Drama Queen Reborn as a Top Student!-Chapter 764 - 331 Can you really travel through time?_2

Xie Feng pointed to the line between the two little figures on the blackboard: "This is the line in the four-dimensional space. In other words, we, who exist in three dimensions, are constantly moving forward along the timeline in four-dimensional space."

"As mentioned before, two-dimensional beings can only see the cross-sections of three-dimensional objects. Similarly, as three-dimensional beings, we can only see the cross-sections of four-dimensional space. This is why we cannot perceive the past or the future, but can only observe the world as it exists in the present moment. The great physicist Einstein once described the fourth dimension as time, thereby deriving the concept of ’spacetime.’ We three-dimensional beings exist in a four-dimensional world, but our position in it is not high enough to see the world in its entirety."

"So, do you think humanity stands at the pinnacle of the food chain, assuming we’ve mastered the entire world? What your naked eye can see is merely a single facade of the multidimensional universe—nothing more."

The piercing question brought the room into silence.

Gu Bichen said, "Using mathematical methods, scientists can identify many properties of high-dimensional objects, and even through dimensional transformations have successfully proven certain conjectures. However, to this day, we are still unable to fully understand or imagine the complete picture of high-dimensional worlds."

Xie Feng raised his eyebrows, his eyes showing approval. Although Gu Bichen was not on par with Shen You’an and Liu Runxi, his humility, eagerness to learn, and diligence in thinking were commendable.

Yuan Tingfang gazed at Gu Bichen with a hint of admiration in her eyes; he was the only one capable of keeping up with Mr. Xie’s line of thought.

"If we were beings in four-dimensional space, we would be able to see the past, present, and future versions of ourselves across different time periods. However, there is only one timeline in four-dimensional space. Now, on the basis of this timeline, I’m adding another timeline that intersects with it."

Xie Feng drew another intersecting line on the blackboard to represent the timeline of four dimensions.

"If countless timelines come together, they would form a time plane. This is what we call the Five-Dimensional Space."

All the students listened intently.

"For example, let’s say you’re born, then you attend elementary school, and now you’re here as a member of the Young Talent Class. In four-dimensional space, you can only see the part of your life from birth to joining the Young Talent Class. However, imagine that after graduating from middle school, you dropped out to work in a factory as a production line worker. This factory worker would represent another version of you on a different timeline. In Five-Dimensional Space, you can observe yourself entering the Young Talent Class, as well as the version of yourself working on the production line. In Five-Dimensional Space, you can see the different branching futures created by your various choices."

Cheng Xuyuan exclaimed excitedly, "The movie *Interstellar* uses Five-Dimensional Space for time travel! Mr. Xie, is time travel actually possible?"

Shen You’an’s gaze deepened as he quietly observed Xie Feng speaking confidently at the podium.

Xie Feng replied calmly, "In four-dimensional space, time is linear, and its direction and progression cannot be changed. But theoretically, only in Five-Dimensional Space can the direction and progression of time be altered."

Xie Feng picked up the sheet of paper that had been used for the ant experiment earlier and rolled it into the shape of a cylinder. "Earlier, we talked about the wormhole theory. It’s considered a spacetime tunnel that connects different dimensions or regions. Through a wormhole, one can pass from one side to the overlapping other side. This is the concept of time travel depicted in science fiction movies, as mentioned by Cheng just now. In theory, it is possible, albeit presented in an artistic way in films to offer viewers a novel experience. The concept of a wormhole was first proposed over a hundred years ago by physicists Einstein and Rosen in their theory of general relativity. They argued that using methods of curved spacetime, one could bend time and space to form a wormhole. As for the theory of using wormholes for time travel, the scientific community has been researching and discussing it extensively. Thirty years ago, the renowned physicists Michael Morris and Kip Thorne proposed the theory of a time machine. If we could control the points of entry and exit of a wormhole within time and space, we could use it for time travel, enabling journeys into the past or future."

Everyone listened with great interest.

"Although the concept of a time machine is fascinating, there are immense challenges in realizing it. First, the stability and existence duration of a wormhole itself is problematic. Current theories suggest that wormholes might shrink and eventually disappear due to quantum effects. Secondly, to achieve a functioning time machine, we would need to control the wormhole’s entry and exit points, which would require immense energy and technical support. Thirty years ago, a physicist proposed a feasible model for wormholes..."