Oscillations & Waves
Image of jet fighter traveling faster than sound. [click to open a bigger picture]
The following are bookmarks you can open by clicking on the link.
http://www.gmi.edu/~drussell/Demos/waves/wavemotion.html More waves
http://library.thinkquest.org/10796/ch8/ch8.htm Even more waves
http://id.mind.net/~zona/mstm/physics/waves/waves.html and in case you want more...yes it's waves again.