Bill Hammack opens up a computer hard drive to show how it is engineered. He describes how the "head" reads the magnetic information on the disk; reveals how a voice coil motor and a slider controls the position of that head. He also discusses how smooth a disk must be, and briefly mentions a mathematical technique that allows engineers to pack more information on a drive.
Other "Engineer Guy" videos
The title says it all: this blog features physics videos found everywhere on the web: animations, demonstrations, lectures, documentaries.