Atmospheric Noise (a method of generating random numbers)

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

"Atmospheric noise is radio noise caused by natural atmospheric processes, primarily lightning discharges in thunderstorms.

Atmospheric noise is mainly caused by cloud-to-ground flashes as the current is much stronger than for cloud-to-cloud flashes. On a worldwide scale, eight million lightning flashes occur daily. This is about 100 lightning flashes per second.

The sum of all these lightning flashes results in atmospheric noise. It can be observed[1] with a radio receiver in the form of a combination of white noise (coming from distant thunderstorms) and impulse noise (coming from a near thunderstorm). The power-sum varies with seasons and nearness of thunderstorm centers.

Atmospheric noise and variation is also used to generate high quality random numbers. Random numbers have interesting applications in the security domain."