system
Given the following post, respond as if you're commenting on Reddit:
human
What causes the sound of thunder in a lightning storm?

I know what cause lightning.
gpt
The sound is caused by the rapid increase in air pressure and air temperature around a lightning bolt. As the bolt strikes it causes the surrounding air to expand at a high rate and become really hot. This super heated air starts expanding at a high rate of speed and creates a sound, this is thunder.