People often estimate the distance to lightning by timing how long it takes for the sound of the thunder to reach the listener. The light from the lightning travels at the speed of light and for all practical purposes arrives at the listener instantaneously.

A good experiment might be to locate a bolt of a lightning by using four "detectors" and the same general ideas developed in this unit. This is definitely a three-dimensional problem. I haven't tried this and don't know how well it will work.

One idea is to make an audio tape recording at each of four detecting sites. The tape recordings should be made using a microphone to listen for thunder and an AM radio. A lightning stroke should produce static. The signal carrying the static travels at the speed of light. By recording the static and thunder on the same tape one can make careful measurements at one's leisure of the time between the static and the thunder.

The link below leads to an interesting Web site with some information about lightning.

http://thunder.msfc.nasa.gov/primer.html