"As everyone knows, the universe is constantly expanding and moving. Inside the universe, all celestial bodies and matter are also in motion. The movement of everything leads to the continuous change of the gravitational systems at a macro level. It's like placing this sheet on the water surface. Look..."
As he spoke, Ren Zhong stirred the water surface with his finger, causing ripples that made the paper curve and undulate.
"In a two-dimensional sense, this paper is still a flat structure. But in three dimensions, it has become undulating and curved. First, I'll freeze it." Ren Zhong flicked his fingers, and the water tank responded to his brainwave command, freezing instantly, even preserving the shape of the water ripples.
"However, if the coordinate system remains flat at this time. The situation is like this..."
Ren Zhong spoke as light projected from his wrist watch onto the water surface, transforming into a new planar coordinate system.
