This is the 4489th most frequent Chinese word.
时空
"Time and space."
In this sentence, '时空' ('space-time') refers to the abstract concept of time and space as a continuous entity.
时空如流水一般，悄然无声地流逝。
Space-time flows like water, silently slipping away.
Here, '时空' is used to describe settings or dimensions of time and space within the narrative context.
电影中的故事跨越了不同的时空，将过去与未来相连接。
The story in the movie spans different dimensions of space-time, connecting the past and the future.
In this usage, '时空' pertains to the scientific concept of space-time as studied in physics.