this sentence means that the stars are like the sea, but they are fleeting between light and shade; Time is ruthless, leaving only monuments of the past. Time is fleeting and never comes back. The past can only be recalled.

This sentence comes from Liu Cixin's science fiction novel "Three-body". It is a literary and refreshing sentence. It describes that time keeps passing like running water, never to return, and regrets the rapid changes in life.

It can be used in composition to add flowery rhetoric, which makes people feel that the pattern is very large. It is suitable for themes such as cherishing time, cherishing time, lamenting the rapid changes of years and personnel.