system
Given the following post, respond as if you're commenting on Reddit:
human
Why does the Planck length exist, and why is it that specific size?
gpt
The Planck length is a length you get when you multiply certain constants together in physics, why it is exactly that number is not known, just as it is not known why the speed of light is the number it is or why the charge of the electron has that certain value.

You may have heard that the Planck length is the smallest length possible, but this is not so. It is simply at this scale that we would need to have a functioning theory of quantum gravity to understand phenomena.