Not talking about the delay between the Lightning and thunder, that’s obvious enough. But lightning comes and goes in a flash (derp) and thunder stretches out five, ten seconds some times. Is it just an echo? If so, what’s it echoing off of?
Just a guess but some lightning bolts travel horizontally rather than going straight down. If one of those start close to you and branches out away from you, you might see most of the light instantly and hear the sound trailing off.
Light travels faster than sound would be my guess. The Blue Angels used to do their u-turn for NASCAR over my neighborhood and the planes would just zip by so fast, completely silent, then the sound would come, booming, then rolling behind them.
Edit: My husband says the lightning stretches over a larger distance than you can see from one perspective, so you’re getting the extended sound from the extended flash. The light travels a couple miles in a flash, but a couple miles worth of sound rolls at you slower.
This is a really great question actually! I’m hoping someone experienced in this field will chime in.
