system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is a Planck’s length the smallest possible distance?

I know it’s only theoretical, but why couldn’t something be just slightly smaller?
gpt
It's a combination of several fundamental constants. Specifically the speed of light, Planck's constant, and the gravitational constant G. If you combine these three constants in a certain way, you get a length, a very very small length, and that is the smallest length where light and gravity have the properties we see that they do.

It's not known if it truly is the smallest scale, only that our laws of physics break down at scales that small.