system
Given the following post, respond as if you're commenting on Reddit:
human
How does a lightning bolt create thunder?

I don't understand how a bolt of light creates sound.
gpt
A lightning strike consists of a high current running through a small channel of ionized gas in the atmosphere. Normally, our atmosphere is a very poor conductor, but if sufficient charge builds up in a cloud, the electric field might become strong enough in some places to start creating a conductive channel. Once this channel is complete and connects cloud to ground (or in some cases, different parts of a cloud with opposite charge), charges can flow freely.

The large current flowing through such a thin channel causes the air in the channel to heat quickly. And hot air takes up more volume than cold air, so the heated channel expands. Rapidly. This rapid expansion of the lightning channel creates a shockwave that we can hear as the boom in a thunder. The shockwave is reflected by elements of the landscape and passes through regions with different temperature, which causes the original shockwave to break up into a longer rumble rather than a short boom.