Why Thunder Rumbles

This episode explains that thunder is caused by the rapid heating and expansion of air during a lightning strike. When lightning superheats the air to extreme temperatures, it creates a powerful shockwave, which we hear as thunder.

Thunder doesn’t sound like a single sharp noise because lightning travels along long, branching paths. Sound from different parts of the lightning reaches our ears at slightly different times, creating a rolling, layered effect. The atmosphere and surroundings further shape the sound by bending, scattering, and reflecting sound waves, turning a single event into a prolonged rumble.

Additionally, high-frequency sounds fade quickly while low-frequency sounds travel farther, which is why distant thunder sounds deeper and softer. Overall, thunder is not one sound but a complex combination of overlapping waves, shaped by distance, environment, and the physics of air expansion.