Extreme Electrical Discharge
Seen either arcing across the sky or hitting a point on the surface of the Earth, lightning is an example of an extremely massive electrical discharge.
Amazing But True
- While there are three different types of lightning, Cloud to Cloud, Intra-Cloud and Cloud to Ground, the one that is of most interest to humans is cloud to ground lightning. Lightning occurs when warm and cold air masses mix, which results in a polarization of the atmosphere. When there is a sufficiently large electrical potential between the cloud and the ground, a lightning bolt or a lightning strike is seen.
- Some of the properties of lightning strikes are:
- The rolling thunder that is often heard is a result of the shock waves from the lightning not originating from a single source, but along the whole lightning bolt.
- If thunder is heard 5 seconds after a lightning flash is seen, this tells you that the strike was approximately 1 mile away.
- Lightning has been observed on other planets.
- One of the earliest known lightning detectors was invented by Andrew Gordon. It consisted of a conducting rod and two metal bells.
- Watch a lightning strike in slow motion: http://www.youtube.com/watch?v=RLWIBrweSU8
Using the information provided above, answer the following questions.
- What are positive streamers?
- Why is there sometimes a delay between seeing a lightning bolt and hearing it?
- Some people that have been struck by lightning have reported a tingling feeling in their body before the strike. What possible physics explanation could you offer that would explain this?