In what way are the cycles of time and tides constant(and keep going)?

I think this was just answered. I can add that you can follow the continuous tide through twilight, darkness, and morning.

The constant rise and fall of the tides emphasizes the reccuring cycle of life in the univers, people go through Different pharas of life and then one Day every person has to Die. The rising tide signifies the beggning of life, and the falling tides signify the end of mortal life. (this is for 3 mark)