Back when we took chemistry, most of what we read and learn went in one ear and out the other. If only we had a cool experiment like this one to perk up our pubescent ADD.
Check out this cool science video to learn how to expand and poof up a wad of shaving cream. By placing the shaving cream in a vacuum chamber, the shaving cream chemicals will expand (shaving cream is filled with air pockets) and the pressure will build. This is a great example of Boyle's Law.