Another Amazing AT&T Video

This one is more focused on history than on a particular bit of theory, but what a treasure trove of history there is in this 1976 flick! Walter Brattain (transistor inventor) reading from his lab notebook! Edison's lab assistant describing the first recording of human speech! Marconi's daughter! Alexander Graham Bell's granddaughter. You guys will like this one. Three cheers for AT&T!

http://techchannel.att.com/play-video.cfm/2011/2/14/AT&T-Archives-1976---To-Communicate-Is-The-Beginning