system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why can you not see through fog when it's ahead of you but you can once you're in it?
gpt
You have a bunch of particles in the fog blocking your vision. Let’s say there are particles directly in front of you blocking ten percent of your field of view and they’re evenly distributed as small bits in the air. And then another. And five feet away, there’s some more particles blocking another ten percent of your vision. That’s twenty percent. The farther away you go, the more particles are there getting in between you and what you want to see.