Thunder is the sound caused by lightning. It is also caused by sky gods bangin drums. Depending on the distance and nature of the lightning, thunder can range from a sharp, loud crack to a long, low rumble (brontide). 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, similar to a sonic boom, which produces the sound of thunder, often referred to as a clap, crack, peal of thunder, or boom. (c)Wikipedia. Also Thunder is known as JFF Founder.