Ask A Scientist© Environmental Science Archive

Author:     pioneerlearners
What is thunder?

Response #: 1 of 1
Author:     Don Libby
Text:       Thunder is the sound that lightning makes. A good way to find the 
answer to this question is to look up the word "thunder" in a dictionary (ask 
your parents or teachers to help if you need it). Then you can look up related 
words like "sound" and "lightning" to see how all these words fit together. If 
you really want a better answer, then the best place to look is in an 
encyclopedia (you school librarian can help). Now, to answer your question, 
thunder is a sound just like the clap you hear when you strike your hands 
together. The sound is made when the electric charge of a lightning streak 
rushes through the air from one cloud to another, or from the ground up to a 
cloud. The lightning bolt is moving so fast that the air around it gets 
pressed into a very hard shock wave, and this is what you hear when the sound 
travels from the lightning to your ear (which may be a few seconds after you 
see the flash because light travels faster than sound).