Thunder & Lightning
The potential difference between the earth and the base of thunder clouds is typically many millions of volts. It is no surprise that when finally a discharge occurs, the lightning bolt that we see heats the air through which it passes to thousands of degrees!
This super-heated air rapidly expands; an explosion outwards sending powerful vibrations of sound through the air. The light from the discharge travels nearly a million times faster. What does this mean for what we observe?
- lightning strikes
- we see the flash of light - nearly instantly
- some time later we hear a rumble of thunder