How is the actual sound of thunder formed?

Question

I've always wondered what makes causes thunder in a storm. Why is it that thunder sort of "rolls around" in the clouds way after a lightning bolt has streaked the sky??

Answer 1

A lightning bolt produces brief but very intense heat in the air or other objects it passes through. (You may notice this when looking at a tree that has been struck by lightning: it has been split apart because the lightning caused the water in the tree to flash-boil and very rapidly expand, breaking the tree in the process.)

In the air, the sudden temperature change causes the air at the bolt to expand and suddenly rise in pressure; the pressure causes air to move outwards, pushing air near the bolt outwards, in other words, a shock wave has been formed in the air. Near the source, this shock wave becomes a short, sharp, and terriffically loud thunderclap.

Further away from the lightning bolt, the shock wave contines moving outward, but gradually loses its intensity as more and more air and air friction saps away its energy. Far from the source, the thunderclap becomes a long, not-too-loud bass roll.

The time lapse is caused by the fact that the lightning reaches your eyes almost instantaneously, but the thunder (sound) takes about five seconds to travel one mile, which is where the old rule of counting seconds to determine the distance to a thunderstorm.

Answer 2

The lightning arc produces sudden expansion and contraction of air near it. This causes sudden change of air pressure resulting in the sound.

Answer 3

Static electricity and friction between molecules makes the sound of thunder.

Answer 4

Light moves faster than sound, so you see the lightening, and then you hear the sound of it breaking the sound barrier.

Answer 5

the sound of the bolts breaking the sound barrier.

Answer 6

http://en.wikipedia.org/wiki/Thunder

Answer 7

its actually the angels.. bowling ;)