system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5; Asked by my 7 year old; Could you Swim in Marbles?

Inspired by Scroge McDuck, of course. We were discussing how you could not swim in gold coins because they stack together and form into a more solid entity, and are not fluid like water. And then we were talking about ball pits and she asked if she had gold marbles in a swimming pool could she swim in those?

I answered no originally but then realized, I don't know for sure.
gpt
The problem with gold specifically is the density.  It’s eight times denser than glass and 19 times denser than water.

You could probably work your way through glass marbles, but gold marbles will collectively weigh many thousands of pounds and you’d struggle to move them by hand at all.