"Of course. The great thing about a gravity bomb is that it ignores defenses. No matter how strong a ship's defenses are, even if they can't be breached from the outside, surely the defenses inside the ship can't be just as strong? Gravity can pass through a warship's armor straight into its interior, inflicting damage on the crew and equipment inside with no blind spots."
"Academician, in that case, wouldn't our own warships also be affected by the curvature engines' tidal gravity? Wouldn't it be dangerous if they crossed the Roche limit?"
"It's different. Curvature engines aren't installed at just one point on a warship; they're distributed all around it. The ones at the front of the ship are only slightly more powerful, so the entire ship remains in a state of relative gravitational balance. That effectively prevents the curvature engines from affecting the ship itself. Once all the engines are activated, it's as if the ship has entered a sliding cableway, where only a small force is needed to pull it along. That small force comes from the slightly more powerful engines at the front. A curvature bomb, or gravity bomb, is different. It unleashes extraordinarily powerful gravity from a single direction. And a gravity bomb doesn't release its gravity all at once. Instead, it adjusts its power at random, tearing at the warship like waves. With our technology, it would be difficult to defend against. As for whether other civilizations can defend against it, we'll have to see how it performs in actual combat."
"Oh, that puts my mind at ease. Academician, what other new things do you have? Bring them all out at once and broaden my horizons." Hu Yu spoke with a cheeky grin. With the major problem solved, Academician Zeng Zhaoyuan was not the only one who was happy. Hu Yu was genuinely happy too, and even his mood had changed.
"Getting greedy, are you? All right. You're the leader, and I'd have to tell you sooner or later anyway. I'll show you one more big move."
"There really is more? Quick, tell me!" Hu Yu was so happy he wanted to pick Academician Zeng up and spin him around a few times.