system
Given the following post, respond as if you're commenting on Reddit:
human
How did humans figure out that the ocean tides had anything to do with the moon?

Early humans certainly realized that tides occurs with predictable regularity. And they knew that the moon had a predictable, regular cycle.

But it's not nearly as obvious to the naked eye that there is a causal relationship between the tides and the celestial body hanging out in the sky.

When did we figure out that the moon causes the tides, and what proved it?
gpt
The tides tend to get stronger and weaker in about a two-week cycle, exactly half the cycle length of the Moon. You can follow that pattern over years or even decades, and it's always linked to the Moon. Full/new Moon: Large tides. Half moon: Small tides. Pretty obvious that they are connected somehow.