| MadSci Network: Environment & Ecology |
Thunder and Lightining are two separate but related events.
Thunder is caused by the lightning. When a lightning bolt travels through the air, it increases the temperature to over 10,000 degrees F. This heat causes the air to expand, and then it cools very rapidly. So air rushes back into this area, and runs into air rushing in from the other side. This impact of air running into air causes the thunder.
Lightning is caused by clouds. As air rises, it cools (which is why there is snow on mountain tops). As air rises the water vapor, called humidity, cools. It changes to water drops and then to snow flakes. But there is a difference in the electrical charge of the rain drops and snow flakes. This is like when you walk across a carpet in the winter, and then touch a doorknob or other metal object-you get a spark.
A lightning bolt is exactly like that little spark, but much, much bigger. So we can see and hear it much further.
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