system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are objects floating in water attracted to each other?
gpt
It can depend on what kind of objects you use.  If you've looked at a glass of water from the side you see the water creeps up the side of the glass slightly (meniscus) from the surface tension.   If you float something less dense than water the meniscus will curve up.  Put two objects in the water and the floating objects want to go 'up' the hill. So they float together.  Heavier objects like paperclip will float if placed correctly on water but these have a downward meniscus. They fall towards each other for similar reason.  Put a floating object next to a paperclip and they repel each other.