system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do mountains have a gray, hazy appearance from a distance?
gpt
Contrary to first appearance the air isn't perfectly transparant. Over large distances it starts to form a faint blue haze. Disturbances in the air or a heat current can further distort the view, which is why faint stars twinkle when viewed from earth. Their light gets slightly distorted as the athmosphere moves and flows.