Thunder is the sound made by lightning. Depending on the nature of the lightning and distance of the hearer, it can range from a sharp, loud crack to a long, low rumble. The sudden increase in pressure and temperature from lightning produces rapid expansion of the air surrounding and within a bolt of lightning. In turn, this expansion of air creates a sonic shock wave which produces the sound of thunder. The cause of thunder The cause of thunder has been the subject of centuries of speculati… (More on Thundering)