341, October 10, 18:00.
After three months of round-the-clock research, the problems within soul transfer technology were finally overcome by Tang Li and Song Pinxuan.
During experiments, Tang Li discovered that the connection between a biological soul and its original body was unbreakable.
Transferring a creature's soul into an intelligent soul vessel and injecting the biological body with a spirit enhancement agent could strengthen the soul's power within the intelligent soul vessel.
The principle might be similar to quantum entanglement.
To have a soul transferred out of an intelligent soul vessel, back to its original body, or to another intelligent soul vessel, it was necessary to use spirit enhancement agents to strengthen the soul to a certain extent.
Each transfer of a soul would cause it to weaken.
Tang Li also noticed that once a creature's original body died, its soul could no longer be strengthened through spirit enhancement agents.
This meant that if a creature's original body died, then during subsequent soul transfers due to the aging or malfunction of the intelligent soul vessel, the creature's soul strength would continuously decline until it could no longer be transferred.
Therefore, achieving immortality through soul transfer technology was impossible.
Only two methods could be used to maximize human lifespan.
One was to ensure the original body had the longest possible lifespan, utilizing hibernation technology to slow the body's aging while using longevity agents, awakening the body only when spirit enhancement agents needed to be injected.
The second was to ensure the soul had the maximum number of transfer times, using sufficient spirit enhancement agents before the original body’s death.
With both approaches, barring unforeseen circumstances, living for tens of thousands of years would not be an issue.
In a way, this was akin to immortality.
The only consideration was that people within intelligent soul vessels could no longer reproduce.
This necessitated that a portion of humanity remain in their physical bodies to continue procreation.
Of course, these were minor issues.
With tens of thousands of years ahead, it was believed that these challenges would be gradually overcome.
With the end of the extreme heat season, the construction progress of underground cities in the hinterland of country Z accelerated.
Those who stayed in their hometowns and refused to migrate, after enduring the first extreme heat season, also moved into the newly built underground cities.
In this life, country Z experienced no chaos and smoothly navigated the early stages of the apocalypse.
This situation made other countries extremely envious.
However, country Z had eradicated the Holy Light organization within its borders and strictly guarded against spies sent by other nations.
Country Z had also abandoned the internet and utilized its own metaverse, making it inaccessible to other countries and preventing them from creating public opinion.
Consequently, they were unable to breach country Z from within.
However, the abnormal weather still made all countries realize that the apocalypse had not yet ended.
Now, it was too late for them to build their own underground cities and underwater cities.
The only option was the underground and underwater cities already constructed by country Z.
They did not concern themselves with the common populace, but they themselves intended to enter.
Thus, they employed both soft and hard tactics, on one hand showing goodwill towards country Z, seeking entry into its underground cities through beneficial exchanges, and on the other hand creating public opinion abroad, preparing to force country Z to open its underground cities through military means.
Country Z did not yield to their displays of goodwill.
Although some people exhibited excessive compassion, wanting country Z to act as a savior, Tang Li and the others, having learned their lesson in the previous life, naturally would not stumble in the same place again in this life.
The high command had unified their stance, and all expressions of excessive compassion were suppressed.
Seeing that soft approaches were ineffective, the Holy Light organization resorted to force.
Before the extreme cold season arrived, they mobilized the armies of country O and country M, advancing towards country Z from the east and west, intending to forcefully seize country Z's underground and underwater cities.
The result, as expected, was their defeat by country Z's combat mechs, with country Z suffering no casualties.
In the following two years, various disasters such as solar storms, severe droughts, major earthquakes, volcanic eruptions, meteor impacts, tsunamis, and widespread plagues caused the gradual demise of all countries outside of country Z, including countries O and M.
During these two years, country Z also accepted foreign refugees who had managed to escape to the country after enduring immense hardships.
Of course, this was contingent on meeting conditions such as passing vetting and holding permanent residency permits.
Otherwise, even if they reached country Z, they would not be eligible to enter the underground or underwater cities and would be left to die on the surface.
After these two years, country Z also completed the construction of its domestic underground cities and underground passages, and began to gradually expand outwards, utilizing global resources.
Unlike Tang Li's second life, humanity in this life had a large population and no age gap. There was no need for artificial wombs to nurture offspring, nor any reform of surnames or names.
Despite this, in 344, Tang Li and Song Pinxuan successfully gave birth to their own children through artificial wombs, though unfortunately, they were not Song Zhaoyang and Tang Chenxi.
Song Zhaoyang and Tang Chenxi, as Tang Li's continuation, remained forever in the spacetime of Tang Li's second life.
Perhaps they would create their own parallel timelines, but that would no longer be related to Tang Li.
With the maturation of soul transfer technology, many people had chosen to transfer their souls into intelligent soul vessels in recent years, placing their physical bodies in cryogenic hibernation.
Among these, the elderly on the verge of death were most numerous.
345, January 1, 8:00.
Tang Guo, along with her grandmother, arrived at the institution responsible for soul transfers.
This institution was present in every underground and underwater city. It not only performed soul transfers but also managed the storage of intelligent soul vessels, the hibernation of physical bodies, and the connection of souls within intelligent soul vessels to the cloud world and the metaverse.
"Sister Tang Guo, Grandma Tang, you're here? Come in quickly, we're all ready."
As soon as Tang Guo arrived, a girl who looked just over 20 years old, dressed neatly and efficiently, greeted her warmly.
Tang Guo smiled upon seeing her and said, "Thank you, Xiao Mo."
This girl was Xiao Mo, who had died in the freezing rain during Tang Li's second life.
In this life, due to their timely migration to the underwater city, she and her parents were still living happily. Moreover, she was assigned to work at the institution responsible for soul transfers.
As Tang Guo took her grandmother for the soul transfer, Tang Li and Song Pinxuan were still busy with their scientific research.
Although humanity was no longer afraid of disasters within the solar system, they would still be unable to survive cosmic disasters like gamma-ray bursts.
Therefore, Tang Li and Song Pinxuan were researching spatial technology.
The universe was so dangerous that only by creating an independent, danger-free plane of existence and transferring humanity from Earth into it could human civilization be eternally preserved.
The research time might be thousands or tens of thousands of years, but one day, it would certainly be understood thoroughly…
(The End.)