Combined with his previous three time and space travels, Bai Lidu immediately realized a major problem......

"Dr. Gao, but when I used the core part you left me to travel through, although the target space-time and space did not build a space-time teleportation array for docking, I still managed to travel back......"

Gao Hongbin hesitated for a moment before replying: "The core component you used before when crossing was actually not developed by me that you are facing now, which is equivalent to your appearance, which not only changed Ling'er's original fate of death, but also had a subtle impact on my research on time and space travel......

Hearing this, Bai Lidu couldn't help but nod......

"As you said, if the target space-time has not built a space-time teleportation array for docking, although it can still be completed in theory, but to put it bluntly, this kind of time-travel is actually a one-way time-travel, if the time-traveler can't have it with him, or if he can't build a space-time teleportation device, then he will definitely not be able to return to the time point of departure......"

Bai Lidu reacted at this time, he was actually playing a game, and as a gamer, he had a game system behind him to support himself in crossing this file, so it wasn't how he could wear it, normally speaking, if he really crossed back, then without the help of the system, how could he return directly after completing the task, at this point, it is indeed as Dr. Gao said, if the time-traveler can't build a space-time teleportation device in the target space-time, It's really a one-way time travel, and there is no return......

And this topic obviously stimulated Gao Hongbin's interest in talking, so he continued:

"Suppose I use the ST-II space-time teleportation array to go directly back to a week before the outbreak of the apocalypse, that is, on December 14, 2102, then according to the law of conservation of matter in time and space, if the future me and the past me meet unexpectedly, it is likely to cause the future memories that the future me has to be erased in an instant, and further, it may also cause one of us to disappear completely, just like the last time, when the two experimental logs you and I took met, the absorption and fusion occurred."

"Ahh How could it be! Hearing this, Bai Lidu was also taken aback, and then asked, "So, Dr. Gao, what if you go back to the past, but try to avoid meeting you face-to-face with your past self?" ”

"For time and space, those historical time and space that have happened in the past, because they have been recognized by the world, have formed the so-called space-time solidification, more figuratively, if the world can look down on the entire space-time, then what you see should be a spiral-shaped space-time snake, but where the space-time nodes that have happened, the body of the space-time snake will be synchronously revealed, forming a solidified space-time trajectory, and those that have not yet happened will be temporarily in a state of nothingness because of the uncertain theory of space-time. But in this nothingness, there are countless possibilities......"

"Hmm......" Bai Lidu also nodded again, indicating that he understood.

"If the space-time snake has a will, then the space-time traveler travels back to the past, which is tantamount to a virus that invades the space-time entity, in order to avoid the space-time traveler from causing too much interference and influence on time and space, it will naturally try its best to get rid of this virus, which is actually like the white blood cells in the human blood, so according to my speculation, even if I don't face to face with the past me in the future, it will still be dangerous, and at that time, if I want not to be cleared by the will of time and space, I can only reduce my sense of existence as much as possible, so that the will of time and space can feel that I am harmless......"

The more Gao Hongbin said it, the more mysterious it became, and he actually pulled out the will of time and space, although Bai Lidu felt that his argument was relatively novel, but it was hard to believe this statement, so he found the previous topic and asked:

"Dr. Gao, then why do the two space-time teleportation arrays have to establish a passage through them?"

Gao Hongbin responded with a smile: "Hehe, you must have heard of the grandmother paradox about time travel, right?" ”

For this grandmother's paradox, Bai Lidu naturally heard of it, so he immediately said:

"Of course I've heard of it, this paradox is that if a person travels back in time and kills his grandmother before she conceives her mother, then it is deduced from the reproductive relationship that she should not exist in this world, but if this is the case, then his grandmother should not be killed......

"That's right! But assuming that his maternal grandmother was really killed by him by mistake, and he did not disappear immediately because of this, then from the point when he killed his maternal grandmother, the original time and space are likely to have a new fork because of this, and in the original time and space, his maternal grandmother will still continue to live, but her grandson has completely disappeared after crossing over, and the world has not changed in any way, and in the new time and space bifurcation, the person killed by him, In fact, it is not his grandmother in the real sense, and there is actually no previous relationship between the two of them, and everything that follows has become unknown again......"

Regarding Dr. Gao's explanation, Bai Lidu naturally understood it, and the theory behind it was also clear.

"Dr. Gao, this should be the so-called parallel universe theory, right?"

"That's right, the parallel universe theory can also be called the parallel space-time theory, although this theory is not specifically created to explain the grandmother's paradox, but it can be a good answer to your question, if there is no exclusive passage between the two space-time teleportation arrays, then when the time-traveler wants to return to his original space-time again, it is likely to be teleported to another parallel space-time, and when he is really aware of this, it will often be because of various operations and interventions, As a result, more parallel space-time will be generated, and if that is the case, the entire space-time serpent will also grow several bodies as a result, and if there is an intersection between the parallel space-time, then it will be a disaster no matter which time and space it is......"

Hearing this, Bai Lidu finally understood......

"Oh, I see, the reason why we need to establish a passage between the two space-time teleportation arrays is actually to enable the time-traveler to accurately return to its original space-time and prevent it from entering other parallel universes......"