vibration
molecular tag
on the lawn through reality
the pulse of joy
Sound moves through substances, mediums, the way a slinky toy moves when one end is jiggled.
Vibrations are caused by many things, and the quality and duration of the sounds depend in great part on what the vibration moves through: metal strings? catgut? nylon? wood? bone? gas? water?
Here are a couple of websites that talk about the way that sound is made and some of the physics behind this very interesting phenomenon.
The Physics of Sound at Thinkquest
The Physics of Sound Module – Glossary at the Foss Science Kit website.
The Physics Classroom Sound pages from the production to the perception of sound, a detailed site with good information and pictures.
I made a change to this in the evening of the day I published it. The extraction is marked with a line-out, and the addition is in italics