Bill shows the world's smallest atomic clock and then describes how the first one made in the 1950s worked. He describes in detail the use of cesium vapor to create a feedback or control loop to control a quartz oscillator. He highlights the importance of atomic team by describing briefly how a GPS receiver uses four satellites to find its position.
Other "Engineer Guy" videos
The title says it all: this blog features physics videos found everywhere on the web: animations, demonstrations, lectures, documentaries.