Explain the timeline.

The protagonist must return to the modern era after four days in the Tang Dynasty, and the time spent in the modern era is four hours. Of course, there may have been instances in certain chapters where there were errors in time calculation

When the protagonist alters history, they enter a new crossroads, at which point a time discrepancy arises

Because the protagonist traveled back to the year 626 AD, altering the history concerning that year

The timeline I mentioned is based on the theory of classic time travel films from the 1980s in the United States as outlined on https://m.hetushu.com

Let us discuss the issue regarding the four days

In the first phase, at a ratio of one to two, the protagonist will return to the modern era only once every eight days in the Tang Dynasty, with the time consumed being four hours each time

Similarly, in modern times, it also requires a return to the Tang Dynasty, where the time spent in the Tang Dynasty is also four hours

Then the timeline appeared, and time and the book machine evolved

You can understand it as a junction appearing on a straight road, at an angle of approximately forty-five degrees. This junction will lead you away from the original timeline, taking you further and further away.

Furthermore, this may increase or decrease due to changes in the timeline

Not afraid of criticism, rejecting trolls and haters

Four days is a relative value

At this moment, there are two distinct timelines and books, each possessing a different future

First and foremost, this book should be regarded as a novel; true science cannot explain the miraculous phenomenon of time travel.

This is the theory of axes

Another theory is the timeline divergence theory

Thank you all for your appreciation of this book. If there are any unreasonable aspects in the design, please feel free to point them out

History possesses immense restorative qualities; perhaps by departing from the original timeline, it may still gravitate back towards the original narrative. However, it is also possible, after a certain distance has been traversed, to reach a state akin to gravitational equilibrium, much like the Moon orbiting the Earth

Four days, originating from a science fiction novel from the 1980s in Europe, is, of course, a novel that lacks scientific validity, so there is no need to study it; let it be regarded as my own design as the author

Time is forcibly compensated, just consider it as saving up several opportunities for back and forth; understanding it this way makes it much simpler

Next, two different theories will emerge. One is the theory of parallel transformation, which suggests that changes will occur in the future

Regarding the issue of age, let me keep it a secret, as it pertains to a future major pitfall, one that is enticing enough to lead everyone to search on Baidu hundreds of times, hahaha

I really want to draw a picture, but unfortunately, I don't know how to place it here

Let me give you an analogy: Five thousand years of history is originally like a straight road, and this road represents the timeline.