This is called rectification, and rectifier diodes are most commonly used in low current power supplies. A switching diode is most often used to turn a circuit on or off, and band switching diodes are used for switching high frequency band signals.
Thunder occurs when energy from lightning heats and rapidly expands the air. The resulting sound wave gets heard as thunder. While lightning and thunder occur at roughly the same time, lightning travels at the speed of light, or at 186,000 miles a second, while thunder travels at the speed of sound, equivalent to one-fifth of a mile in one second. People see the lightning long before they hear the thunder.
Thunder is the sound generated by lightning produced by a sudden and violent expansion of super-heated air in and along the electrical discharge channel path. Thunder can be a sharp or rumbling sound. The intensity and type of sound depends upon atmospheric conditions and distance between lightning and the listener.