What Is Thunder?
Thunder is the sound created by a nearby lightning strike. The intense heat from the lightning causes the air around it to expand explosively. This rapid expansion generates a powerful shockwave that we hear as the sound of thunder.
Section 2: The Process of Thunder Formation
A lightning bolt can heat the air in its path to temperatures hotter than the surface of the sun—up to 50,000°F (30,000°C)—in just a fraction of a second. This extreme, sudden heating forces the air to expand outward at supersonic speeds, creating a shockwave.
Section 3: A Sonic Boom Analogy
This process is very similar to the sonic boom created by a supersonic jet. The sudden compression and then expansion of air molecules create a shockwave. As this wave travels through the atmosphere, it evolves into the acoustic sound wave that we recognize as the sharp crack or low rumble of thunder.
Section 4: Importance in Storm Safety
Understanding thunder is crucial for storm safety. Because light travels much faster than sound, you see lightning before you hear thunder. The time delay between the flash and the sound can be used to estimate the storm's distance. Every five seconds of delay equals approximately one mile of distance.