When Lighting Strikes
The ancient Greek deity Zeus was said to control lightning. Benjamin Franklin carried out experiments involving lightning to demonstrate that it was electricity. Many modern buildings have built-in protection against lightning strikes. Scientists study lightning, but there is still much we do not understand about this beautiful but dangerous phenomenon.
Amazing But True
- Lightning is a result of charge separation between positive and negative ice particles in a thunderstorm. The smaller and lighter particles become positive and rise above the larger and heavier negative particles. A strong electrical potential builds up within the cloud and between the cloud and the ground.
- When the electrical discharge occurs, the air in the vicinity is heated – often temperatures of over 20,000oC can be created. This heated air produces a shock wave which produces sound. Sound travels much more slowly (about 1100 feet or one-fifth mile) in a second while light speeds along at 186,000 miles/second. By counting the number of seconds between flash and sound and dividing by five, you can get a rough estimation of the miles between you and the lightning bolt (the further away the better).
- Lightning can emit a wide range of electromagnetic phenomena. We see light due to excited electrons dropping back down to lower energy levels. However, there are also X-rays, radio waves, and gamma emissions produced during lightning strikes.
- Watch the video to see the formation of a lightning bolt:
Show What You Know
Use the links below to answer the following questions.
- List three different types of lightning.
- You see a lightning flash and hear the thunder ten seconds later. Approximately how far are you from the lightning flash?
- Which part of a cloud is more likely to be positively charged?
- What percentage of lightning strikes are cloud-to-cloud?
- What temperature can be generated by an atomic bomb?