Thunder is the sound produced by lightning as a result of the rapid heating and expansion of the air surrounding the lightning bolt. When lightning strikes, it heats the air in its channel to extremely high temperatures-up to about 50,000 degrees Fahrenheit (around 30,000 degrees Celsius), which is several times hotter than the surface of the sun
. This intense heat causes the air to expand explosively and rapidly, creating a shock wave similar to a small explosion. As the air expands outward, it compresses the surrounding air, and then as it cools, the air contracts quickly. This rapid expansion and contraction generates the sound waves we hear as thunder
. The nature of the thunder sound depends on the distance and the shape of the lightning channel. A sharp crack or click indicates lightning nearby, while a rumbling sound suggests the lightning is farther away or has multiple branches causing overlapping shock waves
. In summary, thunder is caused by the shock wave created when lightning rapidly heats and expands the air, followed by cooling and contraction, producing the characteristic booming sound
