why does thunder roll if sound moves at a fixed speed?

Question

lightning causes thunder. lightning happens instantaneously, but thunder (at a distance) sounds like it’s coming, then it claps, then fades away. this don’t make no damn sense given that light and sound move at fixed rates.

In: 4

Answer 1

The speed of sound actually does depend on humidity/temperature, but the primary source of the “rolling” is echoes as the thunder bounces off trees, houses, the ground, etc., on its way to you.