system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How is gravity both the "strongest and weakest force in the universe"?

I've heard this saying before and don't really understand it.
gpt
Gravity is a very weak force, in comparison to the electrical or magnetic forces, on a unit by unit basis.  That's why if you set a rock on the sidewalk, gravity tries to pull it to the center of the Earth, but the electrons on the outside of the sidewalk have no problems repelling the electrons on the outside of the weight to prevent this sinking.  That's the electrons in a one atom thick layer overpowering all the mass in the entire weight.

The "strongest force in the universe" statement is more poetic than physics.  Gravity shapes galaxies and star systems, giving them their attractive shapes.