system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does a lightning strike instantly appear, then slowly fade away instead of instantly disappearing?
gpt
When you see a lightning strike, you are actually seeing the lightning's glow or the ionization of the air. The air around the lightning bolt is super hot, causing it to give off a bright glow that we see. As the bolt fades away, the air is slowly cooled down to its normal temperature.